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[fs/lustre-release.git] / lustre / ldlm / ldlm_lock.c
1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see
18  * http://www.gnu.org/licenses/gpl-2.0.html
19  *
20  * GPL HEADER END
21  */
22 /*
23  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Use is subject to license terms.
25  *
26  * Copyright (c) 2010, 2017, Intel Corporation.
27  */
28 /*
29  * This file is part of Lustre, http://www.lustre.org/
30  * Lustre is a trademark of Sun Microsystems, Inc.
31  *
32  * lustre/ldlm/ldlm_lock.c
33  *
34  * Author: Peter Braam <braam@clusterfs.com>
35  * Author: Phil Schwan <phil@clusterfs.com>
36  */
37
38 #define DEBUG_SUBSYSTEM S_LDLM
39
40 #include <libcfs/libcfs.h>
41
42 #include <lustre_swab.h>
43 #include <obd_class.h>
44
45 #include "ldlm_internal.h"
46
47 struct kmem_cache *ldlm_glimpse_work_kmem;
48 EXPORT_SYMBOL(ldlm_glimpse_work_kmem);
49
50 /* lock types */
51 char *ldlm_lockname[] = {
52         [0] = "--",
53         [LCK_EX] = "EX",
54         [LCK_PW] = "PW",
55         [LCK_PR] = "PR",
56         [LCK_CW] = "CW",
57         [LCK_CR] = "CR",
58         [LCK_NL] = "NL",
59         [LCK_GROUP] = "GROUP",
60         [LCK_COS] = "COS"
61 };
62 EXPORT_SYMBOL(ldlm_lockname);
63
64 char *ldlm_typename[] = {
65         [LDLM_PLAIN] = "PLN",
66         [LDLM_EXTENT] = "EXT",
67         [LDLM_FLOCK] = "FLK",
68         [LDLM_IBITS] = "IBT",
69 };
70
71 static ldlm_policy_wire_to_local_t ldlm_policy_wire_to_local[] = {
72         [LDLM_PLAIN - LDLM_MIN_TYPE]  = ldlm_plain_policy_wire_to_local,
73         [LDLM_EXTENT - LDLM_MIN_TYPE] = ldlm_extent_policy_wire_to_local,
74         [LDLM_FLOCK - LDLM_MIN_TYPE]  = ldlm_flock_policy_wire_to_local,
75         [LDLM_IBITS - LDLM_MIN_TYPE]  = ldlm_ibits_policy_wire_to_local,
76 };
77
78 static ldlm_policy_local_to_wire_t ldlm_policy_local_to_wire[] = {
79         [LDLM_PLAIN - LDLM_MIN_TYPE]  = ldlm_plain_policy_local_to_wire,
80         [LDLM_EXTENT - LDLM_MIN_TYPE] = ldlm_extent_policy_local_to_wire,
81         [LDLM_FLOCK - LDLM_MIN_TYPE]  = ldlm_flock_policy_local_to_wire,
82         [LDLM_IBITS - LDLM_MIN_TYPE]  = ldlm_ibits_policy_local_to_wire,
83 };
84
85 /**
86  * Converts lock policy from local format to on the wire lock_desc format
87  */
88 void ldlm_convert_policy_to_wire(enum ldlm_type type,
89                                  const union ldlm_policy_data *lpolicy,
90                                  union ldlm_wire_policy_data *wpolicy)
91 {
92         ldlm_policy_local_to_wire_t convert;
93
94         convert = ldlm_policy_local_to_wire[type - LDLM_MIN_TYPE];
95
96         convert(lpolicy, wpolicy);
97 }
98
99 /**
100  * Converts lock policy from on the wire lock_desc format to local format
101  */
102 void ldlm_convert_policy_to_local(struct obd_export *exp, enum ldlm_type type,
103                                   const union ldlm_wire_policy_data *wpolicy,
104                                   union ldlm_policy_data *lpolicy)
105 {
106         ldlm_policy_wire_to_local_t convert;
107
108         convert = ldlm_policy_wire_to_local[type - LDLM_MIN_TYPE];
109
110         convert(wpolicy, lpolicy);
111 }
112
113 const char *ldlm_it2str(enum ldlm_intent_flags it)
114 {
115         switch (it) {
116         case IT_OPEN:
117                 return "open";
118         case IT_CREAT:
119                 return "creat";
120         case (IT_OPEN | IT_CREAT):
121                 return "open|creat";
122         case IT_READDIR:
123                 return "readdir";
124         case IT_GETATTR:
125                 return "getattr";
126         case IT_LOOKUP:
127                 return "lookup";
128         case IT_GETXATTR:
129                 return "getxattr";
130         case IT_LAYOUT:
131                 return "layout";
132         default:
133                 CERROR("Unknown intent 0x%08x\n", it);
134                 return "UNKNOWN";
135         }
136 }
137 EXPORT_SYMBOL(ldlm_it2str);
138
139 #ifdef HAVE_SERVER_SUPPORT
140 static ldlm_processing_policy ldlm_processing_policy_table[] = {
141         [LDLM_PLAIN]    = ldlm_process_plain_lock,
142         [LDLM_EXTENT]   = ldlm_process_extent_lock,
143         [LDLM_FLOCK]    = ldlm_process_flock_lock,
144         [LDLM_IBITS]    = ldlm_process_inodebits_lock,
145 };
146
147 ldlm_processing_policy ldlm_get_processing_policy(struct ldlm_resource *res)
148 {
149         return ldlm_processing_policy_table[res->lr_type];
150 }
151 EXPORT_SYMBOL(ldlm_get_processing_policy);
152
153 static ldlm_reprocessing_policy ldlm_reprocessing_policy_table[] = {
154         [LDLM_PLAIN]    = ldlm_reprocess_queue,
155         [LDLM_EXTENT]   = ldlm_reprocess_queue,
156         [LDLM_FLOCK]    = ldlm_reprocess_queue,
157         [LDLM_IBITS]    = ldlm_reprocess_inodebits_queue,
158 };
159
160 ldlm_reprocessing_policy ldlm_get_reprocessing_policy(struct ldlm_resource *res)
161 {
162         return ldlm_reprocessing_policy_table[res->lr_type];
163 }
164
165 #endif /* HAVE_SERVER_SUPPORT */
166
167 void ldlm_register_intent(struct ldlm_namespace *ns, ldlm_res_policy arg)
168 {
169         ns->ns_policy = arg;
170 }
171 EXPORT_SYMBOL(ldlm_register_intent);
172
173 /*
174  * REFCOUNTED LOCK OBJECTS
175  */
176
177
178 /**
179  * Get a reference on a lock.
180  *
181  * Lock refcounts, during creation:
182  *   - one special one for allocation, dec'd only once in destroy
183  *   - one for being a lock that's in-use
184  *   - one for the addref associated with a new lock
185  */
186 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
187 {
188         refcount_inc(&lock->l_handle.h_ref);
189         return lock;
190 }
191 EXPORT_SYMBOL(ldlm_lock_get);
192
193 static void lock_handle_free(struct rcu_head *rcu)
194 {
195         struct ldlm_lock *lock = container_of(rcu, struct ldlm_lock,
196                                               l_handle.h_rcu);
197
198         OBD_FREE_PRE(lock, sizeof(*lock), "slab-freed");
199         kmem_cache_free(ldlm_lock_slab, lock);
200 }
201
202 /**
203  * Release lock reference.
204  *
205  * Also frees the lock if it was last reference.
206  */
207 void ldlm_lock_put(struct ldlm_lock *lock)
208 {
209         ENTRY;
210
211         LASSERT(lock->l_resource != LP_POISON);
212         LASSERT(refcount_read(&lock->l_handle.h_ref) > 0);
213         if (refcount_dec_and_test(&lock->l_handle.h_ref)) {
214                 struct ldlm_resource *res;
215
216                 LDLM_DEBUG(lock,
217                            "final lock_put on destroyed lock, freeing it.");
218
219                 res = lock->l_resource;
220                 LASSERT(ldlm_is_destroyed(lock));
221                 LASSERT(list_empty(&lock->l_exp_list));
222                 LASSERT(list_empty(&lock->l_res_link));
223                 LASSERT(list_empty(&lock->l_pending_chain));
224
225                 lprocfs_counter_decr(ldlm_res_to_ns(res)->ns_stats,
226                                      LDLM_NSS_LOCKS);
227                 lu_ref_del(&res->lr_reference, "lock", lock);
228                 if (lock->l_export) {
229                         class_export_lock_put(lock->l_export, lock);
230                         lock->l_export = NULL;
231                 }
232
233                 if (lock->l_lvb_data != NULL)
234                         OBD_FREE_LARGE(lock->l_lvb_data, lock->l_lvb_len);
235
236                 if (res->lr_type == LDLM_EXTENT) {
237                         ldlm_interval_free(ldlm_interval_detach(lock));
238                 } else if (res->lr_type == LDLM_IBITS) {
239                         if (lock->l_ibits_node != NULL)
240                                 OBD_SLAB_FREE_PTR(lock->l_ibits_node,
241                                                   ldlm_inodebits_slab);
242                 }
243                 ldlm_resource_putref(res);
244                 lock->l_resource = NULL;
245                 lu_ref_fini(&lock->l_reference);
246                 call_rcu(&lock->l_handle.h_rcu, lock_handle_free);
247         }
248
249         EXIT;
250 }
251 EXPORT_SYMBOL(ldlm_lock_put);
252
253 /**
254  * Removes LDLM lock \a lock from LRU. Assumes LRU is already locked.
255  */
256 int ldlm_lock_remove_from_lru_nolock(struct ldlm_lock *lock)
257 {
258         int rc = 0;
259         if (!list_empty(&lock->l_lru)) {
260                 struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
261
262                 LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
263                 if (ns->ns_last_pos == &lock->l_lru)
264                         ns->ns_last_pos = lock->l_lru.prev;
265                 list_del_init(&lock->l_lru);
266                 LASSERT(ns->ns_nr_unused > 0);
267                 ns->ns_nr_unused--;
268                 rc = 1;
269         }
270         return rc;
271 }
272
273 /**
274  * Removes LDLM lock \a lock from LRU. Obtains the LRU lock first.
275  *
276  * If \a last_use is non-zero, it will remove the lock from LRU only if
277  * it matches lock's l_last_used.
278  *
279  * \retval 0 if \a last_use is set, the lock is not in LRU list or \a last_use
280  *           doesn't match lock's l_last_used;
281  *           otherwise, the lock hasn't been in the LRU list.
282  * \retval 1 the lock was in LRU list and removed.
283  */
284 int ldlm_lock_remove_from_lru_check(struct ldlm_lock *lock, ktime_t last_use)
285 {
286         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
287         int rc = 0;
288
289         ENTRY;
290         if (ldlm_is_ns_srv(lock)) {
291                 LASSERT(list_empty(&lock->l_lru));
292                 RETURN(0);
293         }
294
295         spin_lock(&ns->ns_lock);
296         if (!ktime_compare(last_use, ktime_set(0, 0)) ||
297             !ktime_compare(last_use, lock->l_last_used))
298                 rc = ldlm_lock_remove_from_lru_nolock(lock);
299         spin_unlock(&ns->ns_lock);
300
301         RETURN(rc);
302 }
303
304 /**
305  * Adds LDLM lock \a lock to namespace LRU. Assumes LRU is already locked.
306  */
307 void ldlm_lock_add_to_lru_nolock(struct ldlm_lock *lock)
308 {
309         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
310
311         lock->l_last_used = ktime_get();
312         LASSERT(list_empty(&lock->l_lru));
313         LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
314         list_add_tail(&lock->l_lru, &ns->ns_unused_list);
315         LASSERT(ns->ns_nr_unused >= 0);
316         ns->ns_nr_unused++;
317 }
318
319 /**
320  * Adds LDLM lock \a lock to namespace LRU. Obtains necessary LRU locks
321  * first.
322  */
323 void ldlm_lock_add_to_lru(struct ldlm_lock *lock)
324 {
325         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
326
327         ENTRY;
328         spin_lock(&ns->ns_lock);
329         ldlm_lock_add_to_lru_nolock(lock);
330         spin_unlock(&ns->ns_lock);
331         EXIT;
332 }
333
334 /**
335  * Moves LDLM lock \a lock that is already in namespace LRU to the tail of
336  * the LRU. Performs necessary LRU locking
337  */
338 void ldlm_lock_touch_in_lru(struct ldlm_lock *lock)
339 {
340         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
341
342         ENTRY;
343         if (ldlm_is_ns_srv(lock)) {
344                 LASSERT(list_empty(&lock->l_lru));
345                 EXIT;
346                 return;
347         }
348
349         spin_lock(&ns->ns_lock);
350         if (!list_empty(&lock->l_lru)) {
351                 ldlm_lock_remove_from_lru_nolock(lock);
352                 ldlm_lock_add_to_lru_nolock(lock);
353         }
354         spin_unlock(&ns->ns_lock);
355         EXIT;
356 }
357
358 /**
359  * Helper to destroy a locked lock.
360  *
361  * Used by ldlm_lock_destroy and ldlm_lock_destroy_nolock
362  * Must be called with l_lock and lr_lock held.
363  *
364  * Does not actually free the lock data, but rather marks the lock as
365  * destroyed by setting l_destroyed field in the lock to 1.  Destroys a
366  * handle->lock association too, so that the lock can no longer be found
367  * and removes the lock from LRU list.  Actual lock freeing occurs when
368  * last lock reference goes away.
369  *
370  * Original comment (of some historical value):
371  * This used to have a 'strict' flag, which recovery would use to mark an
372  * in-use lock as needing-to-die.  Lest I am ever tempted to put it back, I
373  * shall explain why it's gone: with the new hash table scheme, once you call
374  * ldlm_lock_destroy, you can never drop your final references on this lock.
