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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 "lvb_table.h"
16#include "memory.h"
17#include "lock.h"
18#include "user.h"
19#include "ast.h"
20
21void dlm_release_callback(struct kref *ref)
22{
23 struct dlm_callback *cb = container_of(ref, struct dlm_callback, ref);
24
25 dlm_free_cb(cb);
26}
27
28void dlm_callback_set_last_ptr(struct dlm_callback **from,
29 struct dlm_callback *to)
30{
31 if (*from)
32 kref_put(&(*from)->ref, dlm_release_callback);
33
34 if (to)
35 kref_get(&to->ref);
36
37 *from = to;
38}
39
40int dlm_enqueue_lkb_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
41 int status, uint32_t sbflags)
42{
43 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
44 int rv = DLM_ENQUEUE_CALLBACK_SUCCESS;
45 struct dlm_callback *cb;
46 int copy_lvb = 0;
47 int prev_mode;
48
49 if (flags & DLM_CB_BAST) {
50 /* if cb is a bast, it should be skipped if the blocking mode is
51 * compatible with the last granted mode
52 */
53 if (lkb->lkb_last_cast) {
54 if (dlm_modes_compat(mode, lkb->lkb_last_cast->mode)) {
55 log_debug(ls, "skip %x bast mode %d for cast mode %d",
56 lkb->lkb_id, mode,
57 lkb->lkb_last_cast->mode);
58 goto out;
59 }
60 }
61
62 /*
63 * Suppress some redundant basts here, do more on removal.
64 * Don't even add a bast if the callback just before it
65 * is a bast for the same mode or a more restrictive mode.
66 * (the addional > PR check is needed for PR/CW inversion)
67 */
68 if (lkb->lkb_last_cb && lkb->lkb_last_cb->flags & DLM_CB_BAST) {
69 prev_mode = lkb->lkb_last_cb->mode;
70
71 if ((prev_mode == mode) ||
72 (prev_mode > mode && prev_mode > DLM_LOCK_PR)) {
73 log_debug(ls, "skip %x add bast mode %d for bast mode %d",
74 lkb->lkb_id, mode, prev_mode);
75 goto out;
76 }
77 }
78 } else if (flags & DLM_CB_CAST) {
79 if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
80 if (lkb->lkb_last_cast)
81 prev_mode = lkb->lkb_last_cb->mode;
82 else
83 prev_mode = -1;
84
85 if (!status && lkb->lkb_lksb->sb_lvbptr &&
86 dlm_lvb_operations[prev_mode + 1][mode + 1])
87 copy_lvb = 1;
88 }
89 }
90
91 cb = dlm_allocate_cb();
92 if (!cb) {
93 rv = DLM_ENQUEUE_CALLBACK_FAILURE;
94 goto out;
95 }
96
97 cb->flags = flags;
98 cb->mode = mode;
99 cb->sb_status = status;
100 cb->sb_flags = (sbflags & 0x000000FF);
101 cb->copy_lvb = copy_lvb;
102 kref_init(&cb->ref);
103 if (!test_and_set_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags))
104 rv = DLM_ENQUEUE_CALLBACK_NEED_SCHED;
105
106 list_add_tail(&cb->list, &lkb->lkb_callbacks);
107
108 if (flags & DLM_CB_CAST)
109 dlm_callback_set_last_ptr(&lkb->lkb_last_cast, cb);
110
111 dlm_callback_set_last_ptr(&lkb->lkb_last_cb, cb);
112
113 out:
114 return rv;
115}
116
117int dlm_dequeue_lkb_callback(struct dlm_lkb *lkb, struct dlm_callback **cb)
118{
119 /* oldest undelivered cb is callbacks first entry */
120 *cb = list_first_entry_or_null(&lkb->lkb_callbacks,
121 struct dlm_callback, list);
122 if (!*cb)
123 return DLM_DEQUEUE_CALLBACK_EMPTY;
124
125 /* remove it from callbacks so shift others down */
126 list_del(&(*cb)->list);
127 if (list_empty(&lkb->lkb_callbacks))
128 return DLM_DEQUEUE_CALLBACK_LAST;
129
130 return DLM_DEQUEUE_CALLBACK_SUCCESS;
131}
132
133void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
134 uint32_t sbflags)
135{
136 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
137 int rv;
138
139 if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
140 dlm_user_add_ast(lkb, flags, mode, status, sbflags);
141 return;
142 }
143
144 spin_lock(&lkb->lkb_cb_lock);
145 rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags);
146 switch (rv) {
147 case DLM_ENQUEUE_CALLBACK_NEED_SCHED:
148 kref_get(&lkb->lkb_ref);
149
150 spin_lock(&ls->ls_cb_lock);
151 if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
152 list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
153 } else {
154 queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
155 }
156 spin_unlock(&ls->ls_cb_lock);
157 break;
158 case DLM_ENQUEUE_CALLBACK_FAILURE:
159 WARN_ON_ONCE(1);
160 break;
161 case DLM_ENQUEUE_CALLBACK_SUCCESS:
162 break;
163 default:
164 WARN_ON_ONCE(1);
165 break;
166 }
167 spin_unlock(&lkb->lkb_cb_lock);
168}
169
170void dlm_callback_work(struct work_struct *work)
171{
172 struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
173 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
174 void (*castfn) (void *astparam);
175 void (*bastfn) (void *astparam, int mode);
176 struct dlm_callback *cb;
177 int rv;
178
