f2fs: Reuse generic_ci_match for ci comparisons

Now that ci_match is part of libfs, make f2fs reuse it instead of having
a different implementation.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com>
Link: https://lore.kernel.org/r/20240606073353.47130-6-eugen.hristev@collabora.comReviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/f2fs/dir.c

@@ -185,58 +185,6 @@ static struct f2fs_dir_entry *find_in_block(struct inode *dir,
 	return f2fs_find_target_dentry(&d, fname, max_slots);
 }
 
-#if IS_ENABLED(CONFIG_UNICODE)
-/*
- * Test whether a case-insensitive directory entry matches the filename
- * being searched for.
- *
- * Returns 1 for a match, 0 for no match, and -errno on an error.
- */
-static int f2fs_match_ci_name(const struct inode *dir, const struct qstr *name,
-			       const u8 *de_name, u32 de_name_len)
-{
-	const struct super_block *sb = dir->i_sb;
-	const struct unicode_map *um = sb->s_encoding;
-	struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len);
-	struct qstr entry = QSTR_INIT(de_name, de_name_len);
-	int res;
-
-	if (IS_ENCRYPTED(dir)) {
-		const struct fscrypt_str encrypted_name =
-			FSTR_INIT((u8 *)de_name, de_name_len);
-
-		if (WARN_ON_ONCE(!fscrypt_has_encryption_key(dir)))
-			return -EINVAL;
-
-		decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL);
-		if (!decrypted_name.name)
-			return -ENOMEM;
-		res = fscrypt_fname_disk_to_usr(dir, 0, 0, &encrypted_name,
-						&decrypted_name);
-		if (res < 0)
-			goto out;
-		entry.name = decrypted_name.name;
-		entry.len = decrypted_name.len;
-	}
-
-	res = utf8_strncasecmp_folded(um, name, &entry);
-	/*
-	 * In strict mode, ignore invalid names.  In non-strict mode,
-	 * fall back to treating them as opaque byte sequences.
-	 */
-	if (res < 0 && !sb_has_strict_encoding(sb)) {
-		res = name->len == entry.len &&
-				memcmp(name->name, entry.name, name->len) == 0;
-	} else {
-		/* utf8_strncasecmp_folded returns 0 on match */
-		res = (res == 0);
-	}
-out:
-	kfree(decrypted_name.name);
-	return res;
-}
-#endif /* CONFIG_UNICODE */
-
 static inline int f2fs_match_name(const struct inode *dir,
 				   const struct f2fs_filename *fname,
 				   const u8 *de_name, u32 de_name_len)
@@ -245,8 +193,10 @@ static inline int f2fs_match_name(const struct inode *dir,
 
 #if IS_ENABLED(CONFIG_UNICODE)
 	if (fname->cf_name.name)
-		return f2fs_match_ci_name(dir, &fname->cf_name,
-					  de_name, de_name_len);
+		return generic_ci_match(dir, fname->usr_fname,
+					&fname->cf_name,
+					de_name, de_name_len);
+
 #endif
 	f.usr_fname = fname->usr_fname;
 	f.disk_name = fname->disk_name;