[thirdparty/kernel/linux.git] / block / blk-rq-qos.c

// SPDX-License-Identifier: GPL-2.0

#include "blk-rq-qos.h"

/*
 * Increment 'v', if 'v' is below 'below'. Returns true if we succeeded,
 * false if 'v' + 1 would be bigger than 'below'.
 */
static bool atomic_inc_below(atomic_t *v, unsigned int below)
{
	unsigned int cur = atomic_read(v);

	do {
		if (cur >= below)
			return false;
	} while (!atomic_try_cmpxchg(v, &cur, cur + 1));

	return true;
}

bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit)
{
	return atomic_inc_below(&rq_wait->inflight, limit);
}

void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio)
{
	do {
		if (rqos->ops->cleanup)
			rqos->ops->cleanup(rqos, bio);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_done(struct rq_qos *rqos, struct request *rq)
{
	do {
		if (rqos->ops->done)
			rqos->ops->done(rqos, rq);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_issue(struct rq_qos *rqos, struct request *rq)
{
	do {
		if (rqos->ops->issue)
			rqos->ops->issue(rqos, rq);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_requeue(struct rq_qos *rqos, struct request *rq)
{
	do {
		if (rqos->ops->requeue)
			rqos->ops->requeue(rqos, rq);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_throttle(struct rq_qos *rqos, struct bio *bio)
{
	do {
		if (rqos->ops->throttle)
			rqos->ops->throttle(rqos, bio);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_track(struct rq_qos *rqos, struct request *rq, struct bio *bio)
{
	do {
		if (rqos->ops->track)
			rqos->ops->track(rqos, rq, bio);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio)
{
	do {
		if (rqos->ops->merge)
			rqos->ops->merge(rqos, rq, bio);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_done_bio(struct rq_qos *rqos, struct bio *bio)
{
	do {
		if (rqos->ops->done_bio)
			rqos->ops->done_bio(rqos, bio);
		rqos = rqos->next;
	} while (rqos);
}

void __rq_qos_queue_depth_changed(struct rq_qos *rqos)
{
	do {
		if (rqos->ops->queue_depth_changed)
			rqos->ops->queue_depth_changed(rqos);
		rqos = rqos->next;
	} while (rqos);
}

/*
 * Return true, if we can't increase the depth further by scaling
 */
bool rq_depth_calc_max_depth(struct rq_depth *rqd)
{
	unsigned int depth;
	bool ret = false;

	/*
	 * For QD=1 devices, this is a special case. It's important for those
	 * to have one request ready when one completes, so force a depth of
	 * 2 for those devices. On the backend, it'll be a depth of 1 anyway,
	 * since the device can't have more than that in flight. If we're
	 * scaling down, then keep a setting of 1/1/1.
	 */
	if (rqd->queue_depth == 1) {
		if (rqd->scale_step > 0)
			rqd->max_depth = 1;
		else {
			rqd->max_depth = 2;
			ret = true;
		}
	} else {
		/*
		 * scale_step == 0 is our default state. If we have suffered
		 * latency spikes, step will be > 0, and we shrink the
		 * allowed write depths. If step is < 0, we're only doing
		 * writes, and we allow a temporarily higher depth to
		 * increase performance.
		 */
		depth = min_t(unsigned int, rqd->default_depth,
			      rqd->queue_depth);
		if (rqd->scale_step > 0)
			depth = 1 + ((depth - 1) >> min(31, rqd->scale_step));
		else if (rqd->scale_step < 0) {
			unsigned int maxd = 3 * rqd->queue_depth / 4;

			depth = 1 + ((depth - 1) << -rqd->scale_step);
			if (depth > maxd) {
				depth = maxd;
				ret = true;
			}
		}

		rqd->max_depth = depth;
	}

	return ret;
}

/* Returns true on success and false if scaling up wasn't possible */
bool rq_depth_scale_up(struct rq_depth *rqd)
{
	/*
	 * Hit max in previous round, stop here
	 */
	if (rqd->scaled_max)
		return false;

	rqd->scale_step--;

