[linux-2.6-block.git] / fs / dlm / ast.c

// SPDX-License-Identifier: GPL-2.0-only
/******************************************************************************
*******************************************************************************
**
**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
**  Copyright (C) 2004-2010 Red Hat, Inc.  All rights reserved.
**
**
*******************************************************************************
******************************************************************************/

#include "dlm_internal.h"
#include "lock.h"
#include "user.h"
#include "ast.h"

static uint64_t dlm_cb_seq;
static DEFINE_SPINLOCK(dlm_cb_seq_spin);

static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb)
{
	int i;

	log_print("last_bast %x %llu flags %x mode %d sb %d %x",
		  lkb->lkb_id,
		  (unsigned long long)lkb->lkb_last_bast.seq,
		  lkb->lkb_last_bast.flags,
		  lkb->lkb_last_bast.mode,
		  lkb->lkb_last_bast.sb_status,
		  lkb->lkb_last_bast.sb_flags);

	log_print("last_cast %x %llu flags %x mode %d sb %d %x",
		  lkb->lkb_id,
		  (unsigned long long)lkb->lkb_last_cast.seq,
		  lkb->lkb_last_cast.flags,
		  lkb->lkb_last_cast.mode,
		  lkb->lkb_last_cast.sb_status,
		  lkb->lkb_last_cast.sb_flags);

	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
		log_print("cb %x %llu flags %x mode %d sb %d %x",
			  lkb->lkb_id,
			  (unsigned long long)lkb->lkb_callbacks[i].seq,
			  lkb->lkb_callbacks[i].flags,
			  lkb->lkb_callbacks[i].mode,
			  lkb->lkb_callbacks[i].sb_status,
			  lkb->lkb_callbacks[i].sb_flags);
	}
}

int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
			 int status, uint32_t sbflags, uint64_t seq)
{
	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
	uint64_t prev_seq;
	int prev_mode;
	int i, rv;

	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
		if (lkb->lkb_callbacks[i].seq)
			continue;

		/*
		 * Suppress some redundant basts here, do more on removal.
		 * Don't even add a bast if the callback just before it
		 * is a bast for the same mode or a more restrictive mode.
		 * (the addional > PR check is needed for PR/CW inversion)
		 */

		if ((i > 0) && (flags & DLM_CB_BAST) &&
		    (lkb->lkb_callbacks[i-1].flags & DLM_CB_BAST)) {

			prev_seq = lkb->lkb_callbacks[i-1].seq;
			prev_mode = lkb->lkb_callbacks[i-1].mode;

			if ((prev_mode == mode) ||
			    (prev_mode > mode && prev_mode > DLM_LOCK_PR)) {

				log_debug(ls, "skip %x add bast %llu mode %d "
					  "for bast %llu mode %d",
					  lkb->lkb_id,
					  (unsigned long long)seq,
					  mode,
					  (unsigned long long)prev_seq,
					  prev_mode);
				rv = 0;
				goto out;
			}
		}

		lkb->lkb_callbacks[i].seq = seq;
		lkb->lkb_callbacks[i].flags = flags;
		lkb->lkb_callbacks[i].mode = mode;
		lkb->lkb_callbacks[i].sb_status = status;
		lkb->lkb_callbacks[i].sb_flags = (sbflags & 0x000000FF);
		rv = 0;
		break;
	}

	if (i == DLM_CALLBACKS_SIZE) {
		log_error(ls, "no callbacks %x %llu flags %x mode %d sb %d %x",
			  lkb->lkb_id, (unsigned long long)seq,
			  flags, mode, status, sbflags);
		dlm_dump_lkb_callbacks(lkb);
		rv = -1;
		goto out;
	}
 out:
	return rv;
}

int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
			 struct dlm_callback *cb, int *resid)
{
	int i, rv;

	*resid = 0;

	if (!lkb->lkb_callbacks[0].seq) {
		rv = -ENOENT;
		goto out;
	}

	/* oldest undelivered cb is callbacks[0] */

	memcpy(cb, &lkb->lkb_callbacks[0], sizeof(struct dlm_callback));
	memset(&lkb->lkb_callbacks[0], 0, sizeof(struct dlm_callback));

