Now we only verify the outmost freeze & unfreeze in current context in case that !q->mq_freeze_depth, so it is reliable to save disk DEAD state when we want to lock the freeze queue since the state is one per-task variable now. Doing this way can kill lots of false positive when freeze queue is called before adding disk[1]. [1] https://lore.kernel.org/linux-block/6741f6b2.050a0220.1cc393.0017.GAE@xxxxxxxxxx/ Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- block/blk-mq.c | 7 +++++-- block/blk.h | 19 +++++++++++++------ block/elevator.c | 4 ++-- block/genhd.c | 4 ++-- include/linux/blkdev.h | 2 ++ 5 files changed, 24 insertions(+), 12 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 6af56b0e8ffd..32b398d0c598 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -130,6 +130,9 @@ static bool blk_freeze_set_owner(struct request_queue *q, if (!q->mq_freeze_depth) { q->mq_freeze_owner = owner; q->mq_freeze_owner_depth = 1; + q->mq_freeze_disk_dead = !q->disk || + test_bit(GD_DEAD, &q->disk->state) || + !blk_queue_registered(q); return true; } @@ -186,7 +189,7 @@ bool __blk_freeze_queue_start(struct request_queue *q, void blk_freeze_queue_start(struct request_queue *q) { if (__blk_freeze_queue_start(q, current)) - blk_freeze_acquire_lock(q, false, false); + blk_freeze_acquire_lock(q, false); } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -234,7 +237,7 @@ bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) void blk_mq_unfreeze_queue(struct request_queue *q) { if (__blk_mq_unfreeze_queue(q, false)) - blk_unfreeze_release_lock(q, false, false); + blk_unfreeze_release_lock(q, false); } EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); diff --git a/block/blk.h b/block/blk.h index 2c26abf505b8..8708168d50e4 100644 --- a/block/blk.h +++ b/block/blk.h @@ -720,22 +720,29 @@ void blk_integrity_verify(struct bio *bio); void blk_integrity_prepare(struct request *rq); void blk_integrity_complete(struct request *rq, unsigned int nr_bytes); -static inline void blk_freeze_acquire_lock(struct request_queue *q, bool - disk_dead, bool queue_dying) +#ifdef CONFIG_LOCKDEP +static inline void blk_freeze_acquire_lock(struct request_queue *q, bool queue_dying) { - if (!disk_dead) + if (!q->mq_freeze_disk_dead) rwsem_acquire(&q->io_lockdep_map, 0, 1, _RET_IP_); if (!queue_dying) rwsem_acquire(&q->q_lockdep_map, 0, 1, _RET_IP_); } -static inline void blk_unfreeze_release_lock(struct request_queue *q, bool - disk_dead, bool queue_dying) +static inline void blk_unfreeze_release_lock(struct request_queue *q, bool queue_dying) { if (!queue_dying) rwsem_release(&q->q_lockdep_map, _RET_IP_); - if (!disk_dead) + if (!q->mq_freeze_disk_dead) rwsem_release(&q->io_lockdep_map, _RET_IP_); } +#else +static inline void blk_freeze_acquire_lock(struct request_queue *q, bool queue_dying) +{ +} +static inline void blk_unfreeze_release_lock(struct request_queue *q, bool queue_dying) +{ +} +#endif #endif /* BLK_INTERNAL_H */ diff --git a/block/elevator.c b/block/elevator.c index 7c3ba80e5ff4..ca0a74369f1c 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -602,14 +602,14 @@ void elevator_init_mq(struct request_queue *q) * Disk isn't added yet, so verifying queue lock only manually. */ blk_freeze_queue_start_non_owner(q); - blk_freeze_acquire_lock(q, true, false); + blk_freeze_acquire_lock(q, false); blk_mq_freeze_queue_wait(q); blk_mq_cancel_work_sync(q); err = blk_mq_init_sched(q, e); - blk_unfreeze_release_lock(q, true, false); + blk_unfreeze_release_lock(q, false); blk_mq_unfreeze_queue_non_owner(q); if (err) { diff --git a/block/genhd.c b/block/genhd.c index 9130e163e191..fa4183cfb436 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -692,7 +692,7 @@ void del_gendisk(struct gendisk *disk) start_drain = __blk_mark_disk_dead(disk); queue_dying = blk_queue_dying(q); if (start_drain) - blk_freeze_acquire_lock(q, true, queue_dying); + blk_freeze_acquire_lock(q, queue_dying); xa_for_each_start(&disk->part_tbl, idx, part, 1) drop_partition(part); mutex_unlock(&disk->open_mutex); @@ -751,7 +751,7 @@ void del_gendisk(struct gendisk *disk) } if (start_drain) - blk_unfreeze_release_lock(q, true, queue_dying); + blk_unfreeze_release_lock(q, queue_dying); } EXPORT_SYMBOL(del_gendisk); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a1fd0ddce5cf..5f7fe8070a53 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -579,6 +579,8 @@ struct request_queue { #ifdef CONFIG_LOCKDEP struct task_struct *mq_freeze_owner; int mq_freeze_owner_depth; + /* Records disk state in current context, used in unfreeze queue */ + bool mq_freeze_disk_dead; #endif wait_queue_head_t mq_freeze_wq; /* -- 2.47.0
