437698e9465fd01114fd117228cd39095445f795
[linux-2.6.git] / fs / ocfs2 / dlm / dlmlock.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * dlmlock.c
5  *
6  * underlying calls for lock creation
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/spinlock.h>
40 #include <linux/delay.h>
41
42
43 #include "cluster/heartbeat.h"
44 #include "cluster/nodemanager.h"
45 #include "cluster/tcp.h"
46
47 #include "dlmapi.h"
48 #include "dlmcommon.h"
49
50 #include "dlmconvert.h"
51
52 #define MLOG_MASK_PREFIX ML_DLM
53 #include "cluster/masklog.h"
54
55 static struct kmem_cache *dlm_lock_cache = NULL;
56
57 static DEFINE_SPINLOCK(dlm_cookie_lock);
58 static u64 dlm_next_cookie = 1;
59
60 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
61                                                struct dlm_lock_resource *res,
62                                                struct dlm_lock *lock, int flags);
63 static void dlm_init_lock(struct dlm_lock *newlock, int type,
64                           u8 node, u64 cookie);
65 static void dlm_lock_release(struct kref *kref);
66 static void dlm_lock_detach_lockres(struct dlm_lock *lock);
67
68 int dlm_init_lock_cache(void)
69 {
70         dlm_lock_cache = kmem_cache_create("o2dlm_lock",
71                                            sizeof(struct dlm_lock),
72                                            0, SLAB_HWCACHE_ALIGN, NULL);
73         if (dlm_lock_cache == NULL)
74                 return -ENOMEM;
75         return 0;
76 }
77
78 void dlm_destroy_lock_cache(void)
79 {
80         if (dlm_lock_cache)
81                 kmem_cache_destroy(dlm_lock_cache);
82 }
83
84 /* Tell us whether we can grant a new lock request.
85  * locking:
86  *   caller needs:  res->spinlock
87  *   taken:         none
88  *   held on exit:  none
89  * returns: 1 if the lock can be granted, 0 otherwise.
90  */
91 static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
92                                   struct dlm_lock *lock)
93 {
94         struct list_head *iter;
95         struct dlm_lock *tmplock;
96
97         list_for_each(iter, &res->granted) {
98                 tmplock = list_entry(iter, struct dlm_lock, list);
99
100                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
101                         return 0;
102         }
103
104         list_for_each(iter, &res->converting) {
105                 tmplock = list_entry(iter, struct dlm_lock, list);
106
107                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
108                         return 0;
109         }
110
111         return 1;
112 }
113
114 /* performs lock creation at the lockres master site
115  * locking:
116  *   caller needs:  none
117  *   taken:         takes and drops res->spinlock
118  *   held on exit:  none
119  * returns: DLM_NORMAL, DLM_NOTQUEUED
120  */
121 static enum dlm_status dlmlock_master(struct dlm_ctxt *dlm,
122                                       struct dlm_lock_resource *res,
123                                       struct dlm_lock *lock, int flags)
124 {
125         int call_ast = 0, kick_thread = 0;
126         enum dlm_status status = DLM_NORMAL;
127
128         mlog_entry("type=%d\n", lock->ml.type);
129
130         spin_lock(&res->spinlock);
131         /* if called from dlm_create_lock_handler, need to
132          * ensure it will not sleep in dlm_wait_on_lockres */
133         status = __dlm_lockres_state_to_status(res);
134         if (status != DLM_NORMAL &&
135             lock->ml.node != dlm->node_num) {
136                 /* erf.  state changed after lock was dropped. */
137                 spin_unlock(&res->spinlock);
138                 dlm_error(status);
139                 return status;
140         }
141         __dlm_wait_on_lockres(res);
142         __dlm_lockres_reserve_ast(res);
143
144         if (dlm_can_grant_new_lock(res, lock)) {
145                 mlog(0, "I can grant this lock right away\n");
146                 /* got it right away */
147                 lock->lksb->status = DLM_NORMAL;
148                 status = DLM_NORMAL;
149                 dlm_lock_get(lock);
150                 list_add_tail(&lock->list, &res->granted);
151
152                 /* for the recovery lock, we can't allow the ast
153                  * to be queued since the dlmthread is already
154                  * frozen.  but the recovery lock is always locked
155                  * with LKM_NOQUEUE so we do not need the ast in
156                  * this special case */
157                 if (!dlm_is_recovery_lock(res->lockname.name,
158                                           res->lockname.len)) {
159                         kick_thread = 1;
160                         call_ast = 1;
161                 } else {
162                         mlog(0, "%s: returning DLM_NORMAL to "
