fs.h revision 1.19
1 /* $NetBSD: fs.h,v 1.19 2001/09/03 14:52:17 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)fs.h 8.13 (Berkeley) 3/21/95 36 */ 37 38 #ifndef _UFS_FFS_FS_H_ 39 #define _UFS_FFS_FS_H_ 40 41 #include <ufs/ufs/dinode.h> 42 43 /* 44 * Each disk drive contains some number of file systems. 45 * A file system consists of a number of cylinder groups. 46 * Each cylinder group has inodes and data. 47 * 48 * A file system is described by its super-block, which in turn 49 * describes the cylinder groups. The super-block is critical 50 * data and is replicated in each cylinder group to protect against 51 * catastrophic loss. This is done at `newfs' time and the critical 52 * super-block data does not change, so the copies need not be 53 * referenced further unless disaster strikes. 54 * 55 * For file system fs, the offsets of the various blocks of interest 56 * are given in the super block as: 57 * [fs->fs_sblkno] Super-block 58 * [fs->fs_cblkno] Cylinder group block 59 * [fs->fs_iblkno] Inode blocks 60 * [fs->fs_dblkno] Data blocks 61 * The beginning of cylinder group cg in fs, is given by 62 * the ``cgbase(fs, cg)'' macro. 63 * 64 * The first boot and super blocks are given in absolute disk addresses. 65 * The byte-offset forms are preferred, as they don't imply a sector size. 66 */ 67 #define BBSIZE 8192 68 #define SBSIZE 8192 69 #define BBOFF ((off_t)(0)) 70 #define SBOFF ((off_t)(BBOFF + BBSIZE)) 71 #define BBLOCK ((ufs_daddr_t)(0)) 72 #define SBLOCK ((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE)) 73 74 /* 75 * Addresses stored in inodes are capable of addressing fragments 76 * of `blocks'. File system blocks of at most size MAXBSIZE can 77 * be optionally broken into 2, 4, or 8 pieces, each of which is 78 * addressable; these pieces may be DEV_BSIZE, or some multiple of 79 * a DEV_BSIZE unit. 80 * 81 * Large files consist of exclusively large data blocks. To avoid 82 * undue wasted disk space, the last data block of a small file may be 83 * allocated as only as many fragments of a large block as are 84 * necessary. The file system format retains only a single pointer 85 * to such a fragment, which is a piece of a single large block that 86 * has been divided. The size of such a fragment is determinable from 87 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro. 88 * 89 * The file system records space availability at the fragment level; 90 * to determine block availability, aligned fragments are examined. 91 */ 92 93 /* 94 * MINBSIZE is the smallest allowable block size. 95 * In order to insure that it is possible to create files of size 96 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096. 97 * MINBSIZE must be big enough to hold a cylinder group block, 98 * thus changes to (struct cg) must keep its size within MINBSIZE. 99 * Note that super blocks are always of size SBSIZE, 100 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE. 101 */ 102 #define MINBSIZE 4096 103 104 /* 105 * The path name on which the file system is mounted is maintained 106 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in 107 * the super block for this name. 108 */ 109 #define MAXMNTLEN 512 110 111 /* 112 * There is a 128-byte region in the superblock reserved for in-core 113 * pointers to summary information. Originally this included an array 114 * of pointers to blocks of struct csum; now there are just two 115 * pointers and the remaining space is padded with fs_ocsp[]. 116 * 117 * NOCSPTRS determines the size of this padding. One pointer (fs_csp) 118 * is taken away to point to a contiguous array of struct csum for 119 * all cylinder groups; a second (fs_maxcluster) points to an array 120 * of cluster sizes that is computed as cylinder groups are inspected. 121 */ 122 #define NOCSPTRS ((128 / sizeof(void *)) - 2) 123 124 /* 125 * A summary of contiguous blocks of various sizes is maintained 126 * in each cylinder group. Normally this is set by the initial 127 * value of fs_maxcontig. To conserve space, a maximum summary size 128 * is set by FS_MAXCONTIG. 