375  * Because it's not in the hash table anymore.  -phil
376  */
377 static int ldlm_lock_destroy_internal(struct ldlm_lock *lock)
378 {
379         ENTRY;
380
381         if (lock->l_readers || lock->l_writers) {
382                 LDLM_ERROR(lock, "lock still has references");
383                 LBUG();
384         }
385
386         if (!list_empty(&lock->l_res_link)) {
387                 LDLM_ERROR(lock, "lock still on resource");
388                 LBUG();
389         }
390
391         if (ldlm_is_destroyed(lock)) {
392                 LASSERT(list_empty(&lock->l_lru));
393                 EXIT;
394                 return 0;
395         }
396         ldlm_set_destroyed(lock);
397
398         if (lock->l_export && lock->l_export->exp_lock_hash) {
399                 /* NB: it's safe to call cfs_hash_del() even lock isn't
400                  * in exp_lock_hash. */
401                 /* In the function below, .hs_keycmp resolves to
402                  * ldlm_export_lock_keycmp() */
403                 /* coverity[overrun-buffer-val] */
404                 cfs_hash_del(lock->l_export->exp_lock_hash,
405                              &lock->l_remote_handle, &lock->l_exp_hash);
406         }
407
408         ldlm_lock_remove_from_lru(lock);
409         class_handle_unhash(&lock->l_handle);
410
411         EXIT;
412         return 1;
413 }
414
415 /**
416  * Destroys a LDLM lock \a lock. Performs necessary locking first.
417  */
418 void ldlm_lock_destroy(struct ldlm_lock *lock)
419 {
420         int first;
421         ENTRY;
422         lock_res_and_lock(lock);
423         first = ldlm_lock_destroy_internal(lock);
424         unlock_res_and_lock(lock);
425
426         /* drop reference from hashtable only for first destroy */
427         if (first) {
428                 lu_ref_del(&lock->l_reference, "hash", lock);
429                 LDLM_LOCK_RELEASE(lock);
430         }
431         EXIT;
432 }
433
434 /**
435  * Destroys a LDLM lock \a lock that is already locked.
436  */
437 void ldlm_lock_destroy_nolock(struct ldlm_lock *lock)
438 {
439         int first;
440         ENTRY;
441         first = ldlm_lock_destroy_internal(lock);
442         /* drop reference from hashtable only for first destroy */
443         if (first) {
444                 lu_ref_del(&lock->l_reference, "hash", lock);
445                 LDLM_LOCK_RELEASE(lock);
446         }
447         EXIT;
448 }
449
450 static const char lock_handle_owner[] = "ldlm";
451
452 /**
453  *
454  * Allocate and initialize new lock structure.
455  *
456  * usage: pass in a resource on which you have done ldlm_resource_get
457  *        new lock will take over the refcount.
458  * returns: lock with refcount 2 - one for current caller and one for remote
459  */
460 static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource)
461 {
462         struct ldlm_lock *lock;
463         ENTRY;
464
465         if (resource == NULL)
466                 LBUG();
467
468         OBD_SLAB_ALLOC_PTR_GFP(lock, ldlm_lock_slab, GFP_NOFS);
469         if (lock == NULL)
470                 RETURN(NULL);
471
472         spin_lock_init(&lock->l_lock);
473         lock->l_resource = resource;
474         lu_ref_add(&resource->lr_reference, "lock", lock);
475
476         refcount_set(&lock->l_handle.h_ref, 2);
477         INIT_LIST_HEAD(&lock->l_res_link);
478         INIT_LIST_HEAD(&lock->l_lru);
479         INIT_LIST_HEAD(&lock->l_pending_chain);
480         INIT_LIST_HEAD(&lock->l_bl_ast);
481         INIT_LIST_HEAD(&lock->l_cp_ast);
482         INIT_LIST_HEAD(&lock->l_rk_ast);
483         init_waitqueue_head(&lock->l_waitq);
484         lock->l_blocking_lock = NULL;
485         INIT_LIST_HEAD(&lock->l_sl_mode);
486         INIT_LIST_HEAD(&lock->l_sl_policy);
487         INIT_HLIST_NODE(&lock->l_exp_hash);
488         INIT_HLIST_NODE(&lock->l_exp_flock_hash);
489
490         lprocfs_counter_incr(ldlm_res_to_ns(resource)->ns_stats,
491                              LDLM_NSS_LOCKS);
492         INIT_HLIST_NODE(&lock->l_handle.h_link);
493         class_handle_hash(&lock->l_handle, lock_handle_owner);
494
495         lu_ref_init(&lock->l_reference);
496         lu_ref_add(&lock->l_reference, "hash", lock);
497         lock->l_callback_timestamp = 0;
498         lock->l_activity = 0;
499
500 #if LUSTRE_TRACKS_LOCK_EXP_REFS
501         INIT_LIST_HEAD(&lock->l_exp_refs_link);
502         lock->l_exp_refs_nr = 0;
503         lock->l_exp_refs_target = NULL;
504 #endif
505         INIT_LIST_HEAD(&lock->l_exp_list);
506
507         RETURN(lock);
508 }
509
510 /**
511  * Moves LDLM lock \a lock to another resource.
512  * This is used on client when server returns some other lock than requested
513  * (typically as a result of intent operation)
514  */
515 int ldlm_lock_change_resource(struct ldlm_namespace *ns, struct ldlm_lock *lock,
516                               const struct ldlm_res_id *new_resid)
517 {
518         struct ldlm_resource *oldres;
519         struct ldlm_resource *newres;
520         int type;
521         ENTRY;
522
523         LASSERT(ns_is_client(ns));
524
525         oldres = lock_res_and_lock(lock);
526         if (memcmp(new_resid, &oldres->lr_name,
527                    sizeof(oldres->lr_name)) == 0) {
528                 /* Nothing to do */
529                 unlock_res_and_lock(lock);
530                 RETURN(0);
531         }
532
533         LASSERT(new_resid->name[0] != 0);
534
535         /* This function assumes that the lock isn't on any lists */
536         LASSERT(list_empty(&lock->l_res_link));
537
538         type = oldres->lr_type;
539         unlock_res_and_lock(lock);
540
541         newres = ldlm_resource_get(ns, NULL, new_resid, type, 1);
542         if (IS_ERR(newres))
543                 RETURN(PTR_ERR(newres));
544
545         lu_ref_add(&newres->lr_reference, "lock", lock);
546         /*
547          * To flip the lock from the old to the new resource, lock, oldres and
548          * newres have to be locked. Resource spin-locks are nested within
549          * lock->l_lock, and are taken in the memory address order to avoid
550          * dead-locks.
551          */
552         spin_lock(&lock->l_lock);
553         oldres = lock->l_resource;
554         if (oldres < newres) {
555                 lock_res(oldres);
556                 lock_res_nested(newres, LRT_NEW);
557         } else {
558                 lock_res(newres);
559                 lock_res_nested(oldres, LRT_NEW);
560         }
561         LASSERT(memcmp(new_resid, &oldres->lr_name,
562                        sizeof oldres->lr_name) != 0);
563         lock->l_resource = newres;
564         unlock_res(oldres);
565         unlock_res_and_lock(lock);
566
567         /* ...and the flowers are still standing! */
568         lu_ref_del(&oldres->lr_reference, "lock", lock);
569         ldlm_resource_putref(oldres);
570
571         RETURN(0);
572 }
573
574 /** \defgroup ldlm_handles LDLM HANDLES
575  * Ways to get hold of locks without any addresses.
576  * @{
577  */
578
579 /**
580  * Fills in handle for LDLM lock \a lock into supplied \a lockh
581  * Does not take any references.
582  */
583 void ldlm_lock2handle(const struct ldlm_lock *lock, struct lustre_handle *lockh)
584 {
585         lockh->cookie = lock->l_handle.h_cookie;
586 }
587 EXPORT_SYMBOL(ldlm_lock2handle);
588
589 /**
590  * Obtain a lock reference by handle.
591  *
592  * if \a flags: atomically get the lock and set the flags.
593  *              Return NULL if flag already set
594  */
595 struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *handle,
596                                      __u64 flags)
597 {
598         struct ldlm_lock *lock;
599         ENTRY;
600
601         LASSERT(handle);
602
603         if (!lustre_handle_is_used(handle))
604                 RETURN(NULL);
605
606         lock = class_handle2object(handle->cookie, lock_handle_owner);
607         if (lock == NULL)
608                 RETURN(NULL);
609
610         if (lock->l_export != NULL && lock->l_export->exp_failed) {
611                 CDEBUG(D_INFO, "lock export failed: lock %p, exp %p\n",
612                        lock, lock->l_export);
613                 LDLM_LOCK_PUT(lock);
614                 RETURN(NULL);
615         }
616
617         /* It's unlikely but possible that someone marked the lock as
618          * destroyed after we did handle2object on it */
619         if ((flags == 0) && !ldlm_is_destroyed(lock)) {
620                 lu_ref_add_atomic(&lock->l_reference, "handle", lock);
621                 RETURN(lock);
622         }
623
624         lock_res_and_lock(lock);
625
626         LASSERT(lock->l_resource != NULL);
627
628         lu_ref_add_atomic(&lock->l_reference, "handle", lock);
629         if (unlikely(ldlm_is_destroyed(lock))) {
630                 unlock_res_and_lock(lock);
631                 CDEBUG(D_INFO, "lock already destroyed: lock %p\n", lock);
632                 LDLM_LOCK_PUT(lock);
633                 RETURN(NULL);
634         }
635
636         /* If we're setting flags, make sure none of them are already set. */
637         if (flags != 0) {
638                 if ((lock->l_flags & flags) != 0) {
639                         unlock_res_and_lock(lock);
640                         LDLM_LOCK_PUT(lock);
641                         RETURN(NULL);
642                 }
643
644                 lock->l_flags |= flags;
645         }
646
647         unlock_res_and_lock(lock);
648         RETURN(lock);
649 }
650 EXPORT_SYMBOL(__ldlm_handle2lock);
651 /** @} ldlm_handles */
652
653 /**
654  * Fill in "on the wire" representation for given LDLM lock into supplied
655  * lock descriptor \a desc structure.
656  */
657 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
658 {
659         ldlm_res2desc(lock->l_resource, &desc->l_resource);
660         desc->l_req_mode = lock->l_req_mode;
661         desc->l_granted_mode = lock->l_granted_mode;
662         ldlm_convert_policy_to_wire(lock->l_resource->lr_type,
663                                     &lock->l_policy_data,
664                                     &desc->l_policy_data);
665 }
666
667 /**
668  * Add a lock to list of conflicting locks to send AST to.
669  *
670  * Only add if we have not sent a blocking AST to the lock yet.
671  */
672 static void ldlm_add_bl_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
673                                   struct list_head *work_list)
674 {
675         if (!ldlm_is_ast_sent(lock)) {
676                 LDLM_DEBUG(lock, "lock incompatible; sending blocking AST.");
677                 ldlm_set_ast_sent(lock);
678                 /* If the enqueuing client said so, tell the AST recipient to
679                  * discard dirty data, rather than writing back. */
680                 if (ldlm_is_ast_discard_data(new))
681                         ldlm_set_discard_data(lock);
682
683                 /* Lock can be converted from a blocking state back to granted
684                  * after lock convert or COS downgrade but still be in an
685                  * older bl_list because it is controlled only by
686                  * ldlm_work_bl_ast_lock(), let it be processed there.
687                  */
688                 if (list_empty(&lock->l_bl_ast)) {
689                         list_add(&lock->l_bl_ast, work_list);
690                         LDLM_LOCK_GET(lock);
691                 }
692                 LASSERT(lock->l_blocking_lock == NULL);
693                 lock->l_blocking_lock = LDLM_LOCK_GET(new);
694         }
695 }
696
697 /**
698  * Add a lock to list of just granted locks to send completion AST to.
699  */
700 static void ldlm_add_cp_work_item(struct ldlm_lock *lock,
701                                   struct list_head *work_list)
702 {
703         if (!ldlm_is_cp_reqd(lock)) {
704                 ldlm_set_cp_reqd(lock);
705                 LDLM_DEBUG(lock, "lock granted; sending completion AST.");
706                 LASSERT(list_empty(&lock->l_cp_ast));
707                 list_add(&lock->l_cp_ast, work_list);
708                 LDLM_LOCK_GET(lock);
709         }
710 }
711
712 /**
713  * Aggregator function to add AST work items into a list. Determines
714  * what sort of an AST work needs to be done and calls the proper
715  * adding function.
716  * Must be called with lr_lock held.
717  */
718 void ldlm_add_ast_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
719                             struct list_head *work_list)
720 {
721         ENTRY;
722         check_res_locked(lock->l_resource);
723         if (new)
724                 ldlm_add_bl_work_item(lock, new, work_list);
725         else
726                 ldlm_add_cp_work_item(lock, work_list);
727         EXIT;
728 }
729
730 /**
731  * Add specified reader/writer reference to LDLM lock with handle \a lockh.
732  * r/w reference type is determined by \a mode
733  * Calls ldlm_lock_addref_internal.
734  */
735 void ldlm_lock_addref(const struct lustre_handle *lockh, enum ldlm_mode mode)
736 {
737         struct ldlm_lock *lock;
738
739         lock = ldlm_handle2lock(lockh);
740         LASSERTF(lock != NULL, "Non-existing lock: %#llx\n", lockh->cookie);
741         ldlm_lock_addref_internal(lock, mode);
742         LDLM_LOCK_PUT(lock);
743 }
744 EXPORT_SYMBOL(ldlm_lock_addref);
745
746 /**
747  * Helper function.
748  * Add specified reader/writer reference to LDLM lock \a lock.
749  * r/w reference type is determined by \a mode
750  * Removes lock from LRU if it is there.
751  * Assumes the LDLM lock is already locked.
752  */
753 void ldlm_lock_addref_internal_nolock(struct ldlm_lock *lock,
754                                       enum ldlm_mode mode)
755 {
756         ldlm_lock_remove_from_lru(lock);
757         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
758                 lock->l_readers++;
759                 lu_ref_add_atomic(&lock->l_reference, "reader", lock);
760         }
761         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS)) {
762                 lock->l_writers++;
763                 lu_ref_add_atomic(&lock->l_reference, "writer", lock);
764         }
765         LDLM_LOCK_GET(lock);
766         lu_ref_add_atomic(&lock->l_reference, "user", lock);
767         LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
768 }
769
770 /**
771  * Attempts to add reader/writer reference to a lock with handle \a lockh, and
772  * fails if lock is already LDLM_FL_CBPENDING or destroyed.
