diff options
Diffstat (limited to 'block/blk-flush.c')
| -rw-r--r-- | block/blk-flush.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c index fd5cee9f1a3b..76c1624cb06c 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -69,7 +69,6 @@ #include <linux/blkdev.h> #include <linux/gfp.h> #include <linux/blk-mq.h> -#include <linux/lockdep.h> #include "blk.h" #include "blk-mq.h" @@ -139,7 +138,7 @@ static void blk_flush_queue_rq(struct request *rq, bool add_front) static void blk_account_io_flush(struct request *rq) { - struct hd_struct *part = &rq->rq_disk->part0; + struct block_device *part = rq->rq_disk->part0; part_stat_lock(); part_stat_inc(part, ios[STAT_FLUSH]); @@ -474,9 +473,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, INIT_LIST_HEAD(&fq->flush_queue[1]); INIT_LIST_HEAD(&fq->flush_data_in_flight); - lockdep_register_key(&fq->key); - lockdep_set_class(&fq->mq_flush_lock, &fq->key); - return fq; fail_rq: @@ -491,7 +487,31 @@ void blk_free_flush_queue(struct blk_flush_queue *fq) if (!fq) return; - lockdep_unregister_key(&fq->key); kfree(fq->flush_rq); kfree(fq); } + +/* + * Allow driver to set its own lock class to fq->mq_flush_lock for + * avoiding lockdep complaint. + * + * flush_end_io() may be called recursively from some driver, such as + * nvme-loop, so lockdep may complain 'possible recursive locking' because + * all 'struct blk_flush_queue' instance share same mq_flush_lock lock class + * key. We need to assign different lock class for these driver's + * fq->mq_flush_lock for avoiding the lockdep warning. + * + * Use dynamically allocated lock class key for each 'blk_flush_queue' + * instance is over-kill, and more worse it introduces horrible boot delay + * issue because synchronize_rcu() is implied in lockdep_unregister_key which + * is called for each hctx release. SCSI probing may synchronously create and + * destroy lots of MQ request_queues for non-existent devices, and some robot + * test kernel always enable lockdep option. It is observed that more than half + * an hour is taken during SCSI MQ probe with per-fq lock class. + */ +void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx, + struct lock_class_key *key) +{ + lockdep_set_class(&hctx->fq->mq_flush_lock, key); +} +EXPORT_SYMBOL_GPL(blk_mq_hctx_set_fq_lock_class); |