[Qemu-devel] [PULL for-2.7 4/5] virtio-blk: Release s->rq queue at system_reset

[Stefan Hajnoczi <stefanha@redhat.com>]

From: Fam Zheng <famz@redhat.com>

At system_reset, there is no point in retrying the queued request,
because the driver that issued the request won't be around any more.

Analyzed-by: Laszlo Ersek <lersek@redhat.com>
Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-id: 1470278654-13525-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/block/virtio-blk.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 475a822..1e348b1 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -654,6 +654,7 @@ static void virtio_blk_reset(VirtIODevice *vdev)
 {
     VirtIOBlock *s = VIRTIO_BLK(vdev);
     AioContext *ctx;
+    VirtIOBlockReq *req;
 
     /*
      * This should cancel pending requests, but can't do nicely until there
@@ -663,6 +664,14 @@ static void virtio_blk_reset(VirtIODevice *vdev)
     aio_context_acquire(ctx);
     blk_drain(s->blk);
 
+    /* We drop queued requests after blk_drain() because blk_drain() itself can
+     * produce them. */
+    while (s->rq) {
+        req = s->rq;
+        s->rq = req->next;
+        virtio_blk_free_request(req);
+    }
+
     if (s->dataplane) {
         virtio_blk_data_plane_stop(s->dataplane);
     }
-- 
2.7.4