linux-sg2042/fs/xfs/libxfs/xfs_attr.h

97 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#ifndef __XFS_ATTR_H__
#define __XFS_ATTR_H__
struct xfs_inode;
struct xfs_da_args;
struct xfs_attr_list_context;
/*
* Large attribute lists are structured around Btrees where all the data
* elements are in the leaf nodes. Attribute names are hashed into an int,
* then that int is used as the index into the Btree. Since the hashval
* of an attribute name may not be unique, we may have duplicate keys.
* The internal links in the Btree are logical block offsets into the file.
*
* Small attribute lists use a different format and are packed as tightly
* as possible so as to fit into the literal area of the inode.
*/
/*
* The maximum size (into the kernel or returned from the kernel) of an
* attribute value or the buffer used for an attr_list() call. Larger
* sizes will result in an ERANGE return code.
*/
#define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */
/*
* Kernel-internal version of the attrlist cursor.
*/
struct xfs_attrlist_cursor_kern {
__u32 hashval; /* hash value of next entry to add */
__u32 blkno; /* block containing entry (suggestion) */
__u32 offset; /* offset in list of equal-hashvals */
__u16 pad1; /* padding to match user-level */
__u8 pad2; /* padding to match user-level */
__u8 initted; /* T/F: cursor has been initialized */
};
/*========================================================================
* Structure used to pass context around among the routines.
*========================================================================*/
/* void; state communicated via *context */
typedef void (*put_listent_func_t)(struct xfs_attr_list_context *, int,
unsigned char *, int, int);
struct xfs_attr_list_context {
struct xfs_trans *tp;
struct xfs_inode *dp; /* inode */
struct xfs_attrlist_cursor_kern cursor; /* position in list */
void *buffer; /* output buffer */
/*
* Abort attribute list iteration if non-zero. Can be used to pass
* error values to the xfs_attr_list caller.
*/
int seen_enough;
bool allow_incomplete;
ssize_t count; /* num used entries */
int dupcnt; /* count dup hashvals seen */
int bufsize; /* total buffer size */
int firstu; /* first used byte in buffer */
unsigned int attr_filter; /* XFS_ATTR_{ROOT,SECURE} */
int resynch; /* T/F: resynch with cursor */
put_listent_func_t put_listent; /* list output fmt function */
int index; /* index into output buffer */
};
/*========================================================================
* Function prototypes for the kernel.
*========================================================================*/
/*
* Overall external interface routines.
*/
int xfs_attr_inactive(struct xfs_inode *dp);
int xfs_attr_list_ilocked(struct xfs_attr_list_context *);
int xfs_attr_list(struct xfs_attr_list_context *);
int xfs_inode_hasattr(struct xfs_inode *ip);
int xfs_attr_get_ilocked(struct xfs_da_args *args);
int xfs_attr_get(struct xfs_da_args *args);
int xfs_attr_set(struct xfs_da_args *args);
int xfs_attr_set_args(struct xfs_da_args *args);
int xfs_has_attr(struct xfs_da_args *args);
int xfs_attr_remove_args(struct xfs_da_args *args);
bool xfs_attr_namecheck(const void *name, size_t length);
#endif /* __XFS_ATTR_H__ */