129 */ 130 #define FS_MAXCONTIG 16 131 132 /* 133 * MINFREE gives the minimum acceptable percentage of file system 134 * blocks which may be free. If the freelist drops below this level 135 * only the superuser may continue to allocate blocks. This may 136 * be set to 0 if no reserve of free blocks is deemed necessary, 137 * however throughput drops by fifty percent if the file system 138 * is run at between 95% and 100% full; thus the minimum default 139 * value of fs_minfree is 5%. However, to get good clustering 140 * performance, 10% is a better choice. hence we use 10% as our 141 * default value. With 10% free space, fragmentation is not a 142 * problem, so we choose to optimize for time. 143 */ 144 #define MINFREE 5 145 #define DEFAULTOPT FS_OPTTIME 146 147 /* 148 * Per cylinder group information; summarized in blocks allocated 149 * from first cylinder group data blocks. These blocks have to be 150 * read in from fs_csaddr (size fs_cssize) in addition to the 151 * super block. 152 */ 153 struct csum { 154 int32_t cs_ndir; /* number of directories */ 155 int32_t cs_nbfree; /* number of free blocks */ 156 int32_t cs_nifree; /* number of free inodes */ 157 int32_t cs_nffree; /* number of free frags */ 158 }; 159 160 /* 161 * Super block for an FFS file system in memory. 162 */ 163 struct fs { 164 int32_t fs_firstfield; /* historic file system linked list, */ 165 int32_t fs_unused_1; /* used for incore super blocks */ 166 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */ 167 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */ 168 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */ 169 ufs_daddr_t fs_dblkno; /* offset of first data after cg */ 170 int32_t fs_cgoffset; /* cylinder group offset in cylinder */ 171 int32_t fs_cgmask; /* used to calc mod fs_ntrak */ 172 int32_t fs_time; /* last time written */ 173 int32_t fs_size; /* number of blocks in fs */ 174 int32_t fs_dsize; /* number of data blocks in fs */ 175 int32_t fs_ncg; /* number of cylinder groups */ 176 int32_t fs_bsize; /* size of basic blocks in fs */ 177 int32_t fs_fsize; /* size of frag blocks in fs */ 178 int32_t fs_frag; /* number of frags in a block in fs */ 179 /* these are configuration parameters */ 180 int32_t fs_minfree; /* minimum percentage of free blocks */ 181 int32_t fs_rotdelay; /* num of ms for optimal next block */ 182 int32_t fs_rps; /* disk revolutions per second */ 183 /* these fields can be computed from the others */ 184 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ 185 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ 186 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ 187 int32_t fs_fshift; /* ``numfrags'' calc number of frags */ 188 /* these are configuration parameters */ 189 int32_t fs_maxcontig; /* max number of contiguous blks */ 190 int32_t fs_maxbpg; /* max number of blks per cyl group */ 191 /* these fields can be computed from the others */ 192 int32_t fs_fragshift; /* block to frag shift */ 193 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 194 int32_t fs_sbsize; /* actual size of super block */ 195 int32_t fs_csmask; /* csum block offset (now unused) */ 196 int32_t fs_csshift; /* csum block number (now unused) */ 197 int32_t fs_nindir; /* value of NINDIR */ 198 int32_t fs_inopb; /* value of INOPB */ 199 int32_t fs_nspf; /* value of NSPF */ 200 /* yet another configuration parameter */ 201 int32_t fs_optim; /* optimization preference, see below */ 202 /* these fields are derived from the hardware */ 203 int32_t fs_npsect; /* # sectors/track including spares */ 204 int32_t fs_interleave; /* hardware sector interleave */ 205 int32_t fs_trackskew; /* sector 0 skew, per track */ 206 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */ 207 int32_t fs_id[2]; /* unique file system id */ 208 /* sizes determined by number of cylinder groups and their sizes */ 209 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ 210 int32_t fs_cssize; /* size of cyl grp summary area */ 211 int32_t fs_cgsize; /* cylinder group size */ 212 /* these fields are derived from the hardware */ 213 int32_t fs_ntrak; /* tracks per cylinder */ 214 int32_t fs_nsect; /* sectors per track */ 215 int32_t fs_spc; /* sectors per cylinder */ 216 /* this comes from the disk driver partitioning */ 217 int32_t fs_ncyl; /* cylinders in file system */ 218 /* these fields can be computed from the others */ 219 int32_t fs_cpg; /* cylinders per group */ 220 int32_t fs_ipg; /* inodes per group */ 221 int32_t fs_fpg; /* blocks per