diff options
Diffstat (limited to 'fs/f2fs/dir.c')
| -rw-r--r-- | fs/f2fs/dir.c | 1143 |
1 files changed, 1143 insertions, 0 deletions
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c new file mode 100644 index 000000000..8aa29fe2e --- /dev/null +++ b/fs/f2fs/dir.c @@ -0,0 +1,1143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fs/f2fs/dir.c + * + * Copyright (c) 2012 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + */ +#include <asm/unaligned.h> +#include <linux/fs.h> +#include <linux/f2fs_fs.h> +#include <linux/sched/signal.h> +#include <linux/unicode.h> +#include "f2fs.h" +#include "node.h" +#include "acl.h" +#include "xattr.h" +#include <trace/events/f2fs.h> + +#if IS_ENABLED(CONFIG_UNICODE) +extern struct kmem_cache *f2fs_cf_name_slab; +#endif + +static unsigned long dir_blocks(struct inode *inode) +{ + return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1)) + >> PAGE_SHIFT; +} + +static unsigned int dir_buckets(unsigned int level, int dir_level) +{ + if (level + dir_level < MAX_DIR_HASH_DEPTH / 2) + return BIT(level + dir_level); + else + return MAX_DIR_BUCKETS; +} + +static unsigned int bucket_blocks(unsigned int level) +{ + if (level < MAX_DIR_HASH_DEPTH / 2) + return 2; + else + return 4; +} + +/* If @dir is casefolded, initialize @fname->cf_name from @fname->usr_fname. */ +int f2fs_init_casefolded_name(const struct inode *dir, + struct f2fs_filename *fname) +{ +#if IS_ENABLED(CONFIG_UNICODE) + struct super_block *sb = dir->i_sb; + + if (IS_CASEFOLDED(dir) && + !is_dot_dotdot(fname->usr_fname->name, fname->usr_fname->len)) { + fname->cf_name.name = f2fs_kmem_cache_alloc(f2fs_cf_name_slab, + GFP_NOFS, false, F2FS_SB(sb)); + if (!fname->cf_name.name) + return -ENOMEM; + fname->cf_name.len = utf8_casefold(sb->s_encoding, + fname->usr_fname, + fname->cf_name.name, + F2FS_NAME_LEN); + if ((int)fname->cf_name.len <= 0) { + kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name); + fname->cf_name.name = NULL; + if (sb_has_strict_encoding(sb)) + return -EINVAL; + /* fall back to treating name as opaque byte sequence */ + } + } +#endif + return 0; +} + +static int __f2fs_setup_filename(const struct inode *dir, + const struct fscrypt_name *crypt_name, + struct f2fs_filename *fname) +{ + int err; + + memset(fname, 0, sizeof(*fname)); + + fname->usr_fname = crypt_name->usr_fname; + fname->disk_name = crypt_name->disk_name; +#ifdef CONFIG_FS_ENCRYPTION + fname->crypto_buf = crypt_name->crypto_buf; +#endif + if (crypt_name->is_nokey_name) { + /* hash was decoded from the no-key name */ + fname->hash = cpu_to_le32(crypt_name->hash); + } else { + err = f2fs_init_casefolded_name(dir, fname); + if (err) { + f2fs_free_filename(fname); + return err; + } + f2fs_hash_filename(dir, fname); + } + return 0; +} + +/* + * Prepare to search for @iname in @dir. This is similar to + * fscrypt_setup_filename(), but this also handles computing the casefolded name + * and the f2fs dirhash if needed, then packing all the information about this + * filename up into a 'struct f2fs_filename'. + */ +int f2fs_setup_filename(struct inode *dir, const struct qstr *iname, + int lookup, struct f2fs_filename *fname) +{ + struct fscrypt_name crypt_name; + int err; + + err = fscrypt_setup_filename(dir, iname, lookup, &crypt_name); + if (err) + return err; + + return __f2fs_setup_filename(dir, &crypt_name, fname); +} + +/* + * Prepare to look up @dentry in @dir. This is similar to + * fscrypt_prepare_lookup(), but this also handles computing the casefolded name + * and the f2fs dirhash if needed, then packing all the information about this + * filename up into a 'struct f2fs_filename'. + */ +int f2fs_prepare_lookup(struct inode *dir, struct dentry *dentry, + struct f2fs_filename *fname) +{ + struct fscrypt_name crypt_name; + int err; + + err = fscrypt_prepare_lookup(dir, dentry, &crypt_name); + if (err) + return err; + + return __f2fs_setup_filename(dir, &crypt_name, fname); +} + +void f2fs_free_filename(struct f2fs_filename *fname) +{ +#ifdef CONFIG_FS_ENCRYPTION + kfree(fname->crypto_buf.name); + fname->crypto_buf.name = NULL; +#endif +#if IS_ENABLED(CONFIG_UNICODE) + if (fname->cf_name.name) { + kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name); + fname->cf_name.name = NULL; + } +#endif +} + +static unsigned long dir_block_index(unsigned int level, + int dir_level, unsigned int idx) +{ + unsigned long i; + unsigned long bidx = 0; + + for (i = 0; i < level; i++) + bidx += dir_buckets(i, dir_level) * bucket_blocks(i); + bidx += idx * bucket_blocks(level); + return bidx; +} + +static struct f2fs_dir_entry *find_in_block(struct inode *dir, + struct page *dentry_page, + const struct f2fs_filename *fname, + int *max_slots) +{ + struct f2fs_dentry_block *dentry_blk; + struct f2fs_dentry_ptr d; + + dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page); + + make_dentry_ptr_block(dir, &d, dentry_blk); + return f2fs_find_target_dentry(&d, fname, max_slots); +} + +#if IS_ENABLED(CONFIG_UNICODE) +/* + * Test whether a case-insensitive directory entry matches the filename + * being searched for. + * + * Returns 1 for a match, 0 for no match, and -errno on an error. + */ +static int f2fs_match_ci_name(const struct inode *dir, const struct qstr *name, + const u8 *de_name, u32 de_name_len) +{ + const struct super_block *sb = dir->i_sb; + const struct unicode_map *um = sb->s_encoding; + struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); + struct qstr entry = QSTR_INIT(de_name, de_name_len); + int res; + + if (IS_ENCRYPTED(dir)) { + const struct fscrypt_str encrypted_name = + FSTR_INIT((u8 *)de_name, de_name_len); + + if (WARN_ON_ONCE(!fscrypt_has_encryption_key(dir))) + return -EINVAL; + + decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); + if (!decrypted_name.name) + return -ENOMEM; + res = fscrypt_fname_disk_to_usr(dir, 0, 0, &encrypted_name, + &decrypted_name); + if (res < 0) + goto out; + entry.name = decrypted_name.name; + entry.len = decrypted_name.len; + } + + res = utf8_strncasecmp_folded(um, name, &entry); + /* + * In strict mode, ignore invalid names. In non-strict mode, + * fall back to treating them as opaque byte sequences. + */ + if (res < 0 && !sb_has_strict_encoding(sb)) { + res = name->len == entry.len && + memcmp(name->name, entry.name, name->len) == 0; + } else { + /* utf8_strncasecmp_folded returns 0 on match */ + res = (res == 0); + } +out: + kfree(decrypted_name.name); + return res; +} +#endif /* CONFIG_UNICODE */ + +static inline int f2fs_match_name(const struct inode *dir, + const struct f2fs_filename *fname, + const u8 *de_name, u32 de_name_len) +{ + struct fscrypt_name f; + +#if IS_ENABLED(CONFIG_UNICODE) + if (fname->cf_name.name) { + struct qstr cf = FSTR_TO_QSTR(&fname->cf_name); + + return f2fs_match_ci_name(dir, &cf, de_name, de_name_len); + } +#endif + f.usr_fname = fname->usr_fname; + f.disk_name = fname->disk_name; +#ifdef CONFIG_FS_ENCRYPTION + f.crypto_buf = fname->crypto_buf; +#endif + return fscrypt_match_name(&f, de_name, de_name_len); +} + +struct f2fs_dir_entry *f2fs_find_target_dentry(const struct f2fs_dentry_ptr *d, + const struct f2fs_filename *fname, int *max_slots) +{ + struct f2fs_dir_entry *de; + unsigned long bit_pos = 0; + int max_len = 0; + int res = 0; + + if (max_slots) + *max_slots = 