163                              "node %u for reco lock\n", dlm->name,
164                              lock->ml.node);
165                 }
166         } else {
167                 /* for NOQUEUE request, unless we get the
168                  * lock right away, return DLM_NOTQUEUED */
169                 if (flags & LKM_NOQUEUE) {
170                         status = DLM_NOTQUEUED;
171                         if (dlm_is_recovery_lock(res->lockname.name,
172                                                  res->lockname.len)) {
173                                 mlog(0, "%s: returning NOTQUEUED to "
174                                      "node %u for reco lock\n", dlm->name,
175                                      lock->ml.node);
176                         }
177                 } else {
178                         dlm_lock_get(lock);
179                         list_add_tail(&lock->list, &res->blocked);
180                         kick_thread = 1;
181                 }
182         }
183         /* reduce the inflight count, this may result in the lockres
184          * being purged below during calc_usage */
185         if (lock->ml.node == dlm->node_num)
186                 dlm_lockres_drop_inflight_ref(dlm, res);
187
188         spin_unlock(&res->spinlock);
189         wake_up(&res->wq);
190
191         /* either queue the ast or release it */
192         if (call_ast)
193                 dlm_queue_ast(dlm, lock);
194         else
195                 dlm_lockres_release_ast(dlm, res);
196
197         dlm_lockres_calc_usage(dlm, res);
198         if (kick_thread)
199                 dlm_kick_thread(dlm, res);
200
201         return status;
202 }
203
204 void dlm_revert_pending_lock(struct dlm_lock_resource *res,
205                              struct dlm_lock *lock)
206 {
207         /* remove from local queue if it failed */
208         list_del_init(&lock->list);
209         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
210 }
211
212
213 /*
214  * locking:
215  *   caller needs:  none
216  *   taken:         takes and drops res->spinlock
217  *   held on exit:  none
218  * returns: DLM_DENIED, DLM_RECOVERING, or net status
219  */
220 static enum dlm_status dlmlock_remote(struct dlm_ctxt *dlm,
221                                       struct dlm_lock_resource *res,
222                                       struct dlm_lock *lock, int flags)
223 {
224         enum dlm_status status = DLM_DENIED;
225         int lockres_changed = 1;
226
227         mlog_entry("type=%d\n", lock->ml.type);
228         mlog(0, "lockres %.*s, flags = 0x%x\n", res->lockname.len,
229              res->lockname.name, flags);
230
231         spin_lock(&res->spinlock);
232
233         /* will exit this call with spinlock held */
234         __dlm_wait_on_lockres(res);
235         res->state |= DLM_LOCK_RES_IN_PROGRESS;
236
237         /* add lock to local (secondary) queue */
238         dlm_lock_get(lock);
239         list_add_tail(&lock->list, &res->blocked);
240         lock->lock_pending = 1;
241         spin_unlock(&res->spinlock);
242
243         /* spec seems to say that you will get DLM_NORMAL when the lock
244          * has been queued, meaning we need to wait for a reply here. */
245         status = dlm_send_remote_lock_request(dlm, res, lock, flags);
246
247         spin_lock(&res->spinlock);
248         res->state &= ~DLM_LOCK_RES_IN_PROGRESS;
249         lock->lock_pending = 0;
250         if (status != DLM_NORMAL) {
251                 if (status == DLM_RECOVERING &&
252                     dlm_is_recovery_lock(res->lockname.name,
253                                          res->lockname.len)) {
254                         /* recovery lock was mastered by dead node.
255                          * we need to have calc_usage shoot down this
256                          * lockres and completely remaster it. */
257                         mlog(0, "%s: recovery lock was owned by "
258                              "dead node %u, remaster it now.\n",
259                              dlm->name, res->owner);
260                 } else if (status != DLM_NOTQUEUED) {
261                         /*
262                          * DO NOT call calc_usage, as this would unhash
263                          * the remote lockres before we ever get to use
264                          * it.  treat as if we never made any change to
265                          * the lockres.
266                          */
267                         lockres_changed = 0;
268                         dlm_error(status);
269                 }
270                 dlm_revert_pending_lock(res, lock);
271                 dlm_lock_put(lock);
272         } else if (dlm_is_recovery_lock(res->lockname.name, 
273                                         res->lockname.len)) {
274                 /* special case for the $RECOVERY lock.
