[deliverable/linux.git] / fs / btrfs / async-thread.c

/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 * Copyright (C) 2014 Fujitsu.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
#include "async-thread.h"
#include "ctree.h"

#define WORK_DONE_BIT 0
#define WORK_ORDER_DONE_BIT 1
#define WORK_HIGH_PRIO_BIT 2

#define NO_THRESHOLD (-1)
#define DFT_THRESHOLD (32)

struct __btrfs_workqueue {
	struct workqueue_struct *normal_wq;

	/* File system this workqueue services */
	struct btrfs_fs_info *fs_info;

	/* List head pointing to ordered work list */
	struct list_head ordered_list;

	/* Spinlock for ordered_list */
	spinlock_t list_lock;

	/* Thresholding related variants */
	atomic_t pending;

	/* Up limit of concurrency workers */
	int limit_active;

	/* Current number of concurrency workers */
	int current_active;

	/* Threshold to change current_active */
	int thresh;
	unsigned int count;
	spinlock_t thres_lock;
};

struct btrfs_workqueue {
	struct __btrfs_workqueue *normal;
	struct __btrfs_workqueue *high;
};

static void normal_work_helper(struct btrfs_work *work);

#define BTRFS_WORK_HELPER(name)					\
void btrfs_##name(struct work_struct *arg)				\
{									\
	struct btrfs_work *work = container_of(arg, struct btrfs_work,	\
					       normal_work);		\
	normal_work_helper(work);					\
}

struct btrfs_fs_info *
btrfs_workqueue_owner(struct __btrfs_workqueue *wq)
{
	return wq->fs_info;
}

struct btrfs_fs_info *
btrfs_work_owner(struct btrfs_work *work)
{
	return work->wq->fs_info;
}

BTRFS_WORK_HELPER(worker_helper);
BTRFS_WORK_HELPER(delalloc_helper);
BTRFS_WORK_HELPER(flush_delalloc_helper);
BTRFS_WORK_HELPER(cache_helper);
BTRFS_WORK_HELPER(submit_helper);
BTRFS_WORK_HELPER(fixup_helper);
BTRFS_WORK_HELPER(endio_helper);
BTRFS_WORK_HELPER(endio_meta_helper);
BTRFS_WORK_HELPER(endio_meta_write_helper);
BTRFS_WORK_HELPER(endio_raid56_helper);
BTRFS_WORK_HELPER(endio_repair_helper);
BTRFS_WORK_HELPER(rmw_helper);
BTRFS_WORK_HELPER(endio_write_helper);
BTRFS_WORK_HELPER(freespace_write_helper);
BTRFS_WORK_HELPER(delayed_meta_helper);
BTRFS_WORK_HELPER(readahead_helper);
BTRFS_WORK_HELPER(qgroup_rescan_helper);
BTRFS_WORK_HELPER(extent_refs_helper);
BTRFS_WORK_HELPER(scrub_helper);
BTRFS_WORK_HELPER(scrubwrc_helper);
BTRFS_WORK_HELPER(scrubnc_helper);
BTRFS_WORK_HELPER(scrubparity_helper);

static struct __btrfs_workqueue *
__btrfs_alloc_workqueue(struct btrfs_fs_info *fs_info, const char *name,
			unsigned int flags, int limit_active, int thresh)
{
	struct __btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_KERNEL);

	if (!ret)
		return NULL;

	ret->fs_info = fs_info;
	ret->limit_active = limit_active;
	atomic_set(&ret->pending, 0);
	if (thresh == 0)
		thresh = DFT_THRESHOLD;
	/* For low threshold, disabling threshold is a better choice */
	if (thresh < DFT_THRESHOLD) {
		ret->current_active = limit_active;
		ret->thresh = NO_THRESHOLD;
	} else {
		/*
		 * For threshold-able wq, let its concurrency grow on demand.
		 * Use minimal max_active at alloc time to reduce resource
		 * usage.
		 */
		ret->current_active = 1;
		ret->thresh = thresh;
	}

	if (flags & WQ_HIGHPRI)
		ret->normal_wq = alloc_workqueue("%s-%s-high", flags,
						 ret->current_active, "btrfs",
						 name);
	else
		ret->normal_wq = alloc_workqueue("%s-%s", flags,
						 ret->current_active, "btrfs",
						 name);
	if (!ret->normal_wq) {
		kfree(ret);
		return NULL;
	}

