linux-sg2042/fs/xfs/linux-2.6/xfs_export.h

109 lines
2.9 KiB
C

/*
* Copyright (c) 2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef __XFS_EXPORT_H__
#define __XFS_EXPORT_H__
/*
* Common defines for code related to exporting XFS filesystems over NFS.
*
* The NFS fileid goes out on the wire as an array of
* 32bit unsigned ints in host order. There are 5 possible
* formats.
*
* (1) fileid_type=0x00
* (no fileid data; handled by the generic code)
*
* (2) fileid_type=0x01
* inode-num
* generation
*
* (3) fileid_type=0x02
* inode-num
* generation
* parent-inode-num
* parent-generation
*
* (4) fileid_type=0x81
* inode-num-lo32
* inode-num-hi32
* generation
*
* (5) fileid_type=0x82
* inode-num-lo32
* inode-num-hi32
* generation
* parent-inode-num-lo32
* parent-inode-num-hi32
* parent-generation
*
* Note, the NFS filehandle also includes an fsid portion which
* may have an inode number in it. That number is hardcoded to
* 32bits and there is no way for XFS to intercept it. In
* practice this means when exporting an XFS filesystem with 64bit
* inodes you should either export the mountpoint (rather than
* a subdirectory) or use the "fsid" export option.
*/
/* This flag goes on the wire. Don't play with it. */
#define XFS_FILEID_TYPE_64FLAG 0x80 /* NFS fileid has 64bit inodes */
/* Calculate the length in u32 units of the fileid data */
static inline int
xfs_fileid_length(int hasparent, int is64)
{
return hasparent ? (is64 ? 6 : 4) : (is64 ? 3 : 2);
}
/*
* Decode encoded inode information (either for the inode itself
* or the parent) into an xfs_fid2_t structure. Advances and
* returns the new data pointer
*/
static inline __u32 *
xfs_fileid_decode_fid2(__u32 *p, xfs_fid2_t *fid, int is64)
{
fid->fid_len = sizeof(xfs_fid2_t) - sizeof(fid->fid_len);
fid->fid_pad = 0;
fid->fid_ino = *p++;
#if XFS_BIG_INUMS
if (is64)
fid->fid_ino |= (((__u64)(*p++)) << 32);
#endif
fid->fid_gen = *p++;
return p;
}
/*
* Encode inode information (either for the inode itself or the
* parent) into a fileid buffer. Advances and returns the new
* data pointer.
*/
static inline __u32 *
xfs_fileid_encode_inode(__u32 *p, struct inode *inode, int is64)
{
*p++ = (__u32)inode->i_ino;
#if XFS_BIG_INUMS
if (is64)
*p++ = (__u32)(inode->i_ino >> 32);
#endif
*p++ = inode->i_generation;
return p;
}
#endif /* __XFS_EXPORT_H__ */