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

Version: ~ [ linux-4.18-rc5 ] ~ [ linux-4.17.6 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.55 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.112 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.140 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.115 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.57 ] ~ [ 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-2.6.27.62 ] ~ [ 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 static int dlm_do_recovery(struct dlm_ctxt *dlm);
 59 
 60 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm);
 61 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node);
 62 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node);
 63 static int dlm_request_all_locks(struct dlm_ctxt *dlm,
 64                                  u8 request_from, u8 dead_node);
 65 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm);
 66 
 67 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res);
 68 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
 69                                         const char *lockname, int namelen,
 70                                         int total_locks, u64 cookie,
 71                                         u8 flags, u8 master);
 72 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
 73                                     struct dlm_migratable_lockres *mres,
 74                                     u8 send_to,
 75                                     struct dlm_lock_resource *res,
 76                                     int total_locks);
 77 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
 78                                      struct dlm_lock_resource *res,
 79                                      struct dlm_migratable_lockres *mres);
 80 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm);
 81 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm,
 82                                  u8 dead_node, u8 send_to);
 83 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node);
 84 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
 85                                         struct list_head *list, u8 dead_node);
 86 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
 87                                               u8 dead_node, u8 new_master);
 88 static void dlm_reco_ast(void *astdata);
 89 static void dlm_reco_bast(void *astdata, int blocked_type);
 90 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st);
 91 static void dlm_request_all_locks_worker(struct dlm_work_item *item,
 92                                          void *data);
 93 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data);
 94 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
 95                                       struct dlm_lock_resource *res,
 96                                       u8 *real_master);
 97 
 98 static u64 dlm_get_next_mig_cookie(void);
 99 
100 static DEFINE_SPINLOCK(dlm_reco_state_lock);
101 static DEFINE_SPINLOCK(dlm_mig_cookie_lock);
102 static u64 dlm_mig_cookie = 1;
103 
104 static u64 dlm_get_next_mig_cookie(void)
105 {
106         u64 c;
107         spin_lock(&dlm_mig_cookie_lock);
108         c = dlm_mig_cookie;
109         if (dlm_mig_cookie == (~0ULL))
110                 dlm_mig_cookie = 1;
111         else
112                 dlm_mig_cookie++;
113         spin_unlock(&dlm_mig_cookie_lock);
114         return c;
115 }
116 
117 static inline void dlm_set_reco_dead_node(struct dlm_ctxt *dlm,
118                                           u8 dead_node)
119 {
120         assert_spin_locked(&dlm->spinlock);
121         if (dlm->reco.dead_node != dead_node)
122                 mlog(0, "%s: changing dead_node from %u to %u\n",
123                      dlm->name, dlm->reco.dead_node, dead_node);
124         dlm->reco.dead_node = dead_node;
125 }
126 
127 static inline void dlm_set_reco_master(struct dlm_ctxt *dlm,
128                                        u8 master)
129 {
130         assert_spin_locked(&dlm->spinlock);
131         mlog(0, "%s: changing new_master from %u to %u\n",
132              dlm->name, dlm->reco.new_master, master);
133         dlm->reco.new_master = master;
134 }
135 
136 static inline void __dlm_reset_recovery(struct dlm_ctxt *dlm)
137 {
138         assert_spin_locked(&dlm->spinlock);
139         clear_bit(dlm->reco.dead_node, dlm->recovery_map);
140         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
141         dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
142 }
143 
144 static inline void dlm_reset_recovery(struct dlm_ctxt *dlm)
145 {
146         spin_lock(&dlm->spinlock);
147         __dlm_reset_recovery(dlm);
148         spin_unlock(&dlm->spinlock);
149 }
150 
151 /* Worker function used during recovery. */
152 void dlm_dispatch_work(struct work_struct *work)
153 {
154         struct dlm_ctxt *dlm =
155                 container_of(work, struct dlm_ctxt, dispatched_work);
156         LIST_HEAD(tmp_list);
157         struct dlm_work_item *item, *next;
158         dlm_workfunc_t *workfunc;
159         int tot=0;
160 
161         spin_lock(&dlm->work_lock);
162         list_splice_init(&dlm->work_list, &tmp_list);
163         spin_unlock(&dlm->work_lock);
164 
165         list_for_each_entry(item, &tmp_list, list) {
166                 tot++;
167         }
168         mlog(0, "%s: work thread has %d work items\n", dlm->name, tot);
169 
170         list_for_each_entry_safe(item, next, &tmp_list, list) {
171                 workfunc = item->func;
172                 list_del_init(&item->list);
173 
174                 /* already have ref on dlm to avoid having
175                  * it disappear.  just double-check. */
176                 BUG_ON(item->dlm != dlm);
177 
178                 /* this is allowed to sleep and
179                  * call network stuff */
180                 workfunc(item, item->data);
181 
182                 dlm_put(dlm);
183                 kfree(item);
184         }
185 }
186 
187 /*
188  * RECOVERY THREAD
189  */
190 
191 void dlm_kick_recovery_thread(struct dlm_ctxt *dlm)
192 {
193         /* wake the recovery thread
194          * this will wake the reco thread in one of three places
195          * 1) sleeping with no recovery happening
196          * 2) sleeping with recovery mastered elsewhere
197          * 3) recovery mastered here, waiting on reco data */
198 
199         wake_up(&dlm->dlm_reco_thread_wq);
200 }
201 
202 /* Launch the recovery thread */
203 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
204 {
205         mlog(0, "starting dlm recovery thread...\n");
206 
207         dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
208                         "dlm_reco-%s", dlm->name);
209         if (IS_ERR(dlm->dlm_reco_thread_task)) {
210                 mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
211                 dlm->dlm_reco_thread_task = NULL;
212                 return -EINVAL;
213         }
214 
215         return 0;
216 }
217 
218 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm)
219 {
220         if (dlm->dlm_reco_thread_task) {
221                 mlog(0, "waiting for dlm recovery thread to exit\n");
222                 kthread_stop(dlm->dlm_reco_thread_task);
223                 dlm->dlm_reco_thread_task = NULL;
224         }
225 }
226 
227 
228 
229 /*
230  * this is lame, but here's how recovery works...
231  * 1) all recovery threads cluster wide will work on recovering
232  *    ONE node at a time
233  * 2) negotiate who will take over all the locks for the dead node.
234  *    thats right... ALL the locks.
235  * 3) once a new master is chosen, everyone scans all locks
236  *    and moves aside those mastered by the dead guy
237  * 4) each of these locks should be locked until recovery is done
238  * 5) the new master collects up all of secondary lock queue info
239  *    one lock at a time, forcing each node to communicate back
240  *    before continuing
241  * 6) each secondary lock queue responds with the full known lock info
242  * 7) once the new master has run all its locks, it sends a ALLDONE!
243  *    message to everyone
244  * 8) upon receiving this message, the secondary queue node unlocks
245  *    and responds to the ALLDONE
246  * 9) once the new master gets responses from everyone, he unlocks
247  *    everything and recovery for this dead node is done
248  *10) go back to 2) while there are still dead nodes
249  *
250  */
251 
252 static void dlm_print_reco_node_status(struct dlm_ctxt *dlm)
253 {
254         struct dlm_reco_node_data *ndata;
255         struct dlm_lock_resource *res;
256 
257         mlog(ML_NOTICE, "%s(%d): recovery info, state=%s, dead=%u, master=%u\n",
258              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
259              dlm->reco.state & DLM_RECO_STATE_ACTIVE ? "ACTIVE" : "inactive",
260              dlm->reco.dead_node, dlm->reco.new_master);
261 
262         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
263                 char *st = "unknown";
264                 switch (ndata->state) {
265                         case DLM_RECO_NODE_DATA_INIT:
266                                 st = "init";
267                                 break;
268                         case DLM_RECO_NODE_DATA_REQUESTING:
269                                 st = "requesting";
270                                 break;
271                         case DLM_RECO_NODE_DATA_DEAD:
272                                 st = "dead";
273                                 break;
274                         case DLM_RECO_NODE_DATA_RECEIVING:
275                                 st = "receiving";
276                                 break;
277                         case DLM_RECO_NODE_DATA_REQUESTED:
278                                 st = "requested";
279                                 break;
280                         case DLM_RECO_NODE_DATA_DONE:
281                                 st = "done";
282                                 break;
283                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
284                                 st = "finalize-sent";
285                                 break;
286                         default:
287                                 st = "bad";
288                                 break;
289                 }
290                 mlog(ML_NOTICE, "%s: reco state, node %u, state=%s\n",
291                      dlm->name, ndata->node_num, st);
292         }
293         list_for_each_entry(res, &dlm->reco.resources, recovering) {
294                 mlog(ML_NOTICE, "%s: lockres %.*s on recovering list\n",
295                      dlm->name, res->lockname.len, res->lockname.name);
296         }
297 }
298 
299 #define DLM_RECO_THREAD_TIMEOUT_MS (5 * 1000)
300 
301 static int dlm_recovery_thread(void *data)
302 {
303         int status;
304         struct dlm_ctxt *dlm = data;
305         unsigned long timeout = msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS);
306 
307         mlog(0, "dlm thread running for %s...\n", dlm->name);
308 
309         while (!kthread_should_stop()) {
310                 if (dlm_domain_fully_joined(dlm)) {
311                         status = dlm_do_recovery(dlm);
312                         if (status == -EAGAIN) {
313                                 /* do not sleep, recheck immediately. */
314                                 continue;
315                         }
316                         if (status < 0)
317                                 mlog_errno(status);
318                 }
319 
320                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
321                                                  kthread_should_stop(),
322                                                  timeout);
323         }
324 
325         mlog(0, "quitting DLM recovery thread\n");
326         return 0;
327 }
328 
329 /* returns true when the recovery master has contacted us */
330 static int dlm_reco_master_ready(struct dlm_ctxt *dlm)
331 {
332         int ready;
333         spin_lock(&dlm->spinlock);
334         ready = (dlm->reco.new_master != O2NM_INVALID_NODE_NUM);
335         spin_unlock(&dlm->spinlock);
336         return ready;
337 }
338 
339 /* returns true if node is no longer in the domain
340  * could be dead or just not joined */
341 int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node)
342 {
343         int dead;
344         spin_lock(&dlm->spinlock);
345         dead = !test_bit(node, dlm->domain_map);
346         spin_unlock(&dlm->spinlock);
347         return dead;
348 }
349 
350 /* returns true if node is no longer in the domain
351  * could be dead or just not joined */
352 static int dlm_is_node_recovered(struct dlm_ctxt *dlm, u8 node)
353 {
354         int recovered;
355         spin_lock(&dlm->spinlock);
356         recovered = !test_bit(node, dlm->recovery_map);
357         spin_unlock(&dlm->spinlock);
358         return recovered;
359 }
360 
361 
362 void dlm_wait_for_node_death(struct dlm_ctxt *dlm, u8 node, int timeout)
363 {
364         if (dlm_is_node_dead(dlm, node))
365                 return;
366 
367         printk(KERN_NOTICE "o2dlm: Waiting on the death of node %u in "
368                "domain %s\n", node, dlm->name);
369 
370         if (timeout)
371                 wait_event_timeout(dlm->dlm_reco_thread_wq,
372                                    dlm_is_node_dead(dlm, node),
373                                    msecs_to_jiffies(timeout));
374         else
375                 wait_event(dlm->dlm_reco_thread_wq,
376                            dlm_is_node_dead(dlm, node));
377 }
378 
379 void dlm_wait_for_node_recovery(struct dlm_ctxt *dlm, u8 node, int timeout)
380 {
381         if (dlm_is_node_recovered(dlm, node))
382                 return;
383 
384         printk(KERN_NOTICE "o2dlm: Waiting on the recovery of node %u in "
385                "domain %s\n", node, dlm->name);
386 
387         if (timeout)
388                 wait_event_timeout(dlm->dlm_reco_thread_wq,
389                                    dlm_is_node_recovered(dlm, node),
390                                    msecs_to_jiffies(timeout));
391         else
392                 wait_event(dlm->dlm_reco_thread_wq,
393                            dlm_is_node_recovered(dlm, node));
394 }
395 
396 /* callers of the top-level api calls (dlmlock/dlmunlock) should
397  * block on the dlm->reco.event when recovery is in progress.
398  * the dlm recovery thread will set this state when it begins
399  * recovering a dead node (as the new master or not) and clear
400  * the state and wake as soon as all affected lock resources have
401  * been marked with the RECOVERY flag */
402 static int dlm_in_recovery(struct dlm_ctxt *dlm)
403 {
404         int in_recovery;
405         spin_lock(&dlm->spinlock);
406         in_recovery = !!(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
407         spin_unlock(&dlm->spinlock);
408         return in_recovery;
409 }
410 
411 
412 void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
413 {
414         if (dlm_in_recovery(dlm)) {
415                 mlog(0, "%s: reco thread %d in recovery: "
416                      "state=%d, master=%u, dead=%u\n",
417                      dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
418                      dlm->reco.state, dlm->reco.new_master,
419                      dlm->reco.dead_node);
420         }
421         wait_event(dlm->reco.event, !dlm_in_recovery(dlm));
422 }
423 
424 static void dlm_begin_recovery(struct dlm_ctxt *dlm)
425 {
426         assert_spin_locked(&dlm->spinlock);
427         BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
428         printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node %u\n",
429                dlm->name, dlm->reco.dead_node);
430         dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
431 }
432 
433 static void dlm_end_recovery(struct dlm_ctxt *dlm)
434 {
435         spin_lock(&dlm->spinlock);
436         BUG_ON(!(dlm->reco.state & DLM_RECO_STATE_ACTIVE));
437         dlm->reco.state &= ~DLM_RECO_STATE_ACTIVE;
438         spin_unlock(&dlm->spinlock);
439         printk(KERN_NOTICE "o2dlm: End recovery on domain %s\n", dlm->name);
440         wake_up(&dlm->reco.event);
441 }
442 
443 static void dlm_print_recovery_master(struct dlm_ctxt *dlm)
444 {
445         printk(KERN_NOTICE "o2dlm: Node %u (%s) is the Recovery Master for the "
446                "dead node %u in domain %s\n", dlm->reco.new_master,
447                (dlm->node_num == dlm->reco.new_master ? "me" : "he"),
448                dlm->reco.dead_node, dlm->name);
449 }
450 
451 static int dlm_do_recovery(struct dlm_ctxt *dlm)
452 {
453         int status = 0;
454         int ret;
455 
456         spin_lock(&dlm->spinlock);
457 
458         if (dlm->migrate_done) {
459                 mlog(0, "%s: no need do recovery after migrating all "
460                      "lock resources\n", dlm->name);
461                 spin_unlock(&dlm->spinlock);
462                 return 0;
463         }
464 
465         /* check to see if the new master has died */
466         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
467             test_bit(dlm->reco.new_master, dlm->recovery_map)) {
468                 mlog(0, "new master %u died while recovering %u!\n",
469                      dlm->reco.new_master, dlm->reco.dead_node);
470                 /* unset the new_master, leave dead_node */
471                 dlm_set_reco_master(dlm, O2NM_INVALID_NODE_NUM);
472         }
473 
474         /* select a target to recover */
475         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
476                 int bit;
477 
478                 bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
479                 if (bit >= O2NM_MAX_NODES || bit < 0)
480                         dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
481                 else
482                         dlm_set_reco_dead_node(dlm, bit);
483         } else if (!test_bit(dlm->reco.dead_node, dlm->recovery_map)) {
484                 /* BUG? */
485                 mlog(ML_ERROR, "dead_node %u no longer in recovery map!\n",
486                      dlm->reco.dead_node);
487                 dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
488         }
489 
490         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
491                 // mlog(0, "nothing to recover!  sleeping now!\n");
492                 spin_unlock(&dlm->spinlock);
493                 /* return to main thread loop and sleep. */
494                 return 0;
495         }
496         mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n",
497              dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
498              dlm->reco.dead_node);
499 
500         /* take write barrier */
501         /* (stops the list reshuffling thread, proxy ast handling) */
502         dlm_begin_recovery(dlm);
503 
504         spin_unlock(&dlm->spinlock);
505 
506         if (dlm->reco.new_master == dlm->node_num)
507                 goto master_here;
508 
509         if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
510                 /* choose a new master, returns 0 if this node
511                  * is the master, -EEXIST if it's another node.
