~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/ocfs2/dlm/dlmrecovery.c

Version: ~ [ linux-5.1-rc2 ] ~ [ linux-5.0.3 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.30 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.107 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.164 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.176 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.136 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.63 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/init.h>
 34 #include <linux/sysctl.h>
 35 #include <linux/random.h>
 36 #include <linux/blkdev.h>
 37 #include <linux/socket.h>
 38 #include <linux/inet.h>
 39 #include <linux/timer.h>
 40 #include <linux/kthread.h>
 41 #include <linux/delay.h>
 42 
 43 
 44 #include "cluster/heartbeat.h"
 45 #include "cluster/nodemanager.h"
 46 #include "cluster/tcp.h"
 47 
 48 #include "dlmapi.h"
 49 #include "dlmcommon.h"
 50 #include "dlmdomain.h"
 51 
 52 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_RECOVERY)
 53 #include "cluster/masklog.h"
 54 
 55 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node);
 56 
 57 static int dlm_recovery_thread(void *data);
 58 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
 59 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
 60 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm);
 61 static int dlm_do_recovery(struct dlm_ctxt *dlm);
 62 
 63 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
 64 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
 65 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
 66 static int dlm_request_all_locks(struct dlm_ctxt *dlm,
 67                                  u8 request_from, u8 dead_node);
 68 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
 69 
 70 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
 71 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
 72                                         const char *lockname, int namelen,
 73                                         int total_locks, u64 cookie,
 74                                         u8 flags, u8 master);
 75 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
 76                                     struct dlm_migratable_lockres *mres,
 77                                     u8 send_to,
 78                                     struct dlm_lock_resource *res,
 79                                     int total_locks);
 80 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
 81                                      struct dlm_lock_resource *res,
 82                                      struct dlm_migratable_lockres *mres);
 83 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
 84 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
 85                                  u8 dead_node, u8 send_to);
 86 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
 87 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
 88                                         struct list_head *list, u8 dead_node);
 89 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
 90                                               u8 dead_node, u8 new_master);
 91 static void dlm_reco_ast(void *astdata);
 92 static void dlm_reco_bast(void *astdata, int blocked_type);
 93 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
 94 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
 95                                          void *data);
 96 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
 97 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
 98                                       struct dlm_lock_resource *res,
 99                                       u8 *real_master);
100 
101 static u64 dlm_get_next_mig_cookie(void);
102 
103 static DEFINE_SPINLOCK(dlm_reco_state_lock);
104 static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
105 static u64 dlm_mig_cookie = 1;
106 
107 static u64 dlm_get_next_mig_cookie(void)
108 {
109         u64 c;
110         spin_lock(&dlm_mig_cookie_lock);
111         c = dlm_mig_cookie;
112         if (dlm_mig_cookie == (~0ULL))
113                 dlm_mig_cookie = 1;
114         else
115                 dlm_mig_cookie++;
116         spin_unlock(&dlm_mig_cookie_lock);
117         return c;
118 }
119 
120 static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
121                                           u8 dead_node)
122 {
123         assert_spin_locked(&dlm->spinlock);
124         if (dlm->reco.dead_node != dead_node)
125                 mlog(0, "%s: changing dead_node from %u to %u\n",
126                      dlm->name, dlm->reco.dead_node, dead_node);
127         dlm->reco.dead_node = dead_node;
128 }
129 
130 static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
131                                        u8 master)
132 {
133         assert_spin_locked(&dlm->spinlock);
134         mlog(0, "%s: changing new_master from %u to %u\n",
135              dlm->name, dlm->reco.new_master, master);
136         dlm->reco.new_master = master;
137 }
138 
139 static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
140 {
141         assert_spin_locked(&dlm->spinlock);
142         clear_bit(dlm->reco.dead_node, dlm->recovery_map);
143         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
144         dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
145 }
146 
147 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
148 {
149         spin_lock(&dlm->spinlock);
150         __dlm_reset_recovery(dlm);
151         spin_unlock(&dlm->spinlock);
152 }
153 
154 /* Worker function used during recovery. */
155 void dlm_dispatch_work(struct work_struct *work)
156 {
157         struct dlm_ctxt *dlm =
158                 container_of(work, struct dlm_ctxt, dispatched_work);
159         LIST_HEAD(tmp_list);
160         struct dlm_work_item *item, *next;
161         dlm_workfunc_t *workfunc;
162         int tot=0;
163 
164         spin_lock(&dlm->work_lock);
165         list_splice_init(&dlm->work_list, &tmp_list);
166         spin_unlock(&dlm->work_lock);
167 
168         list_for_each_entry(item, &tmp_list, list) {
169                 tot++;
170         }
171         mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
172 
173         list_for_each_entry_safe(item, next, &tmp_list, list) {
174                 workfunc = item->func;
175                 list_del_init(&item->list);
176 
177                 /* already have ref on dlm to avoid having
178                  * it disappear.  just double-check. */
179                 BUG_ON(item->dlm != dlm);
180 
181                 /* this is allowed to sleep and
182                  * call network stuff */
183                 workfunc(item, item->data);
184 
185                 dlm_put(dlm);
186                 kfree(item);
187         }
188 }
189 
190 /*
191  * RECOVERY THREAD
192  */
193 
194 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
195 {
196         /* wake the recovery thread
197          * this will wake the reco thread in one of three places
198          * 1) sleeping with no recovery happening
199          * 2) sleeping with recovery mastered elsewhere
200          * 3) recovery mastered here, waiting on reco data */
201 
202         wake_up(&dlm->dlm_reco_thread_wq);
203 }
204 
205 /* Launch the recovery thread */
206 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
207 {
208         mlog(0, "starting dlm recovery thread...\n");
209 
210         dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
211                                                 "dlm_reco_thread");
212         if (IS_ERR(dlm->dlm_reco_thread_task)) {
213                 mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
214                 dlm->dlm_reco_thread_task = NULL;
215                 return -EINVAL;
216         }
217 
218         return 0;
219 }
220 
221 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
222 {
223         if (dlm->dlm_reco_thread_task) {
224                 mlog(0, "waiting for dlm recovery thread to exit\n");
225                 kthread_stop(dlm->dlm_reco_thread_task);
226                 dlm->dlm_reco_thread_task = NULL;
227         }
228 }
229 
230 
231 
232 /*
233  * this is lame, but here's how recovery works...
234  * 1) all recovery threads cluster wide will work on recovering
235  *    ONE node at a time
236  * 2) negotiate who will take over all the locks for the dead node.
237  *    thats right... ALL the locks.
238  * 3) once a new master is chosen, everyone scans all locks
239  *    and moves aside those mastered by the dead guy
240  * 4) each of these locks should be locked until recovery is done
241  * 5) the new master collects up all of secondary lock queue info
242  *    one lock at a time, forcing each node to communicate back
243  *    before continuing
244  * 6) each secondary lock queue responds with the full known lock info
245  * 7) once the new master has run all its locks, it sends a ALLDONE!
246  *    message to everyone
247  * 8) upon receiving this message, the secondary queue node unlocks
248  *    and responds to the ALLDONE
249  * 9) once the new master gets responses from everyone, he unlocks
250  *    everything and recovery for this dead node is done
251  *10) go back to 2) while there are still dead nodes
252  *
253  */
254 
255 static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
256 {
257         struct dlm_reco_node_data *ndata;
258         struct dlm_lock_resource *res;
259 
260         mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
261              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
262              dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
263              dlm->reco.dead_node, dlm->reco.new_master);
264 
265         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
266                 char *st = "unknown";
267                 switch (ndata->state) {
268                         case DLM_RECO_NODE_DATA_INIT:
269                                 st = "init";
270                                 break;
271                         case DLM_RECO_NODE_DATA_REQUESTING:
272                                 st = "requesting";
273                                 break;
274                         case DLM_RECO_NODE_DATA_DEAD:
275                                 st = "dead";
276                                 break;
277                         case DLM_RECO_NODE_DATA_RECEIVING:
278                                 st = "receiving";
279                                 break;
280                         case DLM_RECO_NODE_DATA_REQUESTED:
281                                 st = "requested";
282                                 break;
283                         case DLM_RECO_NODE_DATA_DONE:
284                                 st = "done";
285                                 break;
286                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
287                                 st = "finalize-sent";
288                                 break;
289                         default:
290                                 st = "bad";
291                                 break;
292                 }
293                 mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
294                      dlm->name, ndata->node_num, st);
295         }
296         list_for_each_entry(res, &dlm->reco.resources, recovering) {
297                 mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
298                      dlm->name, res->lockname.len, res->lockname.name);
299         }
300 }
301 
302 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
303 
304 static int dlm_recovery_thread(void *data)
305 {
306         int status;
307         struct dlm_ctxt *dlm = data;
308         unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
309 
310         mlog(0, "dlm thread running for %s...\n", dlm->name);
311 
312         while (!kthread_should_stop()) {
313                 if (dlm_domain_fully_joined(dlm)) {
314                         status = dlm_do_recovery(dlm);
315                         if (status == -EAGAIN) {
316                                 /* do not sleep, recheck immediately. */
317                                 continue;
318                         }
319                         if (status < 0)
320                                 mlog_errno(status);
321                 }
322 
323                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
324                                                  kthread_should_stop(),
325                                                  timeout);
326         }
327 
328         mlog(0, "quitting DLM recovery thread\n");
329         return 0;
330 }
331 
332 /* returns true when the recovery master has contacted us */
333 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
334 {
335         int ready;
336         spin_lock(&dlm->spinlock);
337         ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
338         spin_unlock(&dlm->spinlock);
339         return ready;
340 }
341 
342 /* returns true if node is no longer in the domain
343  * could be dead or just not joined */
344 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
345 {
346         int dead;
347         spin_lock(&dlm->spinlock);
348         dead = !test_bit(node, dlm->domain_map);
349         spin_unlock(&dlm->spinlock);
350         return dead;
351 }
352 
353 /* returns true if node is no longer in the domain
354  * could be dead or just not joined */
355 static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
356 {
357         int recovered;
358         spin_lock(&dlm->spinlock);
359         recovered = !test_bit(node, dlm->recovery_map);
360         spin_unlock(&dlm->spinlock);
361         return recovered;
362 }
363 
364 
365 int dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
366 {
367         if (timeout) {
368                 mlog(ML_NOTICE, "%s: waiting %dms for notification of "
369                      "death of node %u\n", dlm->name, timeout, node);
370                 wait_event_timeout(dlm->dlm_reco_thread_wq,
371                            dlm_is_node_dead(dlm, node),
372                            msecs_to_jiffies(timeout));
373         } else {
374                 mlog(ML_NOTICE, "%s: waiting indefinitely for notification "
375                      "of death of node %u\n", dlm->name, node);
376                 wait_event(dlm->dlm_reco_thread_wq,
377                            dlm_is_node_dead(dlm, node));
378         }
379         /* for now, return 0 */
380         return 0;
381 }
382 
383 int dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
384 {
385         if (timeout) {
386                 mlog(0, "%s: waiting %dms for notification of "
387                      "recovery of node %u\n", dlm->name, timeout, node);
388                 wait_event_timeout(dlm->dlm_reco_thread_wq,
389                            dlm_is_node_recovered(dlm, node),
390                            msecs_to_jiffies(timeout));
391         } else {
392                 mlog(0, "%s: waiting indefinitely for notification "
393                      "of recovery of node %u\n", dlm->name, node);
394                 wait_event(dlm->dlm_reco_thread_wq,
395                            dlm_is_node_recovered(dlm, node));
396         }
397         /* for now, return 0 */
398         return 0;
399 }
400 
401 /* callers of the top-level api calls (dlmlock/dlmunlock) should
402  * block on the dlm->reco.event when recovery is in progress.
