-/* -*- 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 <braam@clusterfs.com> &
- * Phil Schwan <phil@clusterfs.com>
+ * 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.sun.com/software/products/lustre/docs/GPLv2.pdf
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Whamcloud, Inc.
+ */
+/*
+ * 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 <braam@clusterfs.com>
+ * Author: Phil Schwan <phil@clusterfs.com>
*/
#define DEBUG_SUBSYSTEM S_LDLM
+#ifndef __KERNEL__
+# include <liblustre.h>
+#else
+# include <libcfs/libcfs.h>
+#endif
+
+#include <lustre_dlm.h>
+#include <obd_support.h>
+#include <obd.h>
+#include <obd_class.h>
+#include <lustre_lib.h>
+
+#include "ldlm_internal.h"
+
+#ifdef HAVE_SERVER_SUPPORT
+# define LDLM_MAX_GROWN_EXTENT (32 * 1024 * 1024 - 1)
+
+/* fixup the ldlm_extent after expanding */
+static void ldlm_extent_internal_policy_fixup(struct ldlm_lock *req,
+ struct ldlm_extent *new_ex,
+ int conflicting)
+{
+ ldlm_mode_t 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);
+ }
-#include <linux/lustre_dlm.h>
+ if (new_ex->start == 0 && new_ex->end == OBD_OBJECT_EOF) {
+ EXIT;
+ return;
+ }
+
+ /* 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 = CFS_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 "LPX64" grant start "LPU64" req start "LPU64"\n",
+ mask, new_ex->start, req_start);
+ LASSERTF(new_ex->end >= req_end,
+ "mask "LPX64" grant end "LPU64" req end "LPU64"\n",
+ mask, new_ex->end, req_end);
+}
-/* 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.
+/* The purpose of this function is to return:
+ * - the maximum extent
+ * - containing the requested extent
+ * - and not overlapping existing conflicting extents outside the requested one
*
- * 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)
+ * 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)
{
- if (MAX(a->l_extent.start, b->l_extent.start) <=
- MIN(a->l_extent.end, b->l_extent.end))
- RETURN(0);
+ struct ldlm_resource *res = req->l_resource;
+ ldlm_mode_t 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 = { new_ex->start, new_ex->end };
+ int conflicting = 0;
+ int idx;
+ ENTRY;
+
+ lockmode_verify(req_mode);
- RETURN(1);
+ /* using interval tree to handle the ldlm extent granted locks */
+ for (idx = 0; idx < LCK_MODE_NUM; idx++) {
+ struct interval_node_extent ext = { req_start, 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;
}
-static void policy_internal(struct list_head *queue, struct ldlm_extent *req_ex,
- struct ldlm_extent *new_ex, ldlm_mode_t mode)
+/* The purpose of this function is to return:
+ * - the maximum extent
+ * - containing the requested extent
+ * - 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 list_head *tmp;
+ cfs_list_t *tmp;
+ struct ldlm_resource *res = req->l_resource;
+ ldlm_mode_t req_mode = req->l_req_mode;
+ __u64 req_start = req->l_req_extent.start;
+ __u64 req_end = req->l_req_extent.end;
+ int conflicting = 0;
+ ENTRY;
+
+ lockmode_verify(req_mode);
- list_for_each(tmp, queue) {
+ /* for waiting locks */
+ cfs_list_for_each(tmp, &res->lr_waiting) {
struct ldlm_lock *lock;
- lock = list_entry(tmp, struct ldlm_lock, l_res_link);
-
- 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;
+ struct ldlm_extent *l_extent;
+
+ lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
+ 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;
}
- 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;
+
+ /* 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;
}
-/* The purpose of this function is to return:
- * - the maximum extent
- * - containing the requested extent
