[CIFS] cifs: replace remaining __FUNCTION__ occurrences
[sfrench/cifs-2.6.git] / fs / ocfs2 / dlm / dlmrecovery.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dlmrecovery.c
5  *
6  * recovery stuff
7  *
8  * Copyright (C) 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  *
25  */
26
27
28 #include <linux/module.h>
29 #include <linux/fs.h>
30 #include <linux/types.h>
31 #include <linux/slab.h>
32 #include <linux/highmem.h>
33 #include <linux/utsname.h>
34 #include <linux/init.h>
35 #include <linux/sysctl.h>
36 #include <linux/random.h>
37 #include <linux/blkdev.h>
38 #include <linux/socket.h>
39 #include <linux/inet.h>
40 #include <linux/timer.h>
41 #include <linux/kthread.h>
42 #include <linux/delay.h>
43
44
45 #include "cluster/heartbeat.h"
46 #include "cluster/nodemanager.h"
47 #include "cluster/tcp.h"
48
49 #include "dlmapi.h"
50 #include "dlmcommon.h"
51 #include "dlmdomain.h"
52
53 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
54 #include "cluster/masklog.h"
55
56 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
57
58 static int dlm_recovery_thread(void *data);
59 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
60 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
61 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
62 static int dlm_do_recovery(struct dlm_ctxt *dlm);
63
64 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
65 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
66 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
67 static int dlm_request_all_locks(struct dlm_ctxt *dlm,
68                                  u8 request_from, u8 dead_node);
69 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
70
71 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
72 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
73                                         const char *lockname, int namelen,
74                                         int total_locks, u64 cookie,
75                                         u8 flags, u8 master);
76 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
77                                     struct dlm_migratable_lockres *mres,
78                                     u8 send_to,
79                                     struct dlm_lock_resource *res,
80                                     int total_locks);
81 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
82                                      struct dlm_lock_resource *res,
83                                      struct dlm_migratable_lockres *mres);
84 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
85 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
86                                  u8 dead_node, u8 send_to);
87 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
88 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
89                                         struct list_head *list, u8 dead_node);
90 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
91                                               u8 dead_node, u8 new_master);
92 static void dlm_reco_ast(void *astdata);
93 static void dlm_reco_bast(void *astdata, int blocked_type);
94 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
95 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
96                                          void *data);
97 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
98 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
99                                       struct dlm_lock_resource *res,
100                                       u8 *real_master);
101
102 static u64 dlm_get_next_mig_cookie(void);
103
104 static DEFINE_SPINLOCK(dlm_reco_state_lock);
105 static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
106 static u64 dlm_mig_cookie = 1;
107
108 static u64 dlm_get_next_mig_cookie(void)
109 {
110         u64 c;
111         spin_lock(&dlm_mig_cookie_lock);
112         c = dlm_mig_cookie;
113         if (dlm_mig_cookie == (~0ULL))
114                 dlm_mig_cookie = 1;
115         else
116                 dlm_mig_cookie++;
117         spin_unlock(&dlm_mig_cookie_lock);
118         return c;
119 }
120
121 static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
122                                           u8 dead_node)
123 {
124         assert_spin_locked(&dlm->spinlock);
125         if (dlm->reco.dead_node != dead_node)
126                 mlog(0, "%s: changing dead_node from %u to %u\n",
127                      dlm->name, dlm->reco.dead_node, dead_node);
128         dlm->reco.dead_node = dead_node;
129 }
130
131 static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
132                                        u8 master)
133 {
134         assert_spin_locked(&dlm->spinlock);
135         mlog(0, "%s: changing new_master from %u to %u\n",
136              dlm->name, dlm->reco.new_master, master);
137         dlm->reco.new_master = master;
138 }
139
140 static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
141 {
142         assert_spin_locked(&dlm->spinlock);
143         clear_bit(dlm->reco.dead_node, dlm->recovery_map);
144         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
145         dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
146 }
147
148 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
149 {
150         spin_lock(&dlm->spinlock);
151         __dlm_reset_recovery(dlm);
152         spin_unlock(&dlm->spinlock);
153 }
154
155 /* Worker function used during recovery. */
156 void dlm_dispatch_work(struct work_struct *work)
157 {
158         struct dlm_ctxt *dlm =
159                 container_of(work, struct dlm_ctxt, dispatched_work);
160         LIST_HEAD(tmp_list);
161         struct dlm_work_item *item, *next;
162         dlm_workfunc_t *workfunc;
163         int tot=0;
164
165         spin_lock(&dlm->work_lock);
166         list_splice_init(&dlm->work_list, &tmp_list);
167         spin_unlock(&dlm->work_lock);
168
169         list_for_each_entry(item, &tmp_list, list) {
170                 tot++;
171         }
172         mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
173
174         list_for_each_entry_safe(item, next, &tmp_list, list) {
175                 workfunc = item->func;
176                 list_del_init(&item->list);
177
178                 /* already have ref on dlm to avoid having
179                  * it disappear.  just double-check. */
180                 BUG_ON(item->dlm != dlm);
181
182                 /* this is allowed to sleep and
183                  * call network stuff */
184                 workfunc(item, item->data);
185
186                 dlm_put(dlm);
187                 kfree(item);
188         }
189 }
190
191 /*
192  * RECOVERY THREAD
193  */
194
195 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
196 {
197         /* wake the recovery thread
198          * this will wake the reco thread in one of three places
199          * 1) sleeping with no recovery happening
200          * 2) sleeping with recovery mastered elsewhere
201          * 3) recovery mastered here, waiting on reco data */
202
203         wake_up(&dlm->dlm_reco_thread_wq);
204 }
205
206 /* Launch the recovery thread */
207 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
208 {
209         mlog(0, "starting dlm recovery thread...\n");
210
211         dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
212                                                 "dlm_reco_thread");
213         if (IS_ERR(dlm->dlm_reco_thread_task)) {
214                 mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
215                 dlm->dlm_reco_thread_task = NULL;
216                 return -EINVAL;
217         }
218
219         return 0;
220 }
221
222 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
223 {
224         if (dlm->dlm_reco_thread_task) {
225                 mlog(0, "waiting for dlm recovery thread to exit\n");
226                 kthread_stop(dlm->dlm_reco_thread_task);
227                 dlm->dlm_reco_thread_task = NULL;
228         }
229 }
230
231
232
233 /*
234  * this is lame, but here's how recovery works...
235  * 1) all recovery threads cluster wide will work on recovering
236  *    ONE node at a time
237  * 2) negotiate who will take over all the locks for the dead node.
238  *    thats right... ALL the locks.
239  * 3) once a new master is chosen, everyone scans all locks
240  *    and moves aside those mastered by the dead guy
241  * 4) each of these locks should be locked until recovery is done
242  * 5) the new master collects up all of secondary lock queue info
243  *    one lock at a time, forcing each node to communicate back
244  *    before continuing
245  * 6) each secondary lock queue responds with the full known lock info
246  * 7) once the new master has run all its locks, it sends a ALLDONE!
247  *    message to everyone
248  * 8) upon receiving this message, the secondary queue node unlocks
249  *    and responds to the ALLDONE
250  * 9) once the new master gets responses from everyone, he unlocks
251  *    everything and recovery for this dead node is done
252  *10) go back to 2) while there are still dead nodes
253  *
254  */
255
256 static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
257 {
258         struct dlm_reco_node_data *ndata;
259         struct dlm_lock_resource *res;
260
261         mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
262              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
263              dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
264              dlm->reco.dead_node, dlm->reco.new_master);
265
266         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
267                 char *st = "unknown";
268                 switch (ndata->state) {
269                         case DLM_RECO_NODE_DATA_INIT:
270                                 st = "init";
271                                 break;
272                         case DLM_RECO_NODE_DATA_REQUESTING:
273                                 st = "requesting";
274                                 break;
275                         case DLM_RECO_NODE_DATA_DEAD:
276                                 st = "dead";
277                                 break;
278                         case DLM_RECO_NODE_DATA_RECEIVING:
279                                 st = "receiving";
280                                 break;
281                         case DLM_RECO_NODE_DATA_REQUESTED:
282                                 st = "requested";
283                                 break;
284                         case DLM_RECO_NODE_DATA_DONE:
285                                 st = "done";
286                                 break;
287                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
288                                 st = "finalize-sent";
289                                 break;
290                         default:
291                                 st = "bad";
292                                 break;
293                 }
294                 mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
295                      dlm->name, ndata->node_num, st);
296         }
297         list_for_each_entry(res, &dlm->reco.resources, recovering) {
298                 mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
299                      dlm->name, res->lockname.len, res->lockname.name);
300         }
301 }
302
303 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
304
305 static int dlm_recovery_thread(void *data)
306 {
307         int status;
308         struct dlm_ctxt *dlm = data;
309         unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
310
311         mlog(0, "dlm thread running for %s...\n", dlm->name);
312
313         while (!kthread_should_stop()) {
314                 if (dlm_joined(dlm)) {
315                         status = dlm_do_recovery(dlm);
316                         if (status == -EAGAIN) {
317                                 /* do not sleep, recheck immediately. */
318                                 continue;
319                         }
320                         if (status < 0)
321                                 mlog_errno(status);
322                 }
323
324                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
325                                                  kthread_should_stop(),
326                                                  timeout);
327         }
328
329         mlog(0, "quitting DLM recovery thread\n");
330         return 0;
331 }
332
333 /* returns true when the recovery master has contacted us */
334 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
335 {
336         int ready;
337         spin_lock(&dlm->spinlock);
338         ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
339         spin_unlock(&dlm->spinlock);
340         return ready;
341 }
342
343 /* returns true if node is no longer in the domain
344  * could be dead or just not joined */
345 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
346 {
347         int dead;
348         spin_lock(&dlm->spinlock);
349         dead = !test_bit(node, dlm->domain_map);
350         spin_unlock(&dlm->spinlock);
351         return dead;
352 }
353
354 /* returns true if node is no longer in the domain
355  * could be dead or just not joined */
356 static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
357 {
358         int recovered;
359         spin_lock(&dlm->spinlock);
360         recovered = !test_bit(node, dlm->recovery_map);
361         spin_unlock(&dlm->spinlock);
362         return recovered;
363 }
364
365
366 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
367 {
368         if (timeout) {
369                 mlog(ML_NOTICE, "%s: waiting %dms for notification of "
370                      "death of node %u\n", dlm->name, timeout, node);
371                 wait_event_timeout(dlm->dlm_reco_thread_wq,
372                            dlm_is_node_dead(dlm, node),
373                            msecs_to_jiffies(timeout));
374         } else {
375                 mlog(ML_NOTICE, "%s: waiting indefinitely for notification "
376                      "of death of node %u\n", dlm->name, node);
377                 wait_event(dlm->dlm_reco_thread_wq,
378                            dlm_is_node_dead(dlm, node));
379         }
380         /* for now, return 0 */
381         return 0;
382 }
383
384 int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
385 {
386         if (timeout) {
387                 mlog(0, "%s: waiting %dms for notification of "
388                      "recovery of node %u\n", dlm->name, timeout, node);
389                 wait_event_timeout(dlm->dlm_reco_thread_wq,
390                            dlm_is_node_recovered(dlm, node),
391                            msecs_to_jiffies(timeout));
392         } else {
393                 mlog(0, "%s: waiting indefinitely for notification "
394                      "of recovery of node %u\n", dlm->name, node);
395                 wait_event(dlm->dlm_reco_thread_wq,
396                            dlm_is_node_recovered(dlm, node));
397         }
398         /* for now, return 0 */
399         return 0;
400 }
401
402 /* callers of the top-level api calls (dlmlock/dlmunlock) should
403  * block on the dlm->reco.event when recovery is in progress.
