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 * $FreeBSD$ 35 */ 36 37 #ifndef _UFS_FFS_FS_H_ 38 #define _UFS_FFS_FS_H_ 39 40 /* 41 * Each disk drive contains some number of file systems. 42 * A file system consists of a number of cylinder groups. 43 * Each cylinder group has inodes and data. 44 * 45 * A file system is described by its super-block, which in turn 46 * describes the cylinder groups. The super-block is critical 47 * data and is replicated in each cylinder group to protect against 48 * catastrophic loss. This is done at `newfs' time and the critical 49 * super-block data does not change, so the copies need not be 50 * referenced further unless disaster strikes. 51 * 52 * For file system fs, the offsets of the various blocks of interest 53 * are given in the super block as: 54 * [fs->fs_sblkno] Super-block 55 * [fs->fs_cblkno] Cylinder group block 56 * [fs->fs_iblkno] Inode blocks 57 * [fs->fs_dblkno] Data blocks 58 * The beginning of cylinder group cg in fs, is given by 59 * the ``cgbase(fs, cg)'' macro. 60 * 61 * The first boot and super blocks are given in absolute disk addresses. 62 * The byte-offset forms are preferred, as they don't imply a sector size. 63 */ 64 #define BBSIZE 8192 65 #define SBSIZE 8192 66 #define BBOFF ((off_t)(0)) 67 #define SBOFF ((off_t)(BBOFF + BBSIZE)) 68 #define BBLOCK ((ufs_daddr_t)(0)) 69 #define SBLOCK ((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE)) 70 71 /* 72 * Addresses stored in inodes are capable of addressing fragments 73 * of `blocks'. File system 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 file system 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 file system 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 file system 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 two 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 */ 119 #define NOCSPTRS ((128 / sizeof(void *)) - 2) 120 121 /* 122 * A summary of contiguous blocks of various sizes is maintained 123 * in each cylinder group. Normally this is set by the initial 124 * value of fs_maxcontig. To conserve space, a maximum summary size 125 * is set by FS_MAXCONTIG. 126 */ 127 #define FS_MAXCONTIG 16 128 129 /* 130 * MINFREE gives the minimum acceptable percentage of file system 131 * blocks which may be free. If the freelist drops below this level 132 * only the superuser may continue to allocate blocks. This may 133 * be set to 0 if no reserve of free blocks is deemed necessary, 134 * however throughput drops by fifty percent if the file system 135 * is run at between 95% and 100% full; thus the minimum default 136 * value of fs_minfree is 5%. However, to get good clustering 137 * performance, 10% is a better choice. hence we use 10% as our 138 * default value. With 10% free space, fragmentation is not a 139 * problem, so we choose to optimize for time. 140 */ 141 #define MINFREE 8 142 #define DEFAULTOPT FS_OPTTIME 143 144 /* 145 * The maximum number of snapshot nodes that can be associated 146 * with each filesystem. This limit affects only the number of 147 * snapshot files that can be recorded within the superblock so 148 * that they can be found when the filesystem is mounted. However, 149 * maintaining too many will slow the filesystem performance, so 150 * having this limit is a good idea. 151 */ 152 #define FSMAXSNAP 20 153 154 /* 155 * Used to identify special blocks in snapshots: 156 * 157 * BLK_NOCOPY - A block that was unallocated at the time the snapshot 158 * was taken, hence does not need to be copied when written. 159 * BLK_SNAP - A block held by another snapshot that is not needed by this 160 * snapshot. When the other snapshot is freed, the BLK_SNAP entries 161 * are converted to BLK_NOCOPY. These are needed to allow fsck to 162 * identify blocks that are in use by other snapshots (which are 163 * expunged from this snapshot). 164 */ 165 #define BLK_NOCOPY ((ufs_daddr_t)(1)) 166 #define BLK_SNAP ((ufs_daddr_t)(2)) 167 168 /* 169 * Per cylinder group information; summarized in blocks allocated 170 * from first cylinder group data blocks. These blocks have to be 171 * read in from fs_csaddr (size fs_cssize) in addition to the 172 * super block. 173 */ 174 struct csum { 175 int32_t cs_ndir; /* number of directories */ 176 int32_t cs_nbfree; /* number of free blocks */ 177 int32_t cs_nifree; /* number of free inodes */ 178 int32_t cs_nffree; /* number of free frags */ 179 }; 180 181 /* 182 * Super block for an FFS file system. 