403  * the dlm recovery thread will set this state when it begins
404  * recovering a dead node (as the new master or not) and clear
405  * the state and wake as soon as all affected lock resources have
406  * been marked with the RECOVERY flag */
407 static int dlm_in_recovery(struct dlm_ctxt *dlm)
408 {
409         int in_recovery;
410         spin_lock(&dlm->spinlock);
411         in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
412         spin_unlock(&dlm->spinlock);
413         return in_recovery;
414 }
415 
416 
417 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
418 {
419         if (dlm_in_recovery(dlm)) {
420                 mlog(0, "%s: reco thread %d in recovery: "
421                      "state=%d, master=%u, dead=%u\n",
422                      dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
423                      dlm->reco.state, dlm->reco.new_master,
424                      dlm->reco.dead_node);
425         }
426         wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
427 }
428 
429 static void dlm_begin_recovery(struct dlm_ctxt *dlm)
430 {
431         spin_lock(&dlm->spinlock);
432         BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
433         dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
434         spin_unlock(&dlm->spinlock);
435 }
436 
437 static void dlm_end_recovery(struct dlm_ctxt *dlm)
438 {
439         spin_lock(&dlm->spinlock);
440         BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
441         dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
442         spin_unlock(&dlm->spinlock);
443         wake_up(&dlm->reco.event);
444 }
445 
446 static int dlm_do_recovery(struct dlm_ctxt *dlm)
447 {
448         int status = 0;
449         int ret;
450 
451         spin_lock(&dlm->spinlock);
452 
453         /* check to see if the new master has died */
454         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
455             test_bit(dlm->reco.new_master, dlm->recovery_map)) {
456                 mlog(0, "new master %u died while recovering %u!\n",
457                      dlm->reco.new_master, dlm->reco.dead_node);
458                 /* unset the new_master, leave dead_node */
459                 dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
460         }
461 
462         /* select a target to recover */
463         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
464                 int bit;
465 
466                 bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
467                 if (bit >= O2NM_MAX_NODES || bit < 0)
468                         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
469                 else
470                         dlm_set_reco_dead_node(dlm, bit);
471         } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
472                 /* BUG? */
473                 mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
474                      dlm->reco.dead_node);
475                 dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
476         }
477 
478         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
479                 // mlog(0, "nothing to recover!  sleeping now!\n");
480                 spin_unlock(&dlm->spinlock);
481                 /* return to main thread loop and sleep. */
482                 return 0;
483         }
484         mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
485              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
486              dlm->reco.dead_node);
487         spin_unlock(&dlm->spinlock);
488 
489         /* take write barrier */
490         /* (stops the list reshuffling thread, proxy ast handling) */
491         dlm_begin_recovery(dlm);
492 
493         if (dlm->reco.new_master == dlm->node_num)
494                 goto master_here;
495 
496         if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
497                 /* choose a new master, returns 0 if this node
498                  * is the master, -EEXIST if it's another node.
499                  * this does not return until a new master is chosen
500                  * or recovery completes entirely. */
501                 ret = dlm_pick_recovery_master(dlm);
502                 if (!ret) {
503                         /* already notified everyone.  go. */
504                         goto master_here;
505                 }
506                 mlog(0, "another node will master this recovery session.\n");
507         }
508         mlog(0, "dlm=%s (%d), new_master=%u, this node=%u, dead_node=%u\n",
509              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task), dlm->reco.new_master,
510              dlm->node_num, dlm->reco.dead_node);
511 
512         /* it is safe to start everything back up here
513          * because all of the dead node's lock resources
514          * have been marked as in-recovery */
515         dlm_end_recovery(dlm);
516 
517         /* sleep out in main dlm_recovery_thread loop. */
518         return 0;
519 
520 master_here:
521         mlog(ML_NOTICE, "(%d) Node %u is the Recovery Master for the Dead Node "
522              "%u for Domain %s\n", task_pid_nr(dlm->dlm_reco_thread_task),
523              dlm->node_num, dlm->reco.dead_node, dlm->name);
524 
525         status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
526         if (status < 0) {
527                 /* we should never hit this anymore */
528                 mlog(ML_ERROR, "error %d remastering locks for node %u, "
529                      "retrying.\n", status, dlm->reco.dead_node);
530                 /* yield a bit to allow any final network messages
531                  * to get handled on remaining nodes */
532                 msleep(100);
533         } else {
534                 /* success!  see if any other nodes need recovery */
535                 mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
536                      dlm->name, dlm->reco.dead_node, dlm->node_num);
537                 dlm_reset_recovery(dlm);
538         }
539         dlm_end_recovery(dlm);
540 
541         /* continue and look for another dead node */
542         return -EAGAIN;
543 }
544 
545 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
546 {
547         int status = 0;
548         struct dlm_reco_node_data *ndata;
549         int all_nodes_done;
550         int destroy = 0;
551         int pass = 0;
552 
553         do {
554                 /* we have become recovery master.  there is no escaping
555                  * this, so just keep trying until we get it. */
556                 status = dlm_init_recovery_area(dlm, dead_node);
557                 if (status < 0) {
558                         mlog(ML_ERROR, "%s: failed to alloc recovery area, "
559                              "retrying\n", dlm->name);
560                         msleep(1000);
561                 }
562         } while (status != 0);
563 
564         /* safe to access the node data list without a lock, since this
565          * process is the only one to change the list */
566         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
567                 BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
568                 ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
569 
570                 mlog(0, "requesting lock info from node %u\n",
571                      ndata->node_num);
572 
573                 if (ndata->node_num == dlm->node_num) {
574                         ndata->state = DLM_RECO_NODE_DATA_DONE;
575                         continue;
576                 }
577 
578                 do {
579                         status = dlm_request_all_locks(dlm, ndata->node_num,
580                                                        dead_node);
581                         if (status < 0) {
582                                 mlog_errno(status);
583                                 if (dlm_is_host_down(status)) {
584                                         /* node died, ignore it for recovery */
585                                         status = 0;
586                                         ndata->state = DLM_RECO_NODE_DATA_DEAD;
587                                         /* wait for the domain map to catch up
588                                          * with the network state. */
589                                         wait_event_timeout(dlm->dlm_reco_thread_wq,
590                                                            dlm_is_node_dead(dlm,
591                                                                 ndata->node_num),
592                                                            msecs_to_jiffies(1000));
593                                         mlog(0, "waited 1 sec for %u, "
594                                              "dead? %s\n", ndata->node_num,
595                                              dlm_is_node_dead(dlm, ndata->node_num) ?
596                                              "yes" : "no");
597                                 } else {
598                                         /* -ENOMEM on the other node */
599                                         mlog(0, "%s: node %u returned "
600                                              "%d during recovery, retrying "
601                                              "after a short wait\n",
602                                              dlm->name, ndata->node_num,
603                                              status);
604                                         msleep(100);
605                                 }
606                         }
607                 } while (status != 0);
608 
609                 spin_lock(&dlm_reco_state_lock);
610                 switch (ndata->state) {
611                         case DLM_RECO_NODE_DATA_INIT:
612                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
613                         case DLM_RECO_NODE_DATA_REQUESTED:
614                                 BUG();
615                                 break;
616                         case DLM_RECO_NODE_DATA_DEAD:
617                                 mlog(0, "node %u died after requesting "
618                                      "recovery info for node %u\n",
619                                      ndata->node_num, dead_node);
620                                 /* fine.  don't need this node's info.
621                                  * continue without it. */
622                                 break;
623                         case DLM_RECO_NODE_DATA_REQUESTING:
624                                 ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
625                                 mlog(0, "now receiving recovery data from "
626                                      "node %u for dead node %u\n",
627                                      ndata->node_num, dead_node);
628                                 break;
629                         case DLM_RECO_NODE_DATA_RECEIVING:
630                                 mlog(0, "already receiving recovery data from "
631                                      "node %u for dead node %u\n",
632                                      ndata->node_num, dead_node);
633                                 break;
634                         case DLM_RECO_NODE_DATA_DONE:
635                                 mlog(0, "already DONE receiving recovery data "
636                                      "from node %u for dead node %u\n",
637                                      ndata->node_num, dead_node);
638                                 break;
639                 }
640                 spin_unlock(&dlm_reco_state_lock);
641         }
642 
643         mlog(0, "done requesting all lock info\n");
644 
645         /* nodes should be sending reco data now
646          * just need to wait */
647 
648         while (1) {
649                 /* check all the nodes now to see if we are
650                  * done, or if anyone died */
651                 all_nodes_done = 1;
652                 spin_lock(&dlm_reco_state_lock);
653                 list_for_each_entry(ndata, &dlm->reco.node_data, list) {
654                         mlog(0, "checking recovery state of node %u\n",
655                              ndata->node_num);
656                         switch (ndata->state) {
657                                 case DLM_RECO_NODE_DATA_INIT:
658                                 case DLM_RECO_NODE_DATA_REQUESTING:
659                                         mlog(ML_ERROR, "bad ndata state for "
660                                              "node %u: state=%d\n",
661                                              ndata->node_num, ndata->state);
662                                         BUG();
663                                         break;
664                                 case DLM_RECO_NODE_DATA_DEAD:
665                                         mlog(0, "node %u died after "
666                                              "requesting recovery info for "
667                                              "node %u\n", ndata->node_num,
668                                              dead_node);
669                                         break;
670                                 case DLM_RECO_NODE_DATA_RECEIVING:
671                                 case DLM_RECO_NODE_DATA_REQUESTED:
672                                         mlog(0, "%s: node %u still in state %s\n",
673                                              dlm->name, ndata->node_num,
674                                              ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
675                                              "receiving" : "requested");
676                                         all_nodes_done = 0;
677                                         break;
678                                 case DLM_RECO_NODE_DATA_DONE:
679                                         mlog(0, "%s: node %u state is done\n",
680                                              dlm->name, ndata->node_num);
681                                         break;
682                                 case DLM_RECO_NODE_DATA_FINALIZE_SENT:
683                                         mlog(0, "%s: node %u state is finalize\n",
684                                              dlm->name, ndata->node_num);
685                                         break;
686                         }
687                 }
688                 spin_unlock(&dlm_reco_state_lock);
689 
690                 mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
691                      all_nodes_done?"yes":"no");
692                 if (all_nodes_done) {
693                         int ret;
694 
695                         /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
696                          * just send a finalize message to everyone and