	/* shift others down */

	for (i = 1; i < DLM_CALLBACKS_SIZE; i++) {
		if (!lkb->lkb_callbacks[i].seq)
			break;
		memcpy(&lkb->lkb_callbacks[i-1], &lkb->lkb_callbacks[i],
		       sizeof(struct dlm_callback));
		memset(&lkb->lkb_callbacks[i], 0, sizeof(struct dlm_callback));
		(*resid)++;
	}

	/* if cb is a bast, it should be skipped if the blocking mode is
	   compatible with the last granted mode */

	if ((cb->flags & DLM_CB_BAST) && lkb->lkb_last_cast.seq) {
		if (dlm_modes_compat(cb->mode, lkb->lkb_last_cast.mode)) {
			cb->flags |= DLM_CB_SKIP;

			log_debug(ls, "skip %x bast %llu mode %d "
				  "for cast %llu mode %d",
				  lkb->lkb_id,
				  (unsigned long long)cb->seq,
				  cb->mode,
				  (unsigned long long)lkb->lkb_last_cast.seq,
				  lkb->lkb_last_cast.mode);
			rv = 0;
			goto out;
		}
	}

	if (cb->flags & DLM_CB_CAST) {
		memcpy(&lkb->lkb_last_cast, cb, sizeof(struct dlm_callback));
		lkb->lkb_last_cast_time = ktime_get();
	}

	if (cb->flags & DLM_CB_BAST) {
		memcpy(&lkb->lkb_last_bast, cb, sizeof(struct dlm_callback));
		lkb->lkb_last_bast_time = ktime_get();
	}
	rv = 0;
 out:
	return rv;
}

void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
		uint32_t sbflags)
{
	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
	uint64_t new_seq, prev_seq;
	int rv;

	spin_lock(&dlm_cb_seq_spin);
	new_seq = ++dlm_cb_seq;
	if (!dlm_cb_seq)
		new_seq = ++dlm_cb_seq;
	spin_unlock(&dlm_cb_seq_spin);

	if (lkb->lkb_flags & DLM_IFL_USER) {
		dlm_user_add_ast(lkb, flags, mode, status, sbflags, new_seq);
		return;
	}

	mutex_lock(&lkb->lkb_cb_mutex);
	prev_seq = lkb->lkb_callbacks[0].seq;

	rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq);
	if (rv < 0)
		goto out;

	if (!prev_seq) {
		kref_get(&lkb->lkb_ref);

		if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
			mutex_lock(&ls->ls_cb_mutex);
			list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
			mutex_unlock(&ls->ls_cb_mutex);
		} else {
			queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
		}
	}
 out:
	mutex_unlock(&lkb->lkb_cb_mutex);
}

void dlm_callback_work(struct work_struct *work)
{
	struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
	void (*castfn) (void *astparam);
	void (*bastfn) (void *astparam, int mode);
	struct dlm_callback callbacks[DLM_CALLBACKS_SIZE];
	int i, rv, resid;

	memset(&callbacks, 0, sizeof(callbacks));

	mutex_lock(&lkb->lkb_cb_mutex);
	if (!lkb->lkb_callbacks[0].seq) {
		/* no callback work exists, shouldn't happen */
		log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id);
		dlm_print_lkb(lkb);
		dlm_dump_lkb_callbacks(lkb);
	}

	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
		rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
		if (rv < 0)
			break;
	}

	if (resid) {
		/* cbs remain, loop should have removed all, shouldn't happen */
		log_error(ls, "dlm_callback_work %x resid %d", lkb->lkb_id,
			  resid);
		dlm_print_lkb(lkb);
		dlm_dump_lkb_callbacks(lkb);
	}
	mutex_unlock(&lkb->lkb_cb_mutex);

	castfn = lkb->lkb_astfn;
	bastfn = lkb->lkb_bastfn;

