Commit de189a1b authored Jul 01, 2010 by Kevin Wolf

block: Handle multiwrite errors only when all requests have completed



Don't try to be clever by freeing all temporary data and calling all callbacks
when the return value (an error) is certain. Doing so has at least two
important problems:

* The temporary data that is freed (qiov, possibly zero buffer) is still used
  by the requests that have not yet completed.
* Calling the callbacks for all requests in the multiwrite means for the caller
  that it may free buffers etc. which are still in use.

Just remember the error value and do the cleanup when all requests have
completed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

parent 453f9a16

block.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -2042,14 +2042,11 @@ static void multiwrite_cb(void *opaque, int ret)

		if (ret < 0 && !mcb->error) {
		mcb->error = ret;
		multiwrite_user_cb(mcb);
		}

		mcb->num_requests--;
		if (mcb->num_requests == 0) {
		if (mcb->error == 0) {
		multiwrite_user_cb(mcb);
		}
		qemu_free(mcb);
		}
		}