[linux.git] / fs / xfs / xfs_dir2_sf.h

/*
 * Copyright (c) 2000-2001,2005 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_DIR2_SF_H__
#define	__XFS_DIR2_SF_H__

/*
 * Directory layout when stored internal to an inode.
 *
 * Small directories are packed as tightly as possible so as to
 * fit into the literal area of the inode.
 */

struct uio;
struct xfs_dabuf;
struct xfs_da_args;
struct xfs_dir2_block;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;

/*
 * Maximum size of a shortform directory.
 */
#define	XFS_DIR2_SF_MAX_SIZE	\
	(XFS_DINODE_MAX_SIZE - (uint)sizeof(xfs_dinode_core_t) - \
	 (uint)sizeof(xfs_agino_t))

/*
 * Inode number stored as 8 8-bit values.
 */
typedef	struct { __uint8_t i[8]; } xfs_dir2_ino8_t;

/*
 * Inode number stored as 4 8-bit values.
 * Works a lot of the time, when all the inode numbers in a directory
 * fit in 32 bits.
 */
typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;

typedef union {
	xfs_dir2_ino8_t	i8;
	xfs_dir2_ino4_t	i4;
} xfs_dir2_inou_t;
#define	XFS_DIR2_MAX_SHORT_INUM	((xfs_ino_t)0xffffffffULL)

/*
 * Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
 * Only need 16 bits, this is the byte offset into the single block form.
 */
typedef struct { __uint8_t i[2]; } xfs_dir2_sf_off_t;

/*
 * The parent directory has a dedicated field, and the self-pointer must
 * be calculated on the fly.
 *
 * Entries are packed toward the top as tightly as possible.  The header
 * and the elements must be memcpy'd out into a work area to get correct
 * alignment for the inode number fields.
 */
typedef struct xfs_dir2_sf_hdr {
	__uint8_t		count;		/* count of entries */
	__uint8_t		i8count;	/* count of 8-byte inode #s */
	xfs_dir2_inou_t		parent;		/* parent dir inode number */
} xfs_dir2_sf_hdr_t;

typedef struct xfs_dir2_sf_entry {
	__uint8_t		namelen;	/* actual name length */
	xfs_dir2_sf_off_t	offset;		/* saved offset */
	__uint8_t		name[1];	/* name, variable size */
	xfs_dir2_inou_t		inumber;	/* inode number, var. offset */
} xfs_dir2_sf_entry_t;

typedef struct xfs_dir2_sf {
	xfs_dir2_sf_hdr_t	hdr;		/* shortform header */
	xfs_dir2_sf_entry_t	list[1];	/* shortform entries */
} xfs_dir2_sf_t;

#define	XFS_DIR2_SF_HDR_SIZE(i8count)	xfs_dir2_sf_hdr_size(i8count)
static inline int xfs_dir2_sf_hdr_size(int i8count)
{
	return ((uint)sizeof(xfs_dir2_sf_hdr_t) - \
		((i8count) == 0) * \
		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
}

#define	XFS_DIR2_SF_INUMBERP(sfep)	xfs_dir2_sf_inumberp(sfep)
static inline xfs_dir2_inou_t *xfs_dir2_sf_inumberp(xfs_dir2_sf_entry_t *sfep)
{
	return (xfs_dir2_inou_t *)&(sfep)->name[(sfep)->namelen];
}

#define	XFS_DIR2_SF_GET_INUMBER(sfp, from) \
	xfs_dir2_sf_get_inumber(sfp, from)
static inline xfs_intino_t
xfs_dir2_sf_get_inumber(xfs_dir2_sf_t *sfp, xfs_dir2_inou_t *from)
{
	return ((sfp)->hdr.i8count == 0 ? \
		(xfs_intino_t)XFS_GET_DIR_INO4((from)->i4) : \
		(xfs_intino_t)XFS_GET_DIR_INO8((from)->i8));
}

#define	XFS_DIR2_SF_PUT_INUMBER(sfp,from,to) \
	xfs_dir2_sf_put_inumber(sfp,from,to)
static inline void xfs_dir2_sf_put_inumber(xfs_dir2_sf_t *sfp, xfs_ino_t *from,
						xfs_dir2_inou_t *to)
{
	if ((sfp)->hdr.i8count == 0)
		XFS_PUT_DIR_INO4(*(from), (to)->i4);
	else
		XFS_PUT_DIR_INO8(*(from), (to)->i8);
}