	rqd->scaled_max = rq_depth_calc_max_depth(rqd);
	return true;
}

/*
 * Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
 * had a latency violation. Returns true on success and returns false if
 * scaling down wasn't possible.
 */
bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
{
	/*
	 * Stop scaling down when we've hit the limit. This also prevents
	 * ->scale_step from going to crazy values, if the device can't
	 * keep up.
	 */
	if (rqd->max_depth == 1)
		return false;

	if (rqd->scale_step < 0 && hard_throttle)
		rqd->scale_step = 0;
	else
		rqd->scale_step++;

	rqd->scaled_max = false;
	rq_depth_calc_max_depth(rqd);
	return true;
}

struct rq_qos_wait_data {
	struct wait_queue_entry wq;
	struct task_struct *task;
	struct rq_wait *rqw;
	acquire_inflight_cb_t *cb;
	void *private_data;
	bool got_token;
};

static int rq_qos_wake_function(struct wait_queue_entry *curr,
				unsigned int mode, int wake_flags, void *key)
{
	struct rq_qos_wait_data *data = container_of(curr,
						     struct rq_qos_wait_data,
						     wq);

	/*
	 * If we fail to get a budget, return -1 to interrupt the wake up loop
	 * in __wake_up_common.
	 */
	if (!data->cb(data->rqw, data->private_data))
		return -1;

	data->got_token = true;
	smp_wmb();
	list_del_init(&curr->entry);
	wake_up_process(data->task);
	return 1;
}

/**
 * rq_qos_wait - throttle on a rqw if we need to
 * @rqw: rqw to throttle on
 * @private_data: caller provided specific data
 * @acquire_inflight_cb: inc the rqw->inflight counter if we can
 * @cleanup_cb: the callback to cleanup in case we race with a waker
 *
 * This provides a uniform place for the rq_qos users to do their throttling.
 * Since you can end up with a lot of things sleeping at once, this manages the
 * waking up based on the resources available.  The acquire_inflight_cb should
 * inc the rqw->inflight if we have the ability to do so, or return false if not
 * and then we will sleep until the room becomes available.
 *
 * cleanup_cb is in case that we race with a waker and need to cleanup the
 * inflight count accordingly.
 */
void rq_qos_wait(struct rq_wait *rqw, void *private_data,
		 acquire_inflight_cb_t *acquire_inflight_cb,
		 cleanup_cb_t *cleanup_cb)
{
	struct rq_qos_wait_data data = {
		.wq = {
			.func	= rq_qos_wake_function,
			.entry	= LIST_HEAD_INIT(data.wq.entry),
		},
		.task = current,
		.rqw = rqw,
		.cb = acquire_inflight_cb,
		.private_data = private_data,
	};
	bool has_sleeper;

	has_sleeper = wq_has_sleeper(&rqw->wait);
	if (!has_sleeper && acquire_inflight_cb(rqw, private_data))
		return;

	has_sleeper = !prepare_to_wait_exclusive(&rqw->wait, &data.wq,
						 TASK_UNINTERRUPTIBLE);
	do {
		/* The memory barrier in set_task_state saves us here. */
		if (data.got_token)
			break;
		if (!has_sleeper && acquire_inflight_cb(rqw, private_data)) {
			finish_wait(&rqw->wait, &data.wq);

			/*
			 * We raced with rq_qos_wake_function() getting a token,
			 * which means we now have two. Put our local token
			 * and wake anyone else potentially waiting for one.
			 */
			smp_rmb();
			if (data.got_token)
				cleanup_cb(rqw, private_data);
			break;
		}
		io_schedule();
		has_sleeper = true;
		set_current_state(TASK_UNINTERRUPTIBLE);
	} while (1);
	finish_wait(&rqw->wait, &data.wq);
}

void rq_qos_exit(struct request_queue *q)
{
	mutex_lock(&q->rq_qos_mutex);
	while (q->rq_qos) {
		struct rq_qos *rqos = q->rq_qos;
		q->rq_qos = rqos->next;
		rqos->ops->exit(rqos);
	}
	mutex_unlock(&q->rq_qos_mutex);
}

int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
		const struct rq_qos_ops *ops)
{
	struct request_queue *q = disk->queue;

	lockdep_assert_held(&q->rq_qos_mutex);

	rqos->disk = disk;
	rqos->id = id;
	rqos->ops = ops;