697                          * clean up */
698                         mlog(0, "all nodes are done! send finalize\n");
699                         ret = dlm_send_finalize_reco_message(dlm);
700                         if (ret < 0)
701                                 mlog_errno(ret);
702 
703                         spin_lock(&dlm->spinlock);
704                         dlm_finish_local_lockres_recovery(dlm, dead_node,
705                                                           dlm->node_num);
706                         spin_unlock(&dlm->spinlock);
707                         mlog(0, "should be done with recovery!\n");
708 
709                         mlog(0, "finishing recovery of %s at %lu, "
710                              "dead=%u, this=%u, new=%u\n", dlm->name,
711                              jiffies, dlm->reco.dead_node,
712                              dlm->node_num, dlm->reco.new_master);
713                         destroy = 1;
714                         status = 0;
715                         /* rescan everything marked dirty along the way */
716                         dlm_kick_thread(dlm, NULL);
717                         break;
718                 }
719                 /* wait to be signalled, with periodic timeout
720                  * to check for node death */
721                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
722                                          kthread_should_stop(),
723                                          msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
724 
725         }
726 
727         if (destroy)
728                 dlm_destroy_recovery_area(dlm, dead_node);
729 
730         return status;
731 }
732 
733 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
734 {
735         int num=0;
736         struct dlm_reco_node_data *ndata;
737 
738         spin_lock(&dlm->spinlock);
739         memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
740         /* nodes can only be removed (by dying) after dropping
741          * this lock, and death will be trapped later, so this should do */
742         spin_unlock(&dlm->spinlock);
743 
744         while (1) {
745                 num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
746                 if (num >= O2NM_MAX_NODES) {
747                         break;
748                 }
749                 BUG_ON(num == dead_node);
750 
751                 ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
752                 if (!ndata) {
753                         dlm_destroy_recovery_area(dlm, dead_node);
754                         return -ENOMEM;
755                 }
756                 ndata->node_num = num;
757                 ndata->state = DLM_RECO_NODE_DATA_INIT;
758                 spin_lock(&dlm_reco_state_lock);
759                 list_add_tail(&ndata->list, &dlm->reco.node_data);
760                 spin_unlock(&dlm_reco_state_lock);
761                 num++;
762         }
763 
764         return 0;
765 }
766 
767 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
768 {
769         struct dlm_reco_node_data *ndata, *next;
770         LIST_HEAD(tmplist);
771 
772         spin_lock(&dlm_reco_state_lock);
773         list_splice_init(&dlm->reco.node_data, &tmplist);
774         spin_unlock(&dlm_reco_state_lock);
775 
776         list_for_each_entry_safe(ndata, next, &tmplist, list) {
777                 list_del_init(&ndata->list);
778                 kfree(ndata);
779         }
780 }
781 
782 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
783                                  u8 dead_node)
784 {
785         struct dlm_lock_request lr;
786         enum dlm_status ret;
787 
788         mlog(0, "\n");
789 
790 
791         mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
792                   "to %u\n", dead_node, request_from);
793 
794         memset(&lr, 0, sizeof(lr));
795         lr.node_idx = dlm->node_num;
796         lr.dead_node = dead_node;
797 
798         // send message
799         ret = DLM_NOLOCKMGR;
800         ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
801                                  &lr, sizeof(lr), request_from, NULL);
802 
803         /* negative status is handled by caller */
804         if (ret < 0)
805                 mlog(ML_ERROR, "Error %d when sending message %u (key "
806                      "0x%x) to node %u\n", ret, DLM_LOCK_REQUEST_MSG,
807                      dlm->key, request_from);
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                 mlog(ML_ERROR, "Error %d when sending message %u (key "
960                      "0x%x) to node %u\n", ret, DLM_RECO_DATA_DONE_MSG,
961                      dlm->key, send_to);
962                 if (!dlm_is_host_down(ret)) {
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 ? "migration" : "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(ML_ERROR, "Error %d when sending message %u (key "
1131                      "0x%x) to node %u\n", ret, DLM_MIG_LOCKRES_MSG,
1132                      dlm->key, send_to);
1133         } else {
1134                 /* might get an -ENOMEM back here */
1135                 ret = status;
1136                 if (ret < 0) {
1137                         mlog_errno(ret);
1138 
1139                         if (ret == -EFAULT) {
1140                                 mlog(ML_ERROR, "node %u told me to kill "
1141                                      "myself!\n", send_to);
1142                                 BUG();
1143                         }
1144                 }
1145         }
1146 
1147         /* zero and reinit the message buffer */
1148         dlm_init_migratable_lockres(mres, res->lockname.name,
1149                                     res->lockname.len, mres_total_locks,
1150                                     mig_cookie, orig_flags, orig_master);
1151         return ret;
1152 }
1153 
1154 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1155                                         const char *lockname, int namelen,
1156                                         int total_locks, u64 cookie,
1157                                         u8 flags, u8 master)
1158 {
1159         /* mres here is one full page */
1160         clear_page(mres);
1161         mres->lockname_len = namelen;
1162         memcpy(mres->lockname, lockname, namelen);
1163         mres->num_locks = 0;
1164         mres->total_locks = cpu_to_be32(total_locks);
1165         mres->mig_cookie = cpu_to_be64(cookie);
1166         mres->flags = flags;
1167         mres->master = master;
1168 }
1169 
1170 static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
1171                                           struct dlm_migratable_lockres *mres,
1172                                           int queue)
1173 {
1174         if (!lock->lksb)
1175                return;
1176 
1177         /* Ignore lvb in all locks in the blocked list */
1178         if (queue == DLM_BLOCKED_LIST)
1179                 return;
1180 
1181         /* Only consider lvbs in locks with granted EX or PR lock levels */
1182         if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
1183                 return;
1184 
1185         if (dlm_lvb_is_empty(mres->lvb)) {
1186                 memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1187                 return;
1188         }
1189 
1190         /* Ensure the lvb copied for migration matches in other valid locks */
1191         if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
1192                 return;
1193 
1194         mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
1195              "node=%u\n",
1196              dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
1197              dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
1198              lock->lockres->lockname.len, lock->lockres->lockname.name,
1199              lock->ml.node);
1200         dlm_print_one_lock_resource(lock->lockres);
1201         BUG();
1202 }
1203 
1204 /* returns 1 if this lock fills the network structure,
1205  * 0 otherwise */
1206 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1207                                  struct dlm_migratable_lockres *mres, int queue)
1208 {
1209         struct dlm_migratable_lock *ml;
1210         int lock_num = mres->num_locks;
1211 
1212         ml = &(mres->ml[lock_num]);
1213         ml->cookie = lock->ml.cookie;
1214         ml->type = lock->ml.type;
1215         ml->convert_type = lock->ml.convert_type;
1216         ml->highest_blocked = lock->ml.highest_blocked;
1217         ml->list = queue;
1218         if (lock->lksb) {
1219                 ml->flags = lock->lksb->flags;
1220                 dlm_prepare_lvb_for_migration(lock, mres, queue);
1221         }
1222         ml->node = lock->ml.node;
1223         mres->num_locks++;
1224         /* we reached the max, send this network message */
1225         if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1226                 return 1;
1227         return 0;
1228 }
1229 
1230 static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
1231                                struct dlm_migratable_lockres *mres)
1232 {
1233         struct dlm_lock dummy;
1234         memset(&dummy, 0, sizeof(dummy));
1235         dummy.ml.cookie = 0;
1236         dummy.ml.type = LKM_IVMODE;
1237         dummy.ml.convert_type = LKM_IVMODE;
1238         dummy.ml.highest_blocked = LKM_IVMODE;
1239         dummy.lksb = NULL;
1240         dummy.ml.node = dlm->node_num;
1241         dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
1242 }
1243 
1244 static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
1245                                     struct dlm_migratable_lock *ml,
1246                                     u8 *nodenum)
1247 {
1248         if (unlikely(ml->cookie == 0 &&
1249             ml->type == LKM_IVMODE &&
1250             ml->convert_type == LKM_IVMODE &&
1251             ml->highest_blocked == LKM_IVMODE &&
1252             ml->list == DLM_BLOCKED_LIST)) {
1253                 *nodenum = ml->node;
1254                 return 1;
1255         }
1256         return 0;
1257 }
1258 
1259 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1260                          struct dlm_migratable_lockres *mres,
1261                          u8 send_to, u8 flags)
1262 {
1263         struct list_head *queue;
1264         int total_locks, i;
1265         u64 mig_cookie = 0;
1266         struct dlm_lock *lock;
1267         int ret = 0;
1268 
1269         BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1270 
1271         mlog(0, "sending to %u\n", send_to);
1272 
1273         total_locks = dlm_num_locks_in_lockres(res);
1274         if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1275                 /* rare, but possible */
1276                 mlog(0, "argh.  lockres has %d locks.  this will "
1277                           "require more than one network packet to "
1278                           "migrate\n", total_locks);
1279                 mig_cookie = dlm_get_next_mig_cookie();
1280         }
1281 
1282         dlm_init_migratable_lockres(mres, res->lockname.name,
1283                                     res->lockname.len, total_locks,
1284                                     mig_cookie, flags, res->owner);
1285 
1286         total_locks = 0;
1287         for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1288                 queue = dlm_list_idx_to_ptr(res, i);
1289                 list_for_each_entry(lock, queue, list) {
1290                         /* add another lock. */
1291                         total_locks++;
1292                         if (!dlm_add_lock_to_array(lock, mres, i))
1293                                 continue;
1294 
1295                         /* this filled the lock message,
1296                          * we must send it immediately. */
1297                         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1298                                                        res, total_locks);
1299                         if (ret < 0)
1300                                 goto error;
1301                 }
1302         }
1303         if (total_locks == 0) {
1304                 /* send a dummy lock to indicate a mastery reference only */
1305                 mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
1306                      dlm->name, res->lockname.len, res->lockname.name,
1307                      send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
1308                      "migration");
1309                 dlm_add_dummy_lock(dlm, mres);
1310         }
1311         /* flush any remaining locks */
1312         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1313         if (ret < 0)
1314                 goto error;
1315         return ret;
1316 
1317 error:
1318         mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1319              dlm->name, ret);
1320         if (!dlm_is_host_down(ret))
1321                 BUG();
1322         mlog(0, "%s: node %u went down while sending %s "
1323              "lockres %.*s\n", dlm->name, send_to,
1324              flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1325              res->lockname.len, res->lockname.name);
1326         return ret;
1327 }
1328 
1329 
1330 
1331 /*
1332  * this message will contain no more than one page worth of
1333  * recovery data, and it will work on only one lockres.
1334  * there may be many locks in this page, and we may need to wait
1335  * for additional packets to complete all the locks (rare, but
1336  * possible).
1337  */
1338 /*
1339  * NOTE: the allocation error cases here are scary
1340  * we really cannot afford to fail an alloc in recovery
1341  * do we spin?  returning an error only delays the problem really
1342  */
1343 
1344 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
1345                             void **ret_data)
1346 {
1347         struct dlm_ctxt *dlm = data;
1348         struct dlm_migratable_lockres *mres =
1349                 (struct dlm_migratable_lockres *)msg->buf;
1350         int ret = 0;
1351         u8 real_master;
1352         u8 extra_refs = 0;
1353         char *buf = NULL;
1354         struct dlm_work_item *item = NULL;
1355         struct dlm_lock_resource *res = NULL;
1356 
1357         if (!dlm_grab(dlm))
1358                 return -EINVAL;
1359 
1360         BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1361 
1362         real_master = mres->master;
1363         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1364                 /* cannot migrate a lockres with no master */
1365                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1366         }
1367 
1368         mlog(0, "%s message received from node %u\n",
1369                   (mres->flags & DLM_MRES_RECOVERY) ?