773  *
774  * \retval 0 success, lock was addref-ed
775  *
776  * \retval -EAGAIN lock is being canceled.
777  */
778 int ldlm_lock_addref_try(const struct lustre_handle *lockh, enum ldlm_mode mode)
779 {
780         struct ldlm_lock *lock;
781         int               result;
782
783         result = -EAGAIN;
784         lock = ldlm_handle2lock(lockh);
785         if (lock != NULL) {
786                 lock_res_and_lock(lock);
787                 if (lock->l_readers != 0 || lock->l_writers != 0 ||
788                     !ldlm_is_cbpending(lock)) {
789                         ldlm_lock_addref_internal_nolock(lock, mode);
790                         result = 0;
791                 }
792                 unlock_res_and_lock(lock);
793                 LDLM_LOCK_PUT(lock);
794         }
795         return result;
796 }
797 EXPORT_SYMBOL(ldlm_lock_addref_try);
798
799 /**
800  * Add specified reader/writer reference to LDLM lock \a lock.
801  * Locks LDLM lock and calls ldlm_lock_addref_internal_nolock to do the work.
802  * Only called for local locks.
803  */
804 void ldlm_lock_addref_internal(struct ldlm_lock *lock, enum ldlm_mode mode)
805 {
806         lock_res_and_lock(lock);
807         ldlm_lock_addref_internal_nolock(lock, mode);
808         unlock_res_and_lock(lock);
809 }
810
811 /**
812  * Removes reader/writer reference for LDLM lock \a lock.
813  * Assumes LDLM lock is already locked.
814  * only called in ldlm_flock_destroy and for local locks.
815  * Does NOT add lock to LRU if no r/w references left to accomodate flock locks
816  * that cannot be placed in LRU.
817  */
818 void ldlm_lock_decref_internal_nolock(struct ldlm_lock *lock,
819                                       enum ldlm_mode mode)
820 {
821         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
822         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
823                 LASSERT(lock->l_readers > 0);
824                 lu_ref_del(&lock->l_reference, "reader", lock);
825                 lock->l_readers--;
826         }
827         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS)) {
828                 LASSERT(lock->l_writers > 0);
829                 lu_ref_del(&lock->l_reference, "writer", lock);
830                 lock->l_writers--;
831         }
832
833         lu_ref_del(&lock->l_reference, "user", lock);
834         LDLM_LOCK_RELEASE(lock);    /* matches the LDLM_LOCK_GET() in addref */
835 }
836
837 /**
838  * Removes reader/writer reference for LDLM lock \a lock.
839  * Locks LDLM lock first.
840  * If the lock is determined to be client lock on a client and r/w refcount
841  * drops to zero and the lock is not blocked, the lock is added to LRU lock
842  * on the namespace.
843  * For blocked LDLM locks if r/w count drops to zero, blocking_ast is called.
844  */
845 void ldlm_lock_decref_internal(struct ldlm_lock *lock, enum ldlm_mode mode)
846 {
847         struct ldlm_namespace *ns;
848
849         ENTRY;
850
851         lock_res_and_lock(lock);
852
853         ns = ldlm_lock_to_ns(lock);
854
855         ldlm_lock_decref_internal_nolock(lock, mode);
856
857         if ((ldlm_is_local(lock) || lock->l_req_mode == LCK_GROUP) &&
858             !lock->l_readers && !lock->l_writers) {
859                 /* If this is a local lock on a server namespace and this was
860                  * the last reference, cancel the lock.
861                  *
862                  * Group locks are special:
863                  * They must not go in LRU, but they are not called back
864                  * like non-group locks, instead they are manually released.
865                  * They have an l_writers reference which they keep until
866                  * they are manually released, so we remove them when they have
867                  * no more reader or writer references. - LU-6368 */
868                 ldlm_set_cbpending(lock);
869         }
870
871         if (!lock->l_readers && !lock->l_writers && ldlm_is_cbpending(lock)) {
872                 unsigned int mask = D_DLMTRACE;
873
874                 /* If we received a blocked AST and this was the last reference,
875                  * run the callback. */
876                 if (ldlm_is_ns_srv(lock) && lock->l_export)
877                         mask |= D_WARNING;
878                 LDLM_DEBUG_LIMIT(mask, lock,
879                                  "final decref done on %sCBPENDING lock",
880                                  mask & D_WARNING ? "non-local " : "");
881
882                 LDLM_LOCK_GET(lock); /* dropped by bl thread */
883                 ldlm_lock_remove_from_lru(lock);
884                 unlock_res_and_lock(lock);
885
886                 if (ldlm_is_fail_loc(lock))
887                         OBD_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
888
889                 if (ldlm_is_atomic_cb(lock) ||
890                     ldlm_bl_to_thread_lock(ns, NULL, lock) != 0)
891                         ldlm_handle_bl_callback(ns, NULL, lock);
892         } else if (ns_is_client(ns) &&
893                    !lock->l_readers && !lock->l_writers &&
894                    !ldlm_is_no_lru(lock) &&
895                    !ldlm_is_bl_ast(lock) &&
896                    !ldlm_is_converting(lock)) {
897
898                 /* If this is a client-side namespace and this was the last
899                  * reference, put it on the LRU.
900                  */
901                 ldlm_lock_add_to_lru(lock);
902                 unlock_res_and_lock(lock);
903                 LDLM_DEBUG(lock, "add lock into lru list");
904
905                 if (ldlm_is_fail_loc(lock))
906                         OBD_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
907
908                 ldlm_pool_recalc(&ns->ns_pool, true);
909         } else {
910                 LDLM_DEBUG(lock, "do not add lock into lru list");
911                 unlock_res_and_lock(lock);
912         }
913
914         EXIT;
915 }
916
917 /**
918  * Decrease reader/writer refcount for LDLM lock with handle \a lockh
919  */
920 void ldlm_lock_decref(const struct lustre_handle *lockh, enum ldlm_mode mode)
921 {
922         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
923         LASSERTF(lock != NULL, "Non-existing lock: %#llx\n", lockh->cookie);
924         ldlm_lock_decref_internal(lock, mode);
925         LDLM_LOCK_PUT(lock);
926 }
927 EXPORT_SYMBOL(ldlm_lock_decref);
928
929 /**
930  * Decrease reader/writer refcount for LDLM lock with handle
931  * \a lockh and mark it for subsequent cancellation once r/w refcount
932  * drops to zero instead of putting into LRU.
933  *
934  */
935 void ldlm_lock_decref_and_cancel(const struct lustre_handle *lockh,
936                                  enum ldlm_mode mode)
937 {
938         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
939         ENTRY;
940
941         LASSERT(lock != NULL);
942
943         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
944         lock_res_and_lock(lock);
945         ldlm_set_cbpending(lock);
946         unlock_res_and_lock(lock);
947         ldlm_lock_decref_internal(lock, mode);
948         LDLM_LOCK_PUT(lock);
949 }
950 EXPORT_SYMBOL(ldlm_lock_decref_and_cancel);
951
952 struct sl_insert_point {
953         struct list_head *res_link;
954         struct list_head *mode_link;
955         struct list_head *policy_link;
956 };
957
958 /**
959  * Finds a position to insert the new lock into granted lock list.
960  *
961  * Used for locks eligible for skiplist optimization.
962  *
963  * Parameters:
964  *      queue [input]:  the granted list where search acts on;
965  *      req [input]:    the lock whose position to be located;
966  *      prev [output]:  positions within 3 lists to insert @req to
967  * Return Value:
968  *      filled @prev
969  * NOTE: called by
970  *  - ldlm_grant_lock_with_skiplist
971  */
972 static void search_granted_lock(struct list_head *queue,
973                                 struct ldlm_lock *req,
974                                 struct sl_insert_point *prev)
975 {
976         struct list_head *tmp;
977         struct ldlm_lock *lock, *mode_end, *policy_end;
978         ENTRY;
979
980         list_for_each(tmp, queue) {
981                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
982
983                 mode_end = list_entry(lock->l_sl_mode.prev,
984                                           struct ldlm_lock, l_sl_mode);
985
986                 if (lock->l_req_mode != req->l_req_mode) {
987                         /* jump to last lock of mode group */
988                         tmp = &mode_end->l_res_link;
989                         continue;
990                 }
991
992                 /* suitable mode group is found */
993                 if (lock->l_resource->lr_type == LDLM_PLAIN) {
994                         /* insert point is last lock of the mode group */
995                         prev->res_link = &mode_end->l_res_link;
996                         prev->mode_link = &mode_end->l_sl_mode;
997                         prev->policy_link = &req->l_sl_policy;
998                         EXIT;
999                         return;
1000                 } else if (lock->l_resource->lr_type == LDLM_IBITS) {
1001                         for (;;) {
1002                                 policy_end =
1003                                         list_entry(lock->l_sl_policy.prev,
1004                                                        struct ldlm_lock,
1005                                                        l_sl_policy);
1006
1007                                 if (lock->l_policy_data.l_inodebits.bits ==
1008                                     req->l_policy_data.l_inodebits.bits) {
1009                                         /* insert point is last lock of
1010                                          * the policy group */
1011                                         prev->res_link =
1012                                                 &policy_end->l_res_link;
1013                                         prev->mode_link =
1014                                                 &policy_end->l_sl_mode;
1015                                         prev->policy_link =
1016                                                 &policy_end->l_sl_policy;
1017                                         EXIT;
1018                                         return;
1019                                 }
1020
1021                                 if (policy_end == mode_end)
1022                                         /* done with mode group */
1023                                         break;
1024
1025                                 /* go to next policy group within mode group */
1026                                 tmp = policy_end->l_res_link.next;
1027                                 lock = list_entry(tmp, struct ldlm_lock,
1028                                                       l_res_link);
1029                         }  /* loop over policy groups within the mode group */
1030
1031                         /* insert point is last lock of the mode group,
1032                          * new policy group is started */
1033                         prev->res_link = &mode_end->l_res_link;
1034                         prev->mode_link = &mode_end->l_sl_mode;
1035                         prev->policy_link = &req->l_sl_policy;
1036                         EXIT;
1037                         return;
1038                 } else {
1039                         LDLM_ERROR(lock,"is not LDLM_PLAIN or LDLM_IBITS lock");
1040                         LBUG();
1041                 }
1042         }
1043
1044         /* insert point is last lock on the queue,
1045          * new mode group and new policy group are started */
1046         prev->res_link = queue->prev;
1047         prev->mode_link = &req->l_sl_mode;
1048         prev->policy_link = &req->l_sl_policy;
1049         EXIT;
1050 }
1051
1052 /**
1053  * Add a lock into resource granted list after a position described by
1054  * \a prev.
1055  */
1056 static void ldlm_granted_list_add_lock(struct ldlm_lock *lock,
1057                                        struct sl_insert_point *prev)
1058 {
1059         struct ldlm_resource *res = lock->l_resource;
1060         ENTRY;
1061
1062         check_res_locked(res);
1063
1064         ldlm_resource_dump(D_INFO, res);
1065         LDLM_DEBUG(lock, "About to add lock:");
1066
1067         if (ldlm_is_destroyed(lock)) {
1068                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
1069                 return;
1070         }
1071
1072         LASSERT(list_empty(&lock->l_res_link));
1073         LASSERT(list_empty(&lock->l_sl_mode));
1074         LASSERT(list_empty(&lock->l_sl_policy));
1075
1076         /*
1077          * lock->link == prev->link means lock is first starting the group.
1078          * Don't re-add to itself to suppress kernel warnings.
1079          */
1080         if (&lock->l_res_link != prev->res_link)
1081                 list_add(&lock->l_res_link, prev->res_link);
1082         if (&lock->l_sl_mode != prev->mode_link)
1083                 list_add(&lock->l_sl_mode, prev->mode_link);
1084         if (&lock->l_sl_policy != prev->policy_link)
1085                 list_add(&lock->l_sl_policy, prev->policy_link);
1086
1087         EXIT;
1088 }
1089
1090 /**
1091  * Add a lock to granted list on a resource maintaining skiplist
1092  * correctness.
1093  */
1094 void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
1095 {
1096         struct sl_insert_point prev;
1097
1098         LASSERT(ldlm_is_granted(lock));
1099
1100         search_granted_lock(&lock->l_resource->lr_granted, lock, &prev);
1101         ldlm_granted_list_add_lock(lock, &prev);
1102 }
1103
1104 /**
1105  * Perform lock granting bookkeeping.
1106  *
1107  * Includes putting the lock into granted list and updating lock mode.
1108  * NOTE: called by
1109  *  - ldlm_lock_enqueue
1110  *  - ldlm_reprocess_queue
1111  *
1112  * must be called with lr_lock held
1113  */
1114 void ldlm_grant_lock(struct ldlm_lock *lock, struct list_head *work_list)
1115 {
1116         struct ldlm_resource *res = lock->l_resource;
1117         ENTRY;
1118
1119         check_res_locked(res);
1120
1121         lock->l_granted_mode = lock->l_req_mode;
1122
1123         if (work_list && lock->l_completion_ast != NULL)
1124                 ldlm_add_ast_work_item(lock, NULL, work_list);
1125
1126         if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS)
1127                 ldlm_grant_lock_with_skiplist(lock);
1128         else if (res->lr_type == LDLM_EXTENT)
1129                 ldlm_extent_add_lock(res, lock);
1130         else if (res->lr_type == LDLM_FLOCK) {
1131                 /* We should not add locks to granted list in the following
1132                  * cases:
1133                  * - this is an UNLOCK but not a real lock;
1134                  * - this is a TEST lock;
1135                  * - this is a F_CANCELLK lock (async flock has req_mode == 0)
1136                  * - this is a deadlock (flock cannot be granted) */
1137                 if (lock->l_req_mode == 0 ||
1138                     lock->l_req_mode == LCK_NL ||
1139                     ldlm_is_test_lock(lock) ||
1140                     ldlm_is_flock_deadlock(lock))
1141                         RETURN_EXIT;
1142                 ldlm_resource_add_lock(res, &res->lr_granted, lock);
1143         } else {
1144                 LBUG();
1145         }
1146
1147         ldlm_pool_add(&ldlm_res_to_ns(res)->ns_pool, lock);
1148         EXIT;
1149 }
1150
1151 /**
1152  * Check if the given @lock meets the criteria for a match.
