xen/blkfront: realloc ring info in blkif_resume
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@oracle.com>
Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 8a8dc91..83eb9e6 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1873,6 +1873,43 @@
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 @@
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 @@
}
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 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);
/*