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Diffstat (limited to 'serverboot/fs.h')
| -rw-r--r-- | serverboot/fs.h | 455 |
1 files changed, 0 insertions, 455 deletions
diff --git a/serverboot/fs.h b/serverboot/fs.h deleted file mode 100644 index 5809ed93..00000000 --- a/serverboot/fs.h +++ /dev/null @@ -1,455 +0,0 @@ -/* - * Mach Operating System - * Copyright (c) 1991,1990 Carnegie Mellon University - * All Rights Reserved. - * - * Permission to use, copy, modify and distribute this software and its - * documentation is hereby granted, provided that both the copyright - * notice and this permission notice appear in all copies of the - * software, derivative works or modified versions, and any portions - * thereof, and that both notices appear in supporting documentation. - * - * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" - * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR - * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * - * Carnegie Mellon requests users of this software to return to - * - * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU - * School of Computer Science - * Carnegie Mellon University - * Pittsburgh PA 15213-3890 - * - * any improvements or extensions that they make and grant Carnegie Mellon - * the rights to redistribute these changes. - */ -/* - * Copyright (c) 1982, 1986 Regents of the University of California. - * All rights reserved. - * - * Redistribution and use in source and binary forms are permitted - * provided that the above copyright notice and this paragraph are - * duplicated in all such forms and that any documentation, - * advertising materials, and other materials related to such - * distribution and use acknowledge that the software was developed - * by the University of California, Berkeley. The name of the - * University may not be used to endorse or promote products derived - * from this software without specific prior written permission. - * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR - * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED - * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. - * - * @(#)fs.h 7.7 (Berkeley) 5/9/89 - */ - -/* - * 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. - * - * For file system fs, the offsets of the various blocks of interest - * are given in the super block as: - * [fs->fs_sblkno] Super-block - * [fs->fs_cblkno] Cylinder group block - * [fs->fs_iblkno] Inode blocks - * [fs->fs_dblkno] Data blocks - * The beginning of cylinder group cg in fs, is given by - * the ``cgbase(fs, cg)'' macro. - * - * 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 8192 -#define SBSIZE 8192 -#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 fragments - * of `blocks'. File system blocks of at most size MAXBSIZE can - * be optionally broken into 2, 4, or 8 pieces, each of which is - * addressible; these pieces may be DEV_BSIZE, or some multiple of - * a DEV_BSIZE unit. - * - * Large files consist of exclusively large data blocks. To avoid - * undue wasted disk space, the last data block of a small file may be - * allocated as only as many fragments of a large block as are - * necessary. The file system format retains only a single pointer - * to such a fragment, which is a piece of a single large block that - * has been divided. The size of such a fragment is determinable from - * information in the inode, using the ``blksize(fs, ip, lbn)'' macro. - * - * The file system records space availability at the fragment level; - * to determine block availability, aligned fragments are examined. - * - * The root inode is the root of the file system. - * Inode 0 can't be used for normal purposes and - * historically bad blocks were linked to inode 1, - * thus the root inode is 2. (inode 1 is no longer used for - * this purpose, however numerous dump tapes make this - * assumption, so we are stuck with it) - */ -#define ROOTINO ((ino_t)2) /* i number of all roots */ - -/* - * MINBSIZE is the smallest allowable block size. - * In order to insure that it is possible to create files of size - * 2^32 with only two levels of indirection, MINBSIZE is set to 4096. - * 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 MINBSIZE 4096 - -/* - * 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. - * The