+++ /dev/null
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
- * Copyright (c) 2002 Cluster File Systems, Inc.
- * Author: Peter Braam <braam@clusterfs.com>
- * Author: Phil Schwan <phil@clusterfs.com>
- *
- * This file is part of Lustre, http://www.lustre.org.
- *
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * Lustre 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 for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#define DEBUG_SUBSYSTEM S_LDLM
-#ifndef __KERNEL__
-# include <liblustre.h>
-#endif
-
-#include <linux/lustre_dlm.h>
-#include <linux/obd_support.h>
-#include <linux/lustre_lib.h>
-
-/* This function will be called to judge if one extent overlaps with another */
-int ldlm_extent_compat(struct ldlm_lock *a, struct ldlm_lock *b)
-{
- if ((a->l_extent.start <= b->l_extent.end) &&
- (a->l_extent.end >= b->l_extent.start))
- RETURN(0);
-
- RETURN(1);
-}
-
-/* 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
- *
- * An alternative policy is to not shrink the new extent when conflicts exist.
- *
- * To reconstruct our formulas, take a deep breath. */
-static void policy_internal(struct list_head *queue, struct ldlm_extent *req_ex,
- struct ldlm_extent *new_ex, ldlm_mode_t mode)
-{
- struct list_head *tmp;
-
- list_for_each(tmp, queue) {
- struct ldlm_lock *lock;
- lock = list_entry(tmp, struct ldlm_lock, l_res_link);
-
- /* if lock doesn't overlap new_ex, skip it. */
- if (lock->l_extent.end < new_ex->start ||
- lock->l_extent.start > new_ex->end)
- continue;
-
- /* Locks are compatible, overlap doesn't matter */
- if (lockmode_compat(lock->l_req_mode, mode))
- continue;
-
- if (lock->l_extent.start < req_ex->start) {
- if (lock->l_extent.end == ~0) {
- new_ex->start = req_ex->start;
- new_ex->end = req_ex->end;
- return;
- }
- new_ex->start = MIN(lock->l_extent.end + 1,
- req_ex->start);
- }
-
- if (lock->l_extent.end > req_ex->end) {
- if (lock->l_extent.start == 0) {
- new_ex->start = req_ex->start;
- new_ex->end = req_ex->end;
- return;
- }
- new_ex->end = MAX(lock->l_extent.start - 1,
- req_ex->end);
- }
- }
-}
-
-/* apply the internal policy by walking all the lists */
-int ldlm_extent_policy(struct ldlm_namespace *ns, struct ldlm_lock **lockp,
- void *req_cookie, ldlm_mode_t mode, int flags,
- void *data)
-{
- struct ldlm_lock *lock = *lockp;
- struct ldlm_resource *res = lock->l_resource;
- struct ldlm_extent *req_ex = req_cookie;
- struct ldlm_extent new_ex;
- new_ex.start = 0;
- new_ex.end = ~0;
-
- if (!res)
- LBUG();
-
- l_lock(&ns->ns_lock);
- 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);
- l_unlock(&ns->ns_lock);
-
- memcpy(&lock->l_extent, &new_ex, sizeof(new_ex));
-
- LDLM_DEBUG(lock, "requested extent ["LPU64"->"LPU64"], new extent ["
- LPU64"->"LPU64"]",
- req_ex->start, req_ex->end, new_ex.start, new_ex.end);
-
- if (new_ex.end != req_ex->end || new_ex.start != req_ex->start)
- return ELDLM_LOCK_CHANGED;
- else
- return 0;
-}
+++ /dev/null
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
- * Copyright (c) 2002, 2003 Cluster File Systems, Inc.
- * Author: Peter Braam <braam@clusterfs.com>
- * Author: Phil Schwan <phil@clusterfs.com>
- *
- * This file is part of Lustre, http://www.lustre.org.
