1 /******************************************************************************
2 *******************************************************************************
3 **
4 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
5 ** Copyright (C) 2004-2011 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 "lockspace.h"
16 #include "member.h"
17 #include "dir.h"
18 #include "ast.h"
19 #include "recover.h"
20 #include "lowcomms.h"
21 #include "lock.h"
22 #include "requestqueue.h"
23 #include "recoverd.h"
24
25
26 /* If the start for which we're re-enabling locking (seq) has been superseded
27 by a newer stop (ls_recover_seq), we need to leave locking disabled.
28
29 We suspend dlm_recv threads here to avoid the race where dlm_recv a) sees
30 locking stopped and b) adds a message to the requestqueue, but dlm_recoverd
31 enables locking and clears the requestqueue between a and b. */
32
enable_locking(struct dlm_ls * ls,uint64_t seq)33 static int enable_locking(struct dlm_ls *ls, uint64_t seq)
34 {
35 int error = -EINTR;
36
37 down_write(&ls->ls_recv_active);
38
39 spin_lock(&ls->ls_recover_lock);
40 if (ls->ls_recover_seq == seq) {
41 set_bit(LSFL_RUNNING, &ls->ls_flags);
42 /* unblocks processes waiting to enter the dlm */
43 up_write(&ls->ls_in_recovery);
44 clear_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
45 error = 0;
46 }
47 spin_unlock(&ls->ls_recover_lock);
48
49 up_write(&ls->ls_recv_active);
50 return error;
51 }
52
ls_recover(struct dlm_ls * ls,struct dlm_recover * rv)53 static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
54 {
55 unsigned long start;
56 int error, neg = 0;
57
58 log_rinfo(ls, "dlm_recover %llu", (unsigned long long)rv->seq);
59
60 mutex_lock(&ls->ls_recoverd_active);
61
62 dlm_callback_suspend(ls);
63
64 dlm_clear_toss(ls);
65
66 /*
67 * This list of root rsb's will be the basis of most of the recovery
68 * routines.
69 */
70
71 dlm_create_root_list(ls);
72
73 /*
74 * Add or remove nodes from the lockspace's ls_nodes list.
75 */
76
77 error = dlm_recover_members(ls, rv, &neg);
78 if (error) {
79 log_rinfo(ls, "dlm_recover_members error %d", error);
80 goto fail;
81 }
82
83 dlm_recover_dir_nodeid(ls);
84
85 ls->ls_recover_dir_sent_res = 0;
86 ls->ls_recover_dir_sent_msg = 0;
87 ls->ls_recover_locks_in = 0;
88
89 dlm_set_recover_status(ls, DLM_RS_NODES);
90
91 error = dlm_recover_members_wait(ls);
92 if (error) {
93 log_rinfo(ls, "dlm_recover_members_wait error %d", error);
94 goto fail;
95 }
96
97 start = jiffies;
98
99 /*
100 * Rebuild our own share of the directory by collecting from all other
101 * nodes their master rsb names that hash to us.
102 */
103
104 error = dlm_recover_directory(ls);
105 if (error) {
106 log_rinfo(ls, "dlm_recover_directory error %d", error);
107 goto fail;
108 }
109
110 dlm_set_recover_status(ls, DLM_RS_DIR);
111
112 error = dlm_recover_directory_wait(ls);
113 if (error) {
114 log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
115 goto fail;
116 }
117
118 log_rinfo(ls, "dlm_recover_directory %u out %u messages",
119 ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);
120
121 /*
122 * We may have outstanding operations that are waiting for a reply from
123 * a failed node. Mark these to be resent after recovery. Unlock and
124 * cancel ops can just be completed.
125 */
126
127 dlm_recover_waiters_pre(ls);
128
129 error = dlm_recovery_stopped(ls);
130 if (error)
131 goto fail;
132
133 if (neg || dlm_no_directory(ls)) {
134 /*
135 * Clear lkb's for departed nodes.
136 */
137
138 dlm_recover_purge(ls);
139
140 /*
141 * Get new master nodeid's for rsb's that were mastered on
142 * departed nodes.
143 */
144
145 error = dlm_recover_masters(ls);
146 if (error) {
147 log_rinfo(ls, "dlm_recover_masters error %d", error);
148 goto fail;
149 }
150
151 /*
152 * Send our locks on remastered rsb's to the new masters.
153 */
154
155 error = dlm_recover_locks(ls);
156 if (error) {
157 log_rinfo(ls, "dlm_recover_locks error %d", error);
158 goto fail;
159 }
160
161 dlm_set_recover_status(ls, DLM_RS_LOCKS);
162
163 error = dlm_recover_locks_wait(ls);
164 if (error) {
165 log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
166 goto fail;
167 }
168
169 log_rinfo(ls, "dlm_recover_locks %u in",
170 ls->ls_recover_locks_in);
171
172 /*
173 * Finalize state in master rsb's now that all locks can be
174 * checked. This includes conversion resolution and lvb
175 * settings.
