LXR linux/fs/xfs/xfs

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2005 Silicon Graphics, Inc.
   4 * All Rights Reserved.
   5 */
   6#ifndef __XFS_EXPORT_H__
   7#define __XFS_EXPORT_H__
   8
   9/*
  10 * Common defines for code related to exporting XFS filesystems over NFS.
  11 *
  12 * The NFS fileid goes out on the wire as an array of
  13 * 32bit unsigned ints in host order.  There are 5 possible
  14 * formats.
  15 *
  16 * (1)  fileid_type=0x00
  17 *      (no fileid data; handled by the generic code)
  18 *
  19 * (2)  fileid_type=0x01
  20 *      inode-num
  21 *      generation
  22 *
  23 * (3)  fileid_type=0x02
  24 *      inode-num
  25 *      generation
  26 *      parent-inode-num
  27 *      parent-generation
  28 *
  29 * (4)  fileid_type=0x81
  30 *      inode-num-lo32
  31 *      inode-num-hi32
  32 *      generation
  33 *
  34 * (5)  fileid_type=0x82
  35 *      inode-num-lo32
  36 *      inode-num-hi32
  37 *      generation
  38 *      parent-inode-num-lo32
  39 *      parent-inode-num-hi32
  40 *      parent-generation
  41 *
  42 * Note, the NFS filehandle also includes an fsid portion which
  43 * may have an inode number in it.  That number is hardcoded to
  44 * 32bits and there is no way for XFS to intercept it.  In
  45 * practice this means when exporting an XFS filesystem with 64bit
  46 * inodes you should either export the mountpoint (rather than
  47 * a subdirectory) or use the "fsid" export option.
  48 */
  49
  50struct xfs_fid64 {
  51        u64 ino;
  52        u32 gen;
  53        u64 parent_ino;
  54        u32 parent_gen;
  55} __attribute__((packed));
  56
  57/* This flag goes on the wire.  Don't play with it. */
  58#define XFS_FILEID_TYPE_64FLAG  0x80    /* NFS fileid has 64bit inodes */
  59
  60#endif  /* __XFS_EXPORT_H__ */
  61