272 lines
10 KiB
C
272 lines
10 KiB
C
/* $NetBSD: ext2fs.h,v 1.8 1999/02/17 13:09:43 bouyer Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1997 Manuel Bouyer.
|
|
* Copyright (c) 1982, 1986, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)fs.h 8.10 (Berkeley) 10/27/94
|
|
* Modified for ext2fs by Manuel Bouyer.
|
|
*/
|
|
|
|
#include <machine/bswap.h>
|
|
|
|
/*
|
|
* Each disk drive contains some number of file systems.
|
|
* A file system consists of a number of cylinder groups.
|
|
* Each cylinder group has inodes and data.
|
|
*
|
|
* A file system is described by its super-block, which in turn
|
|
* describes the cylinder groups. The super-block is critical
|
|
* data and is replicated in each cylinder group to protect against
|
|
* catastrophic loss. This is done at `newfs' time and the critical
|
|
* super-block data does not change, so the copies need not be
|
|
* referenced further unless disaster strikes.
|
|
*
|
|
* The first boot and super blocks are given in absolute disk addresses.
|
|
* The byte-offset forms are preferred, as they don't imply a sector size.
|
|
*/
|
|
#define BBSIZE 1024
|
|
#define SBSIZE 1024
|
|
#define BBOFF ((off_t)(0))
|
|
#define SBOFF ((off_t)(BBOFF + BBSIZE))
|
|
#define BBLOCK ((ufs_daddr_t)(0))
|
|
#define SBLOCK ((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
|
|
|
|
/*
|
|
* Addresses stored in inodes are capable of addressing blocks
|
|
* XXX
|
|
*/
|
|
|
|
/*
|
|
* MINBSIZE is the smallest allowable block size.
|
|
* MINBSIZE must be big enough to hold a cylinder group block,
|
|
* thus changes to (struct cg) must keep its size within MINBSIZE.
|
|
* Note that super blocks are always of size SBSIZE,
|
|
* and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
|
|
*/
|
|
#define LOG_MINBSIZE 10
|
|
#define MINBSIZE (1 << LOG_MINBSIZE)
|
|
|
|
/*
|
|
* The path name on which the file system is mounted is maintained
|
|
* in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
|
|
* the super block for this name.
|
|
*/
|
|
#define MAXMNTLEN 512
|
|
|
|
/*
|
|
* MINFREE gives the minimum acceptable percentage of file system
|
|
* blocks which may be free. If the freelist drops below this level
|
|
* only the superuser may continue to allocate blocks. This may
|
|
* be set to 0 if no reserve of free blocks is deemed necessary,
|
|
* however throughput drops by fifty percent if the file system
|
|
* is run at between 95% and 100% full; thus the minimum default
|
|
* value of fs_minfree is 5%. However, to get good clustering
|
|
* performance, 10% is a better choice. hence we use 10% as our
|
|
* default value. With 10% free space, fragmentation is not a
|
|
* problem, so we choose to optimize for time.
|
|
*/
|
|
#define MINFREE 5
|
|
|
|
/*
|
|
* Super block for an ext2fs file system.
