Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[linux-2.6] / fs / dlm / recoverd.c
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2004-2007 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26 /* If the start for which we're re-enabling locking (seq) has been superseded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
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                 error = 0;
45         }
46         spin_unlock(&ls->ls_recover_lock);
47
48         up_write(&ls->ls_recv_active);
49         return error;
50 }
51
52 static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
53 {
54         unsigned long start;
55         int error, neg = 0;
56
57         log_debug(ls, "recover %llx", (unsigned long long)rv->seq);
58
59         mutex_lock(&ls->ls_recoverd_active);
60
61         /*
62          * Suspending and resuming dlm_astd ensures that no lkb's from this ls
63          * will be processed by dlm_astd during recovery.
64          */
65
66         dlm_astd_suspend();
67         dlm_astd_resume();
68
69         /*
70          * This list of root rsb's will be the basis of most of the recovery
71          * routines.
72          */
73
74         dlm_create_root_list(ls);
75
76         /*
77          * Free all the tossed rsb's so we don't have to recover them.
78          */
79
80         dlm_clear_toss_list(ls);
81
82         /*
83          * Add or remove nodes from the lockspace's ls_nodes list.
84          * Also waits for all nodes to complete dlm_recover_members.
85          */
86
87         error = dlm_recover_members(ls, rv, &neg);
88         if (error) {
89                 log_debug(ls, "recover_members failed %d", error);
90                 goto fail;
91         }
92         start = jiffies;
93
94         /*
95          * Rebuild our own share of the directory by collecting from all other
96          * nodes their master rsb names that hash to us.
97          */
98
99         error = dlm_recover_directory(ls);
100         if (error) {
101                 log_debug(ls, "recover_directory failed %d", error);
102                 goto fail;
103         }
104
105         /*
106          * Wait for all nodes to complete directory rebuild.
107          */
108
109         error = dlm_recover_directory_wait(ls);
110         if (error) {
111                 log_debug(ls, "recover_directory_wait failed %d", error);
112                 goto fail;
113         }
114
115         /*
116          * We may have outstanding operations that are waiting for a reply from
117          * a failed node.  Mark these to be resent after recovery.  Unlock and
118          * cancel ops can just be completed.
119          */
120
121         dlm_recover_waiters_pre(ls);
122
123         error = dlm_recovery_stopped(ls);
124         if (error)
125                 goto fail;
126
127         if (neg || dlm_no_directory(ls)) {
128                 /*
129                  * Clear lkb's for departed nodes.
130                  */
131
132                 dlm_purge_locks(ls);
133
134                 /*
135                  * Get new master nodeid's for rsb's that were mastered on
136                  * departed nodes.
137                  */
138
139                 error = dlm_recover_masters(ls);
140                 if (error) {
141                         log_debug(ls, "recover_masters failed %d", error);
142                         goto fail;
143                 }
144
145                 /*
146                  * Send our locks on remastered rsb's to the new masters.
147                  */
148
149                 error = dlm_recover_locks(ls);
150                 if (error) {
151                         log_debug(ls, "recover_locks failed %d", error);
152                         goto fail;
153                 }
154
155                 error = dlm_recover_locks_wait(ls);
156                 if (error) {
157                         log_debug(ls, "recover_locks_wait failed %d", error);
158                         goto fail;
159                 }
160
161                 /*
162                  * Finalize state in master rsb's now that all locks can be
163                  * checked.  This includes conversion resolution and lvb
164                  * settings.
165                  */
166
167                 dlm_recover_rsbs(ls);
168         } else {
169                 /*
170                  * Other lockspace members may be going through the "neg" steps
171                  * while also adding us to the lockspace, in which case they'll
172                  * be doing the recover_locks (RS_LOCKS) barrier.
173                  */
174                 dlm_set_recover_status(ls, DLM_RS_LOCKS);
175
176                 error = dlm_recover_locks_wait(ls);
177                 if (error) {
178                         log_debug(ls, "recover_locks_wait failed %d", error);
179                         goto fail;
180                 }
181         }
182
183         dlm_release_root_list(ls);
184
185         /*
186          * Purge directory-related requests that are saved in requestqueue.
