linux/fs/xfs/linux-2.6/xfs_export.h
Christoph Hellwig c38344fe9e xfs: new export ops
This one is a lot more complicated than the previous ones.  XFS already had a
very clever scheme for supporting 64bit inode numbers in filehandles, and I've
reworked this to be some kind of a prototype for the generic 64bit inode
filehandle support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-22 08:13:20 -07:00

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2.0 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.
*/
struct xfs_fid64 {
u64 ino;
u32 gen;
u64 parent_ino;
u32 parent_gen;
} __attribute__((packed));
/* This flag goes on the wire. Don't play with it. */
#define XFS_FILEID_TYPE_64FLAG 0x80 /* NFS fileid has 64bit inodes */
#endif /* __XFS_EXPORT_H__ */