X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Fldlm%2Fldlm_extent.c;h=623563c85a858ed02d243829c7f16a4f3133e753;hb=6e985684b822324143c686e919fe7a75bb16b440;hp=3e7c7232c396384800073178cee0a31db830543b;hpb=142a324303228704ded3a66e20c7755d26f706ad;p=fs%2Flustre-release.git diff --git a/lustre/ldlm/ldlm_extent.c b/lustre/ldlm/ldlm_extent.c index 3e7c723..623563c 100644 --- a/lustre/ldlm/ldlm_extent.c +++ b/lustre/ldlm/ldlm_extent.c @@ -1,85 +1,1141 @@ -/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- - * vim:expandtab:shiftwidth=8:tabstop=8: +/* + * GPL HEADER START * - * Copyright (C) 2002 Cluster File Systems, Inc. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * - * This code is issued under the GNU General Public License. - * See the file COPYING in this distribution + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. * - * by Cluster File Systems, Inc. - * authors, Peter Braam & - * Phil Schwan + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.gnu.org/licenses/gpl-2.0.html + * + * GPL HEADER END + */ +/* + * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2010, 2017, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + * + * lustre/ldlm/ldlm_extent.c + * + * Author: Peter Braam + * Author: Phil Schwan + */ + +/** + * This file contains implementation of EXTENT lock type + * + * EXTENT lock type is for locking a contiguous range of values, represented + * by 64-bit starting and ending offsets (inclusive). There are several extent + * lock modes, some of which may be mutually incompatible. Extent locks are + * considered incompatible if their modes are incompatible and their extents + * intersect. See the lock mode compatibility matrix in lustre_dlm.h. */ #define DEBUG_SUBSYSTEM S_LDLM -#include +#include +#include +#include +#include +#include +#include + +#include "ldlm_internal.h" -/* This function will be called to judge if the granted queue of another child - * (read: another extent) is conflicting and needs its granted queue walked to - * issue callbacks. +#ifdef HAVE_SERVER_SUPPORT +# define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1) + +/** + * Fix up the ldlm_extent after expanding it. * - * This helps to find conflicts between read and write locks on overlapping - * extents. */ -int ldlm_extent_compat(struct ldlm_lock *a, struct ldlm_lock *b) + * After expansion has been done, we might still want to do certain adjusting + * based on overall contention of the resource and the like to avoid granting + * overly wide locks. + */ +static void ldlm_extent_internal_policy_fixup(struct ldlm_lock *req, + struct ldlm_extent *new_ex, + int conflicting) { - if (MAX(a->l_extent.start, b->l_extent.start) <= - MIN(a->l_extent.end, b->l_extent.end)) - RETURN(0); + enum ldlm_mode req_mode = req->l_req_mode; + __u64 req_start = req->l_req_extent.start; + __u64 req_end = req->l_req_extent.end; + __u64 req_align, mask; + + if (conflicting > 32 && (req_mode == LCK_PW || req_mode == LCK_CW)) { + if (req_end < req_start + LDLM_MAX_GROWN_EXTENT) + new_ex->end = min(req_start + LDLM_MAX_GROWN_EXTENT, + new_ex->end); + } + + if (new_ex->start == 0 && new_ex->end == OBD_OBJECT_EOF) { + EXIT; + return; + } - RETURN(1); + /* we need to ensure that the lock extent is properly aligned to what + * the client requested. Also we need to make sure it's also server + * page size aligned otherwise a server page can be covered by two + * write locks. */ + mask = PAGE_SIZE; + req_align = (req_end + 1) | req_start; + if (req_align != 0 && (req_align & (mask - 1)) == 0) { + while ((req_align & mask) == 0) + mask <<= 1; + } + mask -= 1; + /* We can only shrink the lock, not grow it. + * This should never cause lock to be smaller than requested, + * since requested lock was already aligned on these boundaries. */ + new_ex->start = ((new_ex->start - 1) | mask) + 1; + new_ex->end = ((new_ex->end + 1) & ~mask) - 1; + LASSERTF(new_ex->start <= req_start, + "mask %#llx grant start %llu req start %llu\n", + mask, new_ex->start, req_start); + LASSERTF(new_ex->end >= req_end, + "mask %#llx grant end %llu req end %llu\n", + mask, new_ex->end, req_end); } -static void policy_internal(struct list_head *queue, struct ldlm_extent *req_ex, - struct ldlm_extent *new_ex, ldlm_mode_t mode) +/** + * Return the maximum extent that: + * - contains the requested extent + * - does not overlap existing conflicting extents outside the requested one + * + * This allows clients to request a small required extent range, but if there + * is no contention on the lock the full lock can be granted to the client. + * This avoids the need for many smaller lock requests to be granted in the + * common (uncontended) case. + * + * Use interval tree to expand the lock extent for granted lock. + */ +static void ldlm_extent_internal_policy_granted(struct ldlm_lock *req, + struct ldlm_extent *new_ex) { - struct list_head *tmp; + struct ldlm_resource *res = req->l_resource; + enum ldlm_mode req_mode = req->l_req_mode; + __u64 req_start = req->l_req_extent.start; + __u64 req_end = req->l_req_extent.end; + struct ldlm_interval_tree *tree; + struct interval_node_extent limiter = { + .start = new_ex->start, + .end = new_ex->end, + }; + int conflicting = 0; + int idx; + ENTRY; - list_for_each(tmp, queue) { - struct ldlm_lock *lock; - lock = list_entry(tmp, struct ldlm_lock, l_res_link); + lockmode_verify(req_mode); - if (lock->l_extent.end < req_ex->start) - new_ex->start = MIN(lock->l_extent.end, new_ex->start); - else { - if (lock->l_extent.start < req_ex->start && - !lockmode_compat(lock->l_req_mode, mode)) - /* Policy: minimize conflict overlap */ - new_ex->start = req_ex->start; - } - if (lock->l_extent.start > req_ex->end) - new_ex->end = MAX(lock->l_extent.start, new_ex->end); - else { - if (lock->l_extent.end > req_ex->end && - !lockmode_compat(lock->l_req_mode, mode)) - /* Policy: minimize conflict overlap */ - new_ex->end = req_ex->end; - } + /* Using interval tree to handle the LDLM extent granted locks. */ + for (idx = 0; idx < LCK_MODE_NUM; idx++) { + struct interval_node_extent ext = { + .start = req_start, + .end = req_end, + }; + + tree = &res->lr_itree[idx]; + if (lockmode_compat(tree->lit_mode, req_mode)) + continue; + + conflicting += tree->lit_size; + if (conflicting > 4) + limiter.start = req_start; + + if (interval_is_overlapped(tree->lit_root, &ext)) + CDEBUG(D_INFO, + "req_mode = %d, tree->lit_mode = %d, " + "tree->lit_size = %d\n", + req_mode, tree->lit_mode, tree->lit_size); + interval_expand(tree->lit_root, &ext, &limiter); + limiter.start = max(limiter.start, ext.start); + limiter.end = min(limiter.end, ext.end); + if (limiter.start == req_start && limiter.end == req_end) + break; } + + new_ex->start = limiter.start; + new_ex->end = limiter.end; + LASSERT(new_ex->start <= req_start); + LASSERT(new_ex->end >= req_end); + + ldlm_extent_internal_policy_fixup(req, new_ex, conflicting); + EXIT; } /* The purpose of this function is to return: * - the maximum extent * - containing the requested extent - * - and not overlapping existing extents outside the requested one + * - and not overlapping existing conflicting extents outside the requested one + */ +static void +ldlm_extent_internal_policy_waiting(struct ldlm_lock *req, + struct ldlm_extent *new_ex) +{ + struct ldlm_resource *res = req->l_resource; + enum ldlm_mode req_mode = req->l_req_mode; + __u64 req_start = req->l_req_extent.start; + __u64 req_end = req->l_req_extent.end; + struct ldlm_lock *lock; + int conflicting = 0; + ENTRY; + + lockmode_verify(req_mode); + + /* for waiting locks */ + list_for_each_entry(lock, &res->lr_waiting, l_res_link) { + struct ldlm_extent *l_extent = &lock->l_policy_data.l_extent; + + /* We already hit the minimum requested size, search no more */ + if (new_ex->start == req_start && new_ex->end == req_end) { + EXIT; + return; + } + + /* Don't conflict with ourselves */ + if (req == lock) + continue; + + /* Locks are compatible, overlap doesn't matter */ + /* Until bug 20 is fixed, try to avoid granting overlapping + * locks on one client (they take a long time to cancel) */ + if (lockmode_compat(lock->l_req_mode, req_mode) && + lock->l_export != req->l_export) + continue; + + /* If this is a high-traffic lock, don't grow downwards at all + * or grow upwards too much */ + ++conflicting; + if (conflicting > 4) + new_ex->start = req_start; + + /* If lock doesn't overlap new_ex, skip it. */ + if (!ldlm_extent_overlap(l_extent, new_ex)) + continue; + + /* Locks conflicting in requested extents and we can't satisfy + * both locks, so ignore it. Either we will ping-pong this + * extent (we would regardless of what extent we granted) or + * lock is unused and it shouldn't limit our extent growth. */ + if (ldlm_extent_overlap(&lock->l_req_extent,&req->l_req_extent)) + continue; + + /* We grow extents downwards only as far as they don't overlap + * with already-granted locks, on the assumption that clients + * will be writing beyond the initial requested end and would + * then need to enqueue a new lock beyond previous request. + * l_req_extent->end strictly < req_start, checked above. */ + if (l_extent->start < req_start && new_ex->start != req_start) { + if (l_extent->end >= req_start) + new_ex->start = req_start; + else + new_ex->start = min(l_extent->end+1, req_start); + } + + /* If we need to cancel this lock anyways because our request + * overlaps the granted lock, we grow up to its requested + * extent start instead of limiting this extent, assuming that + * clients are writing forwards and the lock had over grown + * its extent downwards before we enqueued our request. */ + if (l_extent->end > req_end) { + if (l_extent->start <= req_end) + new_ex->end = max(lock->l_req_extent.start - 1, + req_end); + else + new_ex->end = max(l_extent->start - 1, req_end); + } + } + + ldlm_extent_internal_policy_fixup(req, new_ex, conflicting); + EXIT; +} + + +/* In order to determine the largest possible extent we can grant, we need + * to scan all of the queues. */ +static void ldlm_extent_policy(struct ldlm_resource *res, + struct ldlm_lock *lock, __u64 *flags) +{ + struct ldlm_extent new_ex = { .start = 0, .end = OBD_OBJECT_EOF }; + + if (lock->l_export == NULL) + /* + * this is a local lock taken by server (e.g., as a part of + * OST-side locking, or unlink handling). Expansion doesn't + * make a lot of sense for local locks, because they are + * dropped immediately on operation completion and would only + * conflict with other threads. + */ + return; + + if (lock->l_policy_data.l_extent.start == 0 && + lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF) + /* fast-path whole file locks */ + return; + + /* Because reprocess_queue zeroes flags and uses it to return + * LDLM_FL_LOCK_CHANGED, we must check for the NO_EXPANSION flag + * in the lock flags rather than the 'flags' argument */ + if (likely(!(lock->l_flags & LDLM_FL_NO_EXPANSION))) { + ldlm_extent_internal_policy_granted(lock, &new_ex); + ldlm_extent_internal_policy_waiting(lock, &new_ex); + } else { + LDLM_DEBUG(lock, "Not expanding manually requested lock.\n"); + new_ex.start = lock->l_policy_data.l_extent.start; + new_ex.end = lock->l_policy_data.l_extent.end; + /* In case the request is not on correct boundaries, we call + * fixup. (normally called in ldlm_extent_internal_policy_*) */ + ldlm_extent_internal_policy_fixup(lock, &new_ex, 0); + } + + if (!ldlm_extent_equal(&new_ex, &lock->l_policy_data.l_extent)) { + *flags |= LDLM_FL_LOCK_CHANGED; + lock->l_policy_data.l_extent.start = new_ex.start; + lock->l_policy_data.l_extent.end = new_ex.end; + } +} + +static int ldlm_check_contention(struct ldlm_lock *lock, int contended_locks) +{ + struct ldlm_resource *res = lock->l_resource; + time64_t now = ktime_get_seconds(); + + if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_SET_CONTENTION)) + return 1; + + CDEBUG(D_DLMTRACE, "contended locks = %d\n", contended_locks); + if (contended_locks > ldlm_res_to_ns(res)->ns_contended_locks) + res->lr_contention_time = now; + + return now < res->lr_contention_time + + ldlm_res_to_ns(res)->ns_contention_time; +} + +struct ldlm_extent_compat_args { + struct list_head *work_list; + struct ldlm_lock *lock; + enum ldlm_mode mode; + int *locks; + int *compat; +}; + +static enum interval_iter ldlm_extent_compat_cb(struct interval_node *n, + void *data) +{ + struct ldlm_extent_compat_args *priv = data; + struct ldlm_interval *node = to_ldlm_interval(n); + struct ldlm_extent *extent; + struct list_head *work_list = priv->work_list; + struct ldlm_lock *lock, *enq = priv->lock; + enum ldlm_mode mode = priv->mode; + int count = 0; + ENTRY; + + LASSERT(!list_empty(&node->li_group)); + + list_for_each_entry(lock, &node->li_group, l_sl_policy) { + /* interval tree is for granted lock */ + LASSERTF(mode == lock->l_granted_mode, + "mode = %s, lock->l_granted_mode = %s\n", + ldlm_lockname[mode], + ldlm_lockname[lock->l_granted_mode]); + count++; + if (lock->l_blocking_ast && + lock->l_granted_mode != LCK_GROUP) + ldlm_add_ast_work_item(lock, enq, work_list); + } + + /* don't count conflicting glimpse locks */ + extent = ldlm_interval_extent(node); + if (!(mode == LCK_PR && + extent->start == 0 && extent->end == OBD_OBJECT_EOF)) + *priv->locks += count; + + if (priv->compat) + *priv->compat = 0; + + RETURN(INTERVAL_ITER_CONT); +} + +/** + * Determine if the lock is compatible with all locks on the queue. + * + * If \a work_list is provided, conflicting locks are linked there. + * If \a work_list is not provided, we exit this function on first conflict. + * + * \retval 0 if the lock is not compatible + * \retval 1 if the lock is compatible + * \retval 2 if \a req is a group lock and it is compatible and requires + * no further checking + * \retval negative error, such as EWOULDBLOCK for group locks + */ +static int +ldlm_extent_compat_queue(struct list_head *queue, struct ldlm_lock *req, + __u64 *flags, enum ldlm_error *err, + struct list_head *work_list, int *contended_locks) +{ + struct ldlm_resource *res = req->l_resource; + enum ldlm_mode req_mode = req->l_req_mode; + __u64 req_start = req->l_req_extent.start; + __u64 req_end = req->l_req_extent.end; + struct ldlm_lock *lock; + int check_contention; + int compat = 1; + int scan = 0; + ENTRY; + + lockmode_verify(req_mode); + + /* Using interval tree for granted lock */ + if (queue == &res->lr_granted) { + struct ldlm_interval_tree *tree; + struct ldlm_extent_compat_args data = {.work_list = work_list, + .lock = req, + .locks = contended_locks, + .compat = &compat }; + struct interval_node_extent ex = { .start = req_start, + .end = req_end }; + int idx, rc; + + for (idx = 0; idx < LCK_MODE_NUM; idx++) { + tree = &res->lr_itree[idx]; + if (tree->lit_root == NULL) /* empty tree, skipped */ + continue; + + data.mode = tree->lit_mode; + if (lockmode_compat(req_mode, tree->lit_mode)) { + struct ldlm_interval *node; + struct ldlm_extent *extent; + + if (req_mode != LCK_GROUP) + continue; + + /* group lock, grant it immediately if + * compatible */ + node = to_ldlm_interval(tree->lit_root); + extent = ldlm_interval_extent(node); + if (req->l_policy_data.l_extent.gid == + extent->gid) + RETURN(2); + } + + if (tree->lit_mode == LCK_GROUP) { + if (*flags & (LDLM_FL_BLOCK_NOWAIT | + LDLM_FL_SPECULATIVE)) { + compat = -EWOULDBLOCK; + goto destroylock; + } + + *flags |= LDLM_FL_NO_TIMEOUT; + if (!work_list) + RETURN(0); + + /* if work list is not NULL,add all + locks in the tree to work list */ + compat = 0; + interval_iterate(tree->lit_root, + ldlm_extent_compat_cb, &data); + continue; + } + + /* We've found a potentially blocking lock, check + * compatibility. This handles locks other than GROUP + * locks, which are handled separately above. + * + * Locks with FL_SPECULATIVE are asynchronous requests + * which must never wait behind another lock, so they + * fail if any conflicting lock is found. */ + if (!work_list || (*flags & LDLM_FL_SPECULATIVE)) { + rc = interval_is_overlapped(tree->lit_root, + &ex); + if (rc) { + if (!work_list) { + RETURN(0); + } else { + compat = -EWOULDBLOCK; + goto destroylock; + } + } + } else { + interval_search(tree->lit_root, &ex, + ldlm_extent_compat_cb, &data); + if (!list_empty(work_list) && compat) + compat = 0; + } + } + } else { /* for waiting queue */ + list_for_each_entry(lock, queue, l_res_link) { + check_contention = 1; + + /* We stop walking the queue if we hit ourselves so + * we don't take conflicting locks enqueued after us + * into account, or we'd wait forever. */ + if (req == lock) + break; + + if (unlikely(scan)) { + /* We only get here if we are queuing GROUP lock + and met some incompatible one. The main idea of this + code is to insert GROUP lock past compatible GROUP + lock in the waiting queue or if there is not any, + then in front of first non-GROUP lock */ + if (lock->l_req_mode != LCK_GROUP) { + /* Ok, we hit non-GROUP lock, there should + * be no more GROUP locks later on, queue in + * front of first non-GROUP lock */ + + ldlm_resource_insert_lock_after(lock, req); + list_del_init(&lock->l_res_link); + ldlm_resource_insert_lock_after(req, lock); + compat = 0; + break; + } + if (req->l_policy_data.l_extent.gid == + lock->l_policy_data.l_extent.gid) { + /* found it */ + ldlm_resource_insert_lock_after(lock, req); + compat = 0; + break; + } + continue; + } + + /* locks are compatible, overlap doesn't matter */ + if (lockmode_compat(lock->l_req_mode, req_mode)) { + if (req_mode == LCK_PR && + ((lock->l_policy_data.l_extent.start <= + req->l_policy_data.l_extent.start) && + (lock->l_policy_data.l_extent.end >= + req->l_policy_data.l_extent.end))) { + /* If we met a PR lock just like us or + wider, and nobody down the list + conflicted with it, that means we + can skip processing of the rest of + the list and safely place ourselves + at the end of the list, or grant + (dependent if we met an conflicting + locks before in the list). In case + of 1st enqueue only we continue + traversing if there is something + conflicting down the list because + we need to make sure that something + is marked as AST_SENT as well, in + cse of empy worklist we would exit + on first conflict met. */ + /* There IS a case where such flag is + not set for a lock, yet it blocks + something. Luckily for us this is + only during destroy, so lock is + exclusive. So here we are safe */ + if (!ldlm_is_ast_sent(lock)) + RETURN(compat); + } + + /* non-group locks are compatible, overlap doesn't + matter */ + if (likely(req_mode != LCK_GROUP)) + continue; + + /* If we are trying to get a GROUP lock and there is + another one of this kind, we need to compare gid */ + if (req->l_policy_data.l_extent.gid == + lock->l_policy_data.l_extent.gid) { + /* If existing lock with matched gid is granted, + we grant new one too. */ + if (lock->l_req_mode == lock->l_granted_mode) + RETURN(2); + + /* Otherwise we are scanning queue of waiting + * locks and it means current request would + * block along with existing lock (that is + * already blocked. + * If we are in nonblocking mode - return + * immediately */ + if (*flags & (LDLM_FL_BLOCK_NOWAIT + | LDLM_FL_SPECULATIVE)) { + compat = -EWOULDBLOCK; + goto destroylock; + } + /* If this group lock is compatible with another + * group lock on the waiting list, they must be + * together in the list, so they can be granted + * at the same time. Otherwise the later lock + * can get stuck behind another, incompatible, + * lock. */ + ldlm_resource_insert_lock_after(lock, req); + /* Because 'lock' is not granted, we can stop + * processing this queue and return immediately. + * There is no need to check the rest of the + * list. */ + RETURN(0); + } + } + + if (unlikely(req_mode == LCK_GROUP && + (lock->l_req_mode != lock->l_granted_mode))) { + scan = 1; + compat = 0; + if (lock->l_req_mode != LCK_GROUP) { + /* Ok, we hit non-GROUP lock, there should be no + more GROUP locks later on, queue in front of + first non-GROUP lock */ + + ldlm_resource_insert_lock_after(lock, req); + list_del_init(&lock->l_res_link); + ldlm_resource_insert_lock_after(req, lock); + break; + } + if (req->l_policy_data.l_extent.gid == + lock->l_policy_data.l_extent.gid) { + /* found it */ + ldlm_resource_insert_lock_after(lock, req); + break; + } + continue; + } + + if (unlikely(lock->l_req_mode == LCK_GROUP)) { + /* If compared lock is GROUP, then requested is + * PR/PW so this is not compatible; extent + * range does not matter */ + if (*flags & (LDLM_FL_BLOCK_NOWAIT + | LDLM_FL_SPECULATIVE)) { + compat = -EWOULDBLOCK; + goto destroylock; + } else { + *flags |= LDLM_FL_NO_TIMEOUT; + } + } else if (lock->l_policy_data.l_extent.end < req_start || + lock->l_policy_data.l_extent.start > req_end) { + /* if a non group lock doesn't overlap skip it */ + continue; + } else if (lock->l_req_extent.end < req_start || + lock->l_req_extent.start > req_end) { + /* false contention, the requests doesn't really overlap */ + check_contention = 0; + } + + if (!work_list) + RETURN(0); + + if (*flags & LDLM_FL_SPECULATIVE) { + compat = -EWOULDBLOCK; + goto destroylock; + } + + /* don't count conflicting glimpse locks */ + if (lock->l_req_mode == LCK_PR && + lock->l_policy_data.l_extent.start == 0 && + lock->l_policy_data.l_extent.end == OBD_OBJECT_EOF) + check_contention = 0; + + *contended_locks += check_contention; + + compat = 0; + if (lock->l_blocking_ast && + lock->l_req_mode != LCK_GROUP) + ldlm_add_ast_work_item(lock, req, work_list); + } + } + + if (ldlm_check_contention(req, *contended_locks) && + compat == 0 && + (*flags & LDLM_FL_DENY_ON_CONTENTION) && + req->l_req_mode != LCK_GROUP && + req_end - req_start <= + ldlm_res_to_ns(req->l_resource)->ns_max_nolock_size) + GOTO(destroylock, compat = -EUSERS); + + RETURN(compat); +destroylock: + list_del_init(&req->l_res_link); + ldlm_lock_destroy_nolock(req); + *err = compat; + RETURN(compat); +} + +/** + * This function refresh eviction timer for cancelled lock. + * \param[in] lock ldlm lock for refresh + * \param[in] arg ldlm prolong arguments, timeout, export, extent + * and counter are used + */ +void ldlm_lock_prolong_one(struct ldlm_lock *lock, + struct ldlm_prolong_args *arg) +{ + time64_t timeout; + + OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_PROLONG_PAUSE, 3); + + if (arg->lpa_export != lock->l_export || + lock->l_flags & LDLM_FL_DESTROYED) + /* ignore unrelated locks */ + return; + + arg->lpa_locks_cnt++; + + if (!(lock->l_flags & LDLM_FL_AST_SENT)) + /* ignore locks not being cancelled */ + return; + + /* We are in the middle of the process - BL AST is sent, CANCEL + * is ahead. Take half of BL AT + IO AT process time. + */ + timeout = arg->lpa_timeout + (ldlm_bl_timeout(lock) >> 1); + + LDLM_DEBUG(lock, "refreshed to %llds.\n", timeout); + + arg->lpa_blocks_cnt++; + + /* OK. this is a possible lock the user holds doing I/O + * let's refresh eviction timer for it. + */ + ldlm_refresh_waiting_lock(lock, timeout); +} +EXPORT_SYMBOL(ldlm_lock_prolong_one); + +static enum interval_iter ldlm_resource_prolong_cb(struct interval_node *n, + void *data) +{ + struct ldlm_prolong_args *arg = data; + struct ldlm_interval *node = to_ldlm_interval(n); + struct ldlm_lock *lock; + + ENTRY; + + LASSERT(!list_empty(&node->li_group)); + + list_for_each_entry(lock, &node->li_group, l_sl_policy) { + ldlm_lock_prolong_one(lock, arg); + } + + RETURN(INTERVAL_ITER_CONT); +} + +/** + * Walk through granted tree and prolong locks if they overlaps extent. * - * An alternative policy is to not shrink the new extent when conflicts exist. + * \param[in] arg prolong args + */ +void ldlm_resource_prolong(struct ldlm_prolong_args *arg) +{ + struct ldlm_interval_tree *tree; + struct ldlm_resource *res; + struct interval_node_extent ex = { .start = arg->lpa_extent.start, + .end = arg->lpa_extent.end }; + int idx; + + ENTRY; + + res = ldlm_resource_get(arg->lpa_export->exp_obd->obd_namespace, NULL, + &arg->lpa_resid, LDLM_EXTENT, 0); + if (IS_ERR(res)) { + CDEBUG(D_DLMTRACE, "Failed to get resource for resid %llu/%llu\n", + arg->lpa_resid.name[0], arg->lpa_resid.name[1]); + RETURN_EXIT; + } + + lock_res(res); + for (idx = 0; idx < LCK_MODE_NUM; idx++) { + tree = &res->lr_itree[idx]; + if (tree->lit_root == NULL) /* empty tree, skipped */ + continue; + + /* There is no possibility to check for the groupID + * so all the group locks are considered as valid + * here, especially because the client is supposed + * to check it has such a lock before sending an RPC. + */ + if (!(tree->lit_mode & arg->lpa_mode)) + continue; + + interval_search(tree->lit_root, &ex, + ldlm_resource_prolong_cb, arg); + } + + unlock_res(res); + ldlm_resource_putref(res); + + EXIT; +} +EXPORT_SYMBOL(ldlm_resource_prolong); + +/** + * Process a granting attempt for extent lock. + * Must be called with ns lock held. * - * To reconstruct our formulas, take a deep breath. */ -int ldlm_extent_policy(struct ldlm_resource *res, struct ldlm_extent *req_ex, - struct ldlm_extent *new_ex, ldlm_mode_t mode, void *data) + * This function looks for any conflicts for \a lock in the granted or + * waiting queues. The lock is granted if no conflicts are found in + * either queue. + */ +int ldlm_process_extent_lock(struct ldlm_lock *lock, __u64 *flags, + enum ldlm_process_intention intention, + enum ldlm_error *err, struct list_head *work_list) +{ + struct ldlm_resource *res = lock->l_resource; + struct list_head rpc_list; + int rc, rc2; + int contended_locks = 0; + ENTRY; + + LASSERT(lock->l_granted_mode != lock->l_req_mode); + LASSERT(!(*flags & LDLM_FL_DENY_ON_CONTENTION) || + !ldlm_is_ast_discard_data(lock)); + INIT_LIST_HEAD(&rpc_list); + check_res_locked(res); + *err = ELDLM_OK; + + if (intention == LDLM_PROCESS_RESCAN) { + /* Careful observers will note that we don't handle -EWOULDBLOCK + * here, but it's ok for a non-obvious reason -- compat_queue + * can only return -EWOULDBLOCK if (flags & BLOCK_NOWAIT | + * SPECULATIVE). flags should always be zero here, and if that + * ever stops being true, we want to find out. */ + LASSERT(*flags == 0); + rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, + err, NULL, &contended_locks); + if (rc == 1) { + rc = ldlm_extent_compat_queue(&res->lr_waiting, lock, + flags, err, NULL, + &contended_locks); + } + if (rc == 0) + RETURN(LDLM_ITER_STOP); + + ldlm_resource_unlink_lock(lock); + + if (!OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_EVICT_RACE)) + ldlm_extent_policy(res, lock, flags); + ldlm_grant_lock(lock, work_list); + RETURN(LDLM_ITER_CONTINUE); + } + + LASSERT((intention == LDLM_PROCESS_ENQUEUE && work_list == NULL) || + (intention == LDLM_PROCESS_RECOVERY && work_list != NULL)); + restart: + contended_locks = 0; + rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, err, + &rpc_list, &contended_locks); + if (rc < 0) + GOTO(out_rpc_list, rc); + + rc2 = 0; + if (rc != 2) { + rc2 = ldlm_extent_compat_queue(&res->lr_waiting, lock, + flags, err, &rpc_list, + &contended_locks); + if (rc2 < 0) + GOTO(out_rpc_list, rc = rc2); + } + + if (rc + rc2 != 2) { + /* Adding LDLM_FL_NO_TIMEOUT flag to granted lock to force + * client to wait for the lock endlessly once the lock is + * enqueued -bzzz */ + rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list, + LDLM_FL_NO_TIMEOUT); + if (rc == -ERESTART) + GOTO(restart, rc); + *err = rc; + } else { + ldlm_extent_policy(res, lock, flags); + ldlm_resource_unlink_lock(lock); + ldlm_grant_lock(lock, work_list); + rc = 0; + } + +out_rpc_list: + if (!list_empty(&rpc_list)) { + LASSERT(!ldlm_is_ast_discard_data(lock)); + ldlm_discard_bl_list(&rpc_list); + } + RETURN(rc); +} +#endif /* HAVE_SERVER_SUPPORT */ + +struct ldlm_kms_shift_args { + __u64 old_kms; + __u64 kms; + bool complete; +}; + +/* Callback for interval_iterate functions, used by ldlm_extent_shift_Kms */ +static enum interval_iter ldlm_kms_shift_cb(struct interval_node *n, + void *args) +{ + struct ldlm_kms_shift_args *arg = args; + struct ldlm_interval *node = to_ldlm_interval(n); + struct ldlm_lock *tmplock; + struct ldlm_lock *lock = NULL; + + ENTRY; + + /* Since all locks in an interval have the same extent, we can just + * use the first lock without kms_ignore set. */ + list_for_each_entry(tmplock, &node->li_group, l_sl_policy) { + if (ldlm_is_kms_ignore(tmplock)) + continue; + + lock = tmplock; + + break; + } + + /* No locks in this interval without kms_ignore set */ + if (!lock) + RETURN(INTERVAL_ITER_CONT); + + /* If we find a lock with a greater or equal kms, we are not the + * highest lock (or we share that distinction with another lock), and + * don't need to update KMS. Return old_kms and stop looking. */ + if (lock->l_policy_data.l_extent.end >= arg->old_kms) { + arg->kms = arg->old_kms; + arg->complete = true; + RETURN(INTERVAL_ITER_STOP); + } + + if (lock->l_policy_data.l_extent.end + 1 > arg->kms) + arg->kms = lock->l_policy_data.l_extent.end + 1; + + /* Since interval_iterate_reverse starts with the highest lock and + * works down, for PW locks, we only need to check if we should update + * the kms, then stop walking the tree. PR locks are not exclusive, so + * the highest start does not imply the highest end and we must + * continue. (Only one group lock is allowed per resource, so this is + * irrelevant for group locks.)*/ + if (lock->l_granted_mode == LCK_PW) + RETURN(INTERVAL_ITER_STOP); + else + RETURN(INTERVAL_ITER_CONT); +} + +/* When a lock is cancelled by a client, the KMS may undergo change if this + * is the "highest lock". This function returns the new KMS value, updating + * it only if we were the highest lock. + * + * Caller must hold lr_lock already. + * + * NB: A lock on [x,y] protects a KMS of up to y + 1 bytes! */ +__u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms) +{ + struct ldlm_resource *res = lock->l_resource; + struct ldlm_interval_tree *tree; + struct ldlm_kms_shift_args args; + int idx = 0; + + ENTRY; + + args.old_kms = old_kms; + args.kms = 0; + args.complete = false; + + /* don't let another thread in ldlm_extent_shift_kms race in + * just after we finish and take our lock into account in its + * calculation of the kms */ + ldlm_set_kms_ignore(lock); + + /* We iterate over the lock trees, looking for the largest kms smaller + * than the current one. */ + for (idx = 0; idx < LCK_MODE_NUM; idx++) { + tree = &res->lr_itree[idx]; + + /* If our already known kms is >= than the highest 'end' in + * this tree, we don't need to check this tree, because + * the kms from a tree can be lower than in_max_high (due to + * kms_ignore), but it can never be higher. */ + if (!tree->lit_root || args.kms >= tree->lit_root->in_max_high) + continue; + + interval_iterate_reverse(tree->lit_root, ldlm_kms_shift_cb, + &args); + + /* this tells us we're not the highest lock, so we don't need + * to check the remaining trees */ + if (args.complete) + break; + } + + LASSERTF(args.kms <= args.old_kms, "kms %llu old_kms %llu\n", args.kms, + args.old_kms); + + RETURN(args.kms); +} +EXPORT_SYMBOL(ldlm_extent_shift_kms); + +struct kmem_cache *ldlm_interval_slab; +struct ldlm_interval *ldlm_interval_alloc(struct ldlm_lock *lock) +{ + struct ldlm_interval *node; + ENTRY; + + LASSERT(lock->l_resource->lr_type == LDLM_EXTENT); + OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, GFP_NOFS); + if (node == NULL) + RETURN(NULL); + + INIT_LIST_HEAD(&node->li_group); + ldlm_interval_attach(node, lock); + RETURN(node); +} + +void ldlm_interval_free(struct ldlm_interval *node) +{ + if (node) { + LASSERT(list_empty(&node->li_group)); + LASSERT(!interval_is_intree(&node->li_node)); + OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node)); + } +} + +/* interval tree, for LDLM_EXTENT. */ +void ldlm_interval_attach(struct ldlm_interval *n, + struct ldlm_lock *l) +{ + LASSERT(l->l_tree_node == NULL); + LASSERT(l->l_resource->lr_type == LDLM_EXTENT); + + list_add_tail(&l->l_sl_policy, &n->li_group); + l->l_tree_node = n; +} + +struct ldlm_interval *ldlm_interval_detach(struct ldlm_lock *l) { - new_ex->start = 0; - new_ex->end = ~0; + struct ldlm_interval *n = l->l_tree_node; + + if (n == NULL) + return NULL; - if (!res) - LBUG(); + LASSERT(!list_empty(&n->li_group)); + l->l_tree_node = NULL; + list_del_init(&l->l_sl_policy); - policy_internal(&res->lr_granted, req_ex, new_ex, mode); - policy_internal(&res->lr_converting, req_ex, new_ex, mode); - policy_internal(&res->lr_waiting, req_ex, new_ex, mode); + return list_empty(&n->li_group) ? n : NULL; +} + +static inline int ldlm_mode_to_index(enum ldlm_mode mode) +{ + int index; - if (new_ex->end != req_ex->end || new_ex->start != req_ex->start) - return ELDLM_LOCK_CHANGED; - return 0; + LASSERT(mode != 0); + LASSERT(is_power_of_2(mode)); + for (index = -1; mode != 0; index++, mode >>= 1) + /* do nothing */; + LASSERT(index < LCK_MODE_NUM); + return index; } + +/** Add newly granted lock into interval tree for the resource. */ +void ldlm_extent_add_lock(struct ldlm_resource *res, + struct ldlm_lock *lock) +{ + struct interval_node *found, **root; + struct ldlm_interval *node; + struct ldlm_extent *extent; + int idx, rc; + + LASSERT(lock->l_granted_mode == lock->l_req_mode); + + node = lock->l_tree_node; + LASSERT(node != NULL); + LASSERT(!interval_is_intree(&node->li_node)); + + idx = ldlm_mode_to_index(lock->l_granted_mode); + LASSERT(lock->l_granted_mode == 1 << idx); + LASSERT(lock->l_granted_mode == res->lr_itree[idx].lit_mode); + + /* node extent initialize */ + extent = &lock->l_policy_data.l_extent; + + rc = interval_set(&node->li_node, extent->start, extent->end); + LASSERT(!rc); + + root = &res->lr_itree[idx].lit_root; + found = interval_insert(&node->li_node, root); + if (found) { /* The policy group found. */ + struct ldlm_interval *tmp = ldlm_interval_detach(lock); + LASSERT(tmp != NULL); + ldlm_interval_free(tmp); + ldlm_interval_attach(to_ldlm_interval(found), lock); + } + res->lr_itree[idx].lit_size++; + + /* even though we use interval tree to manage the extent lock, we also + * add the locks into grant list, for debug purpose, .. */ + ldlm_resource_add_lock(res, &res->lr_granted, lock); + + if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_GRANT_CHECK)) { + struct ldlm_lock *lck; + + list_for_each_entry_reverse(lck, &res->lr_granted, + l_res_link) { + if (lck == lock) + continue; + if (lockmode_compat(lck->l_granted_mode, + lock->l_granted_mode)) + continue; + if (ldlm_extent_overlap(&lck->l_req_extent, + &lock->l_req_extent)) { + CDEBUG(D_ERROR, "granting conflicting lock %p " + "%p\n", lck, lock); + ldlm_resource_dump(D_ERROR, res); + LBUG(); + } + } + } +} + +/** Remove cancelled lock from resource interval tree. */ +void ldlm_extent_unlink_lock(struct ldlm_lock *lock) +{ + struct ldlm_resource *res = lock->l_resource; + struct ldlm_interval *node = lock->l_tree_node; + struct ldlm_interval_tree *tree; + int idx; + + if (!node || !interval_is_intree(&node->li_node)) /* duplicate unlink */ + return; + + idx = ldlm_mode_to_index(lock->l_granted_mode); + LASSERT(lock->l_granted_mode == 1 << idx); + tree = &res->lr_itree[idx]; + + LASSERT(tree->lit_root != NULL); /* assure the tree is not null */ + + tree->lit_size--; + node = ldlm_interval_detach(lock); + if (node) { + interval_erase(&node->li_node, &tree->lit_root); + ldlm_interval_free(node); + } +} + +void ldlm_extent_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy, + union ldlm_policy_data *lpolicy) +{ + lpolicy->l_extent.start = wpolicy->l_extent.start; + lpolicy->l_extent.end = wpolicy->l_extent.end; + lpolicy->l_extent.gid = wpolicy->l_extent.gid; +} + +void ldlm_extent_policy_local_to_wire(const union ldlm_policy_data *lpolicy, + union ldlm_wire_policy_data *wpolicy) +{ + memset(wpolicy, 0, sizeof(*wpolicy)); + wpolicy->l_extent.start = lpolicy->l_extent.start; + wpolicy->l_extent.end = lpolicy->l_extent.end; + wpolicy->l_extent.gid = lpolicy->l_extent.gid; +} +