kernel-ark/include/linux/nfsd/nfsfh.h
Peter Staubach 40ee5dc6af knfsd: 64 bit ino support for NFS server
Modify the NFS server code to support 64 bit ino's, as
appropriate for the system and the NFS protocol version.

The gist of the changes is to query the underlying file system
for attributes and not just to use the cached attributes in the
inode.  For this specific purpose, the inode only contains an
ino field which unsigned long, which is large enough on 64 bit
platforms, but is not large enough on 32 bit platforms.

I haven't been able to find any reason why ->getattr can't be called
while i_mutex.  The specification indicates that i_mutex is not
required to be held in order to invoke ->getattr, but it doesn't say
that i_mutex can't be held while invoking ->getattr.

I also haven't come to any conclusions regarding the value of
lease_get_mtime() and whether it should or should not be invoked
by fill_post_wcc() too.  I chose not to change this because I
thought that it was safer to leave well enough alone.  If we
decide to make a change, it can be done separately.

Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Neil Brown <neilb@suse.de>
2007-10-09 18:31:57 -04:00

356 lines
9.1 KiB
C

/*
* include/linux/nfsd/nfsfh.h
*
* This file describes the layout of the file handles as passed
* over the wire.
*
* Earlier versions of knfsd used to sign file handles using keyed MD5
* or SHA. I've removed this code, because it doesn't give you more
* security than blocking external access to port 2049 on your firewall.
*
* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_NFSD_FH_H
#define _LINUX_NFSD_FH_H
#include <asm/types.h>
#ifdef __KERNEL__
# include <linux/types.h>
# include <linux/string.h>
# include <linux/fs.h>
#endif
#include <linux/nfsd/const.h>
#include <linux/nfsd/debug.h>
/*
* This is the old "dentry style" Linux NFSv2 file handle.
*
* The xino and xdev fields are currently used to transport the
* ino/dev of the exported inode.
*/
struct nfs_fhbase_old {
__u32 fb_dcookie; /* dentry cookie - always 0xfeebbaca */
__u32 fb_ino; /* our inode number */
__u32 fb_dirino; /* dir inode number, 0 for directories */
__u32 fb_dev; /* our device */
__u32 fb_xdev;
__u32 fb_xino;
__u32 fb_generation;
};
/*
* This is the new flexible, extensible style NFSv2/v3 file handle.
* by Neil Brown <neilb@cse.unsw.edu.au> - March 2000
*
* The file handle is seens as a list of 4byte words.
* The first word contains a version number (1) and four 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 4byte values are in host-byte-order.
*
* The auth_type field specifies how the filehandle can be authenticated
* This might allow a file to be confirmed to be in a writable part of a
* filetree without checking the path from it upto the root.
* Current values:
* 0 - No authentication. fb_auth is 0 bytes long
* Possible future values:
* 1 - 4 bytes taken from MD5 hash of the remainer of the file handle
* prefixed by a secret and with the important export flags.
*
* 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
*
* The fileid_type identified how the file within the filesystem is encoded.
* This is (will be) passed to, and set by, the underlying filesystem if it supports
* filehandle operations. The filesystem must not use the value '0' or '0xff' and may
* only use the values 1 and 2 as defined below:
* Current values:
* 0 - The root, or export point, of the filesystem. fb_fileid is 0 bytes.
* 1 - 32bit inode number, 32 bit generation number.
* 2 - 32bit inode number, 32 bit generation number, 32 bit parent directory inode number.
*
*/
struct nfs_fhbase_new {
__u8 fb_version; /* == 1, even => nfs_fhbase_old */
__u8 fb_auth_type;
__u8 fb_fsid_type;
__u8 fb_fileid_type;
__u32 fb_auth[1];
/* __u32 fb_fsid[0]; floating */
