NetBSD-5.0.2/sys/ufs/ext2fs/ext2fs.h
/* $NetBSD: ext2fs.h,v 1.26 2007/12/25 18:33:49 perry Exp $ */
/*
* 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. 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.
*/
/*
* Copyright (c) 1997 Manuel Bouyer.
*
* 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 Manuel Bouyer.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#ifndef _UFS_EXT2FS_EXT2FS_H_
#define _UFS_EXT2FS_EXT2FS_H_
#include <sys/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 ((daddr_t)(0))
#define SBLOCK ((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 e2fs_minrev; /* minor revision level */
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; /* compatible feature set */
u_int32_t e2fs_features_incompat; /* incompatible feature set */
u_int32_t e2fs_features_rocompat; /* RO-compatible feature set */
u_int8_t e2fs_uuid[16]; /* 128-bit uuid for volume */
char e2fs_vname[16]; /* volume name */
char e2fs_fsmnt[64]; /* name mounted on */
u_int32_t e2fs_algo; /* For compression */
u_int8_t e2fs_prealloc; /* # of blocks to preallocate */
u_int8_t e2fs_dir_prealloc; /* # of blocks to preallocate for dir */
u_int16_t e2fs_reserved_ngdb; /* # of reserved gd blocks for resize */
u_int32_t reserved2[204];
};
/* 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_REV0 0 /* GOOD_OLD revision */
#define E2FS_REV1 1 /* Support compat/incompat features */
/* compatible/incompatible features */
#define EXT2F_COMPAT_PREALLOC 0x0001
#define EXT2F_COMPAT_RESIZE 0x0010
#define EXT2F_ROCOMPAT_SPARSESUPER 0x0001
#define EXT2F_ROCOMPAT_LARGEFILE 0x0002
#define EXT2F_ROCOMPAT_BTREE_DIR 0x0004
#define EXT2F_INCOMPAT_COMP 0x0001
#define EXT2F_INCOMPAT_FTYPE 0x0002
/*
* Features supported in this implementation
*
* We support the following REV1 features:
* - EXT2F_ROCOMPAT_SPARSESUPER
* superblock backups stored only in cg_has_sb(bno) groups
* - EXT2F_ROCOMPAT_LARGEFILE
* use e2di_dacl in struct ext2fs_dinode to store
* upper 32bit of size for >2GB files
* - EXT2F_INCOMPAT_FTYPE
* store file type to e2d_type in struct ext2fs_direct
* (on REV0 e2d_namlen is uint16_t and no e2d_type, like ffs)
*/
#define EXT2F_COMPAT_SUPP 0x0000
#define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER \
| EXT2F_ROCOMPAT_LARGEFILE)
#define EXT2F_INCOMPAT_SUPP EXT2F_INCOMPAT_FTYPE
/*
* Definitions of behavior on errors
*/
#define E2FS_BEH_CONTINUE 1 /* continue operation */
#define E2FS_BEH_READONLY 2 /* remount fs read only */
#define E2FS_BEH_PANIC 3 /* cause panic */
#define E2FS_BEH_DEFAULT E2FS_BEH_CONTINUE
/*
* OS identification
*/
#define E2FS_OS_LINUX 0
#define E2FS_OS_HURD 1
#define E2FS_OS_MASIX 2
#define E2FS_OS_FREEBSD 3
#define E2FS_OS_LITES 4
/*
* 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];
};
/*
* If the EXT2F_ROCOMPAT_SPARSESUPER flag is set, the cylinder group has a
* copy of the super and cylinder group descriptors blocks only if it's
* 1, a power of 3, 5 or 7
*/
static __inline int cg_has_sb(int) __unused;
static __inline int
cg_has_sb(int i)
{
int a3, a5, a7;
if (i == 0 || i == 1)
return 1;
for (a3 = 3, a5 = 5, a7 = 7;
a3 <= i || a5 <= i || a7 <= i;
a3 *= 3, a5 *= 5, a7 *= 7)
if (i == a3 || i == a5 || i == a7)
return 1;
return 0;
}
/* 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 h2fs64(x) (x)
# define fs2h16(x) (x)
# define fs2h32(x) (x)
# define fs2h64(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(struct ext2fs *, struct ext2fs *);
void e2fs_cg_bswap(struct ext2_gd *, struct ext2_gd *, int);
# define h2fs16(x) bswap16(x)
# define h2fs32(x) bswap32(x)
# define h2fs64(x) bswap64(x)
# define fs2h16(x) bswap16(x)
# define fs2h32(x) bswap32(x)
# define fs2h64(x) bswap64(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))
#endif /* !_UFS_EXT2FS_EXT2FS_H_ */