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- /* 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 {
- unsigned int fh_size; /*
- * Points to the current size while
- * building a new file handle.
- */
- union {
- char fh_raw[NFS4_FHSIZE];
- struct {
- u8 fh_version; /* == 1 */
- u8 fh_auth_type; /* deprecated */
- u8 fh_fsid_type;
- u8 fh_fileid_type;
- u32 fh_fsid[]; /* flexible-array member */
- };
- };
- };
- static inline __u32 ino_t_to_u32(ino_t ino)
- {
- return (__u32) ino;
- }
- static inline ino_t u32_to_ino_t(__u32 uino)
- {
- return (ino_t) 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.
- */
- typedef struct svc_fh {
- struct knfsd_fh fh_handle; /* FH data */
- int fh_maxsize; /* max size for fh_handle */
- struct dentry * fh_dentry; /* validated dentry */
- struct svc_export * fh_export; /* export pointer */
- bool fh_want_write; /* remount protection taken */
- bool fh_no_wcc; /* no wcc data needed */
- bool fh_no_atomic_attr;
- /*
- * wcc data is not atomic with
- * operation
- */
- int fh_flags; /* FH flags */
- bool fh_post_saved; /* post-op attrs saved */
- bool fh_pre_saved; /* pre-op attrs saved */
- /* Pre-op attributes saved when inode is locked */
- __u64 fh_pre_size; /* size before operation */
- struct timespec64 fh_pre_mtime; /* mtime before oper */
- struct timespec64 fh_pre_ctime; /* ctime before oper */
- /*
- * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
- * to find out if it is valid.
- */
- u64 fh_pre_change;
- /* Post-op attributes saved in fh_fill_post_attrs() */
- struct kstat fh_post_attr; /* full attrs after operation */
- u64 fh_post_change; /* nfsv4 change; see above */
- } svc_fh;
- #define NFSD4_FH_FOREIGN (1<<0)
- #define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
- #define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
- enum nfsd_fsid {
- FSID_DEV = 0,
- FSID_NUM,
- FSID_MAJOR_MINOR,
- FSID_ENCODE_DEV,
- FSID_UUID4_INUM,
- FSID_UUID8,
- FSID_UUID16,
- FSID_UUID16_INUM,
- };
- enum fsid_source {
- FSIDSOURCE_DEV,
- FSIDSOURCE_FSID,
- FSIDSOURCE_UUID,
- };
- 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)
- {
- u32 *up;
- switch(vers) {
- case FSID_DEV:
- fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
- MINOR(dev));
- fsidv[1] = ino_t_to_u32(ino);
- break;
- case FSID_NUM:
- fsidv[0] = fsid;
- break;
- case FSID_MAJOR_MINOR:
- fsidv[0] = (__force __u32)htonl(MAJOR(dev));
- fsidv[1] = (__force __u32)htonl(MINOR(dev));
- fsidv[2] = ino_t_to_u32(ino);
- break;
- case FSID_ENCODE_DEV:
- fsidv[0] = new_encode_dev(dev);
- fsidv[1] = ino_t_to_u32(ino);
- break;
- case FSID_UUID4_INUM:
- /* 4 byte fsid and inode number */
- up = (u32*)uuid;
- fsidv[0] = ino_t_to_u32(ino);
- fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
- break;
- case FSID_UUID8:
- /* 8 byte fsid */
- up = (u32*)uuid;
- fsidv[0] = up[0] ^ up[2];
- fsidv[1] = up[1] ^ up[3];
- break;
- case FSID_UUID16:
- /* 16 byte fsid - NFSv3+ only */
- memcpy(fsidv, uuid, 16);
- break;
- case FSID_UUID16_INUM:
- /* 8 byte inode and 16 byte fsid */
- *(u64*)fsidv = (u64)ino;
- memcpy(fsidv+2, uuid, 16);
- break;
- default: BUG();
- }
- }
- static inline int key_len(int type)
- {
- switch(type) {
- case FSID_DEV: return 8;
- case FSID_NUM: return 4;
- case FSID_MAJOR_MINOR: return 12;
- case FSID_ENCODE_DEV: return 8;
- case FSID_UUID4_INUM: return 8;
- case FSID_UUID8: return 8;
- case FSID_UUID16: return 16;
- case FSID_UUID16_INUM: return 24;
- default: return 0;
- }
- }
- /*
- * 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, struct svc_fh *src)
- {
- WARN_ON(src->fh_dentry);
- *dst = *src;
- return dst;
- }
- static inline void
- fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
- {
- dst->fh_size = src->fh_size;
- memcpy(&dst->fh_raw, &src->fh_raw, src->fh_size);
- }
- static __inline__ struct svc_fh *
- fh_init(struct svc_fh *fhp, int maxsize)
- {
- memset(fhp, 0, sizeof(*fhp));
- fhp->fh_maxsize = maxsize;
- return fhp;
- }
- static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
- {
- if (fh1->fh_size != fh2->fh_size)
- return false;
- if (memcmp(fh1->fh_raw, fh2->fh_raw, fh1->fh_size) != 0)
- return false;
- return true;
- }
- static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
- {
- if (fh1->fh_fsid_type != fh2->fh_fsid_type)
- return false;
- if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
- return false;
- return true;
- }
- #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)
- {
- return ~crc32_le(0xFFFFFFFF, fh->fh_raw, fh->fh_size);
- }
- #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)
- {
- fhp->fh_post_saved = false;
- fhp->fh_pre_saved = false;
- }
- /*
- * We could use i_version alone as the change attribute. However,
- * i_version can go backwards after a reboot. On its own that doesn't
- * necessarily cause a problem, but if i_version goes backwards and then
- * is incremented again it could reuse a value that was previously used
- * before boot, and a client who queried the two values might
- * incorrectly assume nothing changed.
- *
- * By using both ctime and the i_version counter we guarantee that as
- * long as time doesn't go backwards we never reuse an old value.
- */
- static inline u64 nfsd4_change_attribute(struct kstat *stat,
- struct inode *inode)
- {
- if (inode->i_sb->s_export_op->fetch_iversion)
- return inode->i_sb->s_export_op->fetch_iversion(inode);
- else if (IS_I_VERSION(inode)) {
- u64 chattr;
- chattr = stat->ctime.tv_sec;
- chattr <<= 30;
- chattr += stat->ctime.tv_nsec;
- chattr += inode_query_iversion(inode);
- return chattr;
- } else
- return time_to_chattr(&stat->ctime);
- }
- extern void fh_fill_pre_attrs(struct svc_fh *fhp);
- extern void fh_fill_post_attrs(struct svc_fh *fhp);
- extern void fh_fill_both_attrs(struct svc_fh *fhp);
- #endif /* _LINUX_NFSD_NFSFH_H */
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