|
|
*/
|
|
struct ext2fs {
|
|
u_int32_t e2fs_icount; /* Inode count */
|
|
u_int32_t e2fs_bcount; /* blocks count */
|
|
u_int32_t e2fs_rbcount; /* reserved blocks count */
|
|
u_int32_t e2fs_fbcount; /* free blocks count */
|
|
u_int32_t e2fs_ficount; /* free inodes count */
|
|
u_int32_t e2fs_first_dblock; /* first data block */
|
|
u_int32_t e2fs_log_bsize; /* block size = 1024*(2^e2fs_log_bsize) */
|
|
u_int32_t e2fs_fsize; /* fragment size */
|
|
u_int32_t e2fs_bpg; /* blocks per group */
|
|
u_int32_t e2fs_fpg; /* frags per group */
|
|
u_int32_t e2fs_ipg; /* inodes per group */
|
|
u_int32_t e2fs_mtime; /* mount time */
|
|
u_int32_t e2fs_wtime; /* write time */
|
|
u_int16_t e2fs_mnt_count; /* mount count */
|
|
u_int16_t e2fs_max_mnt_count; /* max mount count */
|
|
u_int16_t e2fs_magic; /* magic number */
|
|
u_int16_t e2fs_state; /* file system state */
|
|
u_int16_t e2fs_beh; /* behavior on errors */
|
|
u_int16_t reserved;
|
|
u_int32_t e2fs_lastfsck; /* time of last fsck */
|
|
u_int32_t e2fs_fsckintv; /* max time between fscks */
|
|
u_int32_t e2fs_creator; /* creator OS */
|
|
u_int32_t e2fs_rev; /* revision level */
|
|
u_int16_t e2fs_ruid; /* default uid for reserved blocks */
|
|
u_int16_t e2fs_rgid; /* default gid for reserved blocks */
|
|
/* EXT2_DYNAMIC_REV superblocks */
|
|
u_int32_t e2fs_first_ino; /* first non-reserved inode */
|
|
u_int16_t e2fs_inode_size; /* size of inode structure */
|
|
u_int16_t e2fs_block_group_nr; /* block grp number of this sblk*/
|
|
u_int32_t e2fs_features_compat; /* OK to mount if unknown */
|
|
u_int32_t e2fs_features_incompat; /* not OK to mount if unknown */
|
|
u_int32_t e2fs_features_compat_ro; /* OK to mount ro if unknown */
|
|
u_int32_t reserved2[230];
|
|
};
|
|
|
|
|
|
/* in-memory data for ext2fs */
|
|
struct m_ext2fs {
|
|
struct ext2fs e2fs;
|
|
u_char e2fs_fsmnt[MAXMNTLEN]; /* name mounted on */
|
|
int8_t e2fs_ronly; /* mounted read-only flag */
|
|
int8_t e2fs_fmod; /* super block modified flag */
|
|
int32_t e2fs_bsize; /* block size */
|
|
int32_t e2fs_bshift; /* ``lblkno'' calc of logical blkno */
|
|
int32_t e2fs_bmask; /* ``blkoff'' calc of blk offsets */
|
|
int64_t e2fs_qbmask; /* ~fs_bmask - for use with quad size */
|
|
int32_t e2fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
|
|
int32_t e2fs_ncg; /* number of cylinder groups */
|
|
int32_t e2fs_ngdb; /* number of group descriptor block */
|
|
int32_t e2fs_ipb; /* number of inodes per block */
|
|
int32_t e2fs_itpg; /* number of inode table per group */
|
|
struct ext2_gd *e2fs_gd; /* group descripors */
|
|
};
|
|
|
|
|
|
|
|
/*
|
|
* Filesystem identification
|
|
*/
|
|
#define E2FS_MAGIC 0xef53 /* the ext2fs magic number */
|
|
#define E2FS_REV 0 /* revision level */
|
|
|
|
/*
|
|
* OS identification
|
|
*/
|
|
#define E2FS_OS_LINUX 0
|
|
#define E2FS_OS_HURD 1
|
|
#define E2FS_OS_MASIX 2
|
|
|
|
/*
|
|
* Filesystem clean flags
|
|
*/
|
|
#define E2FS_ISCLEAN 0x01
|
|
#define E2FS_ERRORS 0x02
|
|
|
|
/* ext2 file system block group descriptor */
|
|
|
|
struct ext2_gd {
|
|
u_int32_t ext2bgd_b_bitmap; /* blocks bitmap block */
|
|
u_int32_t ext2bgd_i_bitmap; /* inodes bitmap block */
|
|
u_int32_t ext2bgd_i_tables; /* inodes table block */
|
|
u_int16_t ext2bgd_nbfree; /* number of free blocks */
|
|
u_int16_t ext2bgd_nifree; /* number of free inodes */
|
|
