diff options
Diffstat (limited to 'block/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 41c74b37be85..6febc69a58aa 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -719,6 +719,37 @@ void blk_cleanup_queue(struct request_queue *q) del_timer_sync(&q->backing_dev_info->laptop_mode_wb_timer); blk_sync_queue(q); + /* + * I/O scheduler exit is only safe after the sysfs scheduler attribute + * has been removed. + */ + WARN_ON_ONCE(q->kobj.state_in_sysfs); + + /* + * Since the I/O scheduler exit code may access cgroup information, + * perform I/O scheduler exit before disassociating from the block + * cgroup controller. + */ + if (q->elevator) { + ioc_clear_queue(q); + elevator_exit(q, q->elevator); + q->elevator = NULL; + } + + /* + * Remove all references to @q from the block cgroup controller before + * restoring @q->queue_lock to avoid that restoring this pointer causes + * e.g. blkcg_print_blkgs() to crash. + */ + blkcg_exit_queue(q); + + /* + * Since the cgroup code may dereference the @q->backing_dev_info + * pointer, only decrease its reference count after having removed the + * association with the block cgroup controller. + */ + bdi_put(q->backing_dev_info); + if (q->mq_ops) blk_mq_free_queue(q); percpu_ref_exit(&q->q_usage_counter); |