	INIT_LIST_HEAD(&ret->ordered_list);
	spin_lock_init(&ret->list_lock);
	spin_lock_init(&ret->thres_lock);
	trace_btrfs_workqueue_alloc(ret, name, flags & WQ_HIGHPRI);
	return ret;
}

static inline void
__btrfs_destroy_workqueue(struct __btrfs_workqueue *wq);

struct btrfs_workqueue *btrfs_alloc_workqueue(struct btrfs_fs_info *fs_info,
					      const char *name,
					      unsigned int flags,
					      int limit_active,
					      int thresh)
{
	struct btrfs_workqueue *ret = kzalloc(sizeof(*ret), GFP_KERNEL);

	if (!ret)
		return NULL;

	ret->normal = __btrfs_alloc_workqueue(fs_info, name,
					      flags & ~WQ_HIGHPRI,
					      limit_active, thresh);
	if (!ret->normal) {
		kfree(ret);
		return NULL;
	}

	if (flags & WQ_HIGHPRI) {
		ret->high = __btrfs_alloc_workqueue(fs_info, name, flags,
						    limit_active, thresh);
		if (!ret->high) {
			__btrfs_destroy_workqueue(ret->normal);
			kfree(ret);
			return NULL;
		}
	}
	return ret;
}

/*
 * Hook for threshold which will be called in btrfs_queue_work.
 * This hook WILL be called in IRQ handler context,
 * so workqueue_set_max_active MUST NOT be called in this hook
 */
static inline void thresh_queue_hook(struct __btrfs_workqueue *wq)
{
	if (wq->thresh == NO_THRESHOLD)
		return;
	atomic_inc(&wq->pending);
}

/*
 * Hook for threshold which will be called before executing the work,
 * This hook is called in kthread content.
 * So workqueue_set_max_active is called here.
 */
static inline void thresh_exec_hook(struct __btrfs_workqueue *wq)
{
	int new_current_active;
	long pending;
	int need_change = 0;

	if (wq->thresh == NO_THRESHOLD)
		return;

	atomic_dec(&wq->pending);
	spin_lock(&wq->thres_lock);
	/*
	 * Use wq->count to limit the calling frequency of
	 * workqueue_set_max_active.
	 */
	wq->count++;
	wq->count %= (wq->thresh / 4);
	if (!wq->count)
		goto  out;
	new_current_active = wq->current_active;

	/*
	 * pending may be changed later, but it's OK since we really
	 * don't need it so accurate to calculate new_max_active.
	 */
	pending = atomic_read(&wq->pending);
	if (pending > wq->thresh)
		new_current_active++;
	if (pending < wq->thresh / 2)
		new_current_active--;
	new_current_active = clamp_val(new_current_active, 1, wq->limit_active);
	if (new_current_active != wq->current_active)  {
		need_change = 1;
		wq->current_active = new_current_active;
	}
out:
	spin_unlock(&wq->thres_lock);

	if (need_change) {
		workqueue_set_max_active(wq->normal_wq, wq->current_active);
	}
}

static void run_ordered_work(struct __btrfs_workqueue *wq)
{
	struct list_head *list = &wq->ordered_list;
	struct btrfs_work *work;
	spinlock_t *lock = &wq->list_lock;
	unsigned long flags;

	while (1) {
		spin_lock_irqsave(lock, flags);
		if (list_empty(list))
			break;
		work = list_entry(list->next, struct btrfs_work,
				  ordered_list);
		if (!test_bit(WORK_DONE_BIT, &work->flags))
			break;

		/*
		 * we are going to call the ordered done function, but
		 * we leave the work item on the list as a barrier so
		 * that later work items that are done don't have their
		 * functions called before this one returns
		 */
		if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags))
			break;
		trace_btrfs_ordered_sched(work);
		spin_unlock_irqrestore(lock, flags);
		work->ordered_func(work);