0; + while (bit_pos < d->max) { + if (!test_bit_le(bit_pos, d->bitmap)) { + bit_pos++; + max_len++; + continue; + } + + de = &d->dentry[bit_pos]; + + if (unlikely(!de->name_len)) { + bit_pos++; + continue; + } + + if (de->hash_code == fname->hash) { + res = f2fs_match_name(d->inode, fname, + d->filename[bit_pos], + le16_to_cpu(de->name_len)); + if (res < 0) + return ERR_PTR(res); + if (res) + goto found; + } + + if (max_slots && max_len > *max_slots) + *max_slots = max_len; + max_len = 0; + + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + } + + de = NULL; +found: + if (max_slots && max_len > *max_slots) + *max_slots = max_len; + return de; +} + +static struct f2fs_dir_entry *find_in_level(struct inode *dir, + unsigned int level, + const struct f2fs_filename *fname, + struct page **res_page) +{ + int s = GET_DENTRY_SLOTS(fname->disk_name.len); + unsigned int nbucket, nblock; + unsigned int bidx, end_block; + struct page *dentry_page; + struct f2fs_dir_entry *de = NULL; + pgoff_t next_pgofs; + bool room = false; + int max_slots; + + nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); + nblock = bucket_blocks(level); + + bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, + le32_to_cpu(fname->hash) % nbucket); + end_block = bidx + nblock; + + while (bidx < end_block) { + /* no need to allocate new dentry pages to all the indices */ + dentry_page = f2fs_find_data_page(dir, bidx, &next_pgofs); + if (IS_ERR(dentry_page)) { + if (PTR_ERR(dentry_page) == -ENOENT) { + room = true; + bidx = next_pgofs; + continue; + } else { + *res_page = dentry_page; + break; + } + } + + de = find_in_block(dir, dentry_page, fname, &max_slots); + if (IS_ERR(de)) { + *res_page = ERR_CAST(de); + de = NULL; + break; + } else if (de) { + *res_page = dentry_page; + break; + } + + if (max_slots >= s) + room = true; + f2fs_put_page(dentry_page, 0); + + bidx++; + } + + if (!de && room && F2FS_I(dir)->chash != fname->hash) { + F2FS_I(dir)->chash = fname->hash; + F2FS_I(dir)->clevel = level; + } + + return de; +} + +struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, + const struct f2fs_filename *fname, + struct page **res_page) +{ + unsigned long npages = dir_blocks(dir); + struct f2fs_dir_entry *de = NULL; + unsigned int max_depth; + unsigned int level; + + *res_page = NULL; + + if (f2fs_has_inline_dentry(dir)) { + de = f2fs_find_in_inline_dir(dir, fname, res_page); + goto out; + } + + if (npages == 0) + goto out; + + max_depth = F2FS_I(dir)->i_current_depth; + if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) { + f2fs_warn(F2FS_I_SB(dir), "Corrupted max_depth of %lu: %u", + dir->i_ino, max_depth); + max_depth = MAX_DIR_HASH_DEPTH; + f2fs_i_depth_write(dir, max_depth); + } + + for (level = 0; level < max_depth; level++) { + de = find_in_level(dir, level, fname, res_page); + if (de || IS_ERR(*res_page)) + break; + } +out: + /* This is to increase the speed of f2fs_create */ + if (!de) + F2FS_I(dir)->task = current; + return de; +} + +/* + * Find an entry in the specified directory with the wanted name. + * It returns the page where the entry was found (as a parameter - res_page), + * and the entry itself. Page is returned mapped and unlocked. + * Entry is guaranteed to be valid. + */ +struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir, + const struct qstr *child, struct page **res_page) +{ + struct f2fs_dir_entry *de = NULL; + struct f2fs_filename fname; + int err; + + err = f2fs_setup_filename(dir, child, 1, &fname); + if (err) { + if (err == -ENOENT) + *res_page = NULL; + else + *res_page = ERR_PTR(err); + return NULL; + } + + de = __f2fs_find_entry(dir, &fname, res_page); + + f2fs_free_filename(&fname); + return de; +} + +struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p) +{ + return f2fs_find_entry(dir, &dotdot_name, p); +} + +ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr, + struct page **page) +{ + ino_t res = 0; + struct f2fs_dir_entry *de; + + de = f2fs_find_entry(dir, qstr, page); + if (de) { + res = le32_to_cpu(de->ino); + f2fs_put_page(*page, 0); + } + + return res; +} + +void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de, + struct page *page, struct inode *inode) +{ + enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA; + + lock_page(page); + f2fs_wait_on_page_writeback(page, type, true, true); + de->ino = cpu_to_le32(inode->i_ino); + de->file_type = fs_umode_to_ftype(inode->i_mode); + set_page_dirty(page); + + dir->i_mtime = inode_set_ctime_current(dir); + f2fs_mark_inode_dirty_sync(dir, false); + f2fs_put_page(page, 1); +} + +static void init_dent_inode(struct inode *dir, struct inode *inode, + const struct f2fs_filename *fname, + struct page *ipage) +{ + struct f2fs_inode *ri; + + if (!fname) /* tmpfile case? */ + return; + + f2fs_wait_on_page_writeback(ipage, NODE, true, true); + + /* copy name info. to this inode page */ + ri = F2FS_INODE(ipage); + ri->i_namelen = cpu_to_le32(fname->disk_name.len); + memcpy(ri->i_name, fname->disk_name.name, fname->disk_name.len); + if (IS_ENCRYPTED(dir)) { + file_set_enc_name(inode); + /* + * Roll-forward recovery doesn't have encryption keys available, + * so it can't compute the dirhash for encrypted+casefolded + * filenames. Append it to i_name if possible. Else, disable + * roll-forward recovery of the dentry (i.e., make fsync'ing the + * file force a checkpoint) by setting LOST_PINO. + */ + if (IS_CASEFOLDED(dir)) { + if (fname->disk_name.len + sizeof(f2fs_hash_t) <= + F2FS_NAME_LEN) + put_unaligned(fname->hash, (f2fs_hash_t *) + &ri->i_name[fname->disk_name.len]); + else + file_lost_pino(inode); + } + } + set_page_dirty(ipage); +} + +void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent, + struct f2fs_dentry_ptr *d) +{ + struct fscrypt_str dot = FSTR_INIT(".", 1); + struct fscrypt_str dotdot = FSTR_INIT("..", 2); + + /* update dirent of "." */ + f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0); + + /* update dirent of ".." */ + f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1); +} + +static int make_empty_dir(struct inode *inode, + struct inode *parent, struct page *page) +{ + struct page *dentry_page; + struct f2fs_dentry_block *dentry_blk; + struct f2fs_dentry_ptr d; + + if (f2fs_has_inline_dentry(inode)) + return f2fs_make_empty_inline_dir(inode, parent, page); + + dentry_page = f2fs_get_new_data_page(inode, page, 0, true); + if (IS_ERR(dentry_page)) + return PTR_ERR(dentry_page); + + dentry_blk = page_address(dentry_page); + + make_dentry_ptr_block(NULL, &d, dentry_blk); + f2fs_do_make_empty_dir(inode, parent, &d); + + set_page_dirty(dentry_page); + f2fs_put_page(dentry_page, 1); + return 0; +} + +struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir, + const struct f2fs_filename *fname, struct page *dpage) +{ + struct page *page; + int err; + + if (is_inode_flag_set(inode, FI_NEW_INODE)) { + page = f2fs_new_inode_page(inode); + if (IS_ERR(page)) + return page; + + if (S_ISDIR(inode->i_mode)) { + /* in order to handle error case */ + get_page(page); + err = make_empty_dir(inode, dir, page); + if (err) { + lock_page(page); + goto put_error; + } + put_page(page); + } + + err = f2fs_init_acl(inode, dir, page, dpage); + if (err) + goto put_error; + + err = f2fs_init_security(inode, dir, + fname ? fname->usr_fname : NULL, page); + if (err) + goto put_error; + + if (IS_ENCRYPTED(inode)) { + err = fscrypt_set_context(inode, page); + if (err) + goto put_error; + } + } else { + page = f2fs_get_node_page(F2FS_I_SB(dir), inode->i_ino); + if (IS_ERR(page)) + return page; + } + + init_dent_inode(dir, inode, fname, page); + + /* + * This file should be checkpointed during fsync. + * We lost i_pino from now on. + */ + if (is_inode_flag_set(inode, FI_INC_LINK)) { + if (!S_ISDIR(inode->i_mode)) + file_lost_pino(inode); + /* + * If link the tmpfile to alias through linkat path, + * we should remove this inode from orphan list. + */ + if (inode->i_nlink == 0) + f2fs_remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino); + f2fs_i_links_write(inode, true); + } + return page; + +put_error: + clear_nlink(inode); + f2fs_update_inode(inode, page); + f2fs_put_page(page, 1); + return ERR_PTR(err); +} + +void f2fs_update_parent_metadata(struct inode *dir, struct inode *inode, + unsigned int current_depth) +{ + if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) { + if (S_ISDIR(inode->i_mode)) + f2fs_i_links_write(dir, true); + clear_inode_flag(inode, FI_NEW_INODE); + } + dir->i_mtime = inode_set_ctime_current(dir); + f2fs_mark_inode_dirty_sync(dir, false); + + if (F2FS_I(dir)->i_current_depth != current_depth) + f2fs_i_depth_write(dir, current_depth); + + if (inode && is_inode_flag_set(inode, FI_INC_LINK)) + clear_inode_flag(inode, FI_INC_LINK); +} + +int f2fs_room_for_filename(const void *bitmap, int slots, int max_slots) +{ + int bit_start = 0; + int zero_start, zero_end; +next: + zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start); + if (zero_start >= max_slots) + return max_slots; + + zero_end = find_next_bit_le(bitmap, max_slots, zero_start); + if (zero_end - zero_start >= slots) + return zero_start; + + bit_start = zero_end + 1; + + if (zero_end + 1 >= max_slots) + return max_slots; + goto next; +} + +bool f2fs_has_enough_room(struct inode *dir, struct page *ipage, + const struct f2fs_filename *fname) +{ + struct f2fs_dentry_ptr d; + unsigned int bit_pos; + int slots = GET_DENTRY_SLOTS(fname->disk_name.len); + + make_dentry_ptr_inline(dir, &d, inline_data_addr(dir, ipage)); + + bit_pos = f2fs_room_for_filename(d.bitmap, slots, d.max); + + return bit_pos < d.max; +} + +void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d, + const struct fscrypt_str *name, f2fs_hash_t name_hash, + unsigned int bit_pos) +{ + struct f2fs_dir_entry *de; + int slots = GET_DENTRY_SLOTS(name->len); + int i; + + de = &d->dentry[bit_pos]; + de->hash_code = name_hash; + de->name_len = cpu_to_le16(name->len); + memcpy(d->filename[bit_pos], name->name, name->len); + de->ino = cpu_to_le32(ino); + de->file_type = fs_umode_to_ftype(mode); + for (i = 0; i < slots; i++) { + __set_bit_le(bit_pos + i, (void *)d->bitmap); + /* avoid wrong garbage data for readdir */ + if (i) + (de + i)->name_len = 0; + } +} + +int f2fs_add_regular_entry(struct inode *dir, const struct f2fs_filename *fname, + struct inode *inode, nid_t ino, umode_t mode) +{ + unsigned int bit_pos; + unsigned int level; + unsigned int current_depth; + unsigned long bidx, block; + unsigned int nbucket, nblock; + struct page *dentry_page = NULL; + struct f2fs_dentry_block *dentry_blk = NULL; + struct f2fs_dentry_ptr d; + struct page *page = NULL; + int slots, err = 0; + + level = 0; + slots = GET_DENTRY_SLOTS(fname->disk_name.len); + + current_depth = F2FS_I(dir)->i_current_depth; + if (F2FS_I(dir)->chash == fname->hash) { + level = F2FS_I(dir)->clevel; + F2FS_I(dir)->chash = 0; + } + +start: + if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) + return -ENOSPC; + + if (unlikely(current_depth == MAX_DIR_HASH_DEPTH)) + return -ENOSPC; + + /* Increase the depth, if required */ + if (level == current_depth) + ++current_depth; + + nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); + nblock = bucket_blocks(level); + + bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, + (le32_to_cpu(fname->hash) % nbucket)); + + for (block = bidx; block <= (bidx + nblock - 1); block++) { + dentry_page = f2fs_get_new_data_page(dir, NULL, block, true); + if (IS_ERR(dentry_page)) + return PTR_ERR(dentry_page); + + dentry_blk = page_address(dentry_page); + bit_pos = f2fs_room_for_filename(&dentry_blk->dentry_bitmap, + slots, NR_DENTRY_IN_BLOCK); + if (bit_pos < NR_DENTRY_IN_BLOCK) + goto add_dentry; + + f2fs_put_page(dentry_page, 1); + } + + /* Move to next level to find the empty slot for new dentry */ + ++level; + goto start; +add_dentry: + f2fs_wait_on_page_writeback(dentry_page, DATA, true, true); + + if (inode) { + f2fs_down_write(&F2FS_I(inode)->i_sem); + page = f2fs_init_inode_metadata(inode, dir, fname, NULL); + if (IS_ERR(page)) { + err = PTR_ERR(page); + goto fail; + } + } + + make_dentry_ptr_block(NULL, &d, dentry_blk); + f2fs_update_dentry(ino, mode, &d, &fname->disk_name, fname->hash, + bit_pos); + + set_page_dirty(dentry_page); + + if (inode) { + f2fs_i_pino_write(inode, dir->i_ino); + + /* synchronize inode page's data from inode cache */ + if (is_inode_flag_set(inode, FI_NEW_INODE)) + f2fs_update_inode(inode, page); + + f2fs_put_page(page, 1); + } + + f2fs_update_parent_metadata(dir, inode, current_depth); +fail: + if (inode) + f2fs_up_write(&F2FS_I(inode)->i_sem); + + f2fs_put_page(dentry_page, 1); + + return err; +} + +int f2fs_add_dentry(struct inode *dir, const struct f2fs_filename *fname, + struct inode *inode, nid_t ino, umode_t mode) +{ + int err = -EAGAIN; + + if (f2fs_has_inline_dentry(dir)) { + /* + * Should get i_xattr_sem to keep the lock order: + * i_xattr_sem -> inode_page lock used by f2fs_setxattr. + */ + f2fs_down_read(&F2FS_I(dir)->i_xattr_sem); + err = f2fs_add_inline_entry(dir, fname, inode, ino, mode); + f2fs_up_read(&F2FS_I(dir)->i_xattr_sem); + } + if (err == -EAGAIN) + err = f2fs_add_regular_entry(dir, fname, inode, ino, mode); + + f2fs_update_time(F2FS_I_SB(dir), REQ_TIME); + return err; +} + +/* + * Caller should grab and release a rwsem by calling f2fs_lock_op() and + * f2fs_unlock_op(). + */ +int f2fs_do_add_link(struct inode *dir, const struct qstr *name, + struct inode *inode, nid_t ino, umode_t mode) +{ + struct f2fs_filename fname; + struct page *page = NULL; + struct f2fs_dir_entry *de = NULL; + int err; + + err = f2fs_setup_filename(dir, name, 0, &fname); + if (err) + return err; + + /* + * An immature stackable filesystem shows a race condition between lookup + * and create. If we have same task when doing lookup and create, it's + * definitely fine as expected by VFS normally. Otherwise, let's just + * verify on-disk dentry one more time, which guarantees filesystem + * consistency more. + */ + if (current != F2FS_I(dir)->task) { + de = __f2fs_find_entry(dir, &fname, &page); + F2FS_I(dir)->task = NULL; + } + if (de) { + f2fs_put_page(page, 0); + err = -EEXIST; + } else if (IS_ERR(page)) { + err = PTR_ERR(page); + } else { + err = f2fs_add_dentry(dir, &fname, inode, ino, mode); + } + f2fs_free_filename(&fname); + return err; +} + +int f2fs_do_tmpfile(struct inode *inode, struct inode *dir) +{ + struct page *page; + int err = 0; + + f2fs_down_write(&F2FS_I(inode)->i_sem); + page = f2fs_init_inode_metadata(inode, dir, NULL, NULL); + if (IS_ERR(page)) { + err = PTR_ERR(page); + goto