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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 <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