FreeBSD/Linux Kernel Cross Reference
sys/sys/sysid.h

     /*
      * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
      * 
      * This code is derived from software contributed to The DragonFly Project
      * by Matthew Dillon <dillon@backplane.com>
      * 
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in
     *    the documentation and/or other materials provided with the
     *    distribution.
     * 3. Neither the name of The DragonFly Project nor the names of its
     *    contributors may be used to endorse or promote products derived
     *    from this software without specific, prior written permission.
     * 
     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
     * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
     * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     * 
     * $DragonFly: src/sys/sys/sysid.h,v 1.1 2007/04/29 01:29:31 dillon Exp $
     */
    
    #ifndef _SYS_SYSID_H_
    #define _SYS_SYSID_H_
    
    /*
     * SYSIDs are 64 bit entities and come in two varieties.  Physical SYSIDs
     * are used to efficiently route messages across the mesh, while Logical
     * SYSIDs are persistently assigned identifiers representing specific devices
     * or specific media or named filesystems.  That is, the logical SYSID
     * assigned to a filesystem or ANVIL partition can be stored in that
     * filesystem's superblock and allows the filesystem to migrate or
     * be multi-homed (have multiple physical SYSIDs representing the same
     * logical entity).
     * 
     * Physical SYSIDs can be ever-changing, and any given logical SYSID could
     * in fact have multiple physical SYSIDs associated with it.  The mesh is
     * self-healing and the combination of the logical and physical sysid
     * basically validates the message at the target and determines whether
     * the physical SYSID must be recalculated (looked up again) or not.
     */
    
    typedef u_int64_t       sysid_t;
    
    #endif

Cache object: 72111b2aeb43c6e139b1dc4500d00406