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
20 struct 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 */
29 static inline int nfs_compare_fh(const struct nfs_fh *a, const struct nfs_fh *b)
30 {
31 return a->size != b->size || memcmp(a->data, b->data, a->size) != 0;
32 }
33
34 static 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
40 enum 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 */
57 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
58 {
59 return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
60 }
61 #else /* CONFIG_CRC32 */
62 static 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
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