#define	XFS_DIR2_SF_GET_OFFSET(sfep)	\
	xfs_dir2_sf_get_offset(sfep)
static inline xfs_dir2_data_aoff_t
xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
{
	return INT_GET_UNALIGNED_16_BE(&(sfep)->offset.i);
}

#define	XFS_DIR2_SF_PUT_OFFSET(sfep,off) \
	xfs_dir2_sf_put_offset(sfep,off)
static inline void
xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
{
	INT_SET_UNALIGNED_16_BE(&(sfep)->offset.i, off);
}

#define XFS_DIR2_SF_ENTSIZE_BYNAME(sfp,len)	\
	xfs_dir2_sf_entsize_byname(sfp,len)
static inline int xfs_dir2_sf_entsize_byname(xfs_dir2_sf_t *sfp, int len)
{
	return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (len) - \
		((sfp)->hdr.i8count == 0) * \
		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
}

#define XFS_DIR2_SF_ENTSIZE_BYENTRY(sfp,sfep)	\
	xfs_dir2_sf_entsize_byentry(sfp,sfep)
static inline int
xfs_dir2_sf_entsize_byentry(xfs_dir2_sf_t *sfp, xfs_dir2_sf_entry_t *sfep)
{
	return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (sfep)->namelen - \
		((sfp)->hdr.i8count == 0) * \
		((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
}

#define XFS_DIR2_SF_FIRSTENTRY(sfp)	xfs_dir2_sf_firstentry(sfp)
static inline xfs_dir2_sf_entry_t *xfs_dir2_sf_firstentry(xfs_dir2_sf_t *sfp)
{
	return ((xfs_dir2_sf_entry_t *) \
		((char *)(sfp) + XFS_DIR2_SF_HDR_SIZE(sfp->hdr.i8count)));
}

#define XFS_DIR2_SF_NEXTENTRY(sfp,sfep)	xfs_dir2_sf_nextentry(sfp,sfep)
static inline xfs_dir2_sf_entry_t *
xfs_dir2_sf_nextentry(xfs_dir2_sf_t *sfp, xfs_dir2_sf_entry_t *sfep)
{
	return ((xfs_dir2_sf_entry_t *) \
		((char *)(sfep) + XFS_DIR2_SF_ENTSIZE_BYENTRY(sfp,sfep)));
}

/*
 * Functions.
 */
extern int xfs_dir2_block_sfsize(struct xfs_inode *dp,
				 struct xfs_dir2_block *block,
				 xfs_dir2_sf_hdr_t *sfhp);
extern int xfs_dir2_block_to_sf(struct xfs_da_args *args, struct xfs_dabuf *bp,
				int size, xfs_dir2_sf_hdr_t *sfhp);
extern int xfs_dir2_sf_addname(struct xfs_da_args *args);
extern int xfs_dir2_sf_create(struct xfs_da_args *args, xfs_ino_t pino);
extern int xfs_dir2_sf_getdents(struct xfs_inode *dp, struct uio *uio,
				int *eofp, struct xfs_dirent *dbp,
				xfs_dir2_put_t put);
extern int xfs_dir2_sf_lookup(struct xfs_da_args *args);
extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
extern int xfs_dir2_sf_replace(struct xfs_da_args *args);

