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) 2004-2011 Red Hat, Inc. All rights reserved.
7**
8**
9*******************************************************************************
10******************************************************************************/
11
12#include "dlm_internal.h"
13#include "lockspace.h"
14#include "member.h"
15#include "dir.h"
16#include "ast.h"
17#include "recover.h"
18#include "lowcomms.h"
19#include "lock.h"
20#include "requestqueue.h"
21#include "recoverd.h"
22
23static int dlm_create_masters_list(struct dlm_ls *ls)
24{
25 struct dlm_rsb *r;
26 int error = 0;
27
28 write_lock_bh(&ls->ls_masters_lock);
29 if (!list_empty(head: &ls->ls_masters_list)) {
30 log_error(ls, "root list not empty");
31 error = -EINVAL;
32 goto out;
33 }
34
35 read_lock_bh(&ls->ls_rsbtbl_lock);
36 list_for_each_entry(r, &ls->ls_slow_active, res_slow_list) {
37 if (r->res_nodeid)
38 continue;
39
40 list_add(new: &r->res_masters_list, head: &ls->ls_masters_list);
41 dlm_hold_rsb(r);
42 }
43 read_unlock_bh(&ls->ls_rsbtbl_lock);
44 out:
45 write_unlock_bh(&ls->ls_masters_lock);
46 return error;
47}
48
49static void dlm_release_masters_list(struct dlm_ls *ls)
50{
51 struct dlm_rsb *r, *safe;
52
53 write_lock_bh(&ls->ls_masters_lock);
54 list_for_each_entry_safe(r, safe, &ls->ls_masters_list, res_masters_list) {
55 list_del_init(entry: &r->res_masters_list);
56 dlm_put_rsb(r);
57 }
58 write_unlock_bh(&ls->ls_masters_lock);
59}
60
61static void dlm_create_root_list(struct dlm_ls *ls, struct list_head *root_list)
62{
63 struct dlm_rsb *r;
64
65 read_lock_bh(&ls->ls_rsbtbl_lock);
66 list_for_each_entry(r, &ls->ls_slow_active, res_slow_list) {
67 list_add(new: &r->res_root_list, head: root_list);
68 dlm_hold_rsb(r);
69 }
70
71 WARN_ON_ONCE(!list_empty(&ls->ls_slow_inactive));
72 read_unlock_bh(&ls->ls_rsbtbl_lock);
73}
74
75static void dlm_release_root_list(struct list_head *root_list)
76{
77 struct dlm_rsb *r, *safe;
78
79 list_for_each_entry_safe(r, safe, root_list, res_root_list) {
80 list_del_init(entry: &r->res_root_list);
81 dlm_put_rsb(r);
82 }
83}
84
85/* If the start for which we're re-enabling locking (seq) has been superseded
86 by a newer stop (ls_recover_seq), we need to leave locking disabled.
87
88 We suspend dlm_recv threads here to avoid the race where dlm_recv a) sees
89 locking stopped and b) adds a message to the requestqueue, but dlm_recoverd
90 enables locking and clears the requestqueue between a and b. */
91
92static int enable_locking(struct dlm_ls *ls, uint64_t seq)
93{
94 int error = -EINTR;
95
96 write_lock_bh(&ls->ls_recv_active);
97
98 spin_lock_bh(lock: &ls->ls_recover_lock);
99 if (ls->ls_recover_seq == seq) {
100 set_bit(LSFL_RUNNING, addr: &ls->ls_flags);
101 /* Schedule next timer if recovery put something on inactive.
102 *
103 * The rsbs that was queued while recovery on toss hasn't
104 * started yet because LSFL_RUNNING was set everything
105 * else recovery hasn't started as well because ls_in_recovery
106 * is still hold. So we should not run into the case that
107 * resume_scan_timer() queues a timer that can occur in
108 * a no op.
109 */
110 resume_scan_timer(ls);
111 /* unblocks processes waiting to enter the dlm */
112 up_write(sem: &ls->ls_in_recovery);
113 clear_bit(LSFL_RECOVER_LOCK, addr: &ls->ls_flags);
114 error = 0;
115 }
116 spin_unlock_bh(lock: &ls->ls_recover_lock);
117
118 write_unlock_bh(&ls->ls_recv_active);
119 return error;
120}
121
122static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
123{
124 LIST_HEAD(root_list);
125 unsigned long start;
126 int error, neg = 0;
127
128 log_rinfo(ls, "dlm_recover %llu", (unsigned long long)rv->seq);
129
130 mutex_lock(&ls->ls_recoverd_active);
131
132 dlm_callback_suspend(ls);
133
134 dlm_clear_inactive(ls);
135
136 /*
137 * This list of root rsb's will be the basis of most of the recovery
138 * routines.
139 */
140
141 dlm_create_root_list(ls, root_list: &root_list);
142
143 /*
144 * Add or remove nodes from the lockspace's ls_nodes list.
145 *
146 * Due to the fact that we must report all membership changes to lsops
147 * or midcomms layer, it is not permitted to abort ls_recover() until
148 * this is done.
