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LU-4423 lustre: don't declare extern variables in C files.
[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 #endif /* HAVE_SERVER_SUPPORT */
153
154 void ldlm_register_intent(struct ldlm_namespace *ns, ldlm_res_policy arg)
155 {
156         ns->ns_policy = arg;
157 }
158 EXPORT_SYMBOL(ldlm_register_intent);
159
160 /*
161  * REFCOUNTED LOCK OBJECTS
162  */
163
164
165 /**
166  * Get a reference on a lock.
167  *
168  * Lock refcounts, during creation:
169  *   - one special one for allocation, dec'd only once in destroy
170  *   - one for being a lock that's in-use
171  *   - one for the addref associated with a new lock
172  */
173 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock)
174 {
175         atomic_inc(&lock->l_refc);
176         return lock;
177 }
178 EXPORT_SYMBOL(ldlm_lock_get);
179
180 /**
181  * Release lock reference.
182  *
183  * Also frees the lock if it was last reference.
184  */
185 void ldlm_lock_put(struct ldlm_lock *lock)
186 {
187         ENTRY;
188
189         LASSERT(lock->l_resource != LP_POISON);
190         LASSERT(atomic_read(&lock->l_refc) > 0);
191         if (atomic_dec_and_test(&lock->l_refc)) {
192                 struct ldlm_resource *res;
193
194                 LDLM_DEBUG(lock,
195                            "final lock_put on destroyed lock, freeing it.");
196
197                 res = lock->l_resource;
198                 LASSERT(ldlm_is_destroyed(lock));
199                 LASSERT(list_empty(&lock->l_exp_list));
200                 LASSERT(list_empty(&lock->l_res_link));
201                 LASSERT(list_empty(&lock->l_pending_chain));
202
203                 lprocfs_counter_decr(ldlm_res_to_ns(res)->ns_stats,
204                                      LDLM_NSS_LOCKS);
205                 lu_ref_del(&res->lr_reference, "lock", lock);
206                 ldlm_resource_putref(res);
207                 lock->l_resource = NULL;
208                 if (lock->l_export) {
209                         class_export_lock_put(lock->l_export, lock);
210                         lock->l_export = NULL;
211                 }
212
213                 if (lock->l_lvb_data != NULL)
214                         OBD_FREE_LARGE(lock->l_lvb_data, lock->l_lvb_len);
215
216                 ldlm_interval_free(ldlm_interval_detach(lock));
217                 lu_ref_fini(&lock->l_reference);
218                 OBD_FREE_RCU(lock, sizeof(*lock), &lock->l_handle);
219         }
220
221         EXIT;
222 }
223 EXPORT_SYMBOL(ldlm_lock_put);
224
225 /**
226  * Removes LDLM lock \a lock from LRU. Assumes LRU is already locked.
227  */
228 int ldlm_lock_remove_from_lru_nolock(struct ldlm_lock *lock)
229 {
230         int rc = 0;
231         if (!list_empty(&lock->l_lru)) {
232                 struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
233
234                 LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
235                 if (ns->ns_last_pos == &lock->l_lru)
236                         ns->ns_last_pos = lock->l_lru.prev;
237                 list_del_init(&lock->l_lru);
238                 LASSERT(ns->ns_nr_unused > 0);
239                 ns->ns_nr_unused--;
240                 rc = 1;
241         }
242         return rc;
243 }
244
245 /**
246  * Removes LDLM lock \a lock from LRU. Obtains the LRU lock first.
247  *
248  * If \a last_use is non-zero, it will remove the lock from LRU only if
249  * it matches lock's l_last_used.
250  *
251  * \retval 0 if \a last_use is set, the lock is not in LRU list or \a last_use
252  *           doesn't match lock's l_last_used;
253  *           otherwise, the lock hasn't been in the LRU list.
254  * \retval 1 the lock was in LRU list and removed.
255  */
256 int ldlm_lock_remove_from_lru_check(struct ldlm_lock *lock, ktime_t last_use)
257 {
258         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
259         int rc = 0;
260
261         ENTRY;
262         if (ldlm_is_ns_srv(lock)) {
263                 LASSERT(list_empty(&lock->l_lru));
264                 RETURN(0);
265         }
266
267         spin_lock(&ns->ns_lock);
268         if (!ktime_compare(last_use, ktime_set(0, 0)) ||
269             !ktime_compare(last_use, lock->l_last_used))
270                 rc = ldlm_lock_remove_from_lru_nolock(lock);
271         spin_unlock(&ns->ns_lock);
272
273         RETURN(rc);
274 }
275
276 /**
277  * Adds LDLM lock \a lock to namespace LRU. Assumes LRU is already locked.
278  */
279 void ldlm_lock_add_to_lru_nolock(struct ldlm_lock *lock)
280 {
281         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
282
283         lock->l_last_used = ktime_get();
284         LASSERT(list_empty(&lock->l_lru));
285         LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
286         list_add_tail(&lock->l_lru, &ns->ns_unused_list);
287         LASSERT(ns->ns_nr_unused >= 0);
288         ns->ns_nr_unused++;
289 }
290
291 /**
292  * Adds LDLM lock \a lock to namespace LRU. Obtains necessary LRU locks
293  * first.
294  */
295 void ldlm_lock_add_to_lru(struct ldlm_lock *lock)
296 {
297         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
298
299         ENTRY;
300         spin_lock(&ns->ns_lock);
301         ldlm_lock_add_to_lru_nolock(lock);
302         spin_unlock(&ns->ns_lock);
303         EXIT;
304 }
305
306 /**
307  * Moves LDLM lock \a lock that is already in namespace LRU to the tail of
308  * the LRU. Performs necessary LRU locking
309  */
310 void ldlm_lock_touch_in_lru(struct ldlm_lock *lock)
311 {
312         struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
313
314         ENTRY;
315         if (ldlm_is_ns_srv(lock)) {
316                 LASSERT(list_empty(&lock->l_lru));
317                 EXIT;
318                 return;
319         }
320
321         spin_lock(&ns->ns_lock);
322         if (!list_empty(&lock->l_lru)) {
323                 ldlm_lock_remove_from_lru_nolock(lock);
324                 ldlm_lock_add_to_lru_nolock(lock);
325         }
326         spin_unlock(&ns->ns_lock);
327         EXIT;
328 }
329
330 /**
331  * Helper to destroy a locked lock.
332  *
333  * Used by ldlm_lock_destroy and ldlm_lock_destroy_nolock
334  * Must be called with l_lock and lr_lock held.
335  *
336  * Does not actually free the lock data, but rather marks the lock as
337  * destroyed by setting l_destroyed field in the lock to 1.  Destroys a
338  * handle->lock association too, so that the lock can no longer be found
339  * and removes the lock from LRU list.  Actual lock freeing occurs when
340  * last lock reference goes away.
341  *
342  * Original comment (of some historical value):
343  * This used to have a 'strict' flag, which recovery would use to mark an
344  * in-use lock as needing-to-die.  Lest I am ever tempted to put it back, I
345  * shall explain why it's gone: with the new hash table scheme, once you call
346  * ldlm_lock_destroy, you can never drop your final references on this lock.
347  * Because it's not in the hash table anymore.  -phil
348  */
349 static int ldlm_lock_destroy_internal(struct ldlm_lock *lock)
350 {
351         ENTRY;
352
353         if (lock->l_readers || lock->l_writers) {
354                 LDLM_ERROR(lock, "lock still has references");
355                 LBUG();
356         }
357
358         if (!list_empty(&lock->l_res_link)) {
359                 LDLM_ERROR(lock, "lock still on resource");
360                 LBUG();
361         }
362
363         if (ldlm_is_destroyed(lock)) {
364                 LASSERT(list_empty(&lock->l_lru));
365                 EXIT;
366                 return 0;
367         }
368         ldlm_set_destroyed(lock);
369
370         if (lock->l_export && lock->l_export->exp_lock_hash) {
371                 /* NB: it's safe to call cfs_hash_del() even lock isn't
372                  * in exp_lock_hash. */
373                 /* In the function below, .hs_keycmp resolves to
374                  * ldlm_export_lock_keycmp() */
375                 /* coverity[overrun-buffer-val] */
376                 cfs_hash_del(lock->l_export->exp_lock_hash,
377                              &lock->l_remote_handle, &lock->l_exp_hash);
378         }
379
380         ldlm_lock_remove_from_lru(lock);
381         class_handle_unhash(&lock->l_handle);
382
383         EXIT;
384         return 1;
385 }
386
387 /**
388  * Destroys a LDLM lock \a lock. Performs necessary locking first.
389  */
390 void ldlm_lock_destroy(struct ldlm_lock *lock)
391 {
392         int first;
393         ENTRY;
394         lock_res_and_lock(lock);
395         first = ldlm_lock_destroy_internal(lock);
396         unlock_res_and_lock(lock);
397
398         /* drop reference from hashtable only for first destroy */
399         if (first) {
400                 lu_ref_del(&lock->l_reference, "hash", lock);
401                 LDLM_LOCK_RELEASE(lock);
402         }
403         EXIT;
404 }
405
406 /**
407  * Destroys a LDLM lock \a lock that is already locked.
408  */
409 void ldlm_lock_destroy_nolock(struct ldlm_lock *lock)
410 {
411         int first;
412         ENTRY;
413         first = ldlm_lock_destroy_internal(lock);
414         /* drop reference from hashtable only for first destroy */
415         if (first) {
416                 lu_ref_del(&lock->l_reference, "hash", lock);
417                 LDLM_LOCK_RELEASE(lock);
418         }
419         EXIT;
420 }
421
422 /* this is called by portals_handle2object with the handle lock taken */
423 static void lock_handle_addref(void *lock)
424 {
425         LDLM_LOCK_GET((struct ldlm_lock *)lock);
426 }
427
428 static void lock_handle_free(void *lock, int size)
429 {
430         LASSERT(size == sizeof(struct ldlm_lock));
431         OBD_SLAB_FREE(lock, ldlm_lock_slab, size);
432 }
433
434 static struct portals_handle_ops lock_handle_ops = {
435         .hop_addref = lock_handle_addref,
436         .hop_free   = lock_handle_free,
437 };
438
439 /**
440  *
441  * Allocate and initialize new lock structure.
442  *
443  * usage: pass in a resource on which you have done ldlm_resource_get
444  *        new lock will take over the refcount.
445  * returns: lock with refcount 2 - one for current caller and one for remote
446  */
447 static struct ldlm_lock *ldlm_lock_new(struct ldlm_resource *resource)
448 {
449         struct ldlm_lock *lock;
450         ENTRY;
451
452         if (resource == NULL)
453                 LBUG();
454
455         OBD_SLAB_ALLOC_PTR_GFP(lock, ldlm_lock_slab, GFP_NOFS);
456         if (lock == NULL)
457                 RETURN(NULL);
458
459         spin_lock_init(&lock->l_lock);
460         lock->l_resource = resource;
461         lu_ref_add(&resource->lr_reference, "lock", lock);
462
463         atomic_set(&lock->l_refc, 2);
464         INIT_LIST_HEAD(&lock->l_res_link);
465         INIT_LIST_HEAD(&lock->l_lru);
466         INIT_LIST_HEAD(&lock->l_pending_chain);
467         INIT_LIST_HEAD(&lock->l_bl_ast);
468         INIT_LIST_HEAD(&lock->l_cp_ast);
469         INIT_LIST_HEAD(&lock->l_rk_ast);
470         init_waitqueue_head(&lock->l_waitq);
471         lock->l_blocking_lock = NULL;
472         INIT_LIST_HEAD(&lock->l_sl_mode);
473         INIT_LIST_HEAD(&lock->l_sl_policy);
474         INIT_HLIST_NODE(&lock->l_exp_hash);
475         INIT_HLIST_NODE(&lock->l_exp_flock_hash);
476
477         lprocfs_counter_incr(ldlm_res_to_ns(resource)->ns_stats,
478                              LDLM_NSS_LOCKS);
479         INIT_LIST_HEAD_RCU(&lock->l_handle.h_link);
480         class_handle_hash(&lock->l_handle, &lock_handle_ops);
481
482         lu_ref_init(&lock->l_reference);
483         lu_ref_add(&lock->l_reference, "hash", lock);
484         lock->l_callback_timeout = 0;
485         lock->l_activity = 0;
486
487 #if LUSTRE_TRACKS_LOCK_EXP_REFS
488         INIT_LIST_HEAD(&lock->l_exp_refs_link);
489         lock->l_exp_refs_nr = 0;
490         lock->l_exp_refs_target = NULL;
491 #endif
492         INIT_LIST_HEAD(&lock->l_exp_list);
493
494         RETURN(lock);
495 }
496
497 /**
498  * Moves LDLM lock \a lock to another resource.