1153  * A reference on the lock is taken if matched.
1154  *
1155  * \param lock     test-against this lock
1156  * \param data     parameters
1157  */
1158 static int lock_matches(struct ldlm_lock *lock, struct ldlm_match_data *data)
1159 {
1160         union ldlm_policy_data *lpol = &lock->l_policy_data;
1161         enum ldlm_mode match = LCK_MINMODE;
1162
1163         if (lock == data->lmd_old)
1164                 return INTERVAL_ITER_STOP;
1165
1166         /* Check if this lock can be matched.
1167          * Used by LU-2919(exclusive open) for open lease lock */
1168         if (ldlm_is_excl(lock))
1169                 return INTERVAL_ITER_CONT;
1170
1171         /* llite sometimes wants to match locks that will be
1172          * canceled when their users drop, but we allow it to match
1173          * if it passes in CBPENDING and the lock still has users.
1174          * this is generally only going to be used by children
1175          * whose parents already hold a lock so forward progress
1176          * can still happen. */
1177         if (ldlm_is_cbpending(lock) &&
1178             !(data->lmd_flags & LDLM_FL_CBPENDING))
1179                 return INTERVAL_ITER_CONT;
1180         if (!(data->lmd_match & LDLM_MATCH_UNREF) && ldlm_is_cbpending(lock) &&
1181             lock->l_readers == 0 && lock->l_writers == 0)
1182                 return INTERVAL_ITER_CONT;
1183
1184         if (!(lock->l_req_mode & *data->lmd_mode))
1185                 return INTERVAL_ITER_CONT;
1186
1187         /* When we search for ast_data, we are not doing a traditional match,
1188          * so we don't worry about IBITS or extent matching.
1189          */
1190         if (data->lmd_match & (LDLM_MATCH_AST | LDLM_MATCH_AST_ANY)) {
1191                 if (!lock->l_ast_data)
1192                         return INTERVAL_ITER_CONT;
1193
1194                 if (data->lmd_match & LDLM_MATCH_AST_ANY)
1195                         goto matched;
1196         }
1197
1198         match = lock->l_req_mode;
1199
1200         switch (lock->l_resource->lr_type) {
1201         case LDLM_EXTENT:
1202                 if (lpol->l_extent.start > data->lmd_policy->l_extent.start ||
1203                     lpol->l_extent.end < data->lmd_policy->l_extent.end)
1204                         return INTERVAL_ITER_CONT;
1205
1206                 if (unlikely(match == LCK_GROUP) &&
1207                     data->lmd_policy->l_extent.gid != LDLM_GID_ANY &&
1208                     lpol->l_extent.gid != data->lmd_policy->l_extent.gid)
1209                         return INTERVAL_ITER_CONT;
1210                 break;
1211         case LDLM_IBITS:
1212                 /* We match if we have existing lock with same or wider set
1213                    of bits. */
1214                 if ((lpol->l_inodebits.bits &
1215                      data->lmd_policy->l_inodebits.bits) !=
1216                     data->lmd_policy->l_inodebits.bits)
1217                         return INTERVAL_ITER_CONT;
1218
1219                 if (unlikely(match == LCK_GROUP) &&
1220                     data->lmd_policy->l_inodebits.li_gid != LDLM_GID_ANY &&
1221                     lpol->l_inodebits.li_gid !=
1222                     data->lmd_policy->l_inodebits.li_gid)
1223                         return INTERVAL_ITER_CONT;
1224                 break;
1225         default:
1226                 ;
1227         }
1228
1229         /* We match if we have existing lock with same or wider set
1230            of bits. */
1231         if (!(data->lmd_match & LDLM_MATCH_UNREF) && LDLM_HAVE_MASK(lock, GONE))
1232                 return INTERVAL_ITER_CONT;
1233
1234         if (!equi(data->lmd_flags & LDLM_FL_LOCAL_ONLY, ldlm_is_local(lock)))
1235                 return INTERVAL_ITER_CONT;
1236
1237         /* Filter locks by skipping flags */
1238         if (data->lmd_skip_flags & lock->l_flags)
1239                 return INTERVAL_ITER_CONT;
1240
1241 matched:
1242         if (data->lmd_flags & LDLM_FL_TEST_LOCK) {
1243                 LDLM_LOCK_GET(lock);
1244                 ldlm_lock_touch_in_lru(lock);
1245         } else {
1246                 ldlm_lock_addref_internal_nolock(lock, match);
1247         }
1248
1249         *data->lmd_mode = match;
1250         data->lmd_lock = lock;
1251
1252         return INTERVAL_ITER_STOP;
1253 }
1254
1255 static unsigned int itree_overlap_cb(struct interval_node *in, void *args)
1256 {
1257         struct ldlm_interval *node = to_ldlm_interval(in);
1258         struct ldlm_match_data *data = args;
1259         struct ldlm_lock *lock;
1260         int rc;
1261
1262         list_for_each_entry(lock, &node->li_group, l_sl_policy) {
1263                 rc = lock_matches(lock, data);
1264                 if (rc == INTERVAL_ITER_STOP)
1265                         return INTERVAL_ITER_STOP;
1266         }
1267         return INTERVAL_ITER_CONT;
1268 }
1269
1270 /**
1271  * Search for a lock with given parameters in interval trees.
1272  *
1273  * \param res      search for a lock in this resource
1274  * \param data     parameters
1275  *
1276  * \retval a referenced lock or NULL.
1277  */
1278 struct ldlm_lock *search_itree(struct ldlm_resource *res,
1279                                struct ldlm_match_data *data)
1280 {
1281         struct interval_node_extent ext = {
1282                 .start     = data->lmd_policy->l_extent.start,
1283                 .end       = data->lmd_policy->l_extent.end
1284         };
1285         int idx;
1286
1287         data->lmd_lock = NULL;
1288
1289         for (idx = 0; idx < LCK_MODE_NUM; idx++) {
1290                 struct ldlm_interval_tree *tree = &res->lr_itree[idx];
1291
1292                 if (tree->lit_root == NULL)
1293                         continue;
1294
1295                 if (!(tree->lit_mode & *data->lmd_mode))
1296                         continue;
1297
1298                 interval_search(tree->lit_root, &ext,
1299                                 itree_overlap_cb, data);
1300                 if (data->lmd_lock)
1301                         return data->lmd_lock;
1302         }
1303
1304         return NULL;
1305 }
1306 EXPORT_SYMBOL(search_itree);
1307
1308
1309 /**
1310  * Search for a lock with given properties in a queue.
1311  *
1312  * \param queue    search for a lock in this queue
1313  * \param data     parameters
1314  *
1315  * \retval a referenced lock or NULL.
1316  */
1317 static struct ldlm_lock *search_queue(struct list_head *queue,
1318                                       struct ldlm_match_data *data)
1319 {
1320         struct ldlm_lock *lock;
1321         int rc;
1322
1323         data->lmd_lock = NULL;
1324
1325         list_for_each_entry(lock, queue, l_res_link) {
1326                 rc = lock_matches(lock, data);
1327                 if (rc == INTERVAL_ITER_STOP)
1328                         return data->lmd_lock;
1329         }
1330
1331         return NULL;
1332 }
1333
1334 void ldlm_lock_fail_match_locked(struct ldlm_lock *lock)
1335 {
1336         if ((lock->l_flags & LDLM_FL_FAIL_NOTIFIED) == 0) {
1337                 lock->l_flags |= LDLM_FL_FAIL_NOTIFIED;
1338                 wake_up_all(&lock->l_waitq);
1339         }
1340 }
1341 EXPORT_SYMBOL(ldlm_lock_fail_match_locked);
1342
1343 void ldlm_lock_fail_match(struct ldlm_lock *lock)
1344 {
1345         lock_res_and_lock(lock);
1346         ldlm_lock_fail_match_locked(lock);
1347         unlock_res_and_lock(lock);
1348 }
1349
1350 /**
1351  * Mark lock as "matchable" by OST.
1352  *
1353  * Used to prevent certain races in LOV/OSC where the lock is granted, but LVB
1354  * is not yet valid.
1355  * Assumes LDLM lock is already locked.
1356  */
1357 void ldlm_lock_allow_match_locked(struct ldlm_lock *lock)
1358 {
1359         ldlm_set_lvb_ready(lock);
1360         wake_up_all(&lock->l_waitq);
1361 }
1362 EXPORT_SYMBOL(ldlm_lock_allow_match_locked);
1363
1364 /**
1365  * Mark lock as "matchable" by OST.
1366  * Locks the lock and then \see ldlm_lock_allow_match_locked
1367  */
1368 void ldlm_lock_allow_match(struct ldlm_lock *lock)
1369 {
1370         lock_res_and_lock(lock);
1371         ldlm_lock_allow_match_locked(lock);
1372         unlock_res_and_lock(lock);
1373 }
1374 EXPORT_SYMBOL(ldlm_lock_allow_match);
1375
1376 /**
1377  * Attempt to find a lock with specified properties.
1378  *
1379  * Typically returns a reference to matched lock unless LDLM_FL_TEST_LOCK is
1380  * set in \a flags
1381  *
1382  * Can be called in two ways:
1383  *
1384  * If 'ns' is NULL, then lockh describes an existing lock that we want to look
1385  * for a duplicate of.
1386  *
1387  * Otherwise, all of the fields must be filled in, to match against.
1388  *
1389  * If 'flags' contains LDLM_FL_LOCAL_ONLY, then only match local locks on the
1390  *     server (ie, connh is NULL)
1391  * If 'flags' contains LDLM_FL_BLOCK_GRANTED, then only locks on the granted
1392  *     list will be considered
1393  * If 'flags' contains LDLM_FL_CBPENDING, then locks that have been marked
1394  *     to be canceled can still be matched as long as they still have reader
1395  *     or writer refernces
1396  * If 'flags' contains LDLM_FL_TEST_LOCK, then don't actually reference a lock,
1397  *     just tell us if we would have matched.
1398  *
1399  * \retval 1 if it finds an already-existing lock that is compatible; in this
1400  * case, lockh is filled in with a addref()ed lock
1401  *
1402  * We also check security context, and if that fails we simply return 0 (to
1403  * keep caller code unchanged), the context failure will be discovered by
1404  * caller sometime later.
