1 /*- 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)fs.h 8.13 (Berkeley) 3/21/95 34 * $FreeBSD: src/sys/ufs/ffs/fs.h,v 1.14.2.3 2001/09/21 19:15:22 dillon Exp $ 35 * $DragonFly: src/sys/vfs/ufs/fs.h,v 1.5 2006/04/03 02:02:37 dillon Exp $ 36 */ 37 38 #ifndef _VFS_UFS_FS_H_ 39 #define _VFS_UFS_FS_H_ 40 41 /* 42 * Each disk drive contains some number of filesystems. 43 * A filesystem consists of a number of cylinder groups. 44 * Each cylinder group has inodes and data. 45 * 46 * A filesystem is described by its super-block, which in turn 47 * describes the cylinder groups. The super-block is critical 48 * data and is replicated in each cylinder group to protect against 49 * catastrophic loss. This is done at `newfs' time and the critical 50 * super-block data does not change, so the copies need not be 51 * referenced further unless disaster strikes. 52 * 53 * For filesystem fs, the offsets of the various blocks of interest 54 * are given in the super block as: 55 * [fs->fs_sblkno] Super-block 56 * [fs->fs_cblkno] Cylinder group block 57 * [fs->fs_iblkno] Inode blocks 58 * [fs->fs_dblkno] Data blocks 59 * The beginning of cylinder group cg in fs, is given by 60 * the ``cgbase(fs, cg)'' macro. 61 * 62 * The first boot and super blocks are given in absolute disk addresses. 63 * The byte-offset forms are preferred, as they don't imply a sector size. 64 */ 65 #define BBSIZE 8192 66 #define SBSIZE 8192 67 #define BBOFF ((off_t)(0)) 68 #define SBOFF ((off_t)(BBOFF + BBSIZE)) 69 #define BBLOCK ((ufs_daddr_t)(0)) 70 71 /* 72 * Addresses stored in inodes are capable of addressing fragments 73 * of `blocks'. Filesystem blocks of at most size MAXBSIZE can 74 * be optionally broken into 2, 4, or 8 pieces, each of which is 75 * addressable; these pieces may be DEV_BSIZE, or some multiple of 76 * a DEV_BSIZE unit. 77 * 78 * Large files consist of exclusively large data blocks. To avoid 79 * undue wasted disk space, the last data block of a small file may be 80 * allocated as only as many fragments of a large block as are 81 * necessary. The filesystem format retains only a single pointer 82 * to such a fragment, which is a piece of a single large block that 83 * has been divided. The size of such a fragment is determinable from 84 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro. 85 * 86 * The filesystem records space availability at the fragment level; 87 * to determine block availability, aligned fragments are examined. 88 */ 89 90 /* 91 * MINBSIZE is the smallest allowable block size. 92 * In order to insure that it is possible to create files of size 93 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096. 94 * MINBSIZE must be big enough to hold a cylinder group block, 95 * thus changes to (struct cg) must keep its size within MINBSIZE. 96 * Note that super blocks are always of size SBSIZE, 97 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE. 98 */ 99 #define MINBSIZE 4096 100 101 /* 102 * The path name on which the filesystem is mounted is maintained 103 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in 104 * the super block for this name. 105 */ 106 #define MAXMNTLEN 512 107 108 /* 109 * There is a 128-byte region in the superblock reserved for in-core 110 * pointers to summary information. Originally this included an array 111 * of pointers to blocks of struct csum; now there are just three 112 * pointers and the remaining space is padded with fs_ocsp[]. 113 * 114 * NOCSPTRS determines the size of this padding. One pointer (fs_csp) 115 * is taken away to point to a contiguous array of struct csum for 116 * all cylinder groups; a second (fs_maxcluster) points to an array 117 * of cluster sizes that is computed as cylinder groups are inspected, 118 * and the third points to an array that tracks the creation of new 119 * directories. 120 */ 121 #define NOCSPTRS ((128 / sizeof(void *)) - 3) 122 123 /* 124 * A summary of contiguous blocks of various sizes is maintained 125 * in each cylinder group. Normally this is set by the initial 126 * value of fs_maxcontig. To conserve space, a maximum summary size 127 * is set by FS_MAXCONTIG. 128 */ 129 #define FS_MAXCONTIG 16 130 131 /* 132 * MINFREE gives the minimum acceptable percentage of filesystem 133 * blocks which may be free. If the freelist drops below this level 134 * only the superuser may continue to allocate blocks. This may 135 * be set to 0 if no reserve of free blocks is deemed necessary, 136 * however throughput drops by fifty percent if the filesystem 137 * is run at between 95% and 100% full; thus the minimum default 138 * value of fs_minfree is 5%. However, to get good clustering 139 * performance, 10% is a better choice. hence we use 10% as our 140 * default value. With 10% free space, fragmentation is not a 141 * problem, so we choose to optimize for time. 142 */ 143 #define MINFREE 8 144 #define DEFAULTOPT FS_OPTTIME 145 146 /* 147 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine 148 * tune the layout preferences for directories within a filesystem. 