187          * All dir requests from before recovery are invalid now due to the dir
188          * rebuild and will be resent by the requesting nodes.
189          */
190
191         dlm_purge_requestqueue(ls);
192
193         dlm_set_recover_status(ls, DLM_RS_DONE);
194         error = dlm_recover_done_wait(ls);
195         if (error) {
196                 log_debug(ls, "recover_done_wait failed %d", error);
197                 goto fail;
198         }
199
200         dlm_clear_members_gone(ls);
201
202         dlm_adjust_timeouts(ls);
203
204         error = enable_locking(ls, rv->seq);
205         if (error) {
206                 log_debug(ls, "enable_locking failed %d", error);
207                 goto fail;
208         }
209
210         error = dlm_process_requestqueue(ls);
211         if (error) {
212                 log_debug(ls, "process_requestqueue failed %d", error);
213                 goto fail;
214         }
215
216         error = dlm_recover_waiters_post(ls);
217         if (error) {
218                 log_debug(ls, "recover_waiters_post failed %d", error);
219                 goto fail;
220         }
221
222         dlm_grant_after_purge(ls);
223
224         dlm_astd_wake();
225
226         log_debug(ls, "recover %llx done: %u ms",
227                   (unsigned long long)rv->seq,
228                   jiffies_to_msecs(jiffies - start));
229         mutex_unlock(&ls->ls_recoverd_active);
230
231         return 0;
232
233  fail:
234         dlm_release_root_list(ls);
235         log_debug(ls, "recover %llx error %d",
236                   (unsigned long long)rv->seq, error);
237         mutex_unlock(&ls->ls_recoverd_active);
238         return error;
239 }
240
241 /* The dlm_ls_start() that created the rv we take here may already have been
242    stopped via dlm_ls_stop(); in that case we need to leave the RECOVERY_STOP
243    flag set. */
244
245 static void do_ls_recovery(struct dlm_ls *ls)
246 {
247         struct dlm_recover *rv = NULL;
248
249         spin_lock(&ls->ls_recover_lock);
250         rv = ls->ls_recover_args;
251         ls->ls_recover_args = NULL;
252         if (rv && ls->ls_recover_seq == rv->seq)
253                 clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
254         spin_unlock(&ls->ls_recover_lock);
255
256         if (rv) {
257                 ls_recover(ls, rv);
258                 kfree(rv->nodeids);
259                 kfree(rv);
260         }
261 }
262
263 static int dlm_recoverd(void *arg)
264 {
265         struct dlm_ls *ls;
266
267         ls = dlm_find_lockspace_local(arg);
268         if (!ls) {
269                 log_print("dlm_recoverd: no lockspace %p", arg);
270                 return -1;
271         }
272
273         while (!kthread_should_stop()) {
274                 set_current_state(TASK_INTERRUPTIBLE);
275                 if (!test_bit(LSFL_WORK, &ls->ls_flags))
276                         schedule();
277                 set_current_state(TASK_RUNNING);
278
279                 if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags))
280                         do_ls_recovery(ls);
281         }
282
283         dlm_put_lockspace(ls);
284         return 0;
285 }
286
287 void dlm_recoverd_kick(struct dlm_ls *ls)
288 {
289         set_bit(LSFL_WORK, &ls->ls_flags);
290         wake_up_process(ls->ls_recoverd_task);
291 }
292
293 int dlm_recoverd_start(struct dlm_ls *ls)
294 {
295         struct task_struct *p;
296         int error = 0;
297
298         p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
299         if (IS_ERR(p))
300                 error = PTR_ERR(p);
301         else
302                 ls->ls_recoverd_task = p;
303         return error;
304 }
305
306 void dlm_recoverd_stop(struct dlm_ls *ls)
307 {
308         kthread_stop(ls->ls_recoverd_task);
309 }
310
311 void dlm_recoverd_suspend(struct dlm_ls *ls)
312 {
313         wake_up(&ls->ls_wait_general);
314         mutex_lock(&ls->ls_recoverd_active);
315 }
316
317 void dlm_recoverd_resume(struct dlm_ls *ls)
318 {
319         mutex_unlock(&ls->ls_recoverd_active);
320 }
321