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Encumbrance review done.
Add copyright and license words consistent with GPL.
Refer to http://fsg.melbourne.sgi.com/reviews/ for details.

There is a slight change in the license terms and conditions words
to go with the copyrights, so most of the files are not getting
new GPL's, just updated versions ... but there are 20-30 more files
here as well.

/*
 * Copyright (C) 1999 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; either version 2 of the License, or (at
 * your option) any later version.
 * 
 * This program is distributed in the hope that it will 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., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 */
#ifndef _FS_XFS_DIR2_DATA_H
#define	_FS_XFS_DIR2_DATA_H

#ident "$Revision: 1.1 $"

/*
 * xfs_dir2_data.h
 * Directory format 2, data block structures.
 */

struct xfs_dabuf;
struct xfs_da_args;
struct xfs_inode;
struct xfs_trans;

/*
 * Constants.
 */
#define	XFS_DIR2_DATA_MAGIC	0x58443244	/* XD2D: for multiblock dirs */
#define	XFS_DIR2_DATA_ALIGN_LOG	3		/* i.e., 8 bytes */
#define	XFS_DIR2_DATA_ALIGN	(1 << XFS_DIR2_DATA_ALIGN_LOG)
#define	XFS_DIR2_DATA_FREE_TAG	0xffff
#define	XFS_DIR2_DATA_FD_COUNT	3

/*
 * Directory address space divided into sections,
 * spaces separated by 32gb.
 */
#define	XFS_DIR2_SPACE_SIZE	(1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
#define	XFS_DIR2_DATA_SPACE	0
#define	XFS_DIR2_DATA_OFFSET	(XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
#define	XFS_DIR2_DATA_FIRSTDB(mp)	\
	XFS_DIR2_BYTE_TO_DB(mp, XFS_DIR2_DATA_OFFSET)

/*
 * Offsets of . and .. in data space (always block 0)
 */
#define	XFS_DIR2_DATA_DOT_OFFSET	\
	((xfs_dir2_data_aoff_t)sizeof(xfs_dir2_data_hdr_t))
#define	XFS_DIR2_DATA_DOTDOT_OFFSET	\
	(XFS_DIR2_DATA_DOT_OFFSET + XFS_DIR2_DATA_ENTSIZE(1))
#define	XFS_DIR2_DATA_FIRST_OFFSET		\
	(XFS_DIR2_DATA_DOTDOT_OFFSET + XFS_DIR2_DATA_ENTSIZE(2))

/*
 * Structures.
 */

/*
 * Describe a free area in the data block.
 * The freespace will be formatted as a xfs_dir2_data_unused_t.
 */
typedef struct xfs_dir2_data_free {
	xfs_dir2_data_off_t	offset;		/* start of freespace */
	xfs_dir2_data_off_t	length;		/* length of freespace */
} xfs_dir2_data_free_t;

/*
 * Header for the data blocks.
 * Always at the beginning of a directory-sized block.
 * The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
 */
typedef struct xfs_dir2_data_hdr {
	__uint32_t		magic;		/* XFS_DIR2_DATA_MAGIC */
						/* or XFS_DIR2_BLOCK_MAGIC */
	xfs_dir2_data_free_t	bestfree[XFS_DIR2_DATA_FD_COUNT];
} xfs_dir2_data_hdr_t;

/*
 * Active entry in a data block.  Aligned to 8 bytes.
 * Tag appears as the last 2 bytes.
 */
typedef struct xfs_dir2_data_entry {
	xfs_ino_t		inumber;	/* inode number */
	__uint8_t		namelen;	/* name length */
	__uint8_t		name[1];	/* name bytes, no null */
						/* variable offset */
	xfs_dir2_data_off_t	tag;		/* starting offset of us */
} xfs_dir2_data_entry_t;

/*
 * Unused entry in a data block.  Aligned to 8 bytes.
 * Tag appears as the last 2 bytes.
 */
typedef struct xfs_dir2_data_unused {
	__uint16_t		freetag;	/* XFS_DIR2_DATA_FREE_TAG */
	xfs_dir2_data_off_t	length;		/* total free length */
						/* variable offset */
	xfs_dir2_data_off_t	tag;		/* starting offset of us */
} xfs_dir2_data_unused_t;

typedef union {
	xfs_dir2_data_entry_t	entry;
	xfs_dir2_data_unused_t	unused;
} xfs_dir2_data_union_t;

/*
 * Generic data block structure, for xfs_db.
 */
typedef struct xfs_dir2_data {
	xfs_dir2_data_hdr_t	hdr;		/* magic XFS_DIR2_DATA_MAGIC */
	xfs_dir2_data_union_t	u[1];
} xfs_dir2_data_t;

/*
 * Macros.
 */

/*
 * Size of a data entry.
 */
#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR2_DATA_ENTSIZE)
int xfs_dir2_data_entsize(int n);
#define XFS_DIR2_DATA_ENTSIZE(n)	xfs_dir2_data_entsize(n)
#else
#define	XFS_DIR2_DATA_ENTSIZE(n)	\
	((int)(roundup(offsetof(xfs_dir2_data_entry_t, name[0]) + (n) + \
		 (uint)sizeof(xfs_dir2_data_off_t), XFS_DIR2_DATA_ALIGN)))
#endif

/*
 * Pointer to an entry's tag word.
 */
#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR2_DATA_ENTRY_TAG_P)
xfs_dir2_data_off_t *xfs_dir2_data_entry_tag_p(xfs_dir2_data_entry_t *dep);
#define	XFS_DIR2_DATA_ENTRY_TAG_P(dep)	xfs_dir2_data_entry_tag_p(dep)
#else
#define	XFS_DIR2_DATA_ENTRY_TAG_P(dep)	\
	((xfs_dir2_data_off_t *)\
	 ((char *)(dep) + XFS_DIR2_DATA_ENTSIZE((dep)->namelen) - \
	  (uint)sizeof(xfs_dir2_data_off_t)))
#endif

/*
 * Pointer to a freespace's tag word.
 */
#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR2_DATA_UNUSED_TAG_P)
xfs_dir2_data_off_t *xfs_dir2_data_unused_tag_p(xfs_dir2_data_unused_t *dup);
#define	XFS_DIR2_DATA_UNUSED_TAG_P(dup)	xfs_dir2_data_unused_tag_p(dup)
#else
#define	XFS_DIR2_DATA_UNUSED_TAG_P(dup)	\
	((xfs_dir2_data_off_t *)\
	 ((char *)(dup) + (dup)->length - (uint)sizeof(xfs_dir2_data_off_t)))
#endif

/*
 * Function declarations.
 */

#ifdef DEBUG
extern void
	xfs_dir2_data_check(struct xfs_inode *dp, struct xfs_dabuf *bp);
#else
#define	xfs_dir2_data_check(dp,bp)
#endif

extern xfs_dir2_data_free_t *
	xfs_dir2_data_freefind(xfs_dir2_data_t *d,
			       xfs_dir2_data_unused_t *dup);

extern xfs_dir2_data_free_t *
	xfs_dir2_data_freeinsert(xfs_dir2_data_t *d,
				 xfs_dir2_data_unused_t *dup, int *loghead);

extern void
	xfs_dir2_data_freeremove(xfs_dir2_data_t *d,
				 xfs_dir2_data_free_t *dfp, int *loghead);

extern void
	xfs_dir2_data_freescan(struct xfs_mount *mp, xfs_dir2_data_t *d,
			       int *loghead, char *aendp);

extern int
	xfs_dir2_data_init(struct xfs_da_args *args, xfs_dir2_db_t blkno,
			   struct xfs_dabuf **bpp);

extern void
	xfs_dir2_data_log_entry(struct xfs_trans *tp, struct xfs_dabuf *bp,
				xfs_dir2_data_entry_t *dep);

extern void
	xfs_dir2_data_log_header(struct xfs_trans *tp, struct xfs_dabuf *bp);

extern void
	xfs_dir2_data_log_unused(struct xfs_trans *tp, struct xfs_dabuf *bp,
				 xfs_dir2_data_unused_t *dup);

extern void
	xfs_dir2_data_make_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
				xfs_dir2_data_aoff_t offset,
				xfs_dir2_data_aoff_t len, int *needlogp,
				int *needscanp);

extern void
	xfs_dir2_data_use_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
			       xfs_dir2_data_unused_t *dup,
			       xfs_dir2_data_aoff_t offset,
			       xfs_dir2_data_aoff_t len, int *needlogp,
			       int *needscanp);

#endif	/* !_FS_XFS_DIR2_DATA_H */