4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
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).
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
23 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2010, 2013, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * lustre/ldlm/ldlm_extent.c
34 * Author: Peter Braam <braam@clusterfs.com>
35 * Author: Phil Schwan <phil@clusterfs.com>
39 * This file contains implementation of EXTENT lock type
41 * EXTENT lock type is for locking a contiguous range of values, represented
42 * by 64-bit starting and ending offsets (inclusive). There are several extent
43 * lock modes, some of which may be mutually incompatible. Extent locks are
44 * considered incompatible if their modes are incompatible and their extents
45 * intersect. See the lock mode compatibility matrix in lustre_dlm.h.
48 #define DEBUG_SUBSYSTEM S_LDLM
50 #include <libcfs/libcfs.h>
51 #include <lustre_dlm.h>
52 #include <obd_support.h>
54 #include <obd_class.h>
55 #include <lustre_lib.h>
57 #include "ldlm_internal.h"
59 #ifdef HAVE_SERVER_SUPPORT
60 # define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1)
63 * Fix up the ldlm_extent after expanding it.
65 * After expansion has been done, we might still want to do certain adjusting
66 * based on overall contention of the resource and the like to avoid granting
69 static void ldlm_extent_internal_policy_fixup(struct ldlm_lock *req,
70 struct ldlm_extent *new_ex,
73 enum ldlm_mode req_mode = req->l_req_mode;
74 __u64 req_start = req->l_req_extent.start;
75 __u64 req_end = req->l_req_extent.end;
76 __u64 req_align, mask;
78 if (conflicting > 32 && (req_mode == LCK_PW || req_mode == LCK_CW)) {
79 if (req_end < req_start + LDLM_MAX_GROWN_EXTENT)
80 new_ex->end = min(req_start + LDLM_MAX_GROWN_EXTENT,
84 if (new_ex->start == 0 && new_ex->end == OBD_OBJECT_EOF) {
89 /* we need to ensure that the lock extent is properly aligned to what
90 * the client requested. Also we need to make sure it's also server
91 * page size aligned otherwise a server page can be covered by two
94 req_align = (req_end + 1) | req_start;
95 if (req_align != 0 && (req_align & (mask - 1)) == 0) {
96 while ((req_align & mask) == 0)
100 /* We can only shrink the lock, not grow it.
101 * This should never cause lock to be smaller than requested,
102 * since requested lock was already aligned on these boundaries. */
103 new_ex->start = ((new_ex->start - 1) | mask) + 1;
104 new_ex->end = ((new_ex->end + 1) & ~mask) - 1;
105 LASSERTF(new_ex->start <= req_start,
106 "mask %#llx grant start %llu req start %llu\n",
107 mask, new_ex->start, req_start);
108 LASSERTF(new_ex->end >= req_end,
109 "mask %#llx grant end %llu req end %llu\n",
110 mask, new_ex->end, req_end);
114 * Return the maximum extent that:
115 * - contains the requested extent
116 * - does not overlap existing conflicting extents outside the requested one
118 * This allows clients to request a small required extent range, but if there
119 * is no contention on the lock the full lock can be granted to the client.
120 * This avoids the need for many smaller lock requests to be granted in the
121 * common (uncontended) case.
123 * Use interval tree to expand the lock extent for granted lock.
