linux/fs/xfs/xfs_export.h
Darrick J. Wong 233f4e12bb xfs: add parent pointer ioctls
This patch adds a pair of new file ioctls to retrieve the parent pointer
of a given inode.  They both return the same results, but one operates
on the file descriptor passed to ioctl() whereas the other allows the
caller to specify a file handle for which the caller wants results.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-04-23 07:47:00 -07:00

63 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#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 */
struct inode *xfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 gen);
#endif /* __XFS_EXPORT_H__ */