u_int16_t ext2bgd_ndirs; /* number of directories */
|
|
u_int16_t reserved;
|
|
u_int32_t reserved2[3];
|
|
|
|
};
|
|
|
|
/* EXT2FS metadatas are stored in little-endian byte order. These macros
|
|
* helps reading theses metadatas
|
|
*/
|
|
|
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
|
# define h2fs16(x) (x)
|
|
# define h2fs32(x) (x)
|
|
# define fs2h16(x) (x)
|
|
# define fs2h32(x) (x)
|
|
# define e2fs_sbload(old, new) memcpy((new), (old), SBSIZE);
|
|
# define e2fs_cgload(old, new, size) memcpy((new), (old), (size));
|
|
# define e2fs_sbsave(old, new) memcpy((new), (old), SBSIZE);
|
|
# define e2fs_cgsave(old, new, size) memcpy((new), (old), (size));
|
|
#else
|
|
void e2fs_sb_bswap __P((struct ext2fs *, struct ext2fs *));
|
|
void e2fs_cg_bswap __P((struct ext2_gd *, struct ext2_gd *, int));
|
|
# define h2fs16(x) bswap16(x)
|
|
# define h2fs32(x) bswap32(x)
|
|
# define fs2h16(x) bswap16(x)
|
|
# define fs2h32(x) bswap32(x)
|
|
# define e2fs_sbload(old, new) e2fs_sb_bswap((old), (new))
|
|
# define e2fs_cgload(old, new, size) e2fs_cg_bswap((old), (new), (size));
|
|
# define e2fs_sbsave(old, new) e2fs_sb_bswap((old), (new))
|
|
# define e2fs_cgsave(old, new, size) e2fs_cg_bswap((old), (new), (size));
|
|
#endif
|
|
|
|
/*
|
|
* Turn file system block numbers into disk block addresses.
|
|
* This maps file system blocks to device size blocks.
|
|
*/
|
|
#define fsbtodb(fs, b) ((b) << (fs)->e2fs_fsbtodb)
|
|
#define dbtofsb(fs, b) ((b) >> (fs)->e2fs_fsbtodb)
|
|
|
|
/*
|
|
* Macros for handling inode numbers:
|
|
* inode number to file system block offset.
|
|
* inode number to cylinder group number.
|
|
* inode number to file system block address.
|
|
*/
|
|
#define ino_to_cg(fs, x) (((x) - 1) / (fs)->e2fs.e2fs_ipg)
|
|
#define ino_to_fsba(fs, x) \
|
|
((fs)->e2fs_gd[ino_to_cg(fs, x)].ext2bgd_i_tables + \
|
|
(((x)-1) % (fs)->e2fs.e2fs_ipg)/(fs)->e2fs_ipb)
|
|
#define ino_to_fsbo(fs, x) (((x)-1) % (fs)->e2fs_ipb)
|
|
|
|
/*
|
|
* Give cylinder group number for a file system block.
|
|
* Give cylinder group block number for a file system block.
|
|
*/
|
|
#define dtog(fs, d) (((d) - (fs)->e2fs.e2fs_first_dblock) / (fs)->e2fs.e2fs_fpg)
|
|
#define dtogd(fs, d) \
|
|
(((d) - (fs)->e2fs.e2fs_first_dblock) % (fs)->e2fs.e2fs_fpg)
|
|
|
|
/*
|
|
* The following macros optimize certain frequently calculated
|
|
* quantities by using shifts and masks in place of divisions
|
|
* modulos and multiplications.
|
|
*/
|
|
#define blkoff(fs, loc) /* calculates (loc % fs->e2fs_bsize) */ \
|
|
((loc) & (fs)->e2fs_qbmask)
|
|
#define lblktosize(fs, blk) /* calculates (blk * fs->e2fs_bsize) */ \
|
|
((blk) << (fs)->e2fs_bshift)
|
|
#define lblkno(fs, loc) /* calculates (loc / fs->e2fs_bsize) */ \
|
|
((loc) >> (fs)->e2fs_bshift)
|
|
#define blkroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \
|
|
(((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask)
|
|
#define fragroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \
|
|
(((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask)
|
|
/*
|
|
* Determine the number of available frags given a
|
|
* percentage to hold in reserve.
|
|
*/
|
|
#define freespace(fs) \
|
|
((fs)->e2fs.e2fs_fbcount - (fs)->e2fs.e2fs_rbcount)
|
|
|
|
/*
|
|
* Number of indirects in a file system block.
|
|
*/
|
|
#define NINDIR(fs) ((fs)->e2fs_bsize / sizeof(u_int32_t))
|