183 */ 184 struct fs { 185 int32_t fs_firstfield; /* historic file system linked list, */ 186 int32_t fs_unused_1; /* used for incore super blocks */ 187 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */ 188 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */ 189 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */ 190 ufs_daddr_t fs_dblkno; /* offset of first data after cg */ 191 int32_t fs_cgoffset; /* cylinder group offset in cylinder */ 192 int32_t fs_cgmask; /* used to calc mod fs_ntrak */ 193 time_t fs_time; /* last time written */ 194 int32_t fs_size; /* number of blocks in fs */ 195 int32_t fs_dsize; /* number of data blocks in fs */ 196 int32_t fs_ncg; /* number of cylinder groups */ 197 int32_t fs_bsize; /* size of basic blocks in fs */ 198 int32_t fs_fsize; /* size of frag blocks in fs */ 199 int32_t fs_frag; /* number of frags in a block in fs */ 200 /* these are configuration parameters */ 201 int32_t fs_minfree; /* minimum percentage of free blocks */ 202 int32_t fs_rotdelay; /* num of ms for optimal next block */ 203 int32_t fs_rps; /* disk revolutions per second */ 204 /* these fields can be computed from the others */ 205 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ 206 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ 207 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ 208 int32_t fs_fshift; /* ``numfrags'' calc number of frags */ 209 /* these are configuration parameters */ 210 int32_t fs_maxcontig; /* max number of contiguous blks */ 211 int32_t fs_maxbpg; /* max number of blks per cyl group */ 212 /* these fields can be computed from the others */ 213 int32_t fs_fragshift; /* block to frag shift */ 214 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 215 int32_t fs_sbsize; /* actual size of super block */ 216 int32_t fs_csmask; /* csum block offset (now unused) */ 217 int32_t fs_csshift; /* csum block number (now unused) */ 218 int32_t fs_nindir; /* value of NINDIR */ 219 int32_t fs_inopb; /* value of INOPB */ 220 int32_t fs_nspf; /* value of NSPF */ 221 /* yet another configuration parameter */ 222 int32_t fs_optim; /* optimization preference, see below */ 223 /* these fields are derived from the hardware */ 224 int32_t fs_npsect; /* # sectors/track including spares */ 225 int32_t fs_interleave; /* hardware sector interleave */ 226 int32_t fs_trackskew; /* sector 0 skew, per track */ 227 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */ 228 int32_t fs_id[2]; /* unique filesystem id */ 229 /* sizes determined by number of cylinder groups and their sizes */ 230 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ 231 int32_t fs_cssize; /* size of cyl grp summary area */ 232 int32_t fs_cgsize; /* cylinder group size */ 233 /* these fields are derived from the hardware */ 234 int32_t fs_ntrak; /* tracks per cylinder */ 235 int32_t fs_nsect; /* sectors per track */ 236 int32_t fs_spc; /* sectors per cylinder */ 237 /* this comes from the disk driver partitioning */ 238 int32_t fs_ncyl; /* cylinders in file system */ 239 /* these fields can be computed from the others */ 240 int32_t fs_cpg; /* cylinders per group */ 241 int32_t fs_ipg; /* inodes per group */ 242 int32_t fs_fpg; /* blocks per group * fs_frag */ 243 /* this data must be re-computed after crashes */ 244 struct csum fs_cstotal; /* cylinder summary information */ 245 /* these fields are cleared at mount time */ 246 int8_t fs_fmod; /* super block modified flag */ 247 int8_t fs_clean; /* file system is clean flag */ 248 int8_t fs_ronly; /* mounted read-only flag */ 249 int8_t fs_flags; /* see FS_ flags below */ 250 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 251 /* these fields retain the current block allocation info */ 252 int32_t fs_cgrotor; /* last cg searched */ 253 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */ 254 struct csum *fs_csp; /* cg summary info buffer for fs_cs */ 255 int32_t *fs_maxcluster; /* max cluster in each cyl group */ 256 int32_t fs_cpc; /* cyl per cycle in postbl */ 257 int16_t fs_opostbl[16][8]; /* old rotation block list head */ 258 int32_t fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */ 259 int32_t fs_sparecon[30]; /* reserved for future constants */ 260 int32_t fs_contigsumsize; /* size of cluster summary array */ 261 int32_t fs_maxsymlinklen; /* max length of an internal symlink */ 262 int32_t fs_inodefmt; /* format of on-disk inodes */ 263 u_int64_t fs_maxfilesize; /* maximum representable file size */ 264 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */ 265 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */ 266 int32_t fs_state; /* validate fs_clean field */ 267 int32_t fs_postblformat; /* format of positional layout tables */ 268 int32_t fs_nrpos; /* number of rotational positions */ 269 int32_t fs_postbloff; /* (u_int16) rotation block list head */ 270 int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */ 271 int32_t fs_magic; /* magic number */ 272 u_int8_t fs_space[1]; /* list of blocks for each rotation */ 273 /* actually longer */ 274 }; 275 276 /* 277 * Filesystem identification 278 */ 279 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */ 280 #define FS_OKAY 0x7c269d38 /* superblock checksum */ 281 #define FS_42INODEFMT -1 /* 4.2BSD inode format */ 282 #define FS_44INODEFMT 2 /* 4.4BSD inode format */ 283 284 /* 285 * Preference for optimization. 286 */ 287 #define FS_OPTTIME 0 /* minimize allocation time */ 288 #define FS_OPTSPACE 1 /* minimize disk fragmentation */ 289 290 /* 291 * Filesystem flags. 