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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 if (!dlm_cb_seq)
185 new_seq = ++dlm_cb_seq;
186 spin_unlock(&dlm_cb_seq_spin);
187
188 if (lkb->lkb_flags & DLM_IFL_USER) {
189 dlm_user_add_ast(lkb, flags, mode, status, sbflags, new_seq);
190 return;
191 }
192
193 mutex_lock(&lkb->lkb_cb_mutex);
194 prev_seq = lkb->lkb_callbacks[0].seq;
195
196 rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq);
197 if (rv < 0)
198 goto out;
199
200 if (!prev_seq) {
201 kref_get(&lkb->lkb_ref);
202
203 if (test_bit(LSFL_CB_DELAY, &ls->ls_flags)) {
204 mutex_lock(&ls->ls_cb_mutex);
205 list_add(&lkb->lkb_cb_list, &ls->ls_cb_delay);
206 mutex_unlock(&ls->ls_cb_mutex);
207 } else {
208 queue_work(ls->ls_callback_wq, &lkb->lkb_cb_work);
209 }
210 }
211 out:
212 mutex_unlock(&lkb->lkb_cb_mutex);
213}
214
215void dlm_callback_work(struct work_struct *work)
216{
217 struct dlm_lkb *lkb = container_of(work, struct dlm_lkb, lkb_cb_work);
218 struct dlm_ls *ls = lkb->lkb_resource->res_ls;
219 void (*castfn) (void *astparam);
220 void (*bastfn) (void *astparam, int mode);
221 struct dlm_callback callbacks[DLM_CALLBACKS_SIZE];
222 int i, rv, resid;
223
224 memset(&callbacks, 0, sizeof(callbacks));
225
226 mutex_lock(&lkb->lkb_cb_mutex);
227 if (!lkb->lkb_callbacks[0].seq) {
228 /* no callback work exists, shouldn't happen */
229 log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id);
230 dlm_print_lkb(lkb);
231 dlm_dump_lkb_callbacks(lkb);
232 }
233
234 for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
235 rv = dlm_rem_lkb_callback(ls, lkb, &callbacks[i], &resid);
236 if (rv < 0)
237 break;
238 }
239
240 if (resid) {
241 /* cbs remain, loop should have removed all, shouldn't happen */
242 log_error(ls, "dlm_callback_work %x resid %d", lkb->lkb_id,
243 resid);
244 dlm_print_lkb(lkb);
245 dlm_dump_lkb_callbacks(lkb);
246 }
247 mutex_unlock(&lkb->lkb_cb_mutex);
248
249 castfn = lkb->lkb_astfn;
250 bastfn = lkb->lkb_bastfn;
251
252 for (i = 0; i < DLM_CALLBACKS_SIZE; i++) {
253 if (!callbacks[i].seq)
254 break;
255 if (callbacks[i].flags & DLM_CB_SKIP) {
256 continue;
257 } else if (callbacks[i].flags & DLM_CB_BAST) {
258 bastfn(lkb->lkb_astparam, callbacks[i].mode);
259 } else if (callbacks[i].flags & DLM_CB_CAST) {
260 lkb->lkb_lksb->sb_status = callbacks[i].sb_status;
261 lkb->lkb_lksb->sb_flags = callbacks[i].sb_flags;
262 castfn(lkb->lkb_astparam);
263 }
264 }
265
266 /* undo kref_get from dlm_add_callback, may cause lkb to be freed */
267 dlm_put_lkb(lkb);
268}
269
270int dlm_callback_start(struct dlm_ls *ls)
271{
272 ls->ls_callback_wq = alloc_workqueue("dlm_callback",
273 WQ_HIGHPRI | WQ_MEM_RECLAIM, 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 if (count)
314 log_rinfo(ls, "dlm_callback_resume %d", count);
315}
316
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