404  * the dlm recovery thread will set this state when it begins
405  * recovering a dead node (as the new master or not) and clear
406  * the state and wake as soon as all affected lock resources have
407  * been marked with the RECOVERY flag */
408 static int dlm_in_recovery(struct dlm_ctxt *dlm)
409 {
410         int in_recovery;
411         spin_lock(&dlm->spinlock);
412         in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
413         spin_unlock(&dlm->spinlock);
414         return in_recovery;
415 }
416
417
418 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
419 {
420         if (dlm_in_recovery(dlm)) {
421                 mlog(0, "%s: reco thread %d in recovery: "
422                      "state=%d, master=%u, dead=%u\n",
423                      dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
424                      dlm->reco.state, dlm->reco.new_master,
425                      dlm->reco.dead_node);
426         }
427         wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
428 }
429
430 static void dlm_begin_recovery(struct dlm_ctxt *dlm)
431 {
432         spin_lock(&dlm->spinlock);
433         BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
434         dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
435         spin_unlock(&dlm->spinlock);
436 }
437
438 static void dlm_end_recovery(struct dlm_ctxt *dlm)
439 {
440         spin_lock(&dlm->spinlock);
441         BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
442         dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
443         spin_unlock(&dlm->spinlock);
444         wake_up(&dlm->reco.event);
445 }
446
447 static int dlm_do_recovery(struct dlm_ctxt *dlm)
448 {
449         int status = 0;
450         int ret;
451
452         spin_lock(&dlm->spinlock);
453
454         /* check to see if the new master has died */
455         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
456             test_bit(dlm->reco.new_master, dlm->recovery_map)) {
457                 mlog(0, "new master %u died while recovering %u!\n",
458                      dlm->reco.new_master, dlm->reco.dead_node);
459                 /* unset the new_master, leave dead_node */
460                 dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
461         }
462
463         /* select a target to recover */
464         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
465                 int bit;
466
467                 bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
468                 if (bit >= O2NM_MAX_NODES || bit < 0)
469                         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
470                 else
471                         dlm_set_reco_dead_node(dlm, bit);
472         } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
473                 /* BUG? */
474                 mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
475                      dlm->reco.dead_node);
476                 dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
477         }
478
479         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
480                 // mlog(0, "nothing to recover!  sleeping now!\n");
481                 spin_unlock(&dlm->spinlock);
482                 /* return to main thread loop and sleep. */
483                 return 0;
484         }
485         mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
486              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
487              dlm->reco.dead_node);
488         spin_unlock(&dlm->spinlock);
489
490         /* take write barrier */
491         /* (stops the list reshuffling thread, proxy ast handling) */
492         dlm_begin_recovery(dlm);
493
494         if (dlm->reco.new_master == dlm->node_num)
495                 goto master_here;
496
497         if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
498                 /* choose a new master, returns 0 if this node
499                  * is the master, -EEXIST if it's another node.
500                  * this does not return until a new master is chosen
501                  * or recovery completes entirely. */
502                 ret = dlm_pick_recovery_master(dlm);
503                 if (!ret) {
504                         /* already notified everyone.  go. */
505                         goto master_here;
506                 }
507                 mlog(0, "another node will master this recovery session.\n");
508         }
509         mlog(0, "dlm=%s (%d), new_master=%u, this node=%u, dead_node=%u\n",
510              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task), dlm->reco.new_master,
511              dlm->node_num, dlm->reco.dead_node);
512
513         /* it is safe to start everything back up here
514          * because all of the dead node's lock resources
515          * have been marked as in-recovery */
516         dlm_end_recovery(dlm);
517
518         /* sleep out in main dlm_recovery_thread loop. */
519         return 0;
520
521 master_here:
522         mlog(0, "(%d) mastering recovery of %s:%u here(this=%u)!\n",
523              task_pid_nr(dlm->dlm_reco_thread_task),
524              dlm->name, dlm->reco.dead_node, dlm->node_num);
525
526         status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
527         if (status < 0) {
528                 /* we should never hit this anymore */
529                 mlog(ML_ERROR, "error %d remastering locks for node %u, "
530                      "retrying.\n", status, dlm->reco.dead_node);
531                 /* yield a bit to allow any final network messages
532                  * to get handled on remaining nodes */
533                 msleep(100);
534         } else {
535                 /* success!  see if any other nodes need recovery */
536                 mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
537                      dlm->name, dlm->reco.dead_node, dlm->node_num);
538                 dlm_reset_recovery(dlm);
539         }
540         dlm_end_recovery(dlm);
541
542         /* continue and look for another dead node */
543         return -EAGAIN;
544 }
545
546 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
547 {
548         int status = 0;
549         struct dlm_reco_node_data *ndata;
550         int all_nodes_done;
551         int destroy = 0;
552         int pass = 0;
553
554         do {
555                 /* we have become recovery master.  there is no escaping
556                  * this, so just keep trying until we get it. */
557                 status = dlm_init_recovery_area(dlm, dead_node);
558                 if (status < 0) {
559                         mlog(ML_ERROR, "%s: failed to alloc recovery area, "
560                              "retrying\n", dlm->name);
561                         msleep(1000);
562                 }
563         } while (status != 0);
564
565         /* safe to access the node data list without a lock, since this
566          * process is the only one to change the list */
567         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
568                 BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
569                 ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
570
571                 mlog(0, "requesting lock info from node %u\n",
572                      ndata->node_num);
573
574                 if (ndata->node_num == dlm->node_num) {
575                         ndata->state = DLM_RECO_NODE_DATA_DONE;
576                         continue;
577                 }
578
579                 do {
580                         status = dlm_request_all_locks(dlm, ndata->node_num,
581                                                        dead_node);
582                         if (status < 0) {
583                                 mlog_errno(status);
584                                 if (dlm_is_host_down(status)) {
585                                         /* node died, ignore it for recovery */
586                                         status = 0;
587                                         ndata->state = DLM_RECO_NODE_DATA_DEAD;
588                                         /* wait for the domain map to catch up
589                                          * with the network state. */
590                                         wait_event_timeout(dlm->dlm_reco_thread_wq,
591                                                            dlm_is_node_dead(dlm,
592                                                                 ndata->node_num),
593                                                            msecs_to_jiffies(1000));
594                                         mlog(0, "waited 1 sec for %u, "
595                                              "dead? %s\n", ndata->node_num,
596                                              dlm_is_node_dead(dlm, ndata->node_num) ?
597                                              "yes" : "no");
598                                 } else {
599                                         /* -ENOMEM on the other node */
600                                         mlog(0, "%s: node %u returned "
601                                              "%d during recovery, retrying "
602                                              "after a short wait\n",
603                                              dlm->name, ndata->node_num,
604                                              status);
605                                         msleep(100);
606                                 }
607                         }
608                 } while (status != 0);
609
610                 spin_lock(&dlm_reco_state_lock);
611                 switch (ndata->state) {
612                         case DLM_RECO_NODE_DATA_INIT:
613                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
614                         case DLM_RECO_NODE_DATA_REQUESTED:
615                                 BUG();
616                                 break;
617                         case DLM_RECO_NODE_DATA_DEAD:
618                                 mlog(0, "node %u died after requesting "
619                                      "recovery info for node %u\n",
620                                      ndata->node_num, dead_node);
621                                 /* fine.  don't need this node's info.
622                                  * continue without it. */
623                                 break;
624                         case DLM_RECO_NODE_DATA_REQUESTING:
625                                 ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
626                                 mlog(0, "now receiving recovery data from "
627                                      "node %u for dead node %u\n",
628                                      ndata->node_num, dead_node);
629                                 break;
630                         case DLM_RECO_NODE_DATA_RECEIVING:
631                                 mlog(0, "already receiving recovery data from "
632                                      "node %u for dead node %u\n",
633                                      ndata->node_num, dead_node);
634                                 break;
635                         case DLM_RECO_NODE_DATA_DONE:
636                                 mlog(0, "already DONE receiving recovery data "
637                                      "from node %u for dead node %u\n",
638                                      ndata->node_num, dead_node);
639                                 break;
640                 }
641                 spin_unlock(&dlm_reco_state_lock);
642         }
643
644         mlog(0, "done requesting all lock info\n");
645
646         /* nodes should be sending reco data now
647          * just need to wait */
648
649         while (1) {
650                 /* check all the nodes now to see if we are
651                  * done, or if anyone died */
652                 all_nodes_done = 1;
653                 spin_lock(&dlm_reco_state_lock);
654                 list_for_each_entry(ndata, &dlm->reco.node_data, list) {
655                         mlog(0, "checking recovery state of node %u\n",
656                              ndata->node_num);
657                         switch (ndata->state) {
658                                 case DLM_RECO_NODE_DATA_INIT:
659                                 case DLM_RECO_NODE_DATA_REQUESTING:
660                                         mlog(ML_ERROR, "bad ndata state for "
661                                              "node %u: state=%d\n",
662                                              ndata->node_num, ndata->state);
663                                         BUG();
664                                         break;
665                                 case DLM_RECO_NODE_DATA_DEAD:
666                                         mlog(0, "node %u died after "
667                                              "requesting recovery info for "
668                                              "node %u\n", ndata->node_num,
669                                              dead_node);
670                                         break;
671                                 case DLM_RECO_NODE_DATA_RECEIVING:
672                                 case DLM_RECO_NODE_DATA_REQUESTED:
673                                         mlog(0, "%s: node %u still in state %s\n",
674                                              dlm->name, ndata->node_num,
675                                              ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
676                                              "receiving" : "requested");
677                                         all_nodes_done = 0;
678                                         break;
679                                 case DLM_RECO_NODE_DATA_DONE:
680                                         mlog(0, "%s: node %u state is done\n",
681                                              dlm->name, ndata->node_num);
682                                         break;
683                                 case DLM_RECO_NODE_DATA_FINALIZE_SENT:
684                                         mlog(0, "%s: node %u state is finalize\n",
685                                              dlm->name, ndata->node_num);
686                                         break;
687                         }
688                 }
689                 spin_unlock(&dlm_reco_state_lock);
690
691                 mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
692                      all_nodes_done?"yes":"no");
693                 if (all_nodes_done) {
694                         int ret;
695
696                         /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
697                          * just send a finalize message to everyone and
698                          * clean up */
699                         mlog(0, "all nodes are done! send finalize\n");
700                         ret = dlm_send_finalize_reco_message(dlm);
701                         if (ret < 0)
702                                 mlog_errno(ret);
703
704                         spin_lock(&dlm->spinlock);
705                         dlm_finish_local_lockres_recovery(dlm, dead_node,
706                                                           dlm->node_num);
707                         spin_unlock(&dlm->spinlock);
708                         mlog(0, "should be done with recovery!\n");
709
710                         mlog(0, "finishing recovery of %s at %lu, "
711                              "dead=%u, this=%u, new=%u\n", dlm->name,
712                              jiffies, dlm->reco.dead_node,
713                              dlm->node_num, dlm->reco.new_master);
714                         destroy = 1;
715                         status = 0;
716                         /* rescan everything marked dirty along the way */
717                         dlm_kick_thread(dlm, NULL);
718                         break;
719                 }
720                 /* wait to be signalled, with periodic timeout
721                  * to check for node death */
722                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
723                                          kthread_should_stop(),
724                                          msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
725
726         }
727
728         if (destroy)
729                 dlm_destroy_recovery_area(dlm, dead_node);
730
731         mlog_exit(status);
732         return status;
733 }
734
735 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
736 {
737         int num=0;
738         struct dlm_reco_node_data *ndata;