1370                   "recovery" : "migration", mres->master);
1371         if (mres->flags & DLM_MRES_ALL_DONE)
1372                 mlog(0, "all done flag.  all lockres data received!\n");
1373 
1374         ret = -ENOMEM;
1375         buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1376         item = kzalloc(sizeof(*item), GFP_NOFS);
1377         if (!buf || !item)
1378                 goto leave;
1379 
1380         /* lookup the lock to see if we have a secondary queue for this
1381          * already...  just add the locks in and this will have its owner
1382          * and RECOVERY flag changed when it completes. */
1383         res = dlm_lookup_lockres(dlm, mres->lockname, mres->lockname_len);
1384         if (res) {
1385                 /* this will get a ref on res */
1386                 /* mark it as recovering/migrating and hash it */
1387                 spin_lock(&res->spinlock);
1388                 if (mres->flags & DLM_MRES_RECOVERY) {
1389                         res->state |= DLM_LOCK_RES_RECOVERING;
1390                 } else {
1391                         if (res->state & DLM_LOCK_RES_MIGRATING) {
1392                                 /* this is at least the second
1393                                  * lockres message */
1394                                 mlog(0, "lock %.*s is already migrating\n",
1395                                           mres->lockname_len,
1396                                           mres->lockname);
1397                         } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1398                                 /* caller should BUG */
1399                                 mlog(ML_ERROR, "node is attempting to migrate "
1400                                      "lock %.*s, but marked as recovering!\n",
1401                                      mres->lockname_len, mres->lockname);
1402                                 ret = -EFAULT;
1403                                 spin_unlock(&res->spinlock);
1404                                 goto leave;
1405                         }
1406                         res->state |= DLM_LOCK_RES_MIGRATING;
1407                 }
1408                 spin_unlock(&res->spinlock);
1409         } else {
1410                 /* need to allocate, just like if it was
1411                  * mastered here normally  */
1412                 res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1413                 if (!res)
1414                         goto leave;
1415 
1416                 /* to match the ref that we would have gotten if
1417                  * dlm_lookup_lockres had succeeded */
1418                 dlm_lockres_get(res);
1419 
1420                 /* mark it as recovering/migrating and hash it */
1421                 if (mres->flags & DLM_MRES_RECOVERY)
1422                         res->state |= DLM_LOCK_RES_RECOVERING;
1423                 else
1424                         res->state |= DLM_LOCK_RES_MIGRATING;
1425 
1426                 spin_lock(&dlm->spinlock);
1427                 __dlm_insert_lockres(dlm, res);
1428                 spin_unlock(&dlm->spinlock);
1429 
1430                 /* Add an extra ref for this lock-less lockres lest the
1431                  * dlm_thread purges it before we get the chance to add
1432                  * locks to it */
1433                 dlm_lockres_get(res);
1434 
1435                 /* There are three refs that need to be put.
1436                  * 1. Taken above.
1437                  * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
1438                  * 3. dlm_lookup_lockres()
1439                  * The first one is handled at the end of this function. The
1440                  * other two are handled in the worker thread after locks have
1441                  * been attached. Yes, we don't wait for purge time to match
1442                  * kref_init. The lockres will still have atleast one ref
1443                  * added because it is in the hash __dlm_insert_lockres() */
1444                 extra_refs++;
1445 
1446                 /* now that the new lockres is inserted,
1447                  * make it usable by other processes */
1448                 spin_lock(&res->spinlock);
1449                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1450                 spin_unlock(&res->spinlock);
1451                 wake_up(&res->wq);
1452         }
1453 
1454         /* at this point we have allocated everything we need,
1455          * and we have a hashed lockres with an extra ref and
1456          * the proper res->state flags. */
1457         ret = 0;
1458         spin_lock(&res->spinlock);
1459         /* drop this either when master requery finds a different master
1460          * or when a lock is added by the recovery worker */
1461         dlm_lockres_grab_inflight_ref(dlm, res);
1462         if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1463                 /* migration cannot have an unknown master */
1464                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1465                 mlog(0, "recovery has passed me a lockres with an "
1466                           "unknown owner.. will need to requery: "
1467                           "%.*s\n", mres->lockname_len, mres->lockname);
1468         } else {
1469                 /* take a reference now to pin the lockres, drop it
1470                  * when locks are added in the worker */
1471                 dlm_change_lockres_owner(dlm, res, dlm->node_num);
1472         }
1473         spin_unlock(&res->spinlock);
1474 
1475         /* queue up work for dlm_mig_lockres_worker */
1476         dlm_grab(dlm);  /* get an extra ref for the work item */
1477         memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1478         dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1479         item->u.ml.lockres = res; /* already have a ref */
1480         item->u.ml.real_master = real_master;
1481         item->u.ml.extra_ref = extra_refs;
1482         spin_lock(&dlm->work_lock);
1483         list_add_tail(&item->list, &dlm->work_list);
1484         spin_unlock(&dlm->work_lock);
1485         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1486 
1487 leave:
1488         /* One extra ref taken needs to be put here */
1489         if (extra_refs)
1490                 dlm_lockres_put(res);
1491 
1492         dlm_put(dlm);
1493         if (ret < 0) {
1494                 if (buf)
1495                         kfree(buf);
1496                 if (item)
1497                         kfree(item);
1498                 mlog_errno(ret);
1499         }
1500 
1501         return ret;
1502 }
1503 
1504 
1505 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1506 {
1507         struct dlm_ctxt *dlm;
1508         struct dlm_migratable_lockres *mres;
1509         int ret = 0;
1510         struct dlm_lock_resource *res;
1511         u8 real_master;
1512         u8 extra_ref;
1513 
1514         dlm = item->dlm;
1515         mres = (struct dlm_migratable_lockres *)data;
1516 
1517         res = item->u.ml.lockres;
1518         real_master = item->u.ml.real_master;
1519         extra_ref = item->u.ml.extra_ref;
1520 
1521         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1522                 /* this case is super-rare. only occurs if
1523                  * node death happens during migration. */
1524 again:
1525                 ret = dlm_lockres_master_requery(dlm, res, &real_master);
1526                 if (ret < 0) {
1527                         mlog(0, "dlm_lockres_master_requery ret=%d\n",
1528                                   ret);
1529                         goto again;
1530                 }
1531                 if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1532                         mlog(0, "lockres %.*s not claimed.  "
1533                                    "this node will take it.\n",
1534                                    res->lockname.len, res->lockname.name);
1535                 } else {
1536                         spin_lock(&res->spinlock);
1537                         dlm_lockres_drop_inflight_ref(dlm, res);
1538                         spin_unlock(&res->spinlock);
1539                         mlog(0, "master needs to respond to sender "
1540                                   "that node %u still owns %.*s\n",
1541                                   real_master, res->lockname.len,
1542                                   res->lockname.name);
1543                         /* cannot touch this lockres */
1544                         goto leave;
1545                 }
1546         }
1547 
1548         ret = dlm_process_recovery_data(dlm, res, mres);
1549         if (ret < 0)
1550                 mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1551         else
1552                 mlog(0, "dlm_process_recovery_data succeeded\n");
1553 
1554         if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1555                            (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1556                 ret = dlm_finish_migration(dlm, res, mres->master);
1557                 if (ret < 0)
1558                         mlog_errno(ret);
1559         }
1560 
1561 leave:
1562         /* See comment in dlm_mig_lockres_handler() */
1563         if (res) {
1564                 if (extra_ref)
1565                         dlm_lockres_put(res);
1566                 dlm_lockres_put(res);
1567         }
1568         kfree(data);
1569 }
1570 
1571 
1572 
1573 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1574                                       struct dlm_lock_resource *res,
1575                                       u8 *real_master)
1576 {
1577         struct dlm_node_iter iter;
1578         int nodenum;
1579         int ret = 0;
1580 
1581         *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1582 
1583         /* we only reach here if one of the two nodes in a
1584          * migration died while the migration was in progress.
1585          * at this point we need to requery the master.  we
1586          * know that the new_master got as far as creating
1587          * an mle on at least one node, but we do not know
1588          * if any nodes had actually cleared the mle and set
1589          * the master to the new_master.  the old master
1590          * is supposed to set the owner to UNKNOWN in the
1591          * event of a new_master death, so the only possible
1592          * responses that we can get from nodes here are
1593          * that the master is new_master, or that the master
1594          * is UNKNOWN.
1595          * if all nodes come back with UNKNOWN then we know
1596          * the lock needs remastering here.
1597          * if any node comes back with a valid master, check
1598          * to see if that master is the one that we are
1599          * recovering.  if so, then the new_master died and
1600          * we need to remaster this lock.  if not, then the
1601          * new_master survived and that node will respond to
1602          * other nodes about the owner.
1603          * if there is an owner, this node needs to dump this
1604          * lockres and alert the sender that this lockres
1605          * was rejected. */
1606         spin_lock(&dlm->spinlock);
1607         dlm_node_iter_init(dlm->domain_map, &iter);
1608         spin_unlock(&dlm->spinlock);
1609 
1610         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1611                 /* do not send to self */
1612                 if (nodenum == dlm->node_num)
1613                         continue;
1614                 ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1615                 if (ret < 0) {
1616                         mlog_errno(ret);
1617                         if (!dlm_is_host_down(ret))
1618                                 BUG();
1619                         /* host is down, so answer for that node would be
1620                          * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1621                 }
1622                 if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1623                         mlog(0, "lock master is %u\n", *real_master);
1624                         break;
1625                 }
1626         }
1627         return ret;
1628 }
1629 
1630 
1631 int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1632                           u8 nodenum, u8 *real_master)
1633 {
1634         int ret = -EINVAL;
1635         struct dlm_master_requery req;
1636         int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1637 
1638         memset(&req, 0, sizeof(req));
1639         req.node_idx = dlm->node_num;
1640         req.namelen = res->lockname.len;
1641         memcpy(req.name, res->lockname.name, res->lockname.len);
1642 
1643         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1644                                  &req, sizeof(req), nodenum, &status);
1645         /* XXX: negative status not handled properly here. */
1646         if (ret < 0)
1647                 mlog(ML_ERROR, "Error %d when sending message %u (key "
1648                      "0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
1649                      dlm->key, nodenum);
1650         else {
1651                 BUG_ON(status < 0);
1652                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1653                 *real_master = (u8) (status & 0xff);
1654                 mlog(0, "node %u responded to master requery with %u\n",
1655                           nodenum, *real_master);
1656                 ret = 0;
1657         }
1658         return ret;
1659 }
1660 
1661 
1662 /* this function cannot error, so unless the sending
1663  * or receiving of the message failed, the owner can
1664  * be trusted */
1665 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
1666                                void **ret_data)
1667 {
1668         struct dlm_ctxt *dlm = data;
1669         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1670         struct dlm_lock_resource *res = NULL;
1671         unsigned int hash;
1672         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1673         u32 flags = DLM_ASSERT_MASTER_REQUERY;
1674 
1675         if (!dlm_grab(dlm)) {
1676                 /* since the domain has gone away on this
1677                  * node, the proper response is UNKNOWN */
1678                 return master;
1679         }
1680 
1681         hash = dlm_lockid_hash(req->name, req->namelen);
1682 
1683         spin_lock(&dlm->spinlock);
1684         res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1685         if (res) {
1686                 spin_lock(&res->spinlock);
1687                 master = res->owner;
1688                 if (master == dlm->node_num) {
1689                         int ret = dlm_dispatch_assert_master(dlm, res,
1690                                                              0, 0, flags);
1691                         if (ret < 0) {
1692                                 mlog_errno(-ENOMEM);
1693                                 /* retry!? */
1694                                 BUG();
1695                         }
1696                 } else /* put.. incase we are not the master */
1697                         dlm_lockres_put(res);
1698                 spin_unlock(&res->spinlock);
1699         }
1700         spin_unlock(&dlm->spinlock);
1701 
1702         dlm_put(dlm);
1703         return master;
1704 }
1705 
1706 static inline struct list_head *
1707 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1708 {
1709         struct list_head *ret;
1710         BUG_ON(list_num < 0);
1711         BUG_ON(list_num > 2);
1712         ret = &(res->granted);
1713         ret += list_num;
1714         return ret;
1715 }
1716 /* TODO: do ast flush business
1717  * TODO: do MIGRATING and RECOVERING spinning
1718  */
1719 
1720 /*
1721 * NOTE about in-flight requests during migration:
1722 *
1723 * Before attempting the migrate, the master has marked the lockres as
1724 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1725 * requests either got queued before the MIGRATING flag got set, in which
1726 * case the lock data will reflect the change and a return message is on
1727 * the way, or the request failed to get in before MIGRATING got set.  In
1728 * this case, the caller will be told to spin and wait for the MIGRATING
1729 * flag to be dropped, then recheck the master.
