Messages in this thread Patch in this message | | | From | Rusty Russell <> | Subject | [PATCH 2/6] virtio_blk: don't crash, report error if virtqueue is broken. | Date | Wed, 15 Jan 2014 13:06:07 +1030 |
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A bad implementation of virtio might cause us to mark the virtqueue broken: we'll dev_err() in that case, and the device is useless, but let's not BUG_ON().
ENOMEM or ENOSPC implies the ring is full, and we should try again later (-ENOMEM is documented to happen, but doesn't, as we fall through to ENOSPC).
EIO means it's broken.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- drivers/block/virtio_blk.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 6a680d4de7f1..704d6c814c17 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -158,6 +158,7 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) unsigned long flags; unsigned int num; const bool last = (req->cmd_flags & REQ_END) != 0; + int err; BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); @@ -198,11 +199,16 @@ static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) } spin_lock_irqsave(&vblk->vq_lock, flags); - if (__virtblk_add_req(vblk->vq, vbr, vbr->sg, num) < 0) { + err = __virtblk_add_req(vblk->vq, vbr, vbr->sg, num); + if (err) { virtqueue_kick(vblk->vq); spin_unlock_irqrestore(&vblk->vq_lock, flags); blk_mq_stop_hw_queue(hctx); - return BLK_MQ_RQ_QUEUE_BUSY; + /* Out of mem doesn't actually happen, since we fall back + * to direct descriptors */ + if (err == -ENOMEM || err == -ENOSPC) + return BLK_MQ_RQ_QUEUE_BUSY; + return BLK_MQ_RQ_QUEUE_ERROR; } if (last) -- 1.8.3.2
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