Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5261b85e authored by Rusty Russell's avatar Rusty Russell
Browse files

virtio_blk: don't crash, report error if virtqueue is broken. 



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: default avatarRusty Russell <rusty@rustcorp.com.au>
parent a7c58146

drivers/block/virtio_blk.c

+8 −2
Original line number Diff line number Diff line
@@ -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);

		/* 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)