512                  * this does not return until a new master is chosen
513                  * or recovery completes entirely. */
514                 ret = dlm_pick_recovery_master(dlm);
515                 if (!ret) {
516                         /* already notified everyone.  go. */
517                         goto master_here;
518                 }
519                 mlog(0, "another node will master this recovery session.\n");
520         }
521 
522         dlm_print_recovery_master(dlm);
523 
524         /* it is safe to start everything back up here
525          * because all of the dead node's lock resources
526          * have been marked as in-recovery */
527         dlm_end_recovery(dlm);
528 
529         /* sleep out in main dlm_recovery_thread loop. */
530         return 0;
531 
532 master_here:
533         dlm_print_recovery_master(dlm);
534 
535         status = dlm_remaster_locks(dlm, dlm->reco.dead_node);
536         if (status < 0) {
537                 /* we should never hit this anymore */
538                 mlog(ML_ERROR, "%s: Error %d remastering locks for node %u, "
539                      "retrying.\n", dlm->name, status, dlm->reco.dead_node);
540                 /* yield a bit to allow any final network messages
541                  * to get handled on remaining nodes */
542                 msleep(100);
543         } else {
544                 /* success!  see if any other nodes need recovery */
545                 mlog(0, "DONE mastering recovery of %s:%u here(this=%u)!\n",
546                      dlm->name, dlm->reco.dead_node, dlm->node_num);
547                 spin_lock(&dlm->spinlock);
548                 __dlm_reset_recovery(dlm);
549                 dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
550                 spin_unlock(&dlm->spinlock);
551         }
552         dlm_end_recovery(dlm);
553 
554         /* continue and look for another dead node */
555         return -EAGAIN;
556 }
557 
558 static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
559 {
560         int status = 0;
561         struct dlm_reco_node_data *ndata;
562         int all_nodes_done;
563         int destroy = 0;
564         int pass = 0;
565 
566         do {
567                 /* we have become recovery master.  there is no escaping
568                  * this, so just keep trying until we get it. */
569                 status = dlm_init_recovery_area(dlm, dead_node);
570                 if (status < 0) {
571                         mlog(ML_ERROR, "%s: failed to alloc recovery area, "
572                              "retrying\n", dlm->name);
573                         msleep(1000);
574                 }
575         } while (status != 0);
576 
577         /* safe to access the node data list without a lock, since this
578          * process is the only one to change the list */
579         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
580                 BUG_ON(ndata->state != DLM_RECO_NODE_DATA_INIT);
581                 ndata->state = DLM_RECO_NODE_DATA_REQUESTING;
582 
583                 mlog(0, "%s: Requesting lock info from node %u\n", dlm->name,
584                      ndata->node_num);
585 
586                 if (ndata->node_num == dlm->node_num) {
587                         ndata->state = DLM_RECO_NODE_DATA_DONE;
588                         continue;
589                 }
590 
591                 do {
592                         status = dlm_request_all_locks(dlm, ndata->node_num,
593                                                        dead_node);
594                         if (status < 0) {
595                                 mlog_errno(status);
596                                 if (dlm_is_host_down(status)) {
597                                         /* node died, ignore it for recovery */
598                                         status = 0;
599                                         ndata->state = DLM_RECO_NODE_DATA_DEAD;
600                                         /* wait for the domain map to catch up
601                                          * with the network state. */
602                                         wait_event_timeout(dlm->dlm_reco_thread_wq,
603                                                            dlm_is_node_dead(dlm,
604                                                                 ndata->node_num),
605                                                            msecs_to_jiffies(1000));
606                                         mlog(0, "waited 1 sec for %u, "
607                                              "dead? %s\n", ndata->node_num,
608                                              dlm_is_node_dead(dlm, ndata->node_num) ?
609                                              "yes" : "no");
610                                 } else {
611                                         /* -ENOMEM on the other node */
612                                         mlog(0, "%s: node %u returned "
613                                              "%d during recovery, retrying "
614                                              "after a short wait\n",
615                                              dlm->name, ndata->node_num,
616                                              status);
617                                         msleep(100);
618                                 }
619                         }
620                 } while (status != 0);
621 
622                 spin_lock(&dlm_reco_state_lock);
623                 switch (ndata->state) {
624                         case DLM_RECO_NODE_DATA_INIT:
625                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
626                         case DLM_RECO_NODE_DATA_REQUESTED:
627                                 BUG();
628                                 break;
629                         case DLM_RECO_NODE_DATA_DEAD:
630                                 mlog(0, "node %u died after requesting "
631                                      "recovery info for node %u\n",
632                                      ndata->node_num, dead_node);
633                                 /* fine.  don't need this node's info.
634                                  * continue without it. */
635                                 break;
636                         case DLM_RECO_NODE_DATA_REQUESTING:
637                                 ndata->state = DLM_RECO_NODE_DATA_REQUESTED;
638                                 mlog(0, "now receiving recovery data from "
639                                      "node %u for dead node %u\n",
640                                      ndata->node_num, dead_node);
641                                 break;
642                         case DLM_RECO_NODE_DATA_RECEIVING:
643                                 mlog(0, "already receiving recovery data from "
644                                      "node %u for dead node %u\n",
645                                      ndata->node_num, dead_node);
646                                 break;
647                         case DLM_RECO_NODE_DATA_DONE:
648                                 mlog(0, "already DONE receiving recovery data "
649                                      "from node %u for dead node %u\n",
650                                      ndata->node_num, dead_node);
651                                 break;
652                 }
653                 spin_unlock(&dlm_reco_state_lock);
654         }
655 
656         mlog(0, "%s: Done requesting all lock info\n", dlm->name);
657 
658         /* nodes should be sending reco data now
659          * just need to wait */
660 
661         while (1) {
662                 /* check all the nodes now to see if we are
663                  * done, or if anyone died */
664                 all_nodes_done = 1;
665                 spin_lock(&dlm_reco_state_lock);
666                 list_for_each_entry(ndata, &dlm->reco.node_data, list) {
667                         mlog(0, "checking recovery state of node %u\n",
668                              ndata->node_num);
669                         switch (ndata->state) {
670                                 case DLM_RECO_NODE_DATA_INIT:
671                                 case DLM_RECO_NODE_DATA_REQUESTING:
672                                         mlog(ML_ERROR, "bad ndata state for "
673                                              "node %u: state=%d\n",
674                                              ndata->node_num, ndata->state);
675                                         BUG();
676                                         break;
677                                 case DLM_RECO_NODE_DATA_DEAD:
678                                         mlog(0, "node %u died after "
679                                              "requesting recovery info for "
680                                              "node %u\n", ndata->node_num,
681                                              dead_node);
682                                         break;
683                                 case DLM_RECO_NODE_DATA_RECEIVING:
684                                 case DLM_RECO_NODE_DATA_REQUESTED:
685                                         mlog(0, "%s: node %u still in state %s\n",
686                                              dlm->name, ndata->node_num,
687                                              ndata->state==DLM_RECO_NODE_DATA_RECEIVING ?
688                                              "receiving" : "requested");
689                                         all_nodes_done = 0;
690                                         break;
691                                 case DLM_RECO_NODE_DATA_DONE:
692                                         mlog(0, "%s: node %u state is done\n",
693                                              dlm->name, ndata->node_num);
694                                         break;
695                                 case DLM_RECO_NODE_DATA_FINALIZE_SENT:
696                                         mlog(0, "%s: node %u state is finalize\n",
697                                              dlm->name, ndata->node_num);
698                                         break;
699                         }
700                 }
701                 spin_unlock(&dlm_reco_state_lock);
702 
703                 mlog(0, "pass #%d, all_nodes_done?: %s\n", ++pass,
704                      all_nodes_done?"yes":"no");
705                 if (all_nodes_done) {
706                         int ret;
707 
708                         /* Set this flag on recovery master to avoid
709                          * a new recovery for another dead node start
710                          * before the recovery is not done. That may
711                          * cause recovery hung.*/
712                         spin_lock(&dlm->spinlock);
713                         dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
714                         spin_unlock(&dlm->spinlock);
715 
716                         /* all nodes are now in DLM_RECO_NODE_DATA_DONE state
717                          * just send a finalize message to everyone and
718                          * clean up */
719                         mlog(0, "all nodes are done! send finalize\n");
720                         ret = dlm_send_finalize_reco_message(dlm);
721                         if (ret < 0)
722                                 mlog_errno(ret);
723 
724                         spin_lock(&dlm->spinlock);
725                         dlm_finish_local_lockres_recovery(dlm, dead_node,
726                                                           dlm->node_num);
727                         spin_unlock(&dlm->spinlock);
728                         mlog(0, "should be done with recovery!\n");
729 
730                         mlog(0, "finishing recovery of %s at %lu, "
731                              "dead=%u, this=%u, new=%u\n", dlm->name,
732                              jiffies, dlm->reco.dead_node,
733                              dlm->node_num, dlm->reco.new_master);
734                         destroy = 1;
735                         status = 0;
736                         /* rescan everything marked dirty along the way */
737                         dlm_kick_thread(dlm, NULL);
738                         break;
739                 }
740                 /* wait to be signalled, with periodic timeout
741                  * to check for node death */
742                 wait_event_interruptible_timeout(dlm->dlm_reco_thread_wq,
743                                          kthread_should_stop(),
744                                          msecs_to_jiffies(DLM_RECO_THREAD_TIMEOUT_MS));
745 
746         }
747 
748         if (destroy)
749                 dlm_destroy_recovery_area(dlm);
750 
751         return status;
752 }
753 
754 static int dlm_init_recovery_area(struct dlm_ctxt *dlm, u8 dead_node)
755 {
756         int num=0;
757         struct dlm_reco_node_data *ndata;
758 
759         spin_lock(&dlm->spinlock);
760         memcpy(dlm->reco.node_map, dlm->domain_map, sizeof(dlm->domain_map));
761         /* nodes can only be removed (by dying) after dropping
762          * this lock, and death will be trapped later, so this should do */
763         spin_unlock(&dlm->spinlock);
764 
765         while (1) {
766                 num = find_next_bit (dlm->reco.node_map, O2NM_MAX_NODES, num);
767                 if (num >= O2NM_MAX_NODES) {
768                         break;
769                 }
770                 BUG_ON(num == dead_node);
771 
772                 ndata = kzalloc(sizeof(*ndata), GFP_NOFS);
773                 if (!ndata) {
774                         dlm_destroy_recovery_area(dlm);
775                         return -ENOMEM;
776                 }
777                 ndata->node_num = num;
778                 ndata->state = DLM_RECO_NODE_DATA_INIT;
779                 spin_lock(&dlm_reco_state_lock);
780                 list_add_tail(&ndata->list, &dlm->reco.node_data);
781                 spin_unlock(&dlm_reco_state_lock);
782                 num++;
783         }
784 
785         return 0;
786 }
787 
788 static void dlm_destroy_recovery_area(struct dlm_ctxt *dlm)
789 {
790         struct dlm_reco_node_data *ndata, *next;
791         LIST_HEAD(tmplist);
792 
793         spin_lock(&dlm_reco_state_lock);
794         list_splice_init(&dlm->reco.node_data, &tmplist);
795         spin_unlock(&dlm_reco_state_lock);
796 
797         list_for_each_entry_safe(ndata, next, &tmplist, list) {
798                 list_del_init(&ndata->list);
799                 kfree(ndata);
800         }
801 }
802 
803 static int dlm_request_all_locks(struct dlm_ctxt *dlm, u8 request_from,
804                                  u8 dead_node)
805 {
806         struct dlm_lock_request lr;
807         int ret;
808         int status;
809 
810         mlog(0, "\n");
811 
812 
813         mlog(0, "dlm_request_all_locks: dead node is %u, sending request "
814                   "to %u\n", dead_node, request_from);
815 
816         memset(&lr, 0, sizeof(lr));
817         lr.node_idx = dlm->node_num;
818         lr.dead_node = dead_node;
819 
820         // send message
821         ret = o2net_send_message(DLM_LOCK_REQUEST_MSG, dlm->key,
822                                  &lr, sizeof(lr), request_from, &status);