179 spin_lock(&lkb->lkb_cb_lock);
180 rv = dlm_dequeue_lkb_callback(lkb, &cb);
181 if (WARN_ON_ONCE(rv == DLM_DEQUEUE_CALLBACK_EMPTY)) {
182 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
183 spin_unlock(&lkb->lkb_cb_lock);
184 goto out;
185 }
186 spin_unlock(&lkb->lkb_cb_lock);
187
188 for (;;) {
189 castfn = lkb->lkb_astfn;
190 bastfn = lkb->lkb_bastfn;
191
192 if (cb->flags & DLM_CB_BAST) {
193 trace_dlm_bast(ls, lkb, cb->mode);
194 lkb->lkb_last_bast_time = ktime_get();
195 lkb->lkb_last_bast_mode = cb->mode;
196 bastfn(lkb->lkb_astparam, cb->mode);
197 } else if (cb->flags & DLM_CB_CAST) {
198 lkb->lkb_lksb->sb_status = cb->sb_status;
199 lkb->lkb_lksb->sb_flags = cb->sb_flags;
200 trace_dlm_ast(ls, lkb);
201 lkb->lkb_last_cast_time = ktime_get();
202 castfn(lkb->lkb_astparam);
203 }
204
205 kref_put(&cb->ref, dlm_release_callback);
206
207 spin_lock(&lkb->lkb_cb_lock);
208 rv = dlm_dequeue_lkb_callback(lkb, &cb);
209 if (rv == DLM_DEQUEUE_CALLBACK_EMPTY) {
210 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags);
211 spin_unlock(&lkb->lkb_cb_lock);
212 break;
213 }
214 spin_unlock(&lkb->lkb_cb_lock);
215 }
216
217out:
218 /* undo kref_get from dlm_add_callback, may cause lkb to be freed */
219 dlm_put_lkb(lkb);
220}
221
222int dlm_callback_start(struct dlm_ls *ls)
223{
224 ls->ls_callback_wq = alloc_workqueue("dlm_callback",
225 WQ_HIGHPRI | WQ_MEM_RECLAIM, 0);
226 if (!ls->ls_callback_wq) {
227 log_print("can't start dlm_callback workqueue");
228 return -ENOMEM;
229 }
230 return 0;
231}
232
233void dlm_callback_stop(struct dlm_ls *ls)
234{
235 if (ls->ls_callback_wq)
236 destroy_workqueue(ls->ls_callback_wq);
237}
238
239void dlm_callback_suspend(struct dlm_ls *ls)
240{
241 if (ls->ls_callback_wq) {
242 spin_lock(&ls->ls_cb_lock);
243 set_bit(LSFL_CB_DELAY, &ls->ls_flags);
244 spin_unlock(&ls->ls_cb_lock);
245
246 flush_workqueue(ls->ls_callback_wq);
247 }
248}
249
250#define MAX_CB_QUEUE 25
251
252void dlm_callback_resume(struct dlm_ls *ls)
253{
254 struct dlm_lkb *lkb, *safe;
255 int count = 0, sum = 0;
256 bool empty;
257
258 if (!ls->ls_callback_wq)
259 return;
260
261more:
262 spin_lock(&ls->ls_cb_lock);
263 list_for_each_entry_safe(lkb, safe, &ls->ls_cb_delay, lkb_cb_list) {
264 list_del_init(&lkb->lkb_cb_list);
265 queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
266 count++;
267 if (count == MAX_CB_QUEUE)
268 break;
269 }
270 empty = list_empty(&ls->ls_cb_delay);
271 if (empty)
272 clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
273 spin_unlock(&ls->ls_cb_lock);
274
275 sum += count;
276 if (!empty) {
277 count = 0;
278 cond_resched();
279 goto more;
280 }
281
282 if (sum)
283 log_rinfo(ls, "%s %d", __func__, sum);
284}
285
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 "dlm_internal.h"
13#include "lock.h"
14#include "user.h"
15#include "ast.h"
16
17static uint64_t dlm_cb_seq;
18static DEFINE_SPINLOCK(dlm_cb_seq_spin);
19
20static 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
51int 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;
57 int i, rv;
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);
86 rv = 0;
87 goto out;
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);
96 rv = 0;
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);
105 rv = -1;
106 goto out;
107 }
108 out:
109 return rv;
110}
111
112int dlm_rem_lkb_callback(struct dlm_ls *ls, struct dlm_lkb *lkb,
113 struct dlm_callback *cb, int *resid)
114{
115 int i, rv;
116
117 *resid = 0;
118
119 if (!lkb->lkb_callbacks[0].seq) {
120 rv = -ENOENT;
121 goto out;
122 }
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);
154 rv = 0;
155 goto out;
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 }
168 rv = 0;
169 out:
170 return rv;
171}
172
173void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
174 uint32_t sbflags)
175{
176 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
177 uint64_t new_seq, prev_seq;
178 int rv;
179
180 spin_lock(&dlm_cb_seq_spin);
181 new_seq = ++dlm_cb_seq;
182 if (!dlm_cb_seq)
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_HIGHPRI | 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
293#define MAX_CB_QUEUE 25
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
305more:
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++;
311 if (count == MAX_CB_QUEUE)
312 break;
313 }
314 mutex_unlock(&ls->ls_cb_mutex);
315
316 if (count)
317 log_rinfo(ls, "dlm_callback_resume %d", count);
318 if (count == MAX_CB_QUEUE) {
319 count = 0;
320 cond_resched();
321 goto more;
322 }
323}
324