virtio: fixes

Some bug fixes all over the place.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio fixes from Michael Tsirkin:
 "Some bug fixes all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_balloon: Adjust label in virtballoon_probe
  virtio-blk: improve virtqueue error to BLK_STS
  virtio-blk: fix hw_queue stopped on arbitrary error
  virtio_ring: Fix mem leak with vring_new_virtqueue()

drivers/block/virtio_blk.c

@@ -245,13 +245,20 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
 	err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
 	if (err) {
 		virtqueue_kick(vblk->vqs[qid].vq);
-		blk_mq_stop_hw_queue(hctx);
+		/* Don't stop the queue if -ENOMEM: we may have failed to
+		 * bounce the buffer due to global resource outage.
+		 */
+		if (err == -ENOSPC)
+			blk_mq_stop_hw_queue(hctx);
 		spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
-		/* Out of mem doesn't actually happen, since we fall back
-		 * to direct descriptors */
-		if (err == -ENOMEM || err == -ENOSPC)
+		switch (err) {
+		case -ENOSPC:
 			return BLK_STS_DEV_RESOURCE;
-		return BLK_STS_IOERR;
+		case -ENOMEM:
+			return BLK_STS_RESOURCE;
+		default:
+			return BLK_STS_IOERR;
+		}
 	}
 
 	if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))

drivers/virtio/virtio_balloon.c

@@ -959,8 +959,8 @@ out_iput:
 	iput(vb->vb_dev_info.inode);
 out_kern_unmount:
 	kern_unmount(balloon_mnt);
-#endif
 out_del_vqs:
+#endif
 	vdev->config->del_vqs(vdev);
 out_free_vb:
 	kfree(vb);

drivers/virtio/virtio_ring.c

@@ -2203,10 +2203,10 @@ void vring_del_virtqueue(struct virtqueue *_vq)
 					 vq->split.queue_size_in_bytes,
 					 vq->split.vring.desc,
 					 vq->split.queue_dma_addr);
-
-			kfree(vq->split.desc_state);
 		}
 	}
+	if (!vq->packed_ring)
+		kfree(vq->split.desc_state);
 	list_del(&_vq->list);
 	kfree(vq);
 }