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kernel-fxtec-pro1x/fs/xfs/xfs_dir2_leaf.h
Christoph Hellwig 2282396d81 xfs: cleanup struct xfs_dir2_leaf 
Simplify the confusing xfs_dir2_leaf structure.  It is supposed to describe
an XFS dir2 leaf format btree block, but due to the variable sized nature
of almost all elements in it it can't actuall do anything close to that
job.   Remove the members that are after the first variable sized array,
given that they could only be used for sizeof expressions that can as well
just use the underlying types directly, and make the ents array a real
C99 variable sized array.

Also factor out the xfs_dir2_leaf_size, to make the sizing of a leaf
entry which already was convoluted somewhat readable after using the
longer type names in the sizeof expressions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-07-08 14:35:53 +02:00

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/*
* 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_LEAF_H__
#define __XFS_DIR2_LEAF_H__
/*
* Directory format 2, leaf block structures.
*
* A pure data block looks like the following drawing on disk:
*
* +---------------------------+
* | xfs_dir2_leaf_hdr_t |
* +---------------------------+
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* | xfs_dir2_leaf_entry_t |
* | ... |
* +---------------------------+
* | xfs_dir2_data_off_t |
* | xfs_dir2_data_off_t |
* | xfs_dir2_data_off_t |
* | ... |
* +---------------------------+
* | xfs_dir2_leaf_tail_t |
* +---------------------------+
*
* The bests (xfs_dir2_data_off_t members) and tail are at the end of the
* block for single-leaf only (magic = XFS_DIR2_LEAF1_MAGIC not
* XFS_DIR2_LEAFN_MAGIC).
*
* As all the entries are variable size structures the accessors in this
* file should be used to iterate over them.
*/
struct uio;
struct xfs_dabuf;
struct xfs_da_args;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
/*
* Offset of the leaf/node space. First block in this space
* is the btree root.
*/
#define XFS_DIR2_LEAF_SPACE 1
#define XFS_DIR2_LEAF_OFFSET (XFS_DIR2_LEAF_SPACE * XFS_DIR2_SPACE_SIZE)
#define XFS_DIR2_LEAF_FIRSTDB(mp) \
xfs_dir2_byte_to_db(mp, XFS_DIR2_LEAF_OFFSET)
/*
* Offset in data space of a data entry.
*/
typedef __uint32_t xfs_dir2_dataptr_t;
#define XFS_DIR2_MAX_DATAPTR ((xfs_dir2_dataptr_t)0xffffffff)
#define XFS_DIR2_NULL_DATAPTR ((xfs_dir2_dataptr_t)0)
/*
* Leaf block header.
*/
typedef struct xfs_dir2_leaf_hdr {
xfs_da_blkinfo_t info; /* header for da routines */
__be16 count; /* count of entries */
__be16 stale; /* count of stale entries */
} xfs_dir2_leaf_hdr_t;
/*
* Leaf block entry.
*/
typedef struct xfs_dir2_leaf_entry {
__be32 hashval; /* hash value of name */
__be32 address; /* address of data entry */
} xfs_dir2_leaf_entry_t;
/*
* Leaf block tail.
*/
typedef struct xfs_dir2_leaf_tail {
__be32 bestcount;
} xfs_dir2_leaf_tail_t;
/*
* Leaf block.
*/
typedef struct xfs_dir2_leaf {
xfs_dir2_leaf_hdr_t hdr; /* leaf header */
xfs_dir2_leaf_entry_t ents[]; /* entries */
} xfs_dir2_leaf_t;
/*
* DB blocks here are logical directory block numbers, not filesystem blocks.
*/
static inline int xfs_dir2_max_leaf_ents(struct xfs_mount *mp)
{
return (int)(((mp)->m_dirblksize - (uint)sizeof(xfs_dir2_leaf_hdr_t)) /
(uint)sizeof(xfs_dir2_leaf_entry_t));
}
/*
* Get address of the bestcount field in the single-leaf block.
*/
static inline xfs_dir2_leaf_tail_t *
xfs_dir2_leaf_tail_p(struct xfs_mount *mp, xfs_dir2_leaf_t *lp)
{
return (xfs_dir2_leaf_tail_t *)
((char *)(lp) + (mp)->m_dirblksize -
(uint)sizeof(xfs_dir2_leaf_tail_t));
}
/*
* Get address of the bests array in the single-leaf block.
*/
static inline __be16 *
xfs_dir2_leaf_bests_p(xfs_dir2_leaf_tail_t *ltp)
{
return (__be16 *)ltp - be32_to_cpu(ltp->bestcount);
}
/*
* Convert dataptr to byte in file space
*/
static inline xfs_dir2_off_t
xfs_dir2_dataptr_to_byte(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
{
return (xfs_dir2_off_t)(dp) << XFS_DIR2_DATA_ALIGN_LOG;
}
/*
* Convert byte in file space to dataptr. It had better be aligned.
