Annotation of sys/ufs/ffs/fs.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: fs.h,v 1.32 2007/06/01 07:03:27 otto Exp $ */
! 2: /* $NetBSD: fs.h,v 1.6 1995/04/12 21:21:02 mycroft Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1982, 1986, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: *
! 8: * Redistribution and use in source and binary forms, with or without
! 9: * modification, are permitted provided that the following conditions
! 10: * are met:
! 11: * 1. Redistributions of source code must retain the above copyright
! 12: * notice, this list of conditions and the following disclaimer.
! 13: * 2. Redistributions in binary form must reproduce the above copyright
! 14: * notice, this list of conditions and the following disclaimer in the
! 15: * documentation and/or other materials provided with the distribution.
! 16: * 3. Neither the name of the University nor the names of its contributors
! 17: * may be used to endorse or promote products derived from this software
! 18: * without specific prior written permission.
! 19: *
! 20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 30: * SUCH DAMAGE.
! 31: *
! 32: * @(#)fs.h 8.10 (Berkeley) 10/27/94
! 33: */
! 34:
! 35: /*
! 36: * Each disk drive contains some number of file systems.
! 37: * A file system consists of a number of cylinder groups.
! 38: * Each cylinder group has inodes and data.
! 39: *
! 40: * A file system is described by its super-block, which in turn
! 41: * describes the cylinder groups. The super-block is critical
! 42: * data and is replicated in each cylinder group to protect against
! 43: * catastrophic loss. This is done at `newfs' time and the critical
! 44: * super-block data does not change, so the copies need not be
! 45: * referenced further unless disaster strikes.
! 46: *
! 47: * For file system fs, the offsets of the various blocks of interest
! 48: * are given in the super block as:
! 49: * [fs->fs_sblkno] Super-block
! 50: * [fs->fs_cblkno] Cylinder group block
! 51: * [fs->fs_iblkno] Inode blocks
! 52: * [fs->fs_dblkno] Data blocks
! 53: * The beginning of cylinder group cg in fs, is given by
! 54: * the ``cgbase(fs, cg)'' macro.
! 55: *
! 56: * The first boot and super blocks are given in absolute disk addresses.
! 57: * The byte-offset forms are preferred, as they don't imply a sector size.
! 58: */
! 59: #define BBSIZE 8192
! 60: #define SBSIZE 8192
! 61: #define BBOFF ((off_t)(0))
! 62: #define SBOFF ((off_t)(BBOFF + BBSIZE))
! 63: #define BBLOCK ((daddr_t)(0))
! 64: #define SBLOCK ((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
! 65: #define SBLOCK_UFS1 8192
! 66: #define SBLOCK_UFS2 65536
! 67: #define SBLOCK_PIGGY 262144
! 68: #define SBLOCKSIZE 8192
! 69: #define SBLOCKSEARCH \
! 70: { SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_PIGGY, -1 }
! 71:
! 72: /*
! 73: * Addresses stored in inodes are capable of addressing fragments
! 74: * of `blocks'. File system blocks of at most size MAXBSIZE can
! 75: * be optionally broken into 2, 4, or 8 pieces, each of which is
! 76: * addressible; these pieces may be DEV_BSIZE, or some multiple of
! 77: * a DEV_BSIZE unit.
! 78: *
! 79: * Large files consist of exclusively large data blocks. To avoid
! 80: * undue wasted disk space, the last data block of a small file may be
! 81: * allocated as only as many fragments of a large block as are
! 82: * necessary. The file system format retains only a single pointer
! 83: * to such a fragment, which is a piece of a single large block that
! 84: * has been divided. The size of such a fragment is determinable from
! 85: * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
! 86: *
! 87: * The file system records space availability at the fragment level;
! 88: * to determine block availability, aligned fragments are examined.
! 89: */
! 90:
! 91: /*
! 92: * MINBSIZE is the smallest allowable block size.
! 93: * In order to insure that it is possible to create files of size
! 94: * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
! 95: * MINBSIZE must be big enough to hold a cylinder group block,
! 96: * thus changes to (struct cg) must keep its size within MINBSIZE.
! 97: * Note that super blocks are always of size SBSIZE,
! 98: * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
! 99: */
! 100: #define MINBSIZE 4096
! 101:
! 102: /*
! 103: * The path name on which the file system is mounted is maintained
! 104: * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
! 105: * the super block for this name.
! 106: */
! 107: #define MAXMNTLEN 468
! 108:
! 109: /*
! 110: * The volume name for this file system is kept in fs_volname.