		/* now take the lock again and drop our item from the list */
		spin_lock_irqsave(lock, flags);
		list_del(&work->ordered_list);
		spin_unlock_irqrestore(lock, flags);

		/*
		 * we don't want to call the ordered free functions
		 * with the lock held though
		 */
		work->ordered_free(work);
		trace_btrfs_all_work_done(work);
	}
	spin_unlock_irqrestore(lock, flags);
}

static void normal_work_helper(struct btrfs_work *work)
{
	struct __btrfs_workqueue *wq;
	int need_order = 0;

	/*
	 * We should not touch things inside work in the following cases:
	 * 1) after work->func() if it has no ordered_free
	 *    Since the struct is freed in work->func().
	 * 2) after setting WORK_DONE_BIT
	 *    The work may be freed in other threads almost instantly.
	 * So we save the needed things here.
	 */
	if (work->ordered_func)
		need_order = 1;
	wq = work->wq;

	trace_btrfs_work_sched(work);
	thresh_exec_hook(wq);
	work->func(work);
	if (need_order) {
		set_bit(WORK_DONE_BIT, &work->flags);
		run_ordered_work(wq);
	}
	if (!need_order)
		trace_btrfs_all_work_done(work);
}

void btrfs_init_work(struct btrfs_work *work, btrfs_work_func_t uniq_func,
		     btrfs_func_t func,
		     btrfs_func_t ordered_func,
		     btrfs_func_t ordered_free)
{
	work->func = func;
	work->ordered_func = ordered_func;
	work->ordered_free = ordered_free;
	INIT_WORK(&work->normal_work, uniq_func);
	INIT_LIST_HEAD(&work->ordered_list);
	work->flags = 0;
}

static inline void __btrfs_queue_work(struct __btrfs_workqueue *wq,
				      struct btrfs_work *work)
{
	unsigned long flags;

	work->wq = wq;
	thresh_queue_hook(wq);
	if (work->ordered_func) {
		spin_lock_irqsave(&wq->list_lock, flags);
		list_add_tail(&work->ordered_list, &wq->ordered_list);
		spin_unlock_irqrestore(&wq->list_lock, flags);
	}
	trace_btrfs_work_queued(work);
	queue_work(wq->normal_wq, &work->normal_work);
}

void btrfs_queue_work(struct btrfs_workqueue *wq,
		      struct btrfs_work *work)
{
	struct __btrfs_workqueue *dest_wq;

	if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags) && wq->high)
		dest_wq = wq->high;
	else
		dest_wq = wq->normal;
	__btrfs_queue_work(dest_wq, work);
}

static inline void
__btrfs_destroy_workqueue(struct __btrfs_workqueue *wq)
{
	destroy_workqueue(wq->normal_wq);
	trace_btrfs_workqueue_destroy(wq);
	kfree(wq);
}

void btrfs_destroy_workqueue(struct btrfs_workqueue *wq)
{
	if (!wq)
		return;
	if (wq->high)
		__btrfs_destroy_workqueue(wq->high);
	__btrfs_destroy_workqueue(wq->normal);
	kfree(wq);
}

void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int limit_active)
{
	if (!wq)
		return;
	wq->normal->limit_active = limit_active;
	if (wq->high)
		wq->high->limit_active = limit_active;
}