275                  * there will never be an AST delivered to put
276                  * this lock on the proper secondary queue
277                  * (granted), so do it manually. */
278                 mlog(0, "%s: $RECOVERY lock for this node (%u) is "
279                      "mastered by %u; got lock, manually granting (no ast)\n",
280                      dlm->name, dlm->node_num, res->owner);
281                 list_move_tail(&lock->list, &res->granted);
282         }
283         spin_unlock(&res->spinlock);
284
285         if (lockres_changed)
286                 dlm_lockres_calc_usage(dlm, res);
287
288         wake_up(&res->wq);
289         return status;
290 }
291
292
293 /* for remote lock creation.
294  * locking:
295  *   caller needs:  none, but need res->state & DLM_LOCK_RES_IN_PROGRESS
296  *   taken:         none
297  *   held on exit:  none
298  * returns: DLM_NOLOCKMGR, or net status
299  */
300 static enum dlm_status dlm_send_remote_lock_request(struct dlm_ctxt *dlm,
301                                                struct dlm_lock_resource *res,
302                                                struct dlm_lock *lock, int flags)
303 {
304         struct dlm_create_lock create;
305         int tmpret, status = 0;
306         enum dlm_status ret;
307
308         mlog_entry_void();
309
310         memset(&create, 0, sizeof(create));
311         create.node_idx = dlm->node_num;
312         create.requested_type = lock->ml.type;
313         create.cookie = lock->ml.cookie;
314         create.namelen = res->lockname.len;
315         create.flags = cpu_to_be32(flags);
316         memcpy(create.name, res->lockname.name, create.namelen);
317
318         tmpret = o2net_send_message(DLM_CREATE_LOCK_MSG, dlm->key, &create,
319                                     sizeof(create), res->owner, &status);
320         if (tmpret >= 0) {
321                 // successfully sent and received
322                 ret = status;  // this is already a dlm_status
323                 if (ret == DLM_REJECTED) {
324                         mlog(ML_ERROR, "%s:%.*s: BUG.  this is a stale lockres "
325                              "no longer owned by %u.  that node is coming back "
326                              "up currently.\n", dlm->name, create.namelen,
327                              create.name, res->owner);
328                         dlm_print_one_lock_resource(res);
329                         BUG();
330                 }
331         } else {
332                 mlog_errno(tmpret);
333                 if (dlm_is_host_down(tmpret)) {
334                         ret = DLM_RECOVERING;
335                         mlog(0, "node %u died so returning DLM_RECOVERING "
336                              "from lock message!\n", res->owner);
337                 } else {
338                         ret = dlm_err_to_dlm_status(tmpret);
339                 }
340         }
341
342         return ret;
343 }
344
345 void dlm_lock_get(struct dlm_lock *lock)
346 {
347         kref_get(&lock->lock_refs);
348 }
349
350 void dlm_lock_put(struct dlm_lock *lock)
351 {
352         kref_put(&lock->lock_refs, dlm_lock_release);
353 }
354
355 static void dlm_lock_release(struct kref *kref)
356 {
357         struct dlm_lock *lock;
358
359         lock = container_of(kref, struct dlm_lock, lock_refs);
360
361         BUG_ON(!list_empty(&lock->list));
362         BUG_ON(!list_empty(&lock->ast_list));
363         BUG_ON(!list_empty(&lock->bast_list));
364         BUG_ON(lock->ast_pending);
365         BUG_ON(lock->bast_pending);
366
367         dlm_lock_detach_lockres(lock);
368
369         if (lock->lksb_kernel_allocated) {
370                 mlog(0, "freeing kernel-allocated lksb\n");
371                 kfree(lock->lksb);
372         }
373         kmem_cache_free(dlm_lock_cache, lock);
374 }
375
376 /* associate a lock with it's lockres, getting a ref on the lockres */
377 void dlm_lock_attach_lockres(struct dlm_lock *lock,
378                              struct dlm_lock_resource *res)
379 {
380         dlm_lockres_get(res);
381         lock->lockres = res;
382 }
383
384 /* drop ref on lockres, if there is still one associated with lock */
385 static void dlm_lock_detach_lockres(struct dlm_lock *lock)
386 {
