Xuan Zhuo
2023-Oct-20 09:50 UTC
[PATCH] virtio_ring: add an error code check in virtqueue_resize
On Fri, 20 Oct 2023 05:42:14 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote:> On Fri, Oct 20, 2023 at 05:36:41PM +0800, Xuan Zhuo wrote: > > On Fri, 20 Oct 2023 05:34:32 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > On Fri, Oct 20, 2023 at 05:23:21PM +0800, Su Hui wrote: > > > > virtqueue_resize_packed() or virtqueue_resize_split() can return > > > > error code if failed, so add a check for this. > > > > > > > > Signed-off-by: Su Hui <suhui at nfschina.com> > > > > --- > > > > > > > > I'm not sure that return directly is right or not, > > > > maybe there are some process should do before return. > > > > > > yes - presizely what virtqueue_enable_after_reset does. > > > > > > Error handling in virtqueue_enable_after_reset is really weird BTW. > > > For some reason it overrides the error code returned. > > > > > > > > > > > > > > > > > > > drivers/virtio/virtio_ring.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > index 51d8f3299c10..cf662c3a755b 100644 > > > > --- a/drivers/virtio/virtio_ring.c > > > > +++ b/drivers/virtio/virtio_ring.c > > > > @@ -2759,6 +2759,9 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num, > > > > else > > > > err = virtqueue_resize_split(_vq, num); > > > > > > > > + if (err) > > > > + return err; > > > > + > > > > return virtqueue_enable_after_reset(_vq); > > > > > > So I think it should be something like: > > > > > > int err_reset = virtqueue_enable_after_reset(_vq); > > > BUG_ON(err_reset); > > > > > > return err; > > > > > > > How about WARN and vq->broken? > > > > Thanks. > > Well, what are the cases where it can happen practically?Device error. Such as vp_active_vq() Thanks.> > > > > > > > > > > > > } > > > > EXPORT_SYMBOL_GPL(virtqueue_resize); > > > > -- > > > > 2.30.2 > > > >
Michael S. Tsirkin
2023-Oct-20 10:08 UTC
[PATCH] virtio_ring: add an error code check in virtqueue_resize
On Fri, Oct 20, 2023 at 05:50:22PM +0800, Xuan Zhuo wrote:> On Fri, 20 Oct 2023 05:42:14 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote: > > On Fri, Oct 20, 2023 at 05:36:41PM +0800, Xuan Zhuo wrote: > > > On Fri, 20 Oct 2023 05:34:32 -0400, "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > > On Fri, Oct 20, 2023 at 05:23:21PM +0800, Su Hui wrote: > > > > > virtqueue_resize_packed() or virtqueue_resize_split() can return > > > > > error code if failed, so add a check for this. > > > > > > > > > > Signed-off-by: Su Hui <suhui at nfschina.com> > > > > > --- > > > > > > > > > > I'm not sure that return directly is right or not, > > > > > maybe there are some process should do before return. > > > > > > > > yes - presizely what virtqueue_enable_after_reset does. > > > > > > > > Error handling in virtqueue_enable_after_reset is really weird BTW. > > > > For some reason it overrides the error code returned. > > > > > > > > > > > > > > > > > > > > > > > > > drivers/virtio/virtio_ring.c | 3 +++ > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > > > > index 51d8f3299c10..cf662c3a755b 100644 > > > > > --- a/drivers/virtio/virtio_ring.c > > > > > +++ b/drivers/virtio/virtio_ring.c > > > > > @@ -2759,6 +2759,9 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num, > > > > > else > > > > > err = virtqueue_resize_split(_vq, num); > > > > > > > > > > + if (err) > > > > > + return err; > > > > > + > > > > > return virtqueue_enable_after_reset(_vq); > > > > > > > > So I think it should be something like: > > > > > > > > int err_reset = virtqueue_enable_after_reset(_vq); > > > > BUG_ON(err_reset); > > > > > > > > return err; > > > > > > > > > > How about WARN and vq->broken? > > > > > > Thanks. > > > > Well, what are the cases where it can happen practically? > > Device error. Such as vp_active_vq() > > Thanks.Hmm interesting. OK. But do callers know to recover?> > > > > > > > > > > > > > > > > > > } > > > > > EXPORT_SYMBOL_GPL(virtqueue_resize); > > > > > -- > > > > > 2.30.2 > > > > > >