Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[platform/kernel/linux-rpi.git] / fs / dlm / recoverd.c
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
23
24 /* If the start for which we're re-enabling locking (seq) has been superseded
25    by a newer stop (ls_recover_seq), we need to leave locking disabled.
26
27    We suspend dlm_recv threads here to avoid the race where dlm_recv a) sees
28    locking stopped and b) adds a message to the requestqueue, but dlm_recoverd
29    enables locking and clears the requestqueue between a and b. */
30
31 static int enable_locking(struct dlm_ls *ls, uint64_t seq)
32 {
33         int error = -EINTR;
34
35         down_write(&ls->ls_recv_active);
36
37         spin_lock(&ls->ls_recover_lock);
38         if (ls->ls_recover_seq == seq) {
39                 set_bit(LSFL_RUNNING, &ls->ls_flags);
40                 /* unblocks processes waiting to enter the dlm */
41                 up_write(&ls->ls_in_recovery);
42                 clear_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
43                 error = 0;
44         }
45         spin_unlock(&ls->ls_recover_lock);
46
47         up_write(&ls->ls_recv_active);
48         return error;
49 }
50
51 static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
52 {
53         unsigned long start;
54         int error, neg = 0;
55
56         log_rinfo(ls, "dlm_recover %llu", (unsigned long long)rv->seq);
57
58         mutex_lock(&ls->ls_recoverd_active);
59
60         dlm_callback_suspend(ls);
61
62         dlm_clear_toss(ls);
63
64         /*
65          * This list of root rsb's will be the basis of most of the recovery
66          * routines.
67          */
68
69         dlm_create_root_list(ls);
70
71         /*
72          * Add or remove nodes from the lockspace's ls_nodes list.
73          *
74          * Due to the fact that we must report all membership changes to lsops
75          * or midcomms layer, it is not permitted to abort ls_recover() until
76          * this is done.
77          */
78
79         error = dlm_recover_members(ls, rv, &neg);
80         if (error) {
81                 log_rinfo(ls, "dlm_recover_members error %d", error);
82                 goto fail;
83         }
84
85         dlm_recover_dir_nodeid(ls);
86
87         ls->ls_recover_dir_sent_res = 0;
88         ls->ls_recover_dir_sent_msg = 0;
89         ls->ls_recover_locks_in = 0;
90
91         dlm_set_recover_status(ls, DLM_RS_NODES);
92
93         error = dlm_recover_members_wait(ls, rv->seq);
94         if (error) {
95                 log_rinfo(ls, "dlm_recover_members_wait error %d", error);
96                 goto fail;
97         }
98
99         start = jiffies;
100
101         /*
102          * Rebuild our own share of the directory by collecting from all other
103          * nodes their master rsb names that hash to us.
104          */
105
106         error = dlm_recover_directory(ls, rv->seq);
107         if (error) {
108                 log_rinfo(ls, "dlm_recover_directory error %d", error);
109                 goto fail;
110         }
111
112         dlm_set_recover_status(ls, DLM_RS_DIR);
113
114         error = dlm_recover_directory_wait(ls, rv->seq);
115         if (error) {
116                 log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
117                 goto fail;
118         }
119
120         log_rinfo(ls, "dlm_recover_directory %u out %u messages",
121                   ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);
122
123         /*
124          * We may have outstanding operations that are waiting for a reply from
125          * a failed node.  Mark these to be resent after recovery.  Unlock and
126          * cancel ops can just be completed.
127          */
128
129         dlm_recover_waiters_pre(ls);
130
131         if (dlm_recovery_stopped(ls)) {
132                 error = -EINTR;
133                 goto fail;
134         }
135
136         if (neg || dlm_no_directory(ls)) {
137                 /*
138                  * Clear lkb's for departed nodes.
139                  */
140
141                 dlm_recover_purge(ls);
142
143                 /*
144                  * Get new master nodeid's for rsb's that were mastered on
145                  * departed nodes.
146                  */
147
148                 error = dlm_recover_masters(ls, rv->seq);
149                 if (error) {
150                         log_rinfo(ls, "dlm_recover_masters error %d", error);
151                         goto fail;
152                 }
153
154                 /*
155                  * Send our locks on remastered rsb's to the new masters.
156                  */
157
158                 error = dlm_recover_locks(ls, rv->seq);
159                 if (error) {
160                         log_rinfo(ls, "dlm_recover_locks error %d", error);
161                         goto fail;
162                 }
163
164                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
165
166                 error = dlm_recover_locks_wait(ls, rv->seq);
167                 if (error) {
168                         log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
169                         goto fail;
170                 }
171
172                 log_rinfo(ls, "dlm_recover_locks %u in",
173                           ls->ls_recover_locks_in);
174
175                 /*
176                  * Finalize state in master rsb's now that all locks can be
177                  * checked.  This includes conversion resolution and lvb
178                  * settings.
179                  */
180
181                 dlm_recover_rsbs(ls);
182         } else {
183                 /*
184                  * Other lockspace members may be going through the "neg" steps
185                  * while also adding us to the lockspace, in which case they'll
186                  * be doing the recover_locks (RS_LOCKS) barrier.
187                  */
188                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
189
190                 error = dlm_recover_locks_wait(ls, rv->seq);
191                 if (error) {
192                         log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
193                         goto fail;
194                 }
195         }
196
197         dlm_release_root_list(ls);
198
199         /*
200          * Purge directory-related requests that are saved in requestqueue.