#endif	/* __XFS_DIR2_SF_H__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000-2001,2005 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_DIR2_SF_H__
	19	#define __XFS_DIR2_SF_H__
	20
	21	/*
	22	* Directory layout when stored internal to an inode.
	23	*
	24	* Small directories are packed as tightly as possible so as to
	25	* fit into the literal area of the inode.
	26	*/
	27
	28	struct uio;
	29	struct xfs_dabuf;
	30	struct xfs_da_args;
	31	struct xfs_dir2_block;
	32	struct xfs_inode;
	33	struct xfs_mount;
	34	struct xfs_trans;
	35
	36	/*
	37	* Maximum size of a shortform directory.
	38	*/
	39	#define XFS_DIR2_SF_MAX_SIZE \
	40	(XFS_DINODE_MAX_SIZE - (uint)sizeof(xfs_dinode_core_t) - \
	41	(uint)sizeof(xfs_agino_t))
	42
	43	/*
	44	* Inode number stored as 8 8-bit values.
	45	*/
	46	typedef struct { __uint8_t i[8]; } xfs_dir2_ino8_t;
	47
	48	/*
	49	* Inode number stored as 4 8-bit values.
	50	* Works a lot of the time, when all the inode numbers in a directory
	51	* fit in 32 bits.
	52	*/
	53	typedef struct { __uint8_t i[4]; } xfs_dir2_ino4_t;
	54
	55	typedef union {
	56	xfs_dir2_ino8_t i8;
	57	xfs_dir2_ino4_t i4;
	58	} xfs_dir2_inou_t;
	59	#define XFS_DIR2_MAX_SHORT_INUM ((xfs_ino_t)0xffffffffULL)
	60
	61	/*
	62	* Normalized offset (in a data block) of the entry, really xfs_dir2_data_off_t.
	63	* Only need 16 bits, this is the byte offset into the single block form.
	64	*/
	65	typedef struct { __uint8_t i[2]; } xfs_dir2_sf_off_t;
	66
	67	/*
	68	* The parent directory has a dedicated field, and the self-pointer must
	69	* be calculated on the fly.
	70	*
	71	* Entries are packed toward the top as tightly as possible. The header
	72	* and the elements must be memcpy'd out into a work area to get correct
	73	* alignment for the inode number fields.
	74	*/
	75	typedef struct xfs_dir2_sf_hdr {
	76	__uint8_t count; /* count of entries */
	77	__uint8_t i8count; /* count of 8-byte inode #s */
	78	xfs_dir2_inou_t parent; /* parent dir inode number */
	79	} xfs_dir2_sf_hdr_t;
	80
81	typedef struct xfs_dir2_sf_entry {
82	__uint8_t namelen; /* actual name length */
83	xfs_dir2_sf_off_t offset; /* saved offset */
84	__uint8_t name[1]; /* name, variable size */
85	xfs_dir2_inou_t inumber; /* inode number, var. offset */
86	} xfs_dir2_sf_entry_t;
87
88	typedef struct xfs_dir2_sf {
89	xfs_dir2_sf_hdr_t hdr; /* shortform header */
90	xfs_dir2_sf_entry_t list[1]; /* shortform entries */
91	} xfs_dir2_sf_t;
92
1da177e4	93	#define XFS_DIR2_SF_HDR_SIZE(i8count) xfs_dir2_sf_hdr_size(i8count)
a844f451 NS	94	static inline int xfs_dir2_sf_hdr_size(int i8count)
	95	{
	96	return ((uint)sizeof(xfs_dir2_sf_hdr_t) - \
	97	((i8count) == 0) * \
	98	((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
	99	}
	100
1da177e4	101	#define XFS_DIR2_SF_INUMBERP(sfep) xfs_dir2_sf_inumberp(sfep)
a844f451 NS	102	static inline xfs_dir2_inou_t xfs_dir2_sf_inumberp(xfs_dir2_sf_entry_t sfep)
	103	{
	104	return (xfs_dir2_inou_t *)&(sfep)->name[(sfep)->namelen];
	105	}
1da177e4	106
a844f451 NS	107	#define XFS_DIR2_SF_GET_INUMBER(sfp, from) \
	108	xfs_dir2_sf_get_inumber(sfp, from)
	109	static inline xfs_intino_t
	110	xfs_dir2_sf_get_inumber(xfs_dir2_sf_t sfp, xfs_dir2_inou_t from)
	111	{
	112	return ((sfp)->hdr.i8count == 0 ? \
1da177e4	113	(xfs_intino_t)XFS_GET_DIR_INO4((from)->i4) : \
