1 files changed, 45 insertions, 29 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 8a8dc91c39f7..83eb9e6bf8b0 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1873,6 +1873,43 @@ again:
         return err;
 }
 
+static int negotiate_mq(struct blkfront_info *info)
+{
+        unsigned int backend_max_queues = 0;
+        int err;
+        unsigned int i;
+
+        BUG_ON(info->nr_rings);
+
+        /* Check if backend supports multiple queues. */
+        err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
+                           "multi-queue-max-queues", "%u", &backend_max_queues);
+        if (err < 0)
+                backend_max_queues = 1;
+
+        info->nr_rings = min(backend_max_queues, xen_blkif_max_queues);
+        /* We need at least one ring. */
+        if (!info->nr_rings)
+                info->nr_rings = 1;
+
+        info->rinfo = kzalloc(sizeof(struct blkfront_ring_info) * info->nr_rings, GFP_KERNEL);
+        if (!info->rinfo) {
+                xenbus_dev_fatal(info->xbdev, -ENOMEM, "allocating ring_info structure");
+                return -ENOMEM;
+        }
+
+        for (i = 0; i < info->nr_rings; i++) {
+                struct blkfront_ring_info *rinfo;
+
+                rinfo = &info->rinfo[i];
+                INIT_LIST_HEAD(&rinfo->indirect_pages);
+                INIT_LIST_HEAD(&rinfo->grants);
+                rinfo->dev_info = info;
+                INIT_WORK(&rinfo->work, blkif_restart_queue);
+                spin_lock_init(&rinfo->ring_lock);
+        }
+        return 0;
+}
 /**
  * Entry point to this code when a new device is created.  Allocate the basic
  * structures and the ring buffer for communication with the backend, and
@@ -1883,9 +1920,7 @@ static int blkfront_probe(struct xenbus_device *dev,
                           const struct xenbus_device_id *id)
 {
         int err, vdevice;
-        unsigned int r_index;
         struct blkfront_info *info;
-        unsigned int backend_max_queues = 0;
 
         /* FIXME: Use dynamic device id if this is not set. */
         err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -1936,33 +1971,10 @@ static int blkfront_probe(struct xenbus_device *dev,
         }
 
         info->xbdev = dev;
-        /* Check if backend supports multiple queues. */
-        err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
-                           "multi-queue-max-queues", "%u", &backend_max_queues);
-        if (err < 0)
-                backend_max_queues = 1;
-
-        info->nr_rings = min(backend_max_queues, xen_blkif_max_queues);
-        /* We need at least one ring. */
-        if (!info->nr_rings)
-                info->nr_rings = 1;
-
-        info->rinfo = kzalloc(sizeof(struct blkfront_ring_info) * info->nr_rings, GFP_KERNEL);
-        if (!info->rinfo) {
-                xenbus_dev_fatal(dev, -ENOMEM, "allocating ring_info structure");
+        err = negotiate_mq(info);
+        if (err) {
                 kfree(info);
-                return -ENOMEM;
-        }
-
-        for (r_index = 0; r_index < info->nr_rings; r_index++) {
-                struct blkfront_ring_info *rinfo;
-
-                rinfo = &info->rinfo[r_index];
-                INIT_LIST_HEAD(&rinfo->indirect_pages);
-                INIT_LIST_HEAD(&rinfo->grants);
-                rinfo->dev_info = info;
-                INIT_WORK(&rinfo->work, blkif_restart_queue);
-                spin_lock_init(&rinfo->ring_lock);
+                return err;
         }
 
         mutex_init(&info->mutex);
@@ -2123,12 +2135,16 @@ static int blkif_recover(struct blkfront_info *info)
 static int blkfront_resume(struct xenbus_device *dev)
 {
         struct blkfront_info *info = dev_get_drvdata(&dev->dev);
-        int err;
+        int err = 0;
 
         dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
 
         blkif_free(info, info->connected == BLKIF_STATE_CONNECTED);
 
+        err = negotiate_mq(info);
+        if (err)
+                return err;
+
         err = talk_to_blkback(dev, info);
 
         /*