! 111: * MAXVOLLEN defines the length of the buffer allocated.
! 112: */
! 113: #define MAXVOLLEN 32
! 114:
! 115: /*
! 116: * There is a 128-byte region in the superblock reserved for in-core
! 117: * pointers to summary information. Originally this included an array
! 118: * of pointers to blocks of struct csum; now there are just three
! 119: * pointers and the remaining space is padded with fs_ocsp[].
! 120: *
! 121: * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
! 122: * is taken away to point to a contiguous array of struct csum for
! 123: * all cylinder groups; a second (fs_maxcluster) points to an array
! 124: * of cluster sizes that is computed as cylinder groups are inspected,
! 125: * and the third points to an array that tracks the creation of new
! 126: * directories.
! 127: */
! 128: #define NOCSPTRS ((128 / sizeof(void *)) - 4)
! 129:
! 130: /*
! 131: * A summary of contiguous blocks of various sizes is maintained
! 132: * in each cylinder group. Normally this is set by the initial
! 133: * value of fs_maxcontig. To conserve space, a maximum summary size
! 134: * is set by FS_MAXCONTIG.
! 135: */
! 136: #define FS_MAXCONTIG 16
! 137:
! 138: /*
! 139: * MINFREE gives the minimum acceptable percentage of file system
! 140: * blocks which may be free. If the freelist drops below this level
! 141: * only the superuser may continue to allocate blocks. This may
! 142: * be set to 0 if no reserve of free blocks is deemed necessary,
! 143: * however throughput drops by fifty percent if the file system
! 144: * is run at between 95% and 100% full; thus the minimum default
! 145: * value of fs_minfree is 5%. However, to get good clustering
! 146: * performance, 10% is a better choice. With 5% free space,
! 147: * fragmentation is not a problem, so we choose to optimize for time.
! 148: */
! 149: #define MINFREE 5
! 150: #define DEFAULTOPT FS_OPTTIME
! 151:
! 152: /*
! 153: * The directory preference algorithm(dirpref) can be tuned by adjusting
! 154: * the following parameters which tell the system the average file size
! 155: * and the average number of files per directory. These defaults are well
! 156: * selected for typical filesystems, but may need to be tuned for odd
! 157: * cases like filesystems being used for sqiud caches or news spools.
! 158: */
! 159: #define AVFILESIZ 16384 /* expected average file size */
! 160: #define AFPDIR 64 /* expected number of files per directory */
! 161:
! 162: /*
! 163: * Size of superblock space reserved for snapshots.
! 164: */
! 165: #define FSMAXSNAP 20
! 166:
! 167: /*
! 168: * Per cylinder group information; summarized in blocks allocated
! 169: * from first cylinder group data blocks. These blocks have to be
! 170: * read in from fs_csaddr (size fs_cssize) in addition to the
! 171: * super block.
! 172: */
! 173: struct csum {
! 174: int32_t cs_ndir; /* number of directories */
! 175: int32_t cs_nbfree; /* number of free blocks */
! 176: int32_t cs_nifree; /* number of free inodes */
! 177: int32_t cs_nffree; /* number of free frags */
! 178: };
! 179:
! 180: struct csum_total {
! 181: int64_t cs_ndir; /* number of directories */
! 182: int64_t cs_nbfree; /* number of free blocks */
! 183: int64_t cs_nifree; /* number of free inodes */
! 184: int64_t cs_nffree; /* number of free frags */
! 185: int64_t cs_spare[4]; /* future expansion */
! 186: };
! 187:
! 188: /*
! 189: * Super block for an FFS file system.
