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| author | Zhihao Cheng <chengzhihao1@huawei.com> | 2022-09-11 12:52:04 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2022-09-30 23:46:52 -0400 |
| commit | 7177dd009c7c04290891e9a534cd47d1b620bd04 (patch) | |
| tree | 3878e4fd0fb3c3b7c879d8f3a5f198f23d6d022d /fs | |
| parent | ebd5d23e88b7fc84cbbb7a002aa35bfd5bfadb10 (diff) | |
ext4: fix dir corruption when ext4_dx_add_entry() fails
Following process may lead to fs corruption:
1. ext4_create(dir/foo)
ext4_add_nondir
ext4_add_entry
ext4_dx_add_entry
a. add_dirent_to_buf
ext4_mark_inode_dirty
ext4_handle_dirty_metadata // dir inode bh is recorded into journal
b. ext4_append // dx_get_count(entries) == dx_get_limit(entries)
ext4_bread(EXT4_GET_BLOCKS_CREATE)
ext4_getblk
ext4_map_blocks
ext4_ext_map_blocks
ext4_mb_new_blocks
dquot_alloc_block
dquot_alloc_space_nodirty
inode_add_bytes // update dir's i_blocks
ext4_ext_insert_extent
ext4_ext_dirty // record extent bh into journal
ext4_handle_dirty_metadata(bh)
// record new block into journal
inode->i_size += inode->i_sb->s_blocksize // new size(in mem)
c. ext4_handle_dirty_dx_node(bh2)
// record dir's new block(dx_node) into journal
d. ext4_handle_dirty_dx_node((frame - 1)->bh)
e. ext4_handle_dirty_dx_node(frame->bh)
f. do_split // ret err!
g. add_dirent_to_buf
ext4_mark_inode_dirty(dir) // update raw_inode on disk(skipped)
2. fsck -a /dev/sdb
drop last block(dx_node) which beyonds dir's i_size.
/dev/sdb: recovering journal
/dev/sdb contains a file system with errors, check forced.
/dev/sdb: Inode 12, end of extent exceeds allowed value
(logical block 128, physical block 3938, len 1)
3. fsck -fn /dev/sdb
dx_node->entry[i].blk > dir->i_size
Pass 2: Checking directory structure
Problem in HTREE directory inode 12 (/dir): bad block number 128.
Clear HTree index? no
Problem in HTREE directory inode 12: block #3 has invalid depth (2)
Problem in HTREE directory inode 12: block #3 has bad max hash
Problem in HTREE directory inode 12: block #3 not referenced
Fix it by marking inode dirty directly inside ext4_append().
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216466
Cc: stable@vger.kernel.org
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220911045204.516460-1-chengzhihao1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/namei.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index bc2e0612ec32..4183a4cb4a21 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -85,15 +85,20 @@ static struct buffer_head *ext4_append(handle_t *handle, return bh; inode->i_size += inode->i_sb->s_blocksize; EXT4_I(inode)->i_disksize = inode->i_size; + err = ext4_mark_inode_dirty(handle, inode); + if (err) + goto out; BUFFER_TRACE(bh, "get_write_access"); err = ext4_journal_get_write_access(handle, inode->i_sb, bh, EXT4_JTR_NONE); - if (err) { - brelse(bh); - ext4_std_error(inode->i_sb, err); - return ERR_PTR(err); - } + if (err) + goto out; return bh; + +out: + brelse(bh); + ext4_std_error(inode->i_sb, err); + return ERR_PTR(err); } static int ext4_dx_csum_verify(struct inode *inode, |