1405  */
1406 enum ldlm_mode ldlm_lock_match_with_skip(struct ldlm_namespace *ns,
1407                                          __u64 flags, __u64 skip_flags,
1408                                          const struct ldlm_res_id *res_id,
1409                                          enum ldlm_type type,
1410                                          union ldlm_policy_data *policy,
1411                                          enum ldlm_mode mode,
1412                                          struct lustre_handle *lockh,
1413                                          enum ldlm_match_flags match_flags)
1414 {
1415         struct ldlm_match_data data = {
1416                 .lmd_old = NULL,
1417                 .lmd_lock = NULL,
1418                 .lmd_mode = &mode,
1419                 .lmd_policy = policy,
1420                 .lmd_flags = flags,
1421                 .lmd_skip_flags = skip_flags,
1422                 .lmd_match = match_flags,
1423         };
1424         struct ldlm_resource *res;
1425         struct ldlm_lock *lock;
1426         int matched;
1427
1428         ENTRY;
1429
1430         if (ns == NULL) {
1431                 data.lmd_old = ldlm_handle2lock(lockh);
1432                 LASSERT(data.lmd_old != NULL);
1433
1434                 ns = ldlm_lock_to_ns(data.lmd_old);
1435                 res_id = &data.lmd_old->l_resource->lr_name;
1436                 type = data.lmd_old->l_resource->lr_type;
1437                 *data.lmd_mode = data.lmd_old->l_req_mode;
1438         }
1439
1440         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
1441         if (IS_ERR(res)) {
1442                 LASSERT(data.lmd_old == NULL);
1443                 RETURN(0);
1444         }
1445
1446         LDLM_RESOURCE_ADDREF(res);
1447         lock_res(res);
1448         if (res->lr_type == LDLM_EXTENT)
1449                 lock = search_itree(res, &data);
1450         else
1451                 lock = search_queue(&res->lr_granted, &data);
1452         if (!lock && !(flags & LDLM_FL_BLOCK_GRANTED))
1453                 lock = search_queue(&res->lr_waiting, &data);
1454         matched = lock ? mode : 0;
1455         unlock_res(res);
1456         LDLM_RESOURCE_DELREF(res);
1457         ldlm_resource_putref(res);
1458
1459         if (lock) {
1460                 ldlm_lock2handle(lock, lockh);
1461                 if ((flags & LDLM_FL_LVB_READY) &&
1462                     (!ldlm_is_lvb_ready(lock))) {
1463                         __u64 wait_flags = LDLM_FL_LVB_READY |
1464                                 LDLM_FL_DESTROYED | LDLM_FL_FAIL_NOTIFIED;
1465
1466                         if (lock->l_completion_ast) {
1467                                 int err = lock->l_completion_ast(lock,
1468                                                         LDLM_FL_WAIT_NOREPROC,
1469                                                         NULL);
1470                                 if (err)
1471                                         GOTO(out_fail_match, matched = 0);
1472                         }
1473
1474                         wait_event_idle_timeout(
1475                                 lock->l_waitq,
1476                                 lock->l_flags & wait_flags,
1477                                 cfs_time_seconds(obd_timeout));
1478
1479                         if (!ldlm_is_lvb_ready(lock))
1480                                 GOTO(out_fail_match, matched = 0);
1481                 }
1482
1483                 /* check user's security context */
1484                 if (lock->l_conn_export &&
1485                     sptlrpc_import_check_ctx(
1486                                 class_exp2cliimp(lock->l_conn_export)))
1487                         GOTO(out_fail_match, matched = 0);
1488
1489                 LDLM_DEBUG(lock, "matched (%llu %llu)",
1490                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1491                            res_id->name[2] : policy->l_extent.start,
1492                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1493                            res_id->name[3] : policy->l_extent.end);
1494
1495 out_fail_match:
1496                 if (flags & LDLM_FL_TEST_LOCK)
1497                         LDLM_LOCK_RELEASE(lock);
1498                 else if (!matched)
1499                         ldlm_lock_decref_internal(lock, mode);
1500         }
1501
1502         /* less verbose for test-only */
1503         if (!matched && !(flags & LDLM_FL_TEST_LOCK)) {
1504                 LDLM_DEBUG_NOLOCK("not matched ns %p type %u mode %u res "
1505                                   "%llu/%llu (%llu %llu)", ns,
1506                                   type, mode, res_id->name[0], res_id->name[1],
1507                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1508                                   res_id->name[2] : policy->l_extent.start,
1509                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1510                                   res_id->name[3] : policy->l_extent.end);
1511         }
1512         if (data.lmd_old != NULL)
1513                 LDLM_LOCK_PUT(data.lmd_old);
1514
1515         return matched;
1516 }
1517 EXPORT_SYMBOL(ldlm_lock_match_with_skip);
1518
1519 enum ldlm_mode ldlm_revalidate_lock_handle(const struct lustre_handle *lockh,
1520                                            __u64 *bits)
1521 {
1522         struct ldlm_lock *lock;
1523         enum ldlm_mode mode = 0;
1524         ENTRY;
1525
1526         lock = ldlm_handle2lock(lockh);
1527         if (lock != NULL) {
1528                 lock_res_and_lock(lock);
1529                 if (LDLM_HAVE_MASK(lock, GONE))
1530                         GOTO(out, mode);
1531
1532                 if (ldlm_is_cbpending(lock) &&
1533                     lock->l_readers == 0 && lock->l_writers == 0)
1534                         GOTO(out, mode);
1535
1536                 if (bits)
1537                         *bits = lock->l_policy_data.l_inodebits.bits;
1538                 mode = lock->l_granted_mode;
1539                 ldlm_lock_addref_internal_nolock(lock, mode);
1540         }
1541
1542         EXIT;
1543
1544 out:
1545         if (lock != NULL) {
1546                 unlock_res_and_lock(lock);
1547                 LDLM_LOCK_PUT(lock);
1548         }
1549         return mode;
1550 }
1551 EXPORT_SYMBOL(ldlm_revalidate_lock_handle);
1552
1553 /** The caller must guarantee that the buffer is large enough. */
1554 int ldlm_fill_lvb(struct ldlm_lock *lock, struct req_capsule *pill,
1555                   enum req_location loc, void *data, int size)
1556 {
1557         void *lvb;
1558         ENTRY;
1559
1560         LASSERT(data != NULL);
1561         LASSERT(size >= 0);
1562
1563         switch (lock->l_lvb_type) {
1564         case LVB_T_OST:
1565                 if (size == sizeof(struct ost_lvb)) {
1566                         if (loc == RCL_CLIENT)
1567                                 lvb = req_capsule_client_swab_get(pill,
1568                                                 &RMF_DLM_LVB,
1569                                                 lustre_swab_ost_lvb);
1570                         else
1571                                 lvb = req_capsule_server_swab_get(pill,
1572                                                 &RMF_DLM_LVB,
1573                                                 lustre_swab_ost_lvb);
1574                         if (unlikely(lvb == NULL)) {
1575                                 LDLM_ERROR(lock, "no LVB");
1576                                 RETURN(-EPROTO);
1577                         }
1578
1579                         memcpy(data, lvb, size);
1580                 } else if (size == sizeof(struct ost_lvb_v1)) {
1581                         struct ost_lvb *olvb = data;
1582
1583                         if (loc == RCL_CLIENT)
1584                                 lvb = req_capsule_client_swab_get(pill,
1585                                                 &RMF_DLM_LVB,
1586                                                 lustre_swab_ost_lvb_v1);
1587                         else
1588                                 lvb = req_capsule_server_sized_swab_get(pill,
1589                                                 &RMF_DLM_LVB, size,
1590                                                 lustre_swab_ost_lvb_v1);
1591                         if (unlikely(lvb == NULL)) {
1592                                 LDLM_ERROR(lock, "no LVB");
1593                                 RETURN(-EPROTO);
1594                         }
1595
1596                         memcpy(data, lvb, size);
1597                         olvb->lvb_mtime_ns = 0;
1598                         olvb->lvb_atime_ns = 0;
1599                         olvb->lvb_ctime_ns = 0;
1600                 } else {
1601                         LDLM_ERROR(lock, "Replied unexpected ost LVB size %d",
1602                                    size);
1603                         RETURN(-EINVAL);
1604                 }
1605                 break;
1606         case LVB_T_LQUOTA:
1607                 if (size == sizeof(struct lquota_lvb)) {
1608                         if (loc == RCL_CLIENT)
1609                                 lvb = req_capsule_client_swab_get(pill,
1610                                                 &RMF_DLM_LVB,
1611                                                 lustre_swab_lquota_lvb);
1612                         else
1613                                 lvb = req_capsule_server_swab_get(pill,
1614                                                 &RMF_DLM_LVB,
1615                                                 lustre_swab_lquota_lvb);
1616                         if (unlikely(lvb == NULL)) {
1617                                 LDLM_ERROR(lock, "no LVB");
1618                                 RETURN(-EPROTO);
1619                         }
1620
1621                         memcpy(data, lvb, size);
1622                 } else {
1623                         LDLM_ERROR(lock, "Replied unexpected lquota LVB size %d",
1624                                    size);
1625                         RETURN(-EINVAL);
1626                 }
1627                 break;
1628         case LVB_T_LAYOUT:
1629                 if (size == 0)
1630                         break;
1631
1632                 if (loc == RCL_CLIENT)
1633                         lvb = req_capsule_client_get(pill, &RMF_DLM_LVB);
1634                 else
1635                         lvb = req_capsule_server_get(pill, &RMF_DLM_LVB);
1636                 if (unlikely(lvb == NULL)) {
1637                         LDLM_ERROR(lock, "no LVB");
1638                         RETURN(-EPROTO);
1639                 }
1640
1641                 memcpy(data, lvb, size);
1642                 break;
1643         default:
1644                 LDLM_ERROR(lock, "Unknown LVB type: %d", lock->l_lvb_type);
1645                 libcfs_debug_dumpstack(NULL);
1646                 RETURN(-EINVAL);
1647         }
1648
1649         RETURN(0);
1650 }
1651
1652 /**
1653  * Create and fill in new LDLM lock with specified properties.
1654  * Returns a referenced lock
1655  */
1656 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
1657                                    const struct ldlm_res_id *res_id,
1658                                    enum ldlm_type type,
1659                                    enum ldlm_mode mode,
1660                                    const struct ldlm_callback_suite *cbs,
1661                                    void *data, __u32 lvb_len,
1662                                    enum lvb_type lvb_type)
1663 {
1664         struct ldlm_lock        *lock;
1665         struct ldlm_resource    *res;
1666         int                     rc;
1667         ENTRY;
1668
1669         res = ldlm_resource_get(ns, NULL, res_id, type, 1);
1670         if (IS_ERR(res))
1671                 RETURN(ERR_CAST(res));
1672
1673         lock = ldlm_lock_new(res);
1674         if (lock == NULL)
1675                 RETURN(ERR_PTR(-ENOMEM));
1676
1677         lock->l_req_mode = mode;
1678         lock->l_ast_data = data;
1679         lock->l_pid = current->pid;
1680         if (ns_is_server(ns))
1681                 ldlm_set_ns_srv(lock);
1682         if (cbs) {
1683                 lock->l_blocking_ast = cbs->lcs_blocking;
1684                 lock->l_completion_ast = cbs->lcs_completion;
1685                 lock->l_glimpse_ast = cbs->lcs_glimpse;
1686         }
1687
1688         switch (type) {
1689         case LDLM_EXTENT:
1690                 rc = ldlm_extent_alloc_lock(lock);
1691                 break;
1692         case LDLM_IBITS:
1693                 rc = ldlm_inodebits_alloc_lock(lock);
1694                 break;
1695         default:
1696                 rc = 0;
1697         }
1698         if (rc)
1699                 GOTO(out, rc);
1700
1701         if (lvb_len) {
1702                 lock->l_lvb_len = lvb_len;
1703                 OBD_ALLOC_LARGE(lock->l_lvb_data, lvb_len);
1704                 if (lock->l_lvb_data == NULL)
1705                         GOTO(out, rc = -ENOMEM);
1706         }
1707
1708         lock->l_lvb_type = lvb_type;
1709         if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_NEW_LOCK))
1710                 GOTO(out, rc = -ENOENT);
1711
1712         RETURN(lock);
1713
1714 out:
1715         ldlm_lock_destroy(lock);
1716         LDLM_LOCK_RELEASE(lock);
1717         RETURN(ERR_PTR(rc));
1718 }
1719
1720 #ifdef HAVE_SERVER_SUPPORT
1721 static enum ldlm_error ldlm_lock_enqueue_helper(struct ldlm_lock *lock,
1722                                              __u64 *flags)
1723 {
1724         struct ldlm_resource *res = lock->l_resource;
1725         enum ldlm_error rc = ELDLM_OK;
1726         LIST_HEAD(rpc_list);
1727         ldlm_processing_policy policy;
1728
1729         ENTRY;
1730
1731         policy = ldlm_get_processing_policy(res);
1732         policy(lock, flags, LDLM_PROCESS_ENQUEUE, &rc, &rpc_list);
1733         if (rc == ELDLM_OK && lock->l_granted_mode != lock->l_req_mode &&
1734             res->lr_type != LDLM_FLOCK)
1735                 rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list);
1736
1737         if (!list_empty(&rpc_list))
1738                 ldlm_discard_bl_list(&rpc_list);
1739
1740         RETURN(rc);
1741 }
1742 #endif
1743
1744 /**
1745  * Enqueue (request) a lock.
1746  *
1747  * Does not block. As a result of enqueue the lock would be put
1748  * into granted or waiting list.
1749  *
1750  * If namespace has intent policy sent and the lock has LDLM_FL_HAS_INTENT flag
1751  * set, skip all the enqueueing and delegate lock processing to intent policy
1752  * function.
1753  */
1754 enum ldlm_error ldlm_lock_enqueue(const struct lu_env *env,
1755                                   struct ldlm_namespace *ns,
1756                                   struct ldlm_lock **lockp,
1757                                   void *cookie, __u64 *flags)
1758 {
1759         struct ldlm_lock *lock = *lockp;
1760         struct ldlm_resource *res;
1761         int local = ns_is_client(ns);
1762         enum ldlm_error rc = ELDLM_OK;
1763         struct ldlm_interval *node = NULL;
1764 #ifdef HAVE_SERVER_SUPPORT
1765         bool reconstruct = false;
1766 #endif
1767         ENTRY;
1768
1769         /* policies are not executed on the client or during replay */
1770         if ((*flags & (LDLM_FL_HAS_INTENT|LDLM_FL_REPLAY)) == LDLM_FL_HAS_INTENT
1771             && !local && ns->ns_policy) {
1772                 rc = ns->ns_policy(env, ns, lockp, cookie, lock->l_req_mode,
1773                                    *flags, NULL);
1774                 if (rc == ELDLM_LOCK_REPLACED) {
1775                         /* The lock that was returned has already been granted,
1776                          * and placed into lockp.  If it's not the same as the
1777                          * one we passed in, then destroy the old one and our
1778                          * work here is done. */
1779                         if (lock != *lockp) {
1780                                 ldlm_lock_destroy(lock);
1781                                 LDLM_LOCK_RELEASE(lock);
1782                         }
1783                         *flags |= LDLM_FL_LOCK_CHANGED;
1784                         RETURN(0);
1785                 } else if (rc != ELDLM_OK &&
1786                            ldlm_is_granted(lock)) {
1787                         LASSERT(*flags & LDLM_FL_RESENT);
1788                         /* It may happen that ns_policy returns an error in
1789                          * resend case, object may be unlinked or just some
1790                          * error occurs. It is unclear if lock reached the
1791                          * client in the original reply, just leave the lock on
1792                          * server, not returning it again to client. Due to
1793                          * LU-6529, the server will not OOM. */
1794                         RETURN(rc);
1795                 } else if (rc != ELDLM_OK ||
1796                            (rc == ELDLM_OK && (*flags & LDLM_FL_INTENT_ONLY))) {
1797                         ldlm_lock_destroy(lock);
1798                         RETURN(rc);
1799                 }
1800         }
1801
1802         if (*flags & LDLM_FL_RESENT) {
1803                 /* Reconstruct LDLM_FL_SRV_ENQ_MASK @flags for reply.
1804                  * Set LOCK_CHANGED always.
1805                  * Check if the lock is granted for BLOCK_GRANTED.
1806                  * Take NO_TIMEOUT from the lock as it is inherited through
1807                  * LDLM_FL_INHERIT_MASK */
1808                 *flags |= LDLM_FL_LOCK_CHANGED;
1809                 if (!ldlm_is_granted(lock))
1810                         *flags |= LDLM_FL_BLOCK_GRANTED;
1811                 *flags |= lock->l_flags & LDLM_FL_NO_TIMEOUT;
1812                 RETURN(ELDLM_OK);
1813         }
1814
1815 #ifdef HAVE_SERVER_SUPPORT
1816         /* For a replaying lock, it might be already in granted list. So
1817          * unlinking the lock will cause the interval node to be freed, we
1818          * have to allocate the interval node early otherwise we can't regrant
1819          * this lock in the future. - jay
1820          *
1821          * The only time the ldlm_resource changes for the ldlm_lock is when
1822          * ldlm_lock_change_resource() is called and that only happens for
1823          * the Lustre client case.