292 */ 293 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */ 294 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */ 295 296 /* 297 * Rotational layout table format types 298 */ 299 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */ 300 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */ 301 /* 302 * Macros for access to superblock array structures 303 */ 304 #define fs_postbl(fs, cylno) \ 305 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 306 ? ((fs)->fs_opostbl[cylno]) \ 307 : ((int16_t *)((u_int8_t *)(fs) + \ 308 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos)) 309 #define fs_rotbl(fs) \ 310 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 311 ? ((fs)->fs_space) \ 312 : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff))) 313 314 /* 315 * The size of a cylinder group is calculated by CGSIZE. The maximum size 316 * is limited by the fact that cylinder groups are at most one block. 317 * Its size is derived from the size of the maps maintained in the 318 * cylinder group and the (struct cg) size. 319 */ 320 #define CGSIZE(fs) \ 321 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \ 322 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \ 323 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \ 324 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \ 325 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\ 326 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \ 327 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \ 328 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY))) 329 330 /* 331 * Convert cylinder group to base address of its global summary info. 332 */ 333 #define fs_cs(fs, indx) fs_csp[indx] 334 335 /* 336 * Cylinder group block for a file system. 337 */ 338 #define CG_MAGIC 0x090255 339 struct cg { 340 int32_t cg_firstfield; /* historic cyl groups linked list */ 341 int32_t cg_magic; /* magic number */ 342 time_t cg_time; /* time last written */ 343 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 344 int16_t cg_ncyl; /* number of cyl's this cg */ 345 int16_t cg_niblk; /* number of inode blocks this cg */ 346 int32_t cg_ndblk; /* number of data blocks this cg */ 347 struct csum cg_cs; /* cylinder summary information */ 348 int32_t cg_rotor; /* position of last used block */ 349 int32_t cg_frotor; /* position of last used frag */ 350 int32_t cg_irotor; /* position of last used inode */ 351 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */ 352 int32_t cg_btotoff; /* (int32) block totals per cylinder */ 353 int32_t cg_boff; /* (u_int16) free block positions */ 354 int32_t cg_iusedoff; /* (u_int8) used inode map */ 355 int32_t cg_freeoff; /* (u_int8) free block map */ 356 int32_t cg_nextfreeoff; /* (u_int8) next available space */ 357 int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */ 358 int32_t cg_clusteroff; /* (u_int8) free cluster map */ 359 int32_t cg_nclusterblks; /* number of clusters this cg */ 360 int32_t cg_sparecon[13]; /* reserved for future use */ 361 u_int8_t cg_space[1]; /* space for cylinder group maps */ 362 /* actually longer */ 363 }; 364 365 /* 366 * Macros for access to cylinder group array structures 367 */ 368 #define cg_blktot(cgp) \ 369 (((cgp)->cg_magic != CG_MAGIC) \ 370 ? (((struct ocg *)(cgp))->cg_btot) \ 371 : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff))) 372 #define cg_blks(fs, cgp, cylno) \ 373 (((cgp)->cg_magic != CG_MAGIC) \ 374 ? (((struct ocg *)(cgp))->cg_b[cylno]) \ 375 : ((int16_t *)((u_int8_t *)(cgp) + \ 376 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos)) 377 #define cg_inosused(cgp) \ 378 (((cgp)->cg_magic != CG_MAGIC) \ 379 ? (((struct ocg *)(cgp))->cg_iused) \ 380 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))) 381 #define cg_blksfree(cgp) \ 382 (((cgp)->cg_magic != CG_MAGIC) \ 383 ? (((struct ocg *)(cgp))->cg_free) \ 384 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))) 385 #define cg_chkmagic(cgp) \ 386 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC) 387 #define cg_clustersfree(cgp) \ 388 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff)) 389 #define cg_clustersum(cgp) \ 390 ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff)) 391 392 /* 393 * The following structure is defined 394 * for compatibility with old file systems. 395 */ 396 struct ocg { 397 int32_t cg_firstfield; /* historic linked list of cyl groups */ 398 int32_t cg_unused_1; /* used for incore cyl groups */ 399 time_t cg_time; /* time last written */ 400 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 401 int16_t cg_ncyl; /* number of cyl's this cg */ 402 int16_t cg_niblk; /* number of inode blocks this cg */ 403 int32_t cg_ndblk; /* number of data blocks this cg */ 404 struct csum cg_cs; /* cylinder summary information */ 405 int32_t cg_rotor; /* position of last used block */ 406 int32_t cg_frotor; /* position of last used frag */ 407 int32_t cg_irotor; /* position of last used inode */ 408 int32_t cg_frsum[8]; /* counts of available frags */ 409 int32_t cg_btot[32]; /* block totals per cylinder */ 410 int16_t cg_b[32][8]; /* positions of free blocks */ 411 u_int8_t cg_iused[256]; /* used inode map */ 412 int32_t cg_magic; /* magic number */ 413 u_int8_t cg_free[1]; /* free block map */ 414 /* actually longer */ 415 }; 416 417 /* 418 * Turn file system block numbers into disk block addresses. 