[f2fs-dev] fsck.f2fs: fix to repair hash_code only if c.fix_on is true

Commit Message

Chao Yu April 15, 2025, 11:27 a.m. UTC

w/ below testcase, fsck will fix image accidently:
mkfs.f2fs -f /dev/vdb
mount -t f2fs -o noinline_dentry /dev/vdb /mnt/f2fs
mkdir /mnt/f2fs/dir/
touch /mnt/f2fs/dir/file
umount /mnt/f2fs
inject.f2fs --dent --mb d_hash --nid 5 --val 0x9a2ea068 /dev/vdb
fsck.f2fs -d 1 /dev/vdb

output:
[FIX] (f2fs_check_hash_code:1741)  --> Mismatch hash_code for "file" [9a2ea068:53fcf74e]
[fsck_chk_dentry_blk:2124] [  2] Dentry Block [0x4401] Fixed hash_codes

In f2fs_check_hash_code(), we should only fix hash code and return 1
if c.fix_on is true, otherwise, caller will update fixed value to
dentry block directly.

Signed-off-by: Chao Yu <[e-mail]>
---
 fsck/fsck.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

Patch

diff --git a/fsck/fsck.c b/fsck/fsck.c
index 73fcf07..2cff33f 100644
--- a/fsck/fsck.c
+++ b/fsck/fsck.c
@@ -1738,11 +1738,18 @@  static int f2fs_check_hash_code(int encoding, int casefolded,
 		char new[F2FS_PRINT_NAMELEN];
 
 		pretty_print_filename(name, len, new, enc_name);
-		FIX_MSG("Mismatch hash_code for \"%s\" [%x:%x]",
-				new, le32_to_cpu(dentry->hash_code),
-				hash_code);
-		dentry->hash_code = cpu_to_le32(hash_code);
-		return 1;
+
+		ASSERT_MSG("Mismatch hash_code for \"%s\" [%x:%x]",
+					new, le32_to_cpu(dentry->hash_code),
+					hash_code);
+		if (c.fix_on) {
+			FIX_MSG("Fix hash_code for \"%s\" from %x to %x",
+					new, le32_to_cpu(dentry->hash_code),
+					hash_code);
+			dentry->hash_code = cpu_to_le32(hash_code);
+			return 1;
+		}
+		return 0;
 	}
 	return 0;
 }