include/linux/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
  29 struct 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  */
  38 static 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
  43 static 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
  49 enum 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 #ifdef CONFIG_CRC32
  59 /**
  60  * nfs_fhandle_hash - calculate the crc32 hash for the filehandle
  61  * @fh - pointer to filehandle
  62  *
  63  * returns a crc32 hash for the filehandle that is compatible with
  64  * the one displayed by "wireshark".
  65  */
  66 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
  67 {
  68         return ~crc32_le(0xFFFFFFFF, &fh->data[0], fh->size);
  69 }
  70 #else /* CONFIG_CRC32 */
  71 static inline u32 nfs_fhandle_hash(const struct nfs_fh *fh)
  72 {
  73         return 0;
  74 }
  75 #endif /* CONFIG_CRC32 */
  76 #endif /* _LINUX_NFS_H */