From 3db70a853202c252a8ebefa71ccb088ad149cdd2 Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Wed, 25 Nov 2015 17:52:55 -0500 Subject: [PATCH] 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 Reported-and-Tested-by: Konrad Rzeszutek Wilk Signed-off-by: Konrad Rzeszutek Wilk --- drivers/block/xen-blkfront.c | 74 ++++++++++++++++++++++-------------- 1 file 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); /* -- 2.39.5