1824          */
1825         if (!local && (*flags & LDLM_FL_REPLAY) &&
1826             lock->l_resource->lr_type == LDLM_EXTENT)
1827                 OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, GFP_NOFS);
1828
1829         reconstruct = !local && lock->l_resource->lr_type == LDLM_FLOCK &&
1830                       !(*flags & LDLM_FL_TEST_LOCK);
1831         if (reconstruct) {
1832                 rc = req_can_reconstruct(cookie, NULL);
1833                 if (rc != 0) {
1834                         if (rc == 1)
1835                                 rc = 0;
1836                         RETURN(rc);
1837                 }
1838         }
1839 #endif
1840         res = lock_res_and_lock(lock);
1841         if (local && ldlm_is_granted(lock)) {
1842                 /* The server returned a blocked lock, but it was granted
1843                  * before we got a chance to actually enqueue it.  We don't
1844                  * need to do anything else. */
1845                 *flags &= ~LDLM_FL_BLOCKED_MASK;
1846                 GOTO(out, rc = ELDLM_OK);
1847         }
1848
1849         ldlm_resource_unlink_lock(lock);
1850         if (res->lr_type == LDLM_EXTENT && lock->l_tree_node == NULL) {
1851                 if (node == NULL) {
1852                         ldlm_lock_destroy_nolock(lock);
1853                         GOTO(out, rc = -ENOMEM);
1854                 }
1855
1856                 INIT_LIST_HEAD(&node->li_group);
1857                 ldlm_interval_attach(node, lock);
1858                 node = NULL;
1859         }
1860
1861         /* Some flags from the enqueue want to make it into the AST, via the
1862          * lock's l_flags. */
1863         if (*flags & LDLM_FL_AST_DISCARD_DATA)
1864                 ldlm_set_ast_discard_data(lock);
1865         if (*flags & LDLM_FL_TEST_LOCK)
1866                 ldlm_set_test_lock(lock);
1867         if (*flags & LDLM_FL_COS_INCOMPAT)
1868                 ldlm_set_cos_incompat(lock);
1869         if (*flags & LDLM_FL_COS_ENABLED)
1870                 ldlm_set_cos_enabled(lock);
1871
1872         /* This distinction between local lock trees is very important; a client
1873          * namespace only has information about locks taken by that client, and
1874          * thus doesn't have enough information to decide for itself if it can
1875          * be granted (below).  In this case, we do exactly what the server
1876          * tells us to do, as dictated by the 'flags'.
1877          *
1878          * We do exactly the same thing during recovery, when the server is
1879          * more or less trusting the clients not to lie.
1880          *
1881          * FIXME (bug 268): Detect obvious lies by checking compatibility in
1882          * granted queue. */
1883         if (local) {
1884                 if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
1885                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1886                 else
1887                         ldlm_grant_lock(lock, NULL);
1888                 GOTO(out, rc = ELDLM_OK);
1889 #ifdef HAVE_SERVER_SUPPORT
1890         } else if (*flags & LDLM_FL_REPLAY) {
1891                 if (*flags & LDLM_FL_BLOCK_WAIT) {
1892                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1893                         GOTO(out, rc = ELDLM_OK);
1894                 } else if (*flags & LDLM_FL_BLOCK_GRANTED) {
1895                         ldlm_grant_lock(lock, NULL);
1896                         GOTO(out, rc = ELDLM_OK);
1897                 }
1898                 /* If no flags, fall through to normal enqueue path. */
1899         }
1900
1901         rc = ldlm_lock_enqueue_helper(lock, flags);
1902         GOTO(out, rc);
1903 #else
1904         } else {
1905                 CERROR("This is client-side-only module, cannot handle "
1906                        "LDLM_NAMESPACE_SERVER resource type lock.\n");
1907                 LBUG();
1908         }
1909 #endif
1910
1911 out:
1912         unlock_res_and_lock(lock);
1913
1914 #ifdef HAVE_SERVER_SUPPORT
1915         if (reconstruct) {
1916                 struct ptlrpc_request *req = cookie;
1917
1918                 tgt_mk_reply_data(NULL, NULL,
1919                                   &req->rq_export->exp_target_data,
1920                                   req, 0, NULL, false, 0);
1921         }
1922 #endif
1923         if (node)
1924                 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
1925         return rc;
1926 }
1927
1928 #ifdef HAVE_SERVER_SUPPORT
1929 /**
1930  * Iterate through all waiting locks on a given resource queue and attempt to
1931  * grant them.
1932  *
1933  * Must be called with resource lock held.
1934  */
1935 int ldlm_reprocess_queue(struct ldlm_resource *res, struct list_head *queue,
1936                          struct list_head *work_list,
1937                          enum ldlm_process_intention intention,
1938                          struct ldlm_lock *hint)
1939 {
1940         struct list_head *tmp, *pos;
1941         ldlm_processing_policy policy;
1942         __u64 flags;
1943         int rc = LDLM_ITER_CONTINUE;
1944         enum ldlm_error err;
1945         LIST_HEAD(bl_ast_list);
1946
1947         ENTRY;
1948
1949         check_res_locked(res);
1950
1951         policy = ldlm_get_processing_policy(res);
1952         LASSERT(policy);
1953         LASSERT(intention == LDLM_PROCESS_RESCAN ||
1954                 intention == LDLM_PROCESS_RECOVERY);
1955
1956 restart:
1957         list_for_each_safe(tmp, pos, queue) {
1958                 struct ldlm_lock *pending;
1959                 LIST_HEAD(rpc_list);
1960
1961                 pending = list_entry(tmp, struct ldlm_lock, l_res_link);
1962
1963                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
1964
1965                 flags = 0;
1966                 rc = policy(pending, &flags, intention, &err, &rpc_list);
1967                 if (pending->l_granted_mode == pending->l_req_mode ||
1968                     res->lr_type == LDLM_FLOCK) {
1969                         list_splice(&rpc_list, work_list);
1970                 } else {
1971                         list_splice(&rpc_list, &bl_ast_list);
1972                 }
1973                 /*
1974                  * When this is called from recovery done, we always want
1975                  * to scan the whole list no matter what 'rc' is returned.
1976                  */
1977                 if (rc != LDLM_ITER_CONTINUE &&
1978                     intention == LDLM_PROCESS_RESCAN)
1979                         break;
1980         }
1981
1982         if (!list_empty(&bl_ast_list)) {
1983                 unlock_res(res);
1984
1985                 rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &bl_ast_list,
1986                                        LDLM_WORK_BL_AST);
1987
1988                 lock_res(res);
1989                 if (rc == -ERESTART)
1990                         GOTO(restart, rc);
1991         }
1992
1993         if (!list_empty(&bl_ast_list))
1994                 ldlm_discard_bl_list(&bl_ast_list);
1995
1996         RETURN(intention == LDLM_PROCESS_RESCAN ? rc : LDLM_ITER_CONTINUE);
1997 }
1998
1999 /**
2000  * Conflicting locks are detected for a lock to be enqueued, add the lock
2001  * into waiting list and send blocking ASTs to the conflicting locks.
2002  *
2003  * \param[in] lock              The lock to be enqueued.
2004  * \param[out] flags            Lock flags for the lock to be enqueued.
2005  * \param[in] rpc_list          Conflicting locks list.
2006  *
2007  * \retval -ERESTART:   Some lock was instantly canceled while sending
2008  *                      blocking ASTs, caller needs to re-check conflicting
2009  *                      locks.
2010  * \retval -EAGAIN:     Lock was destroyed, caller should return error.
2011  * \reval 0:            Lock is successfully added in waiting list.
2012  */
2013 int ldlm_handle_conflict_lock(struct ldlm_lock *lock, __u64 *flags,
2014                               struct list_head *rpc_list)
2015 {
2016         struct ldlm_resource *res = lock->l_resource;
2017         int rc;
2018         ENTRY;
2019
2020         check_res_locked(res);
2021
2022         /* If either of the compat_queue()s returned failure, then we
2023          * have ASTs to send and must go onto the waiting list.
2024          *
2025          * bug 2322: we used to unlink and re-add here, which was a
2026          * terrible folly -- if we goto restart, we could get
2027          * re-ordered!  Causes deadlock, because ASTs aren't sent! */
2028         if (list_empty(&lock->l_res_link))
2029                 ldlm_resource_add_lock(res, &res->lr_waiting, lock);
2030         unlock_res(res);
2031
2032         rc = ldlm_run_ast_work(ldlm_res_to_ns(res), rpc_list,
2033                                LDLM_WORK_BL_AST);
2034
2035         if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_OST_FAIL_RACE) &&
2036             !ns_is_client(ldlm_res_to_ns(res)))
2037                 class_fail_export(lock->l_export);
2038
2039         if (rc == -ERESTART)
2040                 ldlm_reprocess_all(res, NULL);
2041
2042         lock_res(res);
2043         if (rc == -ERESTART) {
2044                 /* 15715: The lock was granted and destroyed after
2045                  * resource lock was dropped. Interval node was freed
2046                  * in ldlm_lock_destroy. Anyway, this always happens
2047                  * when a client is being evicted. So it would be
2048                  * ok to return an error. -jay */
2049                 if (ldlm_is_destroyed(lock))
2050                         RETURN(-EAGAIN);
2051
2052                 /* lock was granted while resource was unlocked. */
2053                 if (ldlm_is_granted(lock)) {
2054                         /* bug 11300: if the lock has been granted,
2055                          * break earlier because otherwise, we will go
2056                          * to restart and ldlm_resource_unlink will be
2057                          * called and it causes the interval node to be
2058                          * freed. Then we will fail at
2059                          * ldlm_extent_add_lock() */
2060                         *flags &= ~LDLM_FL_BLOCKED_MASK;
2061                 }
2062
2063         }
2064         *flags |= LDLM_FL_BLOCK_GRANTED;
2065
2066         RETURN(0);
2067 }
2068
2069 /**
2070  * Discard all AST work items from list.
2071  *
2072  * If for whatever reason we do not want to send ASTs to conflicting locks
2073  * anymore, disassemble the list with this function.
2074  */
2075 void ldlm_discard_bl_list(struct list_head *bl_list)
2076 {
2077         struct ldlm_lock *lock, *tmp;
2078
2079         ENTRY;
2080
2081         list_for_each_entry_safe(lock, tmp, bl_list, l_bl_ast) {
2082                 LASSERT(!list_empty(&lock->l_bl_ast));
2083                 list_del_init(&lock->l_bl_ast);
2084                 ldlm_clear_ast_sent(lock);
2085                 LASSERT(lock->l_bl_ast_run == 0);
2086                 ldlm_clear_blocking_lock(lock);
2087                 LDLM_LOCK_RELEASE(lock);
2088         }
2089         EXIT;
2090 }
2091
2092 /**
2093  * Process a call to blocking AST callback for a lock in ast_work list
2094  */
2095 static int
2096 ldlm_work_bl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2097 {
2098         struct ldlm_cb_set_arg *arg = opaq;
2099         struct ldlm_lock *lock;
2100         struct ldlm_lock_desc d;
2101         struct ldlm_bl_desc bld;
2102         int rc;
2103
2104         ENTRY;
2105
2106         if (list_empty(arg->list))
2107                 RETURN(-ENOENT);
2108
2109         lock = list_entry(arg->list->next, struct ldlm_lock, l_bl_ast);
2110
2111         /* nobody should touch l_bl_ast but some locks in the list may become
2112          * granted after lock convert or COS downgrade, these locks should be
2113          * just skipped here and removed from the list.
2114          */
2115         lock_res_and_lock(lock);
2116         list_del_init(&lock->l_bl_ast);
2117
2118         /* lock is not blocking lock anymore, but was kept in the list because
2119          * it can managed only here.
2120          */
2121         if (!ldlm_is_ast_sent(lock)) {
2122                 unlock_res_and_lock(lock);
2123                 LDLM_LOCK_RELEASE(lock);
2124                 RETURN(0);
2125         }
2126
2127         LASSERT(lock->l_blocking_lock);
2128         ldlm_lock2desc(lock->l_blocking_lock, &d);
2129         /* copy blocking lock ibits in cancel_bits as well,
2130          * new client may use them for lock convert and it is
2131          * important to use new field to convert locks from
2132          * new servers only
2133          */
2134         d.l_policy_data.l_inodebits.cancel_bits =
2135                 lock->l_blocking_lock->l_policy_data.l_inodebits.bits;
2136
2137         /* Blocking lock is being destroyed here but some information about it
2138          * may be needed inside l_blocking_ast() function below,
2139          * e.g. in mdt_blocking_ast(). So save needed data in bl_desc.
