[PATCH 8/8] virtio-blk: minimize virtio_blk_reset() AioContext lock region

[Stefan Hajnoczi]

blk_drain() needs the lock because it calls AIO_WAIT_WHILE().

The s->rq loop doesn't need the lock because dataplane has been stopped
when virtio_blk_reset() is called.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/block/virtio-blk.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 771d87cfbe..0b411b3065 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -898,6 +898,7 @@ static void virtio_blk_reset(VirtIODevice *vdev)
     ctx = blk_get_aio_context(s->blk);
     aio_context_acquire(ctx);
     blk_drain(s->blk);
+    aio_context_release(ctx);
 
     /* We drop queued requests after blk_drain() because blk_drain() itself can
      * produce them. */
@@ -908,8 +909,6 @@ static void virtio_blk_reset(VirtIODevice *vdev)
         virtio_blk_free_request(req);
     }
 
-    aio_context_release(ctx);
-
     assert(!s->dataplane_started);
     blk_set_enable_write_cache(s->blk, s->original_wce);
 }
-- 
2.38.1