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, 13 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 702638e21c76..739192d95e71 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1156,12 +1156,6 @@ static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
                                 ctx, len, NULL);
 }
 
-static int f2fs_key_prefix(struct inode *inode, u8 **key)
-{
-        *key = F2FS_I_SB(inode)->key_prefix;
-        return F2FS_I_SB(inode)->key_prefix_size;
-}
-
 static int f2fs_set_context(struct inode *inode, const void *ctx, size_t len,
                                                         void *fs_data)
 {
@@ -1177,8 +1171,8 @@ static unsigned f2fs_max_namelen(struct inode *inode)
 }
 
 static struct fscrypt_operations f2fs_cryptops = {
+        .key_prefix     = "f2fs:",
         .get_context    = f2fs_get_context,
-        .key_prefix     = f2fs_key_prefix,
         .set_context    = f2fs_set_context,
         .is_encrypted   = f2fs_encrypted_inode,
         .empty_dir      = f2fs_empty_dir,
@@ -1518,12 +1512,6 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
         mutex_init(&sbi->wio_mutex[NODE]);
         mutex_init(&sbi->wio_mutex[DATA]);
         spin_lock_init(&sbi->cp_lock);
-
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-        memcpy(sbi->key_prefix, F2FS_KEY_DESC_PREFIX,
-                                F2FS_KEY_DESC_PREFIX_SIZE);
-        sbi->key_prefix_size = F2FS_KEY_DESC_PREFIX_SIZE;
-#endif
 }
 
 static int init_percpu_info(struct f2fs_sb_info *sbi)