125 static void ldlm_extent_internal_policy_granted(struct ldlm_lock *req,
126 struct ldlm_extent *new_ex)
128 struct ldlm_resource *res = req->l_resource;
129 enum ldlm_mode req_mode = req->l_req_mode;
130 __u64 req_start = req->l_req_extent.start;
131 __u64 req_end = req->l_req_extent.end;
132 struct ldlm_interval_tree *tree;
133 struct interval_node_extent limiter = {
134 .start = new_ex->start,
141 lockmode_verify(req_mode);
143 /* Using interval tree to handle the LDLM extent granted locks. */
144 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
145 struct interval_node_extent ext = {
150 tree = &res->lr_itree[idx];
151 if (lockmode_compat(tree->lit_mode, req_mode))
154 conflicting += tree->lit_size;
156 limiter.start = req_start;
158 if (interval_is_overlapped(tree->lit_root, &ext))
160 "req_mode = %d, tree->lit_mode = %d, "
161 "tree->lit_size = %d\n",
162 req_mode, tree->lit_mode, tree->lit_size);
163 interval_expand(tree->lit_root, &ext, &limiter);
164 limiter.start = max(limiter.start, ext.start);
165 limiter.end = min(limiter.end, ext.end);
166 if (limiter.start == req_start && limiter.end == req_end)
170 new_ex->start = limiter.start;
171 new_ex->end = limiter.end;
172 LASSERT(new_ex->start <= req_start);
173 LASSERT(new_ex->end >= req_end);
175 ldlm_extent_internal_policy_fixup(req, new_ex, conflicting);
179 /* The purpose of this function is to return:
180 * - the maximum extent
181 * - containing the requested extent
182 * - and not overlapping existing conflicting extents outside the requested one
185 ldlm_extent_internal_policy_waiting(struct ldlm_lock *req,
186 struct ldlm_extent *new_ex)
188 struct ldlm_resource *res = req->l_resource;
189 enum ldlm_mode req_mode = req->l_req_mode;
190 __u64 req_start = req->l_req_extent.start;
191 __u64 req_end = req->l_req_extent.end;
192 struct ldlm_lock *lock;
196 lockmode_verify(req_mode);
198 /* for waiting locks */
199 list_for_each_entry(lock, &res->lr_waiting, l_res_link) {
200 struct ldlm_extent *l_extent = &lock->l_policy_data.l_extent;
202 /* We already hit the minimum requested size, search no more */
203 if (new_ex->start == req_start && new_ex->end == req_end) {
208 /* Don't conflict with ourselves */
212 /* Locks are compatible, overlap doesn't matter */
213 /* Until bug 20 is fixed, try to avoid granting overlapping
214 * locks on one client (they take a long time to cancel) */
215 if (lockmode_compat(lock->l_req_mode, req_mode) &&
216 lock->l_export != req->l_export)
219 /* If this is a high-traffic lock, don't grow downwards at all
220 * or grow upwards too much */
223 new_ex->start = req_start;
225 /* If lock doesn't overlap new_ex, skip it. */
226 if (!ldlm_extent_overlap(l_extent, new_ex))
229 /* Locks conflicting in requested extents and we can't satisfy
230 * both locks, so ignore it. Either we will ping-pong this
231 * extent (we would regardless of what extent we granted) or
232 * lock is unused and it shouldn't limit our extent growth. */
233 if (ldlm_extent_overlap(&lock->l_req_extent,&req->l_req_extent))
236 /* We grow extents downwards only as far as they don't overlap
237 * with already-granted locks, on the assumption that clients
238 * will be writing beyond the initial requested end and would
239 * then need to enqueue a new lock beyond previous request.
240 * l_req_extent->end strictly < req_start, checked above. */
241 if (l_extent->start < req_start && new_ex->start != req_start) {
242 if (l_extent->end >= req_start)
243 new_ex->start = req_start;
245 new_ex->start = min(l_extent->end+1, req_start);
248 /* If we need to cancel this lock anyways because our request
249 * overlaps the granted lock, we grow up to its requested
250 * extent start instead of limiting this extent, assuming that
251 * clients are writing forwards and the lock had over grown
252 * its extent downwards before we enqueued our request. */
253 if (l_extent->end > req_end) {
254 if (l_extent->start <= req_end)
255 new_ex->end = max(lock->l_req_extent.start - 1,
258 new_ex->end = max(l_extent->start - 1, req_end);
262 ldlm_extent_internal_policy_fixup(req, new_ex, conflicting);
267 /* In order to determine the largest possible extent we can grant, we need
268 * to scan all of the queues. */
269 static void ldlm_extent_policy(struct ldlm_resource *res,
270 struct ldlm_lock *lock, __u64 *flags)
272 struct ldlm_extent new_ex = { .start = 0, .end = OBD_OBJECT_EOF };
274 if (lock->l_export == NULL)
276 * this is local lock taken by server (e.g., as a part of
277 * OST-side locking, or unlink handling). Expansion doesn't
278 * make a lot of sense for local locks, because they are
279 * dropped immediately on operation completion and would only
280 * conflict with other threads.
