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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 "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