! 190: */
! 191: struct fs {
! 192: int32_t fs_firstfield; /* historic file system linked list, */
! 193: int32_t fs_unused_1; /* used for incore super blocks */
! 194: int32_t fs_sblkno; /* addr of super-block / frags */
! 195: int32_t fs_cblkno; /* offset of cyl-block / frags */
! 196: int32_t fs_iblkno; /* offset of inode-blocks / frags */
! 197: int32_t fs_dblkno; /* offset of first data / frags */
! 198: int32_t fs_cgoffset; /* cylinder group offset in cylinder */
! 199: int32_t fs_cgmask; /* used to calc mod fs_ntrak */
! 200: int32_t fs_ffs1_time; /* last time written */
! 201: int32_t fs_ffs1_size; /* # of blocks in fs / frags */
! 202: int32_t fs_ffs1_dsize; /* # of data blocks in fs */
! 203: int32_t fs_ncg; /* # of cylinder groups */
! 204: int32_t fs_bsize; /* size of basic blocks / bytes */
! 205: int32_t fs_fsize; /* size of frag blocks / bytes */
! 206: int32_t fs_frag; /* # of frags in a block in fs */
! 207: /* these are configuration parameters */
! 208: int32_t fs_minfree; /* minimum percentage of free blocks */
! 209: int32_t fs_rotdelay; /* # of ms for optimal next block */
! 210: int32_t fs_rps; /* disk revolutions per second */
! 211: /* these fields can be computed from the others */
! 212: int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
! 213: int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
! 214: int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
! 215: int32_t fs_fshift; /* ``numfrags'' calc # of frags */
! 216: /* these are configuration parameters */
! 217: int32_t fs_maxcontig; /* max # of contiguous blks */
! 218: int32_t fs_maxbpg; /* max # of blks per cyl group */
! 219: /* these fields can be computed from the others */
! 220: int32_t fs_fragshift; /* block to frag shift */
! 221: int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
! 222: int32_t fs_sbsize; /* actual size of super block */
! 223: int32_t fs_csmask; /* csum block offset (now unused) */
! 224: int32_t fs_csshift; /* csum block number (now unused) */
! 225: int32_t fs_nindir; /* value of NINDIR */
! 226: int32_t fs_inopb; /* inodes per file system block */
! 227: int32_t fs_nspf; /* value of NSPF */
! 228: /* yet another configuration parameter */
! 229: int32_t fs_optim; /* optimization preference, see below */
! 230: /* these fields are derived from the hardware */
! 231: int32_t fs_npsect; /* # sectors/track including spares */
! 232: int32_t fs_interleave; /* hardware sector interleave */
! 233: int32_t fs_trackskew; /* sector 0 skew, per track */
! 234: /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
! 235: int32_t fs_id[2]; /* unique filesystem id */
! 236: /* sizes determined by number of cylinder groups and their sizes */
! 237: int32_t fs_ffs1_csaddr; /* blk addr of cyl grp summary area */
! 238: int32_t fs_cssize; /* cyl grp summary area size / bytes */
! 239: int32_t fs_cgsize; /* cyl grp block size / bytes */
! 240: /* these fields are derived from the hardware */
! 241: int32_t fs_ntrak; /* tracks per cylinder */
! 242: int32_t fs_nsect; /* sectors per track */
! 243: int32_t fs_spc; /* sectors per cylinder */
! 244: /* this comes from the disk driver partitioning */
! 245: int32_t fs_ncyl; /* cylinders in file system */
! 246: /* these fields can be computed from the others */
! 247: int32_t fs_cpg; /* cylinders per group */
! 248: int32_t fs_ipg; /* inodes per group */
! 249: int32_t fs_fpg; /* blocks per group * fs_frag */
! 250: /* this data must be re-computed after crashes */
! 251: struct csum fs_ffs1_cstotal; /* cylinder summary information */
! 252: /* these fields are cleared at mount time */
! 253: int8_t fs_fmod; /* super block modified flag */
! 254: int8_t fs_clean; /* file system is clean flag */
! 255: int8_t fs_ronly; /* mounted read-only flag */
! 256: int8_t fs_ffs1_flags; /* see FS_ below */
! 257: u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
! 258: u_char fs_volname[MAXVOLLEN]; /* volume name */
! 259: u_int64_t fs_swuid; /* system-wide uid */
! 260: int32_t fs_pad; /* due to alignment of fs_swuid */
! 261: /* these fields retain the current block allocation info */
! 262: int32_t fs_cgrotor; /* last cg searched */
! 263: void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
! 264: u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */
! 265: struct csum *fs_csp; /* cg summary info buffer for fs_cs */
! 266: int32_t *fs_maxcluster; /* max cluster in each cyl group */
! 267: u_char *fs_active; /* reserved for snapshots */
! 268: int32_t fs_cpc; /* cyl per cycle in postbl */
! 269: /* this area is only allocated if fs_ffs1_flags & FS_FLAGS_UPDATED */
