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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. They consist of a single xfs_dir2_sf_hdr header
* followed by zero or more xfs_dir2_sf_entry structures. Due the different
* inode number storage size and the variable length name field in
* the xfs_dir2_sf_entry all these structure are variable length, and the
* accessors in this file should be used to iterate over them.
*/
struct uio;
struct xfs_dabuf;
struct xfs_da_args;
struct xfs_dir2_data_hdr;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
/*
* 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]; } __arch_pack 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, and thus may
* be misaligned. Care needs to be taken to access them through special
* helpers or copy them into aligned variables first.
*/
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 */
} __arch_pack xfs_dir2_sf_hdr_t;
typedef struct xfs_dir2_sf_entry {
__u8 namelen; /* actual name length */
xfs_dir2_sf_off_t offset; /* saved offset */
__u8 name[]; /* name, variable size */
/*
* A xfs_dir2_ino8_t or xfs_dir2_ino4_t follows here, at a
* variable offset after the name.
*/
} __arch_pack xfs_dir2_sf_entry_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_data_aoff_t
xfs_dir2_sf_get_offset(xfs_dir2_sf_entry_t *sfep)
{
return get_unaligned_be16(&sfep->offset.i);
}
static inline void
xfs_dir2_sf_put_offset(xfs_dir2_sf_entry_t *sfep, xfs_dir2_data_aoff_t off)
{
put_unaligned_be16(off, &sfep->offset.i);
}
static inline int
xfs_dir2_sf_entsize(struct xfs_dir2_sf_hdr *hdr, int len)
{
return sizeof(struct xfs_dir2_sf_entry) + /* namelen + offset */
len + /* name */
(hdr->i8count ? /* ino */
sizeof(xfs_dir2_ino8_t) :
sizeof(xfs_dir2_ino4_t));
}
static inline struct xfs_dir2_sf_entry *
xfs_dir2_sf_firstentry(struct xfs_dir2_sf_hdr *hdr)
{
return (struct xfs_dir2_sf_entry *)
((char *)hdr + xfs_dir2_sf_hdr_size(hdr->i8count));
}
static inline struct xfs_dir2_sf_entry *
xfs_dir2_sf_nextentry(struct xfs_dir2_sf_hdr *hdr,
struct xfs_dir2_sf_entry *sfep)
{
return (struct xfs_dir2_sf_entry *)
((char *)sfep + xfs_dir2_sf_entsize(hdr, sfep->namelen));
}
/*
* Functions.
*/
extern xfs_ino_t xfs_dir2_sf_get_parent_ino(struct xfs_dir2_sf_hdr *sfp);
extern xfs_ino_t xfs_dir2_sfe_get_ino(struct xfs_dir2_sf_hdr *sfp,
struct xfs_dir2_sf_entry *sfep);
extern int xfs_dir2_block_sfsize(struct xfs_inode *dp,
struct xfs_dir2_data_hdr *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__ */
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