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
21 static 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_status, sb_flags, res_name,
34 res_length);
35 lksb->sb_status = sb_status;
36 lksb->sb_flags = sb_flags;
37 astfn(astparam);
38 }
39 }
40
41 static 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
50 static 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
57 bool 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
121 int 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
147 static 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
165 void 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
202 int 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
217 void dlm_callback_stop(struct dlm_ls *ls)
218 {
219 if (ls->ls_callback_wq)
220 destroy_workqueue(ls->ls_callback_wq);
221 }
222
223 void 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
238 void 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
247 more:
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
276
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