1730 * This holds true for the convert, cancel and unlock cases, and since lvb
1731 * updates are tied to these same messages, it applies to lvb updates as
1732 * well.  For the lock case, there is no way a lock can be on the master
1733 * queue and not be on the secondary queue since the lock is always added
1734 * locally first.  This means that the new target node will never be sent
1735 * a lock that he doesn't already have on the list.
1736 * In total, this means that the local lock is correct and should not be
1737 * updated to match the one sent by the master.  Any messages sent back
1738 * from the master before the MIGRATING flag will bring the lock properly
1739 * up-to-date, and the change will be ordered properly for the waiter.
1740 * We will *not* attempt to modify the lock underneath the waiter.
1741 */
1742 
1743 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1744                                      struct dlm_lock_resource *res,
1745                                      struct dlm_migratable_lockres *mres)
1746 {
1747         struct dlm_migratable_lock *ml;
1748         struct list_head *queue;
1749         struct list_head *tmpq = NULL;
1750         struct dlm_lock *newlock = NULL;
1751         struct dlm_lockstatus *lksb = NULL;
1752         int ret = 0;
1753         int i, j, bad;
1754         struct dlm_lock *lock = NULL;
1755         u8 from = O2NM_MAX_NODES;
1756         unsigned int added = 0;
1757         __be64 c;
1758 
1759         mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1760         for (i=0; i<mres->num_locks; i++) {
1761                 ml = &(mres->ml[i]);
1762 
1763                 if (dlm_is_dummy_lock(dlm, ml, &from)) {
1764                         /* placeholder, just need to set the refmap bit */
1765                         BUG_ON(mres->num_locks != 1);
1766                         mlog(0, "%s:%.*s: dummy lock for %u\n",
1767                              dlm->name, mres->lockname_len, mres->lockname,
1768                              from);
1769                         spin_lock(&res->spinlock);
1770                         dlm_lockres_set_refmap_bit(from, res);
1771                         spin_unlock(&res->spinlock);
1772                         added++;
1773                         break;
1774                 }
1775                 BUG_ON(ml->highest_blocked != LKM_IVMODE);
1776                 newlock = NULL;
1777                 lksb = NULL;
1778 
1779                 queue = dlm_list_num_to_pointer(res, ml->list);
1780                 tmpq = NULL;
1781 
1782                 /* if the lock is for the local node it needs to
1783                  * be moved to the proper location within the queue.
1784                  * do not allocate a new lock structure. */
1785                 if (ml->node == dlm->node_num) {
1786                         /* MIGRATION ONLY! */
1787                         BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1788 
1789                         spin_lock(&res->spinlock);
1790                         for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
1791                                 tmpq = dlm_list_idx_to_ptr(res, j);
1792                                 list_for_each_entry(lock, tmpq, list) {
1793                                         if (lock->ml.cookie != ml->cookie)
1794                                                 lock = NULL;
1795                                         else
1796                                                 break;
1797                                 }
1798                                 if (lock)
1799                                         break;
1800                         }
1801 
1802                         /* lock is always created locally first, and
1803                          * destroyed locally last.  it must be on the list */
1804                         if (!lock) {
1805                                 c = ml->cookie;
1806                                 mlog(ML_ERROR, "Could not find local lock "
1807                                                "with cookie %u:%llu, node %u, "
1808                                                "list %u, flags 0x%x, type %d, "
1809                                                "conv %d, highest blocked %d\n",
1810                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1811                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1812                                      ml->node, ml->list, ml->flags, ml->type,
1813                                      ml->convert_type, ml->highest_blocked);
1814                                 __dlm_print_one_lock_resource(res);
1815                                 BUG();
1816                         }
1817 
1818                         if (lock->ml.node != ml->node) {
1819                                 c = lock->ml.cookie;
1820                                 mlog(ML_ERROR, "Mismatched node# in lock "
1821                                      "cookie %u:%llu, name %.*s, node %u\n",
1822                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1823                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1824                                      res->lockname.len, res->lockname.name,
1825                                      lock->ml.node);
1826                                 c = ml->cookie;
1827                                 mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
1828                                      "node %u, list %u, flags 0x%x, type %d, "
1829                                      "conv %d, highest blocked %d\n",
1830                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1831                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1832                                      ml->node, ml->list, ml->flags, ml->type,
1833                                      ml->convert_type, ml->highest_blocked);
1834                                 __dlm_print_one_lock_resource(res);
1835                                 BUG();
1836                         }
1837 
1838                         if (tmpq != queue) {
1839                                 c = ml->cookie;
1840                                 mlog(0, "Lock cookie %u:%llu was on list %u "
1841                                      "instead of list %u for %.*s\n",
1842                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1843                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1844                                      j, ml->list, res->lockname.len,
1845                                      res->lockname.name);
1846                                 __dlm_print_one_lock_resource(res);
1847                                 spin_unlock(&res->spinlock);
1848                                 continue;
1849                         }
1850 
1851                         /* see NOTE above about why we do not update
1852                          * to match the master here */
1853 
1854                         /* move the lock to its proper place */
1855                         /* do not alter lock refcount.  switching lists. */
1856                         list_move_tail(&lock->list, queue);
1857                         spin_unlock(&res->spinlock);
1858                         added++;
1859 
1860                         mlog(0, "just reordered a local lock!\n");
1861                         continue;
1862                 }
1863 
1864                 /* lock is for another node. */
1865                 newlock = dlm_new_lock(ml->type, ml->node,
1866                                        be64_to_cpu(ml->cookie), NULL);
1867                 if (!newlock) {
1868                         ret = -ENOMEM;
1869                         goto leave;
1870                 }
1871                 lksb = newlock->lksb;
1872                 dlm_lock_attach_lockres(newlock, res);
1873 
1874                 if (ml->convert_type != LKM_IVMODE) {
1875                         BUG_ON(queue != &res->converting);
1876                         newlock->ml.convert_type = ml->convert_type;
1877                 }
1878                 lksb->flags |= (ml->flags &
1879                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1880 
1881                 if (ml->type == LKM_NLMODE)
1882                         goto skip_lvb;
1883 
1884                 if (!dlm_lvb_is_empty(mres->lvb)) {
1885                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
1886                                 /* other node was trying to update
1887                                  * lvb when node died.  recreate the
1888                                  * lksb with the updated lvb. */
1889                                 memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1890                                 /* the lock resource lvb update must happen
1891                                  * NOW, before the spinlock is dropped.
1892                                  * we no longer wait for the AST to update
1893                                  * the lvb. */
1894                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1895                         } else {
1896                                 /* otherwise, the node is sending its
1897                                  * most recent valid lvb info */
1898                                 BUG_ON(ml->type != LKM_EXMODE &&
1899                                        ml->type != LKM_PRMODE);
1900                                 if (!dlm_lvb_is_empty(res->lvb) &&
1901                                     (ml->type == LKM_EXMODE ||
1902                                      memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1903                                         int i;
1904                                         mlog(ML_ERROR, "%s:%.*s: received bad "
1905                                              "lvb! type=%d\n", dlm->name,
1906                                              res->lockname.len,
1907                                              res->lockname.name, ml->type);
1908                                         printk("lockres lvb=[");
1909                                         for (i=0; i<DLM_LVB_LEN; i++)
1910                                                 printk("%02x", res->lvb[i]);
1911                                         printk("]\nmigrated lvb=[");
1912                                         for (i=0; i<DLM_LVB_LEN; i++)
1913                                                 printk("%02x", mres->lvb[i]);
1914                                         printk("]\n");
1915                                         dlm_print_one_lock_resource(res);
1916                                         BUG();
1917                                 }
1918                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1919                         }
1920                 }
1921 skip_lvb:
1922 
1923                 /* NOTE:
1924                  * wrt lock queue ordering and recovery:
1925                  *    1. order of locks on granted queue is
1926                  *       meaningless.
1927                  *    2. order of locks on converting queue is
1928                  *       LOST with the node death.  sorry charlie.
1929                  *    3. order of locks on the blocked queue is
1930                  *       also LOST.
1931                  * order of locks does not affect integrity, it
1932                  * just means that a lock request may get pushed
1933                  * back in line as a result of the node death.
1934                  * also note that for a given node the lock order
1935                  * for its secondary queue locks is preserved
1936                  * relative to each other, but clearly *not*
1937                  * preserved relative to locks from other nodes.