387         struct dlm_lock_resource *res;
388
389         res = lock->lockres;
390         if (res) {
391                 lock->lockres = NULL;
392                 mlog(0, "removing lock's lockres reference\n");
393                 dlm_lockres_put(res);
394         }
395 }
396
397 static void dlm_init_lock(struct dlm_lock *newlock, int type,
398                           u8 node, u64 cookie)
399 {
400         INIT_LIST_HEAD(&newlock->list);
401         INIT_LIST_HEAD(&newlock->ast_list);
402         INIT_LIST_HEAD(&newlock->bast_list);
403         spin_lock_init(&newlock->spinlock);
404         newlock->ml.type = type;
405         newlock->ml.convert_type = LKM_IVMODE;
406         newlock->ml.highest_blocked = LKM_IVMODE;
407         newlock->ml.node = node;
408         newlock->ml.pad1 = 0;
409         newlock->ml.list = 0;
410         newlock->ml.flags = 0;
411         newlock->ast = NULL;
412         newlock->bast = NULL;
413         newlock->astdata = NULL;
414         newlock->ml.cookie = cpu_to_be64(cookie);
415         newlock->ast_pending = 0;
416         newlock->bast_pending = 0;
417         newlock->convert_pending = 0;
418         newlock->lock_pending = 0;
419         newlock->unlock_pending = 0;
420         newlock->cancel_pending = 0;
421         newlock->lksb_kernel_allocated = 0;
422
423         kref_init(&newlock->lock_refs);
424 }
425
426 struct dlm_lock * dlm_new_lock(int type, u8 node, u64 cookie,
427                                struct dlm_lockstatus *lksb)
428 {
429         struct dlm_lock *lock;
430         int kernel_allocated = 0;
431
432         lock = (struct dlm_lock *) kmem_cache_zalloc(dlm_lock_cache, GFP_NOFS);
433         if (!lock)
434                 return NULL;
435
436         if (!lksb) {
437                 /* zero memory only if kernel-allocated */
438                 lksb = kzalloc(sizeof(*lksb), GFP_NOFS);
439                 if (!lksb) {
440                         kfree(lock);
441                         return NULL;
442                 }
443                 kernel_allocated = 1;
444         }
445
446         dlm_init_lock(lock, type, node, cookie);
447         if (kernel_allocated)
448                 lock->lksb_kernel_allocated = 1;
449         lock->lksb = lksb;
450         lksb->lockid = lock;
451         return lock;
452 }
453
454 /* handler for lock creation net message
455  * locking:
456  *   caller needs:  none
457  *   taken:         takes and drops res->spinlock
458  *   held on exit:  none
459  * returns: DLM_NORMAL, DLM_SYSERR, DLM_IVLOCKID, DLM_NOTQUEUED
460  */
461 int dlm_create_lock_handler(struct o2net_msg *msg, u32 len, void *data,
462                             void **ret_data)
463 {
464         struct dlm_ctxt *dlm = data;
465         struct dlm_create_lock *create = (struct dlm_create_lock *)msg->buf;
466         struct dlm_lock_resource *res = NULL;
467         struct dlm_lock *newlock = NULL;
468         struct dlm_lockstatus *lksb = NULL;
469         enum dlm_status status = DLM_NORMAL;
470         char *name;
471         unsigned int namelen;
472
473         BUG_ON(!dlm);
474
475         mlog_entry_void();
476
477         if (!dlm_grab(dlm))
478                 return DLM_REJECTED;
479
480         name = create->name;
481         namelen = create->namelen;
482         status = DLM_REJECTED;
483         if (!dlm_domain_fully_joined(dlm)) {
484                 mlog(ML_ERROR, "Domain %s not fully joined, but node %u is "
485                      "sending a create_lock message for lock %.*s!\n",
486                      dlm->name, create->node_idx, namelen, name);
487                 dlm_error(status);
488                 goto leave;
489         }
490
491         status = DLM_IVBUFLEN;
492         if (namelen > DLM_LOCKID_NAME_MAX) {
493                 dlm_error(status);
494                 goto leave;
495         }
496
497         status = DLM_SYSERR;
498         newlock = dlm_new_lock(create->requested_type,
499                                create->node_idx,
500                                be64_to_cpu(create->cookie), NULL);
501         if (!newlock) {
502                 dlm_error(status);
503                 goto leave;
504         }
505
506         lksb = newlock->lksb;
507
508         if (be32_to_cpu(create->flags) & LKM_GET_LVB) {