void btrfs_set_work_high_priority(struct btrfs_work *work)
{
	set_bit(WORK_HIGH_PRIO_BIT, &work->flags);
}
Commit	Line	Data
8b712842 CM	1	/*
8b712842 CM	2	* Copyright (C) 2007 Oracle. All rights reserved.
08a9ff32	3	* Copyright (C) 2014 Fujitsu. All rights reserved.
8b712842 CM	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public
	7	* License v2 as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	* General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public
	15	* License along with this program; if not, write to the
	16	* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	17	* Boston, MA 021110-1307, USA.
	18	*/
	19
	20	#include <linux/kthread.h>
5a0e3ad6	21	#include <linux/slab.h>
8b712842 CM	22	#include <linux/list.h>
8b712842 CM	23	#include <linux/spinlock.h>
b51912c9	24	#include <linux/freezer.h>
8b712842	25	#include "async-thread.h"
52483bc2	26	#include "ctree.h"
8b712842	27
a046e9c8 QW	28	#define WORK_DONE_BIT 0
	29	#define WORK_ORDER_DONE_BIT 1
	30	#define WORK_HIGH_PRIO_BIT 2
4a69a410	31
0bd9289c QW	32	#define NO_THRESHOLD (-1)
	33	#define DFT_THRESHOLD (32)
	34
d458b054	35	struct __btrfs_workqueue {
08a9ff32	36	struct workqueue_struct *normal_wq;
cb001095 JM	37
	38	/* File system this workqueue services */
	39	struct btrfs_fs_info *fs_info;
	40
08a9ff32 QW	41	/* List head pointing to ordered work list */
	42	struct list_head ordered_list;
	43
	44	/* Spinlock for ordered_list */
	45	spinlock_t list_lock;
0bd9289c QW	46
	47	/* Thresholding related variants */
	48	atomic_t pending;
c6dd6ea5 QW	49
	50	/* Up limit of concurrency workers */
	51	int limit_active;
	52
	53	/* Current number of concurrency workers */
	54	int current_active;
	55
	56	/* Threshold to change current_active */
0bd9289c QW	57	int thresh;
	58	unsigned int count;
	59	spinlock_t thres_lock;
08a9ff32 QW	60	};
08a9ff32 QW	61
d458b054 QW	62	struct btrfs_workqueue {
	63	struct __btrfs_workqueue *normal;
	64	struct __btrfs_workqueue *high;
1ca08976 QW	65	};
1ca08976 QW	66
9e0af237 LB	67	static void normal_work_helper(struct btrfs_work *work);
	68
	69	#define BTRFS_WORK_HELPER(name) \
	70	void btrfs_##name(struct work_struct *arg) \
	71	{ \
	72	struct btrfs_work *work = container_of(arg, struct btrfs_work, \
	73	normal_work); \
	74	normal_work_helper(work); \
	75	}
	76
cb001095 JM	77	struct btrfs_fs_info *
	78	btrfs_workqueue_owner(struct __btrfs_workqueue *wq)
	79	{
	80	return wq->fs_info;
	81	}
	82
	83	struct btrfs_fs_info *
	84	btrfs_work_owner(struct btrfs_work *work)
	85	{
	86	return work->wq->fs_info;
	87	}
	88
9e0af237 LB	89	BTRFS_WORK_HELPER(worker_helper);
	90	BTRFS_WORK_HELPER(delalloc_helper);
	91	BTRFS_WORK_HELPER(flush_delalloc_helper);
	92	BTRFS_WORK_HELPER(cache_helper);
	93	BTRFS_WORK_HELPER(submit_helper);
	94	BTRFS_WORK_HELPER(fixup_helper);
	95	BTRFS_WORK_HELPER(endio_helper);
	96	BTRFS_WORK_HELPER(endio_meta_helper);
	97	BTRFS_WORK_HELPER(endio_meta_write_helper);
	98	BTRFS_WORK_HELPER(endio_raid56_helper);
8b110e39	99	BTRFS_WORK_HELPER(endio_repair_helper);
9e0af237 LB	100	BTRFS_WORK_HELPER(rmw_helper);
	101	BTRFS_WORK_HELPER(endio_write_helper);
	102	BTRFS_WORK_HELPER(freespace_write_helper);
	103	BTRFS_WORK_HELPER(delayed_meta_helper);
	104	BTRFS_WORK_HELPER(readahead_helper);