1938                  */
1939                 bad = 0;
1940                 spin_lock(&res->spinlock);
1941                 list_for_each_entry(lock, queue, list) {
1942                         if (lock->ml.cookie == ml->cookie) {
1943                                 c = lock->ml.cookie;
1944                                 mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
1945                                      "exists on this lockres!\n", dlm->name,
1946                                      res->lockname.len, res->lockname.name,
1947                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1948                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)));
1949 
1950                                 mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
1951                                      "node=%u, cookie=%u:%llu, queue=%d\n",
1952                                      ml->type, ml->convert_type, ml->node,
1953                                      dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
1954                                      dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
1955                                      ml->list);
1956 
1957                                 __dlm_print_one_lock_resource(res);
1958                                 bad = 1;
1959                                 break;
1960                         }
1961                 }
1962                 if (!bad) {
1963                         dlm_lock_get(newlock);
1964                         list_add_tail(&newlock->list, queue);
1965                         mlog(0, "%s:%.*s: added lock for node %u, "
1966                              "setting refmap bit\n", dlm->name,
1967                              res->lockname.len, res->lockname.name, ml->node);
1968                         dlm_lockres_set_refmap_bit(ml->node, res);
1969                         added++;
1970                 }
1971                 spin_unlock(&res->spinlock);
1972         }
1973         mlog(0, "done running all the locks\n");
1974 
1975 leave:
1976         /* balance the ref taken when the work was queued */
1977         spin_lock(&res->spinlock);
1978         dlm_lockres_drop_inflight_ref(dlm, res);
1979         spin_unlock(&res->spinlock);
1980 
1981         if (ret < 0) {
1982                 mlog_errno(ret);
1983                 if (newlock)
1984                         dlm_lock_put(newlock);
1985         }
1986 
1987         return ret;
1988 }
1989 
1990 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
1991                                        struct dlm_lock_resource *res)
1992 {
1993         int i;
1994         struct list_head *queue;
1995         struct dlm_lock *lock, *next;
1996 
1997         assert_spin_locked(&dlm->spinlock);
1998         assert_spin_locked(&res->spinlock);
1999         res->state |= DLM_LOCK_RES_RECOVERING;
2000         if (!list_empty(&res->recovering)) {
2001                 mlog(0,
2002                      "Recovering res %s:%.*s, is already on recovery list!\n",
2003                      dlm->name, res->lockname.len, res->lockname.name);
2004                 list_del_init(&res->recovering);
2005                 dlm_lockres_put(res);
2006         }
2007         /* We need to hold a reference while on the recovery list */
2008         dlm_lockres_get(res);
2009         list_add_tail(&res->recovering, &dlm->reco.resources);
2010 
2011         /* find any pending locks and put them back on proper list */
2012         for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
2013                 queue = dlm_list_idx_to_ptr(res, i);
2014                 list_for_each_entry_safe(lock, next, queue, list) {
2015                         dlm_lock_get(lock);
2016                         if (lock->convert_pending) {
2017                                 /* move converting lock back to granted */
2018                                 BUG_ON(i != DLM_CONVERTING_LIST);
2019                                 mlog(0, "node died with convert pending "
2020                                      "on %.*s. move back to granted list.\n",
2021                                      res->lockname.len, res->lockname.name);
2022                                 dlm_revert_pending_convert(res, lock);
2023                                 lock->convert_pending = 0;
2024                         } else if (lock->lock_pending) {
2025                                 /* remove pending lock requests completely */
2026                                 BUG_ON(i != DLM_BLOCKED_LIST);
2027                                 mlog(0, "node died with lock pending "
2028                                      "on %.*s. remove from blocked list and skip.\n",
2029                                      res->lockname.len, res->lockname.name);
2030                                 /* lock will be floating until ref in
2031                                  * dlmlock_remote is freed after the network
2032                                  * call returns.  ok for it to not be on any
2033                                  * list since no ast can be called
2034                                  * (the master is dead). */
2035                                 dlm_revert_pending_lock(res, lock);
2036                                 lock->lock_pending = 0;
2037                         } else if (lock->unlock_pending) {
2038                                 /* if an unlock was in progress, treat as
2039                                  * if this had completed successfully
2040                                  * before sending this lock state to the
2041                                  * new master.  note that the dlm_unlock
2042                                  * call is still responsible for calling
2043                                  * the unlockast.  that will happen after
2044                                  * the network call times out.  for now,
2045                                  * just move lists to prepare the new
2046                                  * recovery master.  */
2047                                 BUG_ON(i != DLM_GRANTED_LIST);
2048                                 mlog(0, "node died with unlock pending "
2049                                      "on %.*s. remove from blocked list and skip.\n",
2050                                      res->lockname.len, res->lockname.name);
2051                                 dlm_commit_pending_unlock(res, lock);
2052                                 lock->unlock_pending = 0;
2053                         } else if (lock->cancel_pending) {
2054                                 /* if a cancel was in progress, treat as
2055                                  * if this had completed successfully
2056                                  * before sending this lock state to the
2057                                  * new master */
2058                                 BUG_ON(i != DLM_CONVERTING_LIST);
2059                                 mlog(0, "node died with cancel pending "
2060                                      "on %.*s. move back to granted list.\n",
2061                                      res->lockname.len, res->lockname.name);
2062                                 dlm_commit_pending_cancel(res, lock);
2063                                 lock->cancel_pending = 0;
2064                         }
2065                         dlm_lock_put(lock);
2066                 }
2067         }
2068 }
2069 
2070 
2071 
2072 /* removes all recovered locks from the recovery list.
2073  * sets the res->owner to the new master.
2074  * unsets the RECOVERY flag and wakes waiters. */
2075 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
2076                                               u8 dead_node, u8 new_master)
2077 {
2078         int i;
2079         struct hlist_node *hash_iter;
2080         struct hlist_head *bucket;
2081         struct dlm_lock_resource *res, *next;
2082 
2083         assert_spin_locked(&dlm->spinlock);
2084 
2085         list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
2086                 if (res->owner == dead_node) {
2087                         list_del_init(&res->recovering);
2088                         spin_lock(&res->spinlock);
2089                         /* new_master has our reference from
2090                          * the lock state sent during recovery */
2091                         dlm_change_lockres_owner(dlm, res, new_master);
2092                         res->state &= ~DLM_LOCK_RES_RECOVERING;
2093                         if (__dlm_lockres_has_locks(res))
2094                                 __dlm_dirty_lockres(dlm, res);
2095                         spin_unlock(&res->spinlock);
2096                         wake_up(&res->wq);
2097                         dlm_lockres_put(res);
2098                 }
2099         }
2100 
2101         /* this will become unnecessary eventually, but
2102          * for now we need to run the whole hash, clear
2103          * the RECOVERING state and set the owner
2104          * if necessary */
2105         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2106                 bucket = dlm_lockres_hash(dlm, i);
2107                 hlist_for_each_entry(res, hash_iter, bucket, hash_node) {
2108                         if (res->state & DLM_LOCK_RES_RECOVERING) {
2109                                 if (res->owner == dead_node) {
2110                                         mlog(0, "(this=%u) res %.*s owner=%u "
2111                                              "was not on recovering list, but "
2112                                              "clearing state anyway\n",
2113                                              dlm->node_num, res->lockname.len,
2114                                              res->lockname.name, new_master);
2115                                 } else if (res->owner == dlm->node_num) {
2116                                         mlog(0, "(this=%u) res %.*s owner=%u "
2117                                              "was not on recovering list, "
2118                                              "owner is THIS node, clearing\n",
2119                                              dlm->node_num, res->lockname.len,
2120                                              res->lockname.name, new_master);
2121                                 } else
2122                                         continue;
2123 
2124                                 if (!list_empty(&res->recovering)) {
2125                                         mlog(0, "%s:%.*s: lockres was "
2126                                              "marked RECOVERING, owner=%u\n",
2127                                              dlm->name, res->lockname.len,
2128                                              res->lockname.name, res->owner);
2129                                         list_del_init(&res->recovering);
2130                                         dlm_lockres_put(res);
2131                                 }
2132                                 spin_lock(&res->spinlock);
2133                                 /* new_master has our reference from
2134                                  * the lock state sent during recovery */
2135                                 dlm_change_lockres_owner(dlm, res, new_master);
2136                                 res->state &= ~DLM_LOCK_RES_RECOVERING;
2137                                 if (__dlm_lockres_has_locks(res))
2138                                         __dlm_dirty_lockres(dlm, res);
2139                                 spin_unlock(&res->spinlock);
2140                                 wake_up(&res->wq);
2141                         }
2142                 }
2143         }
2144 }
2145 
2146 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
2147 {
2148         if (local) {
2149                 if (lock->ml.type != LKM_EXMODE &&
2150                     lock->ml.type != LKM_PRMODE)
2151                         return 1;
2152         } else if (lock->ml.type == LKM_EXMODE)
2153                 return 1;
2154         return 0;
2155 }
2156 
2157 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2158                                struct dlm_lock_resource *res, u8 dead_node)
2159 {
2160         struct list_head *queue;
2161         struct dlm_lock *lock;
2162         int blank_lvb = 0, local = 0;
2163         int i;
2164         u8 search_node;
2165 
2166         assert_spin_locked(&dlm->spinlock);
2167         assert_spin_locked(&res->spinlock);
2168 
2169         if (res->owner == dlm->node_num)
2170                 /* if this node owned the lockres, and if the dead node
2171                  * had an EX when he died, blank out the lvb */
2172                 search_node = dead_node;
2173         else {
2174                 /* if this is a secondary lockres, and we had no EX or PR
2175                  * locks granted, we can no longer trust the lvb */
2176                 search_node = dlm->node_num;
2177                 local = 1;  /* check local state for valid lvb */
2178         }
2179 
2180         for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2181                 queue = dlm_list_idx_to_ptr(res, i);
2182                 list_for_each_entry(lock, queue, list) {
2183                         if (lock->ml.node == search_node) {
2184                                 if (dlm_lvb_needs_invalidation(lock, local)) {
2185                                         /* zero the lksb lvb and lockres lvb */
2186                                         blank_lvb = 1;
2187                                         memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2188                                 }
2189                         }
2190                 }
2191         }
2192 
2193         if (blank_lvb) {
2194                 mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2195                      res->lockname.len, res->lockname.name, dead_node);
2196                 memset(res->lvb, 0, DLM_LVB_LEN);
2197         }
2198 }
2199 
2200 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2201                                 struct dlm_lock_resource *res, u8 dead_node)
2202 {
2203         struct dlm_lock *lock, *next;
2204         unsigned int freed = 0;
2205 
2206         /* this node is the lockres master:
2207          * 1) remove any stale locks for the dead node
2208          * 2) if the dead node had an EX when he died, blank out the lvb
2209          */
2210         assert_spin_locked(&dlm->spinlock);
2211         assert_spin_locked(&res->spinlock);
2212 
2213         /* We do two dlm_lock_put(). One for removing from list and the other is
2214          * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
2215 
2216         /* TODO: check pending_asts, pending_basts here */
2217         list_for_each_entry_safe(lock, next, &res->granted, list) {
2218                 if (lock->ml.node == dead_node) {
2219                         list_del_init(&lock->list);
2220                         dlm_lock_put(lock);
2221                         /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2222                         dlm_lock_put(lock);
2223                         freed++;
2224                 }
2225         }
2226         list_for_each_entry_safe(lock, next, &res->converting, list) {
2227                 if (lock->ml.node == dead_node) {
2228                         list_del_init(&lock->list);
2229                         dlm_lock_put(lock);
2230                         /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2231                         dlm_lock_put(lock);
2232                         freed++;
2233                 }
2234         }
2235         list_for_each_entry_safe(lock, next, &res->blocked, list) {
2236                 if (lock->ml.node == dead_node) {
2237                         list_del_init(&lock->list);
2238                         dlm_lock_put(lock);
2239                         /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2240                         dlm_lock_put(lock);
2241                         freed++;
2242                 }
2243         }
2244 
2245         if (freed) {
2246                 mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
2247                      "dropping ref from lockres\n", dlm->name,
2248                      res->lockname.len, res->lockname.name, freed, dead_node);
2249                 if(!test_bit(dead_node, res->refmap)) {
2250                         mlog(ML_ERROR, "%s:%.*s: freed %u locks for dead node %u, "
2251                              "but ref was not set\n", dlm->name,
2252                              res->lockname.len, res->lockname.name, freed, dead_node);
2253                         __dlm_print_one_lock_resource(res);
2254                 }
2255                 dlm_lockres_clear_refmap_bit(dead_node, res);
2256         } else if (test_bit(dead_node, res->refmap)) {
2257                 mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2258                      "no locks and had not purged before dying\n", dlm->name,
2259                      res->lockname.len, res->lockname.name, dead_node);
2260                 dlm_lockres_clear_refmap_bit(dead_node, res);
2261         }
2262 
2263         /* do not kick thread yet */
2264         __dlm_dirty_lockres(dlm, res);
2265 }
2266 
2267 /* if this node is the recovery master, and there are no
2268  * locks for a given lockres owned by this node that are in
2269  * either PR or EX mode, zero out the lvb before requesting.