149 */
150
151 error = dlm_recover_members(ls, rv, neg_out: &neg);
152 if (error) {
153 log_rinfo(ls, "dlm_recover_members error %d", error);
154 goto fail_root_list;
155 }
156
157 dlm_recover_dir_nodeid(ls, root_list: &root_list);
158
159 /* Create a snapshot of all active rsbs were we are the master of.
160 * During the barrier between dlm_recover_members_wait() and
161 * dlm_recover_directory() other nodes can dump their necessary
162 * directory dlm_rsb (r->res_dir_nodeid == nodeid) in rcom
163 * communication dlm_copy_master_names() handling.
164 *
165 * TODO We should create a per lockspace list that contains rsbs
166 * that we are the master of. Instead of creating this list while
167 * recovery we keep track of those rsbs while locking handling and
168 * recovery can use it when necessary.
169 */
170 error = dlm_create_masters_list(ls);
171 if (error) {
172 log_rinfo(ls, "dlm_create_masters_list error %d", error);
173 goto fail_root_list;
174 }
175
176 ls->ls_recover_locks_in = 0;
177
178 dlm_set_recover_status(ls, DLM_RS_NODES);
179
180 error = dlm_recover_members_wait(ls, seq: rv->seq);
181 if (error) {
182 log_rinfo(ls, "dlm_recover_members_wait error %d", error);
183 dlm_release_masters_list(ls);
184 goto fail_root_list;
185 }
186
187 start = jiffies;
188
189 /*
190 * Rebuild our own share of the directory by collecting from all other
191 * nodes their master rsb names that hash to us.
192 */
193
194 error = dlm_recover_directory(ls, seq: rv->seq);
195 if (error) {
196 log_rinfo(ls, "dlm_recover_directory error %d", error);
197 dlm_release_masters_list(ls);
198 goto fail_root_list;
199 }
200
201 dlm_set_recover_status(ls, DLM_RS_DIR);
202
203 error = dlm_recover_directory_wait(ls, seq: rv->seq);
204 if (error) {
205 log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
206 dlm_release_masters_list(ls);
207 goto fail_root_list;
208 }
209
210 dlm_release_masters_list(ls);
211
212 /*
213 * We may have outstanding operations that are waiting for a reply from
214 * a failed node. Mark these to be resent after recovery. Unlock and
215 * cancel ops can just be completed.
216 */
217
218 dlm_recover_waiters_pre(ls);
219
220 if (dlm_recovery_stopped(ls)) {
221 error = -EINTR;
222 goto fail_root_list;
223 }
224
225 if (neg || dlm_no_directory(ls)) {
226 /*
227 * Clear lkb's for departed nodes.
228 */
229
230 dlm_recover_purge(ls, root_list: &root_list);
231
232 /*
233 * Get new master nodeid's for rsb's that were mastered on
234 * departed nodes.
235 */
236
237 error = dlm_recover_masters(ls, seq: rv->seq, root_list: &root_list);
238 if (error) {
239 log_rinfo(ls, "dlm_recover_masters error %d", error);
240 goto fail_root_list;
241 }
242
243 /*
244 * Send our locks on remastered rsb's to the new masters.
245 */
246
247 error = dlm_recover_locks(ls, seq: rv->seq, root_list: &root_list);
248 if (error) {
249 log_rinfo(ls, "dlm_recover_locks error %d", error);
250 goto fail_root_list;
251 }
252
253 dlm_set_recover_status(ls, DLM_RS_LOCKS);
254
255 error = dlm_recover_locks_wait(ls, seq: rv->seq);
256 if (error) {
257 log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
258 goto fail_root_list;
259 }
260
261 log_rinfo(ls, "dlm_recover_locks %u in",
262 ls->ls_recover_locks_in);
263
264 /*
265 * Finalize state in master rsb's now that all locks can be
266 * checked. This includes conversion resolution and lvb
267 * settings.
268 */
269
270 dlm_recover_rsbs(ls, root_list: &root_list);
271 } else {
272 /*
273 * Other lockspace members may be going through the "neg" steps
274 * while also adding us to the lockspace, in which case they'll
275 * be doing the recover_locks (RS_LOCKS) barrier.
276 */
277 dlm_set_recover_status(ls, DLM_RS_LOCKS);
278
279 error = dlm_recover_locks_wait(ls, seq: rv->seq);
280 if (error) {
281 log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
282 goto fail_root_list;
283 }
284 }
285
286 dlm_release_root_list(root_list: &root_list);
287
288 /*
289 * Purge directory-related requests that are saved in requestqueue.
290 * All dir requests from before recovery are invalid now due to the dir
291 * rebuild and will be resent by the requesting nodes.
