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Commit 1decabc1 authored by Jens Axboe's avatar Jens Axboe
Browse files

Merge branch 'stable/for-jens-4.7' of... 

Merge branch 'stable/for-jens-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus

Konrad writes:

Thishas two fixes for a guest migrating from host that
has multi-queue to one without it (and vice-versa).
parents d366a0ff 2a6f71ad

drivers/block/xen-blkfront.c

+22 −13
Original line number Diff line number Diff line
@@ -874,8 +874,12 @@ static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx, 
			  const struct blk_mq_queue_data *qd)

{

	unsigned long flags;

	struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)hctx->driver_data;

	int qid = hctx->queue_num;

	struct blkfront_info *info = hctx->queue->queuedata;

	struct blkfront_ring_info *rinfo = NULL;



	BUG_ON(info->nr_rings <= qid);

	rinfo = &info->rinfo[qid];

	blk_mq_start_request(qd->rq);

	spin_lock_irqsave(&rinfo->ring_lock, flags);

	if (RING_FULL(&rinfo->ring))
@@ -901,20 +905,9 @@ static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx, 
	return BLK_MQ_RQ_QUEUE_BUSY;

}



static int blk_mq_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,

			    unsigned int index)

{

	struct blkfront_info *info = (struct blkfront_info *)data;



	BUG_ON(info->nr_rings <= index);

	hctx->driver_data = &info->rinfo[index];

	return 0;

}



static struct blk_mq_ops blkfront_mq_ops = {

	.queue_rq = blkif_queue_rq,

	.map_queue = blk_mq_map_queue,

	.init_hctx = blk_mq_init_hctx,

};



static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
@@ -950,6 +943,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, 
		return PTR_ERR(rq);

	}



	rq->queuedata = info;

	queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);



	if (info->feature_discard) {
@@ -2149,6 +2143,8 @@ static int blkfront_resume(struct xenbus_device *dev) 
		return err;



	err = talk_to_blkback(dev, info);

	if (!err)

		blk_mq_update_nr_hw_queues(&info->tag_set, info->nr_rings);



	/*

	 * We have to wait for the backend to switch to
@@ -2485,10 +2481,23 @@ static void blkback_changed(struct xenbus_device *dev, 
		break;



	case XenbusStateConnected:

		if (dev->state != XenbusStateInitialised) {

		/*

		 * talk_to_blkback sets state to XenbusStateInitialised

		 * and blkfront_connect sets it to XenbusStateConnected

		 * (if connection went OK).

		 *

		 * If the backend (or toolstack) decides to poke at backend

		 * state (and re-trigger the watch by setting the state repeatedly

		 * to XenbusStateConnected (4)) we need to deal with this.

		 * This is allowed as this is used to communicate to the guest

		 * that the size of disk has changed!

		 */

		if ((dev->state != XenbusStateInitialised) &&

		    (dev->state != XenbusStateConnected)) {

			if (talk_to_blkback(dev, info))

				break;

		}



		blkfront_connect(info);

		break;