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26/* If the start for which we're re-enabling locking (seq) has been superseded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
33static 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
53static 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
258static 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
276static 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 (!kthread_should_stop()) {
291		set_current_state(TASK_INTERRUPTIBLE);
292		if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
293		    !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags))
294			schedule();
295		set_current_state(TASK_RUNNING);
296
297		if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
298			down_write(&ls->ls_in_recovery);
299			set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
300			wake_up(&ls->ls_recover_lock_wait);
301		}
302
303		if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
304			do_ls_recovery(ls);
305	}
306
307	if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
308		up_write(&ls->ls_in_recovery);
309
310	dlm_put_lockspace(ls);
311	return 0;
312}
313
314int dlm_recoverd_start(struct dlm_ls *ls)
315{
316	struct task_struct *p;
317	int error = 0;
318
319	p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
320	if (IS_ERR(p))
321		error = PTR_ERR(p);
322	else
323                ls->ls_recoverd_task = p;
324	return error;
325}
326
327void dlm_recoverd_stop(struct dlm_ls *ls)
328{
329	kthread_stop(ls->ls_recoverd_task);
330}
331
332void dlm_recoverd_suspend(struct dlm_ls *ls)
333{
334	wake_up(&ls->ls_wait_general);
335	mutex_lock(&ls->ls_recoverd_active);
336}
337
338void dlm_recoverd_resume(struct dlm_ls *ls)
339{
340	mutex_unlock(&ls->ls_recoverd_active);
341}
342
343