149 * His algorithm can be tuned by adjusting the following parameters 150 * which tell the system the average file size and the average number 151 * of files per directory. These defaults are well selected for typical 152 * filesystems, but may need to be tuned for odd cases like filesystems 153 * being used for squid caches or news spools. 154 */ 155 #define AVFILESIZ 16384 /* expected average file size */ 156 #define AFPDIR 64 /* expected number of files per directory */ 157 158 /* 159 * The maximum number of snapshot nodes that can be associated 160 * with each filesystem. This limit affects only the number of 161 * snapshot files that can be recorded within the superblock so 162 * that they can be found when the filesystem is mounted. However, 163 * maintaining too many will slow the filesystem performance, so 164 * having this limit is a good idea. 165 * 166 * VALUE NOT IMPLEMENTED IN DragonFly(and very unlikely to ever be as there are 167 * much better options such as journaling), RESERVED FROM FreeBSD 5.x SO 168 * SUPERBLOCKS REMAIN COMPATIBLE FOR THE TIME BEING. WHY ARE WE YELLING ? 169 */ 170 #define FSMAXSNAP 20 171 172 /* 173 * Per cylinder group information; summarized in blocks allocated 174 * from first cylinder group data blocks. These blocks have to be 175 * read in from fs_csaddr (size fs_cssize) in addition to the 176 * super block. 177 */ 178 struct csum { 179 int32_t cs_ndir; /* number of directories */ 180 int32_t cs_nbfree; /* number of free blocks */ 181 int32_t cs_nifree; /* number of free inodes */ 182 int32_t cs_nffree; /* number of free frags */ 183 }; 184 185 /* 186 * Super block for an FFS filesystem. 187 */ 188 struct fs { 189 int32_t fs_firstfield; /* historic filesystem linked list, */ 190 int32_t fs_unused_1; /* used for incore super blocks */ 191 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */ 192 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */ 193 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */ 194 ufs_daddr_t fs_dblkno; /* offset of first data after cg */ 195 int32_t fs_cgoffset; /* cylinder group offset in cylinder */ 196 int32_t fs_cgmask; /* used to calc mod fs_ntrak */ 197 time_t fs_time; /* last time written */ 198 int32_t fs_size; /* number of blocks in fs */ 199 int32_t fs_dsize; /* number of data blocks in fs */ 200 int32_t fs_ncg; /* number of cylinder groups */ 201 int32_t fs_bsize; /* size of basic blocks in fs */ 202 int32_t fs_fsize; /* size of frag blocks in fs */ 203 int32_t fs_frag; /* number of frags in a block in fs */ 204 /* these are configuration parameters */ 205 int32_t fs_minfree; /* minimum percentage of free blocks */ 206 int32_t fs_rotdelay; /* num of ms for optimal next block */ 207 int32_t fs_rps; /* disk revolutions per second */ 208 /* these fields can be computed from the others */ 209 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ 210 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ 211 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ 212 int32_t fs_fshift; /* ``numfrags'' calc number of frags */ 213 /* these are configuration parameters */ 214 int32_t fs_maxcontig; /* max number of contiguous blks */ 215 int32_t fs_maxbpg; /* max number of blks per cyl group */ 216 /* these fields can be computed from the others */ 217 int32_t fs_fragshift; /* block to frag shift */ 218 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 219 int32_t fs_sbsize; /* actual size of super block */ 220 int32_t fs_csmask; /* csum block offset (now unused) */ 221 int32_t fs_csshift; /* csum block number (now unused) */ 222 int32_t fs_nindir; /* value of NINDIR */ 223 int32_t fs_inopb; /* value of INOPB */ 224 int32_t fs_nspf; /* value of NSPF */ 225 /* yet another configuration parameter */ 226 int32_t fs_optim; /* optimization preference, see below */ 227 /* these fields are derived from the hardware */ 228 int32_t fs_npsect; /* # sectors/track including spares */ 229 int32_t fs_interleave; /* hardware sector interleave */ 230 int32_t fs_trackskew; /* sector 0 skew, per track */ 231 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */ 232 int32_t fs_id[2]; /* unique filesystem id */ 233 /* sizes determined by number of cylinder groups and their sizes */ 234 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ 235 int32_t fs_cssize; /* size of cyl grp summary area */ 236 int32_t