	105	BTRFS_WORK_HELPER(qgroup_rescan_helper);
	106	BTRFS_WORK_HELPER(extent_refs_helper);
	107	BTRFS_WORK_HELPER(scrub_helper);
	108	BTRFS_WORK_HELPER(scrubwrc_helper);
	109	BTRFS_WORK_HELPER(scrubnc_helper);
20b2e302	110	BTRFS_WORK_HELPER(scrubparity_helper);
9e0af237 LB	111
9e0af237 LB	112	static struct __btrfs_workqueue *
cb001095 JM	113	__btrfs_alloc_workqueue(struct btrfs_fs_info fs_info, const char name,
cb001095 JM	114	unsigned int flags, int limit_active, int thresh)
1ca08976	115	{
61dd5ae6	116	struct __btrfs_workqueue ret = kzalloc(sizeof(ret), GFP_KERNEL);
1ca08976	117
5d99a998	118	if (!ret)
1ca08976 QW	119	return NULL;
1ca08976 QW	120
cb001095	121	ret->fs_info = fs_info;
c6dd6ea5	122	ret->limit_active = limit_active;
0bd9289c QW	123	atomic_set(&ret->pending, 0);
	124	if (thresh == 0)
	125	thresh = DFT_THRESHOLD;
	126	/* For low threshold, disabling threshold is a better choice */
	127	if (thresh < DFT_THRESHOLD) {
c6dd6ea5	128	ret->current_active = limit_active;
0bd9289c QW	129	ret->thresh = NO_THRESHOLD;
0bd9289c QW	130	} else {
c6dd6ea5 QW	131	/*
	132	* For threshold-able wq, let its concurrency grow on demand.
	133	* Use minimal max_active at alloc time to reduce resource
	134	* usage.
	135	*/
	136	ret->current_active = 1;
0bd9289c QW	137	ret->thresh = thresh;
	138	}
	139
1ca08976 QW	140	if (flags & WQ_HIGHPRI)
1ca08976 QW	141	ret->normal_wq = alloc_workqueue("%s-%s-high", flags,
c6dd6ea5 QW	142	ret->current_active, "btrfs",
c6dd6ea5 QW	143	name);
1ca08976 QW	144	else
1ca08976 QW	145	ret->normal_wq = alloc_workqueue("%s-%s", flags,
c6dd6ea5	146	ret->current_active, "btrfs",
0bd9289c	147	name);
5d99a998	148	if (!ret->normal_wq) {
1ca08976 QW	149	kfree(ret);
	150	return NULL;
	151	}
	152
	153	INIT_LIST_HEAD(&ret->ordered_list);
	154	spin_lock_init(&ret->list_lock);
0bd9289c	155	spin_lock_init(&ret->thres_lock);
c3a46891	156	trace_btrfs_workqueue_alloc(ret, name, flags & WQ_HIGHPRI);
1ca08976 QW	157	return ret;
	158	}
	159
	160	static inline void
d458b054	161	__btrfs_destroy_workqueue(struct __btrfs_workqueue *wq);
1ca08976	162
cb001095 JM	163	struct btrfs_workqueue btrfs_alloc_workqueue(struct btrfs_fs_info fs_info,
cb001095 JM	164	const char *name,
6f011058	165	unsigned int flags,
c6dd6ea5	166	int limit_active,
d458b054	167	int thresh)
08a9ff32	168	{
61dd5ae6	169	struct btrfs_workqueue ret = kzalloc(sizeof(ret), GFP_KERNEL);
08a9ff32	170
5d99a998	171	if (!ret)
08a9ff32 QW	172	return NULL;
08a9ff32 QW	173
cb001095 JM	174	ret->normal = __btrfs_alloc_workqueue(fs_info, name,
cb001095 JM	175	flags & ~WQ_HIGHPRI,
c6dd6ea5	176	limit_active, thresh);
5d99a998	177	if (!ret->normal) {
08a9ff32 QW	178	kfree(ret);
	179	return NULL;
	180	}
	181
1ca08976	182	if (flags & WQ_HIGHPRI) {
cb001095 JM	183	ret->high = __btrfs_alloc_workqueue(fs_info, name, flags,
cb001095 JM	184	limit_active, thresh);
5d99a998	185	if (!ret->high) {
1ca08976 QW	186	__btrfs_destroy_workqueue(ret->normal);
	187	kfree(ret);
	188	return NULL;
	189	}
	190	}
08a9ff32 QW	191	return ret;
	192	}
	193
0bd9289c QW	194	/*
	195	* Hook for threshold which will be called in btrfs_queue_work.
	196	* This hook WILL be called in IRQ handler context,
	197	* so workqueue_set_max_active MUST NOT be called in this hook