499  * This is used on client when server returns some other lock than requested
500  * (typically as a result of intent operation)
501  */
502 int ldlm_lock_change_resource(struct ldlm_namespace *ns, struct ldlm_lock *lock,
503                               const struct ldlm_res_id *new_resid)
504 {
505         struct ldlm_resource *oldres = lock->l_resource;
506         struct ldlm_resource *newres;
507         int type;
508         ENTRY;
509
510         LASSERT(ns_is_client(ns));
511
512         lock_res_and_lock(lock);
513         if (memcmp(new_resid, &lock->l_resource->lr_name,
514                    sizeof(lock->l_resource->lr_name)) == 0) {
515                 /* Nothing to do */
516                 unlock_res_and_lock(lock);
517                 RETURN(0);
518         }
519
520         LASSERT(new_resid->name[0] != 0);
521
522         /* This function assumes that the lock isn't on any lists */
523         LASSERT(list_empty(&lock->l_res_link));
524
525         type = oldres->lr_type;
526         unlock_res_and_lock(lock);
527
528         newres = ldlm_resource_get(ns, NULL, new_resid, type, 1);
529         if (IS_ERR(newres))
530                 RETURN(PTR_ERR(newres));
531
532         lu_ref_add(&newres->lr_reference, "lock", lock);
533         /*
534          * To flip the lock from the old to the new resource, lock, oldres and
535          * newres have to be locked. Resource spin-locks are nested within
536          * lock->l_lock, and are taken in the memory address order to avoid
537          * dead-locks.
538          */
539         spin_lock(&lock->l_lock);
540         oldres = lock->l_resource;
541         if (oldres < newres) {
542                 lock_res(oldres);
543                 lock_res_nested(newres, LRT_NEW);
544         } else {
545                 lock_res(newres);
546                 lock_res_nested(oldres, LRT_NEW);
547         }
548         LASSERT(memcmp(new_resid, &oldres->lr_name,
549                        sizeof oldres->lr_name) != 0);
550         lock->l_resource = newres;
551         unlock_res(oldres);
552         unlock_res_and_lock(lock);
553
554         /* ...and the flowers are still standing! */
555         lu_ref_del(&oldres->lr_reference, "lock", lock);
556         ldlm_resource_putref(oldres);
557
558         RETURN(0);
559 }
560
561 /** \defgroup ldlm_handles LDLM HANDLES
562  * Ways to get hold of locks without any addresses.
563  * @{
564  */
565
566 /**
567  * Fills in handle for LDLM lock \a lock into supplied \a lockh
568  * Does not take any references.
569  */
570 void ldlm_lock2handle(const struct ldlm_lock *lock, struct lustre_handle *lockh)
571 {
572         lockh->cookie = lock->l_handle.h_cookie;
573 }
574 EXPORT_SYMBOL(ldlm_lock2handle);
575
576 /**
577  * Obtain a lock reference by handle.
578  *
579  * if \a flags: atomically get the lock and set the flags.
580  *              Return NULL if flag already set
581  */
582 struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *handle,
583                                      __u64 flags)
584 {
585         struct ldlm_lock *lock;
586         ENTRY;
587
588         LASSERT(handle);
589
590         lock = class_handle2object(handle->cookie, NULL);
591         if (lock == NULL)
592                 RETURN(NULL);
593
594         if (lock->l_export != NULL && lock->l_export->exp_failed) {
595                 CDEBUG(D_INFO, "lock export failed: lock %p, exp %p\n",
596                        lock, lock->l_export);
597                 LDLM_LOCK_PUT(lock);
598                 RETURN(NULL);
599         }
600
601         /* It's unlikely but possible that someone marked the lock as
602          * destroyed after we did handle2object on it */
603         if ((flags == 0) && !ldlm_is_destroyed(lock)) {
604                 lu_ref_add(&lock->l_reference, "handle", current);
605                 RETURN(lock);
606         }
607
608         lock_res_and_lock(lock);
609
610         LASSERT(lock->l_resource != NULL);
611
612         lu_ref_add_atomic(&lock->l_reference, "handle", current);
613         if (unlikely(ldlm_is_destroyed(lock))) {
614                 unlock_res_and_lock(lock);
615                 CDEBUG(D_INFO, "lock already destroyed: lock %p\n", lock);
616                 LDLM_LOCK_PUT(lock);
617                 RETURN(NULL);
618         }
619
620         /* If we're setting flags, make sure none of them are already set. */
621         if (flags != 0) {
622                 if ((lock->l_flags & flags) != 0) {
623                         unlock_res_and_lock(lock);
624                         LDLM_LOCK_PUT(lock);
625                         RETURN(NULL);
626                 }
627
628                 lock->l_flags |= flags;
629         }
630
631         unlock_res_and_lock(lock);
632         RETURN(lock);
633 }
634 EXPORT_SYMBOL(__ldlm_handle2lock);
635 /** @} ldlm_handles */
636
637 /**
638  * Fill in "on the wire" representation for given LDLM lock into supplied
639  * lock descriptor \a desc structure.
640  */
641 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc)
642 {
643         ldlm_res2desc(lock->l_resource, &desc->l_resource);
644         desc->l_req_mode = lock->l_req_mode;
645         desc->l_granted_mode = lock->l_granted_mode;
646         ldlm_convert_policy_to_wire(lock->l_resource->lr_type,
647                                     &lock->l_policy_data,
648                                     &desc->l_policy_data);
649 }
650
651 /**
652  * Add a lock to list of conflicting locks to send AST to.
653  *
654  * Only add if we have not sent a blocking AST to the lock yet.
655  */
656 static void ldlm_add_bl_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
657                                   struct list_head *work_list)
658 {
659         if (!ldlm_is_ast_sent(lock)) {
660                 LDLM_DEBUG(lock, "lock incompatible; sending blocking AST.");
661                 ldlm_set_ast_sent(lock);
662                 /* If the enqueuing client said so, tell the AST recipient to
663                  * discard dirty data, rather than writing back. */
664                 if (ldlm_is_ast_discard_data(new))
665                         ldlm_set_discard_data(lock);
666
667                 /* Lock can be converted from a blocking state back to granted
668                  * after lock convert or COS downgrade but still be in an
669                  * older bl_list because it is controlled only by
670                  * ldlm_work_bl_ast_lock(), let it be processed there.
671                  */
672                 if (list_empty(&lock->l_bl_ast)) {
673                         list_add(&lock->l_bl_ast, work_list);
674                         LDLM_LOCK_GET(lock);
675                 }
676                 LASSERT(lock->l_blocking_lock == NULL);
677                 lock->l_blocking_lock = LDLM_LOCK_GET(new);
678         }
679 }
680
681 /**
682  * Add a lock to list of just granted locks to send completion AST to.
683  */
684 static void ldlm_add_cp_work_item(struct ldlm_lock *lock,
685                                   struct list_head *work_list)
686 {
687         if (!ldlm_is_cp_reqd(lock)) {
688                 ldlm_set_cp_reqd(lock);
689                 LDLM_DEBUG(lock, "lock granted; sending completion AST.");
690                 LASSERT(list_empty(&lock->l_cp_ast));
691                 list_add(&lock->l_cp_ast, work_list);
692                 LDLM_LOCK_GET(lock);
693         }
694 }
695
696 /**
697  * Aggregator function to add AST work items into a list. Determines
698  * what sort of an AST work needs to be done and calls the proper
699  * adding function.
700  * Must be called with lr_lock held.
701  */
702 void ldlm_add_ast_work_item(struct ldlm_lock *lock, struct ldlm_lock *new,
703                             struct list_head *work_list)
704 {
705         ENTRY;
706         check_res_locked(lock->l_resource);
707         if (new)
708                 ldlm_add_bl_work_item(lock, new, work_list);
709         else
710                 ldlm_add_cp_work_item(lock, work_list);
711         EXIT;
712 }
713
714 /**
715  * Add specified reader/writer reference to LDLM lock with handle \a lockh.
716  * r/w reference type is determined by \a mode
717  * Calls ldlm_lock_addref_internal.
718  */
719 void ldlm_lock_addref(const struct lustre_handle *lockh, enum ldlm_mode mode)
720 {
721         struct ldlm_lock *lock;
722
723         lock = ldlm_handle2lock(lockh);
724         LASSERTF(lock != NULL, "Non-existing lock: %#llx\n", lockh->cookie);
725         ldlm_lock_addref_internal(lock, mode);
726         LDLM_LOCK_PUT(lock);
727 }
728 EXPORT_SYMBOL(ldlm_lock_addref);
729
730 /**
731  * Helper function.
732  * Add specified reader/writer reference to LDLM lock \a lock.
733  * r/w reference type is determined by \a mode
734  * Removes lock from LRU if it is there.
735  * Assumes the LDLM lock is already locked.
736  */
737 void ldlm_lock_addref_internal_nolock(struct ldlm_lock *lock,
738                                       enum ldlm_mode mode)
739 {
740         ldlm_lock_remove_from_lru(lock);
741         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
742                 lock->l_readers++;
743                 lu_ref_add_atomic(&lock->l_reference, "reader", lock);
744         }
745         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS)) {
746                 lock->l_writers++;
747                 lu_ref_add_atomic(&lock->l_reference, "writer", lock);
748         }
749         LDLM_LOCK_GET(lock);
750         lu_ref_add_atomic(&lock->l_reference, "user", lock);
751         LDLM_DEBUG(lock, "ldlm_lock_addref(%s)", ldlm_lockname[mode]);
752 }
753
754 /**
755  * Attempts to add reader/writer reference to a lock with handle \a lockh, and
756  * fails if lock is already LDLM_FL_CBPENDING or destroyed.
757  *
758  * \retval 0 success, lock was addref-ed
759  *
760  * \retval -EAGAIN lock is being canceled.
761  */
762 int ldlm_lock_addref_try(const struct lustre_handle *lockh, enum ldlm_mode mode)
763 {
764         struct ldlm_lock *lock;
765         int               result;
766
767         result = -EAGAIN;
768         lock = ldlm_handle2lock(lockh);
769         if (lock != NULL) {
770                 lock_res_and_lock(lock);
771                 if (lock->l_readers != 0 || lock->l_writers != 0 ||
772                     !ldlm_is_cbpending(lock)) {
773                         ldlm_lock_addref_internal_nolock(lock, mode);
774                         result = 0;
775                 }
776                 unlock_res_and_lock(lock);
777                 LDLM_LOCK_PUT(lock);
778         }
779         return result;
780 }
781 EXPORT_SYMBOL(ldlm_lock_addref_try);
782
783 /**
784  * Add specified reader/writer reference to LDLM lock \a lock.
785  * Locks LDLM lock and calls ldlm_lock_addref_internal_nolock to do the work.
786  * Only called for local locks.
787  */
788 void ldlm_lock_addref_internal(struct ldlm_lock *lock, enum ldlm_mode mode)
789 {
790         lock_res_and_lock(lock);
791         ldlm_lock_addref_internal_nolock(lock, mode);
792         unlock_res_and_lock(lock);
793 }
794
795 /**
796  * Removes reader/writer reference for LDLM lock \a lock.
797  * Assumes LDLM lock is already locked.
798  * only called in ldlm_flock_destroy and for local locks.
799  * Does NOT add lock to LRU if no r/w references left to accomodate flock locks
800  * that cannot be placed in LRU.
801  */
802 void ldlm_lock_decref_internal_nolock(struct ldlm_lock *lock,
803                                       enum ldlm_mode mode)
804 {
805         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
806         if (mode & (LCK_NL | LCK_CR | LCK_PR)) {
807                 LASSERT(lock->l_readers > 0);
808                 lu_ref_del(&lock->l_reference, "reader", lock);
809                 lock->l_readers--;
810         }
811         if (mode & (LCK_EX | LCK_CW | LCK_PW | LCK_GROUP | LCK_COS)) {
812                 LASSERT(lock->l_writers > 0);
813                 lu_ref_del(&lock->l_reference, "writer", lock);
814                 lock->l_writers--;
815         }
816
817         lu_ref_del(&lock->l_reference, "user", lock);
818         LDLM_LOCK_RELEASE(lock);    /* matches the LDLM_LOCK_GET() in addref */
819 }
820
821 /**
822  * Removes reader/writer reference for LDLM lock \a lock.
823  * Locks LDLM lock first.
824  * If the lock is determined to be client lock on a client and r/w refcount
825  * drops to zero and the lock is not blocked, the lock is added to LRU lock
826  * on the namespace.
827  * For blocked LDLM locks if r/w count drops to zero, blocking_ast is called.
828  */
829 void ldlm_lock_decref_internal(struct ldlm_lock *lock, enum ldlm_mode mode)
830 {
831         struct ldlm_namespace *ns;
832         ENTRY;
833
834         lock_res_and_lock(lock);
835
836         ns = ldlm_lock_to_ns(lock);
837
838         ldlm_lock_decref_internal_nolock(lock, mode);
839
840         if ((ldlm_is_local(lock) || lock->l_req_mode == LCK_GROUP) &&
841             !lock->l_readers && !lock->l_writers) {
842                 /* If this is a local lock on a server namespace and this was
843                  * the last reference, cancel the lock.
844                  *
845                  * Group locks are special:
846                  * They must not go in LRU, but they are not called back
847                  * like non-group locks, instead they are manually released.