284 if (lock->l_policy_data.l_extent.start == 0 &&
285 lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF)
286 /* fast-path whole file locks */
289 ldlm_extent_internal_policy_granted(lock, &new_ex);
290 ldlm_extent_internal_policy_waiting(lock, &new_ex);
292 if (new_ex.start != lock->l_policy_data.l_extent.start ||
293 new_ex.end != lock->l_policy_data.l_extent.end) {
294 *flags |= LDLM_FL_LOCK_CHANGED;
295 lock->l_policy_data.l_extent.start = new_ex.start;
296 lock->l_policy_data.l_extent.end = new_ex.end;
300 static int ldlm_check_contention(struct ldlm_lock *lock, int contended_locks)
302 struct ldlm_resource *res = lock->l_resource;
303 cfs_time_t now = cfs_time_current();
305 if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_SET_CONTENTION))
308 CDEBUG(D_DLMTRACE, "contended locks = %d\n", contended_locks);
309 if (contended_locks > ldlm_res_to_ns(res)->ns_contended_locks)
310 res->lr_contention_time = now;
311 return cfs_time_before(now, cfs_time_add(res->lr_contention_time,
312 cfs_time_seconds(ldlm_res_to_ns(res)->ns_contention_time)));
315 struct ldlm_extent_compat_args {
316 struct list_head *work_list;
317 struct ldlm_lock *lock;
323 static enum interval_iter ldlm_extent_compat_cb(struct interval_node *n,
326 struct ldlm_extent_compat_args *priv = data;
327 struct ldlm_interval *node = to_ldlm_interval(n);
328 struct ldlm_extent *extent;
329 struct list_head *work_list = priv->work_list;
330 struct ldlm_lock *lock, *enq = priv->lock;
331 enum ldlm_mode mode = priv->mode;
335 LASSERT(!list_empty(&node->li_group));
337 list_for_each_entry(lock, &node->li_group, l_sl_policy) {
338 /* interval tree is for granted lock */
339 LASSERTF(mode == lock->l_granted_mode,
340 "mode = %s, lock->l_granted_mode = %s\n",
342 ldlm_lockname[lock->l_granted_mode]);
344 if (lock->l_blocking_ast &&
345 lock->l_granted_mode != LCK_GROUP)
346 ldlm_add_ast_work_item(lock, enq, work_list);
349 /* don't count conflicting glimpse locks */
350 extent = ldlm_interval_extent(node);
351 if (!(mode == LCK_PR &&
352 extent->start == 0 && extent->end == OBD_OBJECT_EOF))
353 *priv->locks += count;
358 RETURN(INTERVAL_ITER_CONT);
362 * Determine if the lock is compatible with all locks on the queue.
364 * If \a work_list is provided, conflicting locks are linked there.
365 * If \a work_list is not provided, we exit this function on first conflict.
367 * \retval 0 if the lock is not compatible
368 * \retval 1 if the lock is compatible
369 * \retval 2 if \a req is a group lock and it is compatible and requires
370 * no further checking
371 * \retval negative error, such as EWOULDBLOCK for group locks
374 ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req,
375 __u64 *flags, enum ldlm_error *err,
376 struct list_head *work_list, int *contended_locks)
378 struct ldlm_resource *res = req->l_resource;
379 enum ldlm_mode req_mode = req->l_req_mode;
380 __u64 req_start = req->l_req_extent.start;
381 __u64 req_end = req->l_req_extent.end;
382 struct ldlm_lock *lock;
383 int check_contention;
388 lockmode_verify(req_mode);
390 /* Using interval tree for granted lock */
391 if (queue == &res->lr_granted) {
392 struct ldlm_interval_tree *tree;
393 struct ldlm_extent_compat_args data = {.work_list = work_list,
395 .locks = contended_locks,
397 struct interval_node_extent ex = { .start = req_start,
401 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
402 tree = &res->lr_itree[idx];
403 if (tree->lit_root == NULL) /* empty tree, skipped */
406 data.mode = tree->lit_mode;
407 if (lockmode_compat(req_mode, tree->lit_mode)) {
408 struct ldlm_interval *node;
409 struct ldlm_extent *extent;
411 if (req_mode != LCK_GROUP)
414 /* group lock, grant it immediately if
416 node = to_ldlm_interval(tree->lit_root);
