Remove blkdev warning triggered by using md

As setting and clearing queue flags now requires that we hold a spinlock
on the queue, and as blk_queue_stack_limits is called without that lock,
get the lock inside blk_queue_stack_limits.

For blk_queue_stack_limits to be able to find the right lock, each md
personality needs to set q->queue_lock to point to the appropriate lock.
Those personalities which didn't previously use a spin_lock, us
q->__queue_lock.  So always initialise that lock when allocated.

With this in place, setting/clearing of the QUEUE_FLAG_PLUGGED bit will no
longer cause warnings as it will be clear that the proper lock is held.

Thanks to Dan Williams for review and fixing the silly bugs.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Alistair John Strachan <alistair@devzero.co.uk>
Cc: Nick Piggin <npiggin@suse.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Jacek Luczak <difrost.kernel@gmail.com>
Cc: Prakash Punnoor <prakash@punnoor.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 10 insertions, 2 deletions

diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 0b85117..1074824 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -250,6 +250,7 @@ static int linear_run (mddev_t *mddev)
 {
 	linear_conf_t *conf;
 
+	mddev->queue->queue_lock = &mddev->queue->__queue_lock;
 	conf = linear_conf(mddev, mddev->raid_disks);
 
 	if (!conf)
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 42ee1a2..4f4d1f3 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -417,6 +417,7 @@ static int multipath_run (mddev_t *mddev)
 	 * bookkeeping area. [whatever we allocate in multipath_run(),
 	 * should be freed in multipath_stop()]
 	 */
+	mddev->queue->queue_lock = &mddev->queue->__queue_lock;
 
 	conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL);
 	mddev->private = conf;
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 818b482..914c04d 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -280,6 +280,7 @@ static int raid0_run (mddev_t *mddev)
 	       (mddev->chunk_size>>1)-1);
 	blk_queue_max_sectors(mddev->queue, mddev->chunk_size >> 9);
 	blk_queue_segment_boundary(mddev->queue, (mddev->chunk_size>>1) - 1);
+	mddev->queue->queue_lock = &mddev->queue->__queue_lock;
 
 	conf = kmalloc(sizeof (raid0_conf_t), GFP_KERNEL);
 	if (!conf)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6778b7c..ac409b7 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1935,6 +1935,9 @@ static int run(mddev_t *mddev)
 	if (!conf->r1bio_pool)
 		goto out_no_mem;
 
+	spin_lock_init(&conf->device_lock);
+	mddev->queue->queue_lock = &conf->device_lock;
+
 	rdev_for_each(rdev, tmp, mddev) {
 		disk_idx = rdev->raid_disk;
 		if (disk_idx >= mddev->raid_disks
@@ -1958,7 +1961,6 @@ static int run(mddev_t *mddev)
 	}
 	conf->raid_disks = mddev->raid_disks;
 	conf->mddev = mddev;
-	spin_lock_init(&conf->device_lock);
 	INIT_LIST_HEAD(&conf->retry_list);
 
 	spin_lock_init(&conf->resync_lock);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index faf3d89..8536ede 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2082,6 +2082,9 @@ static int run(mddev_t *mddev)
 		goto out_free_conf;
 	}
 
+	spin_lock_init(&conf->device_lock);
+	mddev->queue->queue_lock = &conf->device_lock;
+
 	rdev_for_each(rdev, tmp, mddev) {
 		disk_idx = rdev->raid_disk;
 		if (disk_idx >= mddev->raid_disks
@@ -2103,7 +2106,6 @@ static int run(mddev_t *mddev)
 
 		disk->head_position = 0;
 	}
-	spin_lock_init(&conf->device_lock);
 	INIT_LIST_HEAD(&conf->retry_list);
 
 	spin_lock_init(&conf->resync_lock);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ee0ea91..93fde48 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4257,6 +4257,7 @@ static int run(mddev_t *mddev)
 			goto abort;
 	}
 	spin_lock_init(&conf->device_lock);
+	mddev->queue->queue_lock = &conf->device_lock;
 	init_waitqueue_head(&conf->wait_for_stripe);
 	init_waitqueue_head(&conf->wait_for_overlap);
 	INIT_LIST_HEAD(&conf->handle_list);