fs/xfs/xfs_export.h

   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
  50 struct 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__ */