diff options
| -rw-r--r-- | block/blk-mq-sysfs.c | 4 | ||||
| -rw-r--r-- | block/blk-mq.c | 4 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 14 |
3 files changed, 14 insertions, 8 deletions
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 3feeeccf8a99..24656980f443 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -61,9 +61,9 @@ static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj, if (!entry->show) return -EIO; - mutex_lock(&q->sysfs_lock); + mutex_lock(&q->elevator_lock); res = entry->show(hctx, page); - mutex_unlock(&q->sysfs_lock); + mutex_unlock(&q->elevator_lock); return res; } diff --git a/block/blk-mq.c b/block/blk-mq.c index 5a2d63927525..b9550a127c8e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4094,6 +4094,8 @@ static void blk_mq_map_swqueue(struct request_queue *q) struct blk_mq_ctx *ctx; struct blk_mq_tag_set *set = q->tag_set; + mutex_lock(&q->elevator_lock); + queue_for_each_hw_ctx(q, hctx, i) { cpumask_clear(hctx->cpumask); hctx->nr_ctx = 0; @@ -4198,6 +4200,8 @@ static void blk_mq_map_swqueue(struct request_queue *q) hctx->next_cpu = blk_mq_first_mapped_cpu(hctx); hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; } + + mutex_unlock(&q->elevator_lock); } /* diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3bee1b4858b6..dcf8fce15e23 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -561,12 +561,14 @@ struct request_queue { struct list_head flush_list; /* - * Protects against I/O scheduler switching, particularly when - * updating q->elevator. Since the elevator update code path may - * also modify q->nr_requests and wbt latency, this lock also - * protects the sysfs attributes nr_requests and wbt_lat_usec. - * To ensure proper locking order during an elevator update, first - * freeze the queue, then acquire ->elevator_lock. + * Protects against I/O scheduler switching, particularly when updating + * q->elevator. Since the elevator update code path may also modify q-> + * nr_requests and wbt latency, this lock also protects the sysfs attrs + * nr_requests and wbt_lat_usec. Additionally the nr_hw_queues update + * may modify hctx tags, reserved-tags and cpumask, so this lock also + * helps protect the hctx attrs. To ensure proper locking order during + * an elevator or nr_hw_queue update, first freeze the queue, then + * acquire ->elevator_lock. */ struct mutex elevator_lock; |