! 270: int32_t fs_maxbsize; /* maximum blocking factor permitted */
! 271: int64_t fs_spareconf64[17]; /* old rotation block list head */
! 272: int64_t fs_sblockloc; /* offset of standard super block */
! 273: struct csum_total fs_cstotal; /* cylinder summary information */
! 274: int64_t fs_time; /* time last written */
! 275: int64_t fs_size; /* number of blocks in fs */
! 276: int64_t fs_dsize; /* number of data blocks in fs */
! 277: int64_t fs_csaddr; /* blk addr of cyl grp summary area */
! 278: int64_t fs_pendingblocks; /* blocks in process of being freed */
! 279: int32_t fs_pendinginodes; /* inodes in process of being freed */
! 280: int32_t fs_snapinum[FSMAXSNAP];/* space reserved for snapshots */
! 281: /* back to stuff that has been around a while */
! 282: int32_t fs_avgfilesize; /* expected average file size */
! 283: int32_t fs_avgfpdir; /* expected # of files per directory */
! 284: int32_t fs_sparecon[26]; /* reserved for future constants */
! 285: u_int32_t fs_flags; /* see FS_ flags below */
! 286: int32_t fs_fscktime; /* last time fsck(8)ed */
! 287: int32_t fs_contigsumsize; /* size of cluster summary array */
! 288: int32_t fs_maxsymlinklen; /* max length of an internal symlink */
! 289: int32_t fs_inodefmt; /* format of on-disk inodes */
! 290: u_int64_t fs_maxfilesize; /* maximum representable file size */
! 291: int64_t fs_qbmask; /* ~fs_bmask - for use with quad size */
! 292: int64_t fs_qfmask; /* ~fs_fmask - for use with quad size */
! 293: int32_t fs_state; /* validate fs_clean field */
! 294: int32_t fs_postblformat; /* format of positional layout tables */
! 295: int32_t fs_nrpos; /* number of rotational positions */
! 296: int32_t fs_postbloff; /* (u_int16) rotation block list head */
! 297: int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */
! 298: int32_t fs_magic; /* magic number */
! 299: u_int8_t fs_space[1]; /* list of blocks for each rotation */
! 300: /* actually longer */
! 301: };
! 302:
! 303: /*
! 304: * Filesystem identification
! 305: */
! 306: #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
! 307: #define FS_UFS1_MAGIC 0x011954 /* the fast filesystem magic number */
! 308: #define FS_UFS2_MAGIC 0x19540119 /* UFS fast filesystem magic number */
! 309: #define FS_OKAY 0x7c269d38 /* superblock checksum */
! 310: #define FS_42INODEFMT -1 /* 4.2BSD inode format */
! 311: #define FS_44INODEFMT 2 /* 4.4BSD inode format */
! 312:
! 313: /*
! 314: * Filesystem clean flags
! 315: */
! 316: #define FS_ISCLEAN 0x01
! 317: #define FS_WASCLEAN 0x02
! 318:
! 319: /*
! 320: * Preference for optimization.
! 321: */
! 322: #define FS_OPTTIME 0 /* minimize allocation time */
! 323: #define FS_OPTSPACE 1 /* minimize disk fragmentation */
! 324:
! 325: /*
! 326: * Filesystem flags.
! 327: */
! 328: #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */
! 329: #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */
! 330: /*
! 331: * The following flag is used to detect a FFS1 file system that had its flags
! 332: * moved to the new (FFS2) location for compatibility.
! 333: */
! 334: #define FS_FLAGS_UPDATED 0x80 /* file system has FFS2-like flags */
! 335:
! 336: /*
! 337: * Rotational layout table format types
! 338: */
! 339: #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
! 340: #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
! 341: /*
! 342: * Macros for access to superblock array structures
! 343: */
! 344: #define fs_rotbl(fs) \
! 345: (((fs)->fs_postblformat == FS_42POSTBLFMT) \
! 346: ? ((fs)->fs_space) \
! 347: : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
! 348:
! 349: /*
! 350: * The size of a cylinder group is calculated by CGSIZE. The maximum size
! 351: * is limited by the fact that cylinder groups are at most one block.
! 352: * Its size is derived from the size of the maps maintained in the
! 353: * cylinder group and the (struct cg) size.
! 354: */
! 355: #define CGSIZE(fs) \
! 356: /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
! 357: /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
! 358: /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
! 359: /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
! 360: /* block map */ howmany((fs)->fs_fpg, NBBY) + \
! 361: /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
! 362: /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
! 363: /* cluster map */ howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY)))
! 364:
! 365: /*
! 366: * Convert cylinder group to base address of its global summary info.
! 367: */
! 368: #define fs_cs(fs, indx) fs_csp[indx]
! 369:
! 370: /*
! 371: * Cylinder group block for a file system.
