xref: /openbmc/linux/fs/dlm/recoverd.c (revision e65e175b)
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24 /* If the start for which we're re-enabling locking (seq) has been superseded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);
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);
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);
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);
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);
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);
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);
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);
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_adjust_timeouts(ls);
218 
219 	dlm_callback_resume(ls);
220 
221 	error = enable_locking(ls, rv->seq);
222 	if (error) {
223 		log_rinfo(ls, "enable_locking error %d", error);
224 		goto fail;
225 	}
226 
227 	error = dlm_process_requestqueue(ls);
228 	if (error) {
229 		log_rinfo(ls, "dlm_process_requestqueue error %d", error);
230 		goto fail;
231 	}
232 
233 	error = dlm_recover_waiters_post(ls);
234 	if (error) {
235 		log_rinfo(ls, "dlm_recover_waiters_post error %d", error);
236 		goto fail;
237 	}
238 
239 	dlm_recover_grant(ls);
240 
241 	log_rinfo(ls, "dlm_recover %llu generation %u done: %u ms",
242 		  (unsigned long long)rv->seq, ls->ls_generation,
243 		  jiffies_to_msecs(jiffies - start));
244 	mutex_unlock(&ls->ls_recoverd_active);
245 
246 	return 0;
247 
248  fail:
249 	dlm_release_root_list(ls);
250 	mutex_unlock(&ls->ls_recoverd_active);
251 
252 	return error;
253 }
254 
255 /* The dlm_ls_start() that created the rv we take here may already have been
256    stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
257    flag set. */
258 
259 static void do_ls_recovery(struct dlm_ls *ls)
260 {
261 	struct dlm_recover *rv = NULL;
262 	int error;
263 
264 	spin_lock(&ls->ls_recover_lock);
265 	rv = ls->ls_recover_args;
266 	ls->ls_recover_args = NULL;
267 	if (rv && ls->ls_recover_seq == rv->seq)
268 		clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
269 	spin_unlock(&ls->ls_recover_lock);
270 
271 	if (rv) {
272 		error = ls_recover(ls, rv);
273 		switch (error) {
274 		case 0:
275 			ls->ls_recovery_result = 0;
276 			complete(&ls->ls_recovery_done);
277 
278 			dlm_lsop_recover_done(ls);
279 			break;
280 		case -EINTR:
281 			/* if recovery was interrupted -EINTR we wait for the next
282 			 * ls_recover() iteration until it hopefully succeeds.
283 			 */
284 			log_rinfo(ls, "%s %llu interrupted and should be queued to run again",
285 				  __func__, (unsigned long long)rv->seq);
286 			break;
287 		default:
288 			log_rinfo(ls, "%s %llu error %d", __func__,
289 				  (unsigned long long)rv->seq, error);
290 
291 			/* let new_lockspace() get aware of critical error */
292 			ls->ls_recovery_result = error;
293 			complete(&ls->ls_recovery_done);
294 			break;
295 		}
296 
297 		kfree(rv->nodes);
298 		kfree(rv);
299 	}
300 }
301 
302 static int dlm_recoverd(void *arg)
303 {
304 	struct dlm_ls *ls;
305 
306 	ls = dlm_find_lockspace_local(arg);
307 	if (!ls) {
308 		log_print("dlm_recoverd: no lockspace %p", arg);
309 		return -1;
310 	}
311 
312 	down_write(&ls->ls_in_recovery);
313 	set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
314 	wake_up(&ls->ls_recover_lock_wait);
315 
316 	while (1) {
317 		/*
318 		 * We call kthread_should_stop() after set_current_state().
319 		 * This is because it works correctly if kthread_stop() is
320 		 * called just before set_current_state().
321 		 */
322 		set_current_state(TASK_INTERRUPTIBLE);
323 		if (kthread_should_stop()) {
324 			set_current_state(TASK_RUNNING);
325 			break;
326 		}
327 		if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
328 		    !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
329 			if (kthread_should_stop())
330 				break;
331 			schedule();
332 		}
333 		set_current_state(TASK_RUNNING);
334 
335 		if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
336 			down_write(&ls->ls_in_recovery);
337 			set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
338 			wake_up(&ls->ls_recover_lock_wait);
339 		}
340 
341 		if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
342 			do_ls_recovery(ls);
343 	}
344 
345 	if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
346 		up_write(&ls->ls_in_recovery);
347 
348 	dlm_put_lockspace(ls);
349 	return 0;
350 }
351 
352 int dlm_recoverd_start(struct dlm_ls *ls)
353 {
354 	struct task_struct *p;
355 	int error = 0;
356 
357 	p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
358 	if (IS_ERR(p))
359 		error = PTR_ERR(p);
360 	else
361                 ls->ls_recoverd_task = p;
362 	return error;
363 }
364 
365 void dlm_recoverd_stop(struct dlm_ls *ls)
366 {
367 	kthread_stop(ls->ls_recoverd_task);
368 }
369 
370 void dlm_recoverd_suspend(struct dlm_ls *ls)
371 {
372 	wake_up(&ls->ls_wait_general);
373 	mutex_lock(&ls->ls_recoverd_active);
374 }
375 
376 void dlm_recoverd_resume(struct dlm_ls *ls)
377 {
378 	mutex_unlock(&ls->ls_recoverd_active);
379 }
380 
381