2270  *
2271  */
2272 
2273 
2274 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2275 {
2276         struct hlist_node *iter;
2277         struct dlm_lock_resource *res;
2278         int i;
2279         struct hlist_head *bucket;
2280         struct dlm_lock *lock;
2281 
2282 
2283         /* purge any stale mles */
2284         dlm_clean_master_list(dlm, dead_node);
2285 
2286         /*
2287          * now clean up all lock resources.  there are two rules:
2288          *
2289          * 1) if the dead node was the master, move the lockres
2290          *    to the recovering list.  set the RECOVERING flag.
2291          *    this lockres needs to be cleaned up before it can
2292          *    be used further.
2293          *
2294          * 2) if this node was the master, remove all locks from
2295          *    each of the lockres queues that were owned by the
2296          *    dead node.  once recovery finishes, the dlm thread
2297          *    can be kicked again to see if any ASTs or BASTs
2298          *    need to be fired as a result.
2299          */
2300         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2301                 bucket = dlm_lockres_hash(dlm, i);
2302                 hlist_for_each_entry(res, iter, bucket, hash_node) {
2303                         /* always prune any $RECOVERY entries for dead nodes,
2304                          * otherwise hangs can occur during later recovery */
2305                         if (dlm_is_recovery_lock(res->lockname.name,
2306                                                  res->lockname.len)) {
2307                                 spin_lock(&res->spinlock);
2308                                 list_for_each_entry(lock, &res->granted, list) {
2309                                         if (lock->ml.node == dead_node) {
2310                                                 mlog(0, "AHA! there was "
2311                                                      "a $RECOVERY lock for dead "
2312                                                      "node %u (%s)!\n",
2313                                                      dead_node, dlm->name);
2314                                                 list_del_init(&lock->list);
2315                                                 dlm_lock_put(lock);
2316                                                 break;
2317                                         }
2318                                 }
2319                                 spin_unlock(&res->spinlock);
2320                                 continue;
2321                         }
2322                         spin_lock(&res->spinlock);
2323                         /* zero the lvb if necessary */
2324                         dlm_revalidate_lvb(dlm, res, dead_node);
2325                         if (res->owner == dead_node) {
2326                                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
2327                                         mlog(ML_NOTICE, "Ignore %.*s for "
2328                                              "recovery as it is being freed\n",
2329                                              res->lockname.len,
2330                                              res->lockname.name);
2331                                 } else
2332                                         dlm_move_lockres_to_recovery_list(dlm,
2333                                                                           res);
2334 
2335                         } else if (res->owner == dlm->node_num) {
2336                                 dlm_free_dead_locks(dlm, res, dead_node);
2337                                 __dlm_lockres_calc_usage(dlm, res);
2338                         }
2339                         spin_unlock(&res->spinlock);
2340                 }
2341         }
2342 
2343 }
2344 
2345 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2346 {
2347         assert_spin_locked(&dlm->spinlock);
2348 
2349         if (dlm->reco.new_master == idx) {
2350                 mlog(0, "%s: recovery master %d just died\n",
2351                      dlm->name, idx);
2352                 if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2353                         /* finalize1 was reached, so it is safe to clear
2354                          * the new_master and dead_node.  that recovery
2355                          * is complete. */
2356                         mlog(0, "%s: dead master %d had reached "
2357                              "finalize1 state, clearing\n", dlm->name, idx);
2358                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2359                         __dlm_reset_recovery(dlm);
2360                 }
2361         }
2362 
2363         /* Clean up join state on node death. */
2364         if (dlm->joining_node == idx) {
2365                 mlog(0, "Clearing join state for node %u\n", idx);
2366                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2367         }
2368 
2369         /* check to see if the node is already considered dead */
2370         if (!test_bit(idx, dlm->live_nodes_map)) {
2371                 mlog(0, "for domain %s, node %d is already dead. "
2372                      "another node likely did recovery already.\n",
2373                      dlm->name, idx);
2374                 return;
2375         }
2376 
2377         /* check to see if we do not care about this node */
2378         if (!test_bit(idx, dlm->domain_map)) {
2379                 /* This also catches the case that we get a node down
2380                  * but haven't joined the domain yet. */
2381                 mlog(0, "node %u already removed from domain!\n", idx);
2382                 return;
2383         }
2384 
2385         clear_bit(idx, dlm->live_nodes_map);
2386 
2387         /* make sure local cleanup occurs before the heartbeat events */
2388         if (!test_bit(idx, dlm->recovery_map))
2389                 dlm_do_local_recovery_cleanup(dlm, idx);
2390 
2391         /* notify anything attached to the heartbeat events */
2392         dlm_hb_event_notify_attached(dlm, idx, 0);
2393 
2394         mlog(0, "node %u being removed from domain map!\n", idx);
2395         clear_bit(idx, dlm->domain_map);
2396         clear_bit(idx, dlm->exit_domain_map);
2397         /* wake up migration waiters if a node goes down.
2398          * perhaps later we can genericize this for other waiters. */
2399         wake_up(&dlm->migration_wq);
2400 
2401         if (test_bit(idx, dlm->recovery_map))
2402                 mlog(0, "domain %s, node %u already added "
2403                      "to recovery map!\n", dlm->name, idx);
2404         else
2405                 set_bit(idx, dlm->recovery_map);
2406 }
2407 
2408 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2409 {
2410         struct dlm_ctxt *dlm = data;
2411 
2412         if (!dlm_grab(dlm))
2413                 return;
2414 
2415         /*
2416          * This will notify any dlm users that a node in our domain
2417          * went away without notifying us first.
2418          */
2419         if (test_bit(idx, dlm->domain_map))
2420                 dlm_fire_domain_eviction_callbacks(dlm, idx);
2421 
2422         spin_lock(&dlm->spinlock);
2423         __dlm_hb_node_down(dlm, idx);
2424         spin_unlock(&dlm->spinlock);
2425 
2426         dlm_put(dlm);
2427 }
2428 
2429 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2430 {
2431         struct dlm_ctxt *dlm = data;
2432 
2433         if (!dlm_grab(dlm))
2434                 return;
2435 
2436         spin_lock(&dlm->spinlock);
2437         set_bit(idx, dlm->live_nodes_map);
2438         /* do NOT notify mle attached to the heartbeat events.
2439          * new nodes are not interesting in mastery until joined. */
2440         spin_unlock(&dlm->spinlock);
2441 
2442         dlm_put(dlm);
2443 }
2444 
2445 static void dlm_reco_ast(void *astdata)
2446 {
2447         struct dlm_ctxt *dlm = astdata;
2448         mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2449              dlm->node_num, dlm->name);
2450 }
2451 static void dlm_reco_bast(void *astdata, int blocked_type)
2452 {
2453         struct dlm_ctxt *dlm = astdata;
2454         mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2455              dlm->node_num, dlm->name);
2456 }
2457 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2458 {
2459         mlog(0, "unlockast for recovery lock fired!\n");
2460 }
2461 
2462 /*
2463  * dlm_pick_recovery_master will continually attempt to use
2464  * dlmlock() on the special "$RECOVERY" lockres with the
2465  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2466  * this function on each node racing to become the recovery
2467  * master will not stop attempting this until either:
2468  * a) this node gets the EX (and becomes the recovery master),
2469  * or b) dlm->reco.new_master gets set to some nodenum
2470  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2471  * so each time a recovery master is needed, the entire cluster
2472  * will sync at this point.  if the new master dies, that will
2473  * be detected in dlm_do_recovery */
2474 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2475 {
2476         enum dlm_status ret;
2477         struct dlm_lockstatus lksb;
2478         int status = -EINVAL;
2479 
2480         mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2481              dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2482 again:
2483         memset(&lksb, 0, sizeof(lksb));
2484 
2485         ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2486                       DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2487                       dlm_reco_ast, dlm, dlm_reco_bast);
2488 
2489         mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2490              dlm->name, ret, lksb.status);
2491 
2492         if (ret == DLM_NORMAL) {
2493                 mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2494                      dlm->name, dlm->node_num);
2495 
2496                 /* got the EX lock.  check to see if another node
2497                  * just became the reco master */
2498                 if (dlm_reco_master_ready(dlm)) {
2499                         mlog(0, "%s: got reco EX lock, but %u will "
2500                              "do the recovery\n", dlm->name,
2501                              dlm->reco.new_master);
2502                         status = -EEXIST;
2503                 } else {
2504                         status = 0;
2505 
2506                         /* see if recovery was already finished elsewhere */
2507                         spin_lock(&dlm->spinlock);
2508                         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2509                                 status = -EINVAL;
2510                                 mlog(0, "%s: got reco EX lock, but "
2511                                      "node got recovered already\n", dlm->name);
2512                                 if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2513                                         mlog(ML_ERROR, "%s: new master is %u "
2514                                              "but no dead node!\n",
2515                                              dlm->name, dlm->reco.new_master);
2516                                         BUG();
2517                                 }
2518                         }
2519                         spin_unlock(&dlm->spinlock);
2520                 }
2521 
2522                 /* if this node has actually become the recovery master,
2523                  * set the master and send the messages to begin recovery */
2524                 if (!status) {
2525                         mlog(0, "%s: dead=%u, this=%u, sending "
2526                              "begin_reco now\n", dlm->name,
2527                              dlm->reco.dead_node, dlm->node_num);
2528                         status = dlm_send_begin_reco_message(dlm,
2529                                       dlm->reco.dead_node);
2530                         /* this always succeeds */
2531                         BUG_ON(status);
2532 
2533                         /* set the new_master to this node */
2534                         spin_lock(&dlm->spinlock);
2535                         dlm_set_reco_master(dlm, dlm->node_num);
2536                         spin_unlock(&dlm->spinlock);
2537                 }
2538 
2539                 /* recovery lock is a special case.  ast will not get fired,
2540                  * so just go ahead and unlock it. */
2541                 ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2542                 if (ret == DLM_DENIED) {
2543                         mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2544                         ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2545                 }
2546                 if (ret != DLM_NORMAL) {
2547                         /* this would really suck. this could only happen
2548                          * if there was a network error during the unlock
2549                          * because of node death.  this means the unlock
2550                          * is actually "done" and the lock structure is
2551                          * even freed.  we can continue, but only
2552                          * because this specific lock name is special. */
2553                         mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2554                 }
2555         } else if (ret == DLM_NOTQUEUED) {
2556                 mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2557                      dlm->name, dlm->node_num);
2558                 /* another node is master. wait on
2559                  * reco.new_master != O2NM_INVALID_NODE_NUM
2560                  * for at most one second */
2561                 wait_event_timeout(dlm->dlm_reco_thread_wq,
2562                                          dlm_reco_master_ready(dlm),
2563                                          msecs_to_jiffies(1000));
2564                 if (!dlm_reco_master_ready(dlm)) {
2565                         mlog(0, "%s: reco master taking awhile\n",
2566                              dlm->name);
2567                         goto again;
2568                 }
2569                 /* another node has informed this one that it is reco master */
2570                 mlog(0, "%s: reco master %u is ready to recover %u\n",
2571                      dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2572                 status = -EEXIST;
2573         } else if (ret == DLM_RECOVERING) {
2574                 mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2575                      dlm->name, dlm->node_num);
2576                 goto again;
2577         } else {
2578                 struct dlm_lock_resource *res;
2579 
2580                 /* dlmlock returned something other than NOTQUEUED or NORMAL */
2581                 mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2582                      "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2583                      dlm_errname(lksb.status));
2584                 res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2585                                          DLM_RECOVERY_LOCK_NAME_LEN);
2586                 if (res) {
2587                         dlm_print_one_lock_resource(res);
2588                         dlm_lockres_put(res);
2589                 } else {
2590                         mlog(ML_ERROR, "recovery lock not found\n");
2591                 }
2592                 BUG();
2593         }
2594 
2595         return status;
2596 }
2597 
2598 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2599 {
2600         struct dlm_begin_reco br;
2601         int ret = 0;
2602         struct dlm_node_iter iter;
2603         int nodenum;
2604         int status;
2605 
2606         mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2607 
2608         spin_lock(&dlm->spinlock);
2609         dlm_node_iter_init(dlm->domain_map, &iter);
2610         spin_unlock(&dlm->spinlock);
2611 
2612         clear_bit(dead_node, iter.node_map);
2613 
2614         memset(&br, 0, sizeof(br));
2615         br.node_idx = dlm->node_num;
2616         br.dead_node = dead_node;
2617 
2618         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2619                 ret = 0;
2620                 if (nodenum == dead_node) {
2621                         mlog(0, "not sending begin reco to dead node "
2622                                   "%u\n", dead_node);
2623                         continue;
2624                 }
2625                 if (nodenum == dlm->node_num) {
2626                         mlog(0, "not sending begin reco to self\n");
2627                         continue;
2628                 }
2629 retry:
2630                 ret = -EINVAL;
2631                 mlog(0, "attempting to send begin reco msg to %d\n",
2632                           nodenum);
2633                 ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2634                                          &br, sizeof(br), nodenum, &status);
2635                 /* negative status is handled ok by caller here */
2636                 if (ret >= 0)
2637                         ret = status;
2638                 if (dlm_is_host_down(ret)) {
2639                         /* node is down.  not involved in recovery
2640                          * so just keep going */
2641                         mlog(ML_NOTICE, "%s: node %u was down when sending "
2642                              "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2643                         ret = 0;
2644                 }
2645 
2646                 /*
2647                  * Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
2648                  * dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
2649                  * We are handling both for compatibility reasons.