	198	*/
d458b054	199	static inline void thresh_queue_hook(struct __btrfs_workqueue *wq)
0bd9289c QW	200	{
	201	if (wq->thresh == NO_THRESHOLD)
	202	return;
	203	atomic_inc(&wq->pending);
	204	}
	205
	206	/*
	207	* Hook for threshold which will be called before executing the work,
	208	* This hook is called in kthread content.
	209	* So workqueue_set_max_active is called here.
	210	*/
d458b054	211	static inline void thresh_exec_hook(struct __btrfs_workqueue *wq)
0bd9289c	212	{
c6dd6ea5	213	int new_current_active;
0bd9289c QW	214	long pending;
	215	int need_change = 0;
	216
	217	if (wq->thresh == NO_THRESHOLD)
	218	return;
	219
	220	atomic_dec(&wq->pending);
	221	spin_lock(&wq->thres_lock);
	222	/*
	223	* Use wq->count to limit the calling frequency of
	224	* workqueue_set_max_active.
	225	*/
	226	wq->count++;
	227	wq->count %= (wq->thresh / 4);
	228	if (!wq->count)
	229	goto out;
c6dd6ea5	230	new_current_active = wq->current_active;
0bd9289c QW	231
	232	/*
	233	* pending may be changed later, but it's OK since we really
	234	* don't need it so accurate to calculate new_max_active.
	235	*/
	236	pending = atomic_read(&wq->pending);
	237	if (pending > wq->thresh)
c6dd6ea5	238	new_current_active++;
0bd9289c	239	if (pending < wq->thresh / 2)
c6dd6ea5 QW	240	new_current_active--;
	241	new_current_active = clamp_val(new_current_active, 1, wq->limit_active);
	242	if (new_current_active != wq->current_active) {
0bd9289c	243	need_change = 1;
c6dd6ea5	244	wq->current_active = new_current_active;
0bd9289c QW	245	}
	246	out:
	247	spin_unlock(&wq->thres_lock);
	248
	249	if (need_change) {
c6dd6ea5	250	workqueue_set_max_active(wq->normal_wq, wq->current_active);
0bd9289c QW	251	}
	252	}
	253
d458b054	254	static void run_ordered_work(struct __btrfs_workqueue *wq)
08a9ff32 QW	255	{
08a9ff32 QW	256	struct list_head *list = &wq->ordered_list;
d458b054	257	struct btrfs_work *work;
08a9ff32 QW	258	spinlock_t *lock = &wq->list_lock;
	259	unsigned long flags;
	260
	261	while (1) {
	262	spin_lock_irqsave(lock, flags);
	263	if (list_empty(list))
	264	break;
d458b054	265	work = list_entry(list->next, struct btrfs_work,
08a9ff32 QW	266	ordered_list);
	267	if (!test_bit(WORK_DONE_BIT, &work->flags))
	268	break;
	269
	270	/*
	271	* we are going to call the ordered done function, but
	272	* we leave the work item on the list as a barrier so
	273	* that later work items that are done don't have their
	274	* functions called before this one returns
	275	*/
	276	if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags))
	277	break;
52483bc2	278	trace_btrfs_ordered_sched(work);
08a9ff32 QW	279	spin_unlock_irqrestore(lock, flags);
	280	work->ordered_func(work);
	281
	282	/* now take the lock again and drop our item from the list */
	283	spin_lock_irqsave(lock, flags);
	284	list_del(&work->ordered_list);
	285	spin_unlock_irqrestore(lock, flags);
	286
	287	/*
	288	* we don't want to call the ordered free functions
	289	* with the lock held though
	290	*/
	291	work->ordered_free(work);
52483bc2	292	trace_btrfs_all_work_done(work);
08a9ff32 QW	293	}
	294	spin_unlock_irqrestore(lock, flags);
	295	}
	296
9e0af237	297	static void normal_work_helper(struct btrfs_work *work)
08a9ff32	298	{
d458b054	299	struct __btrfs_workqueue *wq;
