4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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, 2017, 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 a 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 /* Because reprocess_queue zeroes flags and uses it to return
290 * LDLM_FL_LOCK_CHANGED, we must check for the NO_EXPANSION flag
291 * in the lock flags rather than the 'flags' argument */
292 if (likely(!(lock->l_flags & LDLM_FL_NO_EXPANSION))) {
293 ldlm_extent_internal_policy_granted(lock, &new_ex);
294 ldlm_extent_internal_policy_waiting(lock, &new_ex);
296 LDLM_DEBUG(lock, "Not expanding manually requested lock.\n");
297 new_ex.start = lock->l_policy_data.l_extent.start;
298 new_ex.end = lock->l_policy_data.l_extent.end;
299 /* In case the request is not on correct boundaries, we call
300 * fixup. (normally called in ldlm_extent_internal_policy_*) */
301 ldlm_extent_internal_policy_fixup(lock, &new_ex, 0);
304 if (!ldlm_extent_equal(&new_ex, &lock->l_policy_data.l_extent)) {
305 *flags |= LDLM_FL_LOCK_CHANGED;
306 lock->l_policy_data.l_extent.start = new_ex.start;
307 lock->l_policy_data.l_extent.end = new_ex.end;
311 static int ldlm_check_contention(struct ldlm_lock *lock, int contended_locks)
313 struct ldlm_resource *res = lock->l_resource;
314 time64_t now = ktime_get_seconds();
316 if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_SET_CONTENTION))
319 CDEBUG(D_DLMTRACE, "contended locks = %d\n", contended_locks);
320 if (contended_locks > ldlm_res_to_ns(res)->ns_contended_locks)
321 res->lr_contention_time = now;
323 return now < res->lr_contention_time +
324 ldlm_res_to_ns(res)->ns_contention_time;
327 struct ldlm_extent_compat_args {
328 struct list_head *work_list;
329 struct ldlm_lock *lock;
335 static enum interval_iter ldlm_extent_compat_cb(struct interval_node *n,
338 struct ldlm_extent_compat_args *priv = data;
339 struct ldlm_interval *node = to_ldlm_interval(n);
340 struct ldlm_extent *extent;
341 struct list_head *work_list = priv->work_list;
342 struct ldlm_lock *lock, *enq = priv->lock;
343 enum ldlm_mode mode = priv->mode;
347 LASSERT(!list_empty(&node->li_group));
349 list_for_each_entry(lock, &node->li_group, l_sl_policy) {
350 /* interval tree is for granted lock */
351 LASSERTF(mode == lock->l_granted_mode,
352 "mode = %s, lock->l_granted_mode = %s\n",
354 ldlm_lockname[lock->l_granted_mode]);
356 if (lock->l_blocking_ast &&
357 lock->l_granted_mode != LCK_GROUP)
358 ldlm_add_ast_work_item(lock, enq, work_list);
361 /* don't count conflicting glimpse locks */
362 extent = ldlm_interval_extent(node);
363 if (!(mode == LCK_PR &&
364 extent->start == 0 && extent->end == OBD_OBJECT_EOF))
365 *priv->locks += count;
370 RETURN(INTERVAL_ITER_CONT);
374 * Determine if the lock is compatible with all locks on the queue.
376 * If \a work_list is provided, conflicting locks are linked there.
377 * If \a work_list is not provided, we exit this function on first conflict.