739
740         spin_lock(&dlm->spinlock);
741         memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
742         /* nodes can only be removed (by dying) after dropping
743          * this lock, and death will be trapped later, so this should do */
744         spin_unlock(&dlm->spinlock);
745
746         while (1) {
747                 num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
748                 if (num >= O2NM_MAX_NODES) {
749                         break;
750                 }
751                 BUG_ON(num == dead_node);
752
753                 ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
754                 if (!ndata) {
755                         dlm_destroy_recovery_area(dlm, dead_node);
756                         return -ENOMEM;
757                 }
758                 ndata->node_num = num;
759                 ndata->state = DLM_RECO_NODE_DATA_INIT;
760                 spin_lock(&dlm_reco_state_lock);
761                 list_add_tail(&ndata->list, &dlm->reco.node_data);
762                 spin_unlock(&dlm_reco_state_lock);
763                 num++;
764         }
765
766         return 0;
767 }
768
769 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
770 {
771         struct dlm_reco_node_data *ndata, *next;
772         LIST_HEAD(tmplist);
773
774         spin_lock(&dlm_reco_state_lock);
775         list_splice_init(&dlm->reco.node_data, &tmplist);
776         spin_unlock(&dlm_reco_state_lock);
777
778         list_for_each_entry_safe(ndata, next, &tmplist, list) {
779                 list_del_init(&ndata->list);
780                 kfree(ndata);
781         }
782 }
783
784 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
785                                  u8 dead_node)
786 {
787         struct dlm_lock_request lr;
788         enum dlm_status ret;
789
790         mlog(0, "\n");
791
792
793         mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
794                   "to %u\n", dead_node, request_from);
795
796         memset(&lr, 0, sizeof(lr));
797         lr.node_idx = dlm->node_num;
798         lr.dead_node = dead_node;
799
800         // send message
801         ret = DLM_NOLOCKMGR;
802         ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
803                                  &lr, sizeof(lr), request_from, NULL);
804
805         /* negative status is handled by caller */
806         if (ret < 0)
807                 mlog_errno(ret);
808
809         // return from here, then
810         // sleep until all received or error
811         return ret;
812
813 }
814
815 int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
816                                   void **ret_data)
817 {
818         struct dlm_ctxt *dlm = data;
819         struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
820         char *buf = NULL;
821         struct dlm_work_item *item = NULL;
822
823         if (!dlm_grab(dlm))
824                 return -EINVAL;
825
826         if (lr->dead_node != dlm->reco.dead_node) {
827                 mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
828                      "dead_node is %u\n", dlm->name, lr->node_idx,
829                      lr->dead_node, dlm->reco.dead_node);
830                 dlm_print_reco_node_status(dlm);
831                 /* this is a hack */
832                 dlm_put(dlm);
833                 return -ENOMEM;
834         }
835         BUG_ON(lr->dead_node != dlm->reco.dead_node);
836
837         item = kzalloc(sizeof(*item), GFP_NOFS);
838         if (!item) {
839                 dlm_put(dlm);
840                 return -ENOMEM;
841         }
842
843         /* this will get freed by dlm_request_all_locks_worker */
844         buf = (char *) __get_free_page(GFP_NOFS);
845         if (!buf) {
846                 kfree(item);
847                 dlm_put(dlm);
848                 return -ENOMEM;
849         }
850
851         /* queue up work for dlm_request_all_locks_worker */
852         dlm_grab(dlm);  /* get an extra ref for the work item */
853         dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
854         item->u.ral.reco_master = lr->node_idx;
855         item->u.ral.dead_node = lr->dead_node;
856         spin_lock(&dlm->work_lock);
857         list_add_tail(&item->list, &dlm->work_list);
858         spin_unlock(&dlm->work_lock);
859         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
860
861         dlm_put(dlm);
862         return 0;
863 }
864
865 static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
866 {
867         struct dlm_migratable_lockres *mres;
868         struct dlm_lock_resource *res;
869         struct dlm_ctxt *dlm;
870         LIST_HEAD(resources);
871         int ret;
872         u8 dead_node, reco_master;
873         int skip_all_done = 0;
874
875         dlm = item->dlm;
876         dead_node = item->u.ral.dead_node;
877         reco_master = item->u.ral.reco_master;
878         mres = (struct dlm_migratable_lockres *)data;
879
880         mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
881              dlm->name, dead_node, reco_master);
882
883         if (dead_node != dlm->reco.dead_node ||
884             reco_master != dlm->reco.new_master) {
885                 /* worker could have been created before the recovery master
886                  * died.  if so, do not continue, but do not error. */
887                 if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
888                         mlog(ML_NOTICE, "%s: will not send recovery state, "
889                              "recovery master %u died, thread=(dead=%u,mas=%u)"
890                              " current=(dead=%u,mas=%u)\n", dlm->name,
891                              reco_master, dead_node, reco_master,
892                              dlm->reco.dead_node, dlm->reco.new_master);
893                 } else {
894                         mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
895                              "master=%u), request(dead=%u, master=%u)\n",
896                              dlm->name, dlm->reco.dead_node,
897                              dlm->reco.new_master, dead_node, reco_master);
898                 }
899                 goto leave;
900         }
901
902         /* lock resources should have already been moved to the
903          * dlm->reco.resources list.  now move items from that list
904          * to a temp list if the dead owner matches.  note that the
905          * whole cluster recovers only one node at a time, so we
906          * can safely move UNKNOWN lock resources for each recovery
907          * session. */
908         dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
909
910         /* now we can begin blasting lockreses without the dlm lock */
911
912         /* any errors returned will be due to the new_master dying,
913          * the dlm_reco_thread should detect this */
914         list_for_each_entry(res, &resources, recovering) {
915                 ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
916                                         DLM_MRES_RECOVERY);
917                 if (ret < 0) {
918                         mlog(ML_ERROR, "%s: node %u went down while sending "
919                              "recovery state for dead node %u, ret=%d\n", dlm->name,
920                              reco_master, dead_node, ret);
921                         skip_all_done = 1;
922                         break;
923                 }
924         }
925
926         /* move the resources back to the list */
927         spin_lock(&dlm->spinlock);
928         list_splice_init(&resources, &dlm->reco.resources);
929         spin_unlock(&dlm->spinlock);
930
931         if (!skip_all_done) {
932                 ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
933                 if (ret < 0) {
934                         mlog(ML_ERROR, "%s: node %u went down while sending "
935                              "recovery all-done for dead node %u, ret=%d\n",
936                              dlm->name, reco_master, dead_node, ret);
937                 }
938         }
939 leave:
940         free_page((unsigned long)data);
941 }
942
943
944 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
945 {
946         int ret, tmpret;
947         struct dlm_reco_data_done done_msg;
948
949         memset(&done_msg, 0, sizeof(done_msg));
950         done_msg.node_idx = dlm->node_num;
951         done_msg.dead_node = dead_node;
952         mlog(0, "sending DATA DONE message to %u, "
953              "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
954              done_msg.dead_node);
955
956         ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
957                                  sizeof(done_msg), send_to, &tmpret);
958         if (ret < 0) {
959                 if (!dlm_is_host_down(ret)) {
960                         mlog_errno(ret);
961                         mlog(ML_ERROR, "%s: unknown error sending data-done "
962                              "to %u\n", dlm->name, send_to);
963                         BUG();
964                 }
965         } else
966                 ret = tmpret;
967         return ret;
968 }
969
970
971 int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
972                                void **ret_data)
973 {
974         struct dlm_ctxt *dlm = data;
975         struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
976         struct dlm_reco_node_data *ndata = NULL;
977         int ret = -EINVAL;
978
979         if (!dlm_grab(dlm))
980                 return -EINVAL;
981
982         mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
983              "node_idx=%u, this node=%u\n", done->dead_node,
984              dlm->reco.dead_node, done->node_idx, dlm->node_num);
985
986         mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
987                         "Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
988                         "node_idx=%u, this node=%u\n", done->dead_node,
989                         dlm->reco.dead_node, done->node_idx, dlm->node_num);
990
991         spin_lock(&dlm_reco_state_lock);
992         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
993                 if (ndata->node_num != done->node_idx)
994                         continue;
995
996                 switch (ndata->state) {
997                         /* should have moved beyond INIT but not to FINALIZE yet */
998                         case DLM_RECO_NODE_DATA_INIT:
999                         case DLM_RECO_NODE_DATA_DEAD:
1000                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
1001                                 mlog(ML_ERROR, "bad ndata state for node %u:"
1002                                      " state=%d\n", ndata->node_num,
1003                                      ndata->state);
1004                                 BUG();
1005                                 break;
1006                         /* these states are possible at this point, anywhere along
1007                          * the line of recovery */
1008                         case DLM_RECO_NODE_DATA_DONE:
1009                         case DLM_RECO_NODE_DATA_RECEIVING:
1010                         case DLM_RECO_NODE_DATA_REQUESTED:
1011                         case DLM_RECO_NODE_DATA_REQUESTING:
1012                                 mlog(0, "node %u is DONE sending "
1013                                           "recovery data!\n",
1014                                           ndata->node_num);
1015
1016                                 ndata->state = DLM_RECO_NODE_DATA_DONE;
1017                                 ret = 0;
1018                                 break;
1019                 }
1020         }
1021         spin_unlock(&dlm_reco_state_lock);
1022
1023         /* wake the recovery thread, some node is done */
1024         if (!ret)
1025                 dlm_kick_recovery_thread(dlm);
1026
1027         if (ret < 0)
1028                 mlog(ML_ERROR, "failed to find recovery node data for node "
1029                      "%u\n", done->node_idx);
1030         dlm_put(dlm);
1031
1032         mlog(0, "leaving reco data done handler, ret=%d\n", ret);
1033         return ret;
1034 }
1035
1036 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
1037                                         struct list_head *list,
1038                                         u8 dead_node)
1039 {
1040         struct dlm_lock_resource *res, *next;
1041         struct dlm_lock *lock;
1042
1043         spin_lock(&dlm->spinlock);
1044         list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
1045                 /* always prune any $RECOVERY entries for dead nodes,
1046                  * otherwise hangs can occur during later recovery */
1047                 if (dlm_is_recovery_lock(res->lockname.name,
1048                                          res->lockname.len)) {
1049                         spin_lock(&res->spinlock);
1050                         list_for_each_entry(lock, &res->granted, list) {
1051                                 if (lock->ml.node == dead_node) {
1052                                         mlog(0, "AHA! there was "
1053                                              "a $RECOVERY lock for dead "
1054                                              "node %u (%s)!\n", 
1055                                              dead_node, dlm->name);
1056                                         list_del_init(&lock->list);
1057                                         dlm_lock_put(lock);
1058                                         break;
1059                                 }
1060                         }
1061                         spin_unlock(&res->spinlock);
1062                         continue;
1063                 }
1064
1065                 if (res->owner == dead_node) {
1066                         mlog(0, "found lockres owned by dead node while "
1067                                   "doing recovery for node %u. sending it.\n",
1068                                   dead_node);
1069                         list_move_tail(&res->recovering, list);
1070                 } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
1071                         mlog(0, "found UNKNOWN owner while doing recovery "
1072                                   "for node %u. sending it.\n", dead_node);
1073                         list_move_tail(&res->recovering, list);
1074                 }
1075         }
1076         spin_unlock(&dlm->spinlock);
1077 }
1078
1079 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
1080 {
1081         int total_locks = 0;
1082         struct list_head *iter, *queue = &res->granted;
1083         int i;
1084
1085         for (i=0; i<3; i++) {
1086                 list_for_each(iter, queue)
1087                         total_locks++;
1088                 queue++;
1089         }
1090         return total_locks;
1091 }
1092
1093
1094 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
1095                                       struct dlm_migratable_lockres *mres,
1096                                       u8 send_to,
1097                                       struct dlm_lock_resource *res,
1098                                       int total_locks)
1099 {
1100         u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
1101         int mres_total_locks = be32_to_cpu(mres->total_locks);
1102         int sz, ret = 0, status = 0;
1103         u8 orig_flags = mres->flags,
1104            orig_master = mres->master;
1105
1106         BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
1107         if (!mres->num_locks)
1108                 return 0;
1109
1110         sz = sizeof(struct dlm_migratable_lockres) +
1111                 (mres->num_locks * sizeof(struct dlm_migratable_lock));
1112
1113         /* add an all-done flag if we reached the last lock */
1114         orig_flags = mres->flags;
1115         BUG_ON(total_locks > mres_total_locks);
1116         if (total_locks == mres_total_locks)
1117                 mres->flags |= DLM_MRES_ALL_DONE;
1118
1119         mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
1120              dlm->name, res->lockname.len, res->lockname.name,
1121              orig_flags & DLM_MRES_MIGRATION ? "migrate" : "recovery",
1122              send_to);
1123
1124         /* send it */
1125         ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
1126                                  sz, send_to, &status);
1127         if (ret < 0) {
1128                 /* XXX: negative status is not handled.
