1 /* $OpenBSD: fs.h,v 1.43 2020/06/20 07:49:04 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 #define MAXFRAG 8 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 468 110 111 /* 112 * The volume name for this file system is kept in fs_volname. 113 * MAXVOLLEN defines the length of the buffer allocated. 114 */ 115 #define MAXVOLLEN 32 116 117 /* 118 * There is a 128-byte region in the superblock reserved for in-core 119 * pointers to summary information. Originally this included an array 120 * of pointers to blocks of struct csum; now there are just three 121 * pointers and the remaining space is padded with fs_ocsp[]. 122 * 123 * NOCSPTRS determines the size of this padding. One pointer (fs_csp) 124 * is taken away to point to a contiguous array of struct csum for 125 * all cylinder groups; a second (fs_maxcluster) points to an array 126 * of cluster sizes that is computed as cylinder groups are inspected, 127 * and the third points to an array that tracks the creation of new 128 * directories. 129 */ 130 #define NOCSPTRS ((128 / sizeof(void *)) - 4) 131 132 /* 133 * A summary of contiguous blocks of various sizes is maintained 134 * in each cylinder group. Normally this is set by the initial 135 * value of fs_maxcontig. To conserve space, a maximum summary size 136 * is set by FS_MAXCONTIG. 137 */ 138 #define FS_MAXCONTIG 16 139 140 /* 141 * MINFREE gives the minimum acceptable percentage of file system 142 * blocks which may be free. If the freelist drops below this level 143 * only the superuser may continue to allocate blocks. This may 144 * be set to 0 if no reserve of free blocks is deemed necessary, 145 * however throughput drops by fifty percent if the file system 146 * is run at between 95% and 100% full; thus the minimum default 147 * value of fs_minfree is 5%. However, to get good clustering 148 * performance, 10% is a better choice. With 5% free space, 149 * fragmentation is not a problem, so we choose to optimize for time. 150 */ 151 #define MINFREE 5 152 #define DEFAULTOPT FS_OPTTIME 153 154 /* 155 * The directory preference algorithm(dirpref) can be tuned by adjusting 156 * the following parameters which tell the system the average file size 157 * and the average number of files per directory. These defaults are well 158 * selected for typical filesystems, but may need to be tuned for odd 159 * cases like filesystems being used for squid caches or news spools. 160 */ 161 #define AVFILESIZ 16384 /* expected average file size */ 162 #define AFPDIR 64 /* expected number of files per directory */ 163 164 /* 165 * Size of superblock space reserved for snapshots. 166 */ 167 #define FSMAXSNAP 20 168 169 /* 170 * Per cylinder group information; summarized in blocks allocated 171 * from first cylinder group data blocks. These blocks have to be 172 * read in from fs_csaddr (size fs_cssize) in addition to the 173 * super block. 174 */ 175 struct csum { 176 int32_t cs_ndir; /* number of directories */ 177 int32_t cs_nbfree; /* number of free blocks */ 178 int32_t cs_nifree; /* number of free inodes */ 179 int32_t cs_nffree; /* number of free frags */ 180 }; 181 182 struct csum_total { 183 int64_t cs_ndir; /* number of directories */ 184 int64_t cs_nbfree; /* number of free blocks */ 185 int64_t cs_nifree; /* number of free inodes */ 186 int64_t cs_nffree; /* number of free frags */ 187 int64_t cs_spare[4]; /* future expansion */ 188 }; 189 190 /* 191 * Super block for an FFS file system. 