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