group * fs_frag */ 222 /* this data must be re-computed after crashes */ 223 struct csum fs_cstotal; /* cylinder summary information */ 224 /* these fields are cleared at mount time */ 225 int8_t fs_fmod; /* super block modified flag */ 226 int8_t fs_clean; /* file system is clean flag */ 227 int8_t fs_ronly; /* mounted read-only flag */ 228 int8_t fs_flags; /* see FS_ flags below */ 229 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 230 /* these fields retain the current block allocation info */ 231 int32_t fs_cgrotor; /* last cg searched */ 232 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */ 233 struct csum *fs_csp; /* cg summary info buffer for fs_cs */ 234 int32_t *fs_maxcluster; /* max cluster in each cyl group */ 235 int32_t fs_cpc; /* cyl per cycle in postbl */ 236 int16_t fs_opostbl[16][8]; /* old rotation block list head */ 237 int32_t fs_sparecon[50]; /* RESERVED for future constants */ 238 int32_t fs_contigsumsize; /* size of cluster summary array */ 239 int32_t fs_maxsymlinklen; /* max length of an internal symlink */ 240 int32_t fs_inodefmt; /* format of on-disk inodes */ 241 u_int64_t fs_maxfilesize; /* maximum representable file size */ 242 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */ 243 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */ 244 int32_t fs_state; /* validate fs_clean field (UNUSED) */ 245 int32_t fs_postblformat; /* format of positional layout tables */ 246 int32_t fs_nrpos; /* number of rotational positions */ 247 int32_t fs_postbloff; /* (u_int16) rotation block list head */ 248 int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */ 249 int32_t fs_magic; /* magic number */ 250 u_int8_t fs_space[1]; /* list of blocks for each rotation */ 251 /* actually longer */ 252 }; 253 254 /* 255 * File system identification 256 */ 257 #define FS_MAGIC 0x011954 /* the fast file system magic number */ 258 #define FS_OKAY 0x7c269d38 /* superblock checksum */ 259 #define FS_42INODEFMT -1 /* 4.2BSD inode format */ 260 #define FS_44INODEFMT 2 /* 4.4BSD inode format */ 261 262 /* 263 * File system clean flags 264 */ 265 #define FS_ISCLEAN 0x01 266 #define FS_WASCLEAN 0x02 267 268 /* 269 * Preference for optimization. 270 */ 271 #define FS_OPTTIME 0 /* minimize allocation time */ 272 #define FS_OPTSPACE 1 /* minimize disk fragmentation */ 273 274 /* 275 * File system flags 276 */ 277 #define FS_UNCLEAN 0x01 /* file system not clean at mount (unused) */ 278 #define FS_DOSOFTDEP 0x02 /* file system using soft dependencies */ 279 280 /* 281 * File system internal flags, also in fs_flags. 282 * (Pick highest number to avoid conflicts with others) 283 */ 284 #define FS_SWAPPED 0x80 /* file system is endian swapped */ 285 #define FS_INTERNAL 0x80 /* mask for internal flags */ 286 287 /* 288 * Rotational layout table format types 289 */ 290 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */ 291 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */ 292 /* 293 * Macros for access to superblock array structures 294 */ 295 #define fs_postbl(fs, cylno) \ 296 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 297 ? ((fs)->fs_opostbl[cylno]) \ 298 : ((int16_t *)((u_int8_t *)(fs) + \ 299 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos)) 300 #define fs_rotbl(fs) \ 301 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 302 ? ((fs)->fs_space) \ 303 : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff))) 304 305 /* 306 * The size of a cylinder group is calculated by CGSIZE. The maximum size 307 * is limited by the fact that cylinder groups are at most one block. 308 * Its size is derived from the size of the maps maintained in the 309 * cylinder group and the (struct cg) size. 310 */ 311 #define CGSIZE(fs) \ 312 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \ 313 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \ 314 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \ 315 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \ 316 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\ 317 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \ 318 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \ 319 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY))) 320 321 /* 322 * Convert cylinder group to base address of its global summary info. 323 */ 324 #define fs_cs(fs, indx) fs_csp[indx] 325 326 /* 327 * Cylinder group block for a file system. 