md: avoid spinlock problem in blk_throtl_exit
blk_throtl_exit assumes that ->queue_lock still exists,
so make sure that it does.
To do this, we stop redirecting ->queue_lock to conf->device_lock
and leave it pointing where it is initialised - __queue_lock.
As the blk_plug functions check the ->queue_lock is held, we now
take that spin_lock explicitly around the plug functions. We don't
need the locking, just the warning removal.
This is needed for any kernel with the blk_throtl code, which is
which is 2.6.37 and later.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 8a2f767..0ed7f6b 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -216,7 +216,6 @@
if (md_check_no_bitmap(mddev))
return -EINVAL;
- 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 6d7ddf3..3a62d44 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -435,7 +435,6 @@
* 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 75671df..c0ac457 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -361,7 +361,6 @@
if (md_check_no_bitmap(mddev))
return -EINVAL;
blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
- mddev->queue->queue_lock = &mddev->queue->__queue_lock;
/* if private is not null, we are here after takeover */
if (mddev->private == NULL) {
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a23ffa3..06cd712 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -593,7 +593,10 @@
if (conf->pending_bio_list.head) {
struct bio *bio;
bio = bio_list_get(&conf->pending_bio_list);
+ /* Only take the spinlock to quiet a warning */
+ spin_lock(conf->mddev->queue->queue_lock);
blk_remove_plug(conf->mddev->queue);
+ spin_unlock(conf->mddev->queue->queue_lock);
spin_unlock_irq(&conf->device_lock);
/* flush any pending bitmap writes to
* disk before proceeding w/ I/O */
@@ -959,7 +962,7 @@
atomic_inc(&r1_bio->remaining);
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
- blk_plug_device(mddev->queue);
+ blk_plug_device_unlocked(mddev->queue);
spin_unlock_irqrestore(&conf->device_lock, flags);
}
r1_bio_write_done(r1_bio, bio->bi_vcnt, behind_pages, behind_pages != NULL);
@@ -2021,7 +2024,6 @@
if (IS_ERR(conf))
return PTR_ERR(conf);
- mddev->queue->queue_lock = &conf->device_lock;
list_for_each_entry(rdev, &mddev->disks, same_set) {
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3b607b2..747d061 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -662,7 +662,10 @@
if (conf->pending_bio_list.head) {
struct bio *bio;
bio = bio_list_get(&conf->pending_bio_list);
+ /* Spinlock only taken to quiet a warning */
+ spin_lock(conf->mddev->queue->queue_lock);
blk_remove_plug(conf->mddev->queue);
+ spin_unlock(conf->mddev->queue->queue_lock);
spin_unlock_irq(&conf->device_lock);
/* flush any pending bitmap writes to disk
* before proceeding w/ I/O */
@@ -971,7 +974,7 @@
atomic_inc(&r10_bio->remaining);
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
- blk_plug_device(mddev->queue);
+ blk_plug_device_unlocked(mddev->queue);
spin_unlock_irqrestore(&conf->device_lock, flags);
}
@@ -2304,8 +2307,6 @@
if (!conf)
goto out;
- mddev->queue->queue_lock = &conf->device_lock;
-
mddev->thread = conf->thread;
conf->thread = NULL;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 7028128..78536fd 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5204,7 +5204,6 @@
mddev->queue->backing_dev_info.congested_data = mddev;
mddev->queue->backing_dev_info.congested_fn = raid5_congested;
- mddev->queue->queue_lock = &conf->device_lock;
mddev->queue->unplug_fn = raid5_unplug_queue;
chunk_size = mddev->chunk_sectors << 9;