Commit 6c8b232e authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

blk-mq: make lifetime consistent between hctx and its kobject 



This patch removes kobject_put() over hctx in __blk_mq_unregister_dev(),
and trys to keep lifetime consistent between hctx and hctx's kobject.

Now blk_mq_sysfs_register() and blk_mq_sysfs_unregister() become
totally symmetrical, and kobject's refcounter drops to zero just
when the hctx is freed.

Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
Tested-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 7ea5fe31

block/blk-mq-sysfs.c

+10 −5
Original line number Diff line number Diff line
@@ -17,6 +17,14 @@ static void blk_mq_sysfs_release(struct kobject *kobj) 
{

}



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);

	kfree(hctx->ctxs);

	kfree(hctx);

}



struct blk_mq_ctx_sysfs_entry {

	struct attribute attr;

	ssize_t (*show)(struct blk_mq_ctx *, char *);
@@ -200,7 +208,7 @@ static struct kobj_type blk_mq_ctx_ktype = { 
static struct kobj_type blk_mq_hw_ktype = {

	.sysfs_ops	= &blk_mq_hw_sysfs_ops,

	.default_attrs	= default_hw_ctx_attrs,

	.release	= blk_mq_sysfs_release,

	.release	= blk_mq_hw_sysfs_release,

};



static void blk_mq_unregister_hctx(struct blk_mq_hw_ctx *hctx)
@@ -244,12 +252,9 @@ static void __blk_mq_unregister_dev(struct device *dev, struct request_queue *q) 
	struct blk_mq_hw_ctx *hctx;

	int i;



	queue_for_each_hw_ctx(q, hctx, i) {

	queue_for_each_hw_ctx(q, hctx, i)

		blk_mq_unregister_hctx(hctx);



		kobject_put(&hctx->kobj);

	}



	blk_mq_debugfs_unregister_hctxs(q);



	kobject_uevent(&q->mq_kobj, KOBJ_REMOVE);

block/blk-mq.c

+1 −4
Original line number Diff line number Diff line
@@ -2256,8 +2256,7 @@ void blk_mq_release(struct request_queue *q) 
	queue_for_each_hw_ctx(q, hctx, i) {

		if (!hctx)

			continue;

		kfree(hctx->ctxs);

		kfree(hctx);

		kobject_put(&hctx->kobj);

	}



	q->mq_map = NULL;
@@ -2336,8 +2335,6 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, 
			blk_mq_exit_hctx(q, set, hctx, j);

			free_cpumask_var(hctx->cpumask);

			kobject_put(&hctx->kobj);

			kfree(hctx->ctxs);

			kfree(hctx);

			hctxs[j] = NULL;



		}

CRA Git | Maintained and supported by SUSTech CRA and CCSE