201          * All dir requests from before recovery are invalid now due to the dir
202          * rebuild and will be resent by the requesting nodes.
203          */
204
205         dlm_purge_requestqueue(ls);
206
207         dlm_set_recover_status(ls, DLM_RS_DONE);
208
209         error = dlm_recover_done_wait(ls, rv->seq);
210         if (error) {
211                 log_rinfo(ls, "dlm_recover_done_wait error %d", error);
212                 goto fail;
213         }
214
215         dlm_clear_members_gone(ls);
216
217         dlm_callback_resume(ls);
218
219         error = enable_locking(ls, rv->seq);
220         if (error) {
221                 log_rinfo(ls, "enable_locking error %d", error);
222                 goto fail;
223         }
224
225         error = dlm_process_requestqueue(ls);
226         if (error) {
227                 log_rinfo(ls, "dlm_process_requestqueue error %d", error);
228                 goto fail;
229         }
230
231         error = dlm_recover_waiters_post(ls);
232         if (error) {
233                 log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
234                 goto fail;
235         }
236
237         dlm_recover_grant(ls);
238
239         log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
240                   (unsigned long long)rv->seq, ls->ls_generation,
241                   jiffies_to_msecs(jiffies - start));
242         mutex_unlock(&ls->ls_recoverd_active);
243
244         return 0;
245
246  fail:
247         dlm_release_root_list(ls);
248         mutex_unlock(&ls->ls_recoverd_active);
249
250         return error;
251 }
252
253 /* The dlm_ls_start() that created the rv we take here may already have been
254    stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
255    flag set. */
256
257 static void do_ls_recovery(struct dlm_ls *ls)
258 {
259         struct dlm_recover *rv = NULL;
260         int error;
261
262         spin_lock(&ls->ls_recover_lock);
263         rv = ls->ls_recover_args;
264         ls->ls_recover_args = NULL;
265         if (rv && ls->ls_recover_seq == rv->seq)
266                 clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
267         spin_unlock(&ls->ls_recover_lock);
268
269         if (rv) {
270                 error = ls_recover(ls, rv);
271                 switch (error) {
272                 case 0:
273                         ls->ls_recovery_result = 0;
274                         complete(&ls->ls_recovery_done);
275
276                         dlm_lsop_recover_done(ls);
277                         break;
278                 case -EINTR:
279                         /* if recovery was interrupted -EINTR we wait for the next
280                          * ls_recover() iteration until it hopefully succeeds.
281                          */
282                         log_rinfo(ls, "%s %llu interrupted and should be queued to run again",
283                                   __func__, (unsigned long long)rv->seq);
284                         break;
285                 default:
286                         log_rinfo(ls, "%s %llu error %d", __func__,
287                                   (unsigned long long)rv->seq, error);
288
289                         /* let new_lockspace() get aware of critical error */
290                         ls->ls_recovery_result = error;
291                         complete(&ls->ls_recovery_done);
292                         break;
293                 }
294
295                 kfree(rv->nodes);
296                 kfree(rv);
297         }
298 }
299
300 static int dlm_recoverd(void *arg)
301 {
302         struct dlm_ls *ls;
303
304         ls = dlm_find_lockspace_local(arg);
305         if (!ls) {
306                 log_print("dlm_recoverd: no lockspace %p", arg);
307                 return -1;
308         }
309
310         down_write(&ls->ls_in_recovery);
311         set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
312         wake_up(&ls->ls_recover_lock_wait);
313
314         while (1) {
315                 /*
316                  * We call kthread_should_stop() after set_current_state().
317                  * This is because it works correctly if kthread_stop() is
318                  * called just before set_current_state().
319                  */
320                 set_current_state(TASK_INTERRUPTIBLE);
321                 if (kthread_should_stop()) {
322                         set_current_state(TASK_RUNNING);
323                         break;
324                 }
325                 if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
326                     !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
327                         if (kthread_should_stop())
328                                 break;
329                         schedule();
330                 }
331                 set_current_state(TASK_RUNNING);
332
333                 if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
334                         down_write(&ls->ls_in_recovery);
335                         set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
336                         wake_up(&ls->ls_recover_lock_wait);
337                 }
338
339                 if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
340                         do_ls_recovery(ls);
341         }
342
343         if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
344                 up_write(&ls->ls_in_recovery);
345
346         dlm_put_lockspace(ls);
347         return 0;
348 }
349
350 int dlm_recoverd_start(struct dlm_ls *ls)
351 {
352         struct task_struct *p;
353         int error = 0;
354
355         p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
356         if (IS_ERR(p))
357                 error = PTR_ERR(p);
358         else
359                 ls->ls_recoverd_task = p;
360         return error;
361 }
362
363 void dlm_recoverd_stop(struct dlm_ls *ls)
364 {
365         kthread_stop(ls->ls_recoverd_task);
366 }
367
368 void dlm_recoverd_suspend(struct dlm_ls *ls)
369 {
370         wake_up(&ls->ls_wait_general);
371         mutex_lock(&ls->ls_recoverd_active);
372 }
373
374 void dlm_recoverd_resume(struct dlm_ls *ls)
375 {
376         mutex_unlock(&ls->ls_recoverd_active);
377 }
378