One of the debugfs attributes allows to run a queue. Since running a queue after a queue has entered the "dead" state is not allowed and even can cause a kernel crash, unregister the debugfs attributes before a queue reaches the "dead" state.
Signed-off-by: Bart Van Assche <[email protected]> Cc: Omar Sandoval <[email protected]> Cc: Hannes Reinecke <[email protected]> --- block/blk-mq-sysfs.c | 31 ++++++------------------------- block/blk-sysfs.c | 3 +-- 2 files changed, 7 insertions(+), 27 deletions(-) diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 727e3b675130..1b2107f229ee 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -258,7 +258,7 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) queue_for_each_hw_ctx(q, hctx, i) blk_mq_unregister_hctx(hctx); - blk_mq_debugfs_unregister_hctxs(q); + blk_mq_debugfs_unregister(q); kobject_uevent(&q->mq_kobj, KOBJ_REMOVE); kobject_del(&q->mq_kobj); @@ -306,8 +306,7 @@ void blk_mq_sysfs_init(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; + int ret; WARN_ON_ONCE(!q->kobj.parent); lockdep_assert_held(&q->sysfs_lock); @@ -318,14 +317,7 @@ int __blk_mq_register_dev(struct device *dev, struct request_queue *q) kobject_uevent(&q->mq_kobj, KOBJ_ADD); - blk_mq_debugfs_register(q); - - queue_for_each_hw_ctx(q, hctx, i) { - ret = blk_mq_register_hctx(hctx); - if (ret) - break; - } - + ret = blk_mq_debugfs_register(q); if (ret) __blk_mq_unregister_dev(dev, q); else @@ -351,20 +343,9 @@ EXPORT_SYMBOL_GPL(blk_mq_register_dev); 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) - goto unlock; - - blk_mq_debugfs_unregister_hctxs(q); - - queue_for_each_hw_ctx(q, hctx, i) - blk_mq_unregister_hctx(hctx); - -unlock: + if (q->mq_sysfs_init_done) + blk_mq_debugfs_unregister(q); mutex_unlock(&q->sysfs_lock); } @@ -380,7 +361,7 @@ int blk_mq_sysfs_register(struct request_queue *q) if (!q->mq_sysfs_init_done) goto unlock; - blk_mq_debugfs_register_hctxs(q); + blk_mq_debugfs_register(q); queue_for_each_hw_ctx(q, hctx, i) { ret = blk_mq_register_hctx(hctx); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 726ca28584dc..3b6eca07b7a4 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -823,8 +823,7 @@ static void blk_release_queue(struct kobject *kobj) blk_trace_shutdown(q); - if (q->mq_ops) - blk_mq_debugfs_unregister(q); + WARN_ON_ONCE(q->debugfs_dir); if (q->bio_split) bioset_free(q->bio_split); -- 2.12.2
