text: /*
   * 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 "../../include/linux/libcfs/libcfs.h"
  
  #include "../include/lustre_dlm.h"
  #include "../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_flags & LDLM_FL_NS_SRV) == 0)
  		spin_lock(&lock->l_lock);
  
  	lock_res(lock->l_resource);
  
  	lock->l_flags |= LDLM_FL_RES_LOCKED;
  	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_flags &= ~LDLM_FL_RES_LOCKED;
  
  	unlock_res(lock->l_resource);
  	if ((lock->l_flags & LDLM_FL_NS_SRV) == 0)
  		spin_unlock(&lock->l_lock);
  }
  EXPORT_SYMBOL(unlock_res_and_lock);
  