/* __u32 fb_fileid[0]; floating */
};
struct knfsd_fh {
unsigned int fh_size; /* significant for NFSv3.
* Points to the current size while building
* a new file handle
*/
union {
struct nfs_fhbase_old fh_old;
__u32 fh_pad[NFS4_FHSIZE/4];
struct nfs_fhbase_new fh_new;
} fh_base;
};
#define ofh_dcookie fh_base.fh_old.fb_dcookie
#define ofh_ino fh_base.fh_old.fb_ino
#define ofh_dirino fh_base.fh_old.fb_dirino
#define ofh_dev fh_base.fh_old.fb_dev
#define ofh_xdev fh_base.fh_old.fb_xdev
#define ofh_xino fh_base.fh_old.fb_xino
#define ofh_generation fh_base.fh_old.fb_generation
#define fh_version fh_base.fh_new.fb_version
#define fh_fsid_type fh_base.fh_new.fb_fsid_type
#define fh_auth_type fh_base.fh_new.fb_auth_type
#define fh_fileid_type fh_base.fh_new.fb_fileid_type
#define fh_auth fh_base.fh_new.fb_auth
#define fh_fsid fh_base.fh_new.fb_auth
#ifdef __KERNEL__
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 */
struct dentry * fh_dentry; /* validated dentry */
struct svc_export * fh_export; /* export pointer */
int fh_maxsize; /* max size for fh_handle */
unsigned char fh_locked; /* inode locked by us */
#ifdef CONFIG_NFSD_V3
unsigned char fh_post_saved; /* post-op attrs saved */
unsigned char fh_pre_saved; /* pre-op attrs saved */
/* Pre-op attributes saved during fh_lock */
__u64 fh_pre_size; /* size before operation */
struct timespec fh_pre_mtime; /* mtime before oper */
struct timespec fh_pre_ctime; /* ctime before oper */
/* Post-op attributes saved in fh_unlock */
struct kstat fh_post_attr; /* full attrs after operation */
#endif /* CONFIG_NFSD_V3 */
} svc_fh;
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(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.
*/
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] = 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] = htonl(MAJOR(dev));
fsidv[1] = 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 *, int, 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 || src->fh_locked);
*dst = *src;
return dst;
}
static __inline__ struct svc_fh *
fh_init(struct svc_fh *fhp, int maxsize)
{
memset(fhp, 0, sizeof(*fhp));
fhp->fh_maxsize = maxsize;
return fhp;
}
#ifdef CONFIG_NFSD_V3
/*
* Fill in the pre_op attr for the wcc data
*/
static inline void
fill_pre_wcc(struct svc_fh *fhp)
{
struct inode *inode;
inode = fhp->fh_dentry->d_inode;
if (!fhp->fh_pre_saved) {
fhp->fh_pre_mtime = inode->i_mtime;
fhp->fh_pre_ctime = inode->i_ctime;
fhp->fh_pre_size = inode->i_size;
fhp->fh_pre_saved = 1;
}
}
extern void fill_post_wcc(struct svc_fh *);
#else
#define fill_pre_wcc(ignored)
#define fill_post_wcc(notused)
#endif /* CONFIG_NFSD_V3 */
/*
* Lock a file handle/inode
* NOTE: both fh_lock and fh_unlock are done "by hand" in
* vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
* so, any changes here should be reflected there.
*/
static inline void
fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
{
struct dentry *dentry = fhp->fh_dentry;
struct inode *inode;
dfprintk(FILEOP, "nfsd: fh_lock(%s) locked = %d\n",
SVCFH_fmt(fhp), fhp->fh_locked);
BUG_ON(!dentry);
if (fhp->fh_locked) {
printk(KERN_WARNING "fh_lock: %s/%s already locked!\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
return;
}
inode = dentry->d_inode;
mutex_lock_nested(&inode->i_mutex, subclass);
fill_pre_wcc(fhp);
fhp->fh_locked = 1;
}
static inline void
fh_lock(struct svc_fh *fhp)
{
fh_lock_nested(fhp, I_MUTEX_NORMAL);
}
/*
* Unlock a file handle/inode
*/
static inline void
fh_unlock(struct svc_fh *fhp)
{
BUG_ON(!fhp->fh_dentry);
if (fhp->fh_locked) {
fill_post_wcc(fhp);
mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
fhp->fh_locked = 0;
}
}
#endif /* __KERNEL__ */
#endif /* _LINUX_NFSD_FH_H */