1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3 * This file describes the layout of the file handles as passed
4 * over the wire.
5 *
6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
7 */
8
9 #ifndef _UAPI_LINUX_NFSD_FH_H
10 #define _UAPI_LINUX_NFSD_FH_H
11
12 #include <linux/types.h>
13 #include <linux/nfs.h>
14 #include <linux/nfs2.h>
15 #include <linux/nfs3.h>
16 #include <linux/nfs4.h>
17
18 /*
19 * This is the old "dentry style" Linux NFSv2 file handle.
20 *
21 * The xino and xdev fields are currently used to transport the
22 * ino/dev of the exported inode.
23 */
24 struct nfs_fhbase_old {
25 __u32 fb_dcookie; /* dentry cookie - always 0xfeebbaca */
26 __u32 fb_ino; /* our inode number */
27 __u32 fb_dirino; /* dir inode number, 0 for directories */
28 __u32 fb_dev; /* our device */
29 __u32 fb_xdev;
30 __u32 fb_xino;
31 __u32 fb_generation;
32 };
33
34 /*
35 * This is the new flexible, extensible style NFSv2/v3/v4 file handle.
36 * by Neil Brown <neilb@cse.unsw.edu.au> - March 2000
37 *
38 * The file handle starts with a sequence of four-byte words.
39 * The first word contains a version number (1) and three descriptor bytes
40 * that tell how the remaining 3 variable length fields should be handled.
41 * These three bytes are auth_type, fsid_type and fileid_type.
42 *
43 * All four-byte values are in host-byte-order.
44 *
45 * The auth_type field is deprecated and must be set to 0.
46 *
47 * The fsid_type identifies how the filesystem (or export point) is
48 * encoded.
49 * Current values:
50 * 0 - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
51 * NOTE: we cannot use the kdev_t device id value, because kdev_t.h
52 * says we mustn't. We must break it up and reassemble.
53 * 1 - 4 byte user specified identifier
54 * 2 - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
55 * 3 - 4 byte device id, encoded for user-space, 4 byte inode number
56 * 4 - 4 byte inode number and 4 byte uuid
57 * 5 - 8 byte uuid
58 * 6 - 16 byte uuid
59 * 7 - 8 byte inode number and 16 byte uuid
60 *
61 * The fileid_type identified how the file within the filesystem is encoded.
62 * The values for this field are filesystem specific, exccept that
63 * filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
64 * in include/linux/exportfs.h for currently registered values.
65 */
66 struct nfs_fhbase_new {
67 __u8 fb_version; /* == 1, even => nfs_fhbase_old */
68 __u8 fb_auth_type;
69 __u8 fb_fsid_type;
70 __u8 fb_fileid_type;
71 __u32 fb_auth[1];
72 /* __u32 fb_fsid[0]; floating */
73 /* __u32 fb_fileid[0]; floating */
74 };
75
76 struct knfsd_fh {
77 unsigned int fh_size; /* significant for NFSv3.
78 * Points to the current size while building
79 * a new file handle
80 */
81 union {
82 struct nfs_fhbase_old fh_old;
83 __u32 fh_pad[NFS4_FHSIZE/4];
84 struct nfs_fhbase_new fh_new;
85 } fh_base;
86 };
87
88 #define ofh_dcookie fh_base.fh_old.fb_dcookie
89 #define ofh_ino fh_base.fh_old.fb_ino
90 #define ofh_dirino fh_base.fh_old.fb_dirino
91 #define ofh_dev fh_base.fh_old.fb_dev
92 #define ofh_xdev fh_base.fh_old.fb_xdev
93 #define ofh_xino fh_base.fh_old.fb_xino
94 #define ofh_generation fh_base.fh_old.fb_generation
95
96 #define fh_version fh_base.fh_new.fb_version
97 #define fh_fsid_type fh_base.fh_new.fb_fsid_type
98 #define fh_auth_type fh_base.fh_new.fb_auth_type
99 #define fh_fileid_type fh_base.fh_new.fb_fileid_type
100 #define fh_fsid fh_base.fh_new.fb_auth
101
102 /* Do not use, provided for userspace compatiblity. */
103 #define fh_auth fh_base.fh_new.fb_auth
104
105 #endif /* _UAPI_LINUX_NFSD_FH_H */