823 
824         /* negative status is handled by caller */
825         if (ret < 0)
826                 mlog(ML_ERROR, "%s: Error %d send LOCK_REQUEST to node %u "
827                      "to recover dead node %u\n", dlm->name, ret,
828                      request_from, dead_node);
829         else
830                 ret = status;
831         // return from here, then
832         // sleep until all received or error
833         return ret;
834 
835 }
836 
837 int dlm_request_all_locks_handler(struct o2net_msg *msg, u32 len, void *data,
838                                   void **ret_data)
839 {
840         struct dlm_ctxt *dlm = data;
841         struct dlm_lock_request *lr = (struct dlm_lock_request *)msg->buf;
842         char *buf = NULL;
843         struct dlm_work_item *item = NULL;
844 
845         if (!dlm_grab(dlm))
846                 return -EINVAL;
847 
848         if (lr->dead_node != dlm->reco.dead_node) {
849                 mlog(ML_ERROR, "%s: node %u sent dead_node=%u, but local "
850                      "dead_node is %u\n", dlm->name, lr->node_idx,
851                      lr->dead_node, dlm->reco.dead_node);
852                 dlm_print_reco_node_status(dlm);
853                 /* this is a hack */
854                 dlm_put(dlm);
855                 return -ENOMEM;
856         }
857         BUG_ON(lr->dead_node != dlm->reco.dead_node);
858 
859         item = kzalloc(sizeof(*item), GFP_NOFS);
860         if (!item) {
861                 dlm_put(dlm);
862                 return -ENOMEM;
863         }
864 
865         /* this will get freed by dlm_request_all_locks_worker */
866         buf = (char *) __get_free_page(GFP_NOFS);
867         if (!buf) {
868                 kfree(item);
869                 dlm_put(dlm);
870                 return -ENOMEM;
871         }
872 
873         /* queue up work for dlm_request_all_locks_worker */
874         dlm_grab(dlm);  /* get an extra ref for the work item */
875         dlm_init_work_item(dlm, item, dlm_request_all_locks_worker, buf);
876         item->u.ral.reco_master = lr->node_idx;
877         item->u.ral.dead_node = lr->dead_node;
878         spin_lock(&dlm->work_lock);
879         list_add_tail(&item->list, &dlm->work_list);
880         spin_unlock(&dlm->work_lock);
881         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
882 
883         dlm_put(dlm);
884         return 0;
885 }
886 
887 static void dlm_request_all_locks_worker(struct dlm_work_item *item, void *data)
888 {
889         struct dlm_migratable_lockres *mres;
890         struct dlm_lock_resource *res;
891         struct dlm_ctxt *dlm;
892         LIST_HEAD(resources);
893         int ret;
894         u8 dead_node, reco_master;
895         int skip_all_done = 0;
896 
897         dlm = item->dlm;
898         dead_node = item->u.ral.dead_node;
899         reco_master = item->u.ral.reco_master;
900         mres = (struct dlm_migratable_lockres *)data;
901 
902         mlog(0, "%s: recovery worker started, dead=%u, master=%u\n",
903              dlm->name, dead_node, reco_master);
904 
905         if (dead_node != dlm->reco.dead_node ||
906             reco_master != dlm->reco.new_master) {
907                 /* worker could have been created before the recovery master
908                  * died.  if so, do not continue, but do not error. */
909                 if (dlm->reco.new_master == O2NM_INVALID_NODE_NUM) {
910                         mlog(ML_NOTICE, "%s: will not send recovery state, "
911                              "recovery master %u died, thread=(dead=%u,mas=%u)"
912                              " current=(dead=%u,mas=%u)\n", dlm->name,
913                              reco_master, dead_node, reco_master,
914                              dlm->reco.dead_node, dlm->reco.new_master);
915                 } else {
916                         mlog(ML_NOTICE, "%s: reco state invalid: reco(dead=%u, "
917                              "master=%u), request(dead=%u, master=%u)\n",
918                              dlm->name, dlm->reco.dead_node,
919                              dlm->reco.new_master, dead_node, reco_master);
920                 }
921                 goto leave;
922         }
923 
924         /* lock resources should have already been moved to the
925          * dlm->reco.resources list.  now move items from that list
926          * to a temp list if the dead owner matches.  note that the
927          * whole cluster recovers only one node at a time, so we
928          * can safely move UNKNOWN lock resources for each recovery
929          * session. */
930         dlm_move_reco_locks_to_list(dlm, &resources, dead_node);
931 
932         /* now we can begin blasting lockreses without the dlm lock */
933 
934         /* any errors returned will be due to the new_master dying,
935          * the dlm_reco_thread should detect this */
936         list_for_each_entry(res, &resources, recovering) {
937                 ret = dlm_send_one_lockres(dlm, res, mres, reco_master,
938                                         DLM_MRES_RECOVERY);
939                 if (ret < 0) {
940                         mlog(ML_ERROR, "%s: node %u went down while sending "
941                              "recovery state for dead node %u, ret=%d\n", dlm->name,
942                              reco_master, dead_node, ret);
943                         skip_all_done = 1;
944                         break;
945                 }
946         }
947 
948         /* move the resources back to the list */
949         spin_lock(&dlm->spinlock);
950         list_splice_init(&resources, &dlm->reco.resources);
951         spin_unlock(&dlm->spinlock);
952 
953         if (!skip_all_done) {
954                 ret = dlm_send_all_done_msg(dlm, dead_node, reco_master);
955                 if (ret < 0) {
956                         mlog(ML_ERROR, "%s: node %u went down while sending "
957                              "recovery all-done for dead node %u, ret=%d\n",
958                              dlm->name, reco_master, dead_node, ret);
959                 }
960         }
961 leave:
962         free_page((unsigned long)data);
963 }
964 
965 
966 static int dlm_send_all_done_msg(struct dlm_ctxt *dlm, u8 dead_node, u8 send_to)
967 {
968         int ret, tmpret;
969         struct dlm_reco_data_done done_msg;
970 
971         memset(&done_msg, 0, sizeof(done_msg));
972         done_msg.node_idx = dlm->node_num;
973         done_msg.dead_node = dead_node;
974         mlog(0, "sending DATA DONE message to %u, "
975              "my node=%u, dead node=%u\n", send_to, done_msg.node_idx,
976              done_msg.dead_node);
977 
978         ret = o2net_send_message(DLM_RECO_DATA_DONE_MSG, dlm->key, &done_msg,
979                                  sizeof(done_msg), send_to, &tmpret);
980         if (ret < 0) {
981                 mlog(ML_ERROR, "%s: Error %d send RECO_DATA_DONE to node %u "
982                      "to recover dead node %u\n", dlm->name, ret, send_to,
983                      dead_node);
984                 if (!dlm_is_host_down(ret)) {
985                         BUG();
986                 }
987         } else
988                 ret = tmpret;
989         return ret;
990 }
991 
992 
993 int dlm_reco_data_done_handler(struct o2net_msg *msg, u32 len, void *data,
994                                void **ret_data)
995 {
996         struct dlm_ctxt *dlm = data;
997         struct dlm_reco_data_done *done = (struct dlm_reco_data_done *)msg->buf;
998         struct dlm_reco_node_data *ndata = NULL;
999         int ret = -EINVAL;
1000 
1001         if (!dlm_grab(dlm))
1002                 return -EINVAL;
1003 
1004         mlog(0, "got DATA DONE: dead_node=%u, reco.dead_node=%u, "
1005              "node_idx=%u, this node=%u\n", done->dead_node,
1006              dlm->reco.dead_node, done->node_idx, dlm->node_num);
1007 
1008         mlog_bug_on_msg((done->dead_node != dlm->reco.dead_node),
1009                         "Got DATA DONE: dead_node=%u, reco.dead_node=%u, "
1010                         "node_idx=%u, this node=%u\n", done->dead_node,
1011                         dlm->reco.dead_node, done->node_idx, dlm->node_num);
1012 
1013         spin_lock(&dlm_reco_state_lock);
1014         list_for_each_entry(ndata, &dlm->reco.node_data, list) {
1015                 if (ndata->node_num != done->node_idx)
1016                         continue;
1017 
1018                 switch (ndata->state) {
1019                         /* should have moved beyond INIT but not to FINALIZE yet */
1020                         case DLM_RECO_NODE_DATA_INIT:
1021                         case DLM_RECO_NODE_DATA_DEAD:
1022                         case DLM_RECO_NODE_DATA_FINALIZE_SENT:
1023                                 mlog(ML_ERROR, "bad ndata state for node %u:"
1024                                      " state=%d\n", ndata->node_num,
1025                                      ndata->state);
1026                                 BUG();
1027                                 break;
1028                         /* these states are possible at this point, anywhere along
1029                          * the line of recovery */
1030                         case DLM_RECO_NODE_DATA_DONE:
1031                         case DLM_RECO_NODE_DATA_RECEIVING:
1032                         case DLM_RECO_NODE_DATA_REQUESTED:
1033                         case DLM_RECO_NODE_DATA_REQUESTING:
1034                                 mlog(0, "node %u is DONE sending "
1035                                           "recovery data!\n",
1036                                           ndata->node_num);
1037 
1038                                 ndata->state = DLM_RECO_NODE_DATA_DONE;
1039                                 ret = 0;
1040                                 break;
1041                 }
1042         }
1043         spin_unlock(&dlm_reco_state_lock);
1044 
1045         /* wake the recovery thread, some node is done */
1046         if (!ret)
1047                 dlm_kick_recovery_thread(dlm);
1048 
1049         if (ret < 0)
1050                 mlog(ML_ERROR, "failed to find recovery node data for node "
1051                      "%u\n", done->node_idx);
1052         dlm_put(dlm);
1053 
1054         mlog(0, "leaving reco data done handler, ret=%d\n", ret);
1055         return ret;
1056 }
1057 
1058 static void dlm_move_reco_locks_to_list(struct dlm_ctxt *dlm,
1059                                         struct list_head *list,
1060                                         u8 dead_node)
1061 {
1062         struct dlm_lock_resource *res, *next;
1063         struct dlm_lock *lock;
1064 
1065         spin_lock(&dlm->spinlock);
1066         list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
1067                 /* always prune any $RECOVERY entries for dead nodes,
1068                  * otherwise hangs can occur during later recovery */
1069                 if (dlm_is_recovery_lock(res->lockname.name,
1070                                          res->lockname.len)) {
1071                         spin_lock(&res->spinlock);
1072                         list_for_each_entry(lock, &res->granted, list) {
1073                                 if (lock->ml.node == dead_node) {
1074                                         mlog(0, "AHA! there was "
1075                                              "a $RECOVERY lock for dead "
1076                                              "node %u (%s)!\n",
1077                                              dead_node, dlm->name);
1078                                         list_del_init(&lock->list);
1079                                         dlm_lock_put(lock);
1080                                         /* Can't schedule DLM_UNLOCK_FREE_LOCK
1081                                          * - do manually */
1082                                         dlm_lock_put(lock);
1083                                         break;
1084                                 }
1085                         }
1086                         spin_unlock(&res->spinlock);
1087                         continue;
1088                 }
1089 
1090                 if (res->owner == dead_node) {
1091                         mlog(0, "found lockres owned by dead node while "
1092                                   "doing recovery for node %u. sending it.\n",
1093                                   dead_node);
1094                         list_move_tail(&res->recovering, list);
1095                 } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
1096                         mlog(0, "found UNKNOWN owner while doing recovery "
1097                                   "for node %u. sending it.\n", dead_node);
1098                         list_move_tail(&res->recovering, list);
1099                 }
1100         }
1101         spin_unlock(&dlm->spinlock);
1102 }
1103 
1104 static inline int dlm_num_locks_in_lockres(struct dlm_lock_resource *res)
1105 {
1106         int total_locks = 0;
1107         struct list_head *iter, *queue = &res->granted;
1108         int i;
1109 
1110         for (i=0; i<3; i++) {
1111                 list_for_each(iter, queue)
1112                         total_locks++;
1113                 queue++;
1114         }
1115         return total_locks;
1116 }
1117 
1118 
1119 static int dlm_send_mig_lockres_msg(struct dlm_ctxt *dlm,
1120                                       struct dlm_migratable_lockres *mres,
1121                                       u8 send_to,
1122                                       struct dlm_lock_resource *res,
1123                                       int total_locks)
1124 {
1125         u64 mig_cookie = be64_to_cpu(mres->mig_cookie);
1126         int mres_total_locks = be32_to_cpu(mres->total_locks);
1127         int sz, ret = 0, status = 0;
1128         u8 orig_flags = mres->flags,
1129            orig_master = mres->master;
1130 
1131         BUG_ON(mres->num_locks > DLM_MAX_MIGRATABLE_LOCKS);
1132         if (!mres->num_locks)
1133                 return 0;
1134 
1135         sz = sizeof(struct dlm_migratable_lockres) +
1136                 (mres->num_locks * sizeof(struct dlm_migratable_lock));
1137 
1138         /* add an all-done flag if we reached the last lock */
1139         orig_flags = mres->flags;
1140         BUG_ON(total_locks > mres_total_locks);
1141         if (total_locks == mres_total_locks)
1142                 mres->flags |= DLM_MRES_ALL_DONE;
1143 
1144         mlog(0, "%s:%.*s: sending mig lockres (%s) to %u\n",
1145              dlm->name, res->lockname.len, res->lockname.name,
1146              orig_flags & DLM_MRES_MIGRATION ? "migration" : "recovery",
1147              send_to);
1148 
1149         /* send it */
1150         ret = o2net_send_message(DLM_MIG_LOCKRES_MSG, dlm->key, mres,
1151                                  sz, send_to, &status);
1152         if (ret < 0) {
1153                 /* XXX: negative status is not handled.
1154                  * this will end up killing this node. */
1155                 mlog(ML_ERROR, "%s: res %.*s, Error %d send MIG_LOCKRES to "
1156                      "node %u (%s)\n", dlm->name, mres->lockname_len,
1157                      mres->lockname, ret, send_to,
1158                      (orig_flags & DLM_MRES_MIGRATION ?