fs_cgsize; /* cylinder group size */ 237 /* these fields are derived from the hardware */ 238 int32_t fs_ntrak; /* tracks per cylinder */ 239 int32_t fs_nsect; /* sectors per track */ 240 int32_t fs_spc; /* sectors per cylinder */ 241 /* this comes from the disk driver partitioning */ 242 int32_t fs_ncyl; /* cylinders in filesystem */ 243 /* these fields can be computed from the others */ 244 int32_t fs_cpg; /* cylinders per group */ 245 int32_t fs_ipg; /* inodes per group */ 246 int32_t fs_fpg; /* blocks per group * fs_frag */ 247 /* this data must be re-computed after crashes */ 248 struct csum fs_cstotal; /* cylinder summary information */ 249 /* these fields are cleared at mount time */ 250 int8_t fs_fmod; /* super block modified flag */ 251 int8_t fs_clean; /* filesystem is clean flag */ 252 int8_t fs_ronly; /* mounted read-only flag */ 253 int8_t fs_flags; /* see FS_ flags below */ 254 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 255 /* these fields retain the current block allocation info */ 256 int32_t fs_cgrotor; /* last cg searched */ 257 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */ 258 uint8_t *fs_contigdirs; /* # of contiguously allocated dirs */ 259 struct csum *fs_csp; /* cg summary info buffer for fs_cs */ 260 int32_t *fs_maxcluster; /* max cluster in each cyl group */ 261 int32_t fs_cpc; /* cyl per cycle in postbl */ 262 int16_t fs_opostbl[16][8]; /* old rotation block list head */ 263 int32_t fs_snapinum[FSMAXSNAP];/* RESERVED FROM 5.x */ 264 int32_t fs_avgfilesize; /* expected average file size */ 265 int32_t fs_avgfpdir; /* expected # of files per directory */ 266 int32_t fs_sparecon[26]; /* reserved for future constants */ 267 int32_t fs_pendingblocks; /* RESERVED FROM 5.x */ 268 int32_t fs_pendinginodes; /* RESERVED FROM 5.x */ 269 int32_t fs_contigsumsize; /* size of cluster summary array */ 270 int32_t fs_maxsymlinklen; /* max length of an internal symlink */ 271 int32_t fs_inodefmt; /* format of on-disk inodes */ 272 uint64_t fs_maxfilesize; /* maximum representable file size */ 273 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */ 274 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */ 275 int32_t fs_state; /* validate fs_clean field */ 276 int32_t fs_postblformat; /* format of positional layout tables */ 277 int32_t fs_nrpos; /* number of rotational positions */ 278 int32_t fs_postbloff; /* (uint16) rotation block list head */ 279 int32_t fs_rotbloff; /* (uint8) blocks for each rotation */ 280 int32_t fs_magic; /* magic number */ 281 uint8_t fs_space[1]; /* list of blocks for each rotation */ 282 /* actually longer */ 283 }; 284 285 /* 286 * Filesystem identification 287 */ 288 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */ 289 #define FS_OKAY 0x7c269d38 /* superblock checksum */ 290 #define FS_42INODEFMT -1 /* 4.2BSD inode format */ 291 #define FS_44INODEFMT 2 /* 4.4BSD inode format */ 292 293 /* 294 * Preference for optimization. 295 */ 296 #define FS_OPTTIME 0 /* minimize allocation time */ 297 #define FS_OPTSPACE 1 /* minimize disk fragmentation */ 298 299 /* 300 * Filesystem flags. 301 */ 302 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */ 303 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */ 304 305 /* 306 * Rotational layout table format types 307 */ 308 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */ 309 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */ 310 /* 311 * Macros for access to superblock array structures 312 */ 313 #define fs_postbl(fs, cylno) \ 314 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 315 ? ((fs)->fs_opostbl[cylno]) \ 316 : ((int16_t *)((uint8_t *)(fs) + \ 317 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos)) 318 #define fs_rotbl(fs) \ 319 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 320 ? ((fs)->fs_space) \ 321 : ((uint8_t *)((uint8_t *)(fs) + (fs)->fs_rotbloff))) 322 323 /* 324 * The size of a cylinder group is calculated by CGSIZE. The maximum size 325 * is limited by the fact that cylinder groups are at most one block. 326 * Its size is derived from the size of the maps maintained in the 327 * cylinder group and the (struct cg) size. 328 */ 329 #define CGSIZE(fs) \ 330 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \ 331 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \ 332 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \ 333 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \ 334 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\ 335 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \ 336 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \ 337 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY))) 338 339 /* 340 * Convert cylinder group to base address of its global summary info. 341 */ 342 #define fs_cs(fs, indx) fs_csp[indx] 343 344 /* 345 * Cylinder group block for a filesystem. 