limit on the amount of summary information per file system - * is defined by MAXCSBUFS. It is currently parameterized for a - * maximum of two million cylinders. - */ -#define MAXMNTLEN 512 -#define MAXCSBUFS 32 - -/* - * Per cylinder group information; summarized in blocks allocated - * from first cylinder group data blocks. These blocks have to be - * read in from fs_csaddr (size fs_cssize) in addition to the - * super block. - * - * N.B. sizeof(struct csum) must be a power of two in order for - * the ``fs_cs'' macro to work (see below). - */ -struct csum { - int cs_ndir; /* number of directories */ - int cs_nbfree; /* number of free blocks */ - int cs_nifree; /* number of free inodes */ - int cs_nffree; /* number of free frags */ -}; - -/* - * Super block for a file system. - */ -#define FS_MAGIC 0x011954 -struct fs -{ - int xxx1; /* struct fs *fs_link;*/ - int xxx2; /* struct fs *fs_rlink;*/ - daddr_t fs_sblkno; /* addr of super-block in filesys */ - daddr_t fs_cblkno; /* offset of cyl-block in filesys */ - daddr_t fs_iblkno; /* offset of inode-blocks in filesys */ - daddr_t fs_dblkno; /* offset of first data after cg */ - int fs_cgoffset; /* cylinder group offset in cylinder */ - int fs_cgmask; /* used to calc mod fs_ntrak */ - time_t fs_time; /* last time written */ - int fs_size; /* number of blocks in fs */ - int fs_dsize; /* number of data blocks in fs */ - int fs_ncg; /* number of cylinder groups */ - int fs_bsize; /* size of basic blocks in fs */ - int fs_fsize; /* size of frag blocks in fs */ - int fs_frag; /* number of frags in a block in fs */ -/* these are configuration parameters */ - int fs_minfree; /* minimum percentage of free blocks */ - int fs_rotdelay; /* num of ms for optimal next block */ - int fs_rps; /* disk revolutions per second */ -/* these fields can be computed from the others */ - int fs_bmask; /* ``blkoff'' calc of blk offsets */ - int fs_fmask; /* ``fragoff'' calc of frag offsets */ - int fs_bshift; /* ``lblkno'' calc of logical blkno */ - int fs_fshift; /* ``numfrags'' calc number of frags */ -/* these are configuration parameters */ - int fs_maxcontig; /* max number of contiguous blks */ - int fs_maxbpg; /* max number of blks per cyl group */ -/* these fields can be computed from the others */ - int fs_fragshift; /* block to frag shift */ - int fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ - int fs_sbsize; /* actual size of super block */ - int fs_csmask; /* csum block offset */ - int fs_csshift; /* csum block number */ - int fs_nindir; /* value of NINDIR */ - int fs_inopb; /* value of INOPB */ - int fs_nspf; /* value of NSPF */ -/* yet another configuration parameter */ - int fs_optim; /* optimization preference, see below */ -/* these fields are derived from the hardware */ - int fs_npsect; /* # sectors/track including spares */ - int fs_interleave; /* hardware sector interleave */ - int fs_trackskew; /* sector 0 skew, per track */ - int fs_headswitch; /* head switch time, usec */ - int fs_trkseek; /* track-to-track seek, usec */ -/* sizes determined by number of cylinder groups and their sizes */ - daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ - int fs_cssize; /* size of cyl grp summary area */ - int fs_cgsize; /* cylinder group size */ -/* these fields are derived from the hardware */ - int fs_ntrak; /* tracks per cylinder */ - int fs_nsect; /* sectors per track */ - int fs_spc; /* sectors per cylinder */ -/* this comes from the disk driver partitioning */ - int fs_ncyl; /* cylinders in file system */ -/* these fields can be computed from the others */ - int fs_cpg; /* cylinders per group */ - int fs_ipg; /* inodes per group */ - int fs_fpg; /* blocks per group * fs_frag */ -/* this data must be re-computed after crashes */ - struct csum fs_cstotal; /* cylinder summary information */ -/* these fields are cleared at mount time */ - char fs_fmod; /* super block modified flag */ - char fs_clean; /* file system is clean flag */ - char fs_ronly; /* mounted read-only flag */ - char fs_flags; /* currently unused flag */ - char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ -/* these fields retain the current block allocation info */ - int fs_cgrotor; /* last cg searched */ -#if 1 - int was_fs_csp[MAXCSBUFS]; -#else - struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */ -#endif - int fs_cpc; /* cyl per cycle in postbl */ - short fs_opostbl[16][8]; /* old rotation block list head */ - long fs_sparecon[50]; /* reserved for future constants */ - long fs_contigsumsize; /* size of cluster summary array */ - long fs_maxsymlinklen; /* max length of an internal symlink */ - long fs_inodefmt; /* format of on-disk inodes */ - quad fs_maxfilesize; /* maximum representable file size */ - quad fs_qbmask; /* ~fs_bmask - for use with quad size */ - quad fs_qfmask; /* ~fs_fmask - for use with quad size */ - long fs_state; /* validate fs_clean field */ - int fs_postblformat; /* format of positional layout tables */ - int fs_nrpos; /* number of rotaional positions */ - int fs_postbloff; /* (short) rotation block list head */ - int fs_rotbloff; /* (u_char) blocks for each rotation */ - int fs_magic; /* magic number */ - u_char fs_space[1]; /* list of blocks for each rotation */ -/* actually longer */ -}; -/* - * Preference for optimization. - */ -#define FS_OPTTIME 0 /* minimize allocation time */ -#define FS_OPTSPACE 1 /* minimize disk fragmentation */ - -/* - * Rotational layout table format types - */ -#define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */ -#define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */ -/* - * Macros for access to superblock array structures - */ -#define fs_postbl(fs, cylno) \ - (((fs)->fs_postblformat == FS_42POSTBLFMT) \ - ? ((fs)->fs_opostbl[cylno]) \ - : ((short *)((char *)(fs) + (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos)) -#define fs_rotbl(fs) \ - (((fs)->fs_postblformat == FS_42POSTBLFMT) \ - ? ((fs)->fs_space) \ - : ((u_char *)((char *)(fs) + (fs)->fs_rotbloff))) - -/* - * Convert cylinder group to base address of its global summary info. - * - * N.B. This macro assumes that sizeof(struct csum) is a power of two. - */ -#define fs_cs(fs, indx) \ - fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask] - -/* - * Cylinder group block for a file system. - */ -#define CG_MAGIC 0x090255 -struct cg { - int xxx1; /* struct cg *cg_link;*/ - int cg_magic; /* magic number */ - time_t cg_time; /* time last written */ - int cg_cgx; /* we are the cgx'th cylinder group */ - short cg_ncyl; /* number of cyl's this cg */ - short cg_niblk; /* number of inode blocks this cg */ - int cg_ndblk; /* number of data blocks this cg */ - struct csum cg_cs; /* cylinder summary information */ - int cg_rotor; /* position of last used block */ - int cg_frotor; /* position of last used frag */ - int cg_irotor; /* position of last used inode */ - int cg_frsum[MAXFRAG]; /* counts of available frags */ - int cg_btotoff; /* (long) block totals per cylinder */ - int cg_boff; /* (short) free block positions */ - int cg_iusedoff; /* (char) used inode map */ - int cg_freeoff; /* (u_char) free block map */ - int cg_nextfreeoff; /* (u_char) next available space */ - int cg_sparecon[16]; /* reserved for future use */ - u_char cg_space[1]; /* space for cylinder group maps */ -/* actually longer */ -}; -/* - * Macros for access to cylinder group array structures - */ -#define cg_blktot(cgp) \ - (((cgp)->cg_magic != CG_MAGIC) \ - ? (((struct ocg *)(cgp))->cg_btot) \ - : ((int *)((char *)(cgp) + (cgp)->cg_btotoff))) -#define cg_blks(fs, cgp, cylno) \ - (((cgp)->cg_magic != CG_MAGIC) \ - ? (((struct ocg *)(cgp))->cg_b[cylno]) \ - : ((short *)((char *)(cgp) + (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos)) -#define cg_inosused(cgp) \ - (((cgp)->cg_magic != CG_MAGIC) \ - ? (((struct ocg *)(cgp))->cg_iused) \ - : ((char *)((char *)(cgp) + (cgp)->cg_iusedoff))) -#define cg_blksfree(cgp) \ - (((cgp)->cg_magic != CG_MAGIC) \ - ? (((struct ocg *)(cgp))->cg_free) \ - : ((u_char *)((char *)(cgp) + (cgp)->cg_freeoff))) -#define cg_chkmagic(cgp) \ - ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC) - -/* - * The following structure is defined - * for compatibility with old file systems. - */ -struct ocg { - int xxx1; /* struct ocg *cg_link;*/ - int xxx2; /* struct ocg *cg_rlink;*/ - time_t cg_time; /* time last written */ - int cg_cgx; /* we are the cgx'th cylinder group */ - short cg_ncyl; /* number of cyl's this cg */ - short cg_niblk; /* number of inode blocks this cg */ - int cg_ndblk; /* number of data blocks