417 extent = ldlm_interval_extent(node);
418 if (req->l_policy_data.l_extent.gid ==
423 if (tree->lit_mode == LCK_GROUP) {
424 if (*flags & LDLM_FL_BLOCK_NOWAIT) {
425 compat = -EWOULDBLOCK;
429 *flags |= LDLM_FL_NO_TIMEOUT;
433 /* if work list is not NULL,add all
434 locks in the tree to work list */
436 interval_iterate(tree->lit_root,
437 ldlm_extent_compat_cb, &data);
442 rc = interval_is_overlapped(tree->lit_root,&ex);
446 interval_search(tree->lit_root, &ex,
447 ldlm_extent_compat_cb, &data);
448 if (!list_empty(work_list) && compat)
452 } else { /* for waiting queue */
453 list_for_each_entry(lock, queue, l_res_link) {
454 check_contention = 1;
456 /* We stop walking the queue if we hit ourselves so
457 * we don't take conflicting locks enqueued after us
458 * into account, or we'd wait forever. */
462 if (unlikely(scan)) {
463 /* We only get here if we are queuing GROUP lock
464 and met some incompatible one. The main idea of this
465 code is to insert GROUP lock past compatible GROUP
466 lock in the waiting queue or if there is not any,
467 then in front of first non-GROUP lock */
468 if (lock->l_req_mode != LCK_GROUP) {
469 /* Ok, we hit non-GROUP lock, there should
470 * be no more GROUP locks later on, queue in
471 * front of first non-GROUP lock */
473 ldlm_resource_insert_lock_after(lock, req);
474 list_del_init(&lock->l_res_link);
475 ldlm_resource_insert_lock_after(req, lock);
479 if (req->l_policy_data.l_extent.gid ==
480 lock->l_policy_data.l_extent.gid) {
482 ldlm_resource_insert_lock_after(lock, req);
489 /* locks are compatible, overlap doesn't matter */
490 if (lockmode_compat(lock->l_req_mode, req_mode)) {
491 if (req_mode == LCK_PR &&
492 ((lock->l_policy_data.l_extent.start <=
493 req->l_policy_data.l_extent.start) &&
494 (lock->l_policy_data.l_extent.end >=
495 req->l_policy_data.l_extent.end))) {
496 /* If we met a PR lock just like us or
497 wider, and nobody down the list
498 conflicted with it, that means we
499 can skip processing of the rest of
500 the list and safely place ourselves
501 at the end of the list, or grant
502 (dependent if we met an conflicting
503 locks before in the list). In case
504 of 1st enqueue only we continue
505 traversing if there is something
506 conflicting down the list because
507 we need to make sure that something
508 is marked as AST_SENT as well, in
509 cse of empy worklist we would exit
510 on first conflict met. */
511 /* There IS a case where such flag is
512 not set for a lock, yet it blocks
513 something. Luckily for us this is
514 only during destroy, so lock is
515 exclusive. So here we are safe */
516 if (!ldlm_is_ast_sent(lock))
520 /* non-group locks are compatible, overlap doesn't
522 if (likely(req_mode != LCK_GROUP))
525 /* If we are trying to get a GROUP lock and there is
526 another one of this kind, we need to compare gid */
527 if (req->l_policy_data.l_extent.gid ==
528 lock->l_policy_data.l_extent.gid) {
529 /* If existing lock with matched gid is granted,
530 we grant new one too. */
531 if (lock->l_req_mode == lock->l_granted_mode)
534 /* Otherwise we are scanning queue of waiting
535 * locks and it means current request would
536 * block along with existing lock (that is
538 * If we are in nonblocking mode - return
540 if (*flags & LDLM_FL_BLOCK_NOWAIT) {
541 compat = -EWOULDBLOCK;
544 /* If this group lock is compatible with another
545 * group lock on the waiting list, they must be
546 * together in the list, so they can be granted
547 * at the same time. Otherwise the later lock
548 * can get stuck behind another, incompatible,
550 ldlm_resource_insert_lock_after(lock, req);
551 /* Because 'lock' is not granted, we can stop
552 * processing this queue and return immediately.