346 */ 347 #define CG_MAGIC 0x090255 348 struct cg { 349 int32_t cg_firstfield; /* historic cyl groups linked list */ 350 int32_t cg_magic; /* magic number */ 351 time_t cg_time; /* time last written */ 352 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 353 int16_t cg_ncyl; /* number of cyl's this cg */ 354 int16_t cg_niblk; /* number of inode blocks this cg */ 355 int32_t cg_ndblk; /* number of data blocks this cg */ 356 struct csum cg_cs; /* cylinder summary information */ 357 int32_t cg_rotor; /* position of last used block */ 358 int32_t cg_frotor; /* position of last used frag */ 359 int32_t cg_irotor; /* position of last used inode */ 360 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */ 361 int32_t cg_btotoff; /* (int32) block totals per cylinder */ 362 int32_t cg_boff; /* (uint16) free block positions */ 363 int32_t cg_iusedoff; /* (uint8) used inode map */ 364 int32_t cg_freeoff; /* (uint8) free block map */ 365 int32_t cg_nextfreeoff; /* (uint8) next available space */ 366 int32_t cg_clustersumoff; /* (uint32) counts of avail clusters */ 367 int32_t cg_clusteroff; /* (uint8) free cluster map */ 368 int32_t cg_nclusterblks; /* number of clusters this cg */ 369 int32_t cg_sparecon[13]; /* reserved for future use */ 370 uint8_t cg_space[1]; /* space for cylinder group maps */ 371 /* actually longer */ 372 }; 373 374 /* 375 * Macros for access to cylinder group array structures 376 */ 377 #define cg_blktot(cgp) \ 378 (((cgp)->cg_magic != CG_MAGIC) \ 379 ? (((struct ocg *)(cgp))->cg_btot) \ 380 : ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_btotoff))) 381 #define cg_blks(fs, cgp, cylno) \ 382 (((cgp)->cg_magic != CG_MAGIC) \ 383 ? (((struct ocg *)(cgp))->cg_b[cylno]) \ 384 : ((int16_t *)((uint8_t *)(cgp) + \ 385 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos)) 386 #define cg_inosused(cgp) \ 387 (((cgp)->cg_magic != CG_MAGIC) \ 388 ? (((struct ocg *)(cgp))->cg_iused) \ 389 : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_iusedoff))) 390 #define cg_blksfree(cgp) \ 391 (((cgp)->cg_magic != CG_MAGIC) \ 392 ? (((struct ocg *)(cgp))->cg_free) \ 393 : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_freeoff))) 394 #define cg_chkmagic(cgp) \ 395 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC) 396 #define cg_clustersfree(cgp) \ 397 ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_clusteroff)) 398 #define cg_clustersum(cgp) \ 399 ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_clustersumoff)) 400 401 /* 402 * The following structure is defined 403 * for compatibility with old filesystems. 404 */ 405 struct ocg { 406 int32_t cg_firstfield; /* historic linked list of cyl groups */ 407 int32_t cg_unused_1; /* used for incore cyl groups */ 408 time_t cg_time; /* time last written */ 409 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 410 int16_t cg_ncyl; /* number of cyl's this cg */ 411 int16_t cg_niblk; /* number of inode blocks this cg */ 412 int32_t cg_ndblk; /* number of data blocks this cg */ 413 struct csum cg_cs; /* cylinder summary information */ 414 int32_t cg_rotor; /* position of last used block */ 415 int32_t cg_frotor; /* position of last used frag */ 416 int32_t cg_irotor; /* position of last used inode */ 417 int32_t cg_frsum[8]; /* counts of available frags */ 418 int32_t cg_btot[32]; /* block totals per cylinder */ 419 int16_t cg_b[32][8]; /* positions of free blocks */ 420 uint8_t cg_iused[256]; /* used inode map */ 421 int32_t cg_magic; /* magic number */ 422 uint8_t cg_free[1]; /* free block map */ 423 /* actually longer */ 424 }; 425 426 /* 427 * Turn filesystem block numbers into disk block addresses. 428 * This maps filesystem blocks to device size blocks. 429 */ 430 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb) 431 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb) 432 #define btofsb(fs, b) ((daddr_t)((b) >> ((fs)->fs_fsbtodb + DEV_BSHIFT))) 433 434 /* 435 * Cylinder group macros to locate things in cylinder groups. 436 * They calc filesystem addresses of cylinder group data structures. 437 */ 438 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c))) 439 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */ 440 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */ 441 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */ 442 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */ 443 #define cgstart(fs, c) \ 444 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask))) 445 446 /* 447 * Macros for handling inode numbers: 448 * inode number to filesystem block offset. 