On Thu, Aug 14, 2014 at 02:39:22PM +0400, Michael Tokarev wrote:
> 14.08.2014 14:37, Michael S. Tsirkin wrote:
> > On Thu, Aug 14, 2014 at 03:29:14PM +0800, zhanghailiang wrote:
> >> In function virtio_blk_handle_request, it may freed memory pointed by req,
> >> So do not access member of req after calling this function.
> >>
> >> Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
> >> Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
> >
> > Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
>
> Just a small nitpick...
>
> > Stefan want to pick up this one?
> >
> >> ---
> >> hw/block/virtio-blk.c | 5 +++--
> >> 1 file changed, 3 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> >> index c241c50..54a853a 100644
> >> --- a/hw/block/virtio-blk.c
> >> +++ b/hw/block/virtio-blk.c
> >> @@ -458,7 +458,7 @@ static void virtio_blk_handle_output(VirtIODevice
> >> *vdev, VirtQueue *vq)
> >> static void virtio_blk_dma_restart_bh(void *opaque)
> >> {
> >> VirtIOBlock *s = opaque;
> >> - VirtIOBlockReq *req = s->rq;
> >> + VirtIOBlockReq *req = s->rq, *next = NULL;
>
> There's no need to initialize next here.
> With init like this I for one instinctively start searching below
> how this `NULL' is used (which it isn't).
>
> I'd declare it inside the loop too, since it is a local-to-loop
> var, but that doesn't matter much.
>
> /mjt
Good point, I agree.
> >> MultiReqBuffer mrb = {
> >> .num_writes = 0,
> >> };
> >> @@ -469,8 +469,9 @@ static void virtio_blk_dma_restart_bh(void *opaque)
> >> s->rq = NULL;
> >>
> >> while (req) {
> >> + next = req->next;
> >> virtio_blk_handle_request(req, &mrb);
> >> - req = req->next;
> >> + req = next;
> >> }
> >>
> >> virtio_submit_multiwrite(s->bs, &mrb);
> >> --
> >> 1.7.12.4
> >>
