linux/fs/xfs/xfs_dir2_sf.h

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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_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;
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)));
}
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];
}
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));
}
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);
}
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);
}
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);
}
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)));
}
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)));
}
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)));
}
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__ */