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(a->data, b->data, 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(0xFFFFFFFF, &fh->data[0], 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