linux/fs/nfsd/nfsfh.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <[email protected]>
 *
 * This file describes the layout of the file handles as passed
 * over the wire.
 */
#ifndef _LINUX_NFSD_NFSFH_H
#define _LINUX_NFSD_NFSFH_H

#include <linux/crc32.h>
#include <linux/sunrpc/svc.h>
#include <linux/iversion.h>
#include <linux/exportfs.h>
#include <linux/nfs4.h>

/*
 * The file handle starts with a sequence of four-byte words.
 * The first word contains a version number (1) and three descriptor bytes
 * that tell how the remaining 3 variable length fields should be handled.
 * These three bytes are auth_type, fsid_type and fileid_type.
 *
 * All four-byte values are in host-byte-order.
 *
 * The auth_type field is deprecated and must be set to 0.
 *
 * The fsid_type identifies how the filesystem (or export point) is
 *    encoded.
 *  Current values:
 *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
 *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
 *              says we mustn't.  We must break it up and reassemble.
 *     1  - 4 byte user specified identifier
 *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
 *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
 *     4  - 4 byte inode number and 4 byte uuid
 *     5  - 8 byte uuid
 *     6  - 16 byte uuid
 *     7  - 8 byte inode number and 16 byte uuid
 *
 * The fileid_type identifies how the file within the filesystem is encoded.
 *   The values for this field are filesystem specific, exccept that
 *   filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
 *   in include/linux/exportfs.h for currently registered values.
 */

struct knfsd_fh { … };

static inline __u32 ino_t_to_u32(ino_t ino)
{ … }

static inline ino_t u32_to_ino_t(__u32 uino)
{ … }

/*
 * This is the internal representation of an NFS handle used in knfsd.
 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
 */
svc_fh;
#define NFSD4_FH_FOREIGN …
#define SET_FH_FLAG(c, f) …
#define HAS_FH_FLAG(c, f) …

enum nfsd_fsid { … };

enum fsid_source { … };
extern enum fsid_source fsid_source(const struct svc_fh *fhp);


/*
 * This might look a little large to "inline" but in all calls except
 * one, 'vers' is constant so moste of the function disappears.
 *
 * In some cases the values are considered to be host endian and in
 * others, net endian. fsidv is always considered to be u32 as the
 * callers don't know which it will be. So we must use __force to keep
 * sparse from complaining. Since these values are opaque to the
 * client, that shouldn't be a problem.
 */
static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
			   u32 fsid, unsigned char *uuid)
{ … }

static inline int key_len(int type)
{ … }

/*
 * Shorthand for dprintk()'s
 */
extern char * SVCFH_fmt(struct svc_fh *fhp);

/*
 * Function prototypes
 */
__be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
__be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
__be32	fh_update(struct svc_fh *);
void	fh_put(struct svc_fh *);

static __inline__ struct svc_fh *
fh_copy(struct svc_fh *dst, const struct svc_fh *src)
{ … }

static inline void
fh_copy_shallow(struct knfsd_fh *dst, const struct knfsd_fh *src)
{ … }

static __inline__ struct svc_fh *
fh_init(struct svc_fh *fhp, int maxsize)
{ … }

static inline bool fh_match(const struct knfsd_fh *fh1,
			    const struct knfsd_fh *fh2)
{ … }

static inline bool fh_fsid_match(const struct knfsd_fh *fh1,
				 const struct knfsd_fh *fh2)
{ … }

#ifdef CONFIG_CRC32
/**
 * knfsd_fh_hash - calculate the crc32 hash for the filehandle
 * @fh - pointer to filehandle
 *
 * returns a crc32 hash for the filehandle that is compatible with
 * the one displayed by "wireshark".
 */
static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
{ … }
#else
static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
{
	return 0;
}
#endif

/**
 * fh_clear_pre_post_attrs - Reset pre/post attributes
 * @fhp: file handle to be updated
 *
 */
static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp)
{ … }

u64 nfsd4_change_attribute(const struct kstat *stat,
			   const struct inode *inode);
__be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp);
__be32 fh_fill_post_attrs(struct svc_fh *fhp);
__be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp);
#endif /* _LINUX_NFSD_NFSFH_H */