On Wed, 2019-04-03 at 18:26 +0800, Ming Lei wrote:
diff --git a/block/blk-core.c b/block/blk-core.c index 6583d67f3e34..20298aa5a77c 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -374,7 +374,7 @@ void blk_cleanup_queue(struct request_queue *q) blk_exit_queue(q); if (queue_is_mq(q))
blk_mq_free_queue(q);
blk_mq_exit_queue(q);percpu_ref_exit(&q->q_usage_counter); diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c index 3f9c3f4ac44c..4040e62c3737 100644 --- a/block/blk-mq-sysfs.c +++ b/block/blk-mq-sysfs.c @@ -10,6 +10,7 @@ #include <linux/smp.h> #include <linux/blk-mq.h> +#include "blk.h" #include "blk-mq.h" #include "blk-mq-tag.h" @@ -33,6 +34,11 @@ static void blk_mq_hw_sysfs_release(struct kobject *kobj) { struct blk_mq_hw_ctx *hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
if (hctx->flags & BLK_MQ_F_BLOCKING)cleanup_srcu_struct(hctx->srcu);blk_free_flush_queue(hctx->fq);sbitmap_free(&hctx->ctx_map); free_cpumask_var(hctx->cpumask); kfree(hctx->ctxs); kfree(hctx);diff --git a/block/blk-mq.c b/block/blk-mq.c index b512ba0cb359..afc9912e2e42 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2259,12 +2259,7 @@ static void blk_mq_exit_hctx(struct request_queue *q, if (set->ops->exit_hctx) set->ops->exit_hctx(hctx, hctx_idx);
if (hctx->flags & BLK_MQ_F_BLOCKING)cleanup_srcu_struct(hctx->srcu);blk_mq_remove_cpuhp(hctx);blk_free_flush_queue(hctx->fq);sbitmap_free(&hctx->ctx_map);} static void blk_mq_exit_hw_queues(struct request_queue *q, @@ -2899,7 +2894,8 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, } EXPORT_SYMBOL(blk_mq_init_allocated_queue); -void blk_mq_free_queue(struct request_queue *q) +/* tags can _not_ be used after returning from blk_mq_exit_queue */ +void blk_mq_exit_queue(struct request_queue *q) { struct blk_mq_tag_set *set = q->tag_set; diff --git a/block/blk-mq.h b/block/blk-mq.h index d704fc7766f4..c421e3a16e36 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -37,7 +37,7 @@ struct blk_mq_ctx { struct kobject kobj; } ____cacheline_aligned_in_smp; -void blk_mq_free_queue(struct request_queue *q); +void blk_mq_exit_queue(struct request_queue *q); int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); void blk_mq_wake_waiters(struct request_queue *q); bool blk_mq_dispatch_rq_list(struct request_queue *, struct list_head *, bool);
Isn't this an incomplete solution? The above patch fixes the race between cleaning up a queue and running a queue but does not address the race between running a queue and changing the number of hardware queues.
Thanks,
Bart.