1129                  * this will end up killing this node. */
1130                 mlog_errno(ret);
1131         } else {
1132                 /* might get an -ENOMEM back here */
1133                 ret = status;
1134                 if (ret < 0) {
1135                         mlog_errno(ret);
1136
1137                         if (ret == -EFAULT) {
1138                                 mlog(ML_ERROR, "node %u told me to kill "
1139                                      "myself!\n", send_to);
1140                                 BUG();
1141                         }
1142                 }
1143         }
1144
1145         /* zero and reinit the message buffer */
1146         dlm_init_migratable_lockres(mres, res->lockname.name,
1147                                     res->lockname.len, mres_total_locks,
1148                                     mig_cookie, orig_flags, orig_master);
1149         return ret;
1150 }
1151
1152 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1153                                         const char *lockname, int namelen,
1154                                         int total_locks, u64 cookie,
1155                                         u8 flags, u8 master)
1156 {
1157         /* mres here is one full page */
1158         clear_page(mres);
1159         mres->lockname_len = namelen;
1160         memcpy(mres->lockname, lockname, namelen);
1161         mres->num_locks = 0;
1162         mres->total_locks = cpu_to_be32(total_locks);
1163         mres->mig_cookie = cpu_to_be64(cookie);
1164         mres->flags = flags;
1165         mres->master = master;
1166 }
1167
1168
1169 /* returns 1 if this lock fills the network structure,
1170  * 0 otherwise */
1171 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1172                                  struct dlm_migratable_lockres *mres, int queue)
1173 {
1174         struct dlm_migratable_lock *ml;
1175         int lock_num = mres->num_locks;
1176
1177         ml = &(mres->ml[lock_num]);
1178         ml->cookie = lock->ml.cookie;
1179         ml->type = lock->ml.type;
1180         ml->convert_type = lock->ml.convert_type;
1181         ml->highest_blocked = lock->ml.highest_blocked;
1182         ml->list = queue;
1183         if (lock->lksb) {
1184                 ml->flags = lock->lksb->flags;
1185                 /* send our current lvb */
1186                 if (ml->type == LKM_EXMODE ||
1187                     ml->type == LKM_PRMODE) {
1188                         /* if it is already set, this had better be a PR
1189                          * and it has to match */
1190                         if (!dlm_lvb_is_empty(mres->lvb) &&
1191                             (ml->type == LKM_EXMODE ||
1192                              memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))) {
1193                                 mlog(ML_ERROR, "mismatched lvbs!\n");
1194                                 __dlm_print_one_lock_resource(lock->lockres);
1195                                 BUG();
1196                         }
1197                         memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1198                 }
1199         }
1200         ml->node = lock->ml.node;
1201         mres->num_locks++;
1202         /* we reached the max, send this network message */
1203         if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1204                 return 1;
1205         return 0;
1206 }
1207
1208 static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
1209                                struct dlm_migratable_lockres *mres)
1210 {
1211         struct dlm_lock dummy;
1212         memset(&dummy, 0, sizeof(dummy));
1213         dummy.ml.cookie = 0;
1214         dummy.ml.type = LKM_IVMODE;
1215         dummy.ml.convert_type = LKM_IVMODE;
1216         dummy.ml.highest_blocked = LKM_IVMODE;
1217         dummy.lksb = NULL;
1218         dummy.ml.node = dlm->node_num;
1219         dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
1220 }
1221
1222 static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
1223                                     struct dlm_migratable_lock *ml,
1224                                     u8 *nodenum)
1225 {
1226         if (unlikely(ml->cookie == 0 &&
1227             ml->type == LKM_IVMODE &&
1228             ml->convert_type == LKM_IVMODE &&
1229             ml->highest_blocked == LKM_IVMODE &&
1230             ml->list == DLM_BLOCKED_LIST)) {
1231                 *nodenum = ml->node;
1232                 return 1;
1233         }
1234         return 0;
1235 }
1236
1237 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1238                          struct dlm_migratable_lockres *mres,
1239                          u8 send_to, u8 flags)
1240 {
1241         struct list_head *queue;
1242         int total_locks, i;
1243         u64 mig_cookie = 0;
1244         struct dlm_lock *lock;
1245         int ret = 0;
1246
1247         BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1248
1249         mlog(0, "sending to %u\n", send_to);
1250
1251         total_locks = dlm_num_locks_in_lockres(res);
1252         if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1253                 /* rare, but possible */
1254                 mlog(0, "argh.  lockres has %d locks.  this will "
1255                           "require more than one network packet to "
1256                           "migrate\n", total_locks);
1257                 mig_cookie = dlm_get_next_mig_cookie();
1258         }
1259
1260         dlm_init_migratable_lockres(mres, res->lockname.name,
1261                                     res->lockname.len, total_locks,
1262                                     mig_cookie, flags, res->owner);
1263
1264         total_locks = 0;
1265         for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1266                 queue = dlm_list_idx_to_ptr(res, i);
1267                 list_for_each_entry(lock, queue, list) {
1268                         /* add another lock. */
1269                         total_locks++;
1270                         if (!dlm_add_lock_to_array(lock, mres, i))
1271                                 continue;
1272
1273                         /* this filled the lock message,
1274                          * we must send it immediately. */
1275                         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1276                                                        res, total_locks);
1277                         if (ret < 0)
1278                                 goto error;
1279                 }
1280         }
1281         if (total_locks == 0) {
1282                 /* send a dummy lock to indicate a mastery reference only */
1283                 mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
1284                      dlm->name, res->lockname.len, res->lockname.name,
1285                      send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
1286                      "migration");
1287                 dlm_add_dummy_lock(dlm, mres);
1288         }
1289         /* flush any remaining locks */
1290         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1291         if (ret < 0)
1292                 goto error;
1293         return ret;
1294
1295 error:
1296         mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1297              dlm->name, ret);
1298         if (!dlm_is_host_down(ret))
1299                 BUG();
1300         mlog(0, "%s: node %u went down while sending %s "
1301              "lockres %.*s\n", dlm->name, send_to,
1302              flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1303              res->lockname.len, res->lockname.name);
1304         return ret;
1305 }
1306
1307
1308
1309 /*
1310  * this message will contain no more than one page worth of
1311  * recovery data, and it will work on only one lockres.
1312  * there may be many locks in this page, and we may need to wait
1313  * for additional packets to complete all the locks (rare, but
1314  * possible).
1315  */
1316 /*
1317  * NOTE: the allocation error cases here are scary
1318  * we really cannot afford to fail an alloc in recovery
1319  * do we spin?  returning an error only delays the problem really
1320  */
1321
1322 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
1323                             void **ret_data)
1324 {
1325         struct dlm_ctxt *dlm = data;
1326         struct dlm_migratable_lockres *mres =
1327                 (struct dlm_migratable_lockres *)msg->buf;
1328         int ret = 0;
1329         u8 real_master;
1330         char *buf = NULL;
1331         struct dlm_work_item *item = NULL;
1332         struct dlm_lock_resource *res = NULL;
1333
1334         if (!dlm_grab(dlm))
1335                 return -EINVAL;
1336
1337         BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1338
1339         real_master = mres->master;
1340         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1341                 /* cannot migrate a lockres with no master */
1342                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1343         }
1344
1345         mlog(0, "%s message received from node %u\n",
1346                   (mres->flags & DLM_MRES_RECOVERY) ?
1347                   "recovery" : "migration", mres->master);
1348         if (mres->flags & DLM_MRES_ALL_DONE)
1349                 mlog(0, "all done flag.  all lockres data received!\n");
1350
1351         ret = -ENOMEM;
1352         buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1353         item = kzalloc(sizeof(*item), GFP_NOFS);
1354         if (!buf || !item)
1355                 goto leave;
1356
1357         /* lookup the lock to see if we have a secondary queue for this
1358          * already...  just add the locks in and this will have its owner
1359          * and RECOVERY flag changed when it completes. */
1360         res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1361         if (res) {
1362                 /* this will get a ref on res */
1363                 /* mark it as recovering/migrating and hash it */
1364                 spin_lock(&res->spinlock);
1365                 if (mres->flags & DLM_MRES_RECOVERY) {
1366                         res->state |= DLM_LOCK_RES_RECOVERING;
1367                 } else {
1368                         if (res->state & DLM_LOCK_RES_MIGRATING) {
1369                                 /* this is at least the second
1370                                  * lockres message */
1371                                 mlog(0, "lock %.*s is already migrating\n",
1372                                           mres->lockname_len,
1373                                           mres->lockname);
1374                         } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1375                                 /* caller should BUG */
1376                                 mlog(ML_ERROR, "node is attempting to migrate "
1377                                      "lock %.*s, but marked as recovering!\n",
1378                                      mres->lockname_len, mres->lockname);
1379                                 ret = -EFAULT;
1380                                 spin_unlock(&res->spinlock);
1381                                 goto leave;
1382                         }
1383                         res->state |= DLM_LOCK_RES_MIGRATING;
1384                 }
1385                 spin_unlock(&res->spinlock);
1386         } else {
1387                 /* need to allocate, just like if it was
1388                  * mastered here normally  */
1389                 res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1390                 if (!res)
1391                         goto leave;
1392
1393                 /* to match the ref that we would have gotten if
1394                  * dlm_lookup_lockres had succeeded */
1395                 dlm_lockres_get(res);
1396
1397                 /* mark it as recovering/migrating and hash it */
1398                 if (mres->flags & DLM_MRES_RECOVERY)
1399                         res->state |= DLM_LOCK_RES_RECOVERING;
1400                 else
1401                         res->state |= DLM_LOCK_RES_MIGRATING;
1402
1403                 spin_lock(&dlm->spinlock);
1404                 __dlm_insert_lockres(dlm, res);
1405                 spin_unlock(&dlm->spinlock);
1406
1407                 /* now that the new lockres is inserted,
1408                  * make it usable by other processes */
1409                 spin_lock(&res->spinlock);
1410                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1411                 spin_unlock(&res->spinlock);
1412                 wake_up(&res->wq);
1413
1414                 /* add an extra ref for just-allocated lockres 
1415                  * otherwise the lockres will be purged immediately */
1416                 dlm_lockres_get(res);
1417         }
1418
1419         /* at this point we have allocated everything we need,
1420          * and we have a hashed lockres with an extra ref and
1421          * the proper res->state flags. */
1422         ret = 0;
1423         spin_lock(&res->spinlock);
1424         /* drop this either when master requery finds a different master
1425          * or when a lock is added by the recovery worker */
1426         dlm_lockres_grab_inflight_ref(dlm, res);
1427         if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1428                 /* migration cannot have an unknown master */
1429                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1430                 mlog(0, "recovery has passed me a lockres with an "
1431                           "unknown owner.. will need to requery: "
1432                           "%.*s\n", mres->lockname_len, mres->lockname);
1433         } else {
1434                 /* take a reference now to pin the lockres, drop it
1435                  * when locks are added in the worker */
1436                 dlm_change_lockres_owner(dlm, res, dlm->node_num);
1437         }
1438         spin_unlock(&res->spinlock);
1439
1440         /* queue up work for dlm_mig_lockres_worker */
1441         dlm_grab(dlm);  /* get an extra ref for the work item */
1442         memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1443         dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1444         item->u.ml.lockres = res; /* already have a ref */
1445         item->u.ml.real_master = real_master;
1446         spin_lock(&dlm->work_lock);
1447         list_add_tail(&item->list, &dlm->work_list);
1448         spin_unlock(&dlm->work_lock);
1449         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1450
1451 leave:
1452         dlm_put(dlm);
1453         if (ret < 0) {
1454                 if (buf)
1455                         kfree(buf);
1456                 if (item)
1457                         kfree(item);
1458         }
1459
1460         mlog_exit(ret);
1461         return ret;
1462 }
1463
1464
1465 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1466 {
1467         struct dlm_ctxt *dlm = data;
1468         struct dlm_migratable_lockres *mres;
1469         int ret = 0;
1470         struct dlm_lock_resource *res;
1471         u8 real_master;
1472
1473         dlm = item->dlm;
1474         mres = (struct dlm_migratable_lockres *)data;
1475
1476         res = item->u.ml.lockres;
1477         real_master = item->u.ml.real_master;
1478
1479         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1480                 /* this case is super-rare. only occurs if
1481                  * node death happens during migration. */
1482 again:
1483                 ret = dlm_lockres_master_requery(dlm, res, &real_master);
1484                 if (ret < 0) {
1485                         mlog(0, "dlm_lockres_master_requery ret=%d\n",
1486                                   ret);
1487                         goto again;
1488                 }
1489                 if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1490                         mlog(0, "lockres %.*s not claimed.  "
1491                                    "this node will take it.\n",
1492                                    res->lockname.len, res->lockname.name);
1493                 } else {
1494                         spin_lock(&res->spinlock);
1495                         dlm_lockres_drop_inflight_ref(dlm, res);
1496                         spin_unlock(&res->spinlock);
1497                         mlog(0, "master needs to respond to sender "
1498                                   "that node %u still owns %.*s\n",
1499                                   real_master, res->lockname.len,
1500                                   res->lockname.name);
1501                         /* cannot touch this lockres */
1502                         goto leave;
1503                 }
1504         }
1505
1506         ret = dlm_process_recovery_data(dlm, res, mres);
1507         if (ret < 0)
1508                 mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1509         else
1510                 mlog(0, "dlm_process_recovery_data succeeded\n");
1511
1512         if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1513                            (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1514                 ret = dlm_finish_migration(dlm, res, mres->master);
1515                 if (ret < 0)
1516                         mlog_errno(ret);
1517         }
1518
1519 leave:
1520         kfree(data);
1521         mlog_exit(ret);
1522 }
1523
1524
1525
1526 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1527                                       struct dlm_lock_resource *res,
1528                                       u8 *real_master)
1529 {
1530         struct dlm_node_iter iter;
1531         int nodenum;
1532         int ret = 0;
1533
1534         *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1535
1536         /* we only reach here if one of the two nodes in a
1537          * migration died while the migration was in progress.
