Commit 00703497 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost 

Pull virtio fix from Michael Tsirkin:
 "A last minute revert to fix a regression"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  Revert "virtio-blk: support completion batching for the IRQ path"
parents 69cbeb61 afd384f0

drivers/block/virtio_blk.c

+37 −45
Original line number Diff line number Diff line
@@ -348,63 +348,33 @@ static inline void virtblk_request_done(struct request *req) 
	blk_mq_end_request(req, status);

}



static void virtblk_complete_batch(struct io_comp_batch *iob)

{

	struct request *req;



	rq_list_for_each(&iob->req_list, req) {

		virtblk_unmap_data(req, blk_mq_rq_to_pdu(req));

		virtblk_cleanup_cmd(req);

	}

	blk_mq_end_request_batch(iob);

}



static int virtblk_handle_req(struct virtio_blk_vq *vq,

			      struct io_comp_batch *iob)

{

	struct virtblk_req *vbr;

	int req_done = 0;

	unsigned int len;



	while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) {

		struct request *req = blk_mq_rq_from_pdu(vbr);



		if (likely(!blk_should_fake_timeout(req->q)) &&

		    !blk_mq_complete_request_remote(req) &&

		    !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr),

					 virtblk_complete_batch))

			virtblk_request_done(req);

		req_done++;

	}



	return req_done;

}



static void virtblk_done(struct virtqueue *vq)

{

	struct virtio_blk *vblk = vq->vdev->priv;

	struct virtio_blk_vq *vblk_vq = &vblk->vqs[vq->index];

	int req_done = 0;

	bool req_done = false;

	int qid = vq->index;

	struct virtblk_req *vbr;

	unsigned long flags;

	DEFINE_IO_COMP_BATCH(iob);

	unsigned int len;



	spin_lock_irqsave(&vblk_vq->lock, flags);

	spin_lock_irqsave(&vblk->vqs[qid].lock, flags);

	do {

		virtqueue_disable_cb(vq);

		req_done += virtblk_handle_req(vblk_vq, &iob);

		while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {

			struct request *req = blk_mq_rq_from_pdu(vbr);



			if (likely(!blk_should_fake_timeout(req->q)))

				blk_mq_complete_request(req);

			req_done = true;

		}

		if (unlikely(virtqueue_is_broken(vq)))

			break;

	} while (!virtqueue_enable_cb(vq));



	if (req_done) {

		if (!rq_list_empty(iob.req_list))

			iob.complete(&iob);



	/* In case queue is stopped waiting for more buffers. */

	if (req_done)

		blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);

	}

	spin_unlock_irqrestore(&vblk_vq->lock, flags);

	spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);

}



static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
@@ -1283,15 +1253,37 @@ static void virtblk_map_queues(struct blk_mq_tag_set *set) 
	}

}



static void virtblk_complete_batch(struct io_comp_batch *iob)

{

	struct request *req;



	rq_list_for_each(&iob->req_list, req) {

		virtblk_unmap_data(req, blk_mq_rq_to_pdu(req));

		virtblk_cleanup_cmd(req);

	}

	blk_mq_end_request_batch(iob);

}



static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)

{

	struct virtio_blk *vblk = hctx->queue->queuedata;

	struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx);

	struct virtblk_req *vbr;

	unsigned long flags;

	unsigned int len;

	int found = 0;



	spin_lock_irqsave(&vq->lock, flags);

	found = virtblk_handle_req(vq, iob);



	while ((vbr = virtqueue_get_buf(vq->vq, &len)) != NULL) {

		struct request *req = blk_mq_rq_from_pdu(vbr);



		found++;

		if (!blk_mq_complete_request_remote(req) &&

		    !blk_mq_add_to_batch(req, iob, virtblk_vbr_status(vbr),

						virtblk_complete_batch))

			virtblk_request_done(req);

	}



	if (found)

		blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);