328 */ 329 #define CG_MAGIC 0x090255 330 struct cg { 331 int32_t cg_firstfield; /* historic cyl groups linked list */ 332 int32_t cg_magic; /* magic number */ 333 int32_t cg_time; /* time last written */ 334 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 335 int16_t cg_ncyl; /* number of cyl's this cg */ 336 int16_t cg_niblk; /* number of inode blocks this cg */ 337 int32_t cg_ndblk; /* number of data blocks this cg */ 338 struct csum cg_cs; /* cylinder summary information */ 339 int32_t cg_rotor; /* position of last used block */ 340 int32_t cg_frotor; /* position of last used frag */ 341 int32_t cg_irotor; /* position of last used inode */ 342 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */ 343 int32_t cg_btotoff; /* (int32) block totals per cylinder */ 344 int32_t cg_boff; /* (u_int16) free block positions */ 345 int32_t cg_iusedoff; /* (u_int8) used inode map */ 346 int32_t cg_freeoff; /* (u_int8) free block map */ 347 int32_t cg_nextfreeoff; /* (u_int8) next available space */ 348 int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */ 349 int32_t cg_clusteroff; /* (u_int8) free cluster map */ 350 int32_t cg_nclusterblks; /* number of clusters this cg */ 351 int32_t cg_sparecon[13]; /* reserved for future use */ 352 u_int8_t cg_space[1]; /* space for cylinder group maps */ 353 /* actually longer */ 354 }; 355 356 /* 357 * Macros for access to cylinder group array structures 358 */ 359 #define cg_blktot(cgp, ns) \ 360 ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) \ 361 ? (((struct ocg *)(cgp))->cg_btot) \ 362 : ((int32_t *)((u_int8_t *)(cgp) + \ 363 ufs_rw32((cgp)->cg_btotoff, (ns))))) 364 #define cg_blks(fs, cgp, cylno, ns) \ 365 ((ufs_rw32((cgp)->cg_magic, ns) != CG_MAGIC) \ 366 ? (((struct ocg *)(cgp))->cg_b[cylno]) \ 367 : ((int16_t *)((u_int8_t *)(cgp) + \ 368 ufs_rw32((cgp)->cg_boff, (ns))) + \ 369 (cylno) * (fs)->fs_nrpos)) 370 #define cg_inosused(cgp, ns) \ 371 ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) \ 372 ? (((struct ocg *)(cgp))->cg_iused) \ 373 : ((u_int8_t *)((u_int8_t *)(cgp) + \ 374 ufs_rw32((cgp)->cg_iusedoff, (ns))))) 375 #define cg_blksfree(cgp, ns) \ 376 ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) \ 377 ? (((struct ocg *)(cgp))->cg_free) \ 378 : ((u_int8_t *)((u_int8_t *)(cgp) + \ 379 ufs_rw32((cgp)->cg_freeoff, (ns))))) 380 #define cg_chkmagic(cgp, ns) \ 381 (ufs_rw32((cgp)->cg_magic, (ns)) == CG_MAGIC || \ 382 ufs_rw32(((struct ocg *)(cgp))->cg_magic, (ns)) == \ 383 CG_MAGIC) 384 #define cg_clustersfree(cgp, ns) \ 385 ((u_int8_t *)((u_int8_t *)(cgp) + \ 386 ufs_rw32((cgp)->cg_clusteroff, (ns)))) 387 #define cg_clustersum(cgp, ns) \ 388 ((int32_t *)((u_int8_t *)(cgp) + \ 389 ufs_rw32((cgp)->cg_clustersumoff, (ns)))) 390 391 /* 392 * The following structure is defined 393 * for compatibility with old file systems. 394 */ 395 struct ocg { 396 int32_t cg_firstfield; /* historic linked list of cyl groups */ 397 int32_t cg_unused_1; /* used for incore cyl groups */ 398 int32_t cg_time; /* time last written */ 399 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 400 int16_t cg_ncyl; /* number of cyl's this cg */ 401 int16_t cg_niblk; /* number of inode blocks this cg */ 402 int32_t cg_ndblk; /* number of data blocks this cg */ 403 struct csum cg_cs; /* cylinder summary information */ 404 int32_t cg_rotor; /* position of last used block */ 405 int32_t cg_frotor; /* position of last used frag */ 406 int32_t cg_irotor; /* position of last used inode */ 407 int32_t cg_frsum[8]; /* counts of available frags */ 408 int32_t cg_btot[32]; /* block totals per cylinder */ 409 int16_t cg_b[32][8]; /* positions of free blocks */ 410 u_int8_t cg_iused[256]; /* used inode map */ 411 int32_t cg_magic; /* magic number */ 412 u_int8_t cg_free[1]; /* free block map */ 413 /* actually longer */ 414 }; 415 416 /* 417 * Turn file system block numbers into disk block addresses. 418 * This maps file system blocks to device size blocks. 419 */ 420 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb) 421 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb) 422 423 /* 424 * Cylinder group macros to locate things in cylinder groups. 