1538          * at this point we need to requery the master.  we
1539          * know that the new_master got as far as creating
1540          * an mle on at least one node, but we do not know
1541          * if any nodes had actually cleared the mle and set
1542          * the master to the new_master.  the old master
1543          * is supposed to set the owner to UNKNOWN in the
1544          * event of a new_master death, so the only possible
1545          * responses that we can get from nodes here are
1546          * that the master is new_master, or that the master
1547          * is UNKNOWN.
1548          * if all nodes come back with UNKNOWN then we know
1549          * the lock needs remastering here.
1550          * if any node comes back with a valid master, check
1551          * to see if that master is the one that we are
1552          * recovering.  if so, then the new_master died and
1553          * we need to remaster this lock.  if not, then the
1554          * new_master survived and that node will respond to
1555          * other nodes about the owner.
1556          * if there is an owner, this node needs to dump this
1557          * lockres and alert the sender that this lockres
1558          * was rejected. */
1559         spin_lock(&dlm->spinlock);
1560         dlm_node_iter_init(dlm->domain_map, &iter);
1561         spin_unlock(&dlm->spinlock);
1562
1563         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1564                 /* do not send to self */
1565                 if (nodenum == dlm->node_num)
1566                         continue;
1567                 ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1568                 if (ret < 0) {
1569                         mlog_errno(ret);
1570                         if (!dlm_is_host_down(ret))
1571                                 BUG();
1572                         /* host is down, so answer for that node would be
1573                          * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1574                 }
1575                 if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1576                         mlog(0, "lock master is %u\n", *real_master);
1577                         break;
1578                 }
1579         }
1580         return ret;
1581 }
1582
1583
1584 int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1585                           u8 nodenum, u8 *real_master)
1586 {
1587         int ret = -EINVAL;
1588         struct dlm_master_requery req;
1589         int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1590
1591         memset(&req, 0, sizeof(req));
1592         req.node_idx = dlm->node_num;
1593         req.namelen = res->lockname.len;
1594         memcpy(req.name, res->lockname.name, res->lockname.len);
1595
1596         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1597                                  &req, sizeof(req), nodenum, &status);
1598         /* XXX: negative status not handled properly here. */
1599         if (ret < 0)
1600                 mlog_errno(ret);
1601         else {
1602                 BUG_ON(status < 0);
1603                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1604                 *real_master = (u8) (status & 0xff);
1605                 mlog(0, "node %u responded to master requery with %u\n",
1606                           nodenum, *real_master);
1607                 ret = 0;
1608         }
1609         return ret;
1610 }
1611
1612
1613 /* this function cannot error, so unless the sending
1614  * or receiving of the message failed, the owner can
1615  * be trusted */
1616 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
1617                                void **ret_data)
1618 {
1619         struct dlm_ctxt *dlm = data;
1620         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1621         struct dlm_lock_resource *res = NULL;
1622         unsigned int hash;
1623         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1624         u32 flags = DLM_ASSERT_MASTER_REQUERY;
1625
1626         if (!dlm_grab(dlm)) {
1627                 /* since the domain has gone away on this
1628                  * node, the proper response is UNKNOWN */
1629                 return master;
1630         }
1631
1632         hash = dlm_lockid_hash(req->name, req->namelen);
1633
1634         spin_lock(&dlm->spinlock);
1635         res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1636         if (res) {
1637                 spin_lock(&res->spinlock);
1638                 master = res->owner;
1639                 if (master == dlm->node_num) {
1640                         int ret = dlm_dispatch_assert_master(dlm, res,
1641                                                              0, 0, flags);
1642                         if (ret < 0) {
1643                                 mlog_errno(-ENOMEM);
1644                                 /* retry!? */
1645                                 BUG();
1646                         }
1647                 }
1648                 spin_unlock(&res->spinlock);
1649         }
1650         spin_unlock(&dlm->spinlock);
1651
1652         dlm_put(dlm);
1653         return master;
1654 }
1655
1656 static inline struct list_head *
1657 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1658 {
1659         struct list_head *ret;
1660         BUG_ON(list_num < 0);
1661         BUG_ON(list_num > 2);
1662         ret = &(res->granted);
1663         ret += list_num;
1664         return ret;
1665 }
1666 /* TODO: do ast flush business
1667  * TODO: do MIGRATING and RECOVERING spinning
1668  */
1669
1670 /*
1671 * NOTE about in-flight requests during migration:
1672 *
1673 * Before attempting the migrate, the master has marked the lockres as
1674 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1675 * requests either got queued before the MIGRATING flag got set, in which
1676 * case the lock data will reflect the change and a return message is on
1677 * the way, or the request failed to get in before MIGRATING got set.  In
1678 * this case, the caller will be told to spin and wait for the MIGRATING
1679 * flag to be dropped, then recheck the master.
1680 * This holds true for the convert, cancel and unlock cases, and since lvb
1681 * updates are tied to these same messages, it applies to lvb updates as
1682 * well.  For the lock case, there is no way a lock can be on the master
1683 * queue and not be on the secondary queue since the lock is always added
1684 * locally first.  This means that the new target node will never be sent
1685 * a lock that he doesn't already have on the list.
1686 * In total, this means that the local lock is correct and should not be
1687 * updated to match the one sent by the master.  Any messages sent back
1688 * from the master before the MIGRATING flag will bring the lock properly
1689 * up-to-date, and the change will be ordered properly for the waiter.
1690 * We will *not* attempt to modify the lock underneath the waiter.
1691 */
1692
1693 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1694                                      struct dlm_lock_resource *res,
1695                                      struct dlm_migratable_lockres *mres)
1696 {
1697         struct dlm_migratable_lock *ml;
1698         struct list_head *queue;
1699         struct list_head *tmpq = NULL;
1700         struct dlm_lock *newlock = NULL;
1701         struct dlm_lockstatus *lksb = NULL;
1702         int ret = 0;
1703         int i, j, bad;
1704         struct dlm_lock *lock = NULL;
1705         u8 from = O2NM_MAX_NODES;
1706         unsigned int added = 0;
1707
1708         mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1709         for (i=0; i<mres->num_locks; i++) {
1710                 ml = &(mres->ml[i]);
1711
1712                 if (dlm_is_dummy_lock(dlm, ml, &from)) {
1713                         /* placeholder, just need to set the refmap bit */
1714                         BUG_ON(mres->num_locks != 1);
1715                         mlog(0, "%s:%.*s: dummy lock for %u\n",
1716                              dlm->name, mres->lockname_len, mres->lockname,
1717                              from);
1718                         spin_lock(&res->spinlock);
1719                         dlm_lockres_set_refmap_bit(from, res);
1720                         spin_unlock(&res->spinlock);
1721                         added++;
1722                         break;
1723                 }
1724                 BUG_ON(ml->highest_blocked != LKM_IVMODE);
1725                 newlock = NULL;
1726                 lksb = NULL;
1727
1728                 queue = dlm_list_num_to_pointer(res, ml->list);
1729                 tmpq = NULL;
1730
1731                 /* if the lock is for the local node it needs to
1732                  * be moved to the proper location within the queue.
1733                  * do not allocate a new lock structure. */
1734                 if (ml->node == dlm->node_num) {
1735                         /* MIGRATION ONLY! */
1736                         BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1737
1738                         spin_lock(&res->spinlock);
1739                         for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
1740                                 tmpq = dlm_list_idx_to_ptr(res, j);
1741                                 list_for_each_entry(lock, tmpq, list) {
1742                                         if (lock->ml.cookie != ml->cookie)
1743                                                 lock = NULL;
1744                                         else
1745                                                 break;
1746                                 }
1747                                 if (lock)
1748                                         break;
1749                         }
1750
1751                         /* lock is always created locally first, and
1752                          * destroyed locally last.  it must be on the list */
1753                         if (!lock) {
1754                                 __be64 c = ml->cookie;
1755                                 mlog(ML_ERROR, "could not find local lock "
1756                                                "with cookie %u:%llu!\n",
1757                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1758                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1759                                 __dlm_print_one_lock_resource(res);
1760                                 BUG();
1761                         }
1762                         BUG_ON(lock->ml.node != ml->node);
1763
1764                         if (tmpq != queue) {
1765                                 mlog(0, "lock was on %u instead of %u for %.*s\n",
1766                                      j, ml->list, res->lockname.len, res->lockname.name);
1767                                 spin_unlock(&res->spinlock);
1768                                 continue;
1769                         }
1770
1771                         /* see NOTE above about why we do not update
1772                          * to match the master here */
1773
1774                         /* move the lock to its proper place */
1775                         /* do not alter lock refcount.  switching lists. */
1776                         list_move_tail(&lock->list, queue);
1777                         spin_unlock(&res->spinlock);
1778                         added++;
1779
1780                         mlog(0, "just reordered a local lock!\n");
1781                         continue;
1782                 }
1783
1784                 /* lock is for another node. */
1785                 newlock = dlm_new_lock(ml->type, ml->node,
1786                                        be64_to_cpu(ml->cookie), NULL);
1787                 if (!newlock) {
1788                         ret = -ENOMEM;
1789                         goto leave;
1790                 }
1791                 lksb = newlock->lksb;
1792                 dlm_lock_attach_lockres(newlock, res);
1793
1794                 if (ml->convert_type != LKM_IVMODE) {
1795                         BUG_ON(queue != &res->converting);
1796                         newlock->ml.convert_type = ml->convert_type;
1797                 }
1798                 lksb->flags |= (ml->flags &
1799                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1800
1801                 if (ml->type == LKM_NLMODE)
1802                         goto skip_lvb;
1803
1804                 if (!dlm_lvb_is_empty(mres->lvb)) {
1805                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
1806                                 /* other node was trying to update
1807                                  * lvb when node died.  recreate the
1808                                  * lksb with the updated lvb. */
1809                                 memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1810                                 /* the lock resource lvb update must happen
1811                                  * NOW, before the spinlock is dropped.
