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