this cg */ - struct csum cg_cs; /* cylinder summary information */ - int cg_rotor; /* position of last used block */ - int cg_frotor; /* position of last used frag */ - int cg_irotor; /* position of last used inode */ - int cg_frsum[8]; /* counts of available frags */ - int cg_btot[32]; /* block totals per cylinder */ - short cg_b[32][8]; /* positions of free blocks */ - char cg_iused[256]; /* used inode map */ - int cg_magic; /* magic number */ - u_char cg_free[1]; /* free block map */ -/* actually longer */ -}; - -/* - * Turn file system block numbers into disk block addresses. - * This maps file system blocks to device size blocks. - */ -#define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb) -#define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb) - -/* - * Cylinder group macros to locate things in cylinder groups. - * They calc file system addresses of cylinder group data structures. - */ -#define cgbase(fs, c) ((daddr_t)((fs)->fs_fpg * (c))) -#define cgstart(fs, c) \ - (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask))) -#define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */ -#define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */ -#define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */ -#define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */ - -/* - * 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 itoo(fs, x) ((x) % INOPB(fs)) -#define itog(fs, x) ((x) / (fs)->fs_ipg) -#define itod(fs, x) \ - ((daddr_t)(cgimin(fs, itog(fs, x)) + \ - (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(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)->fs_fpg) -#define dtogd(fs, d) ((d) % (fs)->fs_fpg) - -/* - * Extract the bits for a block from a map. - * Compute the cylinder and rotational position of a cyl block addr. - */ -#define blkmap(fs, map, loc) \ - (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag))) -#define cbtocylno(fs, bno) \ - ((bno) * NSPF(fs) / (fs)->fs_spc) -#define cbtorpos(fs, bno) \ - (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \ - (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \ - (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect) - -/* - * 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)->fs_bmask) -#define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \ - ((loc) & ~(fs)->fs_fmask) -#define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ - ((loc) >> (fs)->fs_bshift) -#define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ - ((loc) >> (fs)->fs_fshift) -#define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \ - (((size) + (fs)->fs_bsize - 1) & (fs)->fs_bmask) -#define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ - (((size) + (fs)->fs_fsize - 1) & (fs)->fs_fmask) -#define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \ - ((frags) >> (fs)->fs_fragshift) -#define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \ - ((blks) << (fs)->fs_fragshift) -#define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \ - ((fsb) & ((fs)->fs_frag - 1)) -#define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \ - ((fsb) &~ ((fs)->fs_frag - 1)) - -/* - * Determine the number of available frags given a - * percentage to hold in reserve - */ -#define freespace(fs, percentreserved) \ - (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \ - (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100)) - -/* - * Determining the size of a file block in the file system. - */ -#define blksize(fs, ip, lbn) \ - (((lbn) >= NDADDR || (ip)->i_size >= ((lbn) + 1) << (fs)->fs_bshift) \ - ? (fs)->fs_bsize \ - : (fragroundup(fs, blkoff(fs, (ip)->i_size)))) -#define dblksize(fs, dip, lbn) \ - (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \ - ? (fs)->fs_bsize \ - : (fragroundup(fs, blkoff(fs, (dip)->di_size)))) - -/* - * Number of disk sectors per block; assumes DEV_BSIZE byte sector size. - */ -#define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift) -#define NSPF(fs) ((fs)->fs_nspf) - -/* - * INOPB is the number of inodes in a secondary storage block. - */ -#define INOPB(fs) ((fs)->fs_inopb) -#define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift) - -/* - * NINDIR is the number of indirects in a file system block. - */ -#define NINDIR(fs) ((fs)->fs_nindir) - |