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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 "lvb_table.h"
16#include "memory.h"
17#include "lock.h"
18#include "user.h"
19#include "ast.h"
20
21static void dlm_run_callback(uint32_t ls_id, uint32_t lkb_id, int8_t mode,
22 uint32_t flags, uint8_t sb_flags, int sb_status,
23 struct dlm_lksb *lksb,
24 void (*astfn)(void *astparam),
25 void (*bastfn)(void *astparam, int mode),
26 void *astparam, const char *res_name,
27 size_t res_length)
28{
29 if (flags & DLM_CB_BAST) {
30 trace_dlm_bast(ls_id, lkb_id, mode, res_name, res_length);
31 bastfn(astparam, mode);
32 } else if (flags & DLM_CB_CAST) {
33 trace_dlm_ast(ls_id, lkb_id, sb_flags, sb_status, res_name,
34 res_length);
35 lksb->sb_status = sb_status;
36 lksb->sb_flags = sb_flags;
37 astfn(astparam);
38 }
39}
40
41static void dlm_do_callback(struct dlm_callback *cb)
42{
43 dlm_run_callback(cb->ls_id, cb->lkb_id, cb->mode, cb->flags,
44 cb->sb_flags, cb->sb_status, cb->lkb_lksb,
45 cb->astfn, cb->bastfn, cb->astparam,
46 cb->res_name, cb->res_length);
47 dlm_free_cb(cb);
48}
49
50static void dlm_callback_work(struct work_struct *work)
51{
52 struct dlm_callback *cb = container_of(work, struct dlm_callback, work);
53
54 dlm_do_callback(cb);
55}
56
57bool dlm_may_skip_callback(struct dlm_lkb *lkb, uint32_t flags, int mode,
58 int status, uint32_t sbflags, int *copy_lvb)
59{
60 struct dlm_rsb *rsb = lkb->lkb_resource;
61 struct dlm_ls *ls = rsb->res_ls;
62 int prev_mode;
63
64 if (copy_lvb)
65 *copy_lvb = 0;
66
67 if (flags & DLM_CB_BAST) {
68 /* if cb is a bast, it should be skipped if the blocking mode is
69 * compatible with the last granted mode
70 */
71 if (lkb->lkb_last_cast_cb_mode != -1) {
72 if (dlm_modes_compat(mode, lkb->lkb_last_cast_cb_mode)) {
73 log_debug(ls, "skip %x bast mode %d for cast mode %d",
74 lkb->lkb_id, mode,
75 lkb->lkb_last_cast_cb_mode);
76 return true;
77 }
78 }
79
80 /*
81 * Suppress some redundant basts here, do more on removal.
82 * Don't even add a bast if the callback just before it
83 * is a bast for the same mode or a more restrictive mode.
84 * (the addional > PR check is needed for PR/CW inversion)
85 */
86 if (lkb->lkb_last_cb_mode != -1 &&
87 lkb->lkb_last_cb_flags & DLM_CB_BAST) {
88 prev_mode = lkb->lkb_last_cb_mode;
89
90 if ((prev_mode == mode) ||
91 (prev_mode > mode && prev_mode > DLM_LOCK_PR)) {
92 log_debug(ls, "skip %x add bast mode %d for bast mode %d",
93 lkb->lkb_id, mode, prev_mode);
94 return true;
95 }
96 }
97
98 lkb->lkb_last_bast_time = ktime_get();
99 lkb->lkb_last_bast_cb_mode = mode;
100 } else if (flags & DLM_CB_CAST) {
101 if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
102 prev_mode = lkb->lkb_last_cast_cb_mode;
103
104 if (!status && lkb->lkb_lksb->sb_lvbptr &&
105 dlm_lvb_operations[prev_mode + 1][mode + 1]) {
106 if (copy_lvb)
107 *copy_lvb = 1;
108 }
109 }
110
111 lkb->lkb_last_cast_cb_mode = mode;
112 lkb->lkb_last_cast_time = ktime_get();
113 }
114
115 lkb->lkb_last_cb_mode = mode;
116 lkb->lkb_last_cb_flags = flags;
117
118 return false;
119}
120
121int dlm_get_cb(struct dlm_lkb *lkb, uint32_t flags, int mode,
122 int status, uint32_t sbflags,
123 struct dlm_callback **cb)
124{
125 struct dlm_rsb *rsb = lkb->lkb_resource;
126 struct dlm_ls *ls = rsb->res_ls;
127
128 *cb = dlm_allocate_cb();
129 if (WARN_ON_ONCE(!*cb))
130 return -ENOMEM;
131
132 /* for tracing */
133 (*cb)->lkb_id = lkb->lkb_id;
134 (*cb)->ls_id = ls->ls_global_id;
135 memcpy((*cb)->res_name, rsb->res_name, rsb->res_length);