1812                                  * we no longer wait for the AST to update
1813                                  * the lvb. */
1814                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1815                         } else {
1816                                 /* otherwise, the node is sending its 
1817                                  * most recent valid lvb info */
1818                                 BUG_ON(ml->type != LKM_EXMODE &&
1819                                        ml->type != LKM_PRMODE);
1820                                 if (!dlm_lvb_is_empty(res->lvb) &&
1821                                     (ml->type == LKM_EXMODE ||
1822                                      memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1823                                         int i;
1824                                         mlog(ML_ERROR, "%s:%.*s: received bad "
1825                                              "lvb! type=%d\n", dlm->name,
1826                                              res->lockname.len,
1827                                              res->lockname.name, ml->type);
1828                                         printk("lockres lvb=[");
1829                                         for (i=0; i<DLM_LVB_LEN; i++)
1830                                                 printk("%02x", res->lvb[i]);
1831                                         printk("]\nmigrated lvb=[");
1832                                         for (i=0; i<DLM_LVB_LEN; i++)
1833                                                 printk("%02x", mres->lvb[i]);
1834                                         printk("]\n");
1835                                         dlm_print_one_lock_resource(res);
1836                                         BUG();
1837                                 }
1838                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1839                         }
1840                 }
1841 skip_lvb:
1842
1843                 /* NOTE:
1844                  * wrt lock queue ordering and recovery:
1845                  *    1. order of locks on granted queue is
1846                  *       meaningless.
1847                  *    2. order of locks on converting queue is
1848                  *       LOST with the node death.  sorry charlie.
1849                  *    3. order of locks on the blocked queue is
1850                  *       also LOST.
1851                  * order of locks does not affect integrity, it
1852                  * just means that a lock request may get pushed
1853                  * back in line as a result of the node death.
1854                  * also note that for a given node the lock order
1855                  * for its secondary queue locks is preserved
1856                  * relative to each other, but clearly *not*
1857                  * preserved relative to locks from other nodes.
1858                  */
1859                 bad = 0;
1860                 spin_lock(&res->spinlock);
1861                 list_for_each_entry(lock, queue, list) {
1862                         if (lock->ml.cookie == ml->cookie) {
1863                                 __be64 c = lock->ml.cookie;
1864                                 mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
1865                                      "exists on this lockres!\n", dlm->name,
1866                                      res->lockname.len, res->lockname.name,
1867                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1868                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1869
1870                                 mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
1871                                      "node=%u, cookie=%u:%llu, queue=%d\n",
1872                                      ml->type, ml->convert_type, ml->node,
1873                                      dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
1874                                      dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
1875                                      ml->list);
1876
1877                                 __dlm_print_one_lock_resource(res);
1878                                 bad = 1;
1879                                 break;
1880                         }
1881                 }
1882                 if (!bad) {
1883                         dlm_lock_get(newlock);
1884                         list_add_tail(&newlock->list, queue);
1885                         mlog(0, "%s:%.*s: added lock for node %u, "
1886                              "setting refmap bit\n", dlm->name,
1887                              res->lockname.len, res->lockname.name, ml->node);
1888                         dlm_lockres_set_refmap_bit(ml->node, res);
1889                         added++;
1890                 }
1891                 spin_unlock(&res->spinlock);
1892         }
1893         mlog(0, "done running all the locks\n");
1894
1895 leave:
1896         /* balance the ref taken when the work was queued */
1897         spin_lock(&res->spinlock);
1898         dlm_lockres_drop_inflight_ref(dlm, res);
1899         spin_unlock(&res->spinlock);
1900
1901         if (ret < 0) {
1902                 mlog_errno(ret);
1903                 if (newlock)
1904                         dlm_lock_put(newlock);
1905         }
1906
1907         mlog_exit(ret);
1908         return ret;
1909 }
1910
1911 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
1912                                        struct dlm_lock_resource *res)
1913 {
1914         int i;
1915         struct list_head *queue;
1916         struct dlm_lock *lock, *next;
1917
1918         res->state |= DLM_LOCK_RES_RECOVERING;
1919         if (!list_empty(&res->recovering)) {
1920                 mlog(0,
1921                      "Recovering res %s:%.*s, is already on recovery list!\n",
1922                      dlm->name, res->lockname.len, res->lockname.name);
1923                 list_del_init(&res->recovering);
1924         }
1925         /* We need to hold a reference while on the recovery list */
1926         dlm_lockres_get(res);
1927         list_add_tail(&res->recovering, &dlm->reco.resources);
1928
1929         /* find any pending locks and put them back on proper list */
1930         for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
1931                 queue = dlm_list_idx_to_ptr(res, i);
1932                 list_for_each_entry_safe(lock, next, queue, list) {
1933                         dlm_lock_get(lock);
1934                         if (lock->convert_pending) {
1935                                 /* move converting lock back to granted */
1936                                 BUG_ON(i != DLM_CONVERTING_LIST);
1937                                 mlog(0, "node died with convert pending "
1938                                      "on %.*s. move back to granted list.\n",
1939                                      res->lockname.len, res->lockname.name);
1940                                 dlm_revert_pending_convert(res, lock);
1941                                 lock->convert_pending = 0;
1942                         } else if (lock->lock_pending) {
1943                                 /* remove pending lock requests completely */
1944                                 BUG_ON(i != DLM_BLOCKED_LIST);
1945                                 mlog(0, "node died with lock pending "
1946                                      "on %.*s. remove from blocked list and skip.\n",
1947                                      res->lockname.len, res->lockname.name);
1948                                 /* lock will be floating until ref in
1949                                  * dlmlock_remote is freed after the network
1950                                  * call returns.  ok for it to not be on any
1951                                  * list since no ast can be called
1952                                  * (the master is dead). */
1953                                 dlm_revert_pending_lock(res, lock);
1954                                 lock->lock_pending = 0;
1955                         } else if (lock->unlock_pending) {
1956                                 /* if an unlock was in progress, treat as
1957                                  * if this had completed successfully
1958                                  * before sending this lock state to the
1959                                  * new master.  note that the dlm_unlock
1960                                  * call is still responsible for calling
1961                                  * the unlockast.  that will happen after
1962                                  * the network call times out.  for now,
1963                                  * just move lists to prepare the new
1964                                  * recovery master.  */
1965                                 BUG_ON(i != DLM_GRANTED_LIST);
1966                                 mlog(0, "node died with unlock pending "
1967                                      "on %.*s. remove from blocked list and skip.\n",
1968                                      res->lockname.len, res->lockname.name);
1969                                 dlm_commit_pending_unlock(res, lock);
1970                                 lock->unlock_pending = 0;
1971                         } else if (lock->cancel_pending) {
1972                                 /* if a cancel was in progress, treat as
1973                                  * if this had completed successfully
1974                                  * before sending this lock state to the
1975                                  * new master */
1976                                 BUG_ON(i != DLM_CONVERTING_LIST);
1977                                 mlog(0, "node died with cancel pending "
1978                                      "on %.*s. move back to granted list.\n",
1979                                      res->lockname.len, res->lockname.name);
1980                                 dlm_commit_pending_cancel(res, lock);
1981                                 lock->cancel_pending = 0;
1982                         }
1983                         dlm_lock_put(lock);
1984                 }
1985         }
1986 }
1987
1988
1989
1990 /* removes all recovered locks from the recovery list.
1991  * sets the res->owner to the new master.
1992  * unsets the RECOVERY flag and wakes waiters. */
1993 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
1994                                               u8 dead_node, u8 new_master)
1995 {
1996         int i;
1997         struct hlist_node *hash_iter;
1998         struct hlist_head *bucket;
1999         struct dlm_lock_resource *res, *next;
2000
2001         mlog_entry_void();
2002
2003         assert_spin_locked(&dlm->spinlock);
2004
2005         list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
2006                 if (res->owner == dead_node) {
2007                         list_del_init(&res->recovering);
2008                         spin_lock(&res->spinlock);
2009                         /* new_master has our reference from
2010                          * the lock state sent during recovery */
2011                         dlm_change_lockres_owner(dlm, res, new_master);
2012                         res->state &= ~DLM_LOCK_RES_RECOVERING;
2013                         if (__dlm_lockres_has_locks(res))
2014                                 __dlm_dirty_lockres(dlm, res);
2015                         spin_unlock(&res->spinlock);
2016                         wake_up(&res->wq);
2017                         dlm_lockres_put(res);
2018                 }
2019         }
2020
2021         /* this will become unnecessary eventually, but
2022          * for now we need to run the whole hash, clear
2023          * the RECOVERING state and set the owner
2024          * if necessary */
2025         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2026                 bucket = dlm_lockres_hash(dlm, i);
2027                 hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
2028                         if (res->state & DLM_LOCK_RES_RECOVERING) {
2029                                 if (res->owner == dead_node) {
2030                                         mlog(0, "(this=%u) res %.*s owner=%u "
2031                                              "was not on recovering list, but "
2032                                              "clearing state anyway\n",
2033                                              dlm->node_num, res->lockname.len,
2034                                              res->lockname.name, new_master);
2035                                 } else if (res->owner == dlm->node_num) {
2036                                         mlog(0, "(this=%u) res %.*s owner=%u "
2037                                              "was not on recovering list, "
2038                                              "owner is THIS node, clearing\n",
2039                                              dlm->node_num, res->lockname.len,
2040                                              res->lockname.name, new_master);
2041                                 } else
2042                                         continue;
2043
2044                                 if (!list_empty(&res->recovering)) {
2045                                         mlog(0, "%s:%.*s: lockres was "
2046                                              "marked RECOVERING, owner=%u\n",
2047                                              dlm->name, res->lockname.len,
2048                                              res->lockname.name, res->owner);
2049                                         list_del_init(&res->recovering);
2050                                         dlm_lockres_put(res);
2051                                 }
2052                                 spin_lock(&res->spinlock);
2053                                 /* new_master has our reference from
2054                                  * the lock state sent during recovery */
2055                                 dlm_change_lockres_owner(dlm, res, new_master);
2056                                 res->state &= ~DLM_LOCK_RES_RECOVERING;
2057                                 if (__dlm_lockres_has_locks(res))
2058                                         __dlm_dirty_lockres(dlm, res);
2059                                 spin_unlock(&res->spinlock);
2060                                 wake_up(&res->wq);
2061                         }
2062                 }
2063         }
2064 }
2065
2066 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
2067 {
2068         if (local) {
2069                 if (lock->ml.type != LKM_EXMODE &&
2070                     lock->ml.type != LKM_PRMODE)
2071                         return 1;
2072         } else if (lock->ml.type == LKM_EXMODE)
2073                 return 1;
2074         return 0;
2075 }
2076
2077 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2078                                struct dlm_lock_resource *res, u8 dead_node)
2079 {
2080         struct list_head *queue;
2081         struct dlm_lock *lock;
2082         int blank_lvb = 0, local = 0;
2083         int i;
2084         u8 search_node;
2085
2086         assert_spin_locked(&dlm->spinlock);
2087         assert_spin_locked(&res->spinlock);
2088
2089         if (res->owner == dlm->node_num)
2090                 /* if this node owned the lockres, and if the dead node 
2091                  * had an EX when he died, blank out the lvb */
2092                 search_node = dead_node;
2093         else {
2094                 /* if this is a secondary lockres, and we had no EX or PR
2095                  * locks granted, we can no longer trust the lvb */
2096                 search_node = dlm->node_num;
2097                 local = 1;  /* check local state for valid lvb */
2098         }
2099
2100         for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2101                 queue = dlm_list_idx_to_ptr(res, i);
2102                 list_for_each_entry(lock, queue, list) {
2103                         if (lock->ml.node == search_node) {
2104                                 if (dlm_lvb_needs_invalidation(lock, local)) {
2105                                         /* zero the lksb lvb and lockres lvb */
2106                                         blank_lvb = 1;
2107                                         memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2108                                 }
2109                         }
2110                 }
2111         }
2112
2113         if (blank_lvb) {
2114                 mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2115                      res->lockname.len, res->lockname.name, dead_node);
2116                 memset(res->lvb, 0, DLM_LVB_LEN);
2117         }
2118 }
2119
2120 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2121                                 struct dlm_lock_resource *res, u8 dead_node)
2122 {
2123         struct dlm_lock *lock, *next;
2124         unsigned int freed = 0;
2125
2126         /* this node is the lockres master:
2127          * 1) remove any stale locks for the dead node
2128          * 2) if the dead node had an EX when he died, blank out the lvb 
2129          */
2130         assert_spin_locked(&dlm->spinlock);
2131         assert_spin_locked(&res->spinlock);
2132
2133         /* TODO: check pending_asts, pending_basts here */
2134         list_for_each_entry_safe(lock, next, &res->granted, list) {
2135                 if (lock->ml.node == dead_node) {
2136                         list_del_init(&lock->list);
2137                         dlm_lock_put(lock);
2138                         freed++;
2139                 }
2140         }
2141         list_for_each_entry_safe(lock, next, &res->converting, list) {
2142                 if (lock->ml.node == dead_node) {
2143                         list_del_init(&lock->list);
2144                         dlm_lock_put(lock);
2145                         freed++;
2146                 }
2147         }
2148         list_for_each_entry_safe(lock, next, &res->blocked, list) {
2149                 if (lock->ml.node == dead_node) {
2150                         list_del_init(&lock->list);
2151                         dlm_lock_put(lock);
2152                         freed++;
2153                 }
2154         }
2155
2156         if (freed) {
2157                 mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
2158                      "dropping ref from lockres\n", dlm->name,
2159                      res->lockname.len, res->lockname.name, freed, dead_node);
2160                 BUG_ON(!test_bit(dead_node, res->refmap));
2161                 dlm_lockres_clear_refmap_bit(dead_node, res);
2162         } else if (test_bit(dead_node, res->refmap)) {
2163                 mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2164                      "no locks and had not purged before dying\n", dlm->name,
2165                      res->lockname.len, res->lockname.name, dead_node);
2166                 dlm_lockres_clear_refmap_bit(dead_node, res);
2167         }
2168
2169         /* do not kick thread yet */
2170         __dlm_dirty_lockres(dlm, res);
2171 }
2172
2173 /* if this node is the recovery master, and there are no
2174  * locks for a given lockres owned by this node that are in
2175  * either PR or EX mode, zero out the lvb before requesting.