292 */
293
294 dlm_purge_requestqueue(ls);
295
296 dlm_set_recover_status(ls, DLM_RS_DONE);
297
298 error = dlm_recover_done_wait(ls, seq: rv->seq);
299 if (error) {
300 log_rinfo(ls, "dlm_recover_done_wait error %d", error);
301 goto fail;
302 }
303
304 dlm_clear_members_gone(ls);
305
306 dlm_callback_resume(ls);
307
308 error = enable_locking(ls, seq: rv->seq);
309 if (error) {
310 log_rinfo(ls, "enable_locking error %d", error);
311 goto fail;
312 }
313
314 error = dlm_process_requestqueue(ls);
315 if (error) {
316 log_rinfo(ls, "dlm_process_requestqueue error %d", error);
317 goto fail;
318 }
319
320 error = dlm_recover_waiters_post(ls);
321 if (error) {
322 log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
323 goto fail;
324 }
325
326 dlm_recover_grant(ls);
327
328 log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
329 (unsigned long long)rv->seq, ls->ls_generation,
330 jiffies_to_msecs(jiffies - start));
331 mutex_unlock(lock: &ls->ls_recoverd_active);
332
333 return 0;
334
335 fail_root_list:
336 dlm_release_root_list(root_list: &root_list);
337 fail:
338 mutex_unlock(lock: &ls->ls_recoverd_active);
339
340 return error;
341}
342
343/* The dlm_ls_start() that created the rv we take here may already have been
344 stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
345 flag set. */
346
347static void do_ls_recovery(struct dlm_ls *ls)
348{
349 struct dlm_recover *rv = NULL;
350 int error;
351
352 spin_lock_bh(lock: &ls->ls_recover_lock);
353 rv = ls->ls_recover_args;
354 ls->ls_recover_args = NULL;
355 if (rv && ls->ls_recover_seq == rv->seq)
356 clear_bit(LSFL_RECOVER_STOP, addr: &ls->ls_flags);
357 spin_unlock_bh(lock: &ls->ls_recover_lock);
358
359 if (rv) {
360 error = ls_recover(ls, rv);
361 switch (error) {
362 case 0:
363 ls->ls_recovery_result = 0;
364 complete(&ls->ls_recovery_done);
365
366 dlm_lsop_recover_done(ls);
367 break;
368 case -EINTR:
369 /* if recovery was interrupted -EINTR we wait for the next
370 * ls_recover() iteration until it hopefully succeeds.
371 */
372 log_rinfo(ls, "%s %llu interrupted and should be queued to run again",
373 __func__, (unsigned long long)rv->seq);
374 break;
375 default:
376 log_rinfo(ls, "%s %llu error %d", __func__,
377 (unsigned long long)rv->seq, error);
378
379 /* let new_lockspace() get aware of critical error */
380 ls->ls_recovery_result = error;
381 complete(&ls->ls_recovery_done);
382 break;
383 }
384
385 kfree(objp: rv->nodes);
386 kfree(objp: rv);
387 }
388}
389
390static int dlm_recoverd(void *arg)
391{
392 struct dlm_ls *ls;
393
394 ls = dlm_find_lockspace_local(id: arg);
395 if (!ls) {
396 log_print("dlm_recoverd: no lockspace %p", arg);
397 return -1;
398 }
399
400 down_write(sem: &ls->ls_in_recovery);
401 set_bit(LSFL_RECOVER_LOCK, addr: &ls->ls_flags);
402 wake_up(&ls->ls_recover_lock_wait);
403
404 while (1) {
405 /*
406 * We call kthread_should_stop() after set_current_state().
407 * This is because it works correctly if kthread_stop() is
408 * called just before set_current_state().
409 */
410 set_current_state(TASK_INTERRUPTIBLE);
411 if (kthread_should_stop()) {
412 set_current_state(TASK_RUNNING);
413 break;
414 }
415 if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
416 !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
417 if (kthread_should_stop())
418 break;
419 schedule();
420 }
421 set_current_state(TASK_RUNNING);
422
423 if (test_and_clear_bit(LSFL_RECOVER_DOWN, addr: &ls->ls_flags)) {
424 down_write(sem: &ls->ls_in_recovery);
425 set_bit(LSFL_RECOVER_LOCK, addr: &ls->ls_flags);
426 wake_up(&ls->ls_recover_lock_wait);
427 }
428
429 if (test_and_clear_bit(LSFL_RECOVER_WORK, addr: &ls->ls_flags))
430 do_ls_recovery(ls);
431 }
432
433 if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
434 up_write(sem: &ls->ls_in_recovery);
435
436 dlm_put_lockspace(ls);
437 return 0;
438}
439
440int dlm_recoverd_start(struct dlm_ls *ls)
441{
442 struct task_struct *p;
443 int error = 0;
444
445 p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
446 if (IS_ERR(ptr: p))
447 error = PTR_ERR(ptr: p);
448 else
449 ls->ls_recoverd_task = p;
450 return error;
451}
452
453void dlm_recoverd_stop(struct dlm_ls *ls)
454{
455 kthread_stop(k: ls->ls_recoverd_task);
456}
457
458void dlm_recoverd_suspend(struct dlm_ls *ls)
459{
460 wake_up(&ls->ls_wait_general);
461 mutex_lock(&ls->ls_recoverd_active);
462}
463
464void dlm_recoverd_resume(struct dlm_ls *ls)
465{
466 mutex_unlock(lock: &ls->ls_recoverd_active);
467}
468
469

source code of linux/fs/dlm/recoverd.c