509                 lksb->flags |= DLM_LKSB_GET_LVB;
510                 mlog(0, "set DLM_LKSB_GET_LVB flag\n");
511         }
512
513         status = DLM_IVLOCKID;
514         res = dlm_lookup_lockres(dlm, name, namelen);
515         if (!res) {
516                 dlm_error(status);
517                 goto leave;
518         }
519
520         spin_lock(&res->spinlock);
521         status = __dlm_lockres_state_to_status(res);
522         spin_unlock(&res->spinlock);
523
524         if (status != DLM_NORMAL) {
525                 mlog(0, "lockres recovering/migrating/in-progress\n");
526                 goto leave;
527         }
528
529         dlm_lock_attach_lockres(newlock, res);
530
531         status = dlmlock_master(dlm, res, newlock, be32_to_cpu(create->flags));
532 leave:
533         if (status != DLM_NORMAL)
534                 if (newlock)
535                         dlm_lock_put(newlock);
536
537         if (res)
538                 dlm_lockres_put(res);
539
540         dlm_put(dlm);
541
542         return status;
543 }
544
545
546 /* fetch next node-local (u8 nodenum + u56 cookie) into u64 */
547 static inline void dlm_get_next_cookie(u8 node_num, u64 *cookie)
548 {
549         u64 tmpnode = node_num;
550
551         /* shift single byte of node num into top 8 bits */
552         tmpnode <<= 56;
553
554         spin_lock(&dlm_cookie_lock);
555         *cookie = (dlm_next_cookie | tmpnode);
556         if (++dlm_next_cookie & 0xff00000000000000ull) {
557                 mlog(0, "This node's cookie will now wrap!\n");
558                 dlm_next_cookie = 1;
559         }
560         spin_unlock(&dlm_cookie_lock);
561 }
562
563 enum dlm_status dlmlock(struct dlm_ctxt *dlm, int mode,
564                         struct dlm_lockstatus *lksb, int flags,
565                         const char *name, int namelen, dlm_astlockfunc_t *ast,
566                         void *data, dlm_bastlockfunc_t *bast)
567 {
568         enum dlm_status status;
569         struct dlm_lock_resource *res = NULL;
570         struct dlm_lock *lock = NULL;
571         int convert = 0, recovery = 0;
572
573         /* yes this function is a mess.
574          * TODO: clean this up.  lots of common code in the
575          *       lock and convert paths, especially in the retry blocks */
576         if (!lksb) {
577                 dlm_error(DLM_BADARGS);
578                 return DLM_BADARGS;
579         }
580
581         status = DLM_BADPARAM;
582         if (mode != LKM_EXMODE && mode != LKM_PRMODE && mode != LKM_NLMODE) {
583                 dlm_error(status);
584                 goto error;
585         }
586
587         if (flags & ~LKM_VALID_FLAGS) {
588                 dlm_error(status);
589                 goto error;
590         }
591
592         convert = (flags & LKM_CONVERT);
593         recovery = (flags & LKM_RECOVERY);
594
595         if (recovery &&
596             (!dlm_is_recovery_lock(name, namelen) || convert) ) {
597                 dlm_error(status);
598                 goto error;
599         }
600         if (convert && (flags & LKM_LOCAL)) {
601                 mlog(ML_ERROR, "strange LOCAL convert request!\n");
602                 goto error;
603         }
604
605         if (convert) {
606                 /* CONVERT request */
607
608                 /* if converting, must pass in a valid dlm_lock */
609                 lock = lksb->lockid;
610                 if (!lock) {
611                         mlog(ML_ERROR, "NULL lock pointer in convert "
612                              "request\n");
613                         goto error;
614                 }
615
616                 res = lock->lockres;
617                 if (!res) {
618                         mlog(ML_ERROR, "NULL lockres pointer in convert "
619                              "request\n");
620                         goto error;
621                 }
622                 dlm_lockres_get(res);
623
624                 /* XXX: for ocfs2 purposes, the ast/bast/astdata/lksb are
625                  * static after the original lock call.  convert requests will
626                  * ensure that everything is the same, or return DLM_BADARGS.
627                  * this means that DLM_DENIED_NOASTS will never be returned.
