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Diffstat (limited to 'fs/ubifs/replay.c')
| -rw-r--r-- | fs/ubifs/replay.c | 1118 |
1 files changed, 1118 insertions, 0 deletions
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c new file mode 100644 index 000000000..673d1f08b --- /dev/null +++ b/fs/ubifs/replay.c @@ -0,0 +1,1118 @@ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * 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> + +/** + * 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; + 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->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); + 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, struct list_head *a, + 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, + 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; + 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, + 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; + 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; +} + +/** + * 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; + 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); + + /* + * 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) { + int deletion = 0; + + cond_resched(); + + if (snod->sqnum >= SQNUM_WATERMARK) { + ubifs_err(c, "file system's life ended"); + goto out_dump; + } + + 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, + &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, + &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, + &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, + &key, snod->sqnum, 1, &used, + old_size, new_size); + 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; + } + + 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; + + 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) { + kfree(bud); + return -ENOMEM; + } + + bud->lnum = lnum; + bud->start = offs; + bud->jhead = jhead; + ubifs_add_bud(c, bud); + + b->bud = bud; + b->sqnum = sqnum; + list_add_tail(&b->list, &c->replay_buds); + + return 0; +} + +/** + * validate_ref - validate a reference node. + * @c: UBIFS file-system description object + * @ref: the reference node to validate + * @ref_lnum: LEB number of the reference node + * @ref_offs: reference node offset + * + * 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); + } + + 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 = 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; +} |