136 (*cb)->res_length = rsb->res_length;
137
138 (*cb)->flags = flags;
139 (*cb)->mode = mode;
140 (*cb)->sb_status = status;
141 (*cb)->sb_flags = (sbflags & 0x000000FF);
142 (*cb)->lkb_lksb = lkb->lkb_lksb;
143
144 return 0;
145}
146
147static int dlm_get_queue_cb(struct dlm_lkb *lkb, uint32_t flags, int mode,
148 int status, uint32_t sbflags,
149 struct dlm_callback **cb)
150{
151 int rv;
152
153 rv = dlm_get_cb(lkb, flags, mode, status, sbflags, cb);
154 if (rv)
155 return rv;
156
157 (*cb)->astfn = lkb->lkb_astfn;
158 (*cb)->bastfn = lkb->lkb_bastfn;
159 (*cb)->astparam = lkb->lkb_astparam;
160 INIT_WORK(&(*cb)->work, dlm_callback_work);
161
162 return 0;
163}
164
165void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
166 uint32_t sbflags)
167{
168 struct dlm_rsb *rsb = lkb->lkb_resource;
169 struct dlm_ls *ls = rsb->res_ls;
170 struct dlm_callback *cb;
171 int rv;
172
173 if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) {
174 dlm_user_add_ast(lkb, flags, mode, status, sbflags);
175 return;
176 }
177
178 if (dlm_may_skip_callback(lkb, flags, mode, status, sbflags, NULL))
179 return;
180
181 spin_lock_bh(&ls->ls_cb_lock);
182 if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
183 rv = dlm_get_queue_cb(lkb, flags, mode, status, sbflags, &cb);
184 if (!rv)
185 list_add(&cb->list, &ls->ls_cb_delay);
186 } else {
187 if (test_bit(LSFL_SOFTIRQ, &ls->ls_flags)) {
188 dlm_run_callback(ls->ls_global_id, lkb->lkb_id, mode, flags,
189 sbflags, status, lkb->lkb_lksb,
190 lkb->lkb_astfn, lkb->lkb_bastfn,
191 lkb->lkb_astparam, rsb->res_name,
192 rsb->res_length);
193 } else {
194 rv = dlm_get_queue_cb(lkb, flags, mode, status, sbflags, &cb);
195 if (!rv)
196 queue_work(ls->ls_callback_wq, &cb->work);
197 }
198 }
199 spin_unlock_bh(&ls->ls_cb_lock);
200}
201
202int dlm_callback_start(struct dlm_ls *ls)
203{
204 if (!test_bit(LSFL_FS, &ls->ls_flags) ||
205 test_bit(LSFL_SOFTIRQ, &ls->ls_flags))
206 return 0;
207
208 ls->ls_callback_wq = alloc_ordered_workqueue("dlm_callback",
209 WQ_HIGHPRI | WQ_MEM_RECLAIM);
210 if (!ls->ls_callback_wq) {
211 log_print("can't start dlm_callback workqueue");
212 return -ENOMEM;
213 }
214 return 0;
215}
216
217void dlm_callback_stop(struct dlm_ls *ls)
218{
219 if (ls->ls_callback_wq)
220 destroy_workqueue(ls->ls_callback_wq);
221}
222
223void dlm_callback_suspend(struct dlm_ls *ls)
224{
225 if (!test_bit(LSFL_FS, &ls->ls_flags))
226 return;
227
228 spin_lock_bh(&ls->ls_cb_lock);
229 set_bit(LSFL_CB_DELAY, &ls->ls_flags);
230 spin_unlock_bh(&ls->ls_cb_lock);
231
232 if (ls->ls_callback_wq)
233 flush_workqueue(ls->ls_callback_wq);
234}
235
236#define MAX_CB_QUEUE 25
237
238void dlm_callback_resume(struct dlm_ls *ls)
239{
240 struct dlm_callback *cb, *safe;
241 int count = 0, sum = 0;
242 bool empty;
243
244 if (!test_bit(LSFL_FS, &ls->ls_flags))
245 return;
246
247more:
248 spin_lock_bh(&ls->ls_cb_lock);
249 list_for_each_entry_safe(cb, safe, &ls->ls_cb_delay, list) {
250 list_del(&cb->list);
251 if (test_bit(LSFL_SOFTIRQ, &ls->ls_flags))
252 dlm_do_callback(cb);
253 else
254 queue_work(ls->ls_callback_wq, &cb->work);
255
256 count++;
257 if (count == MAX_CB_QUEUE)
258 break;
259 }
260 empty = list_empty(&ls->ls_cb_delay);
261 if (empty)
262 clear_bit(LSFL_CB_DELAY, &ls->ls_flags);
263 spin_unlock_bh(&ls->ls_cb_lock);
264
265 sum += count;
266 if (!empty) {
267 count = 0;
268 cond_resched();
269 goto more;
270 }
271
272 if (sum)
273 log_rinfo(ls, "%s %d", __func__, sum);
274}
275