a844f451 NS	114	(xfs_intino_t)XFS_GET_DIR_INO8((from)->i8));
a844f451 NS	115	}
1da177e4	116
a844f451	117	#define XFS_DIR2_SF_PUT_INUMBER(sfp,from,to) \
1da177e4	118	xfs_dir2_sf_put_inumber(sfp,from,to)
a844f451 NS	119	static inline void xfs_dir2_sf_put_inumber(xfs_dir2_sf_t sfp, xfs_ino_t from,
	120	xfs_dir2_inou_t *to)
	121	{
	122	if ((sfp)->hdr.i8count == 0)
	123	XFS_PUT_DIR_INO4(*(from), (to)->i4);
	124	else
	125	XFS_PUT_DIR_INO8(*(from), (to)->i8);
	126	}
	127
1da177e4 LT	128	#define XFS_DIR2_SF_GET_OFFSET(sfep) \
1da177e4 LT	129	xfs_dir2_sf_get_offset(sfep)
a844f451 NS	130	static inline xfs_dir2_data_aoff_t
	131	xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
	132	{
	133	return INT_GET_UNALIGNED_16_BE(&(sfep)->offset.i);
	134	}
1da177e4	135
1da177e4 LT	136	#define XFS_DIR2_SF_PUT_OFFSET(sfep,off) \
1da177e4 LT	137	xfs_dir2_sf_put_offset(sfep,off)
a844f451 NS	138	static inline void
	139	xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
	140	{
	141	INT_SET_UNALIGNED_16_BE(&(sfep)->offset.i, off);
	142	}
1da177e4	143
1da177e4 LT	144	#define XFS_DIR2_SF_ENTSIZE_BYNAME(sfp,len) \
1da177e4 LT	145	xfs_dir2_sf_entsize_byname(sfp,len)
a844f451 NS	146	static inline int xfs_dir2_sf_entsize_byname(xfs_dir2_sf_t *sfp, int len)
	147	{
	148	return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (len) - \
	149	((sfp)->hdr.i8count == 0) * \
	150	((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
	151	}
	152
1da177e4 LT	153	#define XFS_DIR2_SF_ENTSIZE_BYENTRY(sfp,sfep) \
1da177e4 LT	154	xfs_dir2_sf_entsize_byentry(sfp,sfep)
a844f451 NS	155	static inline int
	156	xfs_dir2_sf_entsize_byentry(xfs_dir2_sf_t sfp, xfs_dir2_sf_entry_t sfep)
	157	{
	158	return ((uint)sizeof(xfs_dir2_sf_entry_t) - 1 + (sfep)->namelen - \
	159	((sfp)->hdr.i8count == 0) * \
	160	((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t)));
	161	}
	162
1da177e4	163	#define XFS_DIR2_SF_FIRSTENTRY(sfp) xfs_dir2_sf_firstentry(sfp)
a844f451 NS	164	static inline xfs_dir2_sf_entry_t xfs_dir2_sf_firstentry(xfs_dir2_sf_t sfp)
	165	{
	166	return ((xfs_dir2_sf_entry_t *) \
	167	((char *)(sfp) + XFS_DIR2_SF_HDR_SIZE(sfp->hdr.i8count)));
	168	}
	169
	170	#define XFS_DIR2_SF_NEXTENTRY(sfp,sfep) xfs_dir2_sf_nextentry(sfp,sfep)
	171	static inline xfs_dir2_sf_entry_t *
	172	xfs_dir2_sf_nextentry(xfs_dir2_sf_t sfp, xfs_dir2_sf_entry_t sfep)
	173	{
	174	return ((xfs_dir2_sf_entry_t *) \
	175	((char *)(sfep) + XFS_DIR2_SF_ENTSIZE_BYENTRY(sfp,sfep)));
	176	}
1da177e4 LT	177
	178	/*
	179	* Functions.
	180	*/
a844f451 NS	181	extern int xfs_dir2_block_sfsize(struct xfs_inode *dp,
	182	struct xfs_dir2_block *block,
	183	xfs_dir2_sf_hdr_t *sfhp);
	184	extern int xfs_dir2_block_to_sf(struct xfs_da_args args, struct xfs_dabuf bp,
	185	int size, xfs_dir2_sf_hdr_t *sfhp);
	186	extern int xfs_dir2_sf_addname(struct xfs_da_args *args);
	187	extern int xfs_dir2_sf_create(struct xfs_da_args *args, xfs_ino_t pino);
	188	extern int xfs_dir2_sf_getdents(struct xfs_inode dp, struct uio uio,
	189	int eofp, struct xfs_dirent dbp,
	190	xfs_dir2_put_t put);
	191	extern int xfs_dir2_sf_lookup(struct xfs_da_args *args);
	192	extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
	193	extern int xfs_dir2_sf_replace(struct xfs_da_args *args);
1da177e4 LT	194
1da177e4 LT	195	#endif /* __XFS_DIR2_SF_H__ */