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>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index f2c139305e13b13bd559c8fdc130e3f4d2e7755a..bec5ac54e23e642aae83ceaf52e5b1cf32ea3ad8 100644 (file)
--- 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;