diff options
Diffstat (limited to 'fs/ubifs')
37 files changed, 39312 insertions, 0 deletions
diff --git a/fs/ubifs/Kconfig b/fs/ubifs/Kconfig new file mode 100644 index 000000000..45d3d207f --- /dev/null +++ b/fs/ubifs/Kconfig @@ -0,0 +1,101 @@ +# SPDX-License-Identifier: GPL-2.0-only +config UBIFS_FS + tristate "UBIFS file system support" + select CRC16 + select CRC32 + select CRYPTO if UBIFS_FS_ADVANCED_COMPR + select CRYPTO if UBIFS_FS_LZO + select CRYPTO if UBIFS_FS_ZLIB + select CRYPTO if UBIFS_FS_ZSTD + select CRYPTO_LZO if UBIFS_FS_LZO + select CRYPTO_DEFLATE if UBIFS_FS_ZLIB + select CRYPTO_ZSTD if UBIFS_FS_ZSTD + select CRYPTO_HASH_INFO + select UBIFS_FS_XATTR if FS_ENCRYPTION + select FS_ENCRYPTION_ALGS if FS_ENCRYPTION + depends on MTD_UBI + help + UBIFS is a file system for flash devices which works on top of UBI. + +if UBIFS_FS + +config UBIFS_FS_ADVANCED_COMPR + bool "Advanced compression options" + help + This option allows to explicitly choose which compressions, if any, + are enabled in UBIFS. Removing compressors means inability to read + existing file systems. + + If unsure, say 'N'. + +config UBIFS_FS_LZO + bool "LZO compression support" if UBIFS_FS_ADVANCED_COMPR + default y + help + LZO compressor is generally faster than zlib but compresses worse. + Say 'Y' if unsure. + +config UBIFS_FS_ZLIB + bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR + default y + help + Zlib compresses better than LZO but it is slower. Say 'Y' if unsure. + +config UBIFS_FS_ZSTD + bool "ZSTD compression support" if UBIFS_FS_ADVANCED_COMPR + depends on UBIFS_FS + default y + help + ZSTD compresses is a big win in speed over Zlib and + in compression ratio over LZO. Say 'Y' if unsure. + +config UBIFS_ATIME_SUPPORT + bool "Access time support" + default n + help + Originally UBIFS did not support atime, because it looked like a bad idea due + increased flash wear. This option adds atime support and it is disabled by default + to preserve the old behavior. If you enable this option, UBIFS starts updating atime, + which means that file-system read operations will cause writes (inode atime + updates). This may affect file-system performance and increase flash device wear, + so be careful. How often atime is updated depends on the selected strategy: + strictatime is the "heavy", relatime is "lighter", etc. + + If unsure, say 'N' + +config UBIFS_FS_XATTR + bool "UBIFS XATTR support" + default y + help + Saying Y here includes support for extended attributes (xattrs). + Xattrs are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page). + + If unsure, say Y. + +config UBIFS_FS_SECURITY + bool "UBIFS Security Labels" + depends on UBIFS_FS_XATTR + default y + help + Security labels provide an access control facility to support Linux + Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO + Linux. This option enables an extended attribute handler for file + security labels in the ubifs filesystem, so that it requires enabling + the extended attribute support in advance. + + If you are not using a security module, say N. + +config UBIFS_FS_AUTHENTICATION + bool "UBIFS authentication support" + select KEYS + select CRYPTO_HMAC + select SYSTEM_DATA_VERIFICATION + help + Enable authentication support for UBIFS. This feature offers protection + against offline changes for both data and metadata of the filesystem. + If you say yes here you should also select a hashing algorithm such as + sha256, these are not selected automatically since there are many + different options. + +endif # UBIFS_FS diff --git a/fs/ubifs/Makefile b/fs/ubifs/Makefile new file mode 100644 index 000000000..5c4b84575 --- /dev/null +++ b/fs/ubifs/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_UBIFS_FS) += ubifs.o + +ubifs-y += shrinker.o journal.o file.o dir.o super.o sb.o io.o +ubifs-y += tnc.o master.o scan.o replay.o log.o commit.o gc.o orphan.o +ubifs-y += budget.o find.o tnc_commit.o compress.o lpt.o lprops.o +ubifs-y += recovery.o ioctl.o lpt_commit.o tnc_misc.o debug.o +ubifs-y += misc.o +ubifs-$(CONFIG_FS_ENCRYPTION) += crypto.o +ubifs-$(CONFIG_UBIFS_FS_XATTR) += xattr.o +ubifs-$(CONFIG_UBIFS_FS_AUTHENTICATION) += auth.o diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c new file mode 100644 index 000000000..50e88a2ab --- /dev/null +++ b/fs/ubifs/auth.c @@ -0,0 +1,547 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This file is part of UBIFS. + * + * Copyright (C) 2018 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de> + */ + +/* + * This file implements various helper functions for UBIFS authentication support + */ + +#include <linux/crypto.h> +#include <linux/verification.h> +#include <crypto/hash.h> +#include <crypto/sha.h> +#include <crypto/algapi.h> +#include <keys/user-type.h> +#include <keys/asymmetric-type.h> + +#include "ubifs.h" + +/** + * ubifs_node_calc_hash - calculate the hash of a UBIFS node + * @c: UBIFS file-system description object + * @node: the node to calculate a hash for + * @hash: the returned hash + * + * Returns 0 for success or a negative error code otherwise. + */ +int __ubifs_node_calc_hash(const struct ubifs_info *c, const void *node, + u8 *hash) +{ + const struct ubifs_ch *ch = node; + + return crypto_shash_tfm_digest(c->hash_tfm, node, le32_to_cpu(ch->len), + hash); +} + +/** + * ubifs_hash_calc_hmac - calculate a HMAC from a hash + * @c: UBIFS file-system description object + * @hash: the node to calculate a HMAC for + * @hmac: the returned HMAC + * + * Returns 0 for success or a negative error code otherwise. + */ +static int ubifs_hash_calc_hmac(const struct ubifs_info *c, const u8 *hash, + u8 *hmac) +{ + return crypto_shash_tfm_digest(c->hmac_tfm, hash, c->hash_len, hmac); +} + +/** + * ubifs_prepare_auth_node - Prepare an authentication node + * @c: UBIFS file-system description object + * @node: the node to calculate a hash for + * @inhash: input hash of previous nodes + * + * This function prepares an authentication node for writing onto flash. + * It creates a HMAC from the given input hash and writes it to the node. + * + * Returns 0 for success or a negative error code otherwise. + */ +int ubifs_prepare_auth_node(struct ubifs_info *c, void *node, + struct shash_desc *inhash) +{ + struct ubifs_auth_node *auth = node; + u8 hash[UBIFS_HASH_ARR_SZ]; + int err; + + { + SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm); + + hash_desc->tfm = c->hash_tfm; + ubifs_shash_copy_state(c, inhash, hash_desc); + + err = crypto_shash_final(hash_desc, hash); + if (err) + return err; + } + + err = ubifs_hash_calc_hmac(c, hash, auth->hmac); + if (err) + return err; + + auth->ch.node_type = UBIFS_AUTH_NODE; + ubifs_prepare_node(c, auth, ubifs_auth_node_sz(c), 0); + return 0; +} + +static struct shash_desc *ubifs_get_desc(const struct ubifs_info *c, + struct crypto_shash *tfm) +{ + struct shash_desc *desc; + int err; + + if (!ubifs_authenticated(c)) + return NULL; + + desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(tfm), GFP_KERNEL); + if (!desc) + return ERR_PTR(-ENOMEM); + + desc->tfm = tfm; + + err = crypto_shash_init(desc); + if (err) { + kfree(desc); + return ERR_PTR(err); + } + + return desc; +} + +/** + * __ubifs_hash_get_desc - get a descriptor suitable for hashing a node + * @c: UBIFS file-system description object + * + * This function returns a descriptor suitable for hashing a node. Free after use + * with kfree. + */ +struct shash_desc *__ubifs_hash_get_desc(const struct ubifs_info *c) +{ + return ubifs_get_desc(c, c->hash_tfm); +} + +/** + * ubifs_bad_hash - Report hash mismatches + * @c: UBIFS file-system description object + * @node: the node + * @hash: the expected hash + * @lnum: the LEB @node was read from + * @offs: offset in LEB @node was read from + * + * This function reports a hash mismatch when a node has a different hash than + * expected. + */ +void ubifs_bad_hash(const struct ubifs_info *c, const void *node, const u8 *hash, + int lnum, int offs) +{ + int len = min(c->hash_len, 20); + int cropped = len != c->hash_len; + const char *cont = cropped ? "..." : ""; + + u8 calc[UBIFS_HASH_ARR_SZ]; + + __ubifs_node_calc_hash(c, node, calc); + + ubifs_err(c, "hash mismatch on node at LEB %d:%d", lnum, offs); + ubifs_err(c, "hash expected: %*ph%s", len, hash, cont); + ubifs_err(c, "hash calculated: %*ph%s", len, calc, cont); +} + +/** + * __ubifs_node_check_hash - check the hash of a node against given hash + * @c: UBIFS file-system description object + * @node: the node + * @expected: the expected hash + * + * This function calculates a hash over a node and compares it to the given hash. + * Returns 0 if both hashes are equal or authentication is disabled, otherwise a + * negative error code is returned. + */ +int __ubifs_node_check_hash(const struct ubifs_info *c, const void *node, + const u8 *expected) +{ + u8 calc[UBIFS_HASH_ARR_SZ]; + int err; + + err = __ubifs_node_calc_hash(c, node, calc); + if (err) + return err; + + if (ubifs_check_hash(c, expected, calc)) + return -EPERM; + + return 0; +} + +/** + * ubifs_sb_verify_signature - verify the signature of a superblock + * @c: UBIFS file-system description object + * @sup: The superblock node + * + * To support offline signed images the superblock can be signed with a + * PKCS#7 signature. The signature is placed directly behind the superblock + * node in an ubifs_sig_node. + * + * Returns 0 when the signature can be successfully verified or a negative + * error code if not. + */ +int ubifs_sb_verify_signature(struct ubifs_info *c, + const struct ubifs_sb_node *sup) +{ + int err; + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + const struct ubifs_sig_node *signode; + + sleb = ubifs_scan(c, UBIFS_SB_LNUM, UBIFS_SB_NODE_SZ, c->sbuf, 0); + if (IS_ERR(sleb)) { + err = PTR_ERR(sleb); + return err; + } + + if (sleb->nodes_cnt == 0) { + ubifs_err(c, "Unable to find signature node"); + err = -EINVAL; + goto out_destroy; + } + + snod = list_first_entry(&sleb->nodes, struct ubifs_scan_node, list); + + if (snod->type != UBIFS_SIG_NODE) { + ubifs_err(c, "Signature node is of wrong type"); + err = -EINVAL; + goto out_destroy; + } + + signode = snod->node; + + if (le32_to_cpu(signode->len) > snod->len + sizeof(struct ubifs_sig_node)) { + ubifs_err(c, "invalid signature len %d", le32_to_cpu(signode->len)); + err = -EINVAL; + goto out_destroy; + } + + if (le32_to_cpu(signode->type) != UBIFS_SIGNATURE_TYPE_PKCS7) { + ubifs_err(c, "Signature type %d is not supported\n", + le32_to_cpu(signode->type)); + err = -EINVAL; + goto out_destroy; + } + + err = verify_pkcs7_signature(sup, sizeof(struct ubifs_sb_node), + signode->sig, le32_to_cpu(signode->len), + NULL, VERIFYING_UNSPECIFIED_SIGNATURE, + NULL, NULL); + + if (err) + ubifs_err(c, "Failed to verify signature"); + else + ubifs_msg(c, "Successfully verified super block signature"); + +out_destroy: + ubifs_scan_destroy(sleb); + + return err; +} + +/** + * ubifs_init_authentication - initialize UBIFS authentication support + * @c: UBIFS file-system description object + * + * This function returns 0 for success or a negative error code otherwise. + */ +int ubifs_init_authentication(struct ubifs_info *c) +{ + struct key *keyring_key; + const struct user_key_payload *ukp; + int err; + char hmac_name[CRYPTO_MAX_ALG_NAME]; + + if (!c->auth_hash_name) { + ubifs_err(c, "authentication hash name needed with authentication"); + return -EINVAL; + } + + c->auth_hash_algo = match_string(hash_algo_name, HASH_ALGO__LAST, + c->auth_hash_name); + if ((int)c->auth_hash_algo < 0) { + ubifs_err(c, "Unknown hash algo %s specified", + c->auth_hash_name); + return -EINVAL; + } + + snprintf(hmac_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", + c->auth_hash_name); + + keyring_key = request_key(&key_type_logon, c->auth_key_name, NULL); + + if (IS_ERR(keyring_key)) { + ubifs_err(c, "Failed to request key: %ld", + PTR_ERR(keyring_key)); + return PTR_ERR(keyring_key); + } + + down_read(&keyring_key->sem); + + if (keyring_key->type != &key_type_logon) { + ubifs_err(c, "key type must be logon"); + err = -ENOKEY; + goto out; + } + + ukp = user_key_payload_locked(keyring_key); + if (!ukp) { + /* key was revoked before we acquired its semaphore */ + err = -EKEYREVOKED; + goto out; + } + + c->hash_tfm = crypto_alloc_shash(c->auth_hash_name, 0, 0); + if (IS_ERR(c->hash_tfm)) { + err = PTR_ERR(c->hash_tfm); + ubifs_err(c, "Can not allocate %s: %d", + c->auth_hash_name, err); + goto out; + } + + c->hash_len = crypto_shash_digestsize(c->hash_tfm); + if (c->hash_len > UBIFS_HASH_ARR_SZ) { + ubifs_err(c, "hash %s is bigger than maximum allowed hash size (%d > %d)", + c->auth_hash_name, c->hash_len, UBIFS_HASH_ARR_SZ); + err = -EINVAL; + goto out_free_hash; + } + + c->hmac_tfm = crypto_alloc_shash(hmac_name, 0, 0); + if (IS_ERR(c->hmac_tfm)) { + err = PTR_ERR(c->hmac_tfm); + ubifs_err(c, "Can not allocate %s: %d", hmac_name, err); + goto out_free_hash; + } + + c->hmac_desc_len = crypto_shash_digestsize(c->hmac_tfm); + if (c->hmac_desc_len > UBIFS_HMAC_ARR_SZ) { + ubifs_err(c, "hmac %s is bigger than maximum allowed hmac size (%d > %d)", + hmac_name, c->hmac_desc_len, UBIFS_HMAC_ARR_SZ); + err = -EINVAL; + goto out_free_hmac; + } + + err = crypto_shash_setkey(c->hmac_tfm, ukp->data, ukp->datalen); + if (err) + goto out_free_hmac; + + c->authenticated = true; + + c->log_hash = ubifs_hash_get_desc(c); + if (IS_ERR(c->log_hash)) { + err = PTR_ERR(c->log_hash); + goto out_free_hmac; + } + + err = 0; + +out_free_hmac: + if (err) + crypto_free_shash(c->hmac_tfm); +out_free_hash: + if (err) + crypto_free_shash(c->hash_tfm); +out: + up_read(&keyring_key->sem); + key_put(keyring_key); + + return err; +} + +/** + * __ubifs_exit_authentication - release resource + * @c: UBIFS file-system description object + * + * This function releases the authentication related resources. + */ +void __ubifs_exit_authentication(struct ubifs_info *c) +{ + if (!ubifs_authenticated(c)) + return; + + crypto_free_shash(c->hmac_tfm); + crypto_free_shash(c->hash_tfm); + kfree(c->log_hash); +} + +/** + * ubifs_node_calc_hmac - calculate the HMAC of a UBIFS node + * @c: UBIFS file-system description object + * @node: the node to insert a HMAC into. + * @len: the length of the node + * @ofs_hmac: the offset in the node where the HMAC is inserted + * @hmac: returned HMAC + * + * This function calculates a HMAC of a UBIFS node. The HMAC is expected to be + * embedded into the node, so this area is not covered by the HMAC. Also not + * covered is the UBIFS_NODE_MAGIC and the CRC of the node. + */ +static int ubifs_node_calc_hmac(const struct ubifs_info *c, const void *node, + int len, int ofs_hmac, void *hmac) +{ + SHASH_DESC_ON_STACK(shash, c->hmac_tfm); + int hmac_len = c->hmac_desc_len; + int err; + + ubifs_assert(c, ofs_hmac > 8); + ubifs_assert(c, ofs_hmac + hmac_len < len); + + shash->tfm = c->hmac_tfm; + + err = crypto_shash_init(shash); + if (err) + return err; + + /* behind common node header CRC up to HMAC begin */ + err = crypto_shash_update(shash, node + 8, ofs_hmac - 8); + if (err < 0) + return err; + + /* behind HMAC, if any */ + if (len - ofs_hmac - hmac_len > 0) { + err = crypto_shash_update(shash, node + ofs_hmac + hmac_len, + len - ofs_hmac - hmac_len); + if (err < 0) + return err; + } + + return crypto_shash_final(shash, hmac); +} + +/** + * __ubifs_node_insert_hmac - insert a HMAC into a UBIFS node + * @c: UBIFS file-system description object + * @node: the node to insert a HMAC into. + * @len: the length of the node + * @ofs_hmac: the offset in the node where the HMAC is inserted + * + * This function inserts a HMAC at offset @ofs_hmac into the node given in + * @node. + * + * This function returns 0 for success or a negative error code otherwise. + */ +int __ubifs_node_insert_hmac(const struct ubifs_info *c, void *node, int len, + int ofs_hmac) +{ + return ubifs_node_calc_hmac(c, node, len, ofs_hmac, node + ofs_hmac); +} + +/** + * __ubifs_node_verify_hmac - verify the HMAC of UBIFS node + * @c: UBIFS file-system description object + * @node: the node to insert a HMAC into. + * @len: the length of the node + * @ofs_hmac: the offset in the node where the HMAC is inserted + * + * This function verifies the HMAC at offset @ofs_hmac of the node given in + * @node. Returns 0 if successful or a negative error code otherwise. + */ +int __ubifs_node_verify_hmac(const struct ubifs_info *c, const void *node, + int len, int ofs_hmac) +{ + int hmac_len = c->hmac_desc_len; + u8 *hmac; + int err; + + hmac = kmalloc(hmac_len, GFP_NOFS); + if (!hmac) + return -ENOMEM; + + err = ubifs_node_calc_hmac(c, node, len, ofs_hmac, hmac); + if (err) { + kfree(hmac); + return err; + } + + err = crypto_memneq(hmac, node + ofs_hmac, hmac_len); + + kfree(hmac); + + if (!err) + return 0; + + return -EPERM; +} + +int __ubifs_shash_copy_state(const struct ubifs_info *c, struct shash_desc *src, + struct shash_desc *target) +{ + u8 *state; + int err; + + state = kmalloc(crypto_shash_descsize(src->tfm), GFP_NOFS); + if (!state) + return -ENOMEM; + + err = crypto_shash_export(src, state); + if (err) + goto out; + + err = crypto_shash_import(target, state); + +out: + kfree(state); + + return err; +} + +/** + * ubifs_hmac_wkm - Create a HMAC of the well known message + * @c: UBIFS file-system description object + * @hmac: The HMAC of the well known message + * + * This function creates a HMAC of a well known message. This is used + * to check if the provided key is suitable to authenticate a UBIFS + * image. This is only a convenience to the user to provide a better + * error message when the wrong key is provided. + * + * This function returns 0 for success or a negative error code otherwise. + */ +int ubifs_hmac_wkm(struct ubifs_info *c, u8 *hmac) +{ + SHASH_DESC_ON_STACK(shash, c->hmac_tfm); + int err; + const char well_known_message[] = "UBIFS"; + + if (!ubifs_authenticated(c)) + return 0; + + shash->tfm = c->hmac_tfm; + + err = crypto_shash_init(shash); + if (err) + return err; + + err = crypto_shash_update(shash, well_known_message, + sizeof(well_known_message) - 1); + if (err < 0) + return err; + + err = crypto_shash_final(shash, hmac); + if (err) + return err; + return 0; +} + +/* + * ubifs_hmac_zero - test if a HMAC is zero + * @c: UBIFS file-system description object + * @hmac: the HMAC to test + * + * This function tests if a HMAC is zero and returns true if it is + * and false otherwise. + */ +bool ubifs_hmac_zero(struct ubifs_info *c, const u8 *hmac) +{ + return !memchr_inv(hmac, 0, c->hmac_desc_len); +} diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c new file mode 100644 index 000000000..9cb05ef9b --- /dev/null +++ b/fs/ubifs/budget.c @@ -0,0 +1,717 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements the budgeting sub-system which is responsible for UBIFS + * space management. + * + * Factors such as compression, wasted space at the ends of LEBs, space in other + * journal heads, the effect of updates on the index, and so on, make it + * impossible to accurately predict the amount of space needed. Consequently + * approximations are used. + */ + +#include "ubifs.h" +#include <linux/writeback.h> +#include <linux/math64.h> + +/* + * When pessimistic budget calculations say that there is no enough space, + * UBIFS starts writing back dirty inodes and pages, doing garbage collection, + * or committing. The below constant defines maximum number of times UBIFS + * repeats the operations. + */ +#define MAX_MKSPC_RETRIES 3 + +/* + * The below constant defines amount of dirty pages which should be written + * back at when trying to shrink the liability. + */ +#define NR_TO_WRITE 16 + +/** + * shrink_liability - write-back some dirty pages/inodes. + * @c: UBIFS file-system description object + * @nr_to_write: how many dirty pages to write-back + * + * This function shrinks UBIFS liability by means of writing back some amount + * of dirty inodes and their pages. + * + * Note, this function synchronizes even VFS inodes which are locked + * (@i_mutex) by the caller of the budgeting function, because write-back does + * not touch @i_mutex. + */ +static void shrink_liability(struct ubifs_info *c, int nr_to_write) +{ + down_read(&c->vfs_sb->s_umount); + writeback_inodes_sb_nr(c->vfs_sb, nr_to_write, WB_REASON_FS_FREE_SPACE); + up_read(&c->vfs_sb->s_umount); +} + +/** + * run_gc - run garbage collector. + * @c: UBIFS file-system description object + * + * This function runs garbage collector to make some more free space. Returns + * zero if a free LEB has been produced, %-EAGAIN if commit is required, and a + * negative error code in case of failure. + */ +static int run_gc(struct ubifs_info *c) +{ + int err, lnum; + + /* Make some free space by garbage-collecting dirty space */ + down_read(&c->commit_sem); + lnum = ubifs_garbage_collect(c, 1); + up_read(&c->commit_sem); + if (lnum < 0) + return lnum; + + /* GC freed one LEB, return it to lprops */ + dbg_budg("GC freed LEB %d", lnum); + err = ubifs_return_leb(c, lnum); + if (err) + return err; + return 0; +} + +/** + * get_liability - calculate current liability. + * @c: UBIFS file-system description object + * + * This function calculates and returns current UBIFS liability, i.e. the + * amount of bytes UBIFS has "promised" to write to the media. + */ +static long long get_liability(struct ubifs_info *c) +{ + long long liab; + + spin_lock(&c->space_lock); + liab = c->bi.idx_growth + c->bi.data_growth + c->bi.dd_growth; + spin_unlock(&c->space_lock); + return liab; +} + +/** + * make_free_space - make more free space on the file-system. + * @c: UBIFS file-system description object + * + * This function is called when an operation cannot be budgeted because there + * is supposedly no free space. But in most cases there is some free space: + * o budgeting is pessimistic, so it always budgets more than it is actually + * needed, so shrinking the liability is one way to make free space - the + * cached data will take less space then it was budgeted for; + * o GC may turn some dark space into free space (budgeting treats dark space + * as not available); + * o commit may free some LEB, i.e., turn freeable LEBs into free LEBs. + * + * So this function tries to do the above. Returns %-EAGAIN if some free space + * was presumably made and the caller has to re-try budgeting the operation. + * Returns %-ENOSPC if it couldn't do more free space, and other negative error + * codes on failures. + */ +static int make_free_space(struct ubifs_info *c) +{ + int err, retries = 0; + long long liab1, liab2; + + do { + liab1 = get_liability(c); + /* + * We probably have some dirty pages or inodes (liability), try + * to write them back. + */ + dbg_budg("liability %lld, run write-back", liab1); + shrink_liability(c, NR_TO_WRITE); + + liab2 = get_liability(c); + if (liab2 < liab1) + return -EAGAIN; + + dbg_budg("new liability %lld (not shrunk)", liab2); + + /* Liability did not shrink again, try GC */ + dbg_budg("Run GC"); + err = run_gc(c); + if (!err) + return -EAGAIN; + + if (err != -EAGAIN && err != -ENOSPC) + /* Some real error happened */ + return err; + + dbg_budg("Run commit (retries %d)", retries); + err = ubifs_run_commit(c); + if (err) + return err; + } while (retries++ < MAX_MKSPC_RETRIES); + + return -ENOSPC; +} + +/** + * ubifs_calc_min_idx_lebs - calculate amount of LEBs for the index. + * @c: UBIFS file-system description object + * + * This function calculates and returns the number of LEBs which should be kept + * for index usage. + */ +int ubifs_calc_min_idx_lebs(struct ubifs_info *c) +{ + int idx_lebs; + long long idx_size; + + idx_size = c->bi.old_idx_sz + c->bi.idx_growth + c->bi.uncommitted_idx; + /* And make sure we have thrice the index size of space reserved */ + idx_size += idx_size << 1; + /* + * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes' + * pair, nor similarly the two variables for the new index size, so we + * have to do this costly 64-bit division on fast-path. + */ + idx_lebs = div_u64(idx_size + c->idx_leb_size - 1, c->idx_leb_size); + /* + * The index head is not available for the in-the-gaps method, so add an + * extra LEB to compensate. + */ + idx_lebs += 1; + if (idx_lebs < MIN_INDEX_LEBS) + idx_lebs = MIN_INDEX_LEBS; + return idx_lebs; +} + +/** + * ubifs_calc_available - calculate available FS space. + * @c: UBIFS file-system description object + * @min_idx_lebs: minimum number of LEBs reserved for the index + * + * This function calculates and returns amount of FS space available for use. + */ +long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs) +{ + int subtract_lebs; + long long available; + + available = c->main_bytes - c->lst.total_used; + + /* + * Now 'available' contains theoretically available flash space + * assuming there is no index, so we have to subtract the space which + * is reserved for the index. + */ + subtract_lebs = min_idx_lebs; + + /* Take into account that GC reserves one LEB for its own needs */ + subtract_lebs += 1; + + /* + * Since different write types go to different heads, we should + * reserve one leb for each head. + */ + subtract_lebs += c->jhead_cnt; + + /* We also reserve one LEB for deletions, which bypass budgeting */ + subtract_lebs += 1; + + available -= (long long)subtract_lebs * c->leb_size; + + /* Subtract the dead space which is not available for use */ + available -= c->lst.total_dead; + + /* + * Subtract dark space, which might or might not be usable - it depends + * on the data which we have on the media and which will be written. If + * this is a lot of uncompressed or not-compressible data, the dark + * space cannot be used. + */ + available -= c->lst.total_dark; + + /* + * However, there is more dark space. The index may be bigger than + * @min_idx_lebs. Those extra LEBs are assumed to be available, but + * their dark space is not included in total_dark, so it is subtracted + * here. + */ + if (c->lst.idx_lebs > min_idx_lebs) { + subtract_lebs = c->lst.idx_lebs - min_idx_lebs; + available -= subtract_lebs * c->dark_wm; + } + + /* The calculations are rough and may end up with a negative number */ + return available > 0 ? available : 0; +} + +/** + * can_use_rp - check whether the user is allowed to use reserved pool. + * @c: UBIFS file-system description object + * + * UBIFS has so-called "reserved pool" which is flash space reserved + * for the superuser and for uses whose UID/GID is recorded in UBIFS superblock. + * This function checks whether current user is allowed to use reserved pool. + * Returns %1 current user is allowed to use reserved pool and %0 otherwise. + */ +static int can_use_rp(struct ubifs_info *c) +{ + if (uid_eq(current_fsuid(), c->rp_uid) || capable(CAP_SYS_RESOURCE) || + (!gid_eq(c->rp_gid, GLOBAL_ROOT_GID) && in_group_p(c->rp_gid))) + return 1; + return 0; +} + +/** + * do_budget_space - reserve flash space for index and data growth. + * @c: UBIFS file-system description object + * + * This function makes sure UBIFS has enough free LEBs for index growth and + * data. + * + * When budgeting index space, UBIFS reserves thrice as many LEBs as the index + * would take if it was consolidated and written to the flash. This guarantees + * that the "in-the-gaps" commit method always succeeds and UBIFS will always + * be able to commit dirty index. So this function basically adds amount of + * budgeted index space to the size of the current index, multiplies this by 3, + * and makes sure this does not exceed the amount of free LEBs. + * + * Notes about @c->bi.min_idx_lebs and @c->lst.idx_lebs variables: + * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might + * be large, because UBIFS does not do any index consolidation as long as + * there is free space. IOW, the index may take a lot of LEBs, but the LEBs + * will contain a lot of dirt. + * o @c->bi.min_idx_lebs is the number of LEBS the index presumably takes. IOW, + * the index may be consolidated to take up to @c->bi.min_idx_lebs LEBs. + * + * This function returns zero in case of success, and %-ENOSPC in case of + * failure. + */ +static int do_budget_space(struct ubifs_info *c) +{ + long long outstanding, available; + int lebs, rsvd_idx_lebs, min_idx_lebs; + + /* First budget index space */ + min_idx_lebs = ubifs_calc_min_idx_lebs(c); + + /* Now 'min_idx_lebs' contains number of LEBs to reserve */ + if (min_idx_lebs > c->lst.idx_lebs) + rsvd_idx_lebs = min_idx_lebs - c->lst.idx_lebs; + else + rsvd_idx_lebs = 0; + + /* + * The number of LEBs that are available to be used by the index is: + * + * @c->lst.empty_lebs + @c->freeable_cnt + @c->idx_gc_cnt - + * @c->lst.taken_empty_lebs + * + * @c->lst.empty_lebs are available because they are empty. + * @c->freeable_cnt are available because they contain only free and + * dirty space, @c->idx_gc_cnt are available because they are index + * LEBs that have been garbage collected and are awaiting the commit + * before they can be used. And the in-the-gaps method will grab these + * if it needs them. @c->lst.taken_empty_lebs are empty LEBs that have + * already been allocated for some purpose. + * + * Note, @c->idx_gc_cnt is included to both @c->lst.empty_lebs (because + * these LEBs are empty) and to @c->lst.taken_empty_lebs (because they + * are taken until after the commit). + * + * Note, @c->lst.taken_empty_lebs may temporarily be higher by one + * because of the way we serialize LEB allocations and budgeting. See a + * comment in 'ubifs_find_free_space()'. + */ + lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt - + c->lst.taken_empty_lebs; + if (unlikely(rsvd_idx_lebs > lebs)) { + dbg_budg("out of indexing space: min_idx_lebs %d (old %d), rsvd_idx_lebs %d", + min_idx_lebs, c->bi.min_idx_lebs, rsvd_idx_lebs); + return -ENOSPC; + } + + available = ubifs_calc_available(c, min_idx_lebs); + outstanding = c->bi.data_growth + c->bi.dd_growth; + + if (unlikely(available < outstanding)) { + dbg_budg("out of data space: available %lld, outstanding %lld", + available, outstanding); + return -ENOSPC; + } + + if (available - outstanding <= c->rp_size && !can_use_rp(c)) + return -ENOSPC; + + c->bi.min_idx_lebs = min_idx_lebs; + return 0; +} + +/** + * calc_idx_growth - calculate approximate index growth from budgeting request. + * @c: UBIFS file-system description object + * @req: budgeting request + * + * For now we assume each new node adds one znode. But this is rather poor + * approximation, though. + */ +static int calc_idx_growth(const struct ubifs_info *c, + const struct ubifs_budget_req *req) +{ + int znodes; + + znodes = req->new_ino + (req->new_page << UBIFS_BLOCKS_PER_PAGE_SHIFT) + + req->new_dent; + return znodes * c->max_idx_node_sz; +} + +/** + * calc_data_growth - calculate approximate amount of new data from budgeting + * request. + * @c: UBIFS file-system description object + * @req: budgeting request + */ +static int calc_data_growth(const struct ubifs_info *c, + const struct ubifs_budget_req *req) +{ + int data_growth; + + data_growth = req->new_ino ? c->bi.inode_budget : 0; + if (req->new_page) + data_growth += c->bi.page_budget; + if (req->new_dent) + data_growth += c->bi.dent_budget; + data_growth += req->new_ino_d; + return data_growth; +} + +/** + * calc_dd_growth - calculate approximate amount of data which makes other data + * dirty from budgeting request. + * @c: UBIFS file-system description object + * @req: budgeting request + */ +static int calc_dd_growth(const struct ubifs_info *c, + const struct ubifs_budget_req *req) +{ + int dd_growth; + + dd_growth = req->dirtied_page ? c->bi.page_budget : 0; + + if (req->dirtied_ino) + dd_growth += c->bi.inode_budget * req->dirtied_ino; + if (req->mod_dent) + dd_growth += c->bi.dent_budget; + dd_growth += req->dirtied_ino_d; + return dd_growth; +} + +/** + * ubifs_budget_space - ensure there is enough space to complete an operation. + * @c: UBIFS file-system description object + * @req: budget request + * + * This function allocates budget for an operation. It uses pessimistic + * approximation of how much flash space the operation needs. The goal of this + * function is to make sure UBIFS always has flash space to flush all dirty + * pages, dirty inodes, and dirty znodes (liability). This function may force + * commit, garbage-collection or write-back. Returns zero in case of success, + * %-ENOSPC if there is no free space and other negative error codes in case of + * failures. + */ +int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req) +{ + int err, idx_growth, data_growth, dd_growth, retried = 0; + + ubifs_assert(c, req->new_page <= 1); + ubifs_assert(c, req->dirtied_page <= 1); + ubifs_assert(c, req->new_dent <= 1); + ubifs_assert(c, req->mod_dent <= 1); + ubifs_assert(c, req->new_ino <= 1); + ubifs_assert(c, req->new_ino_d <= UBIFS_MAX_INO_DATA); + ubifs_assert(c, req->dirtied_ino <= 4); + ubifs_assert(c, req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4); + ubifs_assert(c, !(req->new_ino_d & 7)); + ubifs_assert(c, !(req->dirtied_ino_d & 7)); + + data_growth = calc_data_growth(c, req); + dd_growth = calc_dd_growth(c, req); + if (!data_growth && !dd_growth) + return 0; + idx_growth = calc_idx_growth(c, req); + +again: + spin_lock(&c->space_lock); + ubifs_assert(c, c->bi.idx_growth >= 0); + ubifs_assert(c, c->bi.data_growth >= 0); + ubifs_assert(c, c->bi.dd_growth >= 0); + + if (unlikely(c->bi.nospace) && (c->bi.nospace_rp || !can_use_rp(c))) { + dbg_budg("no space"); + spin_unlock(&c->space_lock); + return -ENOSPC; + } + + c->bi.idx_growth += idx_growth; + c->bi.data_growth += data_growth; + c->bi.dd_growth += dd_growth; + + err = do_budget_space(c); + if (likely(!err)) { + req->idx_growth = idx_growth; + req->data_growth = data_growth; + req->dd_growth = dd_growth; + spin_unlock(&c->space_lock); + return 0; + } + + /* Restore the old values */ + c->bi.idx_growth -= idx_growth; + c->bi.data_growth -= data_growth; + c->bi.dd_growth -= dd_growth; + spin_unlock(&c->space_lock); + + if (req->fast) { + dbg_budg("no space for fast budgeting"); + return err; + } + + err = make_free_space(c); + cond_resched(); + if (err == -EAGAIN) { + dbg_budg("try again"); + goto again; + } else if (err == -ENOSPC) { + if (!retried) { + retried = 1; + dbg_budg("-ENOSPC, but anyway try once again"); + goto again; + } + dbg_budg("FS is full, -ENOSPC"); + c->bi.nospace = 1; + if (can_use_rp(c) || c->rp_size == 0) + c->bi.nospace_rp = 1; + smp_wmb(); + } else + ubifs_err(c, "cannot budget space, error %d", err); + return err; +} + +/** + * ubifs_release_budget - release budgeted free space. + * @c: UBIFS file-system description object + * @req: budget request + * + * This function releases the space budgeted by 'ubifs_budget_space()'. Note, + * since the index changes (which were budgeted for in @req->idx_growth) will + * only be written to the media on commit, this function moves the index budget + * from @c->bi.idx_growth to @c->bi.uncommitted_idx. The latter will be zeroed + * by the commit operation. + */ +void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req) +{ + ubifs_assert(c, req->new_page <= 1); + ubifs_assert(c, req->dirtied_page <= 1); + ubifs_assert(c, req->new_dent <= 1); + ubifs_assert(c, req->mod_dent <= 1); + ubifs_assert(c, req->new_ino <= 1); + ubifs_assert(c, req->new_ino_d <= UBIFS_MAX_INO_DATA); + ubifs_assert(c, req->dirtied_ino <= 4); + ubifs_assert(c, req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4); + ubifs_assert(c, !(req->new_ino_d & 7)); + ubifs_assert(c, !(req->dirtied_ino_d & 7)); + if (!req->recalculate) { + ubifs_assert(c, req->idx_growth >= 0); + ubifs_assert(c, req->data_growth >= 0); + ubifs_assert(c, req->dd_growth >= 0); + } + + if (req->recalculate) { + req->data_growth = calc_data_growth(c, req); + req->dd_growth = calc_dd_growth(c, req); + req->idx_growth = calc_idx_growth(c, req); + } + + if (!req->data_growth && !req->dd_growth) + return; + + c->bi.nospace = c->bi.nospace_rp = 0; + smp_wmb(); + + spin_lock(&c->space_lock); + c->bi.idx_growth -= req->idx_growth; + c->bi.uncommitted_idx += req->idx_growth; + c->bi.data_growth -= req->data_growth; + c->bi.dd_growth -= req->dd_growth; + c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); + + ubifs_assert(c, c->bi.idx_growth >= 0); + ubifs_assert(c, c->bi.data_growth >= 0); + ubifs_assert(c, c->bi.dd_growth >= 0); + ubifs_assert(c, c->bi.min_idx_lebs < c->main_lebs); + ubifs_assert(c, !(c->bi.idx_growth & 7)); + ubifs_assert(c, !(c->bi.data_growth & 7)); + ubifs_assert(c, !(c->bi.dd_growth & 7)); + spin_unlock(&c->space_lock); +} + +/** + * ubifs_convert_page_budget - convert budget of a new page. + * @c: UBIFS file-system description object + * + * This function converts budget which was allocated for a new page of data to + * the budget of changing an existing page of data. The latter is smaller than + * the former, so this function only does simple re-calculation and does not + * involve any write-back. + */ +void ubifs_convert_page_budget(struct ubifs_info *c) +{ + spin_lock(&c->space_lock); + /* Release the index growth reservation */ + c->bi.idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT; + /* Release the data growth reservation */ + c->bi.data_growth -= c->bi.page_budget; + /* Increase the dirty data growth reservation instead */ + c->bi.dd_growth += c->bi.page_budget; + /* And re-calculate the indexing space reservation */ + c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); + spin_unlock(&c->space_lock); +} + +/** + * ubifs_release_dirty_inode_budget - release dirty inode budget. + * @c: UBIFS file-system description object + * @ui: UBIFS inode to release the budget for + * + * This function releases budget corresponding to a dirty inode. It is usually + * called when after the inode has been written to the media and marked as + * clean. It also causes the "no space" flags to be cleared. + */ +void ubifs_release_dirty_inode_budget(struct ubifs_info *c, + struct ubifs_inode *ui) +{ + struct ubifs_budget_req req; + + memset(&req, 0, sizeof(struct ubifs_budget_req)); + /* The "no space" flags will be cleared because dd_growth is > 0 */ + req.dd_growth = c->bi.inode_budget + ALIGN(ui->data_len, 8); + ubifs_release_budget(c, &req); +} + +/** + * ubifs_reported_space - calculate reported free space. + * @c: the UBIFS file-system description object + * @free: amount of free space + * + * This function calculates amount of free space which will be reported to + * user-space. User-space application tend to expect that if the file-system + * (e.g., via the 'statfs()' call) reports that it has N bytes available, they + * are able to write a file of size N. UBIFS attaches node headers to each data + * node and it has to write indexing nodes as well. This introduces additional + * overhead, and UBIFS has to report slightly less free space to meet the above + * expectations. + * + * This function assumes free space is made up of uncompressed data nodes and + * full index nodes (one per data node, tripled because we always allow enough + * space to write the index thrice). + * + * Note, the calculation is pessimistic, which means that most of the time + * UBIFS reports less space than it actually has. + */ +long long ubifs_reported_space(const struct ubifs_info *c, long long free) +{ + int divisor, factor, f; + + /* + * Reported space size is @free * X, where X is UBIFS block size + * divided by UBIFS block size + all overhead one data block + * introduces. The overhead is the node header + indexing overhead. + * + * Indexing overhead calculations are based on the following formula: + * I = N/(f - 1) + 1, where I - number of indexing nodes, N - number + * of data nodes, f - fanout. Because effective UBIFS fanout is twice + * as less than maximum fanout, we assume that each data node + * introduces 3 * @c->max_idx_node_sz / (@c->fanout/2 - 1) bytes. + * Note, the multiplier 3 is because UBIFS reserves thrice as more space + * for the index. + */ + f = c->fanout > 3 ? c->fanout >> 1 : 2; + factor = UBIFS_BLOCK_SIZE; + divisor = UBIFS_MAX_DATA_NODE_SZ; + divisor += (c->max_idx_node_sz * 3) / (f - 1); + free *= factor; + return div_u64(free, divisor); +} + +/** + * ubifs_get_free_space_nolock - return amount of free space. + * @c: UBIFS file-system description object + * + * This function calculates amount of free space to report to user-space. + * + * Because UBIFS may introduce substantial overhead (the index, node headers, + * alignment, wastage at the end of LEBs, etc), it cannot report real amount of + * free flash space it has (well, because not all dirty space is reclaimable, + * UBIFS does not actually know the real amount). If UBIFS did so, it would + * bread user expectations about what free space is. Users seem to accustomed + * to assume that if the file-system reports N bytes of free space, they would + * be able to fit a file of N bytes to the FS. This almost works for + * traditional file-systems, because they have way less overhead than UBIFS. + * So, to keep users happy, UBIFS tries to take the overhead into account. + */ +long long ubifs_get_free_space_nolock(struct ubifs_info *c) +{ + int rsvd_idx_lebs, lebs; + long long available, outstanding, free; + + ubifs_assert(c, c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c)); + outstanding = c->bi.data_growth + c->bi.dd_growth; + available = ubifs_calc_available(c, c->bi.min_idx_lebs); + + /* + * When reporting free space to user-space, UBIFS guarantees that it is + * possible to write a file of free space size. This means that for + * empty LEBs we may use more precise calculations than + * 'ubifs_calc_available()' is using. Namely, we know that in empty + * LEBs we would waste only @c->leb_overhead bytes, not @c->dark_wm. + * Thus, amend the available space. + * + * Note, the calculations below are similar to what we have in + * 'do_budget_space()', so refer there for comments. + */ + if (c->bi.min_idx_lebs > c->lst.idx_lebs) + rsvd_idx_lebs = c->bi.min_idx_lebs - c->lst.idx_lebs; + else + rsvd_idx_lebs = 0; + lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt - + c->lst.taken_empty_lebs; + lebs -= rsvd_idx_lebs; + available += lebs * (c->dark_wm - c->leb_overhead); + + if (available > outstanding) + free = ubifs_reported_space(c, available - outstanding); + else + free = 0; + return free; +} + +/** + * ubifs_get_free_space - return amount of free space. + * @c: UBIFS file-system description object + * + * This function calculates and returns amount of free space to report to + * user-space. + */ +long long ubifs_get_free_space(struct ubifs_info *c) +{ + long long free; + + spin_lock(&c->space_lock); + free = ubifs_get_free_space_nolock(c); + spin_unlock(&c->space_lock); + + return free; +} diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c new file mode 100644 index 000000000..b5cdac9b0 --- /dev/null +++ b/fs/ubifs/commit.c @@ -0,0 +1,722 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements functions that manage the running of the commit process. + * Each affected module has its own functions to accomplish their part in the + * commit and those functions are called here. + * + * The commit is the process whereby all updates to the index and LEB properties + * are written out together and the journal becomes empty. This keeps the + * file system consistent - at all times the state can be recreated by reading + * the index and LEB properties and then replaying the journal. + * + * The commit is split into two parts named "commit start" and "commit end". + * During commit start, the commit process has exclusive access to the journal + * by holding the commit semaphore down for writing. As few I/O operations as + * possible are performed during commit start, instead the nodes that are to be + * written are merely identified. During commit end, the commit semaphore is no + * longer held and the journal is again in operation, allowing users to continue + * to use the file system while the bulk of the commit I/O is performed. The + * purpose of this two-step approach is to prevent the commit from causing any + * latency blips. Note that in any case, the commit does not prevent lookups + * (as permitted by the TNC mutex), or access to VFS data structures e.g. page + * cache. + */ + +#include <linux/freezer.h> +#include <linux/kthread.h> +#include <linux/slab.h> +#include "ubifs.h" + +/* + * nothing_to_commit - check if there is nothing to commit. + * @c: UBIFS file-system description object + * + * This is a helper function which checks if there is anything to commit. It is + * used as an optimization to avoid starting the commit if it is not really + * necessary. Indeed, the commit operation always assumes flash I/O (e.g., + * writing the commit start node to the log), and it is better to avoid doing + * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is + * nothing to commit, it is more optimal to avoid any flash I/O. + * + * This function has to be called with @c->commit_sem locked for writing - + * this function does not take LPT/TNC locks because the @c->commit_sem + * guarantees that we have exclusive access to the TNC and LPT data structures. + * + * This function returns %1 if there is nothing to commit and %0 otherwise. + */ +static int nothing_to_commit(struct ubifs_info *c) +{ + /* + * During mounting or remounting from R/O mode to R/W mode we may + * commit for various recovery-related reasons. + */ + if (c->mounting || c->remounting_rw) + return 0; + + /* + * If the root TNC node is dirty, we definitely have something to + * commit. + */ + if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode)) + return 0; + + /* + * Even though the TNC is clean, the LPT tree may have dirty nodes. For + * example, this may happen if the budgeting subsystem invoked GC to + * make some free space, and the GC found an LEB with only dirty and + * free space. In this case GC would just change the lprops of this + * LEB (by turning all space into free space) and unmap it. + */ + if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags)) + return 0; + + ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0); + ubifs_assert(c, c->dirty_pn_cnt == 0); + ubifs_assert(c, c->dirty_nn_cnt == 0); + + return 1; +} + +/** + * do_commit - commit the journal. + * @c: UBIFS file-system description object + * + * This function implements UBIFS commit. It has to be called with commit lock + * locked. Returns zero in case of success and a negative error code in case of + * failure. + */ +static int do_commit(struct ubifs_info *c) +{ + int err, new_ltail_lnum, old_ltail_lnum, i; + struct ubifs_zbranch zroot; + struct ubifs_lp_stats lst; + + dbg_cmt("start"); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + + if (c->ro_error) { + err = -EROFS; + goto out_up; + } + + if (nothing_to_commit(c)) { + up_write(&c->commit_sem); + err = 0; + goto out_cancel; + } + + /* Sync all write buffers (necessary for recovery) */ + for (i = 0; i < c->jhead_cnt; i++) { + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err) + goto out_up; + } + + c->cmt_no += 1; + err = ubifs_gc_start_commit(c); + if (err) + goto out_up; + err = dbg_check_lprops(c); + if (err) + goto out_up; + err = ubifs_log_start_commit(c, &new_ltail_lnum); + if (err) + goto out_up; + err = ubifs_tnc_start_commit(c, &zroot); + if (err) + goto out_up; + err = ubifs_lpt_start_commit(c); + if (err) + goto out_up; + err = ubifs_orphan_start_commit(c); + if (err) + goto out_up; + + ubifs_get_lp_stats(c, &lst); + + up_write(&c->commit_sem); + + err = ubifs_tnc_end_commit(c); + if (err) + goto out; + err = ubifs_lpt_end_commit(c); + if (err) + goto out; + err = ubifs_orphan_end_commit(c); + if (err) + goto out; + err = dbg_check_old_index(c, &zroot); + if (err) + goto out; + + c->mst_node->cmt_no = cpu_to_le64(c->cmt_no); + c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum); + c->mst_node->root_lnum = cpu_to_le32(zroot.lnum); + c->mst_node->root_offs = cpu_to_le32(zroot.offs); + c->mst_node->root_len = cpu_to_le32(zroot.len); + c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum); + c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs); + c->mst_node->index_size = cpu_to_le64(c->bi.old_idx_sz); + c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum); + c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs); + c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum); + c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs); + c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum); + c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs); + c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum); + c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs); + c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum); + c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs); + c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs); + c->mst_node->total_free = cpu_to_le64(lst.total_free); + c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty); + c->mst_node->total_used = cpu_to_le64(lst.total_used); + c->mst_node->total_dead = cpu_to_le64(lst.total_dead); + c->mst_node->total_dark = cpu_to_le64(lst.total_dark); + if (c->no_orphs) + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); + else + c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS); + + old_ltail_lnum = c->ltail_lnum; + err = ubifs_log_end_commit(c, new_ltail_lnum); + if (err) + goto out; + + err = ubifs_log_post_commit(c, old_ltail_lnum); + if (err) + goto out; + err = ubifs_gc_end_commit(c); + if (err) + goto out; + err = ubifs_lpt_post_commit(c); + if (err) + goto out; + +out_cancel: + spin_lock(&c->cs_lock); + c->cmt_state = COMMIT_RESTING; + wake_up(&c->cmt_wq); + dbg_cmt("commit end"); + spin_unlock(&c->cs_lock); + return 0; + +out_up: + up_write(&c->commit_sem); +out: + ubifs_err(c, "commit failed, error %d", err); + spin_lock(&c->cs_lock); + c->cmt_state = COMMIT_BROKEN; + wake_up(&c->cmt_wq); + spin_unlock(&c->cs_lock); + ubifs_ro_mode(c, err); + return err; +} + +/** + * run_bg_commit - run background commit if it is needed. + * @c: UBIFS file-system description object + * + * This function runs background commit if it is needed. Returns zero in case + * of success and a negative error code in case of failure. + */ +static int run_bg_commit(struct ubifs_info *c) +{ + spin_lock(&c->cs_lock); + /* + * Run background commit only if background commit was requested or if + * commit is required. + */ + if (c->cmt_state != COMMIT_BACKGROUND && + c->cmt_state != COMMIT_REQUIRED) + goto out; + spin_unlock(&c->cs_lock); + + down_write(&c->commit_sem); + spin_lock(&c->cs_lock); + if (c->cmt_state == COMMIT_REQUIRED) + c->cmt_state = COMMIT_RUNNING_REQUIRED; + else if (c->cmt_state == COMMIT_BACKGROUND) + c->cmt_state = COMMIT_RUNNING_BACKGROUND; + else + goto out_cmt_unlock; + spin_unlock(&c->cs_lock); + + return do_commit(c); + +out_cmt_unlock: + up_write(&c->commit_sem); +out: + spin_unlock(&c->cs_lock); + return 0; +} + +/** + * ubifs_bg_thread - UBIFS background thread function. + * @info: points to the file-system description object + * + * This function implements various file-system background activities: + * o when a write-buffer timer expires it synchronizes the appropriate + * write-buffer; + * o when the journal is about to be full, it starts in-advance commit. + * + * Note, other stuff like background garbage collection may be added here in + * future. + */ +int ubifs_bg_thread(void *info) +{ + int err; + struct ubifs_info *c = info; + + ubifs_msg(c, "background thread \"%s\" started, PID %d", + c->bgt_name, current->pid); + set_freezable(); + + while (1) { + if (kthread_should_stop()) + break; + + if (try_to_freeze()) + continue; + + set_current_state(TASK_INTERRUPTIBLE); + /* Check if there is something to do */ + if (!c->need_bgt) { + /* + * Nothing prevents us from going sleep now and + * be never woken up and block the task which + * could wait in 'kthread_stop()' forever. + */ + if (kthread_should_stop()) + break; + schedule(); + continue; + } else + __set_current_state(TASK_RUNNING); + + c->need_bgt = 0; + err = ubifs_bg_wbufs_sync(c); + if (err) + ubifs_ro_mode(c, err); + + run_bg_commit(c); + cond_resched(); + } + + ubifs_msg(c, "background thread \"%s\" stops", c->bgt_name); + return 0; +} + +/** + * ubifs_commit_required - set commit state to "required". + * @c: UBIFS file-system description object + * + * This function is called if a commit is required but cannot be done from the + * calling function, so it is just flagged instead. + */ +void ubifs_commit_required(struct ubifs_info *c) +{ + spin_lock(&c->cs_lock); + switch (c->cmt_state) { + case COMMIT_RESTING: + case COMMIT_BACKGROUND: + dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), + dbg_cstate(COMMIT_REQUIRED)); + c->cmt_state = COMMIT_REQUIRED; + break; + case COMMIT_RUNNING_BACKGROUND: + dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), + dbg_cstate(COMMIT_RUNNING_REQUIRED)); + c->cmt_state = COMMIT_RUNNING_REQUIRED; + break; + case COMMIT_REQUIRED: + case COMMIT_RUNNING_REQUIRED: + case COMMIT_BROKEN: + break; + } + spin_unlock(&c->cs_lock); +} + +/** + * ubifs_request_bg_commit - notify the background thread to do a commit. + * @c: UBIFS file-system description object + * + * This function is called if the journal is full enough to make a commit + * worthwhile, so background thread is kicked to start it. + */ +void ubifs_request_bg_commit(struct ubifs_info *c) +{ + spin_lock(&c->cs_lock); + if (c->cmt_state == COMMIT_RESTING) { + dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), + dbg_cstate(COMMIT_BACKGROUND)); + c->cmt_state = COMMIT_BACKGROUND; + spin_unlock(&c->cs_lock); + ubifs_wake_up_bgt(c); + } else + spin_unlock(&c->cs_lock); +} + +/** + * wait_for_commit - wait for commit. + * @c: UBIFS file-system description object + * + * This function sleeps until the commit operation is no longer running. + */ +static int wait_for_commit(struct ubifs_info *c) +{ + dbg_cmt("pid %d goes sleep", current->pid); + + /* + * The following sleeps if the condition is false, and will be woken + * when the commit ends. It is possible, although very unlikely, that we + * will wake up and see the subsequent commit running, rather than the + * one we were waiting for, and go back to sleep. However, we will be + * woken again, so there is no danger of sleeping forever. + */ + wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND && + c->cmt_state != COMMIT_RUNNING_REQUIRED); + dbg_cmt("commit finished, pid %d woke up", current->pid); + return 0; +} + +/** + * ubifs_run_commit - run or wait for commit. + * @c: UBIFS file-system description object + * + * This function runs commit and returns zero in case of success and a negative + * error code in case of failure. + */ +int ubifs_run_commit(struct ubifs_info *c) +{ + int err = 0; + + spin_lock(&c->cs_lock); + if (c->cmt_state == COMMIT_BROKEN) { + err = -EROFS; + goto out; + } + + if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) + /* + * We set the commit state to 'running required' to indicate + * that we want it to complete as quickly as possible. + */ + c->cmt_state = COMMIT_RUNNING_REQUIRED; + + if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { + spin_unlock(&c->cs_lock); + return wait_for_commit(c); + } + spin_unlock(&c->cs_lock); + + /* Ok, the commit is indeed needed */ + + down_write(&c->commit_sem); + spin_lock(&c->cs_lock); + /* + * Since we unlocked 'c->cs_lock', the state may have changed, so + * re-check it. + */ + if (c->cmt_state == COMMIT_BROKEN) { + err = -EROFS; + goto out_cmt_unlock; + } + + if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) + c->cmt_state = COMMIT_RUNNING_REQUIRED; + + if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { + up_write(&c->commit_sem); + spin_unlock(&c->cs_lock); + return wait_for_commit(c); + } + c->cmt_state = COMMIT_RUNNING_REQUIRED; + spin_unlock(&c->cs_lock); + + err = do_commit(c); + return err; + +out_cmt_unlock: + up_write(&c->commit_sem); +out: + spin_unlock(&c->cs_lock); + return err; +} + +/** + * ubifs_gc_should_commit - determine if it is time for GC to run commit. + * @c: UBIFS file-system description object + * + * This function is called by garbage collection to determine if commit should + * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal + * is full enough to start commit, this function returns true. It is not + * absolutely necessary to commit yet, but it feels like this should be better + * then to keep doing GC. This function returns %1 if GC has to initiate commit + * and %0 if not. + */ +int ubifs_gc_should_commit(struct ubifs_info *c) +{ + int ret = 0; + + spin_lock(&c->cs_lock); + if (c->cmt_state == COMMIT_BACKGROUND) { + dbg_cmt("commit required now"); + c->cmt_state = COMMIT_REQUIRED; + } else + dbg_cmt("commit not requested"); + if (c->cmt_state == COMMIT_REQUIRED) + ret = 1; + spin_unlock(&c->cs_lock); + return ret; +} + +/* + * Everything below is related to debugging. + */ + +/** + * struct idx_node - hold index nodes during index tree traversal. + * @list: list + * @iip: index in parent (slot number of this indexing node in the parent + * indexing node) + * @upper_key: all keys in this indexing node have to be less or equivalent to + * this key + * @idx: index node (8-byte aligned because all node structures must be 8-byte + * aligned) + */ +struct idx_node { + struct list_head list; + int iip; + union ubifs_key upper_key; + struct ubifs_idx_node idx __aligned(8); +}; + +/** + * dbg_old_index_check_init - get information for the next old index check. + * @c: UBIFS file-system description object + * @zroot: root of the index + * + * This function records information about the index that will be needed for the + * next old index check i.e. 'dbg_check_old_index()'. + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot) +{ + struct ubifs_idx_node *idx; + int lnum, offs, len, err = 0; + struct ubifs_debug_info *d = c->dbg; + + d->old_zroot = *zroot; + lnum = d->old_zroot.lnum; + offs = d->old_zroot.offs; + len = d->old_zroot.len; + + idx = kmalloc(c->max_idx_node_sz, GFP_NOFS); + if (!idx) + return -ENOMEM; + + err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs); + if (err) + goto out; + + d->old_zroot_level = le16_to_cpu(idx->level); + d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum); +out: + kfree(idx); + return err; +} + +/** + * dbg_check_old_index - check the old copy of the index. + * @c: UBIFS file-system description object + * @zroot: root of the new index + * + * In order to be able to recover from an unclean unmount, a complete copy of + * the index must exist on flash. This is the "old" index. The commit process + * must write the "new" index to flash without overwriting or destroying any + * part of the old index. This function is run at commit end in order to check + * that the old index does indeed exist completely intact. + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot) +{ + int lnum, offs, len, err = 0, last_level, child_cnt; + int first = 1, iip; + struct ubifs_debug_info *d = c->dbg; + union ubifs_key lower_key, upper_key, l_key, u_key; + unsigned long long last_sqnum; + struct ubifs_idx_node *idx; + struct list_head list; + struct idx_node *i; + size_t sz; + + if (!dbg_is_chk_index(c)) + return 0; + + INIT_LIST_HEAD(&list); + + sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) - + UBIFS_IDX_NODE_SZ; + + /* Start at the old zroot */ + lnum = d->old_zroot.lnum; + offs = d->old_zroot.offs; + len = d->old_zroot.len; + iip = 0; + + /* + * Traverse the index tree preorder depth-first i.e. do a node and then + * its subtrees from left to right. + */ + while (1) { + struct ubifs_branch *br; + + /* Get the next index node */ + i = kmalloc(sz, GFP_NOFS); + if (!i) { + err = -ENOMEM; + goto out_free; + } + i->iip = iip; + /* Keep the index nodes on our path in a linked list */ + list_add_tail(&i->list, &list); + /* Read the index node */ + idx = &i->idx; + err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs); + if (err) + goto out_free; + /* Validate index node */ + child_cnt = le16_to_cpu(idx->child_cnt); + if (child_cnt < 1 || child_cnt > c->fanout) { + err = 1; + goto out_dump; + } + if (first) { + first = 0; + /* Check root level and sqnum */ + if (le16_to_cpu(idx->level) != d->old_zroot_level) { + err = 2; + goto out_dump; + } + if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) { + err = 3; + goto out_dump; + } + /* Set last values as though root had a parent */ + last_level = le16_to_cpu(idx->level) + 1; + last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1; + key_read(c, ubifs_idx_key(c, idx), &lower_key); + highest_ino_key(c, &upper_key, INUM_WATERMARK); + } + key_copy(c, &upper_key, &i->upper_key); + if (le16_to_cpu(idx->level) != last_level - 1) { + err = 3; + goto out_dump; + } + /* + * The index is always written bottom up hence a child's sqnum + * is always less than the parents. + */ + if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) { + err = 4; + goto out_dump; + } + /* Check key range */ + key_read(c, ubifs_idx_key(c, idx), &l_key); + br = ubifs_idx_branch(c, idx, child_cnt - 1); + key_read(c, &br->key, &u_key); + if (keys_cmp(c, &lower_key, &l_key) > 0) { + err = 5; + goto out_dump; + } + if (keys_cmp(c, &upper_key, &u_key) < 0) { + err = 6; + goto out_dump; + } + if (keys_cmp(c, &upper_key, &u_key) == 0) + if (!is_hash_key(c, &u_key)) { + err = 7; + goto out_dump; + } + /* Go to next index node */ + if (le16_to_cpu(idx->level) == 0) { + /* At the bottom, so go up until can go right */ + while (1) { + /* Drop the bottom of the list */ + list_del(&i->list); + kfree(i); + /* No more list means we are done */ + if (list_empty(&list)) + goto out; + /* Look at the new bottom */ + i = list_entry(list.prev, struct idx_node, + list); + idx = &i->idx; + /* Can we go right */ + if (iip + 1 < le16_to_cpu(idx->child_cnt)) { + iip = iip + 1; + break; + } else + /* Nope, so go up again */ + iip = i->iip; + } + } else + /* Go down left */ + iip = 0; + /* + * We have the parent in 'idx' and now we set up for reading the + * child pointed to by slot 'iip'. + */ + last_level = le16_to_cpu(idx->level); + last_sqnum = le64_to_cpu(idx->ch.sqnum); + br = ubifs_idx_branch(c, idx, iip); + lnum = le32_to_cpu(br->lnum); + offs = le32_to_cpu(br->offs); + len = le32_to_cpu(br->len); + key_read(c, &br->key, &lower_key); + if (iip + 1 < le16_to_cpu(idx->child_cnt)) { + br = ubifs_idx_branch(c, idx, iip + 1); + key_read(c, &br->key, &upper_key); + } else + key_copy(c, &i->upper_key, &upper_key); + } +out: + err = dbg_old_index_check_init(c, zroot); + if (err) + goto out_free; + + return 0; + +out_dump: + ubifs_err(c, "dumping index node (iip=%d)", i->iip); + ubifs_dump_node(c, idx); + list_del(&i->list); + kfree(i); + if (!list_empty(&list)) { + i = list_entry(list.prev, struct idx_node, list); + ubifs_err(c, "dumping parent index node"); + ubifs_dump_node(c, &i->idx); + } +out_free: + while (!list_empty(&list)) { + i = list_entry(list.next, struct idx_node, list); + list_del(&i->list); + kfree(i); + } + ubifs_err(c, "failed, error %d", err); + if (err > 0) + err = -EINVAL; + return err; +} diff --git a/fs/ubifs/compress.c b/fs/ubifs/compress.c new file mode 100644 index 000000000..3a92e6af6 --- /dev/null +++ b/fs/ubifs/compress.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * Copyright (C) 2006, 2007 University of Szeged, Hungary + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + * Zoltan Sogor + */ + +/* + * This file provides a single place to access to compression and + * decompression. + */ + +#include <linux/crypto.h> +#include "ubifs.h" + +/* Fake description object for the "none" compressor */ +static struct ubifs_compressor none_compr = { + .compr_type = UBIFS_COMPR_NONE, + .name = "none", + .capi_name = "", +}; + +#ifdef CONFIG_UBIFS_FS_LZO +static DEFINE_MUTEX(lzo_mutex); + +static struct ubifs_compressor lzo_compr = { + .compr_type = UBIFS_COMPR_LZO, + .comp_mutex = &lzo_mutex, + .name = "lzo", + .capi_name = "lzo", +}; +#else +static struct ubifs_compressor lzo_compr = { + .compr_type = UBIFS_COMPR_LZO, + .name = "lzo", +}; +#endif + +#ifdef CONFIG_UBIFS_FS_ZLIB +static DEFINE_MUTEX(deflate_mutex); +static DEFINE_MUTEX(inflate_mutex); + +static struct ubifs_compressor zlib_compr = { + .compr_type = UBIFS_COMPR_ZLIB, + .comp_mutex = &deflate_mutex, + .decomp_mutex = &inflate_mutex, + .name = "zlib", + .capi_name = "deflate", +}; +#else +static struct ubifs_compressor zlib_compr = { + .compr_type = UBIFS_COMPR_ZLIB, + .name = "zlib", +}; +#endif + +#ifdef CONFIG_UBIFS_FS_ZSTD +static DEFINE_MUTEX(zstd_enc_mutex); +static DEFINE_MUTEX(zstd_dec_mutex); + +static struct ubifs_compressor zstd_compr = { + .compr_type = UBIFS_COMPR_ZSTD, + .comp_mutex = &zstd_enc_mutex, + .decomp_mutex = &zstd_dec_mutex, + .name = "zstd", + .capi_name = "zstd", +}; +#else +static struct ubifs_compressor zstd_compr = { + .compr_type = UBIFS_COMPR_ZSTD, + .name = "zstd", +}; +#endif + +/* All UBIFS compressors */ +struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT]; + +/** + * ubifs_compress - compress data. + * @in_buf: data to compress + * @in_len: length of the data to compress + * @out_buf: output buffer where compressed data should be stored + * @out_len: output buffer length is returned here + * @compr_type: type of compression to use on enter, actually used compression + * type on exit + * + * This function compresses input buffer @in_buf of length @in_len and stores + * the result in the output buffer @out_buf and the resulting length in + * @out_len. If the input buffer does not compress, it is just copied to the + * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if + * compression error occurred. + * + * Note, if the input buffer was not compressed, it is copied to the output + * buffer and %UBIFS_COMPR_NONE is returned in @compr_type. + */ +void ubifs_compress(const struct ubifs_info *c, const void *in_buf, + int in_len, void *out_buf, int *out_len, int *compr_type) +{ + int err; + struct ubifs_compressor *compr = ubifs_compressors[*compr_type]; + + if (*compr_type == UBIFS_COMPR_NONE) + goto no_compr; + + /* If the input data is small, do not even try to compress it */ + if (in_len < UBIFS_MIN_COMPR_LEN) + goto no_compr; + + if (compr->comp_mutex) + mutex_lock(compr->comp_mutex); + err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf, + (unsigned int *)out_len); + if (compr->comp_mutex) + mutex_unlock(compr->comp_mutex); + if (unlikely(err)) { + ubifs_warn(c, "cannot compress %d bytes, compressor %s, error %d, leave data uncompressed", + in_len, compr->name, err); + goto no_compr; + } + + /* + * If the data compressed only slightly, it is better to leave it + * uncompressed to improve read speed. + */ + if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF) + goto no_compr; + + return; + +no_compr: + memcpy(out_buf, in_buf, in_len); + *out_len = in_len; + *compr_type = UBIFS_COMPR_NONE; +} + +/** + * ubifs_decompress - decompress data. + * @in_buf: data to decompress + * @in_len: length of the data to decompress + * @out_buf: output buffer where decompressed data should + * @out_len: output length is returned here + * @compr_type: type of compression + * + * This function decompresses data from buffer @in_buf into buffer @out_buf. + * The length of the uncompressed data is returned in @out_len. This functions + * returns %0 on success or a negative error code on failure. + */ +int ubifs_decompress(const struct ubifs_info *c, const void *in_buf, + int in_len, void *out_buf, int *out_len, int compr_type) +{ + int err; + struct ubifs_compressor *compr; + + if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) { + ubifs_err(c, "invalid compression type %d", compr_type); + return -EINVAL; + } + + compr = ubifs_compressors[compr_type]; + + if (unlikely(!compr->capi_name)) { + ubifs_err(c, "%s compression is not compiled in", compr->name); + return -EINVAL; + } + + if (compr_type == UBIFS_COMPR_NONE) { + memcpy(out_buf, in_buf, in_len); + *out_len = in_len; + return 0; + } + + if (compr->decomp_mutex) + mutex_lock(compr->decomp_mutex); + err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf, + (unsigned int *)out_len); + if (compr->decomp_mutex) + mutex_unlock(compr->decomp_mutex); + if (err) + ubifs_err(c, "cannot decompress %d bytes, compressor %s, error %d", + in_len, compr->name, err); + + return err; +} + +/** + * compr_init - initialize a compressor. + * @compr: compressor description object + * + * This function initializes the requested compressor and returns zero in case + * of success or a negative error code in case of failure. + */ +static int __init compr_init(struct ubifs_compressor *compr) +{ + if (compr->capi_name) { + compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0); + if (IS_ERR(compr->cc)) { + pr_err("UBIFS error (pid %d): cannot initialize compressor %s, error %ld", + current->pid, compr->name, PTR_ERR(compr->cc)); + return PTR_ERR(compr->cc); + } + } + + ubifs_compressors[compr->compr_type] = compr; + return 0; +} + +/** + * compr_exit - de-initialize a compressor. + * @compr: compressor description object + */ +static void compr_exit(struct ubifs_compressor *compr) +{ + if (compr->capi_name) + crypto_free_comp(compr->cc); + return; +} + +/** + * ubifs_compressors_init - initialize UBIFS compressors. + * + * This function initializes the compressor which were compiled in. Returns + * zero in case of success and a negative error code in case of failure. + */ +int __init ubifs_compressors_init(void) +{ + int err; + + err = compr_init(&lzo_compr); + if (err) + return err; + + err = compr_init(&zstd_compr); + if (err) + goto out_lzo; + + err = compr_init(&zlib_compr); + if (err) + goto out_zstd; + + ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr; + return 0; + +out_zstd: + compr_exit(&zstd_compr); +out_lzo: + compr_exit(&lzo_compr); + return err; +} + +/** + * ubifs_compressors_exit - de-initialize UBIFS compressors. + */ +void ubifs_compressors_exit(void) +{ + compr_exit(&lzo_compr); + compr_exit(&zlib_compr); + compr_exit(&zstd_compr); +} diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c new file mode 100644 index 000000000..22be7aeb9 --- /dev/null +++ b/fs/ubifs/crypto.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "ubifs.h" + +static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len) +{ + return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT, + ctx, len); +} + +static int ubifs_crypt_set_context(struct inode *inode, const void *ctx, + size_t len, void *fs_data) +{ + /* + * Creating an encryption context is done unlocked since we + * operate on a new inode which is not visible to other users + * at this point. So, no need to check whether inode is locked. + */ + return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT, + ctx, len, 0, false); +} + +static bool ubifs_crypt_empty_dir(struct inode *inode) +{ + return ubifs_check_dir_empty(inode) == 0; +} + +int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, + unsigned int in_len, unsigned int *out_len, int block) +{ + struct ubifs_info *c = inode->i_sb->s_fs_info; + void *p = &dn->data; + unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE); + int err; + + ubifs_assert(c, pad_len <= *out_len); + dn->compr_size = cpu_to_le16(in_len); + + /* pad to full block cipher length */ + if (pad_len != in_len) + memset(p + in_len, 0, pad_len - in_len); + + err = fscrypt_encrypt_block_inplace(inode, virt_to_page(p), pad_len, + offset_in_page(p), block, GFP_NOFS); + if (err) { + ubifs_err(c, "fscrypt_encrypt_block_inplace() failed: %d", err); + return err; + } + *out_len = pad_len; + + return 0; +} + +int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, + unsigned int *out_len, int block) +{ + struct ubifs_info *c = inode->i_sb->s_fs_info; + int err; + unsigned int clen = le16_to_cpu(dn->compr_size); + unsigned int dlen = *out_len; + + if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) { + ubifs_err(c, "bad compr_size: %i", clen); + return -EINVAL; + } + + ubifs_assert(c, dlen <= UBIFS_BLOCK_SIZE); + err = fscrypt_decrypt_block_inplace(inode, virt_to_page(&dn->data), + dlen, offset_in_page(&dn->data), + block); + if (err) { + ubifs_err(c, "fscrypt_decrypt_block_inplace() failed: %d", err); + return err; + } + *out_len = clen; + + return 0; +} + +const struct fscrypt_operations ubifs_crypt_operations = { + .flags = FS_CFLG_OWN_PAGES, + .key_prefix = "ubifs:", + .get_context = ubifs_crypt_get_context, + .set_context = ubifs_crypt_set_context, + .empty_dir = ubifs_crypt_empty_dir, + .max_namelen = UBIFS_MAX_NLEN, +}; diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c new file mode 100644 index 000000000..ebff43f80 --- /dev/null +++ b/fs/ubifs/debug.c @@ -0,0 +1,3026 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements most of the debugging stuff which is compiled in only + * when it is enabled. But some debugging check functions are implemented in + * corresponding subsystem, just because they are closely related and utilize + * various local functions of those subsystems. + */ + +#include <linux/module.h> +#include <linux/debugfs.h> +#include <linux/math64.h> +#include <linux/uaccess.h> +#include <linux/random.h> +#include <linux/ctype.h> +#include "ubifs.h" + +static DEFINE_SPINLOCK(dbg_lock); + +static const char *get_key_fmt(int fmt) +{ + switch (fmt) { + case UBIFS_SIMPLE_KEY_FMT: + return "simple"; + default: + return "unknown/invalid format"; + } +} + +static const char *get_key_hash(int hash) +{ + switch (hash) { + case UBIFS_KEY_HASH_R5: + return "R5"; + case UBIFS_KEY_HASH_TEST: + return "test"; + default: + return "unknown/invalid name hash"; + } +} + +static const char *get_key_type(int type) +{ + switch (type) { + case UBIFS_INO_KEY: + return "inode"; + case UBIFS_DENT_KEY: + return "direntry"; + case UBIFS_XENT_KEY: + return "xentry"; + case UBIFS_DATA_KEY: + return "data"; + case UBIFS_TRUN_KEY: + return "truncate"; + default: + return "unknown/invalid key"; + } +} + +static const char *get_dent_type(int type) +{ + switch (type) { + case UBIFS_ITYPE_REG: + return "file"; + case UBIFS_ITYPE_DIR: + return "dir"; + case UBIFS_ITYPE_LNK: + return "symlink"; + case UBIFS_ITYPE_BLK: + return "blkdev"; + case UBIFS_ITYPE_CHR: + return "char dev"; + case UBIFS_ITYPE_FIFO: + return "fifo"; + case UBIFS_ITYPE_SOCK: + return "socket"; + default: + return "unknown/invalid type"; + } +} + +const char *dbg_snprintf_key(const struct ubifs_info *c, + const union ubifs_key *key, char *buffer, int len) +{ + char *p = buffer; + int type = key_type(c, key); + + if (c->key_fmt == UBIFS_SIMPLE_KEY_FMT) { + switch (type) { + case UBIFS_INO_KEY: + len -= snprintf(p, len, "(%lu, %s)", + (unsigned long)key_inum(c, key), + get_key_type(type)); + break; + case UBIFS_DENT_KEY: + case UBIFS_XENT_KEY: + len -= snprintf(p, len, "(%lu, %s, %#08x)", + (unsigned long)key_inum(c, key), + get_key_type(type), key_hash(c, key)); + break; + case UBIFS_DATA_KEY: + len -= snprintf(p, len, "(%lu, %s, %u)", + (unsigned long)key_inum(c, key), + get_key_type(type), key_block(c, key)); + break; + case UBIFS_TRUN_KEY: + len -= snprintf(p, len, "(%lu, %s)", + (unsigned long)key_inum(c, key), + get_key_type(type)); + break; + default: + len -= snprintf(p, len, "(bad key type: %#08x, %#08x)", + key->u32[0], key->u32[1]); + } + } else + len -= snprintf(p, len, "bad key format %d", c->key_fmt); + ubifs_assert(c, len > 0); + return p; +} + +const char *dbg_ntype(int type) +{ + switch (type) { + case UBIFS_PAD_NODE: + return "padding node"; + case UBIFS_SB_NODE: + return "superblock node"; + case UBIFS_MST_NODE: + return "master node"; + case UBIFS_REF_NODE: + return "reference node"; + case UBIFS_INO_NODE: + return "inode node"; + case UBIFS_DENT_NODE: + return "direntry node"; + case UBIFS_XENT_NODE: + return "xentry node"; + case UBIFS_DATA_NODE: + return "data node"; + case UBIFS_TRUN_NODE: + return "truncate node"; + case UBIFS_IDX_NODE: + return "indexing node"; + case UBIFS_CS_NODE: + return "commit start node"; + case UBIFS_ORPH_NODE: + return "orphan node"; + case UBIFS_AUTH_NODE: + return "auth node"; + default: + return "unknown node"; + } +} + +static const char *dbg_gtype(int type) +{ + switch (type) { + case UBIFS_NO_NODE_GROUP: + return "no node group"; + case UBIFS_IN_NODE_GROUP: + return "in node group"; + case UBIFS_LAST_OF_NODE_GROUP: + return "last of node group"; + default: + return "unknown"; + } +} + +const char *dbg_cstate(int cmt_state) +{ + switch (cmt_state) { + case COMMIT_RESTING: + return "commit resting"; + case COMMIT_BACKGROUND: + return "background commit requested"; + case COMMIT_REQUIRED: + return "commit required"; + case COMMIT_RUNNING_BACKGROUND: + return "BACKGROUND commit running"; + case COMMIT_RUNNING_REQUIRED: + return "commit running and required"; + case COMMIT_BROKEN: + return "broken commit"; + default: + return "unknown commit state"; + } +} + +const char *dbg_jhead(int jhead) +{ + switch (jhead) { + case GCHD: + return "0 (GC)"; + case BASEHD: + return "1 (base)"; + case DATAHD: + return "2 (data)"; + default: + return "unknown journal head"; + } +} + +static void dump_ch(const struct ubifs_ch *ch) +{ + pr_err("\tmagic %#x\n", le32_to_cpu(ch->magic)); + pr_err("\tcrc %#x\n", le32_to_cpu(ch->crc)); + pr_err("\tnode_type %d (%s)\n", ch->node_type, + dbg_ntype(ch->node_type)); + pr_err("\tgroup_type %d (%s)\n", ch->group_type, + dbg_gtype(ch->group_type)); + pr_err("\tsqnum %llu\n", + (unsigned long long)le64_to_cpu(ch->sqnum)); + pr_err("\tlen %u\n", le32_to_cpu(ch->len)); +} + +void ubifs_dump_inode(struct ubifs_info *c, const struct inode *inode) +{ + const struct ubifs_inode *ui = ubifs_inode(inode); + struct fscrypt_name nm = {0}; + union ubifs_key key; + struct ubifs_dent_node *dent, *pdent = NULL; + int count = 2; + + pr_err("Dump in-memory inode:"); + pr_err("\tinode %lu\n", inode->i_ino); + pr_err("\tsize %llu\n", + (unsigned long long)i_size_read(inode)); + pr_err("\tnlink %u\n", inode->i_nlink); + pr_err("\tuid %u\n", (unsigned int)i_uid_read(inode)); + pr_err("\tgid %u\n", (unsigned int)i_gid_read(inode)); + pr_err("\tatime %u.%u\n", + (unsigned int)inode->i_atime.tv_sec, + (unsigned int)inode->i_atime.tv_nsec); + pr_err("\tmtime %u.%u\n", + (unsigned int)inode->i_mtime.tv_sec, + (unsigned int)inode->i_mtime.tv_nsec); + pr_err("\tctime %u.%u\n", + (unsigned int)inode->i_ctime.tv_sec, + (unsigned int)inode->i_ctime.tv_nsec); + pr_err("\tcreat_sqnum %llu\n", ui->creat_sqnum); + pr_err("\txattr_size %u\n", ui->xattr_size); + pr_err("\txattr_cnt %u\n", ui->xattr_cnt); + pr_err("\txattr_names %u\n", ui->xattr_names); + pr_err("\tdirty %u\n", ui->dirty); + pr_err("\txattr %u\n", ui->xattr); + pr_err("\tbulk_read %u\n", ui->bulk_read); + pr_err("\tsynced_i_size %llu\n", + (unsigned long long)ui->synced_i_size); + pr_err("\tui_size %llu\n", + (unsigned long long)ui->ui_size); + pr_err("\tflags %d\n", ui->flags); + pr_err("\tcompr_type %d\n", ui->compr_type); + pr_err("\tlast_page_read %lu\n", ui->last_page_read); + pr_err("\tread_in_a_row %lu\n", ui->read_in_a_row); + pr_err("\tdata_len %d\n", ui->data_len); + + if (!S_ISDIR(inode->i_mode)) + return; + + pr_err("List of directory entries:\n"); + ubifs_assert(c, !mutex_is_locked(&c->tnc_mutex)); + + lowest_dent_key(c, &key, inode->i_ino); + while (1) { + dent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(dent)) { + if (PTR_ERR(dent) != -ENOENT) + pr_err("error %ld\n", PTR_ERR(dent)); + break; + } + + pr_err("\t%d: inode %llu, type %s, len %d\n", + count++, (unsigned long long) le64_to_cpu(dent->inum), + get_dent_type(dent->type), + le16_to_cpu(dent->nlen)); + + fname_name(&nm) = dent->name; + fname_len(&nm) = le16_to_cpu(dent->nlen); + kfree(pdent); + pdent = dent; + key_read(c, &dent->key, &key); + } + kfree(pdent); +} + +void ubifs_dump_node(const struct ubifs_info *c, const void *node) +{ + int i, n; + union ubifs_key key; + const struct ubifs_ch *ch = node; + char key_buf[DBG_KEY_BUF_LEN]; + + /* If the magic is incorrect, just hexdump the first bytes */ + if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) { + pr_err("Not a node, first %zu bytes:", UBIFS_CH_SZ); + print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 32, 1, + (void *)node, UBIFS_CH_SZ, 1); + return; + } + + spin_lock(&dbg_lock); + dump_ch(node); + + switch (ch->node_type) { + case UBIFS_PAD_NODE: + { + const struct ubifs_pad_node *pad = node; + + pr_err("\tpad_len %u\n", le32_to_cpu(pad->pad_len)); + break; + } + case UBIFS_SB_NODE: + { + const struct ubifs_sb_node *sup = node; + unsigned int sup_flags = le32_to_cpu(sup->flags); + + pr_err("\tkey_hash %d (%s)\n", + (int)sup->key_hash, get_key_hash(sup->key_hash)); + pr_err("\tkey_fmt %d (%s)\n", + (int)sup->key_fmt, get_key_fmt(sup->key_fmt)); + pr_err("\tflags %#x\n", sup_flags); + pr_err("\tbig_lpt %u\n", + !!(sup_flags & UBIFS_FLG_BIGLPT)); + pr_err("\tspace_fixup %u\n", + !!(sup_flags & UBIFS_FLG_SPACE_FIXUP)); + pr_err("\tmin_io_size %u\n", le32_to_cpu(sup->min_io_size)); + pr_err("\tleb_size %u\n", le32_to_cpu(sup->leb_size)); + pr_err("\tleb_cnt %u\n", le32_to_cpu(sup->leb_cnt)); + pr_err("\tmax_leb_cnt %u\n", le32_to_cpu(sup->max_leb_cnt)); + pr_err("\tmax_bud_bytes %llu\n", + (unsigned long long)le64_to_cpu(sup->max_bud_bytes)); + pr_err("\tlog_lebs %u\n", le32_to_cpu(sup->log_lebs)); + pr_err("\tlpt_lebs %u\n", le32_to_cpu(sup->lpt_lebs)); + pr_err("\torph_lebs %u\n", le32_to_cpu(sup->orph_lebs)); + pr_err("\tjhead_cnt %u\n", le32_to_cpu(sup->jhead_cnt)); + pr_err("\tfanout %u\n", le32_to_cpu(sup->fanout)); + pr_err("\tlsave_cnt %u\n", le32_to_cpu(sup->lsave_cnt)); + pr_err("\tdefault_compr %u\n", + (int)le16_to_cpu(sup->default_compr)); + pr_err("\trp_size %llu\n", + (unsigned long long)le64_to_cpu(sup->rp_size)); + pr_err("\trp_uid %u\n", le32_to_cpu(sup->rp_uid)); + pr_err("\trp_gid %u\n", le32_to_cpu(sup->rp_gid)); + pr_err("\tfmt_version %u\n", le32_to_cpu(sup->fmt_version)); + pr_err("\ttime_gran %u\n", le32_to_cpu(sup->time_gran)); + pr_err("\tUUID %pUB\n", sup->uuid); + break; + } + case UBIFS_MST_NODE: + { + const struct ubifs_mst_node *mst = node; + + pr_err("\thighest_inum %llu\n", + (unsigned long long)le64_to_cpu(mst->highest_inum)); + pr_err("\tcommit number %llu\n", + (unsigned long long)le64_to_cpu(mst->cmt_no)); + pr_err("\tflags %#x\n", le32_to_cpu(mst->flags)); + pr_err("\tlog_lnum %u\n", le32_to_cpu(mst->log_lnum)); + pr_err("\troot_lnum %u\n", le32_to_cpu(mst->root_lnum)); + pr_err("\troot_offs %u\n", le32_to_cpu(mst->root_offs)); + pr_err("\troot_len %u\n", le32_to_cpu(mst->root_len)); + pr_err("\tgc_lnum %u\n", le32_to_cpu(mst->gc_lnum)); + pr_err("\tihead_lnum %u\n", le32_to_cpu(mst->ihead_lnum)); + pr_err("\tihead_offs %u\n", le32_to_cpu(mst->ihead_offs)); + pr_err("\tindex_size %llu\n", + (unsigned long long)le64_to_cpu(mst->index_size)); + pr_err("\tlpt_lnum %u\n", le32_to_cpu(mst->lpt_lnum)); + pr_err("\tlpt_offs %u\n", le32_to_cpu(mst->lpt_offs)); + pr_err("\tnhead_lnum %u\n", le32_to_cpu(mst->nhead_lnum)); + pr_err("\tnhead_offs %u\n", le32_to_cpu(mst->nhead_offs)); + pr_err("\tltab_lnum %u\n", le32_to_cpu(mst->ltab_lnum)); + pr_err("\tltab_offs %u\n", le32_to_cpu(mst->ltab_offs)); + pr_err("\tlsave_lnum %u\n", le32_to_cpu(mst->lsave_lnum)); + pr_err("\tlsave_offs %u\n", le32_to_cpu(mst->lsave_offs)); + pr_err("\tlscan_lnum %u\n", le32_to_cpu(mst->lscan_lnum)); + pr_err("\tleb_cnt %u\n", le32_to_cpu(mst->leb_cnt)); + pr_err("\tempty_lebs %u\n", le32_to_cpu(mst->empty_lebs)); + pr_err("\tidx_lebs %u\n", le32_to_cpu(mst->idx_lebs)); + pr_err("\ttotal_free %llu\n", + (unsigned long long)le64_to_cpu(mst->total_free)); + pr_err("\ttotal_dirty %llu\n", + (unsigned long long)le64_to_cpu(mst->total_dirty)); + pr_err("\ttotal_used %llu\n", + (unsigned long long)le64_to_cpu(mst->total_used)); + pr_err("\ttotal_dead %llu\n", + (unsigned long long)le64_to_cpu(mst->total_dead)); + pr_err("\ttotal_dark %llu\n", + (unsigned long long)le64_to_cpu(mst->total_dark)); + break; + } + case UBIFS_REF_NODE: + { + const struct ubifs_ref_node *ref = node; + + pr_err("\tlnum %u\n", le32_to_cpu(ref->lnum)); + pr_err("\toffs %u\n", le32_to_cpu(ref->offs)); + pr_err("\tjhead %u\n", le32_to_cpu(ref->jhead)); + break; + } + case UBIFS_INO_NODE: + { + const struct ubifs_ino_node *ino = node; + + key_read(c, &ino->key, &key); + pr_err("\tkey %s\n", + dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN)); + pr_err("\tcreat_sqnum %llu\n", + (unsigned long long)le64_to_cpu(ino->creat_sqnum)); + pr_err("\tsize %llu\n", + (unsigned long long)le64_to_cpu(ino->size)); + pr_err("\tnlink %u\n", le32_to_cpu(ino->nlink)); + pr_err("\tatime %lld.%u\n", + (long long)le64_to_cpu(ino->atime_sec), + le32_to_cpu(ino->atime_nsec)); + pr_err("\tmtime %lld.%u\n", + (long long)le64_to_cpu(ino->mtime_sec), + le32_to_cpu(ino->mtime_nsec)); + pr_err("\tctime %lld.%u\n", + (long long)le64_to_cpu(ino->ctime_sec), + le32_to_cpu(ino->ctime_nsec)); + pr_err("\tuid %u\n", le32_to_cpu(ino->uid)); + pr_err("\tgid %u\n", le32_to_cpu(ino->gid)); + pr_err("\tmode %u\n", le32_to_cpu(ino->mode)); + pr_err("\tflags %#x\n", le32_to_cpu(ino->flags)); + pr_err("\txattr_cnt %u\n", le32_to_cpu(ino->xattr_cnt)); + pr_err("\txattr_size %u\n", le32_to_cpu(ino->xattr_size)); + pr_err("\txattr_names %u\n", le32_to_cpu(ino->xattr_names)); + pr_err("\tcompr_type %#x\n", + (int)le16_to_cpu(ino->compr_type)); + pr_err("\tdata len %u\n", le32_to_cpu(ino->data_len)); + break; + } + case UBIFS_DENT_NODE: + case UBIFS_XENT_NODE: + { + const struct ubifs_dent_node *dent = node; + int nlen = le16_to_cpu(dent->nlen); + + key_read(c, &dent->key, &key); + pr_err("\tkey %s\n", + dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN)); + pr_err("\tinum %llu\n", + (unsigned long long)le64_to_cpu(dent->inum)); + pr_err("\ttype %d\n", (int)dent->type); + pr_err("\tnlen %d\n", nlen); + pr_err("\tname "); + + if (nlen > UBIFS_MAX_NLEN) + pr_err("(bad name length, not printing, bad or corrupted node)"); + else { + for (i = 0; i < nlen && dent->name[i]; i++) + pr_cont("%c", isprint(dent->name[i]) ? + dent->name[i] : '?'); + } + pr_cont("\n"); + + break; + } + case UBIFS_DATA_NODE: + { + const struct ubifs_data_node *dn = node; + int dlen = le32_to_cpu(ch->len) - UBIFS_DATA_NODE_SZ; + + key_read(c, &dn->key, &key); + pr_err("\tkey %s\n", + dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN)); + pr_err("\tsize %u\n", le32_to_cpu(dn->size)); + pr_err("\tcompr_typ %d\n", + (int)le16_to_cpu(dn->compr_type)); + pr_err("\tdata size %d\n", dlen); + pr_err("\tdata:\n"); + print_hex_dump(KERN_ERR, "\t", DUMP_PREFIX_OFFSET, 32, 1, + (void *)&dn->data, dlen, 0); + break; + } + case UBIFS_TRUN_NODE: + { + const struct ubifs_trun_node *trun = node; + + pr_err("\tinum %u\n", le32_to_cpu(trun->inum)); + pr_err("\told_size %llu\n", + (unsigned long long)le64_to_cpu(trun->old_size)); + pr_err("\tnew_size %llu\n", + (unsigned long long)le64_to_cpu(trun->new_size)); + break; + } + case UBIFS_IDX_NODE: + { + const struct ubifs_idx_node *idx = node; + + n = le16_to_cpu(idx->child_cnt); + pr_err("\tchild_cnt %d\n", n); + pr_err("\tlevel %d\n", (int)le16_to_cpu(idx->level)); + pr_err("\tBranches:\n"); + + for (i = 0; i < n && i < c->fanout - 1; i++) { + const struct ubifs_branch *br; + + br = ubifs_idx_branch(c, idx, i); + key_read(c, &br->key, &key); + pr_err("\t%d: LEB %d:%d len %d key %s\n", + i, le32_to_cpu(br->lnum), le32_to_cpu(br->offs), + le32_to_cpu(br->len), + dbg_snprintf_key(c, &key, key_buf, + DBG_KEY_BUF_LEN)); + } + break; + } + case UBIFS_CS_NODE: + break; + case UBIFS_ORPH_NODE: + { + const struct ubifs_orph_node *orph = node; + + pr_err("\tcommit number %llu\n", + (unsigned long long) + le64_to_cpu(orph->cmt_no) & LLONG_MAX); + pr_err("\tlast node flag %llu\n", + (unsigned long long)(le64_to_cpu(orph->cmt_no)) >> 63); + n = (le32_to_cpu(ch->len) - UBIFS_ORPH_NODE_SZ) >> 3; + pr_err("\t%d orphan inode numbers:\n", n); + for (i = 0; i < n; i++) + pr_err("\t ino %llu\n", + (unsigned long long)le64_to_cpu(orph->inos[i])); + break; + } + case UBIFS_AUTH_NODE: + { + break; + } + default: + pr_err("node type %d was not recognized\n", + (int)ch->node_type); + } + spin_unlock(&dbg_lock); +} + +void ubifs_dump_budget_req(const struct ubifs_budget_req *req) +{ + spin_lock(&dbg_lock); + pr_err("Budgeting request: new_ino %d, dirtied_ino %d\n", + req->new_ino, req->dirtied_ino); + pr_err("\tnew_ino_d %d, dirtied_ino_d %d\n", + req->new_ino_d, req->dirtied_ino_d); + pr_err("\tnew_page %d, dirtied_page %d\n", + req->new_page, req->dirtied_page); + pr_err("\tnew_dent %d, mod_dent %d\n", + req->new_dent, req->mod_dent); + pr_err("\tidx_growth %d\n", req->idx_growth); + pr_err("\tdata_growth %d dd_growth %d\n", + req->data_growth, req->dd_growth); + spin_unlock(&dbg_lock); +} + +void ubifs_dump_lstats(const struct ubifs_lp_stats *lst) +{ + spin_lock(&dbg_lock); + pr_err("(pid %d) Lprops statistics: empty_lebs %d, idx_lebs %d\n", + current->pid, lst->empty_lebs, lst->idx_lebs); + pr_err("\ttaken_empty_lebs %d, total_free %lld, total_dirty %lld\n", + lst->taken_empty_lebs, lst->total_free, lst->total_dirty); + pr_err("\ttotal_used %lld, total_dark %lld, total_dead %lld\n", + lst->total_used, lst->total_dark, lst->total_dead); + spin_unlock(&dbg_lock); +} + +void ubifs_dump_budg(struct ubifs_info *c, const struct ubifs_budg_info *bi) +{ + int i; + struct rb_node *rb; + struct ubifs_bud *bud; + struct ubifs_gced_idx_leb *idx_gc; + long long available, outstanding, free; + + spin_lock(&c->space_lock); + spin_lock(&dbg_lock); + pr_err("(pid %d) Budgeting info: data budget sum %lld, total budget sum %lld\n", + current->pid, bi->data_growth + bi->dd_growth, + bi->data_growth + bi->dd_growth + bi->idx_growth); + pr_err("\tbudg_data_growth %lld, budg_dd_growth %lld, budg_idx_growth %lld\n", + bi->data_growth, bi->dd_growth, bi->idx_growth); + pr_err("\tmin_idx_lebs %d, old_idx_sz %llu, uncommitted_idx %lld\n", + bi->min_idx_lebs, bi->old_idx_sz, bi->uncommitted_idx); + pr_err("\tpage_budget %d, inode_budget %d, dent_budget %d\n", + bi->page_budget, bi->inode_budget, bi->dent_budget); + pr_err("\tnospace %u, nospace_rp %u\n", bi->nospace, bi->nospace_rp); + pr_err("\tdark_wm %d, dead_wm %d, max_idx_node_sz %d\n", + c->dark_wm, c->dead_wm, c->max_idx_node_sz); + + if (bi != &c->bi) + /* + * If we are dumping saved budgeting data, do not print + * additional information which is about the current state, not + * the old one which corresponded to the saved budgeting data. + */ + goto out_unlock; + + pr_err("\tfreeable_cnt %d, calc_idx_sz %lld, idx_gc_cnt %d\n", + c->freeable_cnt, c->calc_idx_sz, c->idx_gc_cnt); + pr_err("\tdirty_pg_cnt %ld, dirty_zn_cnt %ld, clean_zn_cnt %ld\n", + atomic_long_read(&c->dirty_pg_cnt), + atomic_long_read(&c->dirty_zn_cnt), + atomic_long_read(&c->clean_zn_cnt)); + pr_err("\tgc_lnum %d, ihead_lnum %d\n", c->gc_lnum, c->ihead_lnum); + + /* If we are in R/O mode, journal heads do not exist */ + if (c->jheads) + for (i = 0; i < c->jhead_cnt; i++) + pr_err("\tjhead %s\t LEB %d\n", + dbg_jhead(c->jheads[i].wbuf.jhead), + c->jheads[i].wbuf.lnum); + for (rb = rb_first(&c->buds); rb; rb = rb_next(rb)) { + bud = rb_entry(rb, struct ubifs_bud, rb); + pr_err("\tbud LEB %d\n", bud->lnum); + } + list_for_each_entry(bud, &c->old_buds, list) + pr_err("\told bud LEB %d\n", bud->lnum); + list_for_each_entry(idx_gc, &c->idx_gc, list) + pr_err("\tGC'ed idx LEB %d unmap %d\n", + idx_gc->lnum, idx_gc->unmap); + pr_err("\tcommit state %d\n", c->cmt_state); + + /* Print budgeting predictions */ + available = ubifs_calc_available(c, c->bi.min_idx_lebs); + outstanding = c->bi.data_growth + c->bi.dd_growth; + free = ubifs_get_free_space_nolock(c); + pr_err("Budgeting predictions:\n"); + pr_err("\tavailable: %lld, outstanding %lld, free %lld\n", + available, outstanding, free); +out_unlock: + spin_unlock(&dbg_lock); + spin_unlock(&c->space_lock); +} + +void ubifs_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp) +{ + int i, spc, dark = 0, dead = 0; + struct rb_node *rb; + struct ubifs_bud *bud; + + spc = lp->free + lp->dirty; + if (spc < c->dead_wm) + dead = spc; + else + dark = ubifs_calc_dark(c, spc); + + if (lp->flags & LPROPS_INDEX) + pr_err("LEB %-7d free %-8d dirty %-8d used %-8d free + dirty %-8d flags %#x (", + lp->lnum, lp->free, lp->dirty, c->leb_size - spc, spc, + lp->flags); + else + pr_err("LEB %-7d free %-8d dirty %-8d used %-8d free + dirty %-8d dark %-4d dead %-4d nodes fit %-3d flags %#-4x (", + lp->lnum, lp->free, lp->dirty, c->leb_size - spc, spc, + dark, dead, (int)(spc / UBIFS_MAX_NODE_SZ), lp->flags); + + if (lp->flags & LPROPS_TAKEN) { + if (lp->flags & LPROPS_INDEX) + pr_cont("index, taken"); + else + pr_cont("taken"); + } else { + const char *s; + + if (lp->flags & LPROPS_INDEX) { + switch (lp->flags & LPROPS_CAT_MASK) { + case LPROPS_DIRTY_IDX: + s = "dirty index"; + break; + case LPROPS_FRDI_IDX: + s = "freeable index"; + break; + default: + s = "index"; + } + } else { + switch (lp->flags & LPROPS_CAT_MASK) { + case LPROPS_UNCAT: + s = "not categorized"; + break; + case LPROPS_DIRTY: + s = "dirty"; + break; + case LPROPS_FREE: + s = "free"; + break; + case LPROPS_EMPTY: + s = "empty"; + break; + case LPROPS_FREEABLE: + s = "freeable"; + break; + default: + s = NULL; + break; + } + } + pr_cont("%s", s); + } + + for (rb = rb_first((struct rb_root *)&c->buds); rb; rb = rb_next(rb)) { + bud = rb_entry(rb, struct ubifs_bud, rb); + if (bud->lnum == lp->lnum) { + int head = 0; + for (i = 0; i < c->jhead_cnt; i++) { + /* + * Note, if we are in R/O mode or in the middle + * of mounting/re-mounting, the write-buffers do + * not exist. + */ + if (c->jheads && + lp->lnum == c->jheads[i].wbuf.lnum) { + pr_cont(", jhead %s", dbg_jhead(i)); + head = 1; + } + } + if (!head) + pr_cont(", bud of jhead %s", + dbg_jhead(bud->jhead)); + } + } + if (lp->lnum == c->gc_lnum) + pr_cont(", GC LEB"); + pr_cont(")\n"); +} + +void ubifs_dump_lprops(struct ubifs_info *c) +{ + int lnum, err; + struct ubifs_lprops lp; + struct ubifs_lp_stats lst; + + pr_err("(pid %d) start dumping LEB properties\n", current->pid); + ubifs_get_lp_stats(c, &lst); + ubifs_dump_lstats(&lst); + + for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { + err = ubifs_read_one_lp(c, lnum, &lp); + if (err) { + ubifs_err(c, "cannot read lprops for LEB %d", lnum); + continue; + } + + ubifs_dump_lprop(c, &lp); + } + pr_err("(pid %d) finish dumping LEB properties\n", current->pid); +} + +void ubifs_dump_lpt_info(struct ubifs_info *c) +{ + int i; + + spin_lock(&dbg_lock); + pr_err("(pid %d) dumping LPT information\n", current->pid); + pr_err("\tlpt_sz: %lld\n", c->lpt_sz); + pr_err("\tpnode_sz: %d\n", c->pnode_sz); + pr_err("\tnnode_sz: %d\n", c->nnode_sz); + pr_err("\tltab_sz: %d\n", c->ltab_sz); + pr_err("\tlsave_sz: %d\n", c->lsave_sz); + pr_err("\tbig_lpt: %d\n", c->big_lpt); + pr_err("\tlpt_hght: %d\n", c->lpt_hght); + pr_err("\tpnode_cnt: %d\n", c->pnode_cnt); + pr_err("\tnnode_cnt: %d\n", c->nnode_cnt); + pr_err("\tdirty_pn_cnt: %d\n", c->dirty_pn_cnt); + pr_err("\tdirty_nn_cnt: %d\n", c->dirty_nn_cnt); + pr_err("\tlsave_cnt: %d\n", c->lsave_cnt); + pr_err("\tspace_bits: %d\n", c->space_bits); + pr_err("\tlpt_lnum_bits: %d\n", c->lpt_lnum_bits); + pr_err("\tlpt_offs_bits: %d\n", c->lpt_offs_bits); + pr_err("\tlpt_spc_bits: %d\n", c->lpt_spc_bits); + pr_err("\tpcnt_bits: %d\n", c->pcnt_bits); + pr_err("\tlnum_bits: %d\n", c->lnum_bits); + pr_err("\tLPT root is at %d:%d\n", c->lpt_lnum, c->lpt_offs); + pr_err("\tLPT head is at %d:%d\n", + c->nhead_lnum, c->nhead_offs); + pr_err("\tLPT ltab is at %d:%d\n", c->ltab_lnum, c->ltab_offs); + if (c->big_lpt) + pr_err("\tLPT lsave is at %d:%d\n", + c->lsave_lnum, c->lsave_offs); + for (i = 0; i < c->lpt_lebs; i++) + pr_err("\tLPT LEB %d free %d dirty %d tgc %d cmt %d\n", + i + c->lpt_first, c->ltab[i].free, c->ltab[i].dirty, + c->ltab[i].tgc, c->ltab[i].cmt); + spin_unlock(&dbg_lock); +} + +void ubifs_dump_sleb(const struct ubifs_info *c, + const struct ubifs_scan_leb *sleb, int offs) +{ + struct ubifs_scan_node *snod; + + pr_err("(pid %d) start dumping scanned data from LEB %d:%d\n", + current->pid, sleb->lnum, offs); + + list_for_each_entry(snod, &sleb->nodes, list) { + cond_resched(); + pr_err("Dumping node at LEB %d:%d len %d\n", + sleb->lnum, snod->offs, snod->len); + ubifs_dump_node(c, snod->node); + } +} + +void ubifs_dump_leb(const struct ubifs_info *c, int lnum) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + void *buf; + + pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum); + + buf = __vmalloc(c->leb_size, GFP_NOFS); + if (!buf) { + ubifs_err(c, "cannot allocate memory for dumping LEB %d", lnum); + return; + } + + sleb = ubifs_scan(c, lnum, 0, buf, 0); + if (IS_ERR(sleb)) { + ubifs_err(c, "scan error %d", (int)PTR_ERR(sleb)); + goto out; + } + + pr_err("LEB %d has %d nodes ending at %d\n", lnum, + sleb->nodes_cnt, sleb->endpt); + + list_for_each_entry(snod, &sleb->nodes, list) { + cond_resched(); + pr_err("Dumping node at LEB %d:%d len %d\n", lnum, + snod->offs, snod->len); + ubifs_dump_node(c, snod->node); + } + + pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum); + ubifs_scan_destroy(sleb); + +out: + vfree(buf); + return; +} + +void ubifs_dump_znode(const struct ubifs_info *c, + const struct ubifs_znode *znode) +{ + int n; + const struct ubifs_zbranch *zbr; + char key_buf[DBG_KEY_BUF_LEN]; + + spin_lock(&dbg_lock); + if (znode->parent) + zbr = &znode->parent->zbranch[znode->iip]; + else + zbr = &c->zroot; + + pr_err("znode %p, LEB %d:%d len %d parent %p iip %d level %d child_cnt %d flags %lx\n", + znode, zbr->lnum, zbr->offs, zbr->len, znode->parent, znode->iip, + znode->level, znode->child_cnt, znode->flags); + + if (znode->child_cnt <= 0 || znode->child_cnt > c->fanout) { + spin_unlock(&dbg_lock); + return; + } + + pr_err("zbranches:\n"); + for (n = 0; n < znode->child_cnt; n++) { + zbr = &znode->zbranch[n]; + if (znode->level > 0) + pr_err("\t%d: znode %p LEB %d:%d len %d key %s\n", + n, zbr->znode, zbr->lnum, zbr->offs, zbr->len, + dbg_snprintf_key(c, &zbr->key, key_buf, + DBG_KEY_BUF_LEN)); + else + pr_err("\t%d: LNC %p LEB %d:%d len %d key %s\n", + n, zbr->znode, zbr->lnum, zbr->offs, zbr->len, + dbg_snprintf_key(c, &zbr->key, key_buf, + DBG_KEY_BUF_LEN)); + } + spin_unlock(&dbg_lock); +} + +void ubifs_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat) +{ + int i; + + pr_err("(pid %d) start dumping heap cat %d (%d elements)\n", + current->pid, cat, heap->cnt); + for (i = 0; i < heap->cnt; i++) { + struct ubifs_lprops *lprops = heap->arr[i]; + + pr_err("\t%d. LEB %d hpos %d free %d dirty %d flags %d\n", + i, lprops->lnum, lprops->hpos, lprops->free, + lprops->dirty, lprops->flags); + } + pr_err("(pid %d) finish dumping heap\n", current->pid); +} + +void ubifs_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode, + struct ubifs_nnode *parent, int iip) +{ + int i; + + pr_err("(pid %d) dumping pnode:\n", current->pid); + pr_err("\taddress %zx parent %zx cnext %zx\n", + (size_t)pnode, (size_t)parent, (size_t)pnode->cnext); + pr_err("\tflags %lu iip %d level %d num %d\n", + pnode->flags, iip, pnode->level, pnode->num); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_lprops *lp = &pnode->lprops[i]; + + pr_err("\t%d: free %d dirty %d flags %d lnum %d\n", + i, lp->free, lp->dirty, lp->flags, lp->lnum); + } +} + +void ubifs_dump_tnc(struct ubifs_info *c) +{ + struct ubifs_znode *znode; + int level; + + pr_err("\n"); + pr_err("(pid %d) start dumping TNC tree\n", current->pid); + znode = ubifs_tnc_levelorder_next(c, c->zroot.znode, NULL); + level = znode->level; + pr_err("== Level %d ==\n", level); + while (znode) { + if (level != znode->level) { + level = znode->level; + pr_err("== Level %d ==\n", level); + } + ubifs_dump_znode(c, znode); + znode = ubifs_tnc_levelorder_next(c, c->zroot.znode, znode); + } + pr_err("(pid %d) finish dumping TNC tree\n", current->pid); +} + +static int dump_znode(struct ubifs_info *c, struct ubifs_znode *znode, + void *priv) +{ + ubifs_dump_znode(c, znode); + return 0; +} + +/** + * ubifs_dump_index - dump the on-flash index. + * @c: UBIFS file-system description object + * + * This function dumps whole UBIFS indexing B-tree, unlike 'ubifs_dump_tnc()' + * which dumps only in-memory znodes and does not read znodes which from flash. + */ +void ubifs_dump_index(struct ubifs_info *c) +{ + dbg_walk_index(c, NULL, dump_znode, NULL); +} + +/** + * dbg_save_space_info - save information about flash space. + * @c: UBIFS file-system description object + * + * This function saves information about UBIFS free space, dirty space, etc, in + * order to check it later. + */ +void dbg_save_space_info(struct ubifs_info *c) +{ + struct ubifs_debug_info *d = c->dbg; + int freeable_cnt; + + spin_lock(&c->space_lock); + memcpy(&d->saved_lst, &c->lst, sizeof(struct ubifs_lp_stats)); + memcpy(&d->saved_bi, &c->bi, sizeof(struct ubifs_budg_info)); + d->saved_idx_gc_cnt = c->idx_gc_cnt; + + /* + * We use a dirty hack here and zero out @c->freeable_cnt, because it + * affects the free space calculations, and UBIFS might not know about + * all freeable eraseblocks. Indeed, we know about freeable eraseblocks + * only when we read their lprops, and we do this only lazily, upon the + * need. So at any given point of time @c->freeable_cnt might be not + * exactly accurate. + * + * Just one example about the issue we hit when we did not zero + * @c->freeable_cnt. + * 1. The file-system is mounted R/O, c->freeable_cnt is %0. We save the + * amount of free space in @d->saved_free + * 2. We re-mount R/W, which makes UBIFS to read the "lsave" + * information from flash, where we cache LEBs from various + * categories ('ubifs_remount_fs()' -> 'ubifs_lpt_init()' + * -> 'lpt_init_wr()' -> 'read_lsave()' -> 'ubifs_lpt_lookup()' + * -> 'ubifs_get_pnode()' -> 'update_cats()' + * -> 'ubifs_add_to_cat()'). + * 3. Lsave contains a freeable eraseblock, and @c->freeable_cnt + * becomes %1. + * 4. We calculate the amount of free space when the re-mount is + * finished in 'dbg_check_space_info()' and it does not match + * @d->saved_free. + */ + freeable_cnt = c->freeable_cnt; + c->freeable_cnt = 0; + d->saved_free = ubifs_get_free_space_nolock(c); + c->freeable_cnt = freeable_cnt; + spin_unlock(&c->space_lock); +} + +/** + * dbg_check_space_info - check flash space information. + * @c: UBIFS file-system description object + * + * This function compares current flash space information with the information + * which was saved when the 'dbg_save_space_info()' function was called. + * Returns zero if the information has not changed, and %-EINVAL it it has + * changed. + */ +int dbg_check_space_info(struct ubifs_info *c) +{ + struct ubifs_debug_info *d = c->dbg; + struct ubifs_lp_stats lst; + long long free; + int freeable_cnt; + + spin_lock(&c->space_lock); + freeable_cnt = c->freeable_cnt; + c->freeable_cnt = 0; + free = ubifs_get_free_space_nolock(c); + c->freeable_cnt = freeable_cnt; + spin_unlock(&c->space_lock); + + if (free != d->saved_free) { + ubifs_err(c, "free space changed from %lld to %lld", + d->saved_free, free); + goto out; + } + + return 0; + +out: + ubifs_msg(c, "saved lprops statistics dump"); + ubifs_dump_lstats(&d->saved_lst); + ubifs_msg(c, "saved budgeting info dump"); + ubifs_dump_budg(c, &d->saved_bi); + ubifs_msg(c, "saved idx_gc_cnt %d", d->saved_idx_gc_cnt); + ubifs_msg(c, "current lprops statistics dump"); + ubifs_get_lp_stats(c, &lst); + ubifs_dump_lstats(&lst); + ubifs_msg(c, "current budgeting info dump"); + ubifs_dump_budg(c, &c->bi); + dump_stack(); + return -EINVAL; +} + +/** + * dbg_check_synced_i_size - check synchronized inode size. + * @c: UBIFS file-system description object + * @inode: inode to check + * + * If inode is clean, synchronized inode size has to be equivalent to current + * inode size. This function has to be called only for locked inodes (@i_mutex + * has to be locked). Returns %0 if synchronized inode size if correct, and + * %-EINVAL if not. + */ +int dbg_check_synced_i_size(const struct ubifs_info *c, struct inode *inode) +{ + int err = 0; + struct ubifs_inode *ui = ubifs_inode(inode); + + if (!dbg_is_chk_gen(c)) + return 0; + if (!S_ISREG(inode->i_mode)) + return 0; + + mutex_lock(&ui->ui_mutex); + spin_lock(&ui->ui_lock); + if (ui->ui_size != ui->synced_i_size && !ui->dirty) { + ubifs_err(c, "ui_size is %lld, synced_i_size is %lld, but inode is clean", + ui->ui_size, ui->synced_i_size); + ubifs_err(c, "i_ino %lu, i_mode %#x, i_size %lld", inode->i_ino, + inode->i_mode, i_size_read(inode)); + dump_stack(); + err = -EINVAL; + } + spin_unlock(&ui->ui_lock); + mutex_unlock(&ui->ui_mutex); + return err; +} + +/* + * dbg_check_dir - check directory inode size and link count. + * @c: UBIFS file-system description object + * @dir: the directory to calculate size for + * @size: the result is returned here + * + * This function makes sure that directory size and link count are correct. + * Returns zero in case of success and a negative error code in case of + * failure. + * + * Note, it is good idea to make sure the @dir->i_mutex is locked before + * calling this function. + */ +int dbg_check_dir(struct ubifs_info *c, const struct inode *dir) +{ + unsigned int nlink = 2; + union ubifs_key key; + struct ubifs_dent_node *dent, *pdent = NULL; + struct fscrypt_name nm = {0}; + loff_t size = UBIFS_INO_NODE_SZ; + + if (!dbg_is_chk_gen(c)) + return 0; + + if (!S_ISDIR(dir->i_mode)) + return 0; + + lowest_dent_key(c, &key, dir->i_ino); + while (1) { + int err; + + dent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(dent)) { + err = PTR_ERR(dent); + if (err == -ENOENT) + break; + kfree(pdent); + return err; + } + + fname_name(&nm) = dent->name; + fname_len(&nm) = le16_to_cpu(dent->nlen); + size += CALC_DENT_SIZE(fname_len(&nm)); + if (dent->type == UBIFS_ITYPE_DIR) + nlink += 1; + kfree(pdent); + pdent = dent; + key_read(c, &dent->key, &key); + } + kfree(pdent); + + if (i_size_read(dir) != size) { + ubifs_err(c, "directory inode %lu has size %llu, but calculated size is %llu", + dir->i_ino, (unsigned long long)i_size_read(dir), + (unsigned long long)size); + ubifs_dump_inode(c, dir); + dump_stack(); + return -EINVAL; + } + if (dir->i_nlink != nlink) { + ubifs_err(c, "directory inode %lu has nlink %u, but calculated nlink is %u", + dir->i_ino, dir->i_nlink, nlink); + ubifs_dump_inode(c, dir); + dump_stack(); + return -EINVAL; + } + + return 0; +} + +/** + * dbg_check_key_order - make sure that colliding keys are properly ordered. + * @c: UBIFS file-system description object + * @zbr1: first zbranch + * @zbr2: following zbranch + * + * In UBIFS indexing B-tree colliding keys has to be sorted in binary order of + * names of the direntries/xentries which are referred by the keys. This + * function reads direntries/xentries referred by @zbr1 and @zbr2 and makes + * sure the name of direntry/xentry referred by @zbr1 is less than + * direntry/xentry referred by @zbr2. Returns zero if this is true, %1 if not, + * and a negative error code in case of failure. + */ +static int dbg_check_key_order(struct ubifs_info *c, struct ubifs_zbranch *zbr1, + struct ubifs_zbranch *zbr2) +{ + int err, nlen1, nlen2, cmp; + struct ubifs_dent_node *dent1, *dent2; + union ubifs_key key; + char key_buf[DBG_KEY_BUF_LEN]; + + ubifs_assert(c, !keys_cmp(c, &zbr1->key, &zbr2->key)); + dent1 = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); + if (!dent1) + return -ENOMEM; + dent2 = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); + if (!dent2) { + err = -ENOMEM; + goto out_free; + } + + err = ubifs_tnc_read_node(c, zbr1, dent1); + if (err) + goto out_free; + err = ubifs_validate_entry(c, dent1); + if (err) + goto out_free; + + err = ubifs_tnc_read_node(c, zbr2, dent2); + if (err) + goto out_free; + err = ubifs_validate_entry(c, dent2); + if (err) + goto out_free; + + /* Make sure node keys are the same as in zbranch */ + err = 1; + key_read(c, &dent1->key, &key); + if (keys_cmp(c, &zbr1->key, &key)) { + ubifs_err(c, "1st entry at %d:%d has key %s", zbr1->lnum, + zbr1->offs, dbg_snprintf_key(c, &key, key_buf, + DBG_KEY_BUF_LEN)); + ubifs_err(c, "but it should have key %s according to tnc", + dbg_snprintf_key(c, &zbr1->key, key_buf, + DBG_KEY_BUF_LEN)); + ubifs_dump_node(c, dent1); + goto out_free; + } + + key_read(c, &dent2->key, &key); + if (keys_cmp(c, &zbr2->key, &key)) { + ubifs_err(c, "2nd entry at %d:%d has key %s", zbr1->lnum, + zbr1->offs, dbg_snprintf_key(c, &key, key_buf, + DBG_KEY_BUF_LEN)); + ubifs_err(c, "but it should have key %s according to tnc", + dbg_snprintf_key(c, &zbr2->key, key_buf, + DBG_KEY_BUF_LEN)); + ubifs_dump_node(c, dent2); + goto out_free; + } + + nlen1 = le16_to_cpu(dent1->nlen); + nlen2 = le16_to_cpu(dent2->nlen); + + cmp = memcmp(dent1->name, dent2->name, min_t(int, nlen1, nlen2)); + if (cmp < 0 || (cmp == 0 && nlen1 < nlen2)) { + err = 0; + goto out_free; + } + if (cmp == 0 && nlen1 == nlen2) + ubifs_err(c, "2 xent/dent nodes with the same name"); + else + ubifs_err(c, "bad order of colliding key %s", + dbg_snprintf_key(c, &key, key_buf, DBG_KEY_BUF_LEN)); + + ubifs_msg(c, "first node at %d:%d\n", zbr1->lnum, zbr1->offs); + ubifs_dump_node(c, dent1); + ubifs_msg(c, "second node at %d:%d\n", zbr2->lnum, zbr2->offs); + ubifs_dump_node(c, dent2); + +out_free: + kfree(dent2); + kfree(dent1); + return err; +} + +/** + * dbg_check_znode - check if znode is all right. + * @c: UBIFS file-system description object + * @zbr: zbranch which points to this znode + * + * This function makes sure that znode referred to by @zbr is all right. + * Returns zero if it is, and %-EINVAL if it is not. + */ +static int dbg_check_znode(struct ubifs_info *c, struct ubifs_zbranch *zbr) +{ + struct ubifs_znode *znode = zbr->znode; + struct ubifs_znode *zp = znode->parent; + int n, err, cmp; + + if (znode->child_cnt <= 0 || znode->child_cnt > c->fanout) { + err = 1; + goto out; + } + if (znode->level < 0) { + err = 2; + goto out; + } + if (znode->iip < 0 || znode->iip >= c->fanout) { + err = 3; + goto out; + } + + if (zbr->len == 0) + /* Only dirty zbranch may have no on-flash nodes */ + if (!ubifs_zn_dirty(znode)) { + err = 4; + goto out; + } + + if (ubifs_zn_dirty(znode)) { + /* + * If znode is dirty, its parent has to be dirty as well. The + * order of the operation is important, so we have to have + * memory barriers. + */ + smp_mb(); + if (zp && !ubifs_zn_dirty(zp)) { + /* + * The dirty flag is atomic and is cleared outside the + * TNC mutex, so znode's dirty flag may now have + * been cleared. The child is always cleared before the + * parent, so we just need to check again. + */ + smp_mb(); + if (ubifs_zn_dirty(znode)) { + err = 5; + goto out; + } + } + } + + if (zp) { + const union ubifs_key *min, *max; + + if (znode->level != zp->level - 1) { + err = 6; + goto out; + } + + /* Make sure the 'parent' pointer in our znode is correct */ + err = ubifs_search_zbranch(c, zp, &zbr->key, &n); + if (!err) { + /* This zbranch does not exist in the parent */ + err = 7; + goto out; + } + + if (znode->iip >= zp->child_cnt) { + err = 8; + goto out; + } + + if (znode->iip != n) { + /* This may happen only in case of collisions */ + if (keys_cmp(c, &zp->zbranch[n].key, + &zp->zbranch[znode->iip].key)) { + err = 9; + goto out; + } + n = znode->iip; + } + + /* + * Make sure that the first key in our znode is greater than or + * equal to the key in the pointing zbranch. + */ + min = &zbr->key; + cmp = keys_cmp(c, min, &znode->zbranch[0].key); + if (cmp == 1) { + err = 10; + goto out; + } + + if (n + 1 < zp->child_cnt) { + max = &zp->zbranch[n + 1].key; + + /* + * Make sure the last key in our znode is less or + * equivalent than the key in the zbranch which goes + * after our pointing zbranch. + */ + cmp = keys_cmp(c, max, + &znode->zbranch[znode->child_cnt - 1].key); + if (cmp == -1) { + err = 11; + goto out; + } + } + } else { + /* This may only be root znode */ + if (zbr != &c->zroot) { + err = 12; + goto out; + } + } + + /* + * Make sure that next key is greater or equivalent then the previous + * one. + */ + for (n = 1; n < znode->child_cnt; n++) { + cmp = keys_cmp(c, &znode->zbranch[n - 1].key, + &znode->zbranch[n].key); + if (cmp > 0) { + err = 13; + goto out; + } + if (cmp == 0) { + /* This can only be keys with colliding hash */ + if (!is_hash_key(c, &znode->zbranch[n].key)) { + err = 14; + goto out; + } + + if (znode->level != 0 || c->replaying) + continue; + + /* + * Colliding keys should follow binary order of + * corresponding xentry/dentry names. + */ + err = dbg_check_key_order(c, &znode->zbranch[n - 1], + &znode->zbranch[n]); + if (err < 0) + return err; + if (err) { + err = 15; + goto out; + } + } + } + + for (n = 0; n < znode->child_cnt; n++) { + if (!znode->zbranch[n].znode && + (znode->zbranch[n].lnum == 0 || + znode->zbranch[n].len == 0)) { + err = 16; + goto out; + } + + if (znode->zbranch[n].lnum != 0 && + znode->zbranch[n].len == 0) { + err = 17; + goto out; + } + + if (znode->zbranch[n].lnum == 0 && + znode->zbranch[n].len != 0) { + err = 18; + goto out; + } + + if (znode->zbranch[n].lnum == 0 && + znode->zbranch[n].offs != 0) { + err = 19; + goto out; + } + + if (znode->level != 0 && znode->zbranch[n].znode) + if (znode->zbranch[n].znode->parent != znode) { + err = 20; + goto out; + } + } + + return 0; + +out: + ubifs_err(c, "failed, error %d", err); + ubifs_msg(c, "dump of the znode"); + ubifs_dump_znode(c, znode); + if (zp) { + ubifs_msg(c, "dump of the parent znode"); + ubifs_dump_znode(c, zp); + } + dump_stack(); + return -EINVAL; +} + +/** + * dbg_check_tnc - check TNC tree. + * @c: UBIFS file-system description object + * @extra: do extra checks that are possible at start commit + * + * This function traverses whole TNC tree and checks every znode. Returns zero + * if everything is all right and %-EINVAL if something is wrong with TNC. + */ +int dbg_check_tnc(struct ubifs_info *c, int extra) +{ + struct ubifs_znode *znode; + long clean_cnt = 0, dirty_cnt = 0; + int err, last; + + if (!dbg_is_chk_index(c)) + return 0; + + ubifs_assert(c, mutex_is_locked(&c->tnc_mutex)); + if (!c->zroot.znode) + return 0; + + znode = ubifs_tnc_postorder_first(c->zroot.znode); + while (1) { + struct ubifs_znode *prev; + struct ubifs_zbranch *zbr; + + if (!znode->parent) + zbr = &c->zroot; + else + zbr = &znode->parent->zbranch[znode->iip]; + + err = dbg_check_znode(c, zbr); + if (err) + return err; + + if (extra) { + if (ubifs_zn_dirty(znode)) + dirty_cnt += 1; + else + clean_cnt += 1; + } + + prev = znode; + znode = ubifs_tnc_postorder_next(c, znode); + if (!znode) + break; + + /* + * If the last key of this znode is equivalent to the first key + * of the next znode (collision), then check order of the keys. + */ + last = prev->child_cnt - 1; + if (prev->level == 0 && znode->level == 0 && !c->replaying && + !keys_cmp(c, &prev->zbranch[last].key, + &znode->zbranch[0].key)) { + err = dbg_check_key_order(c, &prev->zbranch[last], + &znode->zbranch[0]); + if (err < 0) + return err; + if (err) { + ubifs_msg(c, "first znode"); + ubifs_dump_znode(c, prev); + ubifs_msg(c, "second znode"); + ubifs_dump_znode(c, znode); + return -EINVAL; + } + } + } + + if (extra) { + if (clean_cnt != atomic_long_read(&c->clean_zn_cnt)) { + ubifs_err(c, "incorrect clean_zn_cnt %ld, calculated %ld", + atomic_long_read(&c->clean_zn_cnt), + clean_cnt); + return -EINVAL; + } + if (dirty_cnt != atomic_long_read(&c->dirty_zn_cnt)) { + ubifs_err(c, "incorrect dirty_zn_cnt %ld, calculated %ld", + atomic_long_read(&c->dirty_zn_cnt), + dirty_cnt); + return -EINVAL; + } + } + + return 0; +} + +/** + * dbg_walk_index - walk the on-flash index. + * @c: UBIFS file-system description object + * @leaf_cb: called for each leaf node + * @znode_cb: called for each indexing node + * @priv: private data which is passed to callbacks + * + * This function walks the UBIFS index and calls the @leaf_cb for each leaf + * node and @znode_cb for each indexing node. Returns zero in case of success + * and a negative error code in case of failure. + * + * It would be better if this function removed every znode it pulled to into + * the TNC, so that the behavior more closely matched the non-debugging + * behavior. + */ +int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb, + dbg_znode_callback znode_cb, void *priv) +{ + int err; + struct ubifs_zbranch *zbr; + struct ubifs_znode *znode, *child; + + mutex_lock(&c->tnc_mutex); + /* If the root indexing node is not in TNC - pull it */ + if (!c->zroot.znode) { + c->zroot.znode = ubifs_load_znode(c, &c->zroot, NULL, 0); + if (IS_ERR(c->zroot.znode)) { + err = PTR_ERR(c->zroot.znode); + c->zroot.znode = NULL; + goto out_unlock; + } + } + + /* + * We are going to traverse the indexing tree in the postorder manner. + * Go down and find the leftmost indexing node where we are going to + * start from. + */ + znode = c->zroot.znode; + while (znode->level > 0) { + zbr = &znode->zbranch[0]; + child = zbr->znode; + if (!child) { + child = ubifs_load_znode(c, zbr, znode, 0); + if (IS_ERR(child)) { + err = PTR_ERR(child); + goto out_unlock; + } + } + + znode = child; + } + + /* Iterate over all indexing nodes */ + while (1) { + int idx; + + cond_resched(); + + if (znode_cb) { + err = znode_cb(c, znode, priv); + if (err) { + ubifs_err(c, "znode checking function returned error %d", + err); + ubifs_dump_znode(c, znode); + goto out_dump; + } + } + if (leaf_cb && znode->level == 0) { + for (idx = 0; idx < znode->child_cnt; idx++) { + zbr = &znode->zbranch[idx]; + err = leaf_cb(c, zbr, priv); + if (err) { + ubifs_err(c, "leaf checking function returned error %d, for leaf at LEB %d:%d", + err, zbr->lnum, zbr->offs); + goto out_dump; + } + } + } + + if (!znode->parent) + break; + + idx = znode->iip + 1; + znode = znode->parent; + if (idx < znode->child_cnt) { + /* Switch to the next index in the parent */ + zbr = &znode->zbranch[idx]; + child = zbr->znode; + if (!child) { + child = ubifs_load_znode(c, zbr, znode, idx); + if (IS_ERR(child)) { + err = PTR_ERR(child); + goto out_unlock; + } + zbr->znode = child; + } + znode = child; + } else + /* + * This is the last child, switch to the parent and + * continue. + */ + continue; + + /* Go to the lowest leftmost znode in the new sub-tree */ + while (znode->level > 0) { + zbr = &znode->zbranch[0]; + child = zbr->znode; + if (!child) { + child = ubifs_load_znode(c, zbr, znode, 0); + if (IS_ERR(child)) { + err = PTR_ERR(child); + goto out_unlock; + } + zbr->znode = child; + } + znode = child; + } + } + + mutex_unlock(&c->tnc_mutex); + return 0; + +out_dump: + if (znode->parent) + zbr = &znode->parent->zbranch[znode->iip]; + else + zbr = &c->zroot; + ubifs_msg(c, "dump of znode at LEB %d:%d", zbr->lnum, zbr->offs); + ubifs_dump_znode(c, znode); +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * add_size - add znode size to partially calculated index size. + * @c: UBIFS file-system description object + * @znode: znode to add size for + * @priv: partially calculated index size + * + * This is a helper function for 'dbg_check_idx_size()' which is called for + * every indexing node and adds its size to the 'long long' variable pointed to + * by @priv. + */ +static int add_size(struct ubifs_info *c, struct ubifs_znode *znode, void *priv) +{ + long long *idx_size = priv; + int add; + + add = ubifs_idx_node_sz(c, znode->child_cnt); + add = ALIGN(add, 8); + *idx_size += add; + return 0; +} + +/** + * dbg_check_idx_size - check index size. + * @c: UBIFS file-system description object + * @idx_size: size to check + * + * This function walks the UBIFS index, calculates its size and checks that the + * size is equivalent to @idx_size. Returns zero in case of success and a + * negative error code in case of failure. + */ +int dbg_check_idx_size(struct ubifs_info *c, long long idx_size) +{ + int err; + long long calc = 0; + + if (!dbg_is_chk_index(c)) + return 0; + + err = dbg_walk_index(c, NULL, add_size, &calc); + if (err) { + ubifs_err(c, "error %d while walking the index", err); + return err; + } + + if (calc != idx_size) { + ubifs_err(c, "index size check failed: calculated size is %lld, should be %lld", + calc, idx_size); + dump_stack(); + return -EINVAL; + } + + return 0; +} + +/** + * struct fsck_inode - information about an inode used when checking the file-system. + * @rb: link in the RB-tree of inodes + * @inum: inode number + * @mode: inode type, permissions, etc + * @nlink: inode link count + * @xattr_cnt: count of extended attributes + * @references: how many directory/xattr entries refer this inode (calculated + * while walking the index) + * @calc_cnt: for directory inode count of child directories + * @size: inode size (read from on-flash inode) + * @xattr_sz: summary size of all extended attributes (read from on-flash + * inode) + * @calc_sz: for directories calculated directory size + * @calc_xcnt: count of extended attributes + * @calc_xsz: calculated summary size of all extended attributes + * @xattr_nms: sum of lengths of all extended attribute names belonging to this + * inode (read from on-flash inode) + * @calc_xnms: calculated sum of lengths of all extended attribute names + */ +struct fsck_inode { + struct rb_node rb; + ino_t inum; + umode_t mode; + unsigned int nlink; + unsigned int xattr_cnt; + int references; + int calc_cnt; + long long size; + unsigned int xattr_sz; + long long calc_sz; + long long calc_xcnt; + long long calc_xsz; + unsigned int xattr_nms; + long long calc_xnms; +}; + +/** + * struct fsck_data - private FS checking information. + * @inodes: RB-tree of all inodes (contains @struct fsck_inode objects) + */ +struct fsck_data { + struct rb_root inodes; +}; + +/** + * add_inode - add inode information to RB-tree of inodes. + * @c: UBIFS file-system description object + * @fsckd: FS checking information + * @ino: raw UBIFS inode to add + * + * This is a helper function for 'check_leaf()' which adds information about + * inode @ino to the RB-tree of inodes. Returns inode information pointer in + * case of success and a negative error code in case of failure. + */ +static struct fsck_inode *add_inode(struct ubifs_info *c, + struct fsck_data *fsckd, + struct ubifs_ino_node *ino) +{ + struct rb_node **p, *parent = NULL; + struct fsck_inode *fscki; + ino_t inum = key_inum_flash(c, &ino->key); + struct inode *inode; + struct ubifs_inode *ui; + + p = &fsckd->inodes.rb_node; + while (*p) { + parent = *p; + fscki = rb_entry(parent, struct fsck_inode, rb); + if (inum < fscki->inum) + p = &(*p)->rb_left; + else if (inum > fscki->inum) + p = &(*p)->rb_right; + else + return fscki; + } + + if (inum > c->highest_inum) { + ubifs_err(c, "too high inode number, max. is %lu", + (unsigned long)c->highest_inum); + return ERR_PTR(-EINVAL); + } + + fscki = kzalloc(sizeof(struct fsck_inode), GFP_NOFS); + if (!fscki) + return ERR_PTR(-ENOMEM); + + inode = ilookup(c->vfs_sb, inum); + + fscki->inum = inum; + /* + * If the inode is present in the VFS inode cache, use it instead of + * the on-flash inode which might be out-of-date. E.g., the size might + * be out-of-date. If we do not do this, the following may happen, for + * example: + * 1. A power cut happens + * 2. We mount the file-system R/O, the replay process fixes up the + * inode size in the VFS cache, but on on-flash. + * 3. 'check_leaf()' fails because it hits a data node beyond inode + * size. + */ + if (!inode) { + fscki->nlink = le32_to_cpu(ino->nlink); + fscki->size = le64_to_cpu(ino->size); + fscki->xattr_cnt = le32_to_cpu(ino->xattr_cnt); + fscki->xattr_sz = le32_to_cpu(ino->xattr_size); + fscki->xattr_nms = le32_to_cpu(ino->xattr_names); + fscki->mode = le32_to_cpu(ino->mode); + } else { + ui = ubifs_inode(inode); + fscki->nlink = inode->i_nlink; + fscki->size = inode->i_size; + fscki->xattr_cnt = ui->xattr_cnt; + fscki->xattr_sz = ui->xattr_size; + fscki->xattr_nms = ui->xattr_names; + fscki->mode = inode->i_mode; + iput(inode); + } + + if (S_ISDIR(fscki->mode)) { + fscki->calc_sz = UBIFS_INO_NODE_SZ; + fscki->calc_cnt = 2; + } + + rb_link_node(&fscki->rb, parent, p); + rb_insert_color(&fscki->rb, &fsckd->inodes); + + return fscki; +} + +/** + * search_inode - search inode in the RB-tree of inodes. + * @fsckd: FS checking information + * @inum: inode number to search + * + * This is a helper function for 'check_leaf()' which searches inode @inum in + * the RB-tree of inodes and returns an inode information pointer or %NULL if + * the inode was not found. + */ +static struct fsck_inode *search_inode(struct fsck_data *fsckd, ino_t inum) +{ + struct rb_node *p; + struct fsck_inode *fscki; + + p = fsckd->inodes.rb_node; + while (p) { + fscki = rb_entry(p, struct fsck_inode, rb); + if (inum < fscki->inum) + p = p->rb_left; + else if (inum > fscki->inum) + p = p->rb_right; + else + return fscki; + } + return NULL; +} + +/** + * read_add_inode - read inode node and add it to RB-tree of inodes. + * @c: UBIFS file-system description object + * @fsckd: FS checking information + * @inum: inode number to read + * + * This is a helper function for 'check_leaf()' which finds inode node @inum in + * the index, reads it, and adds it to the RB-tree of inodes. Returns inode + * information pointer in case of success and a negative error code in case of + * failure. + */ +static struct fsck_inode *read_add_inode(struct ubifs_info *c, + struct fsck_data *fsckd, ino_t inum) +{ + int n, err; + union ubifs_key key; + struct ubifs_znode *znode; + struct ubifs_zbranch *zbr; + struct ubifs_ino_node *ino; + struct fsck_inode *fscki; + + fscki = search_inode(fsckd, inum); + if (fscki) + return fscki; + + ino_key_init(c, &key, inum); + err = ubifs_lookup_level0(c, &key, &znode, &n); + if (!err) { + ubifs_err(c, "inode %lu not found in index", (unsigned long)inum); + return ERR_PTR(-ENOENT); + } else if (err < 0) { + ubifs_err(c, "error %d while looking up inode %lu", + err, (unsigned long)inum); + return ERR_PTR(err); + } + + zbr = &znode->zbranch[n]; + if (zbr->len < UBIFS_INO_NODE_SZ) { + ubifs_err(c, "bad node %lu node length %d", + (unsigned long)inum, zbr->len); + return ERR_PTR(-EINVAL); + } + + ino = kmalloc(zbr->len, GFP_NOFS); + if (!ino) + return ERR_PTR(-ENOMEM); + + err = ubifs_tnc_read_node(c, zbr, ino); + if (err) { + ubifs_err(c, "cannot read inode node at LEB %d:%d, error %d", + zbr->lnum, zbr->offs, err); + kfree(ino); + return ERR_PTR(err); + } + + fscki = add_inode(c, fsckd, ino); + kfree(ino); + if (IS_ERR(fscki)) { + ubifs_err(c, "error %ld while adding inode %lu node", + PTR_ERR(fscki), (unsigned long)inum); + return fscki; + } + + return fscki; +} + +/** + * check_leaf - check leaf node. + * @c: UBIFS file-system description object + * @zbr: zbranch of the leaf node to check + * @priv: FS checking information + * + * This is a helper function for 'dbg_check_filesystem()' which is called for + * every single leaf node while walking the indexing tree. It checks that the + * leaf node referred from the indexing tree exists, has correct CRC, and does + * some other basic validation. This function is also responsible for building + * an RB-tree of inodes - it adds all inodes into the RB-tree. It also + * calculates reference count, size, etc for each inode in order to later + * compare them to the information stored inside the inodes and detect possible + * inconsistencies. Returns zero in case of success and a negative error code + * in case of failure. + */ +static int check_leaf(struct ubifs_info *c, struct ubifs_zbranch *zbr, + void *priv) +{ + ino_t inum; + void *node; + struct ubifs_ch *ch; + int err, type = key_type(c, &zbr->key); + struct fsck_inode *fscki; + + if (zbr->len < UBIFS_CH_SZ) { + ubifs_err(c, "bad leaf length %d (LEB %d:%d)", + zbr->len, zbr->lnum, zbr->offs); + return -EINVAL; + } + + node = kmalloc(zbr->len, GFP_NOFS); + if (!node) + return -ENOMEM; + + err = ubifs_tnc_read_node(c, zbr, node); + if (err) { + ubifs_err(c, "cannot read leaf node at LEB %d:%d, error %d", + zbr->lnum, zbr->offs, err); + goto out_free; + } + + /* If this is an inode node, add it to RB-tree of inodes */ + if (type == UBIFS_INO_KEY) { + fscki = add_inode(c, priv, node); + if (IS_ERR(fscki)) { + err = PTR_ERR(fscki); + ubifs_err(c, "error %d while adding inode node", err); + goto out_dump; + } + goto out; + } + + if (type != UBIFS_DENT_KEY && type != UBIFS_XENT_KEY && + type != UBIFS_DATA_KEY) { + ubifs_err(c, "unexpected node type %d at LEB %d:%d", + type, zbr->lnum, zbr->offs); + err = -EINVAL; + goto out_free; + } + + ch = node; + if (le64_to_cpu(ch->sqnum) > c->max_sqnum) { + ubifs_err(c, "too high sequence number, max. is %llu", + c->max_sqnum); + err = -EINVAL; + goto out_dump; + } + + if (type == UBIFS_DATA_KEY) { + long long blk_offs; + struct ubifs_data_node *dn = node; + + ubifs_assert(c, zbr->len >= UBIFS_DATA_NODE_SZ); + + /* + * Search the inode node this data node belongs to and insert + * it to the RB-tree of inodes. + */ + inum = key_inum_flash(c, &dn->key); + fscki = read_add_inode(c, priv, inum); + if (IS_ERR(fscki)) { + err = PTR_ERR(fscki); + ubifs_err(c, "error %d while processing data node and trying to find inode node %lu", + err, (unsigned long)inum); + goto out_dump; + } + + /* Make sure the data node is within inode size */ + blk_offs = key_block_flash(c, &dn->key); + blk_offs <<= UBIFS_BLOCK_SHIFT; + blk_offs += le32_to_cpu(dn->size); + if (blk_offs > fscki->size) { + ubifs_err(c, "data node at LEB %d:%d is not within inode size %lld", + zbr->lnum, zbr->offs, fscki->size); + err = -EINVAL; + goto out_dump; + } + } else { + int nlen; + struct ubifs_dent_node *dent = node; + struct fsck_inode *fscki1; + + ubifs_assert(c, zbr->len >= UBIFS_DENT_NODE_SZ); + + err = ubifs_validate_entry(c, dent); + if (err) + goto out_dump; + + /* + * Search the inode node this entry refers to and the parent + * inode node and insert them to the RB-tree of inodes. + */ + inum = le64_to_cpu(dent->inum); + fscki = read_add_inode(c, priv, inum); + if (IS_ERR(fscki)) { + err = PTR_ERR(fscki); + ubifs_err(c, "error %d while processing entry node and trying to find inode node %lu", + err, (unsigned long)inum); + goto out_dump; + } + + /* Count how many direntries or xentries refers this inode */ + fscki->references += 1; + + inum = key_inum_flash(c, &dent->key); + fscki1 = read_add_inode(c, priv, inum); + if (IS_ERR(fscki1)) { + err = PTR_ERR(fscki1); + ubifs_err(c, "error %d while processing entry node and trying to find parent inode node %lu", + err, (unsigned long)inum); + goto out_dump; + } + + nlen = le16_to_cpu(dent->nlen); + if (type == UBIFS_XENT_KEY) { + fscki1->calc_xcnt += 1; + fscki1->calc_xsz += CALC_DENT_SIZE(nlen); + fscki1->calc_xsz += CALC_XATTR_BYTES(fscki->size); + fscki1->calc_xnms += nlen; + } else { + fscki1->calc_sz += CALC_DENT_SIZE(nlen); + if (dent->type == UBIFS_ITYPE_DIR) + fscki1->calc_cnt += 1; + } + } + +out: + kfree(node); + return 0; + +out_dump: + ubifs_msg(c, "dump of node at LEB %d:%d", zbr->lnum, zbr->offs); + ubifs_dump_node(c, node); +out_free: + kfree(node); + return err; +} + +/** + * free_inodes - free RB-tree of inodes. + * @fsckd: FS checking information + */ +static void free_inodes(struct fsck_data *fsckd) +{ + struct fsck_inode *fscki, *n; + + rbtree_postorder_for_each_entry_safe(fscki, n, &fsckd->inodes, rb) + kfree(fscki); +} + +/** + * check_inodes - checks all inodes. + * @c: UBIFS file-system description object + * @fsckd: FS checking information + * + * This is a helper function for 'dbg_check_filesystem()' which walks the + * RB-tree of inodes after the index scan has been finished, and checks that + * inode nlink, size, etc are correct. Returns zero if inodes are fine, + * %-EINVAL if not, and a negative error code in case of failure. + */ +static int check_inodes(struct ubifs_info *c, struct fsck_data *fsckd) +{ + int n, err; + union ubifs_key key; + struct ubifs_znode *znode; + struct ubifs_zbranch *zbr; + struct ubifs_ino_node *ino; + struct fsck_inode *fscki; + struct rb_node *this = rb_first(&fsckd->inodes); + + while (this) { + fscki = rb_entry(this, struct fsck_inode, rb); + this = rb_next(this); + + if (S_ISDIR(fscki->mode)) { + /* + * Directories have to have exactly one reference (they + * cannot have hardlinks), although root inode is an + * exception. + */ + if (fscki->inum != UBIFS_ROOT_INO && + fscki->references != 1) { + ubifs_err(c, "directory inode %lu has %d direntries which refer it, but should be 1", + (unsigned long)fscki->inum, + fscki->references); + goto out_dump; + } + if (fscki->inum == UBIFS_ROOT_INO && + fscki->references != 0) { + ubifs_err(c, "root inode %lu has non-zero (%d) direntries which refer it", + (unsigned long)fscki->inum, + fscki->references); + goto out_dump; + } + if (fscki->calc_sz != fscki->size) { + ubifs_err(c, "directory inode %lu size is %lld, but calculated size is %lld", + (unsigned long)fscki->inum, + fscki->size, fscki->calc_sz); + goto out_dump; + } + if (fscki->calc_cnt != fscki->nlink) { + ubifs_err(c, "directory inode %lu nlink is %d, but calculated nlink is %d", + (unsigned long)fscki->inum, + fscki->nlink, fscki->calc_cnt); + goto out_dump; + } + } else { + if (fscki->references != fscki->nlink) { + ubifs_err(c, "inode %lu nlink is %d, but calculated nlink is %d", + (unsigned long)fscki->inum, + fscki->nlink, fscki->references); + goto out_dump; + } + } + if (fscki->xattr_sz != fscki->calc_xsz) { + ubifs_err(c, "inode %lu has xattr size %u, but calculated size is %lld", + (unsigned long)fscki->inum, fscki->xattr_sz, + fscki->calc_xsz); + goto out_dump; + } + if (fscki->xattr_cnt != fscki->calc_xcnt) { + ubifs_err(c, "inode %lu has %u xattrs, but calculated count is %lld", + (unsigned long)fscki->inum, + fscki->xattr_cnt, fscki->calc_xcnt); + goto out_dump; + } + if (fscki->xattr_nms != fscki->calc_xnms) { + ubifs_err(c, "inode %lu has xattr names' size %u, but calculated names' size is %lld", + (unsigned long)fscki->inum, fscki->xattr_nms, + fscki->calc_xnms); + goto out_dump; + } + } + + return 0; + +out_dump: + /* Read the bad inode and dump it */ + ino_key_init(c, &key, fscki->inum); + err = ubifs_lookup_level0(c, &key, &znode, &n); + if (!err) { + ubifs_err(c, "inode %lu not found in index", + (unsigned long)fscki->inum); + return -ENOENT; + } else if (err < 0) { + ubifs_err(c, "error %d while looking up inode %lu", + err, (unsigned long)fscki->inum); + return err; + } + + zbr = &znode->zbranch[n]; + ino = kmalloc(zbr->len, GFP_NOFS); + if (!ino) + return -ENOMEM; + + err = ubifs_tnc_read_node(c, zbr, ino); + if (err) { + ubifs_err(c, "cannot read inode node at LEB %d:%d, error %d", + zbr->lnum, zbr->offs, err); + kfree(ino); + return err; + } + + ubifs_msg(c, "dump of the inode %lu sitting in LEB %d:%d", + (unsigned long)fscki->inum, zbr->lnum, zbr->offs); + ubifs_dump_node(c, ino); + kfree(ino); + return -EINVAL; +} + +/** + * dbg_check_filesystem - check the file-system. + * @c: UBIFS file-system description object + * + * This function checks the file system, namely: + * o makes sure that all leaf nodes exist and their CRCs are correct; + * o makes sure inode nlink, size, xattr size/count are correct (for all + * inodes). + * + * The function reads whole indexing tree and all nodes, so it is pretty + * heavy-weight. Returns zero if the file-system is consistent, %-EINVAL if + * not, and a negative error code in case of failure. + */ +int dbg_check_filesystem(struct ubifs_info *c) +{ + int err; + struct fsck_data fsckd; + + if (!dbg_is_chk_fs(c)) + return 0; + + fsckd.inodes = RB_ROOT; + err = dbg_walk_index(c, check_leaf, NULL, &fsckd); + if (err) + goto out_free; + + err = check_inodes(c, &fsckd); + if (err) + goto out_free; + + free_inodes(&fsckd); + return 0; + +out_free: + ubifs_err(c, "file-system check failed with error %d", err); + dump_stack(); + free_inodes(&fsckd); + return err; +} + +/** + * dbg_check_data_nodes_order - check that list of data nodes is sorted. + * @c: UBIFS file-system description object + * @head: the list of nodes ('struct ubifs_scan_node' objects) + * + * This function returns zero if the list of data nodes is sorted correctly, + * and %-EINVAL if not. + */ +int dbg_check_data_nodes_order(struct ubifs_info *c, struct list_head *head) +{ + struct list_head *cur; + struct ubifs_scan_node *sa, *sb; + + if (!dbg_is_chk_gen(c)) + return 0; + + for (cur = head->next; cur->next != head; cur = cur->next) { + ino_t inuma, inumb; + uint32_t blka, blkb; + + cond_resched(); + sa = container_of(cur, struct ubifs_scan_node, list); + sb = container_of(cur->next, struct ubifs_scan_node, list); + + if (sa->type != UBIFS_DATA_NODE) { + ubifs_err(c, "bad node type %d", sa->type); + ubifs_dump_node(c, sa->node); + return -EINVAL; + } + if (sb->type != UBIFS_DATA_NODE) { + ubifs_err(c, "bad node type %d", sb->type); + ubifs_dump_node(c, sb->node); + return -EINVAL; + } + + inuma = key_inum(c, &sa->key); + inumb = key_inum(c, &sb->key); + + if (inuma < inumb) + continue; + if (inuma > inumb) { + ubifs_err(c, "larger inum %lu goes before inum %lu", + (unsigned long)inuma, (unsigned long)inumb); + goto error_dump; + } + + blka = key_block(c, &sa->key); + blkb = key_block(c, &sb->key); + + if (blka > blkb) { + ubifs_err(c, "larger block %u goes before %u", blka, blkb); + goto error_dump; + } + if (blka == blkb) { + ubifs_err(c, "two data nodes for the same block"); + goto error_dump; + } + } + + return 0; + +error_dump: + ubifs_dump_node(c, sa->node); + ubifs_dump_node(c, sb->node); + return -EINVAL; +} + +/** + * dbg_check_nondata_nodes_order - check that list of data nodes is sorted. + * @c: UBIFS file-system description object + * @head: the list of nodes ('struct ubifs_scan_node' objects) + * + * This function returns zero if the list of non-data nodes is sorted correctly, + * and %-EINVAL if not. + */ +int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head) +{ + struct list_head *cur; + struct ubifs_scan_node *sa, *sb; + + if (!dbg_is_chk_gen(c)) + return 0; + + for (cur = head->next; cur->next != head; cur = cur->next) { + ino_t inuma, inumb; + uint32_t hasha, hashb; + + cond_resched(); + sa = container_of(cur, struct ubifs_scan_node, list); + sb = container_of(cur->next, struct ubifs_scan_node, list); + + if (sa->type != UBIFS_INO_NODE && sa->type != UBIFS_DENT_NODE && + sa->type != UBIFS_XENT_NODE) { + ubifs_err(c, "bad node type %d", sa->type); + ubifs_dump_node(c, sa->node); + return -EINVAL; + } + if (sb->type != UBIFS_INO_NODE && sb->type != UBIFS_DENT_NODE && + sb->type != UBIFS_XENT_NODE) { + ubifs_err(c, "bad node type %d", sb->type); + ubifs_dump_node(c, sb->node); + return -EINVAL; + } + + if (sa->type != UBIFS_INO_NODE && sb->type == UBIFS_INO_NODE) { + ubifs_err(c, "non-inode node goes before inode node"); + goto error_dump; + } + + if (sa->type == UBIFS_INO_NODE && sb->type != UBIFS_INO_NODE) + continue; + + if (sa->type == UBIFS_INO_NODE && sb->type == UBIFS_INO_NODE) { + /* Inode nodes are sorted in descending size order */ + if (sa->len < sb->len) { + ubifs_err(c, "smaller inode node goes first"); + goto error_dump; + } + continue; + } + + /* + * This is either a dentry or xentry, which should be sorted in + * ascending (parent ino, hash) order. + */ + inuma = key_inum(c, &sa->key); + inumb = key_inum(c, &sb->key); + + if (inuma < inumb) + continue; + if (inuma > inumb) { + ubifs_err(c, "larger inum %lu goes before inum %lu", + (unsigned long)inuma, (unsigned long)inumb); + goto error_dump; + } + + hasha = key_block(c, &sa->key); + hashb = key_block(c, &sb->key); + + if (hasha > hashb) { + ubifs_err(c, "larger hash %u goes before %u", + hasha, hashb); + goto error_dump; + } + } + + return 0; + +error_dump: + ubifs_msg(c, "dumping first node"); + ubifs_dump_node(c, sa->node); + ubifs_msg(c, "dumping second node"); + ubifs_dump_node(c, sb->node); + return -EINVAL; + return 0; +} + +static inline int chance(unsigned int n, unsigned int out_of) +{ + return !!