Re: [Qemu-devel] [PATCH v10 10/20] qcow2: make qcow2_encrypt_sectors encrypt in place

[Alberto Garcia]

On Fri 23 Jun 2017 06:24:09 PM CEST, Daniel P. Berrange wrote:
> Instead of requiring separate input/output buffers for
> encrypting data, change qcow2_encrypt_sectors() to assume
> use of a single buffer, encrypting in place. The current
> callers all used the same buffer for input/output already.
>
> Signed-off-by: Daniel P. Berrange 

Reviewed-by: Alberto Garcia 

Berto

[Qemu-devel] [PATCH v10 10/20] qcow2: make qcow2_encrypt_sectors encrypt in place

[Daniel P. Berrange]

Instead of requiring separate input/output buffers for
encrypting data, change qcow2_encrypt_sectors() to assume
use of a single buffer, encrypting in place. The current
callers all used the same buffer for input/output already.

Signed-off-by: Daniel P. Berrange 
---
 block/qcow2-cluster.c | 17 ++---
 block/qcow2.c |  4 ++--
 block/qcow2.h |  3 +--
 3 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 3d341fd..a570929 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -358,11 +358,9 @@ static int count_contiguous_clusters_unallocated(int 
nb_clusters,
 }
 
 /* The crypt function is compatible with the linux cryptoloop
-   algorithm for < 4 GB images. NOTE: out_buf == in_buf is
-   supported */
+   algorithm for < 4 GB images. */
 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
-  uint8_t *out_buf, const uint8_t *in_buf,
-  int nb_sectors, bool enc,
+  uint8_t *buf, int nb_sectors, bool enc,
   Error **errp)
 {
 union {
@@ -382,14 +380,12 @@ int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t 
sector_num,
 }
 if (enc) {
 ret = qcrypto_cipher_encrypt(s->cipher,
- in_buf,
- out_buf,
+ buf, buf,
  512,
  errp);
 } else {
 ret = qcrypto_cipher_decrypt(s->cipher,
- in_buf,
- out_buf,
+ buf, buf,
  512,
  errp);
 }
@@ -397,8 +393,7 @@ int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t 
sector_num,
 return -1;
 }
 sector_num++;
-in_buf += 512;
-out_buf += 512;
+buf += 512;
 }
 return 0;
 }
@@ -446,7 +441,7 @@ static bool coroutine_fn 
do_perform_cow_encrypt(BlockDriverState *bs,
 assert(s->cipher);
 assert((offset_in_cluster & ~BDRV_SECTOR_MASK) == 0);
 assert((bytes & ~BDRV_SECTOR_MASK) == 0);
-if (qcow2_encrypt_sectors(s, sector, buffer, buffer,
+if (qcow2_encrypt_sectors(s, sector, buffer,
   bytes >> BDRV_SECTOR_BITS, true, NULL) < 0) {
 return false;
 }
diff --git a/block/qcow2.c b/block/qcow2.c
index 67fb50d..f4b5207 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1543,7 +1543,7 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState 
*bs, uint64_t offset,
 assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
 Error *err = NULL;
 if (qcow2_encrypt_sectors(s, offset >> BDRV_SECTOR_BITS,
-  cluster_data, cluster_data,
+  cluster_data,
   cur_bytes >> BDRV_SECTOR_BITS,
   false, ) < 0) {
 error_free(err);
@@ -1677,7 +1677,7 @@ static coroutine_fn int qcow2_co_pwritev(BlockDriverState 
*bs, uint64_t offset,
 qemu_iovec_to_buf(_qiov, 0, cluster_data, hd_qiov.size);
 
 if (qcow2_encrypt_sectors(s, offset >> BDRV_SECTOR_BITS,
-  cluster_data, cluster_data,
+  cluster_data,
   cur_bytes >>BDRV_SECTOR_BITS,
   true, ) < 0) {
 error_free(err);
diff --git a/block/qcow2.h b/block/qcow2.h
index 87b15eb..5a3f07e 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -545,8 +545,7 @@ int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t 
min_size,
 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
-  uint8_t *out_buf, const uint8_t *in_buf,
-  int nb_sectors, bool enc, Error **errp);
+  uint8_t *buf, int nb_sectors, bool enc, Error 
**errp);
 
 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
  unsigned int *bytes, uint64_t *cluster_offset);
-- 
2.9.3