	/*
	 * No IO can be in-flight when adding rqos, so freeze queue, which
	 * is fine since we only support rq_qos for blk-mq queue.
	 */
	blk_mq_freeze_queue(q);

	if (rq_qos_id(q, rqos->id))
		goto ebusy;
	rqos->next = q->rq_qos;
	q->rq_qos = rqos;

	blk_mq_unfreeze_queue(q);

	if (rqos->ops->debugfs_attrs) {
		mutex_lock(&q->debugfs_mutex);
		blk_mq_debugfs_register_rqos(rqos);
		mutex_unlock(&q->debugfs_mutex);
	}

	return 0;
ebusy:
	blk_mq_unfreeze_queue(q);
	return -EBUSY;
}

void rq_qos_del(struct rq_qos *rqos)
{
	struct request_queue *q = rqos->disk->queue;
	struct rq_qos **cur;

	lockdep_assert_held(&q->rq_qos_mutex);

	blk_mq_freeze_queue(q);
	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
		if (*cur == rqos) {
			*cur = rqos->next;
			break;
		}
	}
	blk_mq_unfreeze_queue(q);

	mutex_lock(&q->debugfs_mutex);
	blk_mq_debugfs_unregister_rqos(rqos);
	mutex_unlock(&q->debugfs_mutex);
}
Commit	Line	Data
3dcf60bc CH	1	// SPDX-License-Identifier: GPL-2.0
3dcf60bc CH	2
a7905043 JB	3	#include "blk-rq-qos.h"
a7905043 JB	4
a7905043 JB	5	/*
	6	* Increment 'v', if 'v' is below 'below'. Returns true if we succeeded,
	7	* false if 'v' + 1 would be bigger than 'below'.
	8	*/
22f17952	9	static bool atomic_inc_below(atomic_t *v, unsigned int below)
a7905043	10	{
22f17952	11	unsigned int cur = atomic_read(v);
a7905043	12
f4b1e27d	13	do {
a7905043 JB	14	if (cur >= below)
a7905043 JB	15	return false;
f4b1e27d	16	} while (!atomic_try_cmpxchg(v, &cur, cur + 1));
a7905043 JB	17
	18	return true;
	19	}
	20
22f17952	21	bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit)
a7905043 JB	22	{
	23	return atomic_inc_below(&rq_wait->inflight, limit);
	24	}
	25
e5045454	26	void __rq_qos_cleanup(struct rq_qos rqos, struct bio bio)
a7905043	27	{
e5045454	28	do {
a7905043	29	if (rqos->ops->cleanup)
c1c80384	30	rqos->ops->cleanup(rqos, bio);
e5045454 JA	31	rqos = rqos->next;
e5045454 JA	32	} while (rqos);
a7905043 JB	33	}
a7905043 JB	34
e5045454	35	void __rq_qos_done(struct rq_qos rqos, struct request rq)
a7905043	36	{
e5045454	37	do {
a7905043 JB	38	if (rqos->ops->done)
a7905043 JB	39	rqos->ops->done(rqos, rq);
e5045454 JA	40	rqos = rqos->next;
e5045454 JA	41	} while (rqos);
a7905043 JB	42	}
a7905043 JB	43
e5045454	44	void __rq_qos_issue(struct rq_qos rqos, struct request rq)
a7905043	45	{
e5045454	46	do {
a7905043 JB	47	if (rqos->ops->issue)
a7905043 JB	48	rqos->ops->issue(rqos, rq);
e5045454 JA	49	rqos = rqos->next;
e5045454 JA	50	} while (rqos);
a7905043 JB	51	}
a7905043 JB	52
e5045454	53	void __rq_qos_requeue(struct rq_qos rqos, struct request rq)
a7905043	54	{
e5045454	55	do {
a7905043 JB	56	if (rqos->ops->requeue)
a7905043 JB	57	rqos->ops->requeue(rqos, rq);
e5045454 JA	58	rqos = rqos->next;
e5045454 JA	59	} while (rqos);
a7905043 JB	60	}
a7905043 JB	61
e5045454	62	void __rq_qos_throttle(struct rq_qos rqos, struct bio bio)
a7905043	63	{
e5045454	64	do {
a7905043	65	if (rqos->ops->throttle)
d5337560	66	rqos->ops->throttle(rqos, bio);
e5045454 JA	67	rqos = rqos->next;
e5045454 JA	68	} while (rqos);
c1c80384 JB	69	}
c1c80384 JB	70
e5045454	71	void __rq_qos_track(struct rq_qos rqos, struct request rq, struct bio *bio)
c1c80384	72	{
e5045454	73	do {
c1c80384 JB	74	if (rqos->ops->track)
c1c80384 JB	75	rqos->ops->track(rqos, rq, bio);
d3e65fff TH	76	rqos = rqos->next;
	77	} while (rqos);
	78	}
	79
	80	void __rq_qos_merge(struct rq_qos rqos, struct request rq, struct bio *bio)
	81	{
	82	do {
	83	if (rqos->ops->merge)
	84	rqos->ops->merge(rqos, rq, bio);
e5045454 JA	85	rqos = rqos->next;
e5045454 JA	86	} while (rqos);
a7905043 JB	87	}
a7905043 JB	88
e5045454	89	void __rq_qos_done_bio(struct rq_qos rqos, struct bio bio)
67b42d0b	90	{
e5045454	91	do {
67b42d0b JB	92	if (rqos->ops->done_bio)
67b42d0b JB	93	rqos->ops->done_bio(rqos, bio);
e5045454 JA	94	rqos = rqos->next;
e5045454 JA	95	} while (rqos);
67b42d0b JB	96	}
67b42d0b JB	97
9677a3e0 TH	98	void __rq_qos_queue_depth_changed(struct rq_qos *rqos)
	99	{
	100	do {
	101	if (rqos->ops->queue_depth_changed)
	102	rqos->ops->queue_depth_changed(rqos);
	103	rqos = rqos->next;
	104	} while (rqos);
	105	}
	106
a7905043 JB	107	/*
	108	* Return true, if we can't increase the depth further by scaling
	109	*/
	110	bool rq_depth_calc_max_depth(struct rq_depth *rqd)
	111	{
	112	unsigned int depth;
	113	bool ret = false;
	114
	115	/*
	116	* For QD=1 devices, this is a special case. It's important for those
	117	* to have one request ready when one completes, so force a depth of
	118	* 2 for those devices. On the backend, it'll be a depth of 1 anyway,
	119	* since the device can't have more than that in flight. If we're
	120	* scaling down, then keep a setting of 1/1/1.
	121	*/
	122	if (rqd->queue_depth == 1) {
	123	if (rqd->scale_step > 0)
	124	rqd->max_depth = 1;
	125	else {
	126	rqd->max_depth = 2;
	127	ret = true;
	128	}
	129	} else {
	130	/*
	131	* scale_step == 0 is our default state. If we have suffered
	132	* latency spikes, step will be > 0, and we shrink the
	133	* allowed write depths. If step is < 0, we're only doing
	134	* writes, and we allow a temporarily higher depth to
	135	* increase performance.
	136	*/
	137	depth = min_t(unsigned int, rqd->default_depth,
	138	rqd->queue_depth);
	139	if (rqd->scale_step > 0)
	140	depth = 1 + ((depth - 1) >> min(31, rqd->scale_step));
	141	else if (rqd->scale_step < 0) {
	142	unsigned int maxd = 3 * rqd->queue_depth / 4;
	143
	144	depth = 1 + ((depth - 1) << -rqd->scale_step);
	145	if (depth > maxd) {
	146	depth = maxd;
	147	ret = true;
	148	}
	149	}
	150
	151	rqd->max_depth = depth;
	152	}
	153
	154	return ret;
	155	}
	156
b84477d3 HS	157	/* Returns true on success and false if scaling up wasn't possible */
b84477d3 HS	158	bool rq_depth_scale_up(struct rq_depth *rqd)
a7905043 JB	159	{
	160	/*
	161	* Hit max in previous round, stop here
	162	*/
	163	if (rqd->scaled_max)
b84477d3	164	return false;
a7905043 JB	165
	166	rqd->scale_step--;
	167