((prandom_u32() % out_of) + 1 <= n); + +} + +static int power_cut_emulated(struct ubifs_info *c, int lnum, int write) +{ + struct ubifs_debug_info *d = c->dbg; + + ubifs_assert(c, dbg_is_tst_rcvry(c)); + + if (!d->pc_cnt) { + /* First call - decide delay to the power cut */ + if (chance(1, 2)) { + unsigned long delay; + + if (chance(1, 2)) { + d->pc_delay = 1; + /* Fail within 1 minute */ + delay = prandom_u32() % 60000; + d->pc_timeout = jiffies; + d->pc_timeout += msecs_to_jiffies(delay); + ubifs_warn(c, "failing after %lums", delay); + } else { + d->pc_delay = 2; + delay = prandom_u32() % 10000; + /* Fail within 10000 operations */ + d->pc_cnt_max = delay; + ubifs_warn(c, "failing after %lu calls", delay); + } + } + + d->pc_cnt += 1; + } + + /* Determine if failure delay has expired */ + if (d->pc_delay == 1 && time_before(jiffies, d->pc_timeout)) + return 0; + if (d->pc_delay == 2 && d->pc_cnt++ < d->pc_cnt_max) + return 0; + + if (lnum == UBIFS_SB_LNUM) { + if (write && chance(1, 2)) + return 0; + if (chance(19, 20)) + return 0; + ubifs_warn(c, "failing in super block LEB %d", lnum); + } else if (lnum == UBIFS_MST_LNUM || lnum == UBIFS_MST_LNUM + 1) { + if (chance(19, 20)) + return 0; + ubifs_warn(c, "failing in master LEB %d", lnum); + } else if (lnum >= UBIFS_LOG_LNUM && lnum <= c->log_last) { + if (write && chance(99, 100)) + return 0; + if (chance(399, 400)) + return 0; + ubifs_warn(c, "failing in log LEB %d", lnum); + } else if (lnum >= c->lpt_first && lnum <= c->lpt_last) { + if (write && chance(7, 8)) + return 0; + if (chance(19, 20)) + return 0; + ubifs_warn(c, "failing in LPT LEB %d", lnum); + } else if (lnum >= c->orph_first && lnum <= c->orph_last) { + if (write && chance(1, 2)) + return 0; + if (chance(9, 10)) + return 0; + ubifs_warn(c, "failing in orphan LEB %d", lnum); + } else if (lnum == c->ihead_lnum) { + if (chance(99, 100)) + return 0; + ubifs_warn(c, "failing in index head LEB %d", lnum); + } else if (c->jheads && lnum == c->jheads[GCHD].wbuf.lnum) { + if (chance(9, 10)) + return 0; + ubifs_warn(c, "failing in GC head LEB %d", lnum); + } else if (write && !RB_EMPTY_ROOT(&c->buds) && + !ubifs_search_bud(c, lnum)) { + if (chance(19, 20)) + return 0; + ubifs_warn(c, "failing in non-bud LEB %d", lnum); + } else if (c->cmt_state == COMMIT_RUNNING_BACKGROUND || + c->cmt_state == COMMIT_RUNNING_REQUIRED) { + if (chance(999, 1000)) + return 0; + ubifs_warn(c, "failing in bud LEB %d commit running", lnum); + } else { + if (chance(9999, 10000)) + return 0; + ubifs_warn(c, "failing in bud LEB %d commit not running", lnum); + } + + d->pc_happened = 1; + ubifs_warn(c, "========== Power cut emulated =========="); + dump_stack(); + return 1; +} + +static int corrupt_data(const struct ubifs_info *c, const void *buf, + unsigned int len) +{ + unsigned int from, to, ffs = chance(1, 2); + unsigned char *p = (void *)buf; + + from = prandom_u32() % len; + /* Corruption span max to end of write unit */ + to = min(len, ALIGN(from + 1, c->max_write_size)); + + ubifs_warn(c, "filled bytes %u-%u with %s", from, to - 1, + ffs ? "0xFFs" : "random data"); + + if (ffs) + memset(p + from, 0xFF, to - from); + else + prandom_bytes(p + from, to - from); + + return to; +} + +int dbg_leb_write(struct ubifs_info *c, int lnum, const void *buf, + int offs, int len) +{ + int err, failing; + + if (dbg_is_power_cut(c)) + return -EROFS; + + failing = power_cut_emulated(c, lnum, 1); + if (failing) { + len = corrupt_data(c, buf, len); + ubifs_warn(c, "actually write %d bytes to LEB %d:%d (the buffer was corrupted)", + len, lnum, offs); + } + err = ubi_leb_write(c->ubi, lnum, buf, offs, len); + if (err) + return err; + if (failing) + return -EROFS; + return 0; +} + +int dbg_leb_change(struct ubifs_info *c, int lnum, const void *buf, + int len) +{ + int err; + + if (dbg_is_power_cut(c)) + return -EROFS; + if (power_cut_emulated(c, lnum, 1)) + return -EROFS; + err = ubi_leb_change(c->ubi, lnum, buf, len); + if (err) + return err; + if (power_cut_emulated(c, lnum, 1)) + return -EROFS; + return 0; +} + +int dbg_leb_unmap(struct ubifs_info *c, int lnum) +{ + int err; + + if (dbg_is_power_cut(c)) + return -EROFS; + if (power_cut_emulated(c, lnum, 0)) + return -EROFS; + err = ubi_leb_unmap(c->ubi, lnum); + if (err) + return err; + if (power_cut_emulated(c, lnum, 0)) + return -EROFS; + return 0; +} + +int dbg_leb_map(struct ubifs_info *c, int lnum) +{ + int err; + + if (dbg_is_power_cut(c)) + return -EROFS; + if (power_cut_emulated(c, lnum, 0)) + return -EROFS; + err = ubi_leb_map(c->ubi, lnum); + if (err) + return err; + if (power_cut_emulated(c, lnum, 0)) + return -EROFS; + return 0; +} + +/* + * Root directory for UBIFS stuff in debugfs. Contains sub-directories which + * contain the stuff specific to particular file-system mounts. + */ +static struct dentry *dfs_rootdir; + +static int dfs_file_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return nonseekable_open(inode, file); +} + +/** + * provide_user_output - provide output to the user reading a debugfs file. + * @val: boolean value for the answer + * @u: the buffer to store the answer at + * @count: size of the buffer + * @ppos: position in the @u output buffer + * + * This is a simple helper function which stores @val boolean value in the user + * buffer when the user reads one of UBIFS debugfs files. Returns amount of + * bytes written to @u in case of success and a negative error code in case of + * failure. + */ +static int provide_user_output(int val, char __user *u, size_t count, + loff_t *ppos) +{ + char buf[3]; + + if (val) + buf[0] = '1'; + else + buf[0] = '0'; + buf[1] = '\n'; + buf[2] = 0x00; + + return simple_read_from_buffer(u, count, ppos, buf, 2); +} + +static ssize_t dfs_file_read(struct file *file, char __user *u, size_t count, + loff_t *ppos) +{ + struct dentry *dent = file->f_path.dentry; + struct ubifs_info *c = file->private_data; + struct ubifs_debug_info *d = c->dbg; + int val; + + if (dent == d->dfs_chk_gen) + val = d->chk_gen; + else if (dent == d->dfs_chk_index) + val = d->chk_index; + else if (dent == d->dfs_chk_orph) + val = d->chk_orph; + else if (dent == d->dfs_chk_lprops) + val = d->chk_lprops; + else if (dent == d->dfs_chk_fs) + val = d->chk_fs; + else if (dent == d->dfs_tst_rcvry) + val = d->tst_rcvry; + else if (dent == d->dfs_ro_error) + val = c->ro_error; + else + return -EINVAL; + + return provide_user_output(val, u, count, ppos); +} + +/** + * interpret_user_input - interpret user debugfs file input. + * @u: user-provided buffer with the input + * @count: buffer size + * + * This is a helper function which interpret user input to a boolean UBIFS + * debugfs file. Returns %0 or %1 in case of success and a negative error code + * in case of failure. + */ +static int interpret_user_input(const char __user *u, size_t count) +{ + size_t buf_size; + char buf[8]; + + buf_size = min_t(size_t, count, (sizeof(buf) - 1)); + if (copy_from_user(buf, u, buf_size)) + return -EFAULT; + + if (buf[0] == '1') + return 1; + else if (buf[0] == '0') + return 0; + + return -EINVAL; +} + +static ssize_t dfs_file_write(struct file *file, const char __user *u, + size_t count, loff_t *ppos) +{ + struct ubifs_info *c = file->private_data; + struct ubifs_debug_info *d = c->dbg; + struct dentry *dent = file->f_path.dentry; + int val; + + if (file->f_path.dentry == d->dfs_dump_lprops) { + ubifs_dump_lprops(c); + return count; + } + if (file->f_path.dentry == d->dfs_dump_budg) { + ubifs_dump_budg(c, &c->bi); + return count; + } + if (file->f_path.dentry == d->dfs_dump_tnc) { + mutex_lock(&c->tnc_mutex); + ubifs_dump_tnc(c); + mutex_unlock(&c->tnc_mutex); + return count; + } + + val = interpret_user_input(u, count); + if (val < 0) + return val; + + if (dent == d->dfs_chk_gen) + d->chk_gen = val; + else if (dent == d->dfs_chk_index) + d->chk_index = val; + else if (dent == d->dfs_chk_orph) + d->chk_orph = val; + else if (dent == d->dfs_chk_lprops) + d->chk_lprops = val; + else if (dent == d->dfs_chk_fs) + d->chk_fs = val; + else if (dent == d->dfs_tst_rcvry) + d->tst_rcvry = val; + else if (dent == d->dfs_ro_error) + c->ro_error = !!val; + else + return -EINVAL; + + return count; +} + +static const struct file_operations dfs_fops = { + .open = dfs_file_open, + .read = dfs_file_read, + .write = dfs_file_write, + .owner = THIS_MODULE, + .llseek = no_llseek, +}; + +/** + * dbg_debugfs_init_fs - initialize debugfs for UBIFS instance. + * @c: UBIFS file-system description object + * + * This function creates all debugfs files for this instance of UBIFS. + * + * Note, the only reason we have not merged this function with the + * 'ubifs_debugging_init()' function is because it is better to initialize + * debugfs interfaces at the very end of the mount process, and remove them at + * the very beginning of the mount process. + */ +void dbg_debugfs_init_fs(struct ubifs_info *c) +{ + int n; + const char *fname; + struct ubifs_debug_info *d = c->dbg; + + n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME, + c->vi.ubi_num, c->vi.vol_id); + if (n == UBIFS_DFS_DIR_LEN) { + /* The array size is too small */ + return; + } + + fname = d->dfs_dir_name; + d->dfs_dir = debugfs_create_dir(fname, dfs_rootdir); + + fname = "dump_lprops"; + d->dfs_dump_lprops = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, + &dfs_fops); + + fname = "dump_budg"; + d->dfs_dump_budg = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, + &dfs_fops); + + fname = "dump_tnc"; + d->dfs_dump_tnc = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, c, + &dfs_fops); + + fname = "chk_general"; + d->dfs_chk_gen = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); + + fname = "chk_index"; + d->dfs_chk_index = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); + + fname = "chk_orphans"; + d->dfs_chk_orph = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); + + fname = "chk_lprops"; + d->dfs_chk_lprops = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); + + fname = "chk_fs"; + d->dfs_chk_fs = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); + + fname = "tst_recovery"; + d->dfs_tst_rcvry = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); + + fname = "ro_error"; + d->dfs_ro_error = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + d->dfs_dir, c, &dfs_fops); +} + +/** + * dbg_debugfs_exit_fs - remove all debugfs files. + * @c: UBIFS file-system description object + */ +void dbg_debugfs_exit_fs(struct ubifs_info *c) +{ + debugfs_remove_recursive(c->dbg->dfs_dir); +} + +struct ubifs_global_debug_info ubifs_dbg; + +static struct dentry *dfs_chk_gen; +static struct dentry *dfs_chk_index; +static struct dentry *dfs_chk_orph; +static struct dentry *dfs_chk_lprops; +static struct dentry *dfs_chk_fs; +static struct dentry *dfs_tst_rcvry; + +static ssize_t dfs_global_file_read(struct file *file, char __user *u, + size_t count, loff_t *ppos) +{ + struct dentry *dent = file->f_path.dentry; + int val; + + if (dent == dfs_chk_gen) + val = ubifs_dbg.chk_gen; + else if (dent == dfs_chk_index) + val = ubifs_dbg.chk_index; + else if (dent == dfs_chk_orph) + val = ubifs_dbg.chk_orph; + else if (dent == dfs_chk_lprops) + val = ubifs_dbg.chk_lprops; + else if (dent == dfs_chk_fs) + val = ubifs_dbg.chk_fs; + else if (dent == dfs_tst_rcvry) + val = ubifs_dbg.tst_rcvry; + else + return -EINVAL; + + return provide_user_output(val, u, count, ppos); +} + +static ssize_t dfs_global_file_write(struct file *file, const char __user *u, + size_t count, loff_t *ppos) +{ + struct dentry *dent = file->f_path.dentry; + int val; + + val = interpret_user_input(u, count); + if (val < 0) + return val; + + if (dent == dfs_chk_gen) + ubifs_dbg.chk_gen = val; + else if (dent == dfs_chk_index) + ubifs_dbg.chk_index = val; + else if (dent == dfs_chk_orph) + ubifs_dbg.chk_orph = val; + else if (dent == dfs_chk_lprops) + ubifs_dbg.chk_lprops = val; + else if (dent == dfs_chk_fs) + ubifs_dbg.chk_fs = val; + else if (dent == dfs_tst_rcvry) + ubifs_dbg.tst_rcvry = val; + else + return -EINVAL; + + return count; +} + +static const struct file_operations dfs_global_fops = { + .read = dfs_global_file_read, + .write = dfs_global_file_write, + .owner = THIS_MODULE, + .llseek = no_llseek, +}; + +/** + * dbg_debugfs_init - initialize debugfs file-system. + * + * UBIFS uses debugfs file-system to expose various debugging knobs to + * user-space. This function creates "ubifs" directory in the debugfs + * file-system. + */ +void dbg_debugfs_init(void) +{ + const char *fname; + + fname = "ubifs"; + dfs_rootdir = debugfs_create_dir(fname, NULL); + + fname = "chk_general"; + dfs_chk_gen = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, + NULL, &dfs_global_fops); + + fname = "chk_index"; + dfs_chk_index = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + dfs_rootdir, NULL, &dfs_global_fops); + + fname = "chk_orphans"; + dfs_chk_orph = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + dfs_rootdir, NULL, &dfs_global_fops); + + fname = "chk_lprops"; + dfs_chk_lprops = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + dfs_rootdir, NULL, &dfs_global_fops); + + fname = "chk_fs"; + dfs_chk_fs = debugfs_create_file(fname, S_IRUSR | S_IWUSR, dfs_rootdir, + NULL, &dfs_global_fops); + + fname = "tst_recovery"; + dfs_tst_rcvry = debugfs_create_file(fname, S_IRUSR | S_IWUSR, + dfs_rootdir, NULL, &dfs_global_fops); +} + +/** + * dbg_debugfs_exit - remove the "ubifs" directory from debugfs file-system. + */ +void dbg_debugfs_exit(void) +{ + debugfs_remove_recursive(dfs_rootdir); +} + +void ubifs_assert_failed(struct ubifs_info *c, const char *expr, + const char *file, int line) +{ + ubifs_err(c, "UBIFS assert failed: %s, in %s:%u", expr, file, line); + + switch (c->assert_action) { + case ASSACT_PANIC: + BUG(); + break; + + case ASSACT_RO: + ubifs_ro_mode(c, -EINVAL); + break; + + case ASSACT_REPORT: + default: + dump_stack(); + break; + + } +} + +/** + * ubifs_debugging_init - initialize UBIFS debugging. + * @c: UBIFS file-system description object + * + * This function initializes debugging-related data for the file system. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +int ubifs_debugging_init(struct ubifs_info *c) +{ + c->dbg = kzalloc(sizeof(struct ubifs_debug_info), GFP_KERNEL); + if (!c->dbg) + return -ENOMEM; + + return 0; +} + +/** + * ubifs_debugging_exit - free debugging data. + * @c: UBIFS file-system description object + */ +void ubifs_debugging_exit(struct ubifs_info *c) +{ + kfree(c->dbg); +} diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h new file mode 100644 index 000000000..7763639a4 --- /dev/null +++ b/fs/ubifs/debug.h @@ -0,0 +1,305 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +#ifndef __UBIFS_DEBUG_H__ +#define __UBIFS_DEBUG_H__ + +/* Checking helper functions */ +typedef int (*dbg_leaf_callback)(struct ubifs_info *c, + struct ubifs_zbranch *zbr, void *priv); +typedef int (*dbg_znode_callback)(struct ubifs_info *c, + struct ubifs_znode *znode, void *priv); + +/* + * The UBIFS debugfs directory name pattern and maximum name length (3 for "ubi" + * + 1 for "_" and plus 2x2 for 2 UBI numbers and 1 for the trailing zero byte. + */ +#define UBIFS_DFS_DIR_NAME "ubi%d_%d" +#define UBIFS_DFS_DIR_LEN (3 + 1 + 2*2 + 1) + +/** + * ubifs_debug_info - per-FS debugging information. + * @old_zroot: old index root - used by 'dbg_check_old_index()' + * @old_zroot_level: old index root level - used by 'dbg_check_old_index()' + * @old_zroot_sqnum: old index root sqnum - used by 'dbg_check_old_index()' + * + * @pc_happened: non-zero if an emulated power cut happened + * @pc_delay: 0=>don't delay, 1=>delay a time, 2=>delay a number of calls + * @pc_timeout: time in jiffies when delay of failure mode expires + * @pc_cnt: current number of calls to failure mode I/O functions + * @pc_cnt_max: number of calls by which to delay failure mode + * + * @chk_lpt_sz: used by LPT tree size checker + * @chk_lpt_sz2: used by LPT tree size checker + * @chk_lpt_wastage: used by LPT tree size checker + * @chk_lpt_lebs: used by LPT tree size checker + * @new_nhead_offs: used by LPT tree size checker + * @new_ihead_lnum: used by debugging to check @c->ihead_lnum + * @new_ihead_offs: used by debugging to check @c->ihead_offs + * + * @saved_lst: saved lprops statistics (used by 'dbg_save_space_info()') + * @saved_bi: saved budgeting information + * @saved_free: saved amount of free space + * @saved_idx_gc_cnt: saved value of @c->idx_gc_cnt + * + * @chk_gen: if general extra checks are enabled + * @chk_index: if index xtra checks are enabled + * @chk_orph: if orphans extra checks are enabled + * @chk_lprops: if lprops extra checks are enabled + * @chk_fs: if UBIFS contents extra checks are enabled + * @tst_rcvry: if UBIFS recovery testing mode enabled + * + * @dfs_dir_name: name of debugfs directory containing this file-system's files + * @dfs_dir: direntry object of the file-system debugfs directory + * @dfs_dump_lprops: "dump lprops" debugfs knob + * @dfs_dump_budg: "dump budgeting information" debugfs knob + * @dfs_dump_tnc: "dump TNC" debugfs knob + * @dfs_chk_gen: debugfs knob to enable UBIFS general extra checks + * @dfs_chk_index: debugfs knob to enable UBIFS index extra checks + * @dfs_chk_orph: debugfs knob to enable UBIFS orphans extra checks + * @dfs_chk_lprops: debugfs knob to enable UBIFS LEP properties extra checks + * @dfs_chk_fs: debugfs knob to enable UBIFS contents extra checks + * @dfs_tst_rcvry: debugfs knob to enable UBIFS recovery testing + * @dfs_ro_error: debugfs knob to switch UBIFS to R/O mode (different to + * re-mounting to R/O mode because it does not flush any buffers + * and UBIFS just starts returning -EROFS on all write + * operations) + */ +struct ubifs_debug_info { + struct ubifs_zbranch old_zroot; + int old_zroot_level; + unsigned long long old_zroot_sqnum; + + int pc_happened; + int pc_delay; + unsigned long pc_timeout; + unsigned int pc_cnt; + unsigned int pc_cnt_max; + + long long chk_lpt_sz; + long long chk_lpt_sz2; + long long chk_lpt_wastage; + int chk_lpt_lebs; + int new_nhead_offs; + int new_ihead_lnum; + int new_ihead_offs; + + struct ubifs_lp_stats saved_lst; + struct ubifs_budg_info saved_bi; + long long saved_free; + int saved_idx_gc_cnt; + + unsigned int chk_gen:1; + unsigned int chk_index:1; + unsigned int chk_orph:1; + unsigned int chk_lprops:1; + unsigned int chk_fs:1; + unsigned int tst_rcvry:1; + + char dfs_dir_name[UBIFS_DFS_DIR_LEN + 1]; + struct dentry *dfs_dir; + struct dentry *dfs_dump_lprops; + struct dentry *dfs_dump_budg; + struct dentry *dfs_dump_tnc; + struct dentry *dfs_chk_gen; + struct dentry *dfs_chk_index; + struct dentry *dfs_chk_orph; + struct dentry *dfs_chk_lprops; + struct dentry *dfs_chk_fs; + struct dentry *dfs_tst_rcvry; + struct dentry *dfs_ro_error; +}; + +/** + * ubifs_global_debug_info - global (not per-FS) UBIFS debugging information. + * + * @chk_gen: if general extra checks are enabled + * @chk_index: if index xtra checks are enabled + * @chk_orph: if orphans extra checks are enabled + * @chk_lprops: if lprops extra checks are enabled + * @chk_fs: if UBIFS contents extra checks are enabled + * @tst_rcvry: if UBIFS recovery testing mode enabled + */ +struct ubifs_global_debug_info { + unsigned int chk_gen:1; + unsigned int chk_index:1; + unsigned int chk_orph:1; + unsigned int chk_lprops:1; + unsigned int chk_fs:1; + unsigned int tst_rcvry:1; +}; + +void ubifs_assert_failed(struct ubifs_info *c, const char *expr, + const char *file, int line); + +#define ubifs_assert(c, expr) do { \ + if (unlikely(!(expr))) { \ + ubifs_assert_failed((struct ubifs_info *)c, #expr, __FILE__, \ + __LINE__); \ + } \ +} while (0) + +#define ubifs_assert_cmt_locked(c) do { \ + if (unlikely(down_write_trylock(&(c)->commit_sem))) { \ + up_write(&(c)->commit_sem); \ + ubifs_err(c, "commit lock is not locked!\n"); \ + ubifs_assert(c, 0); \ + } \ +} while (0) + +#define ubifs_dbg_msg(type, fmt, ...) \ + pr_debug("UBIFS DBG " type " (pid %d): " fmt "\n", current->pid, \ + ##__VA_ARGS__) + +#define DBG_KEY_BUF_LEN 48 +#define ubifs_dbg_msg_key(type, key, fmt, ...) do { \ + char __tmp_key_buf[DBG_KEY_BUF_LEN]; \ + pr_debug("UBIFS DBG " type " (pid %d): " fmt "%s\n", current->pid, \ + ##__VA_ARGS__, \ + dbg_snprintf_key(c, key, __tmp_key_buf, DBG_KEY_BUF_LEN)); \ +} while (0) + +/* General messages */ +#define dbg_gen(fmt, ...) ubifs_dbg_msg("gen", fmt, ##__VA_ARGS__) +/* Additional journal messages */ +#define dbg_jnl(fmt, ...) ubifs_dbg_msg("jnl", fmt, ##__VA_ARGS__) +#define dbg_jnlk(key, fmt, ...) \ + ubifs_dbg_msg_key("jnl", key, fmt, ##__VA_ARGS__) +/* Additional TNC messages */ +#define dbg_tnc(fmt, ...) ubifs_dbg_msg("tnc", fmt, ##__VA_ARGS__) +#define dbg_tnck(key, fmt, ...) \ + ubifs_dbg_msg_key("tnc", key, fmt, ##__VA_ARGS__) +/* Additional lprops messages */ +#define dbg_lp(fmt, ...) ubifs_dbg_msg("lp", fmt, ##__VA_ARGS__) +/* Additional LEB find messages */ +#define dbg_find(fmt, ...) ubifs_dbg_msg("find", fmt, ##__VA_ARGS__) +/* Additional mount messages */ +#define dbg_mnt(fmt, ...) ubifs_dbg_msg("mnt", fmt, ##__VA_ARGS__) +#define dbg_mntk(key, fmt, ...) \ + ubifs_dbg_msg_key("mnt", key, fmt, ##__VA_ARGS__) +/* Additional I/O messages */ +#define dbg_io(fmt, ...) ubifs_dbg_msg("io", fmt, ##__VA_ARGS__) +/* Additional commit messages */ +#define dbg_cmt(fmt, ...) ubifs_dbg_msg("cmt", fmt, ##__VA_ARGS__) +/* Additional budgeting messages */ +#define dbg_budg(fmt, ...) ubifs_dbg_msg("budg", fmt, ##__VA_ARGS__) +/* Additional log messages */ +#define dbg_log(fmt, ...) ubifs_dbg_msg("log", fmt, ##__VA_ARGS__) +/* Additional gc messages */ +#define dbg_gc(fmt, ...) ubifs_dbg_msg("gc", fmt, ##__VA_ARGS__) +/* Additional scan messages */ +#define dbg_scan(fmt, ...) ubifs_dbg_msg("scan", fmt, ##__VA_ARGS__) +/* Additional recovery messages */ +#define dbg_rcvry(fmt, ...) ubifs_dbg_msg("rcvry", fmt, ##__VA_ARGS__) + +extern struct ubifs_global_debug_info ubifs_dbg; + +static inline int dbg_is_chk_gen(const struct ubifs_info *c) +{ + return !!(ubifs_dbg.chk_gen || c->dbg->chk_gen); +} +static inline int dbg_is_chk_index(const struct ubifs_info *c) +{ + return !!(ubifs_dbg.chk_index || c->dbg->chk_index); +} +static inline int dbg_is_chk_orph(const struct ubifs_info *c) +{ + return !!(ubifs_dbg.chk_orph || c->dbg->chk_orph); +} +static inline int dbg_is_chk_lprops(const struct ubifs_info *c) +{ + return !!(ubifs_dbg.chk_lprops || c->dbg->chk_lprops); +} +static inline int dbg_is_chk_fs(const struct ubifs_info *c) +{ + return !!(ubifs_dbg.chk_fs || c->dbg->chk_fs); +} +static inline int dbg_is_tst_rcvry(const struct ubifs_info *c) +{ + return !!(ubifs_dbg.tst_rcvry || c->dbg->tst_rcvry); +} +static inline int dbg_is_power_cut(const struct ubifs_info *c) +{ + return !!c->dbg->pc_happened; +} + +int ubifs_debugging_init(struct ubifs_info *c); +void ubifs_debugging_exit(struct ubifs_info *c); + +/* Dump functions */ +const char *dbg_ntype(int type); +const char *dbg_cstate(int cmt_state); +const char *dbg_jhead(int jhead); +const char *dbg_get_key_dump(const struct ubifs_info *c, + const union ubifs_key *key); +const char *dbg_snprintf_key(const struct ubifs_info *c, + const union ubifs_key *key, char *buffer, int len); +void ubifs_dump_inode(struct ubifs_info *c, const struct inode *inode); +void ubifs_dump_node(const struct ubifs_info *c, const void *node); +void ubifs_dump_budget_req(const struct ubifs_budget_req *req); +void ubifs_dump_lstats(const struct ubifs_lp_stats *lst); +void ubifs_dump_budg(struct ubifs_info *c, const struct ubifs_budg_info *bi); +void ubifs_dump_lprop(const struct ubifs_info *c, + const struct ubifs_lprops *lp); +void ubifs_dump_lprops(struct ubifs_info *c); +void ubifs_dump_lpt_info(struct ubifs_info *c); +void ubifs_dump_leb(const struct ubifs_info *c, int lnum); +void ubifs_dump_sleb(const struct ubifs_info *c, + const struct ubifs_scan_leb *sleb, int offs); +void ubifs_dump_znode(const struct ubifs_info *c, + const struct ubifs_znode *znode); +void ubifs_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, + int cat); +void ubifs_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode, + struct ubifs_nnode *parent, int iip); +void ubifs_dump_tnc(struct ubifs_info *c); +void ubifs_dump_index(struct ubifs_info *c); +void ubifs_dump_lpt_lebs(const struct ubifs_info *c); + +int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb, + dbg_znode_callback znode_cb, void *priv); + +/* Checking functions */ +void dbg_save_space_info(struct ubifs_info *c); +int dbg_check_space_info(struct ubifs_info *c); +int dbg_check_lprops(struct ubifs_info *c); +int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot); +int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot); +int dbg_check_cats(struct ubifs_info *c); +int dbg_check_ltab(struct ubifs_info *c); +int dbg_chk_lpt_free_spc(struct ubifs_info *c); +int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len); +int dbg_check_synced_i_size(const struct ubifs_info *c, struct inode *inode); +int dbg_check_dir(struct ubifs_info *c, const struct inode *dir); +int dbg_check_tnc(struct ubifs_info *c, int extra); +int dbg_check_idx_size(struct ubifs_info *c, long long idx_size); +int dbg_check_filesystem(struct ubifs_info *c); +void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat, + int add_pos); +int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode, + int row, int col); +int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode, + loff_t size); +int dbg_check_data_nodes_order(struct ubifs_info *c, struct list_head *head); +int dbg_check_nondata_nodes_order(struct ubifs_info *c, struct list_head *head); + +int dbg_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, + int len); +int dbg_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len); +int dbg_leb_unmap(struct ubifs_info *c, int lnum); +int dbg_leb_map(struct ubifs_info *c, int lnum); + +/* Debugfs-related stuff */ +void dbg_debugfs_init(void); +void dbg_debugfs_exit(void); +void dbg_debugfs_init_fs(struct ubifs_info *c); +void dbg_debugfs_exit_fs(struct ubifs_info *c); + +#endif /* !__UBIFS_DEBUG_H__ */ diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c new file mode 100644 index 000000000..bc562b107 --- /dev/null +++ b/fs/ubifs/dir.c @@ -0,0 +1,1687 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * Copyright (C) 2006, 2007 University of Szeged, Hungary + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + * Zoltan Sogor + */ + +/* + * This file implements directory operations. + * + * All FS operations in this file allocate budget before writing anything to the + * media. If they fail to allocate it, the error is returned. The only + * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even + * if they unable to allocate the budget, because deletion %-ENOSPC failure is + * not what users are usually ready to get. UBIFS budgeting subsystem has some + * space reserved for these purposes. + * + * All operations in this file write all inodes which they change straight + * away, instead of marking them dirty. For example, 'ubifs_link()' changes + * @i_size of the parent inode and writes the parent inode together with the + * target inode. This was done to simplify file-system recovery which would + * otherwise be very difficult to do. The only exception is rename which marks + * the re-named inode dirty (because its @i_ctime is updated) but does not + * write it, but just marks it as dirty. + */ + +#include "ubifs.h" + +/** + * inherit_flags - inherit flags of the parent inode. + * @dir: parent inode + * @mode: new inode mode flags + * + * This is a helper function for 'ubifs_new_inode()' which inherits flag of the + * parent directory inode @dir. UBIFS inodes inherit the following flags: + * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on + * sub-directory basis; + * o %UBIFS_SYNC_FL - useful for the same reasons; + * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories. + * + * This function returns the inherited flags. + */ +static int inherit_flags(const struct inode *dir, umode_t mode) +{ + int flags; + const struct ubifs_inode *ui = ubifs_inode(dir); + + if (!S_ISDIR(dir->i_mode)) + /* + * The parent is not a directory, which means that an extended + * attribute inode is being created. No flags. + */ + return 0; + + flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL); + if (!S_ISDIR(mode)) + /* The "DIRSYNC" flag only applies to directories */ + flags &= ~UBIFS_DIRSYNC_FL; + return flags; +} + +/** + * ubifs_new_inode - allocate new UBIFS inode object. + * @c: UBIFS file-system description object + * @dir: parent directory inode + * @mode: inode mode flags + * + * This function finds an unused inode number, allocates new inode and + * initializes it. Returns new inode in case of success and an error code in + * case of failure. + */ +struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, + umode_t mode) +{ + int err; + struct inode *inode; + struct ubifs_inode *ui; + bool encrypted = false; + + inode = new_inode(c->vfs_sb); + ui = ubifs_inode(inode); + if (!inode) + return ERR_PTR(-ENOMEM); + + /* + * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and + * marking them dirty in file write path (see 'file_update_time()'). + * UBIFS has to fully control "clean <-> dirty" transitions of inodes + * to make budgeting work. + */ + inode->i_flags |= S_NOCMTIME; + + inode_init_owner(inode, dir, mode); + inode->i_mtime = inode->i_atime = inode->i_ctime = + current_time(inode); + inode->i_mapping->nrpages = 0; + + err = fscrypt_prepare_new_inode(dir, inode, &encrypted); + if (err) { + ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err); + goto out_iput; + } + + switch (mode & S_IFMT) { + case S_IFREG: + inode->i_mapping->a_ops = &ubifs_file_address_operations; + inode->i_op = &ubifs_file_inode_operations; + inode->i_fop = &ubifs_file_operations; + break; + case S_IFDIR: + inode->i_op = &ubifs_dir_inode_operations; + inode->i_fop = &ubifs_dir_operations; + inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ; + break; + case S_IFLNK: + inode->i_op = &ubifs_symlink_inode_operations; + break; + case S_IFSOCK: + case S_IFIFO: + case S_IFBLK: + case S_IFCHR: + inode->i_op = &ubifs_file_inode_operations; + break; + default: + BUG(); + } + + ui->flags = inherit_flags(dir, mode); + ubifs_set_inode_flags(inode); + if (S_ISREG(mode)) + ui->compr_type = c->default_compr; + else + ui->compr_type = UBIFS_COMPR_NONE; + ui->synced_i_size = 0; + + spin_lock(&c->cnt_lock); + /* Inode number overflow is currently not supported */ + if (c->highest_inum >= INUM_WARN_WATERMARK) { + if (c->highest_inum >= INUM_WATERMARK) { + spin_unlock(&c->cnt_lock); + ubifs_err(c, "out of inode numbers"); + err = -EINVAL; + goto out_iput; + } + ubifs_warn(c, "running out of inode numbers (current %lu, max %u)", + (unsigned long)c->highest_inum, INUM_WATERMARK); + } + + inode->i_ino = ++c->highest_inum; + /* + * The creation sequence number remains with this inode for its + * lifetime. All nodes for this inode have a greater sequence number, + * and so it is possible to distinguish obsolete nodes belonging to a + * previous incarnation of the same inode number - for example, for the + * purpose of rebuilding the index. + */ + ui->creat_sqnum = ++c->max_sqnum; + spin_unlock(&c->cnt_lock); + + if (encrypted) { + err = fscrypt_set_context(inode, NULL); + if (err) { + ubifs_err(c, "fscrypt_set_context failed: %i", err); + goto out_iput; + } + } + + return inode; + +out_iput: + make_bad_inode(inode); + iput(inode); + return ERR_PTR(err); +} + +static int dbg_check_name(const struct ubifs_info *c, + const struct ubifs_dent_node *dent, + const struct fscrypt_name *nm) +{ + if (!dbg_is_chk_gen(c)) + return 0; + if (le16_to_cpu(dent->nlen) != fname_len(nm)) + return -EINVAL; + if (memcmp(dent->name, fname_name(nm), fname_len(nm))) + return -EINVAL; + return 0; +} + +static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + int err; + union ubifs_key key; + struct inode *inode = NULL; + struct ubifs_dent_node *dent = NULL; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm; + + dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino); + + err = fscrypt_prepare_lookup(dir, dentry, &nm); + if (err == -ENOENT) + return d_splice_alias(NULL, dentry); + if (err) + return ERR_PTR(err); + + if (fname_len(&nm) > UBIFS_MAX_NLEN) { + inode = ERR_PTR(-ENAMETOOLONG); + goto done; + } + + dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); + if (!dent) { + inode = ERR_PTR(-ENOMEM); + goto done; + } + + if (fname_name(&nm) == NULL) { + if (nm.hash & ~UBIFS_S_KEY_HASH_MASK) + goto done; /* ENOENT */ + dent_key_init_hash(c, &key, dir->i_ino, nm.hash); + err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash); + } else { + dent_key_init(c, &key, dir->i_ino, &nm); + err = ubifs_tnc_lookup_nm(c, &key, dent, &nm); + } + + if (err) { + if (err == -ENOENT) + dbg_gen("not found"); + else + inode = ERR_PTR(err); + goto done; + } + + if (dbg_check_name(c, dent, &nm)) { + inode = ERR_PTR(-EINVAL); + goto done; + } + + inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum)); + if (IS_ERR(inode)) { + /* + * This should not happen. Probably the file-system needs + * checking. + */ + err = PTR_ERR(inode); + ubifs_err(c, "dead directory entry '%pd', error %d", + dentry, err); + ubifs_ro_mode(c, err); + goto done; + } + + if (IS_ENCRYPTED(dir) && + (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && + !fscrypt_has_permitted_context(dir, inode)) { + ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu", + dir->i_ino, inode->i_ino); + iput(inode); + inode = ERR_PTR(-EPERM); + } + +done: + kfree(dent); + fscrypt_free_filename(&nm); + return d_splice_alias(inode, dentry); +} + +static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry, + struct fscrypt_name *nm) +{ + if (fscrypt_is_nokey_name(dentry)) + return -ENOKEY; + + return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm); +} + +static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, + bool excl) +{ + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .dirtied_ino = 1 }; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + struct fscrypt_name nm; + int err, sz_change; + + /* + * Budget request settings: new inode, new direntry, changing the + * parent directory inode. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + err = ubifs_prepare_create(dir, dentry, &nm); + if (err) + goto out_budg; + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_fname; + } + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + mutex_lock(&dir_ui->ui_mutex); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + if (err) + goto out_cancel; + mutex_unlock(&dir_ui->ui_mutex); + + ubifs_release_budget(c, &req); + fscrypt_free_filename(&nm); + insert_inode_hash(inode); + d_instantiate(dentry, inode); + return 0; + +out_cancel: + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + mutex_unlock(&dir_ui->ui_mutex); +out_inode: + make_bad_inode(inode); + iput(inode); +out_fname: + fscrypt_free_filename(&nm); +out_budg: + ubifs_release_budget(c, &req); + ubifs_err(c, "cannot create regular file, error %d", err); + return err; +} + +static int do_tmpfile(struct inode *dir, struct dentry *dentry, + umode_t mode, struct inode **whiteout) +{ + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .dirtied_ino = 1}; + struct ubifs_budget_req ino_req = { .dirtied_ino = 1 }; + struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir); + int err, instantiated = 0; + struct fscrypt_name nm; + + /* + * Budget request settings: new inode, new direntry, changing the + * parent directory inode. + * Allocate budget separately for new dirtied inode, the budget will + * be released via writeback. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return err; + + err = ubifs_budget_space(c, &req); + if (err) { + fscrypt_free_filename(&nm); + return err; + } + + err = ubifs_budget_space(c, &ino_req); + if (err) { + ubifs_release_budget(c, &req); + fscrypt_free_filename(&nm); + return err; + } + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_budg; + } + ui = ubifs_inode(inode); + + if (whiteout) { + init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); + ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); + } + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + mutex_lock(&ui->ui_mutex); + insert_inode_hash(inode); + + if (whiteout) { + mark_inode_dirty(inode); + drop_nlink(inode); + *whiteout = inode; + } else { + d_tmpfile(dentry, inode); + } + ubifs_assert(c, ui->dirty); + + instantiated = 1; + mutex_unlock(&ui->ui_mutex); + + mutex_lock(&dir_ui->ui_mutex); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); + if (err) + goto out_cancel; + mutex_unlock(&dir_ui->ui_mutex); + + ubifs_release_budget(c, &req); + fscrypt_free_filename(&nm); + + return 0; + +out_cancel: + mutex_unlock(&dir_ui->ui_mutex); +out_inode: + make_bad_inode(inode); + if (!instantiated) + iput(inode); + else if (whiteout) + iput(*whiteout); +out_budg: + ubifs_release_budget(c, &req); + if (!instantiated) + ubifs_release_budget(c, &ino_req); + fscrypt_free_filename(&nm); + ubifs_err(c, "cannot create temporary file, error %d", err); + return err; +} + +static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry, + umode_t mode) +{ + return do_tmpfile(dir, dentry, mode, NULL); +} + +/** + * vfs_dent_type - get VFS directory entry type. + * @type: UBIFS directory entry type + * + * This function converts UBIFS directory entry type into VFS directory entry + * type. + */ +static unsigned int vfs_dent_type(uint8_t type) +{ + switch (type) { + case UBIFS_ITYPE_REG: + return DT_REG; + case UBIFS_ITYPE_DIR: + return DT_DIR; + case UBIFS_ITYPE_LNK: + return DT_LNK; + case UBIFS_ITYPE_BLK: + return DT_BLK; + case UBIFS_ITYPE_CHR: + return DT_CHR; + case UBIFS_ITYPE_FIFO: + return DT_FIFO; + case UBIFS_ITYPE_SOCK: + return DT_SOCK; + default: + BUG(); + } + return 0; +} + +/* + * The classical Unix view for directory is that it is a linear array of + * (name, inode number) entries. Linux/VFS assumes this model as well. + * Particularly, 'readdir()' call wants us to return a directory entry offset + * which later may be used to continue 'readdir()'ing the directory or to + * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this + * model because directory entries are identified by keys, which may collide. + * + * UBIFS uses directory entry hash value for directory offsets, so + * 'seekdir()'/'telldir()' may not always work because of possible key + * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work + * properly by means of saving full directory entry name in the private field + * of the file description object. + * + * This means that UBIFS cannot support NFS which requires full + * 'seekdir()'/'telldir()' support. + */ +static int ubifs_readdir(struct file *file, struct dir_context *ctx) +{ + int fstr_real_len = 0, err = 0; + struct fscrypt_name nm; + struct fscrypt_str fstr = {0}; + union ubifs_key key; + struct ubifs_dent_node *dent; + struct inode *dir = file_inode(file); + struct ubifs_info *c = dir->i_sb->s_fs_info; + bool encrypted = IS_ENCRYPTED(dir); + + dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos); + + if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2) + /* + * The directory was seek'ed to a senseless position or there + * are no more entries. + */ + return 0; + + if (encrypted) { + err = fscrypt_get_encryption_info(dir); + if (err) + return err; + + err = fscrypt_fname_alloc_buffer(UBIFS_MAX_NLEN, &fstr); + if (err) + return err; + + fstr_real_len = fstr.len; + } + + if (file->f_version == 0) { + /* + * The file was seek'ed, which means that @file->private_data + * is now invalid. This may also be just the first + * 'ubifs_readdir()' invocation, in which case + * @file->private_data is NULL, and the below code is + * basically a no-op. + */ + kfree(file->private_data); + file->private_data = NULL; + } + + /* + * 'generic_file_llseek()' unconditionally sets @file->f_version to + * zero, and we use this for detecting whether the file was seek'ed. + */ + file->f_version = 1; + + /* File positions 0 and 1 correspond to "." and ".." */ + if (ctx->pos < 2) { + ubifs_assert(c, !file->private_data); + if (!dir_emit_dots(file, ctx)) { + if (encrypted) + fscrypt_fname_free_buffer(&fstr); + return 0; + } + + /* Find the first entry in TNC and save it */ + lowest_dent_key(c, &key, dir->i_ino); + fname_len(&nm) = 0; + dent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(dent)) { + err = PTR_ERR(dent); + goto out; + } + + ctx->pos = key_hash_flash(c, &dent->key); + file->private_data = dent; + } + + dent = file->private_data; + if (!dent) { + /* + * The directory was seek'ed to and is now readdir'ed. + * Find the entry corresponding to @ctx->pos or the closest one. + */ + dent_key_init_hash(c, &key, dir->i_ino, ctx->pos); + fname_len(&nm) = 0; + dent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(dent)) { + err = PTR_ERR(dent); + goto out; + } + ctx->pos = key_hash_flash(c, &dent->key); + file->private_data = dent; + } + + while (1) { + dbg_gen("ino %llu, new f_pos %#x", + (unsigned long long)le64_to_cpu(dent->inum), + key_hash_flash(c, &dent->key)); + ubifs_assert(c, le64_to_cpu(dent->ch.sqnum) > + ubifs_inode(dir)->creat_sqnum); + + fname_len(&nm) = le16_to_cpu(dent->nlen); + fname_name(&nm) = dent->name; + + if (encrypted) { + fstr.len = fstr_real_len; + + err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c, + &dent->key), + le32_to_cpu(dent->cookie), + &nm.disk_name, &fstr); + if (err) + goto out; + } else { + fstr.len = fname_len(&nm); + fstr.name = fname_name(&nm); + } + + if (!dir_emit(ctx, fstr.name, fstr.len, + le64_to_cpu(dent->inum), + vfs_dent_type(dent->type))) { + if (encrypted) + fscrypt_fname_free_buffer(&fstr); + return 0; + } + + /* Switch to the next entry */ + key_read(c, &dent->key, &key); + dent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(dent)) { + err = PTR_ERR(dent); + goto out; + } + + kfree(file->private_data); + ctx->pos = key_hash_flash(c, &dent->key); + file->private_data = dent; + cond_resched(); + } + +out: + kfree(file->private_data); + file->private_data = NULL; + + if (encrypted) + fscrypt_fname_free_buffer(&fstr); + + if (err != -ENOENT) + ubifs_err(c, "cannot find next direntry, error %d", err); + else + /* + * -ENOENT is a non-fatal error in this context, the TNC uses + * it to indicate that the cursor moved past the current directory + * and readdir() has to stop. + */ + err = 0; + + + /* 2 is a special value indicating that there are no more direntries */ + ctx->pos = 2; + return err; +} + +/* Free saved readdir() state when the directory is closed */ +static int ubifs_dir_release(struct inode *dir, struct file *file) +{ + kfree(file->private_data); + file->private_data = NULL; + return 0; +} + +/** + * lock_2_inodes - a wrapper for locking two UBIFS inodes. + * @inode1: first inode + * @inode2: second inode + * + * We do not implement any tricks to guarantee strict lock ordering, because + * VFS has already done it for us on the @i_mutex. So this is just a simple + * wrapper function. + */ +static void lock_2_inodes(struct inode *inode1, struct inode *inode2) +{ + mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); + mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); +} + +/** + * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. + * @inode1: first inode + * @inode2: second inode + */ +static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) +{ + mutex_unlock(&ubifs_inode(inode2)->ui_mutex); + mutex_unlock(&ubifs_inode(inode1)->ui_mutex); +} + +static int ubifs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct inode *inode = d_inode(old_dentry); + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_inode *dir_ui = ubifs_inode(dir); + int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len); + struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2, + .dirtied_ino_d = ALIGN(ui->data_len, 8) }; + struct fscrypt_name nm; + + /* + * Budget request settings: new direntry, changing the target inode, + * changing the parent inode. + */ + + dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu", + dentry, inode->i_ino, + inode->i_nlink, dir->i_ino); + ubifs_assert(c, inode_is_locked(dir)); + ubifs_assert(c, inode_is_locked(inode)); + + err = fscrypt_prepare_link(old_dentry, dir, dentry); + if (err) + return err; + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return err; + + err = dbg_check_synced_i_size(c, inode); + if (err) + goto out_fname; + + err = ubifs_budget_space(c, &req); + if (err) + goto out_fname; + + lock_2_inodes(dir, inode); + + /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */ + if (inode->i_nlink == 0) + ubifs_delete_orphan(c, inode->i_ino); + + inc_nlink(inode); + ihold(inode); + inode->i_ctime = current_time(inode); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + if (err) + goto out_cancel; + unlock_2_inodes(dir, inode); + + ubifs_release_budget(c, &req); + d_instantiate(dentry, inode); + fscrypt_free_filename(&nm); + return 0; + +out_cancel: + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + drop_nlink(inode); + if (inode->i_nlink == 0) + ubifs_add_orphan(c, inode->i_ino); + unlock_2_inodes(dir, inode); + ubifs_release_budget(c, &req); + iput(inode); +out_fname: + fscrypt_free_filename(&nm); + return err; +} + +static int ubifs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct inode *inode = d_inode(dentry); + struct ubifs_inode *dir_ui = ubifs_inode(dir); + int err, sz_change, budgeted = 1; + struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; + unsigned int saved_nlink = inode->i_nlink; + struct fscrypt_name nm; + + /* + * Budget request settings: deletion direntry, deletion inode (+1 for + * @dirtied_ino), changing the parent directory inode. If budgeting + * fails, go ahead anyway because we have extra space reserved for + * deletions. + */ + + dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu", + dentry, inode->i_ino, + inode->i_nlink, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm); + if (err) + return err; + + err = ubifs_purge_xattrs(inode); + if (err) + return err; + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + ubifs_assert(c, inode_is_locked(dir)); + ubifs_assert(c, inode_is_locked(inode)); + err = dbg_check_synced_i_size(c, inode); + if (err) + goto out_fname; + + err = ubifs_budget_space(c, &req); + if (err) { + if (err != -ENOSPC) + goto out_fname; + budgeted = 0; + } + + lock_2_inodes(dir, inode); + inode->i_ctime = current_time(dir); + drop_nlink(inode); + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); + if (err) + goto out_cancel; + unlock_2_inodes(dir, inode); + + if (budgeted) + ubifs_release_budget(c, &req); + else { + /* We've deleted something - clean the "no space" flags */ + c->bi.nospace = c->bi.nospace_rp = 0; + smp_wmb(); + } + fscrypt_free_filename(&nm); + return 0; + +out_cancel: + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + set_nlink(inode, saved_nlink); + unlock_2_inodes(dir, inode); + if (budgeted) + ubifs_release_budget(c, &req); +out_fname: + fscrypt_free_filename(&nm); + return err; +} + +/** + * check_dir_empty - check if a directory is empty or not. + * @dir: VFS inode object of the directory to check + * + * This function checks if directory @dir is empty. Returns zero if the + * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes + * in case of of errors. + */ +int ubifs_check_dir_empty(struct inode *dir) +{ + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm = { 0 }; + struct ubifs_dent_node *dent; + union ubifs_key key; + int err; + + lowest_dent_key(c, &key, dir->i_ino); + dent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(dent)) { + err = PTR_ERR(dent); + if (err == -ENOENT) + err = 0; + } else { + kfree(dent); + err = -ENOTEMPTY; + } + return err; +} + +static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct inode *inode = d_inode(dentry); + int err, sz_change, budgeted = 1; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 }; + struct fscrypt_name nm; + + /* + * Budget request settings: deletion direntry, deletion inode and + * changing the parent inode. If budgeting fails, go ahead anyway + * because we have extra space reserved for deletions. + */ + + dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry, + inode->i_ino, dir->i_ino); + ubifs_assert(c, inode_is_locked(dir)); + ubifs_assert(c, inode_is_locked(inode)); + err = ubifs_check_dir_empty(d_inode(dentry)); + if (err) + return err; + + err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm); + if (err) + return err; + + err = ubifs_purge_xattrs(inode); + if (err) + return err; + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + err = ubifs_budget_space(c, &req); + if (err) { + if (err != -ENOSPC) + goto out_fname; + budgeted = 0; + } + + lock_2_inodes(dir, inode); + inode->i_ctime = current_time(dir); + clear_nlink(inode); + drop_nlink(dir); + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); + if (err) + goto out_cancel; + unlock_2_inodes(dir, inode); + + if (budgeted) + ubifs_release_budget(c, &req); + else { + /* We've deleted something - clean the "no space" flags */ + c->bi.nospace = c->bi.nospace_rp = 0; + smp_wmb(); + } + fscrypt_free_filename(&nm); + return 0; + +out_cancel: + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + inc_nlink(dir); + set_nlink(inode, 2); + unlock_2_inodes(dir, inode); + if (budgeted) + ubifs_release_budget(c, &req); +out_fname: + fscrypt_free_filename(&nm); + return err; +} + +static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct inode *inode; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + struct ubifs_info *c = dir->i_sb->s_fs_info; + int err, sz_change; + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .dirtied_ino = 1}; + struct fscrypt_name nm; + + /* + * Budget request settings: new inode, new direntry and changing parent + * directory inode. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + err = ubifs_prepare_create(dir, dentry, &nm); + if (err) + goto out_budg; + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + inode = ubifs_new_inode(c, dir, S_IFDIR | mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_fname; + } + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + mutex_lock(&dir_ui->ui_mutex); + insert_inode_hash(inode); + inc_nlink(inode); + inc_nlink(dir); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + if (err) { + ubifs_err(c, "cannot create directory, error %d", err); + goto out_cancel; + } + mutex_unlock(&dir_ui->ui_mutex); + + ubifs_release_budget(c, &req); + d_instantiate(dentry, inode); + fscrypt_free_filename(&nm); + return 0; + +out_cancel: + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + drop_nlink(dir); + mutex_unlock(&dir_ui->ui_mutex); +out_inode: + make_bad_inode(inode); + iput(inode); +out_fname: + fscrypt_free_filename(&nm); +out_budg: + ubifs_release_budget(c, &req); + return err; +} + +static int ubifs_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t rdev) +{ + struct inode *inode; + struct ubifs_inode *ui; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + struct ubifs_info *c = dir->i_sb->s_fs_info; + union ubifs_dev_desc *dev = NULL; + int sz_change; + int err, devlen = 0; + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .dirtied_ino = 1 }; + struct fscrypt_name nm; + + /* + * Budget request settings: new inode, new direntry and changing parent + * directory inode. + */ + + dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino); + + if (S_ISBLK(mode) || S_ISCHR(mode)) { + dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); + if (!dev) + return -ENOMEM; + devlen = ubifs_encode_dev(dev, rdev); + } + + req.new_ino_d = ALIGN(devlen, 8); + err = ubifs_budget_space(c, &req); + if (err) { + kfree(dev); + return err; + } + + err = ubifs_prepare_create(dir, dentry, &nm); + if (err) { + kfree(dev); + goto out_budg; + } + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + kfree(dev); + err = PTR_ERR(inode); + goto out_fname; + } + + init_special_inode(inode, inode->i_mode, rdev); + inode->i_size = ubifs_inode(inode)->ui_size = devlen; + ui = ubifs_inode(inode); + ui->data = dev; + ui->data_len = devlen; + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + mutex_lock(&dir_ui->ui_mutex); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + if (err) + goto out_cancel; + mutex_unlock(&dir_ui->ui_mutex); + + ubifs_release_budget(c, &req); + insert_inode_hash(inode); + d_instantiate(dentry, inode); + fscrypt_free_filename(&nm); + return 0; + +out_cancel: + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + mutex_unlock(&dir_ui->ui_mutex); +out_inode: + make_bad_inode(inode); + iput(inode); +out_fname: + fscrypt_free_filename(&nm); +out_budg: + ubifs_release_budget(c, &req); + return err; +} + +static int ubifs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct inode *inode; + struct ubifs_inode *ui; + struct ubifs_inode *dir_ui = ubifs_inode(dir); + struct ubifs_info *c = dir->i_sb->s_fs_info; + int err, sz_change, len = strlen(symname); + struct fscrypt_str disk_link; + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .dirtied_ino = 1 }; + struct fscrypt_name nm; + + dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry, + symname, dir->i_ino); + + err = fscrypt_prepare_symlink(dir, symname, len, UBIFS_MAX_INO_DATA, + &disk_link); + if (err) + return err; + + /* + * Budget request settings: new inode, new direntry and changing parent + * directory inode. + */ + req.new_ino_d = ALIGN(disk_link.len - 1, 8); + err = ubifs_budget_space(c, &req); + if (err) + return err; + + err = ubifs_prepare_create(dir, dentry, &nm); + if (err) + goto out_budg; + + sz_change = CALC_DENT_SIZE(fname_len(&nm)); + + inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_fname; + } + + ui = ubifs_inode(inode); + ui->data = kmalloc(disk_link.len, GFP_NOFS); + if (!ui->data) { + err = -ENOMEM; + goto out_inode; + } + + if (IS_ENCRYPTED(inode)) { + disk_link.name = ui->data; /* encrypt directly into ui->data */ + err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); + if (err) + goto out_inode; + } else { + memcpy(ui->data, disk_link.name, disk_link.len); + inode->i_link = ui->data; + } + + /* + * The terminating zero byte is not written to the flash media and it + * is put just to make later in-memory string processing simpler. Thus, + * data length is @disk_link.len - 1, not @disk_link.len. + */ + ui->data_len = disk_link.len - 1; + inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1; + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + mutex_lock(&dir_ui->ui_mutex); + dir->i_size += sz_change; + dir_ui->ui_size = dir->i_size; + dir->i_mtime = dir->i_ctime = inode->i_ctime; + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + if (err) + goto out_cancel; + mutex_unlock(&dir_ui->ui_mutex); + + insert_inode_hash(inode); + d_instantiate(dentry, inode); + err = 0; + goto out_fname; + +out_cancel: + dir->i_size -= sz_change; + dir_ui->ui_size = dir->i_size; + mutex_unlock(&dir_ui->ui_mutex); +out_inode: + make_bad_inode(inode); + iput(inode); +out_fname: + fscrypt_free_filename(&nm); +out_budg: + ubifs_release_budget(c, &req); + return err; +} + +/** + * lock_4_inodes - a wrapper for locking three UBIFS inodes. + * @inode1: first inode + * @inode2: second inode + * @inode3: third inode + * @inode4: fouth inode + * + * This function is used for 'ubifs_rename()' and @inode1 may be the same as + * @inode2 whereas @inode3 and @inode4 may be %NULL. + * + * We do not implement any tricks to guarantee strict lock ordering, because + * VFS has already done it for us on the @i_mutex. So this is just a simple + * wrapper function. + */ +static void lock_4_inodes(struct inode *inode1, struct inode *inode2, + struct inode *inode3, struct inode *inode4) +{ + mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); + if (inode2 != inode1) + mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); + if (inode3) + mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3); + if (inode4) + mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4); +} + +/** + * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename. + * @inode1: first inode + * @inode2: second inode + * @inode3: third inode + * @inode4: fouth inode + */ +static void unlock_4_inodes(struct inode *inode1, struct inode *inode2, + struct inode *inode3, struct inode *inode4) +{ + if (inode4) + mutex_unlock(&ubifs_inode(inode4)->ui_mutex); + if (inode3) + mutex_unlock(&ubifs_inode(inode3)->ui_mutex); + if (inode1 != inode2) + mutex_unlock(&ubifs_inode(inode2)->ui_mutex); + mutex_unlock(&ubifs_inode(inode1)->ui_mutex); +} + +static int do_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + struct ubifs_info *c = old_dir->i_sb->s_fs_info; + struct inode *old_inode = d_inode(old_dentry); + struct inode *new_inode = d_inode(new_dentry); + struct inode *whiteout = NULL; + struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode); + struct ubifs_inode *whiteout_ui = NULL; + int err, release, sync = 0, move = (new_dir != old_dir); + int is_dir = S_ISDIR(old_inode->i_mode); + int unlink = !!new_inode, new_sz, old_sz; + struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, + .dirtied_ino = 3 }; + struct ubifs_budget_req ino_req = { .dirtied_ino = 1, + .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; + struct timespec64 time; + unsigned int saved_nlink; + struct fscrypt_name old_nm, new_nm; + + /* + * Budget request settings: deletion direntry, new direntry, removing + * the old inode, and changing old and new parent directory inodes. + * + * However, this operation also marks the target inode as dirty and + * does not write it, so we allocate budget for the target inode + * separately. + */ + + dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", + old_dentry, old_inode->i_ino, old_dir->i_ino, + new_dentry, new_dir->i_ino, flags); + + if (unlink) { + ubifs_assert(c, inode_is_locked(new_inode)); + + /* Budget for old inode's data when its nlink > 1. */ + req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8); + err = ubifs_purge_xattrs(new_inode); + if (err) + return err; + } + + if (unlink && is_dir) { + err = ubifs_check_dir_empty(new_inode); + if (err) + return err; + } + + err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm); + if (err) + return err; + + err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm); + if (err) { + fscrypt_free_filename(&old_nm); + return err; + } + + new_sz = CALC_DENT_SIZE(fname_len(&new_nm)); + old_sz = CALC_DENT_SIZE(fname_len(&old_nm)); + + err = ubifs_budget_space(c, &req); + if (err) { + fscrypt_free_filename(&old_nm); + fscrypt_free_filename(&new_nm); + return err; + } + err = ubifs_budget_space(c, &ino_req); + if (err) { + fscrypt_free_filename(&old_nm); + fscrypt_free_filename(&new_nm); + ubifs_release_budget(c, &req); + return err; + } + + if (flags & RENAME_WHITEOUT) { + union ubifs_dev_desc *dev = NULL; + struct ubifs_budget_req wht_req; + + dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); + if (!dev) { + err = -ENOMEM; + goto out_release; + } + + err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); + if (err) { + kfree(dev); + goto out_release; + } + + spin_lock(&whiteout->i_lock); + whiteout->i_state |= I_LINKABLE; + spin_unlock(&whiteout->i_lock); + + whiteout_ui = ubifs_inode(whiteout); + whiteout_ui->data = dev; + whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); + ubifs_assert(c, !whiteout_ui->dirty); + + memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); + wht_req.dirtied_ino = 1; + wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + /* + * To avoid deadlock between space budget (holds ui_mutex and + * waits wb work) and writeback work(waits ui_mutex), do space + * budget before ubifs inodes locked. + */ + err = ubifs_budget_space(c, &wht_req); + if (err) { + iput(whiteout); + goto out_release; + } + + /* Add the old_dentry size to the old_dir size. */ + old_sz -= CALC_DENT_SIZE(fname_len(&old_nm)); + } + + lock_4_inodes(old_dir, new_dir, new_inode, whiteout); + + /* + * Like most other Unix systems, set the @i_ctime for inodes on a + * rename. + */ + time = current_time(old_dir); + old_inode->i_ctime = time; + + /* We must adjust parent link count when renaming directories */ + if (is_dir) { + if (move) { + /* + * @old_dir loses a link because we are moving + * @old_inode to a different directory. + */ + drop_nlink(old_dir); + /* + * @new_dir only gains a link if we are not also + * overwriting an existing directory. + */ + if (!unlink) + inc_nlink(new_dir); + } else { + /* + * @old_inode is not moving to a different directory, + * but @old_dir still loses a link if we are + * overwriting an existing directory. + */ + if (unlink) + drop_nlink(old_dir); + } + } + + old_dir->i_size -= old_sz; + ubifs_inode(old_dir)->ui_size = old_dir->i_size; + old_dir->i_mtime = old_dir->i_ctime = time; + new_dir->i_mtime = new_dir->i_ctime = time; + + /* + * And finally, if we unlinked a direntry which happened to have the + * same name as the moved direntry, we have to decrement @i_nlink of + * the unlinked inode and change its ctime. + */ + if (unlink) { + /* + * Directories cannot have hard-links, so if this is a + * directory, just clear @i_nlink. + */ + saved_nlink = new_inode->i_nlink; + if (is_dir) + clear_nlink(new_inode); + else + drop_nlink(new_inode); + new_inode->i_ctime = time; + } else { + new_dir->i_size += new_sz; + ubifs_inode(new_dir)->ui_size = new_dir->i_size; + } + + /* + * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode + * is dirty, because this will be done later on at the end of + * 'ubifs_rename()'. + */ + if (IS_SYNC(old_inode)) { + sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); + if (unlink && IS_SYNC(new_inode)) + sync = 1; + } + + if (whiteout) { + inc_nlink(whiteout); + mark_inode_dirty(whiteout); + + spin_lock(&whiteout->i_lock); + whiteout->i_state &= ~I_LINKABLE; + spin_unlock(&whiteout->i_lock); + + iput(whiteout); + } + + err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, + new_inode, &new_nm, whiteout, sync); + if (err) + goto out_cancel; + + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); + ubifs_release_budget(c, &req); + + mutex_lock(&old_inode_ui->ui_mutex); + release = old_inode_ui->dirty; + mark_inode_dirty_sync(old_inode); + mutex_unlock(&old_inode_ui->ui_mutex); + + if (release) + ubifs_release_budget(c, &ino_req); + if (IS_SYNC(old_inode)) + err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); + + fscrypt_free_filename(&old_nm); + fscrypt_free_filename(&new_nm); + return err; + +out_cancel: + if (unlink) { + set_nlink(new_inode, saved_nlink); + } else { + new_dir->i_size -= new_sz; + ubifs_inode(new_dir)->ui_size = new_dir->i_size; + } + old_dir->i_size += old_sz; + ubifs_inode(old_dir)->ui_size = old_dir->i_size; + if (is_dir) { + if (move) { + inc_nlink(old_dir); + if (!unlink) + drop_nlink(new_dir); + } else { + if (unlink) + inc_nlink(old_dir); + } + } + if (whiteout) { + drop_nlink(whiteout); + iput(whiteout); + } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); +out_release: + ubifs_release_budget(c, &ino_req); + ubifs_release_budget(c, &req); + fscrypt_free_filename(&old_nm); + fscrypt_free_filename(&new_nm); + return err; +} + +static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + struct ubifs_info *c = old_dir->i_sb->s_fs_info; + struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1, + .dirtied_ino = 2 }; + int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); + struct inode *fst_inode = d_inode(old_dentry); + struct inode *snd_inode = d_inode(new_dentry); + struct timespec64 time; + int err; + struct fscrypt_name fst_nm, snd_nm; + + ubifs_assert(c, fst_inode && snd_inode); + + err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm); + if (err) + return err; + + err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm); + if (err) { + fscrypt_free_filename(&fst_nm); + return err; + } + + err = ubifs_budget_space(c, &req); + if (err) + goto out; + + lock_4_inodes(old_dir, new_dir, NULL, NULL); + + time = current_time(old_dir); + fst_inode->i_ctime = time; + snd_inode->i_ctime = time; + old_dir->i_mtime = old_dir->i_ctime = time; + new_dir->i_mtime = new_dir->i_ctime = time; + + if (old_dir != new_dir) { + if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) { + inc_nlink(new_dir); + drop_nlink(old_dir); + } + else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) { + drop_nlink(new_dir); + inc_nlink(old_dir); + } + } + + err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir, + snd_inode, &snd_nm, sync); + + unlock_4_inodes(old_dir, new_dir, NULL, NULL); + ubifs_release_budget(c, &req); + +out: + fscrypt_free_filename(&fst_nm); + fscrypt_free_filename(&snd_nm); + return err; +} + +static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + int err; + struct ubifs_info *c = old_dir->i_sb->s_fs_info; + + if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE)) + return -EINVAL; + + ubifs_assert(c, inode_is_locked(old_dir)); + ubifs_assert(c, inode_is_locked(new_dir)); + + err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, + flags); + if (err) + return err; + + if (flags & RENAME_EXCHANGE) + return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry); + + return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags); +} + +int ubifs_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int flags) +{ + loff_t size; + struct inode *inode = d_inode(path->dentry); + struct ubifs_inode *ui = ubifs_inode(inode); + + mutex_lock(&ui->ui_mutex); + + if (ui->flags & UBIFS_APPEND_FL) + stat->attributes |= STATX_ATTR_APPEND; + if (ui->flags & UBIFS_COMPR_FL) + stat->attributes |= STATX_ATTR_COMPRESSED; + if (ui->flags & UBIFS_CRYPT_FL) + stat->attributes |= STATX_ATTR_ENCRYPTED; + if (ui->flags & UBIFS_IMMUTABLE_FL) + stat->attributes |= STATX_ATTR_IMMUTABLE; + + stat->attributes_mask |= (STATX_ATTR_APPEND | + STATX_ATTR_COMPRESSED | + STATX_ATTR_ENCRYPTED | + STATX_ATTR_IMMUTABLE); + + generic_fillattr(inode, stat); + stat->blksize = UBIFS_BLOCK_SIZE; + stat->size = ui->ui_size; + + /* + * Unfortunately, the 'stat()' system call was designed for block + * device based file systems, and it is not appropriate for UBIFS, + * because UBIFS does not have notion of "block". For example, it is + * difficult to tell how many block a directory takes - it actually + * takes less than 300 bytes, but we have to round it to block size, + * which introduces large mistake. This makes utilities like 'du' to + * report completely senseless numbers. This is the reason why UBIFS + * goes the same way as JFFS2 - it reports zero blocks for everything + * but regular files, which makes more sense than reporting completely + * wrong sizes. + */ + if (S_ISREG(inode->i_mode)) { + size = ui->xattr_size; + size += stat->size; + size = ALIGN(size, UBIFS_BLOCK_SIZE); + /* + * Note, user-space expects 512-byte blocks count irrespectively + * of what was reported in @stat->size. + */ + stat->blocks = size >> 9; + } else + stat->blocks = 0; + mutex_unlock(&ui->ui_mutex); + return 0; +} + +static int ubifs_dir_open(struct inode *dir, struct file *file) +{ + if (IS_ENCRYPTED(dir)) + return fscrypt_get_encryption_info(dir) ? -EACCES : 0; + + return 0; +} + +const struct inode_operations ubifs_dir_inode_operations = { + .lookup = ubifs_lookup, + .create = ubifs_create, + .link = ubifs_link, + .symlink = ubifs_symlink, + .unlink = ubifs_unlink, + .mkdir = ubifs_mkdir, + .rmdir = ubifs_rmdir, + .mknod = ubifs_mknod, + .rename = ubifs_rename, + .setattr = ubifs_setattr, + .getattr = ubifs_getattr, +#ifdef CONFIG_UBIFS_FS_XATTR + .listxattr = ubifs_listxattr, +#endif + .update_time = ubifs_update_time, + .tmpfile = ubifs_tmpfile, +}; + +const struct file_operations ubifs_dir_operations = { + .llseek = generic_file_llseek, + .release = ubifs_dir_release, + .read = generic_read_dir, + .iterate_shared = ubifs_readdir, + .fsync = ubifs_fsync, + .unlocked_ioctl = ubifs_ioctl, + .open = ubifs_dir_open, +#ifdef CONFIG_COMPAT + .compat_ioctl = ubifs_compat_ioctl, +#endif +}; diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c new file mode 100644 index 000000000..19fdcda04 --- /dev/null +++ b/fs/ubifs/file.c @@ -0,0 +1,1693 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements VFS file and inode operations for regular files, device + * nodes and symlinks as well as address space operations. + * + * UBIFS uses 2 page flags: @PG_private and @PG_checked. @PG_private is set if + * the page is dirty and is used for optimization purposes - dirty pages are + * not budgeted so the flag shows that 'ubifs_write_end()' should not release + * the budget for this page. The @PG_checked flag is set if full budgeting is + * required for the page e.g., when it corresponds to a file hole or it is + * beyond the file size. The budgeting is done in 'ubifs_write_begin()', because + * it is OK to fail in this function, and the budget is released in + * 'ubifs_write_end()'. So the @PG_private and @PG_checked flags carry + * information about how the page was budgeted, to make it possible to release + * the budget properly. + * + * A thing to keep in mind: inode @i_mutex is locked in most VFS operations we + * implement. However, this is not true for 'ubifs_writepage()', which may be + * called with @i_mutex unlocked. For example, when flusher thread is doing + * background write-back, it calls 'ubifs_writepage()' with unlocked @i_mutex. + * At "normal" work-paths the @i_mutex is locked in 'ubifs_writepage()', e.g. + * in the "sys_write -> alloc_pages -> direct reclaim path". So, in + * 'ubifs_writepage()' we are only guaranteed that the page is locked. + * + * Similarly, @i_mutex is not always locked in 'ubifs_readpage()', e.g., the + * read-ahead path does not lock it ("sys_read -> generic_file_aio_read -> + * ondemand_readahead -> readpage"). In case of readahead, @I_SYNC flag is not + * set as well. However, UBIFS disables readahead. + */ + +#include "ubifs.h" +#include <linux/mount.h> +#include <linux/slab.h> +#include <linux/migrate.h> + +static int read_block(struct inode *inode, void *addr, unsigned int block, + struct ubifs_data_node *dn) +{ + struct ubifs_info *c = inode->i_sb->s_fs_info; + int err, len, out_len; + union ubifs_key key; + unsigned int dlen; + + data_key_init(c, &key, inode->i_ino, block); + err = ubifs_tnc_lookup(c, &key, dn); + if (err) { + if (err == -ENOENT) + /* Not found, so it must be a hole */ + memset(addr, 0, UBIFS_BLOCK_SIZE); + return err; + } + + ubifs_assert(c, le64_to_cpu(dn->ch.sqnum) > + ubifs_inode(inode)->creat_sqnum); + len = le32_to_cpu(dn->size); + if (len <= 0 || len > UBIFS_BLOCK_SIZE) + goto dump; + + dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; + + if (IS_ENCRYPTED(inode)) { + err = ubifs_decrypt(inode, dn, &dlen, block); + if (err) + goto dump; + } + + out_len = UBIFS_BLOCK_SIZE; + err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len, + le16_to_cpu(dn->compr_type)); + if (err || len != out_len) + goto dump; + + /* + * Data length can be less than a full block, even for blocks that are + * not the last in the file (e.g., as a result of making a hole and + * appending data). Ensure that the remainder is zeroed out. + */ + if (len < UBIFS_BLOCK_SIZE) + memset(addr + len, 0, UBIFS_BLOCK_SIZE - len); + + return 0; + +dump: + ubifs_err(c, "bad data node (block %u, inode %lu)", + block, inode->i_ino); + ubifs_dump_node(c, dn); + return -EINVAL; +} + +static int do_readpage(struct page *page) +{ + void *addr; + int err = 0, i; + unsigned int block, beyond; + struct ubifs_data_node *dn; + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + loff_t i_size = i_size_read(inode); + + dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx", + inode->i_ino, page->index, i_size, page->flags); + ubifs_assert(c, !PageChecked(page)); + ubifs_assert(c, !PagePrivate(page)); + + addr = kmap(page); + + block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; + beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; + if (block >= beyond) { + /* Reading beyond inode */ + SetPageChecked(page); + memset(addr, 0, PAGE_SIZE); + goto out; + } + + dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS); + if (!dn) { + err = -ENOMEM; + goto error; + } + + i = 0; + while (1) { + int ret; + + if (block >= beyond) { + /* Reading beyond inode */ + err = -ENOENT; + memset(addr, 0, UBIFS_BLOCK_SIZE); + } else { + ret = read_block(inode, addr, block, dn); + if (ret) { + err = ret; + if (err != -ENOENT) + break; + } else if (block + 1 == beyond) { + int dlen = le32_to_cpu(dn->size); + int ilen = i_size & (UBIFS_BLOCK_SIZE - 1); + + if (ilen && ilen < dlen) + memset(addr + ilen, 0, dlen - ilen); + } + } + if (++i >= UBIFS_BLOCKS_PER_PAGE) + break; + block += 1; + addr += UBIFS_BLOCK_SIZE; + } + if (err) { + struct ubifs_info *c = inode->i_sb->s_fs_info; + if (err == -ENOENT) { + /* Not found, so it must be a hole */ + SetPageChecked(page); + dbg_gen("hole"); + goto out_free; + } + ubifs_err(c, "cannot read page %lu of inode %lu, error %d", + page->index, inode->i_ino, err); + goto error; + } + +out_free: + kfree(dn); +out: + SetPageUptodate(page); + ClearPageError(page); + flush_dcache_page(page); + kunmap(page); + return 0; + +error: + kfree(dn); + ClearPageUptodate(page); + SetPageError(page); + flush_dcache_page(page); + kunmap(page); + return err; +} + +/** + * release_new_page_budget - release budget of a new page. + * @c: UBIFS file-system description object + * + * This is a helper function which releases budget corresponding to the budget + * of one new page of data. + */ +static void release_new_page_budget(struct ubifs_info *c) +{ + struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 }; + + ubifs_release_budget(c, &req); +} + +/** + * release_existing_page_budget - release budget of an existing page. + * @c: UBIFS file-system description object + * + * This is a helper function which releases budget corresponding to the budget + * of changing one one page of data which already exists on the flash media. + */ +static void release_existing_page_budget(struct ubifs_info *c) +{ + struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget}; + + ubifs_release_budget(c, &req); +} + +static int write_begin_slow(struct address_space *mapping, + loff_t pos, unsigned len, struct page **pagep, + unsigned flags) +{ + struct inode *inode = mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + pgoff_t index = pos >> PAGE_SHIFT; + struct ubifs_budget_req req = { .new_page = 1 }; + int err, appending = !!(pos + len > inode->i_size); + struct page *page; + + dbg_gen("ino %lu, pos %llu, len %u, i_size %lld", + inode->i_ino, pos, len, inode->i_size); + + /* + * At the slow path we have to budget before locking the page, because + * budgeting may force write-back, which would wait on locked pages and + * deadlock if we had the page locked. At this point we do not know + * anything about the page, so assume that this is a new page which is + * written to a hole. This corresponds to largest budget. Later the + * budget will be amended if this is not true. + */ + if (appending) + /* We are appending data, budget for inode change */ + req.dirtied_ino = 1; + + err = ubifs_budget_space(c, &req); + if (unlikely(err)) + return err; + + page = grab_cache_page_write_begin(mapping, index, flags); + if (unlikely(!page)) { + ubifs_release_budget(c, &req); + return -ENOMEM; + } + + if (!PageUptodate(page)) { + if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) + SetPageChecked(page); + else { + err = do_readpage(page); + if (err) { + unlock_page(page); + put_page(page); + ubifs_release_budget(c, &req); + return err; + } + } + + SetPageUptodate(page); + ClearPageError(page); + } + + if (PagePrivate(page)) + /* + * The page is dirty, which means it was budgeted twice: + * o first time the budget was allocated by the task which + * made the page dirty and set the PG_private flag; + * o and then we budgeted for it for the second time at the + * very beginning of this function. + * + * So what we have to do is to release the page budget we + * allocated. + */ + release_new_page_budget(c); + else if (!PageChecked(page)) + /* + * We are changing a page which already exists on the media. + * This means that changing the page does not make the amount + * of indexing information larger, and this part of the budget + * which we have already acquired may be released. + */ + ubifs_convert_page_budget(c); + + if (appending) { + struct ubifs_inode *ui = ubifs_inode(inode); + + /* + * 'ubifs_write_end()' is optimized from the fast-path part of + * 'ubifs_write_begin()' and expects the @ui_mutex to be locked + * if data is appended. + */ + mutex_lock(&ui->ui_mutex); + if (ui->dirty) + /* + * The inode is dirty already, so we may free the + * budget we allocated. + */ + ubifs_release_dirty_inode_budget(c, ui); + } + + *pagep = page; + return 0; +} + +/** + * allocate_budget - allocate budget for 'ubifs_write_begin()'. + * @c: UBIFS file-system description object + * @page: page to allocate budget for + * @ui: UBIFS inode object the page belongs to + * @appending: non-zero if the page is appended + * + * This is a helper function for 'ubifs_write_begin()' which allocates budget + * for the operation. The budget is allocated differently depending on whether + * this is appending, whether the page is dirty or not, and so on. This + * function leaves the @ui->ui_mutex locked in case of appending. Returns zero + * in case of success and %-ENOSPC in case of failure. + */ +static int allocate_budget(struct ubifs_info *c, struct page *page, + struct ubifs_inode *ui, int appending) +{ + struct ubifs_budget_req req = { .fast = 1 }; + + if (PagePrivate(page)) { + if (!appending) + /* + * The page is dirty and we are not appending, which + * means no budget is needed at all. + */ + return 0; + + mutex_lock(&ui->ui_mutex); + if (ui->dirty) + /* + * The page is dirty and we are appending, so the inode + * has to be marked as dirty. However, it is already + * dirty, so we do not need any budget. We may return, + * but @ui->ui_mutex hast to be left locked because we + * should prevent write-back from flushing the inode + * and freeing the budget. The lock will be released in + * 'ubifs_write_end()'. + */ + return 0; + + /* + * The page is dirty, we are appending, the inode is clean, so + * we need to budget the inode change. + */ + req.dirtied_ino = 1; + } else { + if (PageChecked(page)) + /* + * The page corresponds to a hole and does not + * exist on the media. So changing it makes + * make the amount of indexing information + * larger, and we have to budget for a new + * page. + */ + req.new_page = 1; + else + /* + * Not a hole, the change will not add any new + * indexing information, budget for page + * change. + */ + req.dirtied_page = 1; + + if (appending) { + mutex_lock(&ui->ui_mutex); + if (!ui->dirty) + /* + * The inode is clean but we will have to mark + * it as dirty because we are appending. This + * needs a budget. + */ + req.dirtied_ino = 1; + } + } + + return ubifs_budget_space(c, &req); +} + +/* + * This function is called when a page of data is going to be written. Since + * the page of data will not necessarily go to the flash straight away, UBIFS + * has to reserve space on the media for it, which is done by means of + * budgeting. + * + * This is the hot-path of the file-system and we are trying to optimize it as + * much as possible. For this reasons it is split on 2 parts - slow and fast. + * + * There many budgeting cases: + * o a new page is appended - we have to budget for a new page and for + * changing the inode; however, if the inode is already dirty, there is + * no need to budget for it; + * o an existing clean page is changed - we have budget for it; if the page + * does not exist on the media (a hole), we have to budget for a new + * page; otherwise, we may budget for changing an existing page; the + * difference between these cases is that changing an existing page does + * not introduce anything new to the FS indexing information, so it does + * not grow, and smaller budget is acquired in this case; + * o an existing dirty page is changed - no need to budget at all, because + * the page budget has been acquired by earlier, when the page has been + * marked dirty. + * + * UBIFS budgeting sub-system may force write-back if it thinks there is no + * space to reserve. This imposes some locking restrictions and makes it + * impossible to take into account the above cases, and makes it impossible to + * optimize budgeting. + * + * The solution for this is that the fast path of 'ubifs_write_begin()' assumes + * there is a plenty of flash space and the budget will be acquired quickly, + * without forcing write-back. The slow path does not make this assumption. + */ +static int ubifs_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) +{ + struct inode *inode = mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_inode *ui = ubifs_inode(inode); + pgoff_t index = pos >> PAGE_SHIFT; + int err, appending = !!(pos + len > inode->i_size); + int skipped_read = 0; + struct page *page; + + ubifs_assert(c, ubifs_inode(inode)->ui_size == inode->i_size); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + + if (unlikely(c->ro_error)) + return -EROFS; + + /* Try out the fast-path part first */ + page = grab_cache_page_write_begin(mapping, index, flags); + if (unlikely(!page)) + return -ENOMEM; + + if (!PageUptodate(page)) { + /* The page is not loaded from the flash */ + if (!(pos & ~PAGE_MASK) && len == PAGE_SIZE) { + /* + * We change whole page so no need to load it. But we + * do not know whether this page exists on the media or + * not, so we assume the latter because it requires + * larger budget. The assumption is that it is better + * to budget a bit more than to read the page from the + * media. Thus, we are setting the @PG_checked flag + * here. + */ + SetPageChecked(page); + skipped_read = 1; + } else { + err = do_readpage(page); + if (err) { + unlock_page(page); + put_page(page); + return err; + } + } + + SetPageUptodate(page); + ClearPageError(page); + } + + err = allocate_budget(c, page, ui, appending); + if (unlikely(err)) { + ubifs_assert(c, err == -ENOSPC); + /* + * If we skipped reading the page because we were going to + * write all of it, then it is not up to date. + */ + if (skipped_read) { + ClearPageChecked(page); + ClearPageUptodate(page); + } + /* + * Budgeting failed which means it would have to force + * write-back but didn't, because we set the @fast flag in the + * request. Write-back cannot be done now, while we have the + * page locked, because it would deadlock. Unlock and free + * everything and fall-back to slow-path. + */ + if (appending) { + ubifs_assert(c, mutex_is_locked(&ui->ui_mutex)); + mutex_unlock(&ui->ui_mutex); + } + unlock_page(page); + put_page(page); + + return write_begin_slow(mapping, pos, len, pagep, flags); + } + + /* + * Whee, we acquired budgeting quickly - without involving + * garbage-collection, committing or forcing write-back. We return + * with @ui->ui_mutex locked if we are appending pages, and unlocked + * otherwise. This is an optimization (slightly hacky though). + */ + *pagep = page; + return 0; + +} + +/** + * cancel_budget - cancel budget. + * @c: UBIFS file-system description object + * @page: page to cancel budget for + * @ui: UBIFS inode object the page belongs to + * @appending: non-zero if the page is appended + * + * This is a helper function for a page write operation. It unlocks the + * @ui->ui_mutex in case of appending. + */ +static void cancel_budget(struct ubifs_info *c, struct page *page, + struct ubifs_inode *ui, int appending) +{ + if (appending) { + if (!ui->dirty) + ubifs_release_dirty_inode_budget(c, ui); + mutex_unlock(&ui->ui_mutex); + } + if (!PagePrivate(page)) { + if (PageChecked(page)) + release_new_page_budget(c); + else + release_existing_page_budget(c); + } +} + +static int ubifs_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + struct inode *inode = mapping->host; + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_info *c = inode->i_sb->s_fs_info; + loff_t end_pos = pos + len; + int appending = !!(end_pos > inode->i_size); + + dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld", + inode->i_ino, pos, page->index, len, copied, inode->i_size); + + if (unlikely(copied < len && len == PAGE_SIZE)) { + /* + * VFS copied less data to the page that it intended and + * declared in its '->write_begin()' call via the @len + * argument. If the page was not up-to-date, and @len was + * @PAGE_SIZE, the 'ubifs_write_begin()' function did + * not load it from the media (for optimization reasons). This + * means that part of the page contains garbage. So read the + * page now. + */ + dbg_gen("copied %d instead of %d, read page and repeat", + copied, len); + cancel_budget(c, page, ui, appending); + ClearPageChecked(page); + + /* + * Return 0 to force VFS to repeat the whole operation, or the + * error code if 'do_readpage()' fails. + */ + copied = do_readpage(page); + goto out; + } + + if (!PagePrivate(page)) { + attach_page_private(page, (void *)1); + atomic_long_inc(&c->dirty_pg_cnt); + __set_page_dirty_nobuffers(page); + } + + if (appending) { + i_size_write(inode, end_pos); + ui->ui_size = end_pos; + /* + * Note, we do not set @I_DIRTY_PAGES (which means that the + * inode has dirty pages), this has been done in + * '__set_page_dirty_nobuffers()'. + */ + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); + ubifs_assert(c, mutex_is_locked(&ui->ui_mutex)); + mutex_unlock(&ui->ui_mutex); + } + +out: + unlock_page(page); + put_page(page); + return copied; +} + +/** + * populate_page - copy data nodes into a page for bulk-read. + * @c: UBIFS file-system description object + * @page: page + * @bu: bulk-read information + * @n: next zbranch slot + * + * This function returns %0 on success and a negative error code on failure. + */ +static int populate_page(struct ubifs_info *c, struct page *page, + struct bu_info *bu, int *n) +{ + int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0; + struct inode *inode = page->mapping->host; + loff_t i_size = i_size_read(inode); + unsigned int page_block; + void *addr, *zaddr; + pgoff_t end_index; + + dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx", + inode->i_ino, page->index, i_size, page->flags); + + addr = zaddr = kmap(page); + + end_index = (i_size - 1) >> PAGE_SHIFT; + if (!i_size || page->index > end_index) { + hole = 1; + memset(addr, 0, PAGE_SIZE); + goto out_hole; + } + + page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; + while (1) { + int err, len, out_len, dlen; + + if (nn >= bu->cnt) { + hole = 1; + memset(addr, 0, UBIFS_BLOCK_SIZE); + } else if (key_block(c, &bu->zbranch[nn].key) == page_block) { + struct ubifs_data_node *dn; + + dn = bu->buf + (bu->zbranch[nn].offs - offs); + + ubifs_assert(c, le64_to_cpu(dn->ch.sqnum) > + ubifs_inode(inode)->creat_sqnum); + + len = le32_to_cpu(dn->size); + if (len <= 0 || len > UBIFS_BLOCK_SIZE) + goto out_err; + + dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; + out_len = UBIFS_BLOCK_SIZE; + + if (IS_ENCRYPTED(inode)) { + err = ubifs_decrypt(inode, dn, &dlen, page_block); + if (err) + goto out_err; + } + + err = ubifs_decompress(c, &dn->data, dlen, addr, &out_len, + le16_to_cpu(dn->compr_type)); + if (err || len != out_len) + goto out_err; + + if (len < UBIFS_BLOCK_SIZE) + memset(addr + len, 0, UBIFS_BLOCK_SIZE - len); + + nn += 1; + read = (i << UBIFS_BLOCK_SHIFT) + len; + } else if (key_block(c, &bu->zbranch[nn].key) < page_block) { + nn += 1; + continue; + } else { + hole = 1; + memset(addr, 0, UBIFS_BLOCK_SIZE); + } + if (++i >= UBIFS_BLOCKS_PER_PAGE) + break; + addr += UBIFS_BLOCK_SIZE; + page_block += 1; + } + + if (end_index == page->index) { + int len = i_size & (PAGE_SIZE - 1); + + if (len && len < read) + memset(zaddr + len, 0, read - len); + } + +out_hole: + if (hole) { + SetPageChecked(page); + dbg_gen("hole"); + } + + SetPageUptodate(page); + ClearPageError(page); + flush_dcache_page(page); + kunmap(page); + *n = nn; + return 0; + +out_err: + ClearPageUptodate(page); + SetPageError(page); + flush_dcache_page(page); + kunmap(page); + ubifs_err(c, "bad data node (block %u, inode %lu)", + page_block, inode->i_ino); + return -EINVAL; +} + +/** + * ubifs_do_bulk_read - do bulk-read. + * @c: UBIFS file-system description object + * @bu: bulk-read information + * @page1: first page to read + * + * This function returns %1 if the bulk-read is done, otherwise %0 is returned. + */ +static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu, + struct page *page1) +{ + pgoff_t offset = page1->index, end_index; + struct address_space *mapping = page1->mapping; + struct inode *inode = mapping->host; + struct ubifs_inode *ui = ubifs_inode(inode); + int err, page_idx, page_cnt, ret = 0, n = 0; + int allocate = bu->buf ? 0 : 1; + loff_t isize; + gfp_t ra_gfp_mask = readahead_gfp_mask(mapping) & ~__GFP_FS; + + err = ubifs_tnc_get_bu_keys(c, bu); + if (err) + goto out_warn; + + if (bu->eof) { + /* Turn off bulk-read at the end of the file */ + ui->read_in_a_row = 1; + ui->bulk_read = 0; + } + + page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT; + if (!page_cnt) { + /* + * This happens when there are multiple blocks per page and the + * blocks for the first page we are looking for, are not + * together. If all the pages were like this, bulk-read would + * reduce performance, so we turn it off for a while. + */ + goto out_bu_off; + } + + if (bu->cnt) { + if (allocate) { + /* + * Allocate bulk-read buffer depending on how many data + * nodes we are going to read. + */ + bu->buf_len = bu->zbranch[bu->cnt - 1].offs + + bu->zbranch[bu->cnt - 1].len - + bu->zbranch[0].offs; + ubifs_assert(c, bu->buf_len > 0); + ubifs_assert(c, bu->buf_len <= c->leb_size); + bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN); + if (!bu->buf) + goto out_bu_off; + } + + err = ubifs_tnc_bulk_read(c, bu); + if (err) + goto out_warn; + } + + err = populate_page(c, page1, bu, &n); + if (err) + goto out_warn; + + unlock_page(page1); + ret = 1; + + isize = i_size_read(inode); + if (isize == 0) + goto out_free; + end_index = ((isize - 1) >> PAGE_SHIFT); + + for (page_idx = 1; page_idx < page_cnt; page_idx++) { + pgoff_t page_offset = offset + page_idx; + struct page *page; + + if (page_offset > end_index) + break; + page = pagecache_get_page(mapping, page_offset, + FGP_LOCK|FGP_ACCESSED|FGP_CREAT|FGP_NOWAIT, + ra_gfp_mask); + if (!page) + break; + if (!PageUptodate(page)) + err = populate_page(c, page, bu, &n); + unlock_page(page); + put_page(page); + if (err) + break; + } + + ui->last_page_read = offset + page_idx - 1; + +out_free: + if (allocate) + kfree(bu->buf); + return ret; + +out_warn: + ubifs_warn(c, "ignoring error %d and skipping bulk-read", err); + goto out_free; + +out_bu_off: + ui->read_in_a_row = ui->bulk_read = 0; + goto out_free; +} + +/** + * ubifs_bulk_read - determine whether to bulk-read and, if so, do it. + * @page: page from which to start bulk-read. + * + * Some flash media are capable of reading sequentially at faster rates. UBIFS + * bulk-read facility is designed to take advantage of that, by reading in one + * go consecutive data nodes that are also located consecutively in the same + * LEB. This function returns %1 if a bulk-read is done and %0 otherwise. + */ +static int ubifs_bulk_read(struct page *page) +{ + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_inode *ui = ubifs_inode(inode); + pgoff_t index = page->index, last_page_read = ui->last_page_read; + struct bu_info *bu; + int err = 0, allocated = 0; + + ui->last_page_read = index; + if (!c->bulk_read) + return 0; + + /* + * Bulk-read is protected by @ui->ui_mutex, but it is an optimization, + * so don't bother if we cannot lock the mutex. + */ + if (!mutex_trylock(&ui->ui_mutex)) + return 0; + + if (index != last_page_read + 1) { + /* Turn off bulk-read if we stop reading sequentially */ + ui->read_in_a_row = 1; + if (ui->bulk_read) + ui->bulk_read = 0; + goto out_unlock; + } + + if (!ui->bulk_read) { + ui->read_in_a_row += 1; + if (ui->read_in_a_row < 3) + goto out_unlock; + /* Three reads in a row, so switch on bulk-read */ + ui->bulk_read = 1; + } + + /* + * If possible, try to use pre-allocated bulk-read information, which + * is protected by @c->bu_mutex. + */ + if (mutex_trylock(&c->bu_mutex)) + bu = &c->bu; + else { + bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN); + if (!bu) + goto out_unlock; + + bu->buf = NULL; + allocated = 1; + } + + bu->buf_len = c->max_bu_buf_len; + data_key_init(c, &bu->key, inode->i_ino, + page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT); + err = ubifs_do_bulk_read(c, bu, page); + + if (!allocated) + mutex_unlock(&c->bu_mutex); + else + kfree(bu); + +out_unlock: + mutex_unlock(&ui->ui_mutex); + return err; +} + +static int ubifs_readpage(struct file *file, struct page *page) +{ + if (ubifs_bulk_read(page)) + return 0; + do_readpage(page); + unlock_page(page); + return 0; +} + +static int do_writepage(struct page *page, int len) +{ + int err = 0, i, blen; + unsigned int block; + void *addr; + union ubifs_key key; + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + +#ifdef UBIFS_DEBUG + struct ubifs_inode *ui = ubifs_inode(inode); + spin_lock(&ui->ui_lock); + ubifs_assert(c, page->index <= ui->synced_i_size >> PAGE_SHIFT); + spin_unlock(&ui->ui_lock); +#endif + + /* Update radix tree tags */ + set_page_writeback(page); + + addr = kmap(page); + block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT; + i = 0; + while (len) { + blen = min_t(int, len, UBIFS_BLOCK_SIZE); + data_key_init(c, &key, inode->i_ino, block); + err = ubifs_jnl_write_data(c, inode, &key, addr, blen); + if (err) + break; + if (++i >= UBIFS_BLOCKS_PER_PAGE) + break; + block += 1; + addr += blen; + len -= blen; + } + if (err) { + SetPageError(page); + ubifs_err(c, "cannot write page %lu of inode %lu, error %d", + page->index, inode->i_ino, err); + ubifs_ro_mode(c, err); + } + + ubifs_assert(c, PagePrivate(page)); + if (PageChecked(page)) + release_new_page_budget(c); + else + release_existing_page_budget(c); + + atomic_long_dec(&c->dirty_pg_cnt); + detach_page_private(page); + ClearPageChecked(page); + + kunmap(page); + unlock_page(page); + end_page_writeback(page); + return err; +} + +/* + * When writing-back dirty inodes, VFS first writes-back pages belonging to the + * inode, then the inode itself. For UBIFS this may cause a problem. Consider a + * situation when a we have an inode with size 0, then a megabyte of data is + * appended to the inode, then write-back starts and flushes some amount of the + * dirty pages, the journal becomes full, commit happens and finishes, and then + * an unclean reboot happens. When the file system is mounted next time, the + * inode size would still be 0, but there would be many pages which are beyond + * the inode size, they would be indexed and consume flash space. Because the + * journal has been committed, the replay would not be able to detect this + * situation and correct the inode size. This means UBIFS would have to scan + * whole index and correct all inode sizes, which is long an unacceptable. + * + * To prevent situations like this, UBIFS writes pages back only if they are + * within the last synchronized inode size, i.e. the size which has been + * written to the flash media last time. Otherwise, UBIFS forces inode + * write-back, thus making sure the on-flash inode contains current inode size, + * and then keeps writing pages back. + * + * Some locking issues explanation. 'ubifs_writepage()' first is called with + * the page locked, and it locks @ui_mutex. However, write-back does take inode + * @i_mutex, which means other VFS operations may be run on this inode at the + * same time. And the problematic one is truncation to smaller size, from where + * we have to call 'truncate_setsize()', which first changes @inode->i_size, + * then drops the truncated pages. And while dropping the pages, it takes the + * page lock. This means that 'do_truncation()' cannot call 'truncate_setsize()' + * with @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'. + * This means that @inode->i_size is changed while @ui_mutex is unlocked. + * + * XXX(truncate): with the new truncate sequence this is not true anymore, + * and the calls to truncate_setsize can be move around freely. They should + * be moved to the very end of the truncate sequence. + * + * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond + * inode size. How do we do this if @inode->i_size may became smaller while we + * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the + * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size + * internally and updates it under @ui_mutex. + * + * Q: why we do not worry that if we race with truncation, we may end up with a + * situation when the inode is truncated while we are in the middle of + * 'do_writepage()', so we do write beyond inode size? + * A: If we are in the middle of 'do_writepage()', truncation would be locked + * on the page lock and it would not write the truncated inode node to the + * journal before we have finished. + */ +static int ubifs_writepage(struct page *page, struct writeback_control *wbc) +{ + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_inode *ui = ubifs_inode(inode); + loff_t i_size = i_size_read(inode), synced_i_size; + pgoff_t end_index = i_size >> PAGE_SHIFT; + int err, len = i_size & (PAGE_SIZE - 1); + void *kaddr; + + dbg_gen("ino %lu, pg %lu, pg flags %#lx", + inode->i_ino, page->index, page->flags); + ubifs_assert(c, PagePrivate(page)); + + /* Is the page fully outside @i_size? (truncate in progress) */ + if (page->index > end_index || (page->index == end_index && !len)) { + err = 0; + goto out_unlock; + } + + spin_lock(&ui->ui_lock); + synced_i_size = ui->synced_i_size; + spin_unlock(&ui->ui_lock); + + /* Is the page fully inside @i_size? */ + if (page->index < end_index) { + if (page->index >= synced_i_size >> PAGE_SHIFT) { + err = inode->i_sb->s_op->write_inode(inode, NULL); + if (err) + goto out_redirty; + /* + * The inode has been written, but the write-buffer has + * not been synchronized, so in case of an unclean + * reboot we may end up with some pages beyond inode + * size, but they would be in the journal (because + * commit flushes write buffers) and recovery would deal + * with this. + */ + } + return do_writepage(page, PAGE_SIZE); + } + + /* + * The page straddles @i_size. It must be zeroed out on each and every + * writepage invocation because it may be mmapped. "A file is mapped + * in multiples of the page size. For a file that is not a multiple of + * the page size, the remaining memory is zeroed when mapped, and + * writes to that region are not written out to the file." + */ + kaddr = kmap_atomic(page); + memset(kaddr + len, 0, PAGE_SIZE - len); + flush_dcache_page(page); + kunmap_atomic(kaddr); + + if (i_size > synced_i_size) { + err = inode->i_sb->s_op->write_inode(inode, NULL); + if (err) + goto out_redirty; + } + + return do_writepage(page, len); +out_redirty: + /* + * redirty_page_for_writepage() won't call ubifs_dirty_inode() because + * it passes I_DIRTY_PAGES flag while calling __mark_inode_dirty(), so + * there is no need to do space budget for dirty inode. + */ + redirty_page_for_writepage(wbc, page); +out_unlock: + unlock_page(page); + return err; +} + +/** + * do_attr_changes - change inode attributes. + * @inode: inode to change attributes for + * @attr: describes attributes to change + */ +static void do_attr_changes(struct inode *inode, const struct iattr *attr) +{ + if (attr->ia_valid & ATTR_UID) + inode->i_uid = attr->ia_uid; + if (attr->ia_valid & ATTR_GID) + inode->i_gid = attr->ia_gid; + if (attr->ia_valid & ATTR_ATIME) + inode->i_atime = attr->ia_atime; + if (attr->ia_valid & ATTR_MTIME) + inode->i_mtime = attr->ia_mtime; + if (attr->ia_valid & ATTR_CTIME) + inode->i_ctime = attr->ia_ctime; + if (attr->ia_valid & ATTR_MODE) { + umode_t mode = attr->ia_mode; + + if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) + mode &= ~S_ISGID; + inode->i_mode = mode; + } +} + +/** + * do_truncation - truncate an inode. + * @c: UBIFS file-system description object + * @inode: inode to truncate + * @attr: inode attribute changes description + * + * This function implements VFS '->setattr()' call when the inode is truncated + * to a smaller size. Returns zero in case of success and a negative error code + * in case of failure. + */ +static int do_truncation(struct ubifs_info *c, struct inode *inode, + const struct iattr *attr) +{ + int err; + struct ubifs_budget_req req; + loff_t old_size = inode->i_size, new_size = attr->ia_size; + int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1; + struct ubifs_inode *ui = ubifs_inode(inode); + + dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size); + memset(&req, 0, sizeof(struct ubifs_budget_req)); + + /* + * If this is truncation to a smaller size, and we do not truncate on a + * block boundary, budget for changing one data block, because the last + * block will be re-written. + */ + if (new_size & (UBIFS_BLOCK_SIZE - 1)) + req.dirtied_page = 1; + + req.dirtied_ino = 1; + /* A funny way to budget for truncation node */ + req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ; + err = ubifs_budget_space(c, &req); + if (err) { + /* + * Treat truncations to zero as deletion and always allow them, + * just like we do for '->unlink()'. + */ + if (new_size || err != -ENOSPC) + return err; + budgeted = 0; + } + + truncate_setsize(inode, new_size); + + if (offset) { + pgoff_t index = new_size >> PAGE_SHIFT; + struct page *page; + + page = find_lock_page(inode->i_mapping, index); + if (page) { + if (PageDirty(page)) { + /* + * 'ubifs_jnl_truncate()' will try to truncate + * the last data node, but it contains + * out-of-date data because the page is dirty. + * Write the page now, so that + * 'ubifs_jnl_truncate()' will see an already + * truncated (and up to date) data node. + */ + ubifs_assert(c, PagePrivate(page)); + + clear_page_dirty_for_io(page); + if (UBIFS_BLOCKS_PER_PAGE_SHIFT) + offset = new_size & + (PAGE_SIZE - 1); + err = do_writepage(page, offset); + put_page(page); + if (err) + goto out_budg; + /* + * We could now tell 'ubifs_jnl_truncate()' not + * to read the last block. + */ + } else { + /* + * We could 'kmap()' the page and pass the data + * to 'ubifs_jnl_truncate()' to save it from + * having to read it. + */ + unlock_page(page); + put_page(page); + } + } + } + + mutex_lock(&ui->ui_mutex); + ui->ui_size = inode->i_size; + /* Truncation changes inode [mc]time */ + inode->i_mtime = inode->i_ctime = current_time(inode); + /* Other attributes may be changed at the same time as well */ + do_attr_changes(inode, attr); + err = ubifs_jnl_truncate(c, inode, old_size, new_size); + mutex_unlock(&ui->ui_mutex); + +out_budg: + if (budgeted) + ubifs_release_budget(c, &req); + else { + c->bi.nospace = c->bi.nospace_rp = 0; + smp_wmb(); + } + return err; +} + +/** + * do_setattr - change inode attributes. + * @c: UBIFS file-system description object + * @inode: inode to change attributes for + * @attr: inode attribute changes description + * + * This function implements VFS '->setattr()' call for all cases except + * truncations to smaller size. Returns zero in case of success and a negative + * error code in case of failure. + */ +static int do_setattr(struct ubifs_info *c, struct inode *inode, + const struct iattr *attr) +{ + int err, release; + loff_t new_size = attr->ia_size; + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_budget_req req = { .dirtied_ino = 1, + .dirtied_ino_d = ALIGN(ui->data_len, 8) }; + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + if (attr->ia_valid & ATTR_SIZE) { + dbg_gen("size %lld -> %lld", inode->i_size, new_size); + truncate_setsize(inode, new_size); + } + + mutex_lock(&ui->ui_mutex); + if (attr->ia_valid & ATTR_SIZE) { + /* Truncation changes inode [mc]time */ + inode->i_mtime = inode->i_ctime = current_time(inode); + /* 'truncate_setsize()' changed @i_size, update @ui_size */ + ui->ui_size = inode->i_size; + } + + do_attr_changes(inode, attr); + + release = ui->dirty; + if (attr->ia_valid & ATTR_SIZE) + /* + * Inode length changed, so we have to make sure + * @I_DIRTY_DATASYNC is set. + */ + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); + else + mark_inode_dirty_sync(inode); + mutex_unlock(&ui->ui_mutex); + + if (release) + ubifs_release_budget(c, &req); + if (IS_SYNC(inode)) + err = inode->i_sb->s_op->write_inode(inode, NULL); + return err; +} + +int ubifs_setattr(struct dentry *dentry, struct iattr *attr) +{ + int err; + struct inode *inode = d_inode(dentry); + struct ubifs_info *c = inode->i_sb->s_fs_info; + + dbg_gen("ino %lu, mode %#x, ia_valid %#x", + inode->i_ino, inode->i_mode, attr->ia_valid); + err = setattr_prepare(dentry, attr); + if (err) + return err; + + err = dbg_check_synced_i_size(c, inode); + if (err) + return err; + + err = fscrypt_prepare_setattr(dentry, attr); + if (err) + return err; + + if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size) + /* Truncation to a smaller size */ + err = do_truncation(c, inode, attr); + else + err = do_setattr(c, inode, attr); + + return err; +} + +static void ubifs_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + + ubifs_assert(c, PagePrivate(page)); + if (offset || length < PAGE_SIZE) + /* Partial page remains dirty */ + return; + + if (PageChecked(page)) + release_new_page_budget(c); + else + release_existing_page_budget(c); + + atomic_long_dec(&c->dirty_pg_cnt); + detach_page_private(page); + ClearPageChecked(page); +} + +int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct inode *inode = file->f_mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + int err; + + dbg_gen("syncing inode %lu", inode->i_ino); + + if (c->ro_mount) + /* + * For some really strange reasons VFS does not filter out + * 'fsync()' for R/O mounted file-systems as per 2.6.39. + */ + return 0; + + err = file_write_and_wait_range(file, start, end); + if (err) + return err; + inode_lock(inode); + + /* Synchronize the inode unless this is a 'datasync()' call. */ + if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) { + err = inode->i_sb->s_op->write_inode(inode, NULL); + if (err) + goto out; + } + + /* + * Nodes related to this inode may still sit in a write-buffer. Flush + * them. + */ + err = ubifs_sync_wbufs_by_inode(c, inode); +out: + inode_unlock(inode); + return err; +} + +/** + * mctime_update_needed - check if mtime or ctime update is needed. + * @inode: the inode to do the check for + * @now: current time + * + * This helper function checks if the inode mtime/ctime should be updated or + * not. If current values of the time-stamps are within the UBIFS inode time + * granularity, they are not updated. This is an optimization. + */ +static inline int mctime_update_needed(const struct inode *inode, + const struct timespec64 *now) +{ + if (!timespec64_equal(&inode->i_mtime, now) || + !timespec64_equal(&inode->i_ctime, now)) + return 1; + return 0; +} + +/** + * ubifs_update_time - update time of inode. + * @inode: inode to update + * + * This function updates time of the inode. + */ +int ubifs_update_time(struct inode *inode, struct timespec64 *time, + int flags) +{ + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_budget_req req = { .dirtied_ino = 1, + .dirtied_ino_d = ALIGN(ui->data_len, 8) }; + int err, release; + + if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) + return generic_update_time(inode, time, flags); + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + mutex_lock(&ui->ui_mutex); + if (flags & S_ATIME) + inode->i_atime = *time; + if (flags & S_CTIME) + inode->i_ctime = *time; + if (flags & S_MTIME) + inode->i_mtime = *time; + + release = ui->dirty; + __mark_inode_dirty(inode, I_DIRTY_SYNC); + mutex_unlock(&ui->ui_mutex); + if (release) + ubifs_release_budget(c, &req); + return 0; +} + +/** + * update_mctime - update mtime and ctime of an inode. + * @inode: inode to update + * + * This function updates mtime and ctime of the inode if it is not equivalent to + * current time. Returns zero in case of success and a negative error code in + * case of failure. + */ +static int update_mctime(struct inode *inode) +{ + struct timespec64 now = current_time(inode); + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_info *c = inode->i_sb->s_fs_info; + + if (mctime_update_needed(inode, &now)) { + int err, release; + struct ubifs_budget_req req = { .dirtied_ino = 1, + .dirtied_ino_d = ALIGN(ui->data_len, 8) }; + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + mutex_lock(&ui->ui_mutex); + inode->i_mtime = inode->i_ctime = current_time(inode); + release = ui->dirty; + mark_inode_dirty_sync(inode); + mutex_unlock(&ui->ui_mutex); + if (release) + ubifs_release_budget(c, &req); + } + + return 0; +} + +static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + int err = update_mctime(file_inode(iocb->ki_filp)); + if (err) + return err; + + return generic_file_write_iter(iocb, from); +} + +static int ubifs_set_page_dirty(struct page *page) +{ + int ret; + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + + ret = __set_page_dirty_nobuffers(page); + /* + * An attempt to dirty a page without budgeting for it - should not + * happen. + */ + ubifs_assert(c, ret == 0); + return ret; +} + +#ifdef CONFIG_MIGRATION +static int ubifs_migrate_page(struct address_space *mapping, + struct page *newpage, struct page *page, enum migrate_mode mode) +{ + int rc; + + rc = migrate_page_move_mapping(mapping, newpage, page, 0); + if (rc != MIGRATEPAGE_SUCCESS) + return rc; + + if (PagePrivate(page)) { + detach_page_private(page); + attach_page_private(newpage, (void *)1); + } + + if (mode != MIGRATE_SYNC_NO_COPY) + migrate_page_copy(newpage, page); + else + migrate_page_states(newpage, page); + return MIGRATEPAGE_SUCCESS; +} +#endif + +static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags) +{ + struct inode *inode = page->mapping->host; + struct ubifs_info *c = inode->i_sb->s_fs_info; + + /* + * An attempt to release a dirty page without budgeting for it - should + * not happen. + */ + if (PageWriteback(page)) + return 0; + ubifs_assert(c, PagePrivate(page)); + ubifs_assert(c, 0); + detach_page_private(page); + ClearPageChecked(page); + return 1; +} + +/* + * mmap()d file has taken write protection fault and is being made writable. + * UBIFS must ensure page is budgeted for. + */ +static vm_fault_t ubifs_vm_page_mkwrite(struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct inode *inode = file_inode(vmf->vma->vm_file); + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct timespec64 now = current_time(inode); + struct ubifs_budget_req req = { .new_page = 1 }; + int err, update_time; + + dbg_gen("ino %lu, pg %lu, i_size %lld", inode->i_ino, page->index, + i_size_read(inode)); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + + if (unlikely(c->ro_error)) + return VM_FAULT_SIGBUS; /* -EROFS */ + + /* + * We have not locked @page so far so we may budget for changing the + * page. Note, we cannot do this after we locked the page, because + * budgeting may cause write-back which would cause deadlock. + * + * At the moment we do not know whether the page is dirty or not, so we + * assume that it is not and budget for a new page. We could look at + * the @PG_private flag and figure this out, but we may race with write + * back and the page state may change by the time we lock it, so this + * would need additional care. We do not bother with this at the + * moment, although it might be good idea to do. Instead, we allocate + * budget for a new page and amend it later on if the page was in fact + * dirty. + * + * The budgeting-related logic of this function is similar to what we + * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there + * for more comments. + */ + update_time = mctime_update_needed(inode, &now); + if (update_time) + /* + * We have to change inode time stamp which requires extra + * budgeting. + */ + req.dirtied_ino = 1; + + err = ubifs_budget_space(c, &req); + if (unlikely(err)) { + if (err == -ENOSPC) + ubifs_warn(c, "out of space for mmapped file (inode number %lu)", + inode->i_ino); + return VM_FAULT_SIGBUS; + } + + lock_page(page); + if (unlikely(page->mapping != inode->i_mapping || + page_offset(page) > i_size_read(inode))) { + /* Page got truncated out from underneath us */ + goto sigbus; + } + + if (PagePrivate(page)) + release_new_page_budget(c); + else { + if (!PageChecked(page)) + ubifs_convert_page_budget(c); + attach_page_private(page, (void *)1); + atomic_long_inc(&c->dirty_pg_cnt); + __set_page_dirty_nobuffers(page); + } + + if (update_time) { + int release; + struct ubifs_inode *ui = ubifs_inode(inode); + + mutex_lock(&ui->ui_mutex); + inode->i_mtime = inode->i_ctime = current_time(inode); + release = ui->dirty; + mark_inode_dirty_sync(inode); + mutex_unlock(&ui->ui_mutex); + if (release) + ubifs_release_dirty_inode_budget(c, ui); + } + + wait_for_stable_page(page); + return VM_FAULT_LOCKED; + +sigbus: + unlock_page(page); + ubifs_release_budget(c, &req); + return VM_FAULT_SIGBUS; +} + +static const struct vm_operations_struct ubifs_file_vm_ops = { + .fault = filemap_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = ubifs_vm_page_mkwrite, +}; + +static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma) +{ + int err; + + err = generic_file_mmap(file, vma); + if (err) + return err; + vma->vm_ops = &ubifs_file_vm_ops; + + if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) + file_accessed(file); + + return 0; +} + +static const char *ubifs_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + struct ubifs_inode *ui = ubifs_inode(inode); + + if (!IS_ENCRYPTED(inode)) + return ui->data; + + if (!dentry) + return ERR_PTR(-ECHILD); + + return fscrypt_get_symlink(inode, ui->data, ui->data_len, done); +} + +static int ubifs_symlink_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + ubifs_getattr(path, stat, request_mask, query_flags); + + if (IS_ENCRYPTED(d_inode(path->dentry))) + return fscrypt_symlink_getattr(path, stat); + return 0; +} + +const struct address_space_operations ubifs_file_address_operations = { + .readpage = ubifs_readpage, + .writepage = ubifs_writepage, + .write_begin = ubifs_write_begin, + .write_end = ubifs_write_end, + .invalidatepage = ubifs_invalidatepage, + .set_page_dirty = ubifs_set_page_dirty, +#ifdef CONFIG_MIGRATION + .migratepage = ubifs_migrate_page, +#endif + .releasepage = ubifs_releasepage, +}; + +const struct inode_operations ubifs_file_inode_operations = { + .setattr = ubifs_setattr, + .getattr = ubifs_getattr, +#ifdef CONFIG_UBIFS_FS_XATTR + .listxattr = ubifs_listxattr, +#endif + .update_time = ubifs_update_time, +}; + +const struct inode_operations ubifs_symlink_inode_operations = { + .get_link = ubifs_get_link, + .setattr = ubifs_setattr, + .getattr = ubifs_symlink_getattr, +#ifdef CONFIG_UBIFS_FS_XATTR + .listxattr = ubifs_listxattr, +#endif + .update_time = ubifs_update_time, +}; + +const struct file_operations ubifs_file_operations = { + .llseek = generic_file_llseek, + .read_iter = generic_file_read_iter, + .write_iter = ubifs_write_iter, + .mmap = ubifs_file_mmap, + .fsync = ubifs_fsync, + .unlocked_ioctl = ubifs_ioctl, + .splice_read = generic_file_splice_read, + .splice_write = iter_file_splice_write, + .open = fscrypt_file_open, +#ifdef CONFIG_COMPAT + .compat_ioctl = ubifs_compat_ioctl, +#endif +}; diff --git a/fs/ubifs/find.c b/fs/ubifs/find.c new file mode 100644 index 000000000..873e6e1c9 --- /dev/null +++ b/fs/ubifs/find.c @@ -0,0 +1,963 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file contains functions for finding LEBs for various purposes e.g. + * garbage collection. In general, lprops category heaps and lists are used + * for fast access, falling back on scanning the LPT as a last resort. + */ + +#include <linux/sort.h> +#include "ubifs.h" + +/** + * struct scan_data - data provided to scan callback functions + * @min_space: minimum number of bytes for which to scan + * @pick_free: whether it is OK to scan for empty LEBs + * @lnum: LEB number found is returned here + * @exclude_index: whether to exclude index LEBs + */ +struct scan_data { + int min_space; + int pick_free; + int lnum; + int exclude_index; +}; + +/** + * valuable - determine whether LEB properties are valuable. + * @c: the UBIFS file-system description object + * @lprops: LEB properties + * + * This function return %1 if the LEB properties should be added to the LEB + * properties tree in memory. Otherwise %0 is returned. + */ +static int valuable(struct ubifs_info *c, const struct ubifs_lprops *lprops) +{ + int n, cat = lprops->flags & LPROPS_CAT_MASK; + struct ubifs_lpt_heap *heap; + + switch (cat) { + case LPROPS_DIRTY: + case LPROPS_DIRTY_IDX: + case LPROPS_FREE: + heap = &c->lpt_heap[cat - 1]; + if (heap->cnt < heap->max_cnt) + return 1; + if (lprops->free + lprops->dirty >= c->dark_wm) + return 1; + return 0; + case LPROPS_EMPTY: + n = c->lst.empty_lebs + c->freeable_cnt - + c->lst.taken_empty_lebs; + if (n < c->lsave_cnt) + return 1; + return 0; + case LPROPS_FREEABLE: + return 1; + case LPROPS_FRDI_IDX: + return 1; + } + return 0; +} + +/** + * scan_for_dirty_cb - dirty space scan callback. + * @c: the UBIFS file-system description object + * @lprops: LEB properties to scan + * @in_tree: whether the LEB properties are in main memory + * @data: information passed to and from the caller of the scan + * + * This function returns a code that indicates whether the scan should continue + * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree + * in main memory (%LPT_SCAN_ADD), or whether the scan should stop + * (%LPT_SCAN_STOP). + */ +static int scan_for_dirty_cb(struct ubifs_info *c, + const struct ubifs_lprops *lprops, int in_tree, + struct scan_data *data) +{ + int ret = LPT_SCAN_CONTINUE; + + /* Exclude LEBs that are currently in use */ + if (lprops->flags & LPROPS_TAKEN) + return LPT_SCAN_CONTINUE; + /* Determine whether to add these LEB properties to the tree */ + if (!in_tree && valuable(c, lprops)) + ret |= LPT_SCAN_ADD; + /* Exclude LEBs with too little space */ + if (lprops->free + lprops->dirty < data->min_space) + return ret; + /* If specified, exclude index LEBs */ + if (data->exclude_index && lprops->flags & LPROPS_INDEX) + return ret; + /* If specified, exclude empty or freeable LEBs */ + if (lprops->free + lprops->dirty == c->leb_size) { + if (!data->pick_free) + return ret; + /* Exclude LEBs with too little dirty space (unless it is empty) */ + } else if (lprops->dirty < c->dead_wm) + return ret; + /* Finally we found space */ + data->lnum = lprops->lnum; + return LPT_SCAN_ADD | LPT_SCAN_STOP; +} + +/** + * scan_for_dirty - find a data LEB with free space. + * @c: the UBIFS file-system description object + * @min_space: minimum amount free plus dirty space the returned LEB has to + * have + * @pick_free: if it is OK to return a free or freeable LEB + * @exclude_index: whether to exclude index LEBs + * + * This function returns a pointer to the LEB properties found or a negative + * error code. + */ +static const struct ubifs_lprops *scan_for_dirty(struct ubifs_info *c, + int min_space, int pick_free, + int exclude_index) +{ + const struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + struct scan_data data; + int err, i; + + /* There may be an LEB with enough dirty space on the free heap */ + heap = &c->lpt_heap[LPROPS_FREE - 1]; + for (i = 0; i < heap->cnt; i++) { + lprops = heap->arr[i]; + if (lprops->free + lprops->dirty < min_space) + continue; + if (lprops->dirty < c->dead_wm) + continue; + return lprops; + } + /* + * A LEB may have fallen off of the bottom of the dirty heap, and ended + * up as uncategorized even though it has enough dirty space for us now, + * so check the uncategorized list. N.B. neither empty nor freeable LEBs + * can end up as uncategorized because they are kept on lists not + * finite-sized heaps. + */ + list_for_each_entry(lprops, &c->uncat_list, list) { + if (lprops->flags & LPROPS_TAKEN) + continue; + if (lprops->free + lprops->dirty < min_space) + continue; + if (exclude_index && (lprops->flags & LPROPS_INDEX)) + continue; + if (lprops->dirty < c->dead_wm) + continue; + return lprops; + } + /* We have looked everywhere in main memory, now scan the flash */ + if (c->pnodes_have >= c->pnode_cnt) + /* All pnodes are in memory, so skip scan */ + return ERR_PTR(-ENOSPC); + data.min_space = min_space; + data.pick_free = pick_free; + data.lnum = -1; + data.exclude_index = exclude_index; + err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum, + (ubifs_lpt_scan_callback)scan_for_dirty_cb, + &data); + if (err) + return ERR_PTR(err); + ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt); + c->lscan_lnum = data.lnum; + lprops = ubifs_lpt_lookup_dirty(c, data.lnum); + if (IS_ERR(lprops)) + return lprops; + ubifs_assert(c, lprops->lnum == data.lnum); + ubifs_assert(c, lprops->free + lprops->dirty >= min_space); + ubifs_assert(c, lprops->dirty >= c->dead_wm || + (pick_free && + lprops->free + lprops->dirty == c->leb_size)); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, !exclude_index || !(lprops->flags & LPROPS_INDEX)); + return lprops; +} + +/** + * ubifs_find_dirty_leb - find a dirty LEB for the Garbage Collector. + * @c: the UBIFS file-system description object + * @ret_lp: LEB properties are returned here on exit + * @min_space: minimum amount free plus dirty space the returned LEB has to + * have + * @pick_free: controls whether it is OK to pick empty or index LEBs + * + * This function tries to find a dirty logical eraseblock which has at least + * @min_space free and dirty space. It prefers to take an LEB from the dirty or + * dirty index heap, and it falls-back to LPT scanning if the heaps are empty + * or do not have an LEB which satisfies the @min_space criteria. + * + * Note, LEBs which have less than dead watermark of free + dirty space are + * never picked by this function. + * + * The additional @pick_free argument controls if this function has to return a + * free or freeable LEB if one is present. For example, GC must to set it to %1, + * when called from the journal space reservation function, because the + * appearance of free space may coincide with the loss of enough dirty space + * for GC to succeed anyway. + * + * In contrast, if the Garbage Collector is called from budgeting, it should + * just make free space, not return LEBs which are already free or freeable. + * + * In addition @pick_free is set to %2 by the recovery process in order to + * recover gc_lnum in which case an index LEB must not be returned. + * + * This function returns zero and the LEB properties of found dirty LEB in case + * of success, %-ENOSPC if no dirty LEB was found and a negative error code in + * case of other failures. The returned LEB is marked as "taken". + */ +int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp, + int min_space, int pick_free) +{ + int err = 0, sum, exclude_index = pick_free == 2 ? 