379 * \retval 0 if the lock is not compatible
380 * \retval 1 if the lock is compatible
381 * \retval 2 if \a req is a group lock and it is compatible and requires
382 * no further checking
383 * \retval negative error, such as EWOULDBLOCK for group locks
386 ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req,
387 __u64 *flags, enum ldlm_error *err,
388 struct list_head *work_list, int *contended_locks)
390 struct ldlm_resource *res = req->l_resource;
391 enum ldlm_mode req_mode = req->l_req_mode;
392 __u64 req_start = req->l_req_extent.start;
393 __u64 req_end = req->l_req_extent.end;
394 struct ldlm_lock *lock;
395 int check_contention;
400 lockmode_verify(req_mode);
402 /* Using interval tree for granted lock */
403 if (queue == &res->lr_granted) {
404 struct ldlm_interval_tree *tree;
405 struct ldlm_extent_compat_args data = {.work_list = work_list,
407 .locks = contended_locks,
409 struct interval_node_extent ex = { .start = req_start,
413 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
414 tree = &res->lr_itree[idx];
415 if (tree->lit_root == NULL) /* empty tree, skipped */
418 data.mode = tree->lit_mode;
419 if (lockmode_compat(req_mode, tree->lit_mode)) {
420 struct ldlm_interval *node;
421 struct ldlm_extent *extent;
423 if (req_mode != LCK_GROUP)
426 /* group lock, grant it immediately if
428 node = to_ldlm_interval(tree->lit_root);
429 extent = ldlm_interval_extent(node);
430 if (req->l_policy_data.l_extent.gid ==
435 if (tree->lit_mode == LCK_GROUP) {
436 if (*flags & (LDLM_FL_BLOCK_NOWAIT |
437 LDLM_FL_SPECULATIVE)) {
438 compat = -EWOULDBLOCK;
442 *flags |= LDLM_FL_NO_TIMEOUT;
446 /* if work list is not NULL,add all
447 locks in the tree to work list */
449 interval_iterate(tree->lit_root,
450 ldlm_extent_compat_cb, &data);
454 /* We've found a potentially blocking lock, check
455 * compatibility. This handles locks other than GROUP
456 * locks, which are handled separately above.
458 * Locks with FL_SPECULATIVE are asynchronous requests
459 * which must never wait behind another lock, so they
460 * fail if any conflicting lock is found. */
461 if (!work_list || (*flags & LDLM_FL_SPECULATIVE)) {
462 rc = interval_is_overlapped(tree->lit_root,
468 compat = -EWOULDBLOCK;
473 interval_search(tree->lit_root, &ex,
474 ldlm_extent_compat_cb, &data);
475 if (!list_empty(work_list) && compat)
479 } else { /* for waiting queue */
480 list_for_each_entry(lock, queue, l_res_link) {
481 check_contention = 1;
483 /* We stop walking the queue if we hit ourselves so
484 * we don't take conflicting locks enqueued after us
485 * into account, or we'd wait forever. */
489 if (unlikely(scan)) {
490 /* We only get here if we are queuing GROUP lock
491 and met some incompatible one. The main idea of this
492 code is to insert GROUP lock past compatible GROUP
493 lock in the waiting queue or if there is not any,
494 then in front of first non-GROUP lock */
495 if (lock->l_req_mode != LCK_GROUP) {
496 /* Ok, we hit non-GROUP lock, there should
497 * be no more GROUP locks later on, queue in
498 * front of first non-GROUP lock */
500 ldlm_resource_insert_lock_after(lock, req);
501 list_del_init(&lock->l_res_link);
502 ldlm_resource_insert_lock_after(req, lock);
506 if (req->l_policy_data.l_extent.gid ==
507 lock->l_policy_data.l_extent.gid) {
509 ldlm_resource_insert_lock_after(lock, req);
516 /* locks are compatible, overlap doesn't matter */
517 if (lockmode_compat(lock->l_req_mode, req_mode)) {
518 if (req_mode == LCK_PR &&
519 ((lock->l_policy_data.l_extent.start <=
520 req->l_policy_data.l_extent.start) &&
521 (lock->l_policy_data.l_extent.end >=
522 req->l_policy_data.l_extent.end))) {
523 /* If we met a PR lock just like us or
524 wider, and nobody down the list
525 conflicted with it, that means we
526 can skip processing of the rest of
527 the list and safely place ourselves
528 at the end of the list, or grant
529 (dependent if we met an conflicting
530 locks before in the list). In case
531 of 1st enqueue only we continue
532 traversing if there is something
533 conflicting down the list because
534 we need to make sure that something
535 is marked as AST_SENT as well, in
536 cse of empy worklist we would exit
537 on first conflict met. */
538 /* There IS a case where such flag is
539 not set for a lock, yet it blocks
540 something. Luckily for us this is
541 only during destroy, so lock is
542 exclusive. So here we are safe */
543 if (!ldlm_is_ast_sent(lock))
547 /* non-group locks are compatible, overlap doesn't
549 if (likely(req_mode != LCK_GROUP))
552 /* If we are trying to get a GROUP lock and there is
553 another one of this kind, we need to compare gid */
554 if (req->l_policy_data.l_extent.gid ==
555 lock->l_policy_data.l_extent.gid) {
556 /* If existing lock with matched gid is granted,
557 we grant new one too. */
558 if (ldlm_is_granted(lock))
561 /* Otherwise we are scanning queue of waiting
562 * locks and it means current request would
563 * block along with existing lock (that is
565 * If we are in nonblocking mode - return
567 if (*flags & (LDLM_FL_BLOCK_NOWAIT
568 | LDLM_FL_SPECULATIVE)) {
569 compat = -EWOULDBLOCK;
572 /* If this group lock is compatible with another
573 * group lock on the waiting list, they must be
574 * together in the list, so they can be granted
575 * at the same time. Otherwise the later lock
576 * can get stuck behind another, incompatible,
578 ldlm_resource_insert_lock_after(lock, req);
579 /* Because 'lock' is not granted, we can stop
580 * processing this queue and return immediately.
