diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/ldlm/l_lock.c')
-rw-r--r-- | drivers/staging/lustre/lustre/ldlm/l_lock.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/ldlm/l_lock.c b/drivers/staging/lustre/lustre/ldlm/l_lock.c new file mode 100644 index 000000000000..853409aa945d --- /dev/null +++ b/drivers/staging/lustre/lustre/ldlm/l_lock.c @@ -0,0 +1,76 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * 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. + * + * 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) 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + */ + +#define DEBUG_SUBSYSTEM S_LDLM +#include <linux/libcfs/libcfs.h> + +#include <lustre_dlm.h> +#include <lustre_lib.h> + +/** + * Lock a lock and its resource. + * + * 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 lock->l_resource = new_res + * being an atomic operation. + */ +struct ldlm_resource *lock_res_and_lock(struct ldlm_lock *lock) +{ + /* on server-side resource of lock doesn't change */ + if (!lock->l_ns_srv) + spin_lock(&lock->l_lock); + + lock_res(lock->l_resource); + + lock->l_res_locked = 1; + return lock->l_resource; +} +EXPORT_SYMBOL(lock_res_and_lock); + +/** + * Unlock a lock and its resource previously locked with lock_res_and_lock + */ +void unlock_res_and_lock(struct ldlm_lock *lock) +{ + /* on server-side resource of lock doesn't change */ + lock->l_res_locked = 0; + + unlock_res(lock->l_resource); + if (!lock->l_ns_srv) + spin_unlock(&lock->l_lock); +} +EXPORT_SYMBOL(unlock_res_and_lock); |