	168	rqd->scaled_max = rq_depth_calc_max_depth(rqd);
b84477d3	169	return true;
a7905043 JB	170	}
	171
	172	/*
	173	* Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
b84477d3 HS	174	* had a latency violation. Returns true on success and returns false if
b84477d3 HS	175	* scaling down wasn't possible.
a7905043	176	*/
b84477d3	177	bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
a7905043 JB	178	{
	179	/*
	180	* Stop scaling down when we've hit the limit. This also prevents
	181	* ->scale_step from going to crazy values, if the device can't
	182	* keep up.
	183	*/
	184	if (rqd->max_depth == 1)
b84477d3	185	return false;
a7905043 JB	186
	187	if (rqd->scale_step < 0 && hard_throttle)
	188	rqd->scale_step = 0;
	189	else
	190	rqd->scale_step++;
	191
	192	rqd->scaled_max = false;
	193	rq_depth_calc_max_depth(rqd);
b84477d3	194	return true;
a7905043 JB	195	}
a7905043 JB	196
84f60324 JB	197	struct rq_qos_wait_data {
	198	struct wait_queue_entry wq;
	199	struct task_struct *task;
	200	struct rq_wait *rqw;
	201	acquire_inflight_cb_t *cb;
	202	void *private_data;
	203	bool got_token;
	204	};
	205
	206	static int rq_qos_wake_function(struct wait_queue_entry *curr,
	207	unsigned int mode, int wake_flags, void *key)
	208	{
	209	struct rq_qos_wait_data *data = container_of(curr,
	210	struct rq_qos_wait_data,
	211	wq);
	212
	213	/*
	214	* If we fail to get a budget, return -1 to interrupt the wake up loop
	215	* in __wake_up_common.
	216	*/
	217	if (!data->cb(data->rqw, data->private_data))
	218	return -1;
	219
	220	data->got_token = true;
ac38297f	221	smp_wmb();
84f60324 JB	222	list_del_init(&curr->entry);
	223	wake_up_process(data->task);
	224	return 1;
	225	}
	226
	227	/**
	228	* rq_qos_wait - throttle on a rqw if we need to
83826a50 BVA	229	* @rqw: rqw to throttle on
	230	* @private_data: caller provided specific data
	231	* @acquire_inflight_cb: inc the rqw->inflight counter if we can
	232	* @cleanup_cb: the callback to cleanup in case we race with a waker
84f60324 JB	233	*
	234	* This provides a uniform place for the rq_qos users to do their throttling.
	235	* Since you can end up with a lot of things sleeping at once, this manages the
	236	* waking up based on the resources available. The acquire_inflight_cb should
	237	* inc the rqw->inflight if we have the ability to do so, or return false if not
	238	* and then we will sleep until the room becomes available.
	239	*
	240	* cleanup_cb is in case that we race with a waker and need to cleanup the
	241	* inflight count accordingly.
	242	*/
	243	void rq_qos_wait(struct rq_wait rqw, void private_data,
	244	acquire_inflight_cb_t *acquire_inflight_cb,
	245	cleanup_cb_t *cleanup_cb)
	246	{
	247	struct rq_qos_wait_data data = {
	248	.wq = {
	249	.func = rq_qos_wake_function,
	250	.entry = LIST_HEAD_INIT(data.wq.entry),
	251	},
	252	.task = current,
	253	.rqw = rqw,
	254	.cb = acquire_inflight_cb,
	255	.private_data = private_data,
	256	};
	257	bool has_sleeper;
	258
