[PATCH AUTOSEL 6.6 11/58] ext4: ext4_search_dir should return a proper error

Sasha Levin
2024-10-04T18:25:23Z

From: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>

[ Upstream commit cd69f8f9de280e331c9e6ff689ced0a688a9ce8f ]

ext4_search_dir currently returns -1 in case of a failure, while it returns
0 when the name is not found. In such failure cases, it should return an
error code instead.

This becomes even more important when ext4_find_inline_entry returns an
error code as well in the next commit.

-EFSCORRUPTED seems appropriate as such error code as these failures would
be caused by unexpected record lengths and is in line with other instances
of ext4_check_dir_entry failures.

In the case of ext4_dx_find_entry, the current use of ERR_BAD_DX_DIR was
left as is to reduce the risk of regressions.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://patch.msgid.link/20240821152324.3621860-2-cascardo@igalia.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext4/namei.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 3bd2301cb48e7..9913aa37e697c 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1526,7 +1526,7 @@ static bool ext4_match(struct inode *parent,
}

/*
- * Returns 0 if not found, -1 on failure, and 1 on success
+ * Returns 0 if not found, -EFSCORRUPTED on failure, and 1 on success
*/
int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
struct inode *dir, struct ext4_filename *fname,
@@ -1547,7 +1547,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
* a full check */
if (ext4_check_dir_entry(dir, NULL, de, bh, search_buf,
buf_size, offset))
- return -1;
+ return -EFSCORRUPTED;
*res_dir = de;
return 1;
}
@@ -1555,7 +1555,7 @@ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size,
de_len = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
if (de_len <= 0)
- return -1;
+ return -EFSCORRUPTED;
offset += de_len;
de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
}
@@ -1707,8 +1707,10 @@ static struct buffer_head *__ext4_find_entry(struct inode *dir,
goto cleanup_and_exit;
} else {
brelse(bh);
- if (i < 0)
+ if (i < 0) {
+ ret = ERR_PTR(i);
goto cleanup_and_exit;
+ }
}
next:
if (++block >= nblocks)
@@ -1803,7 +1805,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
if (retval == 1)
goto success;
brelse(bh);
- if (retval == -1) {
+ if (retval < 0) {
bh = ERR_PTR(ERR_BAD_DX_DIR);
goto errout;
}
--
2.43.0