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authorJens Axboe <axboe@fb.com>2016-06-09 09:49:55 -0600
committerJens Axboe <axboe@fb.com>2016-06-09 09:49:55 -0600
commit1decabc1a70b97ef7412224df3dcb59d1227e3af (patch)
tree3e235b7bc0b1a2edc027f90b8cab5c1a590728a8 /drivers
parentd366a0ff1cf73f93796f2377e7b0361a94c41c35 (diff)
parent2a6f71ad99cabe436e70c3f5fcf58072cb3bc07f (diff)
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).
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/xen-blkfront.c35
1 files changed, 22 insertions, 13 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index ca13df854639..2e6d1e9c3345 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -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 @@ out_busy:
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;