[PATCH v14 7/9] f2fs: Log error when lookup of encoded dentry fails

From: Eugen Hristev
Date: Wed Mar 20 2024 - 04:49:13 EST


If the volume is in strict mode, generi c_ci_compare can report a broken
encoding name. This will not trigger on a bad lookup, which is caught
earlier, only if the actual disk name is bad.

Suggested-by: Gabriel Krisman Bertazi <krisman@xxxxxxx>
Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
---
fs/f2fs/dir.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 88b0045d0c4f..3b0003e8767a 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -192,11 +192,22 @@ static inline int f2fs_match_name(const struct inode *dir,
struct fscrypt_name f;

#if IS_ENABLED(CONFIG_UNICODE)
- if (fname->cf_name.name)
- return generic_ci_match(dir, fname->usr_fname,
- &fname->cf_name,
- de_name, de_name_len);
-
+ if (fname->cf_name.name) {
+ int ret = generic_ci_match(dir, fname->usr_fname,
+ &fname->cf_name,
+ de_name, de_name_len);
+ if (ret < 0) {
+ /*
+ * Treat comparison errors as not a match. The
+ * only case where it happens is on a disk
+ * corruption or ENOMEM.
+ */
+ if (ret == -EINVAL)
+ f2fs_warn(F2FS_SB(dir->i_sb),
+ "Directory contains filename that is invalid UTF-8");
+ }
+ return ret;
+ }
#endif
f.usr_fname = fname->usr_fname;
f.disk_name = fname->disk_name;
--
2.34.1