2176  *
2177  */
2178
2179
2180 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2181 {
2182         struct hlist_node *iter;
2183         struct dlm_lock_resource *res;
2184         int i;
2185         struct hlist_head *bucket;
2186         struct dlm_lock *lock;
2187
2188
2189         /* purge any stale mles */
2190         dlm_clean_master_list(dlm, dead_node);
2191
2192         /*
2193          * now clean up all lock resources.  there are two rules:
2194          *
2195          * 1) if the dead node was the master, move the lockres
2196          *    to the recovering list.  set the RECOVERING flag.
2197          *    this lockres needs to be cleaned up before it can
2198          *    be used further.
2199          *
2200          * 2) if this node was the master, remove all locks from
2201          *    each of the lockres queues that were owned by the
2202          *    dead node.  once recovery finishes, the dlm thread
2203          *    can be kicked again to see if any ASTs or BASTs
2204          *    need to be fired as a result.
2205          */
2206         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2207                 bucket = dlm_lockres_hash(dlm, i);
2208                 hlist_for_each_entry(res, iter, bucket, hash_node) {
2209                         /* always prune any $RECOVERY entries for dead nodes,
2210                          * otherwise hangs can occur during later recovery */
2211                         if (dlm_is_recovery_lock(res->lockname.name,
2212                                                  res->lockname.len)) {
2213                                 spin_lock(&res->spinlock);
2214                                 list_for_each_entry(lock, &res->granted, list) {
2215                                         if (lock->ml.node == dead_node) {
2216                                                 mlog(0, "AHA! there was "
2217                                                      "a $RECOVERY lock for dead "
2218                                                      "node %u (%s)!\n",
2219                                                      dead_node, dlm->name);
2220                                                 list_del_init(&lock->list);
2221                                                 dlm_lock_put(lock);
2222                                                 break;
2223                                         }
2224                                 }
2225                                 spin_unlock(&res->spinlock);
2226                                 continue;
2227                         }                       
2228                         spin_lock(&res->spinlock);
2229                         /* zero the lvb if necessary */
2230                         dlm_revalidate_lvb(dlm, res, dead_node);
2231                         if (res->owner == dead_node) {
2232                                 if (res->state & DLM_LOCK_RES_DROPPING_REF)
2233                                         mlog(0, "%s:%.*s: owned by "
2234                                              "dead node %u, this node was "
2235                                              "dropping its ref when it died. "
2236                                              "continue, dropping the flag.\n",
2237                                              dlm->name, res->lockname.len,
2238                                              res->lockname.name, dead_node);
2239
2240                                 /* the wake_up for this will happen when the
2241                                  * RECOVERING flag is dropped later */
2242                                 res->state &= ~DLM_LOCK_RES_DROPPING_REF;
2243
2244                                 dlm_move_lockres_to_recovery_list(dlm, res);
2245                         } else if (res->owner == dlm->node_num) {
2246                                 dlm_free_dead_locks(dlm, res, dead_node);
2247                                 __dlm_lockres_calc_usage(dlm, res);
2248                         }
2249                         spin_unlock(&res->spinlock);
2250                 }
2251         }
2252
2253 }
2254
2255 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2256 {
2257         assert_spin_locked(&dlm->spinlock);
2258
2259         if (dlm->reco.new_master == idx) {
2260                 mlog(0, "%s: recovery master %d just died\n",
2261                      dlm->name, idx);
2262                 if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2263                         /* finalize1 was reached, so it is safe to clear
2264                          * the new_master and dead_node.  that recovery
2265                          * is complete. */
2266                         mlog(0, "%s: dead master %d had reached "
2267                              "finalize1 state, clearing\n", dlm->name, idx);
2268                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2269                         __dlm_reset_recovery(dlm);
2270                 }
2271         }
2272
2273         /* Clean up join state on node death. */
2274         if (dlm->joining_node == idx) {
2275                 mlog(0, "Clearing join state for node %u\n", idx);
2276                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2277         }
2278
2279         /* check to see if the node is already considered dead */
2280         if (!test_bit(idx, dlm->live_nodes_map)) {
2281                 mlog(0, "for domain %s, node %d is already dead. "
2282                      "another node likely did recovery already.\n",
2283                      dlm->name, idx);
2284                 return;
2285         }
2286
2287         /* check to see if we do not care about this node */
2288         if (!test_bit(idx, dlm->domain_map)) {
2289                 /* This also catches the case that we get a node down
2290                  * but haven't joined the domain yet. */
2291                 mlog(0, "node %u already removed from domain!\n", idx);
2292                 return;
2293         }
2294
2295         clear_bit(idx, dlm->live_nodes_map);
2296
2297         /* make sure local cleanup occurs before the heartbeat events */
2298         if (!test_bit(idx, dlm->recovery_map))
2299                 dlm_do_local_recovery_cleanup(dlm, idx);
2300
2301         /* notify anything attached to the heartbeat events */
2302         dlm_hb_event_notify_attached(dlm, idx, 0);
2303
2304         mlog(0, "node %u being removed from domain map!\n", idx);
2305         clear_bit(idx, dlm->domain_map);
2306         /* wake up migration waiters if a node goes down.
2307          * perhaps later we can genericize this for other waiters. */
2308         wake_up(&dlm->migration_wq);
2309
2310         if (test_bit(idx, dlm->recovery_map))
2311                 mlog(0, "domain %s, node %u already added "
2312                      "to recovery map!\n", dlm->name, idx);
2313         else
2314                 set_bit(idx, dlm->recovery_map);
2315 }
2316
2317 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2318 {
2319         struct dlm_ctxt *dlm = data;
2320
2321         if (!dlm_grab(dlm))
2322                 return;
2323
2324         /*
2325          * This will notify any dlm users that a node in our domain
2326          * went away without notifying us first.
2327          */
2328         if (test_bit(idx, dlm->domain_map))
2329                 dlm_fire_domain_eviction_callbacks(dlm, idx);
2330
2331         spin_lock(&dlm->spinlock);
2332         __dlm_hb_node_down(dlm, idx);
2333         spin_unlock(&dlm->spinlock);
2334
2335         dlm_put(dlm);
2336 }
2337
2338 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2339 {
2340         struct dlm_ctxt *dlm = data;
2341
2342         if (!dlm_grab(dlm))
2343                 return;
2344
2345         spin_lock(&dlm->spinlock);
2346         set_bit(idx, dlm->live_nodes_map);
2347         /* do NOT notify mle attached to the heartbeat events.