848                  * They have an l_writers reference which they keep until
849                  * they are manually released, so we remove them when they have
850                  * no more reader or writer references. - LU-6368 */
851                 ldlm_set_cbpending(lock);
852         }
853
854         if (!lock->l_readers && !lock->l_writers && ldlm_is_cbpending(lock)) {
855                 /* If we received a blocked AST and this was the last reference,
856                  * run the callback. */
857                 if (ldlm_is_ns_srv(lock) && lock->l_export)
858                         CERROR("FL_CBPENDING set on non-local lock--just a "
859                                "warning\n");
860
861                 LDLM_DEBUG(lock, "final decref done on cbpending lock");
862
863                 LDLM_LOCK_GET(lock); /* dropped by bl thread */
864                 ldlm_lock_remove_from_lru(lock);
865                 unlock_res_and_lock(lock);
866
867                 if (ldlm_is_fail_loc(lock))
868                         OBD_RACE(OBD_FAIL_LDLM_CP_BL_RACE);
869
870                 if (ldlm_is_atomic_cb(lock) ||
871                     ldlm_bl_to_thread_lock(ns, NULL, lock) != 0)
872                         ldlm_handle_bl_callback(ns, NULL, lock);
873         } else if (ns_is_client(ns) &&
874                    !lock->l_readers && !lock->l_writers &&
875                    !ldlm_is_no_lru(lock) &&
876                    !ldlm_is_bl_ast(lock) &&
877                    !ldlm_is_converting(lock)) {
878
879                 LDLM_DEBUG(lock, "add lock into lru list");
880
881                 /* If this is a client-side namespace and this was the last
882                  * reference, put it on the LRU. */
883                 ldlm_lock_add_to_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                 /* Call ldlm_cancel_lru() only if EARLY_CANCEL and LRU RESIZE
890                  * are not supported by the server, otherwise, it is done on
891                  * enqueue. */
892                 if (!exp_connect_cancelset(lock->l_conn_export) &&
893                     !ns_connect_lru_resize(ns))
894                         ldlm_cancel_lru(ns, 0, LCF_ASYNC, 0);
895         } else {
896                 LDLM_DEBUG(lock, "do not add lock into lru list");
897                 unlock_res_and_lock(lock);
898         }
899
900         EXIT;
901 }
902
903 /**
904  * Decrease reader/writer refcount for LDLM lock with handle \a lockh
905  */
906 void ldlm_lock_decref(const struct lustre_handle *lockh, enum ldlm_mode mode)
907 {
908         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
909         LASSERTF(lock != NULL, "Non-existing lock: %#llx\n", lockh->cookie);
910         ldlm_lock_decref_internal(lock, mode);
911         LDLM_LOCK_PUT(lock);
912 }
913 EXPORT_SYMBOL(ldlm_lock_decref);
914
915 /**
916  * Decrease reader/writer refcount for LDLM lock with handle
917  * \a lockh and mark it for subsequent cancellation once r/w refcount
918  * drops to zero instead of putting into LRU.
919  *
920  */
921 void ldlm_lock_decref_and_cancel(const struct lustre_handle *lockh,
922                                  enum ldlm_mode mode)
923 {
924         struct ldlm_lock *lock = __ldlm_handle2lock(lockh, 0);
925         ENTRY;
926
927         LASSERT(lock != NULL);
928
929         LDLM_DEBUG(lock, "ldlm_lock_decref(%s)", ldlm_lockname[mode]);
930         lock_res_and_lock(lock);
931         ldlm_set_cbpending(lock);
932         unlock_res_and_lock(lock);
933         ldlm_lock_decref_internal(lock, mode);
934         LDLM_LOCK_PUT(lock);
935 }
936 EXPORT_SYMBOL(ldlm_lock_decref_and_cancel);
937
938 struct sl_insert_point {
939         struct list_head *res_link;
940         struct list_head *mode_link;
941         struct list_head *policy_link;
942 };
943
944 /**
945  * Finds a position to insert the new lock into granted lock list.
946  *
947  * Used for locks eligible for skiplist optimization.
948  *
949  * Parameters:
950  *      queue [input]:  the granted list where search acts on;
951  *      req [input]:    the lock whose position to be located;
952  *      prev [output]:  positions within 3 lists to insert @req to
953  * Return Value:
954  *      filled @prev
955  * NOTE: called by
956  *  - ldlm_grant_lock_with_skiplist
957  */
958 static void search_granted_lock(struct list_head *queue,
959                                 struct ldlm_lock *req,
960                                 struct sl_insert_point *prev)
961 {
962         struct list_head *tmp;
963         struct ldlm_lock *lock, *mode_end, *policy_end;
964         ENTRY;
965
966         list_for_each(tmp, queue) {
967                 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
968
969                 mode_end = list_entry(lock->l_sl_mode.prev,
970                                           struct ldlm_lock, l_sl_mode);
971
972                 if (lock->l_req_mode != req->l_req_mode) {
973                         /* jump to last lock of mode group */
974                         tmp = &mode_end->l_res_link;
975                         continue;
976                 }
977
978                 /* suitable mode group is found */
979                 if (lock->l_resource->lr_type == LDLM_PLAIN) {
980                         /* insert point is last lock of the mode group */
981                         prev->res_link = &mode_end->l_res_link;
982                         prev->mode_link = &mode_end->l_sl_mode;
983                         prev->policy_link = &req->l_sl_policy;
984                         EXIT;
985                         return;
986                 } else if (lock->l_resource->lr_type == LDLM_IBITS) {
987                         for (;;) {
988                                 policy_end =
989                                         list_entry(lock->l_sl_policy.prev,
990                                                        struct ldlm_lock,
991                                                        l_sl_policy);
992
993                                 if (lock->l_policy_data.l_inodebits.bits ==
994                                     req->l_policy_data.l_inodebits.bits) {
995                                         /* insert point is last lock of
996                                          * the policy group */
997                                         prev->res_link =
998                                                 &policy_end->l_res_link;
999                                         prev->mode_link =
1000                                                 &policy_end->l_sl_mode;
1001                                         prev->policy_link =
1002                                                 &policy_end->l_sl_policy;
1003                                         EXIT;
1004                                         return;
1005                                 }
1006
1007                                 if (policy_end == mode_end)
1008                                         /* done with mode group */
1009                                         break;
1010
1011                                 /* go to next policy group within mode group */
1012                                 tmp = policy_end->l_res_link.next;
1013                                 lock = list_entry(tmp, struct ldlm_lock,
1014                                                       l_res_link);
1015                         }  /* loop over policy groups within the mode group */
1016
1017                         /* insert point is last lock of the mode group,
1018                          * new policy group is started */
1019                         prev->res_link = &mode_end->l_res_link;
1020                         prev->mode_link = &mode_end->l_sl_mode;
1021                         prev->policy_link = &req->l_sl_policy;
1022                         EXIT;
1023                         return;
1024                 } else {
1025                         LDLM_ERROR(lock,"is not LDLM_PLAIN or LDLM_IBITS lock");
1026                         LBUG();
1027                 }
1028         }
1029
1030         /* insert point is last lock on the queue,
1031          * new mode group and new policy group are started */
1032         prev->res_link = queue->prev;
1033         prev->mode_link = &req->l_sl_mode;
1034         prev->policy_link = &req->l_sl_policy;
1035         EXIT;
1036         return;
1037 }
1038
1039 /**
1040  * Add a lock into resource granted list after a position described by
1041  * \a prev.
1042  */
1043 static void ldlm_granted_list_add_lock(struct ldlm_lock *lock,
1044                                        struct sl_insert_point *prev)
1045 {
1046         struct ldlm_resource *res = lock->l_resource;
1047         ENTRY;
1048
1049         check_res_locked(res);
1050
1051         ldlm_resource_dump(D_INFO, res);
1052         LDLM_DEBUG(lock, "About to add lock:");
1053
1054         if (ldlm_is_destroyed(lock)) {
1055                 CDEBUG(D_OTHER, "Lock destroyed, not adding to resource\n");
1056                 return;
1057         }
1058
1059         LASSERT(list_empty(&lock->l_res_link));
1060         LASSERT(list_empty(&lock->l_sl_mode));
1061         LASSERT(list_empty(&lock->l_sl_policy));
1062
1063         /*
1064          * lock->link == prev->link means lock is first starting the group.
1065          * Don't re-add to itself to suppress kernel warnings.
1066          */
1067         if (&lock->l_res_link != prev->res_link)
1068                 list_add(&lock->l_res_link, prev->res_link);
1069         if (&lock->l_sl_mode != prev->mode_link)
1070                 list_add(&lock->l_sl_mode, prev->mode_link);
1071         if (&lock->l_sl_policy != prev->policy_link)
1072                 list_add(&lock->l_sl_policy, prev->policy_link);
1073
1074         EXIT;
1075 }
1076
1077 /**
1078  * Add a lock to granted list on a resource maintaining skiplist
1079  * correctness.
1080  */
1081 void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
1082 {
1083         struct sl_insert_point prev;
1084
1085         LASSERT(ldlm_is_granted(lock));
1086
1087         search_granted_lock(&lock->l_resource->lr_granted, lock, &prev);
1088         ldlm_granted_list_add_lock(lock, &prev);
1089 }
1090
1091 /**
1092  * Perform lock granting bookkeeping.
1093  *
1094  * Includes putting the lock into granted list and updating lock mode.
1095  * NOTE: called by
1096  *  - ldlm_lock_enqueue
1097  *  - ldlm_reprocess_queue
1098  *
1099  * must be called with lr_lock held
1100  */
1101 void ldlm_grant_lock(struct ldlm_lock *lock, struct list_head *work_list)
1102 {
1103         struct ldlm_resource *res = lock->l_resource;
1104         ENTRY;
1105
1106         check_res_locked(res);
1107
1108         lock->l_granted_mode = lock->l_req_mode;
1109
1110         if (work_list && lock->l_completion_ast != NULL)
1111                 ldlm_add_ast_work_item(lock, NULL, work_list);
1112
1113         if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS)
1114                 ldlm_grant_lock_with_skiplist(lock);
1115         else if (res->lr_type == LDLM_EXTENT)
1116                 ldlm_extent_add_lock(res, lock);
1117         else if (res->lr_type == LDLM_FLOCK) {
1118                 /* We should not add locks to granted list in the following
1119                  * cases:
1120                  * - this is an UNLOCK but not a real lock;
1121                  * - this is a TEST lock;
1122                  * - this is a F_CANCELLK lock (async flock has req_mode == 0)
1123                  * - this is a deadlock (flock cannot be granted) */
1124                 if (lock->l_req_mode == 0 ||
1125                     lock->l_req_mode == LCK_NL ||
1126                     ldlm_is_test_lock(lock) ||
1127                     ldlm_is_flock_deadlock(lock))
1128                         RETURN_EXIT;
1129                 ldlm_resource_add_lock(res, &res->lr_granted, lock);
1130         } else {
1131                 LBUG();
1132         }
1133
1134         ldlm_pool_add(&ldlm_res_to_ns(res)->ns_pool, lock);
1135         EXIT;
1136 }
1137
1138 /**
1139  * Describe the overlap between two locks.  itree_overlap_cb data.
1140  */
1141 struct lock_match_data {
1142         struct ldlm_lock        *lmd_old;
1143         struct ldlm_lock        *lmd_lock;
1144         enum ldlm_mode          *lmd_mode;
1145         union ldlm_policy_data  *lmd_policy;
1146         __u64                    lmd_flags;
1147         __u64                    lmd_skip_flags;
1148         int                      lmd_unref;
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 lock_match_data *data)
1159 {
1160         union ldlm_policy_data *lpol = &lock->l_policy_data;
1161         enum ldlm_mode match;
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_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         match = lock->l_req_mode;
1187
1188         switch (lock->l_resource->lr_type) {
1189         case LDLM_EXTENT:
1190                 if (lpol->l_extent.start > data->lmd_policy->l_extent.start ||
1191                     lpol->l_extent.end < data->lmd_policy->l_extent.end)
1192                         return INTERVAL_ITER_CONT;
1193
1194                 if (unlikely(match == LCK_GROUP) &&
1195                     data->lmd_policy->l_extent.gid != LDLM_GID_ANY &&
1196                     lpol->l_extent.gid != data->lmd_policy->l_extent.gid)
1197                         return INTERVAL_ITER_CONT;
1198                 break;
1199         case LDLM_IBITS:
1200                 /* We match if we have existing lock with same or wider set
1201                    of bits. */
1202                 if ((lpol->l_inodebits.bits &
1203                      data->lmd_policy->l_inodebits.bits) !=
1204                     data->lmd_policy->l_inodebits.bits)
1205                         return INTERVAL_ITER_CONT;
1206                 break;
1207         default:
1208                 ;
1209         }
1210
1211         /* We match if we have existing lock with same or wider set
1212            of bits. */
1213         if (!data->lmd_unref && LDLM_HAVE_MASK(lock, GONE))
1214                 return INTERVAL_ITER_CONT;
1215
1216         if (!equi(data->lmd_flags & LDLM_FL_LOCAL_ONLY, ldlm_is_local(lock)))
1217                 return INTERVAL_ITER_CONT;
1218
1219         /* Filter locks by skipping flags */
1220         if (data->lmd_skip_flags & lock->l_flags)
1221                 return INTERVAL_ITER_CONT;
1222
1223         if (data->lmd_flags & LDLM_FL_TEST_LOCK) {
1224                 LDLM_LOCK_GET(lock);
1225                 ldlm_lock_touch_in_lru(lock);
1226         } else {
1227                 ldlm_lock_addref_internal_nolock(lock, match);
1228         }
1229
1230         *data->lmd_mode = match;
1231         data->lmd_lock = lock;
1232
1233         return INTERVAL_ITER_STOP;
1234 }
1235
1236 static unsigned int itree_overlap_cb(struct interval_node *in, void *args)
1237 {
1238         struct ldlm_interval *node = to_ldlm_interval(in);
1239         struct lock_match_data *data = args;
1240         struct ldlm_lock *lock;
1241         int rc;
1242
1243         list_for_each_entry(lock, &node->li_group, l_sl_policy) {
1244                 rc = lock_matches(lock, data);
1245                 if (rc == INTERVAL_ITER_STOP)
1246                         return INTERVAL_ITER_STOP;
1247         }
1248         return INTERVAL_ITER_CONT;
1249 }
1250
1251 /**
1252  * Search for a lock with given parameters in interval trees.
