block: Assert qiov length matches request length

At least raw-posix relies on this because it can allocate bounce buffers
based on the request length, but access it using all of the qiov entries
later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block.c b/block.c
index 0143268..3e252a2 100644
--- a/block.c
+++ b/block.c
@@ -3010,6 +3010,7 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
 
     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(!qiov || bytes == qiov->size);
 
     /* Handle Copy on Read and associated serialisation */
     if (flags & BDRV_REQ_COPY_ON_READ) {
@@ -3279,6 +3280,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 
     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
+    assert(!qiov || bytes == qiov->size);
 
     waited = wait_serialising_requests(req);
     assert(!waited || !req->serialising);