08a9ff32 QW	300	int need_order = 0;
08a9ff32 QW	301
08a9ff32 QW	302	/*
	303	* We should not touch things inside work in the following cases:
	304	* 1) after work->func() if it has no ordered_free
	305	* Since the struct is freed in work->func().
	306	* 2) after setting WORK_DONE_BIT
	307	* The work may be freed in other threads almost instantly.
	308	* So we save the needed things here.
	309	*/
	310	if (work->ordered_func)
	311	need_order = 1;
	312	wq = work->wq;
	313
52483bc2	314	trace_btrfs_work_sched(work);
0bd9289c	315	thresh_exec_hook(wq);
08a9ff32 QW	316	work->func(work);
	317	if (need_order) {
	318	set_bit(WORK_DONE_BIT, &work->flags);
	319	run_ordered_work(wq);
	320	}
52483bc2 QW	321	if (!need_order)
52483bc2 QW	322	trace_btrfs_all_work_done(work);
08a9ff32 QW	323	}
08a9ff32 QW	324
9e0af237	325	void btrfs_init_work(struct btrfs_work *work, btrfs_work_func_t uniq_func,
6db8914f QW	326	btrfs_func_t func,
	327	btrfs_func_t ordered_func,
	328	btrfs_func_t ordered_free)
08a9ff32 QW	329	{
	330	work->func = func;
	331	work->ordered_func = ordered_func;
	332	work->ordered_free = ordered_free;
9e0af237	333	INIT_WORK(&work->normal_work, uniq_func);
08a9ff32 QW	334	INIT_LIST_HEAD(&work->ordered_list);
	335	work->flags = 0;
	336	}
	337
d458b054 QW	338	static inline void __btrfs_queue_work(struct __btrfs_workqueue *wq,
d458b054 QW	339	struct btrfs_work *work)
08a9ff32 QW	340	{
	341	unsigned long flags;
	342
	343	work->wq = wq;
0bd9289c	344	thresh_queue_hook(wq);
08a9ff32 QW	345	if (work->ordered_func) {
	346	spin_lock_irqsave(&wq->list_lock, flags);
	347	list_add_tail(&work->ordered_list, &wq->ordered_list);
	348	spin_unlock_irqrestore(&wq->list_lock, flags);
	349	}
52483bc2	350	trace_btrfs_work_queued(work);
0a95b851	351	queue_work(wq->normal_wq, &work->normal_work);
08a9ff32 QW	352	}
08a9ff32 QW	353
d458b054 QW	354	void btrfs_queue_work(struct btrfs_workqueue *wq,
d458b054 QW	355	struct btrfs_work *work)
1ca08976	356	{
d458b054	357	struct __btrfs_workqueue *dest_wq;
1ca08976 QW	358
	359	if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags) && wq->high)
	360	dest_wq = wq->high;
	361	else
	362	dest_wq = wq->normal;
	363	__btrfs_queue_work(dest_wq, work);
	364	}
	365
	366	static inline void
d458b054	367	__btrfs_destroy_workqueue(struct __btrfs_workqueue *wq)
08a9ff32 QW	368	{
08a9ff32 QW	369	destroy_workqueue(wq->normal_wq);
c3a46891	370	trace_btrfs_workqueue_destroy(wq);
08a9ff32 QW	371	kfree(wq);
	372	}
	373
d458b054	374	void btrfs_destroy_workqueue(struct btrfs_workqueue *wq)
1ca08976 QW	375	{
	376	if (!wq)
	377	return;
	378	if (wq->high)
	379	__btrfs_destroy_workqueue(wq->high);
	380	__btrfs_destroy_workqueue(wq->normal);
ef66af10	381	kfree(wq);
1ca08976 QW	382	}
1ca08976 QW	383
c6dd6ea5	384	void btrfs_workqueue_set_max(struct btrfs_workqueue *wq, int limit_active)
08a9ff32	385	{
800ee224 ST	386	if (!wq)
800ee224 ST	387	return;
c6dd6ea5	388	wq->normal->limit_active = limit_active;
1ca08976	389	if (wq->high)
c6dd6ea5	390	wq->high->limit_active = limit_active;
1ca08976 QW	391	}
1ca08976 QW	392
d458b054	393	void btrfs_set_work_high_priority(struct btrfs_work *work)
1ca08976 QW	394	{
1ca08976 QW	395	set_bit(WORK_HIGH_PRIO_BIT, &work->flags);
08a9ff32	396	}