block: bdrv_aligned_pwritev: Assert overlap range

This adds assertions that the request that we actually end up passing to
the block driver (which includes RMW data and has therefore potentially
been rounded to alignment boundaries) is fully covered by the
overlap_{offset,size} fields of the associated BdrvTrackedRequest.

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block.c b/block.c
index c1d1f74b88..a027823ea4 100644
--- a/block.c
+++ b/block.c
@@ -3134,6 +3134,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 
     waited = wait_serialising_requests(req);
     assert(!waited || !req->serialising);
+    assert(req->overlap_offset <= offset);
+    assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
 
     ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);