X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fldlm%2Fl_lock.c;h=cb08f5b257ab914ab2be0eb6f9c5393af63a395e;hp=ebf49d6f246056507097c80f893f4b5eee024ddf;hb=cf45b9d3ec9aa0872d3654a72f1b5cc9c5fff373;hpb=a4c80e2baf6f61118d9b4c965bf3eef928838176

diff --git a/lustre/ldlm/l_lock.c b/lustre/ldlm/l_lock.c
index ebf49d6..cb08f5b 100644
--- a/lustre/ldlm/l_lock.c
+++ b/lustre/ldlm/l_lock.c
@@ -1,115 +1,80 @@
 /* -*- 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);
 }