1 : 0; + const struct ubifs_lprops *lp = NULL, *idx_lp = NULL; + struct ubifs_lpt_heap *heap, *idx_heap; + + ubifs_get_lprops(c); + + if (pick_free) { + int lebs, rsvd_idx_lebs = 0; + + spin_lock(&c->space_lock); + lebs = c->lst.empty_lebs + c->idx_gc_cnt; + lebs += c->freeable_cnt - c->lst.taken_empty_lebs; + + /* + * Note, the index may consume more LEBs than have been reserved + * for it. It is OK because it might be consolidated by GC. + * But if the index takes fewer LEBs than it is reserved for it, + * this function must avoid picking those reserved LEBs. + */ + if (c->bi.min_idx_lebs >= c->lst.idx_lebs) { + rsvd_idx_lebs = c->bi.min_idx_lebs - c->lst.idx_lebs; + exclude_index = 1; + } + spin_unlock(&c->space_lock); + + /* Check if there are enough free LEBs for the index */ + if (rsvd_idx_lebs < lebs) { + /* OK, try to find an empty LEB */ + lp = ubifs_fast_find_empty(c); + if (lp) + goto found; + + /* Or a freeable LEB */ + lp = ubifs_fast_find_freeable(c); + if (lp) + goto found; + } else + /* + * We cannot pick free/freeable LEBs in the below code. + */ + pick_free = 0; + } else { + spin_lock(&c->space_lock); + exclude_index = (c->bi.min_idx_lebs >= c->lst.idx_lebs); + spin_unlock(&c->space_lock); + } + + /* Look on the dirty and dirty index heaps */ + heap = &c->lpt_heap[LPROPS_DIRTY - 1]; + idx_heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; + + if (idx_heap->cnt && !exclude_index) { + idx_lp = idx_heap->arr[0]; + sum = idx_lp->free + idx_lp->dirty; + /* + * Since we reserve thrice as much space for the index than it + * actually takes, it does not make sense to pick indexing LEBs + * with less than, say, half LEB of dirty space. May be half is + * not the optimal boundary - this should be tested and + * checked. This boundary should determine how much we use + * in-the-gaps to consolidate the index comparing to how much + * we use garbage collector to consolidate it. The "half" + * criteria just feels to be fine. + */ + if (sum < min_space || sum < c->half_leb_size) + idx_lp = NULL; + } + + if (heap->cnt) { + lp = heap->arr[0]; + if (lp->dirty + lp->free < min_space) + lp = NULL; + } + + /* Pick the LEB with most space */ + if (idx_lp && lp) { + if (idx_lp->free + idx_lp->dirty >= lp->free + lp->dirty) + lp = idx_lp; + } else if (idx_lp && !lp) + lp = idx_lp; + + if (lp) { + ubifs_assert(c, lp->free + lp->dirty >= c->dead_wm); + goto found; + } + + /* Did not find a dirty LEB on the dirty heaps, have to scan */ + dbg_find("scanning LPT for a dirty LEB"); + lp = scan_for_dirty(c, min_space, pick_free, exclude_index); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + ubifs_assert(c, lp->dirty >= c->dead_wm || + (pick_free && lp->free + lp->dirty == c->leb_size)); + +found: + dbg_find("found LEB %d, free %d, dirty %d, flags %#x", + lp->lnum, lp->free, lp->dirty, lp->flags); + + lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC, + lp->flags | LPROPS_TAKEN, 0); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + memcpy(ret_lp, lp, sizeof(struct ubifs_lprops)); + +out: + ubifs_release_lprops(c); + return err; +} + +/** + * scan_for_free_cb - free space scan callback. + * @c: the UBIFS file-system description object + * @lprops: LEB properties to scan + * @in_tree: whether the LEB properties are in main memory + * @data: information passed to and from the caller of the scan + * + * This function returns a code that indicates whether the scan should continue + * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree + * in main memory (%LPT_SCAN_ADD), or whether the scan should stop + * (%LPT_SCAN_STOP). + */ +static int scan_for_free_cb(struct ubifs_info *c, + const struct ubifs_lprops *lprops, int in_tree, + struct scan_data *data) +{ + int ret = LPT_SCAN_CONTINUE; + + /* Exclude LEBs that are currently in use */ + if (lprops->flags & LPROPS_TAKEN) + return LPT_SCAN_CONTINUE; + /* Determine whether to add these LEB properties to the tree */ + if (!in_tree && valuable(c, lprops)) + ret |= LPT_SCAN_ADD; + /* Exclude index LEBs */ + if (lprops->flags & LPROPS_INDEX) + return ret; + /* Exclude LEBs with too little space */ + if (lprops->free < data->min_space) + return ret; + /* If specified, exclude empty LEBs */ + if (!data->pick_free && lprops->free == c->leb_size) + return ret; + /* + * LEBs that have only free and dirty space must not be allocated + * because they may have been unmapped already or they may have data + * that is obsolete only because of nodes that are still sitting in a + * wbuf. + */ + if (lprops->free + lprops->dirty == c->leb_size && lprops->dirty > 0) + return ret; + /* Finally we found space */ + data->lnum = lprops->lnum; + return LPT_SCAN_ADD | LPT_SCAN_STOP; +} + +/** + * do_find_free_space - find a data LEB with free space. + * @c: the UBIFS file-system description object + * @min_space: minimum amount of free space required + * @pick_free: whether it is OK to scan for empty LEBs + * @squeeze: whether to try to find space in a non-empty LEB first + * + * This function returns a pointer to the LEB properties found or a negative + * error code. + */ +static +const struct ubifs_lprops *do_find_free_space(struct ubifs_info *c, + int min_space, int pick_free, + int squeeze) +{ + const struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + struct scan_data data; + int err, i; + + if (squeeze) { + lprops = ubifs_fast_find_free(c); + if (lprops && lprops->free >= min_space) + return lprops; + } + if (pick_free) { + lprops = ubifs_fast_find_empty(c); + if (lprops) + return lprops; + } + if (!squeeze) { + lprops = ubifs_fast_find_free(c); + if (lprops && lprops->free >= min_space) + return lprops; + } + /* There may be an LEB with enough free space on the dirty heap */ + heap = &c->lpt_heap[LPROPS_DIRTY - 1]; + for (i = 0; i < heap->cnt; i++) { + lprops = heap->arr[i]; + if (lprops->free >= min_space) + return lprops; + } + /* + * A LEB may have fallen off of the bottom of the free heap, and ended + * up as uncategorized even though it has enough free space for us now, + * so check the uncategorized list. N.B. neither empty nor freeable LEBs + * can end up as uncategorized because they are kept on lists not + * finite-sized heaps. + */ + list_for_each_entry(lprops, &c->uncat_list, list) { + if (lprops->flags & LPROPS_TAKEN) + continue; + if (lprops->flags & LPROPS_INDEX) + continue; + if (lprops->free >= min_space) + return lprops; + } + /* We have looked everywhere in main memory, now scan the flash */ + if (c->pnodes_have >= c->pnode_cnt) + /* All pnodes are in memory, so skip scan */ + return ERR_PTR(-ENOSPC); + data.min_space = min_space; + data.pick_free = pick_free; + data.lnum = -1; + err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum, + (ubifs_lpt_scan_callback)scan_for_free_cb, + &data); + if (err) + return ERR_PTR(err); + ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt); + c->lscan_lnum = data.lnum; + lprops = ubifs_lpt_lookup_dirty(c, data.lnum); + if (IS_ERR(lprops)) + return lprops; + ubifs_assert(c, lprops->lnum == data.lnum); + ubifs_assert(c, lprops->free >= min_space); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lprops->flags & LPROPS_INDEX)); + return lprops; +} + +/** + * ubifs_find_free_space - find a data LEB with free space. + * @c: the UBIFS file-system description object + * @min_space: minimum amount of required free space + * @offs: contains offset of where free space starts on exit + * @squeeze: whether to try to find space in a non-empty LEB first + * + * This function looks for an LEB with at least @min_space bytes of free space. + * It tries to find an empty LEB if possible. If no empty LEBs are available, + * this function searches for a non-empty data LEB. The returned LEB is marked + * as "taken". + * + * This function returns found LEB number in case of success, %-ENOSPC if it + * failed to find a LEB with @min_space bytes of free space and other a negative + * error codes in case of failure. + */ +int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs, + int squeeze) +{ + const struct ubifs_lprops *lprops; + int lebs, rsvd_idx_lebs, pick_free = 0, err, lnum, flags; + + dbg_find("min_space %d", min_space); + ubifs_get_lprops(c); + + /* Check if there are enough empty LEBs for commit */ + spin_lock(&c->space_lock); + if (c->bi.min_idx_lebs > c->lst.idx_lebs) + rsvd_idx_lebs = c->bi.min_idx_lebs - c->lst.idx_lebs; + else + rsvd_idx_lebs = 0; + lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt - + c->lst.taken_empty_lebs; + if (rsvd_idx_lebs < lebs) + /* + * OK to allocate an empty LEB, but we still don't want to go + * looking for one if there aren't any. + */ + if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) { + pick_free = 1; + /* + * Because we release the space lock, we must account + * for this allocation here. After the LEB properties + * flags have been updated, we subtract one. Note, the + * result of this is that lprops also decreases + * @taken_empty_lebs in 'ubifs_change_lp()', so it is + * off by one for a short period of time which may + * introduce a small disturbance to budgeting + * calculations, but this is harmless because at the + * worst case this would make the budgeting subsystem + * be more pessimistic than needed. + * + * Fundamentally, this is about serialization of the + * budgeting and lprops subsystems. We could make the + * @space_lock a mutex and avoid dropping it before + * calling 'ubifs_change_lp()', but mutex is more + * heavy-weight, and we want budgeting to be as fast as + * possible. + */ + c->lst.taken_empty_lebs += 1; + } + spin_unlock(&c->space_lock); + + lprops = do_find_free_space(c, min_space, pick_free, squeeze); + if (IS_ERR(lprops)) { + err = PTR_ERR(lprops); + goto out; + } + + lnum = lprops->lnum; + flags = lprops->flags | LPROPS_TAKEN; + + lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC, flags, 0); + if (IS_ERR(lprops)) { + err = PTR_ERR(lprops); + goto out; + } + + if (pick_free) { + spin_lock(&c->space_lock); + c->lst.taken_empty_lebs -= 1; + spin_unlock(&c->space_lock); + } + + *offs = c->leb_size - lprops->free; + ubifs_release_lprops(c); + + if (*offs == 0) { + /* + * Ensure that empty LEBs have been unmapped. They may not have + * been, for example, because of an unclean unmount. Also + * LEBs that were freeable LEBs (free + dirty == leb_size) will + * not have been unmapped. + */ + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + + dbg_find("found LEB %d, free %d", lnum, c->leb_size - *offs); + ubifs_assert(c, *offs <= c->leb_size - min_space); + return lnum; + +out: + if (pick_free) { + spin_lock(&c->space_lock); + c->lst.taken_empty_lebs -= 1; + spin_unlock(&c->space_lock); + } + ubifs_release_lprops(c); + return err; +} + +/** + * scan_for_idx_cb - callback used by the scan for a free LEB for the index. + * @c: the UBIFS file-system description object + * @lprops: LEB properties to scan + * @in_tree: whether the LEB properties are in main memory + * @data: information passed to and from the caller of the scan + * + * This function returns a code that indicates whether the scan should continue + * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree + * in main memory (%LPT_SCAN_ADD), or whether the scan should stop + * (%LPT_SCAN_STOP). + */ +static int scan_for_idx_cb(struct ubifs_info *c, + const struct ubifs_lprops *lprops, int in_tree, + struct scan_data *data) +{ + int ret = LPT_SCAN_CONTINUE; + + /* Exclude LEBs that are currently in use */ + if (lprops->flags & LPROPS_TAKEN) + return LPT_SCAN_CONTINUE; + /* Determine whether to add these LEB properties to the tree */ + if (!in_tree && valuable(c, lprops)) + ret |= LPT_SCAN_ADD; + /* Exclude index LEBS */ + if (lprops->flags & LPROPS_INDEX) + return ret; + /* Exclude LEBs that cannot be made empty */ + if (lprops->free + lprops->dirty != c->leb_size) + return ret; + /* + * We are allocating for the index so it is safe to allocate LEBs with + * only free and dirty space, because write buffers are sync'd at commit + * start. + */ + data->lnum = lprops->lnum; + return LPT_SCAN_ADD | LPT_SCAN_STOP; +} + +/** + * scan_for_leb_for_idx - scan for a free LEB for the index. + * @c: the UBIFS file-system description object + */ +static const struct ubifs_lprops *scan_for_leb_for_idx(struct ubifs_info *c) +{ + const struct ubifs_lprops *lprops; + struct scan_data data; + int err; + + data.lnum = -1; + err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum, + (ubifs_lpt_scan_callback)scan_for_idx_cb, + &data); + if (err) + return ERR_PTR(err); + ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt); + c->lscan_lnum = data.lnum; + lprops = ubifs_lpt_lookup_dirty(c, data.lnum); + if (IS_ERR(lprops)) + return lprops; + ubifs_assert(c, lprops->lnum == data.lnum); + ubifs_assert(c, lprops->free + lprops->dirty == c->leb_size); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lprops->flags & LPROPS_INDEX)); + return lprops; +} + +/** + * ubifs_find_free_leb_for_idx - find a free LEB for the index. + * @c: the UBIFS file-system description object + * + * This function looks for a free LEB and returns that LEB number. The returned + * LEB is marked as "taken", "index". + * + * Only empty LEBs are allocated. This is for two reasons. First, the commit + * calculates the number of LEBs to allocate based on the assumption that they + * will be empty. Secondly, free space at the end of an index LEB is not + * guaranteed to be empty because it may have been used by the in-the-gaps + * method prior to an unclean unmount. + * + * If no LEB is found %-ENOSPC is returned. For other failures another negative + * error code is returned. + */ +int ubifs_find_free_leb_for_idx(struct ubifs_info *c) +{ + const struct ubifs_lprops *lprops; + int lnum = -1, err, flags; + + ubifs_get_lprops(c); + + lprops = ubifs_fast_find_empty(c); + if (!lprops) { + lprops = ubifs_fast_find_freeable(c); + if (!lprops) { + /* + * The first condition means the following: go scan the + * LPT if there are uncategorized lprops, which means + * there may be freeable LEBs there (UBIFS does not + * store the information about freeable LEBs in the + * master node). + */ + if (c->in_a_category_cnt != c->main_lebs || + c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) { + ubifs_assert(c, c->freeable_cnt == 0); + lprops = scan_for_leb_for_idx(c); + if (IS_ERR(lprops)) { + err = PTR_ERR(lprops); + goto out; + } + } + } + } + + if (!lprops) { + err = -ENOSPC; + goto out; + } + + lnum = lprops->lnum; + + dbg_find("found LEB %d, free %d, dirty %d, flags %#x", + lnum, lprops->free, lprops->dirty, lprops->flags); + + flags = lprops->flags | LPROPS_TAKEN | LPROPS_INDEX; + lprops = ubifs_change_lp(c, lprops, c->leb_size, 0, flags, 0); + if (IS_ERR(lprops)) { + err = PTR_ERR(lprops); + goto out; + } + + ubifs_release_lprops(c); + + /* + * Ensure that empty LEBs have been unmapped. They may not have been, + * for example, because of an unclean unmount. Also LEBs that were + * freeable LEBs (free + dirty == leb_size) will not have been unmapped. + */ + err = ubifs_leb_unmap(c, lnum); + if (err) { + ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_TAKEN | LPROPS_INDEX, 0); + return err; + } + + return lnum; + +out: + ubifs_release_lprops(c); + return err; +} + +static int cmp_dirty_idx(const struct ubifs_lprops **a, + const struct ubifs_lprops **b) +{ + const struct ubifs_lprops *lpa = *a; + const struct ubifs_lprops *lpb = *b; + + return lpa->dirty + lpa->free - lpb->dirty - lpb->free; +} + +/** + * ubifs_save_dirty_idx_lnums - save an array of the most dirty index LEB nos. + * @c: the UBIFS file-system description object + * + * This function is called each commit to create an array of LEB numbers of + * dirty index LEBs sorted in order of dirty and free space. This is used by + * the in-the-gaps method of TNC commit. + */ +int ubifs_save_dirty_idx_lnums(struct ubifs_info *c) +{ + int i; + + ubifs_get_lprops(c); + /* Copy the LPROPS_DIRTY_IDX heap */ + c->dirty_idx.cnt = c->lpt_heap[LPROPS_DIRTY_IDX - 1].cnt; + memcpy(c->dirty_idx.arr, c->lpt_heap[LPROPS_DIRTY_IDX - 1].arr, + sizeof(void *) * c->dirty_idx.cnt); + /* Sort it so that the dirtiest is now at the end */ + sort(c->dirty_idx.arr, c->dirty_idx.cnt, sizeof(void *), + (int (*)(const void *, const void *))cmp_dirty_idx, NULL); + dbg_find("found %d dirty index LEBs", c->dirty_idx.cnt); + if (c->dirty_idx.cnt) + dbg_find("dirtiest index LEB is %d with dirty %d and free %d", + c->dirty_idx.arr[c->dirty_idx.cnt - 1]->lnum, + c->dirty_idx.arr[c->dirty_idx.cnt - 1]->dirty, + c->dirty_idx.arr[c->dirty_idx.cnt - 1]->free); + /* Replace the lprops pointers with LEB numbers */ + for (i = 0; i < c->dirty_idx.cnt; i++) + c->dirty_idx.arr[i] = (void *)(size_t)c->dirty_idx.arr[i]->lnum; + ubifs_release_lprops(c); + return 0; +} + +/** + * scan_dirty_idx_cb - callback used by the scan for a dirty index LEB. + * @c: the UBIFS file-system description object + * @lprops: LEB properties to scan + * @in_tree: whether the LEB properties are in main memory + * @data: information passed to and from the caller of the scan + * + * This function returns a code that indicates whether the scan should continue + * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree + * in main memory (%LPT_SCAN_ADD), or whether the scan should stop + * (%LPT_SCAN_STOP). + */ +static int scan_dirty_idx_cb(struct ubifs_info *c, + const struct ubifs_lprops *lprops, int in_tree, + struct scan_data *data) +{ + int ret = LPT_SCAN_CONTINUE; + + /* Exclude LEBs that are currently in use */ + if (lprops->flags & LPROPS_TAKEN) + return LPT_SCAN_CONTINUE; + /* Determine whether to add these LEB properties to the tree */ + if (!in_tree && valuable(c, lprops)) + ret |= LPT_SCAN_ADD; + /* Exclude non-index LEBs */ + if (!(lprops->flags & LPROPS_INDEX)) + return ret; + /* Exclude LEBs with too little space */ + if (lprops->free + lprops->dirty < c->min_idx_node_sz) + return ret; + /* Finally we found space */ + data->lnum = lprops->lnum; + return LPT_SCAN_ADD | LPT_SCAN_STOP; +} + +/** + * find_dirty_idx_leb - find a dirty index LEB. + * @c: the UBIFS file-system description object + * + * This function returns LEB number upon success and a negative error code upon + * failure. In particular, -ENOSPC is returned if a dirty index LEB is not + * found. + * + * Note that this function scans the entire LPT but it is called very rarely. + */ +static int find_dirty_idx_leb(struct ubifs_info *c) +{ + const struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + struct scan_data data; + int err, i, ret; + + /* Check all structures in memory first */ + data.lnum = -1; + heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; + for (i = 0; i < heap->cnt; i++) { + lprops = heap->arr[i]; + ret = scan_dirty_idx_cb(c, lprops, 1, &data); + if (ret & LPT_SCAN_STOP) + goto found; + } + list_for_each_entry(lprops, &c->frdi_idx_list, list) { + ret = scan_dirty_idx_cb(c, lprops, 1, &data); + if (ret & LPT_SCAN_STOP) + goto found; + } + list_for_each_entry(lprops, &c->uncat_list, list) { + ret = scan_dirty_idx_cb(c, lprops, 1, &data); + if (ret & LPT_SCAN_STOP) + goto found; + } + if (c->pnodes_have >= c->pnode_cnt) + /* All pnodes are in memory, so skip scan */ + return -ENOSPC; + err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum, + (ubifs_lpt_scan_callback)scan_dirty_idx_cb, + &data); + if (err) + return err; +found: + ubifs_assert(c, data.lnum >= c->main_first && data.lnum < c->leb_cnt); + c->lscan_lnum = data.lnum; + lprops = ubifs_lpt_lookup_dirty(c, data.lnum); + if (IS_ERR(lprops)) + return PTR_ERR(lprops); + ubifs_assert(c, lprops->lnum == data.lnum); + ubifs_assert(c, lprops->free + lprops->dirty >= c->min_idx_node_sz); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, (lprops->flags & LPROPS_INDEX)); + + dbg_find("found dirty LEB %d, free %d, dirty %d, flags %#x", + lprops->lnum, lprops->free, lprops->dirty, lprops->flags); + + lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC, + lprops->flags | LPROPS_TAKEN, 0); + if (IS_ERR(lprops)) + return PTR_ERR(lprops); + + return lprops->lnum; +} + +/** + * get_idx_gc_leb - try to get a LEB number from trivial GC. + * @c: the UBIFS file-system description object + */ +static int get_idx_gc_leb(struct ubifs_info *c) +{ + const struct ubifs_lprops *lp; + int err, lnum; + + err = ubifs_get_idx_gc_leb(c); + if (err < 0) + return err; + lnum = err; + /* + * The LEB was due to be unmapped after the commit but + * it is needed now for this commit. + */ + lp = ubifs_lpt_lookup_dirty(c, lnum); + if (IS_ERR(lp)) + return PTR_ERR(lp); + lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC, + lp->flags | LPROPS_INDEX, -1); + if (IS_ERR(lp)) + return PTR_ERR(lp); + dbg_find("LEB %d, dirty %d and free %d flags %#x", + lp->lnum, lp->dirty, lp->free, lp->flags); + return lnum; +} + +/** + * find_dirtiest_idx_leb - find dirtiest index LEB from dirtiest array. + * @c: the UBIFS file-system description object + */ +static int find_dirtiest_idx_leb(struct ubifs_info *c) +{ + const struct ubifs_lprops *lp; + int lnum; + + while (1) { + if (!c->dirty_idx.cnt) + return -ENOSPC; + /* The lprops pointers were replaced by LEB numbers */ + lnum = (size_t)c->dirty_idx.arr[--c->dirty_idx.cnt]; + lp = ubifs_lpt_lookup(c, lnum); + if (IS_ERR(lp)) + return PTR_ERR(lp); + if ((lp->flags & LPROPS_TAKEN) || !(lp->flags & LPROPS_INDEX)) + continue; + lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC, + lp->flags | LPROPS_TAKEN, 0); + if (IS_ERR(lp)) + return PTR_ERR(lp); + break; + } + dbg_find("LEB %d, dirty %d and free %d flags %#x", lp->lnum, lp->dirty, + lp->free, lp->flags); + ubifs_assert(c, lp->flags & LPROPS_TAKEN); + ubifs_assert(c, lp->flags & LPROPS_INDEX); + return lnum; +} + +/** + * ubifs_find_dirty_idx_leb - try to find dirtiest index LEB as at last commit. + * @c: the UBIFS file-system description object + * + * This function attempts to find an untaken index LEB with the most free and + * dirty space that can be used without overwriting index nodes that were in the + * last index committed. + */ +int ubifs_find_dirty_idx_leb(struct ubifs_info *c) +{ + int err; + + ubifs_get_lprops(c); + + /* + * We made an array of the dirtiest index LEB numbers as at the start of + * last commit. Try that array first. + */ + err = find_dirtiest_idx_leb(c); + + /* Next try scanning the entire LPT */ + if (err == -ENOSPC) + err = find_dirty_idx_leb(c); + + /* Finally take any index LEBs awaiting trivial GC */ + if (err == -ENOSPC) + err = get_idx_gc_leb(c); + + ubifs_release_lprops(c); + return err; +} diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c new file mode 100644 index 000000000..dc3e26e9e --- /dev/null +++ b/fs/ubifs/gc.c @@ -0,0 +1,1002 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements garbage collection. The procedure for garbage collection + * is different depending on whether a LEB as an index LEB (contains index + * nodes) or not. For non-index LEBs, garbage collection finds a LEB which + * contains a lot of dirty space (obsolete nodes), and copies the non-obsolete + * nodes to the journal, at which point the garbage-collected LEB is free to be + * reused. For index LEBs, garbage collection marks the non-obsolete index nodes + * dirty in the TNC, and after the next commit, the garbage-collected LEB is + * to be reused. Garbage collection will cause the number of dirty index nodes + * to grow, however sufficient space is reserved for the index to ensure the + * commit will never run out of space. + * + * Notes about dead watermark. At current UBIFS implementation we assume that + * LEBs which have less than @c->dead_wm bytes of free + dirty space are full + * and not worth garbage-collecting. The dead watermark is one min. I/O unit + * size, or min. UBIFS node size, depending on what is greater. Indeed, UBIFS + * Garbage Collector has to synchronize the GC head's write buffer before + * returning, so this is about wasting one min. I/O unit. However, UBIFS GC can + * actually reclaim even very small pieces of dirty space by garbage collecting + * enough dirty LEBs, but we do not bother doing this at this implementation. + * + * Notes about dark watermark. The results of GC work depends on how big are + * the UBIFS nodes GC deals with. Large nodes make GC waste more space. Indeed, + * if GC move data from LEB A to LEB B and nodes in LEB A are large, GC would + * have to waste large pieces of free space at the end of LEB B, because nodes + * from LEB A would not fit. And the worst situation is when all nodes are of + * maximum size. So dark watermark is the amount of free + dirty space in LEB + * which are guaranteed to be reclaimable. If LEB has less space, the GC might + * be unable to reclaim it. So, LEBs with free + dirty greater than dark + * watermark are "good" LEBs from GC's point of view. The other LEBs are not so + * good, and GC takes extra care when moving them. + */ + +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/list_sort.h> +#include "ubifs.h" + +/* + * GC may need to move more than one LEB to make progress. The below constants + * define "soft" and "hard" limits on the number of LEBs the garbage collector + * may move. + */ +#define SOFT_LEBS_LIMIT 4 +#define HARD_LEBS_LIMIT 32 + +/** + * switch_gc_head - switch the garbage collection journal head. + * @c: UBIFS file-system description object + * + * This function switch the GC head to the next LEB which is reserved in + * @c->gc_lnum. Returns %0 in case of success, %-EAGAIN if commit is required, + * and other negative error code in case of failures. + */ +static int switch_gc_head(struct ubifs_info *c) +{ + int err, gc_lnum = c->gc_lnum; + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; + + ubifs_assert(c, gc_lnum != -1); + dbg_gc("switch GC head from LEB %d:%d to LEB %d (waste %d bytes)", + wbuf->lnum, wbuf->offs + wbuf->used, gc_lnum, + c->leb_size - wbuf->offs - wbuf->used); + + err = ubifs_wbuf_sync_nolock(wbuf); + if (err) + return err; + + /* + * The GC write-buffer was synchronized, we may safely unmap + * 'c->gc_lnum'. + */ + err = ubifs_leb_unmap(c, gc_lnum); + if (err) + return err; + + err = ubifs_add_bud_to_log(c, GCHD, gc_lnum, 0); + if (err) + return err; + + c->gc_lnum = -1; + err = ubifs_wbuf_seek_nolock(wbuf, gc_lnum, 0); + return err; +} + +/** + * data_nodes_cmp - compare 2 data nodes. + * @priv: UBIFS file-system description object + * @a: first data node + * @b: second data node + * + * This function compares data nodes @a and @b. Returns %1 if @a has greater + * inode or block number, and %-1 otherwise. + */ +static int data_nodes_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + ino_t inuma, inumb; + struct ubifs_info *c = priv; + struct ubifs_scan_node *sa, *sb; + + cond_resched(); + if (a == b) + return 0; + + sa = list_entry(a, struct ubifs_scan_node, list); + sb = list_entry(b, struct ubifs_scan_node, list); + + ubifs_assert(c, key_type(c, &sa->key) == UBIFS_DATA_KEY); + ubifs_assert(c, key_type(c, &sb->key) == UBIFS_DATA_KEY); + ubifs_assert(c, sa->type == UBIFS_DATA_NODE); + ubifs_assert(c, sb->type == UBIFS_DATA_NODE); + + inuma = key_inum(c, &sa->key); + inumb = key_inum(c, &sb->key); + + if (inuma == inumb) { + unsigned int blka = key_block(c, &sa->key); + unsigned int blkb = key_block(c, &sb->key); + + if (blka <= blkb) + return -1; + } else if (inuma <= inumb) + return -1; + + return 1; +} + +/* + * nondata_nodes_cmp - compare 2 non-data nodes. + * @priv: UBIFS file-system description object + * @a: first node + * @a: second node + * + * This function compares nodes @a and @b. It makes sure that inode nodes go + * first and sorted by length in descending order. Directory entry nodes go + * after inode nodes and are sorted in ascending hash valuer order. + */ +static int nondata_nodes_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + ino_t inuma, inumb; + struct ubifs_info *c = priv; + struct ubifs_scan_node *sa, *sb; + + cond_resched(); + if (a == b) + return 0; + + sa = list_entry(a, struct ubifs_scan_node, list); + sb = list_entry(b, struct ubifs_scan_node, list); + + ubifs_assert(c, key_type(c, &sa->key) != UBIFS_DATA_KEY && + key_type(c, &sb->key) != UBIFS_DATA_KEY); + ubifs_assert(c, sa->type != UBIFS_DATA_NODE && + sb->type != UBIFS_DATA_NODE); + + /* Inodes go before directory entries */ + if (sa->type == UBIFS_INO_NODE) { + if (sb->type == UBIFS_INO_NODE) + return sb->len - sa->len; + return -1; + } + if (sb->type == UBIFS_INO_NODE) + return 1; + + ubifs_assert(c, key_type(c, &sa->key) == UBIFS_DENT_KEY || + key_type(c, &sa->key) == UBIFS_XENT_KEY); + ubifs_assert(c, key_type(c, &sb->key) == UBIFS_DENT_KEY || + key_type(c, &sb->key) == UBIFS_XENT_KEY); + ubifs_assert(c, sa->type == UBIFS_DENT_NODE || + sa->type == UBIFS_XENT_NODE); + ubifs_assert(c, sb->type == UBIFS_DENT_NODE || + sb->type == UBIFS_XENT_NODE); + + inuma = key_inum(c, &sa->key); + inumb = key_inum(c, &sb->key); + + if (inuma == inumb) { + uint32_t hasha = key_hash(c, &sa->key); + uint32_t hashb = key_hash(c, &sb->key); + + if (hasha <= hashb) + return -1; + } else if (inuma <= inumb) + return -1; + + return 1; +} + +/** + * sort_nodes - sort nodes for GC. + * @c: UBIFS file-system description object + * @sleb: describes nodes to sort and contains the result on exit + * @nondata: contains non-data nodes on exit + * @min: minimum node size is returned here + * + * This function sorts the list of inodes to garbage collect. First of all, it + * kills obsolete nodes and separates data and non-data nodes to the + * @sleb->nodes and @nondata lists correspondingly. + * + * Data nodes are then sorted in block number order - this is important for + * bulk-read; data nodes with lower inode number go before data nodes with + * higher inode number, and data nodes with lower block number go before data + * nodes with higher block number; + * + * Non-data nodes are sorted as follows. + * o First go inode nodes - they are sorted in descending length order. + * o Then go directory entry nodes - they are sorted in hash order, which + * should supposedly optimize 'readdir()'. Direntry nodes with lower parent + * inode number go before direntry nodes with higher parent inode number, + * and direntry nodes with lower name hash values go before direntry nodes + * with higher name hash values. + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int sort_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb, + struct list_head *nondata, int *min) +{ + int err; + struct ubifs_scan_node *snod, *tmp; + + *min = INT_MAX; + + /* Separate data nodes and non-data nodes */ + list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) { + ubifs_assert(c, snod->type == UBIFS_INO_NODE || + snod->type == UBIFS_DATA_NODE || + snod->type == UBIFS_DENT_NODE || + snod->type == UBIFS_XENT_NODE || + snod->type == UBIFS_TRUN_NODE || + snod->type == UBIFS_AUTH_NODE); + + if (snod->type != UBIFS_INO_NODE && + snod->type != UBIFS_DATA_NODE && + snod->type != UBIFS_DENT_NODE && + snod->type != UBIFS_XENT_NODE) { + /* Probably truncation node, zap it */ + list_del(&snod->list); + kfree(snod); + continue; + } + + ubifs_assert(c, key_type(c, &snod->key) == UBIFS_DATA_KEY || + key_type(c, &snod->key) == UBIFS_INO_KEY || + key_type(c, &snod->key) == UBIFS_DENT_KEY || + key_type(c, &snod->key) == UBIFS_XENT_KEY); + + err = ubifs_tnc_has_node(c, &snod->key, 0, sleb->lnum, + snod->offs, 0); + if (err < 0) + return err; + + if (!err) { + /* The node is obsolete, remove it from the list */ + list_del(&snod->list); + kfree(snod); + continue; + } + + if (snod->len < *min) + *min = snod->len; + + if (key_type(c, &snod->key) != UBIFS_DATA_KEY) + list_move_tail(&snod->list, nondata); + } + + /* Sort data and non-data nodes */ + list_sort(c, &sleb->nodes, &data_nodes_cmp); + list_sort(c, nondata, &nondata_nodes_cmp); + + err = dbg_check_data_nodes_order(c, &sleb->nodes); + if (err) + return err; + err = dbg_check_nondata_nodes_order(c, nondata); + if (err) + return err; + return 0; +} + +/** + * move_node - move a node. + * @c: UBIFS file-system description object + * @sleb: describes the LEB to move nodes from + * @snod: the mode to move + * @wbuf: write-buffer to move node to + * + * This function moves node @snod to @wbuf, changes TNC correspondingly, and + * destroys @snod. Returns zero in case of success and a negative error code in + * case of failure. + */ +static int move_node(struct ubifs_info *c, struct ubifs_scan_leb *sleb, + struct ubifs_scan_node *snod, struct ubifs_wbuf *wbuf) +{ + int err, new_lnum = wbuf->lnum, new_offs = wbuf->offs + wbuf->used; + + cond_resched(); + err = ubifs_wbuf_write_nolock(wbuf, snod->node, snod->len); + if (err) + return err; + + err = ubifs_tnc_replace(c, &snod->key, sleb->lnum, + snod->offs, new_lnum, new_offs, + snod->len); + list_del(&snod->list); + kfree(snod); + return err; +} + +/** + * move_nodes - move nodes. + * @c: UBIFS file-system description object + * @sleb: describes the LEB to move nodes from + * + * This function moves valid nodes from data LEB described by @sleb to the GC + * journal head. This function returns zero in case of success, %-EAGAIN if + * commit is required, and other negative error codes in case of other + * failures. + */ +static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb) +{ + int err, min; + LIST_HEAD(nondata); + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; + + if (wbuf->lnum == -1) { + /* + * The GC journal head is not set, because it is the first GC + * invocation since mount. + */ + err = switch_gc_head(c); + if (err) + return err; + } + + err = sort_nodes(c, sleb, &nondata, &min); + if (err) + goto out; + + /* Write nodes to their new location. Use the first-fit strategy */ + while (1) { + int avail, moved = 0; + struct ubifs_scan_node *snod, *tmp; + + /* Move data nodes */ + list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) { + avail = c->leb_size - wbuf->offs - wbuf->used - + ubifs_auth_node_sz(c); + if (snod->len > avail) + /* + * Do not skip data nodes in order to optimize + * bulk-read. + */ + break; + + err = ubifs_shash_update(c, c->jheads[GCHD].log_hash, + snod->node, snod->len); + if (err) + goto out; + + err = move_node(c, sleb, snod, wbuf); + if (err) + goto out; + moved = 1; + } + + /* Move non-data nodes */ + list_for_each_entry_safe(snod, tmp, &nondata, list) { + avail = c->leb_size - wbuf->offs - wbuf->used - + ubifs_auth_node_sz(c); + if (avail < min) + break; + + if (snod->len > avail) { + /* + * Keep going only if this is an inode with + * some data. Otherwise stop and switch the GC + * head. IOW, we assume that data-less inode + * nodes and direntry nodes are roughly of the + * same size. + */ + if (key_type(c, &snod->key) == UBIFS_DENT_KEY || + snod->len == UBIFS_INO_NODE_SZ) + break; + continue; + } + + err = ubifs_shash_update(c, c->jheads[GCHD].log_hash, + snod->node, snod->len); + if (err) + goto out; + + err = move_node(c, sleb, snod, wbuf); + if (err) + goto out; + moved = 1; + } + + if (ubifs_authenticated(c) && moved) { + struct ubifs_auth_node *auth; + + auth = kmalloc(ubifs_auth_node_sz(c), GFP_NOFS); + if (!auth) { + err = -ENOMEM; + goto out; + } + + err = ubifs_prepare_auth_node(c, auth, + c->jheads[GCHD].log_hash); + if (err) { + kfree(auth); + goto out; + } + + err = ubifs_wbuf_write_nolock(wbuf, auth, + ubifs_auth_node_sz(c)); + if (err) { + kfree(auth); + goto out; + } + + ubifs_add_dirt(c, wbuf->lnum, ubifs_auth_node_sz(c)); + } + + if (list_empty(&sleb->nodes) && list_empty(&nondata)) + break; + + /* + * Waste the rest of the space in the LEB and switch to the + * next LEB. + */ + err = switch_gc_head(c); + if (err) + goto out; + } + + return 0; + +out: + list_splice_tail(&nondata, &sleb->nodes); + return err; +} + +/** + * gc_sync_wbufs - sync write-buffers for GC. + * @c: UBIFS file-system description object + * + * We must guarantee that obsoleting nodes are on flash. Unfortunately they may + * be in a write-buffer instead. That is, a node could be written to a + * write-buffer, obsoleting another node in a LEB that is GC'd. If that LEB is + * erased before the write-buffer is sync'd and then there is an unclean + * unmount, then an existing node is lost. To avoid this, we sync all + * write-buffers. + * + * This function returns %0 on success or a negative error code on failure. + */ +static int gc_sync_wbufs(struct ubifs_info *c) +{ + int err, i; + + for (i = 0; i < c->jhead_cnt; i++) { + if (i == GCHD) + continue; + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err) + return err; + } + return 0; +} + +/** + * ubifs_garbage_collect_leb - garbage-collect a logical eraseblock. + * @c: UBIFS file-system description object + * @lp: describes the LEB to garbage collect + * + * This function garbage-collects an LEB and returns one of the @LEB_FREED, + * @LEB_RETAINED, etc positive codes in case of success, %-EAGAIN if commit is + * required, and other negative error codes in case of failures. + */ +int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; + int err = 0, lnum = lp->lnum; + + ubifs_assert(c, c->gc_lnum != -1 || wbuf->offs + wbuf->used == 0 || + c->need_recovery); + ubifs_assert(c, c->gc_lnum != lnum); + ubifs_assert(c, wbuf->lnum != lnum); + + if (lp->free + lp->dirty == c->leb_size) { + /* Special case - a free LEB */ + dbg_gc("LEB %d is free, return it", lp->lnum); + ubifs_assert(c, !(lp->flags & LPROPS_INDEX)); + + if (lp->free != c->leb_size) { + /* + * Write buffers must be sync'd before unmapping + * freeable LEBs, because one of them may contain data + * which obsoletes something in 'lp->lnum'. + */ + err = gc_sync_wbufs(c); + if (err) + return err; + err = ubifs_change_one_lp(c, lp->lnum, c->leb_size, + 0, 0, 0, 0); + if (err) + return err; + } + err = ubifs_leb_unmap(c, lp->lnum); + if (err) + return err; + + if (c->gc_lnum == -1) { + c->gc_lnum = lnum; + return LEB_RETAINED; + } + + return LEB_FREED; + } + + /* + * We scan the entire LEB even though we only really need to scan up to + * (c->leb_size - lp->free). + */ + sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0); + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + + ubifs_assert(c, !list_empty(&sleb->nodes)); + snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list); + + if (snod->type == UBIFS_IDX_NODE) { + struct ubifs_gced_idx_leb *idx_gc; + + dbg_gc("indexing LEB %d (free %d, dirty %d)", + lnum, lp->free, lp->dirty); + list_for_each_entry(snod, &sleb->nodes, list) { + struct ubifs_idx_node *idx = snod->node; + int level = le16_to_cpu(idx->level); + + ubifs_assert(c, snod->type == UBIFS_IDX_NODE); + key_read(c, ubifs_idx_key(c, idx), &snod->key); + err = ubifs_dirty_idx_node(c, &snod->key, level, lnum, + snod->offs); + if (err) + goto out; + } + + idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS); + if (!idx_gc) { + err = -ENOMEM; + goto out; + } + + idx_gc->lnum = lnum; + idx_gc->unmap = 0; + list_add(&idx_gc->list, &c->idx_gc); + + /* + * Don't release the LEB until after the next commit, because + * it may contain data which is needed for recovery. So + * although we freed this LEB, it will become usable only after + * the commit. + */ + err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, + LPROPS_INDEX, 1); + if (err) + goto out; + err = LEB_FREED_IDX; + } else { + dbg_gc("data LEB %d (free %d, dirty %d)", + lnum, lp->free, lp->dirty); + + err = move_nodes(c, sleb); + if (err) + goto out_inc_seq; + + err = gc_sync_wbufs(c); + if (err) + goto out_inc_seq; + + err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, 0, 0); + if (err) + goto out_inc_seq; + + /* Allow for races with TNC */ + c->gced_lnum = lnum; + smp_wmb(); + c->gc_seq += 1; + smp_wmb(); + + if (c->gc_lnum == -1) { + c->gc_lnum = lnum; + err = LEB_RETAINED; + } else { + err = ubifs_wbuf_sync_nolock(wbuf); + if (err) + goto out; + + err = ubifs_leb_unmap(c, lnum); + if (err) + goto out; + + err = LEB_FREED; + } + } + +out: + ubifs_scan_destroy(sleb); + return err; + +out_inc_seq: + /* We may have moved at least some nodes so allow for races with TNC */ + c->gced_lnum = lnum; + smp_wmb(); + c->gc_seq += 1; + smp_wmb(); + goto out; +} + +/** + * ubifs_garbage_collect - UBIFS garbage collector. + * @c: UBIFS file-system description object + * @anyway: do GC even if there are free LEBs + * + * This function does out-of-place garbage collection. The return codes are: + * o positive LEB number if the LEB has been freed and may be used; + * o %-EAGAIN if the caller has to run commit; + * o %-ENOSPC if GC failed to make any progress; + * o other negative error codes in case of other errors. + * + * Garbage collector writes data to the journal when GC'ing data LEBs, and just + * marking indexing nodes dirty when GC'ing indexing LEBs. Thus, at some point + * commit may be required. But commit cannot be run from inside GC, because the + * caller might be holding the commit lock, so %-EAGAIN is returned instead; + * And this error code means that the caller has to run commit, and re-run GC + * if there is still no free space. + * + * There are many reasons why this function may return %-EAGAIN: + * o the log is full and there is no space to write an LEB reference for + * @c->gc_lnum; + * o the journal is too large and exceeds size limitations; + * o GC moved indexing LEBs, but they can be used only after the commit; + * o the shrinker fails to find clean znodes to free and requests the commit; + * o etc. + * + * Note, if the file-system is close to be full, this function may return + * %-EAGAIN infinitely, so the caller has to limit amount of re-invocations of + * the function. E.g., this happens if the limits on the journal size are too + * tough and GC writes too much to the journal before an LEB is freed. This + * might also mean that the journal is too large, and the TNC becomes to big, + * so that the shrinker is constantly called, finds not clean znodes to free, + * and requests commit. Well, this may also happen if the journal is all right, + * but another kernel process consumes too much memory. Anyway, infinite + * %-EAGAIN may happen, but in some extreme/misconfiguration cases. + */ +int ubifs_garbage_collect(struct ubifs_info *c, int anyway) +{ + int i, err, ret, min_space = c->dead_wm; + struct ubifs_lprops lp; + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; + + ubifs_assert_cmt_locked(c); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + + if (ubifs_gc_should_commit(c)) + return -EAGAIN; + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + + if (c->ro_error) { + ret = -EROFS; + goto out_unlock; + } + + /* We expect the write-buffer to be empty on entry */ + ubifs_assert(c, !wbuf->used); + + for (i = 0; ; i++) { + int space_before, space_after; + + cond_resched(); + + /* Give the commit an opportunity to run */ + if (ubifs_gc_should_commit(c)) { + ret = -EAGAIN; + break; + } + + if (i > SOFT_LEBS_LIMIT && !list_empty(&c->idx_gc)) { + /* + * We've done enough iterations. Indexing LEBs were + * moved and will be available after the commit. + */ + dbg_gc("soft limit, some index LEBs GC'ed, -EAGAIN"); + ubifs_commit_required(c); + ret = -EAGAIN; + break; + } + + if (i > HARD_LEBS_LIMIT) { + /* + * We've moved too many LEBs and have not made + * progress, give up. + */ + dbg_gc("hard limit, -ENOSPC"); + ret = -ENOSPC; + break; + } + + /* + * Empty and freeable LEBs can turn up while we waited for + * the wbuf lock, or while we have been running GC. In that + * case, we should just return one of those instead of + * continuing to GC dirty LEBs. Hence we request + * 'ubifs_find_dirty_leb()' to return an empty LEB if it can. + */ + ret = ubifs_find_dirty_leb(c, &lp, min_space, anyway ? 0 : 1); + if (ret) { + if (ret == -ENOSPC) + dbg_gc("no more dirty LEBs"); + break; + } + + dbg_gc("found LEB %d: free %d, dirty %d, sum %d (min. space %d)", + lp.lnum, lp.free, lp.dirty, lp.free + lp.dirty, + min_space); + + space_before = c->leb_size - wbuf->offs - wbuf->used; + if (wbuf->lnum == -1) + space_before = 0; + + ret = ubifs_garbage_collect_leb(c, &lp); + if (ret < 0) { + if (ret == -EAGAIN) { + /* + * This is not error, so we have to return the + * LEB to lprops. But if 'ubifs_return_leb()' + * fails, its failure code is propagated to the + * caller instead of the original '-EAGAIN'. + */ + err = ubifs_return_leb(c, lp.lnum); + if (err) + ret = err; + break; + } + goto out; + } + + if (ret == LEB_FREED) { + /* An LEB has been freed and is ready for use */ + dbg_gc("LEB %d freed, return", lp.lnum); + ret = lp.lnum; + break; + } + + if (ret == LEB_FREED_IDX) { + /* + * This was an indexing LEB and it cannot be + * immediately used. And instead of requesting the + * commit straight away, we try to garbage collect some + * more. + */ + dbg_gc("indexing LEB %d freed, continue", lp.lnum); + continue; + } + + ubifs_assert(c, ret == LEB_RETAINED); + space_after = c->leb_size - wbuf->offs - wbuf->used; + dbg_gc("LEB %d retained, freed %d bytes", lp.lnum, + space_after - space_before); + + if (space_after > space_before) { + /* GC makes progress, keep working */ + min_space >>= 1; + if (min_space < c->dead_wm) + min_space = c->dead_wm; + continue; + } + + dbg_gc("did not make progress"); + + /* + * GC moved an LEB bud have not done any progress. This means + * that the previous GC head LEB contained too few free space + * and the LEB which was GC'ed contained only large nodes which + * did not fit that space. + * + * We can do 2 things: + * 1. pick another LEB in a hope it'll contain a small node + * which will fit the space we have at the end of current GC + * head LEB, but there is no guarantee, so we try this out + * unless we have already been working for too long; + * 2. request an LEB with more dirty space, which will force + * 'ubifs_find_dirty_leb()' to start scanning the lprops + * table, instead of just picking one from the heap + * (previously it already picked the dirtiest LEB). + */ + if (i < SOFT_LEBS_LIMIT) { + dbg_gc("try again"); + continue; + } + + min_space <<= 1; + if (min_space > c->dark_wm) + min_space = c->dark_wm; + dbg_gc("set min. space to %d", min_space); + } + + if (ret == -ENOSPC && !list_empty(&c->idx_gc)) { + dbg_gc("no space, some index LEBs GC'ed, -EAGAIN"); + ubifs_commit_required(c); + ret = -EAGAIN; + } + + err = ubifs_wbuf_sync_nolock(wbuf); + if (!err) + err = ubifs_leb_unmap(c, c->gc_lnum); + if (err) { + ret = err; + goto out; + } +out_unlock: + mutex_unlock(&wbuf->io_mutex); + return ret; + +out: + ubifs_assert(c, ret < 0); + ubifs_assert(c, ret != -ENOSPC && ret != -EAGAIN); + ubifs_wbuf_sync_nolock(wbuf); + ubifs_ro_mode(c, ret); + mutex_unlock(&wbuf->io_mutex); + ubifs_return_leb(c, lp.lnum); + return ret; +} + +/** + * ubifs_gc_start_commit - garbage collection at start of commit. + * @c: UBIFS file-system description object + * + * If a LEB has only dirty and free space, then we may safely unmap it and make + * it free. Note, we cannot do this with indexing LEBs because dirty space may + * correspond index nodes that are required for recovery. In that case, the + * LEB cannot be unmapped until after the next commit. + * + * This function returns %0 upon success and a negative error code upon failure. + */ +int ubifs_gc_start_commit(struct ubifs_info *c) +{ + struct ubifs_gced_idx_leb *idx_gc; + const struct ubifs_lprops *lp; + int err = 0, flags; + + ubifs_get_lprops(c); + + /* + * Unmap (non-index) freeable LEBs. Note that recovery requires that all + * wbufs are sync'd before this, which is done in 'do_commit()'. + */ + while (1) { + lp = ubifs_fast_find_freeable(c); + if (!lp) + break; + ubifs_assert(c, !(lp->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lp->flags & LPROPS_INDEX)); + err = ubifs_leb_unmap(c, lp->lnum); + if (err) + goto out; + lp = ubifs_change_lp(c, lp, c->leb_size, 0, lp->flags, 0); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + ubifs_assert(c, !(lp->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lp->flags & LPROPS_INDEX)); + } + + /* Mark GC'd index LEBs OK to unmap after this commit finishes */ + list_for_each_entry(idx_gc, &c->idx_gc, list) + idx_gc->unmap = 1; + + /* Record index freeable LEBs for unmapping after commit */ + while (1) { + lp = ubifs_fast_find_frdi_idx(c); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + if (!lp) + break; + idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS); + if (!idx_gc) { + err = -ENOMEM; + goto out; + } + ubifs_assert(c, !(lp->flags & LPROPS_TAKEN)); + ubifs_assert(c, lp->flags & LPROPS_INDEX); + /* Don't release the LEB until after the next commit */ + flags = (lp->flags | LPROPS_TAKEN) ^ LPROPS_INDEX; + lp = ubifs_change_lp(c, lp, c->leb_size, 0, flags, 1); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + kfree(idx_gc); + goto out; + } + ubifs_assert(c, lp->flags & LPROPS_TAKEN); + ubifs_assert(c, !(lp->flags & LPROPS_INDEX)); + idx_gc->lnum = lp->lnum; + idx_gc->unmap = 1; + list_add(&idx_gc->list, &c->idx_gc); + } +out: + ubifs_release_lprops(c); + return err; +} + +/** + * ubifs_gc_end_commit - garbage collection at end of commit. + * @c: UBIFS file-system description object + * + * This function completes out-of-place garbage collection of index LEBs. + */ +int ubifs_gc_end_commit(struct ubifs_info *c) +{ + struct ubifs_gced_idx_leb *idx_gc, *tmp; + struct ubifs_wbuf *wbuf; + int err = 0; + + wbuf = &c->jheads[GCHD].wbuf; + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + list_for_each_entry_safe(idx_gc, tmp, &c->idx_gc, list) + if (idx_gc->unmap) { + dbg_gc("LEB %d", idx_gc->lnum); + err = ubifs_leb_unmap(c, idx_gc->lnum); + if (err) + goto out; + err = ubifs_change_one_lp(c, idx_gc->lnum, LPROPS_NC, + LPROPS_NC, 0, LPROPS_TAKEN, -1); + if (err) + goto out; + list_del(&idx_gc->list); + kfree(idx_gc); + } +out: + mutex_unlock(&wbuf->io_mutex); + return err; +} + +/** + * ubifs_destroy_idx_gc - destroy idx_gc list. + * @c: UBIFS file-system description object + * + * This function destroys the @c->idx_gc list. It is called when unmounting + * so locks are not needed. Returns zero in case of success and a negative + * error code in case of failure. + */ +void ubifs_destroy_idx_gc(struct ubifs_info *c) +{ + while (!list_empty(&c->idx_gc)) { + struct ubifs_gced_idx_leb *idx_gc; + + idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb, + list); + c->idx_gc_cnt -= 1; + list_del(&idx_gc->list); + kfree(idx_gc); + } +} + +/** + * ubifs_get_idx_gc_leb - get a LEB from GC'd index LEB list. + * @c: UBIFS file-system description object + * + * Called during start commit so locks are not needed. + */ +int ubifs_get_idx_gc_leb(struct ubifs_info *c) +{ + struct ubifs_gced_idx_leb *idx_gc; + int lnum; + + if (list_empty(&c->idx_gc)) + return -ENOSPC; + idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb, list); + lnum = idx_gc->lnum; + /* c->idx_gc_cnt is updated by the caller when lprops are updated */ + list_del(&idx_gc->list); + kfree(idx_gc); + return lnum; +} diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c new file mode 100644 index 000000000..89b671ad0 --- /dev/null +++ b/fs/ubifs/io.c @@ -0,0 +1,1260 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * Copyright (C) 2006, 2007 University of Szeged, Hungary + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + * Zoltan Sogor + */ + +/* + * This file implements UBIFS I/O subsystem which provides various I/O-related + * helper functions (reading/writing/checking/validating nodes) and implements + * write-buffering support. Write buffers help to save space which otherwise + * would have been wasted for padding to the nearest minimal I/O unit boundary. + * Instead, data first goes to the write-buffer and is flushed when the + * buffer is full or when it is not used for some time (by timer). This is + * similar to the mechanism is used by JFFS2. + * + * UBIFS distinguishes between minimum write size (@c->min_io_size) and maximum + * write size (@c->max_write_size). The latter is the maximum amount of bytes + * the underlying flash is able to program at a time, and writing in + * @c->max_write_size units should presumably be faster. Obviously, + * @c->min_io_size <= @c->max_write_size. Write-buffers are of + * @c->max_write_size bytes in size for maximum performance. However, when a + * write-buffer is flushed, only the portion of it (aligned to @c->min_io_size + * boundary) which contains data is written, not the whole write-buffer, + * because this is more space-efficient. + * + * This optimization adds few complications to the code. Indeed, on the one + * hand, we want to write in optimal @c->max_write_size bytes chunks, which + * also means aligning writes at the @c->max_write_size bytes offsets. On the + * other hand, we do not want to waste space when synchronizing the write + * buffer, so during synchronization we writes in smaller chunks. And this makes + * the next write offset to be not aligned to @c->max_write_size bytes. So the + * have to make sure that the write-buffer offset (@wbuf->offs) becomes aligned + * to @c->max_write_size bytes again. We do this by temporarily shrinking + * write-buffer size (@wbuf->size). + * + * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by + * mutexes defined inside these objects. Since sometimes upper-level code + * has to lock the write-buffer (e.g. journal space reservation code), many + * functions related to write-buffers have "nolock" suffix which means that the + * caller has to lock the write-buffer before calling this function. + * + * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not + * aligned, UBIFS starts the next node from the aligned address, and the padded + * bytes may contain any rubbish. In other words, UBIFS does not put padding + * bytes in those small gaps. Common headers of nodes store real node lengths, + * not aligned lengths. Indexing nodes also store real lengths in branches. + * + * UBIFS uses padding when it pads to the next min. I/O unit. In this case it + * uses padding nodes or padding bytes, if the padding node does not fit. + * + * All UBIFS nodes are protected by CRC checksums and UBIFS checks CRC when + * they are read from the flash media. + */ + +#include <linux/crc32.h> +#include <linux/slab.h> +#include "ubifs.h" + +/** + * ubifs_ro_mode - switch UBIFS to read read-only mode. + * @c: UBIFS file-system description object + * @err: error code which is the reason of switching to R/O mode + */ +void ubifs_ro_mode(struct ubifs_info *c, int err) +{ + if (!c->ro_error) { + c->ro_error = 1; + c->no_chk_data_crc = 0; + c->vfs_sb->s_flags |= SB_RDONLY; + ubifs_warn(c, "switched to read-only mode, error %d", err); + dump_stack(); + } +} + +/* + * Below are simple wrappers over UBI I/O functions which include some + * additional checks and UBIFS debugging stuff. See corresponding UBI function + * for more information. + */ + +int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, + int len, int even_ebadmsg) +{ + int err; + + err = ubi_read(c->ubi, lnum, buf, offs, len); + /* + * In case of %-EBADMSG print the error message only if the + * @even_ebadmsg is true. + */ + if (err && (err != -EBADMSG || even_ebadmsg)) { + ubifs_err(c, "reading %d bytes from LEB %d:%d failed, error %d", + len, lnum, offs, err); + dump_stack(); + } + return err; +} + +int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, + int len) +{ + int err; + + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->ro_error) + return -EROFS; + if (!dbg_is_tst_rcvry(c)) + err = ubi_leb_write(c->ubi, lnum, buf, offs, len); + else + err = dbg_leb_write(c, lnum, buf, offs, len); + if (err) { + ubifs_err(c, "writing %d bytes to LEB %d:%d failed, error %d", + len, lnum, offs, err); + ubifs_ro_mode(c, err); + dump_stack(); + } + return err; +} + +int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len) +{ + int err; + + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->ro_error) + return -EROFS; + if (!dbg_is_tst_rcvry(c)) + err = ubi_leb_change(c->ubi, lnum, buf, len); + else + err = dbg_leb_change(c, lnum, buf, len); + if (err) { + ubifs_err(c, "changing %d bytes in LEB %d failed, error %d", + len, lnum, err); + ubifs_ro_mode(c, err); + dump_stack(); + } + return err; +} + +int ubifs_leb_unmap(struct ubifs_info *c, int lnum) +{ + int err; + + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->ro_error) + return -EROFS; + if (!dbg_is_tst_rcvry(c)) + err = ubi_leb_unmap(c->ubi, lnum); + else + err = dbg_leb_unmap(c, lnum); + if (err) { + ubifs_err(c, "unmap LEB %d failed, error %d", lnum, err); + ubifs_ro_mode(c, err); + dump_stack(); + } + return err; +} + +int ubifs_leb_map(struct ubifs_info *c, int lnum) +{ + int err; + + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->ro_error) + return -EROFS; + if (!dbg_is_tst_rcvry(c)) + err = ubi_leb_map(c->ubi, lnum); + else + err = dbg_leb_map(c, lnum); + if (err) { + ubifs_err(c, "mapping LEB %d failed, error %d", lnum, err); + ubifs_ro_mode(c, err); + dump_stack(); + } + return err; +} + +int ubifs_is_mapped(const struct ubifs_info *c, int lnum) +{ + int err; + + err = ubi_is_mapped(c->ubi, lnum); + if (err < 0) { + ubifs_err(c, "ubi_is_mapped failed for LEB %d, error %d", + lnum, err); + dump_stack(); + } + return err; +} + +/** + * ubifs_check_node - check node. + * @c: UBIFS file-system description object + * @buf: node to check + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * @quiet: print no messages + * @must_chk_crc: indicates whether to always check the CRC + * + * This function checks node magic number and CRC checksum. This function also + * validates node length to prevent UBIFS from becoming crazy when an attacker + * feeds it a file-system image with incorrect nodes. For example, too large + * node length in the common header could cause UBIFS to read memory outside of + * allocated buffer when checking the CRC checksum. + * + * This function may skip data nodes CRC checking if @c->no_chk_data_crc is + * true, which is controlled by corresponding UBIFS mount option. However, if + * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is + * checked. Similarly, if @c->mounting or @c->remounting_rw is true (we are + * mounting or re-mounting to R/W mode), @c->no_chk_data_crc is ignored and CRC + * is checked. This is because during mounting or re-mounting from R/O mode to + * R/W mode we may read journal nodes (when replying the journal or doing the + * recovery) and the journal nodes may potentially be corrupted, so checking is + * required. + * + * This function returns zero in case of success and %-EUCLEAN in case of bad + * CRC or magic. + */ +int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, + int offs, int quiet, int must_chk_crc) +{ + int err = -EINVAL, type, node_len, dump_node = 1; + uint32_t crc, node_crc, magic; + const struct ubifs_ch *ch = buf; + + ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt && offs >= 0); + ubifs_assert(c, !(offs & 7) && offs < c->leb_size); + + magic = le32_to_cpu(ch->magic); + if (magic != UBIFS_NODE_MAGIC) { + if (!quiet) + ubifs_err(c, "bad magic %#08x, expected %#08x", + magic, UBIFS_NODE_MAGIC); + err = -EUCLEAN; + goto out; + } + + type = ch->node_type; + if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { + if (!quiet) + ubifs_err(c, "bad node type %d", type); + goto out; + } + + node_len = le32_to_cpu(ch->len); + if (node_len + offs > c->leb_size) + goto out_len; + + if (c->ranges[type].max_len == 0) { + if (node_len != c->ranges[type].len) + goto out_len; + } else if (node_len < c->ranges[type].min_len || + node_len > c->ranges[type].max_len) + goto out_len; + + if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->mounting && + !c->remounting_rw && c->no_chk_data_crc) + return 0; + + crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); + node_crc = le32_to_cpu(ch->crc); + if (crc != node_crc) { + if (!quiet) + ubifs_err(c, "bad CRC: calculated %#08x, read %#08x", + crc, node_crc); + err = -EUCLEAN; + goto out; + } + + return 0; + +out_len: + if (!quiet) + ubifs_err(c, "bad node length %d", node_len); + if (type == UBIFS_DATA_NODE && node_len > UBIFS_DATA_NODE_SZ) + dump_node = 0; +out: + if (!quiet) { + ubifs_err(c, "bad node at LEB %d:%d", lnum, offs); + if (dump_node) { + ubifs_dump_node(c, buf); + } else { + int safe_len = min3(node_len, c->leb_size - offs, + (int)UBIFS_MAX_DATA_NODE_SZ); + pr_err("\tprevent out-of-bounds memory access\n"); + pr_err("\ttruncated data node length %d\n", safe_len); + pr_err("\tcorrupted data node:\n"); + print_hex_dump(KERN_ERR, "\t", DUMP_PREFIX_OFFSET, 32, 1, + buf, safe_len, 0); + } + dump_stack(); + } + return err; +} + +/** + * ubifs_pad - pad flash space. + * @c: UBIFS file-system description object + * @buf: buffer to put padding to + * @pad: how many bytes to pad + * + * The flash media obliges us to write only in chunks of %c->min_io_size and + * when we have to write less data we add padding node to the write-buffer and + * pad it to the next minimal I/O unit's boundary. Padding nodes help when the + * media is being scanned. If the amount of wasted space is not enough to fit a + * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes + * pattern (%UBIFS_PADDING_BYTE). + * + * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is + * used. + */ +void ubifs_pad(const struct ubifs_info *c, void *buf, int pad) +{ + uint32_t crc; + + ubifs_assert(c, pad >= 0); + + if (pad >= UBIFS_PAD_NODE_SZ) { + struct ubifs_ch *ch = buf; + struct ubifs_pad_node *pad_node = buf; + + ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); + ch->node_type = UBIFS_PAD_NODE; + ch->group_type = UBIFS_NO_NODE_GROUP; + ch->padding[0] = ch->padding[1] = 0; + ch->sqnum = 0; + ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ); + pad -= UBIFS_PAD_NODE_SZ; + pad_node->pad_len = cpu_to_le32(pad); + crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8); + ch->crc = cpu_to_le32(crc); + memset(buf + UBIFS_PAD_NODE_SZ, 0, pad); + } else if (pad > 0) + /* Too little space, padding node won't fit */ + memset(buf, UBIFS_PADDING_BYTE, pad); +} + +/** + * next_sqnum - get next sequence number. + * @c: UBIFS file-system description object + */ +static unsigned long long next_sqnum(struct ubifs_info *c) +{ + unsigned long long sqnum; + + spin_lock(&c->cnt_lock); + sqnum = ++c->max_sqnum; + spin_unlock(&c->cnt_lock); + + if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) { + if (sqnum >= SQNUM_WATERMARK) { + ubifs_err(c, "sequence number overflow %llu, end of life", + sqnum); + ubifs_ro_mode(c, -EINVAL); + } + ubifs_warn(c, "running out of sequence numbers, end of life soon"); + } + + return sqnum; +} + +void ubifs_init_node(struct ubifs_info *c, void *node, int len, int pad) +{ + struct ubifs_ch *ch = node; + unsigned long long sqnum = next_sqnum(c); + + ubifs_assert(c, len >= UBIFS_CH_SZ); + + ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); + ch->len = cpu_to_le32(len); + ch->group_type = UBIFS_NO_NODE_GROUP; + ch->sqnum = cpu_to_le64(sqnum); + ch->padding[0] = ch->padding[1] = 0; + + if (pad) { + len = ALIGN(len, 8); + pad = ALIGN(len, c->min_io_size) - len; + ubifs_pad(c, node + len, pad); + } +} + +void ubifs_crc_node(struct ubifs_info *c, void *node, int len) +{ + struct ubifs_ch *ch = node; + uint32_t crc; + + crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); + ch->crc = cpu_to_le32(crc); +} + +/** + * ubifs_prepare_node_hmac - prepare node to be written to flash. + * @c: UBIFS file-system description object + * @node: the node to pad + * @len: node length + * @hmac_offs: offset of the HMAC in the node + * @pad: if the buffer has to be padded + * + * This function prepares node at @node to be written to the media - it + * calculates node CRC, fills the common header, and adds proper padding up to + * the next minimum I/O unit if @pad is not zero. if @hmac_offs is positive then + * a HMAC is inserted into the node at the given offset. + * + * This function returns 0 for success or a negative error code otherwise. + */ +int ubifs_prepare_node_hmac(struct ubifs_info *c, void *node, int len, + int hmac_offs, int pad) +{ + int err; + + ubifs_init_node(c, node, len, pad); + + if (hmac_offs > 0) { + err = ubifs_node_insert_hmac(c, node, len, hmac_offs); + if (err) + return err; + } + + ubifs_crc_node(c, node, len); + + return 0; +} + +/** + * ubifs_prepare_node - prepare node to be written to flash. + * @c: UBIFS file-system description object + * @node: the node to pad + * @len: node length + * @pad: if the buffer has to be padded + * + * This function prepares node at @node to be written to the media - it + * calculates node CRC, fills the common header, and adds proper padding up to + * the next minimum I/O unit if @pad is not zero. + */ +void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad) +{ + /* + * Deliberately ignore return value since this function can only fail + * when a hmac offset is given. + */ + ubifs_prepare_node_hmac(c, node, len, 0, pad); +} + +/** + * ubifs_prep_grp_node - prepare node of a group to be written to flash. + * @c: UBIFS file-system description object + * @node: the node to pad + * @len: node length + * @last: indicates the last node of the group + * + * This function prepares node at @node to be written to the media - it + * calculates node CRC and fills the common header. + */ +void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last) +{ + uint32_t crc; + struct ubifs_ch *ch = node; + unsigned long long sqnum = next_sqnum(c); + + ubifs_assert(c, len >= UBIFS_CH_SZ); + + ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); + ch->len = cpu_to_le32(len); + if (last) + ch->group_type = UBIFS_LAST_OF_NODE_GROUP; + else + ch->group_type = UBIFS_IN_NODE_GROUP; + ch->sqnum = cpu_to_le64(sqnum); + ch->padding[0] = ch->padding[1] = 0; + crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); + ch->crc = cpu_to_le32(crc); +} + +/** + * wbuf_timer_callback - write-buffer timer callback function. + * @timer: timer data (write-buffer descriptor) + * + * This function is called when the write-buffer timer expires. + */ +static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) +{ + struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer); + + dbg_io("jhead %s", dbg_jhead(wbuf->jhead)); + wbuf->need_sync = 1; + wbuf->c->need_wbuf_sync = 1; + ubifs_wake_up_bgt(wbuf->c); + return HRTIMER_NORESTART; +} + +/** + * new_wbuf_timer - start new write-buffer timer. + * @c: UBIFS file-system description object + * @wbuf: write-buffer descriptor + */ +static void new_wbuf_timer_nolock(struct ubifs_info *c, struct ubifs_wbuf *wbuf) +{ + ktime_t softlimit = ms_to_ktime(dirty_writeback_interval * 10); + unsigned long long delta = dirty_writeback_interval; + + /* centi to milli, milli to nano, then 10% */ + delta *= 10ULL * NSEC_PER_MSEC / 10ULL; + + ubifs_assert(c, !hrtimer_active(&wbuf->timer)); + ubifs_assert(c, delta <= ULONG_MAX); + + if (wbuf->no_timer) + return; + dbg_io("set timer for jhead %s, %llu-%llu millisecs", + dbg_jhead(wbuf->jhead), + div_u64(ktime_to_ns(softlimit), USEC_PER_SEC), + div_u64(ktime_to_ns(softlimit) + delta, USEC_PER_SEC)); + hrtimer_start_range_ns(&wbuf->timer, softlimit, delta, + HRTIMER_MODE_REL); +} + +/** + * cancel_wbuf_timer - cancel write-buffer timer. + * @wbuf: write-buffer descriptor + */ +static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) +{ + if (wbuf->no_timer) + return; + wbuf->need_sync = 0; + hrtimer_cancel(&wbuf->timer); +} + +/** + * ubifs_wbuf_sync_nolock - synchronize write-buffer. + * @wbuf: write-buffer to synchronize + * + * This function synchronizes write-buffer @buf and returns zero in case of + * success or a negative error code in case of failure. + * + * Note, although write-buffers are of @c->max_write_size, this function does + * not necessarily writes all @c->max_write_size bytes to the flash. Instead, + * if the write-buffer is only partially filled with data, only the used part + * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized. + * This way we waste less space. + */ +int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) +{ + struct ubifs_info *c = wbuf->c; + int err, dirt, sync_len; + + cancel_wbuf_timer_nolock(wbuf); + if (!wbuf->used || wbuf->lnum == -1) + /* Write-buffer is empty or not seeked */ + return 0; + + dbg_io("LEB %d:%d, %d bytes, jhead %s", + wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead)); + ubifs_assert(c, !(wbuf->avail & 7)); + ubifs_assert(c, wbuf->offs + wbuf->size <= c->leb_size); + ubifs_assert(c, wbuf->size >= c->min_io_size); + ubifs_assert(c, wbuf->size <= c->max_write_size); + ubifs_assert(c, wbuf->size % c->min_io_size == 0); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->leb_size - wbuf->offs >= c->max_write_size) + ubifs_assert(c, !((wbuf->offs + wbuf->size) % c->max_write_size)); + + if (c->ro_error) + return -EROFS; + + /* + * Do not write whole write buffer but write only the minimum necessary + * amount of min. I/O units. + */ + sync_len = ALIGN(wbuf->used, c->min_io_size); + dirt = sync_len - wbuf->used; + if (dirt) + ubifs_pad(c, wbuf->buf + wbuf->used, dirt); + err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len); + if (err) + return err; + + spin_lock(&wbuf->lock); + wbuf->offs += sync_len; + /* + * Now @wbuf->offs is not necessarily aligned to @c->max_write_size. + * But our goal is to optimize writes and make sure we write in + * @c->max_write_size chunks and to @c->max_write_size-aligned offset. + * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make + * sure that @wbuf->offs + @wbuf->size is aligned to + * @c->max_write_size. This way we make sure that after next + * write-buffer flush we are again at the optimal offset (aligned to + * @c->max_write_size). + */ + if (c->leb_size - wbuf->offs < c->max_write_size) + wbuf->size = c->leb_size - wbuf->offs; + else if (wbuf->offs & (c->max_write_size - 1)) + wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; + else + wbuf->size = c->max_write_size; + wbuf->avail = wbuf->size; + wbuf->used = 0; + wbuf->next_ino = 0; + spin_unlock(&wbuf->lock); + + if (wbuf->sync_callback) + err = wbuf->sync_callback(c, wbuf->lnum, + c->leb_size - wbuf->offs, dirt); + return err; +} + +/** + * ubifs_wbuf_seek_nolock - seek write-buffer. + * @wbuf: write-buffer + * @lnum: logical eraseblock number to seek to + * @offs: logical eraseblock offset to seek to + * + * This function targets the write-buffer to logical eraseblock @lnum:@offs. + * The write-buffer has to be empty. Returns zero in case of success and a + * negative error code in case of failure. + */ +int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs) +{ + const struct ubifs_info *c = wbuf->c; + + dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead)); + ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt); + ubifs_assert(c, offs >= 0 && offs <= c->leb_size); + ubifs_assert(c, offs % c->min_io_size == 0 && !(offs & 7)); + ubifs_assert(c, lnum != wbuf->lnum); + ubifs_assert(c, wbuf->used == 0); + + spin_lock(&wbuf->lock); + wbuf->lnum = lnum; + wbuf->offs = offs; + if (c->leb_size - wbuf->offs < c->max_write_size) + wbuf->size = c->leb_size - wbuf->offs; + else if (wbuf->offs & (c->max_write_size - 1)) + wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; + else + wbuf->size = c->max_write_size; + wbuf->avail = wbuf->size; + wbuf->used = 0; + spin_unlock(&wbuf->lock); + + return 0; +} + +/** + * ubifs_bg_wbufs_sync - synchronize write-buffers. + * @c: UBIFS file-system description object + * + * This function is called by background thread to synchronize write-buffers. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +int ubifs_bg_wbufs_sync(struct ubifs_info *c) +{ + int err, i; + + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (!c->need_wbuf_sync) + return 0; + c->need_wbuf_sync = 0; + + if (c->ro_error) { + err = -EROFS; + goto out_timers; + } + + dbg_io("synchronize"); + for (i = 0; i < c->jhead_cnt; i++) { + struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; + + cond_resched(); + + /* + * If the mutex is locked then wbuf is being changed, so + * synchronization is not necessary. + */ + if (mutex_is_locked(&wbuf->io_mutex)) + continue; + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + if (!wbuf->need_sync) { + mutex_unlock(&wbuf->io_mutex); + continue; + } + + err = ubifs_wbuf_sync_nolock(wbuf); + mutex_unlock(&wbuf->io_mutex); + if (err) { + ubifs_err(c, "cannot sync write-buffer, error %d", err); + ubifs_ro_mode(c, err); + goto out_timers; + } + } + + return 0; + +out_timers: + /* Cancel all timers to prevent repeated errors */ + for (i = 0; i < c->jhead_cnt; i++) { + struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + cancel_wbuf_timer_nolock(wbuf); + mutex_unlock(&wbuf->io_mutex); + } + return err; +} + +/** + * ubifs_wbuf_write_nolock - write data to flash via write-buffer. + * @wbuf: write-buffer + * @buf: node to write + * @len: node length + * + * This function writes data to flash via write-buffer @wbuf. This means that + * the last piece of the node won't reach the flash media immediately if it + * does not take whole max. write unit (@c->max_write_size). Instead, the node + * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or + * because more data are appended to the write-buffer). + * + * This function returns zero in case of success and a negative error code in + * case of failure. If the node cannot be written because there is no more + * space in this logical eraseblock, %-ENOSPC is returned. + */ +int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) +{ + struct ubifs_info *c = wbuf->c; + int err, written, n, aligned_len = ALIGN(len, 8); + + dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len, + dbg_ntype(((struct ubifs_ch *)buf)->node_type), + dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used); + ubifs_assert(c, len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); + ubifs_assert(c, wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); + ubifs_assert(c, !(wbuf->offs & 7) && wbuf->offs <= c->leb_size); + ubifs_assert(c, wbuf->avail > 0 && wbuf->avail <= wbuf->size); + ubifs_assert(c, wbuf->size >= c->min_io_size); + ubifs_assert(c, wbuf->size <= c->max_write_size); + ubifs_assert(c, wbuf->size % c->min_io_size == 0); + ubifs_assert(c, mutex_is_locked(&wbuf->io_mutex)); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + ubifs_assert(c, !c->space_fixup); + if (c->leb_size - wbuf->offs >= c->max_write_size) + ubifs_assert(c, !((wbuf->offs + wbuf->size) % c->max_write_size)); + + if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { + err = -ENOSPC; + goto out; + } + + cancel_wbuf_timer_nolock(wbuf); + + if (c->ro_error) + return -EROFS; + + if (aligned_len <= wbuf->avail) { + /* + * The node is not very large and fits entirely within + * write-buffer. + */ + memcpy(wbuf->buf + wbuf->used, buf, len); + if (aligned_len > len) { + ubifs_assert(c, aligned_len - len < 8); + ubifs_pad(c, wbuf->buf + wbuf->used + len, aligned_len - len); + } + + if (aligned_len == wbuf->avail) { + dbg_io("flush jhead %s wbuf to LEB %d:%d", + dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); + err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, + wbuf->offs, wbuf->size); + if (err) + goto out; + + spin_lock(&wbuf->lock); + wbuf->offs += wbuf->size; + if (c->leb_size - wbuf->offs >= c->max_write_size) + wbuf->size = c->max_write_size; + else + wbuf->size = c->leb_size - wbuf->offs; + wbuf->avail = wbuf->size; + wbuf->used = 0; + wbuf->next_ino = 0; + spin_unlock(&wbuf->lock); + } else { + spin_lock(&wbuf->lock); + wbuf->avail -= aligned_len; + wbuf->used += aligned_len; + spin_unlock(&wbuf->lock); + } + + goto exit; + } + + written = 0; + + if (wbuf->used) { + /* + * The node is large enough and does not fit entirely within + * current available space. We have to fill and flush + * write-buffer and switch to the next max. write unit. + */ + dbg_io("flush jhead %s wbuf to LEB %d:%d", + dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); + memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); + err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, + wbuf->size); + if (err) + goto out; + + wbuf->offs += wbuf->size; + len -= wbuf->avail; + aligned_len -= wbuf->avail; + written += wbuf->avail; + } else if (wbuf->offs & (c->max_write_size - 1)) { + /* + * The write-buffer offset is not aligned to + * @c->max_write_size and @wbuf->size is less than + * @c->max_write_size. Write @wbuf->size bytes to make sure the + * following writes are done in optimal @c->max_write_size + * chunks. + */ + dbg_io("write %d bytes to LEB %d:%d", + wbuf->size, wbuf->lnum, wbuf->offs); + err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs, + wbuf->size); + if (err) + goto out; + + wbuf->offs += wbuf->size; + len -= wbuf->size; + aligned_len -= wbuf->size; + written += wbuf->size; + } + + /* + * The remaining data may take more whole max. write units, so write the + * remains multiple to max. write unit size directly to the flash media. + * We align node length to 8-byte boundary because we anyway flash wbuf + * if the remaining space is less than 8 bytes. + */ + n = aligned_len >> c->max_write_shift; + if (n) { + int m = n - 1; + + dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, + wbuf->offs); + + if (m) { + /* '(n-1)<<c->max_write_shift < len' is always true. */ + m <<= c->max_write_shift; + err = ubifs_leb_write(c, wbuf->lnum, buf + written, + wbuf->offs, m); + if (err) + goto out; + wbuf->offs += m; + aligned_len -= m; + len -= m; + written += m; + } + + /* + * The non-written len of buf may be less than 'n' because + * parameter 'len' is not 8 bytes aligned, so here we read + * min(len, n) bytes from buf. + */ + n = 1 << c->max_write_shift; + memcpy(wbuf->buf, buf + written, min(len, n)); + if (n > len) { + ubifs_assert(c, n - len < 8); + ubifs_pad(c, wbuf->buf + len, n - len); + } + + err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, n); + if (err) + goto out; + wbuf->offs += n; + aligned_len -= n; + len -= min(len, n); + written += n; + } + + spin_lock(&wbuf->lock); + if (aligned_len) { + /* + * And now we have what's left and what does not take whole + * max. write unit, so write it to the write-buffer and we are + * done. + */ + memcpy(wbuf->buf, buf + written, len); + if (aligned_len > len) { + ubifs_assert(c, aligned_len - len < 8); + ubifs_pad(c, wbuf->buf + len, aligned_len - len); + } + } + + if (c->leb_size - wbuf->offs >= c->max_write_size) + wbuf->size = c->max_write_size; + else + wbuf->size = c->leb_size - wbuf->offs; + wbuf->avail = wbuf->size - aligned_len; + wbuf->used = aligned_len; + wbuf->next_ino = 0; + spin_unlock(&wbuf->lock); + +exit: + if (wbuf->sync_callback) { + int free = c->leb_size - wbuf->offs - wbuf->used; + + err = wbuf->sync_callback(c, wbuf->lnum, free, 0); + if (err) + goto out; + } + + if (wbuf->used) + new_wbuf_timer_nolock(c, wbuf); + + return 0; + +out: + ubifs_err(c, "cannot write %d bytes to LEB %d:%d, error %d", + len, wbuf->lnum, wbuf->offs, err); + ubifs_dump_node(c, buf); + dump_stack(); + ubifs_dump_leb(c, wbuf->lnum); + return err; +} + +/** + * ubifs_write_node_hmac - write node to the media. + * @c: UBIFS file-system description object + * @buf: the node to write + * @len: node length + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * @hmac_offs: offset of the HMAC within the node + * + * This function automatically fills node magic number, assigns sequence + * number, and calculates node CRC checksum. The length of the @buf buffer has + * to be aligned to the minimal I/O unit size. This function automatically + * appends padding node and padding bytes if needed. Returns zero in case of + * success and a negative error code in case of failure. + */ +int ubifs_write_node_hmac(struct ubifs_info *c, void *buf, int len, int lnum, + int offs, int hmac_offs) +{ + int err, buf_len = ALIGN(len, c->min_io_size); + + dbg_io("LEB %d:%d, %s, length %d (aligned %d)", + lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, + buf_len); + ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt && offs >= 0); + ubifs_assert(c, offs % c->min_io_size == 0 && offs < c->leb_size); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + ubifs_assert(c, !c->space_fixup); + + if (c->ro_error) + return -EROFS; + + err = ubifs_prepare_node_hmac(c, buf, len, hmac_offs, 1); + if (err) + return err; + + err = ubifs_leb_write(c, lnum, buf, offs, buf_len); + if (err) + ubifs_dump_node(c, buf); + + return err; +} + +/** + * ubifs_write_node - write node to the media. + * @c: UBIFS file-system description object + * @buf: the node to write + * @len: node length + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * + * This function automatically fills node magic number, assigns sequence + * number, and calculates node CRC checksum. The length of the @buf buffer has + * to be aligned to the minimal I/O unit size. This function automatically + * appends padding node and padding bytes if needed. Returns zero in case of + * success and a negative error code in case of failure. + */ +int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, + int offs) +{ + return ubifs_write_node_hmac(c, buf, len, lnum, offs, -1); +} + +/** + * ubifs_read_node_wbuf - read node from the media or write-buffer. + * @wbuf: wbuf to check for un-written data + * @buf: buffer to read to + * @type: node type + * @len: node length + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * + * This function reads a node of known type and length, checks it and stores + * in @buf. If the node partially or fully sits in the write-buffer, this + * function takes data from the buffer, otherwise it reads the flash media. + * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative + * error code in case of failure. + */ +int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, + int lnum, int offs) +{ + const struct ubifs_info *c = wbuf->c; + int err, rlen, overlap; + struct ubifs_ch *ch = buf; + + dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs, + dbg_ntype(type), len, dbg_jhead(wbuf->jhead)); + ubifs_assert(c, wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); + ubifs_assert(c, !(offs & 7) && offs < c->leb_size); + ubifs_assert(c, type >= 0 && type < UBIFS_NODE_TYPES_CNT); + + spin_lock(&wbuf->lock); + overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); + if (!overlap) { + /* We may safely unlock the write-buffer and read the data */ + spin_unlock(&wbuf->lock); + return ubifs_read_node(c, buf, type, len, lnum, offs); + } + + /* Don't read under wbuf */ + rlen = wbuf->offs - offs; + if (rlen < 0) + rlen = 0; + + /* Copy the rest from the write-buffer */ + memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); + spin_unlock(&wbuf->lock); + + if (rlen > 0) { + /* Read everything that goes before write-buffer */ + err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0); + if (err && err != -EBADMSG) + return err; + } + + if (type != ch->node_type) { + ubifs_err(c, "bad node type (%d but expected %d)", + ch->node_type, type); + goto out; + } + + err = ubifs_check_node(c, buf, lnum, offs, 0, 0); + if (err) { + ubifs_err(c, "expected node type %d", type); + return err; + } + + rlen = le32_to_cpu(ch->len); + if (rlen != len) { + ubifs_err(c, "bad node length %d, expected %d", rlen, len); + goto out; + } + + return 0; + +out: + ubifs_err(c, "bad node at LEB %d:%d", lnum, offs); + ubifs_dump_node(c, buf); + dump_stack(); + return -EINVAL; +} + +/** + * ubifs_read_node - read node. + * @c: UBIFS file-system description object + * @buf: buffer to read to + * @type: node type + * @len: node length (not aligned) + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * + * This function reads a node of known type and and length, checks it and + * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched + * and a negative error code in case of failure. + */ +int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, + int lnum, int offs) +{ + int err, l; + struct ubifs_ch *ch = buf; + + dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); + ubifs_assert(c, lnum >= 0 && lnum < c->leb_cnt && offs >= 0); + ubifs_assert(c, len >= UBIFS_CH_SZ && offs + len <= c->leb_size); + ubifs_assert(c, !(offs & 7) && offs < c->leb_size); + ubifs_assert(c, type >= 0 && type < UBIFS_NODE_TYPES_CNT); + + err = ubifs_leb_read(c, lnum, buf, offs, len, 0); + if (err && err != -EBADMSG) + return err; + + if (type != ch->node_type) { + ubifs_errc(c, "bad node type (%d but expected %d)", + ch->node_type, type); + goto out; + } + + err = ubifs_check_node(c, buf, lnum, offs, 0, 0); + if (err) { + ubifs_errc(c, "expected node type %d", type); + return err; + } + + l = le32_to_cpu(ch->len); + if (l != len) { + ubifs_errc(c, "bad node length %d, expected %d", l, len); + goto out; + } + + return 0; + +out: + ubifs_errc(c, "bad node at LEB %d:%d, LEB mapping status %d", lnum, + offs, ubi_is_mapped(c->ubi, lnum)); + if (!c->probing) { + ubifs_dump_node(c, buf); + dump_stack(); + } + return -EINVAL; +} + +/** + * ubifs_wbuf_init - initialize write-buffer. + * @c: UBIFS file-system description object + * @wbuf: write-buffer to initialize + * + * This function initializes write-buffer. Returns zero in case of success + * %-ENOMEM in case of failure. + */ +int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) +{ + size_t size; + + wbuf->buf = kmalloc(c->max_write_size, GFP_KERNEL); + if (!wbuf->buf) + return -ENOMEM; + + size = (c->max_write_size / UBIFS_CH_SZ + 1) * sizeof(ino_t); + wbuf->inodes = kmalloc(size, GFP_KERNEL); + if (!wbuf->inodes) { + kfree(wbuf->buf); + wbuf->buf = NULL; + return -ENOMEM; + } + + wbuf->used = 0; + wbuf->lnum = wbuf->offs = -1; + /* + * If the LEB starts at the max. write size aligned address, then + * write-buffer size has to be set to @c->max_write_size. Otherwise, + * set it to something smaller so that it ends at the closest max. + * write size boundary. + */ + size = c->max_write_size - (c->leb_start % c->max_write_size); + wbuf->avail = wbuf->size = size; + wbuf->sync_callback = NULL; + mutex_init(&wbuf->io_mutex); + spin_lock_init(&wbuf->lock); + wbuf->c = c; + wbuf->next_ino = 0; + + hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + wbuf->timer.function = wbuf_timer_callback_nolock; + return 0; +} + +/** + * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array. + * @wbuf: the write-buffer where to add + * @inum: the inode number + * + * This function adds an inode number to the inode array of the write-buffer. + */ +void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum) +{ + if (!wbuf->buf) + /* NOR flash or something similar */ + return; + + spin_lock(&wbuf->lock); + if (wbuf->used) + wbuf->inodes[wbuf->next_ino++] = inum; + spin_unlock(&wbuf->lock); +} + +/** + * wbuf_has_ino - returns if the wbuf contains data from the inode. + * @wbuf: the write-buffer + * @inum: the inode number + * + * This function returns with %1 if the write-buffer contains some data from the + * given inode otherwise it returns with %0. + */ +static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum) +{ + int i, ret = 0; + + spin_lock(&wbuf->lock); + for (i = 0; i < wbuf->next_ino; i++) + if (inum == wbuf->inodes[i]) { + ret = 1; + break; + } + spin_unlock(&wbuf->lock); + + return ret; +} + +/** + * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode. + * @c: UBIFS file-system description object + * @inode: inode to synchronize + * + * This function synchronizes write-buffers which contain nodes belonging to + * @inode. Returns zero in case of success and a negative error code in case of + * failure. + */ +int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode) +{ + int i, err = 0; + + for (i = 0; i < c->jhead_cnt; i++) { + struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; + + if (i == GCHD) + /* + * GC head is special, do not look at it. Even if the + * head contains something related to this inode, it is + * a _copy_ of corresponding on-flash node which sits + * somewhere else. + */ + continue; + + if (!wbuf_has_ino(wbuf, inode->i_ino)) + continue; + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + if (wbuf_has_ino(wbuf, inode->i_ino)) + err = ubifs_wbuf_sync_nolock(wbuf); + mutex_unlock(&wbuf->io_mutex); + + if (err) { + ubifs_ro_mode(c, err); + return err; + } + } + return 0; +} diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c new file mode 100644 index 000000000..8db380a00 --- /dev/null +++ b/fs/ubifs/ioctl.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * Copyright (C) 2006, 2007 University of Szeged, Hungary + * + * Authors: Zoltan Sogor + * Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* This file implements EXT2-compatible extended attribute ioctl() calls */ + +#include <linux/compat.h> +#include <linux/mount.h> +#include "ubifs.h" + +/* Need to be kept consistent with checked flags in ioctl2ubifs() */ +#define UBIFS_SETTABLE_IOCTL_FLAGS \ + (FS_COMPR_FL | FS_SYNC_FL | FS_APPEND_FL | \ + FS_IMMUTABLE_FL | FS_DIRSYNC_FL) + +/* Need to be kept consistent with checked flags in ubifs2ioctl() */ +#define UBIFS_GETTABLE_IOCTL_FLAGS \ + (UBIFS_SETTABLE_IOCTL_FLAGS | FS_ENCRYPT_FL) + +/** + * ubifs_set_inode_flags - set VFS inode flags. + * @inode: VFS inode to set flags for + * + * This function propagates flags from UBIFS inode object to VFS inode object. + */ +void ubifs_set_inode_flags(struct inode *inode) +{ + unsigned int flags = ubifs_inode(inode)->flags; + + inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC | + S_ENCRYPTED); + if (flags & UBIFS_SYNC_FL) + inode->i_flags |= S_SYNC; + if (flags & UBIFS_APPEND_FL) + inode->i_flags |= S_APPEND; + if (flags & UBIFS_IMMUTABLE_FL) + inode->i_flags |= S_IMMUTABLE; + if (flags & UBIFS_DIRSYNC_FL) + inode->i_flags |= S_DIRSYNC; + if (flags & UBIFS_CRYPT_FL) + inode->i_flags |= S_ENCRYPTED; +} + +/* + * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags. + * @ioctl_flags: flags to convert + * + * This function converts ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags + * (@UBIFS_COMPR_FL, etc). + */ +static int ioctl2ubifs(int ioctl_flags) +{ + int ubifs_flags = 0; + + if (ioctl_flags & FS_COMPR_FL) + ubifs_flags |= UBIFS_COMPR_FL; + if (ioctl_flags & FS_SYNC_FL) + ubifs_flags |= UBIFS_SYNC_FL; + if (ioctl_flags & FS_APPEND_FL) + ubifs_flags |= UBIFS_APPEND_FL; + if (ioctl_flags & FS_IMMUTABLE_FL) + ubifs_flags |= UBIFS_IMMUTABLE_FL; + if (ioctl_flags & FS_DIRSYNC_FL) + ubifs_flags |= UBIFS_DIRSYNC_FL; + + return ubifs_flags; +} + +/* + * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags. + * @ubifs_flags: flags to convert + * + * This function converts UBIFS inode flags (@UBIFS_COMPR_FL, etc) to ioctl + * flags (@FS_COMPR_FL, etc). + */ +static int ubifs2ioctl(int ubifs_flags) +{ + int ioctl_flags = 0; + + if (ubifs_flags & UBIFS_COMPR_FL) + ioctl_flags |= FS_COMPR_FL; + if (ubifs_flags & UBIFS_SYNC_FL) + ioctl_flags |= FS_SYNC_FL; + if (ubifs_flags & UBIFS_APPEND_FL) + ioctl_flags |= FS_APPEND_FL; + if (ubifs_flags & UBIFS_IMMUTABLE_FL) + ioctl_flags |= FS_IMMUTABLE_FL; + if (ubifs_flags & UBIFS_DIRSYNC_FL) + ioctl_flags |= FS_DIRSYNC_FL; + if (ubifs_flags & UBIFS_CRYPT_FL) + ioctl_flags |= FS_ENCRYPT_FL; + + return ioctl_flags; +} + +static int setflags(struct inode *inode, int flags) +{ + int oldflags, err, release; + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_budget_req req = { .dirtied_ino = 1, + .dirtied_ino_d = ALIGN(ui->data_len, 8) }; + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + mutex_lock(&ui->ui_mutex); + oldflags = ubifs2ioctl(ui->flags); + err = vfs_ioc_setflags_prepare(inode, oldflags, flags); + if (err) + goto out_unlock; + + ui->flags &= ~ioctl2ubifs(UBIFS_SETTABLE_IOCTL_FLAGS); + ui->flags |= ioctl2ubifs(flags); + ubifs_set_inode_flags(inode); + inode->i_ctime = current_time(inode); + release = ui->dirty; + mark_inode_dirty_sync(inode); + mutex_unlock(&ui->ui_mutex); + + if (release) + ubifs_release_budget(c, &req); + if (IS_SYNC(inode)) + err = write_inode_now(inode, 1); + return err; + +out_unlock: + mutex_unlock(&ui->ui_mutex); + ubifs_release_budget(c, &req); + return err; +} + +long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + int flags, err; + struct inode *inode = file_inode(file); + + switch (cmd) { + case FS_IOC_GETFLAGS: + flags = ubifs2ioctl(ubifs_inode(inode)->flags); + + dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags); + return put_user(flags, (int __user *) arg); + + case FS_IOC_SETFLAGS: { + if (IS_RDONLY(inode)) + return -EROFS; + + if (!inode_owner_or_capable(inode)) + return -EACCES; + + if (get_user(flags, (int __user *) arg)) + return -EFAULT; + + if (flags & ~UBIFS_GETTABLE_IOCTL_FLAGS) + return -EOPNOTSUPP; + flags &= UBIFS_SETTABLE_IOCTL_FLAGS; + + if (!S_ISDIR(inode->i_mode)) + flags &= ~FS_DIRSYNC_FL; + + /* + * Make sure the file-system is read-write and make sure it + * will not become read-only while we are changing the flags. + */ + err = mnt_want_write_file(file); + if (err) + return err; + dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags); + err = setflags(inode, flags); + mnt_drop_write_file(file); + return err; + } + case FS_IOC_SET_ENCRYPTION_POLICY: { + struct ubifs_info *c = inode->i_sb->s_fs_info; + + err = ubifs_enable_encryption(c); + if (err) + return err; + + return fscrypt_ioctl_set_policy(file, (const void __user *)arg); + } + case FS_IOC_GET_ENCRYPTION_POLICY: + return fscrypt_ioctl_get_policy(file, (void __user *)arg); + + case FS_IOC_GET_ENCRYPTION_POLICY_EX: + return fscrypt_ioctl_get_policy_ex(file, (void __user *)arg); + + case FS_IOC_ADD_ENCRYPTION_KEY: + return fscrypt_ioctl_add_key(file, (void __user *)arg); + + case FS_IOC_REMOVE_ENCRYPTION_KEY: + return fscrypt_ioctl_remove_key(file, (void __user *)arg); + + case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS: + return fscrypt_ioctl_remove_key_all_users(file, + (void __user *)arg); + case FS_IOC_GET_ENCRYPTION_KEY_STATUS: + return fscrypt_ioctl_get_key_status(file, (void __user *)arg); + + case FS_IOC_GET_ENCRYPTION_NONCE: + return fscrypt_ioctl_get_nonce(file, (void __user *)arg); + + default: + return -ENOTTY; + } +} + +#ifdef CONFIG_COMPAT +long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + switch (cmd) { + case FS_IOC32_GETFLAGS: + cmd = FS_IOC_GETFLAGS; + break; + case FS_IOC32_SETFLAGS: + cmd = FS_IOC_SETFLAGS; + break; + case FS_IOC_SET_ENCRYPTION_POLICY: + case FS_IOC_GET_ENCRYPTION_POLICY: + case FS_IOC_GET_ENCRYPTION_POLICY_EX: + case FS_IOC_ADD_ENCRYPTION_KEY: + case FS_IOC_REMOVE_ENCRYPTION_KEY: + case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS: + case FS_IOC_GET_ENCRYPTION_KEY_STATUS: + case FS_IOC_GET_ENCRYPTION_NONCE: + break; + default: + return -ENOIOCTLCMD; + } + return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); +} +#endif diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c new file mode 100644 index 000000000..7274bd238 --- /dev/null +++ b/fs/ubifs/journal.c @@ -0,0 +1,1872 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements UBIFS journal. + * + * The journal consists of 2 parts - the log and bud LEBs. The log has fixed + * length and position, while a bud logical eraseblock is any LEB in the main + * area. Buds contain file system data - data nodes, inode nodes, etc. The log + * contains only references to buds and some other stuff like commit + * start node. The idea is that when we commit the journal, we do + * not copy the data, the buds just become indexed. Since after the commit the + * nodes in bud eraseblocks become leaf nodes of the file system index tree, we + * use term "bud". Analogy is obvious, bud eraseblocks contain nodes which will + * become leafs in the future. + * + * The journal is multi-headed because we want to write data to the journal as + * optimally as possible. It is nice to have nodes belonging to the same inode + * in one LEB, so we may write data owned by different inodes to different + * journal heads, although at present only one data head is used. + * + * For recovery reasons, the base head contains all inode nodes, all directory + * entry nodes and all truncate nodes. This means that the other heads contain + * only data nodes. + * + * Bud LEBs may be half-indexed. For example, if the bud was not full at the + * time of commit, the bud is retained to continue to be used in the journal, + * even though the "front" of the LEB is now indexed. In that case, the log + * reference contains the offset where the bud starts for the purposes of the + * journal. + * + * The journal size has to be limited, because the larger is the journal, the + * longer it takes to mount UBIFS (scanning the journal) and the more memory it + * takes (indexing in the TNC). + * + * All the journal write operations like 'ubifs_jnl_update()' here, which write + * multiple UBIFS nodes to the journal at one go, are atomic with respect to + * unclean reboots. Should the unclean reboot happen, the recovery code drops + * all the nodes. + */ + +#include "ubifs.h" + +/** + * zero_ino_node_unused - zero out unused fields of an on-flash inode node. + * @ino: the inode to zero out + */ +static inline void zero_ino_node_unused(struct ubifs_ino_node *ino) +{ + memset(ino->padding1, 0, 4); + memset(ino->padding2, 0, 26); +} + +/** + * zero_dent_node_unused - zero out unused fields of an on-flash directory + * entry node. + * @dent: the directory entry to zero out + */ +static inline void zero_dent_node_unused(struct ubifs_dent_node *dent) +{ + dent->padding1 = 0; +} + +/** + * zero_trun_node_unused - zero out unused fields of an on-flash truncation + * node. + * @trun: the truncation node to zero out + */ +static inline void zero_trun_node_unused(struct ubifs_trun_node *trun) +{ + memset(trun->padding, 0, 12); +} + +static void ubifs_add_auth_dirt(struct ubifs_info *c, int lnum) +{ + if (ubifs_authenticated(c)) + ubifs_add_dirt(c, lnum, ubifs_auth_node_sz(c)); +} + +/** + * reserve_space - reserve space in the journal. + * @c: UBIFS file-system description object + * @jhead: journal head number + * @len: node length + * + * This function reserves space in journal head @head. If the reservation + * succeeded, the journal head stays locked and later has to be unlocked using + * 'release_head()'. Returns zero in case of success, %-EAGAIN if commit has to + * be done, and other negative error codes in case of other failures. + */ +static int reserve_space(struct ubifs_info *c, int jhead, int len) +{ + int err = 0, err1, retries = 0, avail, lnum, offs, squeeze; + struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf; + + /* + * Typically, the base head has smaller nodes written to it, so it is + * better to try to allocate space at the ends of eraseblocks. This is + * what the squeeze parameter does. + */ + ubifs_assert(c, !c->ro_media && !c->ro_mount); + squeeze = (jhead == BASEHD); +again: + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + + if (c->ro_error) { + err = -EROFS; + goto out_unlock; + } + + avail = c->leb_size - wbuf->offs - wbuf->used; + if (wbuf->lnum != -1 && avail >= len) + return 0; + + /* + * Write buffer wasn't seek'ed or there is no enough space - look for an + * LEB with some empty space. + */ + lnum = ubifs_find_free_space(c, len, &offs, squeeze); + if (lnum >= 0) + goto out; + + err = lnum; + if (err != -ENOSPC) + goto out_unlock; + + /* + * No free space, we have to run garbage collector to make + * some. But the write-buffer mutex has to be unlocked because + * GC also takes it. + */ + dbg_jnl("no free space in jhead %s, run GC", dbg_jhead(jhead)); + mutex_unlock(&wbuf->io_mutex); + + lnum = ubifs_garbage_collect(c, 0); + if (lnum < 0) { + err = lnum; + if (err != -ENOSPC) + return err; + + /* + * GC could not make a free LEB. But someone else may + * have allocated new bud for this journal head, + * because we dropped @wbuf->io_mutex, so try once + * again. + */ + dbg_jnl("GC couldn't make a free LEB for jhead %s", + dbg_jhead(jhead)); + if (retries++ < 2) { + dbg_jnl("retry (%d)", retries); + goto again; + } + + dbg_jnl("return -ENOSPC"); + return err; + } + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + dbg_jnl("got LEB %d for jhead %s", lnum, dbg_jhead(jhead)); + avail = c->leb_size - wbuf->offs - wbuf->used; + + if (wbuf->lnum != -1 && avail >= len) { + /* + * Someone else has switched the journal head and we have + * enough space now. This happens when more than one process is + * trying to write to the same journal head at the same time. + */ + dbg_jnl("return LEB %d back, already have LEB %d:%d", + lnum, wbuf->lnum, wbuf->offs + wbuf->used); + err = ubifs_return_leb(c, lnum); + if (err) + goto out_unlock; + return 0; + } + + offs = 0; + +out: + /* + * Make sure we synchronize the write-buffer before we add the new bud + * to the log. Otherwise we may have a power cut after the log + * reference node for the last bud (@lnum) is written but before the + * write-buffer data are written to the next-to-last bud + * (@wbuf->lnum). And the effect would be that the recovery would see + * that there is corruption in the next-to-last bud. + */ + err = ubifs_wbuf_sync_nolock(wbuf); + if (err) + goto out_return; + err = ubifs_add_bud_to_log(c, jhead, lnum, offs); + if (err) + goto out_return; + err = ubifs_wbuf_seek_nolock(wbuf, lnum, offs); + if (err) + goto out_unlock; + + return 0; + +out_unlock: + mutex_unlock(&wbuf->io_mutex); + return err; + +out_return: + /* An error occurred and the LEB has to be returned to lprops */ + ubifs_assert(c, err < 0); + err1 = ubifs_return_leb(c, lnum); + if (err1 && err == -EAGAIN) + /* + * Return original error code only if it is not %-EAGAIN, + * which is not really an error. Otherwise, return the error + * code of 'ubifs_return_leb()'. + */ + err = err1; + mutex_unlock(&wbuf->io_mutex); + return err; +} + +static int ubifs_hash_nodes(struct ubifs_info *c, void *node, + int len, struct shash_desc *hash) +{ + int auth_node_size = ubifs_auth_node_sz(c); + int err; + + while (1) { + const struct ubifs_ch *ch = node; + int nodelen = le32_to_cpu(ch->len); + + ubifs_assert(c, len >= auth_node_size); + + if (len == auth_node_size) + break; + + ubifs_assert(c, len > nodelen); + ubifs_assert(c, ch->magic == cpu_to_le32(UBIFS_NODE_MAGIC)); + + err = ubifs_shash_update(c, hash, (void *)node, nodelen); + if (err) + return err; + + node += ALIGN(nodelen, 8); + len -= ALIGN(nodelen, 8); + } + + return ubifs_prepare_auth_node(c, node, hash); +} + +/** + * write_head - write data to a journal head. + * @c: UBIFS file-system description object + * @jhead: journal head + * @buf: buffer to write + * @len: length to write + * @lnum: LEB number written is returned here + * @offs: offset written is returned here + * @sync: non-zero if the write-buffer has to by synchronized + * + * This function writes data to the reserved space of journal head @jhead. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +static int write_head(struct ubifs_info *c, int jhead, void *buf, int len, + int *lnum, int *offs, int sync) +{ + int err; + struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf; + + ubifs_assert(c, jhead != GCHD); + + *lnum = c->jheads[jhead].wbuf.lnum; + *offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used; + dbg_jnl("jhead %s, LEB %d:%d, len %d", + dbg_jhead(jhead), *lnum, *offs, len); + + if (ubifs_authenticated(c)) { + err = ubifs_hash_nodes(c, buf, len, c->jheads[jhead].log_hash); + if (err) + return err; + } + + err = ubifs_wbuf_write_nolock(wbuf, buf, len); + if (err) + return err; + if (sync) + err = ubifs_wbuf_sync_nolock(wbuf); + return err; +} + +/** + * make_reservation - reserve journal space. + * @c: UBIFS file-system description object + * @jhead: journal head + * @len: how many bytes to reserve + * + * This function makes space reservation in journal head @jhead. The function + * takes the commit lock and locks the journal head, and the caller has to + * unlock the head and finish the reservation with 'finish_reservation()'. + * Returns zero in case of success and a negative error code in case of + * failure. + * + * Note, the journal head may be unlocked as soon as the data is written, while + * the commit lock has to be released after the data has been added to the + * TNC. + */ +static int make_reservation(struct ubifs_info *c, int jhead, int len) +{ + int err, cmt_retries = 0, nospc_retries = 0; + +again: + down_read(&c->commit_sem); + err = reserve_space(c, jhead, len); + if (!err) + /* c->commit_sem will get released via finish_reservation(). */ + return 0; + up_read(&c->commit_sem); + + if (err == -ENOSPC) { + /* + * GC could not make any progress. We should try to commit + * once because it could make some dirty space and GC would + * make progress, so make the error -EAGAIN so that the below + * will commit and re-try. + */ + if (nospc_retries++ < 2) { + dbg_jnl("no space, retry"); + err = -EAGAIN; + } + + /* + * This means that the budgeting is incorrect. We always have + * to be able to write to the media, because all operations are + * budgeted. Deletions are not budgeted, though, but we reserve + * an extra LEB for them. + */ + } + + if (err != -EAGAIN) + goto out; + + /* + * -EAGAIN means that the journal is full or too large, or the above + * code wants to do one commit. Do this and re-try. + */ + if (cmt_retries > 128) { + /* + * This should not happen unless the journal size limitations + * are too tough. + */ + ubifs_err(c, "stuck in space allocation"); + err = -ENOSPC; + goto out; + } else if (cmt_retries > 32) + ubifs_warn(c, "too many space allocation re-tries (%d)", + cmt_retries); + + dbg_jnl("-EAGAIN, commit and retry (retried %d times)", + cmt_retries); + cmt_retries += 1; + + err = ubifs_run_commit(c); + if (err) + return err; + goto again; + +out: + ubifs_err(c, "cannot reserve %d bytes in jhead %d, error %d", + len, jhead, err); + if (err == -ENOSPC) { + /* This are some budgeting problems, print useful information */ + down_write(&c->commit_sem); + dump_stack(); + ubifs_dump_budg(c, &c->bi); + ubifs_dump_lprops(c); + cmt_retries = dbg_check_lprops(c); + up_write(&c->commit_sem); + } + return err; +} + +/** + * release_head - release a journal head. + * @c: UBIFS file-system description object + * @jhead: journal head + * + * This function releases journal head @jhead which was locked by + * the 'make_reservation()' function. It has to be called after each successful + * 'make_reservation()' invocation. + */ +static inline void release_head(struct ubifs_info *c, int jhead) +{ + mutex_unlock(&c->jheads[jhead].wbuf.io_mutex); +} + +/** + * finish_reservation - finish a reservation. + * @c: UBIFS file-system description object + * + * This function finishes journal space reservation. It must be called after + * 'make_reservation()'. + */ +static void finish_reservation(struct ubifs_info *c) +{ + up_read(&c->commit_sem); +} + +/** + * get_dent_type - translate VFS inode mode to UBIFS directory entry type. + * @mode: inode mode + */ +static int get_dent_type(int mode) +{ + switch (mode & S_IFMT) { + case S_IFREG: + return UBIFS_ITYPE_REG; + case S_IFDIR: + return UBIFS_ITYPE_DIR; + case S_IFLNK: + return UBIFS_ITYPE_LNK; + case S_IFBLK: + return UBIFS_ITYPE_BLK; + case S_IFCHR: + return UBIFS_ITYPE_CHR; + case S_IFIFO: + return UBIFS_ITYPE_FIFO; + case S_IFSOCK: + return UBIFS_ITYPE_SOCK; + default: + BUG(); + } + return 0; +} + +/** + * pack_inode - pack an inode node. + * @c: UBIFS file-system description object + * @ino: buffer in which to pack inode node + * @inode: inode to pack + * @last: indicates the last node of the group + */ +static void pack_inode(struct ubifs_info *c, struct ubifs_ino_node *ino, + const struct inode *inode, int last) +{ + int data_len = 0, last_reference = !inode->i_nlink; + struct ubifs_inode *ui = ubifs_inode(inode); + + ino->ch.node_type = UBIFS_INO_NODE; + ino_key_init_flash(c, &ino->key, inode->i_ino); + ino->creat_sqnum = cpu_to_le64(ui->creat_sqnum); + ino->atime_sec = cpu_to_le64(inode->i_atime.tv_sec); + ino->atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec); + ino->ctime_sec = cpu_to_le64(inode->i_ctime.tv_sec); + ino->ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec); + ino->mtime_sec = cpu_to_le64(inode->i_mtime.tv_sec); + ino->mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); + ino->uid = cpu_to_le32(i_uid_read(inode)); + ino->gid = cpu_to_le32(i_gid_read(inode)); + ino->mode = cpu_to_le32(inode->i_mode); + ino->flags = cpu_to_le32(ui->flags); + ino->size = cpu_to_le64(ui->ui_size); + ino->nlink = cpu_to_le32(inode->i_nlink); + ino->compr_type = cpu_to_le16(ui->compr_type); + ino->data_len = cpu_to_le32(ui->data_len); + ino->xattr_cnt = cpu_to_le32(ui->xattr_cnt); + ino->xattr_size = cpu_to_le32(ui->xattr_size); + ino->xattr_names = cpu_to_le32(ui->xattr_names); + zero_ino_node_unused(ino); + + /* + * Drop the attached data if this is a deletion inode, the data is not + * needed anymore. + */ + if (!last_reference) { + memcpy(ino->data, ui->data, ui->data_len); + data_len = ui->data_len; + } + + ubifs_prep_grp_node(c, ino, UBIFS_INO_NODE_SZ + data_len, last); +} + +/** + * mark_inode_clean - mark UBIFS inode as clean. + * @c: UBIFS file-system description object + * @ui: UBIFS inode to mark as clean + * + * This helper function marks UBIFS inode @ui as clean by cleaning the + * @ui->dirty flag and releasing its budget. Note, VFS may still treat the + * inode as dirty and try to write it back, but 'ubifs_write_inode()' would + * just do nothing. + */ +static void mark_inode_clean(struct ubifs_info *c, struct ubifs_inode *ui) +{ + if (ui->dirty) + ubifs_release_dirty_inode_budget(c, ui); + ui->dirty = 0; +} + +static void set_dent_cookie(struct ubifs_info *c, struct ubifs_dent_node *dent) +{ + if (c->double_hash) + dent->cookie = (__force __le32) prandom_u32(); + else + dent->cookie = 0; +} + +/** + * ubifs_jnl_update - update inode. + * @c: UBIFS file-system description object + * @dir: parent inode or host inode in case of extended attributes + * @nm: directory entry name + * @inode: inode to update + * @deletion: indicates a directory entry deletion i.e unlink or rmdir + * @xent: non-zero if the directory entry is an extended attribute entry + * + * This function updates an inode by writing a directory entry (or extended + * attribute entry), the inode itself, and the parent directory inode (or the + * host inode) to the journal. + * + * The function writes the host inode @dir last, which is important in case of + * extended attributes. Indeed, then we guarantee that if the host inode gets + * synchronized (with 'fsync()'), and the write-buffer it sits in gets flushed, + * the extended attribute inode gets flushed too. And this is exactly what the + * user expects - synchronizing the host inode synchronizes its extended + * attributes. Similarly, this guarantees that if @dir is synchronized, its + * directory entry corresponding to @nm gets synchronized too. + * + * If the inode (@inode) or the parent directory (@dir) are synchronous, this + * function synchronizes the write-buffer. + * + * This function marks the @dir and @inode inodes as clean and returns zero on + * success. In case of failure, a negative error code is returned. + */ +int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, + const struct fscrypt_name *nm, const struct inode *inode, + int deletion, int xent) +{ + int err, dlen, ilen, len, lnum, ino_offs, dent_offs, orphan_added = 0; + int aligned_dlen, aligned_ilen, sync = IS_DIRSYNC(dir); + int last_reference = !!(deletion && inode->i_nlink == 0); + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_inode *host_ui = ubifs_inode(dir); + struct ubifs_dent_node *dent; + struct ubifs_ino_node *ino; + union ubifs_key dent_key, ino_key; + u8 hash_dent[UBIFS_HASH_ARR_SZ]; + u8 hash_ino[UBIFS_HASH_ARR_SZ]; + u8 hash_ino_host[UBIFS_HASH_ARR_SZ]; + + ubifs_assert(c, mutex_is_locked(&host_ui->ui_mutex)); + + dlen = UBIFS_DENT_NODE_SZ + fname_len(nm) + 1; + ilen = UBIFS_INO_NODE_SZ; + + /* + * If the last reference to the inode is being deleted, then there is + * no need to attach and write inode data, it is being deleted anyway. + * And if the inode is being deleted, no need to synchronize + * write-buffer even if the inode is synchronous. + */ + if (!last_reference) { + ilen += ui->data_len; + sync |= IS_SYNC(inode); + } + + aligned_dlen = ALIGN(dlen, 8); + aligned_ilen = ALIGN(ilen, 8); + + len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ; + /* Make sure to also account for extended attributes */ + if (ubifs_authenticated(c)) + len += ALIGN(host_ui->data_len, 8) + ubifs_auth_node_sz(c); + else + len += host_ui->data_len; + + dent = kzalloc(len, GFP_NOFS); + if (!dent) + return -ENOMEM; + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, BASEHD, len); + if (err) + goto out_free; + + if (!xent) { + dent->ch.node_type = UBIFS_DENT_NODE; + if (fname_name(nm) == NULL) + dent_key_init_hash(c, &dent_key, dir->i_ino, nm->hash); + else + dent_key_init(c, &dent_key, dir->i_ino, nm); + } else { + dent->ch.node_type = UBIFS_XENT_NODE; + xent_key_init(c, &dent_key, dir->i_ino, nm); + } + + key_write(c, &dent_key, dent->key); + dent->inum = deletion ? 0 : cpu_to_le64(inode->i_ino); + dent->type = get_dent_type(inode->i_mode); + dent->nlen = cpu_to_le16(fname_len(nm)); + memcpy(dent->name, fname_name(nm), fname_len(nm)); + dent->name[fname_len(nm)] = '\0'; + set_dent_cookie(c, dent); + + zero_dent_node_unused(dent); + ubifs_prep_grp_node(c, dent, dlen, 0); + err = ubifs_node_calc_hash(c, dent, hash_dent); + if (err) + goto out_release; + + ino = (void *)dent + aligned_dlen; + pack_inode(c, ino, inode, 0); + err = ubifs_node_calc_hash(c, ino, hash_ino); + if (err) + goto out_release; + + ino = (void *)ino + aligned_ilen; + pack_inode(c, ino, dir, 1); + err = ubifs_node_calc_hash(c, ino, hash_ino_host); + if (err) + goto out_release; + + if (last_reference) { + err = ubifs_add_orphan(c, inode->i_ino); + if (err) { + release_head(c, BASEHD); + goto out_finish; + } + ui->del_cmtno = c->cmt_no; + orphan_added = 1; + } + + err = write_head(c, BASEHD, dent, len, &lnum, &dent_offs, sync); + if (err) + goto out_release; + if (!sync) { + struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf; + + ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino); + ubifs_wbuf_add_ino_nolock(wbuf, dir->i_ino); + } + release_head(c, BASEHD); + kfree(dent); + ubifs_add_auth_dirt(c, lnum); + + if (deletion) { + if (fname_name(nm) == NULL) + err = ubifs_tnc_remove_dh(c, &dent_key, nm->minor_hash); + else + err = ubifs_tnc_remove_nm(c, &dent_key, nm); + if (err) + goto out_ro; + err = ubifs_add_dirt(c, lnum, dlen); + } else + err = ubifs_tnc_add_nm(c, &dent_key, lnum, dent_offs, dlen, + hash_dent, nm); + if (err) + goto out_ro; + + /* + * Note, we do not remove the inode from TNC even if the last reference + * to it has just been deleted, because the inode may still be opened. + * Instead, the inode has been added to orphan lists and the orphan + * subsystem will take further care about it. + */ + ino_key_init(c, &ino_key, inode->i_ino); + ino_offs = dent_offs + aligned_dlen; + err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, ilen, hash_ino); + if (err) + goto out_ro; + + ino_key_init(c, &ino_key, dir->i_ino); + ino_offs += aligned_ilen; + err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, + UBIFS_INO_NODE_SZ + host_ui->data_len, hash_ino_host); + if (err) + goto out_ro; + + finish_reservation(c); + spin_lock(&ui->ui_lock); + ui->synced_i_size = ui->ui_size; + spin_unlock(&ui->ui_lock); + if (xent) { + spin_lock(&host_ui->ui_lock); + host_ui->synced_i_size = host_ui->ui_size; + spin_unlock(&host_ui->ui_lock); + } + mark_inode_clean(c, ui); + mark_inode_clean(c, host_ui); + return 0; + +out_finish: + finish_reservation(c); +out_free: + kfree(dent); + return err; + +out_release: + release_head(c, BASEHD); + kfree(dent); +out_ro: + ubifs_ro_mode(c, err); + if (orphan_added) + ubifs_delete_orphan(c, inode->i_ino); + finish_reservation(c); + return err; +} + +/** + * ubifs_jnl_write_data - write a data node to the journal. + * @c: UBIFS file-system description object + * @inode: inode the data node belongs to + * @key: node key + * @buf: buffer to write + * @len: data length (must not exceed %UBIFS_BLOCK_SIZE) + * + * This function writes a data node to the journal. Returns %0 if the data node + * was successfully written, and a negative error code in case of failure. + */ +int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, + const union ubifs_key *key, const void *buf, int len) +{ + struct ubifs_data_node *data; + int err, lnum, offs, compr_type, out_len, compr_len, auth_len; + int dlen = COMPRESSED_DATA_NODE_BUF_SZ, allocated = 1; + int write_len; + struct ubifs_inode *ui = ubifs_inode(inode); + bool encrypted = IS_ENCRYPTED(inode); + u8 hash[UBIFS_HASH_ARR_SZ]; + + dbg_jnlk(key, "ino %lu, blk %u, len %d, key ", + (unsigned long)key_inum(c, key), key_block(c, key), len); + ubifs_assert(c, len <= UBIFS_BLOCK_SIZE); + + if (encrypted) + dlen += UBIFS_CIPHER_BLOCK_SIZE; + + auth_len = ubifs_auth_node_sz(c); + + data = kmalloc(dlen + auth_len, GFP_NOFS | __GFP_NOWARN); + if (!data) { + /* + * Fall-back to the write reserve buffer. Note, we might be + * currently on the memory reclaim path, when the kernel is + * trying to free some memory by writing out dirty pages. The + * write reserve buffer helps us to guarantee that we are + * always able to write the data. + */ + allocated = 0; + mutex_lock(&c->write_reserve_mutex); + data = c->write_reserve_buf; + } + + data->ch.node_type = UBIFS_DATA_NODE; + key_write(c, key, &data->key); + data->size = cpu_to_le32(len); + + if (!(ui->flags & UBIFS_COMPR_FL)) + /* Compression is disabled for this inode */ + compr_type = UBIFS_COMPR_NONE; + else + compr_type = ui->compr_type; + + out_len = compr_len = dlen - UBIFS_DATA_NODE_SZ; + ubifs_compress(c, buf, len, &data->data, &compr_len, &compr_type); + ubifs_assert(c, compr_len <= UBIFS_BLOCK_SIZE); + + if (encrypted) { + err = ubifs_encrypt(inode, data, compr_len, &out_len, key_block(c, key)); + if (err) + goto out_free; + + } else { + data->compr_size = 0; + out_len = compr_len; + } + + dlen = UBIFS_DATA_NODE_SZ + out_len; + if (ubifs_authenticated(c)) + write_len = ALIGN(dlen, 8) + auth_len; + else + write_len = dlen; + + data->compr_type = cpu_to_le16(compr_type); + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, DATAHD, write_len); + if (err) + goto out_free; + + ubifs_prepare_node(c, data, dlen, 0); + err = write_head(c, DATAHD, data, write_len, &lnum, &offs, 0); + if (err) + goto out_release; + + err = ubifs_node_calc_hash(c, data, hash); + if (err) + goto out_release; + + ubifs_wbuf_add_ino_nolock(&c->jheads[DATAHD].wbuf, key_inum(c, key)); + release_head(c, DATAHD); + + ubifs_add_auth_dirt(c, lnum); + + err = ubifs_tnc_add(c, key, lnum, offs, dlen, hash); + if (err) + goto out_ro; + + finish_reservation(c); + if (!allocated) + mutex_unlock(&c->write_reserve_mutex); + else + kfree(data); + return 0; + +out_release: + release_head(c, DATAHD); +out_ro: + ubifs_ro_mode(c, err); + finish_reservation(c); +out_free: + if (!allocated) + mutex_unlock(&c->write_reserve_mutex); + else + kfree(data); + return err; +} + +/** + * ubifs_jnl_write_inode - flush inode to the journal. + * @c: UBIFS file-system description object + * @inode: inode to flush + * + * This function writes inode @inode to the journal. If the inode is + * synchronous, it also synchronizes the write-buffer. Returns zero in case of + * success and a negative error code in case of failure. + */ +int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode) +{ + int err, lnum, offs; + struct ubifs_ino_node *ino, *ino_start; + struct ubifs_inode *ui = ubifs_inode(inode); + int sync = 0, write_len = 0, ilen = UBIFS_INO_NODE_SZ; + int last_reference = !inode->i_nlink; + int kill_xattrs = ui->xattr_cnt && last_reference; + u8 hash[UBIFS_HASH_ARR_SZ]; + + dbg_jnl("ino %lu, nlink %u", inode->i_ino, inode->i_nlink); + + /* + * If the inode is being deleted, do not write the attached data. No + * need to synchronize the write-buffer either. + */ + if (!last_reference) { + ilen += ui->data_len; + sync = IS_SYNC(inode); + } else if (kill_xattrs) { + write_len += UBIFS_INO_NODE_SZ * ui->xattr_cnt; + } + + if (ubifs_authenticated(c)) + write_len += ALIGN(ilen, 8) + ubifs_auth_node_sz(c); + else + write_len += ilen; + + ino_start = ino = kmalloc(write_len, GFP_NOFS); + if (!ino) + return -ENOMEM; + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, BASEHD, write_len); + if (err) + goto out_free; + + if (kill_xattrs) { + union ubifs_key key; + struct fscrypt_name nm = {0}; + struct inode *xino; + struct ubifs_dent_node *xent, *pxent = NULL; + + if (ui->xattr_cnt > ubifs_xattr_max_cnt(c)) { + err = -EPERM; + ubifs_err(c, "Cannot delete inode, it has too much xattrs!"); + goto out_release; + } + + lowest_xent_key(c, &key, inode->i_ino); + while (1) { + xent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(xent)) { + err = PTR_ERR(xent); + if (err == -ENOENT) + break; + + kfree(pxent); + goto out_release; + } + + fname_name(&nm) = xent->name; + fname_len(&nm) = le16_to_cpu(xent->nlen); + + xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum)); + if (IS_ERR(xino)) { + err = PTR_ERR(xino); + ubifs_err(c, "dead directory entry '%s', error %d", + xent->name, err); + ubifs_ro_mode(c, err); + kfree(pxent); + kfree(xent); + goto out_release; + } + ubifs_assert(c, ubifs_inode(xino)->xattr); + + clear_nlink(xino); + pack_inode(c, ino, xino, 0); + ino = (void *)ino + UBIFS_INO_NODE_SZ; + iput(xino); + + kfree(pxent); + pxent = xent; + key_read(c, &xent->key, &key); + } + kfree(pxent); + } + + pack_inode(c, ino, inode, 1); + err = ubifs_node_calc_hash(c, ino, hash); + if (err) + goto out_release; + + err = write_head(c, BASEHD, ino_start, write_len, &lnum, &offs, sync); + if (err) + goto out_release; + if (!sync) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + inode->i_ino); + release_head(c, BASEHD); + + if (last_reference) { + err = ubifs_tnc_remove_ino(c, inode->i_ino); + if (err) + goto out_ro; + ubifs_delete_orphan(c, inode->i_ino); + err = ubifs_add_dirt(c, lnum, write_len); + } else { + union ubifs_key key; + + ubifs_add_auth_dirt(c, lnum); + + ino_key_init(c, &key, inode->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, ilen, hash); + } + if (err) + goto out_ro; + + finish_reservation(c); + spin_lock(&ui->ui_lock); + ui->synced_i_size = ui->ui_size; + spin_unlock(&ui->ui_lock); + kfree(ino_start); + return 0; + +out_release: + release_head(c, BASEHD); +out_ro: + ubifs_ro_mode(c, err); + finish_reservation(c); +out_free: + kfree(ino_start); + return err; +} + +/** + * ubifs_jnl_delete_inode - delete an inode. + * @c: UBIFS file-system description object + * @inode: inode to delete + * + * This function deletes inode @inode which includes removing it from orphans, + * deleting it from TNC and, in some cases, writing a deletion inode to the + * journal. + * + * When regular file inodes are unlinked or a directory inode is removed, the + * 'ubifs_jnl_update()' function writes a corresponding deletion inode and + * direntry to the media, and adds the inode to orphans. After this, when the + * last reference to this inode has been dropped, this function is called. In + * general, it has to write one more deletion inode to the media, because if + * a commit happened between 'ubifs_jnl_update()' and + * 'ubifs_jnl_delete_inode()', the deletion inode is not in the journal + * anymore, and in fact it might not be on the flash anymore, because it might + * have been garbage-collected already. And for optimization reasons UBIFS does + * not read the orphan area if it has been unmounted cleanly, so it would have + * no indication in the journal that there is a deleted inode which has to be + * removed from TNC. + * + * However, if there was no commit between 'ubifs_jnl_update()' and + * 'ubifs_jnl_delete_inode()', then there is no need to write the deletion + * inode to the media for the second time. And this is quite a typical case. + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode) +{ + int err; + struct ubifs_inode *ui = ubifs_inode(inode); + + ubifs_assert(c, inode->i_nlink == 0); + + if (ui->xattr_cnt || ui->del_cmtno != c->cmt_no) + /* A commit happened for sure or inode hosts xattrs */ + return ubifs_jnl_write_inode(c, inode); + + down_read(&c->commit_sem); + /* + * Check commit number again, because the first test has been done + * without @c->commit_sem, so a commit might have happened. + */ + if (ui->del_cmtno != c->cmt_no) { + up_read(&c->commit_sem); + return ubifs_jnl_write_inode(c, inode); + } + + err = ubifs_tnc_remove_ino(c, inode->i_ino); + if (err) + ubifs_ro_mode(c, err); + else + ubifs_delete_orphan(c, inode->i_ino); + up_read(&c->commit_sem); + return err; +} + +/** + * ubifs_jnl_xrename - cross rename two directory entries. + * @c: UBIFS file-system description object + * @fst_dir: parent inode of 1st directory entry to exchange + * @fst_inode: 1st inode to exchange + * @fst_nm: name of 1st inode to exchange + * @snd_dir: parent inode of 2nd directory entry to exchange + * @snd_inode: 2nd inode to exchange + * @snd_nm: name of 2nd inode to exchange + * @sync: non-zero if the write-buffer has to be synchronized + * + * This function implements the cross rename operation which may involve + * writing 2 inodes and 2 directory entries. It marks the written inodes as clean + * and returns zero on success. In case of failure, a negative error code is + * returned. + */ +int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, + const struct inode *fst_inode, + const struct fscrypt_name *fst_nm, + const struct inode *snd_dir, + const struct inode *snd_inode, + const struct fscrypt_name *snd_nm, int sync) +{ + union ubifs_key key; + struct ubifs_dent_node *dent1, *dent2; + int err, dlen1, dlen2, lnum, offs, len, plen = UBIFS_INO_NODE_SZ; + int aligned_dlen1, aligned_dlen2; + int twoparents = (fst_dir != snd_dir); + void *p; + u8 hash_dent1[UBIFS_HASH_ARR_SZ]; + u8 hash_dent2[UBIFS_HASH_ARR_SZ]; + u8 hash_p1[UBIFS_HASH_ARR_SZ]; + u8 hash_p2[UBIFS_HASH_ARR_SZ]; + + ubifs_assert(c, ubifs_inode(fst_dir)->data_len == 0); + ubifs_assert(c, ubifs_inode(snd_dir)->data_len == 0); + ubifs_assert(c, mutex_is_locked(&ubifs_inode(fst_dir)->ui_mutex)); + ubifs_assert(c, mutex_is_locked(&ubifs_inode(snd_dir)->ui_mutex)); + + dlen1 = UBIFS_DENT_NODE_SZ + fname_len(snd_nm) + 1; + dlen2 = UBIFS_DENT_NODE_SZ + fname_len(fst_nm) + 1; + aligned_dlen1 = ALIGN(dlen1, 8); + aligned_dlen2 = ALIGN(dlen2, 8); + + len = aligned_dlen1 + aligned_dlen2 + ALIGN(plen, 8); + if (twoparents) + len += plen; + + len += ubifs_auth_node_sz(c); + + dent1 = kzalloc(len, GFP_NOFS); + if (!dent1) + return -ENOMEM; + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, BASEHD, len); + if (err) + goto out_free; + + /* Make new dent for 1st entry */ + dent1->ch.node_type = UBIFS_DENT_NODE; + dent_key_init_flash(c, &dent1->key, snd_dir->i_ino, snd_nm); + dent1->inum = cpu_to_le64(fst_inode->i_ino); + dent1->type = get_dent_type(fst_inode->i_mode); + dent1->nlen = cpu_to_le16(fname_len(snd_nm)); + memcpy(dent1->name, fname_name(snd_nm), fname_len(snd_nm)); + dent1->name[fname_len(snd_nm)] = '\0'; + set_dent_cookie(c, dent1); + zero_dent_node_unused(dent1); + ubifs_prep_grp_node(c, dent1, dlen1, 0); + err = ubifs_node_calc_hash(c, dent1, hash_dent1); + if (err) + goto out_release; + + /* Make new dent for 2nd entry */ + dent2 = (void *)dent1 + aligned_dlen1; + dent2->ch.node_type = UBIFS_DENT_NODE; + dent_key_init_flash(c, &dent2->key, fst_dir->i_ino, fst_nm); + dent2->inum = cpu_to_le64(snd_inode->i_ino); + dent2->type = get_dent_type(snd_inode->i_mode); + dent2->nlen = cpu_to_le16(fname_len(fst_nm)); + memcpy(dent2->name, fname_name(fst_nm), fname_len(fst_nm)); + dent2->name[fname_len(fst_nm)] = '\0'; + set_dent_cookie(c, dent2); + zero_dent_node_unused(dent2); + ubifs_prep_grp_node(c, dent2, dlen2, 0); + err = ubifs_node_calc_hash(c, dent2, hash_dent2); + if (err) + goto out_release; + + p = (void *)dent2 + aligned_dlen2; + if (!twoparents) { + pack_inode(c, p, fst_dir, 1); + err = ubifs_node_calc_hash(c, p, hash_p1); + if (err) + goto out_release; + } else { + pack_inode(c, p, fst_dir, 0); + err = ubifs_node_calc_hash(c, p, hash_p1); + if (err) + goto out_release; + p += ALIGN(plen, 8); + pack_inode(c, p, snd_dir, 1); + err = ubifs_node_calc_hash(c, p, hash_p2); + if (err) + goto out_release; + } + + err = write_head(c, BASEHD, dent1, len, &lnum, &offs, sync); + if (err) + goto out_release; + if (!sync) { + struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf; + + ubifs_wbuf_add_ino_nolock(wbuf, fst_dir->i_ino); + ubifs_wbuf_add_ino_nolock(wbuf, snd_dir->i_ino); + } + release_head(c, BASEHD); + + ubifs_add_auth_dirt(c, lnum); + + dent_key_init(c, &key, snd_dir->i_ino, snd_nm); + err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, hash_dent1, snd_nm); + if (err) + goto out_ro; + + offs += aligned_dlen1; + dent_key_init(c, &key, fst_dir->i_ino, fst_nm); + err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, fst_nm); + if (err) + goto out_ro; + + offs += aligned_dlen2; + + ino_key_init(c, &key, fst_dir->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_p1); + if (err) + goto out_ro; + + if (twoparents) { + offs += ALIGN(plen, 8); + ino_key_init(c, &key, snd_dir->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_p2); + if (err) + goto out_ro; + } + + finish_reservation(c); + + mark_inode_clean(c, ubifs_inode(fst_dir)); + if (twoparents) + mark_inode_clean(c, ubifs_inode(snd_dir)); + kfree(dent1); + return 0; + +out_release: + release_head(c, BASEHD); +out_ro: + ubifs_ro_mode(c, err); + finish_reservation(c); +out_free: + kfree(dent1); + return err; +} + +/** + * ubifs_jnl_rename - rename a directory entry. + * @c: UBIFS file-system description object + * @old_dir: parent inode of directory entry to rename + * @old_dentry: directory entry to rename + * @new_dir: parent inode of directory entry to rename + * @new_dentry: new directory entry (or directory entry to replace) + * @sync: non-zero if the write-buffer has to be synchronized + * + * This function implements the re-name operation which may involve writing up + * to 4 inodes and 2 directory entries. It marks the written inodes as clean + * and returns zero on success. In case of failure, a negative error code is + * returned. + */ +int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, + const struct inode *old_inode, + const struct fscrypt_name *old_nm, + const struct inode *new_dir, + const struct inode *new_inode, + const struct fscrypt_name *new_nm, + const struct inode *whiteout, int sync) +{ + void *p; + union ubifs_key key; + struct ubifs_dent_node *dent, *dent2; + int err, dlen1, dlen2, ilen, lnum, offs, len, orphan_added = 0; + int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ; + int last_reference = !!(new_inode && new_inode->i_nlink == 0); + int move = (old_dir != new_dir); + struct ubifs_inode *new_ui; + u8 hash_old_dir[UBIFS_HASH_ARR_SZ]; + u8 hash_new_dir[UBIFS_HASH_ARR_SZ]; + u8 hash_new_inode[UBIFS_HASH_ARR_SZ]; + u8 hash_dent1[UBIFS_HASH_ARR_SZ]; + u8 hash_dent2[UBIFS_HASH_ARR_SZ]; + + ubifs_assert(c, ubifs_inode(old_dir)->data_len == 0); + ubifs_assert(c, ubifs_inode(new_dir)->data_len == 0); + ubifs_assert(c, mutex_is_locked(&ubifs_inode(old_dir)->ui_mutex)); + ubifs_assert(c, mutex_is_locked(&ubifs_inode(new_dir)->ui_mutex)); + + dlen1 = UBIFS_DENT_NODE_SZ + fname_len(new_nm) + 1; + dlen2 = UBIFS_DENT_NODE_SZ + fname_len(old_nm) + 1; + if (new_inode) { + new_ui = ubifs_inode(new_inode); + ubifs_assert(c, mutex_is_locked(&new_ui->ui_mutex)); + ilen = UBIFS_INO_NODE_SZ; + if (!last_reference) + ilen += new_ui->data_len; + } else + ilen = 0; + + aligned_dlen1 = ALIGN(dlen1, 8); + aligned_dlen2 = ALIGN(dlen2, 8); + len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); + if (move) + len += plen; + + len += ubifs_auth_node_sz(c); + + dent = kzalloc(len, GFP_NOFS); + if (!dent) + return -ENOMEM; + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, BASEHD, len); + if (err) + goto out_free; + + /* Make new dent */ + dent->ch.node_type = UBIFS_DENT_NODE; + dent_key_init_flash(c, &dent->key, new_dir->i_ino, new_nm); + dent->inum = cpu_to_le64(old_inode->i_ino); + dent->type = get_dent_type(old_inode->i_mode); + dent->nlen = cpu_to_le16(fname_len(new_nm)); + memcpy(dent->name, fname_name(new_nm), fname_len(new_nm)); + dent->name[fname_len(new_nm)] = '\0'; + set_dent_cookie(c, dent); + zero_dent_node_unused(dent); + ubifs_prep_grp_node(c, dent, dlen1, 0); + err = ubifs_node_calc_hash(c, dent, hash_dent1); + if (err) + goto out_release; + + dent2 = (void *)dent + aligned_dlen1; + dent2->ch.node_type = UBIFS_DENT_NODE; + dent_key_init_flash(c, &dent2->key, old_dir->i_ino, old_nm); + + if (whiteout) { + dent2->inum = cpu_to_le64(whiteout->i_ino); + dent2->type = get_dent_type(whiteout->i_mode); + } else { + /* Make deletion dent */ + dent2->inum = 0; + dent2->type = DT_UNKNOWN; + } + dent2->nlen = cpu_to_le16(fname_len(old_nm)); + memcpy(dent2->name, fname_name(old_nm), fname_len(old_nm)); + dent2->name[fname_len(old_nm)] = '\0'; + set_dent_cookie(c, dent2); + zero_dent_node_unused(dent2); + ubifs_prep_grp_node(c, dent2, dlen2, 0); + err = ubifs_node_calc_hash(c, dent2, hash_dent2); + if (err) + goto out_release; + + p = (void *)dent2 + aligned_dlen2; + if (new_inode) { + pack_inode(c, p, new_inode, 0); + err = ubifs_node_calc_hash(c, p, hash_new_inode); + if (err) + goto out_release; + + p += ALIGN(ilen, 8); + } + + if (!move) { + pack_inode(c, p, old_dir, 1); + err = ubifs_node_calc_hash(c, p, hash_old_dir); + if (err) + goto out_release; + } else { + pack_inode(c, p, old_dir, 0); + err = ubifs_node_calc_hash(c, p, hash_old_dir); + if (err) + goto out_release; + + p += ALIGN(plen, 8); + pack_inode(c, p, new_dir, 1); + err = ubifs_node_calc_hash(c, p, hash_new_dir); + if (err) + goto out_release; + } + + if (last_reference) { + err = ubifs_add_orphan(c, new_inode->i_ino); + if (err) { + release_head(c, BASEHD); + goto out_finish; + } + new_ui->del_cmtno = c->cmt_no; + orphan_added = 1; + } + + err = write_head(c, BASEHD, dent, len, &lnum, &offs, sync); + if (err) + goto out_release; + if (!sync) { + struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf; + + ubifs_wbuf_add_ino_nolock(wbuf, new_dir->i_ino); + ubifs_wbuf_add_ino_nolock(wbuf, old_dir->i_ino); + if (new_inode) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + new_inode->i_ino); + } + release_head(c, BASEHD); + + ubifs_add_auth_dirt(c, lnum); + + dent_key_init(c, &key, new_dir->i_ino, new_nm); + err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, hash_dent1, new_nm); + if (err) + goto out_ro; + + offs += aligned_dlen1; + if (whiteout) { + dent_key_init(c, &key, old_dir->i_ino, old_nm); + err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, old_nm); + if (err) + goto out_ro; + + ubifs_delete_orphan(c, whiteout->i_ino); + } else { + err = ubifs_add_dirt(c, lnum, dlen2); + if (err) + goto out_ro; + + dent_key_init(c, &key, old_dir->i_ino, old_nm); + err = ubifs_tnc_remove_nm(c, &key, old_nm); + if (err) + goto out_ro; + } + + offs += aligned_dlen2; + if (new_inode) { + ino_key_init(c, &key, new_inode->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, ilen, hash_new_inode); + if (err) + goto out_ro; + offs += ALIGN(ilen, 8); + } + + ino_key_init(c, &key, old_dir->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_old_dir); + if (err) + goto out_ro; + + if (move) { + offs += ALIGN(plen, 8); + ino_key_init(c, &key, new_dir->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_new_dir); + if (err) + goto out_ro; + } + + finish_reservation(c); + if (new_inode) { + mark_inode_clean(c, new_ui); + spin_lock(&new_ui->ui_lock); + new_ui->synced_i_size = new_ui->ui_size; + spin_unlock(&new_ui->ui_lock); + } + mark_inode_clean(c, ubifs_inode(old_dir)); + if (move) + mark_inode_clean(c, ubifs_inode(new_dir)); + kfree(dent); + return 0; + +out_release: + release_head(c, BASEHD); +out_ro: + ubifs_ro_mode(c, err); + if (orphan_added) + ubifs_delete_orphan(c, new_inode->i_ino); +out_finish: + finish_reservation(c); +out_free: + kfree(dent); + return err; +} + +/** + * truncate_data_node - re-compress/encrypt a truncated data node. + * @c: UBIFS file-system description object + * @inode: inode which referes to the data node + * @block: data block number + * @dn: data node to re-compress + * @new_len: new length + * + * This function is used when an inode is truncated and the last data node of + * the inode has to be re-compressed/encrypted and re-written. + */ +static int truncate_data_node(const struct ubifs_info *c, const struct inode *inode, + unsigned int block, struct ubifs_data_node *dn, + int *new_len) +{ + void *buf; + int err, dlen, compr_type, out_len, old_dlen; + + out_len = le32_to_cpu(dn->size); + buf = kmalloc_array(out_len, WORST_COMPR_FACTOR, GFP_NOFS); + if (!buf) + return -ENOMEM; + + dlen = old_dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; + compr_type = le16_to_cpu(dn->compr_type); + + if (IS_ENCRYPTED(inode)) { + err = ubifs_decrypt(inode, dn, &dlen, block); + if (err) + goto out; + } + + if (compr_type == UBIFS_COMPR_NONE) { + out_len = *new_len; + } else { + err = ubifs_decompress(c, &dn->data, dlen, buf, &out_len, compr_type); + if (err) + goto out; + + ubifs_compress(c, buf, *new_len, &dn->data, &out_len, &compr_type); + } + + if (IS_ENCRYPTED(inode)) { + err = ubifs_encrypt(inode, dn, out_len, &old_dlen, block); + if (err) + goto out; + + out_len = old_dlen; + } else { + dn->compr_size = 0; + } + + ubifs_assert(c, out_len <= UBIFS_BLOCK_SIZE); + dn->compr_type = cpu_to_le16(compr_type); + dn->size = cpu_to_le32(*new_len); + *new_len = UBIFS_DATA_NODE_SZ + out_len; + err = 0; +out: + kfree(buf); + return err; +} + +/** + * ubifs_jnl_truncate - update the journal for a truncation. + * @c: UBIFS file-system description object + * @inode: inode to truncate + * @old_size: old size + * @new_size: new size + * + * When the size of a file decreases due to truncation, a truncation node is + * written, the journal tree is updated, and the last data block is re-written + * if it has been affected. The inode is also updated in order to synchronize + * the new inode size. + * + * This function marks the inode as clean and returns zero on success. In case + * of failure, a negative error code is returned. + */ +int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode, + loff_t old_size, loff_t new_size) +{ + union ubifs_key key, to_key; + struct ubifs_ino_node *ino; + struct ubifs_trun_node *trun; + struct ubifs_data_node *dn; + int err, dlen, len, lnum, offs, bit, sz, sync = IS_SYNC(inode); + struct ubifs_inode *ui = ubifs_inode(inode); + ino_t inum = inode->i_ino; + unsigned int blk; + u8 hash_ino[UBIFS_HASH_ARR_SZ]; + u8 hash_dn[UBIFS_HASH_ARR_SZ]; + + dbg_jnl("ino %lu, size %lld -> %lld", + (unsigned long)inum, old_size, new_size); + ubifs_assert(c, !ui->data_len); + ubifs_assert(c, S_ISREG(inode->i_mode)); + ubifs_assert(c, mutex_is_locked(&ui->ui_mutex)); + + sz = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ + + UBIFS_MAX_DATA_NODE_SZ * WORST_COMPR_FACTOR; + + sz += ubifs_auth_node_sz(c); + + ino = kmalloc(sz, GFP_NOFS); + if (!ino) + return -ENOMEM; + + trun = (void *)ino + UBIFS_INO_NODE_SZ; + trun->ch.node_type = UBIFS_TRUN_NODE; + trun->inum = cpu_to_le32(inum); + trun->old_size = cpu_to_le64(old_size); + trun->new_size = cpu_to_le64(new_size); + zero_trun_node_unused(trun); + + dlen = new_size & (UBIFS_BLOCK_SIZE - 1); + if (dlen) { + /* Get last data block so it can be truncated */ + dn = (void *)trun + UBIFS_TRUN_NODE_SZ; + blk = new_size >> UBIFS_BLOCK_SHIFT; + data_key_init(c, &key, inum, blk); + dbg_jnlk(&key, "last block key "); + err = ubifs_tnc_lookup(c, &key, dn); + if (err == -ENOENT) + dlen = 0; /* Not found (so it is a hole) */ + else if (err) + goto out_free; + else { + int dn_len = le32_to_cpu(dn->size); + + if (dn_len <= 0 || dn_len > UBIFS_BLOCK_SIZE) { + ubifs_err(c, "bad data node (block %u, inode %lu)", + blk, inode->i_ino); + ubifs_dump_node(c, dn); + goto out_free; + } + + if (dn_len <= dlen) + dlen = 0; /* Nothing to do */ + else { + err = truncate_data_node(c, inode, blk, dn, &dlen); + if (err) + goto out_free; + } + } + } + + /* Must make reservation before allocating sequence numbers */ + len = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ; + + if (ubifs_authenticated(c)) + len += ALIGN(dlen, 8) + ubifs_auth_node_sz(c); + else + len += dlen; + + err = make_reservation(c, BASEHD, len); + if (err) + goto out_free; + + pack_inode(c, ino, inode, 0); + err = ubifs_node_calc_hash(c, ino, hash_ino); + if (err) + goto out_release; + + ubifs_prep_grp_node(c, trun, UBIFS_TRUN_NODE_SZ, dlen ? 0 : 1); + if (dlen) { + ubifs_prep_grp_node(c, dn, dlen, 1); + err = ubifs_node_calc_hash(c, dn, hash_dn); + if (err) + goto out_release; + } + + err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync); + if (err) + goto out_release; + if (!sync) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, inum); + release_head(c, BASEHD); + + ubifs_add_auth_dirt(c, lnum); + + if (dlen) { + sz = offs + UBIFS_INO_NODE_SZ + UBIFS_TRUN_NODE_SZ; + err = ubifs_tnc_add(c, &key, lnum, sz, dlen, hash_dn); + if (err) + goto out_ro; + } + + ino_key_init(c, &key, inum); + err = ubifs_tnc_add(c, &key, lnum, offs, UBIFS_INO_NODE_SZ, hash_ino); + if (err) + goto out_ro; + + err = ubifs_add_dirt(c, lnum, UBIFS_TRUN_NODE_SZ); + if (err) + goto out_ro; + + bit = new_size & (UBIFS_BLOCK_SIZE - 1); + blk = (new_size >> UBIFS_BLOCK_SHIFT) + (bit ? 1 : 0); + data_key_init(c, &key, inum, blk); + + bit = old_size & (UBIFS_BLOCK_SIZE - 1); + blk = (old_size >> UBIFS_BLOCK_SHIFT) - (bit ? 0 : 1); + data_key_init(c, &to_key, inum, blk); + + err = ubifs_tnc_remove_range(c, &key, &to_key); + if (err) + goto out_ro; + + finish_reservation(c); + spin_lock(&ui->ui_lock); + ui->synced_i_size = ui->ui_size; + spin_unlock(&ui->ui_lock); + mark_inode_clean(c, ui); + kfree(ino); + return 0; + +out_release: + release_head(c, BASEHD); +out_ro: + ubifs_ro_mode(c, err); + finish_reservation(c); +out_free: + kfree(ino); + return err; +} + + +/** + * ubifs_jnl_delete_xattr - delete an extended attribute. + * @c: UBIFS file-system description object + * @host: host inode + * @inode: extended attribute inode + * @nm: extended attribute entry name + * + * This function delete an extended attribute which is very similar to + * un-linking regular files - it writes a deletion xentry, a deletion inode and + * updates the target inode. Returns zero in case of success and a negative + * error code in case of failure. + */ +int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host, + const struct inode *inode, + const struct fscrypt_name *nm) +{ + int err, xlen, hlen, len, lnum, xent_offs, aligned_xlen, write_len; + struct ubifs_dent_node *xent; + struct ubifs_ino_node *ino; + union ubifs_key xent_key, key1, key2; + int sync = IS_DIRSYNC(host); + struct ubifs_inode *host_ui = ubifs_inode(host); + u8 hash[UBIFS_HASH_ARR_SZ]; + + ubifs_assert(c, inode->i_nlink == 0); + ubifs_assert(c, mutex_is_locked(&host_ui->ui_mutex)); + + /* + * Since we are deleting the inode, we do not bother to attach any data + * to it and assume its length is %UBIFS_INO_NODE_SZ. + */ + xlen = UBIFS_DENT_NODE_SZ + fname_len(nm) + 1; + aligned_xlen = ALIGN(xlen, 8); + hlen = host_ui->data_len + UBIFS_INO_NODE_SZ; + len = aligned_xlen + UBIFS_INO_NODE_SZ + ALIGN(hlen, 8); + + write_len = len + ubifs_auth_node_sz(c); + + xent = kzalloc(write_len, GFP_NOFS); + if (!xent) + return -ENOMEM; + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, BASEHD, write_len); + if (err) { + kfree(xent); + return err; + } + + xent->ch.node_type = UBIFS_XENT_NODE; + xent_key_init(c, &xent_key, host->i_ino, nm); + key_write(c, &xent_key, xent->key); + xent->inum = 0; + xent->type = get_dent_type(inode->i_mode); + xent->nlen = cpu_to_le16(fname_len(nm)); + memcpy(xent->name, fname_name(nm), fname_len(nm)); + xent->name[fname_len(nm)] = '\0'; + zero_dent_node_unused(xent); + ubifs_prep_grp_node(c, xent, xlen, 0); + + ino = (void *)xent + aligned_xlen; + pack_inode(c, ino, inode, 0); + ino = (void *)ino + UBIFS_INO_NODE_SZ; + pack_inode(c, ino, host, 1); + err = ubifs_node_calc_hash(c, ino, hash); + if (err) + goto out_release; + + err = write_head(c, BASEHD, xent, write_len, &lnum, &xent_offs, sync); + if (!sync && !err) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, host->i_ino); + release_head(c, BASEHD); + + ubifs_add_auth_dirt(c, lnum); + kfree(xent); + if (err) + goto out_ro; + + /* Remove the extended attribute entry from TNC */ + err = ubifs_tnc_remove_nm(c, &xent_key, nm); + if (err) + goto out_ro; + err = ubifs_add_dirt(c, lnum, xlen); + if (err) + goto out_ro; + + /* + * Remove all nodes belonging to the extended attribute inode from TNC. + * Well, there actually must be only one node - the inode itself. + */ + lowest_ino_key(c, &key1, inode->i_ino); + highest_ino_key(c, &key2, inode->i_ino); + err = ubifs_tnc_remove_range(c, &key1, &key2); + if (err) + goto out_ro; + err = ubifs_add_dirt(c, lnum, UBIFS_INO_NODE_SZ); + if (err) + goto out_ro; + + /* And update TNC with the new host inode position */ + ino_key_init(c, &key1, host->i_ino); + err = ubifs_tnc_add(c, &key1, lnum, xent_offs + len - hlen, hlen, hash); + if (err) + goto out_ro; + + finish_reservation(c); + spin_lock(&host_ui->ui_lock); + host_ui->synced_i_size = host_ui->ui_size; + spin_unlock(&host_ui->ui_lock); + mark_inode_clean(c, host_ui); + return 0; + +out_release: + kfree(xent); + release_head(c, BASEHD); +out_ro: + ubifs_ro_mode(c, err); + finish_reservation(c); + return err; +} + +/** + * ubifs_jnl_change_xattr - change an extended attribute. + * @c: UBIFS file-system description object + * @inode: extended attribute inode + * @host: host inode + * + * This function writes the updated version of an extended attribute inode and + * the host inode to the journal (to the base head). The host inode is written + * after the extended attribute inode in order to guarantee that the extended + * attribute will be flushed when the inode is synchronized by 'fsync()' and + * consequently, the write-buffer is synchronized. This function returns zero + * in case of success and a negative error code in case of failure. + */ +int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode, + const struct inode *host) +{ + int err, len1, len2, aligned_len, aligned_len1, lnum, offs; + struct ubifs_inode *host_ui = ubifs_inode(host); + struct ubifs_ino_node *ino; + union ubifs_key key; + int sync = IS_DIRSYNC(host); + u8 hash_host[UBIFS_HASH_ARR_SZ]; + u8 hash[UBIFS_HASH_ARR_SZ]; + + dbg_jnl("ino %lu, ino %lu", host->i_ino, inode->i_ino); + ubifs_assert(c, inode->i_nlink > 0); + ubifs_assert(c, mutex_is_locked(&host_ui->ui_mutex)); + + len1 = UBIFS_INO_NODE_SZ + host_ui->data_len; + len2 = UBIFS_INO_NODE_SZ + ubifs_inode(inode)->data_len; + aligned_len1 = ALIGN(len1, 8); + aligned_len = aligned_len1 + ALIGN(len2, 8); + + aligned_len += ubifs_auth_node_sz(c); + + ino = kzalloc(aligned_len, GFP_NOFS); + if (!ino) + return -ENOMEM; + + /* Make reservation before allocating sequence numbers */ + err = make_reservation(c, BASEHD, aligned_len); + if (err) + goto out_free; + + pack_inode(c, ino, host, 0); + err = ubifs_node_calc_hash(c, ino, hash_host); + if (err) + goto out_release; + pack_inode(c, (void *)ino + aligned_len1, inode, 1); + err = ubifs_node_calc_hash(c, (void *)ino + aligned_len1, hash); + if (err) + goto out_release; + + err = write_head(c, BASEHD, ino, aligned_len, &lnum, &offs, 0); + if (!sync && !err) { + struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf; + + ubifs_wbuf_add_ino_nolock(wbuf, host->i_ino); + ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino); + } + release_head(c, BASEHD); + if (err) + goto out_ro; + + ubifs_add_auth_dirt(c, lnum); + + ino_key_init(c, &key, host->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, len1, hash_host); + if (err) + goto out_ro; + + ino_key_init(c, &key, inode->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs + aligned_len1, len2, hash); + if (err) + goto out_ro; + + finish_reservation(c); + spin_lock(&host_ui->ui_lock); + host_ui->synced_i_size = host_ui->ui_size; + spin_unlock(&host_ui->ui_lock); + mark_inode_clean(c, host_ui); + kfree(ino); + return 0; + +out_release: + release_head(c, BASEHD); +out_ro: + ubifs_ro_mode(c, err); + finish_reservation(c); +out_free: + kfree(ino); + return err; +} + diff --git a/fs/ubifs/key.h b/fs/ubifs/key.h new file mode 100644 index 000000000..8142d9d6f --- /dev/null +++ b/fs/ubifs/key.h @@ -0,0 +1,543 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This header contains various key-related definitions and helper function. + * UBIFS allows several key schemes, so we access key fields only via these + * helpers. At the moment only one key scheme is supported. + * + * Simple key scheme + * ~~~~~~~~~~~~~~~~~ + * + * Keys are 64-bits long. First 32-bits are inode number (parent inode number + * in case of direntry key). Next 3 bits are node type. The last 29 bits are + * 4KiB offset in case of inode node, and direntry hash in case of a direntry + * node. We use "r5" hash borrowed from reiserfs. + */ + +/* + * Lot's of the key helpers require a struct ubifs_info *c as the first parameter. + * But we are not using it at all currently. That's designed for future extensions of + * different c->key_format. But right now, there is only one key type, UBIFS_SIMPLE_KEY_FMT. + */ + +#ifndef __UBIFS_KEY_H__ +#define __UBIFS_KEY_H__ + +/** + * key_mask_hash - mask a valid hash value. + * @val: value to be masked + * + * We use hash values as offset in directories, so values %0 and %1 are + * reserved for "." and "..". %2 is reserved for "end of readdir" marker. This + * function makes sure the reserved values are not used. + */ +static inline uint32_t key_mask_hash(uint32_t hash) +{ + hash &= UBIFS_S_KEY_HASH_MASK; + if (unlikely(hash <= 2)) + hash += 3; + return hash; +} + +/** + * key_r5_hash - R5 hash function (borrowed from reiserfs). + * @s: direntry name + * @len: name length + */ +static inline uint32_t key_r5_hash(const char *s, int len) +{ + uint32_t a = 0; + const signed char *str = (const signed char *)s; + + while (len--) { + a += *str << 4; + a += *str >> 4; + a *= 11; + str++; + } + + return key_mask_hash(a); +} + +/** + * key_test_hash - testing hash function. + * @str: direntry name + * @len: name length + */ +static inline uint32_t key_test_hash(const char *str, int len) +{ + uint32_t a = 0; + + len = min_t(uint32_t, len, 4); + memcpy(&a, str, len); + return key_mask_hash(a); +} + +/** + * ino_key_init - initialize inode key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: inode number + */ +static inline void ino_key_init(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + key->u32[0] = inum; + key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS; +} + +/** + * ino_key_init_flash - initialize on-flash inode key. + * @c: UBIFS file-system description object + * @k: key to initialize + * @inum: inode number + */ +static inline void ino_key_init_flash(const struct ubifs_info *c, void *k, + ino_t inum) +{ + union ubifs_key *key = k; + + key->j32[0] = cpu_to_le32(inum); + key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS); + memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8); +} + +/** + * lowest_ino_key - get the lowest possible inode key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: inode number + */ +static inline void lowest_ino_key(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + key->u32[0] = inum; + key->u32[1] = 0; +} + +/** + * highest_ino_key - get the highest possible inode key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: inode number + */ +static inline void highest_ino_key(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + key->u32[0] = inum; + key->u32[1] = 0xffffffff; +} + +/** + * dent_key_init - initialize directory entry key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: parent inode number + * @nm: direntry name and length. Not a string when encrypted! + */ +static inline void dent_key_init(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum, + const struct fscrypt_name *nm) +{ + uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm)); + + ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK)); + key->u32[0] = inum; + key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS); +} + +/** + * dent_key_init_hash - initialize directory entry key without re-calculating + * hash function. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: parent inode number + * @hash: direntry name hash + */ +static inline void dent_key_init_hash(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum, + uint32_t hash) +{ + ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK)); + key->u32[0] = inum; + key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS); +} + +/** + * dent_key_init_flash - initialize on-flash directory entry key. + * @c: UBIFS file-system description object + * @k: key to initialize + * @inum: parent inode number + * @nm: direntry name and length + */ +static inline void dent_key_init_flash(const struct ubifs_info *c, void *k, + ino_t inum, + const struct fscrypt_name *nm) +{ + union ubifs_key *key = k; + uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm)); + + ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK)); + key->j32[0] = cpu_to_le32(inum); + key->j32[1] = cpu_to_le32(hash | + (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS)); + memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8); +} + +/** + * lowest_dent_key - get the lowest possible directory entry key. + * @c: UBIFS file-system description object + * @key: where to store the lowest key + * @inum: parent inode number + */ +static inline void lowest_dent_key(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + key->u32[0] = inum; + key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS; +} + +/** + * xent_key_init - initialize extended attribute entry key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: host inode number + * @nm: extended attribute entry name and length + */ +static inline void xent_key_init(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum, + const struct fscrypt_name *nm) +{ + uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm)); + + ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK)); + key->u32[0] = inum; + key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS); +} + +/** + * xent_key_init_flash - initialize on-flash extended attribute entry key. + * @c: UBIFS file-system description object + * @k: key to initialize + * @inum: host inode number + * @nm: extended attribute entry name and length + */ +static inline void xent_key_init_flash(const struct ubifs_info *c, void *k, + ino_t inum, const struct fscrypt_name *nm) +{ + union ubifs_key *key = k; + uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm)); + + ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK)); + key->j32[0] = cpu_to_le32(inum); + key->j32[1] = cpu_to_le32(hash | + (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS)); + memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8); +} + +/** + * lowest_xent_key - get the lowest possible extended attribute entry key. + * @c: UBIFS file-system description object + * @key: where to store the lowest key + * @inum: host inode number + */ +static inline void lowest_xent_key(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + key->u32[0] = inum; + key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS; +} + +/** + * data_key_init - initialize data key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: inode number + * @block: block number + */ +static inline void data_key_init(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum, + unsigned int block) +{ + ubifs_assert(c, !(block & ~UBIFS_S_KEY_BLOCK_MASK)); + key->u32[0] = inum; + key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS); +} + +/** + * highest_data_key - get the highest possible data key for an inode. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: inode number + */ +static inline void highest_data_key(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + data_key_init(c, key, inum, UBIFS_S_KEY_BLOCK_MASK); +} + +/** + * trun_key_init - initialize truncation node key. + * @c: UBIFS file-system description object + * @key: key to initialize + * @inum: inode number + * + * Note, UBIFS does not have truncation keys on the media and this function is + * only used for purposes of replay. + */ +static inline void trun_key_init(const struct ubifs_info *c, + union ubifs_key *key, ino_t inum) +{ + key->u32[0] = inum; + key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS; +} + +/** + * invalid_key_init - initialize invalid node key. + * @c: UBIFS file-system description object + * @key: key to initialize + * + * This is a helper function which marks a @key object as invalid. + */ +static inline void invalid_key_init(const struct ubifs_info *c, + union ubifs_key *key) +{ + key->u32[0] = 0xDEADBEAF; + key->u32[1] = UBIFS_INVALID_KEY; +} + +/** + * key_type - get key type. + * @c: UBIFS file-system description object + * @key: key to get type of + */ +static inline int key_type(const struct ubifs_info *c, + const union ubifs_key *key) +{ + return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS; +} + +/** + * key_type_flash - get type of a on-flash formatted key. + * @c: UBIFS file-system description object + * @k: key to get type of + */ +static inline int key_type_flash(const struct ubifs_info *c, const void *k) +{ + const union ubifs_key *key = k; + + return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS; +} + +/** + * key_inum - fetch inode number from key. + * @c: UBIFS file-system description object + * @k: key to fetch inode number from + */ +static inline ino_t key_inum(const struct ubifs_info *c, const void *k) +{ + const union ubifs_key *key = k; + + return key->u32[0]; +} + +/** + * key_inum_flash - fetch inode number from an on-flash formatted key. + * @c: UBIFS file-system description object + * @k: key to fetch inode number from + */ +static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k) +{ + const union ubifs_key *key = k; + + return le32_to_cpu(key->j32[0]); +} + +/** + * key_hash - get directory entry hash. + * @c: UBIFS file-system description object + * @key: the key to get hash from + */ +static inline uint32_t key_hash(const struct ubifs_info *c, + const union ubifs_key *key) +{ + return key->u32[1] & UBIFS_S_KEY_HASH_MASK; +} + +/** + * key_hash_flash - get directory entry hash from an on-flash formatted key. + * @c: UBIFS file-system description object + * @k: the key to get hash from + */ +static inline uint32_t key_hash_flash(const struct ubifs_info *c, const void *k) +{ + const union ubifs_key *key = k; + + return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK; +} + +/** + * key_block - get data block number. + * @c: UBIFS file-system description object + * @key: the key to get the block number from + */ +static inline unsigned int key_block(const struct ubifs_info *c, + const union ubifs_key *key) +{ + return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK; +} + +/** + * key_block_flash - get data block number from an on-flash formatted key. + * @c: UBIFS file-system description object + * @k: the key to get the block number from + */ +static inline unsigned int key_block_flash(const struct ubifs_info *c, + const void *k) +{ + const union ubifs_key *key = k; + + return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK; +} + +/** + * key_read - transform a key to in-memory format. + * @c: UBIFS file-system description object + * @from: the key to transform + * @to: the key to store the result + */ +static inline void key_read(const struct ubifs_info *c, const void *from, + union ubifs_key *to) +{ + const union ubifs_key *f = from; + + to->u32[0] = le32_to_cpu(f->j32[0]); + to->u32[1] = le32_to_cpu(f->j32[1]); +} + +/** + * key_write - transform a key from in-memory format. + * @c: UBIFS file-system description object + * @from: the key to transform + * @to: the key to store the result + */ +static inline void key_write(const struct ubifs_info *c, + const union ubifs_key *from, void *to) +{ + union ubifs_key *t = to; + + t->j32[0] = cpu_to_le32(from->u32[0]); + t->j32[1] = cpu_to_le32(from->u32[1]); + memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8); +} + +/** + * key_write_idx - transform a key from in-memory format for the index. + * @c: UBIFS file-system description object + * @from: the key to transform + * @to: the key to store the result + */ +static inline void key_write_idx(const struct ubifs_info *c, + const union ubifs_key *from, void *to) +{ + union ubifs_key *t = to; + + t->j32[0] = cpu_to_le32(from->u32[0]); + t->j32[1] = cpu_to_le32(from->u32[1]); +} + +/** + * key_copy - copy a key. + * @c: UBIFS file-system description object + * @from: the key to copy from + * @to: the key to copy to + */ +static inline void key_copy(const struct ubifs_info *c, + const union ubifs_key *from, union ubifs_key *to) +{ + to->u64[0] = from->u64[0]; +} + +/** + * keys_cmp - compare keys. + * @c: UBIFS file-system description object + * @key1: the first key to compare + * @key2: the second key to compare + * + * This function compares 2 keys and returns %-1 if @key1 is less than + * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2. + */ +static inline int keys_cmp(const struct ubifs_info *c, + const union ubifs_key *key1, + const union ubifs_key *key2) +{ + if (key1->u32[0] < key2->u32[0]) + return -1; + if (key1->u32[0] > key2->u32[0]) + return 1; + if (key1->u32[1] < key2->u32[1]) + return -1; + if (key1->u32[1] > key2->u32[1]) + return 1; + + return 0; +} + +/** + * keys_eq - determine if keys are equivalent. + * @c: UBIFS file-system description object + * @key1: the first key to compare + * @key2: the second key to compare + * + * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and + * %0 if not. + */ +static inline int keys_eq(const struct ubifs_info *c, + const union ubifs_key *key1, + const union ubifs_key *key2) +{ + if (key1->u32[0] != key2->u32[0]) + return 0; + if (key1->u32[1] != key2->u32[1]) + return 0; + return 1; +} + +/** + * is_hash_key - is a key vulnerable to hash collisions. + * @c: UBIFS file-system description object + * @key: key + * + * This function returns %1 if @key is a hashed key or %0 otherwise. + */ +static inline int is_hash_key(const struct ubifs_info *c, + const union ubifs_key *key) +{ + int type = key_type(c, key); + + return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY; +} + +/** + * key_max_inode_size - get maximum file size allowed by current key format. + * @c: UBIFS file-system description object + */ +static inline unsigned long long key_max_inode_size(const struct ubifs_info *c) +{ + switch (c->key_fmt) { + case UBIFS_SIMPLE_KEY_FMT: + return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE; + default: + return 0; + } +} + +#endif /* !__UBIFS_KEY_H__ */ diff --git a/fs/ubifs/log.c b/fs/ubifs/log.c new file mode 100644 index 000000000..b6ac9c428 --- /dev/null +++ b/fs/ubifs/log.c @@ -0,0 +1,762 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file is a part of UBIFS journal implementation and contains various + * functions which manipulate the log. The log is a fixed area on the flash + * which does not contain any data but refers to buds. The log is a part of the + * journal. + */ + +#include "ubifs.h" + +static int dbg_check_bud_bytes(struct ubifs_info *c); + +/** + * ubifs_search_bud - search bud LEB. + * @c: UBIFS file-system description object + * @lnum: logical eraseblock number to search + * + * This function searches bud LEB @lnum. Returns bud description object in case + * of success and %NULL if there is no bud with this LEB number. + */ +struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum) +{ + struct rb_node *p; + struct ubifs_bud *bud; + + spin_lock(&c->buds_lock); + p = c->buds.rb_node; + while (p) { + bud = rb_entry(p, struct ubifs_bud, rb); + if (lnum < bud->lnum) + p = p->rb_left; + else if (lnum > bud->lnum) + p = p->rb_right; + else { + spin_unlock(&c->buds_lock); + return bud; + } + } + spin_unlock(&c->buds_lock); + return NULL; +} + +/** + * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one. + * @c: UBIFS file-system description object + * @lnum: logical eraseblock number to search + * + * This functions returns the wbuf for @lnum or %NULL if there is not one. + */ +struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum) +{ + struct rb_node *p; + struct ubifs_bud *bud; + int jhead; + + if (!c->jheads) + return NULL; + + spin_lock(&c->buds_lock); + p = c->buds.rb_node; + while (p) { + bud = rb_entry(p, struct ubifs_bud, rb); + if (lnum < bud->lnum) + p = p->rb_left; + else if (lnum > bud->lnum) + p = p->rb_right; + else { + jhead = bud->jhead; + spin_unlock(&c->buds_lock); + return &c->jheads[jhead].wbuf; + } + } + spin_unlock(&c->buds_lock); + return NULL; +} + +/** + * empty_log_bytes - calculate amount of empty space in the log. + * @c: UBIFS file-system description object + */ +static inline long long empty_log_bytes(const struct ubifs_info *c) +{ + long long h, t; + + h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs; + t = (long long)c->ltail_lnum * c->leb_size; + + if (h > t) + return c->log_bytes - h + t; + else if (h != t) + return t - h; + else if (c->lhead_lnum != c->ltail_lnum) + return 0; + else + return c->log_bytes; +} + +/** + * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list. + * @c: UBIFS file-system description object + * @bud: the bud to add + */ +void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud) +{ + struct rb_node **p, *parent = NULL; + struct ubifs_bud *b; + struct ubifs_jhead *jhead; + + spin_lock(&c->buds_lock); + p = &c->buds.rb_node; + while (*p) { + parent = *p; + b = rb_entry(parent, struct ubifs_bud, rb); + ubifs_assert(c, bud->lnum != b->lnum); + if (bud->lnum < b->lnum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + + rb_link_node(&bud->rb, parent, p); + rb_insert_color(&bud->rb, &c->buds); + if (c->jheads) { + jhead = &c->jheads[bud->jhead]; + list_add_tail(&bud->list, &jhead->buds_list); + } else + ubifs_assert(c, c->replaying && c->ro_mount); + + /* + * Note, although this is a new bud, we anyway account this space now, + * before any data has been written to it, because this is about to + * guarantee fixed mount time, and this bud will anyway be read and + * scanned. + */ + c->bud_bytes += c->leb_size - bud->start; + + dbg_log("LEB %d:%d, jhead %s, bud_bytes %lld", bud->lnum, + bud->start, dbg_jhead(bud->jhead), c->bud_bytes); + spin_unlock(&c->buds_lock); +} + +/** + * ubifs_add_bud_to_log - add a new bud to the log. + * @c: UBIFS file-system description object + * @jhead: journal head the bud belongs to + * @lnum: LEB number of the bud + * @offs: starting offset of the bud + * + * This function writes a reference node for the new bud LEB @lnum to the log, + * and adds it to the buds trees. It also makes sure that log size does not + * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success, + * %-EAGAIN if commit is required, and a negative error code in case of + * failure. + */ +int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs) +{ + int err; + struct ubifs_bud *bud; + struct ubifs_ref_node *ref; + + bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS); + if (!bud) + return -ENOMEM; + ref = kzalloc(c->ref_node_alsz, GFP_NOFS); + if (!ref) { + kfree(bud); + return -ENOMEM; + } + + mutex_lock(&c->log_mutex); + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->ro_error) { + err = -EROFS; + goto out_unlock; + } + + /* Make sure we have enough space in the log */ + if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) { + dbg_log("not enough log space - %lld, required %d", + empty_log_bytes(c), c->min_log_bytes); + ubifs_commit_required(c); + err = -EAGAIN; + goto out_unlock; + } + + /* + * Make sure the amount of space in buds will not exceed the + * 'c->max_bud_bytes' limit, because we want to guarantee mount time + * limits. + * + * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes + * because we are holding @c->log_mutex. All @c->bud_bytes take place + * when both @c->log_mutex and @c->bud_bytes are locked. + */ + if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) { + dbg_log("bud bytes %lld (%lld max), require commit", + c->bud_bytes, c->max_bud_bytes); + ubifs_commit_required(c); + err = -EAGAIN; + goto out_unlock; + } + + /* + * If the journal is full enough - start background commit. Note, it is + * OK to read 'c->cmt_state' without spinlock because integer reads + * are atomic in the kernel. + */ + if (c->bud_bytes >= c->bg_bud_bytes && + c->cmt_state == COMMIT_RESTING) { + dbg_log("bud bytes %lld (%lld max), initiate BG commit", + c->bud_bytes, c->max_bud_bytes); + ubifs_request_bg_commit(c); + } + + bud->lnum = lnum; + bud->start = offs; + bud->jhead = jhead; + bud->log_hash = NULL; + + ref->ch.node_type = UBIFS_REF_NODE; + ref->lnum = cpu_to_le32(bud->lnum); + ref->offs = cpu_to_le32(bud->start); + ref->jhead = cpu_to_le32(jhead); + + if (c->lhead_offs > c->leb_size - c->ref_node_alsz) { + c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); + ubifs_assert(c, c->lhead_lnum != c->ltail_lnum); + c->lhead_offs = 0; + } + + if (c->lhead_offs == 0) { + /* Must ensure next log LEB has been unmapped */ + err = ubifs_leb_unmap(c, c->lhead_lnum); + if (err) + goto out_unlock; + } + + if (bud->start == 0) { + /* + * Before writing the LEB reference which refers an empty LEB + * to the log, we have to make sure it is mapped, because + * otherwise we'd risk to refer an LEB with garbage in case of + * an unclean reboot, because the target LEB might have been + * unmapped, but not yet physically erased. + */ + err = ubifs_leb_map(c, bud->lnum); + if (err) + goto out_unlock; + } + + dbg_log("write ref LEB %d:%d", + c->lhead_lnum, c->lhead_offs); + err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum, + c->lhead_offs); + if (err) + goto out_unlock; + + err = ubifs_shash_update(c, c->log_hash, ref, UBIFS_REF_NODE_SZ); + if (err) + goto out_unlock; + + err = ubifs_shash_copy_state(c, c->log_hash, c->jheads[jhead].log_hash); + if (err) + goto out_unlock; + + c->lhead_offs += c->ref_node_alsz; + + ubifs_add_bud(c, bud); + + mutex_unlock(&c->log_mutex); + kfree(ref); + return 0; + +out_unlock: + mutex_unlock(&c->log_mutex); + kfree(ref); + kfree(bud); + return err; +} + +/** + * remove_buds - remove used buds. + * @c: UBIFS file-system description object + * + * This function removes use buds from the buds tree. It does not remove the + * buds which are pointed to by journal heads. + */ +static void remove_buds(struct ubifs_info *c) +{ + struct rb_node *p; + + ubifs_assert(c, list_empty(&c->old_buds)); + c->cmt_bud_bytes = 0; + spin_lock(&c->buds_lock); + p = rb_first(&c->buds); + while (p) { + struct rb_node *p1 = p; + struct ubifs_bud *bud; + struct ubifs_wbuf *wbuf; + + p = rb_next(p); + bud = rb_entry(p1, struct ubifs_bud, rb); + wbuf = &c->jheads[bud->jhead].wbuf; + + if (wbuf->lnum == bud->lnum) { + /* + * Do not remove buds which are pointed to by journal + * heads (non-closed buds). + */ + c->cmt_bud_bytes += wbuf->offs - bud->start; + dbg_log("preserve %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld", + bud->lnum, bud->start, dbg_jhead(bud->jhead), + wbuf->offs - bud->start, c->cmt_bud_bytes); + bud->start = wbuf->offs; + } else { + c->cmt_bud_bytes += c->leb_size - bud->start; + dbg_log("remove %d:%d, jhead %s, bud bytes %d, cmt_bud_bytes %lld", + bud->lnum, bud->start, dbg_jhead(bud->jhead), + c->leb_size - bud->start, c->cmt_bud_bytes); + rb_erase(p1, &c->buds); + /* + * If the commit does not finish, the recovery will need + * to replay the journal, in which case the old buds + * must be unchanged. Do not release them until post + * commit i.e. do not allow them to be garbage + * collected. + */ + list_move(&bud->list, &c->old_buds); + } + } + spin_unlock(&c->buds_lock); +} + +/** + * ubifs_log_start_commit - start commit. + * @c: UBIFS file-system description object + * @ltail_lnum: return new log tail LEB number + * + * The commit operation starts with writing "commit start" node to the log and + * reference nodes for all journal heads which will define new journal after + * the commit has been finished. The commit start and reference nodes are + * written in one go to the nearest empty log LEB (hence, when commit is + * finished UBIFS may safely unmap all the previous log LEBs). This function + * returns zero in case of success and a negative error code in case of + * failure. + */ +int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum) +{ + void *buf; + struct ubifs_cs_node *cs; + struct ubifs_ref_node *ref; + int err, i, max_len, len; + + err = dbg_check_bud_bytes(c); + if (err) + return err; + + max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ; + max_len = ALIGN(max_len, c->min_io_size); + buf = cs = kmalloc(max_len, GFP_NOFS); + if (!buf) + return -ENOMEM; + + cs->ch.node_type = UBIFS_CS_NODE; + cs->cmt_no = cpu_to_le64(c->cmt_no); + ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0); + + err = ubifs_shash_init(c, c->log_hash); + if (err) + goto out; + + err = ubifs_shash_update(c, c->log_hash, cs, UBIFS_CS_NODE_SZ); + if (err < 0) + goto out; + + /* + * Note, we do not lock 'c->log_mutex' because this is the commit start + * phase and we are exclusively using the log. And we do not lock + * write-buffer because nobody can write to the file-system at this + * phase. + */ + + len = UBIFS_CS_NODE_SZ; + for (i = 0; i < c->jhead_cnt; i++) { + int lnum = c->jheads[i].wbuf.lnum; + int offs = c->jheads[i].wbuf.offs; + + if (lnum == -1 || offs == c->leb_size) + continue; + + dbg_log("add ref to LEB %d:%d for jhead %s", + lnum, offs, dbg_jhead(i)); + ref = buf + len; + ref->ch.node_type = UBIFS_REF_NODE; + ref->lnum = cpu_to_le32(lnum); + ref->offs = cpu_to_le32(offs); + ref->jhead = cpu_to_le32(i); + + ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0); + len += UBIFS_REF_NODE_SZ; + + err = ubifs_shash_update(c, c->log_hash, ref, + UBIFS_REF_NODE_SZ); + if (err) + goto out; + ubifs_shash_copy_state(c, c->log_hash, c->jheads[i].log_hash); + } + + ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len); + + /* Switch to the next log LEB */ + if (c->lhead_offs) { + c->lhead_lnum = ubifs_next_log_lnum(c, c->lhead_lnum); + ubifs_assert(c, c->lhead_lnum != c->ltail_lnum); + c->lhead_offs = 0; + } + + /* Must ensure next LEB has been unmapped */ + err = ubifs_leb_unmap(c, c->lhead_lnum); + if (err) + goto out; + + len = ALIGN(len, c->min_io_size); + dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len); + err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len); + if (err) + goto out; + + *ltail_lnum = c->lhead_lnum; + + c->lhead_offs += len; + ubifs_assert(c, c->lhead_offs < c->leb_size); + + remove_buds(c); + + /* + * We have started the commit and now users may use the rest of the log + * for new writes. + */ + c->min_log_bytes = 0; + +out: + kfree(buf); + return err; +} + +/** + * ubifs_log_end_commit - end commit. + * @c: UBIFS file-system description object + * @ltail_lnum: new log tail LEB number + * + * This function is called on when the commit operation was finished. It + * moves log tail to new position and updates the master node so that it stores + * the new log tail LEB number. Returns zero in case of success and a negative + * error code in case of failure. + */ +int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum) +{ + int err; + + /* + * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS + * writes during commit. Its only short "commit" start phase when + * writers are blocked. + */ + mutex_lock(&c->log_mutex); + + dbg_log("old tail was LEB %d:0, new tail is LEB %d:0", + c->ltail_lnum, ltail_lnum); + + c->ltail_lnum = ltail_lnum; + /* + * The commit is finished and from now on it must be guaranteed that + * there is always enough space for the next commit. + */ + c->min_log_bytes = c->leb_size; + + spin_lock(&c->buds_lock); + c->bud_bytes -= c->cmt_bud_bytes; + spin_unlock(&c->buds_lock); + + err = dbg_check_bud_bytes(c); + if (err) + goto out; + + err = ubifs_write_master(c); + +out: + mutex_unlock(&c->log_mutex); + return err; +} + +/** + * ubifs_log_post_commit - things to do after commit is completed. + * @c: UBIFS file-system description object + * @old_ltail_lnum: old log tail LEB number + * + * Release buds only after commit is completed, because they must be unchanged + * if recovery is needed. + * + * Unmap log LEBs only after commit is completed, because they may be needed for + * recovery. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum) +{ + int lnum, err = 0; + + while (!list_empty(&c->old_buds)) { + struct ubifs_bud *bud; + + bud = list_entry(c->old_buds.next, struct ubifs_bud, list); + err = ubifs_return_leb(c, bud->lnum); + if (err) + return err; + list_del(&bud->list); + kfree(bud->log_hash); + kfree(bud); + } + mutex_lock(&c->log_mutex); + for (lnum = old_ltail_lnum; lnum != c->ltail_lnum; + lnum = ubifs_next_log_lnum(c, lnum)) { + dbg_log("unmap log LEB %d", lnum); + err = ubifs_leb_unmap(c, lnum); + if (err) + goto out; + } +out: + mutex_unlock(&c->log_mutex); + return err; +} + +/** + * struct done_ref - references that have been done. + * @rb: rb-tree node + * @lnum: LEB number + */ +struct done_ref { + struct rb_node rb; + int lnum; +}; + +/** + * done_already - determine if a reference has been done already. + * @done_tree: rb-tree to store references that have been done + * @lnum: LEB number of reference + * + * This function returns %1 if the reference has been done, %0 if not, otherwise + * a negative error code is returned. + */ +static int done_already(struct rb_root *done_tree, int lnum) +{ + struct rb_node **p = &done_tree->rb_node, *parent = NULL; + struct done_ref *dr; + + while (*p) { + parent = *p; + dr = rb_entry(parent, struct done_ref, rb); + if (lnum < dr->lnum) + p = &(*p)->rb_left; + else if (lnum > dr->lnum) + p = &(*p)->rb_right; + else + return 1; + } + + dr = kzalloc(sizeof(struct done_ref), GFP_NOFS); + if (!dr) + return -ENOMEM; + + dr->lnum = lnum; + + rb_link_node(&dr->rb, parent, p); + rb_insert_color(&dr->rb, done_tree); + + return 0; +} + +/** + * destroy_done_tree - destroy the done tree. + * @done_tree: done tree to destroy + */ +static void destroy_done_tree(struct rb_root *done_tree) +{ + struct done_ref *dr, *n; + + rbtree_postorder_for_each_entry_safe(dr, n, done_tree, rb) + kfree(dr); +} + +/** + * add_node - add a node to the consolidated log. + * @c: UBIFS file-system description object + * @buf: buffer to which to add + * @lnum: LEB number to which to write is passed and returned here + * @offs: offset to where to write is passed and returned here + * @node: node to add + * + * This function returns %0 on success and a negative error code on failure. + */ +static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs, + void *node) +{ + struct ubifs_ch *ch = node; + int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs; + + if (len > remains) { + int sz = ALIGN(*offs, c->min_io_size), err; + + ubifs_pad(c, buf + *offs, sz - *offs); + err = ubifs_leb_change(c, *lnum, buf, sz); + if (err) + return err; + *lnum = ubifs_next_log_lnum(c, *lnum); + *offs = 0; + } + memcpy(buf + *offs, node, len); + *offs += ALIGN(len, 8); + return 0; +} + +/** + * ubifs_consolidate_log - consolidate the log. + * @c: UBIFS file-system description object + * + * Repeated failed commits could cause the log to be full, but at least 1 LEB is + * needed for commit. This function rewrites the reference nodes in the log + * omitting duplicates, and failed CS nodes, and leaving no gaps. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_consolidate_log(struct ubifs_info *c) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + struct rb_root done_tree = RB_ROOT; + int lnum, err, first = 1, write_lnum, offs = 0; + void *buf; + + dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum, + c->lhead_lnum); + buf = vmalloc(c->leb_size); + if (!buf) + return -ENOMEM; + lnum = c->ltail_lnum; + write_lnum = lnum; + while (1) { + sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0); + if (IS_ERR(sleb)) { + err = PTR_ERR(sleb); + goto out_free; + } + list_for_each_entry(snod, &sleb->nodes, list) { + switch (snod->type) { + case UBIFS_REF_NODE: { + struct ubifs_ref_node *ref = snod->node; + int ref_lnum = le32_to_cpu(ref->lnum); + + err = done_already(&done_tree, ref_lnum); + if (err < 0) + goto out_scan; + if (err != 1) { + err = add_node(c, buf, &write_lnum, + &offs, snod->node); + if (err) + goto out_scan; + } + break; + } + case UBIFS_CS_NODE: + if (!first) + break; + err = add_node(c, buf, &write_lnum, &offs, + snod->node); + if (err) + goto out_scan; + first = 0; + break; + } + } + ubifs_scan_destroy(sleb); + if (lnum == c->lhead_lnum) + break; + lnum = ubifs_next_log_lnum(c, lnum); + } + if (offs) { + int sz = ALIGN(offs, c->min_io_size); + + ubifs_pad(c, buf + offs, sz - offs); + err = ubifs_leb_change(c, write_lnum, buf, sz); + if (err) + goto out_free; + offs = ALIGN(offs, c->min_io_size); + } + destroy_done_tree(&done_tree); + vfree(buf); + if (write_lnum == c->lhead_lnum) { + ubifs_err(c, "log is too full"); + return -EINVAL; + } + /* Unmap remaining LEBs */ + lnum = write_lnum; + do { + lnum = ubifs_next_log_lnum(c, lnum); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } while (lnum != c->lhead_lnum); + c->lhead_lnum = write_lnum; + c->lhead_offs = offs; + dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs); + return 0; + +out_scan: + ubifs_scan_destroy(sleb); +out_free: + destroy_done_tree(&done_tree); + vfree(buf); + return err; +} + +/** + * dbg_check_bud_bytes - make sure bud bytes calculation are all right. + * @c: UBIFS file-system description object + * + * This function makes sure the amount of flash space used by closed buds + * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in + * case of failure. + */ +static int dbg_check_bud_bytes(struct ubifs_info *c) +{ + int i, err = 0; + struct ubifs_bud *bud; + long long bud_bytes = 0; + + if (!dbg_is_chk_gen(c)) + return 0; + + spin_lock(&c->buds_lock); + for (i = 0; i < c->jhead_cnt; i++) + list_for_each_entry(bud, &c->jheads[i].buds_list, list) + bud_bytes += c->leb_size - bud->start; + + if (c->bud_bytes != bud_bytes) { + ubifs_err(c, "bad bud_bytes %lld, calculated %lld", + c->bud_bytes, bud_bytes); + err = -EINVAL; + } + spin_unlock(&c->buds_lock); + + return err; +} diff --git a/fs/ubifs/lprops.c b/fs/ubifs/lprops.c new file mode 100644 index 000000000..6d6cd85c2 --- /dev/null +++ b/fs/ubifs/lprops.c @@ -0,0 +1,1307 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements the functions that access LEB properties and their + * categories. LEBs are categorized based on the needs of UBIFS, and the + * categories are stored as either heaps or lists to provide a fast way of + * finding a LEB in a particular category. For example, UBIFS may need to find + * an empty LEB for the journal, or a very dirty LEB for garbage collection. + */ + +#include "ubifs.h" + +/** + * get_heap_comp_val - get the LEB properties value for heap comparisons. + * @lprops: LEB properties + * @cat: LEB category + */ +static int get_heap_comp_val(struct ubifs_lprops *lprops, int cat) +{ + switch (cat) { + case LPROPS_FREE: + return lprops->free; + case LPROPS_DIRTY_IDX: + return lprops->free + lprops->dirty; + default: + return lprops->dirty; + } +} + +/** + * move_up_lpt_heap - move a new heap entry up as far as possible. + * @c: UBIFS file-system description object + * @heap: LEB category heap + * @lprops: LEB properties to move + * @cat: LEB category + * + * New entries to a heap are added at the bottom and then moved up until the + * parent's value is greater. In the case of LPT's category heaps, the value + * is either the amount of free space or the amount of dirty space, depending + * on the category. + */ +static void move_up_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, + struct ubifs_lprops *lprops, int cat) +{ + int val1, val2, hpos; + + hpos = lprops->hpos; + if (!hpos) + return; /* Already top of the heap */ + val1 = get_heap_comp_val(lprops, cat); + /* Compare to parent and, if greater, move up the heap */ + do { + int ppos = (hpos - 1) / 2; + + val2 = get_heap_comp_val(heap->arr[ppos], cat); + if (val2 >= val1) + return; + /* Greater than parent so move up */ + heap->arr[ppos]->hpos = hpos; + heap->arr[hpos] = heap->arr[ppos]; + heap->arr[ppos] = lprops; + lprops->hpos = ppos; + hpos = ppos; + } while (hpos); +} + +/** + * adjust_lpt_heap - move a changed heap entry up or down the heap. + * @c: UBIFS file-system description object + * @heap: LEB category heap + * @lprops: LEB properties to move + * @hpos: heap position of @lprops + * @cat: LEB category + * + * Changed entries in a heap are moved up or down until the parent's value is + * greater. In the case of LPT's category heaps, the value is either the amount + * of free space or the amount of dirty space, depending on the category. + */ +static void adjust_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, + struct ubifs_lprops *lprops, int hpos, int cat) +{ + int val1, val2, val3, cpos; + + val1 = get_heap_comp_val(lprops, cat); + /* Compare to parent and, if greater than parent, move up the heap */ + if (hpos) { + int ppos = (hpos - 1) / 2; + + val2 = get_heap_comp_val(heap->arr[ppos], cat); + if (val1 > val2) { + /* Greater than parent so move up */ + while (1) { + heap->arr[ppos]->hpos = hpos; + heap->arr[hpos] = heap->arr[ppos]; + heap->arr[ppos] = lprops; + lprops->hpos = ppos; + hpos = ppos; + if (!hpos) + return; + ppos = (hpos - 1) / 2; + val2 = get_heap_comp_val(heap->arr[ppos], cat); + if (val1 <= val2) + return; + /* Still greater than parent so keep going */ + } + } + } + + /* Not greater than parent, so compare to children */ + while (1) { + /* Compare to left child */ + cpos = hpos * 2 + 1; + if (cpos >= heap->cnt) + return; + val2 = get_heap_comp_val(heap->arr[cpos], cat); + if (val1 < val2) { + /* Less than left child, so promote biggest child */ + if (cpos + 1 < heap->cnt) { + val3 = get_heap_comp_val(heap->arr[cpos + 1], + cat); + if (val3 > val2) + cpos += 1; /* Right child is bigger */ + } + heap->arr[cpos]->hpos = hpos; + heap->arr[hpos] = heap->arr[cpos]; + heap->arr[cpos] = lprops; + lprops->hpos = cpos; + hpos = cpos; + continue; + } + /* Compare to right child */ + cpos += 1; + if (cpos >= heap->cnt) + return; + val3 = get_heap_comp_val(heap->arr[cpos], cat); + if (val1 < val3) { + /* Less than right child, so promote right child */ + heap->arr[cpos]->hpos = hpos; + heap->arr[hpos] = heap->arr[cpos]; + heap->arr[cpos] = lprops; + lprops->hpos = cpos; + hpos = cpos; + continue; + } + return; + } +} + +/** + * add_to_lpt_heap - add LEB properties to a LEB category heap. + * @c: UBIFS file-system description object + * @lprops: LEB properties to add + * @cat: LEB category + * + * This function returns %1 if @lprops is added to the heap for LEB category + * @cat, otherwise %0 is returned because the heap is full. + */ +static int add_to_lpt_heap(struct ubifs_info *c, struct ubifs_lprops *lprops, + int cat) +{ + struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1]; + + if (heap->cnt >= heap->max_cnt) { + const int b = LPT_HEAP_SZ / 2 - 1; + int cpos, val1, val2; + + /* Compare to some other LEB on the bottom of heap */ + /* Pick a position kind of randomly */ + cpos = (((size_t)lprops >> 4) & b) + b; + ubifs_assert(c, cpos >= b); + ubifs_assert(c, cpos < LPT_HEAP_SZ); + ubifs_assert(c, cpos < heap->cnt); + + val1 = get_heap_comp_val(lprops, cat); + val2 = get_heap_comp_val(heap->arr[cpos], cat); + if (val1 > val2) { + struct ubifs_lprops *lp; + + lp = heap->arr[cpos]; + lp->flags &= ~LPROPS_CAT_MASK; + lp->flags |= LPROPS_UNCAT; + list_add(&lp->list, &c->uncat_list); + lprops->hpos = cpos; + heap->arr[cpos] = lprops; + move_up_lpt_heap(c, heap, lprops, cat); + dbg_check_heap(c, heap, cat, lprops->hpos); + return 1; /* Added to heap */ + } + dbg_check_heap(c, heap, cat, -1); + return 0; /* Not added to heap */ + } else { + lprops->hpos = heap->cnt++; + heap->arr[lprops->hpos] = lprops; + move_up_lpt_heap(c, heap, lprops, cat); + dbg_check_heap(c, heap, cat, lprops->hpos); + return 1; /* Added to heap */ + } +} + +/** + * remove_from_lpt_heap - remove LEB properties from a LEB category heap. + * @c: UBIFS file-system description object + * @lprops: LEB properties to remove + * @cat: LEB category + */ +static void remove_from_lpt_heap(struct ubifs_info *c, + struct ubifs_lprops *lprops, int cat) +{ + struct ubifs_lpt_heap *heap; + int hpos = lprops->hpos; + + heap = &c->lpt_heap[cat - 1]; + ubifs_assert(c, hpos >= 0 && hpos < heap->cnt); + ubifs_assert(c, heap->arr[hpos] == lprops); + heap->cnt -= 1; + if (hpos < heap->cnt) { + heap->arr[hpos] = heap->arr[heap->cnt]; + heap->arr[hpos]->hpos = hpos; + adjust_lpt_heap(c, heap, heap->arr[hpos], hpos, cat); + } + dbg_check_heap(c, heap, cat, -1); +} + +/** + * lpt_heap_replace - replace lprops in a category heap. + * @c: UBIFS file-system description object + * @new_lprops: LEB properties with which to replace + * @cat: LEB category + * + * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode) + * and the lprops that the pnode contains. When that happens, references in + * the category heaps to those lprops must be updated to point to the new + * lprops. This function does that. + */ +static void lpt_heap_replace(struct ubifs_info *c, + struct ubifs_lprops *new_lprops, int cat) +{ + struct ubifs_lpt_heap *heap; + int hpos = new_lprops->hpos; + + heap = &c->lpt_heap[cat - 1]; + heap->arr[hpos] = new_lprops; +} + +/** + * ubifs_add_to_cat - add LEB properties to a category list or heap. + * @c: UBIFS file-system description object + * @lprops: LEB properties to add + * @cat: LEB category to which to add + * + * LEB properties are categorized to enable fast find operations. + */ +void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops, + int cat) +{ + switch (cat) { + case LPROPS_DIRTY: + case LPROPS_DIRTY_IDX: + case LPROPS_FREE: + if (add_to_lpt_heap(c, lprops, cat)) + break; + /* No more room on heap so make it un-categorized */ + cat = LPROPS_UNCAT; + fallthrough; + case LPROPS_UNCAT: + list_add(&lprops->list, &c->uncat_list); + break; + case LPROPS_EMPTY: + list_add(&lprops->list, &c->empty_list); + break; + case LPROPS_FREEABLE: + list_add(&lprops->list, &c->freeable_list); + c->freeable_cnt += 1; + break; + case LPROPS_FRDI_IDX: + list_add(&lprops->list, &c->frdi_idx_list); + break; + default: + ubifs_assert(c, 0); + } + + lprops->flags &= ~LPROPS_CAT_MASK; + lprops->flags |= cat; + c->in_a_category_cnt += 1; + ubifs_assert(c, c->in_a_category_cnt <= c->main_lebs); +} + +/** + * ubifs_remove_from_cat - remove LEB properties from a category list or heap. + * @c: UBIFS file-system description object + * @lprops: LEB properties to remove + * @cat: LEB category from which to remove + * + * LEB properties are categorized to enable fast find operations. + */ +static void ubifs_remove_from_cat(struct ubifs_info *c, + struct ubifs_lprops *lprops, int cat) +{ + switch (cat) { + case LPROPS_DIRTY: + case LPROPS_DIRTY_IDX: + case LPROPS_FREE: + remove_from_lpt_heap(c, lprops, cat); + break; + case LPROPS_FREEABLE: + c->freeable_cnt -= 1; + ubifs_assert(c, c->freeable_cnt >= 0); + fallthrough; + case LPROPS_UNCAT: + case LPROPS_EMPTY: + case LPROPS_FRDI_IDX: + ubifs_assert(c, !list_empty(&lprops->list)); + list_del(&lprops->list); + break; + default: + ubifs_assert(c, 0); + } + + c->in_a_category_cnt -= 1; + ubifs_assert(c, c->in_a_category_cnt >= 0); +} + +/** + * ubifs_replace_cat - replace lprops in a category list or heap. + * @c: UBIFS file-system description object + * @old_lprops: LEB properties to replace + * @new_lprops: LEB properties with which to replace + * + * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode) + * and the lprops that the pnode contains. When that happens, references in + * category lists and heaps must be replaced. This function does that. + */ +void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops, + struct ubifs_lprops *new_lprops) +{ + int cat; + + cat = new_lprops->flags & LPROPS_CAT_MASK; + switch (cat) { + case LPROPS_DIRTY: + case LPROPS_DIRTY_IDX: + case LPROPS_FREE: + lpt_heap_replace(c, new_lprops, cat); + break; + case LPROPS_UNCAT: + case LPROPS_EMPTY: + case LPROPS_FREEABLE: + case LPROPS_FRDI_IDX: + list_replace(&old_lprops->list, &new_lprops->list); + break; + default: + ubifs_assert(c, 0); + } +} + +/** + * ubifs_ensure_cat - ensure LEB properties are categorized. + * @c: UBIFS file-system description object + * @lprops: LEB properties + * + * A LEB may have fallen off of the bottom of a heap, and ended up as + * un-categorized even though it has enough space for us now. If that is the + * case this function will put the LEB back onto a heap. + */ +void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops) +{ + int cat = lprops->flags & LPROPS_CAT_MASK; + + if (cat != LPROPS_UNCAT) + return; + cat = ubifs_categorize_lprops(c, lprops); + if (cat == LPROPS_UNCAT) + return; + ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT); + ubifs_add_to_cat(c, lprops, cat); +} + +/** + * ubifs_categorize_lprops - categorize LEB properties. + * @c: UBIFS file-system description object + * @lprops: LEB properties to categorize + * + * LEB properties are categorized to enable fast find operations. This function + * returns the LEB category to which the LEB properties belong. Note however + * that if the LEB category is stored as a heap and the heap is full, the + * LEB properties may have their category changed to %LPROPS_UNCAT. + */ +int ubifs_categorize_lprops(const struct ubifs_info *c, + const struct ubifs_lprops *lprops) +{ + if (lprops->flags & LPROPS_TAKEN) + return LPROPS_UNCAT; + + if (lprops->free == c->leb_size) { + ubifs_assert(c, !(lprops->flags & LPROPS_INDEX)); + return LPROPS_EMPTY; + } + + if (lprops->free + lprops->dirty == c->leb_size) { + if (lprops->flags & LPROPS_INDEX) + return LPROPS_FRDI_IDX; + else + return LPROPS_FREEABLE; + } + + if (lprops->flags & LPROPS_INDEX) { + if (lprops->dirty + lprops->free >= c->min_idx_node_sz) + return LPROPS_DIRTY_IDX; + } else { + if (lprops->dirty >= c->dead_wm && + lprops->dirty > lprops->free) + return LPROPS_DIRTY; + if (lprops->free > 0) + return LPROPS_FREE; + } + + return LPROPS_UNCAT; +} + +/** + * change_category - change LEB properties category. + * @c: UBIFS file-system description object + * @lprops: LEB properties to re-categorize + * + * LEB properties are categorized to enable fast find operations. When the LEB + * properties change they must be re-categorized. + */ +static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops) +{ + int old_cat = lprops->flags & LPROPS_CAT_MASK; + int new_cat = ubifs_categorize_lprops(c, lprops); + + if (old_cat == new_cat) { + struct ubifs_lpt_heap *heap; + + /* lprops on a heap now must be moved up or down */ + if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT) + return; /* Not on a heap */ + heap = &c->lpt_heap[new_cat - 1]; + adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat); + } else { + ubifs_remove_from_cat(c, lprops, old_cat); + ubifs_add_to_cat(c, lprops, new_cat); + } +} + +/** + * ubifs_calc_dark - calculate LEB dark space size. + * @c: the UBIFS file-system description object + * @spc: amount of free and dirty space in the LEB + * + * This function calculates and returns amount of dark space in an LEB which + * has @spc bytes of free and dirty space. + * + * UBIFS is trying to account the space which might not be usable, and this + * space is called "dark space". For example, if an LEB has only %512 free + * bytes, it is dark space, because it cannot fit a large data node. + */ +int ubifs_calc_dark(const struct ubifs_info *c, int spc) +{ + ubifs_assert(c, !(spc & 7)); + + if (spc < c->dark_wm) + return spc; + + /* + * If we have slightly more space then the dark space watermark, we can + * anyway safely assume it we'll be able to write a node of the + * smallest size there. + */ + if (spc - c->dark_wm < MIN_WRITE_SZ) + return spc - MIN_WRITE_SZ; + + return c->dark_wm; +} + +/** + * is_lprops_dirty - determine if LEB properties are dirty. + * @c: the UBIFS file-system description object + * @lprops: LEB properties to test + */ +static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops) +{ + struct ubifs_pnode *pnode; + int pos; + + pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1); + pnode = (struct ubifs_pnode *)container_of(lprops - pos, + struct ubifs_pnode, + lprops[0]); + return !test_bit(COW_CNODE, &pnode->flags) && + test_bit(DIRTY_CNODE, &pnode->flags); +} + +/** + * ubifs_change_lp - change LEB properties. + * @c: the UBIFS file-system description object + * @lp: LEB properties to change + * @free: new free space amount + * @dirty: new dirty space amount + * @flags: new flags + * @idx_gc_cnt: change to the count of @idx_gc list + * + * This function changes LEB properties (@free, @dirty or @flag). However, the + * property which has the %LPROPS_NC value is not changed. Returns a pointer to + * the updated LEB properties on success and a negative error code on failure. + * + * Note, the LEB properties may have had to be copied (due to COW) and + * consequently the pointer returned may not be the same as the pointer + * passed. + */ +const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c, + const struct ubifs_lprops *lp, + int free, int dirty, int flags, + int idx_gc_cnt) +{ + /* + * This is the only function that is allowed to change lprops, so we + * discard the "const" qualifier. + */ + struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp; + + dbg_lp("LEB %d, free %d, dirty %d, flags %d", + lprops->lnum, free, dirty, flags); + + ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); + ubifs_assert(c, c->lst.empty_lebs >= 0 && + c->lst.empty_lebs <= c->main_lebs); + ubifs_assert(c, c->freeable_cnt >= 0); + ubifs_assert(c, c->freeable_cnt <= c->main_lebs); + ubifs_assert(c, c->lst.taken_empty_lebs >= 0); + ubifs_assert(c, c->lst.taken_empty_lebs <= c->lst.empty_lebs); + ubifs_assert(c, !(c->lst.total_free & 7) && !(c->lst.total_dirty & 7)); + ubifs_assert(c, !(c->lst.total_dead & 7) && !(c->lst.total_dark & 7)); + ubifs_assert(c, !(c->lst.total_used & 7)); + ubifs_assert(c, free == LPROPS_NC || free >= 0); + ubifs_assert(c, dirty == LPROPS_NC || dirty >= 0); + + if (!is_lprops_dirty(c, lprops)) { + lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum); + if (IS_ERR(lprops)) + return lprops; + } else + ubifs_assert(c, lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum)); + + ubifs_assert(c, !(lprops->free & 7) && !(lprops->dirty & 7)); + + spin_lock(&c->space_lock); + if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size) + c->lst.taken_empty_lebs -= 1; + + if (!(lprops->flags & LPROPS_INDEX)) { + int old_spc; + + old_spc = lprops->free + lprops->dirty; + if (old_spc < c->dead_wm) + c->lst.total_dead -= old_spc; + else + c->lst.total_dark -= ubifs_calc_dark(c, old_spc); + + c->lst.total_used -= c->leb_size - old_spc; + } + + if (free != LPROPS_NC) { + free = ALIGN(free, 8); + c->lst.total_free += free - lprops->free; + + /* Increase or decrease empty LEBs counter if needed */ + if (free == c->leb_size) { + if (lprops->free != c->leb_size) + c->lst.empty_lebs += 1; + } else if (lprops->free == c->leb_size) + c->lst.empty_lebs -= 1; + lprops->free = free; + } + + if (dirty != LPROPS_NC) { + dirty = ALIGN(dirty, 8); + c->lst.total_dirty += dirty - lprops->dirty; + lprops->dirty = dirty; + } + + if (flags != LPROPS_NC) { + /* Take care about indexing LEBs counter if needed */ + if ((lprops->flags & LPROPS_INDEX)) { + if (!(flags & LPROPS_INDEX)) + c->lst.idx_lebs -= 1; + } else if (flags & LPROPS_INDEX) + c->lst.idx_lebs += 1; + lprops->flags = flags; + } + + if (!(lprops->flags & LPROPS_INDEX)) { + int new_spc; + + new_spc = lprops->free + lprops->dirty; + if (new_spc < c->dead_wm) + c->lst.total_dead += new_spc; + else + c->lst.total_dark += ubifs_calc_dark(c, new_spc); + + c->lst.total_used += c->leb_size - new_spc; + } + + if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size) + c->lst.taken_empty_lebs += 1; + + change_category(c, lprops); + c->idx_gc_cnt += idx_gc_cnt; + spin_unlock(&c->space_lock); + return lprops; +} + +/** + * ubifs_get_lp_stats - get lprops statistics. + * @c: UBIFS file-system description object + * @lst: return statistics + */ +void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst) +{ + spin_lock(&c->space_lock); + memcpy(lst, &c->lst, sizeof(struct ubifs_lp_stats)); + spin_unlock(&c->space_lock); +} + +/** + * ubifs_change_one_lp - change LEB properties. + * @c: the UBIFS file-system description object + * @lnum: LEB to change properties for + * @free: amount of free space + * @dirty: amount of dirty space + * @flags_set: flags to set + * @flags_clean: flags to clean + * @idx_gc_cnt: change to the count of idx_gc list + * + * This function changes properties of LEB @lnum. It is a helper wrapper over + * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the + * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and + * a negative error code in case of failure. + */ +int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty, + int flags_set, int flags_clean, int idx_gc_cnt) +{ + int err = 0, flags; + const struct ubifs_lprops *lp; + + ubifs_get_lprops(c); + + lp = ubifs_lpt_lookup_dirty(c, lnum); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + flags = (lp->flags | flags_set) & ~flags_clean; + lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt); + if (IS_ERR(lp)) + err = PTR_ERR(lp); + +out: + ubifs_release_lprops(c); + if (err) + ubifs_err(c, "cannot change properties of LEB %d, error %d", + lnum, err); + return err; +} + +/** + * ubifs_update_one_lp - update LEB properties. + * @c: the UBIFS file-system description object + * @lnum: LEB to change properties for + * @free: amount of free space + * @dirty: amount of dirty space to add + * @flags_set: flags to set + * @flags_clean: flags to clean + * + * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to + * current dirty space, not substitutes it. + */ +int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty, + int flags_set, int flags_clean) +{ + int err = 0, flags; + const struct ubifs_lprops *lp; + + ubifs_get_lprops(c); + + lp = ubifs_lpt_lookup_dirty(c, lnum); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + flags = (lp->flags | flags_set) & ~flags_clean; + lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0); + if (IS_ERR(lp)) + err = PTR_ERR(lp); + +out: + ubifs_release_lprops(c); + if (err) + ubifs_err(c, "cannot update properties of LEB %d, error %d", + lnum, err); + return err; +} + +/** + * ubifs_read_one_lp - read LEB properties. + * @c: the UBIFS file-system description object + * @lnum: LEB to read properties for + * @lp: where to store read properties + * + * This helper function reads properties of a LEB @lnum and stores them in @lp. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp) +{ + int err = 0; + const struct ubifs_lprops *lpp; + + ubifs_get_lprops(c); + + lpp = ubifs_lpt_lookup(c, lnum); + if (IS_ERR(lpp)) { + err = PTR_ERR(lpp); + ubifs_err(c, "cannot read properties of LEB %d, error %d", + lnum, err); + goto out; + } + + memcpy(lp, lpp, sizeof(struct ubifs_lprops)); + +out: + ubifs_release_lprops(c); + return err; +} + +/** + * ubifs_fast_find_free - try to find a LEB with free space quickly. + * @c: the UBIFS file-system description object + * + * This function returns LEB properties for a LEB with free space or %NULL if + * the function is unable to find a LEB quickly. + */ +const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + + ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); + + heap = &c->lpt_heap[LPROPS_FREE - 1]; + if (heap->cnt == 0) + return NULL; + + lprops = heap->arr[0]; + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lprops->flags & LPROPS_INDEX)); + return lprops; +} + +/** + * ubifs_fast_find_empty - try to find an empty LEB quickly. + * @c: the UBIFS file-system description object + * + * This function returns LEB properties for an empty LEB or %NULL if the + * function is unable to find an empty LEB quickly. + */ +const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + + ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); + + if (list_empty(&c->empty_list)) + return NULL; + + lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lprops->flags & LPROPS_INDEX)); + ubifs_assert(c, lprops->free == c->leb_size); + return lprops; +} + +/** + * ubifs_fast_find_freeable - try to find a freeable LEB quickly. + * @c: the UBIFS file-system description object + * + * This function returns LEB properties for a freeable LEB or %NULL if the + * function is unable to find a freeable LEB quickly. + */ +const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + + ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); + + if (list_empty(&c->freeable_list)) + return NULL; + + lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, !(lprops->flags & LPROPS_INDEX)); + ubifs_assert(c, lprops->free + lprops->dirty == c->leb_size); + ubifs_assert(c, c->freeable_cnt > 0); + return lprops; +} + +/** + * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly. + * @c: the UBIFS file-system description object + * + * This function returns LEB properties for a freeable index LEB or %NULL if the + * function is unable to find a freeable index LEB quickly. + */ +const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + + ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); + + if (list_empty(&c->frdi_idx_list)) + return NULL; + + lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list); + ubifs_assert(c, !(lprops->flags & LPROPS_TAKEN)); + ubifs_assert(c, (lprops->flags & LPROPS_INDEX)); + ubifs_assert(c, lprops->free + lprops->dirty == c->leb_size); + return lprops; +} + +/* + * Everything below is related to debugging. + */ + +/** + * dbg_check_cats - check category heaps and lists. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_check_cats(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + struct list_head *pos; + int i, cat; + + if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c)) + return 0; + + list_for_each_entry(lprops, &c->empty_list, list) { + if (lprops->free != c->leb_size) { + ubifs_err(c, "non-empty LEB %d on empty list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + if (lprops->flags & LPROPS_TAKEN) { + ubifs_err(c, "taken LEB %d on empty list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + } + + i = 0; + list_for_each_entry(lprops, &c->freeable_list, list) { + if (lprops->free + lprops->dirty != c->leb_size) { + ubifs_err(c, "non-freeable LEB %d on freeable list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + if (lprops->flags & LPROPS_TAKEN) { + ubifs_err(c, "taken LEB %d on freeable list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + i += 1; + } + if (i != c->freeable_cnt) { + ubifs_err(c, "freeable list count %d expected %d", i, + c->freeable_cnt); + return -EINVAL; + } + + i = 0; + list_for_each(pos, &c->idx_gc) + i += 1; + if (i != c->idx_gc_cnt) { + ubifs_err(c, "idx_gc list count %d expected %d", i, + c->idx_gc_cnt); + return -EINVAL; + } + + list_for_each_entry(lprops, &c->frdi_idx_list, list) { + if (lprops->free + lprops->dirty != c->leb_size) { + ubifs_err(c, "non-freeable LEB %d on frdi_idx list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + if (lprops->flags & LPROPS_TAKEN) { + ubifs_err(c, "taken LEB %d on frdi_idx list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + if (!(lprops->flags & LPROPS_INDEX)) { + ubifs_err(c, "non-index LEB %d on frdi_idx list (free %d dirty %d flags %d)", + lprops->lnum, lprops->free, lprops->dirty, + lprops->flags); + return -EINVAL; + } + } + + for (cat = 1; cat <= LPROPS_HEAP_CNT; cat++) { + struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1]; + + for (i = 0; i < heap->cnt; i++) { + lprops = heap->arr[i]; + if (!lprops) { + ubifs_err(c, "null ptr in LPT heap cat %d", cat); + return -EINVAL; + } + if (lprops->hpos != i) { + ubifs_err(c, "bad ptr in LPT heap cat %d", cat); + return -EINVAL; + } + if (lprops->flags & LPROPS_TAKEN) { + ubifs_err(c, "taken LEB in LPT heap cat %d", cat); + return -EINVAL; + } + } + } + + return 0; +} + +void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat, + int add_pos) +{ + int i = 0, j, err = 0; + + if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c)) + return; + + for (i = 0; i < heap->cnt; i++) { + struct ubifs_lprops *lprops = heap->arr[i]; + struct ubifs_lprops *lp; + + if (i != add_pos) + if ((lprops->flags & LPROPS_CAT_MASK) != cat) { + err = 1; + goto out; + } + if (lprops->hpos != i) { + err = 2; + goto out; + } + lp = ubifs_lpt_lookup(c, lprops->lnum); + if (IS_ERR(lp)) { + err = 3; + goto out; + } + if (lprops != lp) { + ubifs_err(c, "lprops %zx lp %zx lprops->lnum %d lp->lnum %d", + (size_t)lprops, (size_t)lp, lprops->lnum, + lp->lnum); + err = 4; + goto out; + } + for (j = 0; j < i; j++) { + lp = heap->arr[j]; + if (lp == lprops) { + err = 5; + goto out; + } + if (lp->lnum == lprops->lnum) { + err = 6; + goto out; + } + } + } +out: + if (err) { + ubifs_err(c, "failed cat %d hpos %d err %d", cat, i, err); + dump_stack(); + ubifs_dump_heap(c, heap, cat); + } +} + +/** + * scan_check_cb - scan callback. + * @c: the UBIFS file-system description object + * @lp: LEB properties to scan + * @in_tree: whether the LEB properties are in main memory + * @lst: lprops statistics to update + * + * This function returns a code that indicates whether the scan should continue + * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree + * in main memory (%LPT_SCAN_ADD), or whether the scan should stop + * (%LPT_SCAN_STOP). + */ +static int scan_check_cb(struct ubifs_info *c, + const struct ubifs_lprops *lp, int in_tree, + struct ubifs_lp_stats *lst) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty, ret; + void *buf = NULL; + + cat = lp->flags & LPROPS_CAT_MASK; + if (cat != LPROPS_UNCAT) { + cat = ubifs_categorize_lprops(c, lp); + if (cat != (lp->flags & LPROPS_CAT_MASK)) { + ubifs_err(c, "bad LEB category %d expected %d", + (lp->flags & LPROPS_CAT_MASK), cat); + return -EINVAL; + } + } + + /* Check lp is on its category list (if it has one) */ + if (in_tree) { + struct list_head *list = NULL; + + switch (cat) { + case LPROPS_EMPTY: + list = &c->empty_list; + break; + case LPROPS_FREEABLE: + list = &c->freeable_list; + break; + case LPROPS_FRDI_IDX: + list = &c->frdi_idx_list; + break; + case LPROPS_UNCAT: + list = &c->uncat_list; + break; + } + if (list) { + struct ubifs_lprops *lprops; + int found = 0; + + list_for_each_entry(lprops, list, list) { + if (lprops == lp) { + found = 1; + break; + } + } + if (!found) { + ubifs_err(c, "bad LPT list (category %d)", cat); + return -EINVAL; + } + } + } + + /* Check lp is on its category heap (if it has one) */ + if (in_tree && cat > 0 && cat <= LPROPS_HEAP_CNT) { + struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1]; + + if ((lp->hpos != -1 && heap->arr[lp->hpos]->lnum != lnum) || + lp != heap->arr[lp->hpos]) { + ubifs_err(c, "bad LPT heap (category %d)", cat); + return -EINVAL; + } + } + + /* + * After an unclean unmount, empty and freeable LEBs + * may contain garbage - do not scan them. + */ + if (lp->free == c->leb_size) { + lst->empty_lebs += 1; + lst->total_free += c->leb_size; + lst->total_dark += ubifs_calc_dark(c, c->leb_size); + return LPT_SCAN_CONTINUE; + } + if (lp->free + lp->dirty == c->leb_size && + !(lp->flags & LPROPS_INDEX)) { + lst->total_free += lp->free; + lst->total_dirty += lp->dirty; + lst->total_dark += ubifs_calc_dark(c, c->leb_size); + return LPT_SCAN_CONTINUE; + } + + buf = __vmalloc(c->leb_size, GFP_NOFS); + if (!buf) + return -ENOMEM; + + sleb = ubifs_scan(c, lnum, 0, buf, 0); + if (IS_ERR(sleb)) { + ret = PTR_ERR(sleb); + if (ret == -EUCLEAN) { + ubifs_dump_lprops(c); + ubifs_dump_budg(c, &c->bi); + } + goto out; + } + + is_idx = -1; + list_for_each_entry(snod, &sleb->nodes, list) { + int found, level = 0; + + cond_resched(); + + if (is_idx == -1) + is_idx = (snod->type == UBIFS_IDX_NODE) ? 1 : 0; + + if (is_idx && snod->type != UBIFS_IDX_NODE) { + ubifs_err(c, "indexing node in data LEB %d:%d", + lnum, snod->offs); + goto out_destroy; + } + + if (snod->type == UBIFS_IDX_NODE) { + struct ubifs_idx_node *idx = snod->node; + + key_read(c, ubifs_idx_key(c, idx), &snod->key); + level = le16_to_cpu(idx->level); + } + + found = ubifs_tnc_has_node(c, &snod->key, level, lnum, + snod->offs, is_idx); + if (found) { + if (found < 0) + goto out_destroy; + used += ALIGN(snod->len, 8); + } + } + + free = c->leb_size - sleb->endpt; + dirty = sleb->endpt - used; + + if (free > c->leb_size || free < 0 || dirty > c->leb_size || + dirty < 0) { + ubifs_err(c, "bad calculated accounting for LEB %d: free %d, dirty %d", + lnum, free, dirty); + goto out_destroy; + } + + if (lp->free + lp->dirty == c->leb_size && + free + dirty == c->leb_size) + if ((is_idx && !(lp->flags & LPROPS_INDEX)) || + (!is_idx && free == c->leb_size) || + lp->free == c->leb_size) { + /* + * Empty or freeable LEBs could contain index + * nodes from an uncompleted commit due to an + * unclean unmount. Or they could be empty for + * the same reason. Or it may simply not have been + * unmapped. + */ + free = lp->free; + dirty = lp->dirty; + is_idx = 0; + } + + if (is_idx && lp->free + lp->dirty == free + dirty && + lnum != c->ihead_lnum) { + /* + * After an unclean unmount, an index LEB could have a different + * amount of free space than the value recorded by lprops. That + * is because the in-the-gaps method may use free space or + * create free space (as a side-effect of using ubi_leb_change + * and not writing the whole LEB). The incorrect free space + * value is not a problem because the index is only ever + * allocated empty LEBs, so there will never be an attempt to + * write to the free space at the end of an index LEB - except + * by the in-the-gaps method for which it is not a problem. + */ + free = lp->free; + dirty = lp->dirty; + } + + if (lp->free != free || lp->dirty != dirty) + goto out_print; + + if (is_idx && !(lp->flags & LPROPS_INDEX)) { + if (free == c->leb_size) + /* Free but not unmapped LEB, it's fine */ + is_idx = 0; + else { + ubifs_err(c, "indexing node without indexing flag"); + goto out_print; + } + } + + if (!is_idx && (lp->flags & LPROPS_INDEX)) { + ubifs_err(c, "data node with indexing flag"); + goto out_print; + } + + if (free == c->leb_size) + lst->empty_lebs += 1; + + if (is_idx) + lst->idx_lebs += 1; + + if (!(lp->flags & LPROPS_INDEX)) + lst->total_used += c->leb_size - free - dirty; + lst->total_free += free; + lst->total_dirty += dirty; + + if (!(lp->flags & LPROPS_INDEX)) { + int spc = free + dirty; + + if (spc < c->dead_wm) + lst->total_dead += spc; + else + lst->total_dark += ubifs_calc_dark(c, spc); + } + + ubifs_scan_destroy(sleb); + vfree(buf); + return LPT_SCAN_CONTINUE; + +out_print: + ubifs_err(c, "bad accounting of LEB %d: free %d, dirty %d flags %#x, should be free %d, dirty %d", + lnum, lp->free, lp->dirty, lp->flags, free, dirty); + ubifs_dump_leb(c, lnum); +out_destroy: + ubifs_scan_destroy(sleb); + ret = -EINVAL; +out: + vfree(buf); + return ret; +} + +/** + * dbg_check_lprops - check all LEB properties. + * @c: UBIFS file-system description object + * + * This function checks all LEB properties and makes sure they are all correct. + * It returns zero if everything is fine, %-EINVAL if there is an inconsistency + * and other negative error codes in case of other errors. This function is + * called while the file system is locked (because of commit start), so no + * additional locking is required. Note that locking the LPT mutex would cause + * a circular lock dependency with the TNC mutex. + */ +int dbg_check_lprops(struct ubifs_info *c) +{ + int i, err; + struct ubifs_lp_stats lst; + + if (!dbg_is_chk_lprops(c)) + return 0; + + /* + * As we are going to scan the media, the write buffers have to be + * synchronized. + */ + for (i = 0; i < c->jhead_cnt; i++) { + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err) + return err; + } + + memset(&lst, 0, sizeof(struct ubifs_lp_stats)); + err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1, + (ubifs_lpt_scan_callback)scan_check_cb, + &lst); + if (err && err != -ENOSPC) + goto out; + + if (lst.empty_lebs != c->lst.empty_lebs || + lst.idx_lebs != c->lst.idx_lebs || + lst.total_free != c->lst.total_free || + lst.total_dirty != c->lst.total_dirty || + lst.total_used != c->lst.total_used) { + ubifs_err(c, "bad overall accounting"); + ubifs_err(c, "calculated: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld", + lst.empty_lebs, lst.idx_lebs, lst.total_free, + lst.total_dirty, lst.total_used); + ubifs_err(c, "read from lprops: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld", + c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free, + c->lst.total_dirty, c->lst.total_used); + err = -EINVAL; + goto out; + } + + if (lst.total_dead != c->lst.total_dead || + lst.total_dark != c->lst.total_dark) { + ubifs_err(c, "bad dead/dark space accounting"); + ubifs_err(c, "calculated: total_dead %lld, total_dark %lld", + lst.total_dead, lst.total_dark); + ubifs_err(c, "read from lprops: total_dead %lld, total_dark %lld", + c->lst.total_dead, c->lst.total_dark); + err = -EINVAL; + goto out; + } + + err = dbg_check_cats(c); +out: + return err; +} diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c new file mode 100644 index 000000000..6e0a153b7 --- /dev/null +++ b/fs/ubifs/lpt.c @@ -0,0 +1,2435 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements the LEB properties tree (LPT) area. The LPT area + * contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and + * (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits + * between the log and the orphan area. + * + * The LPT area is like a miniature self-contained file system. It is required + * that it never runs out of space, is fast to access and update, and scales + * logarithmically. The LEB properties tree is implemented as a wandering tree + * much like the TNC, and the LPT area has its own garbage collection. + * + * The LPT has two slightly different forms called the "small model" and the + * "big model". The small model is used when the entire LEB properties table + * can be written into a single eraseblock. In that case, garbage collection + * consists of just writing the whole table, which therefore makes all other + * eraseblocks reusable. In the case of the big model, dirty eraseblocks are + * selected for garbage collection, which consists of marking the clean nodes in + * that LEB as dirty, and then only the dirty nodes are written out. Also, in + * the case of the big model, a table of LEB numbers is saved so that the entire + * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first + * mounted. + */ + +#include "ubifs.h" +#include <linux/crc16.h> +#include <linux/math64.h> +#include <linux/slab.h> + +/** + * do_calc_lpt_geom - calculate sizes for the LPT area. + * @c: the UBIFS file-system description object + * + * Calculate the sizes of LPT bit fields, nodes, and tree, based on the + * properties of the flash and whether LPT is "big" (c->big_lpt). + */ +static void do_calc_lpt_geom(struct ubifs_info *c) +{ + int i, n, bits, per_leb_wastage, max_pnode_cnt; + long long sz, tot_wastage; + + n = c->main_lebs + c->max_leb_cnt - c->leb_cnt; + max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT); + + c->lpt_hght = 1; + n = UBIFS_LPT_FANOUT; + while (n < max_pnode_cnt) { + c->lpt_hght += 1; + n <<= UBIFS_LPT_FANOUT_SHIFT; + } + + c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); + + n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT); + c->nnode_cnt = n; + for (i = 1; i < c->lpt_hght; i++) { + n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT); + c->nnode_cnt += n; + } + + c->space_bits = fls(c->leb_size) - 3; + c->lpt_lnum_bits = fls(c->lpt_lebs); + c->lpt_offs_bits = fls(c->leb_size - 1); + c->lpt_spc_bits = fls(c->leb_size); + + n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT); + c->pcnt_bits = fls(n - 1); + + c->lnum_bits = fls(c->max_leb_cnt - 1); + + bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS + + (c->big_lpt ? c->pcnt_bits : 0) + + (c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT; + c->pnode_sz = (bits + 7) / 8; + + bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS + + (c->big_lpt ? c->pcnt_bits : 0) + + (c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT; + c->nnode_sz = (bits + 7) / 8; + + bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS + + c->lpt_lebs * c->lpt_spc_bits * 2; + c->ltab_sz = (bits + 7) / 8; + + bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS + + c->lnum_bits * c->lsave_cnt; + c->lsave_sz = (bits + 7) / 8; + + /* Calculate the minimum LPT size */ + c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz; + c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz; + c->lpt_sz += c->ltab_sz; + if (c->big_lpt) + c->lpt_sz += c->lsave_sz; + + /* Add wastage */ + sz = c->lpt_sz; + per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz); + sz += per_leb_wastage; + tot_wastage = per_leb_wastage; + while (sz > c->leb_size) { + sz += per_leb_wastage; + sz -= c->leb_size; + tot_wastage += per_leb_wastage; + } + tot_wastage += ALIGN(sz, c->min_io_size) - sz; + c->lpt_sz += tot_wastage; +} + +/** + * ubifs_calc_lpt_geom - calculate and check sizes for the LPT area. + * @c: the UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_calc_lpt_geom(struct ubifs_info *c) +{ + int lebs_needed; + long long sz; + + do_calc_lpt_geom(c); + + /* Verify that lpt_lebs is big enough */ + sz = c->lpt_sz * 2; /* Must have at least 2 times the size */ + lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size); + if (lebs_needed > c->lpt_lebs) { + ubifs_err(c, "too few LPT LEBs"); + return -EINVAL; + } + + /* Verify that ltab fits in a single LEB (since ltab is a single node */ + if (c->ltab_sz > c->leb_size) { + ubifs_err(c, "LPT ltab too big"); + return -EINVAL; + } + + c->check_lpt_free = c->big_lpt; + return 0; +} + +/** + * calc_dflt_lpt_geom - calculate default LPT geometry. + * @c: the UBIFS file-system description object + * @main_lebs: number of main area LEBs is passed and returned here + * @big_lpt: whether the LPT area is "big" is returned here + * + * The size of the LPT area depends on parameters that themselves are dependent + * on the size of the LPT area. This function, successively recalculates the LPT + * area geometry until the parameters and resultant geometry are consistent. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs, + int *big_lpt) +{ + int i, lebs_needed; + long long sz; + + /* Start by assuming the minimum number of LPT LEBs */ + c->lpt_lebs = UBIFS_MIN_LPT_LEBS; + c->main_lebs = *main_lebs - c->lpt_lebs; + if (c->main_lebs <= 0) + return -EINVAL; + + /* And assume we will use the small LPT model */ + c->big_lpt = 0; + + /* + * Calculate the geometry based on assumptions above and then see if it + * makes sense + */ + do_calc_lpt_geom(c); + + /* Small LPT model must have lpt_sz < leb_size */ + if (c->lpt_sz > c->leb_size) { + /* Nope, so try again using big LPT model */ + c->big_lpt = 1; + do_calc_lpt_geom(c); + } + + /* Now check there are enough LPT LEBs */ + for (i = 0; i < 64 ; i++) { + sz = c->lpt_sz * 4; /* Allow 4 times the size */ + lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size); + if (lebs_needed > c->lpt_lebs) { + /* Not enough LPT LEBs so try again with more */ + c->lpt_lebs = lebs_needed; + c->main_lebs = *main_lebs - c->lpt_lebs; + if (c->main_lebs <= 0) + return -EINVAL; + do_calc_lpt_geom(c); + continue; + } + if (c->ltab_sz > c->leb_size) { + ubifs_err(c, "LPT ltab too big"); + return -EINVAL; + } + *main_lebs = c->main_lebs; + *big_lpt = c->big_lpt; + return 0; + } + return -EINVAL; +} + +/** + * pack_bits - pack bit fields end-to-end. + * @c: UBIFS file-system description object + * @addr: address at which to pack (passed and next address returned) + * @pos: bit position at which to pack (passed and next position returned) + * @val: value to pack + * @nrbits: number of bits of value to pack (1-32) + */ +static void pack_bits(const struct ubifs_info *c, uint8_t **addr, int *pos, uint32_t val, int nrbits) +{ + uint8_t *p = *addr; + int b = *pos; + + ubifs_assert(c, nrbits > 0); + ubifs_assert(c, nrbits <= 32); + ubifs_assert(c, *pos >= 0); + ubifs_assert(c, *pos < 8); + ubifs_assert(c, (val >> nrbits) == 0 || nrbits == 32); + if (b) { + *p |= ((uint8_t)val) << b; + nrbits += b; + if (nrbits > 8) { + *++p = (uint8_t)(val >>= (8 - b)); + if (nrbits > 16) { + *++p = (uint8_t)(val >>= 8); + if (nrbits > 24) { + *++p = (uint8_t)(val >>= 8); + if (nrbits > 32) + *++p = (uint8_t)(val >>= 8); + } + } + } + } else { + *p = (uint8_t)val; + if (nrbits > 8) { + *++p = (uint8_t)(val >>= 8); + if (nrbits > 16) { + *++p = (uint8_t)(val >>= 8); + if (nrbits > 24) + *++p = (uint8_t)(val >>= 8); + } + } + } + b = nrbits & 7; + if (b == 0) + p++; + *addr = p; + *pos = b; +} + +/** + * ubifs_unpack_bits - unpack bit fields. + * @c: UBIFS file-system description object + * @addr: address at which to unpack (passed and next address returned) + * @pos: bit position at which to unpack (passed and next position returned) + * @nrbits: number of bits of value to unpack (1-32) + * + * This functions returns the value unpacked. + */ +uint32_t ubifs_unpack_bits(const struct ubifs_info *c, uint8_t **addr, int *pos, int nrbits) +{ + const int k = 32 - nrbits; + uint8_t *p = *addr; + int b = *pos; + uint32_t val; + const int bytes = (nrbits + b + 7) >> 3; + + ubifs_assert(c, nrbits > 0); + ubifs_assert(c, nrbits <= 32); + ubifs_assert(c, *pos >= 0); + ubifs_assert(c, *pos < 8); + if (b) { + switch (bytes) { + case 2: + val = p[1]; + break; + case 3: + val = p[1] | ((uint32_t)p[2] << 8); + break; + case 4: + val = p[1] | ((uint32_t)p[2] << 8) | + ((uint32_t)p[3] << 16); + break; + case 5: + val = p[1] | ((uint32_t)p[2] << 8) | + ((uint32_t)p[3] << 16) | + ((uint32_t)p[4] << 24); + } + val <<= (8 - b); + val |= *p >> b; + nrbits += b; + } else { + switch (bytes) { + case 1: + val = p[0]; + break; + case 2: + val = p[0] | ((uint32_t)p[1] << 8); + break; + case 3: + val = p[0] | ((uint32_t)p[1] << 8) | + ((uint32_t)p[2] << 16); + break; + case 4: + val = p[0] | ((uint32_t)p[1] << 8) | + ((uint32_t)p[2] << 16) | + ((uint32_t)p[3] << 24); + break; + } + } + val <<= k; + val >>= k; + b = nrbits & 7; + p += nrbits >> 3; + *addr = p; + *pos = b; + ubifs_assert(c, (val >> nrbits) == 0 || nrbits - b == 32); + return val; +} + +/** + * ubifs_pack_pnode - pack all the bit fields of a pnode. + * @c: UBIFS file-system description object + * @buf: buffer into which to pack + * @pnode: pnode to pack + */ +void ubifs_pack_pnode(struct ubifs_info *c, void *buf, + struct ubifs_pnode *pnode) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0; + uint16_t crc; + + pack_bits(c, &addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS); + if (c->big_lpt) + pack_bits(c, &addr, &pos, pnode->num, c->pcnt_bits); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + pack_bits(c, &addr, &pos, pnode->lprops[i].free >> 3, + c->space_bits); + pack_bits(c, &addr, &pos, pnode->lprops[i].dirty >> 3, + c->space_bits); + if (pnode->lprops[i].flags & LPROPS_INDEX) + pack_bits(c, &addr, &pos, 1, 1); + else + pack_bits(c, &addr, &pos, 0, 1); + } + crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + c->pnode_sz - UBIFS_LPT_CRC_BYTES); + addr = buf; + pos = 0; + pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS); +} + +/** + * ubifs_pack_nnode - pack all the bit fields of a nnode. + * @c: UBIFS file-system description object + * @buf: buffer into which to pack + * @nnode: nnode to pack + */ +void ubifs_pack_nnode(struct ubifs_info *c, void *buf, + struct ubifs_nnode *nnode) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0; + uint16_t crc; + + pack_bits(c, &addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS); + if (c->big_lpt) + pack_bits(c, &addr, &pos, nnode->num, c->pcnt_bits); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + int lnum = nnode->nbranch[i].lnum; + + if (lnum == 0) + lnum = c->lpt_last + 1; + pack_bits(c, &addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits); + pack_bits(c, &addr, &pos, nnode->nbranch[i].offs, + c->lpt_offs_bits); + } + crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + c->nnode_sz - UBIFS_LPT_CRC_BYTES); + addr = buf; + pos = 0; + pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS); +} + +/** + * ubifs_pack_ltab - pack the LPT's own lprops table. + * @c: UBIFS file-system description object + * @buf: buffer into which to pack + * @ltab: LPT's own lprops table to pack + */ +void ubifs_pack_ltab(struct ubifs_info *c, void *buf, + struct ubifs_lpt_lprops *ltab) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0; + uint16_t crc; + + pack_bits(c, &addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS); + for (i = 0; i < c->lpt_lebs; i++) { + pack_bits(c, &addr, &pos, ltab[i].free, c->lpt_spc_bits); + pack_bits(c, &addr, &pos, ltab[i].dirty, c->lpt_spc_bits); + } + crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + c->ltab_sz - UBIFS_LPT_CRC_BYTES); + addr = buf; + pos = 0; + pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS); +} + +/** + * ubifs_pack_lsave - pack the LPT's save table. + * @c: UBIFS file-system description object + * @buf: buffer into which to pack + * @lsave: LPT's save table to pack + */ +void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0; + uint16_t crc; + + pack_bits(c, &addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS); + for (i = 0; i < c->lsave_cnt; i++) + pack_bits(c, &addr, &pos, lsave[i], c->lnum_bits); + crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + c->lsave_sz - UBIFS_LPT_CRC_BYTES); + addr = buf; + pos = 0; + pack_bits(c, &addr, &pos, crc, UBIFS_LPT_CRC_BITS); +} + +/** + * ubifs_add_lpt_dirt - add dirty space to LPT LEB properties. + * @c: UBIFS file-system description object + * @lnum: LEB number to which to add dirty space + * @dirty: amount of dirty space to add + */ +void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty) +{ + if (!dirty || !lnum) + return; + dbg_lp("LEB %d add %d to %d", + lnum, dirty, c->ltab[lnum - c->lpt_first].dirty); + ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last); + c->ltab[lnum - c->lpt_first].dirty += dirty; +} + +/** + * set_ltab - set LPT LEB properties. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @free: amount of free space + * @dirty: amount of dirty space + */ +static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty) +{ + dbg_lp("LEB %d free %d dirty %d to %d %d", + lnum, c->ltab[lnum - c->lpt_first].free, + c->ltab[lnum - c->lpt_first].dirty, free, dirty); + ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last); + c->ltab[lnum - c->lpt_first].free = free; + c->ltab[lnum - c->lpt_first].dirty = dirty; +} + +/** + * ubifs_add_nnode_dirt - add dirty space to LPT LEB properties. + * @c: UBIFS file-system description object + * @nnode: nnode for which to add dirt + */ +void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode) +{ + struct ubifs_nnode *np = nnode->parent; + + if (np) + ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum, + c->nnode_sz); + else { + ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz); + if (!(c->lpt_drty_flgs & LTAB_DIRTY)) { + c->lpt_drty_flgs |= LTAB_DIRTY; + ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz); + } + } +} + +/** + * add_pnode_dirt - add dirty space to LPT LEB properties. + * @c: UBIFS file-system description object + * @pnode: pnode for which to add dirt + */ +static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode) +{ + ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum, + c->pnode_sz); +} + +/** + * calc_nnode_num - calculate nnode number. + * @row: the row in the tree (root is zero) + * @col: the column in the row (leftmost is zero) + * + * The nnode number is a number that uniquely identifies a nnode and can be used + * easily to traverse the tree from the root to that nnode. + * + * This function calculates and returns the nnode number for the nnode at @row + * and @col. + */ +static int calc_nnode_num(int row, int col) +{ + int num, bits; + + num = 1; + while (row--) { + bits = (col & (UBIFS_LPT_FANOUT - 1)); + col >>= UBIFS_LPT_FANOUT_SHIFT; + num <<= UBIFS_LPT_FANOUT_SHIFT; + num |= bits; + } + return num; +} + +/** + * calc_nnode_num_from_parent - calculate nnode number. + * @c: UBIFS file-system description object + * @parent: parent nnode + * @iip: index in parent + * + * The nnode number is a number that uniquely identifies a nnode and can be used + * easily to traverse the tree from the root to that nnode. + * + * This function calculates and returns the nnode number based on the parent's + * nnode number and the index in parent. + */ +static int calc_nnode_num_from_parent(const struct ubifs_info *c, + struct ubifs_nnode *parent, int iip) +{ + int num, shft; + + if (!parent) + return 1; + shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT; + num = parent->num ^ (1 << shft); + num |= (UBIFS_LPT_FANOUT + iip) << shft; + return num; +} + +/** + * calc_pnode_num_from_parent - calculate pnode number. + * @c: UBIFS file-system description object + * @parent: parent nnode + * @iip: index in parent + * + * The pnode number is a number that uniquely identifies a pnode and can be used + * easily to traverse the tree from the root to that pnode. + * + * This function calculates and returns the pnode number based on the parent's + * nnode number and the index in parent. + */ +static int calc_pnode_num_from_parent(const struct ubifs_info *c, + struct ubifs_nnode *parent, int iip) +{ + int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0; + + for (i = 0; i < n; i++) { + num <<= UBIFS_LPT_FANOUT_SHIFT; + num |= pnum & (UBIFS_LPT_FANOUT - 1); + pnum >>= UBIFS_LPT_FANOUT_SHIFT; + } + num <<= UBIFS_LPT_FANOUT_SHIFT; + num |= iip; + return num; +} + +/** + * ubifs_create_dflt_lpt - create default LPT. + * @c: UBIFS file-system description object + * @main_lebs: number of main area LEBs is passed and returned here + * @lpt_first: LEB number of first LPT LEB + * @lpt_lebs: number of LEBs for LPT is passed and returned here + * @big_lpt: use big LPT model is passed and returned here + * @hash: hash of the LPT is returned here + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first, + int *lpt_lebs, int *big_lpt, u8 *hash) +{ + int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row; + int blnum, boffs, bsz, bcnt; + struct ubifs_pnode *pnode = NULL; + struct ubifs_nnode *nnode = NULL; + void *buf = NULL, *p; + struct ubifs_lpt_lprops *ltab = NULL; + int *lsave = NULL; + struct shash_desc *desc; + + err = calc_dflt_lpt_geom(c, main_lebs, big_lpt); + if (err) + return err; + *lpt_lebs = c->lpt_lebs; + + /* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */ + c->lpt_first = lpt_first; + /* Needed by 'set_ltab()' */ + c->lpt_last = lpt_first + c->lpt_lebs - 1; + /* Needed by 'ubifs_pack_lsave()' */ + c->main_first = c->leb_cnt - *main_lebs; + + desc = ubifs_hash_get_desc(c); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + lsave = kmalloc_array(c->lsave_cnt, sizeof(int), GFP_KERNEL); + pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL); + nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL); + buf = vmalloc(c->leb_size); + ltab = vmalloc(array_size(sizeof(struct ubifs_lpt_lprops), + c->lpt_lebs)); + if (!pnode || !nnode || !buf || !ltab || !lsave) { + err = -ENOMEM; + goto out; + } + + ubifs_assert(c, !c->ltab); + c->ltab = ltab; /* Needed by set_ltab */ + + /* Initialize LPT's own lprops */ + for (i = 0; i < c->lpt_lebs; i++) { + ltab[i].free = c->leb_size; + ltab[i].dirty = 0; + ltab[i].tgc = 0; + ltab[i].cmt = 0; + } + + lnum = lpt_first; + p = buf; + /* Number of leaf nodes (pnodes) */ + cnt = c->pnode_cnt; + + /* + * The first pnode contains the LEB properties for the LEBs that contain + * the root inode node and the root index node of the index tree. + */ + node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8); + iopos = ALIGN(node_sz, c->min_io_size); + pnode->lprops[0].free = c->leb_size - iopos; + pnode->lprops[0].dirty = iopos - node_sz; + pnode->lprops[0].flags = LPROPS_INDEX; + + node_sz = UBIFS_INO_NODE_SZ; + iopos = ALIGN(node_sz, c->min_io_size); + pnode->lprops[1].free = c->leb_size - iopos; + pnode->lprops[1].dirty = iopos - node_sz; + + for (i = 2; i < UBIFS_LPT_FANOUT; i++) + pnode->lprops[i].free = c->leb_size; + + /* Add first pnode */ + ubifs_pack_pnode(c, p, pnode); + err = ubifs_shash_update(c, desc, p, c->pnode_sz); + if (err) + goto out; + + p += c->pnode_sz; + len = c->pnode_sz; + pnode->num += 1; + + /* Reset pnode values for remaining pnodes */ + pnode->lprops[0].free = c->leb_size; + pnode->lprops[0].dirty = 0; + pnode->lprops[0].flags = 0; + + pnode->lprops[1].free = c->leb_size; + pnode->lprops[1].dirty = 0; + + /* + * To calculate the internal node branches, we keep information about + * the level below. + */ + blnum = lnum; /* LEB number of level below */ + boffs = 0; /* Offset of level below */ + bcnt = cnt; /* Number of nodes in level below */ + bsz = c->pnode_sz; /* Size of nodes in level below */ + + /* Add all remaining pnodes */ + for (i = 1; i < cnt; i++) { + if (len + c->pnode_sz > c->leb_size) { + alen = ALIGN(len, c->min_io_size); + set_ltab(c, lnum, c->leb_size - alen, alen - len); + memset(p, 0xff, alen - len); + err = ubifs_leb_change(c, lnum++, buf, alen); + if (err) + goto out; + p = buf; + len = 0; + } + ubifs_pack_pnode(c, p, pnode); + err = ubifs_shash_update(c, desc, p, c->pnode_sz); + if (err) + goto out; + + p += c->pnode_sz; + len += c->pnode_sz; + /* + * pnodes are simply numbered left to right starting at zero, + * which means the pnode number can be used easily to traverse + * down the tree to the corresponding pnode. + */ + pnode->num += 1; + } + + row = 0; + for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT) + row += 1; + /* Add all nnodes, one level at a time */ + while (1) { + /* Number of internal nodes (nnodes) at next level */ + cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT); + for (i = 0; i < cnt; i++) { + if (len + c->nnode_sz > c->leb_size) { + alen = ALIGN(len, c->min_io_size); + set_ltab(c, lnum, c->leb_size - alen, + alen - len); + memset(p, 0xff, alen - len); + err = ubifs_leb_change(c, lnum++, buf, alen); + if (err) + goto out; + p = buf; + len = 0; + } + /* Only 1 nnode at this level, so it is the root */ + if (cnt == 1) { + c->lpt_lnum = lnum; + c->lpt_offs = len; + } + /* Set branches to the level below */ + for (j = 0; j < UBIFS_LPT_FANOUT; j++) { + if (bcnt) { + if (boffs + bsz > c->leb_size) { + blnum += 1; + boffs = 0; + } + nnode->nbranch[j].lnum = blnum; + nnode->nbranch[j].offs = boffs; + boffs += bsz; + bcnt--; + } else { + nnode->nbranch[j].lnum = 0; + nnode->nbranch[j].offs = 0; + } + } + nnode->num = calc_nnode_num(row, i); + ubifs_pack_nnode(c, p, nnode); + p += c->nnode_sz; + len += c->nnode_sz; + } + /* Only 1 nnode at this level, so it is the root */ + if (cnt == 1) + break; + /* Update the information about the level below */ + bcnt = cnt; + bsz = c->nnode_sz; + row -= 1; + } + + if (*big_lpt) { + /* Need to add LPT's save table */ + if (len + c->lsave_sz > c->leb_size) { + alen = ALIGN(len, c->min_io_size); + set_ltab(c, lnum, c->leb_size - alen, alen - len); + memset(p, 0xff, alen - len); + err = ubifs_leb_change(c, lnum++, buf, alen); + if (err) + goto out; + p = buf; + len = 0; + } + + c->lsave_lnum = lnum; + c->lsave_offs = len; + + for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++) + lsave[i] = c->main_first + i; + for (; i < c->lsave_cnt; i++) + lsave[i] = c->main_first; + + ubifs_pack_lsave(c, p, lsave); + p += c->lsave_sz; + len += c->lsave_sz; + } + + /* Need to add LPT's own LEB properties table */ + if (len + c->ltab_sz > c->leb_size) { + alen = ALIGN(len, c->min_io_size); + set_ltab(c, lnum, c->leb_size - alen, alen - len); + memset(p, 0xff, alen - len); + err = ubifs_leb_change(c, lnum++, buf, alen); + if (err) + goto out; + p = buf; + len = 0; + } + + c->ltab_lnum = lnum; + c->ltab_offs = len; + + /* Update ltab before packing it */ + len += c->ltab_sz; + alen = ALIGN(len, c->min_io_size); + set_ltab(c, lnum, c->leb_size - alen, alen - len); + + ubifs_pack_ltab(c, p, ltab); + p += c->ltab_sz; + + /* Write remaining buffer */ + memset(p, 0xff, alen - len); + err = ubifs_leb_change(c, lnum, buf, alen); + if (err) + goto out; + + err = ubifs_shash_final(c, desc, hash); + if (err) + goto out; + + c->nhead_lnum = lnum; + c->nhead_offs = ALIGN(len, c->min_io_size); + + dbg_lp("space_bits %d", c->space_bits); + dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits); + dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits); + dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits); + dbg_lp("pcnt_bits %d", c->pcnt_bits); + dbg_lp("lnum_bits %d", c->lnum_bits); + dbg_lp("pnode_sz %d", c->pnode_sz); + dbg_lp("nnode_sz %d", c->nnode_sz); + dbg_lp("ltab_sz %d", c->ltab_sz); + dbg_lp("lsave_sz %d", c->lsave_sz); + dbg_lp("lsave_cnt %d", c->lsave_cnt); + dbg_lp("lpt_hght %d", c->lpt_hght); + dbg_lp("big_lpt %d", c->big_lpt); + dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs); + dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs); + dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs); + if (c->big_lpt) + dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs); +out: + c->ltab = NULL; + kfree(desc); + kfree(lsave); + vfree(ltab); + vfree(buf); + kfree(nnode); + kfree(pnode); + return err; +} + +/** + * update_cats - add LEB properties of a pnode to LEB category lists and heaps. + * @c: UBIFS file-system description object + * @pnode: pnode + * + * When a pnode is loaded into memory, the LEB properties it contains are added, + * by this function, to the LEB category lists and heaps. + */ +static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode) +{ + int i; + + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK; + int lnum = pnode->lprops[i].lnum; + + if (!lnum) + return; + ubifs_add_to_cat(c, &pnode->lprops[i], cat); + } +} + +/** + * replace_cats - add LEB properties of a pnode to LEB category lists and heaps. + * @c: UBIFS file-system description object + * @old_pnode: pnode copied + * @new_pnode: pnode copy + * + * During commit it is sometimes necessary to copy a pnode + * (see dirty_cow_pnode). When that happens, references in + * category lists and heaps must be replaced. This function does that. + */ +static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode, + struct ubifs_pnode *new_pnode) +{ + int i; + + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (!new_pnode->lprops[i].lnum) + return; + ubifs_replace_cat(c, &old_pnode->lprops[i], + &new_pnode->lprops[i]); + } +} + +/** + * check_lpt_crc - check LPT node crc is correct. + * @c: UBIFS file-system description object + * @buf: buffer containing node + * @len: length of node + * + * This function returns %0 on success and a negative error code on failure. + */ +static int check_lpt_crc(const struct ubifs_info *c, void *buf, int len) +{ + int pos = 0; + uint8_t *addr = buf; + uint16_t crc, calc_crc; + + crc = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_CRC_BITS); + calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + len - UBIFS_LPT_CRC_BYTES); + if (crc != calc_crc) { + ubifs_err(c, "invalid crc in LPT node: crc %hx calc %hx", + crc, calc_crc); + dump_stack(); + return -EINVAL; + } + return 0; +} + +/** + * check_lpt_type - check LPT node type is correct. + * @c: UBIFS file-system description object + * @addr: address of type bit field is passed and returned updated here + * @pos: position of type bit field is passed and returned updated here + * @type: expected type + * + * This function returns %0 on success and a negative error code on failure. + */ +static int check_lpt_type(const struct ubifs_info *c, uint8_t **addr, + int *pos, int type) +{ + int node_type; + + node_type = ubifs_unpack_bits(c, addr, pos, UBIFS_LPT_TYPE_BITS); + if (node_type != type) { + ubifs_err(c, "invalid type (%d) in LPT node type %d", + node_type, type); + dump_stack(); + return -EINVAL; + } + return 0; +} + +/** + * unpack_pnode - unpack a pnode. + * @c: UBIFS file-system description object + * @buf: buffer containing packed pnode to unpack + * @pnode: pnode structure to fill + * + * This function returns %0 on success and a negative error code on failure. + */ +static int unpack_pnode(const struct ubifs_info *c, void *buf, + struct ubifs_pnode *pnode) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0, err; + + err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_PNODE); + if (err) + return err; + if (c->big_lpt) + pnode->num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_lprops * const lprops = &pnode->lprops[i]; + + lprops->free = ubifs_unpack_bits(c, &addr, &pos, c->space_bits); + lprops->free <<= 3; + lprops->dirty = ubifs_unpack_bits(c, &addr, &pos, c->space_bits); + lprops->dirty <<= 3; + + if (ubifs_unpack_bits(c, &addr, &pos, 1)) + lprops->flags = LPROPS_INDEX; + else + lprops->flags = 0; + lprops->flags |= ubifs_categorize_lprops(c, lprops); + } + err = check_lpt_crc(c, buf, c->pnode_sz); + return err; +} + +/** + * ubifs_unpack_nnode - unpack a nnode. + * @c: UBIFS file-system description object + * @buf: buffer containing packed nnode to unpack + * @nnode: nnode structure to fill + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf, + struct ubifs_nnode *nnode) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0, err; + + err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_NNODE); + if (err) + return err; + if (c->big_lpt) + nnode->num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + int lnum; + + lnum = ubifs_unpack_bits(c, &addr, &pos, c->lpt_lnum_bits) + + c->lpt_first; + if (lnum == c->lpt_last + 1) + lnum = 0; + nnode->nbranch[i].lnum = lnum; + nnode->nbranch[i].offs = ubifs_unpack_bits(c, &addr, &pos, + c->lpt_offs_bits); + } + err = check_lpt_crc(c, buf, c->nnode_sz); + return err; +} + +/** + * unpack_ltab - unpack the LPT's own lprops table. + * @c: UBIFS file-system description object + * @buf: buffer from which to unpack + * + * This function returns %0 on success and a negative error code on failure. + */ +static int unpack_ltab(const struct ubifs_info *c, void *buf) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0, err; + + err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LTAB); + if (err) + return err; + for (i = 0; i < c->lpt_lebs; i++) { + int free = ubifs_unpack_bits(c, &addr, &pos, c->lpt_spc_bits); + int dirty = ubifs_unpack_bits(c, &addr, &pos, c->lpt_spc_bits); + + if (free < 0 || free > c->leb_size || dirty < 0 || + dirty > c->leb_size || free + dirty > c->leb_size) + return -EINVAL; + + c->ltab[i].free = free; + c->ltab[i].dirty = dirty; + c->ltab[i].tgc = 0; + c->ltab[i].cmt = 0; + } + err = check_lpt_crc(c, buf, c->ltab_sz); + return err; +} + +/** + * unpack_lsave - unpack the LPT's save table. + * @c: UBIFS file-system description object + * @buf: buffer from which to unpack + * + * This function returns %0 on success and a negative error code on failure. + */ +static int unpack_lsave(const struct ubifs_info *c, void *buf) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int i, pos = 0, err; + + err = check_lpt_type(c, &addr, &pos, UBIFS_LPT_LSAVE); + if (err) + return err; + for (i = 0; i < c->lsave_cnt; i++) { + int lnum = ubifs_unpack_bits(c, &addr, &pos, c->lnum_bits); + + if (lnum < c->main_first || lnum >= c->leb_cnt) + return -EINVAL; + c->lsave[i] = lnum; + } + err = check_lpt_crc(c, buf, c->lsave_sz); + return err; +} + +/** + * validate_nnode - validate a nnode. + * @c: UBIFS file-system description object + * @nnode: nnode to validate + * @parent: parent nnode (or NULL for the root nnode) + * @iip: index in parent + * + * This function returns %0 on success and a negative error code on failure. + */ +static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode, + struct ubifs_nnode *parent, int iip) +{ + int i, lvl, max_offs; + + if (c->big_lpt) { + int num = calc_nnode_num_from_parent(c, parent, iip); + + if (nnode->num != num) + return -EINVAL; + } + lvl = parent ? parent->level - 1 : c->lpt_hght; + if (lvl < 1) + return -EINVAL; + if (lvl == 1) + max_offs = c->leb_size - c->pnode_sz; + else + max_offs = c->leb_size - c->nnode_sz; + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + int lnum = nnode->nbranch[i].lnum; + int offs = nnode->nbranch[i].offs; + + if (lnum == 0) { + if (offs != 0) + return -EINVAL; + continue; + } + if (lnum < c->lpt_first || lnum > c->lpt_last) + return -EINVAL; + if (offs < 0 || offs > max_offs) + return -EINVAL; + } + return 0; +} + +/** + * validate_pnode - validate a pnode. + * @c: UBIFS file-system description object + * @pnode: pnode to validate + * @parent: parent nnode + * @iip: index in parent + * + * This function returns %0 on success and a negative error code on failure. + */ +static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode, + struct ubifs_nnode *parent, int iip) +{ + int i; + + if (c->big_lpt) { + int num = calc_pnode_num_from_parent(c, parent, iip); + + if (pnode->num != num) + return -EINVAL; + } + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + int free = pnode->lprops[i].free; + int dirty = pnode->lprops[i].dirty; + + if (free < 0 || free > c->leb_size || free % c->min_io_size || + (free & 7)) + return -EINVAL; + if (dirty < 0 || dirty > c->leb_size || (dirty & 7)) + return -EINVAL; + if (dirty + free > c->leb_size) + return -EINVAL; + } + return 0; +} + +/** + * set_pnode_lnum - set LEB numbers on a pnode. + * @c: UBIFS file-system description object + * @pnode: pnode to update + * + * This function calculates the LEB numbers for the LEB properties it contains + * based on the pnode number. + */ +static void set_pnode_lnum(const struct ubifs_info *c, + struct ubifs_pnode *pnode) +{ + int i, lnum; + + lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first; + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (lnum >= c->leb_cnt) + return; + pnode->lprops[i].lnum = lnum++; + } +} + +/** + * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory. + * @c: UBIFS file-system description object + * @parent: parent nnode (or NULL for the root) + * @iip: index in parent + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip) +{ + struct ubifs_nbranch *branch = NULL; + struct ubifs_nnode *nnode = NULL; + void *buf = c->lpt_nod_buf; + int err, lnum, offs; + + if (parent) { + branch = &parent->nbranch[iip]; + lnum = branch->lnum; + offs = branch->offs; + } else { + lnum = c->lpt_lnum; + offs = c->lpt_offs; + } + nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS); + if (!nnode) { + err = -ENOMEM; + goto out; + } + if (lnum == 0) { + /* + * This nnode was not written which just means that the LEB + * properties in the subtree below it describe empty LEBs. We + * make the nnode as though we had read it, which in fact means + * doing almost nothing. + */ + if (c->big_lpt) + nnode->num = calc_nnode_num_from_parent(c, parent, iip); + } else { + err = ubifs_leb_read(c, lnum, buf, offs, c->nnode_sz, 1); + if (err) + goto out; + err = ubifs_unpack_nnode(c, buf, nnode); + if (err) + goto out; + } + err = validate_nnode(c, nnode, parent, iip); + if (err) + goto out; + if (!c->big_lpt) + nnode->num = calc_nnode_num_from_parent(c, parent, iip); + if (parent) { + branch->nnode = nnode; + nnode->level = parent->level - 1; + } else { + c->nroot = nnode; + nnode->level = c->lpt_hght; + } + nnode->parent = parent; + nnode->iip = iip; + return 0; + +out: + ubifs_err(c, "error %d reading nnode at %d:%d", err, lnum, offs); + dump_stack(); + kfree(nnode); + return err; +} + +/** + * read_pnode - read a pnode from flash and link it to the tree in memory. + * @c: UBIFS file-system description object + * @parent: parent nnode + * @iip: index in parent + * + * This function returns %0 on success and a negative error code on failure. + */ +static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip) +{ + struct ubifs_nbranch *branch; + struct ubifs_pnode *pnode = NULL; + void *buf = c->lpt_nod_buf; + int err, lnum, offs; + + branch = &parent->nbranch[iip]; + lnum = branch->lnum; + offs = branch->offs; + pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS); + if (!pnode) + return -ENOMEM; + + if (lnum == 0) { + /* + * This pnode was not written which just means that the LEB + * properties in it describe empty LEBs. We make the pnode as + * though we had read it. + */ + int i; + + if (c->big_lpt) + pnode->num = calc_pnode_num_from_parent(c, parent, iip); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_lprops * const lprops = &pnode->lprops[i]; + + lprops->free = c->leb_size; + lprops->flags = ubifs_categorize_lprops(c, lprops); + } + } else { + err = ubifs_leb_read(c, lnum, buf, offs, c->pnode_sz, 1); + if (err) + goto out; + err = unpack_pnode(c, buf, pnode); + if (err) + goto out; + } + err = validate_pnode(c, pnode, parent, iip); + if (err) + goto out; + if (!c->big_lpt) + pnode->num = calc_pnode_num_from_parent(c, parent, iip); + branch->pnode = pnode; + pnode->parent = parent; + pnode->iip = iip; + set_pnode_lnum(c, pnode); + c->pnodes_have += 1; + return 0; + +out: + ubifs_err(c, "error %d reading pnode at %d:%d", err, lnum, offs); + ubifs_dump_pnode(c, pnode, parent, iip); + dump_stack(); + ubifs_err(c, "calc num: %d", calc_pnode_num_from_parent(c, parent, iip)); + kfree(pnode); + return err; +} + +/** + * read_ltab - read LPT's own lprops table. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int read_ltab(struct ubifs_info *c) +{ + int err; + void *buf; + + buf = vmalloc(c->ltab_sz); + if (!buf) + return -ENOMEM; + err = ubifs_leb_read(c, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz, 1); + if (err) + goto out; + err = unpack_ltab(c, buf); +out: + vfree(buf); + return err; +} + +/** + * read_lsave - read LPT's save table. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int read_lsave(struct ubifs_info *c) +{ + int err, i; + void *buf; + + buf = vmalloc(c->lsave_sz); + if (!buf) + return -ENOMEM; + err = ubifs_leb_read(c, c->lsave_lnum, buf, c->lsave_offs, + c->lsave_sz, 1); + if (err) + goto out; + err = unpack_lsave(c, buf); + if (err) + goto out; + for (i = 0; i < c->lsave_cnt; i++) { + int lnum = c->lsave[i]; + struct ubifs_lprops *lprops; + + /* + * Due to automatic resizing, the values in the lsave table + * could be beyond the volume size - just ignore them. + */ + if (lnum >= c->leb_cnt) + continue; + lprops = ubifs_lpt_lookup(c, lnum); + if (IS_ERR(lprops)) { + err = PTR_ERR(lprops); + goto out; + } + } +out: + vfree(buf); + return err; +} + +/** + * ubifs_get_nnode - get a nnode. + * @c: UBIFS file-system description object + * @parent: parent nnode (or NULL for the root) + * @iip: index in parent + * + * This function returns a pointer to the nnode on success or a negative error + * code on failure. + */ +struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c, + struct ubifs_nnode *parent, int iip) +{ + struct ubifs_nbranch *branch; + struct ubifs_nnode *nnode; + int err; + + branch = &parent->nbranch[iip]; + nnode = branch->nnode; + if (nnode) + return nnode; + err = ubifs_read_nnode(c, parent, iip); + if (err) + return ERR_PTR(err); + return branch->nnode; +} + +/** + * ubifs_get_pnode - get a pnode. + * @c: UBIFS file-system description object + * @parent: parent nnode + * @iip: index in parent + * + * This function returns a pointer to the pnode on success or a negative error + * code on failure. + */ +struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c, + struct ubifs_nnode *parent, int iip) +{ + struct ubifs_nbranch *branch; + struct ubifs_pnode *pnode; + int err; + + branch = &parent->nbranch[iip]; + pnode = branch->pnode; + if (pnode) + return pnode; + err = read_pnode(c, parent, iip); + if (err) + return ERR_PTR(err); + update_cats(c, branch->pnode); + return branch->pnode; +} + +/** + * ubifs_pnode_lookup - lookup a pnode in the LPT. + * @c: UBIFS file-system description object + * @i: pnode number (0 to (main_lebs - 1) / UBIFS_LPT_FANOUT) + * + * This function returns a pointer to the pnode on success or a negative + * error code on failure. + */ +struct ubifs_pnode *ubifs_pnode_lookup(struct ubifs_info *c, int i) +{ + int err, h, iip, shft; + struct ubifs_nnode *nnode; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return ERR_PTR(err); + } + i <<= UBIFS_LPT_FANOUT_SHIFT; + nnode = c->nroot; + shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT; + for (h = 1; h < c->lpt_hght; h++) { + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + shft -= UBIFS_LPT_FANOUT_SHIFT; + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return ERR_CAST(nnode); + } + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + return ubifs_get_pnode(c, nnode, iip); +} + +/** + * ubifs_lpt_lookup - lookup LEB properties in the LPT. + * @c: UBIFS file-system description object + * @lnum: LEB number to lookup + * + * This function returns a pointer to the LEB properties on success or a + * negative error code on failure. + */ +struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum) +{ + int i, iip; + struct ubifs_pnode *pnode; + + i = lnum - c->main_first; + pnode = ubifs_pnode_lookup(c, i >> UBIFS_LPT_FANOUT_SHIFT); + if (IS_ERR(pnode)) + return ERR_CAST(pnode); + iip = (i & (UBIFS_LPT_FANOUT - 1)); + dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum, + pnode->lprops[iip].free, pnode->lprops[iip].dirty, + pnode->lprops[iip].flags); + return &pnode->lprops[iip]; +} + +/** + * dirty_cow_nnode - ensure a nnode is not being committed. + * @c: UBIFS file-system description object + * @nnode: nnode to check + * + * Returns dirtied nnode on success or negative error code on failure. + */ +static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c, + struct ubifs_nnode *nnode) +{ + struct ubifs_nnode *n; + int i; + + if (!test_bit(COW_CNODE, &nnode->flags)) { + /* nnode is not being committed */ + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + } + return nnode; + } + + /* nnode is being committed, so copy it */ + n = kmemdup(nnode, sizeof(struct ubifs_nnode), GFP_NOFS); + if (unlikely(!n)) + return ERR_PTR(-ENOMEM); + + n->cnext = NULL; + __set_bit(DIRTY_CNODE, &n->flags); + __clear_bit(COW_CNODE, &n->flags); + + /* The children now have new parent */ + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_nbranch *branch = &n->nbranch[i]; + + if (branch->cnode) + branch->cnode->parent = n; + } + + ubifs_assert(c, !test_bit(OBSOLETE_CNODE, &nnode->flags)); + __set_bit(OBSOLETE_CNODE, &nnode->flags); + + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + if (nnode->parent) + nnode->parent->nbranch[n->iip].nnode = n; + else + c->nroot = n; + return n; +} + +/** + * dirty_cow_pnode - ensure a pnode is not being committed. + * @c: UBIFS file-system description object + * @pnode: pnode to check + * + * Returns dirtied pnode on success or negative error code on failure. + */ +static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c, + struct ubifs_pnode *pnode) +{ + struct ubifs_pnode *p; + + if (!test_bit(COW_CNODE, &pnode->flags)) { + /* pnode is not being committed */ + if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) { + c->dirty_pn_cnt += 1; + add_pnode_dirt(c, pnode); + } + return pnode; + } + + /* pnode is being committed, so copy it */ + p = kmemdup(pnode, sizeof(struct ubifs_pnode), GFP_NOFS); + if (unlikely(!p)) + return ERR_PTR(-ENOMEM); + + p->cnext = NULL; + __set_bit(DIRTY_CNODE, &p->flags); + __clear_bit(COW_CNODE, &p->flags); + replace_cats(c, pnode, p); + + ubifs_assert(c, !test_bit(OBSOLETE_CNODE, &pnode->flags)); + __set_bit(OBSOLETE_CNODE, &pnode->flags); + + c->dirty_pn_cnt += 1; + add_pnode_dirt(c, pnode); + pnode->parent->nbranch[p->iip].pnode = p; + return p; +} + +/** + * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT. + * @c: UBIFS file-system description object + * @lnum: LEB number to lookup + * + * This function returns a pointer to the LEB properties on success or a + * negative error code on failure. + */ +struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum) +{ + int err, i, h, iip, shft; + struct ubifs_nnode *nnode; + struct ubifs_pnode *pnode; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return ERR_PTR(err); + } + nnode = c->nroot; + nnode = dirty_cow_nnode(c, nnode); + if (IS_ERR(nnode)) + return ERR_CAST(nnode); + i = lnum - c->main_first; + shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT; + for (h = 1; h < c->lpt_hght; h++) { + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + shft -= UBIFS_LPT_FANOUT_SHIFT; + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return ERR_CAST(nnode); + nnode = dirty_cow_nnode(c, nnode); + if (IS_ERR(nnode)) + return ERR_CAST(nnode); + } + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + pnode = ubifs_get_pnode(c, nnode, iip); + if (IS_ERR(pnode)) + return ERR_CAST(pnode); + pnode = dirty_cow_pnode(c, pnode); + if (IS_ERR(pnode)) + return ERR_CAST(pnode); + iip = (i & (UBIFS_LPT_FANOUT - 1)); + dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum, + pnode->lprops[iip].free, pnode->lprops[iip].dirty, + pnode->lprops[iip].flags); + ubifs_assert(c, test_bit(DIRTY_CNODE, &pnode->flags)); + return &pnode->lprops[iip]; +} + +/** + * ubifs_lpt_calc_hash - Calculate hash of the LPT pnodes + * @c: UBIFS file-system description object + * @hash: the returned hash of the LPT pnodes + * + * This function iterates over the LPT pnodes and creates a hash over them. + * Returns 0 for success or a negative error code otherwise. + */ +int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash) +{ + struct ubifs_nnode *nnode, *nn; + struct ubifs_cnode *cnode; + struct shash_desc *desc; + int iip = 0, i; + int bufsiz = max_t(int, c->nnode_sz, c->pnode_sz); + void *buf; + int err; + + if (!ubifs_authenticated(c)) + return 0; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return err; + } + + desc = ubifs_hash_get_desc(c); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + buf = kmalloc(bufsiz, GFP_NOFS); + if (!buf) { + err = -ENOMEM; + goto out; + } + + cnode = (struct ubifs_cnode *)c->nroot; + + while (cnode) { + nnode = cnode->parent; + nn = (struct ubifs_nnode *)cnode; + if (cnode->level > 1) { + while (iip < UBIFS_LPT_FANOUT) { + if (nn->nbranch[iip].lnum == 0) { + /* Go right */ + iip++; + continue; + } + + nnode = ubifs_get_nnode(c, nn, iip); + if (IS_ERR(nnode)) { + err = PTR_ERR(nnode); + goto out; + } + + /* Go down */ + iip = 0; + cnode = (struct ubifs_cnode *)nnode; + break; + } + if (iip < UBIFS_LPT_FANOUT) + continue; + } else { + struct ubifs_pnode *pnode; + + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (nn->nbranch[i].lnum == 0) + continue; + pnode = ubifs_get_pnode(c, nn, i); + if (IS_ERR(pnode)) { + err = PTR_ERR(pnode); + goto out; + } + + ubifs_pack_pnode(c, buf, pnode); + err = ubifs_shash_update(c, desc, buf, + c->pnode_sz); + if (err) + goto out; + } + } + /* Go up and to the right */ + iip = cnode->iip + 1; + cnode = (struct ubifs_cnode *)nnode; + } + + err = ubifs_shash_final(c, desc, hash); +out: + kfree(desc); + kfree(buf); + + return err; +} + +/** + * lpt_check_hash - check the hash of the LPT. + * @c: UBIFS file-system description object + * + * This function calculates a hash over all pnodes in the LPT and compares it with + * the hash stored in the master node. Returns %0 on success and a negative error + * code on failure. + */ +static int lpt_check_hash(struct ubifs_info *c) +{ + int err; + u8 hash[UBIFS_HASH_ARR_SZ]; + + if (!ubifs_authenticated(c)) + return 0; + + err = ubifs_lpt_calc_hash(c, hash); + if (err) + return err; + + if (ubifs_check_hash(c, c->mst_node->hash_lpt, hash)) { + err = -EPERM; + ubifs_err(c, "Failed to authenticate LPT"); + } else { + err = 0; + } + + return err; +} + +/** + * lpt_init_rd - initialize the LPT for reading. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int lpt_init_rd(struct ubifs_info *c) +{ + int err, i; + + c->ltab = vmalloc(array_size(sizeof(struct ubifs_lpt_lprops), + c->lpt_lebs)); + if (!c->ltab) + return -ENOMEM; + + i = max_t(int, c->nnode_sz, c->pnode_sz); + c->lpt_nod_buf = kmalloc(i, GFP_KERNEL); + if (!c->lpt_nod_buf) + return -ENOMEM; + + for (i = 0; i < LPROPS_HEAP_CNT; i++) { + c->lpt_heap[i].arr = kmalloc_array(LPT_HEAP_SZ, + sizeof(void *), + GFP_KERNEL); + if (!c->lpt_heap[i].arr) + return -ENOMEM; + c->lpt_heap[i].cnt = 0; + c->lpt_heap[i].max_cnt = LPT_HEAP_SZ; + } + + c->dirty_idx.arr = kmalloc_array(LPT_HEAP_SZ, sizeof(void *), + GFP_KERNEL); + if (!c->dirty_idx.arr) + return -ENOMEM; + c->dirty_idx.cnt = 0; + c->dirty_idx.max_cnt = LPT_HEAP_SZ; + + err = read_ltab(c); + if (err) + return err; + + err = lpt_check_hash(c); + if (err) + return err; + + dbg_lp("space_bits %d", c->space_bits); + dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits); + dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits); + dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits); + dbg_lp("pcnt_bits %d", c->pcnt_bits); + dbg_lp("lnum_bits %d", c->lnum_bits); + dbg_lp("pnode_sz %d", c->pnode_sz); + dbg_lp("nnode_sz %d", c->nnode_sz); + dbg_lp("ltab_sz %d", c->ltab_sz); + dbg_lp("lsave_sz %d", c->lsave_sz); + dbg_lp("lsave_cnt %d", c->lsave_cnt); + dbg_lp("lpt_hght %d", c->lpt_hght); + dbg_lp("big_lpt %d", c->big_lpt); + dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs); + dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs); + dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs); + if (c->big_lpt) + dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs); + + return 0; +} + +/** + * lpt_init_wr - initialize the LPT for writing. + * @c: UBIFS file-system description object + * + * 'lpt_init_rd()' must have been called already. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int lpt_init_wr(struct ubifs_info *c) +{ + int err, i; + + c->ltab_cmt = vmalloc(array_size(sizeof(struct ubifs_lpt_lprops), + c->lpt_lebs)); + if (!c->ltab_cmt) + return -ENOMEM; + + c->lpt_buf = vmalloc(c->leb_size); + if (!c->lpt_buf) + return -ENOMEM; + + if (c->big_lpt) { + c->lsave = kmalloc_array(c->lsave_cnt, sizeof(int), GFP_NOFS); + if (!c->lsave) + return -ENOMEM; + err = read_lsave(c); + if (err) + return err; + } + + for (i = 0; i < c->lpt_lebs; i++) + if (c->ltab[i].free == c->leb_size) { + err = ubifs_leb_unmap(c, i + c->lpt_first); + if (err) + return err; + } + + return 0; +} + +/** + * ubifs_lpt_init - initialize the LPT. + * @c: UBIFS file-system description object + * @rd: whether to initialize lpt for reading + * @wr: whether to initialize lpt for writing + * + * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true + * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is + * true. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr) +{ + int err; + + if (rd) { + err = lpt_init_rd(c); + if (err) + goto out_err; + } + + if (wr) { + err = lpt_init_wr(c); + if (err) + goto out_err; + } + + return 0; + +out_err: + if (wr) + ubifs_lpt_free(c, 1); + if (rd) + ubifs_lpt_free(c, 0); + return err; +} + +/** + * struct lpt_scan_node - somewhere to put nodes while we scan LPT. + * @nnode: where to keep a nnode + * @pnode: where to keep a pnode + * @cnode: where to keep a cnode + * @in_tree: is the node in the tree in memory + * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in + * the tree + * @ptr.pnode: ditto for pnode + * @ptr.cnode: ditto for cnode + */ +struct lpt_scan_node { + union { + struct ubifs_nnode nnode; + struct ubifs_pnode pnode; + struct ubifs_cnode cnode; + }; + int in_tree; + union { + struct ubifs_nnode *nnode; + struct ubifs_pnode *pnode; + struct ubifs_cnode *cnode; + } ptr; +}; + +/** + * scan_get_nnode - for the scan, get a nnode from either the tree or flash. + * @c: the UBIFS file-system description object + * @path: where to put the nnode + * @parent: parent of the nnode + * @iip: index in parent of the nnode + * + * This function returns a pointer to the nnode on success or a negative error + * code on failure. + */ +static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c, + struct lpt_scan_node *path, + struct ubifs_nnode *parent, int iip) +{ + struct ubifs_nbranch *branch; + struct ubifs_nnode *nnode; + void *buf = c->lpt_nod_buf; + int err; + + branch = &parent->nbranch[iip]; + nnode = branch->nnode; + if (nnode) { + path->in_tree = 1; + path->ptr.nnode = nnode; + return nnode; + } + nnode = &path->nnode; + path->in_tree = 0; + path->ptr.nnode = nnode; + memset(nnode, 0, sizeof(struct ubifs_nnode)); + if (branch->lnum == 0) { + /* + * This nnode was not written which just means that the LEB + * properties in the subtree below it describe empty LEBs. We + * make the nnode as though we had read it, which in fact means + * doing almost nothing. + */ + if (c->big_lpt) + nnode->num = calc_nnode_num_from_parent(c, parent, iip); + } else { + err = ubifs_leb_read(c, branch->lnum, buf, branch->offs, + c->nnode_sz, 1); + if (err) + return ERR_PTR(err); + err = ubifs_unpack_nnode(c, buf, nnode); + if (err) + return ERR_PTR(err); + } + err = validate_nnode(c, nnode, parent, iip); + if (err) + return ERR_PTR(err); + if (!c->big_lpt) + nnode->num = calc_nnode_num_from_parent(c, parent, iip); + nnode->level = parent->level - 1; + nnode->parent = parent; + nnode->iip = iip; + return nnode; +} + +/** + * scan_get_pnode - for the scan, get a pnode from either the tree or flash. + * @c: the UBIFS file-system description object + * @path: where to put the pnode + * @parent: parent of the pnode + * @iip: index in parent of the pnode + * + * This function returns a pointer to the pnode on success or a negative error + * code on failure. + */ +static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c, + struct lpt_scan_node *path, + struct ubifs_nnode *parent, int iip) +{ + struct ubifs_nbranch *branch; + struct ubifs_pnode *pnode; + void *buf = c->lpt_nod_buf; + int err; + + branch = &parent->nbranch[iip]; + pnode = branch->pnode; + if (pnode) { + path->in_tree = 1; + path->ptr.pnode = pnode; + return pnode; + } + pnode = &path->pnode; + path->in_tree = 0; + path->ptr.pnode = pnode; + memset(pnode, 0, sizeof(struct ubifs_pnode)); + if (branch->lnum == 0) { + /* + * This pnode was not written which just means that the LEB + * properties in it describe empty LEBs. We make the pnode as + * though we had read it. + */ + int i; + + if (c->big_lpt) + pnode->num = calc_pnode_num_from_parent(c, parent, iip); + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_lprops * const lprops = &pnode->lprops[i]; + + lprops->free = c->leb_size; + lprops->flags = ubifs_categorize_lprops(c, lprops); + } + } else { + ubifs_assert(c, branch->lnum >= c->lpt_first && + branch->lnum <= c->lpt_last); + ubifs_assert(c, branch->offs >= 0 && branch->offs < c->leb_size); + err = ubifs_leb_read(c, branch->lnum, buf, branch->offs, + c->pnode_sz, 1); + if (err) + return ERR_PTR(err); + err = unpack_pnode(c, buf, pnode); + if (err) + return ERR_PTR(err); + } + err = validate_pnode(c, pnode, parent, iip); + if (err) + return ERR_PTR(err); + if (!c->big_lpt) + pnode->num = calc_pnode_num_from_parent(c, parent, iip); + pnode->parent = parent; + pnode->iip = iip; + set_pnode_lnum(c, pnode); + return pnode; +} + +/** + * ubifs_lpt_scan_nolock - scan the LPT. + * @c: the UBIFS file-system description object + * @start_lnum: LEB number from which to start scanning + * @end_lnum: LEB number at which to stop scanning + * @scan_cb: callback function called for each lprops + * @data: data to be passed to the callback function + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum, + ubifs_lpt_scan_callback scan_cb, void *data) +{ + int err = 0, i, h, iip, shft; + struct ubifs_nnode *nnode; + struct ubifs_pnode *pnode; + struct lpt_scan_node *path; + + if (start_lnum == -1) { + start_lnum = end_lnum + 1; + if (start_lnum >= c->leb_cnt) + start_lnum = c->main_first; + } + + ubifs_assert(c, start_lnum >= c->main_first && start_lnum < c->leb_cnt); + ubifs_assert(c, end_lnum >= c->main_first && end_lnum < c->leb_cnt); + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return err; + } + + path = kmalloc_array(c->lpt_hght + 1, sizeof(struct lpt_scan_node), + GFP_NOFS); + if (!path) + return -ENOMEM; + + path[0].ptr.nnode = c->nroot; + path[0].in_tree = 1; +again: + /* Descend to the pnode containing start_lnum */ + nnode = c->nroot; + i = start_lnum - c->main_first; + shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT; + for (h = 1; h < c->lpt_hght; h++) { + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + shft -= UBIFS_LPT_FANOUT_SHIFT; + nnode = scan_get_nnode(c, path + h, nnode, iip); + if (IS_ERR(nnode)) { + err = PTR_ERR(nnode); + goto out; + } + } + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + pnode = scan_get_pnode(c, path + h, nnode, iip); + if (IS_ERR(pnode)) { + err = PTR_ERR(pnode); + goto out; + } + iip = (i & (UBIFS_LPT_FANOUT - 1)); + + /* Loop for each lprops */ + while (1) { + struct ubifs_lprops *lprops = &pnode->lprops[iip]; + int ret, lnum = lprops->lnum; + + ret = scan_cb(c, lprops, path[h].in_tree, data); + if (ret < 0) { + err = ret; + goto out; + } + if (ret & LPT_SCAN_ADD) { + /* Add all the nodes in path to the tree in memory */ + for (h = 1; h < c->lpt_hght; h++) { + const size_t sz = sizeof(struct ubifs_nnode); + struct ubifs_nnode *parent; + + if (path[h].in_tree) + continue; + nnode = kmemdup(&path[h].nnode, sz, GFP_NOFS); + if (!nnode) { + err = -ENOMEM; + goto out; + } + parent = nnode->parent; + parent->nbranch[nnode->iip].nnode = nnode; + path[h].ptr.nnode = nnode; + path[h].in_tree = 1; + path[h + 1].cnode.parent = nnode; + } + if (path[h].in_tree) + ubifs_ensure_cat(c, lprops); + else { + const size_t sz = sizeof(struct ubifs_pnode); + struct ubifs_nnode *parent; + + pnode = kmemdup(&path[h].pnode, sz, GFP_NOFS); + if (!pnode) { + err = -ENOMEM; + goto out; + } + parent = pnode->parent; + parent->nbranch[pnode->iip].pnode = pnode; + path[h].ptr.pnode = pnode; + path[h].in_tree = 1; + update_cats(c, pnode); + c->pnodes_have += 1; + } + err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *) + c->nroot, 0, 0); + if (err) + goto out; + err = dbg_check_cats(c); + if (err) + goto out; + } + if (ret & LPT_SCAN_STOP) { + err = 0; + break; + } + /* Get the next lprops */ + if (lnum == end_lnum) { + /* + * We got to the end without finding what we were + * looking for + */ + err = -ENOSPC; + goto out; + } + if (lnum + 1 >= c->leb_cnt) { + /* Wrap-around to the beginning */ + start_lnum = c->main_first; + goto again; + } + if (iip + 1 < UBIFS_LPT_FANOUT) { + /* Next lprops is in the same pnode */ + iip += 1; + continue; + } + /* We need to get the next pnode. Go up until we can go right */ + iip = pnode->iip; + while (1) { + h -= 1; + ubifs_assert(c, h >= 0); + nnode = path[h].ptr.nnode; + if (iip + 1 < UBIFS_LPT_FANOUT) + break; + iip = nnode->iip; + } + /* Go right */ + iip += 1; + /* Descend to the pnode */ + h += 1; + for (; h < c->lpt_hght; h++) { + nnode = scan_get_nnode(c, path + h, nnode, iip); + if (IS_ERR(nnode)) { + err = PTR_ERR(nnode); + goto out; + } + iip = 0; + } + pnode = scan_get_pnode(c, path + h, nnode, iip); + if (IS_ERR(pnode)) { + err = PTR_ERR(pnode); + goto out; + } + iip = 0; + } +out: + kfree(path); + return err; +} + +/** + * dbg_chk_pnode - check a pnode. + * @c: the UBIFS file-system description object + * @pnode: pnode to check + * @col: pnode column + * + * This function returns %0 on success and a negative error code on failure. + */ +static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode, + int col) +{ + int i; + + if (pnode->num != col) { + ubifs_err(c, "pnode num %d expected %d parent num %d iip %d", + pnode->num, col, pnode->parent->num, pnode->iip); + return -EINVAL; + } + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_lprops *lp, *lprops = &pnode->lprops[i]; + int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i + + c->main_first; + int found, cat = lprops->flags & LPROPS_CAT_MASK; + struct ubifs_lpt_heap *heap; + struct list_head *list = NULL; + + if (lnum >= c->leb_cnt) + continue; + if (lprops->lnum != lnum) { + ubifs_err(c, "bad LEB number %d expected %d", + lprops->lnum, lnum); + return -EINVAL; + } + if (lprops->flags & LPROPS_TAKEN) { + if (cat != LPROPS_UNCAT) { + ubifs_err(c, "LEB %d taken but not uncat %d", + lprops->lnum, cat); + return -EINVAL; + } + continue; + } + if (lprops->flags & LPROPS_INDEX) { + switch (cat) { + case LPROPS_UNCAT: + case LPROPS_DIRTY_IDX: + case LPROPS_FRDI_IDX: + break; + default: + ubifs_err(c, "LEB %d index but cat %d", + lprops->lnum, cat); + return -EINVAL; + } + } else { + switch (cat) { + case LPROPS_UNCAT: + case LPROPS_DIRTY: + case LPROPS_FREE: + case LPROPS_EMPTY: + case LPROPS_FREEABLE: + break; + default: + ubifs_err(c, "LEB %d not index but cat %d", + lprops->lnum, cat); + return -EINVAL; + } + } + switch (cat) { + case LPROPS_UNCAT: + list = &c->uncat_list; + break; + case LPROPS_EMPTY: + list = &c->empty_list; + break; + case LPROPS_FREEABLE: + list = &c->freeable_list; + break; + case LPROPS_FRDI_IDX: + list = &c->frdi_idx_list; + break; + } + found = 0; + switch (cat) { + case LPROPS_DIRTY: + case LPROPS_DIRTY_IDX: + case LPROPS_FREE: + heap = &c->lpt_heap[cat - 1]; + if (lprops->hpos < heap->cnt && + heap->arr[lprops->hpos] == lprops) + found = 1; + break; + case LPROPS_UNCAT: + case LPROPS_EMPTY: + case LPROPS_FREEABLE: + case LPROPS_FRDI_IDX: + list_for_each_entry(lp, list, list) + if (lprops == lp) { + found = 1; + break; + } + break; + } + if (!found) { + ubifs_err(c, "LEB %d cat %d not found in cat heap/list", + lprops->lnum, cat); + return -EINVAL; + } + switch (cat) { + case LPROPS_EMPTY: + if (lprops->free != c->leb_size) { + ubifs_err(c, "LEB %d cat %d free %d dirty %d", + lprops->lnum, cat, lprops->free, + lprops->dirty); + return -EINVAL; + } + break; + case LPROPS_FREEABLE: + case LPROPS_FRDI_IDX: + if (lprops->free + lprops->dirty != c->leb_size) { + ubifs_err(c, "LEB %d cat %d free %d dirty %d", + lprops->lnum, cat, lprops->free, + lprops->dirty); + return -EINVAL; + } + break; + } + } + return 0; +} + +/** + * dbg_check_lpt_nodes - check nnodes and pnodes. + * @c: the UBIFS file-system description object + * @cnode: next cnode (nnode or pnode) to check + * @row: row of cnode (root is zero) + * @col: column of cnode (leftmost is zero) + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode, + int row, int col) +{ + struct ubifs_nnode *nnode, *nn; + struct ubifs_cnode *cn; + int num, iip = 0, err; + + if (!dbg_is_chk_lprops(c)) + return 0; + + while (cnode) { + ubifs_assert(c, row >= 0); + nnode = cnode->parent; + if (cnode->level) { + /* cnode is a nnode */ + num = calc_nnode_num(row, col); + if (cnode->num != num) { + ubifs_err(c, "nnode num %d expected %d parent num %d iip %d", + cnode->num, num, + (nnode ? nnode->num : 0), cnode->iip); + return -EINVAL; + } + nn = (struct ubifs_nnode *)cnode; + while (iip < UBIFS_LPT_FANOUT) { + cn = nn->nbranch[iip].cnode; + if (cn) { + /* Go down */ + row += 1; + col <<= UBIFS_LPT_FANOUT_SHIFT; + col += iip; + iip = 0; + cnode = cn; + break; + } + /* Go right */ + iip += 1; + } + if (iip < UBIFS_LPT_FANOUT) + continue; + } else { + struct ubifs_pnode *pnode; + + /* cnode is a pnode */ + pnode = (struct ubifs_pnode *)cnode; + err = dbg_chk_pnode(c, pnode, col); + if (err) + return err; + } + /* Go up and to the right */ + row -= 1; + col >>= UBIFS_LPT_FANOUT_SHIFT; + iip = cnode->iip + 1; + cnode = (struct ubifs_cnode *)nnode; + } + return 0; +} diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c new file mode 100644 index 000000000..d76a19e46 --- /dev/null +++ b/fs/ubifs/lpt_commit.c @@ -0,0 +1,1997 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements commit-related functionality of the LEB properties + * subsystem. + */ + +#include <linux/crc16.h> +#include <linux/slab.h> +#include <linux/random.h> +#include "ubifs.h" + +static int dbg_populate_lsave(struct ubifs_info *c); + +/** + * first_dirty_cnode - find first dirty cnode. + * @c: UBIFS file-system description object + * @nnode: nnode at which to start + * + * This function returns the first dirty cnode or %NULL if there is not one. + */ +static struct ubifs_cnode *first_dirty_cnode(const struct ubifs_info *c, struct ubifs_nnode *nnode) +{ + ubifs_assert(c, nnode); + while (1) { + int i, cont = 0; + + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_cnode *cnode; + + cnode = nnode->nbranch[i].cnode; + if (cnode && + test_bit(DIRTY_CNODE, &cnode->flags)) { + if (cnode->level == 0) + return cnode; + nnode = (struct ubifs_nnode *)cnode; + cont = 1; + break; + } + } + if (!cont) + return (struct ubifs_cnode *)nnode; + } +} + +/** + * next_dirty_cnode - find next dirty cnode. + * @c: UBIFS file-system description object + * @cnode: cnode from which to begin searching + * + * This function returns the next dirty cnode or %NULL if there is not one. + */ +static struct ubifs_cnode *next_dirty_cnode(const struct ubifs_info *c, struct ubifs_cnode *cnode) +{ + struct ubifs_nnode *nnode; + int i; + + ubifs_assert(c, cnode); + nnode = cnode->parent; + if (!nnode) + return NULL; + for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) { + cnode = nnode->nbranch[i].cnode; + if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) { + if (cnode->level == 0) + return cnode; /* cnode is a pnode */ + /* cnode is a nnode */ + return first_dirty_cnode(c, (struct ubifs_nnode *)cnode); + } + } + return (struct ubifs_cnode *)nnode; +} + +/** + * get_cnodes_to_commit - create list of dirty cnodes to commit. + * @c: UBIFS file-system description object + * + * This function returns the number of cnodes to commit. + */ +static int get_cnodes_to_commit(struct ubifs_info *c) +{ + struct ubifs_cnode *cnode, *cnext; + int cnt = 0; + + if (!c->nroot) + return 0; + + if (!test_bit(DIRTY_CNODE, &c->nroot->flags)) + return 0; + + c->lpt_cnext = first_dirty_cnode(c, c->nroot); + cnode = c->lpt_cnext; + if (!cnode) + return 0; + cnt += 1; + while (1) { + ubifs_assert(c, !test_bit(COW_CNODE, &cnode->flags)); + __set_bit(COW_CNODE, &cnode->flags); + cnext = next_dirty_cnode(c, cnode); + if (!cnext) { + cnode->cnext = c->lpt_cnext; + break; + } + cnode->cnext = cnext; + cnode = cnext; + cnt += 1; + } + dbg_cmt("committing %d cnodes", cnt); + dbg_lp("committing %d cnodes", cnt); + ubifs_assert(c, cnt == c->dirty_nn_cnt + c->dirty_pn_cnt); + return cnt; +} + +/** + * upd_ltab - update LPT LEB properties. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @free: amount of free space + * @dirty: amount of dirty space to add + */ +static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty) +{ + dbg_lp("LEB %d free %d dirty %d to %d +%d", + lnum, c->ltab[lnum - c->lpt_first].free, + c->ltab[lnum - c->lpt_first].dirty, free, dirty); + ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last); + c->ltab[lnum - c->lpt_first].free = free; + c->ltab[lnum - c->lpt_first].dirty += dirty; +} + +/** + * alloc_lpt_leb - allocate an LPT LEB that is empty. + * @c: UBIFS file-system description object + * @lnum: LEB number is passed and returned here + * + * This function finds the next empty LEB in the ltab starting from @lnum. If a + * an empty LEB is found it is returned in @lnum and the function returns %0. + * Otherwise the function returns -ENOSPC. Note however, that LPT is designed + * never to run out of space. + */ +static int alloc_lpt_leb(struct ubifs_info *c, int *lnum) +{ + int i, n; + + n = *lnum - c->lpt_first + 1; + for (i = n; i < c->lpt_lebs; i++) { + if (c->ltab[i].tgc || c->ltab[i].cmt) + continue; + if (c->ltab[i].free == c->leb_size) { + c->ltab[i].cmt = 1; + *lnum = i + c->lpt_first; + return 0; + } + } + + for (i = 0; i < n; i++) { + if (c->ltab[i].tgc || c->ltab[i].cmt) + continue; + if (c->ltab[i].free == c->leb_size) { + c->ltab[i].cmt = 1; + *lnum = i + c->lpt_first; + return 0; + } + } + return -ENOSPC; +} + +/** + * layout_cnodes - layout cnodes for commit. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int layout_cnodes(struct ubifs_info *c) +{ + int lnum, offs, len, alen, done_lsave, done_ltab, err; + struct ubifs_cnode *cnode; + + err = dbg_chk_lpt_sz(c, 0, 0); + if (err) + return err; + cnode = c->lpt_cnext; + if (!cnode) + return 0; + lnum = c->nhead_lnum; + offs = c->nhead_offs; + /* Try to place lsave and ltab nicely */ + done_lsave = !c->big_lpt; + done_ltab = 0; + if (!done_lsave && offs + c->lsave_sz <= c->leb_size) { + done_lsave = 1; + c->lsave_lnum = lnum; + c->lsave_offs = offs; + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + if (offs + c->ltab_sz <= c->leb_size) { + done_ltab = 1; + c->ltab_lnum = lnum; + c->ltab_offs = offs; + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + do { + if (cnode->level) { + len = c->nnode_sz; + c->dirty_nn_cnt -= 1; + } else { + len = c->pnode_sz; + c->dirty_pn_cnt -= 1; + } + while (offs + len > c->leb_size) { + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = alloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = 0; + ubifs_assert(c, lnum >= c->lpt_first && + lnum <= c->lpt_last); + /* Try to place lsave and ltab nicely */ + if (!done_lsave) { + done_lsave = 1; + c->lsave_lnum = lnum; + c->lsave_offs = offs; + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + continue; + } + if (!done_ltab) { + done_ltab = 1; + c->ltab_lnum = lnum; + c->ltab_offs = offs; + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + continue; + } + break; + } + if (cnode->parent) { + cnode->parent->nbranch[cnode->iip].lnum = lnum; + cnode->parent->nbranch[cnode->iip].offs = offs; + } else { + c->lpt_lnum = lnum; + c->lpt_offs = offs; + } + offs += len; + dbg_chk_lpt_sz(c, 1, len); + cnode = cnode->cnext; + } while (cnode && cnode != c->lpt_cnext); + + /* Make sure to place LPT's save table */ + if (!done_lsave) { + if (offs + c->lsave_sz > c->leb_size) { + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = alloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = 0; + ubifs_assert(c, lnum >= c->lpt_first && + lnum <= c->lpt_last); + } + done_lsave = 1; + c->lsave_lnum = lnum; + c->lsave_offs = offs; + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + /* Make sure to place LPT's own lprops table */ + if (!done_ltab) { + if (offs + c->ltab_sz > c->leb_size) { + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = alloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = 0; + ubifs_assert(c, lnum >= c->lpt_first && + lnum <= c->lpt_last); + } + c->ltab_lnum = lnum; + c->ltab_offs = offs; + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 4, alen - offs); + err = dbg_chk_lpt_sz(c, 3, alen); + if (err) + return err; + return 0; + +no_space: + ubifs_err(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d", + lnum, offs, len, done_ltab, done_lsave); + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + return err; +} + +/** + * realloc_lpt_leb - allocate an LPT LEB that is empty. + * @c: UBIFS file-system description object + * @lnum: LEB number is passed and returned here + * + * This function duplicates exactly the results of the function alloc_lpt_leb. + * It is used during end commit to reallocate the same LEB numbers that were + * allocated by alloc_lpt_leb during start commit. + * + * This function finds the next LEB that was allocated by the alloc_lpt_leb + * function starting from @lnum. If a LEB is found it is returned in @lnum and + * the function returns %0. Otherwise the function returns -ENOSPC. + * Note however, that LPT is designed never to run out of space. + */ +static int realloc_lpt_leb(struct ubifs_info *c, int *lnum) +{ + int i, n; + + n = *lnum - c->lpt_first + 1; + for (i = n; i < c->lpt_lebs; i++) + if (c->ltab[i].cmt) { + c->ltab[i].cmt = 0; + *lnum = i + c->lpt_first; + return 0; + } + + for (i = 0; i < n; i++) + if (c->ltab[i].cmt) { + c->ltab[i].cmt = 0; + *lnum = i + c->lpt_first; + return 0; + } + return -ENOSPC; +} + +/** + * write_cnodes - write cnodes for commit. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int write_cnodes(struct ubifs_info *c) +{ + int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave; + struct ubifs_cnode *cnode; + void *buf = c->lpt_buf; + + cnode = c->lpt_cnext; + if (!cnode) + return 0; + lnum = c->nhead_lnum; + offs = c->nhead_offs; + from = offs; + /* Ensure empty LEB is unmapped */ + if (offs == 0) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + /* Try to place lsave and ltab nicely */ + done_lsave = !c->big_lpt; + done_ltab = 0; + if (!done_lsave && offs + c->lsave_sz <= c->leb_size) { + done_lsave = 1; + ubifs_pack_lsave(c, buf + offs, c->lsave); + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + if (offs + c->ltab_sz <= c->leb_size) { + done_ltab = 1; + ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + /* Loop for each cnode */ + do { + if (cnode->level) + len = c->nnode_sz; + else + len = c->pnode_sz; + while (offs + len > c->leb_size) { + wlen = offs - from; + if (wlen) { + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, + alen); + if (err) + return err; + } + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = realloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = from = 0; + ubifs_assert(c, lnum >= c->lpt_first && + lnum <= c->lpt_last); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + /* Try to place lsave and ltab nicely */ + if (!done_lsave) { + done_lsave = 1; + ubifs_pack_lsave(c, buf + offs, c->lsave); + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + continue; + } + if (!done_ltab) { + done_ltab = 1; + ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + continue; + } + break; + } + if (cnode->level) + ubifs_pack_nnode(c, buf + offs, + (struct ubifs_nnode *)cnode); + else + ubifs_pack_pnode(c, buf + offs, + (struct ubifs_pnode *)cnode); + /* + * The reason for the barriers is the same as in case of TNC. + * See comment in 'write_index()'. 'dirty_cow_nnode()' and + * 'dirty_cow_pnode()' are the functions for which this is + * important. + */ + clear_bit(DIRTY_CNODE, &cnode->flags); + smp_mb__before_atomic(); + clear_bit(COW_CNODE, &cnode->flags); + smp_mb__after_atomic(); + offs += len; + dbg_chk_lpt_sz(c, 1, len); + cnode = cnode->cnext; + } while (cnode && cnode != c->lpt_cnext); + + /* Make sure to place LPT's save table */ + if (!done_lsave) { + if (offs + c->lsave_sz > c->leb_size) { + wlen = offs - from; + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, alen); + if (err) + return err; + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = realloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = from = 0; + ubifs_assert(c, lnum >= c->lpt_first && + lnum <= c->lpt_last); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + done_lsave = 1; + ubifs_pack_lsave(c, buf + offs, c->lsave); + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + /* Make sure to place LPT's own lprops table */ + if (!done_ltab) { + if (offs + c->ltab_sz > c->leb_size) { + wlen = offs - from; + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, alen); + if (err) + return err; + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = realloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = from = 0; + ubifs_assert(c, lnum >= c->lpt_first && + lnum <= c->lpt_last); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + /* Write remaining data in buffer */ + wlen = offs - from; + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, alen); + if (err) + return err; + + dbg_chk_lpt_sz(c, 4, alen - wlen); + err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size)); + if (err) + return err; + + c->nhead_lnum = lnum; + c->nhead_offs = ALIGN(offs, c->min_io_size); + + dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs); + dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs); + dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs); + if (c->big_lpt) + dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs); + + return 0; + +no_space: + ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d", + lnum, offs, len, done_ltab, done_lsave); + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + return err; +} + +/** + * next_pnode_to_dirty - find next pnode to dirty. + * @c: UBIFS file-system description object + * @pnode: pnode + * + * This function returns the next pnode to dirty or %NULL if there are no more + * pnodes. Note that pnodes that have never been written (lnum == 0) are + * skipped. + */ +static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c, + struct ubifs_pnode *pnode) +{ + struct ubifs_nnode *nnode; + int iip; + + /* Try to go right */ + nnode = pnode->parent; + for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) { + if (nnode->nbranch[iip].lnum) + return ubifs_get_pnode(c, nnode, iip); + } + + /* Go up while can't go right */ + do { + iip = nnode->iip + 1; + nnode = nnode->parent; + if (!nnode) + return NULL; + for (; iip < UBIFS_LPT_FANOUT; iip++) { + if (nnode->nbranch[iip].lnum) + break; + } + } while (iip >= UBIFS_LPT_FANOUT); + + /* Go right */ + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return (void *)nnode; + + /* Go down to level 1 */ + while (nnode->level > 1) { + for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) { + if (nnode->nbranch[iip].lnum) + break; + } + if (iip >= UBIFS_LPT_FANOUT) { + /* + * Should not happen, but we need to keep going + * if it does. + */ + iip = 0; + } + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return (void *)nnode; + } + + for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) + if (nnode->nbranch[iip].lnum) + break; + if (iip >= UBIFS_LPT_FANOUT) + /* Should not happen, but we need to keep going if it does */ + iip = 0; + return ubifs_get_pnode(c, nnode, iip); +} + +/** + * add_pnode_dirt - add dirty space to LPT LEB properties. + * @c: UBIFS file-system description object + * @pnode: pnode for which to add dirt + */ +static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode) +{ + ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum, + c->pnode_sz); +} + +/** + * do_make_pnode_dirty - mark a pnode dirty. + * @c: UBIFS file-system description object + * @pnode: pnode to mark dirty + */ +static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode) +{ + /* Assumes cnext list is empty i.e. not called during commit */ + if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) { + struct ubifs_nnode *nnode; + + c->dirty_pn_cnt += 1; + add_pnode_dirt(c, pnode); + /* Mark parent and ancestors dirty too */ + nnode = pnode->parent; + while (nnode) { + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + nnode = nnode->parent; + } else + break; + } + } +} + +/** + * make_tree_dirty - mark the entire LEB properties tree dirty. + * @c: UBIFS file-system description object + * + * This function is used by the "small" LPT model to cause the entire LEB + * properties tree to be written. The "small" LPT model does not use LPT + * garbage collection because it is more efficient to write the entire tree + * (because it is small). + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_tree_dirty(struct ubifs_info *c) +{ + struct ubifs_pnode *pnode; + + pnode = ubifs_pnode_lookup(c, 0); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + + while (pnode) { + do_make_pnode_dirty(c, pnode); + pnode = next_pnode_to_dirty(c, pnode); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + } + return 0; +} + +/** + * need_write_all - determine if the LPT area is running out of free space. + * @c: UBIFS file-system description object + * + * This function returns %1 if the LPT area is running out of free space and %0 + * if it is not. + */ +static int need_write_all(struct ubifs_info *c) +{ + long long free = 0; + int i; + + for (i = 0; i < c->lpt_lebs; i++) { + if (i + c->lpt_first == c->nhead_lnum) + free += c->leb_size - c->nhead_offs; + else if (c->ltab[i].free == c->leb_size) + free += c->leb_size; + else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size) + free += c->leb_size; + } + /* Less than twice the size left */ + if (free <= c->lpt_sz * 2) + return 1; + return 0; +} + +/** + * lpt_tgc_start - start trivial garbage collection of LPT LEBs. + * @c: UBIFS file-system description object + * + * LPT trivial garbage collection is where a LPT LEB contains only dirty and + * free space and so may be reused as soon as the next commit is completed. + * This function is called during start commit to mark LPT LEBs for trivial GC. + */ +static void lpt_tgc_start(struct ubifs_info *c) +{ + int i; + + for (i = 0; i < c->lpt_lebs; i++) { + if (i + c->lpt_first == c->nhead_lnum) + continue; + if (c->ltab[i].dirty > 0 && + c->ltab[i].free + c->ltab[i].dirty == c->leb_size) { + c->ltab[i].tgc = 1; + c->ltab[i].free = c->leb_size; + c->ltab[i].dirty = 0; + dbg_lp("LEB %d", i + c->lpt_first); + } + } +} + +/** + * lpt_tgc_end - end trivial garbage collection of LPT LEBs. + * @c: UBIFS file-system description object + * + * LPT trivial garbage collection is where a LPT LEB contains only dirty and + * free space and so may be reused as soon as the next commit is completed. + * This function is called after the commit is completed (master node has been + * written) and un-maps LPT LEBs that were marked for trivial GC. + */ +static int lpt_tgc_end(struct ubifs_info *c) +{ + int i, err; + + for (i = 0; i < c->lpt_lebs; i++) + if (c->ltab[i].tgc) { + err = ubifs_leb_unmap(c, i + c->lpt_first); + if (err) + return err; + c->ltab[i].tgc = 0; + dbg_lp("LEB %d", i + c->lpt_first); + } + return 0; +} + +/** + * populate_lsave - fill the lsave array with important LEB numbers. + * @c: the UBIFS file-system description object + * + * This function is only called for the "big" model. It records a small number + * of LEB numbers of important LEBs. Important LEBs are ones that are (from + * most important to least important): empty, freeable, freeable index, dirty + * index, dirty or free. Upon mount, we read this list of LEB numbers and bring + * their pnodes into memory. That will stop us from having to scan the LPT + * straight away. For the "small" model we assume that scanning the LPT is no + * big deal. + */ +static void populate_lsave(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + int i, cnt = 0; + + ubifs_assert(c, c->big_lpt); + if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) { + c->lpt_drty_flgs |= LSAVE_DIRTY; + ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz); + } + + if (dbg_populate_lsave(c)) + return; + + list_for_each_entry(lprops, &c->empty_list, list) { + c->lsave[cnt++] = lprops->lnum; + if (cnt >= c->lsave_cnt) + return; + } + list_for_each_entry(lprops, &c->freeable_list, list) { + c->lsave[cnt++] = lprops->lnum; + if (cnt >= c->lsave_cnt) + return; + } + list_for_each_entry(lprops, &c->frdi_idx_list, list) { + c->lsave[cnt++] = lprops->lnum; + if (cnt >= c->lsave_cnt) + return; + } + heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; + for (i = 0; i < heap->cnt; i++) { + c->lsave[cnt++] = heap->arr[i]->lnum; + if (cnt >= c->lsave_cnt) + return; + } + heap = &c->lpt_heap[LPROPS_DIRTY - 1]; + for (i = 0; i < heap->cnt; i++) { + c->lsave[cnt++] = heap->arr[i]->lnum; + if (cnt >= c->lsave_cnt) + return; + } + heap = &c->lpt_heap[LPROPS_FREE - 1]; + for (i = 0; i < heap->cnt; i++) { + c->lsave[cnt++] = heap->arr[i]->lnum; + if (cnt >= c->lsave_cnt) + return; + } + /* Fill it up completely */ + while (cnt < c->lsave_cnt) + c->lsave[cnt++] = c->main_first; +} + +/** + * nnode_lookup - lookup a nnode in the LPT. + * @c: UBIFS file-system description object + * @i: nnode number + * + * This function returns a pointer to the nnode on success or a negative + * error code on failure. + */ +static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i) +{ + int err, iip; + struct ubifs_nnode *nnode; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return ERR_PTR(err); + } + nnode = c->nroot; + while (1) { + iip = i & (UBIFS_LPT_FANOUT - 1); + i >>= UBIFS_LPT_FANOUT_SHIFT; + if (!i) + break; + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return nnode; + } + return nnode; +} + +/** + * make_nnode_dirty - find a nnode and, if found, make it dirty. + * @c: UBIFS file-system description object + * @node_num: nnode number of nnode to make dirty + * @lnum: LEB number where nnode was written + * @offs: offset where nnode was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum, + int offs) +{ + struct ubifs_nnode *nnode; + + nnode = nnode_lookup(c, node_num); + if (IS_ERR(nnode)) + return PTR_ERR(nnode); + if (nnode->parent) { + struct ubifs_nbranch *branch; + + branch = &nnode->parent->nbranch[nnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + return 0; /* nnode is obsolete */ + } else if (c->lpt_lnum != lnum || c->lpt_offs != offs) + return 0; /* nnode is obsolete */ + /* Assumes cnext list is empty i.e. not called during commit */ + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + /* Mark parent and ancestors dirty too */ + nnode = nnode->parent; + while (nnode) { + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + nnode = nnode->parent; + } else + break; + } + } + return 0; +} + +/** + * make_pnode_dirty - find a pnode and, if found, make it dirty. + * @c: UBIFS file-system description object + * @node_num: pnode number of pnode to make dirty + * @lnum: LEB number where pnode was written + * @offs: offset where pnode was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum, + int offs) +{ + struct ubifs_pnode *pnode; + struct ubifs_nbranch *branch; + + pnode = ubifs_pnode_lookup(c, node_num); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + branch = &pnode->parent->nbranch[pnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + return 0; + do_make_pnode_dirty(c, pnode); + return 0; +} + +/** + * make_ltab_dirty - make ltab node dirty. + * @c: UBIFS file-system description object + * @lnum: LEB number where ltab was written + * @offs: offset where ltab was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->ltab_lnum || offs != c->ltab_offs) + return 0; /* This ltab node is obsolete */ + if (!(c->lpt_drty_flgs & LTAB_DIRTY)) { + c->lpt_drty_flgs |= LTAB_DIRTY; + ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz); + } + return 0; +} + +/** + * make_lsave_dirty - make lsave node dirty. + * @c: UBIFS file-system description object + * @lnum: LEB number where lsave was written + * @offs: offset where lsave was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->lsave_lnum || offs != c->lsave_offs) + return 0; /* This lsave node is obsolete */ + if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) { + c->lpt_drty_flgs |= LSAVE_DIRTY; + ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz); + } + return 0; +} + +/** + * make_node_dirty - make node dirty. + * @c: UBIFS file-system description object + * @node_type: LPT node type + * @node_num: node number + * @lnum: LEB number where node was written + * @offs: offset where node was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num, + int lnum, int offs) +{ + switch (node_type) { + case UBIFS_LPT_NNODE: + return make_nnode_dirty(c, node_num, lnum, offs); + case UBIFS_LPT_PNODE: + return make_pnode_dirty(c, node_num, lnum, offs); + case UBIFS_LPT_LTAB: + return make_ltab_dirty(c, lnum, offs); + case UBIFS_LPT_LSAVE: + return make_lsave_dirty(c, lnum, offs); + } + return -EINVAL; +} + +/** + * get_lpt_node_len - return the length of a node based on its type. + * @c: UBIFS file-system description object + * @node_type: LPT node type + */ +static int get_lpt_node_len(const struct ubifs_info *c, int node_type) +{ + switch (node_type) { + case UBIFS_LPT_NNODE: + return c->nnode_sz; + case UBIFS_LPT_PNODE: + return c->pnode_sz; + case UBIFS_LPT_LTAB: + return c->ltab_sz; + case UBIFS_LPT_LSAVE: + return c->lsave_sz; + } + return 0; +} + +/** + * get_pad_len - return the length of padding in a buffer. + * @c: UBIFS file-system description object + * @buf: buffer + * @len: length of buffer + */ +static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len) +{ + int offs, pad_len; + + if (c->min_io_size == 1) + return 0; + offs = c->leb_size - len; + pad_len = ALIGN(offs, c->min_io_size) - offs; + return pad_len; +} + +/** + * get_lpt_node_type - return type (and node number) of a node in a buffer. + * @c: UBIFS file-system description object + * @buf: buffer + * @node_num: node number is returned here + */ +static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf, + int *node_num) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int pos = 0, node_type; + + node_type = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_TYPE_BITS); + *node_num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits); + return node_type; +} + +/** + * is_a_node - determine if a buffer contains a node. + * @c: UBIFS file-system description object + * @buf: buffer + * @len: length of buffer + * + * This function returns %1 if the buffer contains a node or %0 if it does not. + */ +static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int pos = 0, node_type, node_len; + uint16_t crc, calc_crc; + + if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8) + return 0; + node_type = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_TYPE_BITS); + if (node_type == UBIFS_LPT_NOT_A_NODE) + return 0; + node_len = get_lpt_node_len(c, node_type); + if (!node_len || node_len > len) + return 0; + pos = 0; + addr = buf; + crc = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_CRC_BITS); + calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + node_len - UBIFS_LPT_CRC_BYTES); + if (crc != calc_crc) + return 0; + return 1; +} + +/** + * lpt_gc_lnum - garbage collect a LPT LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number to garbage collect + * + * LPT garbage collection is used only for the "big" LPT model + * (c->big_lpt == 1). Garbage collection simply involves marking all the nodes + * in the LEB being garbage-collected as dirty. The dirty nodes are written + * next commit, after which the LEB is free to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int lpt_gc_lnum(struct ubifs_info *c, int lnum) +{ + int err, len = c->leb_size, node_type, node_num, node_len, offs; + void *buf = c->lpt_buf; + + dbg_lp("LEB %d", lnum); + + err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1); + if (err) + return err; + + while (1) { + if (!is_a_node(c, buf, len)) { + int pad_len; + + pad_len = get_pad_len(c, buf, len); + if (pad_len) { + buf += pad_len; + len -= pad_len; + continue; + } + return 0; + } + node_type = get_lpt_node_type(c, buf, &node_num); + node_len = get_lpt_node_len(c, node_type); + offs = c->leb_size - len; + ubifs_assert(c, node_len != 0); + mutex_lock(&c->lp_mutex); + err = make_node_dirty(c, node_type, node_num, lnum, offs); + mutex_unlock(&c->lp_mutex); + if (err) + return err; + buf += node_len; + len -= node_len; + } + return 0; +} + +/** + * lpt_gc - LPT garbage collection. + * @c: UBIFS file-system description object + * + * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'. + * Returns %0 on success and a negative error code on failure. + */ +static int lpt_gc(struct ubifs_info *c) +{ + int i, lnum = -1, dirty = 0; + + mutex_lock(&c->lp_mutex); + for (i = 0; i < c->lpt_lebs; i++) { + ubifs_assert(c, !c->ltab[i].tgc); + if (i + c->lpt_first == c->nhead_lnum || + c->ltab[i].free + c->ltab[i].dirty == c->leb_size) + continue; + if (c->ltab[i].dirty > dirty) { + dirty = c->ltab[i].dirty; + lnum = i + c->lpt_first; + } + } + mutex_unlock(&c->lp_mutex); + if (lnum == -1) + return -ENOSPC; + return lpt_gc_lnum(c, lnum); +} + +/** + * ubifs_lpt_start_commit - UBIFS commit starts. + * @c: the UBIFS file-system description object + * + * This function has to be called when UBIFS starts the commit operation. + * This function "freezes" all currently dirty LEB properties and does not + * change them anymore. Further changes are saved and tracked separately + * because they are not part of this commit. This function returns zero in case + * of success and a negative error code in case of failure. + */ +int ubifs_lpt_start_commit(struct ubifs_info *c) +{ + int err, cnt; + + dbg_lp(""); + + mutex_lock(&c->lp_mutex); + err = dbg_chk_lpt_free_spc(c); + if (err) + goto out; + err = dbg_check_ltab(c); + if (err) + goto out; + + if (c->check_lpt_free) { + /* + * We ensure there is enough free space in + * ubifs_lpt_post_commit() by marking nodes dirty. That + * information is lost when we unmount, so we also need + * to check free space once after mounting also. + */ + c->check_lpt_free = 0; + while (need_write_all(c)) { + mutex_unlock(&c->lp_mutex); + err = lpt_gc(c); + if (err) + return err; + mutex_lock(&c->lp_mutex); + } + } + + lpt_tgc_start(c); + + if (!c->dirty_pn_cnt) { + dbg_cmt("no cnodes to commit"); + err = 0; + goto out; + } + + if (!c->big_lpt && need_write_all(c)) { + /* If needed, write everything */ + err = make_tree_dirty(c); + if (err) + goto out; + lpt_tgc_start(c); + } + + if (c->big_lpt) + populate_lsave(c); + + cnt = get_cnodes_to_commit(c); + ubifs_assert(c, cnt != 0); + + err = layout_cnodes(c); + if (err) + goto out; + + err = ubifs_lpt_calc_hash(c, c->mst_node->hash_lpt); + if (err) + goto out; + + /* Copy the LPT's own lprops for end commit to write */ + memcpy(c->ltab_cmt, c->ltab, + sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs); + c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY); + +out: + mutex_unlock(&c->lp_mutex); + return err; +} + +/** + * free_obsolete_cnodes - free obsolete cnodes for commit end. + * @c: UBIFS file-system description object + */ +static void free_obsolete_cnodes(struct ubifs_info *c) +{ + struct ubifs_cnode *cnode, *cnext; + + cnext = c->lpt_cnext; + if (!cnext) + return; + do { + cnode = cnext; + cnext = cnode->cnext; + if (test_bit(OBSOLETE_CNODE, &cnode->flags)) + kfree(cnode); + else + cnode->cnext = NULL; + } while (cnext != c->lpt_cnext); + c->lpt_cnext = NULL; +} + +/** + * ubifs_lpt_end_commit - finish the commit operation. + * @c: the UBIFS file-system description object + * + * This function has to be called when the commit operation finishes. It + * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to + * the media. Returns zero in case of success and a negative error code in case + * of failure. + */ +int ubifs_lpt_end_commit(struct ubifs_info *c) +{ + int err; + + dbg_lp(""); + + if (!c->lpt_cnext) + return 0; + + err = write_cnodes(c); + if (err) + return err; + + mutex_lock(&c->lp_mutex); + free_obsolete_cnodes(c); + mutex_unlock(&c->lp_mutex); + + return 0; +} + +/** + * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC. + * @c: UBIFS file-system description object + * + * LPT trivial GC is completed after a commit. Also LPT GC is done after a + * commit for the "big" LPT model. + */ +int ubifs_lpt_post_commit(struct ubifs_info *c) +{ + int err; + + mutex_lock(&c->lp_mutex); + err = lpt_tgc_end(c); + if (err) + goto out; + if (c->big_lpt) + while (need_write_all(c)) { + mutex_unlock(&c->lp_mutex); + err = lpt_gc(c); + if (err) + return err; + mutex_lock(&c->lp_mutex); + } +out: + mutex_unlock(&c->lp_mutex); + return err; +} + +/** + * first_nnode - find the first nnode in memory. + * @c: UBIFS file-system description object + * @hght: height of tree where nnode found is returned here + * + * This function returns a pointer to the nnode found or %NULL if no nnode is + * found. This function is a helper to 'ubifs_lpt_free()'. + */ +static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght) +{ + struct ubifs_nnode *nnode; + int h, i, found; + + nnode = c->nroot; + *hght = 0; + if (!nnode) + return NULL; + for (h = 1; h < c->lpt_hght; h++) { + found = 0; + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (nnode->nbranch[i].nnode) { + found = 1; + nnode = nnode->nbranch[i].nnode; + *hght = h; + break; + } + } + if (!found) + break; + } + return nnode; +} + +/** + * next_nnode - find the next nnode in memory. + * @c: UBIFS file-system description object + * @nnode: nnode from which to start. + * @hght: height of tree where nnode is, is passed and returned here + * + * This function returns a pointer to the nnode found or %NULL if no nnode is + * found. This function is a helper to 'ubifs_lpt_free()'. + */ +static struct ubifs_nnode *next_nnode(struct ubifs_info *c, + struct ubifs_nnode *nnode, int *hght) +{ + struct ubifs_nnode *parent; + int iip, h, i, found; + + parent = nnode->parent; + if (!parent) + return NULL; + if (nnode->iip == UBIFS_LPT_FANOUT - 1) { + *hght -= 1; + return parent; + } + for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) { + nnode = parent->nbranch[iip].nnode; + if (nnode) + break; + } + if (!nnode) { + *hght -= 1; + return parent; + } + for (h = *hght + 1; h < c->lpt_hght; h++) { + found = 0; + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (nnode->nbranch[i].nnode) { + found = 1; + nnode = nnode->nbranch[i].nnode; + *hght = h; + break; + } + } + if (!found) + break; + } + return nnode; +} + +/** + * ubifs_lpt_free - free resources owned by the LPT. + * @c: UBIFS file-system description object + * @wr_only: free only resources used for writing + */ +void ubifs_lpt_free(struct ubifs_info *c, int wr_only) +{ + struct ubifs_nnode *nnode; + int i, hght; + + /* Free write-only things first */ + + free_obsolete_cnodes(c); /* Leftover from a failed commit */ + + vfree(c->ltab_cmt); + c->ltab_cmt = NULL; + vfree(c->lpt_buf); + c->lpt_buf = NULL; + kfree(c->lsave); + c->lsave = NULL; + + if (wr_only) + return; + + /* Now free the rest */ + + nnode = first_nnode(c, &hght); + while (nnode) { + for (i = 0; i < UBIFS_LPT_FANOUT; i++) + kfree(nnode->nbranch[i].nnode); + nnode = next_nnode(c, nnode, &hght); + } + for (i = 0; i < LPROPS_HEAP_CNT; i++) + kfree(c->lpt_heap[i].arr); + kfree(c->dirty_idx.arr); + kfree(c->nroot); + vfree(c->ltab); + kfree(c->lpt_nod_buf); +} + +/* + * Everything below is related to debugging. + */ + +/** + * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes. + * @buf: buffer + * @len: buffer length + */ +static int dbg_is_all_ff(uint8_t *buf, int len) +{ + int i; + + for (i = 0; i < len; i++) + if (buf[i] != 0xff) + return 0; + return 1; +} + +/** + * dbg_is_nnode_dirty - determine if a nnode is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where nnode was written + * @offs: offset where nnode was written + */ +static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs) +{ + struct ubifs_nnode *nnode; + int hght; + + /* Entire tree is in memory so first_nnode / next_nnode are OK */ + nnode = first_nnode(c, &hght); + for (; nnode; nnode = next_nnode(c, nnode, &hght)) { + struct ubifs_nbranch *branch; + + cond_resched(); + if (nnode->parent) { + branch = &nnode->parent->nbranch[nnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + continue; + if (test_bit(DIRTY_CNODE, &nnode->flags)) + return 1; + return 0; + } else { + if (c->lpt_lnum != lnum || c->lpt_offs != offs) + continue; + if (test_bit(DIRTY_CNODE, &nnode->flags)) + return 1; + return 0; + } + } + return 1; +} + +/** + * dbg_is_pnode_dirty - determine if a pnode is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where pnode was written + * @offs: offset where pnode was written + */ +static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs) +{ + int i, cnt; + + cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); + for (i = 0; i < cnt; i++) { + struct ubifs_pnode *pnode; + struct ubifs_nbranch *branch; + + cond_resched(); + pnode = ubifs_pnode_lookup(c, i); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + branch = &pnode->parent->nbranch[pnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + continue; + if (test_bit(DIRTY_CNODE, &pnode->flags)) + return 1; + return 0; + } + return 1; +} + +/** + * dbg_is_ltab_dirty - determine if a ltab node is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where ltab node was written + * @offs: offset where ltab node was written + */ +static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->ltab_lnum || offs != c->ltab_offs) + return 1; + return (c->lpt_drty_flgs & LTAB_DIRTY) != 0; +} + +/** + * dbg_is_lsave_dirty - determine if a lsave node is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where lsave node was written + * @offs: offset where lsave node was written + */ +static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->lsave_lnum || offs != c->lsave_offs) + return 1; + return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0; +} + +/** + * dbg_is_node_dirty - determine if a node is dirty. + * @c: the UBIFS file-system description object + * @node_type: node type + * @lnum: LEB number where node was written + * @offs: offset where node was written + */ +static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum, + int offs) +{ + switch (node_type) { + case UBIFS_LPT_NNODE: + return dbg_is_nnode_dirty(c, lnum, offs); + case UBIFS_LPT_PNODE: + return dbg_is_pnode_dirty(c, lnum, offs); + case UBIFS_LPT_LTAB: + return dbg_is_ltab_dirty(c, lnum, offs); + case UBIFS_LPT_LSAVE: + return dbg_is_lsave_dirty(c, lnum, offs); + } + return 1; +} + +/** + * dbg_check_ltab_lnum - check the ltab for a LPT LEB number. + * @c: the UBIFS file-system description object + * @lnum: LEB number where node was written + * + * This function returns %0 on success and a negative error code on failure. + */ +static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum) +{ + int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len; + int ret; + void *buf, *p; + + if (!dbg_is_chk_lprops(c)) + return 0; + + buf = p = __vmalloc(c->leb_size, GFP_NOFS); + if (!buf) { + ubifs_err(c, "cannot allocate memory for ltab checking"); + return 0; + } + + dbg_lp("LEB %d", lnum); + + err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1); + if (err) + goto out; + + while (1) { + if (!is_a_node(c, p, len)) { + int i, pad_len; + + pad_len = get_pad_len(c, p, len); + if (pad_len) { + p += pad_len; + len -= pad_len; + dirty += pad_len; + continue; + } + if (!dbg_is_all_ff(p, len)) { + ubifs_err(c, "invalid empty space in LEB %d at %d", + lnum, c->leb_size - len); + err = -EINVAL; + } + i = lnum - c->lpt_first; + if (len != c->ltab[i].free) { + ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)", + lnum, len, c->ltab[i].free); + err = -EINVAL; + } + if (dirty != c->ltab[i].dirty) { + ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)", + lnum, dirty, c->ltab[i].dirty); + err = -EINVAL; + } + goto out; + } + node_type = get_lpt_node_type(c, p, &node_num); + node_len = get_lpt_node_len(c, node_type); + ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len); + if (ret == 1) + dirty += node_len; + p += node_len; + len -= node_len; + } + + err = 0; +out: + vfree(buf); + return err; +} + +/** + * dbg_check_ltab - check the free and dirty space in the ltab. + * @c: the UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_check_ltab(struct ubifs_info *c) +{ + int lnum, err, i, cnt; + + if (!dbg_is_chk_lprops(c)) + return 0; + + /* Bring the entire tree into memory */ + cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); + for (i = 0; i < cnt; i++) { + struct ubifs_pnode *pnode; + + pnode = ubifs_pnode_lookup(c, i); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + cond_resched(); + } + + /* Check nodes */ + err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0); + if (err) + return err; + + /* Check each LEB */ + for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { + err = dbg_check_ltab_lnum(c, lnum); + if (err) { + ubifs_err(c, "failed at LEB %d", lnum); + return err; + } + } + + dbg_lp("succeeded"); + return 0; +} + +/** + * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT. + * @c: the UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_chk_lpt_free_spc(struct ubifs_info *c) +{ + long long free = 0; + int i; + + if (!dbg_is_chk_lprops(c)) + return 0; + + for (i = 0; i < c->lpt_lebs; i++) { + if (c->ltab[i].tgc || c->ltab[i].cmt) + continue; + if (i + c->lpt_first == c->nhead_lnum) + free += c->leb_size - c->nhead_offs; + else if (c->ltab[i].free == c->leb_size) + free += c->leb_size; + } + if (free < c->lpt_sz) { + ubifs_err(c, "LPT space error: free %lld lpt_sz %lld", + free, c->lpt_sz); + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + return -EINVAL; + } + return 0; +} + +/** + * dbg_chk_lpt_sz - check LPT does not write more than LPT size. + * @c: the UBIFS file-system description object + * @action: what to do + * @len: length written + * + * This function returns %0 on success and a negative error code on failure. + * The @action argument may be one of: + * o %0 - LPT debugging checking starts, initialize debugging variables; + * o %1 - wrote an LPT node, increase LPT size by @len bytes; + * o %2 - switched to a different LEB and wasted @len bytes; + * o %3 - check that we've written the right number of bytes. + * o %4 - wasted @len bytes; + */ +int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len) +{ + struct ubifs_debug_info *d = c->dbg; + long long chk_lpt_sz, lpt_sz; + int err = 0; + + if (!dbg_is_chk_lprops(c)) + return 0; + + switch (action) { + case 0: + d->chk_lpt_sz = 0; + d->chk_lpt_sz2 = 0; + d->chk_lpt_lebs = 0; + d->chk_lpt_wastage = 0; + if (c->dirty_pn_cnt > c->pnode_cnt) { + ubifs_err(c, "dirty pnodes %d exceed max %d", + c->dirty_pn_cnt, c->pnode_cnt); + err = -EINVAL; + } + if (c->dirty_nn_cnt > c->nnode_cnt) { + ubifs_err(c, "dirty nnodes %d exceed max %d", + c->dirty_nn_cnt, c->nnode_cnt); + err = -EINVAL; + } + return err; + case 1: + d->chk_lpt_sz += len; + return 0; + case 2: + d->chk_lpt_sz += len; + d->chk_lpt_wastage += len; + d->chk_lpt_lebs += 1; + return 0; + case 3: + chk_lpt_sz = c->leb_size; + chk_lpt_sz *= d->chk_lpt_lebs; + chk_lpt_sz += len - c->nhead_offs; + if (d->chk_lpt_sz != chk_lpt_sz) { + ubifs_err(c, "LPT wrote %lld but space used was %lld", + d->chk_lpt_sz, chk_lpt_sz); + err = -EINVAL; + } + if (d->chk_lpt_sz > c->lpt_sz) { + ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld", + d->chk_lpt_sz, c->lpt_sz); + err = -EINVAL; + } + if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) { + ubifs_err(c, "LPT layout size %lld but wrote %lld", + d->chk_lpt_sz, d->chk_lpt_sz2); + err = -EINVAL; + } + if (d->chk_lpt_sz2 && d->new_nhead_offs != len) { + ubifs_err(c, "LPT new nhead offs: expected %d was %d", + d->new_nhead_offs, len); + err = -EINVAL; + } + lpt_sz = (long long)c->pnode_cnt * c->pnode_sz; + lpt_sz += (long long)c->nnode_cnt * c->nnode_sz; + lpt_sz += c->ltab_sz; + if (c->big_lpt) + lpt_sz += c->lsave_sz; + if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) { + ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld", + d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz); + err = -EINVAL; + } + if (err) { + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + } + d->chk_lpt_sz2 = d->chk_lpt_sz; + d->chk_lpt_sz = 0; + d->chk_lpt_wastage = 0; + d->chk_lpt_lebs = 0; + d->new_nhead_offs = len; + return err; + case 4: + d->chk_lpt_sz += len; + d->chk_lpt_wastage += len; + return 0; + default: + return -EINVAL; + } +} + +/** + * dump_lpt_leb - dump an LPT LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number to dump + * + * This function dumps an LEB from LPT area. Nodes in this area are very + * different to nodes in the main area (e.g., they do not have common headers, + * they do not have 8-byte alignments, etc), so we have a separate function to + * dump LPT area LEBs. Note, LPT has to be locked by the caller. + */ +static void dump_lpt_leb(const struct ubifs_info *c, int lnum) +{ + int err, len = c->leb_size, node_type, node_num, node_len, offs; + void *buf, *p; + + pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum); + buf = p = __vmalloc(c->leb_size, GFP_NOFS); + if (!buf) { + ubifs_err(c, "cannot allocate memory to dump LPT"); + return; + } + + err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1); + if (err) + goto out; + + while (1) { + offs = c->leb_size - len; + if (!is_a_node(c, p, len)) { + int pad_len; + + pad_len = get_pad_len(c, p, len); + if (pad_len) { + pr_err("LEB %d:%d, pad %d bytes\n", + lnum, offs, pad_len); + p += pad_len; + len -= pad_len; + continue; + } + if (len) + pr_err("LEB %d:%d, free %d bytes\n", + lnum, offs, len); + break; + } + + node_type = get_lpt_node_type(c, p, &node_num); + switch (node_type) { + case UBIFS_LPT_PNODE: + { + node_len = c->pnode_sz; + if (c->big_lpt) + pr_err("LEB %d:%d, pnode num %d\n", + lnum, offs, node_num); + else + pr_err("LEB %d:%d, pnode\n", lnum, offs); + break; + } + case UBIFS_LPT_NNODE: + { + int i; + struct ubifs_nnode nnode; + + node_len = c->nnode_sz; + if (c->big_lpt) + pr_err("LEB %d:%d, nnode num %d, ", + lnum, offs, node_num); + else + pr_err("LEB %d:%d, nnode, ", + lnum, offs); + err = ubifs_unpack_nnode(c, p, &nnode); + if (err) { + pr_err("failed to unpack_node, error %d\n", + err); + break; + } + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + pr_cont("%d:%d", nnode.nbranch[i].lnum, + nnode.nbranch[i].offs); + if (i != UBIFS_LPT_FANOUT - 1) + pr_cont(", "); + } + pr_cont("\n"); + break; + } + case UBIFS_LPT_LTAB: + node_len = c->ltab_sz; + pr_err("LEB %d:%d, ltab\n", lnum, offs); + break; + case UBIFS_LPT_LSAVE: + node_len = c->lsave_sz; + pr_err("LEB %d:%d, lsave len\n", lnum, offs); + break; + default: + ubifs_err(c, "LPT node type %d not recognized", node_type); + goto out; + } + + p += node_len; + len -= node_len; + } + + pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum); +out: + vfree(buf); + return; +} + +/** + * ubifs_dump_lpt_lebs - dump LPT lebs. + * @c: UBIFS file-system description object + * + * This function dumps all LPT LEBs. The caller has to make sure the LPT is + * locked. + */ +void ubifs_dump_lpt_lebs(const struct ubifs_info *c) +{ + int i; + + pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid); + for (i = 0; i < c->lpt_lebs; i++) + dump_lpt_leb(c, i + c->lpt_first); + pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid); +} + +/** + * dbg_populate_lsave - debugging version of 'populate_lsave()' + * @c: UBIFS file-system description object + * + * This is a debugging version for 'populate_lsave()' which populates lsave + * with random LEBs instead of useful LEBs, which is good for test coverage. + * Returns zero if lsave has not been populated (this debugging feature is + * disabled) an non-zero if lsave has been populated. + */ +static int dbg_populate_lsave(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + int i; + + if (!dbg_is_chk_gen(c)) + return 0; + if (prandom_u32() & 3) + return 0; + + for (i = 0; i < c->lsave_cnt; i++) + c->lsave[i] = c->main_first; + + list_for_each_entry(lprops, &c->empty_list, list) + c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum; + list_for_each_entry(lprops, &c->freeable_list, list) + c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum; + list_for_each_entry(lprops, &c->frdi_idx_list, list) + c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum; + + heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; + for (i = 0; i < heap->cnt; i++) + c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum; + heap = &c->lpt_heap[LPROPS_DIRTY - 1]; + for (i = 0; i < heap->cnt; i++) + c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum; + heap = &c->lpt_heap[LPROPS_FREE - 1]; + for (i = 0; i < heap->cnt; i++) + c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum; + + return 1; +} diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c new file mode 100644 index 000000000..911d0555b --- /dev/null +++ b/fs/ubifs/master.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* This file implements reading and writing the master node */ + +#include "ubifs.h" + +/** + * ubifs_compare_master_node - compare two UBIFS master nodes + * @c: UBIFS file-system description object + * @m1: the first node + * @m2: the second node + * + * This function compares two UBIFS master nodes. Returns 0 if they are equal + * and nonzero if not. + */ +int ubifs_compare_master_node(struct ubifs_info *c, void *m1, void *m2) +{ + int ret; + int behind; + int hmac_offs = offsetof(struct ubifs_mst_node, hmac); + + /* + * Do not compare the common node header since the sequence number and + * hence the CRC are different. + */ + ret = memcmp(m1 + UBIFS_CH_SZ, m2 + UBIFS_CH_SZ, + hmac_offs - UBIFS_CH_SZ); + if (ret) + return ret; + + /* + * Do not compare the embedded HMAC aswell which also must be different + * due to the different common node header. + */ + behind = hmac_offs + UBIFS_MAX_HMAC_LEN; + + if (UBIFS_MST_NODE_SZ > behind) + return memcmp(m1 + behind, m2 + behind, UBIFS_MST_NODE_SZ - behind); + + return 0; +} + +/* mst_node_check_hash - Check hash of a master node + * @c: UBIFS file-system description object + * @mst: The master node + * @expected: The expected hash of the master node + * + * This checks the hash of a master node against a given expected hash. + * Note that we have two master nodes on a UBIFS image which have different + * sequence numbers and consequently different CRCs. To be able to match + * both master nodes we exclude the common node header containing the sequence + * number and CRC from the hash. + * + * Returns 0 if the hashes are equal, a negative error code otherwise. + */ +static int mst_node_check_hash(const struct ubifs_info *c, + const struct ubifs_mst_node *mst, + const u8 *expected) +{ + u8 calc[UBIFS_MAX_HASH_LEN]; + const void *node = mst; + + crypto_shash_tfm_digest(c->hash_tfm, node + sizeof(struct ubifs_ch), + UBIFS_MST_NODE_SZ - sizeof(struct ubifs_ch), + calc); + + if (ubifs_check_hash(c, expected, calc)) + return -EPERM; + + return 0; +} + +/** + * scan_for_master - search the valid master node. + * @c: UBIFS file-system description object + * + * This function scans the master node LEBs and search for the latest master + * node. Returns zero in case of success, %-EUCLEAN if there master area is + * corrupted and requires recovery, and a negative error code in case of + * failure. + */ +static int scan_for_master(struct ubifs_info *c) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + int lnum, offs = 0, nodes_cnt, err; + + lnum = UBIFS_MST_LNUM; + + sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + nodes_cnt = sleb->nodes_cnt; + if (nodes_cnt > 0) { + snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, + list); + if (snod->type != UBIFS_MST_NODE) + goto out_dump; + memcpy(c->mst_node, snod->node, snod->len); + offs = snod->offs; + } + ubifs_scan_destroy(sleb); + + lnum += 1; + + sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + if (sleb->nodes_cnt != nodes_cnt) + goto out; + if (!sleb->nodes_cnt) + goto out; + snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list); + if (snod->type != UBIFS_MST_NODE) + goto out_dump; + if (snod->offs != offs) + goto out; + if (ubifs_compare_master_node(c, c->mst_node, snod->node)) + goto out; + + c->mst_offs = offs; + ubifs_scan_destroy(sleb); + + if (!ubifs_authenticated(c)) + return 0; + + if (ubifs_hmac_zero(c, c->mst_node->hmac)) { + err = mst_node_check_hash(c, c->mst_node, + c->sup_node->hash_mst); + if (err) + ubifs_err(c, "Failed to verify master node hash"); + } else { + err = ubifs_node_verify_hmac(c, c->mst_node, + sizeof(struct ubifs_mst_node), + offsetof(struct ubifs_mst_node, hmac)); + if (err) + ubifs_err(c, "Failed to verify master node HMAC"); + } + + if (err) + return -EPERM; + + return 0; + +out: + ubifs_scan_destroy(sleb); + return -EUCLEAN; + +out_dump: + ubifs_err(c, "unexpected node type %d master LEB %d:%d", + snod->type, lnum, snod->offs); + ubifs_scan_destroy(sleb); + return -EINVAL; +} + +/** + * validate_master - validate master node. + * @c: UBIFS file-system description object + * + * This function validates data which was read from master node. Returns zero + * if the data is all right and %-EINVAL if not. + */ +static int validate_master(const struct ubifs_info *c) +{ + long long main_sz; + int err; + + if (c->max_sqnum >= SQNUM_WATERMARK) { + err = 1; + goto out; + } + + if (c->cmt_no >= c->max_sqnum) { + err = 2; + goto out; + } + + if (c->highest_inum >= INUM_WATERMARK) { + err = 3; + goto out; + } + + if (c->lhead_lnum < UBIFS_LOG_LNUM || + c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs || + c->lhead_offs < 0 || c->lhead_offs >= c->leb_size || + c->lhead_offs & (c->min_io_size - 1)) { + err = 4; + goto out; + } + + if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first || + c->zroot.offs >= c->leb_size || c->zroot.offs & 7) { + err = 5; + goto out; + } + + if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len || + c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) { + err = 6; + goto out; + } + + if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) { + err = 7; + goto out; + } + + if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first || + c->ihead_offs % c->min_io_size || c->ihead_offs < 0 || + c->ihead_offs > c->leb_size || c->ihead_offs & 7) { + err = 8; + goto out; + } + + main_sz = (long long)c->main_lebs * c->leb_size; + if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) { + err = 9; + goto out; + } + + if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last || + c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) { + err = 10; + goto out; + } + + if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last || + c->nhead_offs < 0 || c->nhead_offs % c->min_io_size || + c->nhead_offs > c->leb_size) { + err = 11; + goto out; + } + + if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last || + c->ltab_offs < 0 || + c->ltab_offs + c->ltab_sz > c->leb_size) { + err = 12; + goto out; + } + + if (c->big_lpt && (c->lsave_lnum < c->lpt_first || + c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 || + c->lsave_offs + c->lsave_sz > c->leb_size)) { + err = 13; + goto out; + } + + if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) { + err = 14; + goto out; + } + + if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) { + err = 15; + goto out; + } + + if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) { + err = 16; + goto out; + } + + if (c->lst.total_free < 0 || c->lst.total_free > main_sz || + c->lst.total_free & 7) { + err = 17; + goto out; + } + + if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) { + err = 18; + goto out; + } + + if (c->lst.total_used < 0 || (c->lst.total_used & 7)) { + err = 19; + goto out; + } + + if (c->lst.total_free + c->lst.total_dirty + + c->lst.total_used > main_sz) { + err = 20; + goto out; + } + + if (c->lst.total_dead + c->lst.total_dark + + c->lst.total_used + c->bi.old_idx_sz > main_sz) { + err = 21; + goto out; + } + + if (c->lst.total_dead < 0 || + c->lst.total_dead > c->lst.total_free + c->lst.total_dirty || + c->lst.total_dead & 7) { + err = 22; + goto out; + } + + if (c->lst.total_dark < 0 || + c->lst.total_dark > c->lst.total_free + c->lst.total_dirty || + c->lst.total_dark & 7) { + err = 23; + goto out; + } + + return 0; + +out: + ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err); + ubifs_dump_node(c, c->mst_node); + return -EINVAL; +} + +/** + * ubifs_read_master - read master node. + * @c: UBIFS file-system description object + * + * This function finds and reads the master node during file-system mount. If + * the flash is empty, it creates default master node as well. Returns zero in + * case of success and a negative error code in case of failure. + */ +int ubifs_read_master(struct ubifs_info *c) +{ + int err, old_leb_cnt; + + c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL); + if (!c->mst_node) + return -ENOMEM; + + err = scan_for_master(c); + if (err) { + if (err == -EUCLEAN) + err = ubifs_recover_master_node(c); + if (err) + /* + * Note, we do not free 'c->mst_node' here because the + * unmount routine will take care of this. + */ + return err; + } + + /* Make sure that the recovery flag is clear */ + c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY); + + c->max_sqnum = le64_to_cpu(c->mst_node->ch.sqnum); + c->highest_inum = le64_to_cpu(c->mst_node->highest_inum); + c->cmt_no = le64_to_cpu(c->mst_node->cmt_no); + c->zroot.lnum = le32_to_cpu(c->mst_node->root_lnum); + c->zroot.offs = le32_to_cpu(c->mst_node->root_offs); + c->zroot.len = le32_to_cpu(c->mst_node->root_len); + c->lhead_lnum = le32_to_cpu(c->mst_node->log_lnum); + c->gc_lnum = le32_to_cpu(c->mst_node->gc_lnum); + c->ihead_lnum = le32_to_cpu(c->mst_node->ihead_lnum); + c->ihead_offs = le32_to_cpu(c->mst_node->ihead_offs); + c->bi.old_idx_sz = le64_to_cpu(c->mst_node->index_size); + c->lpt_lnum = le32_to_cpu(c->mst_node->lpt_lnum); + c->lpt_offs = le32_to_cpu(c->mst_node->lpt_offs); + c->nhead_lnum = le32_to_cpu(c->mst_node->nhead_lnum); + c->nhead_offs = le32_to_cpu(c->mst_node->nhead_offs); + c->ltab_lnum = le32_to_cpu(c->mst_node->ltab_lnum); + c->ltab_offs = le32_to_cpu(c->mst_node->ltab_offs); + c->lsave_lnum = le32_to_cpu(c->mst_node->lsave_lnum); + c->lsave_offs = le32_to_cpu(c->mst_node->lsave_offs); + c->lscan_lnum = le32_to_cpu(c->mst_node->lscan_lnum); + c->lst.empty_lebs = le32_to_cpu(c->mst_node->empty_lebs); + c->lst.idx_lebs = le32_to_cpu(c->mst_node->idx_lebs); + old_leb_cnt = le32_to_cpu(c->mst_node->leb_cnt); + c->lst.total_free = le64_to_cpu(c->mst_node->total_free); + c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty); + c->lst.total_used = le64_to_cpu(c->mst_node->total_used); + c->lst.total_dead = le64_to_cpu(c->mst_node->total_dead); + c->lst.total_dark = le64_to_cpu(c->mst_node->total_dark); + + ubifs_copy_hash(c, c->mst_node->hash_root_idx, c->zroot.hash); + + c->calc_idx_sz = c->bi.old_idx_sz; + + if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS)) + c->no_orphs = 1; + + if (old_leb_cnt != c->leb_cnt) { + /* The file system has been resized */ + int growth = c->leb_cnt - old_leb_cnt; + + if (c->leb_cnt < old_leb_cnt || + c->leb_cnt < UBIFS_MIN_LEB_CNT) { + ubifs_err(c, "bad leb_cnt on master node"); + ubifs_dump_node(c, c->mst_node); + return -EINVAL; + } + + dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs", + old_leb_cnt, c->leb_cnt); + c->lst.empty_lebs += growth; + c->lst.total_free += growth * (long long)c->leb_size; + c->lst.total_dark += growth * (long long)c->dark_wm; + + /* + * Reflect changes back onto the master node. N.B. the master + * node gets written immediately whenever mounting (or + * remounting) in read-write mode, so we do not need to write it + * here. + */ + c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt); + c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs); + c->mst_node->total_free = cpu_to_le64(c->lst.total_free); + c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark); + } + + err = validate_master(c); + if (err) + return err; + + err = dbg_old_index_check_init(c, &c->zroot); + + return err; +} + +/** + * ubifs_write_master - write master node. + * @c: UBIFS file-system description object + * + * This function writes the master node. Returns zero in case of success and a + * negative error code in case of failure. The master node is written twice to + * enable recovery. + */ +int ubifs_write_master(struct ubifs_info *c) +{ + int err, lnum, offs, len; + + ubifs_assert(c, !c->ro_media && !c->ro_mount); + if (c->ro_error) + return -EROFS; + + lnum = UBIFS_MST_LNUM; + offs = c->mst_offs + c->mst_node_alsz; + len = UBIFS_MST_NODE_SZ; + + if (offs + UBIFS_MST_NODE_SZ > c->leb_size) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + offs = 0; + } + + c->mst_offs = offs; + c->mst_node->highest_inum = cpu_to_le64(c->highest_inum); + + ubifs_copy_hash(c, c->zroot.hash, c->mst_node->hash_root_idx); + err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs, + offsetof(struct ubifs_mst_node, hmac)); + if (err) + return err; + + lnum += 1; + + if (offs == 0) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs, + offsetof(struct ubifs_mst_node, hmac)); + + return err; +} diff --git a/fs/ubifs/misc.c b/fs/ubifs/misc.c new file mode 100644 index 000000000..cd23de0f2 --- /dev/null +++ b/fs/ubifs/misc.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include "ubifs.h" + +/* Normal UBIFS messages */ +void ubifs_msg(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_notice("UBIFS (ubi%d:%d): %pV\n", + c->vi.ubi_num, c->vi.vol_id, &vaf); + + va_end(args); +} \ + +/* UBIFS error messages */ +void ubifs_err(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_err("UBIFS error (ubi%d:%d pid %d): %ps: %pV\n", + c->vi.ubi_num, c->vi.vol_id, current->pid, + __builtin_return_address(0), + &vaf); + + va_end(args); +} \ + +/* UBIFS warning messages */ +void ubifs_warn(const struct ubifs_info *c, const char *fmt, ...) +{ + struct va_format vaf; + va_list args; + + va_start(args, fmt); + + vaf.fmt = fmt; + vaf.va = &args; + + pr_warn("UBIFS warning (ubi%d:%d pid %d): %ps: %pV\n", + c->vi.ubi_num, c->vi.vol_id, current->pid, + __builtin_return_address(0), + &vaf); + + va_end(args); +} + +static char *assert_names[] = { + [ASSACT_REPORT] = "report", + [ASSACT_RO] = "read-only", + [ASSACT_PANIC] = "panic", +}; + +const char *ubifs_assert_action_name(struct ubifs_info *c) +{ + return assert_names[c->assert_action]; +} diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h new file mode 100644 index 000000000..615878e88 --- /dev/null +++ b/fs/ubifs/misc.h @@ -0,0 +1,289 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file contains miscellaneous helper functions. + */ + +#ifndef __UBIFS_MISC_H__ +#define __UBIFS_MISC_H__ + +/** + * ubifs_zn_dirty - check if znode is dirty. + * @znode: znode to check + * + * This helper function returns %1 if @znode is dirty and %0 otherwise. + */ +static inline int ubifs_zn_dirty(const struct ubifs_znode *znode) +{ + return !!test_bit(DIRTY_ZNODE, &znode->flags); +} + +/** + * ubifs_zn_obsolete - check if znode is obsolete. + * @znode: znode to check + * + * This helper function returns %1 if @znode is obsolete and %0 otherwise. + */ +static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode) +{ + return !!test_bit(OBSOLETE_ZNODE, &znode->flags); +} + +/** + * ubifs_zn_cow - check if znode has to be copied on write. + * @znode: znode to check + * + * This helper function returns %1 if @znode is has COW flag set and %0 + * otherwise. + */ +static inline int ubifs_zn_cow(const struct ubifs_znode *znode) +{ + return !!test_bit(COW_ZNODE, &znode->flags); +} + +/** + * ubifs_wake_up_bgt - wake up background thread. + * @c: UBIFS file-system description object + */ +static inline void ubifs_wake_up_bgt(struct ubifs_info *c) +{ + if (c->bgt && !c->need_bgt) { + c->need_bgt = 1; + wake_up_process(c->bgt); + } +} + +/** + * ubifs_tnc_find_child - find next child in znode. + * @znode: znode to search at + * @start: the zbranch index to start at + * + * This helper function looks for znode child starting at index @start. Returns + * the child or %NULL if no children were found. + */ +static inline struct ubifs_znode * +ubifs_tnc_find_child(struct ubifs_znode *znode, int start) +{ + while (start < znode->child_cnt) { + if (znode->zbranch[start].znode) + return znode->zbranch[start].znode; + start += 1; + } + + return NULL; +} + +/** + * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object. + * @inode: the VFS 'struct inode' pointer + */ +static inline struct ubifs_inode *ubifs_inode(const struct inode *inode) +{ + return container_of(inode, struct ubifs_inode, vfs_inode); +} + +/** + * ubifs_compr_present - check if compressor was compiled in. + * @compr_type: compressor type to check + * @c: the UBIFS file-system description object + * + * This function returns %1 of compressor of type @compr_type is present, and + * %0 if not. + */ +static inline int ubifs_compr_present(struct ubifs_info *c, int compr_type) +{ + ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); + return !!ubifs_compressors[compr_type]->capi_name; +} + +/** + * ubifs_compr_name - get compressor name string by its type. + * @compr_type: compressor type + * @c: the UBIFS file-system description object + * + * This function returns compressor type string. + */ +static inline const char *ubifs_compr_name(struct ubifs_info *c, int compr_type) +{ + ubifs_assert(c, compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); + return ubifs_compressors[compr_type]->name; +} + +/** + * ubifs_wbuf_sync - synchronize write-buffer. + * @wbuf: write-buffer to synchronize + * + * This is the same as 'ubifs_wbuf_sync_nolock()' but it does not assume + * that the write-buffer is already locked. + */ +static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf) +{ + int err; + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + err = ubifs_wbuf_sync_nolock(wbuf); + mutex_unlock(&wbuf->io_mutex); + return err; +} + +/** + * ubifs_encode_dev - encode device node IDs. + * @dev: UBIFS device node information + * @rdev: device IDs to encode + * + * This is a helper function which encodes major/minor numbers of a device node + * into UBIFS device node description. We use standard Linux "new" and "huge" + * encodings. + */ +static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev) +{ + dev->new = cpu_to_le32(new_encode_dev(rdev)); + return sizeof(dev->new); +} + +/** + * ubifs_add_dirt - add dirty space to LEB properties. + * @c: the UBIFS file-system description object + * @lnum: LEB to add dirty space for + * @dirty: dirty space to add + * + * This is a helper function which increased amount of dirty LEB space. Returns + * zero in case of success and a negative error code in case of failure. + */ +static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty) +{ + return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0); +} + +/** + * ubifs_return_leb - return LEB to lprops. + * @c: the UBIFS file-system description object + * @lnum: LEB to return + * + * This helper function cleans the "taken" flag of a logical eraseblock in the + * lprops. Returns zero in case of success and a negative error code in case of + * failure. + */ +static inline int ubifs_return_leb(struct ubifs_info *c, int lnum) +{ + return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_TAKEN, 0); +} + +/** + * ubifs_idx_node_sz - return index node size. + * @c: the UBIFS file-system description object + * @child_cnt: number of children of this index node + */ +static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt) +{ + return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len + c->hash_len) + * child_cnt; +} + +/** + * ubifs_idx_branch - return pointer to an index branch. + * @c: the UBIFS file-system description object + * @idx: index node + * @bnum: branch number + */ +static inline +struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c, + const struct ubifs_idx_node *idx, + int bnum) +{ + return (struct ubifs_branch *)((void *)idx->branches + + (UBIFS_BRANCH_SZ + c->key_len + c->hash_len) * bnum); +} + +/** + * ubifs_idx_key - return pointer to an index key. + * @c: the UBIFS file-system description object + * @idx: index node + */ +static inline void *ubifs_idx_key(const struct ubifs_info *c, + const struct ubifs_idx_node *idx) +{ + return (void *)((struct ubifs_branch *)idx->branches)->key; +} + +/** + * ubifs_tnc_lookup - look up a file-system node. + * @c: UBIFS file-system description object + * @key: node key to lookup + * @node: the node is returned here + * + * This function look up and reads node with key @key. The caller has to make + * sure the @node buffer is large enough to fit the node. Returns zero in case + * of success, %-ENOENT if the node was not found, and a negative error code in + * case of failure. + */ +static inline int ubifs_tnc_lookup(struct ubifs_info *c, + const union ubifs_key *key, void *node) +{ + return ubifs_tnc_locate(c, key, node, NULL, NULL); +} + +/** + * ubifs_get_lprops - get reference to LEB properties. + * @c: the UBIFS file-system description object + * + * This function locks lprops. Lprops have to be unlocked by + * 'ubifs_release_lprops()'. + */ +static inline void ubifs_get_lprops(struct ubifs_info *c) +{ + mutex_lock(&c->lp_mutex); +} + +/** + * ubifs_release_lprops - release lprops lock. + * @c: the UBIFS file-system description object + * + * This function has to be called after each 'ubifs_get_lprops()' call to + * unlock lprops. + */ +static inline void ubifs_release_lprops(struct ubifs_info *c) +{ + ubifs_assert(c, mutex_is_locked(&c->lp_mutex)); + ubifs_assert(c, c->lst.empty_lebs >= 0 && + c->lst.empty_lebs <= c->main_lebs); + mutex_unlock(&c->lp_mutex); +} + +/** + * ubifs_next_log_lnum - switch to the next log LEB. + * @c: UBIFS file-system description object + * @lnum: current log LEB + * + * This helper function returns the log LEB number which goes next after LEB + * 'lnum'. + */ +static inline int ubifs_next_log_lnum(const struct ubifs_info *c, int lnum) +{ + lnum += 1; + if (lnum > c->log_last) + lnum = UBIFS_LOG_LNUM; + + return lnum; +} + +static inline int ubifs_xattr_max_cnt(struct ubifs_info *c) +{ + int max_xattrs = (c->leb_size / 2) / UBIFS_INO_NODE_SZ; + + ubifs_assert(c, max_xattrs < c->max_orphans); + return max_xattrs; +} + +const char *ubifs_assert_action_name(struct ubifs_info *c); + +#endif /* __UBIFS_MISC_H__ */ diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c new file mode 100644 index 000000000..0fb619561 --- /dev/null +++ b/fs/ubifs/orphan.c @@ -0,0 +1,1050 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Author: Adrian Hunter + */ + +#include "ubifs.h" + +/* + * An orphan is an inode number whose inode node has been committed to the index + * with a link count of zero. That happens when an open file is deleted + * (unlinked) and then a commit is run. In the normal course of events the inode + * would be deleted when the file is closed. However in the case of an unclean + * unmount, orphans need to be accounted for. After an unclean unmount, the + * orphans' inodes must be deleted which means either scanning the entire index + * looking for them, or keeping a list on flash somewhere. This unit implements + * the latter approach. + * + * The orphan area is a fixed number of LEBs situated between the LPT area and + * the main area. The number of orphan area LEBs is specified when the file + * system is created. The minimum number is 1. The size of the orphan area + * should be so that it can hold the maximum number of orphans that are expected + * to ever exist at one time. + * + * The number of orphans that can fit in a LEB is: + * + * (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64) + * + * For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough. + * + * Orphans are accumulated in a rb-tree. When an inode's link count drops to + * zero, the inode number is added to the rb-tree. It is removed from the tree + * when the inode is deleted. Any new orphans that are in the orphan tree when + * the commit is run, are written to the orphan area in 1 or more orphan nodes. + * If the orphan area is full, it is consolidated to make space. There is + * always enough space because validation prevents the user from creating more + * than the maximum number of orphans allowed. + */ + +static int dbg_check_orphans(struct ubifs_info *c); + +static struct ubifs_orphan *orphan_add(struct ubifs_info *c, ino_t inum, + struct ubifs_orphan *parent_orphan) +{ + struct ubifs_orphan *orphan, *o; + struct rb_node **p, *parent = NULL; + + orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_NOFS); + if (!orphan) + return ERR_PTR(-ENOMEM); + orphan->inum = inum; + orphan->new = 1; + INIT_LIST_HEAD(&orphan->child_list); + + spin_lock(&c->orphan_lock); + if (c->tot_orphans >= c->max_orphans) { + spin_unlock(&c->orphan_lock); + kfree(orphan); + return ERR_PTR(-ENFILE); + } + p = &c->orph_tree.rb_node; + while (*p) { + parent = *p; + o = rb_entry(parent, struct ubifs_orphan, rb); + if (inum < o->inum) + p = &(*p)->rb_left; + else if (inum > o->inum) + p = &(*p)->rb_right; + else { + ubifs_err(c, "orphaned twice"); + spin_unlock(&c->orphan_lock); + kfree(orphan); + return ERR_PTR(-EINVAL); + } + } + c->tot_orphans += 1; + c->new_orphans += 1; + rb_link_node(&orphan->rb, parent, p); + rb_insert_color(&orphan->rb, &c->orph_tree); + list_add_tail(&orphan->list, &c->orph_list); + list_add_tail(&orphan->new_list, &c->orph_new); + + if (parent_orphan) { + list_add_tail(&orphan->child_list, + &parent_orphan->child_list); + } + + spin_unlock(&c->orphan_lock); + dbg_gen("ino %lu", (unsigned long)inum); + return orphan; +} + +static struct ubifs_orphan *lookup_orphan(struct ubifs_info *c, ino_t inum) +{ + struct ubifs_orphan *o; + struct rb_node *p; + + p = c->orph_tree.rb_node; + while (p) { + o = rb_entry(p, struct ubifs_orphan, rb); + if (inum < o->inum) + p = p->rb_left; + else if (inum > o->inum) + p = p->rb_right; + else { + return o; + } + } + return NULL; +} + +static void __orphan_drop(struct ubifs_info *c, struct ubifs_orphan *o) +{ + rb_erase(&o->rb, &c->orph_tree); + list_del(&o->list); + c->tot_orphans -= 1; + + if (o->new) { + list_del(&o->new_list); + c->new_orphans -= 1; + } + + kfree(o); +} + +static void orphan_delete(struct ubifs_info *c, struct ubifs_orphan *orph) +{ + if (orph->del) { + dbg_gen("deleted twice ino %lu", (unsigned long)orph->inum); + return; + } + + if (orph->cmt) { + orph->del = 1; + orph->dnext = c->orph_dnext; + c->orph_dnext = orph; + dbg_gen("delete later ino %lu", (unsigned long)orph->inum); + return; + } + + __orphan_drop(c, orph); +} + +/** + * ubifs_add_orphan - add an orphan. + * @c: UBIFS file-system description object + * @inum: orphan inode number + * + * Add an orphan. This function is called when an inodes link count drops to + * zero. + */ +int ubifs_add_orphan(struct ubifs_info *c, ino_t inum) +{ + int err = 0; + ino_t xattr_inum; + union ubifs_key key; + struct ubifs_dent_node *xent, *pxent = NULL; + struct fscrypt_name nm = {0}; + struct ubifs_orphan *xattr_orphan; + struct ubifs_orphan *orphan; + + orphan = orphan_add(c, inum, NULL); + if (IS_ERR(orphan)) + return PTR_ERR(orphan); + + lowest_xent_key(c, &key, inum); + while (1) { + xent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(xent)) { + err = PTR_ERR(xent); + if (err == -ENOENT) + break; + kfree(pxent); + return err; + } + + fname_name(&nm) = xent->name; + fname_len(&nm) = le16_to_cpu(xent->nlen); + xattr_inum = le64_to_cpu(xent->inum); + + xattr_orphan = orphan_add(c, xattr_inum, orphan); + if (IS_ERR(xattr_orphan)) { + kfree(pxent); + kfree(xent); + return PTR_ERR(xattr_orphan); + } + + kfree(pxent); + pxent = xent; + key_read(c, &xent->key, &key); + } + kfree(pxent); + + return 0; +} + +/** + * ubifs_delete_orphan - delete an orphan. + * @c: UBIFS file-system description object + * @inum: orphan inode number + * + * Delete an orphan. This function is called when an inode is deleted. + */ +void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum) +{ + struct ubifs_orphan *orph, *child_orph, *tmp_o; + + spin_lock(&c->orphan_lock); + + orph = lookup_orphan(c, inum); + if (!orph) { + spin_unlock(&c->orphan_lock); + ubifs_err(c, "missing orphan ino %lu", (unsigned long)inum); + dump_stack(); + + return; + } + + list_for_each_entry_safe(child_orph, tmp_o, &orph->child_list, child_list) { + list_del(&child_orph->child_list); + orphan_delete(c, child_orph); + } + + orphan_delete(c, orph); + + spin_unlock(&c->orphan_lock); +} + +/** + * ubifs_orphan_start_commit - start commit of orphans. + * @c: UBIFS file-system description object + * + * Start commit of orphans. + */ +int ubifs_orphan_start_commit(struct ubifs_info *c) +{ + struct ubifs_orphan *orphan, **last; + + spin_lock(&c->orphan_lock); + last = &c->orph_cnext; + list_for_each_entry(orphan, &c->orph_new, new_list) { + ubifs_assert(c, orphan->new); + ubifs_assert(c, !orphan->cmt); + orphan->new = 0; + orphan->cmt = 1; + *last = orphan; + last = &orphan->cnext; + } + *last = NULL; + c->cmt_orphans = c->new_orphans; + c->new_orphans = 0; + dbg_cmt("%d orphans to commit", c->cmt_orphans); + INIT_LIST_HEAD(&c->orph_new); + if (c->tot_orphans == 0) + c->no_orphs = 1; + else + c->no_orphs = 0; + spin_unlock(&c->orphan_lock); + return 0; +} + +/** + * avail_orphs - calculate available space. + * @c: UBIFS file-system description object + * + * This function returns the number of orphans that can be written in the + * available space. + */ +static int avail_orphs(struct ubifs_info *c) +{ + int avail_lebs, avail, gap; + + avail_lebs = c->orph_lebs - (c->ohead_lnum - c->orph_first) - 1; + avail = avail_lebs * + ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)); + gap = c->leb_size - c->ohead_offs; + if (gap >= UBIFS_ORPH_NODE_SZ + sizeof(__le64)) + avail += (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64); + return avail; +} + +/** + * tot_avail_orphs - calculate total space. + * @c: UBIFS file-system description object + * + * This function returns the number of orphans that can be written in half + * the total space. That leaves half the space for adding new orphans. + */ +static int tot_avail_orphs(struct ubifs_info *c) +{ + int avail_lebs, avail; + + avail_lebs = c->orph_lebs; + avail = avail_lebs * + ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)); + return avail / 2; +} + +/** + * do_write_orph_node - write a node to the orphan head. + * @c: UBIFS file-system description object + * @len: length of node + * @atomic: write atomically + * + * This function writes a node to the orphan head from the orphan buffer. If + * %atomic is not zero, then the write is done atomically. On success, %0 is + * returned, otherwise a negative error code is returned. + */ +static int do_write_orph_node(struct ubifs_info *c, int len, int atomic) +{ + int err = 0; + + if (atomic) { + ubifs_assert(c, c->ohead_offs == 0); + ubifs_prepare_node(c, c->orph_buf, len, 1); + len = ALIGN(len, c->min_io_size); + err = ubifs_leb_change(c, c->ohead_lnum, c->orph_buf, len); + } else { + if (c->ohead_offs == 0) { + /* Ensure LEB has been unmapped */ + err = ubifs_leb_unmap(c, c->ohead_lnum); + if (err) + return err; + } + err = ubifs_write_node(c, c->orph_buf, len, c->ohead_lnum, + c->ohead_offs); + } + return err; +} + +/** + * write_orph_node - write an orphan node. + * @c: UBIFS file-system description object + * @atomic: write atomically + * + * This function builds an orphan node from the cnext list and writes it to the + * orphan head. On success, %0 is returned, otherwise a negative error code + * is returned. + */ +static int write_orph_node(struct ubifs_info *c, int atomic) +{ + struct ubifs_orphan *orphan, *cnext; + struct ubifs_orph_node *orph; + int gap, err, len, cnt, i; + + ubifs_assert(c, c->cmt_orphans > 0); + gap = c->leb_size - c->ohead_offs; + if (gap < UBIFS_ORPH_NODE_SZ + sizeof(__le64)) { + c->ohead_lnum += 1; + c->ohead_offs = 0; + gap = c->leb_size; + if (c->ohead_lnum > c->orph_last) { + /* + * We limit the number of orphans so that this should + * never happen. + */ + ubifs_err(c, "out of space in orphan area"); + return -EINVAL; + } + } + cnt = (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64); + if (cnt > c->cmt_orphans) + cnt = c->cmt_orphans; + len = UBIFS_ORPH_NODE_SZ + cnt * sizeof(__le64); + ubifs_assert(c, c->orph_buf); + orph = c->orph_buf; + orph->ch.node_type = UBIFS_ORPH_NODE; + spin_lock(&c->orphan_lock); + cnext = c->orph_cnext; + for (i = 0; i < cnt; i++) { + orphan = cnext; + ubifs_assert(c, orphan->cmt); + orph->inos[i] = cpu_to_le64(orphan->inum); + orphan->cmt = 0; + cnext = orphan->cnext; + orphan->cnext = NULL; + } + c->orph_cnext = cnext; + c->cmt_orphans -= cnt; + spin_unlock(&c->orphan_lock); + if (c->cmt_orphans) + orph->cmt_no = cpu_to_le64(c->cmt_no); + else + /* Mark the last node of the commit */ + orph->cmt_no = cpu_to_le64((c->cmt_no) | (1ULL << 63)); + ubifs_assert(c, c->ohead_offs + len <= c->leb_size); + ubifs_assert(c, c->ohead_lnum >= c->orph_first); + ubifs_assert(c, c->ohead_lnum <= c->orph_last); + err = do_write_orph_node(c, len, atomic); + c->ohead_offs += ALIGN(len, c->min_io_size); + c->ohead_offs = ALIGN(c->ohead_offs, 8); + return err; +} + +/** + * write_orph_nodes - write orphan nodes until there are no more to commit. + * @c: UBIFS file-system description object + * @atomic: write atomically + * + * This function writes orphan nodes for all the orphans to commit. On success, + * %0 is returned, otherwise a negative error code is returned. + */ +static int write_orph_nodes(struct ubifs_info *c, int atomic) +{ + int err; + + while (c->cmt_orphans > 0) { + err = write_orph_node(c, atomic); + if (err) + return err; + } + if (atomic) { + int lnum; + + /* Unmap any unused LEBs after consolidation */ + for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + } + return 0; +} + +/** + * consolidate - consolidate the orphan area. + * @c: UBIFS file-system description object + * + * This function enables consolidation by putting all the orphans into the list + * to commit. The list is in the order that the orphans were added, and the + * LEBs are written atomically in order, so at no time can orphans be lost by + * an unclean unmount. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int consolidate(struct ubifs_info *c) +{ + int tot_avail = tot_avail_orphs(c), err = 0; + + spin_lock(&c->orphan_lock); + dbg_cmt("there is space for %d orphans and there are %d", + tot_avail, c->tot_orphans); + if (c->tot_orphans - c->new_orphans <= tot_avail) { + struct ubifs_orphan *orphan, **last; + int cnt = 0; + + /* Change the cnext list to include all non-new orphans */ + last = &c->orph_cnext; + list_for_each_entry(orphan, &c->orph_list, list) { + if (orphan->new) + continue; + orphan->cmt = 1; + *last = orphan; + last = &orphan->cnext; + cnt += 1; + } + *last = NULL; + ubifs_assert(c, cnt == c->tot_orphans - c->new_orphans); + c->cmt_orphans = cnt; + c->ohead_lnum = c->orph_first; + c->ohead_offs = 0; + } else { + /* + * We limit the number of orphans so that this should + * never happen. + */ + ubifs_err(c, "out of space in orphan area"); + err = -EINVAL; + } + spin_unlock(&c->orphan_lock); + return err; +} + +/** + * commit_orphans - commit orphans. + * @c: UBIFS file-system description object + * + * This function commits orphans to flash. On success, %0 is returned, + * otherwise a negative error code is returned. + */ +static int commit_orphans(struct ubifs_info *c) +{ + int avail, atomic = 0, err; + + ubifs_assert(c, c->cmt_orphans > 0); + avail = avail_orphs(c); + if (avail < c->cmt_orphans) { + /* Not enough space to write new orphans, so consolidate */ + err = consolidate(c); + if (err) + return err; + atomic = 1; + } + err = write_orph_nodes(c, atomic); + return err; +} + +/** + * erase_deleted - erase the orphans marked for deletion. + * @c: UBIFS file-system description object + * + * During commit, the orphans being committed cannot be deleted, so they are + * marked for deletion and deleted by this function. Also, the recovery + * adds killed orphans to the deletion list, and therefore they are deleted + * here too. + */ +static void erase_deleted(struct ubifs_info *c) +{ + struct ubifs_orphan *orphan, *dnext; + + spin_lock(&c->orphan_lock); + dnext = c->orph_dnext; + while (dnext) { + orphan = dnext; + dnext = orphan->dnext; + ubifs_assert(c, !orphan->new); + ubifs_assert(c, orphan->del); + rb_erase(&orphan->rb, &c->orph_tree); + list_del(&orphan->list); + c->tot_orphans -= 1; + dbg_gen("deleting orphan ino %lu", (unsigned long)orphan->inum); + kfree(orphan); + } + c->orph_dnext = NULL; + spin_unlock(&c->orphan_lock); +} + +/** + * ubifs_orphan_end_commit - end commit of orphans. + * @c: UBIFS file-system description object + * + * End commit of orphans. + */ +int ubifs_orphan_end_commit(struct ubifs_info *c) +{ + int err; + + if (c->cmt_orphans != 0) { + err = commit_orphans(c); + if (err) + return err; + } + erase_deleted(c); + err = dbg_check_orphans(c); + return err; +} + +/** + * ubifs_clear_orphans - erase all LEBs used for orphans. + * @c: UBIFS file-system description object + * + * If recovery is not required, then the orphans from the previous session + * are not needed. This function locates the LEBs used to record + * orphans, and un-maps them. + */ +int ubifs_clear_orphans(struct ubifs_info *c) +{ + int lnum, err; + + for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + c->ohead_lnum = c->orph_first; + c->ohead_offs = 0; + return 0; +} + +/** + * insert_dead_orphan - insert an orphan. + * @c: UBIFS file-system description object + * @inum: orphan inode number + * + * This function is a helper to the 'do_kill_orphans()' function. The orphan + * must be kept until the next commit, so it is added to the rb-tree and the + * deletion list. + */ +static int insert_dead_orphan(struct ubifs_info *c, ino_t inum) +{ + struct ubifs_orphan *orphan, *o; + struct rb_node **p, *parent = NULL; + + orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL); + if (!orphan) + return -ENOMEM; + orphan->inum = inum; + + p = &c->orph_tree.rb_node; + while (*p) { + parent = *p; + o = rb_entry(parent, struct ubifs_orphan, rb); + if (inum < o->inum) + p = &(*p)->rb_left; + else if (inum > o->inum) + p = &(*p)->rb_right; + else { + /* Already added - no problem */ + kfree(orphan); + return 0; + } + } + c->tot_orphans += 1; + rb_link_node(&orphan->rb, parent, p); + rb_insert_color(&orphan->rb, &c->orph_tree); + list_add_tail(&orphan->list, &c->orph_list); + orphan->del = 1; + orphan->dnext = c->orph_dnext; + c->orph_dnext = orphan; + dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum, + c->new_orphans, c->tot_orphans); + return 0; +} + +/** + * do_kill_orphans - remove orphan inodes from the index. + * @c: UBIFS file-system description object + * @sleb: scanned LEB + * @last_cmt_no: cmt_no of last orphan node read is passed and returned here + * @outofdate: whether the LEB is out of date is returned here + * @last_flagged: whether the end orphan node is encountered + * + * This function is a helper to the 'kill_orphans()' function. It goes through + * every orphan node in a LEB and for every inode number recorded, removes + * all keys for that inode from the TNC. + */ +static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb, + unsigned long long *last_cmt_no, int *outofdate, + int *last_flagged) +{ + struct ubifs_scan_node *snod; + struct ubifs_orph_node *orph; + struct ubifs_ino_node *ino = NULL; + unsigned long long cmt_no; + ino_t inum; + int i, n, err, first = 1; + + ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS); + if (!ino) + return -ENOMEM; + + list_for_each_entry(snod, &sleb->nodes, list) { + if (snod->type != UBIFS_ORPH_NODE) { + ubifs_err(c, "invalid node type %d in orphan area at %d:%d", + snod->type, sleb->lnum, snod->offs); + ubifs_dump_node(c, snod->node); + err = -EINVAL; + goto out_free; + } + + orph = snod->node; + + /* Check commit number */ + cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX; + /* + * The commit number on the master node may be less, because + * of a failed commit. If there are several failed commits in a + * row, the commit number written on orphan nodes will continue + * to increase (because the commit number is adjusted here) even + * though the commit number on the master node stays the same + * because the master node has not been re-written. + */ + if (cmt_no > c->cmt_no) + c->cmt_no = cmt_no; + if (cmt_no < *last_cmt_no && *last_flagged) { + /* + * The last orphan node had a higher commit number and + * was flagged as the last written for that commit + * number. That makes this orphan node, out of date. + */ + if (!first) { + ubifs_err(c, "out of order commit number %llu in orphan node at %d:%d", + cmt_no, sleb->lnum, snod->offs); + ubifs_dump_node(c, snod->node); + err = -EINVAL; + goto out_free; + } + dbg_rcvry("out of date LEB %d", sleb->lnum); + *outofdate = 1; + err = 0; + goto out_free; + } + + if (first) + first = 0; + + n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3; + for (i = 0; i < n; i++) { + union ubifs_key key1, key2; + + inum = le64_to_cpu(orph->inos[i]); + + ino_key_init(c, &key1, inum); + err = ubifs_tnc_lookup(c, &key1, ino); + if (err && err != -ENOENT) + goto out_free; + + /* + * Check whether an inode can really get deleted. + * linkat() with O_TMPFILE allows rebirth of an inode. + */ + if (err == 0 && ino->nlink == 0) { + dbg_rcvry("deleting orphaned inode %lu", + (unsigned long)inum); + + lowest_ino_key(c, &key1, inum); + highest_ino_key(c, &key2, inum); + + err = ubifs_tnc_remove_range(c, &key1, &key2); + if (err) + goto out_ro; + } + + err = insert_dead_orphan(c, inum); + if (err) + goto out_free; + } + + *last_cmt_no = cmt_no; + if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) { + dbg_rcvry("last orph node for commit %llu at %d:%d", + cmt_no, sleb->lnum, snod->offs); + *last_flagged = 1; + } else + *last_flagged = 0; + } + + err = 0; +out_free: + kfree(ino); + return err; + +out_ro: + ubifs_ro_mode(c, err); + kfree(ino); + return err; +} + +/** + * kill_orphans - remove all orphan inodes from the index. + * @c: UBIFS file-system description object + * + * If recovery is required, then orphan inodes recorded during the previous + * session (which ended with an unclean unmount) must be deleted from the index. + * This is done by updating the TNC, but since the index is not updated until + * the next commit, the LEBs where the orphan information is recorded are not + * erased until the next commit. + */ +static int kill_orphans(struct ubifs_info *c) +{ + unsigned long long last_cmt_no = 0; + int lnum, err = 0, outofdate = 0, last_flagged = 0; + + c->ohead_lnum = c->orph_first; + c->ohead_offs = 0; + /* Check no-orphans flag and skip this if no orphans */ + if (c->no_orphs) { + dbg_rcvry("no orphans"); + return 0; + } + /* + * Orph nodes always start at c->orph_first and are written to each + * successive LEB in turn. Generally unused LEBs will have been unmapped + * but may contain out of date orphan nodes if the unmap didn't go + * through. In addition, the last orphan node written for each commit is + * marked (top bit of orph->cmt_no is set to 1). It is possible that + * there are orphan nodes from the next commit (i.e. the commit did not + * complete successfully). In that case, no orphans will have been lost + * due to the way that orphans are written, and any orphans added will + * be valid orphans anyway and so can be deleted. + */ + for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { + struct ubifs_scan_leb *sleb; + + dbg_rcvry("LEB %d", lnum); + sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1); + if (IS_ERR(sleb)) { + if (PTR_ERR(sleb) == -EUCLEAN) + sleb = ubifs_recover_leb(c, lnum, 0, + c->sbuf, -1); + if (IS_ERR(sleb)) { + err = PTR_ERR(sleb); + break; + } + } + err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate, + &last_flagged); + if (err || outofdate) { + ubifs_scan_destroy(sleb); + break; + } + if (sleb->endpt) { + c->ohead_lnum = lnum; + c->ohead_offs = sleb->endpt; + } + ubifs_scan_destroy(sleb); + } + return err; +} + +/** + * ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them. + * @c: UBIFS file-system description object + * @unclean: indicates recovery from unclean unmount + * @read_only: indicates read only mount + * + * This function is called when mounting to erase orphans from the previous + * session. If UBIFS was not unmounted cleanly, then the inodes recorded as + * orphans are deleted. + */ +int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only) +{ + int err = 0; + + c->max_orphans = tot_avail_orphs(c); + + if (!read_only) { + c->orph_buf = vmalloc(c->leb_size); + if (!c->orph_buf) + return -ENOMEM; + } + + if (unclean) + err = kill_orphans(c); + else if (!read_only) + err = ubifs_clear_orphans(c); + + return err; +} + +/* + * Everything below is related to debugging. + */ + +struct check_orphan { + struct rb_node rb; + ino_t inum; +}; + +struct check_info { + unsigned long last_ino; + unsigned long tot_inos; + unsigned long missing; + unsigned long long leaf_cnt; + struct ubifs_ino_node *node; + struct rb_root root; +}; + +static bool dbg_find_orphan(struct ubifs_info *c, ino_t inum) +{ + bool found = false; + + spin_lock(&c->orphan_lock); + found = !!lookup_orphan(c, inum); + spin_unlock(&c->orphan_lock); + + return found; +} + +static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum) +{ + struct check_orphan *orphan, *o; + struct rb_node **p, *parent = NULL; + + orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS); + if (!orphan) + return -ENOMEM; + orphan->inum = inum; + + p = &root->rb_node; + while (*p) { + parent = *p; + o = rb_entry(parent, struct check_orphan, rb); + if (inum < o->inum) + p = &(*p)->rb_left; + else if (inum > o->inum) + p = &(*p)->rb_right; + else { + kfree(orphan); + return 0; + } + } + rb_link_node(&orphan->rb, parent, p); + rb_insert_color(&orphan->rb, root); + return 0; +} + +static int dbg_find_check_orphan(struct rb_root *root, ino_t inum) +{ + struct check_orphan *o; + struct rb_node *p; + + p = root->rb_node; + while (p) { + o = rb_entry(p, struct check_orphan, rb); + if (inum < o->inum) + p = p->rb_left; + else if (inum > o->inum) + p = p->rb_right; + else + return 1; + } + return 0; +} + +static void dbg_free_check_tree(struct rb_root *root) +{ + struct check_orphan *o, *n; + + rbtree_postorder_for_each_entry_safe(o, n, root, rb) + kfree(o); +} + +static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr, + void *priv) +{ + struct check_info *ci = priv; + ino_t inum; + int err; + + inum = key_inum(c, &zbr->key); + if (inum != ci->last_ino) { + /* Lowest node type is the inode node, so it comes first */ + if (key_type(c, &zbr->key) != UBIFS_INO_KEY) + ubifs_err(c, "found orphan node ino %lu, type %d", + (unsigned long)inum, key_type(c, &zbr->key)); + ci->last_ino = inum; + ci->tot_inos += 1; + err = ubifs_tnc_read_node(c, zbr, ci->node); + if (err) { + ubifs_err(c, "node read failed, error %d", err); + return err; + } + if (ci->node->nlink == 0) + /* Must be recorded as an orphan */ + if (!dbg_find_check_orphan(&ci->root, inum) && + !dbg_find_orphan(c, inum)) { + ubifs_err(c, "missing orphan, ino %lu", + (unsigned long)inum); + ci->missing += 1; + } + } + ci->leaf_cnt += 1; + return 0; +} + +static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb) +{ + struct ubifs_scan_node *snod; + struct ubifs_orph_node *orph; + ino_t inum; + int i, n, err; + + list_for_each_entry(snod, &sleb->nodes, list) { + cond_resched(); + if (snod->type != UBIFS_ORPH_NODE) + continue; + orph = snod->node; + n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3; + for (i = 0; i < n; i++) { + inum = le64_to_cpu(orph->inos[i]); + err = dbg_ins_check_orphan(&ci->root, inum); + if (err) + return err; + } + } + return 0; +} + +static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci) +{ + int lnum, err = 0; + void *buf; + + /* Check no-orphans flag and skip this if no orphans */ + if (c->no_orphs) + return 0; + + buf = __vmalloc(c->leb_size, GFP_NOFS); + if (!buf) { + ubifs_err(c, "cannot allocate memory to check orphans"); + return 0; + } + + for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { + struct ubifs_scan_leb *sleb; + + sleb = ubifs_scan(c, lnum, 0, buf, 0); + if (IS_ERR(sleb)) { + err = PTR_ERR(sleb); + break; + } + + err = dbg_read_orphans(ci, sleb); + ubifs_scan_destroy(sleb); + if (err) + break; + } + + vfree(buf); + return err; +} + +static int dbg_check_orphans(struct ubifs_info *c) +{ + struct check_info ci; + int err; + + if (!dbg_is_chk_orph(c)) + return 0; + + ci.last_ino = 0; + ci.tot_inos = 0; + ci.missing = 0; + ci.leaf_cnt = 0; + ci.root = RB_ROOT; + ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS); + if (!ci.node) { + ubifs_err(c, "out of memory"); + return -ENOMEM; + } + + err = dbg_scan_orphans(c, &ci); + if (err) + goto out; + + err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci); + if (err) { + ubifs_err(c, "cannot scan TNC, error %d", err); + goto out; + } + + if (ci.missing) { + ubifs_err(c, "%lu missing orphan(s)", ci.missing); + err = -EINVAL; + goto out; + } + + dbg_cmt("last inode number is %lu", ci.last_ino); + dbg_cmt("total number of inodes is %lu", ci.tot_inos); + dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt); + +out: + dbg_free_check_tree(&ci.root); + kfree(ci.node); + return err; +} diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c new file mode 100644 index 000000000..f116f7b3f --- /dev/null +++ b/fs/ubifs/recovery.c @@ -0,0 +1,1588 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements functions needed to recover from unclean un-mounts. + * When UBIFS is mounted, it checks a flag on the master node to determine if + * an un-mount was completed successfully. If not, the process of mounting + * incorporates additional checking and fixing of on-flash data structures. + * UBIFS always cleans away all remnants of an unclean un-mount, so that + * errors do not accumulate. However UBIFS defers recovery if it is mounted + * read-only, and the flash is not modified in that case. + * + * The general UBIFS approach to the recovery is that it recovers from + * corruptions which could be caused by power cuts, but it refuses to recover + * from corruption caused by other reasons. And UBIFS tries to distinguish + * between these 2 reasons of corruptions and silently recover in the former + * case and loudly complain in the latter case. + * + * UBIFS writes only to erased LEBs, so it writes only to the flash space + * containing only 0xFFs. UBIFS also always writes strictly from the beginning + * of the LEB to the end. And UBIFS assumes that the underlying flash media + * writes in @c->max_write_size bytes at a time. + * + * Hence, if UBIFS finds a corrupted node at offset X, it expects only the min. + * I/O unit corresponding to offset X to contain corrupted data, all the + * following min. I/O units have to contain empty space (all 0xFFs). If this is + * not true, the corruption cannot be the result of a power cut, and UBIFS + * refuses to mount. + */ + +#include <linux/crc32.h> +#include <linux/slab.h> +#include "ubifs.h" + +/** + * is_empty - determine whether a buffer is empty (contains all 0xff). + * @buf: buffer to clean + * @len: length of buffer + * + * This function returns %1 if the buffer is empty (contains all 0xff) otherwise + * %0 is returned. + */ +static int is_empty(void *buf, int len) +{ + uint8_t *p = buf; + int i; + + for (i = 0; i < len; i++) + if (*p++ != 0xff) + return 0; + return 1; +} + +/** + * first_non_ff - find offset of the first non-0xff byte. + * @buf: buffer to search in + * @len: length of buffer + * + * This function returns offset of the first non-0xff byte in @buf or %-1 if + * the buffer contains only 0xff bytes. + */ +static int first_non_ff(void *buf, int len) +{ + uint8_t *p = buf; + int i; + + for (i = 0; i < len; i++) + if (*p++ != 0xff) + return i; + return -1; +} + +/** + * get_master_node - get the last valid master node allowing for corruption. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @pbuf: buffer containing the LEB read, is returned here + * @mst: master node, if found, is returned here + * @cor: corruption, if found, is returned here + * + * This function allocates a buffer, reads the LEB into it, and finds and + * returns the last valid master node allowing for one area of corruption. + * The corrupt area, if there is one, must be consistent with the assumption + * that it is the result of an unclean unmount while the master node was being + * written. Under those circumstances, it is valid to use the previously written + * master node. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int get_master_node(const struct ubifs_info *c, int lnum, void **pbuf, + struct ubifs_mst_node **mst, void **cor) +{ + const int sz = c->mst_node_alsz; + int err, offs, len; + void *sbuf, *buf; + + sbuf = vmalloc(c->leb_size); + if (!sbuf) + return -ENOMEM; + + err = ubifs_leb_read(c, lnum, sbuf, 0, c->leb_size, 0); + if (err && err != -EBADMSG) + goto out_free; + + /* Find the first position that is definitely not a node */ + offs = 0; + buf = sbuf; + len = c->leb_size; + while (offs + UBIFS_MST_NODE_SZ <= c->leb_size) { + struct ubifs_ch *ch = buf; + + if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) + break; + offs += sz; + buf += sz; + len -= sz; + } + /* See if there was a valid master node before that */ + if (offs) { + int ret; + + offs -= sz; + buf -= sz; + len += sz; + ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); + if (ret != SCANNED_A_NODE && offs) { + /* Could have been corruption so check one place back */ + offs -= sz; + buf -= sz; + len += sz; + ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); + if (ret != SCANNED_A_NODE) + /* + * We accept only one area of corruption because + * we are assuming that it was caused while + * trying to write a master node. + */ + goto out_err; + } + if (ret == SCANNED_A_NODE) { + struct ubifs_ch *ch = buf; + + if (ch->node_type != UBIFS_MST_NODE) + goto out_err; + dbg_rcvry("found a master node at %d:%d", lnum, offs); + *mst = buf; + offs += sz; + buf += sz; + len -= sz; + } + } + /* Check for corruption */ + if (offs < c->leb_size) { + if (!is_empty(buf, min_t(int, len, sz))) { + *cor = buf; + dbg_rcvry("found corruption at %d:%d", lnum, offs); + } + offs += sz; + buf += sz; + len -= sz; + } + /* Check remaining empty space */ + if (offs < c->leb_size) + if (!is_empty(buf, len)) + goto out_err; + *pbuf = sbuf; + return 0; + +out_err: + err = -EINVAL; +out_free: + vfree(sbuf); + *mst = NULL; + *cor = NULL; + return err; +} + +/** + * write_rcvrd_mst_node - write recovered master node. + * @c: UBIFS file-system description object + * @mst: master node + * + * This function returns %0 on success and a negative error code on failure. + */ +static int write_rcvrd_mst_node(struct ubifs_info *c, + struct ubifs_mst_node *mst) +{ + int err = 0, lnum = UBIFS_MST_LNUM, sz = c->mst_node_alsz; + __le32 save_flags; + + dbg_rcvry("recovery"); + + save_flags = mst->flags; + mst->flags |= cpu_to_le32(UBIFS_MST_RCVRY); + + err = ubifs_prepare_node_hmac(c, mst, UBIFS_MST_NODE_SZ, + offsetof(struct ubifs_mst_node, hmac), 1); + if (err) + goto out; + err = ubifs_leb_change(c, lnum, mst, sz); + if (err) + goto out; + err = ubifs_leb_change(c, lnum + 1, mst, sz); + if (err) + goto out; +out: + mst->flags = save_flags; + return err; +} + +/** + * ubifs_recover_master_node - recover the master node. + * @c: UBIFS file-system description object + * + * This function recovers the master node from corruption that may occur due to + * an unclean unmount. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_recover_master_node(struct ubifs_info *c) +{ + void *buf1 = NULL, *buf2 = NULL, *cor1 = NULL, *cor2 = NULL; + struct ubifs_mst_node *mst1 = NULL, *mst2 = NULL, *mst; + const int sz = c->mst_node_alsz; + int err, offs1, offs2; + + dbg_rcvry("recovery"); + + err = get_master_node(c, UBIFS_MST_LNUM, &buf1, &mst1, &cor1); + if (err) + goto out_free; + + err = get_master_node(c, UBIFS_MST_LNUM + 1, &buf2, &mst2, &cor2); + if (err) + goto out_free; + + if (mst1) { + offs1 = (void *)mst1 - buf1; + if ((le32_to_cpu(mst1->flags) & UBIFS_MST_RCVRY) && + (offs1 == 0 && !cor1)) { + /* + * mst1 was written by recovery at offset 0 with no + * corruption. + */ + dbg_rcvry("recovery recovery"); + mst = mst1; + } else if (mst2) { + offs2 = (void *)mst2 - buf2; + if (offs1 == offs2) { + /* Same offset, so must be the same */ + if (ubifs_compare_master_node(c, mst1, mst2)) + goto out_err; + mst = mst1; + } else if (offs2 + sz == offs1) { + /* 1st LEB was written, 2nd was not */ + if (cor1) + goto out_err; + mst = mst1; + } else if (offs1 == 0 && + c->leb_size - offs2 - sz < sz) { + /* 1st LEB was unmapped and written, 2nd not */ + if (cor1) + goto out_err; + mst = mst1; + } else + goto out_err; + } else { + /* + * 2nd LEB was unmapped and about to be written, so + * there must be only one master node in the first LEB + * and no corruption. + */ + if (offs1 != 0 || cor1) + goto out_err; + mst = mst1; + } + } else { + if (!mst2) + goto out_err; + /* + * 1st LEB was unmapped and about to be written, so there must + * be no room left in 2nd LEB. + */ + offs2 = (void *)mst2 - buf2; + if (offs2 + sz + sz <= c->leb_size) + goto out_err; + mst = mst2; + } + + ubifs_msg(c, "recovered master node from LEB %d", + (mst == mst1 ? UBIFS_MST_LNUM : UBIFS_MST_LNUM + 1)); + + memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ); + + if (c->ro_mount) { + /* Read-only mode. Keep a copy for switching to rw mode */ + c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL); + if (!c->rcvrd_mst_node) { + err = -ENOMEM; + goto out_free; + } + memcpy(c->rcvrd_mst_node, c->mst_node, UBIFS_MST_NODE_SZ); + + /* + * We had to recover the master node, which means there was an + * unclean reboot. However, it is possible that the master node + * is clean at this point, i.e., %UBIFS_MST_DIRTY is not set. + * E.g., consider the following chain of events: + * + * 1. UBIFS was cleanly unmounted, so the master node is clean + * 2. UBIFS is being mounted R/W and starts changing the master + * node in the first (%UBIFS_MST_LNUM). A power cut happens, + * so this LEB ends up with some amount of garbage at the + * end. + * 3. UBIFS is being mounted R/O. We reach this place and + * recover the master node from the second LEB + * (%UBIFS_MST_LNUM + 1). But we cannot update the media + * because we are being mounted R/O. We have to defer the + * operation. + * 4. However, this master node (@c->mst_node) is marked as + * clean (since the step 1). And if we just return, the + * mount code will be confused and won't recover the master + * node when it is re-mounter R/W later. + * + * Thus, to force the recovery by marking the master node as + * dirty. + */ + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); + } else { + /* Write the recovered master node */ + c->max_sqnum = le64_to_cpu(mst->ch.sqnum) - 1; + err = write_rcvrd_mst_node(c, c->mst_node); + if (err) + goto out_free; + } + + vfree(buf2); + vfree(buf1); + + return 0; + +out_err: + err = -EINVAL; +out_free: + ubifs_err(c, "failed to recover master node"); + if (mst1) { + ubifs_err(c, "dumping first master node"); + ubifs_dump_node(c, mst1); + } + if (mst2) { + ubifs_err(c, "dumping second master node"); + ubifs_dump_node(c, mst2); + } + vfree(buf2); + vfree(buf1); + return err; +} + +/** + * ubifs_write_rcvrd_mst_node - write the recovered master node. + * @c: UBIFS file-system description object + * + * This function writes the master node that was recovered during mounting in + * read-only mode and must now be written because we are remounting rw. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_write_rcvrd_mst_node(struct ubifs_info *c) +{ + int err; + + if (!c->rcvrd_mst_node) + return 0; + c->rcvrd_mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); + err = write_rcvrd_mst_node(c, c->rcvrd_mst_node); + if (err) + return err; + kfree(c->rcvrd_mst_node); + c->rcvrd_mst_node = NULL; + return 0; +} + +/** + * is_last_write - determine if an offset was in the last write to a LEB. + * @c: UBIFS file-system description object + * @buf: buffer to check + * @offs: offset to check + * + * This function returns %1 if @offs was in the last write to the LEB whose data + * is in @buf, otherwise %0 is returned. The determination is made by checking + * for subsequent empty space starting from the next @c->max_write_size + * boundary. + */ +static int is_last_write(const struct ubifs_info *c, void *buf, int offs) +{ + int empty_offs, check_len; + uint8_t *p; + + /* + * Round up to the next @c->max_write_size boundary i.e. @offs is in + * the last wbuf written. After that should be empty space. + */ + empty_offs = ALIGN(offs + 1, c->max_write_size); + check_len = c->leb_size - empty_offs; + p = buf + empty_offs - offs; + return is_empty(p, check_len); +} + +/** + * clean_buf - clean the data from an LEB sitting in a buffer. + * @c: UBIFS file-system description object + * @buf: buffer to clean + * @lnum: LEB number to clean + * @offs: offset from which to clean + * @len: length of buffer + * + * This function pads up to the next min_io_size boundary (if there is one) and + * sets empty space to all 0xff. @buf, @offs and @len are updated to the next + * @c->min_io_size boundary. + */ +static void clean_buf(const struct ubifs_info *c, void **buf, int lnum, + int *offs, int *len) +{ + int empty_offs, pad_len; + + dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs); + + ubifs_assert(c, !(*offs & 7)); + empty_offs = ALIGN(*offs, c->min_io_size); + pad_len = empty_offs - *offs; + ubifs_pad(c, *buf, pad_len); + *offs += pad_len; + *buf += pad_len; + *len -= pad_len; + memset(*buf, 0xff, c->leb_size - empty_offs); +} + +/** + * no_more_nodes - determine if there are no more nodes in a buffer. + * @c: UBIFS file-system description object + * @buf: buffer to check + * @len: length of buffer + * @lnum: LEB number of the LEB from which @buf was read + * @offs: offset from which @buf was read + * + * This function ensures that the corrupted node at @offs is the last thing + * written to a LEB. This function returns %1 if more data is not found and + * %0 if more data is found. + */ +static int no_more_nodes(const struct ubifs_info *c, void *buf, int len, + int lnum, int offs) +{ + struct ubifs_ch *ch = buf; + int skip, dlen = le32_to_cpu(ch->len); + + /* Check for empty space after the corrupt node's common header */ + skip = ALIGN(offs + UBIFS_CH_SZ, c->max_write_size) - offs; + if (is_empty(buf + skip, len - skip)) + return 1; + /* + * The area after the common header size is not empty, so the common + * header must be intact. Check it. + */ + if (ubifs_check_node(c, buf, lnum, offs, 1, 0) != -EUCLEAN) { + dbg_rcvry("unexpected bad common header at %d:%d", lnum, offs); + return 0; + } + /* Now we know the corrupt node's length we can skip over it */ + skip = ALIGN(offs + dlen, c->max_write_size) - offs; + /* After which there should be empty space */ + if (is_empty(buf + skip, len - skip)) + return 1; + dbg_rcvry("unexpected data at %d:%d", lnum, offs + skip); + return 0; +} + +/** + * fix_unclean_leb - fix an unclean LEB. + * @c: UBIFS file-system description object + * @sleb: scanned LEB information + * @start: offset where scan started + */ +static int fix_unclean_leb(struct ubifs_info *c, struct ubifs_scan_leb *sleb, + int start) +{ + int lnum = sleb->lnum, endpt = start; + + /* Get the end offset of the last node we are keeping */ + if (!list_empty(&sleb->nodes)) { + struct ubifs_scan_node *snod; + + snod = list_entry(sleb->nodes.prev, + struct ubifs_scan_node, list); + endpt = snod->offs + snod->len; + } + + if (c->ro_mount && !c->remounting_rw) { + /* Add to recovery list */ + struct ubifs_unclean_leb *ucleb; + + dbg_rcvry("need to fix LEB %d start %d endpt %d", + lnum, start, sleb->endpt); + ucleb = kzalloc(sizeof(struct ubifs_unclean_leb), GFP_NOFS); + if (!ucleb) + return -ENOMEM; + ucleb->lnum = lnum; + ucleb->endpt = endpt; + list_add_tail(&ucleb->list, &c->unclean_leb_list); + } else { + /* Write the fixed LEB back to flash */ + int err; + + dbg_rcvry("fixing LEB %d start %d endpt %d", + lnum, start, sleb->endpt); + if (endpt == 0) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } else { + int len = ALIGN(endpt, c->min_io_size); + + if (start) { + err = ubifs_leb_read(c, lnum, sleb->buf, 0, + start, 1); + if (err) + return err; + } + /* Pad to min_io_size */ + if (len > endpt) { + int pad_len = len - ALIGN(endpt, 8); + + if (pad_len > 0) { + void *buf = sleb->buf + len - pad_len; + + ubifs_pad(c, buf, pad_len); + } + } + err = ubifs_leb_change(c, lnum, sleb->buf, len); + if (err) + return err; + } + } + return 0; +} + +/** + * drop_last_group - drop the last group of nodes. + * @sleb: scanned LEB information + * @offs: offset of dropped nodes is returned here + * + * This is a helper function for 'ubifs_recover_leb()' which drops the last + * group of nodes of the scanned LEB. + */ +static void drop_last_group(struct ubifs_scan_leb *sleb, int *offs) +{ + while (!list_empty(&sleb->nodes)) { + struct ubifs_scan_node *snod; + struct ubifs_ch *ch; + + snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, + list); + ch = snod->node; + if (ch->group_type != UBIFS_IN_NODE_GROUP) + break; + + dbg_rcvry("dropping grouped node at %d:%d", + sleb->lnum, snod->offs); + *offs = snod->offs; + list_del(&snod->list); + kfree(snod); + sleb->nodes_cnt -= 1; + } +} + +/** + * drop_last_node - drop the last node. + * @sleb: scanned LEB information + * @offs: offset of dropped nodes is returned here + * + * This is a helper function for 'ubifs_recover_leb()' which drops the last + * node of the scanned LEB. + */ +static void drop_last_node(struct ubifs_scan_leb *sleb, int *offs) +{ + struct ubifs_scan_node *snod; + + if (!list_empty(&sleb->nodes)) { + snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, + list); + + dbg_rcvry("dropping last node at %d:%d", + sleb->lnum, snod->offs); + *offs = snod->offs; + list_del(&snod->list); + kfree(snod); + sleb->nodes_cnt -= 1; + } +} + +/** + * ubifs_recover_leb - scan and recover a LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @offs: offset + * @sbuf: LEB-sized buffer to use + * @jhead: journal head number this LEB belongs to (%-1 if the LEB does not + * belong to any journal head) + * + * This function does a scan of a LEB, but caters for errors that might have + * been caused by the unclean unmount from which we are attempting to recover. + * Returns the scanned information on success and a negative error code on + * failure. + */ +struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, + int offs, void *sbuf, int jhead) +{ + int ret = 0, err, len = c->leb_size - offs, start = offs, min_io_unit; + int grouped = jhead == -1 ? 0 : c->jheads[jhead].grouped; + struct ubifs_scan_leb *sleb; + void *buf = sbuf + offs; + + dbg_rcvry("%d:%d, jhead %d, grouped %d", lnum, offs, jhead, grouped); + + sleb = ubifs_start_scan(c, lnum, offs, sbuf); + if (IS_ERR(sleb)) + return sleb; + + ubifs_assert(c, len >= 8); + while (len >= 8) { + dbg_scan("look at LEB %d:%d (%d bytes left)", + lnum, offs, len); + + cond_resched(); + + /* + * Scan quietly until there is an error from which we cannot + * recover + */ + ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); + if (ret == SCANNED_A_NODE) { + /* A valid node, and not a padding node */ + struct ubifs_ch *ch = buf; + int node_len; + + err = ubifs_add_snod(c, sleb, buf, offs); + if (err) + goto error; + node_len = ALIGN(le32_to_cpu(ch->len), 8); + offs += node_len; + buf += node_len; + len -= node_len; + } else if (ret > 0) { + /* Padding bytes or a valid padding node */ + offs += ret; + buf += ret; + len -= ret; + } else if (ret == SCANNED_EMPTY_SPACE || + ret == SCANNED_GARBAGE || + ret == SCANNED_A_BAD_PAD_NODE || + ret == SCANNED_A_CORRUPT_NODE) { + dbg_rcvry("found corruption (%d) at %d:%d", + ret, lnum, offs); + break; + } else { + ubifs_err(c, "unexpected return value %d", ret); + err = -EINVAL; + goto error; + } + } + + if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE) { + if (!is_last_write(c, buf, offs)) + goto corrupted_rescan; + } else if (ret == SCANNED_A_CORRUPT_NODE) { + if (!no_more_nodes(c, buf, len, lnum, offs)) + goto corrupted_rescan; + } else if (!is_empty(buf, len)) { + if (!is_last_write(c, buf, offs)) { + int corruption = first_non_ff(buf, len); + + /* + * See header comment for this file for more + * explanations about the reasons we have this check. + */ + ubifs_err(c, "corrupt empty space LEB %d:%d, corruption starts at %d", + lnum, offs, corruption); + /* Make sure we dump interesting non-0xFF data */ + offs += corruption; + buf += corruption; + goto corrupted; + } + } + + min_io_unit = round_down(offs, c->min_io_size); + if (grouped) + /* + * If nodes are grouped, always drop the incomplete group at + * the end. + */ + drop_last_group(sleb, &offs); + + if (jhead == GCHD) { + /* + * If this LEB belongs to the GC head then while we are in the + * middle of the same min. I/O unit keep dropping nodes. So + * basically, what we want is to make sure that the last min. + * I/O unit where we saw the corruption is dropped completely + * with all the uncorrupted nodes which may possibly sit there. + * + * In other words, let's name the min. I/O unit where the + * corruption starts B, and the previous min. I/O unit A. The + * below code tries to deal with a situation when half of B + * contains valid nodes or the end of a valid node, and the + * second half of B contains corrupted data or garbage. This + * means that UBIFS had been writing to B just before the power + * cut happened. I do not know how realistic is this scenario + * that half of the min. I/O unit had been written successfully + * and the other half not, but this is possible in our 'failure + * mode emulation' infrastructure at least. + * + * So what is the problem, why we need to drop those nodes? Why + * can't we just clean-up the second half of B by putting a + * padding node there? We can, and this works fine with one + * exception which was reproduced with power cut emulation + * testing and happens extremely rarely. + * + * Imagine the file-system is full, we run GC which starts + * moving valid nodes from LEB X to LEB Y (obviously, LEB Y is + * the current GC head LEB). The @c->gc_lnum is -1, which means + * that GC will retain LEB X and will try to continue. Imagine + * that LEB X is currently the dirtiest LEB, and the amount of + * used space in LEB Y is exactly the same as amount of free + * space in LEB X. + * + * And a power cut happens when nodes are moved from LEB X to + * LEB Y. We are here trying to recover LEB Y which is the GC + * head LEB. We find the min. I/O unit B as described above. + * Then we clean-up LEB Y by padding min. I/O unit. And later + * 'ubifs_rcvry_gc_commit()' function fails, because it cannot + * find a dirty LEB which could be GC'd into LEB Y! Even LEB X + * does not match because the amount of valid nodes there does + * not fit the free space in LEB Y any more! And this is + * because of the padding node which we added to LEB Y. The + * user-visible effect of this which I once observed and + * analysed is that we cannot mount the file-system with + * -ENOSPC error. + * + * So obviously, to make sure that situation does not happen we + * should free min. I/O unit B in LEB Y completely and the last + * used min. I/O unit in LEB Y should be A. This is basically + * what the below code tries to do. + */ + while (offs > min_io_unit) + drop_last_node(sleb, &offs); + } + + buf = sbuf + offs; + len = c->leb_size - offs; + + clean_buf(c, &buf, lnum, &offs, &len); + ubifs_end_scan(c, sleb, lnum, offs); + + err = fix_unclean_leb(c, sleb, start); + if (err) + goto error; + + return sleb; + +corrupted_rescan: + /* Re-scan the corrupted data with verbose messages */ + ubifs_err(c, "corruption %d", ret); + ubifs_scan_a_node(c, buf, len, lnum, offs, 0); +corrupted: + ubifs_scanned_corruption(c, lnum, offs, buf); + err = -EUCLEAN; +error: + ubifs_err(c, "LEB %d scanning failed", lnum); + ubifs_scan_destroy(sleb); + return ERR_PTR(err); +} + +/** + * get_cs_sqnum - get commit start sequence number. + * @c: UBIFS file-system description object + * @lnum: LEB number of commit start node + * @offs: offset of commit start node + * @cs_sqnum: commit start sequence number is returned here + * + * This function returns %0 on success and a negative error code on failure. + */ +static int get_cs_sqnum(struct ubifs_info *c, int lnum, int offs, + unsigned long long *cs_sqnum) +{ + struct ubifs_cs_node *cs_node = NULL; + int err, ret; + + dbg_rcvry("at %d:%d", lnum, offs); + cs_node = kmalloc(UBIFS_CS_NODE_SZ, GFP_KERNEL); + if (!cs_node) + return -ENOMEM; + if (c->leb_size - offs < UBIFS_CS_NODE_SZ) + goto out_err; + err = ubifs_leb_read(c, lnum, (void *)cs_node, offs, + UBIFS_CS_NODE_SZ, 0); + if (err && err != -EBADMSG) + goto out_free; + ret = ubifs_scan_a_node(c, cs_node, UBIFS_CS_NODE_SZ, lnum, offs, 0); + if (ret != SCANNED_A_NODE) { + ubifs_err(c, "Not a valid node"); + goto out_err; + } + if (cs_node->ch.node_type != UBIFS_CS_NODE) { + ubifs_err(c, "Not a CS node, type is %d", cs_node->ch.node_type); + goto out_err; + } + if (le64_to_cpu(cs_node->cmt_no) != c->cmt_no) { + ubifs_err(c, "CS node cmt_no %llu != current cmt_no %llu", + (unsigned long long)le64_to_cpu(cs_node->cmt_no), + c->cmt_no); + goto out_err; + } + *cs_sqnum = le64_to_cpu(cs_node->ch.sqnum); + dbg_rcvry("commit start sqnum %llu", *cs_sqnum); + kfree(cs_node); + return 0; + +out_err: + err = -EINVAL; +out_free: + ubifs_err(c, "failed to get CS sqnum"); + kfree(cs_node); + return err; +} + +/** + * ubifs_recover_log_leb - scan and recover a log LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @offs: offset + * @sbuf: LEB-sized buffer to use + * + * This function does a scan of a LEB, but caters for errors that might have + * been caused by unclean reboots from which we are attempting to recover + * (assume that only the last log LEB can be corrupted by an unclean reboot). + * + * This function returns %0 on success and a negative error code on failure. + */ +struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum, + int offs, void *sbuf) +{ + struct ubifs_scan_leb *sleb; + int next_lnum; + + dbg_rcvry("LEB %d", lnum); + next_lnum = lnum + 1; + if (next_lnum >= UBIFS_LOG_LNUM + c->log_lebs) + next_lnum = UBIFS_LOG_LNUM; + if (next_lnum != c->ltail_lnum) { + /* + * We can only recover at the end of the log, so check that the + * next log LEB is empty or out of date. + */ + sleb = ubifs_scan(c, next_lnum, 0, sbuf, 0); + if (IS_ERR(sleb)) + return sleb; + if (sleb->nodes_cnt) { + struct ubifs_scan_node *snod; + unsigned long long cs_sqnum = c->cs_sqnum; + + snod = list_entry(sleb->nodes.next, + struct ubifs_scan_node, list); + if (cs_sqnum == 0) { + int err; + + err = get_cs_sqnum(c, lnum, offs, &cs_sqnum); + if (err) { + ubifs_scan_destroy(sleb); + return ERR_PTR(err); + } + } + if (snod->sqnum > cs_sqnum) { + ubifs_err(c, "unrecoverable log corruption in LEB %d", + lnum); + ubifs_scan_destroy(sleb); + return ERR_PTR(-EUCLEAN); + } + } + ubifs_scan_destroy(sleb); + } + return ubifs_recover_leb(c, lnum, offs, sbuf, -1); +} + +/** + * recover_head - recover a head. + * @c: UBIFS file-system description object + * @lnum: LEB number of head to recover + * @offs: offset of head to recover + * @sbuf: LEB-sized buffer to use + * + * This function ensures that there is no data on the flash at a head location. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int recover_head(struct ubifs_info *c, int lnum, int offs, void *sbuf) +{ + int len = c->max_write_size, err; + + if (offs + len > c->leb_size) + len = c->leb_size - offs; + + if (!len) + return 0; + + /* Read at the head location and check it is empty flash */ + err = ubifs_leb_read(c, lnum, sbuf, offs, len, 1); + if (err || !is_empty(sbuf, len)) { + dbg_rcvry("cleaning head at %d:%d", lnum, offs); + if (offs == 0) + return ubifs_leb_unmap(c, lnum); + err = ubifs_leb_read(c, lnum, sbuf, 0, offs, 1); + if (err) + return err; + return ubifs_leb_change(c, lnum, sbuf, offs); + } + + return 0; +} + +/** + * ubifs_recover_inl_heads - recover index and LPT heads. + * @c: UBIFS file-system description object + * @sbuf: LEB-sized buffer to use + * + * This function ensures that there is no data on the flash at the index and + * LPT head locations. + * + * This deals with the recovery of a half-completed journal commit. UBIFS is + * careful never to overwrite the last version of the index or the LPT. Because + * the index and LPT are wandering trees, data from a half-completed commit will + * not be referenced anywhere in UBIFS. The data will be either in LEBs that are + * assumed to be empty and will be unmapped anyway before use, or in the index + * and LPT heads. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_recover_inl_heads(struct ubifs_info *c, void *sbuf) +{ + int err; + + ubifs_assert(c, !c->ro_mount || c->remounting_rw); + + dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs); + err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf); + if (err) + return err; + + dbg_rcvry("checking LPT head at %d:%d", c->nhead_lnum, c->nhead_offs); + + return recover_head(c, c->nhead_lnum, c->nhead_offs, sbuf); +} + +/** + * clean_an_unclean_leb - read and write a LEB to remove corruption. + * @c: UBIFS file-system description object + * @ucleb: unclean LEB information + * @sbuf: LEB-sized buffer to use + * + * This function reads a LEB up to a point pre-determined by the mount recovery, + * checks the nodes, and writes the result back to the flash, thereby cleaning + * off any following corruption, or non-fatal ECC errors. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int clean_an_unclean_leb(struct ubifs_info *c, + struct ubifs_unclean_leb *ucleb, void *sbuf) +{ + int err, lnum = ucleb->lnum, offs = 0, len = ucleb->endpt, quiet = 1; + void *buf = sbuf; + + dbg_rcvry("LEB %d len %d", lnum, len); + + if (len == 0) { + /* Nothing to read, just unmap it */ + return ubifs_leb_unmap(c, lnum); + } + + err = ubifs_leb_read(c, lnum, buf, offs, len, 0); + if (err && err != -EBADMSG) + return err; + + while (len >= 8) { + int ret; + + cond_resched(); + + /* Scan quietly until there is an error */ + ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet); + + if (ret == SCANNED_A_NODE) { + /* A valid node, and not a padding node */ + struct ubifs_ch *ch = buf; + int node_len; + + node_len = ALIGN(le32_to_cpu(ch->len), 8); + offs += node_len; + buf += node_len; + len -= node_len; + continue; + } + + if (ret > 0) { + /* Padding bytes or a valid padding node */ + offs += ret; + buf += ret; + len -= ret; + continue; + } + + if (ret == SCANNED_EMPTY_SPACE) { + ubifs_err(c, "unexpected empty space at %d:%d", + lnum, offs); + return -EUCLEAN; + } + + if (quiet) { + /* Redo the last scan but noisily */ + quiet = 0; + continue; + } + + ubifs_scanned_corruption(c, lnum, offs, buf); + return -EUCLEAN; + } + + /* Pad to min_io_size */ + len = ALIGN(ucleb->endpt, c->min_io_size); + if (len > ucleb->endpt) { + int pad_len = len - ALIGN(ucleb->endpt, 8); + + if (pad_len > 0) { + buf = c->sbuf + len - pad_len; + ubifs_pad(c, buf, pad_len); + } + } + + /* Write back the LEB atomically */ + err = ubifs_leb_change(c, lnum, sbuf, len); + if (err) + return err; + + dbg_rcvry("cleaned LEB %d", lnum); + + return 0; +} + +/** + * ubifs_clean_lebs - clean LEBs recovered during read-only mount. + * @c: UBIFS file-system description object + * @sbuf: LEB-sized buffer to use + * + * This function cleans a LEB identified during recovery that needs to be + * written but was not because UBIFS was mounted read-only. This happens when + * remounting to read-write mode. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_clean_lebs(struct ubifs_info *c, void *sbuf) +{ + dbg_rcvry("recovery"); + while (!list_empty(&c->unclean_leb_list)) { + struct ubifs_unclean_leb *ucleb; + int err; + + ucleb = list_entry(c->unclean_leb_list.next, + struct ubifs_unclean_leb, list); + err = clean_an_unclean_leb(c, ucleb, sbuf); + if (err) + return err; + list_del(&ucleb->list); + kfree(ucleb); + } + return 0; +} + +/** + * grab_empty_leb - grab an empty LEB to use as GC LEB and run commit. + * @c: UBIFS file-system description object + * + * This is a helper function for 'ubifs_rcvry_gc_commit()' which grabs an empty + * LEB to be used as GC LEB (@c->gc_lnum), and then runs the commit. Returns + * zero in case of success and a negative error code in case of failure. + */ +static int grab_empty_leb(struct ubifs_info *c) +{ + int lnum, err; + + /* + * Note, it is very important to first search for an empty LEB and then + * run the commit, not vice-versa. The reason is that there might be + * only one empty LEB at the moment, the one which has been the + * @c->gc_lnum just before the power cut happened. During the regular + * UBIFS operation (not now) @c->gc_lnum is marked as "taken", so no + * one but GC can grab it. But at this moment this single empty LEB is + * not marked as taken, so if we run commit - what happens? Right, the + * commit will grab it and write the index there. Remember that the + * index always expands as long as there is free space, and it only + * starts consolidating when we run out of space. + * + * IOW, if we run commit now, we might not be able to find a free LEB + * after this. + */ + lnum = ubifs_find_free_leb_for_idx(c); + if (lnum < 0) { + ubifs_err(c, "could not find an empty LEB"); + ubifs_dump_lprops(c); + ubifs_dump_budg(c, &c->bi); + return lnum; + } + + /* Reset the index flag */ + err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_INDEX, 0); + if (err) + return err; + + c->gc_lnum = lnum; + dbg_rcvry("found empty LEB %d, run commit", lnum); + + return ubifs_run_commit(c); +} + +/** + * ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit. + * @c: UBIFS file-system description object + * + * Out-of-place garbage collection requires always one empty LEB with which to + * start garbage collection. The LEB number is recorded in c->gc_lnum and is + * written to the master node on unmounting. In the case of an unclean unmount + * the value of gc_lnum recorded in the master node is out of date and cannot + * be used. Instead, recovery must allocate an empty LEB for this purpose. + * However, there may not be enough empty space, in which case it must be + * possible to GC the dirtiest LEB into the GC head LEB. + * + * This function also runs the commit which causes the TNC updates from + * size-recovery and orphans to be written to the flash. That is important to + * ensure correct replay order for subsequent mounts. + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_rcvry_gc_commit(struct ubifs_info *c) +{ + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; + struct ubifs_lprops lp; + int err; + + dbg_rcvry("GC head LEB %d, offs %d", wbuf->lnum, wbuf->offs); + + c->gc_lnum = -1; + if (wbuf->lnum == -1 || wbuf->offs == c->leb_size) + return grab_empty_leb(c); + + err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2); + if (err) { + if (err != -ENOSPC) + return err; + + dbg_rcvry("could not find a dirty LEB"); + return grab_empty_leb(c); + } + + ubifs_assert(c, !