	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
		if (!callbacks[i].seq)
			break;
		if (callbacks[i].flags & DLM_CB_SKIP) {
			continue;
		} else if (callbacks[i].flags & DLM_CB_BAST) {
			bastfn(lkb->lkb_astparam, callbacks[i].mode);
		} else if (callbacks[i].flags & DLM_CB_CAST) {
			lkb->lkb_lksb->sb_status = callbacks[i].sb_status;
			lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags;
			castfn(lkb->lkb_astparam);
		}
	}

	/* undo kref_get from dlm_add_callback, may cause lkb to be freed */
	dlm_put_lkb(lkb);
}

int dlm_callback_start(struct dlm_ls *ls)
{
	ls->ls_callback_wq = alloc_workqueue("dlm_callback",
					     WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
	if (!ls->ls_callback_wq) {
		log_print("can't start dlm_callback workqueue");
		return -ENOMEM;
	}
	return 0;
}

void dlm_callback_stop(struct dlm_ls *ls)
{
	if (ls->ls_callback_wq)
		destroy_workqueue(ls->ls_callback_wq);
}

void dlm_callback_suspend(struct dlm_ls *ls)
{
	set_bit(LSFL_CB_DELAY, &ls->ls_flags);

	if (ls->ls_callback_wq)
		flush_workqueue(ls->ls_callback_wq);
}

#define MAX_CB_QUEUE 25

void dlm_callback_resume(struct dlm_ls *ls)
{
	struct dlm_lkb *lkb, *safe;
	int count = 0;

	clear_bit(LSFL_CB_DELAY, &ls->ls_flags);

	if (!ls->ls_callback_wq)
		return;

more:
	mutex_lock(&ls->ls_cb_mutex);
	list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) {
		list_del_init(&lkb->lkb_cb_list);
		queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
		count++;
		if (count == MAX_CB_QUEUE)
			break;
	}
	mutex_unlock(&ls->ls_cb_mutex);