1159                       "migration" : "recovery"));
1160         } else {
1161                 /* might get an -ENOMEM back here */
1162                 ret = status;
1163                 if (ret < 0) {
1164                         mlog_errno(ret);
1165 
1166                         if (ret == -EFAULT) {
1167                                 mlog(ML_ERROR, "node %u told me to kill "
1168                                      "myself!\n", send_to);
1169                                 BUG();
1170                         }
1171                 }
1172         }
1173 
1174         /* zero and reinit the message buffer */
1175         dlm_init_migratable_lockres(mres, res->lockname.name,
1176                                     res->lockname.len, mres_total_locks,
1177                                     mig_cookie, orig_flags, orig_master);
1178         return ret;
1179 }
1180 
1181 static void dlm_init_migratable_lockres(struct dlm_migratable_lockres *mres,
1182                                         const char *lockname, int namelen,
1183                                         int total_locks, u64 cookie,
1184                                         u8 flags, u8 master)
1185 {
1186         /* mres here is one full page */
1187         clear_page(mres);
1188         mres->lockname_len = namelen;
1189         memcpy(mres->lockname, lockname, namelen);
1190         mres->num_locks = 0;
1191         mres->total_locks = cpu_to_be32(total_locks);
1192         mres->mig_cookie = cpu_to_be64(cookie);
1193         mres->flags = flags;
1194         mres->master = master;
1195 }
1196 
1197 static void dlm_prepare_lvb_for_migration(struct dlm_lock *lock,
1198                                           struct dlm_migratable_lockres *mres,
1199                                           int queue)
1200 {
1201         if (!lock->lksb)
1202                return;
1203 
1204         /* Ignore lvb in all locks in the blocked list */
1205         if (queue == DLM_BLOCKED_LIST)
1206                 return;
1207 
1208         /* Only consider lvbs in locks with granted EX or PR lock levels */
1209         if (lock->ml.type != LKM_EXMODE && lock->ml.type != LKM_PRMODE)
1210                 return;
1211 
1212         if (dlm_lvb_is_empty(mres->lvb)) {
1213                 memcpy(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN);
1214                 return;
1215         }
1216 
1217         /* Ensure the lvb copied for migration matches in other valid locks */
1218         if (!memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))
1219                 return;
1220 
1221         mlog(ML_ERROR, "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, "
1222              "node=%u\n",
1223              dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
1224              dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
1225              lock->lockres->lockname.len, lock->lockres->lockname.name,
1226              lock->ml.node);
1227         dlm_print_one_lock_resource(lock->lockres);
1228         BUG();
1229 }
1230 
1231 /* returns 1 if this lock fills the network structure,
1232  * 0 otherwise */
1233 static int dlm_add_lock_to_array(struct dlm_lock *lock,
1234                                  struct dlm_migratable_lockres *mres, int queue)
1235 {
1236         struct dlm_migratable_lock *ml;
1237         int lock_num = mres->num_locks;
1238 
1239         ml = &(mres->ml[lock_num]);
1240         ml->cookie = lock->ml.cookie;
1241         ml->type = lock->ml.type;
1242         ml->convert_type = lock->ml.convert_type;
1243         ml->highest_blocked = lock->ml.highest_blocked;
1244         ml->list = queue;
1245         if (lock->lksb) {
1246                 ml->flags = lock->lksb->flags;
1247                 dlm_prepare_lvb_for_migration(lock, mres, queue);
1248         }
1249         ml->node = lock->ml.node;
1250         mres->num_locks++;
1251         /* we reached the max, send this network message */
1252         if (mres->num_locks == DLM_MAX_MIGRATABLE_LOCKS)
1253                 return 1;
1254         return 0;
1255 }
1256 
1257 static void dlm_add_dummy_lock(struct dlm_ctxt *dlm,
1258                                struct dlm_migratable_lockres *mres)
1259 {
1260         struct dlm_lock dummy;
1261         memset(&dummy, 0, sizeof(dummy));
1262         dummy.ml.cookie = 0;
1263         dummy.ml.type = LKM_IVMODE;
1264         dummy.ml.convert_type = LKM_IVMODE;
1265         dummy.ml.highest_blocked = LKM_IVMODE;
1266         dummy.lksb = NULL;
1267         dummy.ml.node = dlm->node_num;
1268         dlm_add_lock_to_array(&dummy, mres, DLM_BLOCKED_LIST);
1269 }
1270 
1271 static inline int dlm_is_dummy_lock(struct dlm_ctxt *dlm,
1272                                     struct dlm_migratable_lock *ml,
1273                                     u8 *nodenum)
1274 {
1275         if (unlikely(ml->cookie == 0 &&
1276             ml->type == LKM_IVMODE &&
1277             ml->convert_type == LKM_IVMODE &&
1278             ml->highest_blocked == LKM_IVMODE &&
1279             ml->list == DLM_BLOCKED_LIST)) {
1280                 *nodenum = ml->node;
1281                 return 1;
1282         }
1283         return 0;
1284 }
1285 
1286 int dlm_send_one_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1287                          struct dlm_migratable_lockres *mres,
1288                          u8 send_to, u8 flags)
1289 {
1290         struct list_head *queue;
1291         int total_locks, i;
1292         u64 mig_cookie = 0;
1293         struct dlm_lock *lock;
1294         int ret = 0;
1295 
1296         BUG_ON(!(flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1297 
1298         mlog(0, "sending to %u\n", send_to);
1299 
1300         total_locks = dlm_num_locks_in_lockres(res);
1301         if (total_locks > DLM_MAX_MIGRATABLE_LOCKS) {
1302                 /* rare, but possible */
1303                 mlog(0, "argh.  lockres has %d locks.  this will "
1304                           "require more than one network packet to "
1305                           "migrate\n", total_locks);
1306                 mig_cookie = dlm_get_next_mig_cookie();
1307         }
1308 
1309         dlm_init_migratable_lockres(mres, res->lockname.name,
1310                                     res->lockname.len, total_locks,
1311                                     mig_cookie, flags, res->owner);
1312 
1313         total_locks = 0;
1314         for (i=DLM_GRANTED_LIST; i<=DLM_BLOCKED_LIST; i++) {
1315                 queue = dlm_list_idx_to_ptr(res, i);
1316                 list_for_each_entry(lock, queue, list) {
1317                         /* add another lock. */
1318                         total_locks++;
1319                         if (!dlm_add_lock_to_array(lock, mres, i))
1320                                 continue;
1321 
1322                         /* this filled the lock message,
1323                          * we must send it immediately. */
1324                         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to,
1325                                                        res, total_locks);
1326                         if (ret < 0)
1327                                 goto error;
1328                 }
1329         }
1330         if (total_locks == 0) {
1331                 /* send a dummy lock to indicate a mastery reference only */
1332                 mlog(0, "%s:%.*s: sending dummy lock to %u, %s\n",
1333                      dlm->name, res->lockname.len, res->lockname.name,
1334                      send_to, flags & DLM_MRES_RECOVERY ? "recovery" :
1335                      "migration");
1336                 dlm_add_dummy_lock(dlm, mres);
1337         }
1338         /* flush any remaining locks */
1339         ret = dlm_send_mig_lockres_msg(dlm, mres, send_to, res, total_locks);
1340         if (ret < 0)
1341                 goto error;
1342         return ret;
1343 
1344 error:
1345         mlog(ML_ERROR, "%s: dlm_send_mig_lockres_msg returned %d\n",
1346              dlm->name, ret);
1347         if (!dlm_is_host_down(ret))
1348                 BUG();
1349         mlog(0, "%s: node %u went down while sending %s "
1350              "lockres %.*s\n", dlm->name, send_to,
1351              flags & DLM_MRES_RECOVERY ?  "recovery" : "migration",
1352              res->lockname.len, res->lockname.name);
1353         return ret;
1354 }
1355 
1356 
1357 
1358 /*
1359  * this message will contain no more than one page worth of
1360  * recovery data, and it will work on only one lockres.
1361  * there may be many locks in this page, and we may need to wait
1362  * for additional packets to complete all the locks (rare, but
1363  * possible).
1364  */
1365 /*
1366  * NOTE: the allocation error cases here are scary
1367  * we really cannot afford to fail an alloc in recovery
1368  * do we spin?  returning an error only delays the problem really
1369  */
1370 
1371 int dlm_mig_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
1372                             void **ret_data)
1373 {
1374         struct dlm_ctxt *dlm = data;
1375         struct dlm_migratable_lockres *mres =
1376                 (struct dlm_migratable_lockres *)msg->buf;
1377         int ret = 0;
1378         u8 real_master;
1379         u8 extra_refs = 0;
1380         char *buf = NULL;
1381         struct dlm_work_item *item = NULL;
1382         struct dlm_lock_resource *res = NULL;
1383         unsigned int hash;
1384 
1385         if (!dlm_grab(dlm))
1386                 return -EINVAL;
1387 
1388         if (!dlm_joined(dlm)) {
1389                 mlog(ML_ERROR, "Domain %s not joined! "
1390                           "lockres %.*s, master %u\n",
1391                           dlm->name, mres->lockname_len,
1392                           mres->lockname, mres->master);
1393                 dlm_put(dlm);
1394                 return -EINVAL;
1395         }
1396 
1397         BUG_ON(!(mres->flags & (DLM_MRES_RECOVERY|DLM_MRES_MIGRATION)));
1398 
1399         real_master = mres->master;
1400         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1401                 /* cannot migrate a lockres with no master */
1402                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1403         }
1404 
1405         mlog(0, "%s message received from node %u\n",
1406                   (mres->flags & DLM_MRES_RECOVERY) ?
1407                   "recovery" : "migration", mres->master);
1408         if (mres->flags & DLM_MRES_ALL_DONE)
1409                 mlog(0, "all done flag.  all lockres data received!\n");
1410 
1411         ret = -ENOMEM;
1412         buf = kmalloc(be16_to_cpu(msg->data_len), GFP_NOFS);
1413         item = kzalloc(sizeof(*item), GFP_NOFS);
1414         if (!buf || !item)
1415                 goto leave;
1416 
1417         /* lookup the lock to see if we have a secondary queue for this
1418          * already...  just add the locks in and this will have its owner
1419          * and RECOVERY flag changed when it completes. */
1420         hash = dlm_lockid_hash(mres->lockname, mres->lockname_len);
1421         spin_lock(&dlm->spinlock);
1422         res = __dlm_lookup_lockres_full(dlm, mres->lockname, mres->lockname_len,
1423                         hash);
1424         if (res) {
1425                 /* this will get a ref on res */
1426                 /* mark it as recovering/migrating and hash it */
1427                 spin_lock(&res->spinlock);
1428                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
1429                         mlog(0, "%s: node is attempting to migrate "
1430                                 "lockres %.*s, but marked as dropping "
1431                                 " ref!\n", dlm->name,
1432                                 mres->lockname_len, mres->lockname);
1433                         ret = -EINVAL;
1434                         spin_unlock(&res->spinlock);
1435                         spin_unlock(&dlm->spinlock);
1436                         dlm_lockres_put(res);
1437                         goto leave;
1438                 }
1439 
1440                 if (mres->flags & DLM_MRES_RECOVERY) {
1441                         res->state |= DLM_LOCK_RES_RECOVERING;
1442                 } else {
1443                         if (res->state & DLM_LOCK_RES_MIGRATING) {
1444                                 /* this is at least the second
1445                                  * lockres message */
1446                                 mlog(0, "lock %.*s is already migrating\n",
1447                                           mres->lockname_len,
1448                                           mres->lockname);
1449                         } else if (res->state & DLM_LOCK_RES_RECOVERING) {
1450                                 /* caller should BUG */
1451                                 mlog(ML_ERROR, "node is attempting to migrate "
1452                                      "lock %.*s, but marked as recovering!\n",
1453                                      mres->lockname_len, mres->lockname);
1454                                 ret = -EFAULT;
1455                                 spin_unlock(&res->spinlock);
1456                                 spin_unlock(&dlm->spinlock);
1457                                 dlm_lockres_put(res);
1458                                 goto leave;
1459                         }
1460                         res->state |= DLM_LOCK_RES_MIGRATING;
1461                 }
1462                 spin_unlock(&res->spinlock);
1463                 spin_unlock(&dlm->spinlock);
1464         } else {
1465                 spin_unlock(&dlm->spinlock);
1466                 /* need to allocate, just like if it was
1467                  * mastered here normally  */
1468                 res = dlm_new_lockres(dlm, mres->lockname, mres->lockname_len);
1469                 if (!res)
1470                         goto leave;
1471 
1472                 /* to match the ref that we would have gotten if
1473                  * dlm_lookup_lockres had succeeded */
1474                 dlm_lockres_get(res);
1475 
1476                 /* mark it as recovering/migrating and hash it */
1477                 if (mres->flags & DLM_MRES_RECOVERY)
1478                         res->state |= DLM_LOCK_RES_RECOVERING;
1479                 else
1480                         res->state |= DLM_LOCK_RES_MIGRATING;
1481 
1482                 spin_lock(&dlm->spinlock);
1483                 __dlm_insert_lockres(dlm, res);
1484                 spin_unlock(&dlm->spinlock);
1485 
1486                 /* Add an extra ref for this lock-less lockres lest the
1487                  * dlm_thread purges it before we get the chance to add
1488                  * locks to it */
1489                 dlm_lockres_get(res);
1490 
1491                 /* There are three refs that need to be put.
1492                  * 1. Taken above.
1493                  * 2. kref_init in dlm_new_lockres()->dlm_init_lockres().
1494                  * 3. dlm_lookup_lockres()
1495                  * The first one is handled at the end of this function. The
1496                  * other two are handled in the worker thread after locks have
1497                  * been attached. Yes, we don't wait for purge time to match
1498                  * kref_init. The lockres will still have atleast one ref
1499                  * added because it is in the hash __dlm_insert_lockres() */
1500                 extra_refs++;
1501 
1502                 /* now that the new lockres is inserted,
1503                  * make it usable by other processes */
1504                 spin_lock(&res->spinlock);
1505                 res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
1506                 spin_unlock(&res->spinlock);
1507                 wake_up(&res->wq);
1508         }
1509 
1510         /* at this point we have allocated everything we need,
1511          * and we have a hashed lockres with an extra ref and
1512          * the proper res->state flags. */
1513         ret = 0;
1514         spin_lock(&res->spinlock);
1515         /* drop this either when master requery finds a different master
1516          * or when a lock is added by the recovery worker */
1517         dlm_lockres_grab_inflight_ref(dlm, res);
1518         if (mres->master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1519                 /* migration cannot have an unknown master */
1520                 BUG_ON(!(mres->flags & DLM_MRES_RECOVERY));
1521                 mlog(0, "recovery has passed me a lockres with an "
1522                           "unknown owner.. will need to requery: "
1523                           "%.*s\n", mres->lockname_len, mres->lockname);
1524         } else {
1525                 /* take a reference now to pin the lockres, drop it
1526                  * when locks are added in the worker */
1527                 dlm_change_lockres_owner(dlm, res, dlm->node_num);
1528         }
1529         spin_unlock(&res->spinlock);
1530 
1531         /* queue up work for dlm_mig_lockres_worker */
1532         dlm_grab(dlm);  /* get an extra ref for the work item */
1533         memcpy(buf, msg->buf, be16_to_cpu(msg->data_len));  /* copy the whole message */
1534         dlm_init_work_item(dlm, item, dlm_mig_lockres_worker, buf);
1535         item->u.ml.lockres = res; /* already have a ref */
1536         item->u.ml.real_master = real_master;
1537         item->u.ml.extra_ref = extra_refs;
1538         spin_lock(&dlm->work_lock);
1539         list_add_tail(&item->list, &dlm->work_list);
1540         spin_unlock(&dlm->work_lock);
1541         queue_work(dlm->dlm_worker, &dlm->dispatched_work);
1542 
1543 leave:
1544         /* One extra ref taken needs to be put here */
1545         if (extra_refs)
1546                 dlm_lockres_put(res);
1547 
1548         dlm_put(dlm);
1549         if (ret < 0) {
1550                 kfree(buf);
1551                 kfree(item);
1552                 mlog_errno(ret);
1553         }
1554 
1555         return ret;
1556 }
1557 
1558 
1559 static void dlm_mig_lockres_worker(struct dlm_work_item *item, void *data)
1560 {
1561         struct dlm_ctxt *dlm;
1562         struct dlm_migratable_lockres *mres;
1563         int ret = 0;
1564         struct dlm_lock_resource *res;
1565         u8 real_master;
1566         u8 extra_ref;
1567 
1568         dlm = item->dlm;
1569         mres = (struct dlm_migratable_lockres *)data;
1570 
1571         res = item->u.ml.lockres;
1572         real_master = item->u.ml.real_master;
1573         extra_ref = item->u.ml.extra_ref;
1574 
1575         if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1576                 /* this case is super-rare. only occurs if
1577                  * node death happens during migration. */
1578 again:
1579                 ret = dlm_lockres_master_requery(dlm, res, &real_master);
1580                 if (ret < 0) {
1581                         mlog(0, "dlm_lockres_master_requery ret=%d\n",
1582                                   ret);
1583                         goto again;
1584                 }
1585                 if (real_master == DLM_LOCK_RES_OWNER_UNKNOWN) {
1586                         mlog(0, "lockres %.*s not claimed.  "
1587                                    "this node will take it.\n",
1588                                    res->lockname.len, res->lockname.name);
1589                 } else {
1590                         spin_lock(&res->spinlock);
1591                         dlm_lockres_drop_inflight_ref(dlm, res);
1592                         spin_unlock(&res->spinlock);
1593                         mlog(0, "master needs to respond to sender "
1594                                   "that node %u still owns %.*s\n",
1595                                   real_master, res->lockname.len,
1596                                   res->lockname.name);
1597                         /* cannot touch this lockres */
1598                         goto leave;
1599                 }
1600         }
1601 
1602         ret = dlm_process_recovery_data(dlm, res, mres);
1603         if (ret < 0)
1604                 mlog(0, "dlm_process_recovery_data returned  %d\n", ret);
1605         else
1606                 mlog(0, "dlm_process_recovery_data succeeded\n");
1607 
1608         if ((mres->flags & (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) ==
1609                            (DLM_MRES_MIGRATION|DLM_MRES_ALL_DONE)) {
1610                 ret = dlm_finish_migration(dlm, res, mres->master);
1611                 if (ret < 0)
1612                         mlog_errno(ret);
1613         }
1614 
1615 leave:
1616         /* See comment in dlm_mig_lockres_handler() */
1617         if (res) {
1618                 if (extra_ref)
1619                         dlm_lockres_put(res);
1620                 dlm_lockres_put(res);
1621         }
1622         kfree(data);
1623 }
1624 
1625 
1626 
1627 static int dlm_lockres_master_requery(struct dlm_ctxt *dlm,
1628                                       struct dlm_lock_resource *res,
1629                                       u8 *real_master)
1630 {
1631         struct dlm_node_iter iter;
1632         int nodenum;
1633         int ret = 0;
1634 
1635         *real_master = DLM_LOCK_RES_OWNER_UNKNOWN;
1636 
1637         /* we only reach here if one of the two nodes in a
1638          * migration died while the migration was in progress.