192 */ 193 struct fs { 194 int32_t fs_firstfield; /* historic file system linked list, */ 195 int32_t fs_unused_1; /* used for incore super blocks */ 196 int32_t fs_sblkno; /* addr of super-block / frags */ 197 int32_t fs_cblkno; /* offset of cyl-block / frags */ 198 int32_t fs_iblkno; /* offset of inode-blocks / frags */ 199 int32_t fs_dblkno; /* offset of first data / frags */ 200 int32_t fs_cgoffset; /* cylinder group offset in cylinder */ 201 int32_t fs_cgmask; /* used to calc mod fs_ntrak */ 202 int32_t fs_ffs1_time; /* last time written */ 203 int32_t fs_ffs1_size; /* # of blocks in fs / frags */ 204 int32_t fs_ffs1_dsize; /* # of data blocks in fs */ 205 u_int32_t fs_ncg; /* # of cylinder groups */ 206 int32_t fs_bsize; /* size of basic blocks / bytes */ 207 int32_t fs_fsize; /* size of frag blocks / bytes */ 208 int32_t fs_frag; /* # of frags in a block in fs */ 209 /* these are configuration parameters */ 210 int32_t fs_minfree; /* minimum percentage of free blocks */ 211 int32_t fs_rotdelay; /* # of ms for optimal next block */ 212 int32_t fs_rps; /* disk revolutions per second */ 213 /* these fields can be computed from the others */ 214 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ 215 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ 216 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ 217 int32_t fs_fshift; /* ``numfrags'' calc # of frags */ 218 /* these are configuration parameters */ 219 int32_t fs_maxcontig; /* max # of contiguous blks */ 220 int32_t fs_maxbpg; /* max # of blks per cyl group */ 221 /* these fields can be computed from the others */ 222 int32_t fs_fragshift; /* block to frag shift */ 223 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 224 int32_t fs_sbsize; /* actual size of super block */ 225 int32_t fs_csmask; /* csum block offset (now unused) */ 226 int32_t fs_csshift; /* csum block number (now unused) */ 227 int32_t fs_nindir; /* value of NINDIR */ 228 u_int32_t fs_inopb; /* inodes per file system block */ 229 int32_t fs_nspf; /* DEV_BSIZE sectors per frag */ 230 /* yet another configuration parameter */ 231 int32_t fs_optim; /* optimization preference, see below */ 232 /* these fields are derived from the hardware */ 233 int32_t fs_npsect; /* DEV_BSIZE sectors/track + spares */ 234 int32_t fs_interleave; /* DEV_BSIZE sector interleave */ 235 int32_t fs_trackskew; /* sector 0 skew, per track */ 236 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */ 237 int32_t fs_id[2]; /* unique filesystem id */ 238 /* sizes determined by number of cylinder groups and their sizes */ 239 int32_t fs_ffs1_csaddr; /* blk addr of cyl grp summary area */ 240 int32_t fs_cssize; /* cyl grp summary area size / bytes */ 241 int32_t fs_cgsize; /* cyl grp block size / bytes */ 242 /* these fields are derived from the hardware */ 243 int32_t fs_ntrak; /* tracks per cylinder */ 244 int32_t fs_nsect; /* DEV_BSIZE sectors per track */ 245 int32_t fs_spc; /* DEV_BSIZE sectors per cylinder */ 246 /* this comes from the disk driver partitioning */ 247 int32_t fs_ncyl; /* cylinders in file system */ 248 /* these fields can be computed from the others */ 249 int32_t fs_cpg; /* cylinders per group */ 250 u_int32_t fs_ipg; /* inodes per group */ 251 int32_t fs_fpg; /* blocks per group * fs_frag */ 252 /* this data must be re-computed after crashes */ 253 struct csum fs_ffs1_cstotal; /* cylinder summary information */ 254 /* these fields are cleared at mount time */ 255 int8_t fs_fmod; /* super block modified flag */ 256 int8_t fs_clean; /* file system is clean flag */ 257 int8_t fs_ronly; /* mounted read-only flag */ 258 int8_t fs_ffs1_flags; /* see FS_ below */ 259 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 260 u_char fs_volname[MAXVOLLEN]; /* volume name */ 261 u_int64_t fs_swuid; /* system-wide uid */ 262 int32_t fs_pad; /* due to alignment of fs_swuid */ 263 /* these fields retain the current block allocation info */ 264 int32_t fs_cgrotor; /* last cg searched */ 265 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */ 266 u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */ 267 struct csum *fs_csp; /* cg summary info buffer for fs_cs */ 268 int32_t *fs_maxcluster; /* max cluster in each cyl group */ 269 u_char *fs_active; /* reserved for snapshots */ 270 int32_t fs_cpc; /* cyl per cycle in postbl */ 271 /* this area is only allocated if fs_ffs1_flags & FS_FLAGS_UPDATED */ 272 int32_t fs_maxbsize; /* maximum blocking factor permitted */ 273 int64_t fs_spareconf64[17]; /* old rotation block list head */ 274 int64_t fs_sblockloc; /* offset of standard super block */ 275 struct csum_total fs_cstotal; /* cylinder