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linux-next/fs/xfs/xfs_dir2_sf.h
Christoph Hellwig 051e7cd44a [XFS] use filldir internally
Currently xfs has a rather complicated internal scheme to allow for
different directory formats in IRIX. This patch rips all code related to
this out and pushes useage of the Linux filldir callback into the lowlevel
directory code. This does not make the code any less portable because
filldir can be used to create dirents of all possible variations
(including the IRIX ones as proved by the IRIX binary emulation code under
arch/mips/).

This patch get rid of an unessecary copy in the readdir path, about 400
lines of code and one of the last two users of the uio structure.

This version is updated to deal with dmapi aswell which greatly simplifies
the get_dirattrs code. The dmapi part has been tested using the
get_dirattrs tools from the xfstest dmapi suite1 with various small and
large directories.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29478a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-10-15 16:49:49 +10:00

179 lines
5.4 KiB
C

/*
* 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, void *dirent,
xfs_off_t *offset, filldir_t filldir);
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__ */