Merge tag 'arm-soc/for-4.8/soc' of http://github.com/Broadcom/stblinux into next/soc

[cascardo/linux.git] / drivers / block / xen-blkfront.c

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 6405b65..2e6d1e9 100644 (file)
--- 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) {
@@ -998,7 +992,8 @@ static const char *flush_info(unsigned int feature_flush)
 
 static void xlvbd_flush(struct blkfront_info *info)
 {
-       blk_queue_flush(info->rq, info->feature_flush);
+       blk_queue_write_cache(info->rq, info->feature_flush & REQ_FLUSH,
+                               info->feature_flush & REQ_FUA);
        pr_info("blkfront: %s: %s %s %s %s %s\n",
                info->gd->disk_name, flush_info(info->feature_flush),
                "persistent grants:", info->feature_persistent ?
@@ -2148,6 +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
@@ -2484,10 +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;