1639          * at this point we need to requery the master.  we
1640          * know that the new_master got as far as creating
1641          * an mle on at least one node, but we do not know
1642          * if any nodes had actually cleared the mle and set
1643          * the master to the new_master.  the old master
1644          * is supposed to set the owner to UNKNOWN in the
1645          * event of a new_master death, so the only possible
1646          * responses that we can get from nodes here are
1647          * that the master is new_master, or that the master
1648          * is UNKNOWN.
1649          * if all nodes come back with UNKNOWN then we know
1650          * the lock needs remastering here.
1651          * if any node comes back with a valid master, check
1652          * to see if that master is the one that we are
1653          * recovering.  if so, then the new_master died and
1654          * we need to remaster this lock.  if not, then the
1655          * new_master survived and that node will respond to
1656          * other nodes about the owner.
1657          * if there is an owner, this node needs to dump this
1658          * lockres and alert the sender that this lockres
1659          * was rejected. */
1660         spin_lock(&dlm->spinlock);
1661         dlm_node_iter_init(dlm->domain_map, &iter);
1662         spin_unlock(&dlm->spinlock);
1663 
1664         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
1665                 /* do not send to self */
1666                 if (nodenum == dlm->node_num)
1667                         continue;
1668                 ret = dlm_do_master_requery(dlm, res, nodenum, real_master);
1669                 if (ret < 0) {
1670                         mlog_errno(ret);
1671                         if (!dlm_is_host_down(ret))
1672                                 BUG();
1673                         /* host is down, so answer for that node would be
1674                          * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
1675                 }
1676                 if (*real_master != DLM_LOCK_RES_OWNER_UNKNOWN) {
1677                         mlog(0, "lock master is %u\n", *real_master);
1678                         break;
1679                 }
1680         }
1681         return ret;
1682 }
1683 
1684 
1685 int dlm_do_master_requery(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
1686                           u8 nodenum, u8 *real_master)
1687 {
1688         int ret = -EINVAL;
1689         struct dlm_master_requery req;
1690         int status = DLM_LOCK_RES_OWNER_UNKNOWN;
1691 
1692         memset(&req, 0, sizeof(req));
1693         req.node_idx = dlm->node_num;
1694         req.namelen = res->lockname.len;
1695         memcpy(req.name, res->lockname.name, res->lockname.len);
1696 
1697 resend:
1698         ret = o2net_send_message(DLM_MASTER_REQUERY_MSG, dlm->key,
1699                                  &req, sizeof(req), nodenum, &status);
1700         if (ret < 0)
1701                 mlog(ML_ERROR, "Error %d when sending message %u (key "
1702                      "0x%x) to node %u\n", ret, DLM_MASTER_REQUERY_MSG,
1703                      dlm->key, nodenum);
1704         else if (status == -ENOMEM) {
1705                 mlog_errno(status);
1706                 msleep(50);
1707                 goto resend;
1708         } else {
1709                 BUG_ON(status < 0);
1710                 BUG_ON(status > DLM_LOCK_RES_OWNER_UNKNOWN);
1711                 *real_master = (u8) (status & 0xff);
1712                 mlog(0, "node %u responded to master requery with %u\n",
1713                           nodenum, *real_master);
1714                 ret = 0;
1715         }
1716         return ret;
1717 }
1718 
1719 
1720 /* this function cannot error, so unless the sending
1721  * or receiving of the message failed, the owner can
1722  * be trusted */
1723 int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
1724                                void **ret_data)
1725 {
1726         struct dlm_ctxt *dlm = data;
1727         struct dlm_master_requery *req = (struct dlm_master_requery *)msg->buf;
1728         struct dlm_lock_resource *res = NULL;
1729         unsigned int hash;
1730         int master = DLM_LOCK_RES_OWNER_UNKNOWN;
1731         u32 flags = DLM_ASSERT_MASTER_REQUERY;
1732         int dispatched = 0;
1733 
1734         if (!dlm_grab(dlm)) {
1735                 /* since the domain has gone away on this
1736                  * node, the proper response is UNKNOWN */
1737                 return master;
1738         }
1739 
1740         hash = dlm_lockid_hash(req->name, req->namelen);
1741 
1742         spin_lock(&dlm->spinlock);
1743         res = __dlm_lookup_lockres(dlm, req->name, req->namelen, hash);
1744         if (res) {
1745                 spin_lock(&res->spinlock);
1746                 master = res->owner;
1747                 if (master == dlm->node_num) {
1748                         int ret = dlm_dispatch_assert_master(dlm, res,
1749                                                              0, 0, flags);
1750                         if (ret < 0) {
1751                                 mlog_errno(ret);
1752                                 spin_unlock(&res->spinlock);
1753                                 dlm_lockres_put(res);
1754                                 spin_unlock(&dlm->spinlock);
1755                                 dlm_put(dlm);
1756                                 /* sender will take care of this and retry */
1757                                 return ret;
1758                         } else {
1759                                 dispatched = 1;
1760                                 __dlm_lockres_grab_inflight_worker(dlm, res);
1761                                 spin_unlock(&res->spinlock);
1762                         }
1763                 } else {
1764                         /* put.. incase we are not the master */
1765                         spin_unlock(&res->spinlock);
1766                         dlm_lockres_put(res);
1767                 }
1768         }
1769         spin_unlock(&dlm->spinlock);
1770 
1771         if (!dispatched)
1772                 dlm_put(dlm);
1773         return master;
1774 }
1775 
1776 static inline struct list_head *
1777 dlm_list_num_to_pointer(struct dlm_lock_resource *res, int list_num)
1778 {
1779         struct list_head *ret;
1780         BUG_ON(list_num < 0);
1781         BUG_ON(list_num > 2);
1782         ret = &(res->granted);
1783         ret += list_num;
1784         return ret;
1785 }
1786 /* TODO: do ast flush business
1787  * TODO: do MIGRATING and RECOVERING spinning
1788  */
1789 
1790 /*
1791 * NOTE about in-flight requests during migration:
1792 *
1793 * Before attempting the migrate, the master has marked the lockres as
1794 * MIGRATING and then flushed all of its pending ASTS.  So any in-flight
1795 * requests either got queued before the MIGRATING flag got set, in which
1796 * case the lock data will reflect the change and a return message is on
1797 * the way, or the request failed to get in before MIGRATING got set.  In
1798 * this case, the caller will be told to spin and wait for the MIGRATING
1799 * flag to be dropped, then recheck the master.
1800 * This holds true for the convert, cancel and unlock cases, and since lvb
1801 * updates are tied to these same messages, it applies to lvb updates as
1802 * well.  For the lock case, there is no way a lock can be on the master
1803 * queue and not be on the secondary queue since the lock is always added
1804 * locally first.  This means that the new target node will never be sent
1805 * a lock that he doesn't already have on the list.
1806 * In total, this means that the local lock is correct and should not be
1807 * updated to match the one sent by the master.  Any messages sent back
1808 * from the master before the MIGRATING flag will bring the lock properly
1809 * up-to-date, and the change will be ordered properly for the waiter.
1810 * We will *not* attempt to modify the lock underneath the waiter.
1811 */
1812 
1813 static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
1814                                      struct dlm_lock_resource *res,
1815                                      struct dlm_migratable_lockres *mres)
1816 {
1817         struct dlm_migratable_lock *ml;
1818         struct list_head *queue, *iter;
1819         struct list_head *tmpq = NULL;
1820         struct dlm_lock *newlock = NULL;
1821         struct dlm_lockstatus *lksb = NULL;
1822         int ret = 0;
1823         int i, j, bad;
1824         struct dlm_lock *lock;
1825         u8 from = O2NM_MAX_NODES;
1826         __be64 c;
1827 
1828         mlog(0, "running %d locks for this lockres\n", mres->num_locks);
1829         for (i=0; i<mres->num_locks; i++) {
1830                 ml = &(mres->ml[i]);
1831 
1832                 if (dlm_is_dummy_lock(dlm, ml, &from)) {
1833                         /* placeholder, just need to set the refmap bit */
1834                         BUG_ON(mres->num_locks != 1);
1835                         mlog(0, "%s:%.*s: dummy lock for %u\n",
1836                              dlm->name, mres->lockname_len, mres->lockname,
1837                              from);
1838                         spin_lock(&res->spinlock);
1839                         dlm_lockres_set_refmap_bit(dlm, res, from);
1840                         spin_unlock(&res->spinlock);
1841                         break;
1842                 }
1843                 BUG_ON(ml->highest_blocked != LKM_IVMODE);
1844                 newlock = NULL;
1845                 lksb = NULL;
1846 
1847                 queue = dlm_list_num_to_pointer(res, ml->list);
1848                 tmpq = NULL;
1849 
1850                 /* if the lock is for the local node it needs to
1851                  * be moved to the proper location within the queue.
1852                  * do not allocate a new lock structure. */
1853                 if (ml->node == dlm->node_num) {
1854                         /* MIGRATION ONLY! */
1855                         BUG_ON(!(mres->flags & DLM_MRES_MIGRATION));
1856 
1857                         lock = NULL;
1858                         spin_lock(&res->spinlock);
1859                         for (j = DLM_GRANTED_LIST; j <= DLM_BLOCKED_LIST; j++) {
1860                                 tmpq = dlm_list_idx_to_ptr(res, j);
1861                                 list_for_each(iter, tmpq) {
1862                                         lock = list_entry(iter,
1863                                                   struct dlm_lock, list);
1864                                         if (lock->ml.cookie == ml->cookie)
1865                                                 break;
1866                                         lock = NULL;
1867                                 }
1868                                 if (lock)
1869                                         break;
1870                         }
1871 
1872                         /* lock is always created locally first, and
1873                          * destroyed locally last.  it must be on the list */
1874                         if (!lock) {
1875                                 c = ml->cookie;
1876                                 mlog(ML_ERROR, "Could not find local lock "
1877                                                "with cookie %u:%llu, node %u, "
1878                                                "list %u, flags 0x%x, type %d, "
1879                                                "conv %d, highest blocked %d\n",
1880                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1881                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1882                                      ml->node, ml->list, ml->flags, ml->type,
1883                                      ml->convert_type, ml->highest_blocked);
1884                                 __dlm_print_one_lock_resource(res);
1885                                 BUG();
1886                         }
1887 
1888                         if (lock->ml.node != ml->node) {
1889                                 c = lock->ml.cookie;
1890                                 mlog(ML_ERROR, "Mismatched node# in lock "
1891                                      "cookie %u:%llu, name %.*s, node %u\n",
1892                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1893                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1894                                      res->lockname.len, res->lockname.name,
1895                                      lock->ml.node);
1896                                 c = ml->cookie;
1897                                 mlog(ML_ERROR, "Migrate lock cookie %u:%llu, "
1898                                      "node %u, list %u, flags 0x%x, type %d, "
1899                                      "conv %d, highest blocked %d\n",
1900                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1901                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1902                                      ml->node, ml->list, ml->flags, ml->type,
1903                                      ml->convert_type, ml->highest_blocked);
1904                                 __dlm_print_one_lock_resource(res);
1905                                 BUG();
1906                         }
1907 
1908                         if (tmpq != queue) {
1909                                 c = ml->cookie;
1910                                 mlog(0, "Lock cookie %u:%llu was on list %u "
1911                                      "instead of list %u for %.*s\n",
1912                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
1913                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)),
1914                                      j, ml->list, res->lockname.len,
1915                                      res->lockname.name);
1916                                 __dlm_print_one_lock_resource(res);
1917                                 spin_unlock(&res->spinlock);
1918                                 continue;
1919                         }
1920 
1921                         /* see NOTE above about why we do not update
1922                          * to match the master here */
1923 
1924                         /* move the lock to its proper place */
1925                         /* do not alter lock refcount.  switching lists. */
1926                         list_move_tail(&lock->list, queue);
1927                         spin_unlock(&res->spinlock);
1928 
1929                         mlog(0, "just reordered a local lock!\n");
1930                         continue;
1931                 }
1932 
1933                 /* lock is for another node. */
1934                 newlock = dlm_new_lock(ml->type, ml->node,
1935                                        be64_to_cpu(ml->cookie), NULL);
1936                 if (!newlock) {
1937                         ret = -ENOMEM;
1938                         goto leave;
1939                 }
1940                 lksb = newlock->lksb;
1941                 dlm_lock_attach_lockres(newlock, res);
1942 
1943                 if (ml->convert_type != LKM_IVMODE) {
1944                         BUG_ON(queue != &res->converting);
1945                         newlock->ml.convert_type = ml->convert_type;
1946                 }
1947                 lksb->flags |= (ml->flags &
1948                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
1949 
1950                 if (ml->type == LKM_NLMODE)
1951                         goto skip_lvb;
1952 
1953                 /*
1954                  * If the lock is in the blocked list it can't have a valid lvb,
1955                  * so skip it
1956                  */
1957                 if (ml->list == DLM_BLOCKED_LIST)
1958                         goto skip_lvb;
1959 
1960                 if (!dlm_lvb_is_empty(mres->lvb)) {
1961                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
1962                                 /* other node was trying to update
1963                                  * lvb when node died.  recreate the
1964                                  * lksb with the updated lvb. */
1965                                 memcpy(lksb->lvb, mres->lvb, DLM_LVB_LEN);
1966                                 /* the lock resource lvb update must happen
1967                                  * NOW, before the spinlock is dropped.
