fscrypto: make filename crypto functions return 0 on success

Several filename crypto functions: fname_decrypt(),
fscrypt_fname_disk_to_usr(), and fscrypt_fname_usr_to_disk(), returned
the output length on success or -errno on failure.  However, the output
length was redundant with the value written to 'oname->len'.  It is also
potentially error-prone to make callers have to check for '< 0' instead
of '!= 0'.

Therefore, make these functions return 0 instead of a length, and make
the callers who cared about the return value being a length use
'oname->len' instead.  For consistency also make other callers check for
a nonzero result rather than a negative result.

This change also fixes the inconsistency of fname_encrypt() actually
already returning 0 on success, not a length like the other filename
crypto functions and as documented in its function comment.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 9054aeac8015..8716943335b1 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -786,7 +786,7 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 
 		if (f2fs_encrypted_inode(d->inode)) {
 			int save_len = fstr->len;
-			int ret;
+			int err;
 
 			de_name.name = f2fs_kmalloc(de_name.len, GFP_NOFS);
 			if (!de_name.name)
@@ -794,11 +794,11 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 
 			memcpy(de_name.name, d->filename[bit_pos], de_name.len);
 
-			ret = fscrypt_fname_disk_to_usr(d->inode,
+			err = fscrypt_fname_disk_to_usr(d->inode,
 						(u32)de->hash_code, 0,
 						&de_name, fstr);
 			kfree(de_name.name);
-			if (ret < 0)
+			if (err)
 				return true;
 
 			de_name = *fstr;