nfs.h

 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/cred.h>
12#include <linux/sunrpc/auth.h>
13#include <linux/sunrpc/msg_prot.h>
14#include <linux/string.h>
15#include <linux/crc32.h>
16#include <uapi/linux/nfs.h>
17
18/* The LOCALIO program is entirely private to Linux and is
19 * NOT part of the uapi.
20 */
21#define NFS_LOCALIO_PROGRAM		400122
22#define LOCALIOPROC_NULL		0
23#define LOCALIOPROC_UUID_IS_LOCAL	1
24
25/*
26 * This is the kernel NFS client file handle representation
27 */
28#define NFS_MAXFHSIZE		128
29struct nfs_fh {
30	unsigned short		size;
31	unsigned char		data[NFS_MAXFHSIZE];
32};
33
34/*
35 * Returns a zero iff the size and data fields match.
36 * Checks only "size" bytes in the data field.
37 */
38static inline int nfs_compare_fh(const struct nfs_fh *a, const struct nfs_fh *b)
39{
40	return a->size != b->size || memcmp(a->data, b->data, a->size) != 0;
41}
42
43static inline void nfs_copy_fh(struct nfs_fh *target, const struct nfs_fh *source)
44{
45	target->size = source->size;
46	memcpy(target->data, source->data, source->size);
47}
48
49enum nfs3_stable_how {
50	NFS_UNSTABLE = 0,
51	NFS_DATA_SYNC = 1,
52	NFS_FILE_SYNC = 2,
53
54	/* used by direct.c to mark verf as invalid */
55	NFS_INVALID_STABLE_HOW = -1
56};
57
58/**
59 * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
60 * @fh - pointer to filehandle
61 *
62 * returns a crc32 hash for the filehandle that is compatible with
63 * the one displayed by "wireshark".
64 */
65static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
66{
67	return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
68}
69#endif /* _LINUX_NFS_H */