Remove blkdev warning triggered by using md
Neil Brown [Wed, 14 May 2008 23:05:54 +0000 (16:05 -0700)]
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>

block/blk-core.c
block/blk-settings.c
drivers/md/linear.c
drivers/md/multipath.c
drivers/md/raid0.c
drivers/md/raid1.c
drivers/md/raid10.c
drivers/md/raid5.c

index 2987fe4..6a9cc0d 100644 (file)
@@ -482,6 +482,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
        kobject_init(&q->kobj, &blk_queue_ktype);
 
        mutex_init(&q->sysfs_lock);
+       spin_lock_init(&q->__queue_lock);
 
        return q;
 }
@@ -544,10 +545,8 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
         * if caller didn't supply a lock, they get per-queue locking with
         * our embedded lock
         */
-       if (!lock) {
-               spin_lock_init(&q->__queue_lock);
+       if (!lock)
                lock = &q->__queue_lock;
-       }
 
        q->request_fn           = rfn;
        q->prep_rq_fn           = NULL;
index bb93d4c..8dd8641 100644 (file)
@@ -286,8 +286,14 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
        t->max_hw_segments = min(t->max_hw_segments, b->max_hw_segments);
        t->max_segment_size = min(t->max_segment_size, b->max_segment_size);
        t->hardsect_size = max(t->hardsect_size, b->hardsect_size);
-       if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags))
+       if (!t->queue_lock)
+               WARN_ON_ONCE(1);
+       else if (!test_bit(QUEUE_FLAG_CLUSTER, &b->queue_flags)) {
+               unsigned long flags;
+               spin_lock_irqsave(t->queue_lock, flags);
                queue_flag_clear(QUEUE_FLAG_CLUSTER, t);
+               spin_unlock_irqrestore(t->queue_lock, flags);
+       }
 }
 EXPORT_SYMBOL(blk_queue_stack_limits);
 
index 0b85117..1074824 100644 (file)
@@ -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)
index 42ee1a2..4f4d1f3 100644 (file)
@@ -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;
index 818b482..914c04d 100644 (file)
@@ -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)
index 6778b7c..ac409b7 100644 (file)
@@ -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);
index faf3d89..8536ede 100644 (file)
@@ -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);
index ee0ea91..93fde48 100644 (file)
@@ -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);