fs/xfs/xfs_export.h

   1 /*
   2  * Copyright (c) 2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_EXPORT_H__
  19 #define __XFS_EXPORT_H__
  20
  21 /*
  22  * Common defines for code related to exporting XFS filesystems over NFS.
  23  *
  24  * The NFS fileid goes out on the wire as an array of
  25  * 32bit unsigned ints in host order.  There are 5 possible
  26  * formats.
  27  *
  28  * (1)  fileid_type=0x00
  29  *      (no fileid data; handled by the generic code)
  30  *
  31  * (2)  fileid_type=0x01
  32  *      inode-num
  33  *      generation
  34  *
  35  * (3)  fileid_type=0x02
  36  *      inode-num
  37  *      generation
  38  *      parent-inode-num
  39  *      parent-generation
  40  *
  41  * (4)  fileid_type=0x81
  42  *      inode-num-lo32
  43  *      inode-num-hi32
  44  *      generation
  45  *
  46  * (5)  fileid_type=0x82
  47  *      inode-num-lo32
  48  *      inode-num-hi32
  49  *      generation
  50  *      parent-inode-num-lo32
  51  *      parent-inode-num-hi32
  52  *      parent-generation
  53  *
  54  * Note, the NFS filehandle also includes an fsid portion which
  55  * may have an inode number in it.  That number is hardcoded to
  56  * 32bits and there is no way for XFS to intercept it.  In
  57  * practice this means when exporting an XFS filesystem with 64bit
  58  * inodes you should either export the mountpoint (rather than
  59  * a subdirectory) or use the "fsid" export option.
  60  */
  61
  62 struct xfs_fid64 {
  63         u64 ino;
  64         u32 gen;
  65         u64 parent_ino;
  66         u32 parent_gen;
  67 } __attribute__((packed));
  68
  69 /* This flag goes on the wire.  Don't play with it. */
  70 #define XFS_FILEID_TYPE_64FLAG  0x80    /* NFS fileid has 64bit inodes */
  71
  72 #endif  /* __XFS_EXPORT_H__ */