2140          */
2141         bld.bl_same_client = lock->l_client_cookie ==
2142                              lock->l_blocking_lock->l_client_cookie;
2143         bld.bl_cos_incompat = ldlm_is_cos_incompat(lock->l_blocking_lock);
2144         arg->bl_desc = &bld;
2145
2146         LASSERT(ldlm_is_ast_sent(lock));
2147         LASSERT(lock->l_bl_ast_run == 0);
2148         lock->l_bl_ast_run++;
2149         ldlm_clear_blocking_lock(lock);
2150         unlock_res_and_lock(lock);
2151
2152         rc = lock->l_blocking_ast(lock, &d, (void *)arg, LDLM_CB_BLOCKING);
2153
2154         LDLM_LOCK_RELEASE(lock);
2155
2156         RETURN(rc);
2157 }
2158
2159 /**
2160  * Process a call to revocation AST callback for a lock in ast_work list
2161  */
2162 static int
2163 ldlm_work_revoke_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2164 {
2165         struct ldlm_cb_set_arg *arg = opaq;
2166         struct ldlm_lock_desc   desc;
2167         int                     rc;
2168         struct ldlm_lock       *lock;
2169         ENTRY;
2170
2171         if (list_empty(arg->list))
2172                 RETURN(-ENOENT);
2173
2174         lock = list_entry(arg->list->next, struct ldlm_lock, l_rk_ast);
2175         list_del_init(&lock->l_rk_ast);
2176
2177         /* the desc just pretend to exclusive */
2178         ldlm_lock2desc(lock, &desc);
2179         desc.l_req_mode = LCK_EX;
2180         desc.l_granted_mode = 0;
2181
2182         rc = lock->l_blocking_ast(lock, &desc, (void*)arg, LDLM_CB_BLOCKING);
2183         LDLM_LOCK_RELEASE(lock);
2184
2185         RETURN(rc);
2186 }
2187
2188 /**
2189  * Process a call to glimpse AST callback for a lock in ast_work list
2190  */
2191 int ldlm_work_gl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2192 {
2193         struct ldlm_cb_set_arg          *arg = opaq;
2194         struct ldlm_glimpse_work        *gl_work;
2195         struct ldlm_lock                *lock;
2196         int                              rc = 0;
2197         ENTRY;
2198
2199         if (list_empty(arg->list))
2200                 RETURN(-ENOENT);
2201
2202         gl_work = list_entry(arg->list->next, struct ldlm_glimpse_work,
2203                                  gl_list);
2204         list_del_init(&gl_work->gl_list);
2205
2206         lock = gl_work->gl_lock;
2207
2208         /* transfer the glimpse descriptor to ldlm_cb_set_arg */
2209         arg->gl_desc = gl_work->gl_desc;
2210         arg->gl_interpret_reply = gl_work->gl_interpret_reply;
2211         arg->gl_interpret_data = gl_work->gl_interpret_data;
2212
2213         /* invoke the actual glimpse callback */
2214         rc = lock->l_glimpse_ast(lock, (void *)arg);
2215         if (rc == 0)
2216                 rc = 1; /* update LVB if this is server lock */
2217         else if (rc == -ELDLM_NO_LOCK_DATA)
2218                 ldlm_lvbo_update(lock->l_resource, lock, NULL, 1);
2219
2220         LDLM_LOCK_RELEASE(lock);
2221         if (gl_work->gl_flags & LDLM_GL_WORK_SLAB_ALLOCATED)
2222                 OBD_SLAB_FREE_PTR(gl_work, ldlm_glimpse_work_kmem);
2223         else
2224                 OBD_FREE_PTR(gl_work);
2225
2226         RETURN(rc);
2227 }
2228 #endif
2229
2230 /**
2231  * Process a call to completion AST callback for a lock in ast_work list
2232  */
2233 static int
2234 ldlm_work_cp_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2235 {
2236         struct ldlm_cb_set_arg *arg = opaq;
2237         struct ldlm_lock *lock;
2238         ldlm_completion_callback completion_callback;
2239         int rc = 0;
2240
2241         ENTRY;
2242
2243         if (list_empty(arg->list))
2244                 RETURN(-ENOENT);
2245
2246         lock = list_entry(arg->list->next, struct ldlm_lock, l_cp_ast);
2247
2248         /* It's possible to receive a completion AST before we've set
2249          * the l_completion_ast pointer: either because the AST arrived
2250          * before the reply, or simply because there's a small race
2251          * window between receiving the reply and finishing the local
2252          * enqueue. (bug 842)
2253          *
2254          * This can't happen with the blocking_ast, however, because we
2255          * will never call the local blocking_ast until we drop our
2256          * reader/writer reference, which we won't do until we get the
2257          * reply and finish enqueueing. */
2258
2259         /* nobody should touch l_cp_ast */
2260         lock_res_and_lock(lock);
2261         list_del_init(&lock->l_cp_ast);
2262         LASSERT(ldlm_is_cp_reqd(lock));
2263         /* save l_completion_ast since it can be changed by
2264          * mds_intent_policy(), see bug 14225 */
2265         completion_callback = lock->l_completion_ast;
2266         ldlm_clear_cp_reqd(lock);
2267         unlock_res_and_lock(lock);
2268
2269         if (completion_callback != NULL)
2270                 rc = completion_callback(lock, 0, (void *)arg);
2271         LDLM_LOCK_RELEASE(lock);
2272
2273         RETURN(rc);
2274 }
2275
2276 /**
2277  * Process list of locks in need of ASTs being sent.
2278  *
2279  * Used on server to send multiple ASTs together instead of sending one by
2280  * one.
2281  */
2282 int ldlm_run_ast_work(struct ldlm_namespace *ns, struct list_head *rpc_list,
2283                       ldlm_desc_ast_t ast_type)
2284 {
2285         struct ldlm_cb_set_arg *arg;
2286         set_producer_func work_ast_lock;
2287         int rc;
2288
2289         if (list_empty(rpc_list))
2290                 RETURN(0);
2291
2292         OBD_ALLOC_PTR(arg);
2293         if (arg == NULL)
2294                 RETURN(-ENOMEM);
2295
2296         atomic_set(&arg->restart, 0);
2297         arg->list = rpc_list;
2298
2299         switch (ast_type) {
2300         case LDLM_WORK_CP_AST:
2301                 arg->type = LDLM_CP_CALLBACK;
2302                 work_ast_lock = ldlm_work_cp_ast_lock;
2303                 break;
2304 #ifdef HAVE_SERVER_SUPPORT
2305         case LDLM_WORK_BL_AST:
2306                 arg->type = LDLM_BL_CALLBACK;
2307                 work_ast_lock = ldlm_work_bl_ast_lock;
2308                 break;
2309         case LDLM_WORK_REVOKE_AST:
2310                 arg->type = LDLM_BL_CALLBACK;
2311                 work_ast_lock = ldlm_work_revoke_ast_lock;
2312                 break;
2313         case LDLM_WORK_GL_AST:
2314                 arg->type = LDLM_GL_CALLBACK;
2315                 work_ast_lock = ldlm_work_gl_ast_lock;
2316                 break;
2317 #endif
2318         default:
2319                 LBUG();
2320         }
2321
2322         /* We create a ptlrpc request set with flow control extension.
2323          * This request set will use the work_ast_lock function to produce new
2324          * requests and will send a new request each time one completes in order
2325          * to keep the number of requests in flight to ns_max_parallel_ast */
2326         arg->set = ptlrpc_prep_fcset(ns->ns_max_parallel_ast ? : UINT_MAX,
2327                                      work_ast_lock, arg);
2328         if (arg->set == NULL)
2329                 GOTO(out, rc = -ENOMEM);
2330
2331         ptlrpc_set_wait(NULL, arg->set);
2332         ptlrpc_set_destroy(arg->set);
2333
2334         rc = atomic_read(&arg->restart) ? -ERESTART : 0;
2335         GOTO(out, rc);
2336 out:
2337         OBD_FREE_PTR(arg);
2338         return rc;
2339 }
2340
2341 /**
2342  * Try to grant all waiting locks on a resource.
2343  *
2344  * Calls ldlm_reprocess_queue on waiting queue.
2345  *
2346  * Typically called after some resource locks are cancelled to see
2347  * if anything could be granted as a result of the cancellation.
2348  */
2349 static void __ldlm_reprocess_all(struct ldlm_resource *res,
2350                                  enum ldlm_process_intention intention,
2351                                  struct ldlm_lock *hint)
2352 {
2353         LIST_HEAD(rpc_list);
2354 #ifdef HAVE_SERVER_SUPPORT
2355         ldlm_reprocessing_policy reprocess;
2356         struct obd_device *obd;
2357         int rc;
2358
2359         ENTRY;
2360
2361         /* Local lock trees don't get reprocessed. */
2362         if (ns_is_client(ldlm_res_to_ns(res))) {
2363                 EXIT;
2364                 return;
2365         }
2366
2367         /* Disable reprocess during lock replay stage but allow during
2368          * request replay stage.
2369          */
2370         obd = ldlm_res_to_ns(res)->ns_obd;
2371         if (obd->obd_recovering &&
2372             atomic_read(&obd->obd_req_replay_clients) == 0)
2373                 RETURN_EXIT;
2374 restart:
2375         lock_res(res);
2376         reprocess = ldlm_get_reprocessing_policy(res);
2377         reprocess(res, &res->lr_waiting, &rpc_list, intention, hint);
2378         unlock_res(res);
2379
2380         rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
2381                                LDLM_WORK_CP_AST);
2382         if (rc == -ERESTART) {
2383                 LASSERT(list_empty(&rpc_list));
2384                 goto restart;
2385         }
2386 #else
2387         ENTRY;
2388
2389         if (!ns_is_client(ldlm_res_to_ns(res))) {
2390                 CERROR("This is client-side-only module, cannot handle "
2391                        "LDLM_NAMESPACE_SERVER resource type lock.\n");
2392                 LBUG();
2393         }
2394 #endif
2395         EXIT;
2396 }
2397
2398 void ldlm_reprocess_all(struct ldlm_resource *res, struct ldlm_lock *hint)
2399 {
2400         __ldlm_reprocess_all(res, LDLM_PROCESS_RESCAN, hint);
2401 }
2402 EXPORT_SYMBOL(ldlm_reprocess_all);
2403
2404 static int ldlm_reprocess_res(struct cfs_hash *hs, struct cfs_hash_bd *bd,
2405                               struct hlist_node *hnode, void *arg)
2406 {
2407         struct ldlm_resource *res = cfs_hash_object(hs, hnode);
2408
2409         /* This is only called once after recovery done. LU-8306. */
2410         __ldlm_reprocess_all(res, LDLM_PROCESS_RECOVERY, NULL);
2411         return 0;
2412 }
2413
2414 /**
2415  * Iterate through all resources on a namespace attempting to grant waiting
2416  * locks.
2417  */
2418 void ldlm_reprocess_recovery_done(struct ldlm_namespace *ns)
2419 {
2420         ENTRY;
2421
2422         if (ns != NULL) {
2423                 cfs_hash_for_each_nolock(ns->ns_rs_hash,
2424                                          ldlm_reprocess_res, NULL, 0);
2425         }
2426         EXIT;
2427 }
2428
2429 /**
2430  * Helper function to call blocking AST for LDLM lock \a lock in a
2431  * "cancelling" mode.
2432  */
2433 void ldlm_cancel_callback(struct ldlm_lock *lock)
2434 {
2435         check_res_locked(lock->l_resource);
2436         if (!ldlm_is_cancel(lock)) {
2437                 ldlm_set_cancel(lock);
2438                 if (lock->l_blocking_ast) {
2439                         unlock_res_and_lock(lock);
2440                         lock->l_blocking_ast(lock, NULL, lock->l_ast_data,
2441                                              LDLM_CB_CANCELING);
2442                         lock_res_and_lock(lock);
2443                 } else {
2444                         LDLM_DEBUG(lock, "no blocking ast");
2445                 }
2446
2447                 /* only canceller can set bl_done bit */
2448                 ldlm_set_bl_done(lock);
2449                 wake_up_all(&lock->l_waitq);
2450         } else if (!ldlm_is_bl_done(lock)) {
2451                 /* The lock is guaranteed to have been canceled once
2452                  * returning from this function. */
2453                 unlock_res_and_lock(lock);
2454                 wait_event_idle(lock->l_waitq, is_bl_done(lock));
2455                 lock_res_and_lock(lock);
2456         }
2457 }
2458
2459 /**
2460  * Remove skiplist-enabled LDLM lock \a req from granted list
2461  */
2462 void ldlm_unlink_lock_skiplist(struct ldlm_lock *req)
2463 {
2464         if (req->l_resource->lr_type != LDLM_PLAIN &&
2465             req->l_resource->lr_type != LDLM_IBITS)
2466                 return;
2467
2468         list_del_init(&req->l_sl_policy);
2469         list_del_init(&req->l_sl_mode);
2470 }
2471
2472 /**
2473  * Attempts to cancel LDLM lock \a lock that has no reader/writer references.
2474  */
2475 void ldlm_lock_cancel(struct ldlm_lock *lock)
2476 {
2477         struct ldlm_resource *res;
2478         struct ldlm_namespace *ns;
2479         ENTRY;
2480
2481         lock_res_and_lock(lock);
2482
2483         res = lock->l_resource;
2484         ns  = ldlm_res_to_ns(res);
2485
2486         /* Please do not, no matter how tempting, remove this LBUG without
2487          * talking to me first. -phik */
2488         if (lock->l_readers || lock->l_writers) {
2489                 LDLM_ERROR(lock, "lock still has references");
2490                 unlock_res_and_lock(lock);
2491                 LBUG();
2492         }
2493
2494         if (ldlm_is_waited(lock))
2495                 ldlm_del_waiting_lock(lock);
2496
2497         /* Releases cancel callback. */
2498         ldlm_cancel_callback(lock);
2499
2500         /* Yes, second time, just in case it was added again while we were
2501          * running with no res lock in ldlm_cancel_callback */
2502         if (ldlm_is_waited(lock))
2503                 ldlm_del_waiting_lock(lock);
2504
2505         ldlm_resource_unlink_lock(lock);
2506         ldlm_lock_destroy_nolock(lock);
2507
2508         if (ldlm_is_granted(lock))
2509                 ldlm_pool_del(&ns->ns_pool, lock);
2510
2511         /* Make sure we will not be called again for same lock what is possible
2512          * if not to zero out lock->l_granted_mode */
2513         lock->l_granted_mode = LCK_MINMODE;
2514         unlock_res_and_lock(lock);
2515
2516         EXIT;
2517 }
2518 EXPORT_SYMBOL(ldlm_lock_cancel);
2519
2520 /**
2521  * Set opaque data into the lock that only makes sense to upper layer.
2522  */
2523 int ldlm_lock_set_data(const struct lustre_handle *lockh, void *data)
2524 {
2525         struct ldlm_lock *lock = ldlm_handle2lock(lockh);
2526         int rc = -EINVAL;
2527         ENTRY;
2528
2529         if (lock) {
2530                 if (lock->l_ast_data == NULL)
2531                         lock->l_ast_data = data;
2532                 if (lock->l_ast_data == data)
2533                         rc = 0;
2534                 LDLM_LOCK_PUT(lock);
2535         }
2536         RETURN(rc);
2537 }
2538 EXPORT_SYMBOL(ldlm_lock_set_data);
2539
2540 struct export_cl_data {
2541         const struct lu_env     *ecl_env;
2542         struct obd_export       *ecl_exp;
2543         int                     ecl_loop;
2544 };
2545
2546 static void ldlm_cancel_lock_for_export(struct obd_export *exp,
2547                                         struct ldlm_lock *lock,
2548                                         struct export_cl_data *ecl)
2549 {
2550         struct ldlm_resource *res;
2551
2552         res = ldlm_resource_getref(lock->l_resource);
2553
2554         ldlm_lvbo_update(res, lock, NULL, 1);
2555         ldlm_lock_cancel(lock);
2556         if (!exp->exp_obd->obd_stopping)
2557                 ldlm_reprocess_all(res, lock);
2558         ldlm_resource_putref(res);
2559
2560         ecl->ecl_loop++;
2561         if ((ecl->ecl_loop & -ecl->ecl_loop) == ecl->ecl_loop) {
2562                 CDEBUG(D_INFO, "Export %p, %d locks cancelled.\n",
2563                        exp, ecl->ecl_loop);
2564         }
2565 }
2566
2567 /**
2568  * Iterator function for ldlm_export_cancel_locks.
