xref: /OK3568_Linux_fs/kernel/fs/xfs/xfs_export.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright (c) 2005 Silicon Graphics, Inc.
4*4882a593Smuzhiyun  * All Rights Reserved.
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun #ifndef __XFS_EXPORT_H__
7*4882a593Smuzhiyun #define __XFS_EXPORT_H__
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun /*
10*4882a593Smuzhiyun  * Common defines for code related to exporting XFS filesystems over NFS.
11*4882a593Smuzhiyun  *
12*4882a593Smuzhiyun  * The NFS fileid goes out on the wire as an array of
13*4882a593Smuzhiyun  * 32bit unsigned ints in host order.  There are 5 possible
14*4882a593Smuzhiyun  * formats.
15*4882a593Smuzhiyun  *
16*4882a593Smuzhiyun  * (1)	fileid_type=0x00
17*4882a593Smuzhiyun  *	(no fileid data; handled by the generic code)
18*4882a593Smuzhiyun  *
19*4882a593Smuzhiyun  * (2)	fileid_type=0x01
20*4882a593Smuzhiyun  *	inode-num
21*4882a593Smuzhiyun  *	generation
22*4882a593Smuzhiyun  *
23*4882a593Smuzhiyun  * (3)	fileid_type=0x02
24*4882a593Smuzhiyun  *	inode-num
25*4882a593Smuzhiyun  *	generation
26*4882a593Smuzhiyun  *	parent-inode-num
27*4882a593Smuzhiyun  *	parent-generation
28*4882a593Smuzhiyun  *
29*4882a593Smuzhiyun  * (4)	fileid_type=0x81
30*4882a593Smuzhiyun  *	inode-num-lo32
31*4882a593Smuzhiyun  *	inode-num-hi32
32*4882a593Smuzhiyun  *	generation
33*4882a593Smuzhiyun  *
34*4882a593Smuzhiyun  * (5)	fileid_type=0x82
35*4882a593Smuzhiyun  *	inode-num-lo32
36*4882a593Smuzhiyun  *	inode-num-hi32
37*4882a593Smuzhiyun  *	generation
38*4882a593Smuzhiyun  *	parent-inode-num-lo32
39*4882a593Smuzhiyun  *	parent-inode-num-hi32
40*4882a593Smuzhiyun  *	parent-generation
41*4882a593Smuzhiyun  *
42*4882a593Smuzhiyun  * Note, the NFS filehandle also includes an fsid portion which
43*4882a593Smuzhiyun  * may have an inode number in it.  That number is hardcoded to
44*4882a593Smuzhiyun  * 32bits and there is no way for XFS to intercept it.  In
45*4882a593Smuzhiyun  * practice this means when exporting an XFS filesystem with 64bit
46*4882a593Smuzhiyun  * inodes you should either export the mountpoint (rather than
47*4882a593Smuzhiyun  * a subdirectory) or use the "fsid" export option.
48*4882a593Smuzhiyun  */
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun struct xfs_fid64 {
51*4882a593Smuzhiyun 	u64 ino;
52*4882a593Smuzhiyun 	u32 gen;
53*4882a593Smuzhiyun 	u64 parent_ino;
54*4882a593Smuzhiyun 	u32 parent_gen;
55*4882a593Smuzhiyun } __attribute__((packed));
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun /* This flag goes on the wire.  Don't play with it. */
58*4882a593Smuzhiyun #define XFS_FILEID_TYPE_64FLAG	0x80	/* NFS fileid has 64bit inodes */
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun #endif	/* __XFS_EXPORT_H__ */
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