553 * There is no need to check the rest of the
559 if (unlikely(req_mode == LCK_GROUP &&
560 (lock->l_req_mode != lock->l_granted_mode))) {
563 if (lock->l_req_mode != LCK_GROUP) {
564 /* Ok, we hit non-GROUP lock, there should be no
565 more GROUP locks later on, queue in front of
566 first non-GROUP lock */
568 ldlm_resource_insert_lock_after(lock, req);
569 list_del_init(&lock->l_res_link);
570 ldlm_resource_insert_lock_after(req, lock);
573 if (req->l_policy_data.l_extent.gid ==
574 lock->l_policy_data.l_extent.gid) {
576 ldlm_resource_insert_lock_after(lock, req);
582 if (unlikely(lock->l_req_mode == LCK_GROUP)) {
583 /* If compared lock is GROUP, then requested is PR/PW/
584 * so this is not compatible; extent range does not
586 if (*flags & LDLM_FL_BLOCK_NOWAIT) {
587 compat = -EWOULDBLOCK;
590 *flags |= LDLM_FL_NO_TIMEOUT;
592 } else if (lock->l_policy_data.l_extent.end < req_start ||
593 lock->l_policy_data.l_extent.start > req_end) {
594 /* if a non group lock doesn't overlap skip it */
596 } else if (lock->l_req_extent.end < req_start ||
597 lock->l_req_extent.start > req_end) {
598 /* false contention, the requests doesn't really overlap */
599 check_contention = 0;
605 /* don't count conflicting glimpse locks */
606 if (lock->l_req_mode == LCK_PR &&
607 lock->l_policy_data.l_extent.start == 0 &&
608 lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF)
609 check_contention = 0;
611 *contended_locks += check_contention;
614 if (lock->l_blocking_ast &&
615 lock->l_req_mode != LCK_GROUP)
616 ldlm_add_ast_work_item(lock, req, work_list);
620 if (ldlm_check_contention(req, *contended_locks) &&
622 (*flags & LDLM_FL_DENY_ON_CONTENTION) &&
623 req->l_req_mode != LCK_GROUP &&
624 req_end - req_start <=
625 ldlm_res_to_ns(req->l_resource)->ns_max_nolock_size)
626 GOTO(destroylock, compat = -EUSERS);
630 list_del_init(&req->l_res_link);
631 ldlm_lock_destroy_nolock(req);
637 * This function refresh eviction timer for cancelled lock.
638 * \param[in] lock ldlm lock for refresh
639 * \param[in] arg ldlm prolong arguments, timeout, export, extent
640 * and counter are used
642 void ldlm_lock_prolong_one(struct ldlm_lock *lock,
643 struct ldlm_prolong_args *arg)
647 if (arg->lpa_export != lock->l_export ||
648 lock->l_flags & LDLM_FL_DESTROYED)
649 /* ignore unrelated locks */
652 arg->lpa_locks_cnt++;
654 if (!(lock->l_flags & LDLM_FL_AST_SENT))
655 /* ignore locks not being cancelled */
658 /* We are in the middle of the process - BL AST is sent, CANCEL
659 * is ahead. Take half of BL AT + IO AT process time.
661 timeout = arg->lpa_timeout + (ldlm_bl_timeout(lock) >> 1);
663 LDLM_DEBUG(lock, "refreshed to %ds.\n", timeout);
665 arg->lpa_blocks_cnt++;
667 /* OK. this is a possible lock the user holds doing I/O
668 * let's refresh eviction timer for it.
670 ldlm_refresh_waiting_lock(lock, timeout);
672 EXPORT_SYMBOL(ldlm_lock_prolong_one);
674 static enum interval_iter ldlm_resource_prolong_cb(struct interval_node *n,
677 struct ldlm_prolong_args *arg = data;
678 struct ldlm_interval *node = to_ldlm_interval(n);
679 struct ldlm_lock *lock;
683 LASSERT(!list_empty(&node->li_group));
685 list_for_each_entry(lock, &node->li_group, l_sl_policy) {
686 ldlm_lock_prolong_one(lock, arg);
689 RETURN(INTERVAL_ITER_CONT);
693 * Walk through granted tree and prolong locks if they overlaps extent.
