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
17 static uint64_t dlm_cb_seq;
18 static DEFINE_SPINLOCK(dlm_cb_seq_spin);
19
dlm_dump_lkb_callbacks(struct dlm_lkb * lkb)20 static 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
dlm_add_lkb_callback(struct dlm_lkb * lkb,uint32_t flags,int mode,int status,uint32_t sbflags,uint64_t seq)51 int 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
dlm_rem_lkb_callback(struct dlm_ls * ls,struct dlm_lkb * lkb,struct dlm_callback * cb,int * resid)112 int 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
dlm_add_cb(struct dlm_lkb * lkb,uint32_t flags,int mode,int status,uint32_t sbflags)173 void 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
dlm_callback_work(struct work_struct * work)213 void 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
dlm_callback_start(struct dlm_ls * ls)268 int 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
dlm_callback_stop(struct dlm_ls * ls)279 void dlm_callback_stop(struct dlm_ls *ls)
280 {
281 if (ls->ls_callback_wq)
282 destroy_workqueue(ls->ls_callback_wq);
283 }
284
dlm_callback_suspend(struct dlm_ls * ls)285 void 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
dlm_callback_resume(struct dlm_ls * ls)295 void 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 more:
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
325