fail; + } + f2fs_put_page(page, 1); + + clear_inode_flag(inode, FI_NEW_INODE); + f2fs_update_time(F2FS_I_SB(inode), REQ_TIME); +fail: + f2fs_up_write(&F2FS_I(inode)->i_sem); + return err; +} + +void f2fs_drop_nlink(struct inode *dir, struct inode *inode) +{ + struct f2fs_sb_info *sbi = F2FS_I_SB(dir); + + f2fs_down_write(&F2FS_I(inode)->i_sem); + + if (S_ISDIR(inode->i_mode)) + f2fs_i_links_write(dir, false); + inode_set_ctime_current(inode); + + f2fs_i_links_write(inode, false); + if (S_ISDIR(inode->i_mode)) { + f2fs_i_links_write(inode, false); + f2fs_i_size_write(inode, 0); + } + f2fs_up_write(&F2FS_I(inode)->i_sem); + + if (inode->i_nlink == 0) + f2fs_add_orphan_inode(inode); + else + f2fs_release_orphan_inode(sbi); +} + +/* + * It only removes the dentry from the dentry page, corresponding name + * entry in name page does not need to be touched during deletion. + */ +void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page, + struct inode *dir, struct inode *inode) +{ + struct f2fs_dentry_block *dentry_blk; + unsigned int bit_pos; + int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len)); + int i; + + f2fs_update_time(F2FS_I_SB(dir), REQ_TIME); + + if (F2FS_OPTION(F2FS_I_SB(dir)).fsync_mode == FSYNC_MODE_STRICT) + f2fs_add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO); + + if (f2fs_has_inline_dentry(dir)) + return f2fs_delete_inline_entry(dentry, page, dir, inode); + + lock_page(page); + f2fs_wait_on_page_writeback(page, DATA, true, true); + + dentry_blk = page_address(page); + bit_pos = dentry - dentry_blk->dentry; + for (i = 0; i < slots; i++) + __clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap); + + /* Let's check and deallocate this dentry page */ + bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, + NR_DENTRY_IN_BLOCK, + 0); + set_page_dirty(page); + + if (bit_pos == NR_DENTRY_IN_BLOCK && + !f2fs_truncate_hole(dir, page->index, page->index + 1)) { + f2fs_clear_page_cache_dirty_tag(page); + clear_page_dirty_for_io(page); + ClearPageUptodate(page); + clear_page_private_all(page); + + inode_dec_dirty_pages(dir); + f2fs_remove_dirty_inode(dir); + } + f2fs_put_page(page, 1); + + dir->i_mtime = inode_set_ctime_current(dir); + f2fs_mark_inode_dirty_sync(dir, false); + + if (inode) + f2fs_drop_nlink(dir, inode); +} + +bool f2fs_empty_dir(struct inode *dir) +{ + unsigned long bidx = 0; + struct page *dentry_page; + unsigned int bit_pos; + struct f2fs_dentry_block *dentry_blk; + unsigned long nblock = dir_blocks(dir); + + if (f2fs_has_inline_dentry(dir)) + return f2fs_empty_inline_dir(dir); + + while (bidx < nblock) { + pgoff_t next_pgofs; + + dentry_page = f2fs_find_data_page(dir, bidx, &next_pgofs); + if (IS_ERR(dentry_page)) { + if (PTR_ERR(dentry_page) == -ENOENT) { + bidx = next_pgofs; + continue; + } else { + return false; + } + } + + dentry_blk = page_address(dentry_page); + if (bidx == 0) + bit_pos = 2; + else + bit_pos = 0; + bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, + NR_DENTRY_IN_BLOCK, + bit_pos); + + f2fs_put_page(dentry_page, 0); + + if (bit_pos < NR_DENTRY_IN_BLOCK) + return false; + + bidx++; + } + return true; +} + +int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, + unsigned int start_pos, struct fscrypt_str *fstr) +{ + unsigned char d_type = DT_UNKNOWN; + unsigned int bit_pos; + struct f2fs_dir_entry *de = NULL; + struct fscrypt_str de_name = FSTR_INIT(NULL, 0); + struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode); + struct blk_plug plug; + bool readdir_ra = sbi->readdir_ra; + bool found_valid_dirent = false; + int err = 0; + + bit_pos = ((unsigned long)ctx->pos % d->max); + + if (readdir_ra) + blk_start_plug(&plug); + + while (bit_pos < d->max) { + bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos); + if (bit_pos >= d->max) + break; + + de = &d->dentry[bit_pos]; + if (de->name_len == 0) { + if (found_valid_dirent || !bit_pos) { + printk_ratelimited( + "%sF2FS-fs (%s): invalid namelen(0), ino:%u, run fsck to fix.", + KERN_WARNING, sbi->sb->s_id, + le32_to_cpu(de->ino)); + set_sbi_flag(sbi, SBI_NEED_FSCK); + } + bit_pos++; + ctx->pos = start_pos + bit_pos; + continue; + } + + d_type = fs_ftype_to_dtype(de->file_type); + + de_name.name = d->filename[bit_pos]; + de_name.len = le16_to_cpu(de->name_len); + + /* check memory boundary before moving forward */ + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); + if (unlikely(bit_pos > d->max || + le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) { + f2fs_warn(sbi, "%s: corrupted namelen=%d, run fsck to fix.", + __func__, le16_to_cpu(de->name_len)); + set_sbi_flag(sbi, SBI_NEED_FSCK); + err = -EFSCORRUPTED; + f2fs_handle_error(sbi, ERROR_CORRUPTED_DIRENT); + goto out; + } + + if (IS_ENCRYPTED(d->inode)) { + int save_len = fstr->len; + + err = fscrypt_fname_disk_to_usr(d->inode, + (u32)le32_to_cpu(de->hash_code), + 0, &de_name, fstr); + if (err) + goto out; + + de_name = *fstr; + fstr->len = save_len; + } + + if (!dir_emit(ctx, de_name.name, de_name.len, + le32_to_cpu(de->ino), d_type)) { + err = 1; + goto out; + } + + if (readdir_ra) + f2fs_ra_node_page(sbi, le32_to_cpu(de->ino)); + + ctx->pos = start_pos + bit_pos; + found_valid_dirent = true; + } +out: + if (readdir_ra) + blk_finish_plug(&plug); + return err; +} + +static int f2fs_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + unsigned long npages = dir_blocks(inode); + struct f2fs_dentry_block *dentry_blk = NULL; + struct page *dentry_page = NULL; + struct file_ra_state *ra = &file->f_ra; + loff_t start_pos = ctx->pos; + unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK); + struct f2fs_dentry_ptr d; + struct fscrypt_str fstr = FSTR_INIT(NULL, 0); + int err = 0; + + if (IS_ENCRYPTED(inode)) { + err = fscrypt_prepare_readdir(inode); + if (err) + goto out; + + err = fscrypt_fname_alloc_buffer(F2FS_NAME_LEN, &fstr); + if (err < 0) + goto out; + } + + if (f2fs_has_inline_dentry(inode)) { + err = f2fs_read_inline_dir(file, ctx, &fstr); + goto out_free; + } + + for (; n < npages; ctx->pos = n * NR_DENTRY_IN_BLOCK) { + pgoff_t next_pgofs; + + /* allow readdir() to be interrupted */ + if (fatal_signal_pending(current)) { + err = -ERESTARTSYS; + goto out_free; + } + cond_resched(); + + /* readahead for multi pages of dir */ + if (npages - n > 1 && !ra_has_index(ra, n)) + page_cache_sync_readahead(inode->i_mapping, ra, file, n, + min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES)); + + dentry_page = f2fs_find_data_page(inode, n, &next_pgofs); + if (IS_ERR(dentry_page)) { + err = PTR_ERR(dentry_page); + if (err == -ENOENT) { + err = 0; + n = next_pgofs; + continue; + } else { + goto out_free; + } + } + + dentry_blk = page_address(dentry_page); + + make_dentry_ptr_block(inode, &d, dentry_blk); + + err = f2fs_fill_dentries(ctx, &d, + n * NR_DENTRY_IN_BLOCK, &fstr); + if (err) { + f2fs_put_page(dentry_page, 0); + break; + } + + f2fs_put_page(dentry_page, 0); + + n++; + } +out_free: + fscrypt_fname_free_buffer(&fstr); +out: + trace_f2fs_readdir(inode, start_pos, ctx->pos, err); + return err < 0 ? err : 0; +} + +const struct file_operations f2fs_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = f2fs_readdir, + .fsync = f2fs_sync_file, + .unlocked_ioctl = f2fs_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = f2fs_compat_ioctl, +#endif +}; |