	if (count)
		log_rinfo(ls, "dlm_callback_resume %d", count);
	if (count == MAX_CB_QUEUE) {
		count = 0;
		cond_resched();
		goto more;
	}
}
Commit	Line	Data
2522fe45	1	// SPDX-License-Identifier: GPL-2.0-only
e7fd4179 DT	2	/******************************************************************************
	3	*******************************************************************************
	4	**
	5	** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
7fe2b319	6	** Copyright (C) 2004-2010 Red Hat, Inc. All rights reserved.
e7fd4179	7	**
e7fd4179 DT	8	**
	9	*******************************************************************************
	10	******************************************************************************/
	11
	12	#include "dlm_internal.h"
	13	#include "lock.h"
597d0cae	14	#include "user.h"
95058571	15	#include "ast.h"
e7fd4179	16
6ad22916 DT	17	static uint64_t dlm_cb_seq;
6ad22916 DT	18	static DEFINE_SPINLOCK(dlm_cb_seq_spin);
e7fd4179	19
8304d6f2 DT	20	static void dlm_dump_lkb_callbacks(struct dlm_lkb *lkb)
	21	{
	22	int i;
	23
	24	log_print("last_bast %x %llu flags %x mode %d sb %d %x",
	25	lkb->lkb_id,
	26	(unsigned long long)lkb->lkb_last_bast.seq,
	27	lkb->lkb_last_bast.flags,
	28	lkb->lkb_last_bast.mode,
	29	lkb->lkb_last_bast.sb_status,
	30	lkb->lkb_last_bast.sb_flags);
	31
	32	log_print("last_cast %x %llu flags %x mode %d sb %d %x",
	33	lkb->lkb_id,
	34	(unsigned long long)lkb->lkb_last_cast.seq,
	35	lkb->lkb_last_cast.flags,
	36	lkb->lkb_last_cast.mode,
	37	lkb->lkb_last_cast.sb_status,
	38	lkb->lkb_last_cast.sb_flags);
	39
	40	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
	41	log_print("cb %x %llu flags %x mode %d sb %d %x",
	42	lkb->lkb_id,
	43	(unsigned long long)lkb->lkb_callbacks[i].seq,
	44	lkb->lkb_callbacks[i].flags,
	45	lkb->lkb_callbacks[i].mode,
	46	lkb->lkb_callbacks[i].sb_status,
	47	lkb->lkb_callbacks[i].sb_flags);
	48	}
	49	}
	50
8304d6f2 DT	51	int dlm_add_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
	52	int status, uint32_t sbflags, uint64_t seq)
	53	{
	54	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
	55	uint64_t prev_seq;
	56	int prev_mode;
23e8e1aa	57	int i, rv;
8304d6f2 DT	58
	59	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
	60	if (lkb->lkb_callbacks[i].seq)
	61	continue;
	62
	63	/*
	64	* Suppress some redundant basts here, do more on removal.
	65	* Don't even add a bast if the callback just before it
	66	* is a bast for the same mode or a more restrictive mode.
	67	* (the addional > PR check is needed for PR/CW inversion)
	68	*/
	69
	70	if ((i > 0) && (flags & DLM_CB_BAST) &&
	71	(lkb->lkb_callbacks[i-1].flags & DLM_CB_BAST)) {
	72
	73	prev_seq = lkb->lkb_callbacks[i-1].seq;
	74	prev_mode = lkb->lkb_callbacks[i-1].mode;
	75
	76	if ((prev_mode == mode) \|\|
	77	(prev_mode > mode && prev_mode > DLM_LOCK_PR)) {
	78
	79	log_debug(ls, "skip %x add bast %llu mode %d "
	80	"for bast %llu mode %d",
	81	lkb->lkb_id,
	82	(unsigned long long)seq,
	83	mode,
	84	(unsigned long long)prev_seq,
	85	prev_mode);
23e8e1aa DT	86	rv = 0;
23e8e1aa DT	87	goto out;
8304d6f2 DT	88	}
	89	}
	90
	91	lkb->lkb_callbacks[i].seq = seq;
	92	lkb->lkb_callbacks[i].flags = flags;
	93	lkb->lkb_callbacks[i].mode = mode;
	94	lkb->lkb_callbacks[i].sb_status = status;
	95	lkb->lkb_callbacks[i].sb_flags = (sbflags & 0x000000FF);
23e8e1aa	96	rv = 0;
8304d6f2 DT	97	break;
	98	}
	99
	100	if (i == DLM_CALLBACKS_SIZE) {
	101	log_error(ls, "no callbacks %x %llu flags %x mode %d sb %d %x",
	102	lkb->lkb_id, (unsigned long long)seq,
	103	flags, mode, status, sbflags);
