From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <00moses.alexander00@gmail.com> Return-Path: <00moses.alexander00@gmail.com> Date: Sat, 7 Apr 2018 12:21:48 +0200 From: Alexandru Moise <00moses.alexander00@gmail.com> To: axboe@kernel.dk, tj@kernel.org, shli@fb.com, nborisov@suse.com, arnd@arndb.de, gregkh@linuxfoundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] blk-cgroup: remove entries in blkg_tree before queue release Message-ID: <20180407102148.GA9729@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-ID: The q->id is used as an index within the blkg_tree radix tree. If the entry is not released before reclaiming the blk_queue_ida's id blkcg_init_queue() within a different driver from which this id was originally for can fail due to the entry at that index within the radix tree already existing. Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> --- v2: Added no-op for !CONFIG_BLK_CGROUP block/blk-cgroup.c | 2 +- block/blk-sysfs.c | 4 ++++ include/linux/blk-cgroup.h | 3 +++ 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 1c16694ae145..224e937dbb59 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -369,7 +369,7 @@ static void blkg_destroy(struct blkcg_gq *blkg) * * Destroy all blkgs associated with @q. */ -static void blkg_destroy_all(struct request_queue *q) +void blkg_destroy_all(struct request_queue *q) { struct blkcg_gq *blkg, *n; diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index d00d1b0ec109..a72866458f22 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -816,6 +816,10 @@ static void __blk_release_queue(struct work_struct *work) if (q->bio_split) bioset_free(q->bio_split); + spin_lock_irq(q->queue_lock); + blkg_destroy_all(q); + spin_unlock_irq(q->queue_lock); + ida_simple_remove(&blk_queue_ida, q->id); call_rcu(&q->rcu_head, blk_free_queue_rcu); } diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 6c666fd7de3c..3d60b1d1973d 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -179,6 +179,8 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, int blkcg_init_queue(struct request_queue *q); void blkcg_drain_queue(struct request_queue *q); void blkcg_exit_queue(struct request_queue *q); +void blkg_destroy_all(struct request_queue *q); + /* Blkio controller policy registration */ int blkcg_policy_register(struct blkcg_policy *pol); @@ -740,6 +742,7 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { ret static inline int blkcg_init_queue(struct request_queue *q) { return 0; } static inline void blkcg_drain_queue(struct request_queue *q) { } static inline void blkcg_exit_queue(struct request_queue *q) { } +static inline void blkg_destroy_all(struct request_queue *q) { } static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; } static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { } static inline int blkcg_activate_policy(struct request_queue *q, -- 2.16.2