1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * NFS protocol definitions
4 *
5 * This file contains constants mostly for Version 2 of the protocol,
6 * but also has a couple of NFSv3 bits in (notably the error codes).
7 */
8#ifndef _LINUX_NFS_H
9#define _LINUX_NFS_H
10
11#include <linux/sunrpc/msg_prot.h>
12#include <linux/string.h>
13#include <linux/crc32.h>
14#include <uapi/linux/nfs.h>
15
16/*
17 * This is the kernel NFS client file handle representation
18 */
19#define NFS_MAXFHSIZE 128
20struct nfs_fh {
21 unsigned short size;
22 unsigned char data[NFS_MAXFHSIZE];
23};
24
25/*
26 * Returns a zero iff the size and data fields match.
27 * Checks only "size" bytes in the data field.
28 */
29static inline int nfs_compare_fh(const struct nfs_fh *a, const struct nfs_fh *b)
30{
31 return a->size != b->size || memcmp(p: a->data, q: b->data, size: a->size) != 0;
32}
33
34static inline void nfs_copy_fh(struct nfs_fh *target, const struct nfs_fh *source)
35{
36 target->size = source->size;
37 memcpy(target->data, source->data, source->size);
38}
39
40enum nfs3_stable_how {
41 NFS_UNSTABLE = 0,
42 NFS_DATA_SYNC = 1,
43 NFS_FILE_SYNC = 2,
44
45 /* used by direct.c to mark verf as invalid */
46 NFS_INVALID_STABLE_HOW = -1
47};
48
49#ifdef CONFIG_CRC32
50/**
51 * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
52 * @fh - pointer to filehandle
53 *
54 * returns a crc32 hash for the filehandle that is compatible with
55 * the one displayed by "wireshark".
56 */
57static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
58{
59 return ~crc32_le(crc: 0xFFFFFFFF, p: &fh->data[0], len: fh->size);
60}
61#else /* CONFIG_CRC32 */
62static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
63{
64 return 0;
65}
66#endif /* CONFIG_CRC32 */
67#endif /* _LINUX_NFS_H */
68

source code of linux/include/linux/nfs.h