1253  *
1254  * \param res      search for a lock in this resource
1255  * \param data     parameters
1256  *
1257  * \retval a referenced lock or NULL.
1258  */
1259 static struct ldlm_lock *search_itree(struct ldlm_resource *res,
1260                                       struct lock_match_data *data)
1261 {
1262         struct interval_node_extent ext = {
1263                 .start     = data->lmd_policy->l_extent.start,
1264                 .end       = data->lmd_policy->l_extent.end
1265         };
1266         int idx;
1267
1268         data->lmd_lock = NULL;
1269
1270         for (idx = 0; idx < LCK_MODE_NUM; idx++) {
1271                 struct ldlm_interval_tree *tree = &res->lr_itree[idx];
1272
1273                 if (tree->lit_root == NULL)
1274                         continue;
1275
1276                 if (!(tree->lit_mode & *data->lmd_mode))
1277                         continue;
1278
1279                 interval_search(tree->lit_root, &ext,
1280                                 itree_overlap_cb, data);
1281                 if (data->lmd_lock)
1282                         return data->lmd_lock;
1283         }
1284
1285         return NULL;
1286 }
1287
1288
1289 /**
1290  * Search for a lock with given properties in a queue.
1291  *
1292  * \param queue    search for a lock in this queue
1293  * \param data     parameters
1294  *
1295  * \retval a referenced lock or NULL.
1296  */
1297 static struct ldlm_lock *search_queue(struct list_head *queue,
1298                                       struct lock_match_data *data)
1299 {
1300         struct ldlm_lock *lock;
1301         int rc;
1302
1303         data->lmd_lock = NULL;
1304
1305         list_for_each_entry(lock, queue, l_res_link) {
1306                 rc = lock_matches(lock, data);
1307                 if (rc == INTERVAL_ITER_STOP)
1308                         return data->lmd_lock;
1309         }
1310
1311         return NULL;
1312 }
1313
1314 void ldlm_lock_fail_match_locked(struct ldlm_lock *lock)
1315 {
1316         if ((lock->l_flags & LDLM_FL_FAIL_NOTIFIED) == 0) {
1317                 lock->l_flags |= LDLM_FL_FAIL_NOTIFIED;
1318                 wake_up_all(&lock->l_waitq);
1319         }
1320 }
1321 EXPORT_SYMBOL(ldlm_lock_fail_match_locked);
1322
1323 void ldlm_lock_fail_match(struct ldlm_lock *lock)
1324 {
1325         lock_res_and_lock(lock);
1326         ldlm_lock_fail_match_locked(lock);
1327         unlock_res_and_lock(lock);
1328 }
1329
1330 /**
1331  * Mark lock as "matchable" by OST.
1332  *
1333  * Used to prevent certain races in LOV/OSC where the lock is granted, but LVB
1334  * is not yet valid.
1335  * Assumes LDLM lock is already locked.
1336  */
1337 void ldlm_lock_allow_match_locked(struct ldlm_lock *lock)
1338 {
1339         ldlm_set_lvb_ready(lock);
1340         wake_up_all(&lock->l_waitq);
1341 }
1342 EXPORT_SYMBOL(ldlm_lock_allow_match_locked);
1343
1344 /**
1345  * Mark lock as "matchable" by OST.
1346  * Locks the lock and then \see ldlm_lock_allow_match_locked
1347  */
1348 void ldlm_lock_allow_match(struct ldlm_lock *lock)
1349 {
1350         lock_res_and_lock(lock);
1351         ldlm_lock_allow_match_locked(lock);
1352         unlock_res_and_lock(lock);
1353 }
1354 EXPORT_SYMBOL(ldlm_lock_allow_match);
1355
1356 /**
1357  * Attempt to find a lock with specified properties.
1358  *
1359  * Typically returns a reference to matched lock unless LDLM_FL_TEST_LOCK is
1360  * set in \a flags
1361  *
1362  * Can be called in two ways:
1363  *
1364  * If 'ns' is NULL, then lockh describes an existing lock that we want to look
1365  * for a duplicate of.
1366  *
1367  * Otherwise, all of the fields must be filled in, to match against.
1368  *
1369  * If 'flags' contains LDLM_FL_LOCAL_ONLY, then only match local locks on the
1370  *     server (ie, connh is NULL)
1371  * If 'flags' contains LDLM_FL_BLOCK_GRANTED, then only locks on the granted
1372  *     list will be considered
1373  * If 'flags' contains LDLM_FL_CBPENDING, then locks that have been marked
1374  *     to be canceled can still be matched as long as they still have reader
1375  *     or writer refernces
1376  * If 'flags' contains LDLM_FL_TEST_LOCK, then don't actually reference a lock,
1377  *     just tell us if we would have matched.
1378  *
1379  * \retval 1 if it finds an already-existing lock that is compatible; in this
1380  * case, lockh is filled in with a addref()ed lock
1381  *
1382  * We also check security context, and if that fails we simply return 0 (to
1383  * keep caller code unchanged), the context failure will be discovered by
1384  * caller sometime later.
1385  */
1386 enum ldlm_mode ldlm_lock_match_with_skip(struct ldlm_namespace *ns,
1387                                          __u64 flags, __u64 skip_flags,
1388                                          const struct ldlm_res_id *res_id,
1389                                          enum ldlm_type type,
1390                                          union ldlm_policy_data *policy,
1391                                          enum ldlm_mode mode,
1392                                          struct lustre_handle *lockh, int unref)
1393 {
1394         struct lock_match_data data = {
1395                 .lmd_old = NULL,
1396                 .lmd_lock = NULL,
1397                 .lmd_mode = &mode,
1398                 .lmd_policy = policy,
1399                 .lmd_flags = flags,
1400                 .lmd_skip_flags = skip_flags,
1401                 .lmd_unref = unref,
1402         };
1403         struct ldlm_resource *res;
1404         struct ldlm_lock *lock;
1405         int matched;
1406
1407         ENTRY;
1408
1409         if (ns == NULL) {
1410                 data.lmd_old = ldlm_handle2lock(lockh);
1411                 LASSERT(data.lmd_old != NULL);
1412
1413                 ns = ldlm_lock_to_ns(data.lmd_old);
1414                 res_id = &data.lmd_old->l_resource->lr_name;
1415                 type = data.lmd_old->l_resource->lr_type;
1416                 *data.lmd_mode = data.lmd_old->l_req_mode;
1417         }
1418
1419         res = ldlm_resource_get(ns, NULL, res_id, type, 0);
1420         if (IS_ERR(res)) {
1421                 LASSERT(data.lmd_old == NULL);
1422                 RETURN(0);
1423         }
1424
1425         LDLM_RESOURCE_ADDREF(res);
1426         lock_res(res);
1427         if (res->lr_type == LDLM_EXTENT)
1428                 lock = search_itree(res, &data);
1429         else
1430                 lock = search_queue(&res->lr_granted, &data);
1431         if (!lock && !(flags & LDLM_FL_BLOCK_GRANTED))
1432                 lock = search_queue(&res->lr_waiting, &data);
1433         matched = lock ? mode : 0;
1434         unlock_res(res);
1435         LDLM_RESOURCE_DELREF(res);
1436         ldlm_resource_putref(res);
1437
1438         if (lock) {
1439                 ldlm_lock2handle(lock, lockh);
1440                 if ((flags & LDLM_FL_LVB_READY) &&
1441                     (!ldlm_is_lvb_ready(lock))) {
1442                         __u64 wait_flags = LDLM_FL_LVB_READY |
1443                                 LDLM_FL_DESTROYED | LDLM_FL_FAIL_NOTIFIED;
1444                         struct l_wait_info lwi;
1445
1446                         if (lock->l_completion_ast) {
1447                                 int err = lock->l_completion_ast(lock,
1448                                                         LDLM_FL_WAIT_NOREPROC,
1449                                                         NULL);
1450                                 if (err)
1451                                         GOTO(out_fail_match, matched = 0);
1452                         }
1453
1454                         lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(obd_timeout),
1455                                                NULL, LWI_ON_SIGNAL_NOOP, NULL);
1456
1457                         /* XXX FIXME see comment on CAN_MATCH in lustre_dlm.h */
1458                         l_wait_event(lock->l_waitq, lock->l_flags & wait_flags,
1459                                      &lwi);
1460                         if (!ldlm_is_lvb_ready(lock))
1461                                 GOTO(out_fail_match, matched = 0);
1462                 }
1463
1464                 /* check user's security context */
1465                 if (lock->l_conn_export &&
1466                     sptlrpc_import_check_ctx(
1467                                 class_exp2cliimp(lock->l_conn_export)))
1468                         GOTO(out_fail_match, matched = 0);
1469
1470                 LDLM_DEBUG(lock, "matched (%llu %llu)",
1471                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1472                            res_id->name[2] : policy->l_extent.start,
1473                            (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1474                            res_id->name[3] : policy->l_extent.end);
1475
1476 out_fail_match:
1477                 if (flags & LDLM_FL_TEST_LOCK)
1478                         LDLM_LOCK_RELEASE(lock);
1479                 else if (!matched)
1480                         ldlm_lock_decref_internal(lock, mode);
1481         }
1482
1483         /* less verbose for test-only */
1484         if (!matched && !(flags & LDLM_FL_TEST_LOCK)) {
1485                 LDLM_DEBUG_NOLOCK("not matched ns %p type %u mode %u res "
1486                                   "%llu/%llu (%llu %llu)", ns,
1487                                   type, mode, res_id->name[0], res_id->name[1],
1488                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1489                                   res_id->name[2] : policy->l_extent.start,
1490                                   (type == LDLM_PLAIN || type == LDLM_IBITS) ?
1491                                   res_id->name[3] : policy->l_extent.end);
1492         }
1493         if (data.lmd_old != NULL)
1494                 LDLM_LOCK_PUT(data.lmd_old);
1495
1496         return matched;
1497 }
1498 EXPORT_SYMBOL(ldlm_lock_match_with_skip);
1499
1500 enum ldlm_mode ldlm_revalidate_lock_handle(const struct lustre_handle *lockh,
1501                                            __u64 *bits)
1502 {
1503         struct ldlm_lock *lock;
1504         enum ldlm_mode mode = 0;
1505         ENTRY;
1506
1507         lock = ldlm_handle2lock(lockh);
1508         if (lock != NULL) {
1509                 lock_res_and_lock(lock);
1510                 if (LDLM_HAVE_MASK(lock, GONE))
1511                         GOTO(out, mode);
1512
1513                 if (ldlm_is_cbpending(lock) &&
1514                     lock->l_readers == 0 && lock->l_writers == 0)
1515                         GOTO(out, mode);
1516
1517                 if (bits)
1518                         *bits = lock->l_policy_data.l_inodebits.bits;
1519                 mode = lock->l_granted_mode;
1520                 ldlm_lock_addref_internal_nolock(lock, mode);
1521         }
1522
1523         EXIT;
1524
1525 out:
1526         if (lock != NULL) {
1527                 unlock_res_and_lock(lock);
1528                 LDLM_LOCK_PUT(lock);
1529         }
1530         return mode;
1531 }
1532 EXPORT_SYMBOL(ldlm_revalidate_lock_handle);
1533
1534 /** The caller must guarantee that the buffer is large enough. */
1535 int ldlm_fill_lvb(struct ldlm_lock *lock, struct req_capsule *pill,
1536                   enum req_location loc, void *data, int size)
1537 {
1538         void *lvb;
1539         ENTRY;
1540
1541         LASSERT(data != NULL);
1542         LASSERT(size >= 0);
1543
1544         switch (lock->l_lvb_type) {
1545         case LVB_T_OST:
1546                 if (size == sizeof(struct ost_lvb)) {
1547                         if (loc == RCL_CLIENT)
1548                                 lvb = req_capsule_client_swab_get(pill,
1549                                                 &RMF_DLM_LVB,
1550                                                 lustre_swab_ost_lvb);
1551                         else
1552                                 lvb = req_capsule_server_swab_get(pill,
1553                                                 &RMF_DLM_LVB,
1554                                                 lustre_swab_ost_lvb);
1555                         if (unlikely(lvb == NULL)) {
1556                                 LDLM_ERROR(lock, "no LVB");
1557                                 RETURN(-EPROTO);
1558                         }
1559
1560                         memcpy(data, lvb, size);
1561                 } else if (size == sizeof(struct ost_lvb_v1)) {
1562                         struct ost_lvb *olvb = data;
1563
1564                         if (loc == RCL_CLIENT)
1565                                 lvb = req_capsule_client_swab_get(pill,
1566                                                 &RMF_DLM_LVB,
1567                                                 lustre_swab_ost_lvb_v1);
1568                         else
1569                                 lvb = req_capsule_server_sized_swab_get(pill,
1570                                                 &RMF_DLM_LVB, size,
1571                                                 lustre_swab_ost_lvb_v1);
1572                         if (unlikely(lvb == NULL)) {
1573                                 LDLM_ERROR(lock, "no LVB");
1574                                 RETURN(-EPROTO);
1575                         }
1576
1577                         memcpy(data, lvb, size);
1578                         olvb->lvb_mtime_ns = 0;
1579                         olvb->lvb_atime_ns = 0;
1580                         olvb->lvb_ctime_ns = 0;
1581                 } else {
1582                         LDLM_ERROR(lock, "Replied unexpected ost LVB size %d",
1583                                    size);
1584                         RETURN(-EINVAL);
1585                 }
1586                 break;
1587         case LVB_T_LQUOTA:
1588                 if (size == sizeof(struct lquota_lvb)) {
1589                         if (loc == RCL_CLIENT)
1590                                 lvb = req_capsule_client_swab_get(pill,
1591                                                 &RMF_DLM_LVB,
1592                                                 lustre_swab_lquota_lvb);
1593                         else
1594                                 lvb = req_capsule_server_swab_get(pill,
1595                                                 &RMF_DLM_LVB,
1596                                                 lustre_swab_lquota_lvb);
1597                         if (unlikely(lvb == NULL)) {
1598                                 LDLM_ERROR(lock, "no LVB");
1599                                 RETURN(-EPROTO);
1600                         }
1601
1602                         memcpy(data, lvb, size);
1603                 } else {
1604                         LDLM_ERROR(lock, "Replied unexpected lquota LVB size %d",
1605                                    size);
1606                         RETURN(-EINVAL);
1607                 }
1608                 break;
1609         case LVB_T_LAYOUT:
1610                 if (size == 0)
1611                         break;
1612
1613                 if (loc == RCL_CLIENT)
1614                         lvb = req_capsule_client_get(pill, &RMF_DLM_LVB);
1615                 else
1616                         lvb = req_capsule_server_get(pill, &RMF_DLM_LVB);
1617                 if (unlikely(lvb == NULL)) {
1618                         LDLM_ERROR(lock, "no LVB");
1619                         RETURN(-EPROTO);
1620                 }
1621
1622                 memcpy(data, lvb, size);
1623                 break;
1624         default:
1625                 LDLM_ERROR(lock, "Unknown LVB type: %d", lock->l_lvb_type);
1626                 libcfs_debug_dumpstack(NULL);
1627                 RETURN(-EINVAL);
1628         }
1629
1630         RETURN(0);
1631 }
1632
1633 /**
1634  * Create and fill in new LDLM lock with specified properties.
1635  * Returns a referenced lock
1636  */
1637 struct ldlm_lock *ldlm_lock_create(struct ldlm_namespace *ns,
1638                                    const struct ldlm_res_id *res_id,
1639                                    enum ldlm_type type,
1640                                    enum ldlm_mode mode,
1641                                    const struct ldlm_callback_suite *cbs,
1642                                    void *data, __u32 lvb_len,
1643                                    enum lvb_type lvb_type)
1644 {
1645         struct ldlm_lock        *lock;
1646         struct ldlm_resource    *res;
1647         int                     rc;
1648         ENTRY;
1649
1650         res = ldlm_resource_get(ns, NULL, res_id, type, 1);
1651         if (IS_ERR(res))
1652                 RETURN(ERR_CAST(res));
1653
1654         lock = ldlm_lock_new(res);
1655         if (lock == NULL)
1656                 RETURN(ERR_PTR(-ENOMEM));
1657
1658         lock->l_req_mode = mode;
1659         lock->l_ast_data = data;
1660         lock->l_pid = current_pid();
1661         if (ns_is_server(ns))
1662                 ldlm_set_ns_srv(lock);
1663         if (cbs) {
1664                 lock->l_blocking_ast = cbs->lcs_blocking;
1665                 lock->l_completion_ast = cbs->lcs_completion;
1666                 lock->l_glimpse_ast = cbs->lcs_glimpse;
1667         }
1668
1669         lock->l_tree_node = NULL;
1670         /* if this is the extent lock, allocate the interval tree node */
1671         if (type == LDLM_EXTENT)
1672                 if (ldlm_interval_alloc(lock) == NULL)
1673                         GOTO(out, rc = -ENOMEM);
1674
1675         if (lvb_len) {
1676                 lock->l_lvb_len = lvb_len;
1677                 OBD_ALLOC_LARGE(lock->l_lvb_data, lvb_len);
1678                 if (lock->l_lvb_data == NULL)
1679                         GOTO(out, rc = -ENOMEM);
1680         }
1681
1682         lock->l_lvb_type = lvb_type;
1683         if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_NEW_LOCK))
1684                 GOTO(out, rc = -ENOENT);
1685
1686         RETURN(lock);
1687
1688 out:
1689         ldlm_lock_destroy(lock);
1690         LDLM_LOCK_RELEASE(lock);
1691         RETURN(ERR_PTR(rc));
1692 }
1693
1694 #ifdef HAVE_SERVER_SUPPORT
1695 static enum ldlm_error ldlm_lock_enqueue_helper(struct ldlm_lock *lock,
1696                                              __u64 *flags)
1697 {
1698         struct ldlm_resource *res = lock->l_resource;
1699         enum ldlm_error rc = ELDLM_OK;
1700         struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
1701         ldlm_processing_policy policy;
1702         ENTRY;
1703
1704         policy = ldlm_processing_policy_table[res->lr_type];
1705 restart:
1706         policy(lock, flags, LDLM_PROCESS_ENQUEUE, &rc, &rpc_list);
1707         if (rc == ELDLM_OK && lock->l_granted_mode != lock->l_req_mode &&
1708             res->lr_type != LDLM_FLOCK) {
1709                 rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list);
1710                 if (rc == -ERESTART)
1711                         GOTO(restart, rc);
1712         }
1713
1714         if (!list_empty(&rpc_list))
1715                 ldlm_discard_bl_list(&rpc_list);
1716
1717         RETURN(rc);
1718 }
1719 #endif
1720
1721 /**
1722  * Enqueue (request) a lock.
1723  *
1724  * Does not block. As a result of enqueue the lock would be put
1725  * into granted or waiting list.
1726  *
1727  * If namespace has intent policy sent and the lock has LDLM_FL_HAS_INTENT flag
1728  * set, skip all the enqueueing and delegate lock processing to intent policy
1729  * function.
1730  */
1731 enum ldlm_error ldlm_lock_enqueue(const struct lu_env *env,
1732                                   struct ldlm_namespace *ns,
1733                                   struct ldlm_lock **lockp,
1734                                   void *cookie, __u64 *flags)
1735 {
1736         struct ldlm_lock *lock = *lockp;
1737         struct ldlm_resource *res = lock->l_resource;
1738         int local = ns_is_client(ldlm_res_to_ns(res));
1739         enum ldlm_error rc = ELDLM_OK;
1740         struct ldlm_interval *node = NULL;
1741         ENTRY;
1742
1743         /* policies are not executed on the client or during replay */
1744         if ((*flags & (LDLM_FL_HAS_INTENT|LDLM_FL_REPLAY)) == LDLM_FL_HAS_INTENT
1745             && !local && ns->ns_policy) {
1746                 rc = ns->ns_policy(env, ns, lockp, cookie, lock->l_req_mode,
1747                                    *flags, NULL);
1748                 if (rc == ELDLM_LOCK_REPLACED) {
1749                         /* The lock that was returned has already been granted,
1750                          * and placed into lockp.  If it's not the same as the
1751                          * one we passed in, then destroy the old one and our
1752                          * work here is done. */
1753                         if (lock != *lockp) {
1754                                 ldlm_lock_destroy(lock);
1755                                 LDLM_LOCK_RELEASE(lock);
1756                         }
1757                         *flags |= LDLM_FL_LOCK_CHANGED;
1758                         RETURN(0);
1759                 } else if (rc != ELDLM_OK &&
1760                            ldlm_is_granted(lock)) {
1761                         LASSERT(*flags & LDLM_FL_RESENT);
1762                         /* It may happen that ns_policy returns an error in
1763                          * resend case, object may be unlinked or just some
1764                          * error occurs. It is unclear if lock reached the
1765                          * client in the original reply, just leave the lock on
1766                          * server, not returning it again to client. Due to
1767                          * LU-6529, the server will not OOM. */
1768                         RETURN(rc);
1769                 } else if (rc != ELDLM_OK ||
1770                            (rc == ELDLM_OK && (*flags & LDLM_FL_INTENT_ONLY))) {
1771                         ldlm_lock_destroy(lock);
1772                         RETURN(rc);
1773                 }
1774         }
1775
1776         if (*flags & LDLM_FL_RESENT) {
1777                 /* Reconstruct LDLM_FL_SRV_ENQ_MASK @flags for reply.
1778                  * Set LOCK_CHANGED always.
1779                  * Check if the lock is granted for BLOCK_GRANTED.
1780                  * Take NO_TIMEOUT from the lock as it is inherited through
1781                  * LDLM_FL_INHERIT_MASK */
1782                 *flags |= LDLM_FL_LOCK_CHANGED;
1783                 if (!ldlm_is_granted(lock))
1784                         *flags |= LDLM_FL_BLOCK_GRANTED;
1785                 *flags |= lock->l_flags & LDLM_FL_NO_TIMEOUT;
1786                 RETURN(ELDLM_OK);
1787         }
1788
1789         /* For a replaying lock, it might be already in granted list. So
1790          * unlinking the lock will cause the interval node to be freed, we
1791          * have to allocate the interval node early otherwise we can't regrant
1792          * this lock in the future. - jay */
1793         if (!local && (*flags & LDLM_FL_REPLAY) && res->lr_type == LDLM_EXTENT)
1794                 OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, GFP_NOFS);
1795
1796         lock_res_and_lock(lock);
1797         if (local && ldlm_is_granted(lock)) {
1798                 /* The server returned a blocked lock, but it was granted
1799                  * before we got a chance to actually enqueue it.  We don't
1800                  * need to do anything else. */
1801                 *flags &= ~LDLM_FL_BLOCKED_MASK;
1802                 GOTO(out, rc = ELDLM_OK);
1803         }
1804
1805         ldlm_resource_unlink_lock(lock);
1806         if (res->lr_type == LDLM_EXTENT && lock->l_tree_node == NULL) {
1807                 if (node == NULL) {
1808                         ldlm_lock_destroy_nolock(lock);
1809                         GOTO(out, rc = -ENOMEM);
1810                 }
1811
1812                 INIT_LIST_HEAD(&node->li_group);
1813                 ldlm_interval_attach(node, lock);
1814                 node = NULL;
1815         }
1816
1817         /* Some flags from the enqueue want to make it into the AST, via the
1818          * lock's l_flags. */
1819         if (*flags & LDLM_FL_AST_DISCARD_DATA)
1820                 ldlm_set_ast_discard_data(lock);
1821         if (*flags & LDLM_FL_TEST_LOCK)
1822                 ldlm_set_test_lock(lock);
1823         if (*flags & LDLM_FL_COS_INCOMPAT)
1824                 ldlm_set_cos_incompat(lock);
1825         if (*flags & LDLM_FL_COS_ENABLED)
1826                 ldlm_set_cos_enabled(lock);
1827
1828         /* This distinction between local lock trees is very important; a client
1829          * namespace only has information about locks taken by that client, and
1830          * thus doesn't have enough information to decide for itself if it can
1831          * be granted (below).  In this case, we do exactly what the server
1832          * tells us to do, as dictated by the 'flags'.
1833          *
1834          * We do exactly the same thing during recovery, when the server is
1835          * more or less trusting the clients not to lie.
