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>
This commit is contained in:
Bob Liu 2015-11-25 17:52:55 -05:00 committed by Konrad Rzeszutek Wilk
parent c31ecf6c12
commit 3db70a8532

View file

@ -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);
/*