From 44ed8089e991a60d614abe0ee4b9057a28b364e4 Mon Sep 17 00:00:00 2001 From: "Richard W.M. Jones" Date: Thu, 10 Aug 2017 17:56:51 +0100 Subject: [PATCH] scsi: virtio: Reduce BUG if total_sg > virtqueue size to WARN. If using indirect descriptors, you can make the total_sg as large as you want. If not, BUG is too serious because the function later returns -ENOSPC. Signed-off-by: Richard W.M. Jones Reviewed-by: Paolo Bonzini Signed-off-by: Martin K. Petersen --- drivers/virtio/virtio_ring.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 5e1b548..27cbc1e 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -296,7 +296,6 @@ static inline int virtqueue_add(struct virtqueue *_vq, } #endif - BUG_ON(total_sg > vq->vring.num); BUG_ON(total_sg == 0); head = vq->free_head; @@ -305,8 +304,10 @@ static inline int virtqueue_add(struct virtqueue *_vq, * buffers, then go indirect. FIXME: tune this threshold */ if (vq->indirect && total_sg > 1 && vq->vq.num_free) desc = alloc_indirect(_vq, total_sg, gfp); - else + else { desc = NULL; + WARN_ON_ONCE(total_sg > vq->vring.num && !vq->indirect); + } if (desc) { /* Use a single buffer which doesn't continue */ -- 2.7.4