425 * They calc file system addresses of cylinder group data structures. 426 */ 427 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c))) 428 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */ 429 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */ 430 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */ 431 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */ 432 #define cgstart(fs, c) \ 433 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask))) 434 435 /* 436 * Macros for handling inode numbers: 437 * inode number to file system block offset. 438 * inode number to cylinder group number. 439 * inode number to file system block address. 440 */ 441 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg) 442 #define ino_to_fsba(fs, x) \ 443 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \ 444 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs)))))) 445 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs)) 446 447 /* 448 * Give cylinder group number for a file system block. 449 * Give cylinder group block number for a file system block. 450 */ 451 #define dtog(fs, d) ((d) / (fs)->fs_fpg) 452 #define dtogd(fs, d) ((d) % (fs)->fs_fpg) 453 454 /* 455 * Extract the bits for a block from a map. 456 * Compute the cylinder and rotational position of a cyl block addr. 457 */ 458 #define blkmap(fs, map, loc) \ 459 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag))) 460 #define cbtocylno(fs, bno) \ 461 ((bno) * NSPF(fs) / (fs)->fs_spc) 462 #define cbtorpos(fs, bno) \ 463 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \ 464 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \ 465 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect) 466 467 /* 468 * The following macros optimize certain frequently calculated 469 * quantities by using shifts and masks in place of divisions 470 * modulos and multiplications. 471 */ 472 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \ 473 ((loc) & (fs)->fs_qbmask) 474 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \ 475 ((loc) & (fs)->fs_qfmask) 476 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \ 477 ((off_t)(blk) << (fs)->fs_bshift) 478 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ 479 ((loc) >> (fs)->fs_bshift) 480 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ 481 ((loc) >> (fs)->fs_fshift) 482 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \ 483 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask) 484 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ 485 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) 486 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \ 487 ((frags) >> (fs)->fs_fragshift) 488 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \ 489 ((blks) << (fs)->fs_fragshift) 490 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \ 491 ((fsb) & ((fs)->fs_frag - 1)) 492 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \ 493 ((fsb) &~ ((fs)->fs_frag - 1)) 494 495 /* 496 * Determine the number of available frags given a 497 * percentage to hold in reserve. 498 */ 499 #define freespace(fs, percentreserved) \ 500 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \ 501 (fs)->fs_cstotal.cs_nffree - \ 502 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100)) 503 504 /* 505 * Determining the size of a file block in the file system. 506 */ 507 #define blksize(fs, ip, lbn) \ 508 (((lbn) >= NDADDR || (ip)->i_ffs_size >= lblktosize(fs, (lbn) + 1)) \ 509 ? (fs)->fs_bsize \ 510 : (fragroundup(fs, blkoff(fs, (ip)->i_ffs_size)))) 511 #define dblksize(fs, dip, lbn) \ 512 (((lbn) >= NDADDR || (dip)->di_size >= lblktosize(fs, (lbn) + 1)) \ 513 ? (fs)->fs_bsize \ 514 : (fragroundup(fs, blkoff(fs, (dip)->di_size)))) 515 516 /* 517 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte 518 * sector size. 519 */ 520 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift) 521 #define NSPF(fs) ((fs)->fs_nspf) 522 523 /* 524 * Number of inodes in a secondary storage block/fragment. 525 */ 526 #define INOPB(fs) ((fs)->fs_inopb) 527 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift) 528 529 /* 530 * Number of indirects in a file system block. 531 */ 532 #define NINDIR(fs) ((fs)->fs_nindir) 533 534 #endif /* !_UFS_FFS_FS_H_ */ 535
Indexes created Mon Oct 27 20:09:55 GMT 2025