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Diffstat (limited to 'sys/gnu/ext2fs/fs.h')
| -rw-r--r-- | sys/gnu/ext2fs/fs.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/sys/gnu/ext2fs/fs.h b/sys/gnu/ext2fs/fs.h new file mode 100644 index 0000000..28071d4 --- /dev/null +++ b/sys/gnu/ext2fs/fs.h @@ -0,0 +1,157 @@ +/* + * modified for EXT2FS support in Lites 1.1 + * + * Aug 1995, Godmar Back (gback@cs.utah.edu) + * University of Utah, Department of Computer Science + */ +/* + * 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 8.7 (Berkeley) 4/19/94 + */ + +/* + * 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)) + +/* + * 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 + +/* + * Macros for access to superblock array structures + */ + +/* + * Convert cylinder group to base address of its global summary info. + */ +#define fs_cs(fs, cgindx) (((struct ext2_group_desc *) \ + (fs->s_group_desc[cgindx / EXT2_DESC_PER_BLOCK(fs)]->b_data)) \ + [cgindx % EXT2_DESC_PER_BLOCK(fs)]) + +/* + * Turn file system block numbers into disk block addresses. + * This maps file system blocks to device size blocks. + */ +#define fsbtodb(fs, b) ((b) << ((fs)->s_fsbtodb)) +#define dbtofsb(fs, b) ((b) >> ((fs)->s_fsbtodb)) + +/* get group containing inode */ +#define ino_to_cg(fs, x) (((x) - 1) / EXT2_INODES_PER_GROUP(fs)) + +/* get block containing inode from its number x */ +#define ino_to_fsba(fs, x) fs_cs(fs, ino_to_cg(fs, x)).bg_inode_table + \ + (((x)-1) % EXT2_INODES_PER_GROUP(fs))/EXT2_INODES_PER_BLOCK(fs) + +/* get offset for inode in block */ +#define ino_to_fsbo(fs, x) ((x-1) % EXT2_INODES_PER_BLOCK(fs)) + +/* + * 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->s_es->s_first_data_block) / \ + EXT2_BLOCKS_PER_GROUP(fs)) +#define dtogd(fs, d) (((d) - fs->s_es->s_first_data_block) % \ + EXT2_BLOCKS_PER_GROUP(fs)) + +/* + * 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->fs_bsize) */ \ + ((loc) & (fs)->s_qbmask) + +#define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \ + ((blk) << (fs->s_bshift)) + +#define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ + ((loc) >> (fs->s_bshift)) + +/* no fragments -> logical block number equal # of frags */ +#define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ + ((loc) >> (fs->s_bshift)) + +#define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ + roundup(size, fs->s_frag_size) + /* was (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) */ + +/* + * Determining the size of a file block in the file system. + * easy w/o fragments + */ +#define blksize(fs, ip, lbn) ((fs)->s_frag_size) + +/* + * INOPB is the number of inodes in a secondary storage block. + */ +#define INOPB(fs) EXT2_INODES_PER_BLOCK(fs) + +/* + * NINDIR is the number of indirects in a file system block. + */ +#define NINDIR(fs) (EXT2_ADDR_PER_BLOCK(fs)) + +extern int inside[], around[]; +extern u_char *fragtbl[]; + +/* a few remarks about superblock locking/unlocking + * Linux provides special routines for doing so + * I haven't figured out yet what BSD does + * I think I'll try a VOP_LOCK/VOP_UNLOCK on the device vnode + */ +#define DEVVP(inode) (VFSTOUFS(ITOV(inode)->v_mount)->um_devvp) +#define lock_super(devvp) VOP_LOCK(devvp) +#define unlock_super(devvp) VOP_UNLOCK(devvp) + |
