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>
This commit is contained in:
NeilBrown 2011-02-21 18:25:57 +11:00
parent 8f5f02c460
commit da9cf5050a
6 changed files with 8 additions and 9 deletions

View File

@ -216,7 +216,6 @@ static int linear_run (mddev_t *mddev)
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)

View File

@ -435,7 +435,6 @@ 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;

View File

@ -361,7 +361,6 @@ static int raid0_run(mddev_t *mddev)
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) {

View File

@ -593,7 +593,10 @@ static int flush_pending_writes(conf_t *conf)
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 @@ static int make_request(mddev_t *mddev, struct bio * bio)
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 @@ static int run(mddev_t *mddev)
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);

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@ -662,7 +662,10 @@ static int flush_pending_writes(conf_t *conf)
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 @@ static int make_request(mddev_t *mddev, struct bio * bio)
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 @@ static int run(mddev_t *mddev)
if (!conf)
goto out;
mddev->queue->queue_lock = &conf->device_lock;
mddev->thread = conf->thread;
conf->thread = NULL;

View File

@ -5204,7 +5204,6 @@ static int run(mddev_t *mddev)
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;