aboutsummaryrefslogtreecommitdiffstats
path: root/fs/dlm/ast.c
blob: 59711486d80128f8040ab68f763ae3d5bfb900b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
// 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 <trace/events/dlm.h>

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

static void dlm_callback_work(struct work_struct *work)
{
	struct dlm_callback *cb = container_of(work, struct dlm_callback, work);

	if (cb->flags & DLM_CB_BAST) {
		trace_dlm_bast(cb->ls_id, cb->lkb_id, cb->mode, cb->res_name,
			       cb->res_length);
		cb->bastfn(cb->astparam, cb->mode);
	} else if (cb->flags & DLM_CB_CAST) {
		trace_dlm_ast(cb->ls_id, cb->lkb_id, cb->sb_status,
			      cb->sb_flags, cb->res_name, cb->res_length);
		cb->lkb_lksb->sb_status = cb->sb_status;
		cb->lkb_lksb->sb_flags = cb->sb_flags;
		cb->astfn(cb->astparam);
	}

	dlm_free_cb(cb);
}

int dlm_queue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
			   int status, uint32_t sbflags,
			   struct dlm_callback **cb)
{
	struct dlm_rsb *rsb = lkb->lkb_resource;
	int rv = DLM_ENQUEUE_CALLBACK_SUCCESS;
	struct dlm_ls *ls = rsb->res_ls;
	int copy_lvb = 0;
	int prev_mode;

	if (flags & DLM_CB_BAST) {
		/* if cb is a bast, it should be skipped if the blocking mode is
		 * compatible with the last granted mode
		 */
		if (lkb->lkb_last_cast_cb_mode != -1) {
			if (dlm_modes_compat(mode, lkb->lkb_last_cast_cb_mode)) {
				log_debug(ls, "skip %x bast mode %d for cast mode %d",
					  lkb->lkb_id, mode,
					  lkb->lkb_last_cast_cb_mode);
				goto out;
			}
		}

		/*
		 * 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 (lkb->lkb_last_cb_mode != -1 &&
		    lkb->lkb_last_cb_flags & DLM_CB_BAST) {
			prev_mode = lkb->lkb_last_cb_mode;

			if ((prev_mode == mode) ||
			    (prev_mode > mode && prev_mode > DLM_LOCK_PR)) {
				log_debug(ls, "skip %x add bast mode %d for bast mode %d",
					  lkb->lkb_id, mode, prev_mode);
				goto out;
			}
		}

		lkb->lkb_last_bast_time = ktime_get();
		lkb->lkb_last_bast_cb_mode = mode;
	} else if (flags & DLM_CB_CAST) {
		if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
			prev_mode = lkb->lkb_last_cast_cb_mode;

			if (!status && lkb->lkb_lksb->sb_lvbptr &&
			    dlm_lvb_operations[prev_mode + 1][mode + 1])
				copy_lvb = 1;
		}

		lkb->lkb_last_cast_cb_mode = mode;
		lkb->lkb_last_cast_time = ktime_get();
	}

	lkb->lkb_last_cb_mode = mode;
	lkb->lkb_last_cb_flags = flags;

	*cb = dlm_allocate_cb();
	if (!*cb) {
		rv = DLM_ENQUEUE_CALLBACK_FAILURE;
		goto out;
	}

	/* for tracing */
	(*cb)->lkb_id = lkb->lkb_id;
	(*cb)->ls_id = ls->ls_global_id;
	memcpy((*cb)->res_name, rsb->res_name, rsb->res_length);
	(*cb)->res_length = rsb->res_length;

	(*cb)->flags = flags;
	(*cb)->mode = mode;
	(*cb)->sb_status = status;
	(*cb)->sb_flags = (sbflags & 0x000000FF);
	(*cb)->copy_lvb = copy_lvb;
	(*cb)->lkb_lksb = lkb->lkb_lksb;

	rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;

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;
	struct dlm_callback *cb;
	int rv;

	if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
		dlm_user_add_ast(lkb, flags, mode, status, sbflags);
		return;
	}

	rv = dlm_queue_lkb_callback(lkb, flags, mode, status, sbflags,
				    &cb);
	switch (rv) {
	case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
		cb->astfn = lkb->lkb_astfn;
		cb->bastfn = lkb->lkb_bastfn;
		cb->astparam = lkb->lkb_astparam;
		INIT_WORK(&cb->work, dlm_callback_work);

		spin_lock_bh(&ls->ls_cb_lock);
		if (test_bit(LSFL_CB_DELAY, &ls->ls_flags))
			list_add(&cb->list, &ls->ls_cb_delay);
		else
			queue_work(ls->ls_callback_wq, &cb->work);
		spin_unlock_bh(&ls->ls_cb_lock);
		break;
	case DLM_ENQUEUE_CALLBACK_SUCCESS:
		break;
	case DLM_ENQUEUE_CALLBACK_FAILURE:
		fallthrough;
	default:
		WARN_ON_ONCE(1);
		break;
	}
}

int dlm_callback_start(struct dlm_ls *ls)
{
	ls->ls_callback_wq = alloc_ordered_workqueue("dlm_callback",
						     WQ_HIGHPRI | WQ_MEM_RECLAIM);
	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)
{
	if (ls->ls_callback_wq) {
		spin_lock_bh(&ls->ls_cb_lock);
		set_bit(LSFL_CB_DELAY, &ls->ls_flags);
		spin_unlock_bh(&ls->ls_cb_lock);

		flush_workqueue(ls->ls_callback_wq);
	}
}

#define MAX_CB_QUEUE 25

void dlm_callback_resume(struct dlm_ls *ls)
{
	struct dlm_callback *cb, *safe;
	int count = 0, sum = 0;
	bool empty;

	if (!ls->ls_callback_wq)
		return;

more:
	spin_lock_bh(&ls->ls_cb_lock);
	list_for_each_entry_safe(cb, safe, &ls->ls_cb_delay, list) {
		list_del(&cb->list);
		queue_work(ls->ls_callback_wq, &cb->work);
		count++;
		if (count == MAX_CB_QUEUE)
			break;
	}
	empty = list_empty(&ls->ls_cb_delay);
	if (empty)
		clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
	spin_unlock_bh(&ls->ls_cb_lock);

	sum += count;
	if (!empty) {
		count = 0;
		cond_resched();
		goto more;
	}

	if (sum)
		log_rinfo(ls, "%s %d", __func__, sum);
}