581 * There is no need to check the rest of the
587 if (unlikely(req_mode == LCK_GROUP &&
588 !ldlm_is_granted(lock))) {
591 if (lock->l_req_mode != LCK_GROUP) {
592 /* Ok, we hit non-GROUP lock, there should be no
593 more GROUP locks later on, queue in front of
594 first non-GROUP lock */
596 ldlm_resource_insert_lock_after(lock, req);
597 list_del_init(&lock->l_res_link);
598 ldlm_resource_insert_lock_after(req, lock);
601 if (req->l_policy_data.l_extent.gid ==
602 lock->l_policy_data.l_extent.gid) {
604 ldlm_resource_insert_lock_after(lock, req);
610 if (unlikely(lock->l_req_mode == LCK_GROUP)) {
611 /* If compared lock is GROUP, then requested is
612 * PR/PW so this is not compatible; extent
613 * range does not matter */
614 if (*flags & (LDLM_FL_BLOCK_NOWAIT
615 | LDLM_FL_SPECULATIVE)) {
616 compat = -EWOULDBLOCK;
619 *flags |= LDLM_FL_NO_TIMEOUT;
621 } else if (lock->l_policy_data.l_extent.end < req_start ||
622 lock->l_policy_data.l_extent.start > req_end) {
623 /* if a non group lock doesn't overlap skip it */
625 } else if (lock->l_req_extent.end < req_start ||
626 lock->l_req_extent.start > req_end) {
627 /* false contention, the requests doesn't really overlap */
628 check_contention = 0;
634 if (*flags & LDLM_FL_SPECULATIVE) {
635 compat = -EWOULDBLOCK;
639 /* don't count conflicting glimpse locks */
640 if (lock->l_req_mode == LCK_PR &&
641 lock->l_policy_data.l_extent.start == 0 &&
642 lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF)
643 check_contention = 0;
645 *contended_locks += check_contention;
648 if (lock->l_blocking_ast &&
649 lock->l_req_mode != LCK_GROUP)
650 ldlm_add_ast_work_item(lock, req, work_list);
654 if (ldlm_check_contention(req, *contended_locks) &&
656 (*flags & LDLM_FL_DENY_ON_CONTENTION) &&
657 req->l_req_mode != LCK_GROUP &&
658 req_end - req_start <=
659 ldlm_res_to_ns(req->l_resource)->ns_max_nolock_size)
660 GOTO(destroylock, compat = -EUSERS);
664 list_del_init(&req->l_res_link);
665 ldlm_lock_destroy_nolock(req);
671 * This function refresh eviction timer for cancelled lock.
672 * \param[in] lock ldlm lock for refresh
673 * \param[in] arg ldlm prolong arguments, timeout, export, extent
674 * and counter are used
676 void ldlm_lock_prolong_one(struct ldlm_lock *lock,
677 struct ldlm_prolong_args *arg)
681 OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_PROLONG_PAUSE, 3);
683 if (arg->lpa_export != lock->l_export ||
684 lock->l_flags & LDLM_FL_DESTROYED)
685 /* ignore unrelated locks */
688 arg->lpa_locks_cnt++;
690 if (!(lock->l_flags & LDLM_FL_AST_SENT))
691 /* ignore locks not being cancelled */
694 /* We are in the middle of the process - BL AST is sent, CANCEL
695 * is ahead. Take half of BL AT + IO AT process time.
697 timeout = arg->lpa_timeout + (ldlm_bl_timeout(lock) >> 1);
699 LDLM_DEBUG(lock, "refreshed to %llds.\n", timeout);
701 arg->lpa_blocks_cnt++;
703 /* OK. this is a possible lock the user holds doing I/O
704 * let's refresh eviction timer for it.
