From: Zhihao Cheng chengzhihao1@huawei.com
commit 7177dd009c7c04290891e9a534cd47d1b620bd04 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/namei.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
--- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -85,15 +85,20 @@ static struct buffer_head *ext4_append(h 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,