- *
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * Lustre 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 for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#define DEBUG_SUBSYSTEM S_LDLM
-
-#ifdef __KERNEL__
-#include <linux/lustre_dlm.h>
-#include <linux/obd_support.h>
-#include <linux/lustre_lib.h>
-#else
-#include <liblustre.h>
-#endif
-
-static int
-ldlm_plain_compat_queue(struct list_head *queue, struct ldlm_lock *new,
- int send_cbs, int first_enq)
-{
- struct list_head *tmp, *pos;
- ldlm_mode_t mode = new->l_req_mode;
- int compat = 1;
- ENTRY;
-
- list_for_each_safe(tmp, pos, queue) {
- struct ldlm_lock *old;
-
- old = list_entry(tmp, struct ldlm_lock, l_res_link);
- if (old == new)
- continue;
-
- if (lockmode_compat(old->l_req_mode, mode) &&
- lockmode_compat(old->l_granted_mode, mode)) {
- CDEBUG(D_OTHER, "lock modes are compatible, next.\n");
- continue;
- }
-
- compat = 0;
-
- /* if we're reprocessing the lock then the blocking ASTs
- * have already been sent. No need to continue. */
- if (!first_enq)
- break;
-
- if (send_cbs && (old->l_blocking_ast != NULL)) {
- CDEBUG(D_DLMTRACE, "lock %p incompatible; "
- "sending blocking AST.\n", old);
- ldlm_add_ast_work_item(old, new, NULL, 0);
- } else if (!(old->l_flags & LDLM_FL_LOCAL)) {
- CDEBUG(D_DLMTRACE, "lock %p incompatible; "
- "setting blocking AST.\n", old);
- old->l_flags |= LDLM_FL_AST_SENT;
- } else {
- CDEBUG(D_DLMTRACE, "local lock %p incompatible.\n",
- old);
- }
- }
-
- RETURN(compat);
-}
-
-int
-ldlm_plain_enqueue(struct ldlm_lock **lockp, void *cookie, int *flags,
- int first_enq, ldlm_error_t *err)
-{
- struct ldlm_lock *lock = *lockp;
- struct ldlm_resource *res = lock->l_resource;
- int convert_compat = 1;
- int waiting_compat = 1;
- int granted_compat = 1;
- ENTRY;
-
- /* FIXME: We may want to optimize by checking lr_most_restr */
-
- /* On the first enqueue of this lock scan all of the queues
- * to set the LDLM_FL_AST_SENT flag in conflicting locks.
- * When the completion AST on the client side runs and sees
- * this flag is will set the LDLM_FL_CB_PENDING flag in the
- * lock so the client will know to cancel the lock as soon
- * as possible. This saves us from sending a blocking AST
- * in addition to the completion AST.
- *
- * If it's NOT the first enqueue of this lock then it must be
- * the first eligible lock in the queues because of the way that
- * ldlm_reprocess_all() works. So we don't have to check the
- * converting or waiting queues. */
- if (first_enq) {
- if (!list_empty(&res->lr_converting)) {
- convert_compat = 0;
- ldlm_plain_compat_queue(&res->lr_converting,
- lock, 0, first_enq);
- }
- if (!list_empty(&res->lr_waiting)) {
- waiting_compat = 0;
- ldlm_plain_compat_queue(&res->lr_waiting,
- lock, 0, first_enq);
- }
- }
- granted_compat =
- ldlm_plain_compat_queue(&res->lr_granted, lock, 1, first_enq);
-
- if (!convert_compat) {
- *flags |= LDLM_FL_BLOCK_CONV;
- RETURN(LDLM_ITER_STOP);
- }
- if (!waiting_compat) {
- *flags |= LDLM_FL_BLOCK_WAIT;
- RETURN(LDLM_ITER_STOP);
- }
- if (!granted_compat) {
- *flags |= LDLM_FL_BLOCK_GRANTED;
- RETURN(LDLM_ITER_STOP);
- }
-
- list_del_init(&lock->l_res_link);
- ldlm_grant_lock(lock, NULL, 0);
-
- if (lock->l_flags & LDLM_FL_AST_SENT) {
- CDEBUG(D_DLMTRACE, "granted lock %p with AST set\n", lock);
- *flags |= (lock->l_flags & LDLM_FL_AST_SENT);
- }
-
- RETURN(LDLM_ITER_CONTINUE);
-}
git://git.whamcloud.com / fs / lustre-release.git / commitdiff