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>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/xen_platform.c b/hw/xen_platform.c
index 5e792f5..e62eaef 100644
--- a/hw/xen_platform.c
+++ b/hw/xen_platform.c
@@ -120,7 +120,7 @@ static void platform_fixed_ioport_writew(void *opaque, uint32_t addr, uint32_t v
            devices, and bit 2 the non-primary-master IDE devices. */
         if (val & UNPLUG_ALL_IDE_DISKS) {
             DPRINTF("unplug disks\n");
-            qemu_aio_flush();
+            bdrv_drain_all();
             bdrv_flush_all();
             pci_unplug_disks(s->pci_dev.bus);
         }