1836          *
1837          * FIXME (bug 268): Detect obvious lies by checking compatibility in
1838          * granted queue. */
1839         if (local) {
1840                 if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
1841                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1842                 else
1843                         ldlm_grant_lock(lock, NULL);
1844                 GOTO(out, rc = ELDLM_OK);
1845 #ifdef HAVE_SERVER_SUPPORT
1846         } else if (*flags & LDLM_FL_REPLAY) {
1847                 if (*flags & LDLM_FL_BLOCK_WAIT) {
1848                         ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1849                         GOTO(out, rc = ELDLM_OK);
1850                 } else if (*flags & LDLM_FL_BLOCK_GRANTED) {
1851                         ldlm_grant_lock(lock, NULL);
1852                         GOTO(out, rc = ELDLM_OK);
1853                 }
1854                 /* If no flags, fall through to normal enqueue path. */
1855         }
1856
1857         rc = ldlm_lock_enqueue_helper(lock, flags);
1858         GOTO(out, rc);
1859 #else
1860         } else {
1861                 CERROR("This is client-side-only module, cannot handle "
1862                        "LDLM_NAMESPACE_SERVER resource type lock.\n");
1863                 LBUG();
1864         }
1865 #endif
1866
1867 out:
1868         unlock_res_and_lock(lock);
1869         if (node)
1870                 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
1871         return rc;
1872 }
1873
1874 #ifdef HAVE_SERVER_SUPPORT
1875 /**
1876  * Iterate through all waiting locks on a given resource queue and attempt to
1877  * grant them.
1878  *
1879  * Must be called with resource lock held.
1880  */
1881 int ldlm_reprocess_queue(struct ldlm_resource *res, struct list_head *queue,
1882                          struct list_head *work_list,
1883                          enum ldlm_process_intention intention)
1884 {
1885         struct list_head *tmp, *pos;
1886         ldlm_processing_policy policy;
1887         __u64 flags;
1888         int rc = LDLM_ITER_CONTINUE;
1889         enum ldlm_error err;
1890         struct list_head bl_ast_list = LIST_HEAD_INIT(bl_ast_list);
1891         ENTRY;
1892
1893         check_res_locked(res);
1894
1895         policy = ldlm_processing_policy_table[res->lr_type];
1896         LASSERT(policy);
1897         LASSERT(intention == LDLM_PROCESS_RESCAN ||
1898                 intention == LDLM_PROCESS_RECOVERY);
1899
1900 restart:
1901         list_for_each_safe(tmp, pos, queue) {
1902                 struct ldlm_lock *pending;
1903                 struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
1904
1905                 pending = list_entry(tmp, struct ldlm_lock, l_res_link);
1906
1907                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
1908
1909                 flags = 0;
1910                 rc = policy(pending, &flags, intention, &err, &rpc_list);
1911                 if (pending->l_granted_mode == pending->l_req_mode ||
1912                     res->lr_type == LDLM_FLOCK) {
1913                         list_splice(&rpc_list, work_list);
1914                 } else {
1915                         list_splice(&rpc_list, &bl_ast_list);
1916                 }
1917                 /*
1918                  * When this is called from recovery done, we always want
1919                  * to scan the whole list no matter what 'rc' is returned.
1920                  */
1921                 if (rc != LDLM_ITER_CONTINUE &&
1922                     intention == LDLM_PROCESS_RESCAN)
1923                         break;
1924         }
1925
1926         if (!list_empty(&bl_ast_list)) {
1927                 unlock_res(res);
1928
1929                 rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &bl_ast_list,
1930                                        LDLM_WORK_BL_AST);
1931
1932                 lock_res(res);
1933                 if (rc == -ERESTART)
1934                         GOTO(restart, rc);
1935         }
1936
1937         if (!list_empty(&bl_ast_list))
1938                 ldlm_discard_bl_list(&bl_ast_list);
1939
1940         RETURN(intention == LDLM_PROCESS_RESCAN ? rc : LDLM_ITER_CONTINUE);
1941 }
1942
1943 /**
1944  * Conflicting locks are detected for a lock to be enqueued, add the lock
1945  * into waiting list and send blocking ASTs to the conflicting locks.
1946  *
1947  * \param[in] lock              The lock to be enqueued.
1948  * \param[out] flags            Lock flags for the lock to be enqueued.
1949  * \param[in] rpc_list          Conflicting locks list.
1950  *
1951  * \retval -ERESTART:   Some lock was instantly canceled while sending
1952  *                      blocking ASTs, caller needs to re-check conflicting
1953  *                      locks.
1954  * \retval -EAGAIN:     Lock was destroyed, caller should return error.
1955  * \reval 0:            Lock is successfully added in waiting list.
1956  */
1957 int ldlm_handle_conflict_lock(struct ldlm_lock *lock, __u64 *flags,
1958                               struct list_head *rpc_list)
1959 {
1960         struct ldlm_resource *res = lock->l_resource;
1961         int rc;
1962         ENTRY;
1963
1964         check_res_locked(res);
1965
1966         /* If either of the compat_queue()s returned failure, then we
1967          * have ASTs to send and must go onto the waiting list.
1968          *
1969          * bug 2322: we used to unlink and re-add here, which was a
1970          * terrible folly -- if we goto restart, we could get
1971          * re-ordered!  Causes deadlock, because ASTs aren't sent! */
1972         if (list_empty(&lock->l_res_link))
1973                 ldlm_resource_add_lock(res, &res->lr_waiting, lock);
1974         unlock_res(res);
1975
1976         rc = ldlm_run_ast_work(ldlm_res_to_ns(res), rpc_list,
1977                                LDLM_WORK_BL_AST);
1978
1979         if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_OST_FAIL_RACE) &&
1980             !ns_is_client(ldlm_res_to_ns(res)))
1981                 class_fail_export(lock->l_export);
1982
1983         lock_res(res);
1984         if (rc == -ERESTART) {
1985                 /* 15715: The lock was granted and destroyed after
1986                  * resource lock was dropped. Interval node was freed
1987                  * in ldlm_lock_destroy. Anyway, this always happens
1988                  * when a client is being evicted. So it would be
1989                  * ok to return an error. -jay */
1990                 if (ldlm_is_destroyed(lock))
1991                         RETURN(-EAGAIN);
1992
1993                 /* lock was granted while resource was unlocked. */
1994                 if (ldlm_is_granted(lock)) {
1995                         /* bug 11300: if the lock has been granted,
1996                          * break earlier because otherwise, we will go
1997                          * to restart and ldlm_resource_unlink will be
1998                          * called and it causes the interval node to be
1999                          * freed. Then we will fail at
2000                          * ldlm_extent_add_lock() */
2001                         *flags &= ~LDLM_FL_BLOCKED_MASK;
2002                         RETURN(0);
2003                 }
2004
2005                 RETURN(rc);
2006         }
2007         *flags |= LDLM_FL_BLOCK_GRANTED;
2008
2009         RETURN(0);
2010 }
2011
2012 /**
2013  * Discard all AST work items from list.
2014  *
2015  * If for whatever reason we do not want to send ASTs to conflicting locks
2016  * anymore, disassemble the list with this function.
2017  */
2018 void ldlm_discard_bl_list(struct list_head *bl_list)
2019 {
2020         struct ldlm_lock *lock, *tmp;
2021
2022         ENTRY;
2023
2024         list_for_each_entry_safe(lock, tmp, bl_list, l_bl_ast) {
2025                 LASSERT(!list_empty(&lock->l_bl_ast));
2026                 list_del_init(&lock->l_bl_ast);
2027                 ldlm_clear_ast_sent(lock);
2028                 LASSERT(lock->l_bl_ast_run == 0);
2029                 ldlm_clear_blocking_lock(lock);
2030                 LDLM_LOCK_RELEASE(lock);
2031         }
2032         EXIT;
2033 }
2034
2035 /**
2036  * Process a call to blocking AST callback for a lock in ast_work list
2037  */
2038 static int
2039 ldlm_work_bl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2040 {
2041         struct ldlm_cb_set_arg *arg = opaq;
2042         struct ldlm_lock *lock;
2043         struct ldlm_lock_desc d;
2044         struct ldlm_bl_desc bld;
2045         int rc;
2046
2047         ENTRY;
2048
2049         if (list_empty(arg->list))
2050                 RETURN(-ENOENT);
2051
2052         lock = list_entry(arg->list->next, struct ldlm_lock, l_bl_ast);
2053
2054         /* nobody should touch l_bl_ast but some locks in the list may become
2055          * granted after lock convert or COS downgrade, these locks should be
2056          * just skipped here and removed from the list.
2057          */
2058         lock_res_and_lock(lock);
2059         list_del_init(&lock->l_bl_ast);
2060
2061         /* lock is not blocking lock anymore, but was kept in the list because
2062          * it can managed only here.
2063          */
2064         if (!ldlm_is_ast_sent(lock)) {
2065                 unlock_res_and_lock(lock);
2066                 LDLM_LOCK_RELEASE(lock);
2067                 RETURN(0);
2068         }
2069
2070         LASSERT(lock->l_blocking_lock);
2071         ldlm_lock2desc(lock->l_blocking_lock, &d);
2072         /* copy blocking lock ibits in cancel_bits as well,
2073          * new client may use them for lock convert and it is
2074          * important to use new field to convert locks from
2075          * new servers only
2076          */
2077         d.l_policy_data.l_inodebits.cancel_bits =
2078                 lock->l_blocking_lock->l_policy_data.l_inodebits.bits;
2079
2080         /* Blocking lock is being destroyed here but some information about it
2081          * may be needed inside l_blocking_ast() function below,
2082          * e.g. in mdt_blocking_ast(). So save needed data in bl_desc.
2083          */
2084         bld.bl_same_client = lock->l_client_cookie ==
2085                              lock->l_blocking_lock->l_client_cookie;
2086         bld.bl_cos_incompat = ldlm_is_cos_incompat(lock->l_blocking_lock);
2087         arg->bl_desc = &bld;
2088
2089         LASSERT(ldlm_is_ast_sent(lock));
2090         LASSERT(lock->l_bl_ast_run == 0);
2091         lock->l_bl_ast_run++;
2092         ldlm_clear_blocking_lock(lock);
2093         unlock_res_and_lock(lock);
2094
2095         rc = lock->l_blocking_ast(lock, &d, (void *)arg, LDLM_CB_BLOCKING);
2096
2097         LDLM_LOCK_RELEASE(lock);
2098
2099         RETURN(rc);
2100 }
2101
2102 /**
2103  * Process a call to revocation AST callback for a lock in ast_work list
2104  */
2105 static int
2106 ldlm_work_revoke_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2107 {
2108         struct ldlm_cb_set_arg *arg = opaq;
2109         struct ldlm_lock_desc   desc;
2110         int                     rc;
2111         struct ldlm_lock       *lock;
2112         ENTRY;
2113
2114         if (list_empty(arg->list))
2115                 RETURN(-ENOENT);
2116
2117         lock = list_entry(arg->list->next, struct ldlm_lock, l_rk_ast);
2118         list_del_init(&lock->l_rk_ast);
2119
2120         /* the desc just pretend to exclusive */
2121         ldlm_lock2desc(lock, &desc);
2122         desc.l_req_mode = LCK_EX;
2123         desc.l_granted_mode = 0;
2124
2125         rc = lock->l_blocking_ast(lock, &desc, (void*)arg, LDLM_CB_BLOCKING);
2126         LDLM_LOCK_RELEASE(lock);
2127
2128         RETURN(rc);
2129 }
2130
2131 /**
2132  * Process a call to glimpse AST callback for a lock in ast_work list
2133  */
2134 int ldlm_work_gl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2135 {
2136         struct ldlm_cb_set_arg          *arg = opaq;
2137         struct ldlm_glimpse_work        *gl_work;
2138         struct ldlm_lock                *lock;
2139         int                              rc = 0;
2140         ENTRY;
2141
2142         if (list_empty(arg->list))
2143                 RETURN(-ENOENT);
2144
2145         gl_work = list_entry(arg->list->next, struct ldlm_glimpse_work,
2146                                  gl_list);
2147         list_del_init(&gl_work->gl_list);
2148
2149         lock = gl_work->gl_lock;
2150
2151         /* transfer the glimpse descriptor to ldlm_cb_set_arg */
2152         arg->gl_desc = gl_work->gl_desc;
2153         arg->gl_interpret_reply = gl_work->gl_interpret_reply;
2154         arg->gl_interpret_data = gl_work->gl_interpret_data;
2155
2156         /* invoke the actual glimpse callback */
2157         if (lock->l_glimpse_ast(lock, (void*)arg) == 0)
2158                 rc = 1;
2159
2160         LDLM_LOCK_RELEASE(lock);
2161         if (gl_work->gl_flags & LDLM_GL_WORK_SLAB_ALLOCATED)
2162                 OBD_SLAB_FREE_PTR(gl_work, ldlm_glimpse_work_kmem);
2163         else
2164                 OBD_FREE_PTR(gl_work);
2165
2166         RETURN(rc);
2167 }
2168 #endif
2169
2170 /**
2171  * Process a call to completion AST callback for a lock in ast_work list
2172  */
2173 static int
2174 ldlm_work_cp_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
2175 {
2176         struct ldlm_cb_set_arg *arg = opaq;
2177         struct ldlm_lock *lock;
2178         ldlm_completion_callback completion_callback;
2179         int rc = 0;
2180
2181         ENTRY;
2182
2183         if (list_empty(arg->list))
2184                 RETURN(-ENOENT);
2185
2186         lock = list_entry(arg->list->next, struct ldlm_lock, l_cp_ast);
2187
2188         /* It's possible to receive a completion AST before we've set
2189          * the l_completion_ast pointer: either because the AST arrived
2190          * before the reply, or simply because there's a small race
2191          * window between receiving the reply and finishing the local
2192          * enqueue. (bug 842)
2193          *
2194          * This can't happen with the blocking_ast, however, because we
2195          * will never call the local blocking_ast until we drop our
2196          * reader/writer reference, which we won't do until we get the
2197          * reply and finish enqueueing. */
2198
2199         /* nobody should touch l_cp_ast */
2200         lock_res_and_lock(lock);
2201         list_del_init(&lock->l_cp_ast);
2202         LASSERT(ldlm_is_cp_reqd(lock));
2203         /* save l_completion_ast since it can be changed by
2204          * mds_intent_policy(), see bug 14225 */
2205         completion_callback = lock->l_completion_ast;
2206         ldlm_clear_cp_reqd(lock);
2207         unlock_res_and_lock(lock);
2208
2209         if (completion_callback != NULL)
2210                 rc = completion_callback(lock, 0, (void *)arg);
2211         LDLM_LOCK_RELEASE(lock);
2212
2213         RETURN(rc);
2214 }
2215
2216 /**
2217  * Process list of locks in need of ASTs being sent.
