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block/qcow2: refactor encryption code

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* Change the qcow2_co_{encrypt|decrypt} to just receive full host and
  guest offsets and use this function directly instead of calling
  do_perform_cow_encrypt (which is removed by that patch).

* Adjust qcow2_co_encdec to take full host and guest offsets as well.

* Document the qcow2_co_{encrypt|decrypt} arguments
  to prevent the bug fixed in former commit from hopefully
  happening again.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-id: 20190915203655.21638-3-mlevitsk@redhat.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[mreitz: Let perform_cow() return the error value returned by
         qcow2_co_encrypt(), as proposed by Vladimir]
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Maxim Levitsky 2019-09-15 23:36:54 +03:00 committed by Max Reitz
parent 38e7d54bdc
commit 603fbd076c
4 changed files with 69 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
block/qcow2-cluster.c
View File

@ -462,28 +462,6 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs,
return 0;
}
static bool coroutine_fn do_perform_cow_encrypt(BlockDriverState *bs,
uint64_t src_cluster_offset,
uint64_t cluster_offset,
unsigned offset_in_cluster,
uint8_t *buffer,
unsigned bytes)
{
if (bytes && bs->encrypted) {
BDRVQcow2State *s = bs->opaque;
assert(QEMU_IS_ALIGNED(offset_in_cluster, BDRV_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE));
assert(s->crypto);
if (qcow2_co_encrypt(bs,
start_of_cluster(s, cluster_offset + offset_in_cluster),
src_cluster_offset + offset_in_cluster,
buffer, bytes) < 0) {
return false;
}
}
return true;
}
static int coroutine_fn do_perform_cow_write(BlockDriverState *bs,
uint64_t cluster_offset,
unsigned offset_in_cluster,
@ -891,12 +869,19 @@ static int perform_cow(BlockDriverState *bs, QCowL2Meta *m)
/* Encrypt the data if necessary before writing it */
if (bs->encrypted) {
if (!do_perform_cow_encrypt(bs, m->offset, m->alloc_offset,
start->offset, start_buffer,
start->nb_bytes) ||
!do_perform_cow_encrypt(bs, m->offset, m->alloc_offset,
end->offset, end_buffer, end->nb_bytes)) {
ret = -EIO;
ret = qcow2_co_encrypt(bs,
m->alloc_offset + start->offset,
m->offset + start->offset,
start_buffer, start->nb_bytes);
if (ret < 0) {
goto fail;
}
ret = qcow2_co_encrypt(bs,
m->alloc_offset + end->offset,
m->offset + end->offset,
end_buffer, end->nb_bytes);
if (ret < 0) {
goto fail;
}
}

63
block/qcow2-threads.c
View File

@ -234,35 +234,70 @@ static int qcow2_encdec_pool_func(void *opaque)
}
static int coroutine_fn
qcow2_co_encdec(BlockDriverState *bs, uint64_t file_cluster_offset,
uint64_t offset, void *buf, size_t len, Qcow2EncDecFunc func)
qcow2_co_encdec(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len,
Qcow2EncDecFunc func)
{
BDRVQcow2State *s = bs->opaque;
Qcow2EncDecData arg = {
.block = s->crypto,
.offset = s->crypt_physical_offset ?
file_cluster_offset + offset_into_cluster(s, offset) :
offset,
.offset = s->crypt_physical_offset ? host_offset : guest_offset,
.buf = buf,
.len = len,
.func = func,
};
return qcow2_co_process(bs, qcow2_encdec_pool_func, &arg);
assert(QEMU_IS_ALIGNED(guest_offset, BDRV_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(host_offset, BDRV_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(len, BDRV_SECTOR_SIZE));
assert(s->crypto);
return len == 0 ? 0 : qcow2_co_process(bs, qcow2_encdec_pool_func, &arg);
}
/*
* qcow2_co_encrypt()
*
* Encrypts one or more contiguous aligned sectors
*
* @host_offset - underlying storage offset of the first sector of the
* data to be encrypted
*
* @guest_offset - guest (virtual) offset of the first sector of the
* data to be encrypted
*
* @buf - buffer with the data to encrypt, that after encryption
* will be written to the underlying storage device at
* @host_offset
*
* @len - length of the buffer (must be a BDRV_SECTOR_SIZE multiple)
*
* Depending on the encryption method, @host_offset and/or @guest_offset
* may be used for generating the initialization vector for
* encryption.
*
* Note that while the whole range must be aligned on sectors, it
* does not have to be aligned on clusters and can also cross cluster
* boundaries
*/
int coroutine_fn
qcow2_co_encrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
uint64_t offset, void *buf, size_t len)
qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len)
{
return qcow2_co_encdec(bs, file_cluster_offset, offset, buf, len,
qcrypto_block_encrypt);
return qcow2_co_encdec(bs, host_offset, guest_offset, buf, len,
qcrypto_block_encrypt);
}
/*
* qcow2_co_decrypt()
*
* Decrypts one or more contiguous aligned sectors
* Similar to qcow2_co_encrypt
*/
int coroutine_fn
qcow2_co_decrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
uint64_t offset, void *buf, size_t len)
qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len)
{
return qcow2_co_encdec(bs, file_cluster_offset, offset, buf, len,
qcrypto_block_decrypt);
return qcow2_co_encdec(bs, host_offset, guest_offset, buf, len,
qcrypto_block_decrypt);
}

5
block/qcow2.c
View File

@ -2069,7 +2069,8 @@ static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE));
assert(QEMU_IS_ALIGNED(cur_bytes, BDRV_SECTOR_SIZE));
if (qcow2_co_decrypt(bs, cluster_offset, offset,
if (qcow2_co_decrypt(bs, cluster_offset + offset_in_cluster,
offset,
cluster_data, cur_bytes) < 0) {
ret = -EIO;
goto fail;
@ -2288,7 +2289,7 @@ static coroutine_fn int qcow2_co_pwritev_part(
qemu_iovec_to_buf(qiov, qiov_offset + bytes_done,
cluster_data, cur_bytes);
if (qcow2_co_encrypt(bs, cluster_offset, offset,
if (qcow2_co_encrypt(bs, cluster_offset + offset_in_cluster, offset,
cluster_data, cur_bytes) < 0) {
ret = -EIO;
goto out_unlocked;

8
block/qcow2.h
View File

@ -758,10 +758,10 @@ ssize_t coroutine_fn
qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
const void *src, size_t src_size);
int coroutine_fn
qcow2_co_encrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
uint64_t offset, void *buf, size_t len);
qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len);
int coroutine_fn
qcow2_co_decrypt(BlockDriverState *bs, uint64_t file_cluster_offset,
uint64_t offset, void *buf, size_t len);
qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
uint64_t guest_offset, void *buf, size_t len);
#endif