ceph: move AES iv definition to shared header

Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/ceph_fs.h

@@ -74,6 +74,8 @@ int ceph_file_layout_is_valid(const struct ceph_file_layout *layout);
 #define CEPH_CRYPTO_NONE 0x0
 #define CEPH_CRYPTO_AES  0x1
 
+#define CEPH_AES_IV "cephsageyudagreg"
+
 /* security/authentication protocols */
 #define CEPH_AUTH_UNKNOWN	0x0
 #define CEPH_AUTH_NONE	 	0x1

fs/ceph/crypto.c

@@ -75,7 +75,7 @@ static struct crypto_blkcipher *ceph_crypto_alloc_cipher(void)
 	return crypto_alloc_blkcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
 }
 
-static const u8 *aes_iv = "cephsageyudagreg";
+static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
 
 static int ceph_aes_encrypt(const void *key, int key_len,
 			    void *dst, size_t *dst_len,