summary information */ 276 int64_t fs_time; /* time last written */ 277 int64_t fs_size; /* number of blocks in fs */ 278 int64_t fs_dsize; /* number of data blocks in fs */ 279 int64_t fs_csaddr; /* blk addr of cyl grp summary area */ 280 int64_t fs_pendingblocks; /* blocks in process of being freed */ 281 u_int32_t fs_pendinginodes; /* inodes in process of being freed */ 282 u_int32_t fs_snapinum[FSMAXSNAP];/* space reserved for snapshots */ 283 /* back to stuff that has been around a while */ 284 u_int32_t fs_avgfilesize; /* expected average file size */ 285 u_int32_t fs_avgfpdir; /* expected # of files per directory */ 286 int32_t fs_sparecon[26]; /* reserved for future constants */ 287 u_int32_t fs_flags; /* see FS_ flags below */ 288 int32_t fs_fscktime; /* last time fsck(8)ed */ 289 int32_t fs_contigsumsize; /* size of cluster summary array */ 290 int32_t fs_maxsymlinklen; /* max length of an internal symlink */ 291 int32_t fs_inodefmt; /* format of on-disk inodes */ 292 u_int64_t fs_maxfilesize; /* maximum representable file size */ 293 int64_t fs_qbmask; /* ~fs_bmask - for use with quad size */ 294 int64_t fs_qfmask; /* ~fs_fmask - for use with quad size */ 295 int32_t fs_state; /* validate fs_clean field */ 296 int32_t fs_postblformat; /* format of positional layout tables */ 297 int32_t fs_nrpos; /* number of rotational positions */ 298 int32_t fs_postbloff; /* (u_int16) rotation block list head */ 299 int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */ 300 int32_t fs_magic; /* magic number */ 301 u_int8_t fs_space[1]; /* list of blocks for each rotation */ 302 /* actually longer */ 303 }; 304 305 /* 306 * Filesystem identification 307 */ 308 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */ 309 #define FS_UFS1_MAGIC 0x011954 /* the fast filesystem magic number */ 310 #define FS_UFS2_MAGIC 0x19540119 /* UFS fast filesystem magic number */ 311 #define FS_OKAY 0x7c269d38 /* superblock checksum */ 312 #define FS_42INODEFMT -1 /* 4.2BSD inode format */ 313 #define FS_44INODEFMT 2 /* 4.4BSD inode format */ 314 315 /* 316 * Filesystem clean flags 317 */ 318 #define FS_ISCLEAN 0x01 319 #define FS_WASCLEAN 0x02 320 321 /* 322 * Preference for optimization. 323 */ 324 #define FS_OPTTIME 0 /* minimize allocation time */ 325 #define FS_OPTSPACE 1 /* minimize disk fragmentation */ 326 327 /* 328 * Filesystem flags. 329 */ 330 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */ 331 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */ 332 /* 333 * The following flag is used to detect a FFS1 file system that had its flags 334 * moved to the new (FFS2) location for compatibility. 335 */ 336 #define FS_FLAGS_UPDATED 0x80 /* file system has FFS2-like flags */ 337 338 /* 339 * Rotational layout table format types 340 */ 341 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */ 342 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */ 343 /* 344 * Macros for access to superblock array structures 345 */ 346 #define fs_rotbl(fs) \ 347 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 348 ? ((fs)->fs_space) \ 349 : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff))) 350 351 /* 352 * The size of a cylinder group is calculated by CGSIZE. The maximum size 353 * is limited by the fact that cylinder groups are at most one block. 354 * Its size is derived from the size of the maps maintained in the 355 * cylinder group and the (struct cg) size. 356 */ 357 #define CGSIZE(fs) \ 358 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \ 359 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \ 360 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \ 361 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \ 362 /* block map */ howmany((fs)->fs_fpg, NBBY) + \ 363 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \ 364 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \ 365 /* cluster map */ howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY))) 366 367 /* 368 * Convert cylinder group to base address of its global summary info. 369 */ 370 #define fs_cs(fs, indx) fs_csp[indx] 371 372 /* 373 * Cylinder group block for a file system. 