*/
static inline xfs_dir2_dataptr_t
xfs_dir2_byte_to_dataptr(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return (xfs_dir2_dataptr_t)((by) >> XFS_DIR2_DATA_ALIGN_LOG);
}
/*
* Convert byte in space to (DB) block
*/
static inline xfs_dir2_db_t
xfs_dir2_byte_to_db(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return (xfs_dir2_db_t)((by) >> \
((mp)->m_sb.sb_blocklog + (mp)->m_sb.sb_dirblklog));
}
/*
* Convert dataptr to a block number
*/
static inline xfs_dir2_db_t
xfs_dir2_dataptr_to_db(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
{
return xfs_dir2_byte_to_db(mp, xfs_dir2_dataptr_to_byte(mp, dp));
}
/*
* Convert byte in space to offset in a block
*/
static inline xfs_dir2_data_aoff_t
xfs_dir2_byte_to_off(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return (xfs_dir2_data_aoff_t)((by) & \
((1 << ((mp)->m_sb.sb_blocklog + (mp)->m_sb.sb_dirblklog)) - 1));
}
/*
* Convert dataptr to a byte offset in a block
*/
static inline xfs_dir2_data_aoff_t
xfs_dir2_dataptr_to_off(struct xfs_mount *mp, xfs_dir2_dataptr_t dp)
{
return xfs_dir2_byte_to_off(mp, xfs_dir2_dataptr_to_byte(mp, dp));
}
/*
* Convert block and offset to byte in space
*/
static inline xfs_dir2_off_t
xfs_dir2_db_off_to_byte(struct xfs_mount *mp, xfs_dir2_db_t db,
xfs_dir2_data_aoff_t o)
{
return ((xfs_dir2_off_t)(db) << \
((mp)->m_sb.sb_blocklog + (mp)->m_sb.sb_dirblklog)) + (o);
}
/*
* Convert block (DB) to block (dablk)
*/
static inline xfs_dablk_t
xfs_dir2_db_to_da(struct xfs_mount *mp, xfs_dir2_db_t db)
{
return (xfs_dablk_t)((db) << (mp)->m_sb.sb_dirblklog);
}
/*
* Convert byte in space to (DA) block
*/
static inline xfs_dablk_t
xfs_dir2_byte_to_da(struct xfs_mount *mp, xfs_dir2_off_t by)
{
return xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, by));
}
/*
* Convert block and offset to dataptr
*/
static inline xfs_dir2_dataptr_t
xfs_dir2_db_off_to_dataptr(struct xfs_mount *mp, xfs_dir2_db_t db,
xfs_dir2_data_aoff_t o)
{
return xfs_dir2_byte_to_dataptr(mp, xfs_dir2_db_off_to_byte(mp, db, o));
}
/*
* Convert block (dablk) to block (DB)
*/
static inline xfs_dir2_db_t
xfs_dir2_da_to_db(struct xfs_mount *mp, xfs_dablk_t da)
{
return (xfs_dir2_db_t)((da) >> (mp)->m_sb.sb_dirblklog);
}
/*
* Convert block (dablk) to byte offset in space
*/
static inline xfs_dir2_off_t
xfs_dir2_da_to_byte(struct xfs_mount *mp, xfs_dablk_t da)
{
return xfs_dir2_db_off_to_byte(mp, xfs_dir2_da_to_db(mp, da), 0);
}
/*
* Function declarations.
*/
extern int xfs_dir2_block_to_leaf(struct xfs_da_args *args,
struct xfs_dabuf *dbp);
extern int xfs_dir2_leaf_addname(struct xfs_da_args *args);
extern void xfs_dir2_leaf_compact(struct xfs_da_args *args,
struct xfs_dabuf *bp);
extern void xfs_dir2_leaf_compact_x1(struct xfs_dabuf *bp, int *indexp,
int *lowstalep, int *highstalep,
int *lowlogp, int *highlogp);
extern int xfs_dir2_leaf_getdents(struct xfs_inode *dp, void *dirent,
size_t bufsize, xfs_off_t *offset,
filldir_t filldir);
extern int xfs_dir2_leaf_init(struct xfs_da_args *args, xfs_dir2_db_t bno,
struct xfs_dabuf **bpp, int magic);
extern void xfs_dir2_leaf_log_ents(struct xfs_trans *tp, struct xfs_dabuf *bp,
int first, int last);
extern void xfs_dir2_leaf_log_header(struct xfs_trans *tp,
struct xfs_dabuf *bp);
extern int xfs_dir2_leaf_lookup(struct xfs_da_args *args);
extern int xfs_dir2_leaf_removename(struct xfs_da_args *args);
extern int xfs_dir2_leaf_replace(struct xfs_da_args *args);
extern int xfs_dir2_leaf_search_hash(struct xfs_da_args *args,
struct xfs_dabuf *lbp);
extern int xfs_dir2_leaf_trim_data(struct xfs_da_args *args,
struct xfs_dabuf *lbp, xfs_dir2_db_t db);
extern xfs_dir2_leaf_entry_t *xfs_dir2_leaf_find_entry(xfs_dir2_leaf_t *, int,
int, int, int,
int *, int *);
extern int xfs_dir2_node_to_leaf(struct xfs_da_state *state);
#endif /* __XFS_DIR2_LEAF_H__ */
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