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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-04-26 13:47:48 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-04-26 15:09:04 -0600 |
| commit | 2d0364c8c1a97a1d44760895a982221c06af0f35 (patch) | |
| tree | 815eee282e7f3204d4c723e5b190ffc026f0fb02 /block/blk-mq-sysfs.c | |
| parent | 1608fd1ca3b9357ea20ffc3a8ad2d1e4b78301a6 (diff) | |
| download | linux-0-day-2d0364c8c1a97a1d44760895a982221c06af0f35.tar.gz linux-0-day-2d0364c8c1a97a1d44760895a982221c06af0f35.tar.xz | |
blk-mq: Register <dev>/queue/mq after having registered <dev>/queue
A later patch in this series will modify blk_mq_debugfs_register()
such that it uses q->kobj.parent to determine the name of a
request queue. Hence make sure that that pointer is initialized
before blk_mq_debugfs_register() is called. To avoid lock inversion,
protect sysfs / debugfs registration with the queue sysfs_lock
instead of the global mutex all_q_mutex.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-mq-sysfs.c')
| -rw-r--r-- | block/blk-mq-sysfs.c | 35 |
1 files changed, 28 insertions, 7 deletions
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index d745ab81033af..a2dbb1a48e727 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -253,6 +253,8 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; + lockdep_assert_held(&q->sysfs_lock); + queue_for_each_hw_ctx(q, hctx, i) blk_mq_unregister_hctx(hctx); @@ -267,9 +269,9 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) void blk_mq_unregister_dev(struct device *dev, struct request_queue *q) { - blk_mq_disable_hotplug(); + mutex_lock(&q->sysfs_lock); __blk_mq_unregister_dev(dev, q); - blk_mq_enable_hotplug(); + mutex_unlock(&q->sysfs_lock); } void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx) @@ -302,12 +304,13 @@ void blk_mq_sysfs_init(struct request_queue *q) } } -int blk_mq_register_dev(struct device *dev, struct request_queue *q) +int __blk_mq_register_dev(struct device *dev, struct request_queue *q) { struct blk_mq_hw_ctx *hctx; int ret, i; - blk_mq_disable_hotplug(); + WARN_ON_ONCE(!q->kobj.parent); + lockdep_assert_held(&q->sysfs_lock); ret = kobject_add(&q->mq_kobj, kobject_get(&dev->kobj), "%s", "mq"); if (ret < 0) @@ -327,8 +330,18 @@ int blk_mq_register_dev(struct device *dev, struct request_queue *q) __blk_mq_unregister_dev(dev, q); else q->mq_sysfs_init_done = true; + out: - blk_mq_enable_hotplug(); + return ret; +} + +int blk_mq_register_dev(struct device *dev, struct request_queue *q) +{ + int ret; + + mutex_lock(&q->sysfs_lock); + ret = __blk_mq_register_dev(dev, q); + mutex_unlock(&q->sysfs_lock); return ret; } @@ -339,13 +352,17 @@ void blk_mq_sysfs_unregister(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i; + mutex_lock(&q->sysfs_lock); if (!q->mq_sysfs_init_done) - return; + goto unlock; blk_mq_debugfs_unregister_hctxs(q); queue_for_each_hw_ctx(q, hctx, i) blk_mq_unregister_hctx(hctx); + +unlock: + mutex_unlock(&q->sysfs_lock); } int blk_mq_sysfs_register(struct request_queue *q) @@ -353,8 +370,9 @@ int blk_mq_sysfs_register(struct request_queue *q) struct blk_mq_hw_ctx *hctx; int i, ret = 0; + mutex_lock(&q->sysfs_lock); if (!q->mq_sysfs_init_done) - return ret; + goto unlock; blk_mq_debugfs_register_hctxs(q); @@ -364,5 +382,8 @@ int blk_mq_sysfs_register(struct request_queue *q) break; } +unlock: + mutex_unlock(&q->sysfs_lock); + return ret; } |