1968                                  * we no longer wait for the AST to update
1969                                  * the lvb. */
1970                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1971                         } else {
1972                                 /* otherwise, the node is sending its
1973                                  * most recent valid lvb info */
1974                                 BUG_ON(ml->type != LKM_EXMODE &&
1975                                        ml->type != LKM_PRMODE);
1976                                 if (!dlm_lvb_is_empty(res->lvb) &&
1977                                     (ml->type == LKM_EXMODE ||
1978                                      memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
1979                                         int i;
1980                                         mlog(ML_ERROR, "%s:%.*s: received bad "
1981                                              "lvb! type=%d\n", dlm->name,
1982                                              res->lockname.len,
1983                                              res->lockname.name, ml->type);
1984                                         printk("lockres lvb=[");
1985                                         for (i=0; i<DLM_LVB_LEN; i++)
1986                                                 printk("%02x", res->lvb[i]);
1987                                         printk("]\nmigrated lvb=[");
1988                                         for (i=0; i<DLM_LVB_LEN; i++)
1989                                                 printk("%02x", mres->lvb[i]);
1990                                         printk("]\n");
1991                                         dlm_print_one_lock_resource(res);
1992                                         BUG();
1993                                 }
1994                                 memcpy(res->lvb, mres->lvb, DLM_LVB_LEN);
1995                         }
1996                 }
1997 skip_lvb:
1998 
1999                 /* NOTE:
2000                  * wrt lock queue ordering and recovery:
2001                  *    1. order of locks on granted queue is
2002                  *       meaningless.
2003                  *    2. order of locks on converting queue is
2004                  *       LOST with the node death.  sorry charlie.
2005                  *    3. order of locks on the blocked queue is
2006                  *       also LOST.
2007                  * order of locks does not affect integrity, it
2008                  * just means that a lock request may get pushed
2009                  * back in line as a result of the node death.
2010                  * also note that for a given node the lock order
2011                  * for its secondary queue locks is preserved
2012                  * relative to each other, but clearly *not*
2013                  * preserved relative to locks from other nodes.
2014                  */
2015                 bad = 0;
2016                 spin_lock(&res->spinlock);
2017                 list_for_each_entry(lock, queue, list) {
2018                         if (lock->ml.cookie == ml->cookie) {
2019                                 c = lock->ml.cookie;
2020                                 mlog(ML_ERROR, "%s:%.*s: %u:%llu: lock already "
2021                                      "exists on this lockres!\n", dlm->name,
2022                                      res->lockname.len, res->lockname.name,
2023                                      dlm_get_lock_cookie_node(be64_to_cpu(c)),
2024                                      dlm_get_lock_cookie_seq(be64_to_cpu(c)));
2025 
2026                                 mlog(ML_NOTICE, "sent lock: type=%d, conv=%d, "
2027                                      "node=%u, cookie=%u:%llu, queue=%d\n",
2028                                      ml->type, ml->convert_type, ml->node,
2029                                      dlm_get_lock_cookie_node(be64_to_cpu(ml->cookie)),
2030                                      dlm_get_lock_cookie_seq(be64_to_cpu(ml->cookie)),
2031                                      ml->list);
2032 
2033                                 __dlm_print_one_lock_resource(res);
2034                                 bad = 1;
2035                                 break;
2036                         }
2037                 }
2038                 if (!bad) {
2039                         dlm_lock_get(newlock);
2040                         if (mres->flags & DLM_MRES_RECOVERY &&
2041                                         ml->list == DLM_CONVERTING_LIST &&
2042                                         newlock->ml.type >
2043                                         newlock->ml.convert_type) {
2044                                 /* newlock is doing downconvert, add it to the
2045                                  * head of converting list */
2046                                 list_add(&newlock->list, queue);
2047                         } else
2048                                 list_add_tail(&newlock->list, queue);
2049                         mlog(0, "%s:%.*s: added lock for node %u, "
2050                              "setting refmap bit\n", dlm->name,
2051                              res->lockname.len, res->lockname.name, ml->node);
2052                         dlm_lockres_set_refmap_bit(dlm, res, ml->node);
2053                 }
2054                 spin_unlock(&res->spinlock);
2055         }
2056         mlog(0, "done running all the locks\n");
2057 
2058 leave:
2059         /* balance the ref taken when the work was queued */
2060         spin_lock(&res->spinlock);
2061         dlm_lockres_drop_inflight_ref(dlm, res);
2062         spin_unlock(&res->spinlock);
2063 
2064         if (ret < 0)
2065                 mlog_errno(ret);
2066 
2067         return ret;
2068 }
2069 
2070 void dlm_move_lockres_to_recovery_list(struct dlm_ctxt *dlm,
2071                                        struct dlm_lock_resource *res)
2072 {
2073         int i;
2074         struct list_head *queue;
2075         struct dlm_lock *lock, *next;
2076 
2077         assert_spin_locked(&dlm->spinlock);
2078         assert_spin_locked(&res->spinlock);
2079         res->state |= DLM_LOCK_RES_RECOVERING;
2080         if (!list_empty(&res->recovering)) {
2081                 mlog(0,
2082                      "Recovering res %s:%.*s, is already on recovery list!\n",
2083                      dlm->name, res->lockname.len, res->lockname.name);
2084                 list_del_init(&res->recovering);
2085                 dlm_lockres_put(res);
2086         }
2087         /* We need to hold a reference while on the recovery list */
2088         dlm_lockres_get(res);
2089         list_add_tail(&res->recovering, &dlm->reco.resources);
2090 
2091         /* find any pending locks and put them back on proper list */
2092         for (i=DLM_BLOCKED_LIST; i>=DLM_GRANTED_LIST; i--) {
2093                 queue = dlm_list_idx_to_ptr(res, i);
2094                 list_for_each_entry_safe(lock, next, queue, list) {
2095                         dlm_lock_get(lock);
2096                         if (lock->convert_pending) {
2097                                 /* move converting lock back to granted */
2098                                 mlog(0, "node died with convert pending "
2099                                      "on %.*s. move back to granted list.\n",
2100                                      res->lockname.len, res->lockname.name);
2101                                 dlm_revert_pending_convert(res, lock);
2102                                 lock->convert_pending = 0;
2103                         } else if (lock->lock_pending) {
2104                                 /* remove pending lock requests completely */
2105                                 BUG_ON(i != DLM_BLOCKED_LIST);
2106                                 mlog(0, "node died with lock pending "
2107                                      "on %.*s. remove from blocked list and skip.\n",
2108                                      res->lockname.len, res->lockname.name);
2109                                 /* lock will be floating until ref in
2110                                  * dlmlock_remote is freed after the network
2111                                  * call returns.  ok for it to not be on any
2112                                  * list since no ast can be called
2113                                  * (the master is dead). */
2114                                 dlm_revert_pending_lock(res, lock);
2115                                 lock->lock_pending = 0;
2116                         } else if (lock->unlock_pending) {
2117                                 /* if an unlock was in progress, treat as
2118                                  * if this had completed successfully
2119                                  * before sending this lock state to the
2120                                  * new master.  note that the dlm_unlock
2121                                  * call is still responsible for calling
2122                                  * the unlockast.  that will happen after
2123                                  * the network call times out.  for now,
2124                                  * just move lists to prepare the new
2125                                  * recovery master.  */
2126                                 BUG_ON(i != DLM_GRANTED_LIST);
2127                                 mlog(0, "node died with unlock pending "
2128                                      "on %.*s. remove from blocked list and skip.\n",
2129                                      res->lockname.len, res->lockname.name);
2130                                 dlm_commit_pending_unlock(res, lock);
2131                                 lock->unlock_pending = 0;
2132                         } else if (lock->cancel_pending) {
2133                                 /* if a cancel was in progress, treat as
2134                                  * if this had completed successfully
2135                                  * before sending this lock state to the
2136                                  * new master */
2137                                 BUG_ON(i != DLM_CONVERTING_LIST);
2138                                 mlog(0, "node died with cancel pending "
2139                                      "on %.*s. move back to granted list.\n",
2140                                      res->lockname.len, res->lockname.name);
2141                                 dlm_commit_pending_cancel(res, lock);
2142                                 lock->cancel_pending = 0;
2143                         }
2144                         dlm_lock_put(lock);
2145                 }
2146         }
2147 }
2148 
2149 
2150 
2151 /* removes all recovered locks from the recovery list.
2152  * sets the res->owner to the new master.
2153  * unsets the RECOVERY flag and wakes waiters. */
2154 static void dlm_finish_local_lockres_recovery(struct dlm_ctxt *dlm,
2155                                               u8 dead_node, u8 new_master)
2156 {
2157         int i;
2158         struct hlist_head *bucket;
2159         struct dlm_lock_resource *res, *next;
2160 
2161         assert_spin_locked(&dlm->spinlock);
2162 
2163         list_for_each_entry_safe(res, next, &dlm->reco.resources, recovering) {
2164                 if (res->owner == dead_node) {
2165                         mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
2166                              dlm->name, res->lockname.len, res->lockname.name,
2167                              res->owner, new_master);
2168                         list_del_init(&res->recovering);
2169                         spin_lock(&res->spinlock);
2170                         /* new_master has our reference from
2171                          * the lock state sent during recovery */
2172                         dlm_change_lockres_owner(dlm, res, new_master);
2173                         res->state &= ~DLM_LOCK_RES_RECOVERING;
2174                         if (__dlm_lockres_has_locks(res))
2175                                 __dlm_dirty_lockres(dlm, res);
2176                         spin_unlock(&res->spinlock);
2177                         wake_up(&res->wq);
2178                         dlm_lockres_put(res);
2179                 }
2180         }
2181 
2182         /* this will become unnecessary eventually, but
2183          * for now we need to run the whole hash, clear
2184          * the RECOVERING state and set the owner
2185          * if necessary */
2186         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2187                 bucket = dlm_lockres_hash(dlm, i);
2188                 hlist_for_each_entry(res, bucket, hash_node) {
2189                         if (res->state & DLM_LOCK_RES_RECOVERY_WAITING) {
2190                                 spin_lock(&res->spinlock);
2191                                 res->state &= ~DLM_LOCK_RES_RECOVERY_WAITING;
2192                                 spin_unlock(&res->spinlock);
2193                                 wake_up(&res->wq);
2194                         }
2195 
2196                         if (!(res->state & DLM_LOCK_RES_RECOVERING))
2197                                 continue;
2198 
2199                         if (res->owner != dead_node &&
2200                             res->owner != dlm->node_num)
2201                                 continue;
2202 
2203                         if (!list_empty(&res->recovering)) {
2204                                 list_del_init(&res->recovering);
2205                                 dlm_lockres_put(res);
2206                         }
2207 
2208                         /* new_master has our reference from
2209                          * the lock state sent during recovery */
2210                         mlog(0, "%s: res %.*s, Changing owner from %u to %u\n",
2211                              dlm->name, res->lockname.len, res->lockname.name,
2212                              res->owner, new_master);
2213                         spin_lock(&res->spinlock);
2214                         dlm_change_lockres_owner(dlm, res, new_master);
2215                         res->state &= ~DLM_LOCK_RES_RECOVERING;
2216                         if (__dlm_lockres_has_locks(res))
2217                                 __dlm_dirty_lockres(dlm, res);
2218                         spin_unlock(&res->spinlock);
2219                         wake_up(&res->wq);
2220                 }
2221         }
2222 }
2223 
2224 static inline int dlm_lvb_needs_invalidation(struct dlm_lock *lock, int local)
2225 {
2226         if (local) {
2227                 if (lock->ml.type != LKM_EXMODE &&
2228                     lock->ml.type != LKM_PRMODE)
2229                         return 1;
2230         } else if (lock->ml.type == LKM_EXMODE)
2231                 return 1;
2232         return 0;
2233 }
2234 
2235 static void dlm_revalidate_lvb(struct dlm_ctxt *dlm,
2236                                struct dlm_lock_resource *res, u8 dead_node)
2237 {
2238         struct list_head *queue;
2239         struct dlm_lock *lock;
2240         int blank_lvb = 0, local = 0;
2241         int i;
2242         u8 search_node;
2243 
2244         assert_spin_locked(&dlm->spinlock);
2245         assert_spin_locked(&res->spinlock);
2246 
2247         if (res->owner == dlm->node_num)
2248                 /* if this node owned the lockres, and if the dead node
2249                  * had an EX when he died, blank out the lvb */
2250                 search_node = dead_node;
2251         else {
2252                 /* if this is a secondary lockres, and we had no EX or PR
2253                  * locks granted, we can no longer trust the lvb */
2254                 search_node = dlm->node_num;
2255                 local = 1;  /* check local state for valid lvb */
2256         }
2257 
2258         for (i=DLM_GRANTED_LIST; i<=DLM_CONVERTING_LIST; i++) {
2259                 queue = dlm_list_idx_to_ptr(res, i);
2260                 list_for_each_entry(lock, queue, list) {
2261                         if (lock->ml.node == search_node) {
2262                                 if (dlm_lvb_needs_invalidation(lock, local)) {
2263                                         /* zero the lksb lvb and lockres lvb */
2264                                         blank_lvb = 1;
2265                                         memset(lock->lksb->lvb, 0, DLM_LVB_LEN);
2266                                 }
2267                         }
2268                 }
2269         }
2270 
2271         if (blank_lvb) {
2272                 mlog(0, "clearing %.*s lvb, dead node %u had EX\n",
2273                      res->lockname.len, res->lockname.name, dead_node);
2274                 memset(res->lvb, 0, DLM_LVB_LEN);
2275         }
2276 }
2277 
2278 static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
2279                                 struct dlm_lock_resource *res, u8 dead_node)
2280 {
2281         struct dlm_lock *lock, *next;
2282         unsigned int freed = 0;
2283 
2284         /* this node is the lockres master:
2285          * 1) remove any stale locks for the dead node
2286          * 2) if the dead node had an EX when he died, blank out the lvb
2287          */
2288         assert_spin_locked(&dlm->spinlock);
2289         assert_spin_locked(&res->spinlock);
2290 
2291         /* We do two dlm_lock_put(). One for removing from list and the other is
2292          * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
2293 
2294         /* TODO: check pending_asts, pending_basts here */
2295         list_for_each_entry_safe(lock, next, &res->granted, list) {
2296                 if (lock->ml.node == dead_node) {
2297                         list_del_init(&lock->list);
2298                         dlm_lock_put(lock);
2299                         /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2300                         dlm_lock_put(lock);
2301                         freed++;
2302                 }
2303         }
2304         list_for_each_entry_safe(lock, next, &res->converting, list) {
2305                 if (lock->ml.node == dead_node) {
2306                         list_del_init(&lock->list);
2307                         dlm_lock_put(lock);
2308                         /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2309                         dlm_lock_put(lock);
2310                         freed++;
2311                 }
2312         }
2313         list_for_each_entry_safe(lock, next, &res->blocked, list) {
2314                 if (lock->ml.node == dead_node) {
2315                         list_del_init(&lock->list);
2316                         dlm_lock_put(lock);
2317                         /* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
2318                         dlm_lock_put(lock);
2319                         freed++;
2320                 }
2321         }
2322 
2323         if (freed) {
2324                 mlog(0, "%s:%.*s: freed %u locks for dead node %u, "
2325                      "dropping ref from lockres\n", dlm->name,
2326                      res->lockname.len, res->lockname.name, freed, dead_node);
2327                 if(!test_bit(dead_node, res->refmap)) {
2328                         mlog(ML_ERROR, "%s:%.*s: freed %u locks for dead node %u, "
2329                              "but ref was not set\n", dlm->name,
2330                              res->lockname.len, res->lockname.name, freed, dead_node);
2331                         __dlm_print_one_lock_resource(res);
2332                 }
2333                 res->state |= DLM_LOCK_RES_RECOVERY_WAITING;
2334                 dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2335         } else if (test_bit(dead_node, res->refmap)) {
2336                 mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2337                      "no locks and had not purged before dying\n", dlm->name,
2338                      res->lockname.len, res->lockname.name, dead_node);
2339                 dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2340         }
2341 
2342         /* do not kick thread yet */
2343         __dlm_dirty_lockres(dlm, res);
2344 }
2345 
2346 static void dlm_do_local_recovery_cleanup(struct dlm_ctxt *dlm, u8 dead_node)
2347 {
2348         struct dlm_lock_resource *res;
2349         int i;
2350         struct hlist_head *bucket;
2351         struct hlist_node *tmp;
2352         struct dlm_lock *lock;
2353 
2354 
2355         /* purge any stale mles */
2356         dlm_clean_master_list(dlm, dead_node);
2357 
2358         /*
2359          * now clean up all lock resources.  there are two rules:
2360          *
2361          * 1) if the dead node was the master, move the lockres
2362          *    to the recovering list.  set the RECOVERING flag.