2569  * Cancels passed locks.
2570  */
2571 static int
2572 ldlm_cancel_locks_for_export_cb(struct cfs_hash *hs, struct cfs_hash_bd *bd,
2573                                 struct hlist_node *hnode, void *data)
2574
2575 {
2576         struct export_cl_data   *ecl = (struct export_cl_data *)data;
2577         struct obd_export       *exp  = ecl->ecl_exp;
2578         struct ldlm_lock        *lock = cfs_hash_object(hs, hnode);
2579
2580         LDLM_LOCK_GET(lock);
2581         ldlm_cancel_lock_for_export(exp, lock, ecl);
2582         LDLM_LOCK_RELEASE(lock);
2583
2584         return 0;
2585 }
2586
2587 /**
2588  * Cancel all blocked locks for given export.
2589  *
2590  * Typically called on client disconnection/eviction
2591  */
2592 int ldlm_export_cancel_blocked_locks(struct obd_export *exp)
2593 {
2594         struct lu_env env;
2595         struct export_cl_data   ecl = {
2596                 .ecl_exp        = exp,
2597                 .ecl_loop       = 0,
2598         };
2599         int rc;
2600
2601         rc = lu_env_init(&env, LCT_DT_THREAD);
2602         if (rc)
2603                 RETURN(rc);
2604         ecl.ecl_env = &env;
2605
2606         while (!list_empty(&exp->exp_bl_list)) {
2607                 struct ldlm_lock *lock;
2608
2609                 spin_lock_bh(&exp->exp_bl_list_lock);
2610                 if (!list_empty(&exp->exp_bl_list)) {
2611                         lock = list_entry(exp->exp_bl_list.next,
2612                                           struct ldlm_lock, l_exp_list);
2613                         LDLM_LOCK_GET(lock);
2614                         list_del_init(&lock->l_exp_list);
2615                 } else {
2616                         lock = NULL;
2617                 }
2618                 spin_unlock_bh(&exp->exp_bl_list_lock);
2619
2620                 if (lock == NULL)
2621                         break;
2622
2623                 ldlm_cancel_lock_for_export(exp, lock, &ecl);
2624                 LDLM_LOCK_RELEASE(lock);
2625         }
2626
2627         lu_env_fini(&env);
2628
2629         CDEBUG(D_DLMTRACE, "Export %p, canceled %d locks, "
2630                "left on hash table %d.\n", exp, ecl.ecl_loop,
2631                atomic_read(&exp->exp_lock_hash->hs_count));
2632
2633         return ecl.ecl_loop;
2634 }
2635
2636 /**
2637  * Cancel all locks for given export.
2638  *
2639  * Typically called after client disconnection/eviction
2640  */
2641 int ldlm_export_cancel_locks(struct obd_export *exp)
2642 {
2643         struct export_cl_data ecl;
2644         struct lu_env env;
2645         int rc;
2646
2647         rc = lu_env_init(&env, LCT_DT_THREAD);
2648         if (rc)
2649                 RETURN(rc);
2650         ecl.ecl_env = &env;
2651         ecl.ecl_exp = exp;
2652         ecl.ecl_loop = 0;
2653
2654         cfs_hash_for_each_empty(exp->exp_lock_hash,
2655                                 ldlm_cancel_locks_for_export_cb, &ecl);
2656
2657         CDEBUG(D_DLMTRACE, "Export %p, canceled %d locks, "
2658                "left on hash table %d.\n", exp, ecl.ecl_loop,
2659                atomic_read(&exp->exp_lock_hash->hs_count));
2660
2661         if (ecl.ecl_loop > 0 &&
2662             atomic_read(&exp->exp_lock_hash->hs_count) == 0 &&
2663             exp->exp_obd->obd_stopping)
2664                 ldlm_reprocess_recovery_done(exp->exp_obd->obd_namespace);
2665
2666         lu_env_fini(&env);
2667
2668         return ecl.ecl_loop;
2669 }
2670
2671 /**
2672  * Downgrade an PW/EX lock to COS | CR mode.
2673  *
2674  * A lock mode convertion from PW/EX mode to less conflict mode. The
2675  * convertion may fail if lock was canceled before downgrade, but it doesn't
2676  * indicate any problem, because such lock has no reader or writer, and will
2677  * be released soon.
2678  *
2679  * Used by Commit on Sharing (COS) code to force object changes commit in case
2680  * of conflict. Converted lock is considered as new lock and all blocking AST
2681  * things are cleared, so any pending or new blocked lock on that lock will
2682  * cause new call to blocking_ast and force resource object commit.
2683  *
2684  * Also used by layout_change to replace EX lock to CR lock.
2685  *
2686  * \param lock A lock to convert
2687  * \param new_mode new lock mode
2688  */
2689 void ldlm_lock_mode_downgrade(struct ldlm_lock *lock, enum ldlm_mode new_mode)
2690 {
2691 #ifdef HAVE_SERVER_SUPPORT
2692         ENTRY;
2693
2694         LASSERT(new_mode == LCK_COS || new_mode == LCK_CR);
2695
2696         lock_res_and_lock(lock);
2697
2698         if (!(lock->l_granted_mode & (LCK_PW | LCK_EX))) {
2699                 unlock_res_and_lock(lock);
2700
2701                 LASSERT(lock->l_granted_mode == LCK_MINMODE);
2702                 LDLM_DEBUG(lock, "lock was canceled before downgrade");
2703                 RETURN_EXIT;
2704         }
2705
2706         ldlm_resource_unlink_lock(lock);
2707         /*
2708          * Remove the lock from pool as it will be added again in
2709          * ldlm_grant_lock() called below.
2710          */
2711         ldlm_pool_del(&ldlm_lock_to_ns(lock)->ns_pool, lock);
2712
2713         /* Consider downgraded lock as a new lock and clear all states
2714          * related to a previous blocking AST processing.
2715          */
2716         ldlm_clear_blocking_data(lock);
2717
2718         lock->l_req_mode = new_mode;
2719         ldlm_grant_lock(lock, NULL);
2720         unlock_res_and_lock(lock);
2721
2722         ldlm_reprocess_all(lock->l_resource, lock);
2723
2724         EXIT;
2725 #endif
2726 }
2727 EXPORT_SYMBOL(ldlm_lock_mode_downgrade);
2728
2729 /**
2730  * Print lock with lock handle \a lockh description into debug log.
2731  *
2732  * Used when printing all locks on a resource for debug purposes.
2733  */
2734 void ldlm_lock_dump_handle(int level, const struct lustre_handle *lockh)
2735 {
2736         struct ldlm_lock *lock;
2737
2738         if (!((libcfs_debug | D_ERROR) & level))
2739                 return;
2740
2741         lock = ldlm_handle2lock(lockh);
2742         if (lock == NULL)
2743                 return;
2744
2745         LDLM_DEBUG_LIMIT(level, lock, "###");
2746
2747         LDLM_LOCK_PUT(lock);
2748 }
2749 EXPORT_SYMBOL(ldlm_lock_dump_handle);
2750
2751 /**
2752  * Print lock information with custom message into debug log.
2753  * Helper function.
2754  */
2755 void _ldlm_lock_debug(struct ldlm_lock *lock,
2756                       struct libcfs_debug_msg_data *msgdata,
2757                       const char *fmt, ...)
2758 {
2759         va_list args;
2760         struct obd_export *exp = lock->l_export;
2761         struct ldlm_resource *resource = NULL;
2762         struct va_format vaf;
2763         char *nid = "local";
2764
2765         /* on server-side resource of lock doesn't change */
2766         if ((lock->l_flags & LDLM_FL_NS_SRV) != 0) {
2767                 if (lock->l_resource != NULL)
2768                         resource = ldlm_resource_getref(lock->l_resource);
2769         } else if (spin_trylock(&lock->l_lock)) {
2770                 if (lock->l_resource != NULL)
2771                         resource = ldlm_resource_getref(lock->l_resource);
2772                 spin_unlock(&lock->l_lock);
2773         }
2774
2775         va_start(args, fmt);
2776         vaf.fmt = fmt;
2777         vaf.va = &args;
2778
2779         if (exp && exp->exp_connection) {
2780                 nid = obd_export_nid2str(exp);
2781         } else if (exp && exp->exp_obd != NULL) {
2782                 struct obd_import *imp = exp->exp_obd->u.cli.cl_import;
2783                 nid = obd_import_nid2str(imp);
2784         }
2785
2786         if (resource == NULL) {
2787                 libcfs_debug_msg(msgdata,
2788                                  "%pV ns: \?\? lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: \?\? rrc=\?\? type: \?\?\? flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
2789                                  &vaf,
2790                                  lock,
2791                                  lock->l_handle.h_cookie,
2792                                  refcount_read(&lock->l_handle.h_ref),
2793                                  lock->l_readers, lock->l_writers,
2794                                  ldlm_lockname[lock->l_granted_mode],
2795                                  ldlm_lockname[lock->l_req_mode],
2796                                  lock->l_flags, nid,
2797                                  lock->l_remote_handle.cookie,
2798                                  exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
2799                                  lock->l_pid, lock->l_callback_timestamp,
2800                                  lock->l_lvb_type);
2801                 va_end(args);
2802                 return;
2803         }
2804
2805         switch (resource->lr_type) {
2806         case LDLM_EXTENT:
2807                 libcfs_debug_msg(msgdata,
2808                                  "%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s [%llu->%llu] (req %llu->%llu) gid %llu flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
2809                                  &vaf,
2810                                  ldlm_lock_to_ns_name(lock), lock,
2811                                  lock->l_handle.h_cookie,
2812                                  refcount_read(&lock->l_handle.h_ref),
2813                                  lock->l_readers, lock->l_writers,
2814                                  ldlm_lockname[lock->l_granted_mode],
2815                                  ldlm_lockname[lock->l_req_mode],
2816                                  PLDLMRES(resource),
2817                                  atomic_read(&resource->lr_refcount),
2818                                  ldlm_typename[resource->lr_type],
2819                                  lock->l_policy_data.l_extent.start,
2820                                  lock->l_policy_data.l_extent.end,
2821                                  lock->l_req_extent.start, lock->l_req_extent.end,
2822                                  lock->l_req_extent.gid,
2823                                  lock->l_flags, nid,
2824                                  lock->l_remote_handle.cookie,
2825                                  exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
2826                                  lock->l_pid, lock->l_callback_timestamp,
2827                                  lock->l_lvb_type);
2828                 break;
2829
2830         case LDLM_FLOCK:
2831                 libcfs_debug_msg(msgdata,
2832                                  "%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s pid: %d [%llu->%llu] flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld\n",
2833                                  &vaf,
2834                                  ldlm_lock_to_ns_name(lock), lock,
2835                                  lock->l_handle.h_cookie,
2836                                  refcount_read(&lock->l_handle.h_ref),
2837                                  lock->l_readers, lock->l_writers,
2838                                  ldlm_lockname[lock->l_granted_mode],
2839                                  ldlm_lockname[lock->l_req_mode],
2840                                  PLDLMRES(resource),
2841                                  atomic_read(&resource->lr_refcount),
2842                                  ldlm_typename[resource->lr_type],
2843                                  lock->l_policy_data.l_flock.pid,
2844                                  lock->l_policy_data.l_flock.start,
2845                                  lock->l_policy_data.l_flock.end,
2846                                  lock->l_flags, nid,
2847                                  lock->l_remote_handle.cookie,
2848                                  exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
2849                                  lock->l_pid, lock->l_callback_timestamp);
2850                 break;
2851
2852         case LDLM_IBITS:
2853                 libcfs_debug_msg(msgdata,
2854                                  "%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " bits %#llx/%#llx rrc: %d type: %s gid %llu flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
2855                                  &vaf,
2856                                  ldlm_lock_to_ns_name(lock),
2857                                  lock, lock->l_handle.h_cookie,
2858                                  refcount_read(&lock->l_handle.h_ref),
2859                                  lock->l_readers, lock->l_writers,
2860                                  ldlm_lockname[lock->l_granted_mode],
2861                                  ldlm_lockname[lock->l_req_mode],
2862                                  PLDLMRES(resource),
2863                                  lock->l_policy_data.l_inodebits.bits,
2864                                  lock->l_policy_data.l_inodebits.try_bits,
2865                                  atomic_read(&resource->lr_refcount),
2866                                  ldlm_typename[resource->lr_type],
2867                                  lock->l_policy_data.l_inodebits.li_gid,
2868                                  lock->l_flags, nid,
2869                                  lock->l_remote_handle.cookie,
2870                                  exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
2871                                  lock->l_pid, lock->l_callback_timestamp,
2872                                  lock->l_lvb_type);
2873                 break;
2874
2875         default:
2876                 libcfs_debug_msg(msgdata,
2877                                  "%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
2878                                  &vaf,
2879                                  ldlm_lock_to_ns_name(lock),
2880                                  lock, lock->l_handle.h_cookie,
2881                                  refcount_read(&lock->l_handle.h_ref),
2882                                  lock->l_readers, lock->l_writers,
2883                                  ldlm_lockname[lock->l_granted_mode],
2884                                  ldlm_lockname[lock->l_req_mode],
2885                                  PLDLMRES(resource),
2886                                  atomic_read(&resource->lr_refcount),
2887                                  ldlm_typename[resource->lr_type],
2888                                  lock->l_flags, nid,
2889                                  lock->l_remote_handle.cookie,
2890                                  exp ? refcount_read(&exp->exp_handle.h_ref) : -99,
2891                                  lock->l_pid, lock->l_callback_timestamp,
2892                                  lock->l_lvb_type);
2893                 break;
2894         }
2895         va_end(args);
2896         ldlm_resource_putref(resource);
2897 }
2898 EXPORT_SYMBOL(_ldlm_lock_debug);