dm crypt: move private iv fields to structs

Define private structures for IV so it's easy to add further attributes
in a following patch which fixes the way key material is wiped from
memory.  Also move ESSIV destructor and remove unnecessary 'status'
operation.

There are no functional changes in this patch.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 22 insertions, 13 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index f2c139305e13..bec5ac54e23e 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -71,10 +71,17 @@ struct crypt_iv_operations {
         int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
                    const char *opts);
         void (*dtr)(struct crypt_config *cc);
-        const char *(*status)(struct crypt_config *cc);
         int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
 };
 
+struct iv_essiv_private {
+        struct crypto_cipher *tfm;
+};
+
+struct iv_benbi_private {
+        int shift;
+};
+
 /*
  * Crypt: maps a linear range of a block device
  * and encrypts / decrypts at the same time.
@@ -102,8 +109,8 @@ struct crypt_config {
         struct crypt_iv_operations *iv_gen_ops;
         char *iv_mode;
         union {
-                struct crypto_cipher *essiv_tfm;
-                int benbi_shift;
+                struct iv_essiv_private essiv;
+                struct iv_benbi_private benbi;
         } iv_gen_private;
         sector_t iv_offset;
         unsigned int iv_size;
@@ -169,6 +176,14 @@ static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
         return 0;
 }
 
+static void crypt_iv_essiv_dtr(struct crypt_config *cc)
+{
+        struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
+
+        crypto_free_cipher(essiv->tfm);
+        essiv->tfm = NULL;
+}
+
 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
                               const char *opts)
 {
@@ -236,21 +251,15 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
         }
         kfree(salt);
 
-        cc->iv_gen_private.essiv_tfm = essiv_tfm;
+        cc->iv_gen_private.essiv.tfm = essiv_tfm;
         return 0;
 }
 
-static void crypt_iv_essiv_dtr(struct crypt_config *cc)
-{
-        crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
-        cc->iv_gen_private.essiv_tfm = NULL;
-}
-
 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
 {
         memset(iv, 0, cc->iv_size);
         *(u64 *)iv = cpu_to_le64(sector);
-        crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
+        crypto_cipher_encrypt_one(cc->iv_gen_private.essiv.tfm, iv, iv);
         return 0;
 }
 
@@ -273,7 +282,7 @@ static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
                 return -EINVAL;
         }
 
-        cc->iv_gen_private.benbi_shift = 9 - log;
+        cc->iv_gen_private.benbi.shift = 9 - log;
 
         return 0;
 }
@@ -288,7 +297,7 @@ static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
 
         memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 
-        val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
+        val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi.shift) + 1);
         put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 
         return 0;