	104	dlm_dump_lkb_callbacks(lkb);
23e8e1aa DT	105	rv = -1;
23e8e1aa DT	106	goto out;
8304d6f2	107	}
23e8e1aa DT	108	out:
23e8e1aa DT	109	return rv;
8304d6f2 DT	110	}
	111
	112	int dlm_rem_lkb_callback(struct dlm_ls ls, struct dlm_lkb lkb,
	113	struct dlm_callback cb, int resid)
e7fd4179	114	{
23e8e1aa	115	int i, rv;
8304d6f2 DT	116
	117	*resid = 0;
	118
23e8e1aa DT	119	if (!lkb->lkb_callbacks[0].seq) {
	120	rv = -ENOENT;
	121	goto out;
	122	}
8304d6f2 DT	123
	124	/* oldest undelivered cb is callbacks[0] */
	125
	126	memcpy(cb, &lkb->lkb_callbacks[0], sizeof(struct dlm_callback));
	127	memset(&lkb->lkb_callbacks[0], 0, sizeof(struct dlm_callback));
	128
	129	/* shift others down */
	130
	131	for (i = 1; i < DLM_CALLBACKS_SIZE; i++) {
	132	if (!lkb->lkb_callbacks[i].seq)
	133	break;
	134	memcpy(&lkb->lkb_callbacks[i-1], &lkb->lkb_callbacks[i],
	135	sizeof(struct dlm_callback));
	136	memset(&lkb->lkb_callbacks[i], 0, sizeof(struct dlm_callback));
	137	(*resid)++;
	138	}
	139
	140	/* if cb is a bast, it should be skipped if the blocking mode is
	141	compatible with the last granted mode */
	142
	143	if ((cb->flags & DLM_CB_BAST) && lkb->lkb_last_cast.seq) {
	144	if (dlm_modes_compat(cb->mode, lkb->lkb_last_cast.mode)) {
	145	cb->flags \|= DLM_CB_SKIP;
	146
	147	log_debug(ls, "skip %x bast %llu mode %d "
	148	"for cast %llu mode %d",
	149	lkb->lkb_id,
	150	(unsigned long long)cb->seq,
	151	cb->mode,
	152	(unsigned long long)lkb->lkb_last_cast.seq,
	153	lkb->lkb_last_cast.mode);
23e8e1aa DT	154	rv = 0;
23e8e1aa DT	155	goto out;
8304d6f2 DT	156	}
	157	}
	158
	159	if (cb->flags & DLM_CB_CAST) {
	160	memcpy(&lkb->lkb_last_cast, cb, sizeof(struct dlm_callback));
	161	lkb->lkb_last_cast_time = ktime_get();
	162	}
	163
	164	if (cb->flags & DLM_CB_BAST) {
	165	memcpy(&lkb->lkb_last_bast, cb, sizeof(struct dlm_callback));
	166	lkb->lkb_last_bast_time = ktime_get();
	167	}
23e8e1aa DT	168	rv = 0;
	169	out:
	170	return rv;
8304d6f2 DT	171	}
8304d6f2 DT	172
23e8e1aa DT	173	void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
23e8e1aa DT	174	uint32_t sbflags)
8304d6f2	175	{
23e8e1aa DT	176	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
23e8e1aa DT	177	uint64_t new_seq, prev_seq;
8304d6f2 DT	178	int rv;
8304d6f2 DT	179
23e8e1aa DT	180	spin_lock(&dlm_cb_seq_spin);
23e8e1aa DT	181	new_seq = ++dlm_cb_seq;
ccbbea04	182	if (!dlm_cb_seq)
ccbbea04	183	new_seq = ++dlm_cb_seq;
23e8e1aa	184	spin_unlock(&dlm_cb_seq_spin);
8304d6f2	185
597d0cae	186	if (lkb->lkb_flags & DLM_IFL_USER) {
23e8e1aa	187	dlm_user_add_ast(lkb, flags, mode, status, sbflags, new_seq);
597d0cae DT	188	return;
	189	}
	190
23e8e1aa DT	191	mutex_lock(&lkb->lkb_cb_mutex);
23e8e1aa DT	192	prev_seq = lkb->lkb_callbacks[0].seq;
8304d6f2	193
23e8e1aa DT	194	rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq);
	195	if (rv < 0)
	196	goto out;
	197
	198	if (!prev_seq) {
e7fd4179	199	kref_get(&lkb->lkb_ref);
e7fd4179	200
23e8e1aa DT	201	if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
	202	mutex_lock(&ls->ls_cb_mutex);
	203	list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
	204	mutex_unlock(&ls->ls_cb_mutex);
	205	} else {
	206	queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
	207	}
	208	}
	209	out:
	210	mutex_unlock(&lkb->lkb_cb_mutex);
e7fd4179 DT	211	}
e7fd4179 DT	212
23e8e1aa	213	void dlm_callback_work(struct work_struct *work)
e7fd4179	214	{
23e8e1aa DT	215	struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
23e8e1aa DT	216	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
