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Linux kernel mirror (for testing)
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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 filesytem with 64bit
58 * inodes you should either export the mountpoint (rather than
59 * a subdirectory) or use the "fsid" export option.
60 */
61
62/* This flag goes on the wire. Don't play with it. */
63#define XFS_FILEID_TYPE_64FLAG 0x80 /* NFS fileid has 64bit inodes */
64
65/* Calculate the length in u32 units of the fileid data */
66static inline int
67xfs_fileid_length(int hasparent, int is64)
68{
69 return hasparent ? (is64 ? 6 : 4) : (is64 ? 3 : 2);
70}
71
72/*
73 * Decode encoded inode information (either for the inode itself
74 * or the parent) into an xfs_fid2_t structure. Advances and
75 * returns the new data pointer
76 */
77static inline __u32 *
78xfs_fileid_decode_fid2(__u32 *p, xfs_fid2_t *fid, int is64)
79{
80 fid->fid_len = sizeof(xfs_fid2_t) - sizeof(fid->fid_len);
81 fid->fid_pad = 0;
82 fid->fid_ino = *p++;
83#if XFS_BIG_INUMS
84 if (is64)
85 fid->fid_ino |= (((__u64)(*p++)) << 32);
86#endif
87 fid->fid_gen = *p++;
88 return p;
89}
90
91/*
92 * Encode inode information (either for the inode itself or the
93 * parent) into a fileid buffer. Advances and returns the new
94 * data pointer.
95 */
96static inline __u32 *
97xfs_fileid_encode_inode(__u32 *p, struct inode *inode, int is64)
98{
99 *p++ = (__u32)inode->i_ino;
100#if XFS_BIG_INUMS
101 if (is64)
102 *p++ = (__u32)(inode->i_ino >> 32);
103#endif
104 *p++ = inode->i_generation;
105 return p;
106}
107
108#endif /* __XFS_EXPORT_H__ */