449 * inode number to cylinder group number. 450 * inode number to filesystem block address. 451 */ 452 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg) 453 #define ino_to_fsba(fs, x) \ 454 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \ 455 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs)))))) 456 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs)) 457 458 /* 459 * Give cylinder group number for a filesystem block. 460 * Give cylinder group block number for a filesystem block. 461 */ 462 #define dtog(fs, d) ((d) / (fs)->fs_fpg) 463 #define dtogd(fs, d) ((d) % (fs)->fs_fpg) 464 465 /* 466 * Extract the bits for a block from a map. 467 * Compute the cylinder and rotational position of a cyl block addr. 468 */ 469 #define blkmap(fs, map, loc) \ 470 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag))) 471 #define cbtocylno(fs, bno) \ 472 ((bno) * NSPF(fs) / (fs)->fs_spc) 473 #define cbtorpos(fs, bno) \ 474 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \ 475 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \ 476 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect) 477 478 /* 479 * The following macros optimize certain frequently calculated 480 * quantities by using shifts and masks in place of divisions 481 * modulos and multiplications. 482 */ 483 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \ 484 ((loc) & (fs)->fs_qbmask) 485 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \ 486 ((loc) & (fs)->fs_qfmask) 487 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \ 488 ((off_t)(blk) << (fs)->fs_bshift) 489 /* 490 * These functions convert filesystem logical block numbers (typ 8K), 491 * filesystem block numbers (typ 1K), and disk block numbers to 64 bit 492 * offsets for the purposes of bread(), getblk(), etc. 493 * 494 * note: fs_nspf = number of sectors per fragment. For some reason 495 * completely lost to me the superblock doesn't actually store the disk 496 * block size. 497 */ 498 #define lblktodoff(fs, blk) ((off_t)(blk) << (fs)->fs_bshift) 499 #define fsbtodoff(fs, b) ((off_t)(b) << (fs)->fs_fshift) 500 #define dbtodoff(fs, b) ((off_t)(b) * ((fs)->fs_fsize / (fs)->fs_nspf)) 501 #define dofftofsb(fs, b) ((ufs_daddr_t)((b) >> (fs)->fs_fshift)) 502 503 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */ 504 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \ 505 ((blk) << (fs)->fs_bshift) 506 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ 507 ((loc) >> (fs)->fs_bshift) 508 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ 509 ((loc) >> (fs)->fs_fshift) 510 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \ 511 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask) 512 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ 513 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) 514 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \ 515 ((frags) >> (fs)->fs_fragshift) 516 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \ 517 ((blks) << (fs)->fs_fragshift) 518 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \ 519 ((fsb) & ((fs)->fs_frag - 1)) 520 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \ 521 ((fsb) &~ ((fs)->fs_frag - 1)) 522 523 /* 524 * Determine the number of available frags given a 525 * percentage to hold in reserve. 526 */ 527 #define freespace(fs, percentreserved) \ 528 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \ 529 (fs)->fs_cstotal.cs_nffree - \ 530 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100)) 531 532 /* 533 * Determining the size of a file block in the filesystem. 534 */ 535 #define blksize(fs, ip, lbn) \ 536 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \ 537 ? (fs)->fs_bsize \ 538 : (fragroundup(fs, blkoff(fs, (ip)->i_size)))) 539 #define dblksize(fs, dip, lbn) \ 540 (((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \ 541 ? (fs)->fs_bsize \ 542 : (fragroundup(fs, blkoff(fs, (dip)->di_size)))) 543 #define sblksize(fs, size, lbn) \ 544 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \ 545 ? (fs)->fs_bsize \ 546 : (fragroundup(fs, blkoff(fs, (size))))) 547 548 549 /* 550 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte 551 * sector size. 552 */ 553 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift) 554 #define NSPF(fs) ((fs)->fs_nspf) 555 556 /* 557 * Number of inodes in a secondary storage block/fragment. 558 */ 559 #define INOPB(fs) ((fs)->fs_inopb) 560 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift) 561 562 /* 563 * Number of indirects in a filesystem block. 564 */ 565 #define NINDIR(fs) ((fs)->fs_nindir) 566 567 extern int inside[], around[]; 568 extern u_char *fragtbl[]; 569 570 #endif /* !_VFS_UFS_FS_H_ */ 571