628                  */
629                 if (lock->lksb != lksb || lock->ast != ast ||
630                     lock->bast != bast || lock->astdata != data) {
631                         status = DLM_BADARGS;
632                         mlog(ML_ERROR, "new args:  lksb=%p, ast=%p, bast=%p, "
633                              "astdata=%p\n", lksb, ast, bast, data);
634                         mlog(ML_ERROR, "orig args: lksb=%p, ast=%p, bast=%p, "
635                              "astdata=%p\n", lock->lksb, lock->ast,
636                              lock->bast, lock->astdata);
637                         goto error;
638                 }
639 retry_convert:
640                 dlm_wait_for_recovery(dlm);
641
642                 if (res->owner == dlm->node_num)
643                         status = dlmconvert_master(dlm, res, lock, flags, mode);
644                 else
645                         status = dlmconvert_remote(dlm, res, lock, flags, mode);
646                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
647                     status == DLM_FORWARD) {
648                         /* for now, see how this works without sleeping
649                          * and just retry right away.  I suspect the reco
650                          * or migration will complete fast enough that
651                          * no waiting will be necessary */
652                         mlog(0, "retrying convert with migration/recovery/"
653                              "in-progress\n");
654                         msleep(100);
655                         goto retry_convert;
656                 }
657         } else {
658                 u64 tmpcookie;
659
660                 /* LOCK request */
661                 status = DLM_BADARGS;
662                 if (!name) {
663                         dlm_error(status);
664                         goto error;
665                 }
666
667                 status = DLM_IVBUFLEN;
668                 if (namelen > DLM_LOCKID_NAME_MAX || namelen < 1) {
669                         dlm_error(status);
670                         goto error;
671                 }
672
673                 dlm_get_next_cookie(dlm->node_num, &tmpcookie);
674                 lock = dlm_new_lock(mode, dlm->node_num, tmpcookie, lksb);
675                 if (!lock) {
676                         dlm_error(status);
677                         goto error;
678                 }
679
680                 if (!recovery)
681                         dlm_wait_for_recovery(dlm);
682
683                 /* find or create the lock resource */
684                 res = dlm_get_lock_resource(dlm, name, namelen, flags);
685                 if (!res) {
686                         status = DLM_IVLOCKID;
687                         dlm_error(status);
688                         goto error;
689                 }
690
691                 mlog(0, "type=%d, flags = 0x%x\n", mode, flags);
692                 mlog(0, "creating lock: lock=%p res=%p\n", lock, res);
693
694                 dlm_lock_attach_lockres(lock, res);
695                 lock->ast = ast;
696                 lock->bast = bast;
697                 lock->astdata = data;
698
699 retry_lock:
700                 if (flags & LKM_VALBLK) {
701                         mlog(0, "LKM_VALBLK passed by caller\n");
702
703                         /* LVB requests for non PR, PW or EX locks are
704                          * ignored. */
705                         if (mode < LKM_PRMODE)
706                                 flags &= ~LKM_VALBLK;
707                         else {
708                                 flags |= LKM_GET_LVB;
709                                 lock->lksb->flags |= DLM_LKSB_GET_LVB;
710                         }
711                 }
712
713                 if (res->owner == dlm->node_num)
714                         status = dlmlock_master(dlm, res, lock, flags);
715                 else
716                         status = dlmlock_remote(dlm, res, lock, flags);
717
718                 if (status == DLM_RECOVERING || status == DLM_MIGRATING ||
719                     status == DLM_FORWARD) {
720                         mlog(0, "retrying lock with migration/"
721                              "recovery/in progress\n");
722                         msleep(100);
723                         /* no waiting for dlm_reco_thread */
724                         if (recovery) {
725                                 if (status != DLM_RECOVERING)
726                                         goto retry_lock;
727
728                                 mlog(0, "%s: got RECOVERING "
729                                      "for $RECOVERY lock, master "
730                                      "was %u\n", dlm->name,
731                                      res->owner);
732                                 /* wait to see the node go down, then
733                                  * drop down and allow the lockres to
734                                  * get cleaned up.  need to remaster. */
735                                 dlm_wait_for_node_death(dlm, res->owner,
736                                                 DLM_NODE_DEATH_WAIT_MAX);
737                         } else {
738                                 dlm_wait_for_recovery(dlm);
739                                 goto retry_lock;
740                         }
741                 }
742
743                 if (status != DLM_NORMAL) {
744                         lock->lksb->flags &= ~DLM_LKSB_GET_LVB;
745                         if (status != DLM_NOTQUEUED)
746                                 dlm_error(status);
747                         goto error;
748                 }
749         }
750
751 error:
752         if (status != DLM_NORMAL) {
753                 if (lock && !convert)
754                         dlm_lock_put(lock);
755                 // this is kind of unnecessary
756                 lksb->status = status;
757         }
758
759         /* put lockres ref from the convert path
760          * or from dlm_get_lock_resource */
761         if (res)
762                 dlm_lockres_put(res);
763
764         return status;
765 }
766 EXPORT_SYMBOL_GPL(dlmlock);