176 */
177
178 dlm_recover_rsbs(ls);
179 } else {
180 /*
181 * Other lockspace members may be going through the "neg" steps
182 * while also adding us to the lockspace, in which case they'll
183 * be doing the recover_locks (RS_LOCKS) barrier.
184 */
185 dlm_set_recover_status(ls, DLM_RS_LOCKS);
186
187 error = dlm_recover_locks_wait(ls);
188 if (error) {
189 log_rinfo(ls, "dlm_recover_locks_wait error %d", error);
190 goto fail;
191 }
192 }
193
194 dlm_release_root_list(ls);
195
196 /*
197 * Purge directory-related requests that are saved in requestqueue.
198 * All dir requests from before recovery are invalid now due to the dir
199 * rebuild and will be resent by the requesting nodes.
200 */
201
202 dlm_purge_requestqueue(ls);
203
204 dlm_set_recover_status(ls, DLM_RS_DONE);
205
206 error = dlm_recover_done_wait(ls);
207 if (error) {
208 log_rinfo(ls, "dlm_recover_done_wait error %d", error);
209 goto fail;
210 }
211
212 dlm_clear_members_gone(ls);
213
214 dlm_adjust_timeouts(ls);
215
216 dlm_callback_resume(ls);
217
218 error = enable_locking(ls, rv->seq);
219 if (error) {
220 log_rinfo(ls, "enable_locking error %d", error);
221 goto fail;
222 }
223
224 error = dlm_process_requestqueue(ls);
225 if (error) {
226 log_rinfo(ls, "dlm_process_requestqueue error %d", error);
227 goto fail;
228 }
229
230 error = dlm_recover_waiters_post(ls);
231 if (error) {
232 log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
233 goto fail;
234 }
235
236 dlm_recover_grant(ls);
237
238 log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
239 (unsigned long long)rv->seq, ls->ls_generation,
240 jiffies_to_msecs(jiffies - start));
241 mutex_unlock(&ls->ls_recoverd_active);
242
243 dlm_lsop_recover_done(ls);
244 return 0;
245
246 fail:
247 dlm_release_root_list(ls);
248 log_rinfo(ls, "dlm_recover %llu error %d",
249 (unsigned long long)rv->seq, error);
250 mutex_unlock(&ls->ls_recoverd_active);
251 return error;
252 }
253
254 /* The dlm_ls_start() that created the rv we take here may already have been
255 stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
256 flag set. */
257
do_ls_recovery(struct dlm_ls * ls)258 static void do_ls_recovery(struct dlm_ls *ls)
259 {
260 struct dlm_recover *rv = NULL;
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 ls_recover(ls, rv);
271 kfree(rv->nodes);
272 kfree(rv);
273 }
274 }
275
dlm_recoverd(void * arg)276 static int dlm_recoverd(void *arg)
277 {
278 struct dlm_ls *ls;
279
280 ls = dlm_find_lockspace_local(arg);
281 if (!ls) {
282 log_print("dlm_recoverd: no lockspace %p", arg);
283 return -1;
284 }
285
286 down_write(&ls->ls_in_recovery);
287 set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
288 wake_up(&ls->ls_recover_lock_wait);
289
290 while (1) {
291 /*
292 * We call kthread_should_stop() after set_current_state().
293 * This is because it works correctly if kthread_stop() is
294 * called just before set_current_state().
295 */
296 set_current_state(TASK_INTERRUPTIBLE);
297 if (kthread_should_stop()) {
298 set_current_state(TASK_RUNNING);
299 break;
300 }
301 if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
302 !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
303 if (kthread_should_stop())
304 break;
305 schedule();
306 }
307 set_current_state(TASK_RUNNING);
308
309 if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
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
315 if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
316 do_ls_recovery(ls);
317 }
318
319 if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
320 up_write(&ls->ls_in_recovery);
321
322 dlm_put_lockspace(ls);
323 return 0;
324 }
325
dlm_recoverd_start(struct dlm_ls * ls)326 int dlm_recoverd_start(struct dlm_ls *ls)
327 {
328 struct task_struct *p;
329 int error = 0;
330
331 p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
332 if (IS_ERR(p))
333 error = PTR_ERR(p);
334 else
335 ls->ls_recoverd_task = p;
336 return error;
337 }
338
dlm_recoverd_stop(struct dlm_ls * ls)339 void dlm_recoverd_stop(struct dlm_ls *ls)
340 {
341 kthread_stop(ls->ls_recoverd_task);
342 }
343
dlm_recoverd_suspend(struct dlm_ls * ls)344 void dlm_recoverd_suspend(struct dlm_ls *ls)
345 {
346 wake_up(&ls->ls_wait_general);
347 mutex_lock(&ls->ls_recoverd_active);
348 }
349
dlm_recoverd_resume(struct dlm_ls * ls)350 void dlm_recoverd_resume(struct dlm_ls *ls)
351 {
352 mutex_unlock(&ls->ls_recoverd_active);
353 }
354
355