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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-06-14 13:27:50 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-06-14 13:27:50 -0600 |
| commit | dc9edc44de6cd7cc8cc7f5b36c1adb221eda3207 (patch) | |
| tree | f749db9a9accb61b5b6e7d0d88b4e45b16326a46 /block/blk-sysfs.c | |
| parent | 63f700aab4c11d46626de3cd051dae56cf7e9056 (diff) | |
| download | linux-dc9edc44de6cd7cc8cc7f5b36c1adb221eda3207.tar.bz2 | |
block: Fix a blk_exit_rl() regression
Avoid that the following complaint is reported:
BUG: sleeping function called from invalid context at kernel/workqueue.c:2790
in_atomic(): 1, irqs_disabled(): 0, pid: 41, name: rcuop/3
1 lock held by rcuop/3/41:
#0: (rcu_callback){......}, at: [<ffffffff8111f9a2>] rcu_nocb_kthread+0x282/0x500
Call Trace:
dump_stack+0x86/0xcf
___might_sleep+0x174/0x260
__might_sleep+0x4a/0x80
flush_work+0x7e/0x2e0
__cancel_work_timer+0x143/0x1c0
cancel_work_sync+0x10/0x20
blk_throtl_exit+0x25/0x60
blkcg_exit_queue+0x35/0x40
blk_release_queue+0x42/0x130
kobject_put+0xa9/0x190
This happens since we invoke callbacks that need to block from the
queue release handler. Fix this by pushing the final release to
a workqueue.
Reported-by: Ross Zwisler <zwisler@gmail.com>
Fixes: commit b425e5049258 ("block: Avoid that blk_exit_rl() triggers a use-after-free")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Updated changelog
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 34 |
1 files changed, 22 insertions, 12 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 283da7fbe034..27aceab1cc31 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -777,24 +777,25 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head) } /** - * blk_release_queue: - release a &struct request_queue when it is no longer needed - * @kobj: the kobj belonging to the request queue to be released + * __blk_release_queue - release a request queue when it is no longer needed + * @work: pointer to the release_work member of the request queue to be released * * Description: - * blk_release_queue is the pair to blk_init_queue() or - * blk_queue_make_request(). It should be called when a request queue is - * being released; typically when a block device is being de-registered. - * Currently, its primary task it to free all the &struct request - * structures that were allocated to the queue and the queue itself. + * blk_release_queue is the counterpart of blk_init_queue(). It should be + * called when a request queue is being released; typically when a block + * device is being de-registered. Its primary task it to free the queue + * itself. * - * Note: + * Notes: * The low level driver must have finished any outstanding requests first * via blk_cleanup_queue(). - **/ -static void blk_release_queue(struct kobject *kobj) + * + * Although blk_release_queue() may be called with preemption disabled, + * __blk_release_queue() may sleep. + */ +static void __blk_release_queue(struct work_struct *work) { - struct request_queue *q = - container_of(kobj, struct request_queue, kobj); + struct request_queue *q = container_of(work, typeof(*q), release_work); if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) blk_stat_remove_callback(q, q->poll_cb); @@ -834,6 +835,15 @@ static void blk_release_queue(struct kobject *kobj) call_rcu(&q->rcu_head, blk_free_queue_rcu); } +static void blk_release_queue(struct kobject *kobj) +{ + struct request_queue *q = + container_of(kobj, struct request_queue, kobj); + + INIT_WORK(&q->release_work, __blk_release_queue); + schedule_work(&q->release_work); +} + static const struct sysfs_ops queue_sysfs_ops = { .show = queue_attr_show, .store = queue_attr_store, |