	259	has_sleeper = wq_has_sleeper(&rqw->wait);
	260	if (!has_sleeper && acquire_inflight_cb(rqw, private_data))
	261	return;
	262
11c7aa0d JK	263	has_sleeper = !prepare_to_wait_exclusive(&rqw->wait, &data.wq,
11c7aa0d JK	264	TASK_UNINTERRUPTIBLE);
84f60324	265	do {
ac38297f	266	/* The memory barrier in set_task_state saves us here. */
84f60324 JB	267	if (data.got_token)
	268	break;
	269	if (!has_sleeper && acquire_inflight_cb(rqw, private_data)) {
	270	finish_wait(&rqw->wait, &data.wq);
	271
	272	/*
e599ed78	273	* We raced with rq_qos_wake_function() getting a token,
84f60324 JB	274	* which means we now have two. Put our local token
	275	* and wake anyone else potentially waiting for one.
	276	*/
ac38297f	277	smp_rmb();
84f60324 JB	278	if (data.got_token)
	279	cleanup_cb(rqw, private_data);
	280	break;
	281	}
	282	io_schedule();
64e7ea87	283	has_sleeper = true;
d14a9b38	284	set_current_state(TASK_UNINTERRUPTIBLE);
84f60324 JB	285	} while (1);
	286	finish_wait(&rqw->wait, &data.wq);
	287	}
	288
a7905043 JB	289	void rq_qos_exit(struct request_queue *q)
a7905043 JB	290	{
a13bd91b	291	mutex_lock(&q->rq_qos_mutex);
a7905043 JB	292	while (q->rq_qos) {
	293	struct rq_qos *rqos = q->rq_qos;
	294	q->rq_qos = rqos->next;
	295	rqos->ops->exit(rqos);
	296	}
a13bd91b	297	mutex_unlock(&q->rq_qos_mutex);
a7905043	298	}
b494f9c5	299
ce57b558	300	int rq_qos_add(struct rq_qos rqos, struct gendisk disk, enum rq_qos_id id,
3963d84d	301	const struct rq_qos_ops *ops)
b494f9c5	302	{
ce57b558 CH	303	struct request_queue *q = disk->queue;
ce57b558 CH	304
a13bd91b YK	305	lockdep_assert_held(&q->rq_qos_mutex);
a13bd91b YK	306
ba91c849	307	rqos->disk = disk;
ce57b558 CH	308	rqos->id = id;
	309	rqos->ops = ops;
	310
b494f9c5 CH	311	/*
	312	* No IO can be in-flight when adding rqos, so freeze queue, which
	313	* is fine since we only support rq_qos for blk-mq queue.
b494f9c5 CH	314	*/
	315	blk_mq_freeze_queue(q);
	316
b494f9c5 CH	317	if (rq_qos_id(q, rqos->id))
	318	goto ebusy;
	319	rqos->next = q->rq_qos;
	320	q->rq_qos = rqos;
b494f9c5 CH	321
	322	blk_mq_unfreeze_queue(q);
	323
	324	if (rqos->ops->debugfs_attrs) {
	325	mutex_lock(&q->debugfs_mutex);
	326	blk_mq_debugfs_register_rqos(rqos);
	327	mutex_unlock(&q->debugfs_mutex);
	328	}
	329
	330	return 0;
	331	ebusy:
b494f9c5 CH	332	blk_mq_unfreeze_queue(q);
b494f9c5 CH	333	return -EBUSY;
b494f9c5 CH	334	}
b494f9c5 CH	335
ce57b558	336	void rq_qos_del(struct rq_qos *rqos)
b494f9c5	337	{
ba91c849	338	struct request_queue *q = rqos->disk->queue;
b494f9c5 CH	339	struct rq_qos **cur;
b494f9c5 CH	340
a13bd91b	341	lockdep_assert_held(&q->rq_qos_mutex);
b494f9c5	342
a13bd91b	343	blk_mq_freeze_queue(q);
b494f9c5 CH	344	for (cur = &q->rq_qos; cur; cur = &(cur)->next) {
	345	if (*cur == rqos) {
	346	*cur = rqos->next;
	347	break;
	348	}
	349	}
b494f9c5 CH	350	blk_mq_unfreeze_queue(q);
	351
	352	mutex_lock(&q->debugfs_mutex);
	353	blk_mq_debugfs_unregister_rqos(rqos);
	354	mutex_unlock(&q->debugfs_mutex);
	355	}