695 * \param[in] arg prolong args
697 void ldlm_resource_prolong(struct ldlm_prolong_args *arg)
699 struct ldlm_interval_tree *tree;
700 struct ldlm_resource *res;
701 struct interval_node_extent ex = { .start = arg->lpa_extent.start,
702 .end = arg->lpa_extent.end };
707 res = ldlm_resource_get(arg->lpa_export->exp_obd->obd_namespace, NULL,
708 &arg->lpa_resid, LDLM_EXTENT, 0);
710 CDEBUG(D_DLMTRACE, "Failed to get resource for resid %llu/%llu\n",
711 arg->lpa_resid.name[0], arg->lpa_resid.name[1]);
716 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
717 tree = &res->lr_itree[idx];
718 if (tree->lit_root == NULL) /* empty tree, skipped */
721 /* There is no possibility to check for the groupID
722 * so all the group locks are considered as valid
723 * here, especially because the client is supposed
724 * to check it has such a lock before sending an RPC.
726 if (!(tree->lit_mode & arg->lpa_mode))
729 interval_search(tree->lit_root, &ex,
730 ldlm_resource_prolong_cb, arg);
734 ldlm_resource_putref(res);
738 EXPORT_SYMBOL(ldlm_resource_prolong);
741 * Process a granting attempt for extent lock.
742 * Must be called with ns lock held.
744 * This function looks for any conflicts for \a lock in the granted or
745 * waiting queues. The lock is granted if no conflicts are found in
748 int ldlm_process_extent_lock(struct ldlm_lock *lock, __u64 *flags,
749 enum ldlm_process_intention intention,
750 enum ldlm_error *err, struct list_head *work_list)
752 struct ldlm_resource *res = lock->l_resource;
753 struct list_head rpc_list;
755 int contended_locks = 0;
758 LASSERT(lock->l_granted_mode != lock->l_req_mode);
759 LASSERT(list_empty(&res->lr_converting));
760 LASSERT(!(*flags & LDLM_FL_DENY_ON_CONTENTION) ||
761 !ldlm_is_ast_discard_data(lock));
762 INIT_LIST_HEAD(&rpc_list);
763 check_res_locked(res);
766 if (intention == LDLM_PROCESS_RESCAN) {
767 /* Careful observers will note that we don't handle -EWOULDBLOCK
768 * here, but it's ok for a non-obvious reason -- compat_queue
769 * can only return -EWOULDBLOCK if (flags & BLOCK_NOWAIT).
770 * flags should always be zero here, and if that ever stops
771 * being true, we want to find out. */
772 LASSERT(*flags == 0);
773 rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags,
774 err, NULL, &contended_locks);
776 rc = ldlm_extent_compat_queue(&res->lr_waiting, lock,
781 RETURN(LDLM_ITER_STOP);
783 ldlm_resource_unlink_lock(lock);
785 if (!OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_EVICT_RACE))
786 ldlm_extent_policy(res, lock, flags);
787 ldlm_grant_lock(lock, work_list);
788 RETURN(LDLM_ITER_CONTINUE);
791 LASSERT((intention == LDLM_PROCESS_ENQUEUE && work_list == NULL) ||
792 (intention == LDLM_PROCESS_RECOVERY && work_list != NULL));
795 rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, err,
796 &rpc_list, &contended_locks);
798 GOTO(out_rpc_list, rc);
802 rc2 = ldlm_extent_compat_queue(&res->lr_waiting, lock,
803 flags, err, &rpc_list,
806 GOTO(out_rpc_list, rc = rc2);
810 /* Adding LDLM_FL_NO_TIMEOUT flag to granted lock to force
811 * client to wait for the lock endlessly once the lock is
813 rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list,
819 ldlm_extent_policy(res, lock, flags);
820 ldlm_resource_unlink_lock(lock);
821 ldlm_grant_lock(lock, work_list);
826 if (!list_empty(&rpc_list)) {
827 LASSERT(!ldlm_is_ast_discard_data(lock));
828 ldlm_discard_bl_list(&rpc_list);
832 #endif /* HAVE_SERVER_SUPPORT */
834 struct ldlm_kms_shift_args {
840 /* Callback for interval_iterate functions, used by ldlm_extent_shift_Kms */
841 static enum interval_iter ldlm_kms_shift_cb(struct interval_node *n,
