LCOM1920-T02G10

/*        $NetBSD: ext2fs.h,v 1.36 2013/06/23 07:28:37 dholland 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.

 *

 * 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 {

        uint32_t  e2fs_icount;                /* Inode count */

        uint32_t  e2fs_bcount;                /* blocks count */

        uint32_t  e2fs_rbcount;                /* reserved blocks count */

        uint32_t  e2fs_fbcount;                /* free blocks count */

        uint32_t  e2fs_ficount;                /* free inodes count */

        uint32_t  e2fs_first_dblock;        /* first data block */

        uint32_t  e2fs_log_bsize;        /* block size = 1024*(2^e2fs_log_bsize) */

        uint32_t  e2fs_fsize;                /* fragment size */

        uint32_t  e2fs_bpg;                /* blocks per group */

        uint32_t  e2fs_fpg;                /* frags per group */

        uint32_t  e2fs_ipg;                /* inodes per group */

        uint32_t  e2fs_mtime;                /* mount time */

        uint32_t  e2fs_wtime;                /* write time */

        uint16_t  e2fs_mnt_count;        /* mount count */

        uint16_t  e2fs_max_mnt_count;        /* max mount count */

        uint16_t  e2fs_magic;                /* magic number */

        uint16_t  e2fs_state;                /* file system state */

        uint16_t  e2fs_beh;                /* behavior on errors */

        uint16_t  e2fs_minrev;                /* minor revision level */

        uint32_t  e2fs_lastfsck;        /* time of last fsck */

        uint32_t  e2fs_fsckintv;        /* max time between fscks */

        uint32_t  e2fs_creator;                /* creator OS */

        uint32_t  e2fs_rev;                /* revision level */

        uint16_t  e2fs_ruid;                /* default uid for reserved blocks */

        uint16_t  e2fs_rgid;                /* default gid for reserved blocks */

        /* EXT2_DYNAMIC_REV superblocks */

        uint32_t  e2fs_first_ino;        /* first non-reserved inode */

        uint16_t  e2fs_inode_size;        /* size of inode structure */

        uint16_t  e2fs_block_group_nr;        /* block grp number of this sblk*/

        uint32_t  e2fs_features_compat;        /*  compatible feature set */

        uint32_t  e2fs_features_incompat; /* incompatible feature set */

        uint32_t  e2fs_features_rocompat; /* RO-compatible feature set */

        uint8_t   e2fs_uuid[16];        /* 128-bit uuid for volume */

        char      e2fs_vname[16];        /* volume name */

        char      e2fs_fsmnt[64];        /* name mounted on */

        uint32_t  e2fs_algo;                /* For compression */

        uint8_t   e2fs_prealloc;        /* # of blocks to preallocate */

        uint8_t   e2fs_dir_prealloc;        /* # of blocks to preallocate for dir */

        uint16_t  e2fs_reserved_ngdb;        /* # of reserved gd blocks for resize */

        uint32_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_AFS                0x0002

#define EXT2F_COMPAT_HASJOURNAL                0x0004

#define EXT2F_COMPAT_EXTATTR                0x0008

#define EXT2F_COMPAT_RESIZE                0x0010

#define EXT2F_COMPAT_DIRHASHINDEX        0x0020

#define        EXT2F_COMPAT_BITS \

        "\20" \

        "\06COMPAT_DIRHASHINDEX" \

        "\05COMPAT_RESIZE" \

        "\04COMPAT_EXTATTR" \

        "\03COMPAT_HASJOURNAL" \

        "\02COMPAT_AFS" \

        "\01COMPAT_PREALLOC"

#define EXT2F_ROCOMPAT_SPARSESUPER        0x0001

#define EXT2F_ROCOMPAT_LARGEFILE        0x0002

#define EXT2F_ROCOMPAT_BTREE_DIR        0x0004

#define EXT2F_ROCOMPAT_HUGE_FILE        0x0008

#define EXT2F_ROCOMPAT_GDT_CSUM                0x0010

#define EXT2F_ROCOMPAT_DIR_NLINK        0x0020

#define EXT2F_ROCOMPAT_EXTRA_ISIZE        0x0040

#define        EXT2F_ROCOMPAT_BITS \

        "\20" \

        "\07ROCOMPAT_EXTRA_ISIZE" \

        "\06ROCOMPAT_DIR_NLINK" \

        "\05ROCOMPAT_GDT_CSUM" \

        "\04ROCOMPAT_HUGE_FILE" \

        "\03ROCOMPAT_BTREE_DIR" \

        "\02ROCOMPAT_LARGEFILE" \

        "\01ROCOMPAT_SPARSESUPER"

#define EXT2F_INCOMPAT_COMP                0x0001

#define EXT2F_INCOMPAT_FTYPE                0x0002

#define        EXT2F_INCOMPAT_REPLAY_JOURNAL        0x0004

#define        EXT2F_INCOMPAT_USES_JOURNAL        0x0008

#define EXT2F_INCOMPAT_META_BG                0x0010

#define EXT2F_INCOMPAT_EXTENTS                0x0040

#define EXT2F_INCOMPAT_64BIT                0x0080

#define EXT2F_INCOMPAT_MMP                0x0100

#define EXT2F_INCOMPAT_FLEX_BG                0x0200

#define        EXT2F_INCOMPAT_BITS \

        "\20" \

        "\012INCOMPAT_FLEX_BG" \

        "\011INCOMPAT_MMP" \

        "\010INCOMPAT_64BIT" \

        "\07INCOMPAT_EXTENTS" \

        "\05INCOMPAT_META_BG" \

        "\04INCOMPAT_USES_JOURNAL" \

        "\03INCOMPAT_REPLAY_JOURNAL" \

        "\02INCOMPAT_FTYPE" \

        "\01INCOMPAT_COMP"

/*

 * 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 \

                                         | EXT2F_ROCOMPAT_HUGE_FILE)

#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 {

        uint32_t ext2bgd_b_bitmap;        /* blocks bitmap block */

        uint32_t ext2bgd_i_bitmap;        /* inodes bitmap block */

        uint32_t ext2bgd_i_tables;        /* inodes table block  */

        uint16_t ext2bgd_nbfree;        /* number of free blocks */

        uint16_t ext2bgd_nifree;        /* number of free inodes */

        uint16_t ext2bgd_ndirs;                /* number of directories */

        uint16_t reserved;

        uint32_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 EXT2_FSBTODB(fs, b)        ((b) << (fs)->e2fs_fsbtodb)

#define EXT2_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 ext2_blkoff(fs, loc)        /* calculates (loc % fs->e2fs_bsize) */ \

        ((loc) & (fs)->e2fs_qbmask)

#define ext2_lblktosize(fs, blk) /* calculates (blk * fs->e2fs_bsize) */ \

        ((blk) << (fs)->e2fs_bshift)

#define ext2_lblkno(fs, loc)        /* calculates (loc / fs->e2fs_bsize) */ \

        ((loc) >> (fs)->e2fs_bshift)

#define ext2_blkroundup(fs, size) /* calculates roundup(size, fs->e2fs_bsize) */ \

        (((size) + (fs)->e2fs_qbmask) & (fs)->e2fs_bmask)

#define ext2_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        EXT2_NINDIR(fs)        ((fs)->e2fs_bsize / sizeof(uint32_t))

#endif /* !_UFS_EXT2FS_EXT2FS_H_ */