2218  *
2219  * Used on server to send multiple ASTs together instead of sending one by
2220  * one.
2221  */
2222 int ldlm_run_ast_work(struct ldlm_namespace *ns, struct list_head *rpc_list,
2223                       ldlm_desc_ast_t ast_type)
2224 {
2225         struct ldlm_cb_set_arg *arg;
2226         set_producer_func work_ast_lock;
2227         int rc;
2228
2229         if (list_empty(rpc_list))
2230                 RETURN(0);
2231
2232         OBD_ALLOC_PTR(arg);
2233         if (arg == NULL)
2234                 RETURN(-ENOMEM);
2235
2236         atomic_set(&arg->restart, 0);
2237         arg->list = rpc_list;
2238
2239         switch (ast_type) {
2240         case LDLM_WORK_CP_AST:
2241                 arg->type = LDLM_CP_CALLBACK;
2242                 work_ast_lock = ldlm_work_cp_ast_lock;
2243                 break;
2244 #ifdef HAVE_SERVER_SUPPORT
2245         case LDLM_WORK_BL_AST:
2246                 arg->type = LDLM_BL_CALLBACK;
2247                 work_ast_lock = ldlm_work_bl_ast_lock;
2248                 break;
2249         case LDLM_WORK_REVOKE_AST:
2250                 arg->type = LDLM_BL_CALLBACK;
2251                 work_ast_lock = ldlm_work_revoke_ast_lock;
2252                 break;
2253         case LDLM_WORK_GL_AST:
2254                 arg->type = LDLM_GL_CALLBACK;
2255                 work_ast_lock = ldlm_work_gl_ast_lock;
2256                 break;
2257 #endif
2258         default:
2259                 LBUG();
2260         }
2261
2262         /* We create a ptlrpc request set with flow control extension.
2263          * This request set will use the work_ast_lock function to produce new
2264          * requests and will send a new request each time one completes in order
2265          * to keep the number of requests in flight to ns_max_parallel_ast */
2266         arg->set = ptlrpc_prep_fcset(ns->ns_max_parallel_ast ? : UINT_MAX,
2267                                      work_ast_lock, arg);
2268         if (arg->set == NULL)
2269                 GOTO(out, rc = -ENOMEM);
2270
2271         ptlrpc_set_wait(NULL, arg->set);
2272         ptlrpc_set_destroy(arg->set);
2273
2274         rc = atomic_read(&arg->restart) ? -ERESTART : 0;
2275         GOTO(out, rc);
2276 out:
2277         OBD_FREE_PTR(arg);
2278         return rc;
2279 }
2280
2281 /**
2282  * Try to grant all waiting locks on a resource.
2283  *
2284  * Calls ldlm_reprocess_queue on waiting queue.
2285  *
2286  * Typically called after some resource locks are cancelled to see
2287  * if anything could be granted as a result of the cancellation.
2288  */
2289 static void __ldlm_reprocess_all(struct ldlm_resource *res,
2290                                  enum ldlm_process_intention intention)
2291 {
2292         struct list_head rpc_list;
2293 #ifdef HAVE_SERVER_SUPPORT
2294         struct obd_device *obd;
2295         int rc;
2296         ENTRY;
2297
2298         INIT_LIST_HEAD(&rpc_list);
2299         /* Local lock trees don't get reprocessed. */
2300         if (ns_is_client(ldlm_res_to_ns(res))) {
2301                 EXIT;
2302                 return;
2303         }
2304
2305         /* Disable reprocess during lock replay stage but allow during
2306          * request replay stage.
2307          */
2308         obd = ldlm_res_to_ns(res)->ns_obd;
2309         if (obd->obd_recovering &&
2310             atomic_read(&obd->obd_req_replay_clients) == 0)
2311                 RETURN_EXIT;
2312 restart:
2313         lock_res(res);
2314         ldlm_reprocess_queue(res, &res->lr_waiting, &rpc_list, intention);
2315         unlock_res(res);
2316
2317         rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
2318                                LDLM_WORK_CP_AST);
2319         if (rc == -ERESTART) {
2320                 LASSERT(list_empty(&rpc_list));
2321                 goto restart;
2322         }
2323 #else
2324         ENTRY;
2325
2326         INIT_LIST_HEAD(&rpc_list);
2327         if (!ns_is_client(ldlm_res_to_ns(res))) {
2328                 CERROR("This is client-side-only module, cannot handle "
2329                        "LDLM_NAMESPACE_SERVER resource type lock.\n");
2330                 LBUG();
2331         }
2332 #endif
2333         EXIT;
2334 }
2335
2336 void ldlm_reprocess_all(struct ldlm_resource *res)
2337 {
2338         __ldlm_reprocess_all(res, LDLM_PROCESS_RESCAN);
2339 }
2340 EXPORT_SYMBOL(ldlm_reprocess_all);
2341
2342 static int ldlm_reprocess_res(struct cfs_hash *hs, struct cfs_hash_bd *bd,
2343                               struct hlist_node *hnode, void *arg)
2344 {
2345         struct ldlm_resource *res = cfs_hash_object(hs, hnode);
2346
2347         /* This is only called once after recovery done. LU-8306. */
2348         __ldlm_reprocess_all(res, LDLM_PROCESS_RECOVERY);
2349         return 0;
2350 }
2351
2352 /**
2353  * Iterate through all resources on a namespace attempting to grant waiting
2354  * locks.
2355  */
2356 void ldlm_reprocess_recovery_done(struct ldlm_namespace *ns)
2357 {
2358         ENTRY;
2359
2360         if (ns != NULL) {
2361                 cfs_hash_for_each_nolock(ns->ns_rs_hash,
2362                                          ldlm_reprocess_res, NULL, 0);
2363         }
2364         EXIT;
2365 }
2366
2367 /**
2368  * Helper function to call blocking AST for LDLM lock \a lock in a
2369  * "cancelling" mode.
2370  */
2371 void ldlm_cancel_callback(struct ldlm_lock *lock)
2372 {
2373         check_res_locked(lock->l_resource);
2374         if (!ldlm_is_cancel(lock)) {
2375                 ldlm_set_cancel(lock);
2376                 if (lock->l_blocking_ast) {
2377                         unlock_res_and_lock(lock);
2378                         lock->l_blocking_ast(lock, NULL, lock->l_ast_data,
2379                                              LDLM_CB_CANCELING);
2380                         lock_res_and_lock(lock);
2381                 } else {
2382                         LDLM_DEBUG(lock, "no blocking ast");
2383                 }
2384
2385                 /* only canceller can set bl_done bit */
2386                 ldlm_set_bl_done(lock);
2387                 wake_up_all(&lock->l_waitq);
2388         } else if (!ldlm_is_bl_done(lock)) {
2389                 struct l_wait_info lwi = { 0 };
2390
2391                 /* The lock is guaranteed to have been canceled once
2392                  * returning from this function. */
2393                 unlock_res_and_lock(lock);
2394                 l_wait_event(lock->l_waitq, is_bl_done(lock), &lwi);
2395                 lock_res_and_lock(lock);
2396         }
2397 }
2398
2399 /**
2400  * Remove skiplist-enabled LDLM lock \a req from granted list
2401  */
2402 void ldlm_unlink_lock_skiplist(struct ldlm_lock *req)
2403 {
2404         if (req->l_resource->lr_type != LDLM_PLAIN &&
2405             req->l_resource->lr_type != LDLM_IBITS)
2406                 return;
2407
2408         list_del_init(&req->l_sl_policy);
2409         list_del_init(&req->l_sl_mode);
2410 }
2411
2412 /**
2413  * Attempts to cancel LDLM lock \a lock that has no reader/writer references.
2414  */
2415 void ldlm_lock_cancel(struct ldlm_lock *lock)
2416 {
2417         struct ldlm_resource *res;
2418         struct ldlm_namespace *ns;
2419         ENTRY;
2420
2421         lock_res_and_lock(lock);
2422
2423         res = lock->l_resource;
2424         ns  = ldlm_res_to_ns(res);
2425
2426         /* Please do not, no matter how tempting, remove this LBUG without
2427          * talking to me first. -phik */
2428         if (lock->l_readers || lock->l_writers) {
2429                 LDLM_ERROR(lock, "lock still has references");
2430                 unlock_res_and_lock(lock);
2431                 LBUG();
2432         }
2433
2434         if (ldlm_is_waited(lock))
2435                 ldlm_del_waiting_lock(lock);
2436
2437         /* Releases cancel callback. */
2438         ldlm_cancel_callback(lock);
2439
2440         /* Yes, second time, just in case it was added again while we were
2441          * running with no res lock in ldlm_cancel_callback */
2442         if (ldlm_is_waited(lock))
2443                 ldlm_del_waiting_lock(lock);
2444
2445         ldlm_resource_unlink_lock(lock);
2446         ldlm_lock_destroy_nolock(lock);
2447
2448         if (ldlm_is_granted(lock))
2449                 ldlm_pool_del(&ns->ns_pool, lock);
2450
2451         /* Make sure we will not be called again for same lock what is possible
2452          * if not to zero out lock->l_granted_mode */
2453         lock->l_granted_mode = LCK_MINMODE;
2454         unlock_res_and_lock(lock);
2455
2456         EXIT;
2457 }
2458 EXPORT_SYMBOL(ldlm_lock_cancel);
2459
2460 /**
2461  * Set opaque data into the lock that only makes sense to upper layer.
2462  */
2463 int ldlm_lock_set_data(const struct lustre_handle *lockh, void *data)
2464 {
2465         struct ldlm_lock *lock = ldlm_handle2lock(lockh);
2466         int rc = -EINVAL;
2467         ENTRY;
2468
2469         if (lock) {
2470                 if (lock->l_ast_data == NULL)
2471                         lock->l_ast_data = data;
2472                 if (lock->l_ast_data == data)
2473                         rc = 0;
2474                 LDLM_LOCK_PUT(lock);
2475         }
2476         RETURN(rc);
2477 }
2478 EXPORT_SYMBOL(ldlm_lock_set_data);
2479
2480 struct export_cl_data {
2481         const struct lu_env     *ecl_env;
2482         struct obd_export       *ecl_exp;
2483         int                     ecl_loop;
2484 };
2485
2486 static void ldlm_cancel_lock_for_export(struct obd_export *exp,
2487                                         struct ldlm_lock *lock,
2488                                         struct export_cl_data *ecl)
2489 {
2490         struct ldlm_resource *res;
2491
2492         res = ldlm_resource_getref(lock->l_resource);
2493
2494         ldlm_lvbo_update(res, lock, NULL, 1);
2495         ldlm_lock_cancel(lock);
2496         if (!exp->exp_obd->obd_stopping)
2497                 ldlm_reprocess_all(res);
2498         ldlm_resource_putref(res);
2499
2500         ecl->ecl_loop++;
2501         if ((ecl->ecl_loop & -ecl->ecl_loop) == ecl->ecl_loop) {
2502                 CDEBUG(D_INFO, "Export %p, %d locks cancelled.\n",
2503                        exp, ecl->ecl_loop);
2504         }
2505 }
2506
2507 /**
2508  * Iterator function for ldlm_export_cancel_locks.
2509  * Cancels passed locks.
2510  */
2511 static int
2512 ldlm_cancel_locks_for_export_cb(struct cfs_hash *hs, struct cfs_hash_bd *bd,
2513                                 struct hlist_node *hnode, void *data)
2514
2515 {
2516         struct export_cl_data   *ecl = (struct export_cl_data *)data;
2517         struct obd_export       *exp  = ecl->ecl_exp;
2518         struct ldlm_lock        *lock = cfs_hash_object(hs, hnode);
2519
2520         LDLM_LOCK_GET(lock);
2521         ldlm_cancel_lock_for_export(exp, lock, ecl);
2522         LDLM_LOCK_RELEASE(lock);
2523
2524         return 0;
2525 }
2526
2527 /**
2528  * Cancel all blocked locks for given export.