! 372: */
! 373: #define CG_MAGIC 0x090255
! 374: struct cg {
! 375: int32_t cg_firstfield; /* historic cyl groups linked list */
! 376: int32_t cg_magic; /* magic number */
! 377: int32_t cg_time; /* time last written */
! 378: int32_t cg_cgx; /* we are the cgx'th cylinder group */
! 379: int16_t cg_ncyl; /* number of cyl's this cg */
! 380: int16_t cg_niblk; /* number of inode blocks this cg */
! 381: int32_t cg_ndblk; /* number of data blocks this cg */
! 382: struct csum cg_cs; /* cylinder summary information */
! 383: int32_t cg_rotor; /* position of last used block */
! 384: int32_t cg_frotor; /* position of last used frag */
! 385: int32_t cg_irotor; /* position of last used inode */
! 386: int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
! 387: int32_t cg_btotoff; /* (int32) block totals per cylinder */
! 388: int32_t cg_boff; /* (u_int16) free block positions */
! 389: int32_t cg_iusedoff; /* (u_int8) used inode map */
! 390: int32_t cg_freeoff; /* (u_int8) free block map */
! 391: int32_t cg_nextfreeoff; /* (u_int8) next available space */
! 392: int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */
! 393: int32_t cg_clusteroff; /* (u_int8) free cluster map */
! 394: int32_t cg_nclusterblks; /* number of clusters this cg */
! 395: int32_t cg_ffs2_niblk; /* number of inode blocks this cg */
! 396: int32_t cg_initediblk; /* last initialized inode */
! 397: int32_t cg_sparecon32[3]; /* reserved for future use */
! 398: int64_t cg_ffs2_time; /* time last written */
! 399: int64_t cg_sparecon64[3]; /* reserved for future use */
! 400: /* actually longer */
! 401: };
! 402:
! 403: /*
! 404: * Macros for access to cylinder group array structures
! 405: */
! 406: #define cg_blktot(cgp) \
! 407: (((cgp)->cg_magic != CG_MAGIC) \
! 408: ? (((struct ocg *)(cgp))->cg_btot) \
! 409: : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
! 410: #define cg_blks(fs, cgp, cylno) \
! 411: (((cgp)->cg_magic != CG_MAGIC) \
! 412: ? (((struct ocg *)(cgp))->cg_b[cylno]) \
! 413: : ((int16_t *)((u_int8_t *)(cgp) + \
! 414: (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
! 415: #define cg_inosused(cgp) \
! 416: (((cgp)->cg_magic != CG_MAGIC) \
! 417: ? (((struct ocg *)(cgp))->cg_iused) \
! 418: : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
! 419: #define cg_blksfree(cgp) \
! 420: (((cgp)->cg_magic != CG_MAGIC) \
! 421: ? (((struct ocg *)(cgp))->cg_free) \
! 422: : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff)))
! 423: #define cg_chkmagic(cgp) \
! 424: ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
! 425: #define cg_clustersfree(cgp) \
! 426: ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
! 427: #define cg_clustersum(cgp) \
! 428: ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
! 429:
! 430: /*
! 431: * The following structure is defined
! 432: * for compatibility with old file systems.
! 433: */
! 434: struct ocg {
! 435: int32_t cg_firstfield; /* historic linked list of cyl groups */
! 436: int32_t cg_unused_1; /* used for incore cyl groups */
! 437: int32_t cg_time; /* time last written */
! 438: int32_t cg_cgx; /* we are the cgx'th cylinder group */
! 439: int16_t cg_ncyl; /* number of cyl's this cg */
! 440: int16_t cg_niblk; /* number of inode blocks this cg */
! 441: int32_t cg_ndblk; /* number of data blocks this cg */
! 442: struct csum cg_cs; /* cylinder summary information */
! 443: int32_t cg_rotor; /* position of last used block */
! 444: int32_t cg_frotor; /* position of last used frag */
! 445: int32_t cg_irotor; /* position of last used inode */
! 446: int32_t cg_frsum[8]; /* counts of available frags */
! 447: int32_t cg_btot[32]; /* block totals per cylinder */
! 448: int16_t cg_b[32][8]; /* positions of free blocks */
! 449: u_int8_t cg_iused[256]; /* used inode map */
! 450: int32_t cg_magic; /* magic number */
! 451: u_int8_t cg_free[1]; /* free block map */
! 452: /* actually longer */
! 453: };
! 454:
! 455: /*
! 456: * Turn file system block numbers into disk block addresses.
! 457: * This maps file system blocks to device size blocks.
! 458: */
! 459: #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
! 460: #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
! 461:
! 462: /*
! 463: * Cylinder group macros to locate things in cylinder groups.
! 464: * They calc file system addresses of cylinder group data structures.
! 465: */
! 466: #define cgbase(fs, c) ((daddr_t)((fs)->fs_fpg * (c)))
! 467: #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
! 468: #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
! 469: #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
! 470: #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
! 471: #define cgstart(fs, c) \
! 472: (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
! 473:
! 474: /*
! 475: * Macros for handling inode numbers:
! 476: * inode number to file system block offset.
! 477: * inode number to cylinder group number.
! 478: * inode number to file system block address.
! 479: */
! 480: #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
! 481: #define ino_to_fsba(fs, x) \
! 482: ((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
! 483: (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
! 484: #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
! 485:
! 486: /*
! 487: * Give cylinder group number for a file system block.
! 488: * Give frag block number in cylinder group for a file system block.
! 489: */
! 490: #define dtog(fs, d) ((d) / (fs)->fs_fpg)
! 491: #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
! 492:
! 493: /*
! 494: * Extract the bits for a block from a map.
! 495: * Compute the cylinder and rotational position of a cyl block addr.
! 496: */
! 497: #define blkmap(fs, map, loc) \
! 498: (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
! 499: #define cbtocylno(fs, bno) \
! 500: (fsbtodb(fs, bno) / (fs)->fs_spc)
! 501: #define cbtorpos(fs, bno) \
! 502: ((fs)->fs_nrpos <= 1 ? 0 : \
! 503: (fsbtodb(fs, bno) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
! 504: fsbtodb(fs, bno) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
! 505: (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
! 506:
! 507: /*
! 508: * The following macros optimize certain frequently calculated
! 509: * quantities by using shifts and masks in place of divisions
! 510: * modulos and multiplications.
! 511: */
! 512: #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
! 513: ((loc) & (fs)->fs_qbmask)
! 514: #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
! 515: ((loc) & (fs)->fs_qfmask)
! 516: #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \
! 517: ((off_t)(blk) << (fs)->fs_bshift)
! 518: #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
! 519: ((loc) >> (fs)->fs_bshift)
! 520: #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
! 521: ((loc) >> (fs)->fs_fshift)
! 522: #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
! 523: (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
! 524: #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
! 525: (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
! 526: #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
! 527: ((frags) >> (fs)->fs_fragshift)
! 528: #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
! 529: ((blks) << (fs)->fs_fragshift)
! 530: #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
! 531: ((fsb) & ((fs)->fs_frag - 1))
! 532: #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
! 533: ((fsb) &~ ((fs)->fs_frag - 1))
! 534:
! 535: /*
! 536: * Determine the number of available frags given a
! 537: * percentage to hold in reserve.
! 538: */
! 539: #define freespace(fs, percentreserved) \
! 540: (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
! 541: (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
! 542:
! 543: /*
! 544: * Determining the size of a file block in the file system.
! 545: */
! 546: #define blksize(fs, ip, lbn) \
! 547: (((lbn) >= NDADDR || DIP((ip), size) >= ((lbn) + 1) << (fs)->fs_bshift) \
! 548: ? (fs)->fs_bsize \
! 549: : (fragroundup(fs, blkoff(fs, DIP((ip), size)))))
! 550: #define dblksize(fs, dip, lbn) \
! 551: (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
! 552: ? (fs)->fs_bsize \
! 553: : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
! 554:
! 555: #define sblksize(fs, size, lbn) \
! 556: (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
! 557: ? (fs)->fs_bsize \
! 558: : (fragroundup(fs, blkoff(fs, (size)))))
! 559:
! 560:
! 561: /*
! 562: * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
! 563: * sector size.
! 564: */
! 565: #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
! 566: #define NSPF(fs) ((fs)->fs_nspf)
! 567:
! 568: /* Number of inodes per file system block (fs->fs_bsize) */
! 569: #define INOPB(fs) ((fs)->fs_inopb)
! 570: /* Number of inodes per file system fragment (fs->fs_fsize) */
! 571: #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
! 572:
! 573: /*
! 574: * Number of indirects in a file system block.
! 575: */
! 576: #define NINDIR(fs) ((fs)->fs_nindir)
! 577:
! 578: extern const int inside[], around[];
! 579: extern const u_char *fragtbl[];
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