[Qemu-block] [PATCH 2/3] virtio-blk: Use blk_drain() to drain IO requests

[Alexander Yarygin]

Each call of the virtio_blk_reset() function calls blk_drain_all(),
which works for all existing BlockDriverStates, while draining only
one is needed.

This patch replaces blk_drain_all() by blk_drain() in virtio_blk_reset().

Cc: Christian Borntraeger <address@hidden>
Cc: Cornelia Huck <address@hidden>
Cc: Kevin Wolf <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Cc: Stefan Hajnoczi <address@hidden>
Signed-off-by: Alexander Yarygin <address@hidden>
---
 hw/block/virtio-blk.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index e6afe97..2009092 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -652,15 +652,16 @@ static void virtio_blk_reset(VirtIODevice *vdev)
 {
     VirtIOBlock *s = VIRTIO_BLK(vdev);
 
-    if (s->dataplane) {
-        virtio_blk_data_plane_stop(s->dataplane);
-    }
-
     /*
      * This should cancel pending requests, but can't do nicely until there
      * are per-device request lists.
      */
-    blk_drain_all();
+    blk_drain(s->blk);
+
+    if (s->dataplane) {
+        virtio_blk_data_plane_stop(s->dataplane);
+    }
+
     blk_set_enable_write_cache(s->blk, s->original_wce);
 }
 
-- 
1.9.1