844 struct ldlm_kms_shift_args *arg = args;
845 struct ldlm_interval *node = to_ldlm_interval(n);
846 struct ldlm_lock *tmplock;
847 struct ldlm_lock *lock = NULL;
851 /* Since all locks in an interval have the same extent, we can just
852 * use the first lock without kms_ignore set. */
853 list_for_each_entry(tmplock, &node->li_group, l_sl_policy) {
854 if (ldlm_is_kms_ignore(tmplock))
862 /* No locks in this interval without kms_ignore set */
864 RETURN(INTERVAL_ITER_CONT);
866 /* If we find a lock with a greater or equal kms, we are not the
867 * highest lock (or we share that distinction with another lock), and
868 * don't need to update KMS. Return old_kms and stop looking. */
869 if (lock->l_policy_data.l_extent.end >= arg->old_kms) {
870 arg->kms = arg->old_kms;
871 arg->complete = true;
872 RETURN(INTERVAL_ITER_STOP);
875 if (lock->l_policy_data.l_extent.end + 1 > arg->kms)
876 arg->kms = lock->l_policy_data.l_extent.end + 1;
878 /* Since interval_iterate_reverse starts with the highest lock and
879 * works down, for PW locks, we only need to check if we should update
880 * the kms, then stop walking the tree. PR locks are not exclusive, so
881 * the highest start does not imply the highest end and we must
882 * continue. (Only one group lock is allowed per resource, so this is
883 * irrelevant for group locks.)*/
884 if (lock->l_granted_mode == LCK_PW)
885 RETURN(INTERVAL_ITER_STOP);
887 RETURN(INTERVAL_ITER_CONT);
890 /* When a lock is cancelled by a client, the KMS may undergo change if this
891 * is the "highest lock". This function returns the new KMS value, updating
892 * it only if we were the highest lock.
894 * Caller must hold lr_lock already.
896 * NB: A lock on [x,y] protects a KMS of up to y + 1 bytes! */
897 __u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms)
899 struct ldlm_resource *res = lock->l_resource;
900 struct ldlm_interval_tree *tree;
901 struct ldlm_kms_shift_args args;
906 args.old_kms = old_kms;
908 args.complete = false;
910 /* don't let another thread in ldlm_extent_shift_kms race in
911 * just after we finish and take our lock into account in its
912 * calculation of the kms */
913 ldlm_set_kms_ignore(lock);
915 /* We iterate over the lock trees, looking for the largest kms smaller
916 * than the current one. */
917 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
918 tree = &res->lr_itree[idx];
920 /* If our already known kms is >= than the highest 'end' in
921 * this tree, we don't need to check this tree, because
922 * the kms from a tree can be lower than in_max_high (due to
923 * kms_ignore), but it can never be higher. */
924 if (!tree->lit_root || args.kms >= tree->lit_root->in_max_high)
927 interval_iterate_reverse(tree->lit_root, ldlm_kms_shift_cb,
930 /* this tells us we're not the highest lock, so we don't need
931 * to check the remaining trees */
936 LASSERTF(args.kms <= args.old_kms, "kms %llu old_kms %llu\n", args.kms,
941 EXPORT_SYMBOL(ldlm_extent_shift_kms);
943 struct kmem_cache *ldlm_interval_slab;
944 struct ldlm_interval *ldlm_interval_alloc(struct ldlm_lock *lock)
946 struct ldlm_interval *node;
949 LASSERT(lock->l_resource->lr_type == LDLM_EXTENT);
950 OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, GFP_NOFS);
954 INIT_LIST_HEAD(&node->li_group);
955 ldlm_interval_attach(node, lock);
959 void ldlm_interval_free(struct ldlm_interval *node)
962 LASSERT(list_empty(&node->li_group));
963 LASSERT(!interval_is_intree(&node->li_node));
964 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
968 /* interval tree, for LDLM_EXTENT. */