(lp.flags & LPROPS_INDEX)); + ubifs_assert(c, lp.free + lp.dirty >= wbuf->offs); + + /* + * We run the commit before garbage collection otherwise subsequent + * mounts will see the GC and orphan deletion in a different order. + */ + dbg_rcvry("committing"); + err = ubifs_run_commit(c); + if (err) + return err; + + dbg_rcvry("GC'ing LEB %d", lp.lnum); + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + err = ubifs_garbage_collect_leb(c, &lp); + if (err >= 0) { + int err2 = ubifs_wbuf_sync_nolock(wbuf); + + if (err2) + err = err2; + } + mutex_unlock(&wbuf->io_mutex); + if (err < 0) { + ubifs_err(c, "GC failed, error %d", err); + if (err == -EAGAIN) + err = -EINVAL; + return err; + } + + ubifs_assert(c, err == LEB_RETAINED); + if (err != LEB_RETAINED) + return -EINVAL; + + err = ubifs_leb_unmap(c, c->gc_lnum); + if (err) + return err; + + dbg_rcvry("allocated LEB %d for GC", lp.lnum); + return 0; +} + +/** + * struct size_entry - inode size information for recovery. + * @rb: link in the RB-tree of sizes + * @inum: inode number + * @i_size: size on inode + * @d_size: maximum size based on data nodes + * @exists: indicates whether the inode exists + * @inode: inode if pinned in memory awaiting rw mode to fix it + */ +struct size_entry { + struct rb_node rb; + ino_t inum; + loff_t i_size; + loff_t d_size; + int exists; + struct inode *inode; +}; + +/** + * add_ino - add an entry to the size tree. + * @c: UBIFS file-system description object + * @inum: inode number + * @i_size: size on inode + * @d_size: maximum size based on data nodes + * @exists: indicates whether the inode exists + */ +static int add_ino(struct ubifs_info *c, ino_t inum, loff_t i_size, + loff_t d_size, int exists) +{ + struct rb_node **p = &c->size_tree.rb_node, *parent = NULL; + struct size_entry *e; + + while (*p) { + parent = *p; + e = rb_entry(parent, struct size_entry, rb); + if (inum < e->inum) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + + e = kzalloc(sizeof(struct size_entry), GFP_KERNEL); + if (!e) + return -ENOMEM; + + e->inum = inum; + e->i_size = i_size; + e->d_size = d_size; + e->exists = exists; + + rb_link_node(&e->rb, parent, p); + rb_insert_color(&e->rb, &c->size_tree); + + return 0; +} + +/** + * find_ino - find an entry on the size tree. + * @c: UBIFS file-system description object + * @inum: inode number + */ +static struct size_entry *find_ino(struct ubifs_info *c, ino_t inum) +{ + struct rb_node *p = c->size_tree.rb_node; + struct size_entry *e; + + while (p) { + e = rb_entry(p, struct size_entry, rb); + if (inum < e->inum) + p = p->rb_left; + else if (inum > e->inum) + p = p->rb_right; + else + return e; + } + return NULL; +} + +/** + * remove_ino - remove an entry from the size tree. + * @c: UBIFS file-system description object + * @inum: inode number + */ +static void remove_ino(struct ubifs_info *c, ino_t inum) +{ + struct size_entry *e = find_ino(c, inum); + + if (!e) + return; + rb_erase(&e->rb, &c->size_tree); + kfree(e); +} + +/** + * ubifs_destroy_size_tree - free resources related to the size tree. + * @c: UBIFS file-system description object + */ +void ubifs_destroy_size_tree(struct ubifs_info *c) +{ + struct size_entry *e, *n; + + rbtree_postorder_for_each_entry_safe(e, n, &c->size_tree, rb) { + iput(e->inode); + kfree(e); + } + + c->size_tree = RB_ROOT; +} + +/** + * ubifs_recover_size_accum - accumulate inode sizes for recovery. + * @c: UBIFS file-system description object + * @key: node key + * @deletion: node is for a deletion + * @new_size: inode size + * + * This function has two purposes: + * 1) to ensure there are no data nodes that fall outside the inode size + * 2) to ensure there are no data nodes for inodes that do not exist + * To accomplish those purposes, a rb-tree is constructed containing an entry + * for each inode number in the journal that has not been deleted, and recording + * the size from the inode node, the maximum size of any data node (also altered + * by truncations) and a flag indicating a inode number for which no inode node + * was present in the journal. + * + * Note that there is still the possibility that there are data nodes that have + * been committed that are beyond the inode size, however the only way to find + * them would be to scan the entire index. Alternatively, some provision could + * be made to record the size of inodes at the start of commit, which would seem + * very cumbersome for a scenario that is quite unlikely and the only negative + * consequence of which is wasted space. + * + * This functions returns %0 on success and a negative error code on failure. + */ +int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key, + int deletion, loff_t new_size) +{ + ino_t inum = key_inum(c, key); + struct size_entry *e; + int err; + + switch (key_type(c, key)) { + case UBIFS_INO_KEY: + if (deletion) + remove_ino(c, inum); + else { + e = find_ino(c, inum); + if (e) { + e->i_size = new_size; + e->exists = 1; + } else { + err = add_ino(c, inum, new_size, 0, 1); + if (err) + return err; + } + } + break; + case UBIFS_DATA_KEY: + e = find_ino(c, inum); + if (e) { + if (new_size > e->d_size) + e->d_size = new_size; + } else { + err = add_ino(c, inum, 0, new_size, 0); + if (err) + return err; + } + break; + case UBIFS_TRUN_KEY: + e = find_ino(c, inum); + if (e) + e->d_size = new_size; + break; + } + return 0; +} + +/** + * fix_size_in_place - fix inode size in place on flash. + * @c: UBIFS file-system description object + * @e: inode size information for recovery + */ +static int fix_size_in_place(struct ubifs_info *c, struct size_entry *e) +{ + struct ubifs_ino_node *ino = c->sbuf; + unsigned char *p; + union ubifs_key key; + int err, lnum, offs, len; + loff_t i_size; + uint32_t crc; + + /* Locate the inode node LEB number and offset */ + ino_key_init(c, &key, e->inum); + err = ubifs_tnc_locate(c, &key, ino, &lnum, &offs); + if (err) + goto out; + /* + * If the size recorded on the inode node is greater than the size that + * was calculated from nodes in the journal then don't change the inode. + */ + i_size = le64_to_cpu(ino->size); + if (i_size >= e->d_size) + return 0; + /* Read the LEB */ + err = ubifs_leb_read(c, lnum, c->sbuf, 0, c->leb_size, 1); + if (err) + goto out; + /* Change the size field and recalculate the CRC */ + ino = c->sbuf + offs; + ino->size = cpu_to_le64(e->d_size); + len = le32_to_cpu(ino->ch.len); + crc = crc32(UBIFS_CRC32_INIT, (void *)ino + 8, len - 8); + ino->ch.crc = cpu_to_le32(crc); + /* Work out where data in the LEB ends and free space begins */ + p = c->sbuf; + len = c->leb_size - 1; + while (p[len] == 0xff) + len -= 1; + len = ALIGN(len + 1, c->min_io_size); + /* Atomically write the fixed LEB back again */ + err = ubifs_leb_change(c, lnum, c->sbuf, len); + if (err) + goto out; + dbg_rcvry("inode %lu at %d:%d size %lld -> %lld", + (unsigned long)e->inum, lnum, offs, i_size, e->d_size); + return 0; + +out: + ubifs_warn(c, "inode %lu failed to fix size %lld -> %lld error %d", + (unsigned long)e->inum, e->i_size, e->d_size, err); + return err; +} + +/** + * inode_fix_size - fix inode size + * @c: UBIFS file-system description object + * @e: inode size information for recovery + */ +static int inode_fix_size(struct ubifs_info *c, struct size_entry *e) +{ + struct inode *inode; + struct ubifs_inode *ui; + int err; + + if (c->ro_mount) + ubifs_assert(c, !e->inode); + + if (e->inode) { + /* Remounting rw, pick up inode we stored earlier */ + inode = e->inode; + } else { + inode = ubifs_iget(c->vfs_sb, e->inum); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + if (inode->i_size >= e->d_size) { + /* + * The original inode in the index already has a size + * big enough, nothing to do + */ + iput(inode); + return 0; + } + + dbg_rcvry("ino %lu size %lld -> %lld", + (unsigned long)e->inum, + inode->i_size, e->d_size); + + ui = ubifs_inode(inode); + + inode->i_size = e->d_size; + ui->ui_size = e->d_size; + ui->synced_i_size = e->d_size; + + e->inode = inode; + } + + /* + * In readonly mode just keep the inode pinned in memory until we go + * readwrite. In readwrite mode write the inode to the journal with the + * fixed size. + */ + if (c->ro_mount) + return 0; + + err = ubifs_jnl_write_inode(c, inode); + + iput(inode); + + if (err) + return err; + + rb_erase(&e->rb, &c->size_tree); + kfree(e); + + return 0; +} + +/** + * ubifs_recover_size - recover inode size. + * @c: UBIFS file-system description object + * @in_place: If true, do a in-place size fixup + * + * This function attempts to fix inode size discrepancies identified by the + * 'ubifs_recover_size_accum()' function. + * + * This functions returns %0 on success and a negative error code on failure. + */ +int ubifs_recover_size(struct ubifs_info *c, bool in_place) +{ + struct rb_node *this = rb_first(&c->size_tree); + + while (this) { + struct size_entry *e; + int err; + + e = rb_entry(this, struct size_entry, rb); + + this = rb_next(this); + + if (!e->exists) { + union ubifs_key key; + + ino_key_init(c, &key, e->inum); + err = ubifs_tnc_lookup(c, &key, c->sbuf); + if (err && err != -ENOENT) + return err; + if (err == -ENOENT) { + /* Remove data nodes that have no inode */ + dbg_rcvry("removing ino %lu", + (unsigned long)e->inum); + err = ubifs_tnc_remove_ino(c, e->inum); + if (err) + return err; + } else { + struct ubifs_ino_node *ino = c->sbuf; + + e->exists = 1; + e->i_size = le64_to_cpu(ino->size); + } + } + + if (e->exists && e->i_size < e->d_size) { + ubifs_assert(c, !(c->ro_mount && in_place)); + + /* + * We found data that is outside the found inode size, + * fixup the inode size + */ + + if (in_place) { + err = fix_size_in_place(c, e); + if (err) + return err; + iput(e->inode); + } else { + err = inode_fix_size(c, e); + if (err) + return err; + continue; + } + } + + rb_erase(&e->rb, &c->size_tree); + kfree(e); + } + + return 0; +} diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c new file mode 100644 index 000000000..b2f5563d1 --- /dev/null +++ b/fs/ubifs/replay.c @@ -0,0 +1,1251 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file contains journal replay code. It runs when the file-system is being + * mounted and requires no locking. + * + * The larger is the journal, the longer it takes to scan it, so the longer it + * takes to mount UBIFS. This is why the journal has limited size which may be + * changed depending on the system requirements. But a larger journal gives + * faster I/O speed because it writes the index less frequently. So this is a + * trade-off. Also, the journal is indexed by the in-memory index (TNC), so the + * larger is the journal, the more memory its index may consume. + */ + +#include "ubifs.h" +#include <linux/list_sort.h> +#include <crypto/hash.h> +#include <crypto/algapi.h> + +/** + * struct replay_entry - replay list entry. + * @lnum: logical eraseblock number of the node + * @offs: node offset + * @len: node length + * @deletion: non-zero if this entry corresponds to a node deletion + * @sqnum: node sequence number + * @list: links the replay list + * @key: node key + * @nm: directory entry name + * @old_size: truncation old size + * @new_size: truncation new size + * + * The replay process first scans all buds and builds the replay list, then + * sorts the replay list in nodes sequence number order, and then inserts all + * the replay entries to the TNC. + */ +struct replay_entry { + int lnum; + int offs; + int len; + u8 hash[UBIFS_HASH_ARR_SZ]; + unsigned int deletion:1; + unsigned long long sqnum; + struct list_head list; + union ubifs_key key; + union { + struct fscrypt_name nm; + struct { + loff_t old_size; + loff_t new_size; + }; + }; +}; + +/** + * struct bud_entry - entry in the list of buds to replay. + * @list: next bud in the list + * @bud: bud description object + * @sqnum: reference node sequence number + * @free: free bytes in the bud + * @dirty: dirty bytes in the bud + */ +struct bud_entry { + struct list_head list; + struct ubifs_bud *bud; + unsigned long long sqnum; + int free; + int dirty; +}; + +/** + * set_bud_lprops - set free and dirty space used by a bud. + * @c: UBIFS file-system description object + * @b: bud entry which describes the bud + * + * This function makes sure the LEB properties of bud @b are set correctly + * after the replay. Returns zero in case of success and a negative error code + * in case of failure. + */ +static int set_bud_lprops(struct ubifs_info *c, struct bud_entry *b) +{ + const struct ubifs_lprops *lp; + int err = 0, dirty; + + ubifs_get_lprops(c); + + lp = ubifs_lpt_lookup_dirty(c, b->bud->lnum); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + dirty = lp->dirty; + if (b->bud->start == 0 && (lp->free != c->leb_size || lp->dirty != 0)) { + /* + * The LEB was added to the journal with a starting offset of + * zero which means the LEB must have been empty. The LEB + * property values should be @lp->free == @c->leb_size and + * @lp->dirty == 0, but that is not the case. The reason is that + * the LEB had been garbage collected before it became the bud, + * and there was not commit inbetween. The garbage collector + * resets the free and dirty space without recording it + * anywhere except lprops, so if there was no commit then + * lprops does not have that information. + * + * We do not need to adjust free space because the scan has told + * us the exact value which is recorded in the replay entry as + * @b->free. + * + * However we do need to subtract from the dirty space the + * amount of space that the garbage collector reclaimed, which + * is the whole LEB minus the amount of space that was free. + */ + dbg_mnt("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum, + lp->free, lp->dirty); + dbg_gc("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum, + lp->free, lp->dirty); + dirty -= c->leb_size - lp->free; + /* + * If the replay order was perfect the dirty space would now be + * zero. The order is not perfect because the journal heads + * race with each other. This is not a problem but is does mean + * that the dirty space may temporarily exceed c->leb_size + * during the replay. + */ + if (dirty != 0) + dbg_mnt("LEB %d lp: %d free %d dirty replay: %d free %d dirty", + b->bud->lnum, lp->free, lp->dirty, b->free, + b->dirty); + } + lp = ubifs_change_lp(c, lp, b->free, dirty + b->dirty, + lp->flags | LPROPS_TAKEN, 0); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + /* Make sure the journal head points to the latest bud */ + err = ubifs_wbuf_seek_nolock(&c->jheads[b->bud->jhead].wbuf, + b->bud->lnum, c->leb_size - b->free); + +out: + ubifs_release_lprops(c); + return err; +} + +/** + * set_buds_lprops - set free and dirty space for all replayed buds. + * @c: UBIFS file-system description object + * + * This function sets LEB properties for all replayed buds. Returns zero in + * case of success and a negative error code in case of failure. + */ +static int set_buds_lprops(struct ubifs_info *c) +{ + struct bud_entry *b; + int err; + + list_for_each_entry(b, &c->replay_buds, list) { + err = set_bud_lprops(c, b); + if (err) + return err; + } + + return 0; +} + +/** + * trun_remove_range - apply a replay entry for a truncation to the TNC. + * @c: UBIFS file-system description object + * @r: replay entry of truncation + */ +static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r) +{ + unsigned min_blk, max_blk; + union ubifs_key min_key, max_key; + ino_t ino; + + min_blk = r->new_size / UBIFS_BLOCK_SIZE; + if (r->new_size & (UBIFS_BLOCK_SIZE - 1)) + min_blk += 1; + + max_blk = r->old_size / UBIFS_BLOCK_SIZE; + if ((r->old_size & (UBIFS_BLOCK_SIZE - 1)) == 0) + max_blk -= 1; + + ino = key_inum(c, &r->key); + + data_key_init(c, &min_key, ino, min_blk); + data_key_init(c, &max_key, ino, max_blk); + + return ubifs_tnc_remove_range(c, &min_key, &max_key); +} + +/** + * inode_still_linked - check whether inode in question will be re-linked. + * @c: UBIFS file-system description object + * @rino: replay entry to test + * + * O_TMPFILE files can be re-linked, this means link count goes from 0 to 1. + * This case needs special care, otherwise all references to the inode will + * be removed upon the first replay entry of an inode with link count 0 + * is found. + */ +static bool inode_still_linked(struct ubifs_info *c, struct replay_entry *rino) +{ + struct replay_entry *r; + + ubifs_assert(c, rino->deletion); + ubifs_assert(c, key_type(c, &rino->key) == UBIFS_INO_KEY); + + /* + * Find the most recent entry for the inode behind @rino and check + * whether it is a deletion. + */ + list_for_each_entry_reverse(r, &c->replay_list, list) { + ubifs_assert(c, r->sqnum >= rino->sqnum); + if (key_inum(c, &r->key) == key_inum(c, &rino->key) && + key_type(c, &r->key) == UBIFS_INO_KEY) + return r->deletion == 0; + + } + + ubifs_assert(c, 0); + return false; +} + +/** + * apply_replay_entry - apply a replay entry to the TNC. + * @c: UBIFS file-system description object + * @r: replay entry to apply + * + * Apply a replay entry to the TNC. + */ +static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r) +{ + int err; + + dbg_mntk(&r->key, "LEB %d:%d len %d deletion %d sqnum %llu key ", + r->lnum, r->offs, r->len, r->deletion, r->sqnum); + + if (is_hash_key(c, &r->key)) { + if (r->deletion) + err = ubifs_tnc_remove_nm(c, &r->key, &r->nm); + else + err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs, + r->len, r->hash, &r->nm); + } else { + if (r->deletion) + switch (key_type(c, &r->key)) { + case UBIFS_INO_KEY: + { + ino_t inum = key_inum(c, &r->key); + + if (inode_still_linked(c, r)) { + err = 0; + break; + } + + err = ubifs_tnc_remove_ino(c, inum); + break; + } + case UBIFS_TRUN_KEY: + err = trun_remove_range(c, r); + break; + default: + err = ubifs_tnc_remove(c, &r->key); + break; + } + else + err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs, + r->len, r->hash); + if (err) + return err; + + if (c->need_recovery) + err = ubifs_recover_size_accum(c, &r->key, r->deletion, + r->new_size); + } + + return err; +} + +/** + * replay_entries_cmp - compare 2 replay entries. + * @priv: UBIFS file-system description object + * @a: first replay entry + * @b: second replay entry + * + * This is a comparios function for 'list_sort()' which compares 2 replay + * entries @a and @b by comparing their sequence numer. Returns %1 if @a has + * greater sequence number and %-1 otherwise. + */ +static int replay_entries_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + struct ubifs_info *c = priv; + struct replay_entry *ra, *rb; + + cond_resched(); + if (a == b) + return 0; + + ra = list_entry(a, struct replay_entry, list); + rb = list_entry(b, struct replay_entry, list); + ubifs_assert(c, ra->sqnum != rb->sqnum); + if (ra->sqnum > rb->sqnum) + return 1; + return -1; +} + +/** + * apply_replay_list - apply the replay list to the TNC. + * @c: UBIFS file-system description object + * + * Apply all entries in the replay list to the TNC. Returns zero in case of + * success and a negative error code in case of failure. + */ +static int apply_replay_list(struct ubifs_info *c) +{ + struct replay_entry *r; + int err; + + list_sort(c, &c->replay_list, &replay_entries_cmp); + + list_for_each_entry(r, &c->replay_list, list) { + cond_resched(); + + err = apply_replay_entry(c, r); + if (err) + return err; + } + + return 0; +} + +/** + * destroy_replay_list - destroy the replay. + * @c: UBIFS file-system description object + * + * Destroy the replay list. + */ +static void destroy_replay_list(struct ubifs_info *c) +{ + struct replay_entry *r, *tmp; + + list_for_each_entry_safe(r, tmp, &c->replay_list, list) { + if (is_hash_key(c, &r->key)) + kfree(fname_name(&r->nm)); + list_del(&r->list); + kfree(r); + } +} + +/** + * insert_node - insert a node to the replay list + * @c: UBIFS file-system description object + * @lnum: node logical eraseblock number + * @offs: node offset + * @len: node length + * @key: node key + * @sqnum: sequence number + * @deletion: non-zero if this is a deletion + * @used: number of bytes in use in a LEB + * @old_size: truncation old size + * @new_size: truncation new size + * + * This function inserts a scanned non-direntry node to the replay list. The + * replay list contains @struct replay_entry elements, and we sort this list in + * sequence number order before applying it. The replay list is applied at the + * very end of the replay process. Since the list is sorted in sequence number + * order, the older modifications are applied first. This function returns zero + * in case of success and a negative error code in case of failure. + */ +static int insert_node(struct ubifs_info *c, int lnum, int offs, int len, + const u8 *hash, union ubifs_key *key, + unsigned long long sqnum, int deletion, int *used, + loff_t old_size, loff_t new_size) +{ + struct replay_entry *r; + + dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs); + + if (key_inum(c, key) >= c->highest_inum) + c->highest_inum = key_inum(c, key); + + r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL); + if (!r) + return -ENOMEM; + + if (!deletion) + *used += ALIGN(len, 8); + r->lnum = lnum; + r->offs = offs; + r->len = len; + ubifs_copy_hash(c, hash, r->hash); + r->deletion = !!deletion; + r->sqnum = sqnum; + key_copy(c, key, &r->key); + r->old_size = old_size; + r->new_size = new_size; + + list_add_tail(&r->list, &c->replay_list); + return 0; +} + +/** + * insert_dent - insert a directory entry node into the replay list. + * @c: UBIFS file-system description object + * @lnum: node logical eraseblock number + * @offs: node offset + * @len: node length + * @key: node key + * @name: directory entry name + * @nlen: directory entry name length + * @sqnum: sequence number + * @deletion: non-zero if this is a deletion + * @used: number of bytes in use in a LEB + * + * This function inserts a scanned directory entry node or an extended + * attribute entry to the replay list. Returns zero in case of success and a + * negative error code in case of failure. + */ +static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len, + const u8 *hash, union ubifs_key *key, + const char *name, int nlen, unsigned long long sqnum, + int deletion, int *used) +{ + struct replay_entry *r; + char *nbuf; + + dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs); + if (key_inum(c, key) >= c->highest_inum) + c->highest_inum = key_inum(c, key); + + r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL); + if (!r) + return -ENOMEM; + + nbuf = kmalloc(nlen + 1, GFP_KERNEL); + if (!nbuf) { + kfree(r); + return -ENOMEM; + } + + if (!deletion) + *used += ALIGN(len, 8); + r->lnum = lnum; + r->offs = offs; + r->len = len; + ubifs_copy_hash(c, hash, r->hash); + r->deletion = !!deletion; + r->sqnum = sqnum; + key_copy(c, key, &r->key); + fname_len(&r->nm) = nlen; + memcpy(nbuf, name, nlen); + nbuf[nlen] = '\0'; + fname_name(&r->nm) = nbuf; + + list_add_tail(&r->list, &c->replay_list); + return 0; +} + +/** + * ubifs_validate_entry - validate directory or extended attribute entry node. + * @c: UBIFS file-system description object + * @dent: the node to validate + * + * This function validates directory or extended attribute entry node @dent. + * Returns zero if the node is all right and a %-EINVAL if not. + */ +int ubifs_validate_entry(struct ubifs_info *c, + const struct ubifs_dent_node *dent) +{ + int key_type = key_type_flash(c, dent->key); + int nlen = le16_to_cpu(dent->nlen); + + if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 || + dent->type >= UBIFS_ITYPES_CNT || + nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 || + (key_type == UBIFS_XENT_KEY && strnlen(dent->name, nlen) != nlen) || + le64_to_cpu(dent->inum) > MAX_INUM) { + ubifs_err(c, "bad %s node", key_type == UBIFS_DENT_KEY ? + "directory entry" : "extended attribute entry"); + return -EINVAL; + } + + if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) { + ubifs_err(c, "bad key type %d", key_type); + return -EINVAL; + } + + return 0; +} + +/** + * is_last_bud - check if the bud is the last in the journal head. + * @c: UBIFS file-system description object + * @bud: bud description object + * + * This function checks if bud @bud is the last bud in its journal head. This + * information is then used by 'replay_bud()' to decide whether the bud can + * have corruptions or not. Indeed, only last buds can be corrupted by power + * cuts. Returns %1 if this is the last bud, and %0 if not. + */ +static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud) +{ + struct ubifs_jhead *jh = &c->jheads[bud->jhead]; + struct ubifs_bud *next; + uint32_t data; + int err; + + if (list_is_last(&bud->list, &jh->buds_list)) + return 1; + + /* + * The following is a quirk to make sure we work correctly with UBIFS + * images used with older UBIFS. + * + * Normally, the last bud will be the last in the journal head's list + * of bud. However, there is one exception if the UBIFS image belongs + * to older UBIFS. This is fairly unlikely: one would need to use old + * UBIFS, then have a power cut exactly at the right point, and then + * try to mount this image with new UBIFS. + * + * The exception is: it is possible to have 2 buds A and B, A goes + * before B, and B is the last, bud B is contains no data, and bud A is + * corrupted at the end. The reason is that in older versions when the + * journal code switched the next bud (from A to B), it first added a + * log reference node for the new bud (B), and only after this it + * synchronized the write-buffer of current bud (A). But later this was + * changed and UBIFS started to always synchronize the write-buffer of + * the bud (A) before writing the log reference for the new bud (B). + * + * But because older UBIFS always synchronized A's write-buffer before + * writing to B, we can recognize this exceptional situation but + * checking the contents of bud B - if it is empty, then A can be + * treated as the last and we can recover it. + * + * TODO: remove this piece of code in a couple of years (today it is + * 16.05.2011). + */ + next = list_entry(bud->list.next, struct ubifs_bud, list); + if (!list_is_last(&next->list, &jh->buds_list)) + return 0; + + err = ubifs_leb_read(c, next->lnum, (char *)&data, next->start, 4, 1); + if (err) + return 0; + + return data == 0xFFFFFFFF; +} + +/* authenticate_sleb_hash is split out for stack usage */ +static int noinline_for_stack +authenticate_sleb_hash(struct ubifs_info *c, + struct shash_desc *log_hash, u8 *hash) +{ + SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm); + + hash_desc->tfm = c->hash_tfm; + + ubifs_shash_copy_state(c, log_hash, hash_desc); + return crypto_shash_final(hash_desc, hash); +} + +/** + * authenticate_sleb - authenticate one scan LEB + * @c: UBIFS file-system description object + * @sleb: the scan LEB to authenticate + * @log_hash: + * @is_last: if true, this is is the last LEB + * + * This function iterates over the buds of a single LEB authenticating all buds + * with the authentication nodes on this LEB. Authentication nodes are written + * after some buds and contain a HMAC covering the authentication node itself + * and the buds between the last authentication node and the current + * authentication node. It can happen that the last buds cannot be authenticated + * because a powercut happened when some nodes were written but not the + * corresponding authentication node. This function returns the number of nodes + * that could be authenticated or a negative error code. + */ +static int authenticate_sleb(struct ubifs_info *c, struct ubifs_scan_leb *sleb, + struct shash_desc *log_hash, int is_last) +{ + int n_not_auth = 0; + struct ubifs_scan_node *snod; + int n_nodes = 0; + int err; + u8 hash[UBIFS_HASH_ARR_SZ]; + u8 hmac[UBIFS_HMAC_ARR_SZ]; + + if (!ubifs_authenticated(c)) + return sleb->nodes_cnt; + + list_for_each_entry(snod, &sleb->nodes, list) { + + n_nodes++; + + if (snod->type == UBIFS_AUTH_NODE) { + struct ubifs_auth_node *auth = snod->node; + + err = authenticate_sleb_hash(c, log_hash, hash); + if (err) + goto out; + + err = crypto_shash_tfm_digest(c->hmac_tfm, hash, + c->hash_len, hmac); + if (err) + goto out; + + err = ubifs_check_hmac(c, auth->hmac, hmac); + if (err) { + err = -EPERM; + goto out; + } + n_not_auth = 0; + } else { + err = crypto_shash_update(log_hash, snod->node, + snod->len); + if (err) + goto out; + n_not_auth++; + } + } + + /* + * A powercut can happen when some nodes were written, but not yet + * the corresponding authentication node. This may only happen on + * the last bud though. + */ + if (n_not_auth) { + if (is_last) { + dbg_mnt("%d unauthenticated nodes found on LEB %d, Ignoring them", + n_not_auth, sleb->lnum); + err = 0; + } else { + dbg_mnt("%d unauthenticated nodes found on non-last LEB %d", + n_not_auth, sleb->lnum); + err = -EPERM; + } + } else { + err = 0; + } +out: + return err ? err : n_nodes - n_not_auth; +} + +/** + * replay_bud - replay a bud logical eraseblock. + * @c: UBIFS file-system description object + * @b: bud entry which describes the bud + * + * This function replays bud @bud, recovers it if needed, and adds all nodes + * from this bud to the replay list. Returns zero in case of success and a + * negative error code in case of failure. + */ +static int replay_bud(struct ubifs_info *c, struct bud_entry *b) +{ + int is_last = is_last_bud(c, b->bud); + int err = 0, used = 0, lnum = b->bud->lnum, offs = b->bud->start; + int n_nodes, n = 0; + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + + dbg_mnt("replay bud LEB %d, head %d, offs %d, is_last %d", + lnum, b->bud->jhead, offs, is_last); + + if (c->need_recovery && is_last) + /* + * Recover only last LEBs in the journal heads, because power + * cuts may cause corruptions only in these LEBs, because only + * these LEBs could possibly be written to at the power cut + * time. + */ + sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, b->bud->jhead); + else + sleb = ubifs_scan(c, lnum, offs, c->sbuf, 0); + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + + n_nodes = authenticate_sleb(c, sleb, b->bud->log_hash, is_last); + if (n_nodes < 0) { + err = n_nodes; + goto out; + } + + ubifs_shash_copy_state(c, b->bud->log_hash, + c->jheads[b->bud->jhead].log_hash); + + /* + * The bud does not have to start from offset zero - the beginning of + * the 'lnum' LEB may contain previously committed data. One of the + * things we have to do in replay is to correctly update lprops with + * newer information about this LEB. + * + * At this point lprops thinks that this LEB has 'c->leb_size - offs' + * bytes of free space because it only contain information about + * committed data. + * + * But we know that real amount of free space is 'c->leb_size - + * sleb->endpt', and the space in the 'lnum' LEB between 'offs' and + * 'sleb->endpt' is used by bud data. We have to correctly calculate + * how much of these data are dirty and update lprops with this + * information. + * + * The dirt in that LEB region is comprised of padding nodes, deletion + * nodes, truncation nodes and nodes which are obsoleted by subsequent + * nodes in this LEB. So instead of calculating clean space, we + * calculate used space ('used' variable). + */ + + list_for_each_entry(snod, &sleb->nodes, list) { + u8 hash[UBIFS_HASH_ARR_SZ]; + int deletion = 0; + + cond_resched(); + + if (snod->sqnum >= SQNUM_WATERMARK) { + ubifs_err(c, "file system's life ended"); + goto out_dump; + } + + ubifs_node_calc_hash(c, snod->node, hash); + + if (snod->sqnum > c->max_sqnum) + c->max_sqnum = snod->sqnum; + + switch (snod->type) { + case UBIFS_INO_NODE: + { + struct ubifs_ino_node *ino = snod->node; + loff_t new_size = le64_to_cpu(ino->size); + + if (le32_to_cpu(ino->nlink) == 0) + deletion = 1; + err = insert_node(c, lnum, snod->offs, snod->len, hash, + &snod->key, snod->sqnum, deletion, + &used, 0, new_size); + break; + } + case UBIFS_DATA_NODE: + { + struct ubifs_data_node *dn = snod->node; + loff_t new_size = le32_to_cpu(dn->size) + + key_block(c, &snod->key) * + UBIFS_BLOCK_SIZE; + + err = insert_node(c, lnum, snod->offs, snod->len, hash, + &snod->key, snod->sqnum, deletion, + &used, 0, new_size); + break; + } + case UBIFS_DENT_NODE: + case UBIFS_XENT_NODE: + { + struct ubifs_dent_node *dent = snod->node; + + err = ubifs_validate_entry(c, dent); + if (err) + goto out_dump; + + err = insert_dent(c, lnum, snod->offs, snod->len, hash, + &snod->key, dent->name, + le16_to_cpu(dent->nlen), snod->sqnum, + !le64_to_cpu(dent->inum), &used); + break; + } + case UBIFS_TRUN_NODE: + { + struct ubifs_trun_node *trun = snod->node; + loff_t old_size = le64_to_cpu(trun->old_size); + loff_t new_size = le64_to_cpu(trun->new_size); + union ubifs_key key; + + /* Validate truncation node */ + if (old_size < 0 || old_size > c->max_inode_sz || + new_size < 0 || new_size > c->max_inode_sz || + old_size <= new_size) { + ubifs_err(c, "bad truncation node"); + goto out_dump; + } + + /* + * Create a fake truncation key just to use the same + * functions which expect nodes to have keys. + */ + trun_key_init(c, &key, le32_to_cpu(trun->inum)); + err = insert_node(c, lnum, snod->offs, snod->len, hash, + &key, snod->sqnum, 1, &used, + old_size, new_size); + break; + } + case UBIFS_AUTH_NODE: + break; + default: + ubifs_err(c, "unexpected node type %d in bud LEB %d:%d", + snod->type, lnum, snod->offs); + err = -EINVAL; + goto out_dump; + } + if (err) + goto out; + + n++; + if (n == n_nodes) + break; + } + + ubifs_assert(c, ubifs_search_bud(c, lnum)); + ubifs_assert(c, sleb->endpt - offs >= used); + ubifs_assert(c, sleb->endpt % c->min_io_size == 0); + + b->dirty = sleb->endpt - offs - used; + b->free = c->leb_size - sleb->endpt; + dbg_mnt("bud LEB %d replied: dirty %d, free %d", + lnum, b->dirty, b->free); + +out: + ubifs_scan_destroy(sleb); + return err; + +out_dump: + ubifs_err(c, "bad node is at LEB %d:%d", lnum, snod->offs); + ubifs_dump_node(c, snod->node); + ubifs_scan_destroy(sleb); + return -EINVAL; +} + +/** + * replay_buds - replay all buds. + * @c: UBIFS file-system description object + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int replay_buds(struct ubifs_info *c) +{ + struct bud_entry *b; + int err; + unsigned long long prev_sqnum = 0; + + list_for_each_entry(b, &c->replay_buds, list) { + err = replay_bud(c, b); + if (err) + return err; + + ubifs_assert(c, b->sqnum > prev_sqnum); + prev_sqnum = b->sqnum; + } + + return 0; +} + +/** + * destroy_bud_list - destroy the list of buds to replay. + * @c: UBIFS file-system description object + */ +static void destroy_bud_list(struct ubifs_info *c) +{ + struct bud_entry *b; + + while (!list_empty(&c->replay_buds)) { + b = list_entry(c->replay_buds.next, struct bud_entry, list); + list_del(&b->list); + kfree(b); + } +} + +/** + * add_replay_bud - add a bud to the list of buds to replay. + * @c: UBIFS file-system description object + * @lnum: bud logical eraseblock number to replay + * @offs: bud start offset + * @jhead: journal head to which this bud belongs + * @sqnum: reference node sequence number + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead, + unsigned long long sqnum) +{ + struct ubifs_bud *bud; + struct bud_entry *b; + int err; + + dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead); + + bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL); + if (!bud) + return -ENOMEM; + + b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL); + if (!b) { + err = -ENOMEM; + goto out; + } + + bud->lnum = lnum; + bud->start = offs; + bud->jhead = jhead; + bud->log_hash = ubifs_hash_get_desc(c); + if (IS_ERR(bud->log_hash)) { + err = PTR_ERR(bud->log_hash); + goto out; + } + + ubifs_shash_copy_state(c, c->log_hash, bud->log_hash); + + ubifs_add_bud(c, bud); + + b->bud = bud; + b->sqnum = sqnum; + list_add_tail(&b->list, &c->replay_buds); + + return 0; +out: + kfree(bud); + kfree(b); + + return err; +} + +/** + * validate_ref - validate a reference node. + * @c: UBIFS file-system description object + * @ref: the reference node to validate + * + * This function returns %1 if a bud reference already exists for the LEB. %0 is + * returned if the reference node is new, otherwise %-EINVAL is returned if + * validation failed. + */ +static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref) +{ + struct ubifs_bud *bud; + int lnum = le32_to_cpu(ref->lnum); + unsigned int offs = le32_to_cpu(ref->offs); + unsigned int jhead = le32_to_cpu(ref->jhead); + + /* + * ref->offs may point to the end of LEB when the journal head points + * to the end of LEB and we write reference node for it during commit. + * So this is why we require 'offs > c->leb_size'. + */ + if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt || + lnum < c->main_first || offs > c->leb_size || + offs & (c->min_io_size - 1)) + return -EINVAL; + + /* Make sure we have not already looked at this bud */ + bud = ubifs_search_bud(c, lnum); + if (bud) { + if (bud->jhead == jhead && bud->start <= offs) + return 1; + ubifs_err(c, "bud at LEB %d:%d was already referred", lnum, offs); + return -EINVAL; + } + + return 0; +} + +/** + * replay_log_leb - replay a log logical eraseblock. + * @c: UBIFS file-system description object + * @lnum: log logical eraseblock to replay + * @offs: offset to start replaying from + * @sbuf: scan buffer + * + * This function replays a log LEB and returns zero in case of success, %1 if + * this is the last LEB in the log, and a negative error code in case of + * failure. + */ +static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf) +{ + int err; + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + const struct ubifs_cs_node *node; + + dbg_mnt("replay log LEB %d:%d", lnum, offs); + sleb = ubifs_scan(c, lnum, offs, sbuf, c->need_recovery); + if (IS_ERR(sleb)) { + if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery) + return PTR_ERR(sleb); + /* + * Note, the below function will recover this log LEB only if + * it is the last, because unclean reboots can possibly corrupt + * only the tail of the log. + */ + sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf); + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + } + + if (sleb->nodes_cnt == 0) { + err = 1; + goto out; + } + + node = sleb->buf; + snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list); + if (c->cs_sqnum == 0) { + /* + * This is the first log LEB we are looking at, make sure that + * the first node is a commit start node. Also record its + * sequence number so that UBIFS can determine where the log + * ends, because all nodes which were have higher sequence + * numbers. + */ + if (snod->type != UBIFS_CS_NODE) { + ubifs_err(c, "first log node at LEB %d:%d is not CS node", + lnum, offs); + goto out_dump; + } + if (le64_to_cpu(node->cmt_no) != c->cmt_no) { + ubifs_err(c, "first CS node at LEB %d:%d has wrong commit number %llu expected %llu", + lnum, offs, + (unsigned long long)le64_to_cpu(node->cmt_no), + c->cmt_no); + goto out_dump; + } + + c->cs_sqnum = le64_to_cpu(node->ch.sqnum); + dbg_mnt("commit start sqnum %llu", c->cs_sqnum); + + err = ubifs_shash_init(c, c->log_hash); + if (err) + goto out; + + err = ubifs_shash_update(c, c->log_hash, node, UBIFS_CS_NODE_SZ); + if (err < 0) + goto out; + } + + if (snod->sqnum < c->cs_sqnum) { + /* + * This means that we reached end of log and now + * look to the older log data, which was already + * committed but the eraseblock was not erased (UBIFS + * only un-maps it). So this basically means we have to + * exit with "end of log" code. + */ + err = 1; + goto out; + } + + /* Make sure the first node sits at offset zero of the LEB */ + if (snod->offs != 0) { + ubifs_err(c, "first node is not at zero offset"); + goto out_dump; + } + + list_for_each_entry(snod, &sleb->nodes, list) { + cond_resched(); + + if (snod->sqnum >= SQNUM_WATERMARK) { + ubifs_err(c, "file system's life ended"); + goto out_dump; + } + + if (snod->sqnum < c->cs_sqnum) { + ubifs_err(c, "bad sqnum %llu, commit sqnum %llu", + snod->sqnum, c->cs_sqnum); + goto out_dump; + } + + if (snod->sqnum > c->max_sqnum) + c->max_sqnum = snod->sqnum; + + switch (snod->type) { + case UBIFS_REF_NODE: { + const struct ubifs_ref_node *ref = snod->node; + + err = validate_ref(c, ref); + if (err == 1) + break; /* Already have this bud */ + if (err) + goto out_dump; + + err = ubifs_shash_update(c, c->log_hash, ref, + UBIFS_REF_NODE_SZ); + if (err) + goto out; + + err = add_replay_bud(c, le32_to_cpu(ref->lnum), + le32_to_cpu(ref->offs), + le32_to_cpu(ref->jhead), + snod->sqnum); + if (err) + goto out; + + break; + } + case UBIFS_CS_NODE: + /* Make sure it sits at the beginning of LEB */ + if (snod->offs != 0) { + ubifs_err(c, "unexpected node in log"); + goto out_dump; + } + break; + default: + ubifs_err(c, "unexpected node in log"); + goto out_dump; + } + } + + if (sleb->endpt || c->lhead_offs >= c->leb_size) { + c->lhead_lnum = lnum; + c->lhead_offs = sleb->endpt; + } + + err = !sleb->endpt; +out: + ubifs_scan_destroy(sleb); + return err; + +out_dump: + ubifs_err(c, "log error detected while replaying the log at LEB %d:%d", + lnum, offs + snod->offs); + ubifs_dump_node(c, snod->node); + ubifs_scan_destroy(sleb); + return -EINVAL; +} + +/** + * take_ihead - update the status of the index head in lprops to 'taken'. + * @c: UBIFS file-system description object + * + * This function returns the amount of free space in the index head LEB or a + * negative error code. + */ +static int take_ihead(struct ubifs_info *c) +{ + const struct ubifs_lprops *lp; + int err, free; + + ubifs_get_lprops(c); + + lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + free = lp->free; + + lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC, + lp->flags | LPROPS_TAKEN, 0); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + err = free; +out: + ubifs_release_lprops(c); + return err; +} + +/** + * ubifs_replay_journal - replay journal. + * @c: UBIFS file-system description object + * + * This function scans the journal, replays and cleans it up. It makes sure all + * memory data structures related to uncommitted journal are built (dirty TNC + * tree, tree of buds, modified lprops, etc). + */ +int ubifs_replay_journal(struct ubifs_info *c) +{ + int err, lnum, free; + + BUILD_BUG_ON(UBIFS_TRUN_KEY > 5); + + /* Update the status of the index head in lprops to 'taken' */ + free = take_ihead(c); + if (free < 0) + return free; /* Error code */ + + if (c->ihead_offs != c->leb_size - free) { + ubifs_err(c, "bad index head LEB %d:%d", c->ihead_lnum, + c->ihead_offs); + return -EINVAL; + } + + dbg_mnt("start replaying the journal"); + c->replaying = 1; + lnum = c->ltail_lnum = c->lhead_lnum; + + do { + err = replay_log_leb(c, lnum, 0, c->sbuf); + if (err == 1) { + if (lnum != c->lhead_lnum) + /* We hit the end of the log */ + break; + + /* + * The head of the log must always start with the + * "commit start" node on a properly formatted UBIFS. + * But we found no nodes at all, which means that + * something went wrong and we cannot proceed mounting + * the file-system. + */ + ubifs_err(c, "no UBIFS nodes found at the log head LEB %d:%d, possibly corrupted", + lnum, 0); + err = -EINVAL; + } + if (err) + goto out; + lnum = ubifs_next_log_lnum(c, lnum); + } while (lnum != c->ltail_lnum); + + err = replay_buds(c); + if (err) + goto out; + + err = apply_replay_list(c); + if (err) + goto out; + + err = set_buds_lprops(c); + if (err) + goto out; + + /* + * UBIFS budgeting calculations use @c->bi.uncommitted_idx variable + * to roughly estimate index growth. Things like @c->bi.min_idx_lebs + * depend on it. This means we have to initialize it to make sure + * budgeting works properly. + */ + c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt); + c->bi.uncommitted_idx *= c->max_idx_node_sz; + + ubifs_assert(c, c->bud_bytes <= c->max_bud_bytes || c->need_recovery); + dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, highest_inum %lu", + c->lhead_lnum, c->lhead_offs, c->max_sqnum, + (unsigned long)c->highest_inum); +out: + destroy_replay_list(c); + destroy_bud_list(c); + c->replaying = 0; + return err; +} diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c new file mode 100644 index 000000000..c0d3e4008 --- /dev/null +++ b/fs/ubifs/sb.c @@ -0,0 +1,953 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements UBIFS superblock. The superblock is stored at the first + * LEB of the volume and is never changed by UBIFS. Only user-space tools may + * change it. The superblock node mostly contains geometry information. + */ + +#include "ubifs.h" +#include <linux/slab.h> +#include <linux/math64.h> +#include <linux/uuid.h> + +/* + * Default journal size in logical eraseblocks as a percent of total + * flash size. + */ +#define DEFAULT_JNL_PERCENT 5 + +/* Default maximum journal size in bytes */ +#define DEFAULT_MAX_JNL (32*1024*1024) + +/* Default indexing tree fanout */ +#define DEFAULT_FANOUT 8 + +/* Default number of data journal heads */ +#define DEFAULT_JHEADS_CNT 1 + +/* Default positions of different LEBs in the main area */ +#define DEFAULT_IDX_LEB 0 +#define DEFAULT_DATA_LEB 1 +#define DEFAULT_GC_LEB 2 + +/* Default number of LEB numbers in LPT's save table */ +#define DEFAULT_LSAVE_CNT 256 + +/* Default reserved pool size as a percent of maximum free space */ +#define DEFAULT_RP_PERCENT 5 + +/* The default maximum size of reserved pool in bytes */ +#define DEFAULT_MAX_RP_SIZE (5*1024*1024) + +/* Default time granularity in nanoseconds */ +#define DEFAULT_TIME_GRAN 1000000000 + +static int get_default_compressor(struct ubifs_info *c) +{ + if (ubifs_compr_present(c, UBIFS_COMPR_LZO)) + return UBIFS_COMPR_LZO; + + if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB)) + return UBIFS_COMPR_ZLIB; + + return UBIFS_COMPR_NONE; +} + +/** + * create_default_filesystem - format empty UBI volume. + * @c: UBIFS file-system description object + * + * This function creates default empty file-system. Returns zero in case of + * success and a negative error code in case of failure. + */ +static int create_default_filesystem(struct ubifs_info *c) +{ + struct ubifs_sb_node *sup; + struct ubifs_mst_node *mst; + struct ubifs_idx_node *idx; + struct ubifs_branch *br; + struct ubifs_ino_node *ino; + struct ubifs_cs_node *cs; + union ubifs_key key; + int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; + int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; + int min_leb_cnt = UBIFS_MIN_LEB_CNT; + int idx_node_size; + long long tmp64, main_bytes; + __le64 tmp_le64; + struct timespec64 ts; + u8 hash[UBIFS_HASH_ARR_SZ]; + u8 hash_lpt[UBIFS_HASH_ARR_SZ]; + + /* Some functions called from here depend on the @c->key_len filed */ + c->key_len = UBIFS_SK_LEN; + + /* + * First of all, we have to calculate default file-system geometry - + * log size, journal size, etc. + */ + if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) + /* We can first multiply then divide and have no overflow */ + jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; + else + jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; + + if (jnl_lebs < UBIFS_MIN_JNL_LEBS) + jnl_lebs = UBIFS_MIN_JNL_LEBS; + if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) + jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; + + /* + * The log should be large enough to fit reference nodes for all bud + * LEBs. Because buds do not have to start from the beginning of LEBs + * (half of the LEB may contain committed data), the log should + * generally be larger, make it twice as large. + */ + tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; + log_lebs = tmp / c->leb_size; + /* Plus one LEB reserved for commit */ + log_lebs += 1; + if (c->leb_cnt - min_leb_cnt > 8) { + /* And some extra space to allow writes while committing */ + log_lebs += 1; + min_leb_cnt += 1; + } + + max_buds = jnl_lebs - log_lebs; + if (max_buds < UBIFS_MIN_BUD_LEBS) + max_buds = UBIFS_MIN_BUD_LEBS; + + /* + * Orphan nodes are stored in a separate area. One node can store a lot + * of orphan inode numbers, but when new orphan comes we just add a new + * orphan node. At some point the nodes are consolidated into one + * orphan node. + */ + orph_lebs = UBIFS_MIN_ORPH_LEBS; + if (c->leb_cnt - min_leb_cnt > 1) + /* + * For debugging purposes it is better to have at least 2 + * orphan LEBs, because the orphan subsystem would need to do + * consolidations and would be stressed more. + */ + orph_lebs += 1; + + main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; + main_lebs -= orph_lebs; + + lpt_first = UBIFS_LOG_LNUM + log_lebs; + c->lsave_cnt = DEFAULT_LSAVE_CNT; + c->max_leb_cnt = c->leb_cnt; + err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, + &big_lpt, hash_lpt); + if (err) + return err; + + dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, + lpt_first + lpt_lebs - 1); + + main_first = c->leb_cnt - main_lebs; + + sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); + mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); + idx_node_size = ubifs_idx_node_sz(c, 1); + idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL); + ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); + cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); + + if (!sup || !mst || !idx || !ino || !cs) { + err = -ENOMEM; + goto out; + } + + /* Create default superblock */ + + tmp64 = (long long)max_buds * c->leb_size; + if (big_lpt) + sup_flags |= UBIFS_FLG_BIGLPT; + if (ubifs_default_version > 4) + sup_flags |= UBIFS_FLG_DOUBLE_HASH; + + if (ubifs_authenticated(c)) { + sup_flags |= UBIFS_FLG_AUTHENTICATION; + sup->hash_algo = cpu_to_le16(c->auth_hash_algo); + err = ubifs_hmac_wkm(c, sup->hmac_wkm); + if (err) + goto out; + } else { + sup->hash_algo = cpu_to_le16(0xffff); + } + + sup->ch.node_type = UBIFS_SB_NODE; + sup->key_hash = UBIFS_KEY_HASH_R5; + sup->flags = cpu_to_le32(sup_flags); + sup->min_io_size = cpu_to_le32(c->min_io_size); + sup->leb_size = cpu_to_le32(c->leb_size); + sup->leb_cnt = cpu_to_le32(c->leb_cnt); + sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); + sup->max_bud_bytes = cpu_to_le64(tmp64); + sup->log_lebs = cpu_to_le32(log_lebs); + sup->lpt_lebs = cpu_to_le32(lpt_lebs); + sup->orph_lebs = cpu_to_le32(orph_lebs); + sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); + sup->fanout = cpu_to_le32(DEFAULT_FANOUT); + sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); + sup->fmt_version = cpu_to_le32(ubifs_default_version); + sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); + if (c->mount_opts.override_compr) + sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); + else + sup->default_compr = cpu_to_le16(get_default_compressor(c)); + + generate_random_uuid(sup->uuid); + + main_bytes = (long long)main_lebs * c->leb_size; + tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); + if (tmp64 > DEFAULT_MAX_RP_SIZE) + tmp64 = DEFAULT_MAX_RP_SIZE; + sup->rp_size = cpu_to_le64(tmp64); + sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); + + dbg_gen("default superblock created at LEB 0:0"); + + /* Create default master node */ + + mst->ch.node_type = UBIFS_MST_NODE; + mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); + mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); + mst->cmt_no = 0; + mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); + mst->root_offs = 0; + tmp = ubifs_idx_node_sz(c, 1); + mst->root_len = cpu_to_le32(tmp); + mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); + mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); + mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); + mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); + mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); + mst->lpt_offs = cpu_to_le32(c->lpt_offs); + mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); + mst->nhead_offs = cpu_to_le32(c->nhead_offs); + mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); + mst->ltab_offs = cpu_to_le32(c->ltab_offs); + mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); + mst->lsave_offs = cpu_to_le32(c->lsave_offs); + mst->lscan_lnum = cpu_to_le32(main_first); + mst->empty_lebs = cpu_to_le32(main_lebs - 2); + mst->idx_lebs = cpu_to_le32(1); + mst->leb_cnt = cpu_to_le32(c->leb_cnt); + ubifs_copy_hash(c, hash_lpt, mst->hash_lpt); + + /* Calculate lprops statistics */ + tmp64 = main_bytes; + tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); + tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); + mst->total_free = cpu_to_le64(tmp64); + + tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); + ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - + UBIFS_INO_NODE_SZ; + tmp64 += ino_waste; + tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); + mst->total_dirty = cpu_to_le64(tmp64); + + /* The indexing LEB does not contribute to dark space */ + tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); + mst->total_dark = cpu_to_le64(tmp64); + + mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); + + dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); + + /* Create the root indexing node */ + + c->key_fmt = UBIFS_SIMPLE_KEY_FMT; + c->key_hash = key_r5_hash; + + idx->ch.node_type = UBIFS_IDX_NODE; + idx->child_cnt = cpu_to_le16(1); + ino_key_init(c, &key, UBIFS_ROOT_INO); + br = ubifs_idx_branch(c, idx, 0); + key_write_idx(c, &key, &br->key); + br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); + br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); + + dbg_gen("default root indexing node created LEB %d:0", + main_first + DEFAULT_IDX_LEB); + + /* Create default root inode */ + + ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); + ino->ch.node_type = UBIFS_INO_NODE; + ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); + ino->nlink = cpu_to_le32(2); + + ktime_get_coarse_real_ts64(&ts); + tmp_le64 = cpu_to_le64(ts.tv_sec); + ino->atime_sec = tmp_le64; + ino->ctime_sec = tmp_le64; + ino->mtime_sec = tmp_le64; + ino->atime_nsec = 0; + ino->ctime_nsec = 0; + ino->mtime_nsec = 0; + ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); + ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); + + /* Set compression enabled by default */ + ino->flags = cpu_to_le32(UBIFS_COMPR_FL); + + dbg_gen("root inode created at LEB %d:0", + main_first + DEFAULT_DATA_LEB); + + /* + * The first node in the log has to be the commit start node. This is + * always the case during normal file-system operation. Write a fake + * commit start node to the log. + */ + + cs->ch.node_type = UBIFS_CS_NODE; + + err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0, + offsetof(struct ubifs_sb_node, hmac)); + if (err) + goto out; + + err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, + main_first + DEFAULT_DATA_LEB, 0); + if (err) + goto out; + + ubifs_node_calc_hash(c, ino, hash); + ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br)); + + err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0); + if (err) + goto out; + + ubifs_node_calc_hash(c, idx, hash); + ubifs_copy_hash(c, hash, mst->hash_root_idx); + + err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, + offsetof(struct ubifs_mst_node, hmac)); + if (err) + goto out; + + err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, + 0, offsetof(struct ubifs_mst_node, hmac)); + if (err) + goto out; + + err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); + if (err) + goto out; + + ubifs_msg(c, "default file-system created"); + + err = 0; +out: + kfree(sup); + kfree(mst); + kfree(idx); + kfree(ino); + kfree(cs); + + return err; +} + +/** + * validate_sb - validate superblock node. + * @c: UBIFS file-system description object + * @sup: superblock node + * + * This function validates superblock node @sup. Since most of data was read + * from the superblock and stored in @c, the function validates fields in @c + * instead. Returns zero in case of success and %-EINVAL in case of validation + * failure. + */ +static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) +{ + long long max_bytes; + int err = 1, min_leb_cnt; + + if (!c->key_hash) { + err = 2; + goto failed; + } + + if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { + err = 3; + goto failed; + } + + if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { + ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", + le32_to_cpu(sup->min_io_size), c->min_io_size); + goto failed; + } + + if (le32_to_cpu(sup->leb_size) != c->leb_size) { + ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", + le32_to_cpu(sup->leb_size), c->leb_size); + goto failed; + } + + if (c->log_lebs < UBIFS_MIN_LOG_LEBS || + c->lpt_lebs < UBIFS_MIN_LPT_LEBS || + c->orph_lebs < UBIFS_MIN_ORPH_LEBS || + c->main_lebs < UBIFS_MIN_MAIN_LEBS) { + err = 4; + goto failed; + } + + /* + * Calculate minimum allowed amount of main area LEBs. This is very + * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we + * have just read from the superblock. + */ + min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; + min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; + + if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { + ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", + c->leb_cnt, c->vi.size, min_leb_cnt); + goto failed; + } + + if (c->max_leb_cnt < c->leb_cnt) { + ubifs_err(c, "max. LEB count %d less than LEB count %d", + c->max_leb_cnt, c->leb_cnt); + goto failed; + } + + if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { + ubifs_err(c, "too few main LEBs count %d, must be at least %d", + c->main_lebs, UBIFS_MIN_MAIN_LEBS); + goto failed; + } + + max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; + if (c->max_bud_bytes < max_bytes) { + ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", + c->max_bud_bytes, max_bytes); + goto failed; + } + + max_bytes = (long long)c->leb_size * c->main_lebs; + if (c->max_bud_bytes > max_bytes) { + ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", + c->max_bud_bytes, max_bytes); + goto failed; + } + + if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || + c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { + err = 9; + goto failed; + } + + if (c->fanout < UBIFS_MIN_FANOUT || + ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { + err = 10; + goto failed; + } + + if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && + c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - + c->log_lebs - c->lpt_lebs - c->orph_lebs)) { + err = 11; + goto failed; + } + + if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + + c->orph_lebs + c->main_lebs != c->leb_cnt) { + err = 12; + goto failed; + } + + if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { + err = 13; + goto failed; + } + + if (c->rp_size < 0 || max_bytes < c->rp_size) { + err = 14; + goto failed; + } + + if (le32_to_cpu(sup->time_gran) > 1000000000 || + le32_to_cpu(sup->time_gran) < 1) { + err = 15; + goto failed; + } + + if (!c->double_hash && c->fmt_version >= 5) { + err = 16; + goto failed; + } + + if (c->encrypted && c->fmt_version < 5) { + err = 17; + goto failed; + } + + return 0; + +failed: + ubifs_err(c, "bad superblock, error %d", err); + ubifs_dump_node(c, sup); + return -EINVAL; +} + +/** + * ubifs_read_sb_node - read superblock node. + * @c: UBIFS file-system description object + * + * This function returns a pointer to the superblock node or a negative error + * code. Note, the user of this function is responsible of kfree()'ing the + * returned superblock buffer. + */ +static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) +{ + struct ubifs_sb_node *sup; + int err; + + sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); + if (!sup) + return ERR_PTR(-ENOMEM); + + err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, + UBIFS_SB_LNUM, 0); + if (err) { + kfree(sup); + return ERR_PTR(err); + } + + return sup; +} + +static int authenticate_sb_node(struct ubifs_info *c, + const struct ubifs_sb_node *sup) +{ + unsigned int sup_flags = le32_to_cpu(sup->flags); + u8 hmac_wkm[UBIFS_HMAC_ARR_SZ]; + int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION); + int hash_algo; + int err; + + if (c->authenticated && !authenticated) { + ubifs_err(c, "authenticated FS forced, but found FS without authentication"); + return -EINVAL; + } + + if (!c->authenticated && authenticated) { + ubifs_err(c, "authenticated FS found, but no key given"); + return -EINVAL; + } + + ubifs_msg(c, "Mounting in %sauthenticated mode", + c->authenticated ? "" : "un"); + + if (!c->authenticated) + return 0; + + if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) + return -EOPNOTSUPP; + + hash_algo = le16_to_cpu(sup->hash_algo); + if (hash_algo >= HASH_ALGO__LAST) { + ubifs_err(c, "superblock uses unknown hash algo %d", + hash_algo); + return -EINVAL; + } + + if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) { + ubifs_err(c, "This filesystem uses %s for hashing," + " but %s is specified", hash_algo_name[hash_algo], + c->auth_hash_name); + return -EINVAL; + } + + /* + * The super block node can either be authenticated by a HMAC or + * by a signature in a ubifs_sig_node directly following the + * super block node to support offline image creation. + */ + if (ubifs_hmac_zero(c, sup->hmac)) { + err = ubifs_sb_verify_signature(c, sup); + } else { + err = ubifs_hmac_wkm(c, hmac_wkm); + if (err) + return err; + if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { + ubifs_err(c, "provided key does not fit"); + return -ENOKEY; + } + err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), + offsetof(struct ubifs_sb_node, + hmac)); + } + + if (err) + ubifs_err(c, "Failed to authenticate superblock: %d", err); + + return err; +} + +/** + * ubifs_write_sb_node - write superblock node. + * @c: UBIFS file-system description object + * @sup: superblock node read with 'ubifs_read_sb_node()' + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) +{ + int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); + int err; + + err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, + offsetof(struct ubifs_sb_node, hmac), 1); + if (err) + return err; + + return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); +} + +/** + * ubifs_read_superblock - read superblock. + * @c: UBIFS file-system description object + * + * This function finds, reads and checks the superblock. If an empty UBI volume + * is being mounted, this function creates default superblock. Returns zero in + * case of success, and a negative error code in case of failure. + */ +int ubifs_read_superblock(struct ubifs_info *c) +{ + int err, sup_flags; + struct ubifs_sb_node *sup; + + if (c->empty) { + err = create_default_filesystem(c); + if (err) + return err; + } + + sup = ubifs_read_sb_node(c); + if (IS_ERR(sup)) + return PTR_ERR(sup); + + c->sup_node = sup; + + c->fmt_version = le32_to_cpu(sup->fmt_version); + c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); + + /* + * The software supports all previous versions but not future versions, + * due to the unavailability of time-travelling equipment. + */ + if (c->fmt_version > UBIFS_FORMAT_VERSION) { + ubifs_assert(c, !c->ro_media || c->ro_mount); + if (!c->ro_mount || + c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { + ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", + c->fmt_version, c->ro_compat_version, + UBIFS_FORMAT_VERSION, + UBIFS_RO_COMPAT_VERSION); + if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { + ubifs_msg(c, "only R/O mounting is possible"); + err = -EROFS; + } else + err = -EINVAL; + goto out; + } + + /* + * The FS is mounted R/O, and the media format is + * R/O-compatible with the UBIFS implementation, so we can + * mount. + */ + c->rw_incompat = 1; + } + + if (c->fmt_version < 3) { + ubifs_err(c, "on-flash format version %d is not supported", + c->fmt_version); + err = -EINVAL; + goto out; + } + + switch (sup->key_hash) { + case UBIFS_KEY_HASH_R5: + c->key_hash = key_r5_hash; + c->key_hash_type = UBIFS_KEY_HASH_R5; + break; + + case UBIFS_KEY_HASH_TEST: + c->key_hash = key_test_hash; + c->key_hash_type = UBIFS_KEY_HASH_TEST; + break; + } + + c->key_fmt = sup->key_fmt; + + switch (c->key_fmt) { + case UBIFS_SIMPLE_KEY_FMT: + c->key_len = UBIFS_SK_LEN; + break; + default: + ubifs_err(c, "unsupported key format"); + err = -EINVAL; + goto out; + } + + c->leb_cnt = le32_to_cpu(sup->leb_cnt); + c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); + c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); + c->log_lebs = le32_to_cpu(sup->log_lebs); + c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); + c->orph_lebs = le32_to_cpu(sup->orph_lebs); + c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; + c->fanout = le32_to_cpu(sup->fanout); + c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); + c->rp_size = le64_to_cpu(sup->rp_size); + c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); + c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); + sup_flags = le32_to_cpu(sup->flags); + if (!c->mount_opts.override_compr) + c->default_compr = le16_to_cpu(sup->default_compr); + + c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); + memcpy(&c->uuid, &sup->uuid, 16); + c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); + c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); + c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); + c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); + + err = authenticate_sb_node(c, sup); + if (err) + goto out; + + if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { + ubifs_err(c, "Unknown feature flags found: %#x", + sup_flags & ~UBIFS_FLG_MASK); + err = -EINVAL; + goto out; + } + + if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { + ubifs_err(c, "file system contains encrypted files but UBIFS" + " was built without crypto support."); + err = -EINVAL; + goto out; + } + + /* Automatically increase file system size to the maximum size */ + if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { + int old_leb_cnt = c->leb_cnt; + + c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); + sup->leb_cnt = cpu_to_le32(c->leb_cnt); + + c->superblock_need_write = 1; + + dbg_mnt("Auto resizing from %d LEBs to %d LEBs", + old_leb_cnt, c->leb_cnt); + } + + c->log_bytes = (long long)c->log_lebs * c->leb_size; + c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; + c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; + c->lpt_last = c->lpt_first + c->lpt_lebs - 1; + c->orph_first = c->lpt_last + 1; + c->orph_last = c->orph_first + c->orph_lebs - 1; + c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; + c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; + c->main_first = c->leb_cnt - c->main_lebs; + + err = validate_sb(c, sup); +out: + return err; +} + +/** + * fixup_leb - fixup/unmap an LEB containing free space. + * @c: UBIFS file-system description object + * @lnum: the LEB number to fix up + * @len: number of used bytes in LEB (starting at offset 0) + * + * This function reads the contents of the given LEB number @lnum, then fixes + * it up, so that empty min. I/O units in the end of LEB are actually erased on + * flash (rather than being just all-0xff real data). If the LEB is completely + * empty, it is simply unmapped. + */ +static int fixup_leb(struct ubifs_info *c, int lnum, int len) +{ + int err; + + ubifs_assert(c, len >= 0); + ubifs_assert(c, len % c->min_io_size == 0); + ubifs_assert(c, len < c->leb_size); + + if (len == 0) { + dbg_mnt("unmap empty LEB %d", lnum); + return ubifs_leb_unmap(c, lnum); + } + + dbg_mnt("fixup LEB %d, data len %d", lnum, len); + err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); + if (err) + return err; + + return ubifs_leb_change(c, lnum, c->sbuf, len); +} + +/** + * fixup_free_space - find & remap all LEBs containing free space. + * @c: UBIFS file-system description object + * + * This function walks through all LEBs in the filesystem and fiexes up those + * containing free/empty space. + */ +static int fixup_free_space(struct ubifs_info *c) +{ + int lnum, err = 0; + struct ubifs_lprops *lprops; + + ubifs_get_lprops(c); + + /* Fixup LEBs in the master area */ + for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { + err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); + if (err) + goto out; + } + + /* Unmap unused log LEBs */ + lnum = ubifs_next_log_lnum(c, c->lhead_lnum); + while (lnum != c->ltail_lnum) { + err = fixup_leb(c, lnum, 0); + if (err) + goto out; + lnum = ubifs_next_log_lnum(c, lnum); + } + + /* + * Fixup the log head which contains the only a CS node at the + * beginning. + */ + err = fixup_leb(c, c->lhead_lnum, + ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); + if (err) + goto out; + + /* Fixup LEBs in the LPT area */ + for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { + int free = c->ltab[lnum - c->lpt_first].free; + + if (free > 0) { + err = fixup_leb(c, lnum, c->leb_size - free); + if (err) + goto out; + } + } + + /* Unmap LEBs in the orphans area */ + for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { + err = fixup_leb(c, lnum, 0); + if (err) + goto out; + } + + /* Fixup LEBs in the main area */ + for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { + lprops = ubifs_lpt_lookup(c, lnum); + if (IS_ERR(lprops)) { + err = PTR_ERR(lprops); + goto out; + } + + if (lprops->free > 0) { + err = fixup_leb(c, lnum, c->leb_size - lprops->free); + if (err) + goto out; + } + } + +out: + ubifs_release_lprops(c); + return err; +} + +/** + * ubifs_fixup_free_space - find & fix all LEBs with free space. + * @c: UBIFS file-system description object + * + * This function fixes up LEBs containing free space on first mount, if the + * appropriate flag was set when the FS was created. Each LEB with one or more + * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure + * the free space is actually erased. E.g., this is necessary for some NAND + * chips, since the free space may have been programmed like real "0xff" data + * (generating a non-0xff ECC), causing future writes to the not-really-erased + * NAND pages to behave badly. After the space is fixed up, the superblock flag + * is cleared, so that this is skipped for all future mounts. + */ +int ubifs_fixup_free_space(struct ubifs_info *c) +{ + int err; + struct ubifs_sb_node *sup = c->sup_node; + + ubifs_assert(c, c->space_fixup); + ubifs_assert(c, !c->ro_mount); + + ubifs_msg(c, "start fixing up free space"); + + err = fixup_free_space(c); + if (err) + return err; + + /* Free-space fixup is no longer required */ + c->space_fixup = 0; + sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); + + c->superblock_need_write = 1; + + ubifs_msg(c, "free space fixup complete"); + return err; +} + +int ubifs_enable_encryption(struct ubifs_info *c) +{ + int err; + struct ubifs_sb_node *sup = c->sup_node; + + if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) + return -EOPNOTSUPP; + + if (c->encrypted) + return 0; + + if (c->ro_mount || c->ro_media) + return -EROFS; + + if (c->fmt_version < 5) { + ubifs_err(c, "on-flash format version 5 is needed for encryption"); + return -EINVAL; + } + + sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); + + err = ubifs_write_sb_node(c, sup); + if (!err) + c->encrypted = 1; + + return err; +} diff --git a/fs/ubifs/scan.c b/fs/ubifs/scan.c new file mode 100644 index 000000000..c69cdb5e6 --- /dev/null +++ b/fs/ubifs/scan.c @@ -0,0 +1,366 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements the scan which is a general-purpose function for + * determining what nodes are in an eraseblock. The scan is used to replay the + * journal, to do garbage collection. for the TNC in-the-gaps method, and by + * debugging functions. + */ + +#include "ubifs.h" + +/** + * scan_padding_bytes - scan for padding bytes. + * @buf: buffer to scan + * @len: length of buffer + * + * This function returns the number of padding bytes on success and + * %SCANNED_GARBAGE on failure. + */ +static int scan_padding_bytes(void *buf, int len) +{ + int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len); + uint8_t *p = buf; + + dbg_scan("not a node"); + + while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE) + pad_len += 1; + + if (!pad_len || (pad_len & 7)) + return SCANNED_GARBAGE; + + dbg_scan("%d padding bytes", pad_len); + + return pad_len; +} + +/** + * ubifs_scan_a_node - scan for a node or padding. + * @c: UBIFS file-system description object + * @buf: buffer to scan + * @len: length of buffer + * @lnum: logical eraseblock number + * @offs: offset within the logical eraseblock + * @quiet: print no messages + * + * This function returns a scanning code to indicate what was scanned. + */ +int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum, + int offs, int quiet) +{ + struct ubifs_ch *ch = buf; + uint32_t magic; + + magic = le32_to_cpu(ch->magic); + + if (magic == 0xFFFFFFFF) { + dbg_scan("hit empty space at LEB %d:%d", lnum, offs); + return SCANNED_EMPTY_SPACE; + } + + if (magic != UBIFS_NODE_MAGIC) + return scan_padding_bytes(buf, len); + + if (len < UBIFS_CH_SZ) + return SCANNED_GARBAGE; + + dbg_scan("scanning %s at LEB %d:%d", + dbg_ntype(ch->node_type), lnum, offs); + + if (ubifs_check_node(c, buf, lnum, offs, quiet, 1)) + return SCANNED_A_CORRUPT_NODE; + + if (ch->node_type == UBIFS_PAD_NODE) { + struct ubifs_pad_node *pad = buf; + int pad_len = le32_to_cpu(pad->pad_len); + int node_len = le32_to_cpu(ch->len); + + /* Validate the padding node */ + if (pad_len < 0 || + offs + node_len + pad_len > c->leb_size) { + if (!quiet) { + ubifs_err(c, "bad pad node at LEB %d:%d", + lnum, offs); + ubifs_dump_node(c, pad); + } + return SCANNED_A_BAD_PAD_NODE; + } + + /* Make the node pads to 8-byte boundary */ + if ((node_len + pad_len) & 7) { + if (!quiet) + ubifs_err(c, "bad padding length %d - %d", + offs, offs + node_len + pad_len); + return SCANNED_A_BAD_PAD_NODE; + } + + dbg_scan("%d bytes padded at LEB %d:%d, offset now %d", pad_len, + lnum, offs, ALIGN(offs + node_len + pad_len, 8)); + + return node_len + pad_len; + } + + return SCANNED_A_NODE; +} + +/** + * ubifs_start_scan - create LEB scanning information at start of scan. + * @c: UBIFS file-system description object + * @lnum: logical eraseblock number + * @offs: offset to start at (usually zero) + * @sbuf: scan buffer (must be c->leb_size) + * + * This function returns the scanned information on success and a negative error + * code on failure. + */ +struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum, + int offs, void *sbuf) +{ + struct ubifs_scan_leb *sleb; + int err; + + dbg_scan("scan LEB %d:%d", lnum, offs); + + sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS); + if (!sleb) + return ERR_PTR(-ENOMEM); + + sleb->lnum = lnum; + INIT_LIST_HEAD(&sleb->nodes); + sleb->buf = sbuf; + + err = ubifs_leb_read(c, lnum, sbuf + offs, offs, c->leb_size - offs, 0); + if (err && err != -EBADMSG) { + ubifs_err(c, "cannot read %d bytes from LEB %d:%d, error %d", + c->leb_size - offs, lnum, offs, err); + kfree(sleb); + return ERR_PTR(err); + } + + /* + * Note, we ignore integrity errors (EBASMSG) because all the nodes are + * protected by CRC checksums. + */ + return sleb; +} + +/** + * ubifs_end_scan - update LEB scanning information at end of scan. + * @c: UBIFS file-system description object + * @sleb: scanning information + * @lnum: logical eraseblock number + * @offs: offset to start at (usually zero) + */ +void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb, + int lnum, int offs) +{ + dbg_scan("stop scanning LEB %d at offset %d", lnum, offs); + ubifs_assert(c, offs % c->min_io_size == 0); + + sleb->endpt = ALIGN(offs, c->min_io_size); +} + +/** + * ubifs_add_snod - add a scanned node to LEB scanning information. + * @c: UBIFS file-system description object + * @sleb: scanning information + * @buf: buffer containing node + * @offs: offset of node on flash + * + * This function returns %0 on success and a negative error code on failure. + */ +int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb, + void *buf, int offs) +{ + struct ubifs_ch *ch = buf; + struct ubifs_ino_node *ino = buf; + struct ubifs_scan_node *snod; + + snod = kmalloc(sizeof(struct ubifs_scan_node), GFP_NOFS); + if (!snod) + return -ENOMEM; + + snod->sqnum = le64_to_cpu(ch->sqnum); + snod->type = ch->node_type; + snod->offs = offs; + snod->len = le32_to_cpu(ch->len); + snod->node = buf; + + switch (ch->node_type) { + case UBIFS_INO_NODE: + case UBIFS_DENT_NODE: + case UBIFS_XENT_NODE: + case UBIFS_DATA_NODE: + /* + * The key is in the same place in all keyed + * nodes. + */ + key_read(c, &ino->key, &snod->key); + break; + default: + invalid_key_init(c, &snod->key); + break; + } + list_add_tail(&snod->list, &sleb->nodes); + sleb->nodes_cnt += 1; + return 0; +} + +/** + * ubifs_scanned_corruption - print information after UBIFS scanned corruption. + * @c: UBIFS file-system description object + * @lnum: LEB number of corruption + * @offs: offset of corruption + * @buf: buffer containing corruption + */ +void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs, + void *buf) +{ + int len; + + ubifs_err(c, "corruption at LEB %d:%d", lnum, offs); + len = c->leb_size - offs; + if (len > 8192) + len = 8192; + ubifs_err(c, "first %d bytes from LEB %d:%d", len, lnum, offs); + print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1); +} + +/** + * ubifs_scan - scan a logical eraseblock. + * @c: UBIFS file-system description object + * @lnum: logical eraseblock number + * @offs: offset to start at (usually zero) + * @sbuf: scan buffer (must be of @c->leb_size bytes in size) + * @quiet: print no messages + * + * This function scans LEB number @lnum and returns complete information about + * its contents. Returns the scanned information in case of success and, + * %-EUCLEAN if the LEB neads recovery, and other negative error codes in case + * of failure. + * + * If @quiet is non-zero, this function does not print large and scary + * error messages and flash dumps in case of errors. + */ +struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum, + int offs, void *sbuf, int quiet) +{ + void *buf = sbuf + offs; + int err, len = c->leb_size - offs; + struct ubifs_scan_leb *sleb; + + sleb = ubifs_start_scan(c, lnum, offs, sbuf); + if (IS_ERR(sleb)) + return sleb; + + while (len >= 8) { + struct ubifs_ch *ch = buf; + int node_len, ret; + + dbg_scan("look at LEB %d:%d (%d bytes left)", + lnum, offs, len); + + cond_resched(); + + ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet); + if (ret > 0) { + /* Padding bytes or a valid padding node */ + offs += ret; + buf += ret; + len -= ret; + continue; + } + + if (ret == SCANNED_EMPTY_SPACE) + /* Empty space is checked later */ + break; + + switch (ret) { + case SCANNED_GARBAGE: + ubifs_err(c, "garbage"); + goto corrupted; + case SCANNED_A_NODE: + break; + case SCANNED_A_CORRUPT_NODE: + case SCANNED_A_BAD_PAD_NODE: + ubifs_err(c, "bad node"); + goto corrupted; + default: + ubifs_err(c, "unknown"); + err = -EINVAL; + goto error; + } + + err = ubifs_add_snod(c, sleb, buf, offs); + if (err) + goto error; + + node_len = ALIGN(le32_to_cpu(ch->len), 8); + offs += node_len; + buf += node_len; + len -= node_len; + } + + if (offs % c->min_io_size) { + if (!quiet) + ubifs_err(c, "empty space starts at non-aligned offset %d", + offs); + goto corrupted; + } + + ubifs_end_scan(c, sleb, lnum, offs); + + for (; len > 4; offs += 4, buf = buf + 4, len -= 4) + if (*(uint32_t *)buf != 0xffffffff) + break; + for (; len; offs++, buf++, len--) + if (*(uint8_t *)buf != 0xff) { + if (!quiet) + ubifs_err(c, "corrupt empty space at LEB %d:%d", + lnum, offs); + goto corrupted; + } + + return sleb; + +corrupted: + if (!quiet) { + ubifs_scanned_corruption(c, lnum, offs, buf); + ubifs_err(c, "LEB %d scanning failed", lnum); + } + err = -EUCLEAN; + ubifs_scan_destroy(sleb); + return ERR_PTR(err); + +error: + ubifs_err(c, "LEB %d scanning failed, error %d", lnum, err); + ubifs_scan_destroy(sleb); + return ERR_PTR(err); +} + +/** + * ubifs_scan_destroy - destroy LEB scanning information. + * @sleb: scanning information to free + */ +void ubifs_scan_destroy(struct ubifs_scan_leb *sleb) +{ + struct ubifs_scan_node *node; + struct list_head *head; + + head = &sleb->nodes; + while (!list_empty(head)) { + node = list_entry(head->next, struct ubifs_scan_node, list); + list_del(&node->list); + kfree(node); + } + kfree(sleb); +} diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c new file mode 100644 index 000000000..d00a6f20a --- /dev/null +++ b/fs/ubifs/shrinker.c @@ -0,0 +1,319 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements UBIFS shrinker which evicts clean znodes from the TNC + * tree when Linux VM needs more RAM. + * + * We do not implement any LRU lists to find oldest znodes to free because it + * would add additional overhead to the file system fast paths. So the shrinker + * just walks the TNC tree when searching for znodes to free. + * + * If the root of a TNC sub-tree is clean and old enough, then the children are + * also clean and old enough. So the shrinker walks the TNC in level order and + * dumps entire sub-trees. + * + * The age of znodes is just the time-stamp when they were last looked at. + * The current shrinker first tries to evict old znodes, then young ones. + * + * Since the shrinker is global, it has to protect against races with FS + * un-mounts, which is done by the 'ubifs_infos_lock' and 'c->umount_mutex'. + */ + +#include "ubifs.h" + +/* List of all UBIFS file-system instances */ +LIST_HEAD(ubifs_infos); + +/* + * We number each shrinker run and record the number on the ubifs_info structure + * so that we can easily work out which ubifs_info structures have already been + * done by the current run. + */ +static unsigned int shrinker_run_no; + +/* Protects 'ubifs_infos' list */ +DEFINE_SPINLOCK(ubifs_infos_lock); + +/* Global clean znode counter (for all mounted UBIFS instances) */ +atomic_long_t ubifs_clean_zn_cnt; + +/** + * shrink_tnc - shrink TNC tree. + * @c: UBIFS file-system description object + * @nr: number of znodes to free + * @age: the age of znodes to free + * @contention: if any contention, this is set to %1 + * + * This function traverses TNC tree and frees clean znodes. It does not free + * clean znodes which younger then @age. Returns number of freed znodes. + */ +static int shrink_tnc(struct ubifs_info *c, int nr, int age, int *contention) +{ + int total_freed = 0; + struct ubifs_znode *znode, *zprev; + time64_t time = ktime_get_seconds(); + + ubifs_assert(c, mutex_is_locked(&c->umount_mutex)); + ubifs_assert(c, mutex_is_locked(&c->tnc_mutex)); + + if (!c->zroot.znode || atomic_long_read(&c->clean_zn_cnt) == 0) + return 0; + + /* + * Traverse the TNC tree in levelorder manner, so that it is possible + * to destroy large sub-trees. Indeed, if a znode is old, then all its + * children are older or of the same age. + * + * Note, we are holding 'c->tnc_mutex', so we do not have to lock the + * 'c->space_lock' when _reading_ 'c->clean_zn_cnt', because it is + * changed only when the 'c->tnc_mutex' is held. + */ + zprev = NULL; + znode = ubifs_tnc_levelorder_next(c, c->zroot.znode, NULL); + while (znode && total_freed < nr && + atomic_long_read(&c->clean_zn_cnt) > 0) { + int freed; + + /* + * If the znode is clean, but it is in the 'c->cnext' list, this + * means that this znode has just been written to flash as a + * part of commit and was marked clean. They will be removed + * from the list at end commit. We cannot change the list, + * because it is not protected by any mutex (design decision to + * make commit really independent and parallel to main I/O). So + * we just skip these znodes. + * + * Note, the 'clean_zn_cnt' counters are not updated until + * after the commit, so the UBIFS shrinker does not report + * the znodes which are in the 'c->cnext' list as freeable. + * + * Also note, if the root of a sub-tree is not in 'c->cnext', + * then the whole sub-tree is not in 'c->cnext' as well, so it + * is safe to dump whole sub-tree. + */ + + if (znode->cnext) { + /* + * Very soon these znodes will be removed from the list + * and become freeable. + */ + *contention = 1; + } else if (!ubifs_zn_dirty(znode) && + abs(time - znode->time) >= age) { + if (znode->parent) + znode->parent->zbranch[znode->iip].znode = NULL; + else + c->zroot.znode = NULL; + + freed = ubifs_destroy_tnc_subtree(c, znode); + atomic_long_sub(freed, &ubifs_clean_zn_cnt); + atomic_long_sub(freed, &c->clean_zn_cnt); + total_freed += freed; + znode = zprev; + } + + if (unlikely(!c->zroot.znode)) + break; + + zprev = znode; + znode = ubifs_tnc_levelorder_next(c, c->zroot.znode, znode); + cond_resched(); + } + + return total_freed; +} + +/** + * shrink_tnc_trees - shrink UBIFS TNC trees. + * @nr: number of znodes to free + * @age: the age of znodes to free + * @contention: if any contention, this is set to %1 + * + * This function walks the list of mounted UBIFS file-systems and frees clean + * znodes which are older than @age, until at least @nr znodes are freed. + * Returns the number of freed znodes. + */ +static int shrink_tnc_trees(int nr, int age, int *contention) +{ + struct ubifs_info *c; + struct list_head *p; + unsigned int run_no; + int freed = 0; + + spin_lock(&ubifs_infos_lock); + do { + run_no = ++shrinker_run_no; + } while (run_no == 0); + /* Iterate over all mounted UBIFS file-systems and try to shrink them */ + p = ubifs_infos.next; + while (p != &ubifs_infos) { + c = list_entry(p, struct ubifs_info, infos_list); + /* + * We move the ones we do to the end of the list, so we stop + * when we see one we have already done. + */ + if (c->shrinker_run_no == run_no) + break; + if (!mutex_trylock(&c->umount_mutex)) { + /* Some un-mount is in progress, try next FS */ + *contention = 1; + p = p->next; + continue; + } + /* + * We're holding 'c->umount_mutex', so the file-system won't go + * away. + */ + if (!mutex_trylock(&c->tnc_mutex)) { + mutex_unlock(&c->umount_mutex); + *contention = 1; + p = p->next; + continue; + } + spin_unlock(&ubifs_infos_lock); + /* + * OK, now we have TNC locked, the file-system cannot go away - + * it is safe to reap the cache. + */ + c->shrinker_run_no = run_no; + freed += shrink_tnc(c, nr, age, contention); + mutex_unlock(&c->tnc_mutex); + spin_lock(&ubifs_infos_lock); + /* Get the next list element before we move this one */ + p = p->next; + /* + * Move this one to the end of the list to provide some + * fairness. + */ + list_move_tail(&c->infos_list, &ubifs_infos); + mutex_unlock(&c->umount_mutex); + if (freed >= nr) + break; + } + spin_unlock(&ubifs_infos_lock); + return freed; +} + +/** + * kick_a_thread - kick a background thread to start commit. + * + * This function kicks a background thread to start background commit. Returns + * %-1 if a thread was kicked or there is another reason to assume the memory + * will soon be freed or become freeable. If there are no dirty znodes, returns + * %0. + */ +static int kick_a_thread(void) +{ + int i; + struct ubifs_info *c; + + /* + * Iterate over all mounted UBIFS file-systems and find out if there is + * already an ongoing commit operation there. If no, then iterate for + * the second time and initiate background commit. + */ + spin_lock(&ubifs_infos_lock); + for (i = 0; i < 2; i++) { + list_for_each_entry(c, &ubifs_infos, infos_list) { + long dirty_zn_cnt; + + if (!mutex_trylock(&c->umount_mutex)) { + /* + * Some un-mount is in progress, it will + * certainly free memory, so just return. + */ + spin_unlock(&ubifs_infos_lock); + return -1; + } + + dirty_zn_cnt = atomic_long_read(&c->dirty_zn_cnt); + + if (!dirty_zn_cnt || c->cmt_state == COMMIT_BROKEN || + c->ro_mount || c->ro_error) { + mutex_unlock(&c->umount_mutex); + continue; + } + + if (c->cmt_state != COMMIT_RESTING) { + spin_unlock(&ubifs_infos_lock); + mutex_unlock(&c->umount_mutex); + return -1; + } + + if (i == 1) { + list_move_tail(&c->infos_list, &ubifs_infos); + spin_unlock(&ubifs_infos_lock); + + ubifs_request_bg_commit(c); + mutex_unlock(&c->umount_mutex); + return -1; + } + mutex_unlock(&c->umount_mutex); + } + } + spin_unlock(&ubifs_infos_lock); + + return 0; +} + +unsigned long ubifs_shrink_count(struct shrinker *shrink, + struct shrink_control *sc) +{ + long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt); + + /* + * Due to the way UBIFS updates the clean znode counter it may + * temporarily be negative. + */ + return clean_zn_cnt >= 0 ? clean_zn_cnt : 1; +} + +unsigned long ubifs_shrink_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + unsigned long nr = sc->nr_to_scan; + int contention = 0; + unsigned long freed; + long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt); + + if (!clean_zn_cnt) { + /* + * No clean znodes, nothing to reap. All we can do in this case + * is to kick background threads to start commit, which will + * probably make clean znodes which, in turn, will be freeable. + * And we return -1 which means will make VM call us again + * later. + */ + dbg_tnc("no clean znodes, kick a thread"); + return kick_a_thread(); + } + + freed = shrink_tnc_trees(nr, OLD_ZNODE_AGE, &contention); + if (freed >= nr) + goto out; + + dbg_tnc("not enough old znodes, try to free young ones"); + freed += shrink_tnc_trees(nr - freed, YOUNG_ZNODE_AGE, &contention); + if (freed >= nr) + goto out; + + dbg_tnc("not enough young znodes, free all"); + freed += shrink_tnc_trees(nr - freed, 0, &contention); + + if (!freed && contention) { + dbg_tnc("freed nothing, but contention"); + return SHRINK_STOP; + } + +out: + dbg_tnc("%lu znodes were freed, requested %lu", freed, nr); + return freed; +} diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c new file mode 100644 index 000000000..1df193c87 --- /dev/null +++ b/fs/ubifs/super.c @@ -0,0 +1,2489 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements UBIFS initialization and VFS superblock operations. Some + * initialization stuff which is rather large and complex is placed at + * corresponding subsystems, but most of it is here. + */ + +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/ctype.h> +#include <linux/kthread.h> +#include <linux/parser.h> +#include <linux/seq_file.h> +#include <linux/mount.h> +#include <linux/math64.h> +#include <linux/writeback.h> +#include "ubifs.h" + +static int ubifs_default_version_set(const char *val, const struct kernel_param *kp) +{ + int n = 0, ret; + + ret = kstrtoint(val, 10, &n); + if (ret != 0 || n < 4 || n > UBIFS_FORMAT_VERSION) + return -EINVAL; + return param_set_int(val, kp); +} + +static const struct kernel_param_ops ubifs_default_version_ops = { + .set = ubifs_default_version_set, + .get = param_get_int, +}; + +int ubifs_default_version = UBIFS_FORMAT_VERSION; +module_param_cb(default_version, &ubifs_default_version_ops, &ubifs_default_version, 0600); + +/* + * Maximum amount of memory we may 'kmalloc()' without worrying that we are + * allocating too much. + */ +#define UBIFS_KMALLOC_OK (128*1024) + +/* Slab cache for UBIFS inodes */ +static struct kmem_cache *ubifs_inode_slab; + +/* UBIFS TNC shrinker description */ +static struct shrinker ubifs_shrinker_info = { + .scan_objects = ubifs_shrink_scan, + .count_objects = ubifs_shrink_count, + .seeks = DEFAULT_SEEKS, +}; + +/** + * validate_inode - validate inode. + * @c: UBIFS file-system description object + * @inode: the inode to validate + * + * This is a helper function for 'ubifs_iget()' which validates various fields + * of a newly built inode to make sure they contain sane values and prevent + * possible vulnerabilities. Returns zero if the inode is all right and + * a non-zero error code if not. + */ +static int validate_inode(struct ubifs_info *c, const struct inode *inode) +{ + int err; + const struct ubifs_inode *ui = ubifs_inode(inode); + + if (inode->i_size > c->max_inode_sz) { + ubifs_err(c, "inode is too large (%lld)", + (long long)inode->i_size); + return 1; + } + + if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) { + ubifs_err(c, "unknown compression type %d", ui->compr_type); + return 2; + } + + if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX) + return 3; + + if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA) + return 4; + + if (ui->xattr && !S_ISREG(inode->i_mode)) + return 5; + + if (!ubifs_compr_present(c, ui->compr_type)) { + ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in", + inode->i_ino, ubifs_compr_name(c, ui->compr_type)); + } + + err = dbg_check_dir(c, inode); + return err; +} + +struct inode *ubifs_iget(struct super_block *sb, unsigned long inum) +{ + int err; + union ubifs_key key; + struct ubifs_ino_node *ino; + struct ubifs_info *c = sb->s_fs_info; + struct inode *inode; + struct ubifs_inode *ui; + + dbg_gen("inode %lu", inum); + + inode = iget_locked(sb, inum); + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + ui = ubifs_inode(inode); + + ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS); + if (!ino) { + err = -ENOMEM; + goto out; + } + + ino_key_init(c, &key, inode->i_ino); + + err = ubifs_tnc_lookup(c, &key, ino); + if (err) + goto out_ino; + + inode->i_flags |= S_NOCMTIME; + + if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) + inode->i_flags |= S_NOATIME; + + set_nlink(inode, le32_to_cpu(ino->nlink)); + i_uid_write(inode, le32_to_cpu(ino->uid)); + i_gid_write(inode, le32_to_cpu(ino->gid)); + inode->i_atime.tv_sec = (int64_t)le64_to_cpu(ino->atime_sec); + inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec); + inode->i_mtime.tv_sec = (int64_t)le64_to_cpu(ino->mtime_sec); + inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec); + inode->i_ctime.tv_sec = (int64_t)le64_to_cpu(ino->ctime_sec); + inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec); + inode->i_mode = le32_to_cpu(ino->mode); + inode->i_size = le64_to_cpu(ino->size); + + ui->data_len = le32_to_cpu(ino->data_len); + ui->flags = le32_to_cpu(ino->flags); + ui->compr_type = le16_to_cpu(ino->compr_type); + ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum); + ui->xattr_cnt = le32_to_cpu(ino->xattr_cnt); + ui->xattr_size = le32_to_cpu(ino->xattr_size); + ui->xattr_names = le32_to_cpu(ino->xattr_names); + ui->synced_i_size = ui->ui_size = inode->i_size; + + ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0; + + err = validate_inode(c, inode); + if (err) + goto out_invalid; + + switch (inode->i_mode & S_IFMT) { + case S_IFREG: + inode->i_mapping->a_ops = &ubifs_file_address_operations; + inode->i_op = &ubifs_file_inode_operations; + inode->i_fop = &ubifs_file_operations; + if (ui->xattr) { + ui->data = kmalloc(ui->data_len + 1, GFP_NOFS); + if (!ui->data) { + err = -ENOMEM; + goto out_ino; + } + memcpy(ui->data, ino->data, ui->data_len); + ((char *)ui->data)[ui->data_len] = '\0'; + } else if (ui->data_len != 0) { + err = 10; + goto out_invalid; + } + break; + case S_IFDIR: + inode->i_op = &ubifs_dir_inode_operations; + inode->i_fop = &ubifs_dir_operations; + if (ui->data_len != 0) { + err = 11; + goto out_invalid; + } + break; + case S_IFLNK: + inode->i_op = &ubifs_symlink_inode_operations; + if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) { + err = 12; + goto out_invalid; + } + ui->data = kmalloc(ui->data_len + 1, GFP_NOFS); + if (!ui->data) { + err = -ENOMEM; + goto out_ino; + } + memcpy(ui->data, ino->data, ui->data_len); + ((char *)ui->data)[ui->data_len] = '\0'; + break; + case S_IFBLK: + case S_IFCHR: + { + dev_t rdev; + union ubifs_dev_desc *dev; + + ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); + if (!ui->data) { + err = -ENOMEM; + goto out_ino; + } + + dev = (union ubifs_dev_desc *)ino->data; + if (ui->data_len == sizeof(dev->new)) + rdev = new_decode_dev(le32_to_cpu(dev->new)); + else if (ui->data_len == sizeof(dev->huge)) + rdev = huge_decode_dev(le64_to_cpu(dev->huge)); + else { + err = 13; + goto out_invalid; + } + memcpy(ui->data, ino->data, ui->data_len); + inode->i_op = &ubifs_file_inode_operations; + init_special_inode(inode, inode->i_mode, rdev); + break; + } + case S_IFSOCK: + case S_IFIFO: + inode->i_op = &ubifs_file_inode_operations; + init_special_inode(inode, inode->i_mode, 0); + if (ui->data_len != 0) { + err = 14; + goto out_invalid; + } + break; + default: + err = 15; + goto out_invalid; + } + + kfree(ino); + ubifs_set_inode_flags(inode); + unlock_new_inode(inode); + return inode; + +out_invalid: + ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err); + ubifs_dump_node(c, ino); + ubifs_dump_inode(c, inode); + err = -EINVAL; +out_ino: + kfree(ino); +out: + ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err); + iget_failed(inode); + return ERR_PTR(err); +} + +static struct inode *ubifs_alloc_inode(struct super_block *sb) +{ + struct ubifs_inode *ui; + + ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS); + if (!ui) + return NULL; + + memset((void *)ui + sizeof(struct inode), 0, + sizeof(struct ubifs_inode) - sizeof(struct inode)); + mutex_init(&ui->ui_mutex); + init_rwsem(&ui->xattr_sem); + spin_lock_init(&ui->ui_lock); + return &ui->vfs_inode; +}; + +static void ubifs_free_inode(struct inode *inode) +{ + struct ubifs_inode *ui = ubifs_inode(inode); + + kfree(ui->data); + fscrypt_free_inode(inode); + + kmem_cache_free(ubifs_inode_slab, ui); +} + +/* + * Note, Linux write-back code calls this without 'i_mutex'. + */ +static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + int err = 0; + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_inode *ui = ubifs_inode(inode); + + ubifs_assert(c, !ui->xattr); + if (is_bad_inode(inode)) + return 0; + + mutex_lock(&ui->ui_mutex); + /* + * Due to races between write-back forced by budgeting + * (see 'sync_some_inodes()') and background write-back, the inode may + * have already been synchronized, do not do this again. This might + * also happen if it was synchronized in an VFS operation, e.g. + * 'ubifs_link()'. + */ + if (!ui->dirty) { + mutex_unlock(&ui->ui_mutex); + return 0; + } + + /* + * As an optimization, do not write orphan inodes to the media just + * because this is not needed. + */ + dbg_gen("inode %lu, mode %#x, nlink %u", + inode->i_ino, (int)inode->i_mode, inode->i_nlink); + if (inode->i_nlink) { + err = ubifs_jnl_write_inode(c, inode); + if (err) + ubifs_err(c, "can't write inode %lu, error %d", + inode->i_ino, err); + else + err = dbg_check_inode_size(c, inode, ui->ui_size); + } + + ui->dirty = 0; + mutex_unlock(&ui->ui_mutex); + ubifs_release_dirty_inode_budget(c, ui); + return err; +} + +static int ubifs_drop_inode(struct inode *inode) +{ + int drop = generic_drop_inode(inode); + + if (!drop) + drop = fscrypt_drop_inode(inode); + + return drop; +} + +static void ubifs_evict_inode(struct inode *inode) +{ + int err; + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_inode *ui = ubifs_inode(inode); + + if (ui->xattr) + /* + * Extended attribute inode deletions are fully handled in + * 'ubifs_removexattr()'. These inodes are special and have + * limited usage, so there is nothing to do here. + */ + goto out; + + dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode); + ubifs_assert(c, !atomic_read(&inode->i_count)); + + truncate_inode_pages_final(&inode->i_data); + + if (inode->i_nlink) + goto done; + + if (is_bad_inode(inode)) + goto out; + + ui->ui_size = inode->i_size = 0; + err = ubifs_jnl_delete_inode(c, inode); + if (err) + /* + * Worst case we have a lost orphan inode wasting space, so a + * simple error message is OK here. + */ + ubifs_err(c, "can't delete inode %lu, error %d", + inode->i_ino, err); + +out: + if (ui->dirty) + ubifs_release_dirty_inode_budget(c, ui); + else { + /* We've deleted something - clean the "no space" flags */ + c->bi.nospace = c->bi.nospace_rp = 0; + smp_wmb(); + } +done: + clear_inode(inode); + fscrypt_put_encryption_info(inode); +} + +static void ubifs_dirty_inode(struct inode *inode, int flags) +{ + struct ubifs_info *c = inode->i_sb->s_fs_info; + struct ubifs_inode *ui = ubifs_inode(inode); + + ubifs_assert(c, mutex_is_locked(&ui->ui_mutex)); + if (!ui->dirty) { + ui->dirty = 1; + dbg_gen("inode %lu", inode->i_ino); + } +} + +static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf) +{ + struct ubifs_info *c = dentry->d_sb->s_fs_info; + unsigned long long free; + __le32 *uuid = (__le32 *)c->uuid; + + free = ubifs_get_free_space(c); + dbg_gen("free space %lld bytes (%lld blocks)", + free, free >> UBIFS_BLOCK_SHIFT); + + buf->f_type = UBIFS_SUPER_MAGIC; + buf->f_bsize = UBIFS_BLOCK_SIZE; + buf->f_blocks = c->block_cnt; + buf->f_bfree = free >> UBIFS_BLOCK_SHIFT; + if (free > c->report_rp_size) + buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT; + else + buf->f_bavail = 0; + buf->f_files = 0; + buf->f_ffree = 0; + buf->f_namelen = UBIFS_MAX_NLEN; + buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]); + buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]); + ubifs_assert(c, buf->f_bfree <= c->block_cnt); + return 0; +} + +static int ubifs_show_options(struct seq_file *s, struct dentry *root) +{ + struct ubifs_info *c = root->d_sb->s_fs_info; + + if (c->mount_opts.unmount_mode == 2) + seq_puts(s, ",fast_unmount"); + else if (c->mount_opts.unmount_mode == 1) + seq_puts(s, ",norm_unmount"); + + if (c->mount_opts.bulk_read == 2) + seq_puts(s, ",bulk_read"); + else if (c->mount_opts.bulk_read == 1) + seq_puts(s, ",no_bulk_read"); + + if (c->mount_opts.chk_data_crc == 2) + seq_puts(s, ",chk_data_crc"); + else if (c->mount_opts.chk_data_crc == 1) + seq_puts(s, ",no_chk_data_crc"); + + if (c->mount_opts.override_compr) { + seq_printf(s, ",compr=%s", + ubifs_compr_name(c, c->mount_opts.compr_type)); + } + + seq_printf(s, ",assert=%s", ubifs_assert_action_name(c)); + seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id); + + return 0; +} + +static int ubifs_sync_fs(struct super_block *sb, int wait) +{ + int i, err; + struct ubifs_info *c = sb->s_fs_info; + + /* + * Zero @wait is just an advisory thing to help the file system shove + * lots of data into the queues, and there will be the second + * '->sync_fs()' call, with non-zero @wait. + */ + if (!wait) + return 0; + + /* + * Synchronize write buffers, because 'ubifs_run_commit()' does not + * do this if it waits for an already running commit. + */ + for (i = 0; i < c->jhead_cnt; i++) { + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err) + return err; + } + + /* + * Strictly speaking, it is not necessary to commit the journal here, + * synchronizing write-buffers would be enough. But committing makes + * UBIFS free space predictions much more accurate, so we want to let + * the user be able to get more accurate results of 'statfs()' after + * they synchronize the file system. + */ + err = ubifs_run_commit(c); + if (err) + return err; + + return ubi_sync(c->vi.ubi_num); +} + +/** + * init_constants_early - initialize UBIFS constants. + * @c: UBIFS file-system description object + * + * This function initialize UBIFS constants which do not need the superblock to + * be read. It also checks that the UBI volume satisfies basic UBIFS + * requirements. Returns zero in case of success and a negative error code in + * case of failure. + */ +static int init_constants_early(struct ubifs_info *c) +{ + if (c->vi.corrupted) { + ubifs_warn(c, "UBI volume is corrupted - read-only mode"); + c->ro_media = 1; + } + + if (c->di.ro_mode) { + ubifs_msg(c, "read-only UBI device"); + c->ro_media = 1; + } + + if (c->vi.vol_type == UBI_STATIC_VOLUME) { + ubifs_msg(c, "static UBI volume - read-only mode"); + c->ro_media = 1; + } + + c->leb_cnt = c->vi.size; + c->leb_size = c->vi.usable_leb_size; + c->leb_start = c->di.leb_start; + c->half_leb_size = c->leb_size / 2; + c->min_io_size = c->di.min_io_size; + c->min_io_shift = fls(c->min_io_size) - 1; + c->max_write_size = c->di.max_write_size; + c->max_write_shift = fls(c->max_write_size) - 1; + + if (c->leb_size < UBIFS_MIN_LEB_SZ) { + ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes", + c->leb_size, UBIFS_MIN_LEB_SZ); + return -EINVAL; + } + + if (c->leb_cnt < UBIFS_MIN_LEB_CNT) { + ubifs_errc(c, "too few LEBs (%d), min. is %d", + c->leb_cnt, UBIFS_MIN_LEB_CNT); + return -EINVAL; + } + + if (!is_power_of_2(c->min_io_size)) { + ubifs_errc(c, "bad min. I/O size %d", c->min_io_size); + return -EINVAL; + } + + /* + * Maximum write size has to be greater or equivalent to min. I/O + * size, and be multiple of min. I/O size. + */ + if (c->max_write_size < c->min_io_size || + c->max_write_size % c->min_io_size || + !is_power_of_2(c->max_write_size)) { + ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit", + c->max_write_size, c->min_io_size); + return -EINVAL; + } + + /* + * UBIFS aligns all node to 8-byte boundary, so to make function in + * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is + * less than 8. + */ + if (c->min_io_size < 8) { + c->min_io_size = 8; + c->min_io_shift = 3; + if (c->max_write_size < c->min_io_size) { + c->max_write_size = c->min_io_size; + c->max_write_shift = c->min_io_shift; + } + } + + c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size); + c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size); + + /* + * Initialize node length ranges which are mostly needed for node + * length validation. + */ + c->ranges[UBIFS_PAD_NODE].len = UBIFS_PAD_NODE_SZ; + c->ranges[UBIFS_SB_NODE].len = UBIFS_SB_NODE_SZ; + c->ranges[UBIFS_MST_NODE].len = UBIFS_MST_NODE_SZ; + c->ranges[UBIFS_REF_NODE].len = UBIFS_REF_NODE_SZ; + c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ; + c->ranges[UBIFS_CS_NODE].len = UBIFS_CS_NODE_SZ; + c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ; + c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ + + UBIFS_MAX_HMAC_LEN; + c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ; + c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ; + + c->ranges[UBIFS_INO_NODE].min_len = UBIFS_INO_NODE_SZ; + c->ranges[UBIFS_INO_NODE].max_len = UBIFS_MAX_INO_NODE_SZ; + c->ranges[UBIFS_ORPH_NODE].min_len = + UBIFS_ORPH_NODE_SZ + sizeof(__le64); + c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size; + c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ; + c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ; + c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ; + c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ; + c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ; + c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ; + /* + * Minimum indexing node size is amended later when superblock is + * read and the key length is known. + */ + c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ; + /* + * Maximum indexing node size is amended later when superblock is + * read and the fanout is known. + */ + c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX; + + /* + * Initialize dead and dark LEB space watermarks. See gc.c for comments + * about these values. + */ + c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size); + c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size); + + /* + * Calculate how many bytes would be wasted at the end of LEB if it was + * fully filled with data nodes of maximum size. This is used in + * calculations when reporting free space. + */ + c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ; + + /* Buffer size for bulk-reads */ + c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ; + if (c->max_bu_buf_len > c->leb_size) + c->max_bu_buf_len = c->leb_size; + + /* Log is ready, preserve one LEB for commits. */ + c->min_log_bytes = c->leb_size; + + return 0; +} + +/** + * bud_wbuf_callback - bud LEB write-buffer synchronization call-back. + * @c: UBIFS file-system description object + * @lnum: LEB the write-buffer was synchronized to + * @free: how many free bytes left in this LEB + * @pad: how many bytes were padded + * + * This is a callback function which is called by the I/O unit when the + * write-buffer is synchronized. We need this to correctly maintain space + * accounting in bud logical eraseblocks. This function returns zero in case of + * success and a negative error code in case of failure. + * + * This function actually belongs to the journal, but we keep it here because + * we want to keep it static. + */ +static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad) +{ + return ubifs_update_one_lp(c, lnum, free, pad, 0, 0); +} + +/* + * init_constants_sb - initialize UBIFS constants. + * @c: UBIFS file-system description object + * + * This is a helper function which initializes various UBIFS constants after + * the superblock has been read. It also checks various UBIFS parameters and + * makes sure they are all right. Returns zero in case of success and a + * negative error code in case of failure. + */ +static int init_constants_sb(struct ubifs_info *c) +{ + int tmp, err; + long long tmp64; + + c->main_bytes = (long long)c->main_lebs * c->leb_size; + c->max_znode_sz = sizeof(struct ubifs_znode) + + c->fanout * sizeof(struct ubifs_zbranch); + + tmp = ubifs_idx_node_sz(c, 1); + c->ranges[UBIFS_IDX_NODE].min_len = tmp; + c->min_idx_node_sz = ALIGN(tmp, 8); + + tmp = ubifs_idx_node_sz(c, c->fanout); + c->ranges[UBIFS_IDX_NODE].max_len = tmp; + c->max_idx_node_sz = ALIGN(tmp, 8); + + /* Make sure LEB size is large enough to fit full commit */ + tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt; + tmp = ALIGN(tmp, c->min_io_size); + if (tmp > c->leb_size) { + ubifs_err(c, "too small LEB size %d, at least %d needed", + c->leb_size, tmp); + return -EINVAL; + } + + /* + * Make sure that the log is large enough to fit reference nodes for + * all buds plus one reserved LEB. + */ + tmp64 = c->max_bud_bytes + c->leb_size - 1; + c->max_bud_cnt = div_u64(tmp64, c->leb_size); + tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1); + tmp /= c->leb_size; + tmp += 1; + if (c->log_lebs < tmp) { + ubifs_err(c, "too small log %d LEBs, required min. %d LEBs", + c->log_lebs, tmp); + return -EINVAL; + } + + /* + * When budgeting we assume worst-case scenarios when the pages are not + * be compressed and direntries are of the maximum size. + * + * Note, data, which may be stored in inodes is budgeted separately, so + * it is not included into 'c->bi.inode_budget'. + */ + c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE; + c->bi.inode_budget = UBIFS_INO_NODE_SZ; + c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ; + + /* + * When the amount of flash space used by buds becomes + * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit. + * The writers are unblocked when the commit is finished. To avoid + * writers to be blocked UBIFS initiates background commit in advance, + * when number of bud bytes becomes above the limit defined below. + */ + c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4; + + /* + * Ensure minimum journal size. All the bytes in the journal heads are + * considered to be used, when calculating the current journal usage. + * Consequently, if the journal is too small, UBIFS will treat it as + * always full. + */ + tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1; + if (c->bg_bud_bytes < tmp64) + c->bg_bud_bytes = tmp64; + if (c->max_bud_bytes < tmp64 + c->leb_size) + c->max_bud_bytes = tmp64 + c->leb_size; + + err = ubifs_calc_lpt_geom(c); + if (err) + return err; + + /* Initialize effective LEB size used in budgeting calculations */ + c->idx_leb_size = c->leb_size - c->max_idx_node_sz; + return 0; +} + +/* + * init_constants_master - initialize UBIFS constants. + * @c: UBIFS file-system description object + * + * This is a helper function which initializes various UBIFS constants after + * the master node has been read. It also checks various UBIFS parameters and + * makes sure they are all right. + */ +static void init_constants_master(struct ubifs_info *c) +{ + long long tmp64; + + c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); + c->report_rp_size = ubifs_reported_space(c, c->rp_size); + + /* + * Calculate total amount of FS blocks. This number is not used + * internally because it does not make much sense for UBIFS, but it is + * necessary to report something for the 'statfs()' call. + * + * Subtract the LEB reserved for GC, the LEB which is reserved for + * deletions, minimum LEBs for the index, and assume only one journal + * head is available. + */ + tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1; + tmp64 *= (long long)c->leb_size - c->leb_overhead; + tmp64 = ubifs_reported_space(c, tmp64); + c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT; +} + +/** + * take_gc_lnum - reserve GC LEB. + * @c: UBIFS file-system description object + * + * This function ensures that the LEB reserved for garbage collection is marked + * as "taken" in lprops. We also have to set free space to LEB size and dirty + * space to zero, because lprops may contain out-of-date information if the + * file-system was un-mounted before it has been committed. This function + * returns zero in case of success and a negative error code in case of + * failure. + */ +static int take_gc_lnum(struct ubifs_info *c) +{ + int err; + + if (c->gc_lnum == -1) { + ubifs_err(c, "no LEB for GC"); + return -EINVAL; + } + + /* And we have to tell lprops that this LEB is taken */ + err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0, + LPROPS_TAKEN, 0, 0); + return err; +} + +/** + * alloc_wbufs - allocate write-buffers. + * @c: UBIFS file-system description object + * + * This helper function allocates and initializes UBIFS write-buffers. Returns + * zero in case of success and %-ENOMEM in case of failure. + */ +static int alloc_wbufs(struct ubifs_info *c) +{ + int i, err; + + c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead), + GFP_KERNEL); + if (!c->jheads) + return -ENOMEM; + + /* Initialize journal heads */ + for (i = 0; i < c->jhead_cnt; i++) { + INIT_LIST_HEAD(&c->jheads[i].buds_list); + err = ubifs_wbuf_init(c, &c->jheads[i].wbuf); + if (err) + goto out_wbuf; + + c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback; + c->jheads[i].wbuf.jhead = i; + c->jheads[i].grouped = 1; + c->jheads[i].log_hash = ubifs_hash_get_desc(c); + if (IS_ERR(c->jheads[i].log_hash)) { + err = PTR_ERR(c->jheads[i].log_hash); + goto out_log_hash; + } + } + + /* + * Garbage Collector head does not need to be synchronized by timer. + * Also GC head nodes are not grouped. + */ + c->jheads[GCHD].wbuf.no_timer = 1; + c->jheads[GCHD].grouped = 0; + + return 0; + +out_log_hash: + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); + +out_wbuf: + while (i--) { + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); + kfree(c->jheads[i].log_hash); + } + kfree(c->jheads); + c->jheads = NULL; + + return err; +} + +/** + * free_wbufs - free write-buffers. + * @c: UBIFS file-system description object + */ +static void free_wbufs(struct ubifs_info *c) +{ + int i; + + if (c->jheads) { + for (i = 0; i < c->jhead_cnt; i++) { + kfree(c->jheads[i].wbuf.buf); + kfree(c->jheads[i].wbuf.inodes); + kfree(c->jheads[i].log_hash); + } + kfree(c->jheads); + c->jheads = NULL; + } +} + +/** + * free_orphans - free orphans. + * @c: UBIFS file-system description object + */ +static void free_orphans(struct ubifs_info *c) +{ + struct ubifs_orphan *orph; + + while (c->orph_dnext) { + orph = c->orph_dnext; + c->orph_dnext = orph->dnext; + list_del(&orph->list); + kfree(orph); + } + + while (!list_empty(&c->orph_list)) { + orph = list_entry(c->orph_list.next, struct ubifs_orphan, list); + list_del(&orph->list); + kfree(orph); + ubifs_err(c, "orphan list not empty at unmount"); + } + + vfree(c->orph_buf); + c->orph_buf = NULL; +} + +/** + * free_buds - free per-bud objects. + * @c: UBIFS file-system description object + */ +static void free_buds(struct ubifs_info *c) +{ + struct ubifs_bud *bud, *n; + + rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb) + kfree(bud); +} + +/** + * check_volume_empty - check if the UBI volume is empty. + * @c: UBIFS file-system description object + * + * This function checks if the UBIFS volume is empty by looking if its LEBs are + * mapped or not. The result of checking is stored in the @c->empty variable. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +static int check_volume_empty(struct ubifs_info *c) +{ + int lnum, err; + + c->empty = 1; + for (lnum = 0; lnum < c->leb_cnt; lnum++) { + err = ubifs_is_mapped(c, lnum); + if (unlikely(err < 0)) + return err; + if (err == 1) { + c->empty = 0; + break; + } + + cond_resched(); + } + + return 0; +} + +/* + * UBIFS mount options. + * + * Opt_fast_unmount: do not run a journal commit before un-mounting + * Opt_norm_unmount: run a journal commit before un-mounting + * Opt_bulk_read: enable bulk-reads + * Opt_no_bulk_read: disable bulk-reads + * Opt_chk_data_crc: check CRCs when reading data nodes + * Opt_no_chk_data_crc: do not check CRCs when reading data nodes + * Opt_override_compr: override default compressor + * Opt_assert: set ubifs_assert() action + * Opt_auth_key: The key name used for authentication + * Opt_auth_hash_name: The hash type used for authentication + * Opt_err: just end of array marker + */ +enum { + Opt_fast_unmount, + Opt_norm_unmount, + Opt_bulk_read, + Opt_no_bulk_read, + Opt_chk_data_crc, + Opt_no_chk_data_crc, + Opt_override_compr, + Opt_assert, + Opt_auth_key, + Opt_auth_hash_name, + Opt_ignore, + Opt_err, +}; + +static const match_table_t tokens = { + {Opt_fast_unmount, "fast_unmount"}, + {Opt_norm_unmount, "norm_unmount"}, + {Opt_bulk_read, "bulk_read"}, + {Opt_no_bulk_read, "no_bulk_read"}, + {Opt_chk_data_crc, "chk_data_crc"}, + {Opt_no_chk_data_crc, "no_chk_data_crc"}, + {Opt_override_compr, "compr=%s"}, + {Opt_auth_key, "auth_key=%s"}, + {Opt_auth_hash_name, "auth_hash_name=%s"}, + {Opt_ignore, "ubi=%s"}, + {Opt_ignore, "vol=%s"}, + {Opt_assert, "assert=%s"}, + {Opt_err, NULL}, +}; + +/** + * parse_standard_option - parse a standard mount option. + * @option: the option to parse + * + * Normally, standard mount options like "sync" are passed to file-systems as + * flags. However, when a "rootflags=" kernel boot parameter is used, they may + * be present in the options string. This function tries to deal with this + * situation and parse standard options. Returns 0 if the option was not + * recognized, and the corresponding integer flag if it was. + * + * UBIFS is only interested in the "sync" option, so do not check for anything + * else. + */ +static int parse_standard_option(const char *option) +{ + + pr_notice("UBIFS: parse %s\n", option); + if (!strcmp(option, "sync")) + return SB_SYNCHRONOUS; + return 0; +} + +/** + * ubifs_parse_options - parse mount parameters. + * @c: UBIFS file-system description object + * @options: parameters to parse + * @is_remount: non-zero if this is FS re-mount + * + * This function parses UBIFS mount options and returns zero in case success + * and a negative error code in case of failure. + */ +static int ubifs_parse_options(struct ubifs_info *c, char *options, + int is_remount) +{ + char *p; + substring_t args[MAX_OPT_ARGS]; + + if (!options) + return 0; + + while ((p = strsep(&options, ","))) { + int token; + + if (!*p) + continue; + + token = match_token(p, tokens, args); + switch (token) { + /* + * %Opt_fast_unmount and %Opt_norm_unmount options are ignored. + * We accept them in order to be backward-compatible. But this + * should be removed at some point. + */ + case Opt_fast_unmount: + c->mount_opts.unmount_mode = 2; + break; + case Opt_norm_unmount: + c->mount_opts.unmount_mode = 1; + break; + case Opt_bulk_read: + c->mount_opts.bulk_read = 2; + c->bulk_read = 1; + break; + case Opt_no_bulk_read: + c->mount_opts.bulk_read = 1; + c->bulk_read = 0; + break; + case Opt_chk_data_crc: + c->mount_opts.chk_data_crc = 2; + c->no_chk_data_crc = 0; + break; + case Opt_no_chk_data_crc: + c->mount_opts.chk_data_crc = 1; + c->no_chk_data_crc = 1; + break; + case Opt_override_compr: + { + char *name = match_strdup(&args[0]); + + if (!name) + return -ENOMEM; + if (!strcmp(name, "none")) + c->mount_opts.compr_type = UBIFS_COMPR_NONE; + else if (!strcmp(name, "lzo")) + c->mount_opts.compr_type = UBIFS_COMPR_LZO; + else if (!strcmp(name, "zlib")) + c->mount_opts.compr_type = UBIFS_COMPR_ZLIB; + else if (!strcmp(name, "zstd")) + c->mount_opts.compr_type = UBIFS_COMPR_ZSTD; + else { + ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready? + kfree(name); + return -EINVAL; + } + kfree(name); + c->mount_opts.override_compr = 1; + c->default_compr = c->mount_opts.compr_type; + break; + } + case Opt_assert: + { + char *act = match_strdup(&args[0]); + + if (!act) + return -ENOMEM; + if (!strcmp(act, "report")) + c->assert_action = ASSACT_REPORT; + else if (!strcmp(act, "read-only")) + c->assert_action = ASSACT_RO; + else if (!strcmp(act, "panic")) + c->assert_action = ASSACT_PANIC; + else { + ubifs_err(c, "unknown assert action \"%s\"", act); + kfree(act); + return -EINVAL; + } + kfree(act); + break; + } + case Opt_auth_key: + if (!is_remount) { + c->auth_key_name = kstrdup(args[0].from, + GFP_KERNEL); + if (!c->auth_key_name) + return -ENOMEM; + } + break; + case Opt_auth_hash_name: + if (!is_remount) { + c->auth_hash_name = kstrdup(args[0].from, + GFP_KERNEL); + if (!c->auth_hash_name) + return -ENOMEM; + } + break; + case Opt_ignore: + break; + default: + { + unsigned long flag; + struct super_block *sb = c->vfs_sb; + + flag = parse_standard_option(p); + if (!flag) { + ubifs_err(c, "unrecognized mount option \"%s\" or missing value", + p); + return -EINVAL; + } + sb->s_flags |= flag; + break; + } + } + } + + return 0; +} + +/* + * ubifs_release_options - release mount parameters which have been dumped. + * @c: UBIFS file-system description object + */ +static void ubifs_release_options(struct ubifs_info *c) +{ + kfree(c->auth_key_name); + c->auth_key_name = NULL; + kfree(c->auth_hash_name); + c->auth_hash_name = NULL; +} + +/** + * destroy_journal - destroy journal data structures. + * @c: UBIFS file-system description object + * + * This function destroys journal data structures including those that may have + * been created by recovery functions. + */ +static void destroy_journal(struct ubifs_info *c) +{ + while (!list_empty(&c->unclean_leb_list)) { + struct ubifs_unclean_leb *ucleb; + + ucleb = list_entry(c->unclean_leb_list.next, + struct ubifs_unclean_leb, list); + list_del(&ucleb->list); + kfree(ucleb); + } + while (!list_empty(&c->old_buds)) { + struct ubifs_bud *bud; + + bud = list_entry(c->old_buds.next, struct ubifs_bud, list); + list_del(&bud->list); + kfree(bud); + } + ubifs_destroy_idx_gc(c); + ubifs_destroy_size_tree(c); + ubifs_tnc_close(c); + free_buds(c); +} + +/** + * bu_init - initialize bulk-read information. + * @c: UBIFS file-system description object + */ +static void bu_init(struct ubifs_info *c) +{ + ubifs_assert(c, c->bulk_read == 1); + + if (c->bu.buf) + return; /* Already initialized */ + +again: + c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN); + if (!c->bu.buf) { + if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) { + c->max_bu_buf_len = UBIFS_KMALLOC_OK; + goto again; + } + + /* Just disable bulk-read */ + ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it", + c->max_bu_buf_len); + c->mount_opts.bulk_read = 1; + c->bulk_read = 0; + return; + } +} + +/** + * check_free_space - check if there is enough free space to mount. + * @c: UBIFS file-system description object + * + * This function makes sure UBIFS has enough free space to be mounted in + * read/write mode. UBIFS must always have some free space to allow deletions. + */ +static int check_free_space(struct ubifs_info *c) +{ + ubifs_assert(c, c->dark_wm > 0); + if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) { + ubifs_err(c, "insufficient free space to mount in R/W mode"); + ubifs_dump_budg(c, &c->bi); + ubifs_dump_lprops(c); + return -ENOSPC; + } + return 0; +} + +/** + * mount_ubifs - mount UBIFS file-system. + * @c: UBIFS file-system description object + * + * This function mounts UBIFS file system. Returns zero in case of success and + * a negative error code in case of failure. + */ +static int mount_ubifs(struct ubifs_info *c) +{ + int err; + long long x, y; + size_t sz; + + c->ro_mount = !!sb_rdonly(c->vfs_sb); + /* Suppress error messages while probing if SB_SILENT is set */ + c->probing = !!(c->vfs_sb->s_flags & SB_SILENT); + + err = init_constants_early(c); + if (err) + return err; + + err = ubifs_debugging_init(c); + if (err) + return err; + + err = check_volume_empty(c); + if (err) + goto out_free; + + if (c->empty && (c->ro_mount || c->ro_media)) { + /* + * This UBI volume is empty, and read-only, or the file system + * is mounted read-only - we cannot format it. + */ + ubifs_err(c, "can't format empty UBI volume: read-only %s", + c->ro_media ? "UBI volume" : "mount"); + err = -EROFS; + goto out_free; + } + + if (c->ro_media && !c->ro_mount) { + ubifs_err(c, "cannot mount read-write - read-only media"); + err = -EROFS; + goto out_free; + } + + /* + * The requirement for the buffer is that it should fit indexing B-tree + * height amount of integers. We assume the height if the TNC tree will + * never exceed 64. + */ + err = -ENOMEM; + c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int), + GFP_KERNEL); + if (!c->bottom_up_buf) + goto out_free; + + c->sbuf = vmalloc(c->leb_size); + if (!c->sbuf) + goto out_free; + + if (!c->ro_mount) { + c->ileb_buf = vmalloc(c->leb_size); + if (!c->ileb_buf) + goto out_free; + } + + if (c->bulk_read == 1) + bu_init(c); + + if (!c->ro_mount) { + c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \ + UBIFS_CIPHER_BLOCK_SIZE, + GFP_KERNEL); + if (!c->write_reserve_buf) + goto out_free; + } + + c->mounting = 1; + + if (c->auth_key_name) { + if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) { + err = ubifs_init_authentication(c); + if (err) + goto out_free; + } else { + ubifs_err(c, "auth_key_name, but UBIFS is built without" + " authentication support"); + err = -EINVAL; + goto out_free; + } + } + + err = ubifs_read_superblock(c); + if (err) + goto out_auth; + + c->probing = 0; + + /* + * Make sure the compressor which is set as default in the superblock + * or overridden by mount options is actually compiled in. + */ + if (!ubifs_compr_present(c, c->default_compr)) { + ubifs_err(c, "'compressor \"%s\" is not compiled in", + ubifs_compr_name(c, c->default_compr)); + err = -ENOTSUPP; + goto out_auth; + } + + err = init_constants_sb(c); + if (err) + goto out_auth; + + sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2; + c->cbuf = kmalloc(sz, GFP_NOFS); + if (!c->cbuf) { + err = -ENOMEM; + goto out_auth; + } + + err = alloc_wbufs(c); + if (err) + goto out_cbuf; + + sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id); + if (!c->ro_mount) { + /* Create background thread */ + c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name); + if (IS_ERR(c->bgt)) { + err = PTR_ERR(c->bgt); + c->bgt = NULL; + ubifs_err(c, "cannot spawn \"%s\", error %d", + c->bgt_name, err); + goto out_wbufs; + } + wake_up_process(c->bgt); + } + + err = ubifs_read_master(c); + if (err) + goto out_master; + + init_constants_master(c); + + if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) { + ubifs_msg(c, "recovery needed"); + c->need_recovery = 1; + } + + if (c->need_recovery && !c->ro_mount) { + err = ubifs_recover_inl_heads(c, c->sbuf); + if (err) + goto out_master; + } + + err = ubifs_lpt_init(c, 1, !c->ro_mount); + if (err) + goto out_master; + + if (!c->ro_mount && c->space_fixup) { + err = ubifs_fixup_free_space(c); + if (err) + goto out_lpt; + } + + if (!c->ro_mount && !c->need_recovery) { + /* + * Set the "dirty" flag so that if we reboot uncleanly we + * will notice this immediately on the next mount. + */ + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); + err = ubifs_write_master(c); + if (err) + goto out_lpt; + } + + /* + * Handle offline signed images: Now that the master node is + * written and its validation no longer depends on the hash + * in the superblock, we can update the offline signed + * superblock with a HMAC version, + */ + if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) { + err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm); + if (err) + goto out_lpt; + c->superblock_need_write = 1; + } + + if (!c->ro_mount && c->superblock_need_write) { + err = ubifs_write_sb_node(c, c->sup_node); + if (err) + goto out_lpt; + c->superblock_need_write = 0; + } + + err = dbg_check_idx_size(c, c->bi.old_idx_sz); + if (err) + goto out_lpt; + + err = ubifs_replay_journal(c); + if (err) + goto out_journal; + + /* Calculate 'min_idx_lebs' after journal replay */ + c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); + + err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount); + if (err) + goto out_orphans; + + if (!c->ro_mount) { + int lnum; + + err = check_free_space(c); + if (err) + goto out_orphans; + + /* Check for enough log space */ + lnum = c->lhead_lnum + 1; + if (lnum >= UBIFS_LOG_LNUM + c->log_lebs) + lnum = UBIFS_LOG_LNUM; + if (lnum == c->ltail_lnum) { + err = ubifs_consolidate_log(c); + if (err) + goto out_orphans; + } + + if (c->need_recovery) { + if (!ubifs_authenticated(c)) { + err = ubifs_recover_size(c, true); + if (err) + goto out_orphans; + } + + err = ubifs_rcvry_gc_commit(c); + if (err) + goto out_orphans; + + if (ubifs_authenticated(c)) { + err = ubifs_recover_size(c, false); + if (err) + goto out_orphans; + } + } else { + err = take_gc_lnum(c); + if (err) + goto out_orphans; + + /* + * GC LEB may contain garbage if there was an unclean + * reboot, and it should be un-mapped. + */ + err = ubifs_leb_unmap(c, c->gc_lnum); + if (err) + goto out_orphans; + } + + err = dbg_check_lprops(c); + if (err) + goto out_orphans; + } else if (c->need_recovery) { + err = ubifs_recover_size(c, false); + if (err) + goto out_orphans; + } else { + /* + * Even if we mount read-only, we have to set space in GC LEB + * to proper value because this affects UBIFS free space + * reporting. We do not want to have a situation when + * re-mounting from R/O to R/W changes amount of free space. + */ + err = take_gc_lnum(c); + if (err) + goto out_orphans; + } + + spin_lock(&ubifs_infos_lock); + list_add_tail(&c->infos_list, &ubifs_infos); + spin_unlock(&ubifs_infos_lock); + + if (c->need_recovery) { + if (c->ro_mount) + ubifs_msg(c, "recovery deferred"); + else { + c->need_recovery = 0; + ubifs_msg(c, "recovery completed"); + /* + * GC LEB has to be empty and taken at this point. But + * the journal head LEBs may also be accounted as + * "empty taken" if they are empty. + */ + ubifs_assert(c, c->lst.taken_empty_lebs > 0); + } + } else + ubifs_assert(c, c->lst.taken_empty_lebs > 0); + + err = dbg_check_filesystem(c); + if (err) + goto out_infos; + + dbg_debugfs_init_fs(c); + + c->mounting = 0; + + ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s", + c->vi.ubi_num, c->vi.vol_id, c->vi.name, + c->ro_mount ? ", R/O mode" : ""); + x = (long long)c->main_lebs * c->leb_size; + y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes; + ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes", + c->leb_size, c->leb_size >> 10, c->min_io_size, + c->max_write_size); + ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)", + x, x >> 20, c->main_lebs, + y, y >> 20, c->log_lebs + c->max_bud_cnt); + ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)", + c->report_rp_size, c->report_rp_size >> 10); + ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s", + c->fmt_version, c->ro_compat_version, + UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid, + c->big_lpt ? ", big LPT model" : ", small LPT model"); + + dbg_gen("default compressor: %s", ubifs_compr_name(c, c->default_compr)); + dbg_gen("data journal heads: %d", + c->jhead_cnt - NONDATA_JHEADS_CNT); + dbg_gen("log LEBs: %d (%d - %d)", + c->log_lebs, UBIFS_LOG_LNUM, c->log_last); + dbg_gen("LPT area LEBs: %d (%d - %d)", + c->lpt_lebs, c->lpt_first, c->lpt_last); + dbg_gen("orphan area LEBs: %d (%d - %d)", + c->orph_lebs, c->orph_first, c->orph_last); + dbg_gen("main area LEBs: %d (%d - %d)", + c->main_lebs, c->main_first, c->leb_cnt - 1); + dbg_gen("index LEBs: %d", c->lst.idx_lebs); + dbg_gen("total index bytes: %lld (%lld KiB, %lld MiB)", + c->bi.old_idx_sz, c->bi.old_idx_sz >> 10, + c->bi.old_idx_sz >> 20); + dbg_gen("key hash type: %d", c->key_hash_type); + dbg_gen("tree fanout: %d", c->fanout); + dbg_gen("reserved GC LEB: %d", c->gc_lnum); + dbg_gen("max. znode size %d", c->max_znode_sz); + dbg_gen("max. index node size %d", c->max_idx_node_sz); + dbg_gen("node sizes: data %zu, inode %zu, dentry %zu", + UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ); + dbg_gen("node sizes: trun %zu, sb %zu, master %zu", + UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ); + dbg_gen("node sizes: ref %zu, cmt. start %zu, orph %zu", + UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ); + dbg_gen("max. node sizes: data %zu, inode %zu dentry %zu, idx %d", + UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ, + UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout)); + dbg_gen("dead watermark: %d", c->dead_wm); + dbg_gen("dark watermark: %d", c->dark_wm); + dbg_gen("LEB overhead: %d", c->leb_overhead); + x = (long long)c->main_lebs * c->dark_wm; + dbg_gen("max. dark space: %lld (%lld KiB, %lld MiB)", + x, x >> 10, x >> 20); + dbg_gen("maximum bud bytes: %lld (%lld KiB, %lld MiB)", + c->max_bud_bytes, c->max_bud_bytes >> 10, + c->max_bud_bytes >> 20); + dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)", + c->bg_bud_bytes, c->bg_bud_bytes >> 10, + c->bg_bud_bytes >> 20); + dbg_gen("current bud bytes %lld (%lld KiB, %lld MiB)", + c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20); + dbg_gen("max. seq. number: %llu", c->max_sqnum); + dbg_gen("commit number: %llu", c->cmt_no); + dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c)); + dbg_gen("max orphans: %d", c->max_orphans); + + return 0; + +out_infos: + spin_lock(&ubifs_infos_lock); + list_del(&c->infos_list); + spin_unlock(&ubifs_infos_lock); +out_orphans: + free_orphans(c); +out_journal: + destroy_journal(c); +out_lpt: + ubifs_lpt_free(c, 0); +out_master: + kfree(c->mst_node); + kfree(c->rcvrd_mst_node); + if (c->bgt) + kthread_stop(c->bgt); +out_wbufs: + free_wbufs(c); +out_cbuf: + kfree(c->cbuf); +out_auth: + ubifs_exit_authentication(c); +out_free: + kfree(c->write_reserve_buf); + kfree(c->bu.buf); + vfree(c->ileb_buf); + vfree(c->sbuf); + kfree(c->bottom_up_buf); + kfree(c->sup_node); + ubifs_debugging_exit(c); + return err; +} + +/** + * ubifs_umount - un-mount UBIFS file-system. + * @c: UBIFS file-system description object + * + * Note, this function is called to free allocated resourced when un-mounting, + * as well as free resources when an error occurred while we were half way + * through mounting (error path cleanup function). So it has to make sure the + * resource was actually allocated before freeing it. + */ +static void ubifs_umount(struct ubifs_info *c) +{ + dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num, + c->vi.vol_id); + + dbg_debugfs_exit_fs(c); + spin_lock(&ubifs_infos_lock); + list_del(&c->infos_list); + spin_unlock(&ubifs_infos_lock); + + if (c->bgt) + kthread_stop(c->bgt); + + destroy_journal(c); + free_wbufs(c); + free_orphans(c); + ubifs_lpt_free(c, 0); + ubifs_exit_authentication(c); + + ubifs_release_options(c); + kfree(c->cbuf); + kfree(c->rcvrd_mst_node); + kfree(c->mst_node); + kfree(c->write_reserve_buf); + kfree(c->bu.buf); + vfree(c->ileb_buf); + vfree(c->sbuf); + kfree(c->bottom_up_buf); + kfree(c->sup_node); + ubifs_debugging_exit(c); +} + +/** + * ubifs_remount_rw - re-mount in read-write mode. + * @c: UBIFS file-system description object + * + * UBIFS avoids allocating many unnecessary resources when mounted in read-only + * mode. This function allocates the needed resources and re-mounts UBIFS in + * read-write mode. + */ +static int ubifs_remount_rw(struct ubifs_info *c) +{ + int err, lnum; + + if (c->rw_incompat) { + ubifs_err(c, "the file-system is not R/W-compatible"); + ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", + c->fmt_version, c->ro_compat_version, + UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION); + return -EROFS; + } + + mutex_lock(&c->umount_mutex); + dbg_save_space_info(c); + c->remounting_rw = 1; + c->ro_mount = 0; + + if (c->space_fixup) { + err = ubifs_fixup_free_space(c); + if (err) + goto out; + } + + err = check_free_space(c); + if (err) + goto out; + + if (c->need_recovery) { + ubifs_msg(c, "completing deferred recovery"); + err = ubifs_write_rcvrd_mst_node(c); + if (err) + goto out; + if (!ubifs_authenticated(c)) { + err = ubifs_recover_size(c, true); + if (err) + goto out; + } + err = ubifs_clean_lebs(c, c->sbuf); + if (err) + goto out; + err = ubifs_recover_inl_heads(c, c->sbuf); + if (err) + goto out; + } else { + /* A readonly mount is not allowed to have orphans */ + ubifs_assert(c, c->tot_orphans == 0); + err = ubifs_clear_orphans(c); + if (err) + goto out; + } + + if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) { + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); + err = ubifs_write_master(c); + if (err) + goto out; + } + + if (c->superblock_need_write) { + struct ubifs_sb_node *sup = c->sup_node; + + err = ubifs_write_sb_node(c, sup); + if (err) + goto out; + + c->superblock_need_write = 0; + } + + c->ileb_buf = vmalloc(c->leb_size); + if (!c->ileb_buf) { + err = -ENOMEM; + goto out; + } + + c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \ + UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL); + if (!c->write_reserve_buf) { + err = -ENOMEM; + goto out; + } + + err = ubifs_lpt_init(c, 0, 1); + if (err) + goto out; + + /* Create background thread */ + c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name); + if (IS_ERR(c->bgt)) { + err = PTR_ERR(c->bgt); + c->bgt = NULL; + ubifs_err(c, "cannot spawn \"%s\", error %d", + c->bgt_name, err); + goto out; + } + wake_up_process(c->bgt); + + c->orph_buf = vmalloc(c->leb_size); + if (!c->orph_buf) { + err = -ENOMEM; + goto out; + } + + /* Check for enough log space */ + lnum = c->lhead_lnum + 1; + if (lnum >= UBIFS_LOG_LNUM + c->log_lebs) + lnum = UBIFS_LOG_LNUM; + if (lnum == c->ltail_lnum) { + err = ubifs_consolidate_log(c); + if (err) + goto out; + } + + if (c->need_recovery) { + err = ubifs_rcvry_gc_commit(c); + if (err) + goto out; + + if (ubifs_authenticated(c)) { + err = ubifs_recover_size(c, false); + if (err) + goto out; + } + } else { + err = ubifs_leb_unmap(c, c->gc_lnum); + } + if (err) + goto out; + + dbg_gen("re-mounted read-write"); + c->remounting_rw = 0; + + if (c->need_recovery) { + c->need_recovery = 0; + ubifs_msg(c, "deferred recovery completed"); + } else { + /* + * Do not run the debugging space check if the were doing + * recovery, because when we saved the information we had the + * file-system in a state where the TNC and lprops has been + * modified in memory, but all the I/O operations (including a + * commit) were deferred. So the file-system was in + * "non-committed" state. Now the file-system is in committed + * state, and of course the amount of free space will change + * because, for example, the old index size was imprecise. + */ + err = dbg_check_space_info(c); + } + + mutex_unlock(&c->umount_mutex); + return err; + +out: + c->ro_mount = 1; + vfree(c->orph_buf); + c->orph_buf = NULL; + if (c->bgt) { + kthread_stop(c->bgt); + c->bgt = NULL; + } + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; + vfree(c->ileb_buf); + c->ileb_buf = NULL; + ubifs_lpt_free(c, 1); + c->remounting_rw = 0; + mutex_unlock(&c->umount_mutex); + return err; +} + +/** + * ubifs_remount_ro - re-mount in read-only mode. + * @c: UBIFS file-system description object + * + * We assume VFS has stopped writing. Possibly the background thread could be + * running a commit, however kthread_stop will wait in that case. + */ +static void ubifs_remount_ro(struct ubifs_info *c) +{ + int i, err; + + ubifs_assert(c, !c->need_recovery); + ubifs_assert(c, !c->ro_mount); + + mutex_lock(&c->umount_mutex); + if (c->bgt) { + kthread_stop(c->bgt); + c->bgt = NULL; + } + + dbg_save_space_info(c); + + for (i = 0; i < c->jhead_cnt; i++) { + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err) + ubifs_ro_mode(c, err); + } + + c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY); + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); + c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum); + err = ubifs_write_master(c); + if (err) + ubifs_ro_mode(c, err); + + vfree(c->orph_buf); + c->orph_buf = NULL; + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; + vfree(c->ileb_buf); + c->ileb_buf = NULL; + ubifs_lpt_free(c, 1); + c->ro_mount = 1; + err = dbg_check_space_info(c); + if (err) + ubifs_ro_mode(c, err); + mutex_unlock(&c->umount_mutex); +} + +static void ubifs_put_super(struct super_block *sb) +{ + int i; + struct ubifs_info *c = sb->s_fs_info; + + ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num); + + /* + * The following asserts are only valid if there has not been a failure + * of the media. For example, there will be dirty inodes if we failed + * to write them back because of I/O errors. + */ + if (!c->ro_error) { + ubifs_assert(c, c->bi.idx_growth == 0); + ubifs_assert(c, c->bi.dd_growth == 0); + ubifs_assert(c, c->bi.data_growth == 0); + } + + /* + * The 'c->umount_lock' prevents races between UBIFS memory shrinker + * and file system un-mount. Namely, it prevents the shrinker from + * picking this superblock for shrinking - it will be just skipped if + * the mutex is locked. + */ + mutex_lock(&c->umount_mutex); + if (!c->ro_mount) { + /* + * First of all kill the background thread to make sure it does + * not interfere with un-mounting and freeing resources. + */ + if (c->bgt) { + kthread_stop(c->bgt); + c->bgt = NULL; + } + + /* + * On fatal errors c->ro_error is set to 1, in which case we do + * not write the master node. + */ + if (!c->ro_error) { + int err; + + /* Synchronize write-buffers */ + for (i = 0; i < c->jhead_cnt; i++) { + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err) + ubifs_ro_mode(c, err); + } + + /* + * We are being cleanly unmounted which means the + * orphans were killed - indicate this in the master + * node. Also save the reserved GC LEB number. + */ + c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY); + c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); + c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum); + err = ubifs_write_master(c); + if (err) + /* + * Recovery will attempt to fix the master area + * next mount, so we just print a message and + * continue to unmount normally. + */ + ubifs_err(c, "failed to write master node, error %d", + err); + } else { + for (i = 0; i < c->jhead_cnt; i++) + /* Make sure write-buffer timers are canceled */ + hrtimer_cancel(&c->jheads[i].wbuf.timer); + } + } + + ubifs_umount(c); + ubi_close_volume(c->ubi); + mutex_unlock(&c->umount_mutex); +} + +static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) +{ + int err; + struct ubifs_info *c = sb->s_fs_info; + + sync_filesystem(sb); + dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags); + + err = ubifs_parse_options(c, data, 1); + if (err) { + ubifs_err(c, "invalid or unknown remount parameter"); + return err; + } + + if (c->ro_mount && !