linux/fs/xfs/libxfs/xfs_parent.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

100 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2022-2024 Oracle.
* All Rights Reserved.
*/
#ifndef __XFS_PARENT_H__
#define __XFS_PARENT_H__
/* Metadata validators */
bool xfs_parent_namecheck(unsigned int attr_flags, const void *name,
size_t length);
bool xfs_parent_valuecheck(struct xfs_mount *mp, const void *value,
size_t valuelen);
xfs_dahash_t xfs_parent_hashval(struct xfs_mount *mp, const uint8_t *name,
int namelen, xfs_ino_t parent_ino);
xfs_dahash_t xfs_parent_hashattr(struct xfs_mount *mp, const uint8_t *name,
int namelen, const void *value, int valuelen);
/* Initializes a xfs_parent_rec to be stored as an attribute name. */
static inline void
xfs_parent_rec_init(
struct xfs_parent_rec *rec,
xfs_ino_t ino,
uint32_t gen)
{
rec->p_ino = cpu_to_be64(ino);
rec->p_gen = cpu_to_be32(gen);
}
/* Initializes a xfs_parent_rec to be stored as an attribute name. */
static inline void
xfs_inode_to_parent_rec(
struct xfs_parent_rec *rec,
const struct xfs_inode *dp)
{
xfs_parent_rec_init(rec, dp->i_ino, VFS_IC(dp)->i_generation);
}
extern struct kmem_cache *xfs_parent_args_cache;
/*
* Parent pointer information needed to pass around the deferred xattr update
* machinery.
*/
struct xfs_parent_args {
struct xfs_parent_rec rec;
struct xfs_parent_rec new_rec;
struct xfs_da_args args;
};
/*
* Start a parent pointer update by allocating the context object we need to
* perform a parent pointer update.
*/
static inline int
xfs_parent_start(
struct xfs_mount *mp,
struct xfs_parent_args **ppargsp)
{
if (!xfs_has_parent(mp)) {
*ppargsp = NULL;
return 0;
}
*ppargsp = kmem_cache_zalloc(xfs_parent_args_cache, GFP_KERNEL);
if (!*ppargsp)
return -ENOMEM;
return 0;
}
/* Finish a parent pointer update by freeing the context object. */
static inline void
xfs_parent_finish(
struct xfs_mount *mp,
struct xfs_parent_args *ppargs)
{
if (ppargs)
kmem_cache_free(xfs_parent_args_cache, ppargs);
}
int xfs_parent_addname(struct xfs_trans *tp, struct xfs_parent_args *ppargs,
struct xfs_inode *dp, const struct xfs_name *parent_name,
struct xfs_inode *child);
int xfs_parent_removename(struct xfs_trans *tp, struct xfs_parent_args *ppargs,
struct xfs_inode *dp, const struct xfs_name *parent_name,
struct xfs_inode *child);
int xfs_parent_replacename(struct xfs_trans *tp,
struct xfs_parent_args *ppargs,
struct xfs_inode *old_dp, const struct xfs_name *old_name,
struct xfs_inode *new_dp, const struct xfs_name *new_name,
struct xfs_inode *child);
int xfs_parent_from_attr(struct xfs_mount *mp, unsigned int attr_flags,
const unsigned char *name, unsigned int namelen,
const void *value, unsigned int valuelen,
xfs_ino_t *parent_ino, uint32_t *parent_gen);
#endif /* __XFS_PARENT_H__ */