/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
- * Copyright (C) 2001, 2002 Cluster File Systems, Inc.
+ * GPL HEADER START
*
- * This file is part of Lustre, http://www.sf.net/projects/lustre/
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
- * 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.
+ * 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.
*
- * 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.
+ * 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
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * 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 2008 Sun Microsystems, Inc. All rights reserved
+ * Use is subject to license terms.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
*/
#define DEBUG_SUBSYSTEM S_LDLM
#ifdef __KERNEL__
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/stat.h>
-#include <linux/errno.h>
-#include <linux/unistd.h>
-#include <linux/version.h>
-
-#include <asm/system.h>
-#include <asm/uaccess.h>
-
-#include <linux/fs.h>
-#include <linux/stat.h>
-#include <asm/uaccess.h>
-#include <asm/segment.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/smp_lock.h>
+#include <libcfs/libcfs.h>
#else
#include <liblustre.h>
#endif
-#include <linux/lustre_dlm.h>
-#include <linux/lustre_lib.h>
-
-/* invariants:
- - only the owner of the lock changes l_owner/l_depth
- - if a non-owner changes or checks the variables a spin lock is taken
-*/
+#include <lustre_dlm.h>
+#include <lustre_lib.h>
-void l_lock_init(struct lustre_lock *lock)
+/*
+ * ldlm locking uses resource to serialize access to locks
+ * but there is a case when we change resource of lock upon
+ * enqueue reply. we rely on that lock->l_resource = new_res
+ * is atomic
+ */
+struct ldlm_resource * lock_res_and_lock(struct ldlm_lock *lock)
{
- sema_init(&lock->l_sem, 1);
- spin_lock_init(&lock->l_spin);
-}
+ struct ldlm_resource *res = NULL;
-void l_lock(struct lustre_lock *lock)
-{
- int owner = 0;
+ spin_lock(&lock->l_lock);
+ res = lock->l_resource;
- spin_lock(&lock->l_spin);
- if (lock->l_owner == current)
- owner = 1;
- spin_unlock(&lock->l_spin);
+ if (ns_is_server(res->lr_namespace))
+ /* on server-side resource of lock doesn't change */
+ spin_unlock(&lock->l_lock);
- /* This is safe to increment outside the spinlock because we
- * can only have 1 CPU running on the current task
- * (i.e. l_owner == current), regardless of the number of CPUs.
- */
- if (owner) {
- ++lock->l_depth;
- } else {
- down(&lock->l_sem);
- spin_lock(&lock->l_spin);
- lock->l_owner = current;
- lock->l_depth = 0;
- spin_unlock(&lock->l_spin);
- }
+ lock_res(res);
+ return res;
}
-void l_unlock(struct lustre_lock *lock)
+void unlock_res_and_lock(struct ldlm_lock *lock)
{
- LASSERT(lock->l_owner == current);
- LASSERT(lock->l_depth >= 0);
+ struct ldlm_resource *res = lock->l_resource;
- spin_lock(&lock->l_spin);
- if (--lock->l_depth < 0) {
- lock->l_owner = NULL;
- spin_unlock(&lock->l_spin);
- up(&lock->l_sem);
+ if (ns_is_server(res->lr_namespace)) {
+ /* on server-side resource of lock doesn't change */
+ unlock_res(res);
return;
}
- spin_unlock(&lock->l_spin);
-}
-
-int l_has_lock(struct lustre_lock *lock)
-{
- int depth = -1, owner = 0;
-
- spin_lock(&lock->l_spin);
- if (lock->l_owner == current) {
- depth = lock->l_depth;
- owner = 1;
- }
- spin_unlock(&lock->l_spin);
- if (depth >= 0)
- CDEBUG(D_INFO, "lock_depth: %d\n", depth);
- return owner;
+ unlock_res(res);
+ spin_unlock(&lock->l_lock);
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff