Re: [Qemu-devel] [PATCH] virtio-blk: Release s->rq queue at system_reset

[Paolo Bonzini]

On 29/07/2016 12:22, Fam Zheng wrote:
> 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 <address@hidden>
> Reported-by: Laszlo Ersek <address@hidden>
> Signed-off-by: Fam Zheng <address@hidden>
> ---
>  hw/block/virtio-blk.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 475a822..89eca65 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
> @@ -661,6 +662,11 @@ static void virtio_blk_reset(VirtIODevice *vdev)
>       */
>      ctx = blk_get_aio_context(s->blk);
>      aio_context_acquire(ctx);
> +    while (s->rq) {
> +        req = s->rq;
> +        s->rq = req->next;
> +        virtio_blk_free_request(req);
> +    }
>      blk_drain(s->blk);

blk_drain can consume requests too, so I think it should be the other
way round: first drain, then drop any failed request that's been left in
s->rq.

Paolo

>      if (s->dataplane) {
>