2650                  */
2651                 if (ret == -EAGAIN || ret == EAGAIN) {
2652                         mlog(0, "%s: trying to start recovery of node "
2653                              "%u, but node %u is waiting for last recovery "
2654                              "to complete, backoff for a bit\n", dlm->name,
2655                              dead_node, nodenum);
2656                         msleep(100);
2657                         goto retry;
2658                 }
2659                 if (ret < 0) {
2660                         struct dlm_lock_resource *res;
2661 
2662                         /* this is now a serious problem, possibly ENOMEM
2663                          * in the network stack.  must retry */
2664                         mlog_errno(ret);
2665                         mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2666                              "returned %d\n", dlm->name, nodenum, ret);
2667                         res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2668                                                  DLM_RECOVERY_LOCK_NAME_LEN);
2669                         if (res) {
2670                                 dlm_print_one_lock_resource(res);
2671                                 dlm_lockres_put(res);
2672                         } else {
2673                                 mlog(ML_ERROR, "recovery lock not found\n");
2674                         }
2675                         /* sleep for a bit in hopes that we can avoid
2676                          * another ENOMEM */
2677                         msleep(100);
2678                         goto retry;
2679                 }
2680         }
2681 
2682         return ret;
2683 }
2684 
2685 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2686                            void **ret_data)
2687 {
2688         struct dlm_ctxt *dlm = data;
2689         struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2690 
2691         /* ok to return 0, domain has gone away */
2692         if (!dlm_grab(dlm))
2693                 return 0;
2694 
2695         spin_lock(&dlm->spinlock);
2696         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2697                 mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2698                      "but this node is in finalize state, waiting on finalize2\n",
2699                      dlm->name, br->node_idx, br->dead_node,
2700                      dlm->reco.dead_node, dlm->reco.new_master);
2701                 spin_unlock(&dlm->spinlock);
2702                 return -EAGAIN;
2703         }
2704         spin_unlock(&dlm->spinlock);
2705 
2706         mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2707              dlm->name, br->node_idx, br->dead_node,
2708              dlm->reco.dead_node, dlm->reco.new_master);
2709 
2710         dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2711 
2712         spin_lock(&dlm->spinlock);
2713         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2714                 if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2715                         mlog(0, "%s: new_master %u died, changing "
2716                              "to %u\n", dlm->name, dlm->reco.new_master,
2717                              br->node_idx);
2718                 } else {
2719                         mlog(0, "%s: new_master %u NOT DEAD, changing "
2720                              "to %u\n", dlm->name, dlm->reco.new_master,
2721                              br->node_idx);
2722                         /* may not have seen the new master as dead yet */
2723                 }
2724         }
2725         if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2726                 mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2727                      "node %u changing it to %u\n", dlm->name,
2728                      dlm->reco.dead_node, br->node_idx, br->dead_node);
2729         }
2730         dlm_set_reco_master(dlm, br->node_idx);
2731         dlm_set_reco_dead_node(dlm, br->dead_node);
2732         if (!test_bit(br->dead_node, dlm->recovery_map)) {
2733                 mlog(0, "recovery master %u sees %u as dead, but this "
2734                      "node has not yet.  marking %u as dead\n",
2735                      br->node_idx, br->dead_node, br->dead_node);
2736                 if (!test_bit(br->dead_node, dlm->domain_map) ||
2737                     !test_bit(br->dead_node, dlm->live_nodes_map))
2738                         mlog(0, "%u not in domain/live_nodes map "
2739                              "so setting it in reco map manually\n",
2740                              br->dead_node);
2741                 /* force the recovery cleanup in __dlm_hb_node_down
2742                  * both of these will be cleared in a moment */
2743                 set_bit(br->dead_node, dlm->domain_map);
2744                 set_bit(br->dead_node, dlm->live_nodes_map);
2745                 __dlm_hb_node_down(dlm, br->dead_node);
2746         }
2747         spin_unlock(&dlm->spinlock);
2748 
2749         dlm_kick_recovery_thread(dlm);
2750 
2751         mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2752              dlm->name, br->node_idx, br->dead_node,
2753              dlm->reco.dead_node, dlm->reco.new_master);
2754 
2755         dlm_put(dlm);
2756         return 0;
2757 }
2758 
2759 #define DLM_FINALIZE_STAGE2  0x01
2760 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2761 {
2762         int ret = 0;
2763         struct dlm_finalize_reco fr;
2764         struct dlm_node_iter iter;
2765         int nodenum;
2766         int status;
2767         int stage = 1;
2768 
2769         mlog(0, "finishing recovery for node %s:%u, "
2770              "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2771 
2772         spin_lock(&dlm->spinlock);
2773         dlm_node_iter_init(dlm->domain_map, &iter);
2774         spin_unlock(&dlm->spinlock);
2775 
2776 stage2:
2777         memset(&fr, 0, sizeof(fr));
2778         fr.node_idx = dlm->node_num;
2779         fr.dead_node = dlm->reco.dead_node;
2780         if (stage == 2)
2781                 fr.flags |= DLM_FINALIZE_STAGE2;
2782 
2783         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2784                 if (nodenum == dlm->node_num)
2785                         continue;
2786                 ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2787                                          &fr, sizeof(fr), nodenum, &status);
2788                 if (ret >= 0)
2789                         ret = status;
2790                 if (ret < 0) {
2791                         mlog(ML_ERROR, "Error %d when sending message %u (key "
2792                              "0x%x) to node %u\n", ret, DLM_FINALIZE_RECO_MSG,
2793                              dlm->key, nodenum);
2794                         if (dlm_is_host_down(ret)) {
2795                                 /* this has no effect on this recovery
2796                                  * session, so set the status to zero to
2797                                  * finish out the last recovery */
2798                                 mlog(ML_ERROR, "node %u went down after this "
2799                                      "node finished recovery.\n", nodenum);
2800                                 ret = 0;
2801                                 continue;
2802                         }
2803                         break;
2804                 }
2805         }
2806         if (stage == 1) {
2807                 /* reset the node_iter back to the top and send finalize2 */
2808                 iter.curnode = -1;
2809                 stage = 2;
2810                 goto stage2;
2811         }
2812 
2813         return ret;
2814 }
2815 
2816 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2817                               void **ret_data)
2818 {
2819         struct dlm_ctxt *dlm = data;
2820         struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2821         int stage = 1;
2822 
2823         /* ok to return 0, domain has gone away */
2824         if (!dlm_grab(dlm))
2825                 return 0;
2826 
2827         if (fr->flags & DLM_FINALIZE_STAGE2)
2828                 stage = 2;
2829 
2830         mlog(0, "%s: node %u finalizing recovery stage%d of "
2831              "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2832              fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2833 
2834         spin_lock(&dlm->spinlock);
2835 
2836         if (dlm->reco.new_master != fr->node_idx) {
2837                 mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2838                      "%u is supposed to be the new master, dead=%u\n",
2839                      fr->node_idx, dlm->reco.new_master, fr->dead_node);
2840                 BUG();
2841         }
2842         if (dlm->reco.dead_node != fr->dead_node) {
2843                 mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2844                      "node %u, but node %u is supposed to be dead\n",
2845                      fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2846                 BUG();
2847         }
2848 
2849         switch (stage) {
2850                 case 1:
2851                         dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2852                         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2853                                 mlog(ML_ERROR, "%s: received finalize1 from "
2854                                      "new master %u for dead node %u, but "
2855                                      "this node has already received it!\n",
2856                                      dlm->name, fr->node_idx, fr->dead_node);
2857                                 dlm_print_reco_node_status(dlm);
2858                                 BUG();
2859                         }
2860                         dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2861                         spin_unlock(&dlm->spinlock);
2862                         break;
2863                 case 2:
2864                         if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2865                                 mlog(ML_ERROR, "%s: received finalize2 from "
2866                                      "new master %u for dead node %u, but "
2867                                      "this node did not have finalize1!\n",
2868                                      dlm->name, fr->node_idx, fr->dead_node);
2869                                 dlm_print_reco_node_status(dlm);
2870                                 BUG();
2871                         }
2872                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2873                         spin_unlock(&dlm->spinlock);
2874                         dlm_reset_recovery(dlm);
2875                         dlm_kick_recovery_thread(dlm);
2876                         break;
2877                 default:
2878                         BUG();
2879         }
2880 
2881         mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2882              dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2883 
2884         dlm_put(dlm);
2885         return 0;
2886 }
2887 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp