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Diffstat (limited to 'fs/nfsd/nfsfh.h')
| -rw-r--r-- | fs/nfsd/nfsfh.h | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h new file mode 100644 index 000000000..c3ae6414f --- /dev/null +++ b/fs/nfsd/nfsfh.h @@ -0,0 +1,325 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de> + * + * 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 */ |