706 ldlm_refresh_waiting_lock(lock, timeout);
708 EXPORT_SYMBOL(ldlm_lock_prolong_one);
710 static enum interval_iter ldlm_resource_prolong_cb(struct interval_node *n,
713 struct ldlm_prolong_args *arg = data;
714 struct ldlm_interval *node = to_ldlm_interval(n);
715 struct ldlm_lock *lock;
719 LASSERT(!list_empty(&node->li_group));
721 list_for_each_entry(lock, &node->li_group, l_sl_policy) {
722 ldlm_lock_prolong_one(lock, arg);
725 RETURN(INTERVAL_ITER_CONT);
729 * Walk through granted tree and prolong locks if they overlaps extent.
731 * \param[in] arg prolong args
733 void ldlm_resource_prolong(struct ldlm_prolong_args *arg)
735 struct ldlm_interval_tree *tree;
736 struct ldlm_resource *res;
737 struct interval_node_extent ex = { .start = arg->lpa_extent.start,
738 .end = arg->lpa_extent.end };
743 res = ldlm_resource_get(arg->lpa_export->exp_obd->obd_namespace, NULL,
744 &arg->lpa_resid, LDLM_EXTENT, 0);
746 CDEBUG(D_DLMTRACE, "Failed to get resource for resid %llu/%llu\n",
747 arg->lpa_resid.name[0], arg->lpa_resid.name[1]);
752 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
753 tree = &res->lr_itree[idx];
754 if (tree->lit_root == NULL) /* empty tree, skipped */
757 /* There is no possibility to check for the groupID
758 * so all the group locks are considered as valid
759 * here, especially because the client is supposed
760 * to check it has such a lock before sending an RPC.
762 if (!(tree->lit_mode & arg->lpa_mode))
765 interval_search(tree->lit_root, &ex,
766 ldlm_resource_prolong_cb, arg);
770 ldlm_resource_putref(res);
774 EXPORT_SYMBOL(ldlm_resource_prolong);
777 * Process a granting attempt for extent lock.
778 * Must be called with ns lock held.
780 * This function looks for any conflicts for \a lock in the granted or
781 * waiting queues. The lock is granted if no conflicts are found in
784 int ldlm_process_extent_lock(struct ldlm_lock *lock, __u64 *flags,
785 enum ldlm_process_intention intention,
786 enum ldlm_error *err, struct list_head *work_list)
788 struct ldlm_resource *res = lock->l_resource;
790 int contended_locks = 0;
791 struct list_head *grant_work = intention == LDLM_PROCESS_ENQUEUE ?
795 LASSERT(!ldlm_is_granted(lock));
796 LASSERT(!(*flags & LDLM_FL_DENY_ON_CONTENTION) ||
797 !ldlm_is_ast_discard_data(lock));
798 check_res_locked(res);
801 if (intention == LDLM_PROCESS_RESCAN) {
802 /* Careful observers will note that we don't handle -EWOULDBLOCK
803 * here, but it's ok for a non-obvious reason -- compat_queue
804 * can only return -EWOULDBLOCK if (flags & BLOCK_NOWAIT |
805 * SPECULATIVE). flags should always be zero here, and if that
806 * ever stops being true, we want to find out. */
807 LASSERT(*flags == 0);
808 rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags,
809 err, NULL, &contended_locks);
811 rc = ldlm_extent_compat_queue(&res->lr_waiting, lock,
816 RETURN(LDLM_ITER_STOP);
818 ldlm_resource_unlink_lock(lock);
820 if (!OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_EVICT_RACE))
821 ldlm_extent_policy(res, lock, flags);
822 ldlm_grant_lock(lock, grant_work);
823 RETURN(LDLM_ITER_CONTINUE);
827 rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, err,
828 work_list, &contended_locks);
830 GOTO(out_rpc_list, rc);
834 rc2 = ldlm_extent_compat_queue(&res->lr_waiting, lock,
835 flags, err, work_list,
838 GOTO(out_rpc_list, rc = rc2);
842 ldlm_extent_policy(res, lock, flags);
843 ldlm_resource_unlink_lock(lock);
844 ldlm_grant_lock(lock, grant_work);
846 /* Adding LDLM_FL_NO_TIMEOUT flag to granted lock to
847 * force client to wait for the lock endlessly once
848 * the lock is enqueued -bzzz */
849 *flags |= LDLM_FL_NO_TIMEOUT;
851 rc = LDLM_ITER_CONTINUE;
856 #endif /* HAVE_SERVER_SUPPORT */
858 struct ldlm_kms_shift_args {
864 /* Callback for interval_iterate functions, used by ldlm_extent_shift_Kms */
865 static enum interval_iter ldlm_kms_shift_cb(struct interval_node *n,
868 struct ldlm_kms_shift_args *arg = args;
869 struct ldlm_interval *node = to_ldlm_interval(n);
870 struct ldlm_lock *tmplock;
871 struct ldlm_lock *lock = NULL;
875 /* Since all locks in an interval have the same extent, we can just
876 * use the first lock without kms_ignore set. */
877 list_for_each_entry(tmplock, &node->li_group, l_sl_policy) {
878 if (ldlm_is_kms_ignore(tmplock))
886 /* No locks in this interval without kms_ignore set */
888 RETURN(INTERVAL_ITER_CONT);
890 /* If we find a lock with a greater or equal kms, we are not the
891 * highest lock (or we share that distinction with another lock), and
892 * don't need to update KMS. Return old_kms and stop looking. */
893 if (lock->l_policy_data.l_extent.end >= arg->old_kms) {
894 arg->kms = arg->old_kms;
895 arg->complete = true;
896 RETURN(INTERVAL_ITER_STOP);
899 if (lock->l_policy_data.l_extent.end + 1 > arg->kms)
900 arg->kms = lock->l_policy_data.l_extent.end + 1;
902 /* Since interval_iterate_reverse starts with the highest lock and
903 * works down, for PW locks, we only need to check if we should update
904 * the kms, then stop walking the tree. PR locks are not exclusive, so
905 * the highest start does not imply the highest end and we must
906 * continue. (Only one group lock is allowed per resource, so this is
907 * irrelevant for group locks.)*/
908 if (lock->l_granted_mode == LCK_PW)
909 RETURN(INTERVAL_ITER_STOP);
911 RETURN(INTERVAL_ITER_CONT);
914 /* When a lock is cancelled by a client, the KMS may undergo change if this
915 * is the "highest lock". This function returns the new KMS value, updating
916 * it only if we were the highest lock.
918 * Caller must hold lr_lock already.
920 * NB: A lock on [x,y] protects a KMS of up to y + 1 bytes! */
921 __u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms)
923 struct ldlm_resource *res = lock->l_resource;
924 struct ldlm_interval_tree *tree;
925 struct ldlm_kms_shift_args args;
930 args.old_kms = old_kms;
932 args.complete = false;
934 /* don't let another thread in ldlm_extent_shift_kms race in
935 * just after we finish and take our lock into account in its
936 * calculation of the kms */
937 ldlm_set_kms_ignore(lock);
939 /* We iterate over the lock trees, looking for the largest kms smaller
940 * than the current one. */
941 for (idx = 0; idx < LCK_MODE_NUM; idx++) {
942 tree = &res->lr_itree[idx];
944 /* If our already known kms is >= than the highest 'end' in
945 * this tree, we don't need to check this tree, because
946 * the kms from a tree can be lower than in_max_high (due to
947 * kms_ignore), but it can never be higher. */
948 if (!tree->lit_root || args.kms >= tree->lit_root->in_max_high)
951 interval_iterate_reverse(tree->lit_root, ldlm_kms_shift_cb,
954 /* this tells us we're not the highest lock, so we don't need
955 * to check the remaining trees */
960 LASSERTF(args.kms <= args.old_kms, "kms %llu old_kms %llu\n", args.kms,
965 EXPORT_SYMBOL(ldlm_extent_shift_kms);
967 struct kmem_cache *ldlm_interval_slab;
968 static struct ldlm_interval *ldlm_interval_alloc(struct ldlm_lock *lock)
970 struct ldlm_interval *node;
973 LASSERT(lock->l_resource->lr_type == LDLM_EXTENT);
974 OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, GFP_NOFS);
978 INIT_LIST_HEAD(&node->li_group);
979 ldlm_interval_attach(node, lock);
983 void ldlm_interval_free(struct ldlm_interval *node)
986 LASSERT(list_empty(&node->li_group));
987 LASSERT(!interval_is_intree(&node->li_node));
988 OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
992 /* interval tree, for LDLM_EXTENT. */
993 void ldlm_interval_attach(struct ldlm_interval *n,
996 LASSERT(l->l_tree_node == NULL);
997 LASSERT(l->l_resource->lr_type == LDLM_EXTENT);
999 list_add_tail(&l->l_sl_policy, &n->li_group);
1003 struct ldlm_interval *ldlm_interval_detach(struct ldlm_lock *l)
1005 struct ldlm_interval *n = l->l_tree_node;
1010 LASSERT(!list_empty(&n->li_group));
1011 l->l_tree_node = NULL;
1012 list_del_init(&l->l_sl_policy);
1014 return list_empty(&n->li_group) ? n : NULL;
1017 static inline int ldlm_mode_to_index(enum ldlm_mode mode)
1022 LASSERT(is_power_of_2(mode));
1023 index = ilog2(mode);
1024 LASSERT(index < LCK_MODE_NUM);
1028 int ldlm_extent_alloc_lock(struct ldlm_lock *lock)
1030 lock->l_tree_node = NULL;
1031 if (ldlm_interval_alloc(lock) == NULL)
1036 /** Add newly granted lock into interval tree for the resource. */
1037 void ldlm_extent_add_lock(struct ldlm_resource *res,
1038 struct ldlm_lock *lock)
1040 struct interval_node *found, **root;
1041 struct ldlm_interval *node;
1042 struct ldlm_extent *extent;
1045 LASSERT(ldlm_is_granted(lock));
1047 node = lock->l_tree_node;
1048 LASSERT(node != NULL);
1049 LASSERT(!interval_is_intree(&node->li_node));
1051 idx = ldlm_mode_to_index(lock->l_granted_mode);
1052 LASSERT(lock->l_granted_mode == 1 << idx);
1053 LASSERT(lock->l_granted_mode == res->lr_itree[idx].lit_mode);
1055 /* node extent initialize */
1056 extent = &lock->l_policy_data.l_extent;
1058 rc = interval_set(&node->li_node, extent->start, extent->end);
1061 root = &res->lr_itree[idx].lit_root;
1062 found = interval_insert(&node->li_node, root);
1063 if (found) { /* The policy group found. */
1064 struct ldlm_interval *tmp = ldlm_interval_detach(lock);
1065 LASSERT(tmp != NULL);
1066 ldlm_interval_free(tmp);
1067 ldlm_interval_attach(to_ldlm_interval(found), lock);
1069 res->lr_itree[idx].lit_size++;
1071 /* even though we use interval tree to manage the extent lock, we also
1072 * add the locks into grant list, for debug purpose, .. */
1073 ldlm_resource_add_lock(res, &res->lr_granted, lock);
1075 if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_GRANT_CHECK)) {
1076 struct ldlm_lock *lck;
1078 list_for_each_entry_reverse(lck, &res->lr_granted,
1082 if (lockmode_compat(lck->l_granted_mode,
1083 lock->l_granted_mode))
1085 if (ldlm_extent_overlap(&lck->l_req_extent,
1086 &lock->l_req_extent)) {
1087 CDEBUG(D_ERROR, "granting conflicting lock %p "
1089 ldlm_resource_dump(D_ERROR, res);
1096 /** Remove cancelled lock from resource interval tree. */
1097 void ldlm_extent_unlink_lock(struct ldlm_lock *lock)
1099 struct ldlm_resource *res = lock->l_resource;
1100 struct ldlm_interval *node = lock->l_tree_node;
1101 struct ldlm_interval_tree *tree;
1104 if (!node || !interval_is_intree(&node->li_node)) /* duplicate unlink */
1107 idx = ldlm_mode_to_index(lock->l_granted_mode);
1108 LASSERT(lock->l_granted_mode == 1 << idx);
1109 tree = &res->lr_itree[idx];
1111 LASSERT(tree->lit_root != NULL); /* assure the tree is not null */
1114 node = ldlm_interval_detach(lock);
1116 interval_erase(&node->li_node, &tree->lit_root);
1117 ldlm_interval_free(node);
1121 void ldlm_extent_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
1122 union ldlm_policy_data *lpolicy)
1124 lpolicy->l_extent.start = wpolicy->l_extent.start;
1125 lpolicy->l_extent.end = wpolicy->l_extent.end;
1126 lpolicy->l_extent.gid = wpolicy->l_extent.gid;
1129 void ldlm_extent_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
1130 union ldlm_wire_policy_data *wpolicy)
1132 memset(wpolicy, 0, sizeof(*wpolicy));
1133 wpolicy->l_extent.start = lpolicy->l_extent.start;
1134 wpolicy->l_extent.end = lpolicy->l_extent.end;
1135 wpolicy->l_extent.gid = lpolicy->l_extent.gid;