(*flags & SB_RDONLY)) { + if (c->ro_error) { + ubifs_msg(c, "cannot re-mount R/W due to prior errors"); + return -EROFS; + } + if (c->ro_media) { + ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O"); + return -EROFS; + } + err = ubifs_remount_rw(c); + if (err) + return err; + } else if (!c->ro_mount && (*flags & SB_RDONLY)) { + if (c->ro_error) { + ubifs_msg(c, "cannot re-mount R/O due to prior errors"); + return -EROFS; + } + ubifs_remount_ro(c); + } + + if (c->bulk_read == 1) + bu_init(c); + else { + dbg_gen("disable bulk-read"); + mutex_lock(&c->bu_mutex); + kfree(c->bu.buf); + c->bu.buf = NULL; + mutex_unlock(&c->bu_mutex); + } + + if (!c->need_recovery) + ubifs_assert(c, c->lst.taken_empty_lebs > 0); + + return 0; +} + +const struct super_operations ubifs_super_operations = { + .alloc_inode = ubifs_alloc_inode, + .free_inode = ubifs_free_inode, + .put_super = ubifs_put_super, + .write_inode = ubifs_write_inode, + .drop_inode = ubifs_drop_inode, + .evict_inode = ubifs_evict_inode, + .statfs = ubifs_statfs, + .dirty_inode = ubifs_dirty_inode, + .remount_fs = ubifs_remount_fs, + .show_options = ubifs_show_options, + .sync_fs = ubifs_sync_fs, +}; + +/** + * open_ubi - parse UBI device name string and open the UBI device. + * @name: UBI volume name + * @mode: UBI volume open mode + * + * The primary method of mounting UBIFS is by specifying the UBI volume + * character device node path. However, UBIFS may also be mounted withoug any + * character device node using one of the following methods: + * + * o ubiX_Y - mount UBI device number X, volume Y; + * o ubiY - mount UBI device number 0, volume Y; + * o ubiX:NAME - mount UBI device X, volume with name NAME; + * o ubi:NAME - mount UBI device 0, volume with name NAME. + * + * Alternative '!' separator may be used instead of ':' (because some shells + * like busybox may interpret ':' as an NFS host name separator). This function + * returns UBI volume description object in case of success and a negative + * error code in case of failure. + */ +static struct ubi_volume_desc *open_ubi(const char *name, int mode) +{ + struct ubi_volume_desc *ubi; + int dev, vol; + char *endptr; + + if (!name || !*name) + return ERR_PTR(-EINVAL); + + /* First, try to open using the device node path method */ + ubi = ubi_open_volume_path(name, mode); + if (!IS_ERR(ubi)) + return ubi; + + /* Try the "nodev" method */ + if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i') + return ERR_PTR(-EINVAL); + + /* ubi:NAME method */ + if ((name[3] == ':' || name[3] == '!') && name[4] != '\0') + return ubi_open_volume_nm(0, name + 4, mode); + + if (!isdigit(name[3])) + return ERR_PTR(-EINVAL); + + dev = simple_strtoul(name + 3, &endptr, 0); + + /* ubiY method */ + if (*endptr == '\0') + return ubi_open_volume(0, dev, mode); + + /* ubiX_Y method */ + if (*endptr == '_' && isdigit(endptr[1])) { + vol = simple_strtoul(endptr + 1, &endptr, 0); + if (*endptr != '\0') + return ERR_PTR(-EINVAL); + return ubi_open_volume(dev, vol, mode); + } + + /* ubiX:NAME method */ + if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0') + return ubi_open_volume_nm(dev, ++endptr, mode); + + return ERR_PTR(-EINVAL); +} + +static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi) +{ + struct ubifs_info *c; + + c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL); + if (c) { + spin_lock_init(&c->cnt_lock); + spin_lock_init(&c->cs_lock); + spin_lock_init(&c->buds_lock); + spin_lock_init(&c->space_lock); + spin_lock_init(&c->orphan_lock); + init_rwsem(&c->commit_sem); + mutex_init(&c->lp_mutex); + mutex_init(&c->tnc_mutex); + mutex_init(&c->log_mutex); + mutex_init(&c->umount_mutex); + mutex_init(&c->bu_mutex); + mutex_init(&c->write_reserve_mutex); + init_waitqueue_head(&c->cmt_wq); + c->buds = RB_ROOT; + c->old_idx = RB_ROOT; + c->size_tree = RB_ROOT; + c->orph_tree = RB_ROOT; + INIT_LIST_HEAD(&c->infos_list); + INIT_LIST_HEAD(&c->idx_gc); + INIT_LIST_HEAD(&c->replay_list); + INIT_LIST_HEAD(&c->replay_buds); + INIT_LIST_HEAD(&c->uncat_list); + INIT_LIST_HEAD(&c->empty_list); + INIT_LIST_HEAD(&c->freeable_list); + INIT_LIST_HEAD(&c->frdi_idx_list); + INIT_LIST_HEAD(&c->unclean_leb_list); + INIT_LIST_HEAD(&c->old_buds); + INIT_LIST_HEAD(&c->orph_list); + INIT_LIST_HEAD(&c->orph_new); + c->no_chk_data_crc = 1; + c->assert_action = ASSACT_RO; + + c->highest_inum = UBIFS_FIRST_INO; + c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM; + + ubi_get_volume_info(ubi, &c->vi); + ubi_get_device_info(c->vi.ubi_num, &c->di); + } + return c; +} + +static int ubifs_fill_super(struct super_block *sb, void *data, int silent) +{ + struct ubifs_info *c = sb->s_fs_info; + struct inode *root; + int err; + + c->vfs_sb = sb; + /* Re-open the UBI device in read-write mode */ + c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE); + if (IS_ERR(c->ubi)) { + err = PTR_ERR(c->ubi); + goto out; + } + + err = ubifs_parse_options(c, data, 0); + if (err) + goto out_close; + + /* + * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For + * UBIFS, I/O is not deferred, it is done immediately in readpage, + * which means the user would have to wait not just for their own I/O + * but the read-ahead I/O as well i.e. completely pointless. + * + * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also + * @sb->s_bdi->capabilities are initialized to 0 so there won't be any + * writeback happening. + */ + err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num, + c->vi.vol_id); + if (err) + goto out_close; + sb->s_bdi->ra_pages = 0; + sb->s_bdi->io_pages = 0; + + sb->s_fs_info = c; + sb->s_magic = UBIFS_SUPER_MAGIC; + sb->s_blocksize = UBIFS_BLOCK_SIZE; + sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT; + sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c); + if (c->max_inode_sz > MAX_LFS_FILESIZE) + sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE; + sb->s_op = &ubifs_super_operations; +#ifdef CONFIG_UBIFS_FS_XATTR + sb->s_xattr = ubifs_xattr_handlers; +#endif + fscrypt_set_ops(sb, &ubifs_crypt_operations); + + mutex_lock(&c->umount_mutex); + err = mount_ubifs(c); + if (err) { + ubifs_assert(c, err < 0); + goto out_unlock; + } + + /* Read the root inode */ + root = ubifs_iget(sb, UBIFS_ROOT_INO); + if (IS_ERR(root)) { + err = PTR_ERR(root); + goto out_umount; + } + + sb->s_root = d_make_root(root); + if (!sb->s_root) { + err = -ENOMEM; + goto out_umount; + } + + mutex_unlock(&c->umount_mutex); + return 0; + +out_umount: + ubifs_umount(c); +out_unlock: + mutex_unlock(&c->umount_mutex); +out_close: + ubifs_release_options(c); + ubi_close_volume(c->ubi); +out: + return err; +} + +static int sb_test(struct super_block *sb, void *data) +{ + struct ubifs_info *c1 = data; + struct ubifs_info *c = sb->s_fs_info; + + return c->vi.cdev == c1->vi.cdev; +} + +static int sb_set(struct super_block *sb, void *data) +{ + sb->s_fs_info = data; + return set_anon_super(sb, NULL); +} + +static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags, + const char *name, void *data) +{ + struct ubi_volume_desc *ubi; + struct ubifs_info *c; + struct super_block *sb; + int err; + + dbg_gen("name %s, flags %#x", name, flags); + + /* + * Get UBI device number and volume ID. Mount it read-only so far + * because this might be a new mount point, and UBI allows only one + * read-write user at a time. + */ + ubi = open_ubi(name, UBI_READONLY); + if (IS_ERR(ubi)) { + if (!(flags & SB_SILENT)) + pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d", + current->pid, name, (int)PTR_ERR(ubi)); + return ERR_CAST(ubi); + } + + c = alloc_ubifs_info(ubi); + if (!c) { + err = -ENOMEM; + goto out_close; + } + + dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id); + + sb = sget(fs_type, sb_test, sb_set, flags, c); + if (IS_ERR(sb)) { + err = PTR_ERR(sb); + kfree(c); + goto out_close; + } + + if (sb->s_root) { + struct ubifs_info *c1 = sb->s_fs_info; + kfree(c); + /* A new mount point for already mounted UBIFS */ + dbg_gen("this ubi volume is already mounted"); + if (!!(flags & SB_RDONLY) != c1->ro_mount) { + err = -EBUSY; + goto out_deact; + } + } else { + err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0); + if (err) + goto out_deact; + /* We do not support atime */ + sb->s_flags |= SB_ACTIVE; + if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) + ubifs_msg(c, "full atime support is enabled."); + else + sb->s_flags |= SB_NOATIME; + } + + /* 'fill_super()' opens ubi again so we must close it here */ + ubi_close_volume(ubi); + + return dget(sb->s_root); + +out_deact: + deactivate_locked_super(sb); +out_close: + ubi_close_volume(ubi); + return ERR_PTR(err); +} + +static void kill_ubifs_super(struct super_block *s) +{ + struct ubifs_info *c = s->s_fs_info; + kill_anon_super(s); + kfree(c); +} + +static struct file_system_type ubifs_fs_type = { + .name = "ubifs", + .owner = THIS_MODULE, + .mount = ubifs_mount, + .kill_sb = kill_ubifs_super, +}; +MODULE_ALIAS_FS("ubifs"); + +/* + * Inode slab cache constructor. + */ +static void inode_slab_ctor(void *obj) +{ + struct ubifs_inode *ui = obj; + inode_init_once(&ui->vfs_inode); +} + +static int __init ubifs_init(void) +{ + int err; + + BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24); + + /* Make sure node sizes are 8-byte aligned */ + BUILD_BUG_ON(UBIFS_CH_SZ & 7); + BUILD_BUG_ON(UBIFS_INO_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_SB_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_MST_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_REF_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_CS_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7); + + BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ & 7); + BUILD_BUG_ON(UBIFS_MAX_NODE_SZ & 7); + BUILD_BUG_ON(MIN_WRITE_SZ & 7); + + /* Check min. node size */ + BUILD_BUG_ON(UBIFS_INO_NODE_SZ < MIN_WRITE_SZ); + BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ); + BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ); + BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ); + + BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ); + BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ); + BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ); + BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ > UBIFS_MAX_NODE_SZ); + + /* Defined node sizes */ + BUILD_BUG_ON(UBIFS_SB_NODE_SZ != 4096); + BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512); + BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160); + BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64); + + /* + * We use 2 bit wide bit-fields to store compression type, which should + * be amended if more compressors are added. The bit-fields are: + * @compr_type in 'struct ubifs_inode', @default_compr in + * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'. + */ + BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4); + + /* + * We require that PAGE_SIZE is greater-than-or-equal-to + * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2. + */ + if (PAGE_SIZE < UBIFS_BLOCK_SIZE) { + pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes", + current->pid, (unsigned int)PAGE_SIZE); + return -EINVAL; + } + + ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab", + sizeof(struct ubifs_inode), 0, + SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT | + SLAB_ACCOUNT, &inode_slab_ctor); + if (!ubifs_inode_slab) + return -ENOMEM; + + err = register_shrinker(&ubifs_shrinker_info); + if (err) + goto out_slab; + + err = ubifs_compressors_init(); + if (err) + goto out_shrinker; + + dbg_debugfs_init(); + + err = register_filesystem(&ubifs_fs_type); + if (err) { + pr_err("UBIFS error (pid %d): cannot register file system, error %d", + current->pid, err); + goto out_dbg; + } + return 0; + +out_dbg: + dbg_debugfs_exit(); + ubifs_compressors_exit(); +out_shrinker: + unregister_shrinker(&ubifs_shrinker_info); +out_slab: + kmem_cache_destroy(ubifs_inode_slab); + return err; +} +/* late_initcall to let compressors initialize first */ +late_initcall(ubifs_init); + +static void __exit ubifs_exit(void) +{ + WARN_ON(!list_empty(&ubifs_infos)); + WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0); + + dbg_debugfs_exit(); + ubifs_compressors_exit(); + unregister_shrinker(&ubifs_shrinker_info); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + kmem_cache_destroy(ubifs_inode_slab); + unregister_filesystem(&ubifs_fs_type); +} +module_exit(ubifs_exit); + +MODULE_LICENSE("GPL"); +MODULE_VERSION(__stringify(UBIFS_VERSION)); +MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter"); +MODULE_DESCRIPTION("UBIFS - UBI File System"); diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c new file mode 100644 index 000000000..2313c7174 --- /dev/null +++ b/fs/ubifs/tnc.c @@ -0,0 +1,3584 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements TNC (Tree Node Cache) which caches indexing nodes of + * the UBIFS B-tree. + * + * At the moment the locking rules of the TNC tree are quite simple and + * straightforward. We just have a mutex and lock it when we traverse the + * tree. If a znode is not in memory, we read it from flash while still having + * the mutex locked. + */ + +#include <linux/crc32.h> +#include <linux/slab.h> +#include "ubifs.h" + +static int try_read_node(const struct ubifs_info *c, void *buf, int type, + struct ubifs_zbranch *zbr); +static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_zbranch *zbr, void *node); + +/* + * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions. + * @NAME_LESS: name corresponding to the first argument is less than second + * @NAME_MATCHES: names match + * @NAME_GREATER: name corresponding to the second argument is greater than + * first + * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media + * + * These constants were introduce to improve readability. + */ +enum { + NAME_LESS = 0, + NAME_MATCHES = 1, + NAME_GREATER = 2, + NOT_ON_MEDIA = 3, +}; + +static void do_insert_old_idx(struct ubifs_info *c, + struct ubifs_old_idx *old_idx) +{ + struct ubifs_old_idx *o; + struct rb_node **p, *parent = NULL; + + p = &c->old_idx.rb_node; + while (*p) { + parent = *p; + o = rb_entry(parent, struct ubifs_old_idx, rb); + if (old_idx->lnum < o->lnum) + p = &(*p)->rb_left; + else if (old_idx->lnum > o->lnum) + p = &(*p)->rb_right; + else if (old_idx->offs < o->offs) + p = &(*p)->rb_left; + else if (old_idx->offs > o->offs) + p = &(*p)->rb_right; + else { + ubifs_err(c, "old idx added twice!"); + kfree(old_idx); + } + } + rb_link_node(&old_idx->rb, parent, p); + rb_insert_color(&old_idx->rb, &c->old_idx); +} + +/** + * insert_old_idx - record an index node obsoleted since the last commit start. + * @c: UBIFS file-system description object + * @lnum: LEB number of obsoleted index node + * @offs: offset of obsoleted index node + * + * Returns %0 on success, and a negative error code on failure. + * + * For recovery, there must always be a complete intact version of the index on + * flash at all times. That is called the "old index". It is the index as at the + * time of the last successful commit. Many of the index nodes in the old index + * may be dirty, but they must not be erased until the next successful commit + * (at which point that index becomes the old index). + * + * That means that the garbage collection and the in-the-gaps method of + * committing must be able to determine if an index node is in the old index. + * Most of the old index nodes can be found by looking up the TNC using the + * 'lookup_znode()' function. However, some of the old index nodes may have + * been deleted from the current index or may have been changed so much that + * they cannot be easily found. In those cases, an entry is added to an RB-tree. + * That is what this function does. The RB-tree is ordered by LEB number and + * offset because they uniquely identify the old index node. + */ +static int insert_old_idx(struct ubifs_info *c, int lnum, int offs) +{ + struct ubifs_old_idx *old_idx; + + old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); + if (unlikely(!old_idx)) + return -ENOMEM; + old_idx->lnum = lnum; + old_idx->offs = offs; + do_insert_old_idx(c, old_idx); + + return 0; +} + +/** + * insert_old_idx_znode - record a znode obsoleted since last commit start. + * @c: UBIFS file-system description object + * @znode: znode of obsoleted index node + * + * Returns %0 on success, and a negative error code on failure. + */ +int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode) +{ + if (znode->parent) { + struct ubifs_zbranch *zbr; + + zbr = &znode->parent->zbranch[znode->iip]; + if (zbr->len) + return insert_old_idx(c, zbr->lnum, zbr->offs); + } else + if (c->zroot.len) + return insert_old_idx(c, c->zroot.lnum, + c->zroot.offs); + return 0; +} + +/** + * ins_clr_old_idx_znode - record a znode obsoleted since last commit start. + * @c: UBIFS file-system description object + * @znode: znode of obsoleted index node + * + * Returns %0 on success, and a negative error code on failure. + */ +static int ins_clr_old_idx_znode(struct ubifs_info *c, + struct ubifs_znode *znode) +{ + int err; + + if (znode->parent) { + struct ubifs_zbranch *zbr; + + zbr = &znode->parent->zbranch[znode->iip]; + if (zbr->len) { + err = insert_old_idx(c, zbr->lnum, zbr->offs); + if (err) + return err; + zbr->lnum = 0; + zbr->offs = 0; + zbr->len = 0; + } + } else + if (c->zroot.len) { + err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs); + if (err) + return err; + c->zroot.lnum = 0; + c->zroot.offs = 0; + c->zroot.len = 0; + } + return 0; +} + +/** + * destroy_old_idx - destroy the old_idx RB-tree. + * @c: UBIFS file-system description object + * + * During start commit, the old_idx RB-tree is used to avoid overwriting index + * nodes that were in the index last commit but have since been deleted. This + * is necessary for recovery i.e. the old index must be kept intact until the + * new index is successfully written. The old-idx RB-tree is used for the + * in-the-gaps method of writing index nodes and is destroyed every commit. + */ +void destroy_old_idx(struct ubifs_info *c) +{ + struct ubifs_old_idx *old_idx, *n; + + rbtree_postorder_for_each_entry_safe(old_idx, n, &c->old_idx, rb) + kfree(old_idx); + + c->old_idx = RB_ROOT; +} + +/** + * copy_znode - copy a dirty znode. + * @c: UBIFS file-system description object + * @znode: znode to copy + * + * A dirty znode being committed may not be changed, so it is copied. + */ +static struct ubifs_znode *copy_znode(struct ubifs_info *c, + struct ubifs_znode *znode) +{ + struct ubifs_znode *zn; + + zn = kmemdup(znode, c->max_znode_sz, GFP_NOFS); + if (unlikely(!zn)) + return ERR_PTR(-ENOMEM); + + zn->cnext = NULL; + __set_bit(DIRTY_ZNODE, &zn->flags); + __clear_bit(COW_ZNODE, &zn->flags); + + return zn; +} + +/** + * add_idx_dirt - add dirt due to a dirty znode. + * @c: UBIFS file-system description object + * @lnum: LEB number of index node + * @dirt: size of index node + * + * This function updates lprops dirty space and the new size of the index. + */ +static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt) +{ + c->calc_idx_sz -= ALIGN(dirt, 8); + return ubifs_add_dirt(c, lnum, dirt); +} + +/** + * replace_znode - replace old znode with new znode. + * @c: UBIFS file-system description object + * @new_zn: new znode + * @old_zn: old znode + * @zbr: the branch of parent znode + * + * Replace old znode with new znode in TNC. + */ +static void replace_znode(struct ubifs_info *c, struct ubifs_znode *new_zn, + struct ubifs_znode *old_zn, struct ubifs_zbranch *zbr) +{ + ubifs_assert(c, !ubifs_zn_obsolete(old_zn)); + __set_bit(OBSOLETE_ZNODE, &old_zn->flags); + + if (old_zn->level != 0) { + int i; + const int n = new_zn->child_cnt; + + /* The children now have new parent */ + for (i = 0; i < n; i++) { + struct ubifs_zbranch *child = &new_zn->zbranch[i]; + + if (child->znode) + child->znode->parent = new_zn; + } + } + + zbr->znode = new_zn; + zbr->lnum = 0; + zbr->offs = 0; + zbr->len = 0; + + atomic_long_inc(&c->dirty_zn_cnt); +} + +/** + * dirty_cow_znode - ensure a znode is not being committed. + * @c: UBIFS file-system description object + * @zbr: branch of znode to check + * + * Returns dirtied znode on success or negative error code on failure. + */ +static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c, + struct ubifs_zbranch *zbr) +{ + struct ubifs_znode *znode = zbr->znode; + struct ubifs_znode *zn; + int err; + + if (!ubifs_zn_cow(znode)) { + /* znode is not being committed */ + if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) { + atomic_long_inc(&c->dirty_zn_cnt); + atomic_long_dec(&c->clean_zn_cnt); + atomic_long_dec(&ubifs_clean_zn_cnt); + err = add_idx_dirt(c, zbr->lnum, zbr->len); + if (unlikely(err)) + return ERR_PTR(err); + } + return znode; + } + + zn = copy_znode(c, znode); + if (IS_ERR(zn)) + return zn; + + if (zbr->len) { + struct ubifs_old_idx *old_idx; + + old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); + if (unlikely(!old_idx)) { + err = -ENOMEM; + goto out; + } + old_idx->lnum = zbr->lnum; + old_idx->offs = zbr->offs; + + err = add_idx_dirt(c, zbr->lnum, zbr->len); + if (err) { + kfree(old_idx); + goto out; + } + + do_insert_old_idx(c, old_idx); + } + + replace_znode(c, zn, znode, zbr); + + return zn; + +out: + kfree(zn); + return ERR_PTR(err); +} + +/** + * lnc_add - add a leaf node to the leaf node cache. + * @c: UBIFS file-system description object + * @zbr: zbranch of leaf node + * @node: leaf node + * + * Leaf nodes are non-index nodes directory entry nodes or data nodes. The + * purpose of the leaf node cache is to save re-reading the same leaf node over + * and over again. Most things are cached by VFS, however the file system must + * cache directory entries for readdir and for resolving hash collisions. The + * present implementation of the leaf node cache is extremely simple, and + * allows for error returns that are not used but that may be needed if a more + * complex implementation is created. + * + * Note, this function does not add the @node object to LNC directly, but + * allocates a copy of the object and adds the copy to LNC. The reason for this + * is that @node has been allocated outside of the TNC subsystem and will be + * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC + * may be changed at any time, e.g. freed by the shrinker. + */ +static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr, + const void *node) +{ + int err; + void *lnc_node; + const struct ubifs_dent_node *dent = node; + + ubifs_assert(c, !zbr->leaf); + ubifs_assert(c, zbr->len != 0); + ubifs_assert(c, is_hash_key(c, &zbr->key)); + + err = ubifs_validate_entry(c, dent); + if (err) { + dump_stack(); + ubifs_dump_node(c, dent); + return err; + } + + lnc_node = kmemdup(node, zbr->len, GFP_NOFS); + if (!lnc_node) + /* We don't have to have the cache, so no error */ + return 0; + + zbr->leaf = lnc_node; + return 0; +} + + /** + * lnc_add_directly - add a leaf node to the leaf-node-cache. + * @c: UBIFS file-system description object + * @zbr: zbranch of leaf node + * @node: leaf node + * + * This function is similar to 'lnc_add()', but it does not create a copy of + * @node but inserts @node to TNC directly. + */ +static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr, + void *node) +{ + int err; + + ubifs_assert(c, !zbr->leaf); + ubifs_assert(c, zbr->len != 0); + + err = ubifs_validate_entry(c, node); + if (err) { + dump_stack(); + ubifs_dump_node(c, node); + return err; + } + + zbr->leaf = node; + return 0; +} + +/** + * lnc_free - remove a leaf node from the leaf node cache. + * @zbr: zbranch of leaf node + */ +static void lnc_free(struct ubifs_zbranch *zbr) +{ + if (!zbr->leaf) + return; + kfree(zbr->leaf); + zbr->leaf = NULL; +} + +/** + * tnc_read_hashed_node - read a "hashed" leaf node. + * @c: UBIFS file-system description object + * @zbr: key and position of the node + * @node: node is returned here + * + * This function reads a "hashed" node defined by @zbr from the leaf node cache + * (in it is there) or from the hash media, in which case the node is also + * added to LNC. Returns zero in case of success or a negative negative error + * code in case of failure. + */ +static int tnc_read_hashed_node(struct ubifs_info *c, struct ubifs_zbranch *zbr, + void *node) +{ + int err; + + ubifs_assert(c, is_hash_key(c, &zbr->key)); + + if (zbr->leaf) { + /* Read from the leaf node cache */ + ubifs_assert(c, zbr->len != 0); + memcpy(node, zbr->leaf, zbr->len); + return 0; + } + + if (c->replaying) { + err = fallible_read_node(c, &zbr->key, zbr, node); + /* + * When the node was not found, return -ENOENT, 0 otherwise. + * Negative return codes stay as-is. + */ + if (err == 0) + err = -ENOENT; + else if (err == 1) + err = 0; + } else { + err = ubifs_tnc_read_node(c, zbr, node); + } + if (err) + return err; + + /* Add the node to the leaf node cache */ + err = lnc_add(c, zbr, node); + return err; +} + +/** + * try_read_node - read a node if it is a node. + * @c: UBIFS file-system description object + * @buf: buffer to read to + * @type: node type + * @zbr: the zbranch describing the node to read + * + * This function tries to read a node of known type and length, checks it and + * stores it in @buf. This function returns %1 if a node is present and %0 if + * a node is not present. A negative error code is returned for I/O errors. + * This function performs that same function as ubifs_read_node except that + * it does not require that there is actually a node present and instead + * the return code indicates if a node was read. + * + * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc + * is true (it is controlled by corresponding mount option). However, if + * @c->mounting or @c->remounting_rw is true (we are mounting or re-mounting to + * R/W mode), @c->no_chk_data_crc is ignored and CRC is checked. This is + * because during mounting or re-mounting from R/O mode to R/W mode we may read + * journal nodes (when replying the journal or doing the recovery) and the + * journal nodes may potentially be corrupted, so checking is required. + */ +static int try_read_node(const struct ubifs_info *c, void *buf, int type, + struct ubifs_zbranch *zbr) +{ + int len = zbr->len; + int lnum = zbr->lnum; + int offs = zbr->offs; + int err, node_len; + struct ubifs_ch *ch = buf; + uint32_t crc, node_crc; + + dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); + + err = ubifs_leb_read(c, lnum, buf, offs, len, 1); + if (err) { + ubifs_err(c, "cannot read node type %d from LEB %d:%d, error %d", + type, lnum, offs, err); + return err; + } + + if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) + return 0; + + if (ch->node_type != type) + return 0; + + node_len = le32_to_cpu(ch->len); + if (node_len != len) + return 0; + + if (type != UBIFS_DATA_NODE || !c->no_chk_data_crc || c->mounting || + c->remounting_rw) { + crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); + node_crc = le32_to_cpu(ch->crc); + if (crc != node_crc) + return 0; + } + + err = ubifs_node_check_hash(c, buf, zbr->hash); + if (err) { + ubifs_bad_hash(c, buf, zbr->hash, lnum, offs); + return 0; + } + + return 1; +} + +/** + * fallible_read_node - try to read a leaf node. + * @c: UBIFS file-system description object + * @key: key of node to read + * @zbr: position of node + * @node: node returned + * + * This function tries to read a node and returns %1 if the node is read, %0 + * if the node is not present, and a negative error code in the case of error. + */ +static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_zbranch *zbr, void *node) +{ + int ret; + + dbg_tnck(key, "LEB %d:%d, key ", zbr->lnum, zbr->offs); + + ret = try_read_node(c, node, key_type(c, key), zbr); + if (ret == 1) { + union ubifs_key node_key; + struct ubifs_dent_node *dent = node; + + /* All nodes have key in the same place */ + key_read(c, &dent->key, &node_key); + if (keys_cmp(c, key, &node_key) != 0) + ret = 0; + } + if (ret == 0 && c->replaying) + dbg_mntk(key, "dangling branch LEB %d:%d len %d, key ", + zbr->lnum, zbr->offs, zbr->len); + return ret; +} + +/** + * matches_name - determine if a direntry or xattr entry matches a given name. + * @c: UBIFS file-system description object + * @zbr: zbranch of dent + * @nm: name to match + * + * This function checks if xentry/direntry referred by zbranch @zbr matches name + * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by + * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case + * of failure, a negative error code is returned. + */ +static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr, + const struct fscrypt_name *nm) +{ + struct ubifs_dent_node *dent; + int nlen, err; + + /* If possible, match against the dent in the leaf node cache */ + if (!zbr->leaf) { + dent = kmalloc(zbr->len, GFP_NOFS); + if (!dent) + return -ENOMEM; + + err = ubifs_tnc_read_node(c, zbr, dent); + if (err) + goto out_free; + + /* Add the node to the leaf node cache */ + err = lnc_add_directly(c, zbr, dent); + if (err) + goto out_free; + } else + dent = zbr->leaf; + + nlen = le16_to_cpu(dent->nlen); + err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm))); + if (err == 0) { + if (nlen == fname_len(nm)) + return NAME_MATCHES; + else if (nlen < fname_len(nm)) + return NAME_LESS; + else + return NAME_GREATER; + } else if (err < 0) + return NAME_LESS; + else + return NAME_GREATER; + +out_free: + kfree(dent); + return err; +} + +/** + * get_znode - get a TNC znode that may not be loaded yet. + * @c: UBIFS file-system description object + * @znode: parent znode + * @n: znode branch slot number + * + * This function returns the znode or a negative error code. + */ +static struct ubifs_znode *get_znode(struct ubifs_info *c, + struct ubifs_znode *znode, int n) +{ + struct ubifs_zbranch *zbr; + + zbr = &znode->zbranch[n]; + if (zbr->znode) + znode = zbr->znode; + else + znode = ubifs_load_znode(c, zbr, znode, n); + return znode; +} + +/** + * tnc_next - find next TNC entry. + * @c: UBIFS file-system description object + * @zn: znode is passed and returned here + * @n: znode branch slot number is passed and returned here + * + * This function returns %0 if the next TNC entry is found, %-ENOENT if there is + * no next entry, or a negative error code otherwise. + */ +static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n) +{ + struct ubifs_znode *znode = *zn; + int nn = *n; + + nn += 1; + if (nn < znode->child_cnt) { + *n = nn; + return 0; + } + while (1) { + struct ubifs_znode *zp; + + zp = znode->parent; + if (!zp) + return -ENOENT; + nn = znode->iip + 1; + znode = zp; + if (nn < znode->child_cnt) { + znode = get_znode(c, znode, nn); + if (IS_ERR(znode)) + return PTR_ERR(znode); + while (znode->level != 0) { + znode = get_znode(c, znode, 0); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + nn = 0; + break; + } + } + *zn = znode; + *n = nn; + return 0; +} + +/** + * tnc_prev - find previous TNC entry. + * @c: UBIFS file-system description object + * @zn: znode is returned here + * @n: znode branch slot number is passed and returned here + * + * This function returns %0 if the previous TNC entry is found, %-ENOENT if + * there is no next entry, or a negative error code otherwise. + */ +static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n) +{ + struct ubifs_znode *znode = *zn; + int nn = *n; + + if (nn > 0) { + *n = nn - 1; + return 0; + } + while (1) { + struct ubifs_znode *zp; + + zp = znode->parent; + if (!zp) + return -ENOENT; + nn = znode->iip - 1; + znode = zp; + if (nn >= 0) { + znode = get_znode(c, znode, nn); + if (IS_ERR(znode)) + return PTR_ERR(znode); + while (znode->level != 0) { + nn = znode->child_cnt - 1; + znode = get_znode(c, znode, nn); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + nn = znode->child_cnt - 1; + break; + } + } + *zn = znode; + *n = nn; + return 0; +} + +/** + * resolve_collision - resolve a collision. + * @c: UBIFS file-system description object + * @key: key of a directory or extended attribute entry + * @zn: znode is returned here + * @n: zbranch number is passed and returned here + * @nm: name of the entry + * + * This function is called for "hashed" keys to make sure that the found key + * really corresponds to the looked up node (directory or extended attribute + * entry). It returns %1 and sets @zn and @n if the collision is resolved. + * %0 is returned if @nm is not found and @zn and @n are set to the previous + * entry, i.e. to the entry after which @nm could follow if it were in TNC. + * This means that @n may be set to %-1 if the leftmost key in @zn is the + * previous one. A negative error code is returned on failures. + */ +static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_znode **zn, int *n, + const struct fscrypt_name *nm) +{ + int err; + + err = matches_name(c, &(*zn)->zbranch[*n], nm); + if (unlikely(err < 0)) + return err; + if (err == NAME_MATCHES) + return 1; + + if (err == NAME_GREATER) { + /* Look left */ + while (1) { + err = tnc_prev(c, zn, n); + if (err == -ENOENT) { + ubifs_assert(c, *n == 0); + *n = -1; + return 0; + } + if (err < 0) + return err; + if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { + /* + * We have found the branch after which we would + * like to insert, but inserting in this znode + * may still be wrong. Consider the following 3 + * znodes, in the case where we are resolving a + * collision with Key2. + * + * znode zp + * ---------------------- + * level 1 | Key0 | Key1 | + * ----------------------- + * | | + * znode za | | znode zb + * ------------ ------------ + * level 0 | Key0 | | Key2 | + * ------------ ------------ + * + * The lookup finds Key2 in znode zb. Lets say + * there is no match and the name is greater so + * we look left. When we find Key0, we end up + * here. If we return now, we will insert into + * znode za at slot n = 1. But that is invalid + * according to the parent's keys. Key2 must + * be inserted into znode zb. + * + * Note, this problem is not relevant for the + * case when we go right, because + * 'tnc_insert()' would correct the parent key. + */ + if (*n == (*zn)->child_cnt - 1) { + err = tnc_next(c, zn, n); + if (err) { + /* Should be impossible */ + ubifs_assert(c, 0); + if (err == -ENOENT) + err = -EINVAL; + return err; + } + ubifs_assert(c, *n == 0); + *n = -1; + } + return 0; + } + err = matches_name(c, &(*zn)->zbranch[*n], nm); + if (err < 0) + return err; + if (err == NAME_LESS) + return 0; + if (err == NAME_MATCHES) + return 1; + ubifs_assert(c, err == NAME_GREATER); + } + } else { + int nn = *n; + struct ubifs_znode *znode = *zn; + + /* Look right */ + while (1) { + err = tnc_next(c, &znode, &nn); + if (err == -ENOENT) + return 0; + if (err < 0) + return err; + if (keys_cmp(c, &znode->zbranch[nn].key, key)) + return 0; + err = matches_name(c, &znode->zbranch[nn], nm); + if (err < 0) + return err; + if (err == NAME_GREATER) + return 0; + *zn = znode; + *n = nn; + if (err == NAME_MATCHES) + return 1; + ubifs_assert(c, err == NAME_LESS); + } + } +} + +/** + * fallible_matches_name - determine if a dent matches a given name. + * @c: UBIFS file-system description object + * @zbr: zbranch of dent + * @nm: name to match + * + * This is a "fallible" version of 'matches_name()' function which does not + * panic if the direntry/xentry referred by @zbr does not exist on the media. + * + * This function checks if xentry/direntry referred by zbranch @zbr matches name + * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr + * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA + * if xentry/direntry referred by @zbr does not exist on the media. A negative + * error code is returned in case of failure. + */ +static int fallible_matches_name(struct ubifs_info *c, + struct ubifs_zbranch *zbr, + const struct fscrypt_name *nm) +{ + struct ubifs_dent_node *dent; + int nlen, err; + + /* If possible, match against the dent in the leaf node cache */ + if (!zbr->leaf) { + dent = kmalloc(zbr->len, GFP_NOFS); + if (!dent) + return -ENOMEM; + + err = fallible_read_node(c, &zbr->key, zbr, dent); + if (err < 0) + goto out_free; + if (err == 0) { + /* The node was not present */ + err = NOT_ON_MEDIA; + goto out_free; + } + ubifs_assert(c, err == 1); + + err = lnc_add_directly(c, zbr, dent); + if (err) + goto out_free; + } else + dent = zbr->leaf; + + nlen = le16_to_cpu(dent->nlen); + err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm))); + if (err == 0) { + if (nlen == fname_len(nm)) + return NAME_MATCHES; + else if (nlen < fname_len(nm)) + return NAME_LESS; + else + return NAME_GREATER; + } else if (err < 0) + return NAME_LESS; + else + return NAME_GREATER; + +out_free: + kfree(dent); + return err; +} + +/** + * fallible_resolve_collision - resolve a collision even if nodes are missing. + * @c: UBIFS file-system description object + * @key: key + * @zn: znode is returned here + * @n: branch number is passed and returned here + * @nm: name of directory entry + * @adding: indicates caller is adding a key to the TNC + * + * This is a "fallible" version of the 'resolve_collision()' function which + * does not panic if one of the nodes referred to by TNC does not exist on the + * media. This may happen when replaying the journal if a deleted node was + * Garbage-collected and the commit was not done. A branch that refers to a node + * that is not present is called a dangling branch. The following are the return + * codes for this function: + * o if @nm was found, %1 is returned and @zn and @n are set to the found + * branch; + * o if we are @adding and @nm was not found, %0 is returned; + * o if we are not @adding and @nm was not found, but a dangling branch was + * found, then %1 is returned and @zn and @n are set to the dangling branch; + * o a negative error code is returned in case of failure. + */ +static int fallible_resolve_collision(struct ubifs_info *c, + const union ubifs_key *key, + struct ubifs_znode **zn, int *n, + const struct fscrypt_name *nm, + int adding) +{ + struct ubifs_znode *o_znode = NULL, *znode = *zn; + int o_n, err, cmp, unsure = 0, nn = *n; + + cmp = fallible_matches_name(c, &znode->zbranch[nn], nm); + if (unlikely(cmp < 0)) + return cmp; + if (cmp == NAME_MATCHES) + return 1; + if (cmp == NOT_ON_MEDIA) { + o_znode = znode; + o_n = nn; + /* + * We are unlucky and hit a dangling branch straight away. + * Now we do not really know where to go to find the needed + * branch - to the left or to the right. Well, let's try left. + */ + unsure = 1; + } else if (!adding) + unsure = 1; /* Remove a dangling branch wherever it is */ + + if (cmp == NAME_GREATER || unsure) { + /* Look left */ + while (1) { + err = tnc_prev(c, zn, n); + if (err == -ENOENT) { + ubifs_assert(c, *n == 0); + *n = -1; + break; + } + if (err < 0) + return err; + if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { + /* See comments in 'resolve_collision()' */ + if (*n == (*zn)->child_cnt - 1) { + err = tnc_next(c, zn, n); + if (err) { + /* Should be impossible */ + ubifs_assert(c, 0); + if (err == -ENOENT) + err = -EINVAL; + return err; + } + ubifs_assert(c, *n == 0); + *n = -1; + } + break; + } + err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm); + if (err < 0) + return err; + if (err == NAME_MATCHES) + return 1; + if (err == NOT_ON_MEDIA) { + o_znode = *zn; + o_n = *n; + continue; + } + if (!adding) + continue; + if (err == NAME_LESS) + break; + else + unsure = 0; + } + } + + if (cmp == NAME_LESS || unsure) { + /* Look right */ + *zn = znode; + *n = nn; + while (1) { + err = tnc_next(c, &znode, &nn); + if (err == -ENOENT) + break; + if (err < 0) + return err; + if (keys_cmp(c, &znode->zbranch[nn].key, key)) + break; + err = fallible_matches_name(c, &znode->zbranch[nn], nm); + if (err < 0) + return err; + if (err == NAME_GREATER) + break; + *zn = znode; + *n = nn; + if (err == NAME_MATCHES) + return 1; + if (err == NOT_ON_MEDIA) { + o_znode = znode; + o_n = nn; + } + } + } + + /* Never match a dangling branch when adding */ + if (adding || !o_znode) + return 0; + + dbg_mntk(key, "dangling match LEB %d:%d len %d key ", + o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs, + o_znode->zbranch[o_n].len); + *zn = o_znode; + *n = o_n; + return 1; +} + +/** + * matches_position - determine if a zbranch matches a given position. + * @zbr: zbranch of dent + * @lnum: LEB number of dent to match + * @offs: offset of dent to match + * + * This function returns %1 if @lnum:@offs matches, and %0 otherwise. + */ +static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs) +{ + if (zbr->lnum == lnum && zbr->offs == offs) + return 1; + else + return 0; +} + +/** + * resolve_collision_directly - resolve a collision directly. + * @c: UBIFS file-system description object + * @key: key of directory entry + * @zn: znode is passed and returned here + * @n: zbranch number is passed and returned here + * @lnum: LEB number of dent node to match + * @offs: offset of dent node to match + * + * This function is used for "hashed" keys to make sure the found directory or + * extended attribute entry node is what was looked for. It is used when the + * flash address of the right node is known (@lnum:@offs) which makes it much + * easier to resolve collisions (no need to read entries and match full + * names). This function returns %1 and sets @zn and @n if the collision is + * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the + * previous directory entry. Otherwise a negative error code is returned. + */ +static int resolve_collision_directly(struct ubifs_info *c, + const union ubifs_key *key, + struct ubifs_znode **zn, int *n, + int lnum, int offs) +{ + struct ubifs_znode *znode; + int nn, err; + + znode = *zn; + nn = *n; + if (matches_position(&znode->zbranch[nn], lnum, offs)) + return 1; + + /* Look left */ + while (1) { + err = tnc_prev(c, &znode, &nn); + if (err == -ENOENT) + break; + if (err < 0) + return err; + if (keys_cmp(c, &znode->zbranch[nn].key, key)) + break; + if (matches_position(&znode->zbranch[nn], lnum, offs)) { + *zn = znode; + *n = nn; + return 1; + } + } + + /* Look right */ + znode = *zn; + nn = *n; + while (1) { + err = tnc_next(c, &znode, &nn); + if (err == -ENOENT) + return 0; + if (err < 0) + return err; + if (keys_cmp(c, &znode->zbranch[nn].key, key)) + return 0; + *zn = znode; + *n = nn; + if (matches_position(&znode->zbranch[nn], lnum, offs)) + return 1; + } +} + +/** + * dirty_cow_bottom_up - dirty a znode and its ancestors. + * @c: UBIFS file-system description object + * @znode: znode to dirty + * + * If we do not have a unique key that resides in a znode, then we cannot + * dirty that znode from the top down (i.e. by using lookup_level0_dirty) + * This function records the path back to the last dirty ancestor, and then + * dirties the znodes on that path. + */ +static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c, + struct ubifs_znode *znode) +{ + struct ubifs_znode *zp; + int *path = c->bottom_up_buf, p = 0; + + ubifs_assert(c, c->zroot.znode); + ubifs_assert(c, znode); + if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) { + kfree(c->bottom_up_buf); + c->bottom_up_buf = kmalloc_array(c->zroot.znode->level, + sizeof(int), + GFP_NOFS); + if (!c->bottom_up_buf) + return ERR_PTR(-ENOMEM); + path = c->bottom_up_buf; + } + if (c->zroot.znode->level) { + /* Go up until parent is dirty */ + while (1) { + int n; + + zp = znode->parent; + if (!zp) + break; + n = znode->iip; + ubifs_assert(c, p < c->zroot.znode->level); + path[p++] = n; + if (!zp->cnext && ubifs_zn_dirty(znode)) + break; + znode = zp; + } + } + + /* Come back down, dirtying as we go */ + while (1) { + struct ubifs_zbranch *zbr; + + zp = znode->parent; + if (zp) { + ubifs_assert(c, path[p - 1] >= 0); + ubifs_assert(c, path[p - 1] < zp->child_cnt); + zbr = &zp->zbranch[path[--p]]; + znode = dirty_cow_znode(c, zbr); + } else { + ubifs_assert(c, znode == c->zroot.znode); + znode = dirty_cow_znode(c, &c->zroot); + } + if (IS_ERR(znode) || !p) + break; + ubifs_assert(c, path[p - 1] >= 0); + ubifs_assert(c, path[p - 1] < znode->child_cnt); + znode = znode->zbranch[path[p - 1]].znode; + } + + return znode; +} + +/** + * ubifs_lookup_level0 - search for zero-level znode. + * @c: UBIFS file-system description object + * @key: key to lookup + * @zn: znode is returned here + * @n: znode branch slot number is returned here + * + * This function looks up the TNC tree and search for zero-level znode which + * refers key @key. The found zero-level znode is returned in @zn. There are 3 + * cases: + * o exact match, i.e. the found zero-level znode contains key @key, then %1 + * is returned and slot number of the matched branch is stored in @n; + * o not exact match, which means that zero-level znode does not contain + * @key, then %0 is returned and slot number of the closest branch or %-1 + * is stored in @n; In this case calling tnc_next() is mandatory. + * o @key is so small that it is even less than the lowest key of the + * leftmost zero-level node, then %0 is returned and %0 is stored in @n. + * + * Note, when the TNC tree is traversed, some znodes may be absent, then this + * function reads corresponding indexing nodes and inserts them to TNC. In + * case of failure, a negative error code is returned. + */ +int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_znode **zn, int *n) +{ + int err, exact; + struct ubifs_znode *znode; + time64_t time = ktime_get_seconds(); + + dbg_tnck(key, "search key "); + ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY); + + znode = c->zroot.znode; + if (unlikely(!znode)) { + znode = ubifs_load_znode(c, &c->zroot, NULL, 0); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + + znode->time = time; + + while (1) { + struct ubifs_zbranch *zbr; + + exact = ubifs_search_zbranch(c, znode, key, n); + + if (znode->level == 0) + break; + + if (*n < 0) + *n = 0; + zbr = &znode->zbranch[*n]; + + if (zbr->znode) { + znode->time = time; + znode = zbr->znode; + continue; + } + + /* znode is not in TNC cache, load it from the media */ + znode = ubifs_load_znode(c, zbr, znode, *n); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + + *zn = znode; + if (exact || !is_hash_key(c, key) || *n != -1) { + dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); + return exact; + } + + /* + * Here is a tricky place. We have not found the key and this is a + * "hashed" key, which may collide. The rest of the code deals with + * situations like this: + * + * | 3 | 5 | + * / \ + * | 3 | 5 | | 6 | 7 | (x) + * + * Or more a complex example: + * + * | 1 | 5 | + * / \ + * | 1 | 3 | | 5 | 8 | + * \ / + * | 5 | 5 | | 6 | 7 | (x) + * + * In the examples, if we are looking for key "5", we may reach nodes + * marked with "(x)". In this case what we have do is to look at the + * left and see if there is "5" key there. If there is, we have to + * return it. + * + * Note, this whole situation is possible because we allow to have + * elements which are equivalent to the next key in the parent in the + * children of current znode. For example, this happens if we split a + * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something + * like this: + * | 3 | 5 | + * / \ + * | 3 | 5 | | 5 | 6 | 7 | + * ^ + * And this becomes what is at the first "picture" after key "5" marked + * with "^" is removed. What could be done is we could prohibit + * splitting in the middle of the colliding sequence. Also, when + * removing the leftmost key, we would have to correct the key of the + * parent node, which would introduce additional complications. Namely, + * if we changed the leftmost key of the parent znode, the garbage + * collector would be unable to find it (GC is doing this when GC'ing + * indexing LEBs). Although we already have an additional RB-tree where + * we save such changed znodes (see 'ins_clr_old_idx_znode()') until + * after the commit. But anyway, this does not look easy to implement + * so we did not try this. + */ + err = tnc_prev(c, &znode, n); + if (err == -ENOENT) { + dbg_tnc("found 0, lvl %d, n -1", znode->level); + *n = -1; + return 0; + } + if (unlikely(err < 0)) + return err; + if (keys_cmp(c, key, &znode->zbranch[*n].key)) { + dbg_tnc("found 0, lvl %d, n -1", znode->level); + *n = -1; + return 0; + } + + dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); + *zn = znode; + return 1; +} + +/** + * lookup_level0_dirty - search for zero-level znode dirtying. + * @c: UBIFS file-system description object + * @key: key to lookup + * @zn: znode is returned here + * @n: znode branch slot number is returned here + * + * This function looks up the TNC tree and search for zero-level znode which + * refers key @key. The found zero-level znode is returned in @zn. There are 3 + * cases: + * o exact match, i.e. the found zero-level znode contains key @key, then %1 + * is returned and slot number of the matched branch is stored in @n; + * o not exact match, which means that zero-level znode does not contain @key + * then %0 is returned and slot number of the closed branch is stored in + * @n; + * o @key is so small that it is even less than the lowest key of the + * leftmost zero-level node, then %0 is returned and %-1 is stored in @n. + * + * Additionally all znodes in the path from the root to the located zero-level + * znode are marked as dirty. + * + * Note, when the TNC tree is traversed, some znodes may be absent, then this + * function reads corresponding indexing nodes and inserts them to TNC. In + * case of failure, a negative error code is returned. + */ +static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_znode **zn, int *n) +{ + int err, exact; + struct ubifs_znode *znode; + time64_t time = ktime_get_seconds(); + + dbg_tnck(key, "search and dirty key "); + + znode = c->zroot.znode; + if (unlikely(!znode)) { + znode = ubifs_load_znode(c, &c->zroot, NULL, 0); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + + znode = dirty_cow_znode(c, &c->zroot); + if (IS_ERR(znode)) + return PTR_ERR(znode); + + znode->time = time; + + while (1) { + struct ubifs_zbranch *zbr; + + exact = ubifs_search_zbranch(c, znode, key, n); + + if (znode->level == 0) + break; + + if (*n < 0) + *n = 0; + zbr = &znode->zbranch[*n]; + + if (zbr->znode) { + znode->time = time; + znode = dirty_cow_znode(c, zbr); + if (IS_ERR(znode)) + return PTR_ERR(znode); + continue; + } + + /* znode is not in TNC cache, load it from the media */ + znode = ubifs_load_znode(c, zbr, znode, *n); + if (IS_ERR(znode)) + return PTR_ERR(znode); + znode = dirty_cow_znode(c, zbr); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + + *zn = znode; + if (exact || !is_hash_key(c, key) || *n != -1) { + dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); + return exact; + } + + /* + * See huge comment at 'lookup_level0_dirty()' what is the rest of the + * code. + */ + err = tnc_prev(c, &znode, n); + if (err == -ENOENT) { + *n = -1; + dbg_tnc("found 0, lvl %d, n -1", znode->level); + return 0; + } + if (unlikely(err < 0)) + return err; + if (keys_cmp(c, key, &znode->zbranch[*n].key)) { + *n = -1; + dbg_tnc("found 0, lvl %d, n -1", znode->level); + return 0; + } + + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) + return PTR_ERR(znode); + } + + dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); + *zn = znode; + return 1; +} + +/** + * maybe_leb_gced - determine if a LEB may have been garbage collected. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @gc_seq1: garbage collection sequence number + * + * This function determines if @lnum may have been garbage collected since + * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise + * %0 is returned. + */ +static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1) +{ + int gc_seq2, gced_lnum; + + gced_lnum = c->gced_lnum; + smp_rmb(); + gc_seq2 = c->gc_seq; + /* Same seq means no GC */ + if (gc_seq1 == gc_seq2) + return 0; + /* Different by more than 1 means we don't know */ + if (gc_seq1 + 1 != gc_seq2) + return 1; + /* + * We have seen the sequence number has increased by 1. Now we need to + * be sure we read the right LEB number, so read it again. + */ + smp_rmb(); + if (gced_lnum != c->gced_lnum) + return 1; + /* Finally we can check lnum */ + if (gced_lnum == lnum) + return 1; + return 0; +} + +/** + * ubifs_tnc_locate - look up a file-system node and return it and its location. + * @c: UBIFS file-system description object + * @key: node key to lookup + * @node: the node is returned here + * @lnum: LEB number is returned here + * @offs: offset is returned here + * + * This function looks up and reads node with key @key. The caller has to make + * sure the @node buffer is large enough to fit the node. Returns zero in case + * of success, %-ENOENT if the node was not found, and a negative error code in + * case of failure. The node location can be returned in @lnum and @offs. + */ +int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key, + void *node, int *lnum, int *offs) +{ + int found, n, err, safely = 0, gc_seq1; + struct ubifs_znode *znode; + struct ubifs_zbranch zbr, *zt; + +again: + mutex_lock(&c->tnc_mutex); + found = ubifs_lookup_level0(c, key, &znode, &n); + if (!found) { + err = -ENOENT; + goto out; + } else if (found < 0) { + err = found; + goto out; + } + zt = &znode->zbranch[n]; + if (lnum) { + *lnum = zt->lnum; + *offs = zt->offs; + } + if (is_hash_key(c, key)) { + /* + * In this case the leaf node cache gets used, so we pass the + * address of the zbranch and keep the mutex locked + */ + err = tnc_read_hashed_node(c, zt, node); + goto out; + } + if (safely) { + err = ubifs_tnc_read_node(c, zt, node); + goto out; + } + /* Drop the TNC mutex prematurely and race with garbage collection */ + zbr = znode->zbranch[n]; + gc_seq1 = c->gc_seq; + mutex_unlock(&c->tnc_mutex); + + if (ubifs_get_wbuf(c, zbr.lnum)) { + /* We do not GC journal heads */ + err = ubifs_tnc_read_node(c, &zbr, node); + return err; + } + + err = fallible_read_node(c, key, &zbr, node); + if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) { + /* + * The node may have been GC'ed out from under us so try again + * while keeping the TNC mutex locked. + */ + safely = 1; + goto again; + } + return 0; + +out: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_get_bu_keys - lookup keys for bulk-read. + * @c: UBIFS file-system description object + * @bu: bulk-read parameters and results + * + * Lookup consecutive data node keys for the same inode that reside + * consecutively in the same LEB. This function returns zero in case of success + * and a negative error code in case of failure. + * + * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function + * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares + * maximum possible amount of nodes for bulk-read. + */ +int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu) +{ + int n, err = 0, lnum = -1, offs; + int len; + unsigned int block = key_block(c, &bu->key); + struct ubifs_znode *znode; + + bu->cnt = 0; + bu->blk_cnt = 0; + bu->eof = 0; + + mutex_lock(&c->tnc_mutex); + /* Find first key */ + err = ubifs_lookup_level0(c, &bu->key, &znode, &n); + if (err < 0) + goto out; + if (err) { + /* Key found */ + len = znode->zbranch[n].len; + /* The buffer must be big enough for at least 1 node */ + if (len > bu->buf_len) { + err = -EINVAL; + goto out; + } + /* Add this key */ + bu->zbranch[bu->cnt++] = znode->zbranch[n]; + bu->blk_cnt += 1; + lnum = znode->zbranch[n].lnum; + offs = ALIGN(znode->zbranch[n].offs + len, 8); + } + while (1) { + struct ubifs_zbranch *zbr; + union ubifs_key *key; + unsigned int next_block; + + /* Find next key */ + err = tnc_next(c, &znode, &n); + if (err) + goto out; + zbr = &znode->zbranch[n]; + key = &zbr->key; + /* See if there is another data key for this file */ + if (key_inum(c, key) != key_inum(c, &bu->key) || + key_type(c, key) != UBIFS_DATA_KEY) { + err = -ENOENT; + goto out; + } + if (lnum < 0) { + /* First key found */ + lnum = zbr->lnum; + offs = ALIGN(zbr->offs + zbr->len, 8); + len = zbr->len; + if (len > bu->buf_len) { + err = -EINVAL; + goto out; + } + } else { + /* + * The data nodes must be in consecutive positions in + * the same LEB. + */ + if (zbr->lnum != lnum || zbr->offs != offs) + goto out; + offs += ALIGN(zbr->len, 8); + len = ALIGN(len, 8) + zbr->len; + /* Must not exceed buffer length */ + if (len > bu->buf_len) + goto out; + } + /* Allow for holes */ + next_block = key_block(c, key); + bu->blk_cnt += (next_block - block - 1); + if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) + goto out; + block = next_block; + /* Add this key */ + bu->zbranch[bu->cnt++] = *zbr; + bu->blk_cnt += 1; + /* See if we have room for more */ + if (bu->cnt >= UBIFS_MAX_BULK_READ) + goto out; + if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) + goto out; + } +out: + if (err == -ENOENT) { + bu->eof = 1; + err = 0; + } + bu->gc_seq = c->gc_seq; + mutex_unlock(&c->tnc_mutex); + if (err) + return err; + /* + * An enormous hole could cause bulk-read to encompass too many + * page cache pages, so limit the number here. + */ + if (bu->blk_cnt > UBIFS_MAX_BULK_READ) + bu->blk_cnt = UBIFS_MAX_BULK_READ; + /* + * Ensure that bulk-read covers a whole number of page cache + * pages. + */ + if (UBIFS_BLOCKS_PER_PAGE == 1 || + !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1))) + return 0; + if (bu->eof) { + /* At the end of file we can round up */ + bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1; + return 0; + } + /* Exclude data nodes that do not make up a whole page cache page */ + block = key_block(c, &bu->key) + bu->blk_cnt; + block &= ~(UBIFS_BLOCKS_PER_PAGE - 1); + while (bu->cnt) { + if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block) + break; + bu->cnt -= 1; + } + return 0; +} + +/** + * read_wbuf - bulk-read from a LEB with a wbuf. + * @wbuf: wbuf that may overlap the read + * @buf: buffer into which to read + * @len: read length + * @lnum: LEB number from which to read + * @offs: offset from which to read + * + * This functions returns %0 on success or a negative error code on failure. + */ +static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum, + int offs) +{ + const struct ubifs_info *c = wbuf->c; + int rlen, overlap; + + dbg_io("LEB %d:%d, length %d", lnum, offs, len); + ubifs_assert(c, wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); + ubifs_assert(c, !(offs & 7) && offs < c->leb_size); + ubifs_assert(c, offs + len <= c->leb_size); + + spin_lock(&wbuf->lock); + overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); + if (!overlap) { + /* We may safely unlock the write-buffer and read the data */ + spin_unlock(&wbuf->lock); + return ubifs_leb_read(c, lnum, buf, offs, len, 0); + } + + /* Don't read under wbuf */ + rlen = wbuf->offs - offs; + if (rlen < 0) + rlen = 0; + + /* Copy the rest from the write-buffer */ + memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); + spin_unlock(&wbuf->lock); + + if (rlen > 0) + /* Read everything that goes before write-buffer */ + return ubifs_leb_read(c, lnum, buf, offs, rlen, 0); + + return 0; +} + +/** + * validate_data_node - validate data nodes for bulk-read. + * @c: UBIFS file-system description object + * @buf: buffer containing data node to validate + * @zbr: zbranch of data node to validate + * + * This functions returns %0 on success or a negative error code on failure. + */ +static int validate_data_node(struct ubifs_info *c, void *buf, + struct ubifs_zbranch *zbr) +{ + union ubifs_key key1; + struct ubifs_ch *ch = buf; + int err, len; + + if (ch->node_type != UBIFS_DATA_NODE) { + ubifs_err(c, "bad node type (%d but expected %d)", + ch->node_type, UBIFS_DATA_NODE); + goto out_err; + } + + err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0); + if (err) { + ubifs_err(c, "expected node type %d", UBIFS_DATA_NODE); + goto out; + } + + err = ubifs_node_check_hash(c, buf, zbr->hash); + if (err) { + ubifs_bad_hash(c, buf, zbr->hash, zbr->lnum, zbr->offs); + return err; + } + + len = le32_to_cpu(ch->len); + if (len != zbr->len) { + ubifs_err(c, "bad node length %d, expected %d", len, zbr->len); + goto out_err; + } + + /* Make sure the key of the read node is correct */ + key_read(c, buf + UBIFS_KEY_OFFSET, &key1); + if (!keys_eq(c, &zbr->key, &key1)) { + ubifs_err(c, "bad key in node at LEB %d:%d", + zbr->lnum, zbr->offs); + dbg_tnck(&zbr->key, "looked for key "); + dbg_tnck(&key1, "found node's key "); + goto out_err; + } + + return 0; + +out_err: + err = -EINVAL; +out: + ubifs_err(c, "bad node at LEB %d:%d", zbr->lnum, zbr->offs); + ubifs_dump_node(c, buf); + dump_stack(); + return err; +} + +/** + * ubifs_tnc_bulk_read - read a number of data nodes in one go. + * @c: UBIFS file-system description object + * @bu: bulk-read parameters and results + * + * This functions reads and validates the data nodes that were identified by the + * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success, + * -EAGAIN to indicate a race with GC, or another negative error code on + * failure. + */ +int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu) +{ + int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i; + struct ubifs_wbuf *wbuf; + void *buf; + + len = bu->zbranch[bu->cnt - 1].offs; + len += bu->zbranch[bu->cnt - 1].len - offs; + if (len > bu->buf_len) { + ubifs_err(c, "buffer too small %d vs %d", bu->buf_len, len); + return -EINVAL; + } + + /* Do the read */ + wbuf = ubifs_get_wbuf(c, lnum); + if (wbuf) + err = read_wbuf(wbuf, bu->buf, len, lnum, offs); + else + err = ubifs_leb_read(c, lnum, bu->buf, offs, len, 0); + + /* Check for a race with GC */ + if (maybe_leb_gced(c, lnum, bu->gc_seq)) + return -EAGAIN; + + if (err && err != -EBADMSG) { + ubifs_err(c, "failed to read from LEB %d:%d, error %d", + lnum, offs, err); + dump_stack(); + dbg_tnck(&bu->key, "key "); + return err; + } + + /* Validate the nodes read */ + buf = bu->buf; + for (i = 0; i < bu->cnt; i++) { + err = validate_data_node(c, buf, &bu->zbranch[i]); + if (err) + return err; + buf = buf + ALIGN(bu->zbranch[i].len, 8); + } + + return 0; +} + +/** + * do_lookup_nm- look up a "hashed" node. + * @c: UBIFS file-system description object + * @key: node key to lookup + * @node: the node is returned here + * @nm: node name + * + * This function looks up and reads a node which contains name hash in the key. + * Since the hash may have collisions, there may be many nodes with the same + * key, so we have to sequentially look to all of them until the needed one is + * found. This function returns zero in case of success, %-ENOENT if the node + * was not found, and a negative error code in case of failure. + */ +static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, + void *node, const struct fscrypt_name *nm) +{ + int found, n, err; + struct ubifs_znode *znode; + + dbg_tnck(key, "key "); + mutex_lock(&c->tnc_mutex); + found = ubifs_lookup_level0(c, key, &znode, &n); + if (!found) { + err = -ENOENT; + goto out_unlock; + } else if (found < 0) { + err = found; + goto out_unlock; + } + + ubifs_assert(c, n >= 0); + + err = resolve_collision(c, key, &znode, &n, nm); + dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); + if (unlikely(err < 0)) + goto out_unlock; + if (err == 0) { + err = -ENOENT; + goto out_unlock; + } + + err = tnc_read_hashed_node(c, &znode->zbranch[n], node); + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_lookup_nm - look up a "hashed" node. + * @c: UBIFS file-system description object + * @key: node key to lookup + * @node: the node is returned here + * @nm: node name + * + * This function looks up and reads a node which contains name hash in the key. + * Since the hash may have collisions, there may be many nodes with the same + * key, so we have to sequentially look to all of them until the needed one is + * found. This function returns zero in case of success, %-ENOENT if the node + * was not found, and a negative error code in case of failure. + */ +int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, + void *node, const struct fscrypt_name *nm) +{ + int err, len; + const struct ubifs_dent_node *dent = node; + + /* + * We assume that in most of the cases there are no name collisions and + * 'ubifs_tnc_lookup()' returns us the right direntry. + */ + err = ubifs_tnc_lookup(c, key, node); + if (err) + return err; + + len = le16_to_cpu(dent->nlen); + if (fname_len(nm) == len && !memcmp(dent->name, fname_name(nm), len)) + return 0; + + /* + * Unluckily, there are hash collisions and we have to iterate over + * them look at each direntry with colliding name hash sequentially. + */ + + return do_lookup_nm(c, key, node, nm); +} + +static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_dent_node *dent, uint32_t cookie, + struct ubifs_znode **zn, int *n, int exact) +{ + int err; + struct ubifs_znode *znode = *zn; + struct ubifs_zbranch *zbr; + union ubifs_key *dkey; + + if (!exact) { + err = tnc_next(c, &znode, n); + if (err) + return err; + } + + for (;;) { + zbr = &znode->zbranch[*n]; + dkey = &zbr->key; + + if (key_inum(c, dkey) != key_inum(c, key) || + key_type(c, dkey) != key_type(c, key)) { + return -ENOENT; + } + + err = tnc_read_hashed_node(c, zbr, dent); + if (err) + return err; + + if (key_hash(c, key) == key_hash(c, dkey) && + le32_to_cpu(dent->cookie) == cookie) { + *zn = znode; + return 0; + } + + err = tnc_next(c, &znode, n); + if (err) + return err; + } +} + +static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_dent_node *dent, uint32_t cookie) +{ + int n, err; + struct ubifs_znode *znode; + union ubifs_key start_key; + + ubifs_assert(c, is_hash_key(c, key)); + + lowest_dent_key(c, &start_key, key_inum(c, key)); + + mutex_lock(&c->tnc_mutex); + err = ubifs_lookup_level0(c, &start_key, &znode, &n); + if (unlikely(err < 0)) + goto out_unlock; + + err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err); + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_lookup_dh - look up a "double hashed" node. + * @c: UBIFS file-system description object + * @key: node key to lookup + * @node: the node is returned here + * @cookie: node cookie for collision resolution + * + * This function looks up and reads a node which contains name hash in the key. + * Since the hash may have collisions, there may be many nodes with the same + * key, so we have to sequentially look to all of them until the needed one + * with the same cookie value is found. + * This function returns zero in case of success, %-ENOENT if the node + * was not found, and a negative error code in case of failure. + */ +int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, + void *node, uint32_t cookie) +{ + int err; + const struct ubifs_dent_node *dent = node; + + if (!c->double_hash) + return -EOPNOTSUPP; + + /* + * We assume that in most of the cases there are no name collisions and + * 'ubifs_tnc_lookup()' returns us the right direntry. + */ + err = ubifs_tnc_lookup(c, key, node); + if (err) + return err; + + if (le32_to_cpu(dent->cookie) == cookie) + return 0; + + /* + * Unluckily, there are hash collisions and we have to iterate over + * them look at each direntry with colliding name hash sequentially. + */ + return do_lookup_dh(c, key, node, cookie); +} + +/** + * correct_parent_keys - correct parent znodes' keys. + * @c: UBIFS file-system description object + * @znode: znode to correct parent znodes for + * + * This is a helper function for 'tnc_insert()'. When the key of the leftmost + * zbranch changes, keys of parent znodes have to be corrected. This helper + * function is called in such situations and corrects the keys if needed. + */ +static void correct_parent_keys(const struct ubifs_info *c, + struct ubifs_znode *znode) +{ + union ubifs_key *key, *key1; + + ubifs_assert(c, znode->parent); + ubifs_assert(c, znode->iip == 0); + + key = &znode->zbranch[0].key; + key1 = &znode->parent->zbranch[0].key; + + while (keys_cmp(c, key, key1) < 0) { + key_copy(c, key, key1); + znode = znode->parent; + znode->alt = 1; + if (!znode->parent || znode->iip) + break; + key1 = &znode->parent->zbranch[0].key; + } +} + +/** + * insert_zbranch - insert a zbranch into a znode. + * @c: UBIFS file-system description object + * @znode: znode into which to insert + * @zbr: zbranch to insert + * @n: slot number to insert to + * + * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in + * znode's array of zbranches and keeps zbranches consolidated, so when a new + * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th + * slot, zbranches starting from @n have to be moved right. + */ +static void insert_zbranch(struct ubifs_info *c, struct ubifs_znode *znode, + const struct ubifs_zbranch *zbr, int n) +{ + int i; + + ubifs_assert(c, ubifs_zn_dirty(znode)); + + if (znode->level) { + for (i = znode->child_cnt; i > n; i--) { + znode->zbranch[i] = znode->zbranch[i - 1]; + if (znode->zbranch[i].znode) + znode->zbranch[i].znode->iip = i; + } + if (zbr->znode) + zbr->znode->iip = n; + } else + for (i = znode->child_cnt; i > n; i--) + znode->zbranch[i] = znode->zbranch[i - 1]; + + znode->zbranch[n] = *zbr; + znode->child_cnt += 1; + + /* + * After inserting at slot zero, the lower bound of the key range of + * this znode may have changed. If this znode is subsequently split + * then the upper bound of the key range may change, and furthermore + * it could change to be lower than the original lower bound. If that + * happens, then it will no longer be possible to find this znode in the + * TNC using the key from the index node on flash. That is bad because + * if it is not found, we will assume it is obsolete and may overwrite + * it. Then if there is an unclean unmount, we will start using the + * old index which will be broken. + * + * So we first mark znodes that have insertions at slot zero, and then + * if they are split we add their lnum/offs to the old_idx tree. + */ + if (n == 0) + znode->alt = 1; +} + +/** + * tnc_insert - insert a node into TNC. + * @c: UBIFS file-system description object + * @znode: znode to insert into + * @zbr: branch to insert + * @n: slot number to insert new zbranch to + * + * This function inserts a new node described by @zbr into znode @znode. If + * znode does not have a free slot for new zbranch, it is split. Parent znodes + * are splat as well if needed. Returns zero in case of success or a negative + * error code in case of failure. + */ +static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode, + struct ubifs_zbranch *zbr, int n) +{ + struct ubifs_znode *zn, *zi, *zp; + int i, keep, move, appending = 0; + union ubifs_key *key = &zbr->key, *key1; + + ubifs_assert(c, n >= 0 && n <= c->fanout); + + /* Implement naive insert for now */ +again: + zp = znode->parent; + if (znode->child_cnt < c->fanout) { + ubifs_assert(c, n != c->fanout); + dbg_tnck(key, "inserted at %d level %d, key ", n, znode->level); + + insert_zbranch(c, znode, zbr, n); + + /* Ensure parent's key is correct */ + if (n == 0 && zp && znode->iip == 0) + correct_parent_keys(c, znode); + + return 0; + } + + /* + * Unfortunately, @znode does not have more empty slots and we have to + * split it. + */ + dbg_tnck(key, "splitting level %d, key ", znode->level); + + if (znode->alt) + /* + * We can no longer be sure of finding this znode by key, so we + * record it in the old_idx tree. + */ + ins_clr_old_idx_znode(c, znode); + + zn = kzalloc(c->max_znode_sz, GFP_NOFS); + if (!zn) + return -ENOMEM; + zn->parent = zp; + zn->level = znode->level; + + /* Decide where to split */ + if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) { + /* Try not to split consecutive data keys */ + if (n == c->fanout) { + key1 = &znode->zbranch[n - 1].key; + if (key_inum(c, key1) == key_inum(c, key) && + key_type(c, key1) == UBIFS_DATA_KEY) + appending = 1; + } else + goto check_split; + } else if (appending && n != c->fanout) { + /* Try not to split consecutive data keys */ + appending = 0; +check_split: + if (n >= (c->fanout + 1) / 2) { + key1 = &znode->zbranch[0].key; + if (key_inum(c, key1) == key_inum(c, key) && + key_type(c, key1) == UBIFS_DATA_KEY) { + key1 = &znode->zbranch[n].key; + if (key_inum(c, key1) != key_inum(c, key) || + key_type(c, key1) != UBIFS_DATA_KEY) { + keep = n; + move = c->fanout - keep; + zi = znode; + goto do_split; + } + } + } + } + + if (appending) { + keep = c->fanout; + move = 0; + } else { + keep = (c->fanout + 1) / 2; + move = c->fanout - keep; + } + + /* + * Although we don't at present, we could look at the neighbors and see + * if we can move some zbranches there. + */ + + if (n < keep) { + /* Insert into existing znode */ + zi = znode; + move += 1; + keep -= 1; + } else { + /* Insert into new znode */ + zi = zn; + n -= keep; + /* Re-parent */ + if (zn->level != 0) + zbr->znode->parent = zn; + } + +do_split: + + __set_bit(DIRTY_ZNODE, &zn->flags); + atomic_long_inc(&c->dirty_zn_cnt); + + zn->child_cnt = move; + znode->child_cnt = keep; + + dbg_tnc("moving %d, keeping %d", move, keep); + + /* Move zbranch */ + for (i = 0; i < move; i++) { + zn->zbranch[i] = znode->zbranch[keep + i]; + /* Re-parent */ + if (zn->level != 0) + if (zn->zbranch[i].znode) { + zn->zbranch[i].znode->parent = zn; + zn->zbranch[i].znode->iip = i; + } + } + + /* Insert new key and branch */ + dbg_tnck(key, "inserting at %d level %d, key ", n, zn->level); + + insert_zbranch(c, zi, zbr, n); + + /* Insert new znode (produced by spitting) into the parent */ + if (zp) { + if (n == 0 && zi == znode && znode->iip == 0) + correct_parent_keys(c, znode); + + /* Locate insertion point */ + n = znode->iip + 1; + + /* Tail recursion */ + zbr->key = zn->zbranch[0].key; + zbr->znode = zn; + zbr->lnum = 0; + zbr->offs = 0; + zbr->len = 0; + znode = zp; + + goto again; + } + + /* We have to split root znode */ + dbg_tnc("creating new zroot at level %d", znode->level + 1); + + zi = kzalloc(c->max_znode_sz, GFP_NOFS); + if (!zi) + return -ENOMEM; + + zi->child_cnt = 2; + zi->level = znode->level + 1; + + __set_bit(DIRTY_ZNODE, &zi->flags); + atomic_long_inc(&c->dirty_zn_cnt); + + zi->zbranch[0].key = znode->zbranch[0].key; + zi->zbranch[0].znode = znode; + zi->zbranch[0].lnum = c->zroot.lnum; + zi->zbranch[0].offs = c->zroot.offs; + zi->zbranch[0].len = c->zroot.len; + zi->zbranch[1].key = zn->zbranch[0].key; + zi->zbranch[1].znode = zn; + + c->zroot.lnum = 0; + c->zroot.offs = 0; + c->zroot.len = 0; + c->zroot.znode = zi; + + zn->parent = zi; + zn->iip = 1; + znode->parent = zi; + znode->iip = 0; + + return 0; +} + +/** + * ubifs_tnc_add - add a node to TNC. + * @c: UBIFS file-system description object + * @key: key to add + * @lnum: LEB number of node + * @offs: node offset + * @len: node length + * @hash: The hash over the node + * + * This function adds a node with key @key to TNC. The node may be new or it may + * obsolete some existing one. Returns %0 on success or negative error code on + * failure. + */ +int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum, + int offs, int len, const u8 *hash) +{ + int found, n, err = 0; + struct ubifs_znode *znode; + + mutex_lock(&c->tnc_mutex); + dbg_tnck(key, "%d:%d, len %d, key ", lnum, offs, len); + found = lookup_level0_dirty(c, key, &znode, &n); + if (!found) { + struct ubifs_zbranch zbr; + + zbr.znode = NULL; + zbr.lnum = lnum; + zbr.offs = offs; + zbr.len = len; + ubifs_copy_hash(c, hash, zbr.hash); + key_copy(c, key, &zbr.key); + err = tnc_insert(c, znode, &zbr, n + 1); + } else if (found == 1) { + struct ubifs_zbranch *zbr = &znode->zbranch[n]; + + lnc_free(zbr); + err = ubifs_add_dirt(c, zbr->lnum, zbr->len); + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + ubifs_copy_hash(c, hash, zbr->hash); + } else + err = found; + if (!err) + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + + return err; +} + +/** + * ubifs_tnc_replace - replace a node in the TNC only if the old node is found. + * @c: UBIFS file-system description object + * @key: key to add + * @old_lnum: LEB number of old node + * @old_offs: old node offset + * @lnum: LEB number of node + * @offs: node offset + * @len: node length + * + * This function replaces a node with key @key in the TNC only if the old node + * is found. This function is called by garbage collection when node are moved. + * Returns %0 on success or negative error code on failure. + */ +int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key, + int old_lnum, int old_offs, int lnum, int offs, int len) +{ + int found, n, err = 0; + struct ubifs_znode *znode; + + mutex_lock(&c->tnc_mutex); + dbg_tnck(key, "old LEB %d:%d, new LEB %d:%d, len %d, key ", old_lnum, + old_offs, lnum, offs, len); + found = lookup_level0_dirty(c, key, &znode, &n); + if (found < 0) { + err = found; + goto out_unlock; + } + + if (found == 1) { + struct ubifs_zbranch *zbr = &znode->zbranch[n]; + + found = 0; + if (zbr->lnum == old_lnum && zbr->offs == old_offs) { + lnc_free(zbr); + err = ubifs_add_dirt(c, zbr->lnum, zbr->len); + if (err) + goto out_unlock; + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + found = 1; + } else if (is_hash_key(c, key)) { + found = resolve_collision_directly(c, key, &znode, &n, + old_lnum, old_offs); + dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d", + found, znode, n, old_lnum, old_offs); + if (found < 0) { + err = found; + goto out_unlock; + } + + if (found) { + /* Ensure the znode is dirtied */ + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + } + zbr = &znode->zbranch[n]; + lnc_free(zbr); + err = ubifs_add_dirt(c, zbr->lnum, + zbr->len); + if (err) + goto out_unlock; + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + } + } + } + + if (!found) + err = ubifs_add_dirt(c, lnum, len); + + if (!err) + err = dbg_check_tnc(c, 0); + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_add_nm - add a "hashed" node to TNC. + * @c: UBIFS file-system description object + * @key: key to add + * @lnum: LEB number of node + * @offs: node offset + * @len: node length + * @hash: The hash over the node + * @nm: node name + * + * This is the same as 'ubifs_tnc_add()' but it should be used with keys which + * may have collisions, like directory entry keys. + */ +int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, + int lnum, int offs, int len, const u8 *hash, + const struct fscrypt_name *nm) +{ + int found, n, err = 0; + struct ubifs_znode *znode; + + mutex_lock(&c->tnc_mutex); + dbg_tnck(key, "LEB %d:%d, key ", lnum, offs); + found = lookup_level0_dirty(c, key, &znode, &n); + if (found < 0) { + err = found; + goto out_unlock; + } + + if (found == 1) { + if (c->replaying) + found = fallible_resolve_collision(c, key, &znode, &n, + nm, 1); + else + found = resolve_collision(c, key, &znode, &n, nm); + dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n); + if (found < 0) { + err = found; + goto out_unlock; + } + + /* Ensure the znode is dirtied */ + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + } + + if (found == 1) { + struct ubifs_zbranch *zbr = &znode->zbranch[n]; + + lnc_free(zbr); + err = ubifs_add_dirt(c, zbr->lnum, zbr->len); + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + ubifs_copy_hash(c, hash, zbr->hash); + goto out_unlock; + } + } + + if (!found) { + struct ubifs_zbranch zbr; + + zbr.znode = NULL; + zbr.lnum = lnum; + zbr.offs = offs; + zbr.len = len; + ubifs_copy_hash(c, hash, zbr.hash); + key_copy(c, key, &zbr.key); + err = tnc_insert(c, znode, &zbr, n + 1); + if (err) + goto out_unlock; + if (c->replaying) { + /* + * We did not find it in the index so there may be a + * dangling branch still in the index. So we remove it + * by passing 'ubifs_tnc_remove_nm()' the same key but + * an unmatchable name. + */ + struct fscrypt_name noname = { .disk_name = { .name = "", .len = 1 } }; + + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + if (err) + return err; + return ubifs_tnc_remove_nm(c, key, &noname); + } + } + +out_unlock: + if (!err) + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * tnc_delete - delete a znode form TNC. + * @c: UBIFS file-system description object + * @znode: znode to delete from + * @n: zbranch slot number to delete + * + * This function deletes a leaf node from @n-th slot of @znode. Returns zero in + * case of success and a negative error code in case of failure. + */ +static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n) +{ + struct ubifs_zbranch *zbr; + struct ubifs_znode *zp; + int i, err; + + /* Delete without merge for now */ + ubifs_assert(c, znode->level == 0); + ubifs_assert(c, n >= 0 && n < c->fanout); + dbg_tnck(&znode->zbranch[n].key, "deleting key "); + + zbr = &znode->zbranch[n]; + lnc_free(zbr); + + err = ubifs_add_dirt(c, zbr->lnum, zbr->len); + if (err) { + ubifs_dump_znode(c, znode); + return err; + } + + /* We do not "gap" zbranch slots */ + for (i = n; i < znode->child_cnt - 1; i++) + znode->zbranch[i] = znode->zbranch[i + 1]; + znode->child_cnt -= 1; + + if (znode->child_cnt > 0) + return 0; + + /* + * This was the last zbranch, we have to delete this znode from the + * parent. + */ + + do { + ubifs_assert(c, !ubifs_zn_obsolete(znode)); + ubifs_assert(c, ubifs_zn_dirty(znode)); + + zp = znode->parent; + n = znode->iip; + + atomic_long_dec(&c->dirty_zn_cnt); + + err = insert_old_idx_znode(c, znode); + if (err) + return err; + + if (znode->cnext) { + __set_bit(OBSOLETE_ZNODE, &znode->flags); + atomic_long_inc(&c->clean_zn_cnt); + atomic_long_inc(&ubifs_clean_zn_cnt); + } else + kfree(znode); + znode = zp; + } while (znode->child_cnt == 1); /* while removing last child */ + + /* Remove from znode, entry n - 1 */ + znode->child_cnt -= 1; + ubifs_assert(c, znode->level != 0); + for (i = n; i < znode->child_cnt; i++) { + znode->zbranch[i] = znode->zbranch[i + 1]; + if (znode->zbranch[i].znode) + znode->zbranch[i].znode->iip = i; + } + + /* + * If this is the root and it has only 1 child then + * collapse the tree. + */ + if (!znode->parent) { + while (znode->child_cnt == 1 && znode->level != 0) { + zp = znode; + zbr = &znode->zbranch[0]; + znode = get_znode(c, znode, 0); + if (IS_ERR(znode)) + return PTR_ERR(znode); + znode = dirty_cow_znode(c, zbr); + if (IS_ERR(znode)) + return PTR_ERR(znode); + znode->parent = NULL; + znode->iip = 0; + if (c->zroot.len) { + err = insert_old_idx(c, c->zroot.lnum, + c->zroot.offs); + if (err) + return err; + } + c->zroot.lnum = zbr->lnum; + c->zroot.offs = zbr->offs; + c->zroot.len = zbr->len; + c->zroot.znode = znode; + ubifs_assert(c, !ubifs_zn_obsolete(zp)); + ubifs_assert(c, ubifs_zn_dirty(zp)); + atomic_long_dec(&c->dirty_zn_cnt); + + if (zp->cnext) { + __set_bit(OBSOLETE_ZNODE, &zp->flags); + atomic_long_inc(&c->clean_zn_cnt); + atomic_long_inc(&ubifs_clean_zn_cnt); + } else + kfree(zp); + } + } + + return 0; +} + +/** + * ubifs_tnc_remove - remove an index entry of a node. + * @c: UBIFS file-system description object + * @key: key of node + * + * Returns %0 on success or negative error code on failure. + */ +int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key) +{ + int found, n, err = 0; + struct ubifs_znode *znode; + + mutex_lock(&c->tnc_mutex); + dbg_tnck(key, "key "); + found = lookup_level0_dirty(c, key, &znode, &n); + if (found < 0) { + err = found; + goto out_unlock; + } + if (found == 1) + err = tnc_delete(c, znode, n); + if (!err) + err = dbg_check_tnc(c, 0); + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node. + * @c: UBIFS file-system description object + * @key: key of node + * @nm: directory entry name + * + * Returns %0 on success or negative error code on failure. + */ +int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, + const struct fscrypt_name *nm) +{ + int n, err; + struct ubifs_znode *znode; + + mutex_lock(&c->tnc_mutex); + dbg_tnck(key, "key "); + err = lookup_level0_dirty(c, key, &znode, &n); + if (err < 0) + goto out_unlock; + + if (err) { + if (c->replaying) + err = fallible_resolve_collision(c, key, &znode, &n, + nm, 0); + else + err = resolve_collision(c, key, &znode, &n, nm); + dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); + if (err < 0) + goto out_unlock; + if (err) { + /* Ensure the znode is dirtied */ + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + } + err = tnc_delete(c, znode, n); + } + } + +out_unlock: + if (!err) + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_remove_dh - remove an index entry for a "double hashed" node. + * @c: UBIFS file-system description object + * @key: key of node + * @cookie: node cookie for collision resolution + * + * Returns %0 on success or negative error code on failure. + */ +int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key, + uint32_t cookie) +{ + int n, err; + struct ubifs_znode *znode; + struct ubifs_dent_node *dent; + struct ubifs_zbranch *zbr; + + if (!c->double_hash) + return -EOPNOTSUPP; + + mutex_lock(&c->tnc_mutex); + err = lookup_level0_dirty(c, key, &znode, &n); + if (err <= 0) + goto out_unlock; + + zbr = &znode->zbranch[n]; + dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); + if (!dent) { + err = -ENOMEM; + goto out_unlock; + } + + err = tnc_read_hashed_node(c, zbr, dent); + if (err) + goto out_free; + + /* If the cookie does not match, we're facing a hash collision. */ + if (le32_to_cpu(dent->cookie) != cookie) { + union ubifs_key start_key; + + lowest_dent_key(c, &start_key, key_inum(c, key)); + + err = ubifs_lookup_level0(c, &start_key, &znode, &n); + if (unlikely(err < 0)) + goto out_free; + + err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err); + if (err) + goto out_free; + } + + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_free; + } + } + err = tnc_delete(c, znode, n); + +out_free: + kfree(dent); +out_unlock: + if (!err) + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * key_in_range - determine if a key falls within a range of keys. + * @c: UBIFS file-system description object + * @key: key to check + * @from_key: lowest key in range + * @to_key: highest key in range + * + * This function returns %1 if the key is in range and %0 otherwise. + */ +static int key_in_range(struct ubifs_info *c, union ubifs_key *key, + union ubifs_key *from_key, union ubifs_key *to_key) +{ + if (keys_cmp(c, key, from_key) < 0) + return 0; + if (keys_cmp(c, key, to_key) > 0) + return 0; + return 1; +} + +/** + * ubifs_tnc_remove_range - remove index entries in range. + * @c: UBIFS file-system description object + * @from_key: lowest key to remove + * @to_key: highest key to remove + * + * This function removes index entries starting at @from_key and ending at + * @to_key. This function returns zero in case of success and a negative error + * code in case of failure. + */ +int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, + union ubifs_key *to_key) +{ + int i, n, k, err = 0; + struct ubifs_znode *znode; + union ubifs_key *key; + + mutex_lock(&c->tnc_mutex); + while (1) { + /* Find first level 0 znode that contains keys to remove */ + err = ubifs_lookup_level0(c, from_key, &znode, &n); + if (err < 0) + goto out_unlock; + + if (err) + key = from_key; + else { + err = tnc_next(c, &znode, &n); + if (err == -ENOENT) { + err = 0; + goto out_unlock; + } + if (err < 0) + goto out_unlock; + key = &znode->zbranch[n].key; + if (!key_in_range(c, key, from_key, to_key)) { + err = 0; + goto out_unlock; + } + } + + /* Ensure the znode is dirtied */ + if (znode->cnext || !ubifs_zn_dirty(znode)) { + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + } + + /* Remove all keys in range except the first */ + for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) { + key = &znode->zbranch[i].key; + if (!key_in_range(c, key, from_key, to_key)) + break; + lnc_free(&znode->zbranch[i]); + err = ubifs_add_dirt(c, znode->zbranch[i].lnum, + znode->zbranch[i].len); + if (err) { + ubifs_dump_znode(c, znode); + goto out_unlock; + } + dbg_tnck(key, "removing key "); + } + if (k) { + for (i = n + 1 + k; i < znode->child_cnt; i++) + znode->zbranch[i - k] = znode->zbranch[i]; + znode->child_cnt -= k; + } + + /* Now delete the first */ + err = tnc_delete(c, znode, n); + if (err) + goto out_unlock; + } + +out_unlock: + if (!err) + err = dbg_check_tnc(c, 0); + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_tnc_remove_ino - remove an inode from TNC. + * @c: UBIFS file-system description object + * @inum: inode number to remove + * + * This function remove inode @inum and all the extended attributes associated + * with the anode from TNC and returns zero in case of success or a negative + * error code in case of failure. + */ +int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum) +{ + union ubifs_key key1, key2; + struct ubifs_dent_node *xent, *pxent = NULL; + struct fscrypt_name nm = {0}; + + dbg_tnc("ino %lu", (unsigned long)inum); + + /* + * Walk all extended attribute entries and remove them together with + * corresponding extended attribute inodes. + */ + lowest_xent_key(c, &key1, inum); + while (1) { + ino_t xattr_inum; + int err; + + xent = ubifs_tnc_next_ent(c, &key1, &nm); + if (IS_ERR(xent)) { + err = PTR_ERR(xent); + if (err == -ENOENT) + break; + kfree(pxent); + return err; + } + + xattr_inum = le64_to_cpu(xent->inum); + dbg_tnc("xent '%s', ino %lu", xent->name, + (unsigned long)xattr_inum); + + ubifs_evict_xattr_inode(c, xattr_inum); + + fname_name(&nm) = xent->name; + fname_len(&nm) = le16_to_cpu(xent->nlen); + err = ubifs_tnc_remove_nm(c, &key1, &nm); + if (err) { + kfree(pxent); + kfree(xent); + return err; + } + + lowest_ino_key(c, &key1, xattr_inum); + highest_ino_key(c, &key2, xattr_inum); + err = ubifs_tnc_remove_range(c, &key1, &key2); + if (err) { + kfree(pxent); + kfree(xent); + return err; + } + + kfree(pxent); + pxent = xent; + key_read(c, &xent->key, &key1); + } + + kfree(pxent); + lowest_ino_key(c, &key1, inum); + highest_ino_key(c, &key2, inum); + + return ubifs_tnc_remove_range(c, &key1, &key2); +} + +/** + * ubifs_tnc_next_ent - walk directory or extended attribute entries. + * @c: UBIFS file-system description object + * @key: key of last entry + * @nm: name of last entry found or %NULL + * + * This function finds and reads the next directory or extended attribute entry + * after the given key (@key) if there is one. @nm is used to resolve + * collisions. + * + * If the name of the current entry is not known and only the key is known, + * @nm->name has to be %NULL. In this case the semantics of this function is a + * little bit different and it returns the entry corresponding to this key, not + * the next one. If the key was not found, the closest "right" entry is + * returned. + * + * If the fist entry has to be found, @key has to contain the lowest possible + * key value for this inode and @name has to be %NULL. + * + * This function returns the found directory or extended attribute entry node + * in case of success, %-ENOENT is returned if no entry was found, and a + * negative error code is returned in case of failure. + */ +struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c, + union ubifs_key *key, + const struct fscrypt_name *nm) +{ + int n, err, type = key_type(c, key); + struct ubifs_znode *znode; + struct ubifs_dent_node *dent; + struct ubifs_zbranch *zbr; + union ubifs_key *dkey; + + dbg_tnck(key, "key "); + ubifs_assert(c, is_hash_key(c, key)); + + mutex_lock(&c->tnc_mutex); + err = ubifs_lookup_level0(c, key, &znode, &n); + if (unlikely(err < 0)) + goto out_unlock; + + if (fname_len(nm) > 0) { + if (err) { + /* Handle collisions */ + if (c->replaying) + err = fallible_resolve_collision(c, key, &znode, &n, + nm, 0); + else + err = resolve_collision(c, key, &znode, &n, nm); + dbg_tnc("rc returned %d, znode %p, n %d", + err, znode, n); + if (unlikely(err < 0)) + goto out_unlock; + } + + /* Now find next entry */ + err = tnc_next(c, &znode, &n); + if (unlikely(err)) + goto out_unlock; + } else { + /* + * The full name of the entry was not given, in which case the + * behavior of this function is a little different and it + * returns current entry, not the next one. + */ + if (!err) { + /* + * However, the given key does not exist in the TNC + * tree and @znode/@n variables contain the closest + * "preceding" element. Switch to the next one. + */ + err = tnc_next(c, &znode, &n); + if (err) + goto out_unlock; + } + } + + zbr = &znode->zbranch[n]; + dent = kmalloc(zbr->len, GFP_NOFS); + if (unlikely(!dent)) { + err = -ENOMEM; + goto out_unlock; + } + + /* + * The above 'tnc_next()' call could lead us to the next inode, check + * this. + */ + dkey = &zbr->key; + if (key_inum(c, dkey) != key_inum(c, key) || + key_type(c, dkey) != type) { + err = -ENOENT; + goto out_free; + } + + err = tnc_read_hashed_node(c, zbr, dent); + if (unlikely(err)) + goto out_free; + + mutex_unlock(&c->tnc_mutex); + return dent; + +out_free: + kfree(dent); +out_unlock: + mutex_unlock(&c->tnc_mutex); + return ERR_PTR(err); +} + +/** + * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit. + * @c: UBIFS file-system description object + * + * Destroy left-over obsolete znodes from a failed commit. + */ +static void tnc_destroy_cnext(struct ubifs_info *c) +{ + struct ubifs_znode *cnext; + + if (!c->cnext) + return; + ubifs_assert(c, c->cmt_state == COMMIT_BROKEN); + cnext = c->cnext; + do { + struct ubifs_znode *znode = cnext; + + cnext = cnext->cnext; + if (ubifs_zn_obsolete(znode)) + kfree(znode); + else if (!ubifs_zn_cow(znode)) { + /* + * Don't forget to update clean znode count after + * committing failed, because ubifs will check this + * count while closing tnc. Non-obsolete znode could + * be re-dirtied during committing process, so dirty + * flag is untrustable. The flag 'COW_ZNODE' is set + * for each dirty znode before committing, and it is + * cleared as long as the znode become clean, so we + * can statistic clean znode count according to this + * flag. + */ + atomic_long_inc(&c->clean_zn_cnt); + atomic_long_inc(&ubifs_clean_zn_cnt); + } + } while (cnext && cnext != c->cnext); +} + +/** + * ubifs_tnc_close - close TNC subsystem and free all related resources. + * @c: UBIFS file-system description object + */ +void ubifs_tnc_close(struct ubifs_info *c) +{ + tnc_destroy_cnext(c); + if (c->zroot.znode) { + long n, freed; + + n = atomic_long_read(&c->clean_zn_cnt); + freed = ubifs_destroy_tnc_subtree(c, c->zroot.znode); + ubifs_assert(c, freed == n); + atomic_long_sub(n, &ubifs_clean_zn_cnt); + } + kfree(c->gap_lebs); + kfree(c->ilebs); + destroy_old_idx(c); +} + +/** + * left_znode - get the znode to the left. + * @c: UBIFS file-system description object + * @znode: znode + * + * This function returns a pointer to the znode to the left of @znode or NULL if + * there is not one. A negative error code is returned on failure. + */ +static struct ubifs_znode *left_znode(struct ubifs_info *c, + struct ubifs_znode *znode) +{ + int level = znode->level; + + while (1) { + int n = znode->iip - 1; + + /* Go up until we can go left */ + znode = znode->parent; + if (!znode) + return NULL; + if (n >= 0) { + /* Now go down the rightmost branch to 'level' */ + znode = get_znode(c, znode, n); + if (IS_ERR(znode)) + return znode; + while (znode->level != level) { + n = znode->child_cnt - 1; + znode = get_znode(c, znode, n); + if (IS_ERR(znode)) + return znode; + } + break; + } + } + return znode; +} + +/** + * right_znode - get the znode to the right. + * @c: UBIFS file-system description object + * @znode: znode + * + * This function returns a pointer to the znode to the right of @znode or NULL + * if there is not one. A negative error code is returned on failure. + */ +static struct ubifs_znode *right_znode(struct ubifs_info *c, + struct ubifs_znode *znode) +{ + int level = znode->level; + + while (1) { + int n = znode->iip + 1; + + /* Go up until we can go right */ + znode = znode->parent; + if (!znode) + return NULL; + if (n < znode->child_cnt) { + /* Now go down the leftmost branch to 'level' */ + znode = get_znode(c, znode, n); + if (IS_ERR(znode)) + return znode; + while (znode->level != level) { + znode = get_znode(c, znode, 0); + if (IS_ERR(znode)) + return znode; + } + break; + } + } + return znode; +} + +/** + * lookup_znode - find a particular indexing node from TNC. + * @c: UBIFS file-system description object + * @key: index node key to lookup + * @level: index node level + * @lnum: index node LEB number + * @offs: index node offset + * + * This function searches an indexing node by its first key @key and its + * address @lnum:@offs. It looks up the indexing tree by pulling all indexing + * nodes it traverses to TNC. This function is called for indexing nodes which + * were found on the media by scanning, for example when garbage-collecting or + * when doing in-the-gaps commit. This means that the indexing node which is + * looked for does not have to have exactly the same leftmost key @key, because + * the leftmost key may have been changed, in which case TNC will contain a + * dirty znode which still refers the same @lnum:@offs. This function is clever + * enough to recognize such indexing nodes. + * + * Note, if a znode was deleted or changed too much, then this function will + * not find it. For situations like this UBIFS has the old index RB-tree + * (indexed by @lnum:@offs). + * + * This function returns a pointer to the znode found or %NULL if it is not + * found. A negative error code is returned on failure. + */ +static struct ubifs_znode *lookup_znode(struct ubifs_info *c, + union ubifs_key *key, int level, + int lnum, int offs) +{ + struct ubifs_znode *znode, *zn; + int n, nn; + + ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY); + + /* + * The arguments have probably been read off flash, so don't assume + * they are valid. + */ + if (level < 0) + return ERR_PTR(-EINVAL); + + /* Get the root znode */ + znode = c->zroot.znode; + if (!znode) { + znode = ubifs_load_znode(c, &c->zroot, NULL, 0); + if (IS_ERR(znode)) + return znode; + } + /* Check if it is the one we are looking for */ + if (c->zroot.lnum == lnum && c->zroot.offs == offs) + return znode; + /* Descend to the parent level i.e. (level + 1) */ + if (level >= znode->level) + return NULL; + while (1) { + ubifs_search_zbranch(c, znode, key, &n); + if (n < 0) { + /* + * We reached a znode where the leftmost key is greater + * than the key we are searching for. This is the same + * situation as the one described in a huge comment at + * the end of the 'ubifs_lookup_level0()' function. And + * for exactly the same reasons we have to try to look + * left before giving up. + */ + znode = left_znode(c, znode); + if (!znode) + return NULL; + if (IS_ERR(znode)) + return znode; + ubifs_search_zbranch(c, znode, key, &n); + ubifs_assert(c, n >= 0); + } + if (znode->level == level + 1) + break; + znode = get_znode(c, znode, n); + if (IS_ERR(znode)) + return znode; + } + /* Check if the child is the one we are looking for */ + if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs) + return get_znode(c, znode, n); + /* If the key is unique, there is nowhere else to look */ + if (!is_hash_key(c, key)) + return NULL; + /* + * The key is not unique and so may be also in the znodes to either + * side. + */ + zn = znode; + nn = n; + /* Look left */ + while (1) { + /* Move one branch to the left */ + if (n) + n -= 1; + else { + znode = left_znode(c, znode); + if (!znode) + break; + if (IS_ERR(znode)) + return znode; + n = znode->child_cnt - 1; + } + /* Check it */ + if (znode->zbranch[n].lnum == lnum && + znode->zbranch[n].offs == offs) + return get_znode(c, znode, n); + /* Stop if the key is less than the one we are looking for */ + if (keys_cmp(c, &znode->zbranch[n].key, key) < 0) + break; + } + /* Back to the middle */ + znode = zn; + n = nn; + /* Look right */ + while (1) { + /* Move one branch to the right */ + if (++n >= znode->child_cnt) { + znode = right_znode(c, znode); + if (!znode) + break; + if (IS_ERR(znode)) + return znode; + n = 0; + } + /* Check it */ + if (znode->zbranch[n].lnum == lnum && + znode->zbranch[n].offs == offs) + return get_znode(c, znode, n); + /* Stop if the key is greater than the one we are looking for */ + if (keys_cmp(c, &znode->zbranch[n].key, key) > 0) + break; + } + return NULL; +} + +/** + * is_idx_node_in_tnc - determine if an index node is in the TNC. + * @c: UBIFS file-system description object + * @key: key of index node + * @level: index node level + * @lnum: LEB number of index node + * @offs: offset of index node + * + * This function returns %0 if the index node is not referred to in the TNC, %1 + * if the index node is referred to in the TNC and the corresponding znode is + * dirty, %2 if an index node is referred to in the TNC and the corresponding + * znode is clean, and a negative error code in case of failure. + * + * Note, the @key argument has to be the key of the first child. Also note, + * this function relies on the fact that 0:0 is never a valid LEB number and + * offset for a main-area node. + */ +int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level, + int lnum, int offs) +{ + struct ubifs_znode *znode; + + znode = lookup_znode(c, key, level, lnum, offs); + if (!znode) + return 0; + if (IS_ERR(znode)) + return PTR_ERR(znode); + + return ubifs_zn_dirty(znode) ? 1 : 2; +} + +/** + * is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC. + * @c: UBIFS file-system description object + * @key: node key + * @lnum: node LEB number + * @offs: node offset + * + * This function returns %1 if the node is referred to in the TNC, %0 if it is + * not, and a negative error code in case of failure. + * + * Note, this function relies on the fact that 0:0 is never a valid LEB number + * and offset for a main-area node. + */ +static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, + int lnum, int offs) +{ + struct ubifs_zbranch *zbr; + struct ubifs_znode *znode, *zn; + int n, found, err, nn; + const int unique = !is_hash_key(c, key); + + found = ubifs_lookup_level0(c, key, &znode, &n); + if (found < 0) + return found; /* Error code */ + if (!found) + return 0; + zbr = &znode->zbranch[n]; + if (lnum == zbr->lnum && offs == zbr->offs) + return 1; /* Found it */ + if (unique) + return 0; + /* + * Because the key is not unique, we have to look left + * and right as well + */ + zn = znode; + nn = n; + /* Look left */ + while (1) { + err = tnc_prev(c, &znode, &n); + if (err == -ENOENT) + break; + if (err) + return err; + if (keys_cmp(c, key, &znode->zbranch[n].key)) + break; + zbr = &znode->zbranch[n]; + if (lnum == zbr->lnum && offs == zbr->offs) + return 1; /* Found it */ + } + /* Look right */ + znode = zn; + n = nn; + while (1) { + err = tnc_next(c, &znode, &n); + if (err) { + if (err == -ENOENT) + return 0; + return err; + } + if (keys_cmp(c, key, &znode->zbranch[n].key)) + break; + zbr = &znode->zbranch[n]; + if (lnum == zbr->lnum && offs == zbr->offs) + return 1; /* Found it */ + } + return 0; +} + +/** + * ubifs_tnc_has_node - determine whether a node is in the TNC. + * @c: UBIFS file-system description object + * @key: node key + * @level: index node level (if it is an index node) + * @lnum: node LEB number + * @offs: node offset + * @is_idx: non-zero if the node is an index node + * + * This function returns %1 if the node is in the TNC, %0 if it is not, and a + * negative error code in case of failure. For index nodes, @key has to be the + * key of the first child. An index node is considered to be in the TNC only if + * the corresponding znode is clean or has not been loaded. + */ +int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level, + int lnum, int offs, int is_idx) +{ + int err; + + mutex_lock(&c->tnc_mutex); + if (is_idx) { + err = is_idx_node_in_tnc(c, key, level, lnum, offs); + if (err < 0) + goto out_unlock; + if (err == 1) + /* The index node was found but it was dirty */ + err = 0; + else if (err == 2) + /* The index node was found and it was clean */ + err = 1; + else + BUG_ON(err != 0); + } else + err = is_leaf_node_in_tnc(c, key, lnum, offs); + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * ubifs_dirty_idx_node - dirty an index node. + * @c: UBIFS file-system description object + * @key: index node key + * @level: index node level + * @lnum: index node LEB number + * @offs: index node offset + * + * This function loads and dirties an index node so that it can be garbage + * collected. The @key argument has to be the key of the first child. This + * function relies on the fact that 0:0 is never a valid LEB number and offset + * for a main-area node. Returns %0 on success and a negative error code on + * failure. + */ +int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level, + int lnum, int offs) +{ + struct ubifs_znode *znode; + int err = 0; + + mutex_lock(&c->tnc_mutex); + znode = lookup_znode(c, key, level, lnum, offs); + if (!znode) + goto out_unlock; + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + znode = dirty_cow_bottom_up(c, znode); + if (IS_ERR(znode)) { + err = PTR_ERR(znode); + goto out_unlock; + } + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * dbg_check_inode_size - check if inode size is correct. + * @c: UBIFS file-system description object + * @inode: inode to check + * @size: inode size + * + * This function makes sure that the inode size (@size) is correct and it does + * not have any pages beyond @size. Returns zero if the inode is OK, %-EINVAL + * if it has a data page beyond @size, and other negative error code in case of + * other errors. + */ +int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode, + loff_t size) +{ + int err, n; + union ubifs_key from_key, to_key, *key; + struct ubifs_znode *znode; + unsigned int block; + + if (!S_ISREG(inode->i_mode)) + return 0; + if (!dbg_is_chk_gen(c)) + return 0; + + block = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; + data_key_init(c, &from_key, inode->i_ino, block); + highest_data_key(c, &to_key, inode->i_ino); + + mutex_lock(&c->tnc_mutex); + err = ubifs_lookup_level0(c, &from_key, &znode, &n); + if (err < 0) + goto out_unlock; + + if (err) { + key = &from_key; + goto out_dump; + } + + err = tnc_next(c, &znode, &n); + if (err == -ENOENT) { + err = 0; + goto out_unlock; + } + if (err < 0) + goto out_unlock; + + ubifs_assert(c, err == 0); + key = &znode->zbranch[n].key; + if (!key_in_range(c, key, &from_key, &to_key)) + goto out_unlock; + +out_dump: + block = key_block(c, key); + ubifs_err(c, "inode %lu has size %lld, but there are data at offset %lld", + (unsigned long)inode->i_ino, size, + ((loff_t)block) << UBIFS_BLOCK_SHIFT); + mutex_unlock(&c->tnc_mutex); + ubifs_dump_inode(c, inode); + dump_stack(); + return -EINVAL; + +out_unlock: + mutex_unlock(&c->tnc_mutex); + return err; +} diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c new file mode 100644 index 000000000..234be1c4d --- /dev/null +++ b/fs/ubifs/tnc_commit.c @@ -0,0 +1,1111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* This file implements TNC functions for committing */ + +#include <linux/random.h> +#include "ubifs.h" + +/** + * make_idx_node - make an index node for fill-the-gaps method of TNC commit. + * @c: UBIFS file-system description object + * @idx: buffer in which to place new index node + * @znode: znode from which to make new index node + * @lnum: LEB number where new index node will be written + * @offs: offset where new index node will be written + * @len: length of new index node + */ +static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx, + struct ubifs_znode *znode, int lnum, int offs, int len) +{ + struct ubifs_znode *zp; + u8 hash[UBIFS_HASH_ARR_SZ]; + int i, err; + + /* Make index node */ + idx->ch.node_type = UBIFS_IDX_NODE; + idx->child_cnt = cpu_to_le16(znode->child_cnt); + idx->level = cpu_to_le16(znode->level); + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + key_write_idx(c, &zbr->key, &br->key); + br->lnum = cpu_to_le32(zbr->lnum); + br->offs = cpu_to_le32(zbr->offs); + br->len = cpu_to_le32(zbr->len); + ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br)); + if (!zbr->lnum || !zbr->len) { + ubifs_err(c, "bad ref in znode"); + ubifs_dump_znode(c, znode); + if (zbr->znode) + ubifs_dump_znode(c, zbr->znode); + + return -EINVAL; + } + } + ubifs_prepare_node(c, idx, len, 0); + ubifs_node_calc_hash(c, idx, hash); + + znode->lnum = lnum; + znode->offs = offs; + znode->len = len; + + err = insert_old_idx_znode(c, znode); + + /* Update the parent */ + zp = znode->parent; + if (zp) { + struct ubifs_zbranch *zbr; + + zbr = &zp->zbranch[znode->iip]; + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + ubifs_copy_hash(c, hash, zbr->hash); + } else { + c->zroot.lnum = lnum; + c->zroot.offs = offs; + c->zroot.len = len; + ubifs_copy_hash(c, hash, c->zroot.hash); + } + c->calc_idx_sz += ALIGN(len, 8); + + atomic_long_dec(&c->dirty_zn_cnt); + + ubifs_assert(c, ubifs_zn_dirty(znode)); + ubifs_assert(c, ubifs_zn_cow(znode)); + + /* + * Note, unlike 'write_index()' we do not add memory barriers here + * because this function is called with @c->tnc_mutex locked. + */ + __clear_bit(DIRTY_ZNODE, &znode->flags); + __clear_bit(COW_ZNODE, &znode->flags); + + return err; +} + +/** + * fill_gap - make index nodes in gaps in dirty index LEBs. + * @c: UBIFS file-system description object + * @lnum: LEB number that gap appears in + * @gap_start: offset of start of gap + * @gap_end: offset of end of gap + * @dirt: adds dirty space to this + * + * This function returns the number of index nodes written into the gap. + */ +static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end, + int *dirt) +{ + int len, gap_remains, gap_pos, written, pad_len; + + ubifs_assert(c, (gap_start & 7) == 0); + ubifs_assert(c, (gap_end & 7) == 0); + ubifs_assert(c, gap_end >= gap_start); + + gap_remains = gap_end - gap_start; + if (!gap_remains) + return 0; + gap_pos = gap_start; + written = 0; + while (c->enext) { + len = ubifs_idx_node_sz(c, c->enext->child_cnt); + if (len < gap_remains) { + struct ubifs_znode *znode = c->enext; + const int alen = ALIGN(len, 8); + int err; + + ubifs_assert(c, alen <= gap_remains); + err = make_idx_node(c, c->ileb_buf + gap_pos, znode, + lnum, gap_pos, len); + if (err) + return err; + gap_remains -= alen; + gap_pos += alen; + c->enext = znode->cnext; + if (c->enext == c->cnext) + c->enext = NULL; + written += 1; + } else + break; + } + if (gap_end == c->leb_size) { + c->ileb_len = ALIGN(gap_pos, c->min_io_size); + /* Pad to end of min_io_size */ + pad_len = c->ileb_len - gap_pos; + } else + /* Pad to end of gap */ + pad_len = gap_remains; + dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d", + lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len); + ubifs_pad(c, c->ileb_buf + gap_pos, pad_len); + *dirt += pad_len; + return written; +} + +/** + * find_old_idx - find an index node obsoleted since the last commit start. + * @c: UBIFS file-system description object + * @lnum: LEB number of obsoleted index node + * @offs: offset of obsoleted index node + * + * Returns %1 if found and %0 otherwise. + */ +static int find_old_idx(struct ubifs_info *c, int lnum, int offs) +{ + struct ubifs_old_idx *o; + struct rb_node *p; + + p = c->old_idx.rb_node; + while (p) { + o = rb_entry(p, struct ubifs_old_idx, rb); + if (lnum < o->lnum) + p = p->rb_left; + else if (lnum > o->lnum) + p = p->rb_right; + else if (offs < o->offs) + p = p->rb_left; + else if (offs > o->offs) + p = p->rb_right; + else + return 1; + } + return 0; +} + +/** + * is_idx_node_in_use - determine if an index node can be overwritten. + * @c: UBIFS file-system description object + * @key: key of index node + * @level: index node level + * @lnum: LEB number of index node + * @offs: offset of index node + * + * If @key / @lnum / @offs identify an index node that was not part of the old + * index, then this function returns %0 (obsolete). Else if the index node was + * part of the old index but is now dirty %1 is returned, else if it is clean %2 + * is returned. A negative error code is returned on failure. + */ +static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key, + int level, int lnum, int offs) +{ + int ret; + + ret = is_idx_node_in_tnc(c, key, level, lnum, offs); + if (ret < 0) + return ret; /* Error code */ + if (ret == 0) + if (find_old_idx(c, lnum, offs)) + return 1; + return ret; +} + +/** + * layout_leb_in_gaps - layout index nodes using in-the-gaps method. + * @c: UBIFS file-system description object + * @p: return LEB number in @c->gap_lebs[p] + * + * This function lays out new index nodes for dirty znodes using in-the-gaps + * method of TNC commit. + * This function merely puts the next znode into the next gap, making no attempt + * to try to maximise the number of znodes that fit. + * This function returns the number of index nodes written into the gaps, or a + * negative error code on failure. + */ +static int layout_leb_in_gaps(struct ubifs_info *c, int p) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written; + + tot_written = 0; + /* Get an index LEB with lots of obsolete index nodes */ + lnum = ubifs_find_dirty_idx_leb(c); + if (lnum < 0) + /* + * There also may be dirt in the index head that could be + * filled, however we do not check there at present. + */ + return lnum; /* Error code */ + c->gap_lebs[p] = lnum; + dbg_gc("LEB %d", lnum); + /* + * Scan the index LEB. We use the generic scan for this even though + * it is more comprehensive and less efficient than is needed for this + * purpose. + */ + sleb = ubifs_scan(c, lnum, 0, c->ileb_buf, 0); + c->ileb_len = 0; + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + gap_start = 0; + list_for_each_entry(snod, &sleb->nodes, list) { + struct ubifs_idx_node *idx; + int in_use, level; + + ubifs_assert(c, snod->type == UBIFS_IDX_NODE); + idx = snod->node; + key_read(c, ubifs_idx_key(c, idx), &snod->key); + level = le16_to_cpu(idx->level); + /* Determine if the index node is in use (not obsolete) */ + in_use = is_idx_node_in_use(c, &snod->key, level, lnum, + snod->offs); + if (in_use < 0) { + ubifs_scan_destroy(sleb); + return in_use; /* Error code */ + } + if (in_use) { + if (in_use == 1) + dirt += ALIGN(snod->len, 8); + /* + * The obsolete index nodes form gaps that can be + * overwritten. This gap has ended because we have + * found an index node that is still in use + * i.e. not obsolete + */ + gap_end = snod->offs; + /* Try to fill gap */ + written = fill_gap(c, lnum, gap_start, gap_end, &dirt); + if (written < 0) { + ubifs_scan_destroy(sleb); + return written; /* Error code */ + } + tot_written += written; + gap_start = ALIGN(snod->offs + snod->len, 8); + } + } + ubifs_scan_destroy(sleb); + c->ileb_len = c->leb_size; + gap_end = c->leb_size; + /* Try to fill gap */ + written = fill_gap(c, lnum, gap_start, gap_end, &dirt); + if (written < 0) + return written; /* Error code */ + tot_written += written; + if (tot_written == 0) { + struct ubifs_lprops lp; + + dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written); + err = ubifs_read_one_lp(c, lnum, &lp); + if (err) + return err; + if (lp.free == c->leb_size) { + /* + * We must have snatched this LEB from the idx_gc list + * so we need to correct the free and dirty space. + */ + err = ubifs_change_one_lp(c, lnum, + c->leb_size - c->ileb_len, + dirt, 0, 0, 0); + if (err) + return err; + } + return 0; + } + err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt, + 0, 0, 0); + if (err) + return err; + err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len); + if (err) + return err; + dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written); + return tot_written; +} + +/** + * get_leb_cnt - calculate the number of empty LEBs needed to commit. + * @c: UBIFS file-system description object + * @cnt: number of znodes to commit + * + * This function returns the number of empty LEBs needed to commit @cnt znodes + * to the current index head. The number is not exact and may be more than + * needed. + */ +static int get_leb_cnt(struct ubifs_info *c, int cnt) +{ + int d; + + /* Assume maximum index node size (i.e. overestimate space needed) */ + cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz; + if (cnt < 0) + cnt = 0; + d = c->leb_size / c->max_idx_node_sz; + return DIV_ROUND_UP(cnt, d); +} + +/** + * layout_in_gaps - in-the-gaps method of committing TNC. + * @c: UBIFS file-system description object + * @cnt: number of dirty znodes to commit. + * + * This function lays out new index nodes for dirty znodes using in-the-gaps + * method of TNC commit. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int layout_in_gaps(struct ubifs_info *c, int cnt) +{ + int err, leb_needed_cnt, written, p = 0, old_idx_lebs, *gap_lebs; + + dbg_gc("%d znodes to write", cnt); + + c->gap_lebs = kmalloc_array(c->lst.idx_lebs + 1, sizeof(int), + GFP_NOFS); + if (!c->gap_lebs) + return -ENOMEM; + + old_idx_lebs = c->lst.idx_lebs; + do { + ubifs_assert(c, p < c->lst.idx_lebs); + written = layout_leb_in_gaps(c, p); + if (written < 0) { + err = written; + if (err != -ENOSPC) { + kfree(c->gap_lebs); + c->gap_lebs = NULL; + return err; + } + if (!dbg_is_chk_index(c)) { + /* + * Do not print scary warnings if the debugging + * option which forces in-the-gaps is enabled. + */ + ubifs_warn(c, "out of space"); + ubifs_dump_budg(c, &c->bi); + ubifs_dump_lprops(c); + } + /* Try to commit anyway */ + break; + } + p++; + cnt -= written; + leb_needed_cnt = get_leb_cnt(c, cnt); + dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt, + leb_needed_cnt, c->ileb_cnt); + /* + * Dynamically change the size of @c->gap_lebs to prevent + * oob, because @c->lst.idx_lebs could be increased by + * function @get_idx_gc_leb (called by layout_leb_in_gaps-> + * ubifs_find_dirty_idx_leb) during loop. Only enlarge + * @c->gap_lebs when needed. + * + */ + if (leb_needed_cnt > c->ileb_cnt && p >= old_idx_lebs && + old_idx_lebs < c->lst.idx_lebs) { + old_idx_lebs = c->lst.idx_lebs; + gap_lebs = krealloc(c->gap_lebs, sizeof(int) * + (old_idx_lebs + 1), GFP_NOFS); + if (!gap_lebs) { + kfree(c->gap_lebs); + c->gap_lebs = NULL; + return -ENOMEM; + } + c->gap_lebs = gap_lebs; + } + } while (leb_needed_cnt > c->ileb_cnt); + + c->gap_lebs[p] = -1; + return 0; +} + +/** + * layout_in_empty_space - layout index nodes in empty space. + * @c: UBIFS file-system description object + * + * This function lays out new index nodes for dirty znodes using empty LEBs. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int layout_in_empty_space(struct ubifs_info *c) +{ + struct ubifs_znode *znode, *cnext, *zp; + int lnum, offs, len, next_len, buf_len, buf_offs, used, avail; + int wlen, blen, err; + + cnext = c->enext; + if (!cnext) + return 0; + + lnum = c->ihead_lnum; + buf_offs = c->ihead_offs; + + buf_len = ubifs_idx_node_sz(c, c->fanout); + buf_len = ALIGN(buf_len, c->min_io_size); + used = 0; + avail = buf_len; + + /* Ensure there is enough room for first write */ + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + if (buf_offs + next_len > c->leb_size) + lnum = -1; + + while (1) { + znode = cnext; + + len = ubifs_idx_node_sz(c, znode->child_cnt); + + /* Determine the index node position */ + if (lnum == -1) { + if (c->ileb_nxt >= c->ileb_cnt) { + ubifs_err(c, "out of space"); + return -ENOSPC; + } + lnum = c->ilebs[c->ileb_nxt++]; + buf_offs = 0; + used = 0; + avail = buf_len; + } + + offs = buf_offs + used; + + znode->lnum = lnum; + znode->offs = offs; + znode->len = len; + + /* Update the parent */ + zp = znode->parent; + if (zp) { + struct ubifs_zbranch *zbr; + int i; + + i = znode->iip; + zbr = &zp->zbranch[i]; + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + } else { + c->zroot.lnum = lnum; + c->zroot.offs = offs; + c->zroot.len = len; + } + c->calc_idx_sz += ALIGN(len, 8); + + /* + * Once lprops is updated, we can decrease the dirty znode count + * but it is easier to just do it here. + */ + atomic_long_dec(&c->dirty_zn_cnt); + + /* + * Calculate the next index node length to see if there is + * enough room for it + */ + cnext = znode->cnext; + if (cnext == c->cnext) + next_len = 0; + else + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + + /* Update buffer positions */ + wlen = used + len; + used += ALIGN(len, 8); + avail -= ALIGN(len, 8); + + if (next_len != 0 && + buf_offs + used + next_len <= c->leb_size && + avail > 0) + continue; + + if (avail <= 0 && next_len && + buf_offs + used + next_len <= c->leb_size) + blen = buf_len; + else + blen = ALIGN(wlen, c->min_io_size); + + /* The buffer is full or there are no more znodes to do */ + buf_offs += blen; + if (next_len) { + if (buf_offs + next_len > c->leb_size) { + err = ubifs_update_one_lp(c, lnum, + c->leb_size - buf_offs, blen - used, + 0, 0); + if (err) + return err; + lnum = -1; + } + used -= blen; + if (used < 0) + used = 0; + avail = buf_len - used; + continue; + } + err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs, + blen - used, 0, 0); + if (err) + return err; + break; + } + + c->dbg->new_ihead_lnum = lnum; + c->dbg->new_ihead_offs = buf_offs; + + return 0; +} + +/** + * layout_commit - determine positions of index nodes to commit. + * @c: UBIFS file-system description object + * @no_space: indicates that insufficient empty LEBs were allocated + * @cnt: number of znodes to commit + * + * Calculate and update the positions of index nodes to commit. If there were + * an insufficient number of empty LEBs allocated, then index nodes are placed + * into the gaps created by obsolete index nodes in non-empty index LEBs. For + * this purpose, an obsolete index node is one that was not in the index as at + * the end of the last commit. To write "in-the-gaps" requires that those index + * LEBs are updated atomically in-place. + */ +static int layout_commit(struct ubifs_info *c, int no_space, int cnt) +{ + int err; + + if (no_space) { + err = layout_in_gaps(c, cnt); + if (err) + return err; + } + err = layout_in_empty_space(c); + return err; +} + +/** + * find_first_dirty - find first dirty znode. + * @znode: znode to begin searching from + */ +static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode) +{ + int i, cont; + + if (!znode) + return NULL; + + while (1) { + if (znode->level == 0) { + if (ubifs_zn_dirty(znode)) + return znode; + return NULL; + } + cont = 0; + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + if (zbr->znode && ubifs_zn_dirty(zbr->znode)) { + znode = zbr->znode; + cont = 1; + break; + } + } + if (!cont) { + if (ubifs_zn_dirty(znode)) + return znode; + return NULL; + } + } +} + +/** + * find_next_dirty - find next dirty znode. + * @znode: znode to begin searching from + */ +static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode) +{ + int n = znode->iip + 1; + + znode = znode->parent; + if (!znode) + return NULL; + for (; n < znode->child_cnt; n++) { + struct ubifs_zbranch *zbr = &znode->zbranch[n]; + + if (zbr->znode && ubifs_zn_dirty(zbr->znode)) + return find_first_dirty(zbr->znode); + } + return znode; +} + +/** + * get_znodes_to_commit - create list of dirty znodes to commit. + * @c: UBIFS file-system description object + * + * This function returns the number of znodes to commit. + */ +static int get_znodes_to_commit(struct ubifs_info *c) +{ + struct ubifs_znode *znode, *cnext; + int cnt = 0; + + c->cnext = find_first_dirty(c->zroot.znode); + znode = c->enext = c->cnext; + if (!znode) { + dbg_cmt("no znodes to commit"); + return 0; + } + cnt += 1; + while (1) { + ubifs_assert(c, !ubifs_zn_cow(znode)); + __set_bit(COW_ZNODE, &znode->flags); + znode->alt = 0; + cnext = find_next_dirty(znode); + if (!cnext) { + znode->cnext = c->cnext; + break; + } + znode->cparent = znode->parent; + znode->ciip = znode->iip; + znode->cnext = cnext; + znode = cnext; + cnt += 1; + } + dbg_cmt("committing %d znodes", cnt); + ubifs_assert(c, cnt == atomic_long_read(&c->dirty_zn_cnt)); + return cnt; +} + +/** + * alloc_idx_lebs - allocate empty LEBs to be used to commit. + * @c: UBIFS file-system description object + * @cnt: number of znodes to commit + * + * This function returns %-ENOSPC if it cannot allocate a sufficient number of + * empty LEBs. %0 is returned on success, otherwise a negative error code + * is returned. + */ +static int alloc_idx_lebs(struct ubifs_info *c, int cnt) +{ + int i, leb_cnt, lnum; + + c->ileb_cnt = 0; + c->ileb_nxt = 0; + leb_cnt = get_leb_cnt(c, cnt); + dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt); + if (!leb_cnt) + return 0; + c->ilebs = kmalloc_array(leb_cnt, sizeof(int), GFP_NOFS); + if (!c->ilebs) + return -ENOMEM; + for (i = 0; i < leb_cnt; i++) { + lnum = ubifs_find_free_leb_for_idx(c); + if (lnum < 0) + return lnum; + c->ilebs[c->ileb_cnt++] = lnum; + dbg_cmt("LEB %d", lnum); + } + if (dbg_is_chk_index(c) && !(prandom_u32() & 7)) + return -ENOSPC; + return 0; +} + +/** + * free_unused_idx_lebs - free unused LEBs that were allocated for the commit. + * @c: UBIFS file-system description object + * + * It is possible that we allocate more empty LEBs for the commit than we need. + * This functions frees the surplus. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int free_unused_idx_lebs(struct ubifs_info *c) +{ + int i, err = 0, lnum, er; + + for (i = c->ileb_nxt; i < c->ileb_cnt; i++) { + lnum = c->ilebs[i]; + dbg_cmt("LEB %d", lnum); + er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_INDEX | LPROPS_TAKEN, 0); + if (!err) + err = er; + } + return err; +} + +/** + * free_idx_lebs - free unused LEBs after commit end. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int free_idx_lebs(struct ubifs_info *c) +{ + int err; + + err = free_unused_idx_lebs(c); + kfree(c->ilebs); + c->ilebs = NULL; + return err; +} + +/** + * ubifs_tnc_start_commit - start TNC commit. + * @c: UBIFS file-system description object + * @zroot: new index root position is returned here + * + * This function prepares the list of indexing nodes to commit and lays out + * their positions on flash. If there is not enough free space it uses the + * in-gap commit method. Returns zero in case of success and a negative error + * code in case of failure. + */ +int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot) +{ + int err = 0, cnt; + + mutex_lock(&c->tnc_mutex); + err = dbg_check_tnc(c, 1); + if (err) + goto out; + cnt = get_znodes_to_commit(c); + if (cnt != 0) { + int no_space = 0; + + err = alloc_idx_lebs(c, cnt); + if (err == -ENOSPC) + no_space = 1; + else if (err) + goto out_free; + err = layout_commit(c, no_space, cnt); + if (err) + goto out_free; + ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0); + err = free_unused_idx_lebs(c); + if (err) + goto out; + } + destroy_old_idx(c); + memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch)); + + err = ubifs_save_dirty_idx_lnums(c); + if (err) + goto out; + + spin_lock(&c->space_lock); + /* + * Although we have not finished committing yet, update size of the + * committed index ('c->bi.old_idx_sz') and zero out the index growth + * budget. It is OK to do this now, because we've reserved all the + * space which is needed to commit the index, and it is save for the + * budgeting subsystem to assume the index is already committed, + * even though it is not. + */ + ubifs_assert(c, c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c)); + c->bi.old_idx_sz = c->calc_idx_sz; + c->bi.uncommitted_idx = 0; + c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); + spin_unlock(&c->space_lock); + mutex_unlock(&c->tnc_mutex); + + dbg_cmt("number of index LEBs %d", c->lst.idx_lebs); + dbg_cmt("size of index %llu", c->calc_idx_sz); + return err; + +out_free: + free_idx_lebs(c); +out: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * write_index - write index nodes. + * @c: UBIFS file-system description object + * + * This function writes the index nodes whose positions were laid out in the + * layout_in_empty_space function. + */ +static int write_index(struct ubifs_info *c) +{ + struct ubifs_idx_node *idx; + struct ubifs_znode *znode, *cnext; + int i, lnum, offs, len, next_len, buf_len, buf_offs, used; + int avail, wlen, err, lnum_pos = 0, blen, nxt_offs; + + cnext = c->enext; + if (!cnext) + return 0; + + /* + * Always write index nodes to the index head so that index nodes and + * other types of nodes are never mixed in the same erase block. + */ + lnum = c->ihead_lnum; + buf_offs = c->ihead_offs; + + /* Allocate commit buffer */ + buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size); + used = 0; + avail = buf_len; + + /* Ensure there is enough room for first write */ + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + if (buf_offs + next_len > c->leb_size) { + err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0, + LPROPS_TAKEN); + if (err) + return err; + lnum = -1; + } + + while (1) { + u8 hash[UBIFS_HASH_ARR_SZ]; + + cond_resched(); + + znode = cnext; + idx = c->cbuf + used; + + /* Make index node */ + idx->ch.node_type = UBIFS_IDX_NODE; + idx->child_cnt = cpu_to_le16(znode->child_cnt); + idx->level = cpu_to_le16(znode->level); + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + key_write_idx(c, &zbr->key, &br->key); + br->lnum = cpu_to_le32(zbr->lnum); + br->offs = cpu_to_le32(zbr->offs); + br->len = cpu_to_le32(zbr->len); + ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br)); + if (!zbr->lnum || !zbr->len) { + ubifs_err(c, "bad ref in znode"); + ubifs_dump_znode(c, znode); + if (zbr->znode) + ubifs_dump_znode(c, zbr->znode); + + return -EINVAL; + } + } + len = ubifs_idx_node_sz(c, znode->child_cnt); + ubifs_prepare_node(c, idx, len, 0); + ubifs_node_calc_hash(c, idx, hash); + + mutex_lock(&c->tnc_mutex); + + if (znode->cparent) + ubifs_copy_hash(c, hash, + znode->cparent->zbranch[znode->ciip].hash); + + if (znode->parent) { + if (!ubifs_zn_obsolete(znode)) + ubifs_copy_hash(c, hash, + znode->parent->zbranch[znode->iip].hash); + } else { + ubifs_copy_hash(c, hash, c->zroot.hash); + } + + mutex_unlock(&c->tnc_mutex); + + /* Determine the index node position */ + if (lnum == -1) { + lnum = c->ilebs[lnum_pos++]; + buf_offs = 0; + used = 0; + avail = buf_len; + } + offs = buf_offs + used; + + if (lnum != znode->lnum || offs != znode->offs || + len != znode->len) { + ubifs_err(c, "inconsistent znode posn"); + return -EINVAL; + } + + /* Grab some stuff from znode while we still can */ + cnext = znode->cnext; + + ubifs_assert(c, ubifs_zn_dirty(znode)); + ubifs_assert(c, ubifs_zn_cow(znode)); + + /* + * It is important that other threads should see %DIRTY_ZNODE + * flag cleared before %COW_ZNODE. Specifically, it matters in + * the 'dirty_cow_znode()' function. This is the reason for the + * first barrier. Also, we want the bit changes to be seen to + * other threads ASAP, to avoid unnecesarry copying, which is + * the reason for the second barrier. + */ + clear_bit(DIRTY_ZNODE, &znode->flags); + smp_mb__before_atomic(); + clear_bit(COW_ZNODE, &znode->flags); + smp_mb__after_atomic(); + + /* + * We have marked the znode as clean but have not updated the + * @c->clean_zn_cnt counter. If this znode becomes dirty again + * before 'free_obsolete_znodes()' is called, then + * @c->clean_zn_cnt will be decremented before it gets + * incremented (resulting in 2 decrements for the same znode). + * This means that @c->clean_zn_cnt may become negative for a + * while. + * + * Q: why we cannot increment @c->clean_zn_cnt? + * A: because we do not have the @c->tnc_mutex locked, and the + * following code would be racy and buggy: + * + * if (!ubifs_zn_obsolete(znode)) { + * atomic_long_inc(&c->clean_zn_cnt); + * atomic_long_inc(&ubifs_clean_zn_cnt); + * } + * + * Thus, we just delay the @c->clean_zn_cnt update until we + * have the mutex locked. + */ + + /* Do not access znode from this point on */ + + /* Update buffer positions */ + wlen = used + len; + used += ALIGN(len, 8); + avail -= ALIGN(len, 8); + + /* + * Calculate the next index node length to see if there is + * enough room for it + */ + if (cnext == c->cnext) + next_len = 0; + else + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + + nxt_offs = buf_offs + used + next_len; + if (next_len && nxt_offs <= c->leb_size) { + if (avail > 0) + continue; + else + blen = buf_len; + } else { + wlen = ALIGN(wlen, 8); + blen = ALIGN(wlen, c->min_io_size); + ubifs_pad(c, c->cbuf + wlen, blen - wlen); + } + + /* The buffer is full or there are no more znodes to do */ + err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, blen); + if (err) + return err; + buf_offs += blen; + if (next_len) { + if (nxt_offs > c->leb_size) { + err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, + 0, LPROPS_TAKEN); + if (err) + return err; + lnum = -1; + } + used -= blen; + if (used < 0) + used = 0; + avail = buf_len - used; + memmove(c->cbuf, c->cbuf + blen, used); + continue; + } + break; + } + + if (lnum != c->dbg->new_ihead_lnum || + buf_offs != c->dbg->new_ihead_offs) { + ubifs_err(c, "inconsistent ihead"); + return -EINVAL; + } + + c->ihead_lnum = lnum; + c->ihead_offs = buf_offs; + + return 0; +} + +/** + * free_obsolete_znodes - free obsolete znodes. + * @c: UBIFS file-system description object + * + * At the end of commit end, obsolete znodes are freed. + */ +static void free_obsolete_znodes(struct ubifs_info *c) +{ + struct ubifs_znode *znode, *cnext; + + cnext = c->cnext; + do { + znode = cnext; + cnext = znode->cnext; + if (ubifs_zn_obsolete(znode)) + kfree(znode); + else { + znode->cnext = NULL; + atomic_long_inc(&c->clean_zn_cnt); + atomic_long_inc(&ubifs_clean_zn_cnt); + } + } while (cnext != c->cnext); +} + +/** + * return_gap_lebs - return LEBs used by the in-gap commit method. + * @c: UBIFS file-system description object + * + * This function clears the "taken" flag for the LEBs which were used by the + * "commit in-the-gaps" method. + */ +static int return_gap_lebs(struct ubifs_info *c) +{ + int *p, err; + + if (!c->gap_lebs) + return 0; + + dbg_cmt(""); + for (p = c->gap_lebs; *p != -1; p++) { + err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0, + LPROPS_TAKEN, 0); + if (err) + return err; + } + + kfree(c->gap_lebs); + c->gap_lebs = NULL; + return 0; +} + +/** + * ubifs_tnc_end_commit - update the TNC for commit end. + * @c: UBIFS file-system description object + * + * Write the dirty znodes. + */ +int ubifs_tnc_end_commit(struct ubifs_info *c) +{ + int err; + + if (!c->cnext) + return 0; + + err = return_gap_lebs(c); + if (err) + return err; + + err = write_index(c); + if (err) + return err; + + mutex_lock(&c->tnc_mutex); + + dbg_cmt("TNC height is %d", c->zroot.znode->level + 1); + + free_obsolete_znodes(c); + + c->cnext = NULL; + kfree(c->ilebs); + c->ilebs = NULL; + + mutex_unlock(&c->tnc_mutex); + + return 0; +} diff --git a/fs/ubifs/tnc_misc.c b/fs/ubifs/tnc_misc.c new file mode 100644 index 000000000..ccaf94ea5 --- /dev/null +++ b/fs/ubifs/tnc_misc.c @@ -0,0 +1,503 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file contains miscelanious TNC-related functions shared betweend + * different files. This file does not form any logically separate TNC + * sub-system. The file was created because there is a lot of TNC code and + * putting it all in one file would make that file too big and unreadable. + */ + +#include "ubifs.h" + +/** + * ubifs_tnc_levelorder_next - next TNC tree element in levelorder traversal. + * @c: UBIFS file-system description object + * @zr: root of the subtree to traverse + * @znode: previous znode + * + * This function implements levelorder TNC traversal. The LNC is ignored. + * Returns the next element or %NULL if @znode is already the last one. + */ +struct ubifs_znode *ubifs_tnc_levelorder_next(const struct ubifs_info *c, + struct ubifs_znode *zr, + struct ubifs_znode *znode) +{ + int level, iip, level_search = 0; + struct ubifs_znode *zn; + + ubifs_assert(c, zr); + + if (unlikely(!znode)) + return zr; + + if (unlikely(znode == zr)) { + if (znode->level == 0) + return NULL; + return ubifs_tnc_find_child(zr, 0); + } + + level = znode->level; + + iip = znode->iip; + while (1) { + ubifs_assert(c, znode->level <= zr->level); + + /* + * First walk up until there is a znode with next branch to + * look at. + */ + while (znode->parent != zr && iip >= znode->parent->child_cnt) { + znode = znode->parent; + iip = znode->iip; + } + + if (unlikely(znode->parent == zr && + iip >= znode->parent->child_cnt)) { + /* This level is done, switch to the lower one */ + level -= 1; + if (level_search || level < 0) + /* + * We were already looking for znode at lower + * level ('level_search'). As we are here + * again, it just does not exist. Or all levels + * were finished ('level < 0'). + */ + return NULL; + + level_search = 1; + iip = -1; + znode = ubifs_tnc_find_child(zr, 0); + ubifs_assert(c, znode); + } + + /* Switch to the next index */ + zn = ubifs_tnc_find_child(znode->parent, iip + 1); + if (!zn) { + /* No more children to look at, we have walk up */ + iip = znode->parent->child_cnt; + continue; + } + + /* Walk back down to the level we came from ('level') */ + while (zn->level != level) { + znode = zn; + zn = ubifs_tnc_find_child(zn, 0); + if (!zn) { + /* + * This path is not too deep so it does not + * reach 'level'. Try next path. + */ + iip = znode->iip; + break; + } + } + + if (zn) { + ubifs_assert(c, zn->level >= 0); + return zn; + } + } +} + +/** + * ubifs_search_zbranch - search znode branch. + * @c: UBIFS file-system description object + * @znode: znode to search in + * @key: key to search for + * @n: znode branch slot number is returned here + * + * This is a helper function which search branch with key @key in @znode using + * binary search. The result of the search may be: + * o exact match, then %1 is returned, and the slot number of the branch is + * stored in @n; + * o no exact match, then %0 is returned and the slot number of the left + * closest branch is returned in @n; the slot if all keys in this znode are + * greater than @key, then %-1 is returned in @n. + */ +int ubifs_search_zbranch(const struct ubifs_info *c, + const struct ubifs_znode *znode, + const union ubifs_key *key, int *n) +{ + int beg = 0, end = znode->child_cnt, mid; + int cmp; + const struct ubifs_zbranch *zbr = &znode->zbranch[0]; + + ubifs_assert(c, end > beg); + + while (end > beg) { + mid = (beg + end) >> 1; + cmp = keys_cmp(c, key, &zbr[mid].key); + if (cmp > 0) + beg = mid + 1; + else if (cmp < 0) + end = mid; + else { + *n = mid; + return 1; + } + } + + *n = end - 1; + + /* The insert point is after *n */ + ubifs_assert(c, *n >= -1 && *n < znode->child_cnt); + if (*n == -1) + ubifs_assert(c, keys_cmp(c, key, &zbr[0].key) < 0); + else + ubifs_assert(c, keys_cmp(c, key, &zbr[*n].key) > 0); + if (*n + 1 < znode->child_cnt) + ubifs_assert(c, keys_cmp(c, key, &zbr[*n + 1].key) < 0); + + return 0; +} + +/** + * ubifs_tnc_postorder_first - find first znode to do postorder tree traversal. + * @znode: znode to start at (root of the sub-tree to traverse) + * + * Find the lowest leftmost znode in a subtree of the TNC tree. The LNC is + * ignored. + */ +struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode) +{ + if (unlikely(!znode)) + return NULL; + + while (znode->level > 0) { + struct ubifs_znode *child; + + child = ubifs_tnc_find_child(znode, 0); + if (!child) + return znode; + znode = child; + } + + return znode; +} + +/** + * ubifs_tnc_postorder_next - next TNC tree element in postorder traversal. + * @c: UBIFS file-system description object + * @znode: previous znode + * + * This function implements postorder TNC traversal. The LNC is ignored. + * Returns the next element or %NULL if @znode is already the last one. + */ +struct ubifs_znode *ubifs_tnc_postorder_next(const struct ubifs_info *c, + struct ubifs_znode *znode) +{ + struct ubifs_znode *zn; + + ubifs_assert(c, znode); + if (unlikely(!znode->parent)) + return NULL; + + /* Switch to the next index in the parent */ + zn = ubifs_tnc_find_child(znode->parent, znode->iip + 1); + if (!zn) + /* This is in fact the last child, return parent */ + return znode->parent; + + /* Go to the first znode in this new subtree */ + return ubifs_tnc_postorder_first(zn); +} + +/** + * ubifs_destroy_tnc_subtree - destroy all znodes connected to a subtree. + * @c: UBIFS file-system description object + * @znode: znode defining subtree to destroy + * + * This function destroys subtree of the TNC tree. Returns number of clean + * znodes in the subtree. + */ +long ubifs_destroy_tnc_subtree(const struct ubifs_info *c, + struct ubifs_znode *znode) +{ + struct ubifs_znode *zn = ubifs_tnc_postorder_first(znode); + long clean_freed = 0; + int n; + + ubifs_assert(c, zn); + while (1) { + for (n = 0; n < zn->child_cnt; n++) { + if (!zn->zbranch[n].znode) + continue; + + if (zn->level > 0 && + !ubifs_zn_dirty(zn->zbranch[n].znode)) + clean_freed += 1; + + cond_resched(); + kfree(zn->zbranch[n].znode); + } + + if (zn == znode) { + if (!ubifs_zn_dirty(zn)) + clean_freed += 1; + kfree(zn); + return clean_freed; + } + + zn = ubifs_tnc_postorder_next(c, zn); + } +} + +/** + * read_znode - read an indexing node from flash and fill znode. + * @c: UBIFS file-system description object + * @zzbr: the zbranch describing the node to read + * @znode: znode to read to + * + * This function reads an indexing node from the flash media and fills znode + * with the read data. Returns zero in case of success and a negative error + * code in case of failure. The read indexing node is validated and if anything + * is wrong with it, this function prints complaint messages and returns + * %-EINVAL. + */ +static int read_znode(struct ubifs_info *c, struct ubifs_zbranch *zzbr, + struct ubifs_znode *znode) +{ + int lnum = zzbr->lnum; + int offs = zzbr->offs; + int len = zzbr->len; + int i, err, type, cmp; + struct ubifs_idx_node *idx; + + idx = kmalloc(c->max_idx_node_sz, GFP_NOFS); + if (!idx) + return -ENOMEM; + + err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs); + if (err < 0) { + kfree(idx); + return err; + } + + err = ubifs_node_check_hash(c, idx, zzbr->hash); + if (err) { + ubifs_bad_hash(c, idx, zzbr->hash, lnum, offs); + kfree(idx); + return err; + } + + znode->child_cnt = le16_to_cpu(idx->child_cnt); + znode->level = le16_to_cpu(idx->level); + + dbg_tnc("LEB %d:%d, level %d, %d branch", + lnum, offs, znode->level, znode->child_cnt); + + if (znode->child_cnt > c->fanout || znode->level > UBIFS_MAX_LEVELS) { + ubifs_err(c, "current fanout %d, branch count %d", + c->fanout, znode->child_cnt); + ubifs_err(c, "max levels %d, znode level %d", + UBIFS_MAX_LEVELS, znode->level); + err = 1; + goto out_dump; + } + + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + key_read(c, &br->key, &zbr->key); + zbr->lnum = le32_to_cpu(br->lnum); + zbr->offs = le32_to_cpu(br->offs); + zbr->len = le32_to_cpu(br->len); + ubifs_copy_hash(c, ubifs_branch_hash(c, br), zbr->hash); + zbr->znode = NULL; + + /* Validate branch */ + + if (zbr->lnum < c->main_first || + zbr->lnum >= c->leb_cnt || zbr->offs < 0 || + zbr->offs + zbr->len > c->leb_size || zbr->offs & 7) { + ubifs_err(c, "bad branch %d", i); + err = 2; + goto out_dump; + } + + switch (key_type(c, &zbr->key)) { + case UBIFS_INO_KEY: + case UBIFS_DATA_KEY: + case UBIFS_DENT_KEY: + case UBIFS_XENT_KEY: + break; + default: + ubifs_err(c, "bad key type at slot %d: %d", + i, key_type(c, &zbr->key)); + err = 3; + goto out_dump; + } + + if (znode->level) + continue; + + type = key_type(c, &zbr->key); + if (c->ranges[type].max_len == 0) { + if (zbr->len != c->ranges[type].len) { + ubifs_err(c, "bad target node (type %d) length (%d)", + type, zbr->len); + ubifs_err(c, "have to be %d", c->ranges[type].len); + err = 4; + goto out_dump; + } + } else if (zbr->len < c->ranges[type].min_len || + zbr->len > c->ranges[type].max_len) { + ubifs_err(c, "bad target node (type %d) length (%d)", + type, zbr->len); + ubifs_err(c, "have to be in range of %d-%d", + c->ranges[type].min_len, + c->ranges[type].max_len); + err = 5; + goto out_dump; + } + } + + /* + * Ensure that the next key is greater or equivalent to the + * previous one. + */ + for (i = 0; i < znode->child_cnt - 1; i++) { + const union ubifs_key *key1, *key2; + + key1 = &znode->zbranch[i].key; + key2 = &znode->zbranch[i + 1].key; + + cmp = keys_cmp(c, key1, key2); + if (cmp > 0) { + ubifs_err(c, "bad key order (keys %d and %d)", i, i + 1); + err = 6; + goto out_dump; + } else if (cmp == 0 && !is_hash_key(c, key1)) { + /* These can only be keys with colliding hash */ + ubifs_err(c, "keys %d and %d are not hashed but equivalent", + i, i + 1); + err = 7; + goto out_dump; + } + } + + kfree(idx); + return 0; + +out_dump: + ubifs_err(c, "bad indexing node at LEB %d:%d, error %d", lnum, offs, err); + ubifs_dump_node(c, idx); + kfree(idx); + return -EINVAL; +} + +/** + * ubifs_load_znode - load znode to TNC cache. + * @c: UBIFS file-system description object + * @zbr: znode branch + * @parent: znode's parent + * @iip: index in parent + * + * This function loads znode pointed to by @zbr into the TNC cache and + * returns pointer to it in case of success and a negative error code in case + * of failure. + */ +struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c, + struct ubifs_zbranch *zbr, + struct ubifs_znode *parent, int iip) +{ + int err; + struct ubifs_znode *znode; + + ubifs_assert(c, !zbr->znode); + /* + * A slab cache is not presently used for znodes because the znode size + * depends on the fanout which is stored in the superblock. + */ + znode = kzalloc(c->max_znode_sz, GFP_NOFS); + if (!znode) + return ERR_PTR(-ENOMEM); + + err = read_znode(c, zbr, znode); + if (err) + goto out; + + atomic_long_inc(&c->clean_zn_cnt); + + /* + * Increment the global clean znode counter as well. It is OK that + * global and per-FS clean znode counters may be inconsistent for some + * short time (because we might be preempted at this point), the global + * one is only used in shrinker. + */ + atomic_long_inc(&ubifs_clean_zn_cnt); + + zbr->znode = znode; + znode->parent = parent; + znode->time = ktime_get_seconds(); + znode->iip = iip; + + return znode; + +out: + kfree(znode); + return ERR_PTR(err); +} + +/** + * ubifs_tnc_read_node - read a leaf node from the flash media. + * @c: UBIFS file-system description object + * @zbr: key and position of the node + * @node: node is returned here + * + * This function reads a node defined by @zbr from the flash media. Returns + * zero in case of success or a negative negative error code in case of + * failure. + */ +int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr, + void *node) +{ + union ubifs_key key1, *key = &zbr->key; + int err, type = key_type(c, key); + struct ubifs_wbuf *wbuf; + + /* + * 'zbr' has to point to on-flash node. The node may sit in a bud and + * may even be in a write buffer, so we have to take care about this. + */ + wbuf = ubifs_get_wbuf(c, zbr->lnum); + if (wbuf) + err = ubifs_read_node_wbuf(wbuf, node, type, zbr->len, + zbr->lnum, zbr->offs); + else + err = ubifs_read_node(c, node, type, zbr->len, zbr->lnum, + zbr->offs); + + if (err) { + dbg_tnck(key, "key "); + return err; + } + + /* Make sure the key of the read node is correct */ + key_read(c, node + UBIFS_KEY_OFFSET, &key1); + if (!keys_eq(c, key, &key1)) { + ubifs_err(c, "bad key in node at LEB %d:%d", + zbr->lnum, zbr->offs); + dbg_tnck(key, "looked for key "); + dbg_tnck(&key1, "but found node's key "); + ubifs_dump_node(c, node); + return -EINVAL; + } + + err = ubifs_node_check_hash(c, node, zbr->hash); + if (err) { + ubifs_bad_hash(c, node, zbr->hash, zbr->lnum, zbr->offs); + return err; + } + + return 0; +} diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h new file mode 100644 index 000000000..3c9792cbb --- /dev/null +++ b/fs/ubifs/ubifs-media.h @@ -0,0 +1,855 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file describes UBIFS on-flash format and contains definitions of all the + * relevant data structures and constants. + * + * All UBIFS on-flash objects are stored in the form of nodes. All nodes start + * with the UBIFS node magic number and have the same common header. Nodes + * always sit at 8-byte aligned positions on the media and node header sizes are + * also 8-byte aligned (except for the indexing node and the padding node). + */ + +#ifndef __UBIFS_MEDIA_H__ +#define __UBIFS_MEDIA_H__ + +/* UBIFS node magic number (must not have the padding byte first or last) */ +#define UBIFS_NODE_MAGIC 0x06101831 + +/* + * UBIFS on-flash format version. This version is increased when the on-flash + * format is changing. If this happens, UBIFS is will support older versions as + * well. But older UBIFS code will not support newer formats. Format changes + * will be rare and only when absolutely necessary, e.g. to fix a bug or to add + * a new feature. + * + * UBIFS went into mainline kernel with format version 4. The older formats + * were development formats. + */ +#define UBIFS_FORMAT_VERSION 5 + +/* + * Read-only compatibility version. If the UBIFS format is changed, older UBIFS + * implementations will not be able to mount newer formats in read-write mode. + * However, depending on the change, it may be possible to mount newer formats + * in R/O mode. This is indicated by the R/O compatibility version which is + * stored in the super-block. + * + * This is needed to support boot-loaders which only need R/O mounting. With + * this flag it is possible to do UBIFS format changes without a need to update + * boot-loaders. + */ +#define UBIFS_RO_COMPAT_VERSION 0 + +/* Minimum logical eraseblock size in bytes */ +#define UBIFS_MIN_LEB_SZ (15*1024) + +/* Initial CRC32 value used when calculating CRC checksums */ +#define UBIFS_CRC32_INIT 0xFFFFFFFFU + +/* + * UBIFS does not try to compress data if its length is less than the below + * constant. + */ +#define UBIFS_MIN_COMPR_LEN 128 + +/* + * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes + * shorter than uncompressed data length, UBIFS prefers to leave this data + * node uncompress, because it'll be read faster. + */ +#define UBIFS_MIN_COMPRESS_DIFF 64 + +/* Root inode number */ +#define UBIFS_ROOT_INO 1 + +/* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */ +#define UBIFS_FIRST_INO 64 + +/* + * Maximum file name and extended attribute length (must be a multiple of 8, + * minus 1). + */ +#define UBIFS_MAX_NLEN 255 + +/* Maximum number of data journal heads */ +#define UBIFS_MAX_JHEADS 1 + +/* + * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system, + * which means that it does not treat the underlying media as consisting of + * blocks like in case of hard drives. Do not be confused. UBIFS block is just + * the maximum amount of data which one data node can have or which can be + * attached to an inode node. + */ +#define UBIFS_BLOCK_SIZE 4096 +#define UBIFS_BLOCK_SHIFT 12 + +/* UBIFS padding byte pattern (must not be first or last byte of node magic) */ +#define UBIFS_PADDING_BYTE 0xCE + +/* Maximum possible key length */ +#define UBIFS_MAX_KEY_LEN 16 + +/* Key length ("simple" format) */ +#define UBIFS_SK_LEN 8 + +/* Minimum index tree fanout */ +#define UBIFS_MIN_FANOUT 3 + +/* Maximum number of levels in UBIFS indexing B-tree */ +#define UBIFS_MAX_LEVELS 512 + +/* Maximum amount of data attached to an inode in bytes */ +#define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE + +/* LEB Properties Tree fanout (must be power of 2) and fanout shift */ +#define UBIFS_LPT_FANOUT 4 +#define UBIFS_LPT_FANOUT_SHIFT 2 + +/* LEB Properties Tree bit field sizes */ +#define UBIFS_LPT_CRC_BITS 16 +#define UBIFS_LPT_CRC_BYTES 2 +#define UBIFS_LPT_TYPE_BITS 4 + +/* The key is always at the same position in all keyed nodes */ +#define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key) + +/* Garbage collector journal head number */ +#define UBIFS_GC_HEAD 0 +/* Base journal head number */ +#define UBIFS_BASE_HEAD 1 +/* Data journal head number */ +#define UBIFS_DATA_HEAD 2 + +/* + * LEB Properties Tree node types. + * + * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties) + * UBIFS_LPT_NNODE: LPT internal node + * UBIFS_LPT_LTAB: LPT's own lprops table + * UBIFS_LPT_LSAVE: LPT's save table (big model only) + * UBIFS_LPT_NODE_CNT: count of LPT node types + * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type + */ +enum { + UBIFS_LPT_PNODE, + UBIFS_LPT_NNODE, + UBIFS_LPT_LTAB, + UBIFS_LPT_LSAVE, + UBIFS_LPT_NODE_CNT, + UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1, +}; + +/* + * UBIFS inode types. + * + * UBIFS_ITYPE_REG: regular file + * UBIFS_ITYPE_DIR: directory + * UBIFS_ITYPE_LNK: soft link + * UBIFS_ITYPE_BLK: block device node + * UBIFS_ITYPE_CHR: character device node + * UBIFS_ITYPE_FIFO: fifo + * UBIFS_ITYPE_SOCK: socket + * UBIFS_ITYPES_CNT: count of supported file types + */ +enum { + UBIFS_ITYPE_REG, + UBIFS_ITYPE_DIR, + UBIFS_ITYPE_LNK, + UBIFS_ITYPE_BLK, + UBIFS_ITYPE_CHR, + UBIFS_ITYPE_FIFO, + UBIFS_ITYPE_SOCK, + UBIFS_ITYPES_CNT, +}; + +/* + * Supported key hash functions. + * + * UBIFS_KEY_HASH_R5: R5 hash + * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name + */ +enum { + UBIFS_KEY_HASH_R5, + UBIFS_KEY_HASH_TEST, +}; + +/* + * Supported key formats. + * + * UBIFS_SIMPLE_KEY_FMT: simple key format + */ +enum { + UBIFS_SIMPLE_KEY_FMT, +}; + +/* + * The simple key format uses 29 bits for storing UBIFS block number and hash + * value. + */ +#define UBIFS_S_KEY_BLOCK_BITS 29 +#define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF +#define UBIFS_S_KEY_HASH_BITS UBIFS_S_KEY_BLOCK_BITS +#define UBIFS_S_KEY_HASH_MASK UBIFS_S_KEY_BLOCK_MASK + +/* + * Key types. + * + * UBIFS_INO_KEY: inode node key + * UBIFS_DATA_KEY: data node key + * UBIFS_DENT_KEY: directory entry node key + * UBIFS_XENT_KEY: extended attribute entry key + * UBIFS_KEY_TYPES_CNT: number of supported key types + */ +enum { + UBIFS_INO_KEY, + UBIFS_DATA_KEY, + UBIFS_DENT_KEY, + UBIFS_XENT_KEY, + UBIFS_KEY_TYPES_CNT, +}; + +/* Count of LEBs reserved for the superblock area */ +#define UBIFS_SB_LEBS 1 +/* Count of LEBs reserved for the master area */ +#define UBIFS_MST_LEBS 2 + +/* First LEB of the superblock area */ +#define UBIFS_SB_LNUM 0 +/* First LEB of the master area */ +#define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS) +/* First LEB of the log area */ +#define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS) + +/* + * The below constants define the absolute minimum values for various UBIFS + * media areas. Many of them actually depend of flash geometry and the FS + * configuration (number of journal heads, orphan LEBs, etc). This means that + * the smallest volume size which can be used for UBIFS cannot be pre-defined + * by these constants. The file-system that meets the below limitation will not + * necessarily mount. UBIFS does run-time calculations and validates the FS + * size. + */ + +/* Minimum number of logical eraseblocks in the log */ +#define UBIFS_MIN_LOG_LEBS 2 +/* Minimum number of bud logical eraseblocks (one for each head) */ +#define UBIFS_MIN_BUD_LEBS 3 +/* Minimum number of journal logical eraseblocks */ +#define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS) +/* Minimum number of LPT area logical eraseblocks */ +#define UBIFS_MIN_LPT_LEBS 2 +/* Minimum number of orphan area logical eraseblocks */ +#define UBIFS_MIN_ORPH_LEBS 1 +/* + * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1 + * for GC, 1 for deletions, and at least 1 for committed data). + */ +#define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6) + +/* Minimum number of logical eraseblocks */ +#define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \ + UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \ + UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS) + +/* Node sizes (N.B. these are guaranteed to be multiples of 8) */ +#define UBIFS_CH_SZ sizeof(struct ubifs_ch) +#define UBIFS_INO_NODE_SZ sizeof(struct ubifs_ino_node) +#define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node) +#define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node) +#define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node) +#define UBIFS_PAD_NODE_SZ sizeof(struct ubifs_pad_node) +#define UBIFS_SB_NODE_SZ sizeof(struct ubifs_sb_node) +#define UBIFS_MST_NODE_SZ sizeof(struct ubifs_mst_node) +#define UBIFS_REF_NODE_SZ sizeof(struct ubifs_ref_node) +#define UBIFS_IDX_NODE_SZ sizeof(struct ubifs_idx_node) +#define UBIFS_CS_NODE_SZ sizeof(struct ubifs_cs_node) +#define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node) +#define UBIFS_AUTH_NODE_SZ sizeof(struct ubifs_auth_node) +#define UBIFS_SIG_NODE_SZ sizeof(struct ubifs_sig_node) + +/* Extended attribute entry nodes are identical to directory entry nodes */ +#define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ +/* Only this does not have to be multiple of 8 bytes */ +#define UBIFS_BRANCH_SZ sizeof(struct ubifs_branch) + +/* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */ +#define UBIFS_MAX_DATA_NODE_SZ (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE) +#define UBIFS_MAX_INO_NODE_SZ (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA) +#define UBIFS_MAX_DENT_NODE_SZ (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1) +#define UBIFS_MAX_XENT_NODE_SZ UBIFS_MAX_DENT_NODE_SZ + +/* The largest UBIFS node */ +#define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ + +/* The maxmimum size of a hash, enough for sha512 */ +#define UBIFS_MAX_HASH_LEN 64 + +/* The maxmimum size of a hmac, enough for hmac(sha512) */ +#define UBIFS_MAX_HMAC_LEN 64 + +/* + * xattr name of UBIFS encryption context, we don't use a prefix + * nor a long name to not waste space on the flash. + */ +#define UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT "c" + +/* Type field in ubifs_sig_node */ +#define UBIFS_SIGNATURE_TYPE_PKCS7 1 + +/* + * On-flash inode flags. + * + * UBIFS_COMPR_FL: use compression for this inode + * UBIFS_SYNC_FL: I/O on this inode has to be synchronous + * UBIFS_IMMUTABLE_FL: inode is immutable + * UBIFS_APPEND_FL: writes to the inode may only append data + * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous + * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value + * UBIFS_CRYPT_FL: use encryption for this inode + * + * Note, these are on-flash flags which correspond to ioctl flags + * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not + * have to be the same. + */ +enum { + UBIFS_COMPR_FL = 0x01, + UBIFS_SYNC_FL = 0x02, + UBIFS_IMMUTABLE_FL = 0x04, + UBIFS_APPEND_FL = 0x08, + UBIFS_DIRSYNC_FL = 0x10, + UBIFS_XATTR_FL = 0x20, + UBIFS_CRYPT_FL = 0x40, +}; + +/* Inode flag bits used by UBIFS */ +#define UBIFS_FL_MASK 0x0000001F + +/* + * UBIFS compression algorithms. + * + * UBIFS_COMPR_NONE: no compression + * UBIFS_COMPR_LZO: LZO compression + * UBIFS_COMPR_ZLIB: ZLIB compression + * UBIFS_COMPR_ZSTD: ZSTD compression + * UBIFS_COMPR_TYPES_CNT: count of supported compression types + */ +enum { + UBIFS_COMPR_NONE, + UBIFS_COMPR_LZO, + UBIFS_COMPR_ZLIB, + UBIFS_COMPR_ZSTD, + UBIFS_COMPR_TYPES_CNT, +}; + +/* + * UBIFS node types. + * + * UBIFS_INO_NODE: inode node + * UBIFS_DATA_NODE: data node + * UBIFS_DENT_NODE: directory entry node + * UBIFS_XENT_NODE: extended attribute node + * UBIFS_TRUN_NODE: truncation node + * UBIFS_PAD_NODE: padding node + * UBIFS_SB_NODE: superblock node + * UBIFS_MST_NODE: master node + * UBIFS_REF_NODE: LEB reference node + * UBIFS_IDX_NODE: index node + * UBIFS_CS_NODE: commit start node + * UBIFS_ORPH_NODE: orphan node + * UBIFS_AUTH_NODE: authentication node + * UBIFS_SIG_NODE: signature node + * UBIFS_NODE_TYPES_CNT: count of supported node types + * + * Note, we index arrays by these numbers, so keep them low and contiguous. + * Node type constants for inodes, direntries and so on have to be the same as + * corresponding key type constants. + */ +enum { + UBIFS_INO_NODE, + UBIFS_DATA_NODE, + UBIFS_DENT_NODE, + UBIFS_XENT_NODE, + UBIFS_TRUN_NODE, + UBIFS_PAD_NODE, + UBIFS_SB_NODE, + UBIFS_MST_NODE, + UBIFS_REF_NODE, + UBIFS_IDX_NODE, + UBIFS_CS_NODE, + UBIFS_ORPH_NODE, + UBIFS_AUTH_NODE, + UBIFS_SIG_NODE, + UBIFS_NODE_TYPES_CNT, +}; + +/* + * Master node flags. + * + * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty + * UBIFS_MST_NO_ORPHS: no orphan inodes present + * UBIFS_MST_RCVRY: written by recovery + */ +enum { + UBIFS_MST_DIRTY = 1, + UBIFS_MST_NO_ORPHS = 2, + UBIFS_MST_RCVRY = 4, +}; + +/* + * Node group type (used by recovery to recover whole group or none). + * + * UBIFS_NO_NODE_GROUP: this node is not part of a group + * UBIFS_IN_NODE_GROUP: this node is a part of a group + * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group + */ +enum { + UBIFS_NO_NODE_GROUP = 0, + UBIFS_IN_NODE_GROUP, + UBIFS_LAST_OF_NODE_GROUP, +}; + +/* + * Superblock flags. + * + * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set + * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed + * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to + * support 64bit cookies for lookups by hash + * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files + * UBIFS_FLG_AUTHENTICATION: this filesystem contains hashes for authentication + */ +enum { + UBIFS_FLG_BIGLPT = 0x02, + UBIFS_FLG_SPACE_FIXUP = 0x04, + UBIFS_FLG_DOUBLE_HASH = 0x08, + UBIFS_FLG_ENCRYPTION = 0x10, + UBIFS_FLG_AUTHENTICATION = 0x20, +}; + +#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT | UBIFS_FLG_SPACE_FIXUP | \ + UBIFS_FLG_DOUBLE_HASH | UBIFS_FLG_ENCRYPTION | \ + UBIFS_FLG_AUTHENTICATION) + +/** + * struct ubifs_ch - common header node. + * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC) + * @crc: CRC-32 checksum of the node header + * @sqnum: sequence number + * @len: full node length + * @node_type: node type + * @group_type: node group type + * @padding: reserved for future, zeroes + * + * Every UBIFS node starts with this common part. If the node has a key, the + * key always goes next. + */ +struct ubifs_ch { + __le32 magic; + __le32 crc; + __le64 sqnum; + __le32 len; + __u8 node_type; + __u8 group_type; + __u8 padding[2]; +} __packed; + +/** + * union ubifs_dev_desc - device node descriptor. + * @new: new type device descriptor + * @huge: huge type device descriptor + * + * This data structure describes major/minor numbers of a device node. In an + * inode is a device node then its data contains an object of this type. UBIFS + * uses standard Linux "new" and "huge" device node encodings. + */ +union ubifs_dev_desc { + __le32 new; + __le64 huge; +} __packed; + +/** + * struct ubifs_ino_node - inode node. + * @ch: common header + * @key: node key + * @creat_sqnum: sequence number at time of creation + * @size: inode size in bytes (amount of uncompressed data) + * @atime_sec: access time seconds + * @ctime_sec: creation time seconds + * @mtime_sec: modification time seconds + * @atime_nsec: access time nanoseconds + * @ctime_nsec: creation time nanoseconds + * @mtime_nsec: modification time nanoseconds + * @nlink: number of hard links + * @uid: owner ID + * @gid: group ID + * @mode: access flags + * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc) + * @data_len: inode data length + * @xattr_cnt: count of extended attributes this inode has + * @xattr_size: summarized size of all extended attributes in bytes + * @padding1: reserved for future, zeroes + * @xattr_names: sum of lengths of all extended attribute names belonging to + * this inode + * @compr_type: compression type used for this inode + * @padding2: reserved for future, zeroes + * @data: data attached to the inode + * + * Note, even though inode compression type is defined by @compr_type, some + * nodes of this inode may be compressed with different compressor - this + * happens if compression type is changed while the inode already has data + * nodes. But @compr_type will be use for further writes to the inode. + * + * Note, do not forget to amend 'zero_ino_node_unused()' function when changing + * the padding fields. + */ +struct ubifs_ino_node { + struct ubifs_ch ch; + __u8 key[UBIFS_MAX_KEY_LEN]; + __le64 creat_sqnum; + __le64 size; + __le64 atime_sec; + __le64 ctime_sec; + __le64 mtime_sec; + __le32 atime_nsec; + __le32 ctime_nsec; + __le32 mtime_nsec; + __le32 nlink; + __le32 uid; + __le32 gid; + __le32 mode; + __le32 flags; + __le32 data_len; + __le32 xattr_cnt; + __le32 xattr_size; + __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */ + __le32 xattr_names; + __le16 compr_type; + __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */ + __u8 data[]; +} __packed; + +/** + * struct ubifs_dent_node - directory entry node. + * @ch: common header + * @key: node key + * @inum: target inode number + * @padding1: reserved for future, zeroes + * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc) + * @nlen: name length + * @cookie: A 32bits random number, used to construct a 64bits + * identifier. + * @name: zero-terminated name + * + * Note, do not forget to amend 'zero_dent_node_unused()' function when + * changing the padding fields. + */ +struct ubifs_dent_node { + struct ubifs_ch ch; + __u8 key[UBIFS_MAX_KEY_LEN]; + __le64 inum; + __u8 padding1; + __u8 type; + __le16 nlen; + __le32 cookie; + __u8 name[]; +} __packed; + +/** + * struct ubifs_data_node - data node. + * @ch: common header + * @key: node key + * @size: uncompressed data size in bytes + * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc) + * @compr_size: compressed data size in bytes, only valid when data is encrypted + * @data: data + * + */ +struct ubifs_data_node { + struct ubifs_ch ch; + __u8 key[UBIFS_MAX_KEY_LEN]; + __le32 size; + __le16 compr_type; + __le16 compr_size; + __u8 data[]; +} __packed; + +/** + * struct ubifs_trun_node - truncation node. + * @ch: common header + * @inum: truncated inode number + * @padding: reserved for future, zeroes + * @old_size: size before truncation + * @new_size: size after truncation + * + * This node exists only in the journal and never goes to the main area. Note, + * do not forget to amend 'zero_trun_node_unused()' function when changing the + * padding fields. + */ +struct ubifs_trun_node { + struct ubifs_ch ch; + __le32 inum; + __u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */ + __le64 old_size; + __le64 new_size; +} __packed; + +/** + * struct ubifs_pad_node - padding node. + * @ch: common header + * @pad_len: how many bytes after this node are unused (because padded) + * @padding: reserved for future, zeroes + */ +struct ubifs_pad_node { + struct ubifs_ch ch; + __le32 pad_len; +} __packed; + +/** + * struct ubifs_sb_node - superblock node. + * @ch: common header + * @padding: reserved for future, zeroes + * @key_hash: type of hash function used in keys + * @key_fmt: format of the key + * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc) + * @min_io_size: minimal input/output unit size + * @leb_size: logical eraseblock size in bytes + * @leb_cnt: count of LEBs used by file-system + * @max_leb_cnt: maximum count of LEBs used by file-system + * @max_bud_bytes: maximum amount of data stored in buds + * @log_lebs: log size in logical eraseblocks + * @lpt_lebs: number of LEBs used for lprops table + * @orph_lebs: number of LEBs used for recording orphans + * @jhead_cnt: count of journal heads + * @fanout: tree fanout (max. number of links per indexing node) + * @lsave_cnt: number of LEB numbers in LPT's save table + * @fmt_version: UBIFS on-flash format version + * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc) + * @padding1: reserved for future, zeroes + * @rp_uid: reserve pool UID + * @rp_gid: reserve pool GID + * @rp_size: size of the reserved pool in bytes + * @padding2: reserved for future, zeroes + * @time_gran: time granularity in nanoseconds + * @uuid: UUID generated when the file system image was created + * @ro_compat_version: UBIFS R/O compatibility version + * @hmac: HMAC to authenticate the superblock node + * @hmac_wkm: HMAC of a well known message (the string "UBIFS") as a convenience + * to the user to check if the correct key is passed. + * @hash_algo: The hash algo used for this filesystem (one of enum hash_algo) + * @hash_mst: hash of the master node, only valid for signed images in which the + * master node does not contain a hmac + */ +struct ubifs_sb_node { + struct ubifs_ch ch; + __u8 padding[2]; + __u8 key_hash; + __u8 key_fmt; + __le32 flags; + __le32 min_io_size; + __le32 leb_size; + __le32 leb_cnt; + __le32 max_leb_cnt; + __le64 max_bud_bytes; + __le32 log_lebs; + __le32 lpt_lebs; + __le32 orph_lebs; + __le32 jhead_cnt; + __le32 fanout; + __le32 lsave_cnt; + __le32 fmt_version; + __le16 default_compr; + __u8 padding1[2]; + __le32 rp_uid; + __le32 rp_gid; + __le64 rp_size; + __le32 time_gran; + __u8 uuid[16]; + __le32 ro_compat_version; + __u8 hmac[UBIFS_MAX_HMAC_LEN]; + __u8 hmac_wkm[UBIFS_MAX_HMAC_LEN]; + __le16 hash_algo; + __u8 hash_mst[UBIFS_MAX_HASH_LEN]; + __u8 padding2[3774]; +} __packed; + +/** + * struct ubifs_mst_node - master node. + * @ch: common header + * @highest_inum: highest inode number in the committed index + * @cmt_no: commit number + * @flags: various flags (%UBIFS_MST_DIRTY, etc) + * @log_lnum: start of the log + * @root_lnum: LEB number of the root indexing node + * @root_offs: offset within @root_lnum + * @root_len: root indexing node length + * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was + * not reserved and should be reserved on mount) + * @ihead_lnum: LEB number of index head + * @ihead_offs: offset of index head + * @index_size: size of index on flash + * @total_free: total free space in bytes + * @total_dirty: total dirty space in bytes + * @total_used: total used space in bytes (includes only data LEBs) + * @total_dead: total dead space in bytes (includes only data LEBs) + * @total_dark: total dark space in bytes (includes only data LEBs) + * @lpt_lnum: LEB number of LPT root nnode + * @lpt_offs: offset of LPT root nnode + * @nhead_lnum: LEB number of LPT head + * @nhead_offs: offset of LPT head + * @ltab_lnum: LEB number of LPT's own lprops table + * @ltab_offs: offset of LPT's own lprops table + * @lsave_lnum: LEB number of LPT's save table (big model only) + * @lsave_offs: offset of LPT's save table (big model only) + * @lscan_lnum: LEB number of last LPT scan + * @empty_lebs: number of empty logical eraseblocks + * @idx_lebs: number of indexing logical eraseblocks + * @leb_cnt: count of LEBs used by file-system + * @hash_root_idx: the hash of the root index node + * @hash_lpt: the hash of the LPT + * @hmac: HMAC to authenticate the master node + * @padding: reserved for future, zeroes + */ +struct ubifs_mst_node { + struct ubifs_ch ch; + __le64 highest_inum; + __le64 cmt_no; + __le32 flags; + __le32 log_lnum; + __le32 root_lnum; + __le32 root_offs; + __le32 root_len; + __le32 gc_lnum; + __le32 ihead_lnum; + __le32 ihead_offs; + __le64 index_size; + __le64 total_free; + __le64 total_dirty; + __le64 total_used; + __le64 total_dead; + __le64 total_dark; + __le32 lpt_lnum; + __le32 lpt_offs; + __le32 nhead_lnum; + __le32 nhead_offs; + __le32 ltab_lnum; + __le32 ltab_offs; + __le32 lsave_lnum; + __le32 lsave_offs; + __le32 lscan_lnum; + __le32 empty_lebs; + __le32 idx_lebs; + __le32 leb_cnt; + __u8 hash_root_idx[UBIFS_MAX_HASH_LEN]; + __u8 hash_lpt[UBIFS_MAX_HASH_LEN]; + __u8 hmac[UBIFS_MAX_HMAC_LEN]; + __u8 padding[152]; +} __packed; + +/** + * struct ubifs_ref_node - logical eraseblock reference node. + * @ch: common header + * @lnum: the referred logical eraseblock number + * @offs: start offset in the referred LEB + * @jhead: journal head number + * @padding: reserved for future, zeroes + */ +struct ubifs_ref_node { + struct ubifs_ch ch; + __le32 lnum; + __le32 offs; + __le32 jhead; + __u8 padding[28]; +} __packed; + +/** + * struct ubifs_auth_node - node for authenticating other nodes + * @ch: common header + * @hmac: The HMAC + */ +struct ubifs_auth_node { + struct ubifs_ch ch; + __u8 hmac[]; +} __packed; + +/** + * struct ubifs_sig_node - node for signing other nodes + * @ch: common header + * @type: type of the signature, currently only UBIFS_SIGNATURE_TYPE_PKCS7 + * supported + * @len: The length of the signature data + * @padding: reserved for future, zeroes + * @sig: The signature data + */ +struct ubifs_sig_node { + struct ubifs_ch ch; + __le32 type; + __le32 len; + __u8 padding[32]; + __u8 sig[]; +} __packed; + +/** + * struct ubifs_branch - key/reference/length branch + * @lnum: LEB number of the target node + * @offs: offset within @lnum + * @len: target node length + * @key: key + * + * In an authenticated UBIFS we have the hash of the referenced node after @key. + * This can't be added to the struct type definition because @key is a + * dynamically sized element already. + */ +struct ubifs_branch { + __le32 lnum; + __le32 offs; + __le32 len; + __u8 key[]; +} __packed; + +/** + * struct ubifs_idx_node - indexing node. + * @ch: common header + * @child_cnt: number of child index nodes + * @level: tree level + * @branches: LEB number / offset / length / key branches + */ +struct ubifs_idx_node { + struct ubifs_ch ch; + __le16 child_cnt; + __le16 level; + __u8 branches[]; +} __packed; + +/** + * struct ubifs_cs_node - commit start node. + * @ch: common header + * @cmt_no: commit number + */ +struct ubifs_cs_node { + struct ubifs_ch ch; + __le64 cmt_no; +} __packed; + +/** + * struct ubifs_orph_node - orphan node. + * @ch: common header + * @cmt_no: commit number (also top bit is set on the last node of the commit) + * @inos: inode numbers of orphans + */ +struct ubifs_orph_node { + struct ubifs_ch ch; + __le64 cmt_no; + __le64 inos[]; +} __packed; + +#endif /* __UBIFS_MEDIA_H__ */ diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h new file mode 100644 index 000000000..b66ebab5c --- /dev/null +++ b/fs/ubifs/ubifs.h @@ -0,0 +1,2123 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +#ifndef __UBIFS_H__ +#define __UBIFS_H__ + +#include <asm/div64.h> +#include <linux/statfs.h> +#include <linux/fs.h> +#include <linux/err.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/rwsem.h> +#include <linux/mtd/ubi.h> +#include <linux/pagemap.h> +#include <linux/backing-dev.h> +#include <linux/security.h> +#include <linux/xattr.h> +#include <linux/random.h> +#include <crypto/hash_info.h> +#include <crypto/hash.h> +#include <crypto/algapi.h> + +#include <linux/fscrypt.h> + +#include "ubifs-media.h" + +/* Version of this UBIFS implementation */ +#define UBIFS_VERSION 1 + +/* UBIFS file system VFS magic number */ +#define UBIFS_SUPER_MAGIC 0x24051905 + +/* Number of UBIFS blocks per VFS page */ +#define UBIFS_BLOCKS_PER_PAGE (PAGE_SIZE / UBIFS_BLOCK_SIZE) +#define UBIFS_BLOCKS_PER_PAGE_SHIFT (PAGE_SHIFT - UBIFS_BLOCK_SHIFT) + +/* "File system end of life" sequence number watermark */ +#define SQNUM_WARN_WATERMARK 0xFFFFFFFF00000000ULL +#define SQNUM_WATERMARK 0xFFFFFFFFFF000000ULL + +/* + * Minimum amount of LEBs reserved for the index. At present the index needs at + * least 2 LEBs: one for the index head and one for in-the-gaps method (which + * currently does not cater for the index head and so excludes it from + * consideration). + */ +#define MIN_INDEX_LEBS 2 + +/* Minimum amount of data UBIFS writes to the flash */ +#define MIN_WRITE_SZ (UBIFS_DATA_NODE_SZ + 8) + +/* + * Currently we do not support inode number overlapping and re-using, so this + * watermark defines dangerous inode number level. This should be fixed later, + * although it is difficult to exceed current limit. Another option is to use + * 64-bit inode numbers, but this means more overhead. + */ +#define INUM_WARN_WATERMARK 0xFFF00000 +#define INUM_WATERMARK 0xFFFFFF00 + +/* Maximum number of entries in each LPT (LEB category) heap */ +#define LPT_HEAP_SZ 256 + +/* + * Background thread name pattern. The numbers are UBI device and volume + * numbers. + */ +#define BGT_NAME_PATTERN "ubifs_bgt%d_%d" + +/* Maximum possible inode number (only 32-bit inodes are supported now) */ +#define MAX_INUM 0xFFFFFFFF + +/* Number of non-data journal heads */ +#define NONDATA_JHEADS_CNT 2 + +/* Shorter names for journal head numbers for internal usage */ +#define GCHD UBIFS_GC_HEAD +#define BASEHD UBIFS_BASE_HEAD +#define DATAHD UBIFS_DATA_HEAD + +/* 'No change' value for 'ubifs_change_lp()' */ +#define LPROPS_NC 0x80000001 + +/* + * There is no notion of truncation key because truncation nodes do not exist + * in TNC. However, when replaying, it is handy to introduce fake "truncation" + * keys for truncation nodes because the code becomes simpler. So we define + * %UBIFS_TRUN_KEY type. + * + * But otherwise, out of the journal reply scope, the truncation keys are + * invalid. + */ +#define UBIFS_TRUN_KEY UBIFS_KEY_TYPES_CNT +#define UBIFS_INVALID_KEY UBIFS_KEY_TYPES_CNT + +/* + * How much a directory entry/extended attribute entry adds to the parent/host + * inode. + */ +#define CALC_DENT_SIZE(name_len) ALIGN(UBIFS_DENT_NODE_SZ + (name_len) + 1, 8) + +/* How much an extended attribute adds to the host inode */ +#define CALC_XATTR_BYTES(data_len) ALIGN(UBIFS_INO_NODE_SZ + (data_len) + 1, 8) + +/* + * Znodes which were not touched for 'OLD_ZNODE_AGE' seconds are considered + * "old", and znode which were touched last 'YOUNG_ZNODE_AGE' seconds ago are + * considered "young". This is used by shrinker when selecting znode to trim + * off. + */ +#define OLD_ZNODE_AGE 20 +#define YOUNG_ZNODE_AGE 5 + +/* + * Some compressors, like LZO, may end up with more data then the input buffer. + * So UBIFS always allocates larger output buffer, to be sure the compressor + * will not corrupt memory in case of worst case compression. + */ +#define WORST_COMPR_FACTOR 2 + +#ifdef CONFIG_FS_ENCRYPTION +#define UBIFS_CIPHER_BLOCK_SIZE FS_CRYPTO_BLOCK_SIZE +#else +#define UBIFS_CIPHER_BLOCK_SIZE 0 +#endif + +/* + * How much memory is needed for a buffer where we compress a data node. + */ +#define COMPRESSED_DATA_NODE_BUF_SZ \ + (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR) + +/* Maximum expected tree height for use by bottom_up_buf */ +#define BOTTOM_UP_HEIGHT 64 + +/* Maximum number of data nodes to bulk-read */ +#define UBIFS_MAX_BULK_READ 32 + +#ifdef CONFIG_UBIFS_FS_AUTHENTICATION +#define UBIFS_HASH_ARR_SZ UBIFS_MAX_HASH_LEN +#define UBIFS_HMAC_ARR_SZ UBIFS_MAX_HMAC_LEN +#else +#define UBIFS_HASH_ARR_SZ 0 +#define UBIFS_HMAC_ARR_SZ 0 +#endif + +/* + * Lockdep classes for UBIFS inode @ui_mutex. + */ +enum { + WB_MUTEX_1 = 0, + WB_MUTEX_2 = 1, + WB_MUTEX_3 = 2, + WB_MUTEX_4 = 3, +}; + +/* + * Znode flags (actually, bit numbers which store the flags). + * + * DIRTY_ZNODE: znode is dirty + * COW_ZNODE: znode is being committed and a new instance of this znode has to + * be created before changing this znode + * OBSOLETE_ZNODE: znode is obsolete, which means it was deleted, but it is + * still in the commit list and the ongoing commit operation + * will commit it, and delete this znode after it is done + */ +enum { + DIRTY_ZNODE = 0, + COW_ZNODE = 1, + OBSOLETE_ZNODE = 2, +}; + +/* + * Commit states. + * + * COMMIT_RESTING: commit is not wanted + * COMMIT_BACKGROUND: background commit has been requested + * COMMIT_REQUIRED: commit is required + * COMMIT_RUNNING_BACKGROUND: background commit is running + * COMMIT_RUNNING_REQUIRED: commit is running and it is required + * COMMIT_BROKEN: commit failed + */ +enum { + COMMIT_RESTING = 0, + COMMIT_BACKGROUND, + COMMIT_REQUIRED, + COMMIT_RUNNING_BACKGROUND, + COMMIT_RUNNING_REQUIRED, + COMMIT_BROKEN, +}; + +/* + * 'ubifs_scan_a_node()' return values. + * + * SCANNED_GARBAGE: scanned garbage + * SCANNED_EMPTY_SPACE: scanned empty space + * SCANNED_A_NODE: scanned a valid node + * SCANNED_A_CORRUPT_NODE: scanned a corrupted node + * SCANNED_A_BAD_PAD_NODE: scanned a padding node with invalid pad length + * + * Greater than zero means: 'scanned that number of padding bytes' + */ +enum { + SCANNED_GARBAGE = 0, + SCANNED_EMPTY_SPACE = -1, + SCANNED_A_NODE = -2, + SCANNED_A_CORRUPT_NODE = -3, + SCANNED_A_BAD_PAD_NODE = -4, +}; + +/* + * LPT cnode flag bits. + * + * DIRTY_CNODE: cnode is dirty + * OBSOLETE_CNODE: cnode is being committed and has been copied (or deleted), + * so it can (and must) be freed when the commit is finished + * COW_CNODE: cnode is being committed and must be copied before writing + */ +enum { + DIRTY_CNODE = 0, + OBSOLETE_CNODE = 1, + COW_CNODE = 2, +}; + +/* + * Dirty flag bits (lpt_drty_flgs) for LPT special nodes. + * + * LTAB_DIRTY: ltab node is dirty + * LSAVE_DIRTY: lsave node is dirty + */ +enum { + LTAB_DIRTY = 1, + LSAVE_DIRTY = 2, +}; + +/* + * Return codes used by the garbage collector. + * @LEB_FREED: the logical eraseblock was freed and is ready to use + * @LEB_FREED_IDX: indexing LEB was freed and can be used only after the commit + * @LEB_RETAINED: the logical eraseblock was freed and retained for GC purposes + */ +enum { + LEB_FREED, + LEB_FREED_IDX, + LEB_RETAINED, +}; + +/* + * Action taken upon a failed ubifs_assert(). + * @ASSACT_REPORT: just report the failed assertion + * @ASSACT_RO: switch to read-only mode + * @ASSACT_PANIC: call BUG() and possible panic the kernel + */ +enum { + ASSACT_REPORT = 0, + ASSACT_RO, + ASSACT_PANIC, +}; + +/** + * struct ubifs_old_idx - index node obsoleted since last commit start. + * @rb: rb-tree node + * @lnum: LEB number of obsoleted index node + * @offs: offset of obsoleted index node + */ +struct ubifs_old_idx { + struct rb_node rb; + int lnum; + int offs; +}; + +/* The below union makes it easier to deal with keys */ +union ubifs_key { + uint8_t u8[UBIFS_SK_LEN]; + uint32_t u32[UBIFS_SK_LEN/4]; + uint64_t u64[UBIFS_SK_LEN/8]; + __le32 j32[UBIFS_SK_LEN/4]; +}; + +/** + * struct ubifs_scan_node - UBIFS scanned node information. + * @list: list of scanned nodes + * @key: key of node scanned (if it has one) + * @sqnum: sequence number + * @type: type of node scanned + * @offs: offset with LEB of node scanned + * @len: length of node scanned + * @node: raw node + */ +struct ubifs_scan_node { + struct list_head list; + union ubifs_key key; + unsigned long long sqnum; + int type; + int offs; + int len; + void *node; +}; + +/** + * struct ubifs_scan_leb - UBIFS scanned LEB information. + * @lnum: logical eraseblock number + * @nodes_cnt: number of nodes scanned + * @nodes: list of struct ubifs_scan_node + * @endpt: end point (and therefore the start of empty space) + * @buf: buffer containing entire LEB scanned + */ +struct ubifs_scan_leb { + int lnum; + int nodes_cnt; + struct list_head nodes; + int endpt; + void *buf; +}; + +/** + * struct ubifs_gced_idx_leb - garbage-collected indexing LEB. + * @list: list + * @lnum: LEB number + * @unmap: OK to unmap this LEB + * + * This data structure is used to temporary store garbage-collected indexing + * LEBs - they are not released immediately, but only after the next commit. + * This is needed to guarantee recoverability. + */ +struct ubifs_gced_idx_leb { + struct list_head list; + int lnum; + int unmap; +}; + +/** + * struct ubifs_inode - UBIFS in-memory inode description. + * @vfs_inode: VFS inode description object + * @creat_sqnum: sequence number at time of creation + * @del_cmtno: commit number corresponding to the time the inode was deleted, + * protected by @c->commit_sem; + * @xattr_size: summarized size of all extended attributes in bytes + * @xattr_cnt: count of extended attributes this inode has + * @xattr_names: sum of lengths of all extended attribute names belonging to + * this inode + * @dirty: non-zero if the inode is dirty + * @xattr: non-zero if this is an extended attribute inode + * @bulk_read: non-zero if bulk-read should be used + * @ui_mutex: serializes inode write-back with the rest of VFS operations, + * serializes "clean <-> dirty" state changes, serializes bulk-read, + * protects @dirty, @bulk_read, @ui_size, and @xattr_size + * @xattr_sem: serilizes write operations (remove|set|create) on xattr + * @ui_lock: protects @synced_i_size + * @synced_i_size: synchronized size of inode, i.e. the value of inode size + * currently stored on the flash; used only for regular file + * inodes + * @ui_size: inode size used by UBIFS when writing to flash + * @flags: inode flags (@UBIFS_COMPR_FL, etc) + * @compr_type: default compression type used for this inode + * @last_page_read: page number of last page read (for bulk read) + * @read_in_a_row: number of consecutive pages read in a row (for bulk read) + * @data_len: length of the data attached to the inode + * @data: inode's data + * + * @ui_mutex exists for two main reasons. At first it prevents inodes from + * being written back while UBIFS changing them, being in the middle of an VFS + * operation. This way UBIFS makes sure the inode fields are consistent. For + * example, in 'ubifs_rename()' we change 3 inodes simultaneously, and + * write-back must not write any of them before we have finished. + * + * The second reason is budgeting - UBIFS has to budget all operations. If an + * operation is going to mark an inode dirty, it has to allocate budget for + * this. It cannot just mark it dirty because there is no guarantee there will + * be enough flash space to write the inode back later. This means UBIFS has + * to have full control over inode "clean <-> dirty" transitions (and pages + * actually). But unfortunately, VFS marks inodes dirty in many places, and it + * does not ask the file-system if it is allowed to do so (there is a notifier, + * but it is not enough), i.e., there is no mechanism to synchronize with this. + * So UBIFS has its own inode dirty flag and its own mutex to serialize + * "clean <-> dirty" transitions. + * + * The @synced_i_size field is used to make sure we never write pages which are + * beyond last synchronized inode size. See 'ubifs_writepage()' for more + * information. + * + * The @ui_size is a "shadow" variable for @inode->i_size and UBIFS uses + * @ui_size instead of @inode->i_size. The reason for this is that UBIFS cannot + * make sure @inode->i_size is always changed under @ui_mutex, because it + * cannot call 'truncate_setsize()' with @ui_mutex locked, because it would + * deadlock with 'ubifs_writepage()' (see file.c). All the other inode fields + * are changed under @ui_mutex, so they do not need "shadow" fields. Note, one + * could consider to rework locking and base it on "shadow" fields. + */ +struct ubifs_inode { + struct inode vfs_inode; + unsigned long long creat_sqnum; + unsigned long long del_cmtno; + unsigned int xattr_size; + unsigned int xattr_cnt; + unsigned int xattr_names; + unsigned int dirty:1; + unsigned int xattr:1; + unsigned int bulk_read:1; + unsigned int compr_type:2; + struct mutex ui_mutex; + struct rw_semaphore xattr_sem; + spinlock_t ui_lock; + loff_t synced_i_size; + loff_t ui_size; + int flags; + pgoff_t last_page_read; + pgoff_t read_in_a_row; + int data_len; + void *data; +}; + +/** + * struct ubifs_unclean_leb - records a LEB recovered under read-only mode. + * @list: list + * @lnum: LEB number of recovered LEB + * @endpt: offset where recovery ended + * + * This structure records a LEB identified during recovery that needs to be + * cleaned but was not because UBIFS was mounted read-only. The information + * is used to clean the LEB when remounting to read-write mode. + */ +struct ubifs_unclean_leb { + struct list_head list; + int lnum; + int endpt; +}; + +/* + * LEB properties flags. + * + * LPROPS_UNCAT: not categorized + * LPROPS_DIRTY: dirty > free, dirty >= @c->dead_wm, not index + * LPROPS_DIRTY_IDX: dirty + free > @c->min_idx_node_sze and index + * LPROPS_FREE: free > 0, dirty < @c->dead_wm, not empty, not index + * LPROPS_HEAP_CNT: number of heaps used for storing categorized LEBs + * LPROPS_EMPTY: LEB is empty, not taken + * LPROPS_FREEABLE: free + dirty == leb_size, not index, not taken + * LPROPS_FRDI_IDX: free + dirty == leb_size and index, may be taken + * LPROPS_CAT_MASK: mask for the LEB categories above + * LPROPS_TAKEN: LEB was taken (this flag is not saved on the media) + * LPROPS_INDEX: LEB contains indexing nodes (this flag also exists on flash) + */ +enum { + LPROPS_UNCAT = 0, + LPROPS_DIRTY = 1, + LPROPS_DIRTY_IDX = 2, + LPROPS_FREE = 3, + LPROPS_HEAP_CNT = 3, + LPROPS_EMPTY = 4, + LPROPS_FREEABLE = 5, + LPROPS_FRDI_IDX = 6, + LPROPS_CAT_MASK = 15, + LPROPS_TAKEN = 16, + LPROPS_INDEX = 32, +}; + +/** + * struct ubifs_lprops - logical eraseblock properties. + * @free: amount of free space in bytes + * @dirty: amount of dirty space in bytes + * @flags: LEB properties flags (see above) + * @lnum: LEB number + * @list: list of same-category lprops (for LPROPS_EMPTY and LPROPS_FREEABLE) + * @hpos: heap position in heap of same-category lprops (other categories) + */ +struct ubifs_lprops { + int free; + int dirty; + int flags; + int lnum; + union { + struct list_head list; + int hpos; + }; +}; + +/** + * struct ubifs_lpt_lprops - LPT logical eraseblock properties. + * @free: amount of free space in bytes + * @dirty: amount of dirty space in bytes + * @tgc: trivial GC flag (1 => unmap after commit end) + * @cmt: commit flag (1 => reserved for commit) + */ +struct ubifs_lpt_lprops { + int free; + int dirty; + unsigned tgc:1; + unsigned cmt:1; +}; + +/** + * struct ubifs_lp_stats - statistics of eraseblocks in the main area. + * @empty_lebs: number of empty LEBs + * @taken_empty_lebs: number of taken LEBs + * @idx_lebs: number of indexing LEBs + * @total_free: total free space in bytes (includes all LEBs) + * @total_dirty: total dirty space in bytes (includes all LEBs) + * @total_used: total used space in bytes (does not include index LEBs) + * @total_dead: total dead space in bytes (does not include index LEBs) + * @total_dark: total dark space in bytes (does not include index LEBs) + * + * The @taken_empty_lebs field counts the LEBs that are in the transient state + * of having been "taken" for use but not yet written to. @taken_empty_lebs is + * needed to account correctly for @gc_lnum, otherwise @empty_lebs could be + * used by itself (in which case 'unused_lebs' would be a better name). In the + * case of @gc_lnum, it is "taken" at mount time or whenever a LEB is retained + * by GC, but unlike other empty LEBs that are "taken", it may not be written + * straight away (i.e. before the next commit start or unmount), so either + * @gc_lnum must be specially accounted for, or the current approach followed + * i.e. count it under @taken_empty_lebs. + * + * @empty_lebs includes @taken_empty_lebs. + * + * @total_used, @total_dead and @total_dark fields do not account indexing + * LEBs. + */ +struct ubifs_lp_stats { + int empty_lebs; + int taken_empty_lebs; + int idx_lebs; + long long total_free; + long long total_dirty; + long long total_used; + long long total_dead; + long long total_dark; +}; + +struct ubifs_nnode; + +/** + * struct ubifs_cnode - LEB Properties Tree common node. + * @parent: parent nnode + * @cnext: next cnode to commit + * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE) + * @iip: index in parent + * @level: level in the tree (zero for pnodes, greater than zero for nnodes) + * @num: node number + */ +struct ubifs_cnode { + struct ubifs_nnode *parent; + struct ubifs_cnode *cnext; + unsigned long flags; + int iip; + int level; + int num; +}; + +/** + * struct ubifs_pnode - LEB Properties Tree leaf node. + * @parent: parent nnode + * @cnext: next cnode to commit + * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE) + * @iip: index in parent + * @level: level in the tree (always zero for pnodes) + * @num: node number + * @lprops: LEB properties array + */ +struct ubifs_pnode { + struct ubifs_nnode *parent; + struct ubifs_cnode *cnext; + unsigned long flags; + int iip; + int level; + int num; + struct ubifs_lprops lprops[UBIFS_LPT_FANOUT]; +}; + +/** + * struct ubifs_nbranch - LEB Properties Tree internal node branch. + * @lnum: LEB number of child + * @offs: offset of child + * @nnode: nnode child + * @pnode: pnode child + * @cnode: cnode child + */ +struct ubifs_nbranch { + int lnum; + int offs; + union { + struct ubifs_nnode *nnode; + struct ubifs_pnode *pnode; + struct ubifs_cnode *cnode; + }; +}; + +/** + * struct ubifs_nnode - LEB Properties Tree internal node. + * @parent: parent nnode + * @cnext: next cnode to commit + * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE) + * @iip: index in parent + * @level: level in the tree (always greater than zero for nnodes) + * @num: node number + * @nbranch: branches to child nodes + */ +struct ubifs_nnode { + struct ubifs_nnode *parent; + struct ubifs_cnode *cnext; + unsigned long flags; + int iip; + int level; + int num; + struct ubifs_nbranch nbranch[UBIFS_LPT_FANOUT]; +}; + +/** + * struct ubifs_lpt_heap - heap of categorized lprops. + * @arr: heap array + * @cnt: number in heap + * @max_cnt: maximum number allowed in heap + * + * There are %LPROPS_HEAP_CNT heaps. + */ +struct ubifs_lpt_heap { + struct ubifs_lprops **arr; + int cnt; + int max_cnt; +}; + +/* + * Return codes for LPT scan callback function. + * + * LPT_SCAN_CONTINUE: continue scanning + * LPT_SCAN_ADD: add the LEB properties scanned to the tree in memory + * LPT_SCAN_STOP: stop scanning + */ +enum { + LPT_SCAN_CONTINUE = 0, + LPT_SCAN_ADD = 1, + LPT_SCAN_STOP = 2, +}; + +struct ubifs_info; + +/* Callback used by the 'ubifs_lpt_scan_nolock()' function */ +typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c, + const struct ubifs_lprops *lprops, + int in_tree, void *data); + +/** + * struct ubifs_wbuf - UBIFS write-buffer. + * @c: UBIFS file-system description object + * @buf: write-buffer (of min. flash I/O unit size) + * @lnum: logical eraseblock number the write-buffer points to + * @offs: write-buffer offset in this logical eraseblock + * @avail: number of bytes available in the write-buffer + * @used: number of used bytes in the write-buffer + * @size: write-buffer size (in [@c->min_io_size, @c->max_write_size] range) + * @jhead: journal head the mutex belongs to (note, needed only to shut lockdep + * up by 'mutex_lock_nested()). + * @sync_callback: write-buffer synchronization callback + * @io_mutex: serializes write-buffer I/O + * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes + * fields + * @timer: write-buffer timer + * @no_timer: non-zero if this write-buffer does not have a timer + * @need_sync: non-zero if the timer expired and the wbuf needs sync'ing + * @next_ino: points to the next position of the following inode number + * @inodes: stores the inode numbers of the nodes which are in wbuf + * + * The write-buffer synchronization callback is called when the write-buffer is + * synchronized in order to notify how much space was wasted due to + * write-buffer padding and how much free space is left in the LEB. + * + * Note: the fields @buf, @lnum, @offs, @avail and @used can be read under + * spin-lock or mutex because they are written under both mutex and spin-lock. + * @buf is appended to under mutex but overwritten under both mutex and + * spin-lock. Thus the data between @buf and @buf + @used can be read under + * spinlock. + */ +struct ubifs_wbuf { + struct ubifs_info *c; + void *buf; + int lnum; + int offs; + int avail; + int used; + int size; + int jhead; + int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad); + struct mutex io_mutex; + spinlock_t lock; + struct hrtimer timer; + unsigned int no_timer:1; + unsigned int need_sync:1; + int next_ino; + ino_t *inodes; +}; + +/** + * struct ubifs_bud - bud logical eraseblock. + * @lnum: logical eraseblock number + * @start: where the (uncommitted) bud data starts + * @jhead: journal head number this bud belongs to + * @list: link in the list buds belonging to the same journal head + * @rb: link in the tree of all buds + * @log_hash: the log hash from the commit start node up to this bud + */ +struct ubifs_bud { + int lnum; + int start; + int jhead; + struct list_head list; + struct rb_node rb; + struct shash_desc *log_hash; +}; + +/** + * struct ubifs_jhead - journal head. + * @wbuf: head's write-buffer + * @buds_list: list of bud LEBs belonging to this journal head + * @grouped: non-zero if UBIFS groups nodes when writing to this journal head + * @log_hash: the log hash from the commit start node up to this journal head + * + * Note, the @buds list is protected by the @c->buds_lock. + */ +struct ubifs_jhead { + struct ubifs_wbuf wbuf; + struct list_head buds_list; + unsigned int grouped:1; + struct shash_desc *log_hash; +}; + +/** + * struct ubifs_zbranch - key/coordinate/length branch stored in znodes. + * @key: key + * @znode: znode address in memory + * @lnum: LEB number of the target node (indexing node or data node) + * @offs: target node offset within @lnum + * @len: target node length + * @hash: the hash of the target node + */ +struct ubifs_zbranch { + union ubifs_key key; + union { + struct ubifs_znode *znode; + void *leaf; + }; + int lnum; + int offs; + int len; + u8 hash[UBIFS_HASH_ARR_SZ]; +}; + +/** + * struct ubifs_znode - in-memory representation of an indexing node. + * @parent: parent znode or NULL if it is the root + * @cnext: next znode to commit + * @cparent: parent node for this commit + * @ciip: index in cparent's zbranch array + * @flags: znode flags (%DIRTY_ZNODE, %COW_ZNODE or %OBSOLETE_ZNODE) + * @time: last access time (seconds) + * @level: level of the entry in the TNC tree + * @child_cnt: count of child znodes + * @iip: index in parent's zbranch array + * @alt: lower bound of key range has altered i.e. child inserted at slot 0 + * @lnum: LEB number of the corresponding indexing node + * @offs: offset of the corresponding indexing node + * @len: length of the corresponding indexing node + * @zbranch: array of znode branches (@c->fanout elements) + * + * Note! The @lnum, @offs, and @len fields are not really needed - we have them + * only for internal consistency check. They could be removed to save some RAM. + */ +struct ubifs_znode { + struct ubifs_znode *parent; + struct ubifs_znode *cnext; + struct ubifs_znode *cparent; + int ciip; + unsigned long flags; + time64_t time; + int level; + int child_cnt; + int iip; + int alt; + int lnum; + int offs; + int len; + struct ubifs_zbranch zbranch[]; +}; + +/** + * struct bu_info - bulk-read information. + * @key: first data node key + * @zbranch: zbranches of data nodes to bulk read + * @buf: buffer to read into + * @buf_len: buffer length + * @gc_seq: GC sequence number to detect races with GC + * @cnt: number of data nodes for bulk read + * @blk_cnt: number of data blocks including holes + * @oef: end of file reached + */ +struct bu_info { + union ubifs_key key; + struct ubifs_zbranch zbranch[UBIFS_MAX_BULK_READ]; + void *buf; + int buf_len; + int gc_seq; + int cnt; + int blk_cnt; + int eof; +}; + +/** + * struct ubifs_node_range - node length range description data structure. + * @len: fixed node length + * @min_len: minimum possible node length + * @max_len: maximum possible node length + * + * If @max_len is %0, the node has fixed length @len. + */ +struct ubifs_node_range { + union { + int len; + int min_len; + }; + int max_len; +}; + +/** + * struct ubifs_compressor - UBIFS compressor description structure. + * @compr_type: compressor type (%UBIFS_COMPR_LZO, etc) + * @cc: cryptoapi compressor handle + * @comp_mutex: mutex used during compression + * @decomp_mutex: mutex used during decompression + * @name: compressor name + * @capi_name: cryptoapi compressor name + */ +struct ubifs_compressor { + int compr_type; + struct crypto_comp *cc; + struct mutex *comp_mutex; + struct mutex *decomp_mutex; + const char *name; + const char *capi_name; +}; + +/** + * struct ubifs_budget_req - budget requirements of an operation. + * + * @fast: non-zero if the budgeting should try to acquire budget quickly and + * should not try to call write-back + * @recalculate: non-zero if @idx_growth, @data_growth, and @dd_growth fields + * have to be re-calculated + * @new_page: non-zero if the operation adds a new page + * @dirtied_page: non-zero if the operation makes a page dirty + * @new_dent: non-zero if the operation adds a new directory entry + * @mod_dent: non-zero if the operation removes or modifies an existing + * directory entry + * @new_ino: non-zero if the operation adds a new inode + * @new_ino_d: how much data newly created inode contains + * @dirtied_ino: how many inodes the operation makes dirty + * @dirtied_ino_d: how much data dirtied inode contains + * @idx_growth: how much the index will supposedly grow + * @data_growth: how much new data the operation will supposedly add + * @dd_growth: how much data that makes other data dirty the operation will + * supposedly add + * + * @idx_growth, @data_growth and @dd_growth are not used in budget request. The + * budgeting subsystem caches index and data growth values there to avoid + * re-calculating them when the budget is released. However, if @idx_growth is + * %-1, it is calculated by the release function using other fields. + * + * An inode may contain 4KiB of data at max., thus the widths of @new_ino_d + * is 13 bits, and @dirtied_ino_d - 15, because up to 4 inodes may be made + * dirty by the re-name operation. + * + * Note, UBIFS aligns node lengths to 8-bytes boundary, so the requester has to + * make sure the amount of inode data which contribute to @new_ino_d and + * @dirtied_ino_d fields are aligned. + */ +struct ubifs_budget_req { + unsigned int fast:1; + unsigned int recalculate:1; +#ifndef UBIFS_DEBUG + unsigned int new_page:1; + unsigned int dirtied_page:1; + unsigned int new_dent:1; + unsigned int mod_dent:1; + unsigned int new_ino:1; + unsigned int new_ino_d:13; + unsigned int dirtied_ino:4; + unsigned int dirtied_ino_d:15; +#else + /* Not bit-fields to check for overflows */ + unsigned int new_page; + unsigned int dirtied_page; + unsigned int new_dent; + unsigned int mod_dent; + unsigned int new_ino; + unsigned int new_ino_d; + unsigned int dirtied_ino; + unsigned int dirtied_ino_d; +#endif + int idx_growth; + int data_growth; + int dd_growth; +}; + +/** + * struct ubifs_orphan - stores the inode number of an orphan. + * @rb: rb-tree node of rb-tree of orphans sorted by inode number + * @list: list head of list of orphans in order added + * @new_list: list head of list of orphans added since the last commit + * @child_list: list of xattr childs if this orphan hosts xattrs, list head + * if this orphan is a xattr, not used otherwise. + * @cnext: next orphan to commit + * @dnext: next orphan to delete + * @inum: inode number + * @new: %1 => added since the last commit, otherwise %0 + * @cmt: %1 => commit pending, otherwise %0 + * @del: %1 => delete pending, otherwise %0 + */ +struct ubifs_orphan { + struct rb_node rb; + struct list_head list; + struct list_head new_list; + struct list_head child_list; + struct ubifs_orphan *cnext; + struct ubifs_orphan *dnext; + ino_t inum; + unsigned new:1; + unsigned cmt:1; + unsigned del:1; +}; + +/** + * struct ubifs_mount_opts - UBIFS-specific mount options information. + * @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast) + * @bulk_read: enable/disable bulk-reads (%0 default, %1 disable, %2 enable) + * @chk_data_crc: enable/disable CRC data checking when reading data nodes + * (%0 default, %1 disable, %2 enable) + * @override_compr: override default compressor (%0 - do not override and use + * superblock compressor, %1 - override and use compressor + * specified in @compr_type) + * @compr_type: compressor type to override the superblock compressor with + * (%UBIFS_COMPR_NONE, etc) + */ +struct ubifs_mount_opts { + unsigned int unmount_mode:2; + unsigned int bulk_read:2; + unsigned int chk_data_crc:2; + unsigned int override_compr:1; + unsigned int compr_type:2; +}; + +/** + * struct ubifs_budg_info - UBIFS budgeting information. + * @idx_growth: amount of bytes budgeted for index growth + * @data_growth: amount of bytes budgeted for cached data + * @dd_growth: amount of bytes budgeted for cached data that will make + * other data dirty + * @uncommitted_idx: amount of bytes were budgeted for growth of the index, but + * which still have to be taken into account because the index + * has not been committed so far + * @old_idx_sz: size of index on flash + * @min_idx_lebs: minimum number of LEBs required for the index + * @nospace: non-zero if the file-system does not have flash space (used as + * optimization) + * @nospace_rp: the same as @nospace, but additionally means that even reserved + * pool is full + * @page_budget: budget for a page (constant, never changed after mount) + * @inode_budget: budget for an inode (constant, never changed after mount) + * @dent_budget: budget for a directory entry (constant, never changed after + * mount) + */ +struct ubifs_budg_info { + long long idx_growth; + long long data_growth; + long long dd_growth; + long long uncommitted_idx; + unsigned long long old_idx_sz; + int min_idx_lebs; + unsigned int nospace:1; + unsigned int nospace_rp:1; + int page_budget; + int inode_budget; + int dent_budget; +}; + +struct ubifs_debug_info; + +/** + * struct ubifs_info - UBIFS file-system description data structure + * (per-superblock). + * @vfs_sb: VFS @struct super_block object + * @sup_node: The super block node as read from the device + * + * @highest_inum: highest used inode number + * @max_sqnum: current global sequence number + * @cmt_no: commit number of the last successfully completed commit, protected + * by @commit_sem + * @cnt_lock: protects @highest_inum and @max_sqnum counters + * @fmt_version: UBIFS on-flash format version + * @ro_compat_version: R/O compatibility version + * @uuid: UUID from super block + * + * @lhead_lnum: log head logical eraseblock number + * @lhead_offs: log head offset + * @ltail_lnum: log tail logical eraseblock number (offset is always 0) + * @log_mutex: protects the log, @lhead_lnum, @lhead_offs, @ltail_lnum, and + * @bud_bytes + * @min_log_bytes: minimum required number of bytes in the log + * @cmt_bud_bytes: used during commit to temporarily amount of bytes in + * committed buds + * + * @buds: tree of all buds indexed by bud LEB number + * @bud_bytes: how many bytes of flash is used by buds + * @buds_lock: protects the @buds tree, @bud_bytes, and per-journal head bud + * lists + * @jhead_cnt: count of journal heads + * @jheads: journal heads (head zero is base head) + * @max_bud_bytes: maximum number of bytes allowed in buds + * @bg_bud_bytes: number of bud bytes when background commit is initiated + * @old_buds: buds to be released after commit ends + * @max_bud_cnt: maximum number of buds + * + * @commit_sem: synchronizes committer with other processes + * @cmt_state: commit state + * @cs_lock: commit state lock + * @cmt_wq: wait queue to sleep on if the log is full and a commit is running + * + * @big_lpt: flag that LPT is too big to write whole during commit + * @space_fixup: flag indicating that free space in LEBs needs to be cleaned up + * @double_hash: flag indicating that we can do lookups by hash + * @encrypted: flag indicating that this file system contains encrypted files + * @no_chk_data_crc: do not check CRCs when reading data nodes (except during + * recovery) + * @bulk_read: enable bulk-reads + * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc) + * @rw_incompat: the media is not R/W compatible + * @assert_action: action to take when a ubifs_assert() fails + * @authenticated: flag indigating the FS is mounted in authenticated mode + * + * @tnc_mutex: protects the Tree Node Cache (TNC), @zroot, @cnext, @enext, and + * @calc_idx_sz + * @zroot: zbranch which points to the root index node and znode + * @cnext: next znode to commit + * @enext: next znode to commit to empty space + * @gap_lebs: array of LEBs used by the in-gaps commit method + * @cbuf: commit buffer + * @ileb_buf: buffer for commit in-the-gaps method + * @ileb_len: length of data in ileb_buf + * @ihead_lnum: LEB number of index head + * @ihead_offs: offset of index head + * @ilebs: pre-allocated index LEBs + * @ileb_cnt: number of pre-allocated index LEBs + * @ileb_nxt: next pre-allocated index LEBs + * @old_idx: tree of index nodes obsoleted since the last commit start + * @bottom_up_buf: a buffer which is used by 'dirty_cow_bottom_up()' in tnc.c + * + * @mst_node: master node + * @mst_offs: offset of valid master node + * + * @max_bu_buf_len: maximum bulk-read buffer length + * @bu_mutex: protects the pre-allocated bulk-read buffer and @c->bu + * @bu: pre-allocated bulk-read information + * + * @write_reserve_mutex: protects @write_reserve_buf + * @write_reserve_buf: on the write path we allocate memory, which might + * sometimes be unavailable, in which case we use this + * write reserve buffer + * + * @log_lebs: number of logical eraseblocks in the log + * @log_bytes: log size in bytes + * @log_last: last LEB of the log + * @lpt_lebs: number of LEBs used for lprops table + * @lpt_first: first LEB of the lprops table area + * @lpt_last: last LEB of the lprops table area + * @orph_lebs: number of LEBs used for the orphan area + * @orph_first: first LEB of the orphan area + * @orph_last: last LEB of the orphan area + * @main_lebs: count of LEBs in the main area + * @main_first: first LEB of the main area + * @main_bytes: main area size in bytes + * + * @key_hash_type: type of the key hash + * @key_hash: direntry key hash function + * @key_fmt: key format + * @key_len: key length + * @hash_len: The length of the index node hashes + * @fanout: fanout of the index tree (number of links per indexing node) + * + * @min_io_size: minimal input/output unit size + * @min_io_shift: number of bits in @min_io_size minus one + * @max_write_size: maximum amount of bytes the underlying flash can write at a + * time (MTD write buffer size) + * @max_write_shift: number of bits in @max_write_size minus one + * @leb_size: logical eraseblock size in bytes + * @leb_start: starting offset of logical eraseblocks within physical + * eraseblocks + * @half_leb_size: half LEB size + * @idx_leb_size: how many bytes of an LEB are effectively available when it is + * used to store indexing nodes (@leb_size - @max_idx_node_sz) + * @leb_cnt: count of logical eraseblocks + * @max_leb_cnt: maximum count of logical eraseblocks + * @ro_media: the underlying UBI volume is read-only + * @ro_mount: the file-system was mounted as read-only + * @ro_error: UBIFS switched to R/O mode because an error happened + * + * @dirty_pg_cnt: number of dirty pages (not used) + * @dirty_zn_cnt: number of dirty znodes + * @clean_zn_cnt: number of clean znodes + * + * @space_lock: protects @bi and @lst + * @lst: lprops statistics + * @bi: budgeting information + * @calc_idx_sz: temporary variable which is used to calculate new index size + * (contains accurate new index size at end of TNC commit start) + * + * @ref_node_alsz: size of the LEB reference node aligned to the min. flash + * I/O unit + * @mst_node_alsz: master node aligned size + * @min_idx_node_sz: minimum indexing node aligned on 8-bytes boundary + * @max_idx_node_sz: maximum indexing node aligned on 8-bytes boundary + * @max_inode_sz: maximum possible inode size in bytes + * @max_znode_sz: size of znode in bytes + * + * @leb_overhead: how many bytes are wasted in an LEB when it is filled with + * data nodes of maximum size - used in free space reporting + * @dead_wm: LEB dead space watermark + * @dark_wm: LEB dark space watermark + * @block_cnt: count of 4KiB blocks on the FS + * + * @ranges: UBIFS node length ranges + * @ubi: UBI volume descriptor + * @di: UBI device information + * @vi: UBI volume information + * + * @orph_tree: rb-tree of orphan inode numbers + * @orph_list: list of orphan inode numbers in order added + * @orph_new: list of orphan inode numbers added since last commit + * @orph_cnext: next orphan to commit + * @orph_dnext: next orphan to delete + * @orphan_lock: lock for orph_tree and orph_new + * @orph_buf: buffer for orphan nodes + * @new_orphans: number of orphans since last commit + * @cmt_orphans: number of orphans being committed + * @tot_orphans: number of orphans in the rb_tree + * @max_orphans: maximum number of orphans allowed + * @ohead_lnum: orphan head LEB number + * @ohead_offs: orphan head offset + * @no_orphs: non-zero if there are no orphans + * + * @bgt: UBIFS background thread + * @bgt_name: background thread name + * @need_bgt: if background thread should run + * @need_wbuf_sync: if write-buffers have to be synchronized + * + * @gc_lnum: LEB number used for garbage collection + * @sbuf: a buffer of LEB size used by GC and replay for scanning + * @idx_gc: list of index LEBs that have been garbage collected + * @idx_gc_cnt: number of elements on the idx_gc list + * @gc_seq: incremented for every non-index LEB garbage collected + * @gced_lnum: last non-index LEB that was garbage collected + * + * @infos_list: links all 'ubifs_info' objects + * @umount_mutex: serializes shrinker and un-mount + * @shrinker_run_no: shrinker run number + * + * @space_bits: number of bits needed to record free or dirty space + * @lpt_lnum_bits: number of bits needed to record a LEB number in the LPT + * @lpt_offs_bits: number of bits needed to record an offset in the LPT + * @lpt_spc_bits: number of bits needed to space in the LPT + * @pcnt_bits: number of bits needed to record pnode or nnode number + * @lnum_bits: number of bits needed to record LEB number + * @nnode_sz: size of on-flash nnode + * @pnode_sz: size of on-flash pnode + * @ltab_sz: size of on-flash LPT lprops table + * @lsave_sz: size of on-flash LPT save table + * @pnode_cnt: number of pnodes + * @nnode_cnt: number of nnodes + * @lpt_hght: height of the LPT + * @pnodes_have: number of pnodes in memory + * + * @lp_mutex: protects lprops table and all the other lprops-related fields + * @lpt_lnum: LEB number of the root nnode of the LPT + * @lpt_offs: offset of the root nnode of the LPT + * @nhead_lnum: LEB number of LPT head + * @nhead_offs: offset of LPT head + * @lpt_drty_flgs: dirty flags for LPT special nodes e.g. ltab + * @dirty_nn_cnt: number of dirty nnodes + * @dirty_pn_cnt: number of dirty pnodes + * @check_lpt_free: flag that indicates LPT GC may be needed + * @lpt_sz: LPT size + * @lpt_nod_buf: buffer for an on-flash nnode or pnode + * @lpt_buf: buffer of LEB size used by LPT + * @nroot: address in memory of the root nnode of the LPT + * @lpt_cnext: next LPT node to commit + * @lpt_heap: array of heaps of categorized lprops + * @dirty_idx: a (reverse sorted) copy of the LPROPS_DIRTY_IDX heap as at + * previous commit start + * @uncat_list: list of un-categorized LEBs + * @empty_list: list of empty LEBs + * @freeable_list: list of freeable non-index LEBs (free + dirty == @leb_size) + * @frdi_idx_list: list of freeable index LEBs (free + dirty == @leb_size) + * @freeable_cnt: number of freeable LEBs in @freeable_list + * @in_a_category_cnt: count of lprops which are in a certain category, which + * basically meants that they were loaded from the flash + * + * @ltab_lnum: LEB number of LPT's own lprops table + * @ltab_offs: offset of LPT's own lprops table + * @ltab: LPT's own lprops table + * @ltab_cmt: LPT's own lprops table (commit copy) + * @lsave_cnt: number of LEB numbers in LPT's save table + * @lsave_lnum: LEB number of LPT's save table + * @lsave_offs: offset of LPT's save table + * @lsave: LPT's save table + * @lscan_lnum: LEB number of last LPT scan + * + * @rp_size: size of the reserved pool in bytes + * @report_rp_size: size of the reserved pool reported to user-space + * @rp_uid: reserved pool user ID + * @rp_gid: reserved pool group ID + * + * @hash_tfm: the hash transformation used for hashing nodes + * @hmac_tfm: the HMAC transformation for this filesystem + * @hmac_desc_len: length of the HMAC used for authentication + * @auth_key_name: the authentication key name + * @auth_hash_name: the name of the hash algorithm used for authentication + * @auth_hash_algo: the authentication hash used for this fs + * @log_hash: the log hash from the commit start node up to the latest reference + * node. + * + * @empty: %1 if the UBI device is empty + * @need_recovery: %1 if the file-system needs recovery + * @replaying: %1 during journal replay + * @mounting: %1 while mounting + * @probing: %1 while attempting to mount if SB_SILENT mount flag is set + * @remounting_rw: %1 while re-mounting from R/O mode to R/W mode + * @replay_list: temporary list used during journal replay + * @replay_buds: list of buds to replay + * @cs_sqnum: sequence number of first node in the log (commit start node) + * @unclean_leb_list: LEBs to recover when re-mounting R/O mounted FS to R/W + * mode + * @rcvrd_mst_node: recovered master node to write when re-mounting R/O mounted + * FS to R/W mode + * @size_tree: inode size information for recovery + * @mount_opts: UBIFS-specific mount options + * + * @dbg: debugging-related information + */ +struct ubifs_info { + struct super_block *vfs_sb; + struct ubifs_sb_node *sup_node; + + ino_t highest_inum; + unsigned long long max_sqnum; + unsigned long long cmt_no; + spinlock_t cnt_lock; + int fmt_version; + int ro_compat_version; + unsigned char uuid[16]; + + int lhead_lnum; + int lhead_offs; + int ltail_lnum; + struct mutex log_mutex; + int min_log_bytes; + long long cmt_bud_bytes; + + struct rb_root buds; + long long bud_bytes; + spinlock_t buds_lock; + int jhead_cnt; + struct ubifs_jhead *jheads; + long long max_bud_bytes; + long long bg_bud_bytes; + struct list_head old_buds; + int max_bud_cnt; + + struct rw_semaphore commit_sem; + int cmt_state; + spinlock_t cs_lock; + wait_queue_head_t cmt_wq; + + unsigned int big_lpt:1; + unsigned int space_fixup:1; + unsigned int double_hash:1; + unsigned int encrypted:1; + unsigned int no_chk_data_crc:1; + unsigned int bulk_read:1; + unsigned int default_compr:2; + unsigned int rw_incompat:1; + unsigned int assert_action:2; + unsigned int authenticated:1; + unsigned int superblock_need_write:1; + + struct mutex tnc_mutex; + struct ubifs_zbranch zroot; + struct ubifs_znode *cnext; + struct ubifs_znode *enext; + int *gap_lebs; + void *cbuf; + void *ileb_buf; + int ileb_len; + int ihead_lnum; + int ihead_offs; + int *ilebs; + int ileb_cnt; + int ileb_nxt; + struct rb_root old_idx; + int *bottom_up_buf; + + struct ubifs_mst_node *mst_node; + int mst_offs; + + int max_bu_buf_len; + struct mutex bu_mutex; + struct bu_info bu; + + struct mutex write_reserve_mutex; + void *write_reserve_buf; + + int log_lebs; + long long log_bytes; + int log_last; + int lpt_lebs; + int lpt_first; + int lpt_last; + int orph_lebs; + int orph_first; + int orph_last; + int main_lebs; + int main_first; + long long main_bytes; + + uint8_t key_hash_type; + uint32_t (*key_hash)(const char *str, int len); + int key_fmt; + int key_len; + int hash_len; + int fanout; + + int min_io_size; + int min_io_shift; + int max_write_size; + int max_write_shift; + int leb_size; + int leb_start; + int half_leb_size; + int idx_leb_size; + int leb_cnt; + int max_leb_cnt; + unsigned int ro_media:1; + unsigned int ro_mount:1; + unsigned int ro_error:1; + + atomic_long_t dirty_pg_cnt; + atomic_long_t dirty_zn_cnt; + atomic_long_t clean_zn_cnt; + + spinlock_t space_lock; + struct ubifs_lp_stats lst; + struct ubifs_budg_info bi; + unsigned long long calc_idx_sz; + + int ref_node_alsz; + int mst_node_alsz; + int min_idx_node_sz; + int max_idx_node_sz; + long long max_inode_sz; + int max_znode_sz; + + int leb_overhead; + int dead_wm; + int dark_wm; + int block_cnt; + + struct ubifs_node_range ranges[UBIFS_NODE_TYPES_CNT]; + struct ubi_volume_desc *ubi; + struct ubi_device_info di; + struct ubi_volume_info vi; + + struct rb_root orph_tree; + struct list_head orph_list; + struct list_head orph_new; + struct ubifs_orphan *orph_cnext; + struct ubifs_orphan *orph_dnext; + spinlock_t orphan_lock; + void *orph_buf; + int new_orphans; + int cmt_orphans; + int tot_orphans; + int max_orphans; + int ohead_lnum; + int ohead_offs; + int no_orphs; + + struct task_struct *bgt; + char bgt_name[sizeof(BGT_NAME_PATTERN) + 9]; + int need_bgt; + int need_wbuf_sync; + + int gc_lnum; + void *sbuf; + struct list_head idx_gc; + int idx_gc_cnt; + int gc_seq; + int gced_lnum; + + struct list_head infos_list; + struct mutex umount_mutex; + unsigned int shrinker_run_no; + + int space_bits; + int lpt_lnum_bits; + int lpt_offs_bits; + int lpt_spc_bits; + int pcnt_bits; + int lnum_bits; + int nnode_sz; + int pnode_sz; + int ltab_sz; + int lsave_sz; + int pnode_cnt; + int nnode_cnt; + int lpt_hght; + int pnodes_have; + + struct mutex lp_mutex; + int lpt_lnum; + int lpt_offs; + int nhead_lnum; + int nhead_offs; + int lpt_drty_flgs; + int dirty_nn_cnt; + int dirty_pn_cnt; + int check_lpt_free; + long long lpt_sz; + void *lpt_nod_buf; + void *lpt_buf; + struct ubifs_nnode *nroot; + struct ubifs_cnode *lpt_cnext; + struct ubifs_lpt_heap lpt_heap[LPROPS_HEAP_CNT]; + struct ubifs_lpt_heap dirty_idx; + struct list_head uncat_list; + struct list_head empty_list; + struct list_head freeable_list; + struct list_head frdi_idx_list; + int freeable_cnt; + int in_a_category_cnt; + + int ltab_lnum; + int ltab_offs; + struct ubifs_lpt_lprops *ltab; + struct ubifs_lpt_lprops *ltab_cmt; + int lsave_cnt; + int lsave_lnum; + int lsave_offs; + int *lsave; + int lscan_lnum; + + long long rp_size; + long long report_rp_size; + kuid_t rp_uid; + kgid_t rp_gid; + + struct crypto_shash *hash_tfm; + struct crypto_shash *hmac_tfm; + int hmac_desc_len; + char *auth_key_name; + char *auth_hash_name; + enum hash_algo auth_hash_algo; + + struct shash_desc *log_hash; + + /* The below fields are used only during mounting and re-mounting */ + unsigned int empty:1; + unsigned int need_recovery:1; + unsigned int replaying:1; + unsigned int mounting:1; + unsigned int remounting_rw:1; + unsigned int probing:1; + struct list_head replay_list; + struct list_head replay_buds; + unsigned long long cs_sqnum; + struct list_head unclean_leb_list; + struct ubifs_mst_node *rcvrd_mst_node; + struct rb_root size_tree; + struct ubifs_mount_opts mount_opts; + + struct ubifs_debug_info *dbg; +}; + +extern struct list_head ubifs_infos; +extern spinlock_t ubifs_infos_lock; +extern atomic_long_t ubifs_clean_zn_cnt; +extern const struct super_operations ubifs_super_operations; +extern const struct address_space_operations ubifs_file_address_operations; +extern const struct file_operations ubifs_file_operations; +extern const struct inode_operations ubifs_file_inode_operations; +extern const struct file_operations ubifs_dir_operations; +extern const struct inode_operations ubifs_dir_inode_operations; +extern const struct inode_operations ubifs_symlink_inode_operations; +extern struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT]; +extern int ubifs_default_version; + +/* auth.c */ +static inline int ubifs_authenticated(const struct ubifs_info *c) +{ + return (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) && c->authenticated; +} + +struct shash_desc *__ubifs_hash_get_desc(const struct ubifs_info *c); +static inline struct shash_desc *ubifs_hash_get_desc(const struct ubifs_info *c) +{ + return ubifs_authenticated(c) ? __ubifs_hash_get_desc(c) : NULL; +} + +static inline int ubifs_shash_init(const struct ubifs_info *c, + struct shash_desc *desc) +{ + if (ubifs_authenticated(c)) + return crypto_shash_init(desc); + else + return 0; +} + +static inline int ubifs_shash_update(const struct ubifs_info *c, + struct shash_desc *desc, const void *buf, + unsigned int len) +{ + int err = 0; + + if (ubifs_authenticated(c)) { + err = crypto_shash_update(desc, buf, len); + if (err < 0) + return err; + } + + return 0; +} + +static inline int ubifs_shash_final(const struct ubifs_info *c, + struct shash_desc *desc, u8 *out) +{ + return ubifs_authenticated(c) ? crypto_shash_final(desc, out) : 0; +} + +int __ubifs_node_calc_hash(const struct ubifs_info *c, const void *buf, + u8 *hash); +static inline int ubifs_node_calc_hash(const struct ubifs_info *c, + const void *buf, u8 *hash) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_calc_hash(c, buf, hash); + else + return 0; +} + +int ubifs_prepare_auth_node(struct ubifs_info *c, void *node, + struct shash_desc *inhash); + +/** + * ubifs_check_hash - compare two hashes + * @c: UBIFS file-system description object + * @expected: first hash + * @got: second hash + * + * Compare two hashes @expected and @got. Returns 0 when they are equal, a + * negative error code otherwise. + */ +static inline int ubifs_check_hash(const struct ubifs_info *c, + const u8 *expected, const u8 *got) +{ + return crypto_memneq(expected, got, c->hash_len); +} + +/** + * ubifs_check_hmac - compare two HMACs + * @c: UBIFS file-system description object + * @expected: first HMAC + * @got: second HMAC + * + * Compare two hashes @expected and @got. Returns 0 when they are equal, a + * negative error code otherwise. + */ +static inline int ubifs_check_hmac(const struct ubifs_info *c, + const u8 *expected, const u8 *got) +{ + return crypto_memneq(expected, got, c->hmac_desc_len); +} + +#ifdef CONFIG_UBIFS_FS_AUTHENTICATION +void ubifs_bad_hash(const struct ubifs_info *c, const void *node, + const u8 *hash, int lnum, int offs); +#else +static inline void ubifs_bad_hash(const struct ubifs_info *c, const void *node, + const u8 *hash, int lnum, int offs) {}; +#endif + +int __ubifs_node_check_hash(const struct ubifs_info *c, const void *buf, + const u8 *expected); +static inline int ubifs_node_check_hash(const struct ubifs_info *c, + const void *buf, const u8 *expected) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_check_hash(c, buf, expected); + else + return 0; +} + +int ubifs_init_authentication(struct ubifs_info *c); +void __ubifs_exit_authentication(struct ubifs_info *c); +static inline void ubifs_exit_authentication(struct ubifs_info *c) +{ + if (ubifs_authenticated(c)) + __ubifs_exit_authentication(c); +} + +/** + * ubifs_branch_hash - returns a pointer to the hash of a branch + * @c: UBIFS file-system description object + * @br: branch to get the hash from + * + * This returns a pointer to the hash of a branch. Since the key already is a + * dynamically sized object we cannot use a struct member here. + */ +static inline u8 *ubifs_branch_hash(struct ubifs_info *c, + struct ubifs_branch *br) +{ + return (void *)br + sizeof(*br) + c->key_len; +} + +/** + * ubifs_copy_hash - copy a hash + * @c: UBIFS file-system description object + * @from: source hash + * @to: destination hash + * + * With authentication this copies a hash, otherwise does nothing. + */ +static inline void ubifs_copy_hash(const struct ubifs_info *c, const u8 *from, + u8 *to) +{ + if (ubifs_authenticated(c)) + memcpy(to, from, c->hash_len); +} + +int __ubifs_node_insert_hmac(const struct ubifs_info *c, void *buf, + int len, int ofs_hmac); +static inline int ubifs_node_insert_hmac(const struct ubifs_info *c, void *buf, + int len, int ofs_hmac) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_insert_hmac(c, buf, len, ofs_hmac); + else + return 0; +} + +int __ubifs_node_verify_hmac(const struct ubifs_info *c, const void *buf, + int len, int ofs_hmac); +static inline int ubifs_node_verify_hmac(const struct ubifs_info *c, + const void *buf, int len, int ofs_hmac) +{ + if (ubifs_authenticated(c)) + return __ubifs_node_verify_hmac(c, buf, len, ofs_hmac); + else + return 0; +} + +/** + * ubifs_auth_node_sz - returns the size of an authentication node + * @c: UBIFS file-system description object + * + * This function returns the size of an authentication node which can + * be 0 for unauthenticated filesystems or the real size of an auth node + * authentication is enabled. + */ +static inline int ubifs_auth_node_sz(const struct ubifs_info *c) +{ + if (ubifs_authenticated(c)) + return sizeof(struct ubifs_auth_node) + c->hmac_desc_len; + else + return 0; +} +int ubifs_sb_verify_signature(struct ubifs_info *c, + const struct ubifs_sb_node *sup); +bool ubifs_hmac_zero(struct ubifs_info *c, const u8 *hmac); + +int ubifs_hmac_wkm(struct ubifs_info *c, u8 *hmac); + +int __ubifs_shash_copy_state(const struct ubifs_info *c, struct shash_desc *src, + struct shash_desc *target); +static inline int ubifs_shash_copy_state(const struct ubifs_info *c, + struct shash_desc *src, + struct shash_desc *target) +{ + if (ubifs_authenticated(c)) + return __ubifs_shash_copy_state(c, src, target); + else + return 0; +} + +/* io.c */ +void ubifs_ro_mode(struct ubifs_info *c, int err); +int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, + int len, int even_ebadmsg); +int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, + int len); +int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len); +int ubifs_leb_unmap(struct ubifs_info *c, int lnum); +int ubifs_leb_map(struct ubifs_info *c, int lnum); +int ubifs_is_mapped(const struct ubifs_info *c, int lnum); +int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len); +int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs); +int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf); +int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, + int lnum, int offs); +int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, + int lnum, int offs); +int ubifs_write_node(struct ubifs_info *c, void *node, int len, int lnum, + int offs); +int ubifs_write_node_hmac(struct ubifs_info *c, void *buf, int len, int lnum, + int offs, int hmac_offs); +int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, + int offs, int quiet, int must_chk_crc); +void ubifs_init_node(struct ubifs_info *c, void *buf, int len, int pad); +void ubifs_crc_node(struct ubifs_info *c, void *buf, int len); +void ubifs_prepare_node(struct ubifs_info *c, void *buf, int len, int pad); +int ubifs_prepare_node_hmac(struct ubifs_info *c, void *node, int len, + int hmac_offs, int pad); +void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last); +int ubifs_io_init(struct ubifs_info *c); +void ubifs_pad(const struct ubifs_info *c, void *buf, int pad); +int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf); +int ubifs_bg_wbufs_sync(struct ubifs_info *c); +void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum); +int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode); + +/* scan.c */ +struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum, + int offs, void *sbuf, int quiet); +void ubifs_scan_destroy(struct ubifs_scan_leb *sleb); +int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum, + int offs, int quiet); +struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum, + int offs, void *sbuf); +void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb, + int lnum, int offs); +int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb, + void *buf, int offs); +void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs, + void *buf); + +/* log.c */ +void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud); +void ubifs_create_buds_lists(struct ubifs_info *c); +int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs); +struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum); +struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum); +int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum); +int ubifs_log_end_commit(struct ubifs_info *c, int new_ltail_lnum); +int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum); +int ubifs_consolidate_log(struct ubifs_info *c); + +/* journal.c */ +int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, + const struct fscrypt_name *nm, const struct inode *inode, + int deletion, int xent); +int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, + const union ubifs_key *key, const void *buf, int len); +int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode); +int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode); +int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, + const struct inode *fst_inode, + const struct fscrypt_name *fst_nm, + const struct inode *snd_dir, + const struct inode *snd_inode, + const struct fscrypt_name *snd_nm, int sync); +int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, + const struct inode *old_inode, + const struct fscrypt_name *old_nm, + const struct inode *new_dir, + const struct inode *new_inode, + const struct fscrypt_name *new_nm, + const struct inode *whiteout, int sync); +int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode, + loff_t old_size, loff_t new_size); +int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host, + const struct inode *inode, const struct fscrypt_name *nm); +int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode1, + const struct inode *inode2); + +/* budget.c */ +int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req); +void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req); +void ubifs_release_dirty_inode_budget(struct ubifs_info *c, + struct ubifs_inode *ui); +int ubifs_budget_inode_op(struct ubifs_info *c, struct inode *inode, + struct ubifs_budget_req *req); +void ubifs_release_ino_dirty(struct ubifs_info *c, struct inode *inode, + struct ubifs_budget_req *req); +void ubifs_cancel_ino_op(struct ubifs_info *c, struct inode *inode, + struct ubifs_budget_req *req); +long long ubifs_get_free_space(struct ubifs_info *c); +long long ubifs_get_free_space_nolock(struct ubifs_info *c); +int ubifs_calc_min_idx_lebs(struct ubifs_info *c); +void ubifs_convert_page_budget(struct ubifs_info *c); +long long ubifs_reported_space(const struct ubifs_info *c, long long free); +long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs); + +/* find.c */ +int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs, + int squeeze); +int ubifs_find_free_leb_for_idx(struct ubifs_info *c); +int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp, + int min_space, int pick_free); +int ubifs_find_dirty_idx_leb(struct ubifs_info *c); +int ubifs_save_dirty_idx_lnums(struct ubifs_info *c); + +/* tnc.c */ +int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key, + struct ubifs_znode **zn, int *n); +int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, + void *node, const struct fscrypt_name *nm); +int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, + void *node, uint32_t secondary_hash); +int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key, + void *node, int *lnum, int *offs); +int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum, + int offs, int len, const u8 *hash); +int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key, + int old_lnum, int old_offs, int lnum, int offs, int len); +int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, + int lnum, int offs, int len, const u8 *hash, + const struct fscrypt_name *nm); +int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key); +int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, + const struct fscrypt_name *nm); +int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key, + uint32_t cookie); +int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, + union ubifs_key *to_key); +int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum); +struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c, + union ubifs_key *key, + const struct fscrypt_name *nm); +void ubifs_tnc_close(struct ubifs_info *c); +int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level, + int lnum, int offs, int is_idx); +int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level, + int lnum, int offs); +/* Shared by tnc.c for tnc_commit.c */ +void destroy_old_idx(struct ubifs_info *c); +int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level, + int lnum, int offs); +int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode); +int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu); +int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu); + +/* tnc_misc.c */ +struct ubifs_znode *ubifs_tnc_levelorder_next(const struct ubifs_info *c, + struct ubifs_znode *zr, + struct ubifs_znode *znode); +int ubifs_search_zbranch(const struct ubifs_info *c, + const struct ubifs_znode *znode, + const union ubifs_key *key, int *n); +struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode); +struct ubifs_znode *ubifs_tnc_postorder_next(const struct ubifs_info *c, + struct ubifs_znode *znode); +long ubifs_destroy_tnc_subtree(const struct ubifs_info *c, + struct ubifs_znode *zr); +struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c, + struct ubifs_zbranch *zbr, + struct ubifs_znode *parent, int iip); +int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr, + void *node); + +/* tnc_commit.c */ +int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot); +int ubifs_tnc_end_commit(struct ubifs_info *c); + +/* shrinker.c */ +unsigned long ubifs_shrink_scan(struct shrinker *shrink, + struct shrink_control *sc); +unsigned long ubifs_shrink_count(struct shrinker *shrink, + struct shrink_control *sc); + +/* commit.c */ +int ubifs_bg_thread(void *info); +void ubifs_commit_required(struct ubifs_info *c); +void ubifs_request_bg_commit(struct ubifs_info *c); +int ubifs_run_commit(struct ubifs_info *c); +void ubifs_recovery_commit(struct ubifs_info *c); +int ubifs_gc_should_commit(struct ubifs_info *c); +void ubifs_wait_for_commit(struct ubifs_info *c); + +/* master.c */ +int ubifs_compare_master_node(struct ubifs_info *c, void *m1, void *m2); +int ubifs_read_master(struct ubifs_info *c); +int ubifs_write_master(struct ubifs_info *c); + +/* sb.c */ +int ubifs_read_superblock(struct ubifs_info *c); +int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup); +int ubifs_fixup_free_space(struct ubifs_info *c); +int ubifs_enable_encryption(struct ubifs_info *c); + +/* replay.c */ +int ubifs_validate_entry(struct ubifs_info *c, + const struct ubifs_dent_node *dent); +int ubifs_replay_journal(struct ubifs_info *c); + +/* gc.c */ +int ubifs_garbage_collect(struct ubifs_info *c, int anyway); +int ubifs_gc_start_commit(struct ubifs_info *c); +int ubifs_gc_end_commit(struct ubifs_info *c); +void ubifs_destroy_idx_gc(struct ubifs_info *c); +int ubifs_get_idx_gc_leb(struct ubifs_info *c); +int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp); + +/* orphan.c */ +int ubifs_add_orphan(struct ubifs_info *c, ino_t inum); +void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum); +int ubifs_orphan_start_commit(struct ubifs_info *c); +int ubifs_orphan_end_commit(struct ubifs_info *c); +int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only); +int ubifs_clear_orphans(struct ubifs_info *c); + +/* lpt.c */ +int ubifs_calc_lpt_geom(struct ubifs_info *c); +int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first, + int *lpt_lebs, int *big_lpt, u8 *hash); +int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr); +struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum); +struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum); +int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum, + ubifs_lpt_scan_callback scan_cb, void *data); + +/* Shared by lpt.c for lpt_commit.c */ +void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave); +void ubifs_pack_ltab(struct ubifs_info *c, void *buf, + struct ubifs_lpt_lprops *ltab); +void ubifs_pack_pnode(struct ubifs_info *c, void *buf, + struct ubifs_pnode *pnode); +void ubifs_pack_nnode(struct ubifs_info *c, void *buf, + struct ubifs_nnode *nnode); +struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c, + struct ubifs_nnode *parent, int iip); +struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c, + struct ubifs_nnode *parent, int iip); +struct ubifs_pnode *ubifs_pnode_lookup(struct ubifs_info *c, int i); +int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip); +void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty); +void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode); +uint32_t ubifs_unpack_bits(const struct ubifs_info *c, uint8_t **addr, int *pos, int nrbits); +struct ubifs_nnode *ubifs_first_nnode(struct ubifs_info *c, int *hght); +/* Needed only in debugging code in lpt_commit.c */ +int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf, + struct ubifs_nnode *nnode); +int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash); + +/* lpt_commit.c */ +int ubifs_lpt_start_commit(struct ubifs_info *c); +int ubifs_lpt_end_commit(struct ubifs_info *c); +int ubifs_lpt_post_commit(struct ubifs_info *c); +void ubifs_lpt_free(struct ubifs_info *c, int wr_only); + +/* lprops.c */ +const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c, + const struct ubifs_lprops *lp, + int free, int dirty, int flags, + int idx_gc_cnt); +void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst); +void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops, + int cat); +void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops, + struct ubifs_lprops *new_lprops); +void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops); +int ubifs_categorize_lprops(const struct ubifs_info *c, + const struct ubifs_lprops *lprops); +int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty, + int flags_set, int flags_clean, int idx_gc_cnt); +int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty, + int flags_set, int flags_clean); +int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp); +const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c); +const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c); +const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c); +const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c); +int ubifs_calc_dark(const struct ubifs_info *c, int spc); + +/* file.c */ +int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync); +int ubifs_setattr(struct dentry *dentry, struct iattr *attr); +int ubifs_update_time(struct inode *inode, struct timespec64 *time, int flags); + +/* dir.c */ +struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, + umode_t mode); +int ubifs_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int flags); +int ubifs_check_dir_empty(struct inode *dir); + +/* xattr.c */ +extern const struct xattr_handler *ubifs_xattr_handlers[]; +ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size); +int ubifs_xattr_set(struct inode *host, const char *name, const void *value, + size_t size, int flags, bool check_lock); +ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf, + size_t size); + +#ifdef CONFIG_UBIFS_FS_XATTR +void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum); +int ubifs_purge_xattrs(struct inode *host); +#else +static inline void ubifs_evict_xattr_inode(struct ubifs_info *c, + ino_t xattr_inum) { } +static inline int ubifs_purge_xattrs(struct inode *host) +{ + return 0; +} +#endif + +#ifdef CONFIG_UBIFS_FS_SECURITY +extern int ubifs_init_security(struct inode *dentry, struct inode *inode, + const struct qstr *qstr); +#else +static inline int ubifs_init_security(struct inode *dentry, + struct inode *inode, const struct qstr *qstr) +{ + return 0; +} +#endif + + +/* super.c */ +struct inode *ubifs_iget(struct super_block *sb, unsigned long inum); + +/* recovery.c */ +int ubifs_recover_master_node(struct ubifs_info *c); +int ubifs_write_rcvrd_mst_node(struct ubifs_info *c); +struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum, + int offs, void *sbuf, int jhead); +struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum, + int offs, void *sbuf); +int ubifs_recover_inl_heads(struct ubifs_info *c, void *sbuf); +int ubifs_clean_lebs(struct ubifs_info *c, void *sbuf); +int ubifs_rcvry_gc_commit(struct ubifs_info *c); +int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key, + int deletion, loff_t new_size); +int ubifs_recover_size(struct ubifs_info *c, bool in_place); +void ubifs_destroy_size_tree(struct ubifs_info *c); + +/* ioctl.c */ +long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg); +void ubifs_set_inode_flags(struct inode *inode); +#ifdef CONFIG_COMPAT +long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg); +#endif + +/* compressor.c */ +int __init ubifs_compressors_init(void); +void ubifs_compressors_exit(void); +void ubifs_compress(const struct ubifs_info *c, const void *in_buf, int in_len, + void *out_buf, int *out_len, int *compr_type); +int ubifs_decompress(const struct ubifs_info *c, const void *buf, int len, + void *out, int *out_len, int compr_type); + +#include "debug.h" +#include "misc.h" +#include "key.h" + +#ifndef CONFIG_FS_ENCRYPTION +static inline int ubifs_encrypt(const struct inode *inode, + struct ubifs_data_node *dn, + unsigned int in_len, unsigned int *out_len, + int block) +{ + struct ubifs_info *c = inode->i_sb->s_fs_info; + ubifs_assert(c, 0); + return -EOPNOTSUPP; +} +static inline int ubifs_decrypt(const struct inode *inode, + struct ubifs_data_node *dn, + unsigned int *out_len, int block) +{ + struct ubifs_info *c = inode->i_sb->s_fs_info; + ubifs_assert(c, 0); + return -EOPNOTSUPP; +} +#else +/* crypto.c */ +int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn, + unsigned int in_len, unsigned int *out_len, int block); +int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn, + unsigned int *out_len, int block); +#endif + +extern const struct fscrypt_operations ubifs_crypt_operations; + +/* Normal UBIFS messages */ +__printf(2, 3) +void ubifs_msg(const struct ubifs_info *c, const char *fmt, ...); +__printf(2, 3) +void ubifs_err(const struct ubifs_info *c, const char *fmt, ...); +__printf(2, 3) +void ubifs_warn(const struct ubifs_info *c, const char *fmt, ...); +/* + * A conditional variant of 'ubifs_err()' which doesn't output anything + * if probing (ie. SB_SILENT set). + */ +#define ubifs_errc(c, fmt, ...) \ +do { \ + if (!(c)->probing) \ + ubifs_err(c, fmt, ##__VA_ARGS__); \ +} while (0) + +#endif /* !__UBIFS_H__ */ diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c new file mode 100644 index 000000000..17745f546 --- /dev/null +++ b/fs/ubifs/xattr.c @@ -0,0 +1,748 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Artem Bityutskiy (Битюцкий Артём) + * Adrian Hunter + */ + +/* + * This file implements UBIFS extended attributes support. + * + * Extended attributes are implemented as regular inodes with attached data, + * which limits extended attribute size to UBIFS block size (4KiB). Names of + * extended attributes are described by extended attribute entries (xentries), + * which are almost identical to directory entries, but have different key type. + * + * In other words, the situation with extended attributes is very similar to + * directories. Indeed, any inode (but of course not xattr inodes) may have a + * number of associated xentries, just like directory inodes have associated + * directory entries. Extended attribute entries store the name of the extended + * attribute, the host inode number, and the extended attribute inode number. + * Similarly, direntries store the name, the parent and the target inode + * numbers. Thus, most of the common UBIFS mechanisms may be re-used for + * extended attributes. + * + * The number of extended attributes is not limited, but there is Linux + * limitation on the maximum possible size of the list of all extended + * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure + * the sum of all extended attribute names of the inode does not exceed that + * limit. + * + * Extended attributes are synchronous, which means they are written to the + * flash media synchronously and there is no write-back for extended attribute + * inodes. The extended attribute values are not stored in compressed form on + * the media. + * + * Since extended attributes are represented by regular inodes, they are cached + * in the VFS inode cache. The xentries are cached in the LNC cache (see + * tnc.c). + * + * ACL support is not implemented. + */ + +#include "ubifs.h" +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/xattr.h> + +/* + * Extended attribute type constants. + * + * USER_XATTR: user extended attribute ("user.*") + * TRUSTED_XATTR: trusted extended attribute ("trusted.*) + * SECURITY_XATTR: security extended attribute ("security.*") + */ +enum { + USER_XATTR, + TRUSTED_XATTR, + SECURITY_XATTR, +}; + +static const struct inode_operations empty_iops; +static const struct file_operations empty_fops; + +/** + * create_xattr - create an extended attribute. + * @c: UBIFS file-system description object + * @host: host inode + * @nm: extended attribute name + * @value: extended attribute value + * @size: size of extended attribute value + * + * This is a helper function which creates an extended attribute of name @nm + * and value @value for inode @host. The host inode is also updated on flash + * because the ctime and extended attribute accounting data changes. This + * function returns zero in case of success and a negative error code in case + * of failure. + */ +static int create_xattr(struct ubifs_info *c, struct inode *host, + const struct fscrypt_name *nm, const void *value, int size) +{ + int err, names_len; + struct inode *inode; + struct ubifs_inode *ui, *host_ui = ubifs_inode(host); + struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, + .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1, + .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; + + if (host_ui->xattr_cnt >= ubifs_xattr_max_cnt(c)) { + ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more", + host->i_ino, host_ui->xattr_cnt); + return -ENOSPC; + } + /* + * Linux limits the maximum size of the extended attribute names list + * to %XATTR_LIST_MAX. This means we should not allow creating more + * extended attributes if the name list becomes larger. This limitation + * is artificial for UBIFS, though. + */ + names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1; + if (names_len > XATTR_LIST_MAX) { + ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d", + host->i_ino, names_len, XATTR_LIST_MAX); + return -ENOSPC; + } + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_budg; + } + + /* Re-define all operations to be "nothing" */ + inode->i_mapping->a_ops = &empty_aops; + inode->i_op = &empty_iops; + inode->i_fop = &empty_fops; + + inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME; + ui = ubifs_inode(inode); + ui->xattr = 1; + ui->flags |= UBIFS_XATTR_FL; + ui->data = kmemdup(value, size, GFP_NOFS); + if (!ui->data) { + err = -ENOMEM; + goto out_free; + } + inode->i_size = ui->ui_size = size; + ui->data_len = size; + + mutex_lock(&host_ui->ui_mutex); + host->i_ctime = current_time(host); + host_ui->xattr_cnt += 1; + host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm)); + host_ui->xattr_size += CALC_XATTR_BYTES(size); + host_ui->xattr_names += fname_len(nm); + + /* + * We handle UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT here because we + * have to set the UBIFS_CRYPT_FL flag on the host inode. + * To avoid multiple updates of the same inode in the same operation, + * let's do it here. + */ + if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) + host_ui->flags |= UBIFS_CRYPT_FL; + + err = ubifs_jnl_update(c, host, nm, inode, 0, 1); + if (err) + goto out_cancel; + ubifs_set_inode_flags(host); + mutex_unlock(&host_ui->ui_mutex); + + ubifs_release_budget(c, &req); + insert_inode_hash(inode); + iput(inode); + return 0; + +out_cancel: + host_ui->xattr_cnt -= 1; + host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm)); + host_ui->xattr_size -= CALC_XATTR_BYTES(size); + host_ui->xattr_names -= fname_len(nm); + host_ui->flags &= ~UBIFS_CRYPT_FL; + mutex_unlock(&host_ui->ui_mutex); +out_free: + make_bad_inode(inode); + iput(inode); +out_budg: + ubifs_release_budget(c, &req); + return err; +} + +/** + * change_xattr - change an extended attribute. + * @c: UBIFS file-system description object + * @host: host inode + * @inode: extended attribute inode + * @value: extended attribute value + * @size: size of extended attribute value + * + * This helper function changes the value of extended attribute @inode with new + * data from @value. Returns zero in case of success and a negative error code + * in case of failure. + */ +static int change_xattr(struct ubifs_info *c, struct inode *host, + struct inode *inode, const void *value, int size) +{ + int err; + struct ubifs_inode *host_ui = ubifs_inode(host); + struct ubifs_inode *ui = ubifs_inode(inode); + void *buf = NULL; + int old_size; + struct ubifs_budget_req req = { .dirtied_ino = 2, + .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) }; + + ubifs_assert(c, ui->data_len == inode->i_size); + err = ubifs_budget_space(c, &req); + if (err) + return err; + + buf = kmemdup(value, size, GFP_NOFS); + if (!buf) { + err = -ENOMEM; + goto out_free; + } + mutex_lock(&ui->ui_mutex); + kfree(ui->data); + ui->data = buf; + inode->i_size = ui->ui_size = size; + old_size = ui->data_len; + ui->data_len = size; + mutex_unlock(&ui->ui_mutex); + + mutex_lock(&host_ui->ui_mutex); + host->i_ctime = current_time(host); + host_ui->xattr_size -= CALC_XATTR_BYTES(old_size); + host_ui->xattr_size += CALC_XATTR_BYTES(size); + + /* + * It is important to write the host inode after the xattr inode + * because if the host inode gets synchronized (via 'fsync()'), then + * the extended attribute inode gets synchronized, because it goes + * before the host inode in the write-buffer. + */ + err = ubifs_jnl_change_xattr(c, inode, host); + if (err) + goto out_cancel; + mutex_unlock(&host_ui->ui_mutex); + + ubifs_release_budget(c, &req); + return 0; + +out_cancel: + host_ui->xattr_size -= CALC_XATTR_BYTES(size); + host_ui->xattr_size += CALC_XATTR_BYTES(old_size); + mutex_unlock(&host_ui->ui_mutex); + make_bad_inode(inode); +out_free: + ubifs_release_budget(c, &req); + return err; +} + +static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum) +{ + struct inode *inode; + + inode = ubifs_iget(c->vfs_sb, inum); + if (IS_ERR(inode)) { + ubifs_err(c, "dead extended attribute entry, error %d", + (int)PTR_ERR(inode)); + return inode; + } + if (ubifs_inode(inode)->xattr) + return inode; + ubifs_err(c, "corrupt extended attribute entry"); + iput(inode); + return ERR_PTR(-EINVAL); +} + +int ubifs_xattr_set(struct inode *host, const char *name, const void *value, + size_t size, int flags, bool check_lock) +{ + struct inode *inode; + struct ubifs_info *c = host->i_sb->s_fs_info; + struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; + struct ubifs_dent_node *xent; + union ubifs_key key; + int err; + + if (check_lock) + ubifs_assert(c, inode_is_locked(host)); + + if (size > UBIFS_MAX_INO_DATA) + return -ERANGE; + + if (fname_len(&nm) > UBIFS_MAX_NLEN) + return -ENAMETOOLONG; + + xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); + if (!xent) + return -ENOMEM; + + down_write(&ubifs_inode(host)->xattr_sem); + /* + * The extended attribute entries are stored in LNC, so multiple + * look-ups do not involve reading the flash. + */ + xent_key_init(c, &key, host->i_ino, &nm); + err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); + if (err) { + if (err != -ENOENT) + goto out_free; + + if (flags & XATTR_REPLACE) + /* We are asked not to create the xattr */ + err = -ENODATA; + else + err = create_xattr(c, host, &nm, value, size); + goto out_free; + } + + if (flags & XATTR_CREATE) { + /* We are asked not to replace the xattr */ + err = -EEXIST; + goto out_free; + } + + inode = iget_xattr(c, le64_to_cpu(xent->inum)); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + err = change_xattr(c, host, inode, value, size); + iput(inode); + +out_free: + up_write(&ubifs_inode(host)->xattr_sem); + kfree(xent); + return err; +} + +ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf, + size_t size) +{ + struct inode *inode; + struct ubifs_info *c = host->i_sb->s_fs_info; + struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; + struct ubifs_inode *ui; + struct ubifs_dent_node *xent; + union ubifs_key key; + int err; + + if (fname_len(&nm) > UBIFS_MAX_NLEN) + return -ENAMETOOLONG; + + xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); + if (!xent) + return -ENOMEM; + + down_read(&ubifs_inode(host)->xattr_sem); + xent_key_init(c, &key, host->i_ino, &nm); + err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); + if (err) { + if (err == -ENOENT) + err = -ENODATA; + goto out_cleanup; + } + + inode = iget_xattr(c, le64_to_cpu(xent->inum)); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_cleanup; + } + + ui = ubifs_inode(inode); + ubifs_assert(c, inode->i_size == ui->data_len); + ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len); + + mutex_lock(&ui->ui_mutex); + if (buf) { + /* If @buf is %NULL we are supposed to return the length */ + if (ui->data_len > size) { + err = -ERANGE; + goto out_iput; + } + + memcpy(buf, ui->data, ui->data_len); + } + err = ui->data_len; + +out_iput: + mutex_unlock(&ui->ui_mutex); + iput(inode); +out_cleanup: + up_read(&ubifs_inode(host)->xattr_sem); + kfree(xent); + return err; +} + +static bool xattr_visible(const char *name) +{ + /* File encryption related xattrs are for internal use only */ + if (strcmp(name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) + return false; + + /* Show trusted namespace only for "power" users */ + if (strncmp(name, XATTR_TRUSTED_PREFIX, + XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN)) + return false; + + return true; +} + +ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size) +{ + union ubifs_key key; + struct inode *host = d_inode(dentry); + struct ubifs_info *c = host->i_sb->s_fs_info; + struct ubifs_inode *host_ui = ubifs_inode(host); + struct ubifs_dent_node *xent, *pxent = NULL; + int err, len, written = 0; + struct fscrypt_name nm = {0}; + + dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino, + dentry, size); + + down_read(&host_ui->xattr_sem); + len = host_ui->xattr_names + host_ui->xattr_cnt; + if (!buffer) { + /* + * We should return the minimum buffer size which will fit a + * null-terminated list of all the extended attribute names. + */ + err = len; + goto out_err; + } + + if (len > size) { + err = -ERANGE; + goto out_err; + } + + lowest_xent_key(c, &key, host->i_ino); + while (1) { + xent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(xent)) { + err = PTR_ERR(xent); + break; + } + + fname_name(&nm) = xent->name; + fname_len(&nm) = le16_to_cpu(xent->nlen); + + if (xattr_visible(xent->name)) { + memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1); + written += fname_len(&nm) + 1; + } + + kfree(pxent); + pxent = xent; + key_read(c, &xent->key, &key); + } + kfree(pxent); + up_read(&host_ui->xattr_sem); + + if (err != -ENOENT) { + ubifs_err(c, "cannot find next direntry, error %d", err); + return err; + } + + ubifs_assert(c, written <= size); + return written; + +out_err: + up_read(&host_ui->xattr_sem); + return err; +} + +static int remove_xattr(struct ubifs_info *c, struct inode *host, + struct inode *inode, const struct fscrypt_name *nm) +{ + int err; + struct ubifs_inode *host_ui = ubifs_inode(host); + struct ubifs_inode *ui = ubifs_inode(inode); + struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1, + .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; + + ubifs_assert(c, ui->data_len == inode->i_size); + + err = ubifs_budget_space(c, &req); + if (err) + return err; + + mutex_lock(&host_ui->ui_mutex); + host->i_ctime = current_time(host); + host_ui->xattr_cnt -= 1; + host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm)); + host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); + host_ui->xattr_names -= fname_len(nm); + + err = ubifs_jnl_delete_xattr(c, host, inode, nm); + if (err) + goto out_cancel; + mutex_unlock(&host_ui->ui_mutex); + + ubifs_release_budget(c, &req); + return 0; + +out_cancel: + host_ui->xattr_cnt += 1; + host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm)); + host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len); + host_ui->xattr_names += fname_len(nm); + mutex_unlock(&host_ui->ui_mutex); + ubifs_release_budget(c, &req); + make_bad_inode(inode); + return err; +} + +int ubifs_purge_xattrs(struct inode *host) +{ + union ubifs_key key; + struct ubifs_info *c = host->i_sb->s_fs_info; + struct ubifs_dent_node *xent, *pxent = NULL; + struct inode *xino; + struct fscrypt_name nm = {0}; + int err; + + if (ubifs_inode(host)->xattr_cnt <= ubifs_xattr_max_cnt(c)) + return 0; + + ubifs_warn(c, "inode %lu has too many xattrs, doing a non-atomic deletion", + host->i_ino); + + down_write(&ubifs_inode(host)->xattr_sem); + lowest_xent_key(c, &key, host->i_ino); + while (1) { + xent = ubifs_tnc_next_ent(c, &key, &nm); + if (IS_ERR(xent)) { + err = PTR_ERR(xent); + break; + } + + fname_name(&nm) = xent->name; + fname_len(&nm) = le16_to_cpu(xent->nlen); + + xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum)); + if (IS_ERR(xino)) { + err = PTR_ERR(xino); + ubifs_err(c, "dead directory entry '%s', error %d", + xent->name, err); + ubifs_ro_mode(c, err); + kfree(pxent); + kfree(xent); + goto out_err; + } + + ubifs_assert(c, ubifs_inode(xino)->xattr); + + clear_nlink(xino); + err = remove_xattr(c, host, xino, &nm); + if (err) { + kfree(pxent); + kfree(xent); + iput(xino); + ubifs_err(c, "cannot remove xattr, error %d", err); + goto out_err; + } + + iput(xino); + + kfree(pxent); + pxent = xent; + key_read(c, &xent->key, &key); + } + kfree(pxent); + up_write(&ubifs_inode(host)->xattr_sem); + + if (err != -ENOENT) { + ubifs_err(c, "cannot find next direntry, error %d", err); + return err; + } + + return 0; + +out_err: + up_write(&ubifs_inode(host)->xattr_sem); + return err; +} + +/** + * ubifs_evict_xattr_inode - Evict an xattr inode. + * @c: UBIFS file-system description object + * @xattr_inum: xattr inode number + * + * When an inode that hosts xattrs is being removed we have to make sure + * that cached inodes of the xattrs also get removed from the inode cache + * otherwise we'd waste memory. This function looks up an inode from the + * inode cache and clears the link counter such that iput() will evict + * the inode. + */ +void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum) +{ + struct inode *inode; + + inode = ilookup(c->vfs_sb, xattr_inum); + if (inode) { + clear_nlink(inode); + iput(inode); + } +} + +static int ubifs_xattr_remove(struct inode *host, const char *name) +{ + struct inode *inode; + struct ubifs_info *c = host->i_sb->s_fs_info; + struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; + struct ubifs_dent_node *xent; + union ubifs_key key; + int err; + + ubifs_assert(c, inode_is_locked(host)); + + if (fname_len(&nm) > UBIFS_MAX_NLEN) + return -ENAMETOOLONG; + + xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); + if (!xent) + return -ENOMEM; + + down_write(&ubifs_inode(host)->xattr_sem); + xent_key_init(c, &key, host->i_ino, &nm); + err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); + if (err) { + if (err == -ENOENT) + err = -ENODATA; + goto out_free; + } + + inode = iget_xattr(c, le64_to_cpu(xent->inum)); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + ubifs_assert(c, inode->i_nlink == 1); + clear_nlink(inode); + err = remove_xattr(c, host, inode, &nm); + if (err) + set_nlink(inode, 1); + + /* If @i_nlink is 0, 'iput()' will delete the inode */ + iput(inode); + +out_free: + up_write(&ubifs_inode(host)->xattr_sem); + kfree(xent); + return err; +} + +#ifdef CONFIG_UBIFS_FS_SECURITY +static int init_xattrs(struct inode *inode, const struct xattr *xattr_array, + void *fs_info) +{ + const struct xattr *xattr; + char *name; + int err = 0; + + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + name = kmalloc(XATTR_SECURITY_PREFIX_LEN + + strlen(xattr->name) + 1, GFP_NOFS); + if (!name) { + err = -ENOMEM; + break; + } + strcpy(name, XATTR_SECURITY_PREFIX); + strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); + /* + * creating a new inode without holding the inode rwsem, + * no need to check whether inode is locked. + */ + err = ubifs_xattr_set(inode, name, xattr->value, + xattr->value_len, 0, false); + kfree(name); + if (err < 0) + break; + } + + return err; +} + +int ubifs_init_security(struct inode *dentry, struct inode *inode, + const struct qstr *qstr) +{ + int err; + + err = security_inode_init_security(inode, dentry, qstr, + &init_xattrs, 0); + if (err) { + struct ubifs_info *c = dentry->i_sb->s_fs_info; + ubifs_err(c, "cannot initialize security for inode %lu, error %d", + inode->i_ino, err); + } + return err; +} +#endif + +static int xattr_get(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, void *buffer, size_t size) +{ + dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name, + inode->i_ino, dentry, size); + + name = xattr_full_name(handler, name); + return ubifs_xattr_get(inode, name, buffer, size); +} + +static int xattr_set(const struct xattr_handler *handler, + struct dentry *dentry, struct inode *inode, + const char *name, const void *value, + size_t size, int flags) +{ + dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd", + name, inode->i_ino, dentry, size); + + name = xattr_full_name(handler, name); + + if (value) + return ubifs_xattr_set(inode, name, value, size, flags, true); + else + return ubifs_xattr_remove(inode, name); +} + +static const struct xattr_handler ubifs_user_xattr_handler = { + .prefix = XATTR_USER_PREFIX, + .get = xattr_get, + .set = xattr_set, +}; + +static const struct xattr_handler ubifs_trusted_xattr_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .get = xattr_get, + .set = xattr_set, +}; + +#ifdef CONFIG_UBIFS_FS_SECURITY +static const struct xattr_handler ubifs_security_xattr_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .get = xattr_get, + .set = xattr_set, +}; +#endif + +const struct xattr_handler *ubifs_xattr_handlers[] = { + &ubifs_user_xattr_handler, + &ubifs_trusted_xattr_handler, +#ifdef CONFIG_UBIFS_FS_SECURITY + &ubifs_security_xattr_handler, +#endif + NULL +}; |