- * - and not overlapping existing extents outside the requested one
+
+/* 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, int *flags)
+{
+ struct ldlm_extent new_ex = { .start = 0, .end = OBD_OBJECT_EOF };
+
+ if (lock->l_export == NULL)
+ /*
+ * this is 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;
+
+ ldlm_extent_internal_policy_granted(lock, &new_ex);
+ ldlm_extent_internal_policy_waiting(lock, &new_ex);
+
+ if (new_ex.start != lock->l_policy_data.l_extent.start ||
+ new_ex.end != lock->l_policy_data.l_extent.end) {
+ *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;
+ cfs_time_t now = cfs_time_current();
+
+ 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 cfs_time_before(now, cfs_time_add(res->lr_contention_time,
+ cfs_time_seconds(ldlm_res_to_ns(res)->ns_contention_time)));
+}
+
+struct ldlm_extent_compat_args {
+ cfs_list_t *work_list;
+ struct ldlm_lock *lock;
+ ldlm_mode_t 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;
+ cfs_list_t *work_list = priv->work_list;
+ struct ldlm_lock *lock, *enq = priv->lock;
+ ldlm_mode_t mode = priv->mode;
+ int count = 0;
+ ENTRY;
+
+ LASSERT(!cfs_list_empty(&node->li_group));
+
+ cfs_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)
+ 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.
+ * We stop walking the queue if we hit ourselves so we don't take
+ * conflicting locks enqueued after us into accound, or we'd wait forever.
*
- * An alternative policy is to not shrink the new extent when conflicts exist.
+ * 0 if the lock is not compatible
+ * 1 if the lock is compatible
+ * 2 if this group lock is compatible and requires no further checking
+ * negative error, such as EWOULDBLOCK for group locks
+ */
+static int
+ldlm_extent_compat_queue(cfs_list_t *queue, struct ldlm_lock *req,
+ int *flags, ldlm_error_t *err,
+ cfs_list_t *work_list, int *contended_locks)
+{
+ cfs_list_t *tmp;
+ struct ldlm_lock *lock;
+ struct ldlm_resource *res = req->l_resource;
+ ldlm_mode_t req_mode = req->l_req_mode;
+ __u64 req_start = req->l_req_extent.start;
+ __u64 req_end = req->l_req_extent.end;
+ int compat = 1;
+ int scan = 0;
+ int check_contention;
+ 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) {
+ 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;
+ }
+
+ if (!work_list) {
+ rc = interval_is_overlapped(tree->lit_root,&ex);
+ if (rc)
+ RETURN(0);
+ } else {
+ interval_search(tree->lit_root, &ex,
+ ldlm_extent_compat_cb, &data);
+ if (!cfs_list_empty(work_list) && compat)
+ compat = 0;
+ }
+ }
+ } else { /* for waiting queue */
+ cfs_list_for_each(tmp, queue) {
+ check_contention = 1;
+
+ lock = cfs_list_entry(tmp, struct ldlm_lock,
+ l_res_link);
+
+ 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);
+ cfs_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 (!(lock->l_flags & LDLM_FL_AST_SENT)) {
+ 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) {
+ 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);
+ cfs_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) {
+ 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);
+
+ /* 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)
+ 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:
+ cfs_list_del_init(&req->l_res_link);
+ ldlm_lock_destroy_nolock(req);
+ *err = compat;
+ RETURN(compat);
+}
+
+static void discard_bl_list(cfs_list_t *bl_list)
+{
+ cfs_list_t *tmp, *pos;
+ ENTRY;
+
+ cfs_list_for_each_safe(pos, tmp, bl_list) {
+ struct ldlm_lock *lock =
+ cfs_list_entry(pos, struct ldlm_lock, l_bl_ast);
+
+ cfs_list_del_init(&lock->l_bl_ast);
+ LASSERT(lock->l_flags & LDLM_FL_AST_SENT);