419 * This maps file system blocks to device size blocks. 420 */ 421 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb) 422 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb) 423 424 /* 425 * Cylinder group macros to locate things in cylinder groups. 426 * They calc file system addresses of cylinder group data structures. 427 */ 428 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c))) 429 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */ 430 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */ 431 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */ 432 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */ 433 #define cgstart(fs, c) \ 434 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask))) 435 436 /* 437 * Macros for handling inode numbers: 438 * inode number to file system block offset. 439 * inode number to cylinder group number. 440 * inode number to file system block address. 441 */ 442 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg) 443 #define ino_to_fsba(fs, x) \ 444 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \ 445 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs)))))) 446 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs)) 447 448 /* 449 * Give cylinder group number for a file system block. 450 * Give cylinder group block number for a file system block. 451 */ 452 #define dtog(fs, d) ((d) / (fs)->fs_fpg) 453 #define dtogd(fs, d) ((d) % (fs)->fs_fpg) 454 455 /* 456 * Extract the bits for a block from a map. 457 * Compute the cylinder and rotational position of a cyl block addr. 458 */ 459 #define blkmap(fs, map, loc) \ 460 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag))) 461 #define cbtocylno(fs, bno) \ 462 ((bno) * NSPF(fs) / (fs)->fs_spc) 463 #define cbtorpos(fs, bno) \ 464 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \ 465 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \ 466 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect) 467 468 /* 469 * The following macros optimize certain frequently calculated 470 * quantities by using shifts and masks in place of divisions 471 * modulos and multiplications. 472 */ 473 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \ 474 ((loc) & (fs)->fs_qbmask) 475 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \ 476 ((loc) & (fs)->fs_qfmask) 477 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \ 478 ((off_t)(blk) << (fs)->fs_bshift) 479 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */ 480 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \ 481 ((blk) << (fs)->fs_bshift) 482 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ 483 ((loc) >> (fs)->fs_bshift) 484 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ 485 ((loc) >> (fs)->fs_fshift) 486 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \ 487 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask) 488 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ 489 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) 490 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \ 491 ((frags) >> (fs)->fs_fragshift) 492 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \ 493 ((blks) << (fs)->fs_fragshift) 494 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \ 495 ((fsb) & ((fs)->fs_frag - 1)) 496 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \ 497 ((fsb) &~ ((fs)->fs_frag - 1)) 498 499 /* 500 * Determine the number of available frags given a 501 * percentage to hold in reserve. 502 */ 503 #define freespace(fs, percentreserved) \ 504 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \ 505 (fs)->fs_cstotal.cs_nffree - \ 506 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100)) 507 508 /* 509 * Determining the size of a file block in the file system. 510 */ 511 #define blksize(fs, ip, lbn) \ 512 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \ 513 ? (fs)->fs_bsize \ 514 : (fragroundup(fs, blkoff(fs, (ip)->i_size)))) 515 #define dblksize(fs, dip, lbn) \ 516 (((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \ 517 ? (fs)->fs_bsize \ 518 : (fragroundup(fs, blkoff(fs, (dip)->di_size)))) 519 #define sblksize(fs, size, lbn) \ 520 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \ 521 ? (fs)->fs_bsize \ 522 : (fragroundup(fs, blkoff(fs, (size))))) 523 524 525 /* 526 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte 527 * sector size. 528 */ 529 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift) 530 #define NSPF(fs) ((fs)->fs_nspf) 531 532 /* 533 * Number of inodes in a secondary storage block/fragment. 534 */ 535 #define INOPB(fs) ((fs)->fs_inopb) 536 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift) 537 538 /* 539 * Number of indirects in a file system block. 540 */ 541 #define NINDIR(fs) ((fs)->fs_nindir) 542 543 extern int inside[], around[]; 544 extern u_char *fragtbl[]; 545 546 #endif 547