2363          *    this lockres needs to be cleaned up before it can
2364          *    be used further.
2365          *
2366          * 2) if this node was the master, remove all locks from
2367          *    each of the lockres queues that were owned by the
2368          *    dead node.  once recovery finishes, the dlm thread
2369          *    can be kicked again to see if any ASTs or BASTs
2370          *    need to be fired as a result.
2371          */
2372         for (i = 0; i < DLM_HASH_BUCKETS; i++) {
2373                 bucket = dlm_lockres_hash(dlm, i);
2374                 hlist_for_each_entry_safe(res, tmp, bucket, hash_node) {
2375                         /* always prune any $RECOVERY entries for dead nodes,
2376                          * otherwise hangs can occur during later recovery */
2377                         if (dlm_is_recovery_lock(res->lockname.name,
2378                                                  res->lockname.len)) {
2379                                 spin_lock(&res->spinlock);
2380                                 list_for_each_entry(lock, &res->granted, list) {
2381                                         if (lock->ml.node == dead_node) {
2382                                                 mlog(0, "AHA! there was "
2383                                                      "a $RECOVERY lock for dead "
2384                                                      "node %u (%s)!\n",
2385                                                      dead_node, dlm->name);
2386                                                 list_del_init(&lock->list);
2387                                                 dlm_lock_put(lock);
2388                                                 /* Can't schedule
2389                                                  * DLM_UNLOCK_FREE_LOCK
2390                                                  * - do manually */
2391                                                 dlm_lock_put(lock);
2392                                                 break;
2393                                         }
2394                                 }
2395 
2396                                 if ((res->owner == dead_node) &&
2397                                                         (res->state & DLM_LOCK_RES_DROPPING_REF)) {
2398                                         dlm_lockres_get(res);
2399                                         __dlm_do_purge_lockres(dlm, res);
2400                                         spin_unlock(&res->spinlock);
2401                                         wake_up(&res->wq);
2402                                         dlm_lockres_put(res);
2403                                         continue;
2404                                 } else if (res->owner == dlm->node_num)
2405                                         dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2406                                 spin_unlock(&res->spinlock);
2407                                 continue;
2408                         }
2409                         spin_lock(&res->spinlock);
2410                         /* zero the lvb if necessary */
2411                         dlm_revalidate_lvb(dlm, res, dead_node);
2412                         if (res->owner == dead_node) {
2413                                 if (res->state & DLM_LOCK_RES_DROPPING_REF) {
2414                                         mlog(0, "%s:%.*s: owned by "
2415                                                 "dead node %u, this node was "
2416                                                 "dropping its ref when master died. "
2417                                                 "continue, purging the lockres.\n",
2418                                                 dlm->name, res->lockname.len,
2419                                                 res->lockname.name, dead_node);
2420                                         dlm_lockres_get(res);
2421                                         __dlm_do_purge_lockres(dlm, res);
2422                                         spin_unlock(&res->spinlock);
2423                                         wake_up(&res->wq);
2424                                         dlm_lockres_put(res);
2425                                         continue;
2426                                 }
2427                                 dlm_move_lockres_to_recovery_list(dlm, res);
2428                         } else if (res->owner == dlm->node_num) {
2429                                 dlm_free_dead_locks(dlm, res, dead_node);
2430                                 __dlm_lockres_calc_usage(dlm, res);
2431                         } else if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
2432                                 if (test_bit(dead_node, res->refmap)) {
2433                                         mlog(0, "%s:%.*s: dead node %u had a ref, but had "
2434                                                 "no locks and had not purged before dying\n",
2435                                                 dlm->name, res->lockname.len,
2436                                                 res->lockname.name, dead_node);
2437                                         dlm_lockres_clear_refmap_bit(dlm, res, dead_node);
2438                                 }
2439                         }
2440                         spin_unlock(&res->spinlock);
2441                 }
2442         }
2443 
2444 }
2445 
2446 static void __dlm_hb_node_down(struct dlm_ctxt *dlm, int idx)
2447 {
2448         assert_spin_locked(&dlm->spinlock);
2449 
2450         if (dlm->reco.new_master == idx) {
2451                 mlog(0, "%s: recovery master %d just died\n",
2452                      dlm->name, idx);
2453                 if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2454                         /* finalize1 was reached, so it is safe to clear
2455                          * the new_master and dead_node.  that recovery
2456                          * is complete. */
2457                         mlog(0, "%s: dead master %d had reached "
2458                              "finalize1 state, clearing\n", dlm->name, idx);
2459                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2460                         __dlm_reset_recovery(dlm);
2461                 }
2462         }
2463 
2464         /* Clean up join state on node death. */
2465         if (dlm->joining_node == idx) {
2466                 mlog(0, "Clearing join state for node %u\n", idx);
2467                 __dlm_set_joining_node(dlm, DLM_LOCK_RES_OWNER_UNKNOWN);
2468         }
2469 
2470         /* check to see if the node is already considered dead */
2471         if (!test_bit(idx, dlm->live_nodes_map)) {
2472                 mlog(0, "for domain %s, node %d is already dead. "
2473                      "another node likely did recovery already.\n",
2474                      dlm->name, idx);
2475                 return;
2476         }
2477 
2478         /* check to see if we do not care about this node */
2479         if (!test_bit(idx, dlm->domain_map)) {
2480                 /* This also catches the case that we get a node down
2481                  * but haven't joined the domain yet. */
2482                 mlog(0, "node %u already removed from domain!\n", idx);
2483                 return;
2484         }
2485 
2486         clear_bit(idx, dlm->live_nodes_map);
2487 
2488         /* make sure local cleanup occurs before the heartbeat events */
2489         if (!test_bit(idx, dlm->recovery_map))
2490                 dlm_do_local_recovery_cleanup(dlm, idx);
2491 
2492         /* notify anything attached to the heartbeat events */
2493         dlm_hb_event_notify_attached(dlm, idx, 0);
2494 
2495         mlog(0, "node %u being removed from domain map!\n", idx);
2496         clear_bit(idx, dlm->domain_map);
2497         clear_bit(idx, dlm->exit_domain_map);
2498         /* wake up migration waiters if a node goes down.
2499          * perhaps later we can genericize this for other waiters. */
2500         wake_up(&dlm->migration_wq);
2501 
2502         set_bit(idx, dlm->recovery_map);
2503 }
2504 
2505 void dlm_hb_node_down_cb(struct o2nm_node *node, int idx, void *data)
2506 {
2507         struct dlm_ctxt *dlm = data;
2508 
2509         if (!dlm_grab(dlm))
2510                 return;
2511 
2512         /*
2513          * This will notify any dlm users that a node in our domain
2514          * went away without notifying us first.
2515          */
2516         if (test_bit(idx, dlm->domain_map))
2517                 dlm_fire_domain_eviction_callbacks(dlm, idx);
2518 
2519         spin_lock(&dlm->spinlock);
2520         __dlm_hb_node_down(dlm, idx);
2521         spin_unlock(&dlm->spinlock);
2522 
2523         dlm_put(dlm);
2524 }
2525 
2526 void dlm_hb_node_up_cb(struct o2nm_node *node, int idx, void *data)
2527 {
2528         struct dlm_ctxt *dlm = data;
2529 
2530         if (!dlm_grab(dlm))
2531                 return;
2532 
2533         spin_lock(&dlm->spinlock);
2534         set_bit(idx, dlm->live_nodes_map);
2535         /* do NOT notify mle attached to the heartbeat events.
2536          * new nodes are not interesting in mastery until joined. */
2537         spin_unlock(&dlm->spinlock);
2538 
2539         dlm_put(dlm);
2540 }
2541 
2542 static void dlm_reco_ast(void *astdata)
2543 {
2544         struct dlm_ctxt *dlm = astdata;
2545         mlog(0, "ast for recovery lock fired!, this=%u, dlm=%s\n",
2546              dlm->node_num, dlm->name);
2547 }
2548 static void dlm_reco_bast(void *astdata, int blocked_type)
2549 {
2550         struct dlm_ctxt *dlm = astdata;
2551         mlog(0, "bast for recovery lock fired!, this=%u, dlm=%s\n",
2552              dlm->node_num, dlm->name);
2553 }
2554 static void dlm_reco_unlock_ast(void *astdata, enum dlm_status st)
2555 {
2556         mlog(0, "unlockast for recovery lock fired!\n");
2557 }
2558 
2559 /*
2560  * dlm_pick_recovery_master will continually attempt to use
2561  * dlmlock() on the special "$RECOVERY" lockres with the
2562  * LKM_NOQUEUE flag to get an EX.  every thread that enters
2563  * this function on each node racing to become the recovery
2564  * master will not stop attempting this until either:
2565  * a) this node gets the EX (and becomes the recovery master),
2566  * or b) dlm->reco.new_master gets set to some nodenum
2567  * != O2NM_INVALID_NODE_NUM (another node will do the reco).