+ lock->l_flags &= ~LDLM_FL_AST_SENT;
+ LASSERT(lock->l_bl_ast_run == 0);
+ LASSERT(lock->l_blocking_lock);
+ LDLM_LOCK_RELEASE(lock->l_blocking_lock);
+ lock->l_blocking_lock = NULL;
+ LDLM_LOCK_RELEASE(lock);
+ }
+ EXIT;
+}
+
+/* If first_enq is 0 (ie, called from ldlm_reprocess_queue):
+ * - blocking ASTs have already been sent
+ * - must call this function with the ns lock held
+ *
+ * If first_enq is 1 (ie, called from ldlm_lock_enqueue):
+ * - blocking ASTs have not been sent
+ * - must call this function with the ns lock held once */
+int ldlm_process_extent_lock(struct ldlm_lock *lock, int *flags, int first_enq,
+ ldlm_error_t *err, cfs_list_t *work_list)
+{
+ struct ldlm_resource *res = lock->l_resource;
+ CFS_LIST_HEAD(rpc_list);
+ int rc, rc2;
+ int contended_locks = 0;
+ ENTRY;
+
+ LASSERT(cfs_list_empty(&res->lr_converting));
+ LASSERT(!(*flags & LDLM_FL_DENY_ON_CONTENTION) ||
+ !(lock->l_flags & LDLM_AST_DISCARD_DATA));
+ check_res_locked(res);
+ *err = ELDLM_OK;
+
+ if (!first_enq) {
+ /* 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).
+ * 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);
+ }
+
+ restart:
+ contended_locks = 0;
+ rc = ldlm_extent_compat_queue(&res->lr_granted, lock, flags, err,
+ &rpc_list, &contended_locks);
+ if (rc < 0)
+ GOTO(out, rc); /* lock was destroyed */
+ if (rc == 2)
+ goto grant;
+
+ rc2 = ldlm_extent_compat_queue(&res->lr_waiting, lock, flags, err,
+ &rpc_list, &contended_locks);
+ if (rc2 < 0)
+ GOTO(out, rc = rc2); /* lock was destroyed */
+
+ if (rc + rc2 == 2) {
+ grant:
+ ldlm_extent_policy(res, lock, flags);
+ ldlm_resource_unlink_lock(lock);
+ ldlm_grant_lock(lock, NULL);
+ } else {
+ /* If either of the compat_queue()s returned failure, then we
+ * have ASTs to send and must go onto the waiting list.
+ *
+ * bug 2322: we used to unlink and re-add here, which was a
+ * terrible folly -- if we goto restart, we could get
+ * re-ordered! Causes deadlock, because ASTs aren't sent! */
+ if (cfs_list_empty(&lock->l_res_link))
+ ldlm_resource_add_lock(res, &res->lr_waiting, lock);
+ unlock_res(res);
+ rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
+ LDLM_WORK_BL_AST);
+
+ if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_OST_FAIL_RACE) &&
+ !ns_is_client(ldlm_res_to_ns(res)))
+ class_fail_export(lock->l_export);
+
+ lock_res(res);
+ if (rc == -ERESTART) {
+
+ /* 15715: The lock was granted and destroyed after
+ * resource lock was dropped. Interval node was freed
+ * in ldlm_lock_destroy. Anyway, this always happens
+ * when a client is being evicted. So it would be
+ * ok to return an error. -jay */
+ if (lock->l_destroyed) {
+ *err = -EAGAIN;
+ GOTO(out, rc = -EAGAIN);
+ }
+
+ /* lock was granted while resource was unlocked. */
+ if (lock->l_granted_mode == lock->l_req_mode) {
+ /* bug 11300: if the lock has been granted,
+ * break earlier because otherwise, we will go
+ * to restart and ldlm_resource_unlink will be
+ * called and it causes the interval node to be
+ * freed. Then we will fail at
+ * ldlm_extent_add_lock() */
+ *flags &= ~(LDLM_FL_BLOCK_GRANTED | LDLM_FL_BLOCK_CONV |
+ LDLM_FL_BLOCK_WAIT);
+ GOTO(out, rc = 0);
+ }
+
+ GOTO(restart, -ERESTART);
+ }
+
+ *flags |= LDLM_FL_BLOCK_GRANTED;
+ /* this way we force client to wait for the lock
+ * endlessly once the lock is enqueued -bzzz */
+ *flags |= LDLM_FL_NO_TIMEOUT;
+
+ }
+ RETURN(0);
+out:
+ if (!cfs_list_empty(&rpc_list)) {
+ LASSERT(!(lock->l_flags & LDLM_AST_DISCARD_DATA));
+ discard_bl_list(&rpc_list);
+ }
+ RETURN(rc);
+}
+#endif /* HAVE_SERVER_SUPPORT */
+
+/* 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.
+ * Caller must hold lr_lock already.
*
- * 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)
+ * 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)
{
- new_ex->start = 0;
- new_ex->end = ~0;
+ struct ldlm_resource *res = lock->l_resource;
+ cfs_list_t *tmp;
+ struct ldlm_lock *lck;
+ __u64 kms = 0;
+ ENTRY;
+
+ /* 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 */
+ lock->l_flags |= LDLM_FL_KMS_IGNORE;
- if (!res)
- LBUG();
+ cfs_list_for_each(tmp, &res->lr_granted) {
+ lck = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
- 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);
+ if (lck->l_flags & LDLM_FL_KMS_IGNORE)
+ continue;
- if (new_ex->end != req_ex->end || new_ex->start != req_ex->start)
- return ELDLM_LOCK_CHANGED;
- return 0;
+ if (lck->l_policy_data.l_extent.end >= old_kms)
+ RETURN(old_kms);
+
+ /* This extent _has_ to be smaller than old_kms (checked above)
+ * so kms can only ever be smaller or the same as old_kms. */
+ if (lck->l_policy_data.l_extent.end + 1 > kms)
+ kms = lck->l_policy_data.l_extent.end + 1;
+ }
+ LASSERTF(kms <= old_kms, "kms "LPU64" old_kms "LPU64"\n", kms, old_kms);
+
+ RETURN(kms);
}
+EXPORT_SYMBOL(ldlm_extent_shift_kms);
+
+cfs_mem_cache_t *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, CFS_ALLOC_IO);
+ if (node == NULL)
+ RETURN(NULL);
+
+ CFS_INIT_LIST_HEAD(&node->li_group);
+ ldlm_interval_attach(node, lock);
+ RETURN(node);
+}
+
+void ldlm_interval_free(struct ldlm_interval *node)
+{
+ if (node) {
+ LASSERT(cfs_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);
+
+ cfs_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)
+{
+ struct ldlm_interval *n = l->l_tree_node;
+
+ if (n == NULL)
+ return NULL;
+
+ LASSERT(!cfs_list_empty(&n->li_group));
+ l->l_tree_node = NULL;
+ cfs_list_del_init(&l->l_sl_policy);
+
+ return (cfs_list_empty(&n->li_group) ? n : NULL);
+}
+
+static inline int lock_mode_to_index(ldlm_mode_t mode)
+{
+ int index;
+
+ LASSERT(mode != 0);
+ LASSERT(IS_PO2(mode));
+ for (index = -1; mode; index++, mode >>= 1) ;
+ LASSERT(index < LCK_MODE_NUM);
+ return index;
+}
+
+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;
+
+ 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 = lock_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;
+ interval_set(&node->li_node, extent->start, extent->end);
+
+ 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);
+}
+
+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 = lock_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 ldlm_wire_policy_data_t *wpolicy,
+ ldlm_policy_data_t *lpolicy)
+{
+ memset(lpolicy, 0, sizeof(*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 ldlm_policy_data_t *lpolicy,
+ ldlm_wire_policy_data_t *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;
+}
+
git://git.whamcloud.com / fs / lustre-release.git / blobdiff