7fe2b319 DT	217	void (castfn) (void astparam);
7fe2b319 DT	218	void (bastfn) (void astparam, int mode);
8304d6f2 DT	219	struct dlm_callback callbacks[DLM_CALLBACKS_SIZE];
8304d6f2 DT	220	int i, rv, resid;
722d7421	221
23e8e1aa	222	memset(&callbacks, 0, sizeof(callbacks));
e7fd4179	223
23e8e1aa DT	224	mutex_lock(&lkb->lkb_cb_mutex);
	225	if (!lkb->lkb_callbacks[0].seq) {
	226	/* no callback work exists, shouldn't happen */
	227	log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id);
	228	dlm_print_lkb(lkb);
	229	dlm_dump_lkb_callbacks(lkb);
	230	}
e7fd4179	231
23e8e1aa DT	232	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
	233	rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
	234	if (rv < 0)
	235	break;
	236	}
7fe2b319	237
23e8e1aa DT	238	if (resid) {
	239	/* cbs remain, loop should have removed all, shouldn't happen */
	240	log_error(ls, "dlm_callback_work %x resid %d", lkb->lkb_id,
	241	resid);
	242	dlm_print_lkb(lkb);
	243	dlm_dump_lkb_callbacks(lkb);
	244	}
	245	mutex_unlock(&lkb->lkb_cb_mutex);
7fe2b319	246
23e8e1aa DT	247	castfn = lkb->lkb_astfn;
23e8e1aa DT	248	bastfn = lkb->lkb_bastfn;
7fe2b319	249
23e8e1aa DT	250	for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
	251	if (!callbacks[i].seq)
	252	break;
	253	if (callbacks[i].flags & DLM_CB_SKIP) {
	254	continue;
	255	} else if (callbacks[i].flags & DLM_CB_BAST) {
	256	bastfn(lkb->lkb_astparam, callbacks[i].mode);
	257	} else if (callbacks[i].flags & DLM_CB_CAST) {
	258	lkb->lkb_lksb->sb_status = callbacks[i].sb_status;
	259	lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags;
	260	castfn(lkb->lkb_astparam);
7fe2b319	261	}
e7fd4179	262	}
e7fd4179	263
23e8e1aa DT	264	/* undo kref_get from dlm_add_callback, may cause lkb to be freed */
23e8e1aa DT	265	dlm_put_lkb(lkb);
e7fd4179 DT	266	}
e7fd4179 DT	267
23e8e1aa	268	int dlm_callback_start(struct dlm_ls *ls)
e7fd4179	269	{
23e8e1aa	270	ls->ls_callback_wq = alloc_workqueue("dlm_callback",
aa9f1012	271	WQ_HIGHPRI \| WQ_MEM_RECLAIM, 0);
23e8e1aa DT	272	if (!ls->ls_callback_wq) {
	273	log_print("can't start dlm_callback workqueue");
	274	return -ENOMEM;
e7fd4179 DT	275	}
	276	return 0;
	277	}
	278
23e8e1aa	279	void dlm_callback_stop(struct dlm_ls *ls)
e7fd4179	280	{
23e8e1aa DT	281	if (ls->ls_callback_wq)
23e8e1aa DT	282	destroy_workqueue(ls->ls_callback_wq);
e7fd4179 DT	283	}
e7fd4179 DT	284
23e8e1aa	285	void dlm_callback_suspend(struct dlm_ls *ls)
e7fd4179	286	{
23e8e1aa	287	set_bit(LSFL_CB_DELAY, &ls->ls_flags);
e7fd4179	288
23e8e1aa DT	289	if (ls->ls_callback_wq)
23e8e1aa DT	290	flush_workqueue(ls->ls_callback_wq);
e7fd4179 DT	291	}
e7fd4179 DT	292
216f0efd BP	293	#define MAX_CB_QUEUE 25
216f0efd BP	294
23e8e1aa	295	void dlm_callback_resume(struct dlm_ls *ls)
e7fd4179	296	{
23e8e1aa DT	297	struct dlm_lkb lkb, safe;
23e8e1aa DT	298	int count = 0;
e7fd4179	299
23e8e1aa DT	300	clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
	301
	302	if (!ls->ls_callback_wq)
	303	return;
	304
216f0efd	305	more:
23e8e1aa DT	306	mutex_lock(&ls->ls_cb_mutex);
	307	list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) {
	308	list_del_init(&lkb->lkb_cb_list);
	309	queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
	310	count++;
216f0efd BP	311	if (count == MAX_CB_QUEUE)
216f0efd BP	312	break;
23e8e1aa DT	313	}
	314	mutex_unlock(&ls->ls_cb_mutex);
	315
4875647a	316	if (count)
075f0177	317	log_rinfo(ls, "dlm_callback_resume %d", count);
216f0efd BP	318	if (count == MAX_CB_QUEUE) {
	319	count = 0;
	320	cond_resched();
	321	goto more;
	322	}
e7fd4179 DT	323	}
e7fd4179 DT	324