969 void ldlm_interval_attach(struct ldlm_interval *n,
972 LASSERT(l->l_tree_node == NULL);
973 LASSERT(l->l_resource->lr_type == LDLM_EXTENT);
975 list_add_tail(&l->l_sl_policy, &n->li_group);
979 struct ldlm_interval *ldlm_interval_detach(struct ldlm_lock *l)
981 struct ldlm_interval *n = l->l_tree_node;
986 LASSERT(!list_empty(&n->li_group));
987 l->l_tree_node = NULL;
988 list_del_init(&l->l_sl_policy);
990 return list_empty(&n->li_group) ? n : NULL;
993 static inline int ldlm_mode_to_index(enum ldlm_mode mode)
998 LASSERT(is_power_of_2(mode));
999 for (index = -1; mode != 0; index++, mode >>= 1)
1001 LASSERT(index < LCK_MODE_NUM);
1005 /** Add newly granted lock into interval tree for the resource. */
1006 void ldlm_extent_add_lock(struct ldlm_resource *res,
1007 struct ldlm_lock *lock)
1009 struct interval_node *found, **root;
1010 struct ldlm_interval *node;
1011 struct ldlm_extent *extent;
1014 LASSERT(lock->l_granted_mode == lock->l_req_mode);
1016 node = lock->l_tree_node;
1017 LASSERT(node != NULL);
1018 LASSERT(!interval_is_intree(&node->li_node));
1020 idx = ldlm_mode_to_index(lock->l_granted_mode);
1021 LASSERT(lock->l_granted_mode == 1 << idx);
1022 LASSERT(lock->l_granted_mode == res->lr_itree[idx].lit_mode);
1024 /* node extent initialize */
1025 extent = &lock->l_policy_data.l_extent;
1027 rc = interval_set(&node->li_node, extent->start, extent->end);
1030 root = &res->lr_itree[idx].lit_root;
1031 found = interval_insert(&node->li_node, root);
1032 if (found) { /* The policy group found. */
1033 struct ldlm_interval *tmp = ldlm_interval_detach(lock);
1034 LASSERT(tmp != NULL);
1035 ldlm_interval_free(tmp);
1036 ldlm_interval_attach(to_ldlm_interval(found), lock);
1038 res->lr_itree[idx].lit_size++;
1040 /* even though we use interval tree to manage the extent lock, we also
1041 * add the locks into grant list, for debug purpose, .. */
1042 ldlm_resource_add_lock(res, &res->lr_granted, lock);
1044 if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_GRANT_CHECK)) {
1045 struct ldlm_lock *lck;
1047 list_for_each_entry_reverse(lck, &res->lr_granted,
1051 if (lockmode_compat(lck->l_granted_mode,
1052 lock->l_granted_mode))
1054 if (ldlm_extent_overlap(&lck->l_req_extent,
1055 &lock->l_req_extent)) {
1056 CDEBUG(D_ERROR, "granting conflicting lock %p "
1058 ldlm_resource_dump(D_ERROR, res);
1065 /** Remove cancelled lock from resource interval tree. */
1066 void ldlm_extent_unlink_lock(struct ldlm_lock *lock)
1068 struct ldlm_resource *res = lock->l_resource;
1069 struct ldlm_interval *node = lock->l_tree_node;
1070 struct ldlm_interval_tree *tree;
1073 if (!node || !interval_is_intree(&node->li_node)) /* duplicate unlink */
1076 idx = ldlm_mode_to_index(lock->l_granted_mode);
1077 LASSERT(lock->l_granted_mode == 1 << idx);
1078 tree = &res->lr_itree[idx];
1080 LASSERT(tree->lit_root != NULL); /* assure the tree is not null */
1083 node = ldlm_interval_detach(lock);
1085 interval_erase(&node->li_node, &tree->lit_root);
1086 ldlm_interval_free(node);
1090 void ldlm_extent_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
1091 union ldlm_policy_data *lpolicy)
1093 lpolicy->l_extent.start = wpolicy->l_extent.start;
1094 lpolicy->l_extent.end = wpolicy->l_extent.end;
1095 lpolicy->l_extent.gid = wpolicy->l_extent.gid;
1098 void ldlm_extent_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
1099 union ldlm_wire_policy_data *wpolicy)
1101 memset(wpolicy, 0, sizeof(*wpolicy));
1102 wpolicy->l_extent.start = lpolicy->l_extent.start;
1103 wpolicy->l_extent.end = lpolicy->l_extent.end;
1104 wpolicy->l_extent.gid = lpolicy->l_extent.gid;