fscrypt: make fscrypt_operations.key_prefix a string

There was an unnecessary amount of complexity around requesting the
filesystem-specific key prefix.  It was unclear why; perhaps it was
envisioned that different instances of the same filesystem type could
use different key prefixes, or that key prefixes could be binary.
However, neither of those things were implemented or really make sense
at all.  So simplify the code by making key_prefix a const char *.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 1 insertions, 10 deletions

diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
index 3402720f2b28..6335abcf98df 100644
--- a/fs/ubifs/crypto.c
+++ b/fs/ubifs/crypto.c
@@ -26,15 +26,6 @@ static unsigned int ubifs_crypt_max_namelen(struct inode *inode)
                 return UBIFS_MAX_NLEN;
 }
 
-static int ubifs_key_prefix(struct inode *inode, u8 **key)
-{
-        static char prefix[] = "ubifs:";
-
-        *key = prefix;
-
-        return sizeof(prefix) - 1;
-}
-
 int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
                   unsigned int in_len, unsigned int *out_len, int block)
 {
@@ -88,10 +79,10 @@ int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
 
 struct fscrypt_operations ubifs_crypt_operations = {
         .flags                  = FS_CFLG_OWN_PAGES,
+        .key_prefix             = "ubifs:",
         .get_context            = ubifs_crypt_get_context,
         .set_context            = ubifs_crypt_set_context,
         .is_encrypted           = __ubifs_crypt_is_encrypted,
         .empty_dir              = ubifs_crypt_empty_dir,
         .max_namelen            = ubifs_crypt_max_namelen,
-        .key_prefix             = ubifs_key_prefix,
 };