2529  *
2530  * Typically called on client disconnection/eviction
2531  */
2532 int ldlm_export_cancel_blocked_locks(struct obd_export *exp)
2533 {
2534         struct lu_env env;
2535         struct export_cl_data   ecl = {
2536                 .ecl_exp        = exp,
2537                 .ecl_loop       = 0,
2538         };
2539         int rc;
2540
2541         rc = lu_env_init(&env, LCT_DT_THREAD);
2542         if (rc)
2543                 RETURN(rc);
2544         ecl.ecl_env = &env;
2545
2546         while (!list_empty(&exp->exp_bl_list)) {
2547                 struct ldlm_lock *lock;
2548
2549                 spin_lock_bh(&exp->exp_bl_list_lock);
2550                 if (!list_empty(&exp->exp_bl_list)) {
2551                         lock = list_entry(exp->exp_bl_list.next,
2552                                           struct ldlm_lock, l_exp_list);
2553                         LDLM_LOCK_GET(lock);
2554                         list_del_init(&lock->l_exp_list);
2555                 } else {
2556                         lock = NULL;
2557                 }
2558                 spin_unlock_bh(&exp->exp_bl_list_lock);
2559
2560                 if (lock == NULL)
2561                         break;
2562
2563                 ldlm_cancel_lock_for_export(exp, lock, &ecl);
2564                 LDLM_LOCK_RELEASE(lock);
2565         }
2566
2567         lu_env_fini(&env);
2568
2569         CDEBUG(D_DLMTRACE, "Export %p, canceled %d locks, "
2570                "left on hash table %d.\n", exp, ecl.ecl_loop,
2571                atomic_read(&exp->exp_lock_hash->hs_count));
2572
2573         return ecl.ecl_loop;
2574 }
2575
2576 /**
2577  * Cancel all locks for given export.
2578  *
2579  * Typically called after client disconnection/eviction
2580  */
2581 int ldlm_export_cancel_locks(struct obd_export *exp)
2582 {
2583         struct export_cl_data ecl;
2584         struct lu_env env;
2585         int rc;
2586
2587         rc = lu_env_init(&env, LCT_DT_THREAD);
2588         if (rc)
2589                 RETURN(rc);
2590         ecl.ecl_env = &env;
2591         ecl.ecl_exp = exp;
2592         ecl.ecl_loop = 0;
2593
2594         cfs_hash_for_each_empty(exp->exp_lock_hash,
2595                                 ldlm_cancel_locks_for_export_cb, &ecl);
2596
2597         CDEBUG(D_DLMTRACE, "Export %p, canceled %d locks, "
2598                "left on hash table %d.\n", exp, ecl.ecl_loop,
2599                atomic_read(&exp->exp_lock_hash->hs_count));
2600
2601         if (ecl.ecl_loop > 0 &&
2602             atomic_read(&exp->exp_lock_hash->hs_count) == 0 &&
2603             exp->exp_obd->obd_stopping)
2604                 ldlm_reprocess_recovery_done(exp->exp_obd->obd_namespace);
2605
2606         lu_env_fini(&env);
2607
2608         return ecl.ecl_loop;
2609 }
2610
2611 /**
2612  * Downgrade an PW/EX lock to COS mode.
2613  *
2614  * A lock mode convertion from PW/EX mode to less conflict mode. The
2615  * convertion may fail if lock was canceled before downgrade, but it doesn't
2616  * indicate any problem, because such lock has no reader or writer, and will
2617  * be released soon.
2618  *
2619  * Used by Commit on Sharing (COS) code to force object changes commit in case
2620  * of conflict. Converted lock is considered as new lock and all blocking AST
2621  * things are cleared, so any pending or new blocked lock on that lock will
2622  * cause new call to blocking_ast and force resource object commit.
2623  *
2624  * \param lock A lock to convert
2625  * \param new_mode new lock mode
2626  */
2627 void ldlm_lock_mode_downgrade(struct ldlm_lock *lock, enum ldlm_mode new_mode)
2628 {
2629 #ifdef HAVE_SERVER_SUPPORT
2630         ENTRY;
2631
2632         LASSERT(new_mode == LCK_COS);
2633
2634         lock_res_and_lock(lock);
2635
2636         if (!(lock->l_granted_mode & (LCK_PW | LCK_EX))) {
2637                 unlock_res_and_lock(lock);
2638
2639                 LASSERT(lock->l_granted_mode == LCK_MINMODE);
2640                 LDLM_DEBUG(lock, "lock was canceled before downgrade");
2641                 RETURN_EXIT;
2642         }
2643
2644         ldlm_resource_unlink_lock(lock);
2645         /*
2646          * Remove the lock from pool as it will be added again in
2647          * ldlm_grant_lock() called below.
2648          */
2649         ldlm_pool_del(&ldlm_lock_to_ns(lock)->ns_pool, lock);
2650
2651         /* Consider downgraded lock as a new lock and clear all states
2652          * related to a previous blocking AST processing.
2653          */
2654         ldlm_clear_blocking_data(lock);
2655
2656         lock->l_req_mode = new_mode;
2657         ldlm_grant_lock(lock, NULL);
2658         unlock_res_and_lock(lock);
2659
2660         ldlm_reprocess_all(lock->l_resource);
2661
2662         EXIT;
2663 #endif
2664 }
2665 EXPORT_SYMBOL(ldlm_lock_mode_downgrade);
2666
2667 /**
2668  * Print lock with lock handle \a lockh description into debug log.
2669  *
2670  * Used when printing all locks on a resource for debug purposes.
2671  */
2672 void ldlm_lock_dump_handle(int level, const struct lustre_handle *lockh)
2673 {
2674         struct ldlm_lock *lock;
2675
2676         if (!((libcfs_debug | D_ERROR) & level))
2677                 return;
2678
2679         lock = ldlm_handle2lock(lockh);
2680         if (lock == NULL)
2681                 return;
2682
2683         LDLM_DEBUG_LIMIT(level, lock, "###");
2684
2685         LDLM_LOCK_PUT(lock);
2686 }
2687 EXPORT_SYMBOL(ldlm_lock_dump_handle);
2688
2689 /**
2690  * Print lock information with custom message into debug log.
2691  * Helper function.
2692  */
2693 void _ldlm_lock_debug(struct ldlm_lock *lock,
2694                       struct libcfs_debug_msg_data *msgdata,
2695                       const char *fmt, ...)
2696 {
2697         va_list args;
2698         struct obd_export *exp = lock->l_export;
2699         struct ldlm_resource *resource = NULL;
2700         struct va_format vaf;
2701         char *nid = "local";
2702
2703         /* on server-side resource of lock doesn't change */
2704         if ((lock->l_flags & LDLM_FL_NS_SRV) != 0) {
2705                 if (lock->l_resource != NULL)
2706                         resource = ldlm_resource_getref(lock->l_resource);
2707         } else if (spin_trylock(&lock->l_lock)) {
2708                 if (lock->l_resource != NULL)
2709                         resource = ldlm_resource_getref(lock->l_resource);
2710                 spin_unlock(&lock->l_lock);
2711         }
2712
2713         va_start(args, fmt);
2714         vaf.fmt = fmt;
2715         vaf.va = &args;
2716
2717         if (exp && exp->exp_connection) {
2718                 nid = obd_export_nid2str(exp);
2719         } else if (exp && exp->exp_obd != NULL) {
2720                 struct obd_import *imp = exp->exp_obd->u.cli.cl_import;
2721                 nid = obd_import_nid2str(imp);
2722         }
2723
2724         if (resource == NULL) {
2725                 libcfs_debug_msg(msgdata,
2726                                  "%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",
2727                                  &vaf,
2728                                  lock,
2729                                  lock->l_handle.h_cookie,
2730                                  atomic_read(&lock->l_refc),
2731                                  lock->l_readers, lock->l_writers,
2732                                  ldlm_lockname[lock->l_granted_mode],
2733                                  ldlm_lockname[lock->l_req_mode],
2734                                  lock->l_flags, nid,
2735                                  lock->l_remote_handle.cookie,
2736                                  exp ? atomic_read(&exp->exp_refcount) : -99,
2737                                  lock->l_pid, lock->l_callback_timeout,
2738                                  lock->l_lvb_type);
2739                 va_end(args);
2740                 return;
2741         }
2742
2743         switch (resource->lr_type) {
2744         case LDLM_EXTENT:
2745                 libcfs_debug_msg(msgdata,
2746                                  "%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " rrc: %d type: %s [%llu->%llu] (req %llu->%llu) flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
2747                                  &vaf,
2748                                  ldlm_lock_to_ns_name(lock), lock,
2749                                  lock->l_handle.h_cookie,
2750                                  atomic_read(&lock->l_refc),
2751                                  lock->l_readers, lock->l_writers,
2752                                  ldlm_lockname[lock->l_granted_mode],
2753                                  ldlm_lockname[lock->l_req_mode],
2754                                  PLDLMRES(resource),
2755                                  atomic_read(&resource->lr_refcount),
2756                                  ldlm_typename[resource->lr_type],
2757                                  lock->l_policy_data.l_extent.start,
2758                                  lock->l_policy_data.l_extent.end,
2759                                  lock->l_req_extent.start, lock->l_req_extent.end,
2760                                  lock->l_flags, nid,
2761                                  lock->l_remote_handle.cookie,
2762                                  exp ? atomic_read(&exp->exp_refcount) : -99,
2763                                  lock->l_pid, lock->l_callback_timeout,
2764                                  lock->l_lvb_type);
2765                 break;
2766
2767         case LDLM_FLOCK:
2768                 libcfs_debug_msg(msgdata,
2769                                  "%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",
2770                                  &vaf,
2771                                  ldlm_lock_to_ns_name(lock), lock,
2772                                  lock->l_handle.h_cookie,
2773                                  atomic_read(&lock->l_refc),
2774                                  lock->l_readers, lock->l_writers,
2775                                  ldlm_lockname[lock->l_granted_mode],
2776                                  ldlm_lockname[lock->l_req_mode],
2777                                  PLDLMRES(resource),
2778                                  atomic_read(&resource->lr_refcount),
2779                                  ldlm_typename[resource->lr_type],
2780                                  lock->l_policy_data.l_flock.pid,
2781                                  lock->l_policy_data.l_flock.start,
2782                                  lock->l_policy_data.l_flock.end,
2783                                  lock->l_flags, nid,
2784                                  lock->l_remote_handle.cookie,
2785                                  exp ? atomic_read(&exp->exp_refcount) : -99,
2786                                  lock->l_pid, lock->l_callback_timeout);
2787                 break;
2788
2789         case LDLM_IBITS:
2790                 libcfs_debug_msg(msgdata,
2791                                  "%pV ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s res: " DLDLMRES " bits %#llx/%#llx rrc: %d type: %s flags: %#llx nid: %s remote: %#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
2792                                  &vaf,
2793                                  ldlm_lock_to_ns_name(lock),
2794                                  lock, lock->l_handle.h_cookie,
2795                                  atomic_read(&lock->l_refc),
2796                                  lock->l_readers, lock->l_writers,
2797                                  ldlm_lockname[lock->l_granted_mode],
2798                                  ldlm_lockname[lock->l_req_mode],
2799                                  PLDLMRES(resource),
2800                                  lock->l_policy_data.l_inodebits.bits,
2801                                  lock->l_policy_data.l_inodebits.try_bits,
2802                                  atomic_read(&resource->lr_refcount),
2803                                  ldlm_typename[resource->lr_type],
2804                                  lock->l_flags, nid,
2805                                  lock->l_remote_handle.cookie,
2806                                  exp ? atomic_read(&exp->exp_refcount) : -99,
2807                                  lock->l_pid, lock->l_callback_timeout,
2808                                  lock->l_lvb_type);
2809                 break;
2810
2811         default:
2812                 libcfs_debug_msg(msgdata,
2813                                  "%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",
2814                                  &vaf,
2815                                  ldlm_lock_to_ns_name(lock),
2816                                  lock, lock->l_handle.h_cookie,
2817                                  atomic_read(&lock->l_refc),
2818                                  lock->l_readers, lock->l_writers,
2819                                  ldlm_lockname[lock->l_granted_mode],
2820                                  ldlm_lockname[lock->l_req_mode],
2821                                  PLDLMRES(resource),
2822                                  atomic_read(&resource->lr_refcount),
2823                                  ldlm_typename[resource->lr_type],
2824                                  lock->l_flags, nid,
2825                                  lock->l_remote_handle.cookie,
2826                                  exp ? atomic_read(&exp->exp_refcount) : -99,
2827                                  lock->l_pid, lock->l_callback_timeout,
2828                                  lock->l_lvb_type);
2829                 break;
2830         }
2831         va_end(args);
2832         ldlm_resource_putref(resource);
2833 }
2834 EXPORT_SYMBOL(_ldlm_lock_debug);