2568  * so each time a recovery master is needed, the entire cluster
2569  * will sync at this point.  if the new master dies, that will
2570  * be detected in dlm_do_recovery */
2571 static int dlm_pick_recovery_master(struct dlm_ctxt *dlm)
2572 {
2573         enum dlm_status ret;
2574         struct dlm_lockstatus lksb;
2575         int status = -EINVAL;
2576 
2577         mlog(0, "starting recovery of %s at %lu, dead=%u, this=%u\n",
2578              dlm->name, jiffies, dlm->reco.dead_node, dlm->node_num);
2579 again:
2580         memset(&lksb, 0, sizeof(lksb));
2581 
2582         ret = dlmlock(dlm, LKM_EXMODE, &lksb, LKM_NOQUEUE|LKM_RECOVERY,
2583                       DLM_RECOVERY_LOCK_NAME, DLM_RECOVERY_LOCK_NAME_LEN,
2584                       dlm_reco_ast, dlm, dlm_reco_bast);
2585 
2586         mlog(0, "%s: dlmlock($RECOVERY) returned %d, lksb=%d\n",
2587              dlm->name, ret, lksb.status);
2588 
2589         if (ret == DLM_NORMAL) {
2590                 mlog(0, "dlm=%s dlmlock says I got it (this=%u)\n",
2591                      dlm->name, dlm->node_num);
2592 
2593                 /* got the EX lock.  check to see if another node
2594                  * just became the reco master */
2595                 if (dlm_reco_master_ready(dlm)) {
2596                         mlog(0, "%s: got reco EX lock, but %u will "
2597                              "do the recovery\n", dlm->name,
2598                              dlm->reco.new_master);
2599                         status = -EEXIST;
2600                 } else {
2601                         status = 0;
2602 
2603                         /* see if recovery was already finished elsewhere */
2604                         spin_lock(&dlm->spinlock);
2605                         if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
2606                                 status = -EINVAL;
2607                                 mlog(0, "%s: got reco EX lock, but "
2608                                      "node got recovered already\n", dlm->name);
2609                                 if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2610                                         mlog(ML_ERROR, "%s: new master is %u "
2611                                              "but no dead node!\n",
2612                                              dlm->name, dlm->reco.new_master);
2613                                         BUG();
2614                                 }
2615                         }
2616                         spin_unlock(&dlm->spinlock);
2617                 }
2618 
2619                 /* if this node has actually become the recovery master,
2620                  * set the master and send the messages to begin recovery */
2621                 if (!status) {
2622                         mlog(0, "%s: dead=%u, this=%u, sending "
2623                              "begin_reco now\n", dlm->name,
2624                              dlm->reco.dead_node, dlm->node_num);
2625                         status = dlm_send_begin_reco_message(dlm,
2626                                       dlm->reco.dead_node);
2627                         /* this always succeeds */
2628                         BUG_ON(status);
2629 
2630                         /* set the new_master to this node */
2631                         spin_lock(&dlm->spinlock);
2632                         dlm_set_reco_master(dlm, dlm->node_num);
2633                         spin_unlock(&dlm->spinlock);
2634                 }
2635 
2636                 /* recovery lock is a special case.  ast will not get fired,
2637                  * so just go ahead and unlock it. */
2638                 ret = dlmunlock(dlm, &lksb, 0, dlm_reco_unlock_ast, dlm);
2639                 if (ret == DLM_DENIED) {
2640                         mlog(0, "got DLM_DENIED, trying LKM_CANCEL\n");
2641                         ret = dlmunlock(dlm, &lksb, LKM_CANCEL, dlm_reco_unlock_ast, dlm);
2642                 }
2643                 if (ret != DLM_NORMAL) {
2644                         /* this would really suck. this could only happen
2645                          * if there was a network error during the unlock
2646                          * because of node death.  this means the unlock
2647                          * is actually "done" and the lock structure is
2648                          * even freed.  we can continue, but only
2649                          * because this specific lock name is special. */
2650                         mlog(ML_ERROR, "dlmunlock returned %d\n", ret);
2651                 }
2652         } else if (ret == DLM_NOTQUEUED) {
2653                 mlog(0, "dlm=%s dlmlock says another node got it (this=%u)\n",
2654                      dlm->name, dlm->node_num);
2655                 /* another node is master. wait on
2656                  * reco.new_master != O2NM_INVALID_NODE_NUM
2657                  * for at most one second */
2658                 wait_event_timeout(dlm->dlm_reco_thread_wq,
2659                                          dlm_reco_master_ready(dlm),
2660                                          msecs_to_jiffies(1000));
2661                 if (!dlm_reco_master_ready(dlm)) {
2662                         mlog(0, "%s: reco master taking awhile\n",
2663                              dlm->name);
2664                         goto again;
2665                 }
2666                 /* another node has informed this one that it is reco master */
2667                 mlog(0, "%s: reco master %u is ready to recover %u\n",
2668                      dlm->name, dlm->reco.new_master, dlm->reco.dead_node);
2669                 status = -EEXIST;
2670         } else if (ret == DLM_RECOVERING) {
2671                 mlog(0, "dlm=%s dlmlock says master node died (this=%u)\n",
2672                      dlm->name, dlm->node_num);
2673                 goto again;
2674         } else {
2675                 struct dlm_lock_resource *res;
2676 
2677                 /* dlmlock returned something other than NOTQUEUED or NORMAL */
2678                 mlog(ML_ERROR, "%s: got %s from dlmlock($RECOVERY), "
2679                      "lksb.status=%s\n", dlm->name, dlm_errname(ret),
2680                      dlm_errname(lksb.status));
2681                 res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2682                                          DLM_RECOVERY_LOCK_NAME_LEN);
2683                 if (res) {
2684                         dlm_print_one_lock_resource(res);
2685                         dlm_lockres_put(res);
2686                 } else {
2687                         mlog(ML_ERROR, "recovery lock not found\n");
2688                 }
2689                 BUG();
2690         }
2691 
2692         return status;
2693 }
2694 
2695 static int dlm_send_begin_reco_message(struct dlm_ctxt *dlm, u8 dead_node)
2696 {
2697         struct dlm_begin_reco br;
2698         int ret = 0;
2699         struct dlm_node_iter iter;
2700         int nodenum;
2701         int status;
2702 
2703         mlog(0, "%s: dead node is %u\n", dlm->name, dead_node);
2704 
2705         spin_lock(&dlm->spinlock);
2706         dlm_node_iter_init(dlm->domain_map, &iter);
2707         spin_unlock(&dlm->spinlock);
2708 
2709         clear_bit(dead_node, iter.node_map);
2710 
2711         memset(&br, 0, sizeof(br));
2712         br.node_idx = dlm->node_num;
2713         br.dead_node = dead_node;
2714 
2715         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2716                 ret = 0;
2717                 if (nodenum == dead_node) {
2718                         mlog(0, "not sending begin reco to dead node "
2719                                   "%u\n", dead_node);
2720                         continue;
2721                 }
2722                 if (nodenum == dlm->node_num) {
2723                         mlog(0, "not sending begin reco to self\n");
2724                         continue;
2725                 }
2726 retry:
2727                 ret = -EINVAL;
2728                 mlog(0, "attempting to send begin reco msg to %d\n",
2729                           nodenum);
2730                 ret = o2net_send_message(DLM_BEGIN_RECO_MSG, dlm->key,
2731                                          &br, sizeof(br), nodenum, &status);
2732                 /* negative status is handled ok by caller here */
2733                 if (ret >= 0)
2734                         ret = status;
2735                 if (dlm_is_host_down(ret)) {
2736                         /* node is down.  not involved in recovery
2737                          * so just keep going */
2738                         mlog(ML_NOTICE, "%s: node %u was down when sending "
2739                              "begin reco msg (%d)\n", dlm->name, nodenum, ret);
2740                         ret = 0;
2741                 }
2742 
2743                 /*
2744                  * Prior to commit aad1b15310b9bcd59fa81ab8f2b1513b59553ea8,
2745                  * dlm_begin_reco_handler() returned EAGAIN and not -EAGAIN.
2746                  * We are handling both for compatibility reasons.
2747                  */
2748                 if (ret == -EAGAIN || ret == EAGAIN) {
2749                         mlog(0, "%s: trying to start recovery of node "
2750                              "%u, but node %u is waiting for last recovery "
2751                              "to complete, backoff for a bit\n", dlm->name,
2752                              dead_node, nodenum);
2753                         msleep(100);
2754                         goto retry;
2755                 }
2756                 if (ret < 0) {
2757                         struct dlm_lock_resource *res;
2758 
2759                         /* this is now a serious problem, possibly ENOMEM
2760                          * in the network stack.  must retry */
2761                         mlog_errno(ret);
2762                         mlog(ML_ERROR, "begin reco of dlm %s to node %u "
2763                              "returned %d\n", dlm->name, nodenum, ret);
2764                         res = dlm_lookup_lockres(dlm, DLM_RECOVERY_LOCK_NAME,
2765                                                  DLM_RECOVERY_LOCK_NAME_LEN);
2766                         if (res) {
2767                                 dlm_print_one_lock_resource(res);
2768                                 dlm_lockres_put(res);
2769                         } else {
2770                                 mlog(ML_ERROR, "recovery lock not found\n");
2771                         }
2772                         /* sleep for a bit in hopes that we can avoid
2773                          * another ENOMEM */
2774                         msleep(100);
2775                         goto retry;
2776                 }
2777         }
2778 
2779         return ret;
2780 }
2781 
2782 int dlm_begin_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2783                            void **ret_data)
2784 {
2785         struct dlm_ctxt *dlm = data;
2786         struct dlm_begin_reco *br = (struct dlm_begin_reco *)msg->buf;
2787 
2788         /* ok to return 0, domain has gone away */
2789         if (!dlm_grab(dlm))
2790                 return 0;
2791 
2792         spin_lock(&dlm->spinlock);
2793         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2794                 mlog(0, "%s: node %u wants to recover node %u (%u:%u) "
2795                      "but this node is in finalize state, waiting on finalize2\n",
2796                      dlm->name, br->node_idx, br->dead_node,
2797                      dlm->reco.dead_node, dlm->reco.new_master);
2798                 spin_unlock(&dlm->spinlock);
2799                 dlm_put(dlm);
2800                 return -EAGAIN;
2801         }
2802         spin_unlock(&dlm->spinlock);
2803 
2804         mlog(0, "%s: node %u wants to recover node %u (%u:%u)\n",
2805              dlm->name, br->node_idx, br->dead_node,
2806              dlm->reco.dead_node, dlm->reco.new_master);
2807 
2808         dlm_fire_domain_eviction_callbacks(dlm, br->dead_node);
2809 
2810         spin_lock(&dlm->spinlock);
2811         if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM) {
2812                 if (test_bit(dlm->reco.new_master, dlm->recovery_map)) {
2813                         mlog(0, "%s: new_master %u died, changing "
2814                              "to %u\n", dlm->name, dlm->reco.new_master,
2815                              br->node_idx);
2816                 } else {
2817                         mlog(0, "%s: new_master %u NOT DEAD, changing "
2818                              "to %u\n", dlm->name, dlm->reco.new_master,
2819                              br->node_idx);
2820                         /* may not have seen the new master as dead yet */
2821                 }
2822         }
2823         if (dlm->reco.dead_node != O2NM_INVALID_NODE_NUM) {
2824                 mlog(ML_NOTICE, "%s: dead_node previously set to %u, "
2825                      "node %u changing it to %u\n", dlm->name,
2826                      dlm->reco.dead_node, br->node_idx, br->dead_node);
2827         }
2828         dlm_set_reco_master(dlm, br->node_idx);
2829         dlm_set_reco_dead_node(dlm, br->dead_node);
2830         if (!test_bit(br->dead_node, dlm->recovery_map)) {
2831                 mlog(0, "recovery master %u sees %u as dead, but this "
2832                      "node has not yet.  marking %u as dead\n",
2833                      br->node_idx, br->dead_node, br->dead_node);
2834                 if (!test_bit(br->dead_node, dlm->domain_map) ||
2835                     !test_bit(br->dead_node, dlm->live_nodes_map))
2836                         mlog(0, "%u not in domain/live_nodes map "
2837                              "so setting it in reco map manually\n",
2838                              br->dead_node);
2839                 /* force the recovery cleanup in __dlm_hb_node_down
2840                  * both of these will be cleared in a moment */
2841                 set_bit(br->dead_node, dlm->domain_map);
2842                 set_bit(br->dead_node, dlm->live_nodes_map);
2843                 __dlm_hb_node_down(dlm, br->dead_node);
2844         }
2845         spin_unlock(&dlm->spinlock);
2846 
2847         dlm_kick_recovery_thread(dlm);
2848 
2849         mlog(0, "%s: recovery started by node %u, for %u (%u:%u)\n",
2850              dlm->name, br->node_idx, br->dead_node,
2851              dlm->reco.dead_node, dlm->reco.new_master);
2852 
2853         dlm_put(dlm);
2854         return 0;
2855 }
2856 
2857 #define DLM_FINALIZE_STAGE2  0x01
2858 static int dlm_send_finalize_reco_message(struct dlm_ctxt *dlm)
2859 {
2860         int ret = 0;
2861         struct dlm_finalize_reco fr;
2862         struct dlm_node_iter iter;
2863         int nodenum;
2864         int status;
2865         int stage = 1;
2866 
2867         mlog(0, "finishing recovery for node %s:%u, "
2868              "stage %d\n", dlm->name, dlm->reco.dead_node, stage);
2869 
2870         spin_lock(&dlm->spinlock);
2871         dlm_node_iter_init(dlm->domain_map, &iter);
2872         spin_unlock(&dlm->spinlock);
2873 
2874 stage2:
2875         memset(&fr, 0, sizeof(fr));
2876         fr.node_idx = dlm->node_num;
2877         fr.dead_node = dlm->reco.dead_node;
2878         if (stage == 2)
2879                 fr.flags |= DLM_FINALIZE_STAGE2;
2880 
2881         while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
2882                 if (nodenum == dlm->node_num)
2883                         continue;
2884                 ret = o2net_send_message(DLM_FINALIZE_RECO_MSG, dlm->key,
2885                                          &fr, sizeof(fr), nodenum, &status);
2886                 if (ret >= 0)
2887                         ret = status;
2888                 if (ret < 0) {
2889                         mlog(ML_ERROR, "Error %d when sending message %u (key "
2890                              "0x%x) to node %u\n", ret, DLM_FINALIZE_RECO_MSG,
2891                              dlm->key, nodenum);
2892                         if (dlm_is_host_down(ret)) {
2893                                 /* this has no effect on this recovery
2894                                  * session, so set the status to zero to
2895                                  * finish out the last recovery */
2896                                 mlog(ML_ERROR, "node %u went down after this "
2897                                      "node finished recovery.\n", nodenum);
2898                                 ret = 0;
2899                                 continue;
2900                         }
2901                         break;
2902                 }
2903         }
2904         if (stage == 1) {
2905                 /* reset the node_iter back to the top and send finalize2 */
2906                 iter.curnode = -1;
2907                 stage = 2;
2908                 goto stage2;
2909         }
2910 
2911         return ret;
2912 }
2913 
2914 int dlm_finalize_reco_handler(struct o2net_msg *msg, u32 len, void *data,
2915                               void **ret_data)
2916 {
2917         struct dlm_ctxt *dlm = data;
2918         struct dlm_finalize_reco *fr = (struct dlm_finalize_reco *)msg->buf;
2919         int stage = 1;
2920 
2921         /* ok to return 0, domain has gone away */
2922         if (!dlm_grab(dlm))
2923                 return 0;
2924 
2925         if (fr->flags & DLM_FINALIZE_STAGE2)
2926                 stage = 2;
2927 
2928         mlog(0, "%s: node %u finalizing recovery stage%d of "
2929              "node %u (%u:%u)\n", dlm->name, fr->node_idx, stage,
2930              fr->dead_node, dlm->reco.dead_node, dlm->reco.new_master);
2931 
2932         spin_lock(&dlm->spinlock);
2933 
2934         if (dlm->reco.new_master != fr->node_idx) {
2935                 mlog(ML_ERROR, "node %u sent recovery finalize msg, but node "
2936                      "%u is supposed to be the new master, dead=%u\n",
2937                      fr->node_idx, dlm->reco.new_master, fr->dead_node);
2938                 BUG();
2939         }
2940         if (dlm->reco.dead_node != fr->dead_node) {
2941                 mlog(ML_ERROR, "node %u sent recovery finalize msg for dead "
2942                      "node %u, but node %u is supposed to be dead\n",
2943                      fr->node_idx, fr->dead_node, dlm->reco.dead_node);
2944                 BUG();
2945         }
2946 
2947         switch (stage) {
2948                 case 1:
2949                         dlm_finish_local_lockres_recovery(dlm, fr->dead_node, fr->node_idx);
2950                         if (dlm->reco.state & DLM_RECO_STATE_FINALIZE) {
2951                                 mlog(ML_ERROR, "%s: received finalize1 from "
2952                                      "new master %u for dead node %u, but "
2953                                      "this node has already received it!\n",
2954                                      dlm->name, fr->node_idx, fr->dead_node);
2955                                 dlm_print_reco_node_status(dlm);
2956                                 BUG();
2957                         }
2958                         dlm->reco.state |= DLM_RECO_STATE_FINALIZE;
2959                         spin_unlock(&dlm->spinlock);
2960                         break;
2961                 case 2:
2962                         if (!(dlm->reco.state & DLM_RECO_STATE_FINALIZE)) {
2963                                 mlog(ML_ERROR, "%s: received finalize2 from "
2964                                      "new master %u for dead node %u, but "
2965                                      "this node did not have finalize1!\n",
2966                                      dlm->name, fr->node_idx, fr->dead_node);
2967                                 dlm_print_reco_node_status(dlm);
2968                                 BUG();
2969                         }
2970                         dlm->reco.state &= ~DLM_RECO_STATE_FINALIZE;
2971                         __dlm_reset_recovery(dlm);
2972                         spin_unlock(&dlm->spinlock);
2973                         dlm_kick_recovery_thread(dlm);
2974                         break;
2975         }
2976 
2977         mlog(0, "%s: recovery done, reco master was %u, dead now %u, master now %u\n",
2978              dlm->name, fr->node_idx, dlm->reco.dead_node, dlm->reco.new_master);
2979 
2980         dlm_put(dlm);
2981         return 0;
2982 }
2983 

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