[PATCH AUTOSEL 5.17 13/20] ext2: fix fs corruption when trying to remove a non-empty directory with IO error

Sasha Levin
2022-06-21T21:03:07Z

From: Ye Bin <yebin10@huawei.com>

[ Upstream commit 27cfa258951a465e3eae63ee1e715e902cd45578 ]

We got issue as follows:
[home]# mount /dev/sdd test
[home]# cd test
[test]# ls
dir1 lost+found
[test]# rmdir dir1
ext2_empty_dir: inject fault
[test]# ls
lost+found
[test]# cd ..
[home]# umount test
[home]# fsck.ext2 -fn /dev/sdd
e2fsck 1.42.9 (28-Dec-2013)
Pass 1: Checking inodes, blocks, and sizes
Inode 4065, i_size is 0, should be 1024. Fix? no

Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Unconnected directory inode 4065 (/???)
Connect to /lost+found? no

'..' in ... (4065) is / (2), should be <The NULL inode> (0).
Fix? no

Pass 4: Checking reference counts
Inode 2 ref count is 3, should be 4. Fix? no

Inode 4065 ref count is 2, should be 3. Fix? no

Pass 5: Checking group summary information

/dev/sdd: ********** WARNING: Filesystem still has errors **********

/dev/sdd: 14/128016 files (0.0% non-contiguous), 18477/512000 blocks

Reason is same with commit 7aab5c84a0f6. We can't assume directory
is empty when read directory entry failed.

Link: https://lore.kernel.org/r/20220615090010.1544152-1-yebin10@huawei.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext2/dir.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 2c2f179b6977..43de293cef56 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -672,17 +672,14 @@ int ext2_empty_dir (struct inode * inode)
void *page_addr = NULL;
struct page *page = NULL;
unsigned long i, npages = dir_pages(inode);
- int dir_has_error = 0;

for (i = 0; i < npages; i++) {
char *kaddr;
ext2_dirent * de;
- page = ext2_get_page(inode, i, dir_has_error, &page_addr);
+ page = ext2_get_page(inode, i, 0, &page_addr);

- if (IS_ERR(page)) {
- dir_has_error = 1;
- continue;
- }
+ if (IS_ERR(page))
+ goto not_empty;

kaddr = page_addr;
de = (ext2_dirent *)kaddr;
--
2.35.1