[PATCH 2/2] xen/blkfront: realloc ring info in blkif_resume

[Bob Liu]

Need to reallocate ring info in the resume path, because info->rinfo was freed
in blkif_free(). And 'multi-queue-max-queues' backend reports may have been
changed.

Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
---
 drivers/block/xen-blkfront.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index ef5ce43..9634a65 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1926,12 +1926,38 @@ 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;
+	unsigned int max_queues = 0, r_index;
 
 	dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
 
 	blkif_free(info, info->connected == BLKIF_STATE_CONNECTED);
 
+	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
+			"multi-queue-max-queues", "%u", &max_queues, NULL);
+	if (err)
+		max_queues = 1;
+
+	info->nr_rings = min(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)
+		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);
+	}
+
 	err = talk_to_blkback(dev, info);
 
 	/*
-- 
1.8.3.1


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