linux/fs/xfs/xfs_attr.h

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/*
* Copyright (c) 2000,2002-2003,2005 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_ATTR_H__
#define __XFS_ATTR_H__
/*
* xfs_attr.h
*
* 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.
*/
/*========================================================================
* External interfaces
*========================================================================*/
struct cred;
struct xfs_attr_list_context;
typedef int (*attrset_t)(bhv_vnode_t *, char *, void *, size_t, int);
typedef int (*attrget_t)(bhv_vnode_t *, char *, void *, size_t, int);
typedef int (*attrremove_t)(bhv_vnode_t *, char *, int);
typedef int (*attrexists_t)(bhv_vnode_t *);
typedef int (*attrcapable_t)(bhv_vnode_t *, struct cred *);
typedef struct attrnames {
char * attr_name;
unsigned int attr_namelen;
unsigned int attr_flag;
attrget_t attr_get;
attrset_t attr_set;
attrremove_t attr_remove;
attrexists_t attr_exists;
attrcapable_t attr_capable;
} attrnames_t;
#define ATTR_NAMECOUNT 4
extern struct attrnames attr_user;
extern struct attrnames attr_secure;
extern struct attrnames attr_system;
extern struct attrnames attr_trusted;
extern struct attrnames *attr_namespaces[ATTR_NAMECOUNT];
extern attrnames_t *attr_lookup_namespace(char *, attrnames_t **, int);
extern int attr_generic_list(bhv_vnode_t *, void *, size_t, int, ssize_t *);
#define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */
#define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */
#define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */
#define ATTR_SECURE 0x0008 /* use attrs in security namespace */
#define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */
#define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */
#define ATTR_SYSTEM 0x0100 /* use attrs in system (pseudo) namespace */
#define ATTR_KERNACCESS 0x0400 /* [kernel] iaccess, inode held io-locked */
#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */
#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
#define ATTR_KERNAMELS 0x4000 /* [kernel] list attr names (simple list) */
#define ATTR_KERNORMALS 0x0800 /* [kernel] normal attr list: user+secure */
#define ATTR_KERNROOTLS 0x8000 /* [kernel] include root in the attr list */
#define ATTR_KERNFULLS (ATTR_KERNORMALS|ATTR_KERNROOTLS)
/*
* 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 */
/*
* Define how lists of attribute names are returned to the user from
* the attr_list() call. A large, 32bit aligned, buffer is passed in
* along with its size. We put an array of offsets at the top that each
* reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
*/
typedef struct attrlist {
__s32 al_count; /* number of entries in attrlist */
__s32 al_more; /* T/F: more attrs (do call again) */
__s32 al_offset[1]; /* byte offsets of attrs [var-sized] */
} attrlist_t;
/*
* Show the interesting info about one attribute. This is what the
* al_offset[i] entry points to.
*/
typedef struct attrlist_ent { /* data from attr_list() */
__u32 a_valuelen; /* number bytes in value of attr */
char a_name[1]; /* attr name (NULL terminated) */
} attrlist_ent_t;
/*
* Given a pointer to the (char*) buffer containing the attr_list() result,
* and an index, return a pointer to the indicated attribute in the buffer.
*/
#define ATTR_ENTRY(buffer, index) \
((attrlist_ent_t *) \
&((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
/*
* Multi-attribute operation vector.
*/
typedef struct attr_multiop {
int am_opcode; /* operation to perform (ATTR_OP_GET, etc.) */
int am_error; /* [out arg] result of this sub-op (an errno) */
char *am_attrname; /* attribute name to work with */
char *am_attrvalue; /* [in/out arg] attribute value (raw bytes) */
int am_length; /* [in/out arg] length of value */
int am_flags; /* bitwise OR of attr API flags defined above */
} attr_multiop_t;
#define ATTR_OP_GET 1 /* return the indicated attr's value */
#define ATTR_OP_SET 2 /* set/create the indicated attr/value pair */
#define ATTR_OP_REMOVE 3 /* remove the indicated attr */
/*
* Kernel-internal version of the attrlist cursor.
*/
typedef struct 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 */
} attrlist_cursor_kern_t;
/*========================================================================
* Function prototypes for the kernel.
*========================================================================*/
struct xfs_inode;
struct attrlist_cursor_kern;
struct xfs_da_args;
/*
* Overall external interface routines.
*/
int xfs_attr_set_int(struct xfs_inode *, const char *, int, char *, int, int);
int xfs_attr_remove_int(struct xfs_inode *, const char *, int, int);
int xfs_attr_list_int(struct xfs_attr_list_context *);
int xfs_attr_inactive(struct xfs_inode *dp);
int xfs_attr_shortform_getvalue(struct xfs_da_args *);
int xfs_attr_fetch(struct xfs_inode *, const char *, int,
char *, int *, int, struct cred *);
int xfs_attr_rmtval_get(struct xfs_da_args *args);
#endif /* __XFS_ATTR_H__ */