block: convert qemu_aio_flush() calls to bdrv_drain_all()
Many places in QEMU call qemu_aio_flush() to complete all pending
asynchronous I/O. Most of these places actually want to drain all block
requests but there is no block layer API to do so.
This patch introduces the bdrv_drain_all() API to wait for requests
across all BlockDriverStates to complete. As a bonus we perform checks
after qemu_aio_wait() to ensure that requests really have finished.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/xen-mapcache.c b/xen-mapcache.c
index 7bcb86e..9fecc64 100644
--- a/xen-mapcache.c
+++ b/xen-mapcache.c
@@ -351,7 +351,7 @@
MapCacheRev *reventry;
/* Flush pending AIO before destroying the mapcache */
- qemu_aio_flush();
+ bdrv_drain_all();
QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
DPRINTF("There should be no locked mappings at this time, "