[deliverable/linux.git] / fs / xfs / xfs_attr.h

/*
 * 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__

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.
 */

/*========================================================================
 * External interfaces
 *========================================================================*/


#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_KERNOTIME	0x1000	/* [kernel] don't update inode timestamps */
#define ATTR_KERNOVAL	0x2000	/* [kernel] get attr size only, not value */

#define XFS_ATTR_FLAGS \
	{ ATTR_DONTFOLLOW, 	"DONTFOLLOW" }, \
	{ ATTR_ROOT,		"ROOT" }, \
	{ ATTR_TRUST,		"TRUST" }, \
	{ ATTR_SECURE,		"SECURE" }, \
	{ ATTR_CREATE,		"CREATE" }, \
	{ ATTR_REPLACE,		"REPLACE" }, \
	{ ATTR_KERNOTIME,	"KERNOTIME" }, \
	{ ATTR_KERNOVAL,	"KERNOVAL" }

/*
 * 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] ])

/*
 * 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;


/*========================================================================
 * Structure used to pass context around among the routines.
 *========================================================================*/


/* Return 0 on success, or -errno; other state communicated via *context */
typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int,
			      unsigned char *, int, int, unsigned char *);

typedef struct xfs_attr_list_context {
	struct xfs_inode		*dp;		/* inode */
	struct attrlist_cursor_kern	*cursor;	/* position in list */
	char				*alist;		/* output buffer */
	int				seen_enough;	/* T/F: seen enough of list? */
	ssize_t				count;		/* num used entries */
	int				dupcnt;		/* count dup hashvals seen */
	int				bufsize;	/* total buffer size */
	int				firstu;		/* first used byte in buffer */
	int				flags;		/* from VOP call */
	int				resynch;	/* T/F: resynch with cursor */
	int				put_value;	/* T/F: need value for listent */
	put_listent_func_t		put_listent;	/* list output fmt function */
	int				index;		/* index into output buffer */
} xfs_attr_list_context_t;


/*========================================================================
 * Function prototypes for the kernel.
 *========================================================================*/

/*
 * Overall external interface routines.
 */
int xfs_attr_inactive(struct xfs_inode *dp);
int xfs_attr_list_int(struct xfs_attr_list_context *);
int xfs_inode_hasattr(struct xfs_inode *ip);
int xfs_attr_get(struct xfs_inode *ip, const unsigned char *name,
		 unsigned char *value, int *valuelenp, int flags);
int xfs_attr_set(struct xfs_inode *dp, const unsigned char *name,
		 unsigned char *value, int valuelen, int flags);
int xfs_attr_remove(struct xfs_inode *dp, const unsigned char *name, int flags);
int xfs_attr_list(struct xfs_inode *dp, char *buffer, int bufsize,
		  int flags, struct attrlist_cursor_kern *cursor);


#endif	/* __XFS_ATTR_H__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4 LT	17	*/
	18	#ifndef __XFS_ATTR_H__
	19	#define __XFS_ATTR_H__
	20
ad9b463a CH	21	struct xfs_inode;
	22	struct xfs_da_args;
	23	struct xfs_attr_list_context;
	24
1da177e4	25	/*
1da177e4 LT	26	* Large attribute lists are structured around Btrees where all the data
	27	* elements are in the leaf nodes. Attribute names are hashed into an int,
	28	* then that int is used as the index into the Btree. Since the hashval
	29	* of an attribute name may not be unique, we may have duplicate keys.
	30	* The internal links in the Btree are logical block offsets into the file.
	31	*
	32	* Small attribute lists use a different format and are packed as tightly
	33	* as possible so as to fit into the literal area of the inode.
	34	*/
	35
	36	/*========================================================================
	37	* External interfaces
	38	========================================================================/
	39
1da177e4 LT	40
	41	#define ATTR_DONTFOLLOW 0x0001 /* -- unused, from IRIX -- */
	42	#define ATTR_ROOT 0x0002 /* use attrs in root (trusted) namespace */
	43	#define ATTR_TRUST 0x0004 /* -- unused, from IRIX -- */
	44	#define ATTR_SECURE 0x0008 /* use attrs in security namespace */
	45	#define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */
	46	#define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */
1da177e4	47
1da177e4 LT	48	#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */
1da177e4 LT	49	#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
1da177e4	50
0b1b213f CH	51	#define XFS_ATTR_FLAGS \
	52	{ ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
	53	{ ATTR_ROOT, "ROOT" }, \
	54	{ ATTR_TRUST, "TRUST" }, \
	55	{ ATTR_SECURE, "SECURE" }, \
	56	{ ATTR_CREATE, "CREATE" }, \
	57	{ ATTR_REPLACE, "REPLACE" }, \
	58	{ ATTR_KERNOTIME, "KERNOTIME" }, \
	59	{ ATTR_KERNOVAL, "KERNOVAL" }
	60
1da177e4 LT	61	/*
	62	* The maximum size (into the kernel or returned from the kernel) of an
	63	* attribute value or the buffer used for an attr_list() call. Larger
	64	* sizes will result in an ERANGE return code.
	65	*/
	66	#define ATTR_MAX_VALUELEN (641024) / max length of a value */
	67
	68	/*
	69	* Define how lists of attribute names are returned to the user from
	70	* the attr_list() call. A large, 32bit aligned, buffer is passed in
	71	* along with its size. We put an array of offsets at the top that each
	72	* reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
	73	*/
	74	typedef struct attrlist {
	75	__s32 al_count; /* number of entries in attrlist */
	76	__s32 al_more; /* T/F: more attrs (do call again) */
	77	__s32 al_offset[1]; /* byte offsets of attrs [var-sized] */
	78	} attrlist_t;
	79
	80	/*
	81	* Show the interesting info about one attribute. This is what the
	82	* al_offset[i] entry points to.
	83	*/
	84	typedef struct attrlist_ent { /* data from attr_list() */
	85	__u32 a_valuelen; /* number bytes in value of attr */
	86	char a_name[1]; /* attr name (NULL terminated) */
	87	} attrlist_ent_t;
	88
	89	/*
	90	* Given a pointer to the (char*) buffer containing the attr_list() result,
	91	* and an index, return a pointer to the indicated attribute in the buffer.
	92	*/
	93	#define ATTR_ENTRY(buffer, index) \
	94	((attrlist_ent_t *) \
	95	&((char )buffer)[ ((attrlist_t )(buffer))->al_offset[index] ])
	96
1da177e4 LT	97	/*
	98	* Kernel-internal version of the attrlist cursor.
	99	*/
	100	typedef struct attrlist_cursor_kern {
	101	__u32 hashval; /* hash value of next entry to add */
	102	__u32 blkno; /* block containing entry (suggestion) */
	103	__u32 offset; /* offset in list of equal-hashvals */
	104	__u16 pad1; /* padding to match user-level */
	105	__u8 pad2; /* padding to match user-level */
	106	__u8 initted; /* T/F: cursor has been initialized */
	107	} attrlist_cursor_kern_t;
	108
	109
	110	/*========================================================================
ad9b463a	111	* Structure used to pass context around among the routines.
1da177e4 LT	112	========================================================================/
1da177e4 LT	113
ad9b463a	114
2a6fba6d	115	/* Return 0 on success, or -errno; other state communicated via context /
ad9b463a	116	typedef int (put_listent_func_t)(struct xfs_attr_list_context , int,
a9273ca5	117	unsigned char , int, int, unsigned char );
ad9b463a CH	118
	119	typedef struct xfs_attr_list_context {
	120	struct xfs_inode dp; / inode */
	121	struct attrlist_cursor_kern cursor; / position in list */
	122	char alist; / output buffer */
	123	int seen_enough; /* T/F: seen enough of list? */
61f10fad	124	ssize_t count; /* num used entries */
ad9b463a CH	125	int dupcnt; /* count dup hashvals seen */
	126	int bufsize; /* total buffer size */
	127	int firstu; /* first used byte in buffer */
	128	int flags; /* from VOP call */
	129	int resynch; /* T/F: resynch with cursor */
	130	int put_value; /* T/F: need value for listent */
	131	put_listent_func_t put_listent; /* list output fmt function */
	132	int index; /* index into output buffer */
	133	} xfs_attr_list_context_t;
	134
	135
	136	/*========================================================================
	137	* Function prototypes for the kernel.
	138	========================================================================/
1da177e4 LT	139
	140	/*
	141	* Overall external interface routines.
	142	*/
1da177e4	143	int xfs_attr_inactive(struct xfs_inode *dp);
ad9b463a	144	int xfs_attr_list_int(struct xfs_attr_list_context *);
abec5f2b	145	int xfs_inode_hasattr(struct xfs_inode *ip);
c24b5dfa DC	146	int xfs_attr_get(struct xfs_inode ip, const unsigned char name,
	147	unsigned char value, int valuelenp, int flags);
	148	int xfs_attr_set(struct xfs_inode dp, const unsigned char name,
	149	unsigned char *value, int valuelen, int flags);
	150	int xfs_attr_remove(struct xfs_inode dp, const unsigned char name, int flags);
	151	int xfs_attr_list(struct xfs_inode dp, char buffer, int bufsize,
	152	int flags, struct attrlist_cursor_kern *cursor);
	153
1da177e4 LT	154
1da177e4 LT	155	#endif /* __XFS_ATTR_H__ */