2348          * new nodes are not interesting in mastery until joined. */
2349         spin_unlock(&dlm->spinlock);
2350
2351         dlm_put(dlm);
2352 }
2353
2354 static void dlm_reco_ast(void *astdata)
2355 {
2356         struct dlm_ctxt *dlm = astdata;
2357         mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2358              dlm->node_num, dlm->name);
2359 }
2360 static void dlm_reco_bast(void *astdata, int blocked_type)
2361 {
2362         struct dlm_ctxt *dlm = astdata;
2363         mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2364              dlm->node_num, dlm->name);
2365 }
2366 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2367 {
2368         mlog(0, "unlockast for recovery lock fired!\n");
2369 }
2370
2371 /*
2372  * dlm_pick_recovery_master will continually attempt to use
2373  * dlmlock() on the special "$RECOVERY" lockres with the
2374  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2375  * this function on each node racing to become the recovery
2376  * master will not stop attempting this until either:
2377  * a) this node gets the EX (and becomes the recovery master),
2378  * or b) dlm->reco.new_master gets set to some nodenum 
2379  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2380  * so each time a recovery master is needed, the entire cluster
2381  * will sync at this point.  if the new master dies, that will
2382  * be detected in dlm_do_recovery */
2383 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2384 {
2385         enum dlm_status ret;
2386         struct dlm_lockstatus lksb;
2387         int status = -EINVAL;
2388
2389         mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2390              dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2391 again:  
2392         memset(&lksb, 0, sizeof(lksb));
2393
2394         ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2395                       DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2396                       dlm_reco_ast, dlm, dlm_reco_bast);
2397
2398         mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2399              dlm->name, ret, lksb.status);
2400
2401         if (ret == DLM_NORMAL) {
2402                 mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2403                      dlm->name, dlm->node_num);
2404                 
2405                 /* got the EX lock.  check to see if another node 
2406                  * just became the reco master */
2407                 if (dlm_reco_master_ready(dlm)) {
2408                         mlog(0, "%s: got reco EX lock, but %u will "
2409                              "do the recovery\n", dlm->name,
2410                              dlm->reco.new_master);
2411                         status = -EEXIST;
2412                 } else {
2413                         status = 0;
2414
2415                         /* see if recovery was already finished elsewhere */
2416                         spin_lock(&dlm->spinlock);
2417                         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2418                                 status = -EINVAL;       
2419                                 mlog(0, "%s: got reco EX lock, but "
2420                                      "node got recovered already\n", dlm->name);
2421                                 if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2422                                         mlog(ML_ERROR, "%s: new master is %u "
2423                                              "but no dead node!\n", 
2424                                              dlm->name, dlm->reco.new_master);
2425                                         BUG();
2426                                 }
2427                         }
2428                         spin_unlock(&dlm->spinlock);
2429                 }
2430
2431                 /* if this node has actually become the recovery master,
2432                  * set the master and send the messages to begin recovery */
2433                 if (!status) {
2434                         mlog(0, "%s: dead=%u, this=%u, sending "
2435                              "begin_reco now\n", dlm->name, 
2436                              dlm->reco.dead_node, dlm->node_num);
2437                         status = dlm_send_begin_reco_message(dlm,
2438                                       dlm->reco.dead_node);
2439                         /* this always succeeds */
2440                         BUG_ON(status);
2441
2442                         /* set the new_master to this node */
2443                         spin_lock(&dlm->spinlock);
2444                         dlm_set_reco_master(dlm, dlm->node_num);
2445                         spin_unlock(&dlm->spinlock);
2446                 }
2447
2448                 /* recovery lock is a special case.  ast will not get fired,
2449                  * so just go ahead and unlock it. */
2450                 ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2451                 if (ret == DLM_DENIED) {
2452                         mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2453                         ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2454                 }
2455                 if (ret != DLM_NORMAL) {
2456                         /* this would really suck. this could only happen
2457                          * if there was a network error during the unlock
2458                          * because of node death.  this means the unlock
2459                          * is actually "done" and the lock structure is
2460                          * even freed.  we can continue, but only
2461                          * because this specific lock name is special. */
2462                         mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2463                 }
2464         } else if (ret == DLM_NOTQUEUED) {
2465                 mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2466                      dlm->name, dlm->node_num);
2467                 /* another node is master. wait on
2468                  * reco.new_master != O2NM_INVALID_NODE_NUM 
2469                  * for at most one second */
2470                 wait_event_timeout(dlm->dlm_reco_thread_wq,
2471                                          dlm_reco_master_ready(dlm),
2472                                          msecs_to_jiffies(1000));
2473                 if (!dlm_reco_master_ready(dlm)) {
2474                         mlog(0, "%s: reco master taking awhile\n",
2475                              dlm->name);
2476                         goto again;
2477                 }
2478                 /* another node has informed this one that it is reco master */
2479                 mlog(0, "%s: reco master %u is ready to recover %u\n",
2480                      dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2481                 status = -EEXIST;
2482         } else if (ret == DLM_RECOVERING) {
2483                 mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2484                      dlm->name, dlm->node_num);
2485                 goto again;
2486         } else {
2487                 struct dlm_lock_resource *res;
2488
2489                 /* dlmlock returned something other than NOTQUEUED or NORMAL */
2490                 mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2491                      "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2492                      dlm_errname(lksb.status));
2493                 res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2494                                          DLM_RECOVERY_LOCK_NAME_LEN);
2495                 if (res) {
2496                         dlm_print_one_lock_resource(res);
2497                         dlm_lockres_put(res);
2498                 } else {
2499                         mlog(ML_ERROR, "recovery lock not found\n");
2500                 }
2501                 BUG();
2502         }
2503
2504         return status;
2505 }
2506
2507 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2508 {
2509         struct dlm_begin_reco br;
2510         int ret = 0;
2511         struct dlm_node_iter iter;
2512         int nodenum;
2513         int status;
2514
2515         mlog_entry("%u\n", dead_node);
2516
2517         mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2518
2519         spin_lock(&dlm->spinlock);
2520         dlm_node_iter_init(dlm->domain_map, &iter);
2521         spin_unlock(&dlm->spinlock);
2522
2523         clear_bit(dead_node, iter.node_map);
2524
2525         memset(&br, 0, sizeof(br));
2526         br.node_idx = dlm->node_num;
2527         br.dead_node = dead_node;
2528
2529         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2530                 ret = 0;
2531                 if (nodenum == dead_node) {
2532                         mlog(0, "not sending begin reco to dead node "
2533                                   "%u\n", dead_node);
2534                         continue;
2535                 }
2536                 if (nodenum == dlm->node_num) {
2537                         mlog(0, "not sending begin reco to self\n");
2538                         continue;
2539                 }
2540 retry:
2541                 ret = -EINVAL;
2542                 mlog(0, "attempting to send begin reco msg to %d\n",
2543                           nodenum);
2544                 ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2545                                          &br, sizeof(br), nodenum, &status);
2546                 /* negative status is handled ok by caller here */
2547                 if (ret >= 0)
2548                         ret = status;
2549                 if (dlm_is_host_down(ret)) {
2550                         /* node is down.  not involved in recovery
2551                          * so just keep going */
2552                         mlog(0, "%s: node %u was down when sending "
2553                              "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2554                         ret = 0;
2555                 }
2556                 if (ret < 0) {
2557                         struct dlm_lock_resource *res;
2558                         /* this is now a serious problem, possibly ENOMEM 
2559                          * in the network stack.  must retry */
2560                         mlog_errno(ret);
2561                         mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2562                             " returned %d\n", dlm->name, nodenum, ret);
2563                         res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2564                                                  DLM_RECOVERY_LOCK_NAME_LEN);
2565                         if (res) {
2566                                 dlm_print_one_lock_resource(res);
2567                                 dlm_lockres_put(res);
2568                         } else {
2569                                 mlog(ML_ERROR, "recovery lock not found\n");
2570                         }
2571                         /* sleep for a bit in hopes that we can avoid 
2572                          * another ENOMEM */
2573                         msleep(100);
2574                         goto retry;
2575                 } else if (ret == EAGAIN) {
2576                         mlog(0, "%s: trying to start recovery of node "
2577                              "%u, but node %u is waiting for last recovery "
2578                              "to complete, backoff for a bit\n", dlm->name,
2579                              dead_node, nodenum);
2580                         /* TODO Look into replacing msleep with cond_resched() */
2581                         msleep(100);
2582                         goto retry;
2583                 }
2584         }
2585
2586         return ret;
2587 }
2588
2589 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2590                            void **ret_data)
2591 {
2592         struct dlm_ctxt *dlm = data;
2593         struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2594
2595         /* ok to return 0, domain has gone away */
2596         if (!dlm_grab(dlm))
2597                 return 0;
2598
2599         spin_lock(&dlm->spinlock);
2600         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2601                 mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2602                      "but this node is in finalize state, waiting on finalize2\n",
2603                      dlm->name, br->node_idx, br->dead_node,
2604                      dlm->reco.dead_node, dlm->reco.new_master);
2605                 spin_unlock(&dlm->spinlock);
2606                 return EAGAIN;
2607         }
2608         spin_unlock(&dlm->spinlock);
2609
2610         mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2611              dlm->name, br->node_idx, br->dead_node,
2612              dlm->reco.dead_node, dlm->reco.new_master);
2613
2614         dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2615
2616         spin_lock(&dlm->spinlock);
2617         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2618                 if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2619                         mlog(0, "%s: new_master %u died, changing "
2620                              "to %u\n", dlm->name, dlm->reco.new_master,
2621                              br->node_idx);
2622                 } else {
2623                         mlog(0, "%s: new_master %u NOT DEAD, changing "
2624                              "to %u\n", dlm->name, dlm->reco.new_master,
2625                              br->node_idx);
2626                         /* may not have seen the new master as dead yet */
2627                 }
2628         }
2629         if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2630                 mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2631                      "node %u changing it to %u\n", dlm->name, 
2632                      dlm->reco.dead_node, br->node_idx, br->dead_node);
2633         }
2634         dlm_set_reco_master(dlm, br->node_idx);
2635         dlm_set_reco_dead_node(dlm, br->dead_node);
2636         if (!test_bit(br->dead_node, dlm->recovery_map)) {
2637                 mlog(0, "recovery master %u sees %u as dead, but this "
2638                      "node has not yet.  marking %u as dead\n",
2639                      br->node_idx, br->dead_node, br->dead_node);
2640                 if (!test_bit(br->dead_node, dlm->domain_map) ||
2641                     !test_bit(br->dead_node, dlm->live_nodes_map))
2642                         mlog(0, "%u not in domain/live_nodes map "
2643                              "so setting it in reco map manually\n",
2644                              br->dead_node);
2645                 /* force the recovery cleanup in __dlm_hb_node_down
2646                  * both of these will be cleared in a moment */
2647                 set_bit(br->dead_node, dlm->domain_map);
2648                 set_bit(br->dead_node, dlm->live_nodes_map);
2649                 __dlm_hb_node_down(dlm, br->dead_node);
2650         }
2651         spin_unlock(&dlm->spinlock);
2652
2653         dlm_kick_recovery_thread(dlm);
2654
2655         mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2656              dlm->name, br->node_idx, br->dead_node,
2657              dlm->reco.dead_node, dlm->reco.new_master);
2658
2659         dlm_put(dlm);
2660         return 0;
2661 }
2662
2663 #define DLM_FINALIZE_STAGE2  0x01
2664 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2665 {
2666         int ret = 0;
2667         struct dlm_finalize_reco fr;
2668         struct dlm_node_iter iter;
2669         int nodenum;
2670         int status;
2671         int stage = 1;
2672
2673         mlog(0, "finishing recovery for node %s:%u, "
2674              "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2675
2676         spin_lock(&dlm->spinlock);
2677         dlm_node_iter_init(dlm->domain_map, &iter);
2678         spin_unlock(&dlm->spinlock);
2679
2680 stage2:
2681         memset(&fr, 0, sizeof(fr));
2682         fr.node_idx = dlm->node_num;
2683         fr.dead_node = dlm->reco.dead_node;
2684         if (stage == 2)
2685                 fr.flags |= DLM_FINALIZE_STAGE2;
2686
2687         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2688                 if (nodenum == dlm->node_num)
2689                         continue;
2690                 ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2691                                          &fr, sizeof(fr), nodenum, &status);
2692                 if (ret >= 0)
2693                         ret = status;
2694                 if (ret < 0) {
2695                         mlog_errno(ret);
2696                         if (dlm_is_host_down(ret)) {
2697                                 /* this has no effect on this recovery 
2698                                  * session, so set the status to zero to 
2699                                  * finish out the last recovery */
2700                                 mlog(ML_ERROR, "node %u went down after this "
2701                                      "node finished recovery.\n", nodenum);
2702                                 ret = 0;
2703                                 continue;
2704                         }
2705                         break;
2706                 }
2707         }
2708         if (stage == 1) {
2709                 /* reset the node_iter back to the top and send finalize2 */
2710                 iter.curnode = -1;
2711                 stage = 2;
2712                 goto stage2;
2713         }
2714
2715         return ret;
2716 }
2717
2718 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2719                               void **ret_data)
2720 {
2721         struct dlm_ctxt *dlm = data;
2722         struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2723         int stage = 1;
2724
2725         /* ok to return 0, domain has gone away */
2726         if (!dlm_grab(dlm))
2727                 return 0;
2728
2729         if (fr->flags & DLM_FINALIZE_STAGE2)
2730                 stage = 2;
2731
2732         mlog(0, "%s: node %u finalizing recovery stage%d of "
2733              "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2734              fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2735  
2736         spin_lock(&dlm->spinlock);
2737
2738         if (dlm->reco.new_master != fr->node_idx) {
2739                 mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2740                      "%u is supposed to be the new master, dead=%u\n",
2741                      fr->node_idx, dlm->reco.new_master, fr->dead_node);
2742                 BUG();
2743         }
2744         if (dlm->reco.dead_node != fr->dead_node) {
2745                 mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2746                      "node %u, but node %u is supposed to be dead\n",
2747                      fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2748                 BUG();
2749         }
2750
2751         switch (stage) {
2752                 case 1:
2753                         dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2754                         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2755                                 mlog(ML_ERROR, "%s: received finalize1 from "
2756                                      "new master %u for dead node %u, but "
2757                                      "this node has already received it!\n",
2758                                      dlm->name, fr->node_idx, fr->dead_node);
2759                                 dlm_print_reco_node_status(dlm);
2760                                 BUG();
2761                         }
2762                         dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2763                         spin_unlock(&dlm->spinlock);
2764                         break;
2765                 case 2:
2766                         if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2767                                 mlog(ML_ERROR, "%s: received finalize2 from "
2768                                      "new master %u for dead node %u, but "
2769                                      "this node did not have finalize1!\n",
2770                                      dlm->name, fr->node_idx, fr->dead_node);
2771                                 dlm_print_reco_node_status(dlm);
2772                                 BUG();
2773                         }
2774                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2775                         spin_unlock(&dlm->spinlock);
2776                         dlm_reset_recovery(dlm);
2777                         dlm_kick_recovery_thread(dlm);
2778                         break;
2779                 default:
2780                         BUG();
2781         }
2782
2783         mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2784              dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2785
2786         dlm_put(dlm);
2787         return 0;
2788 }