374 */ 375 #define CG_MAGIC 0x090255 376 struct cg { 377 int32_t cg_firstfield; /* historic cyl groups linked list */ 378 int32_t cg_magic; /* magic number */ 379 int32_t cg_time; /* time last written */ 380 u_int32_t cg_cgx; /* we are the cgx'th cylinder group */ 381 int16_t cg_ncyl; /* number of cyl's this cg */ 382 int16_t cg_niblk; /* number of inode blocks this cg */ 383 u_int32_t cg_ndblk; /* number of data blocks this cg */ 384 struct csum cg_cs; /* cylinder summary information */ 385 u_int32_t cg_rotor; /* position of last used block */ 386 u_int32_t cg_frotor; /* position of last used frag */ 387 u_int32_t cg_irotor; /* position of last used inode */ 388 u_int32_t cg_frsum[MAXFRAG]; /* counts of available frags */ 389 int32_t cg_btotoff; /* (int32) block totals per cylinder */ 390 int32_t cg_boff; /* (u_int16) free block positions */ 391 u_int32_t cg_iusedoff; /* (u_int8) used inode map */ 392 u_int32_t cg_freeoff; /* (u_int8) free block map */ 393 u_int32_t cg_nextfreeoff; /* (u_int8) next available space */ 394 u_int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */ 395 u_int32_t cg_clusteroff; /* (u_int8) free cluster map */ 396 u_int32_t cg_nclusterblks; /* number of clusters this cg */ 397 u_int32_t cg_ffs2_niblk; /* number of inode blocks this cg */ 398 u_int32_t cg_initediblk; /* last initialized inode */ 399 int32_t cg_sparecon32[3]; /* reserved for future use */ 400 int64_t cg_ffs2_time; /* time last written */ 401 int64_t cg_sparecon64[3]; /* reserved for future use */ 402 /* actually longer */ 403 }; 404 405 /* 406 * Macros for access to cylinder group array structures 407 */ 408 #define cg_blktot(cgp) \ 409 (((cgp)->cg_magic != CG_MAGIC) \ 410 ? (((struct ocg *)(cgp))->cg_btot) \ 411 : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff))) 412 #define cg_blks(fs, cgp, cylno) \ 413 (((cgp)->cg_magic != CG_MAGIC) \ 414 ? (((struct ocg *)(cgp))->cg_b[cylno]) \ 415 : ((int16_t *)((u_int8_t *)(cgp) + \ 416 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos)) 417 #define cg_inosused(cgp) \ 418 (((cgp)->cg_magic != CG_MAGIC) \ 419 ? (((struct ocg *)(cgp))->cg_iused) \ 420 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))) 421 #define cg_blksfree(cgp) \ 422 (((cgp)->cg_magic != CG_MAGIC) \ 423 ? (((struct ocg *)(cgp))->cg_free) \ 424 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))) 425 #define cg_chkmagic(cgp) \ 426 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC) 427 #define cg_clustersfree(cgp) \ 428 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff)) 429 #define cg_clustersum(cgp) \ 430 ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff)) 431 432 /* 433 * The following structure is defined 434 * for compatibility with old file systems. 435 */ 436 struct ocg { 437 int32_t cg_firstfield; /* historic linked list of cyl groups */ 438 int32_t cg_unused_1; /* used for incore cyl groups */ 439 int32_t cg_time; /* time last written */ 440 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 441 int16_t cg_ncyl; /* number of cyl's this cg */ 442 int16_t cg_niblk; /* number of inode blocks this cg */ 443 int32_t cg_ndblk; /* number of data blocks this cg */ 444 struct csum cg_cs; /* cylinder summary information */ 445 int32_t cg_rotor; /* position of last used block */ 446 int32_t cg_frotor; /* position of last used frag */ 447 int32_t cg_irotor; /* position of last used inode */ 448 int32_t cg_frsum[8]; /* counts of available frags */ 449 int32_t cg_btot[32]; /* block totals per cylinder */ 450 int16_t cg_b[32][8]; /* positions of free blocks */ 451 u_int8_t cg_iused[256]; /* used inode map */ 452 int32_t cg_magic; /* magic number */ 453 u_int8_t cg_free[1]; /* free block map */ 454 /* actually longer */ 455 }; 456 457 /* 458 * Turn file system block numbers into disk block addresses. 459 * This maps file system blocks to DEV_BSIZE (a.k.a. 512-byte) size disk 460 * blocks. 461 */ 462 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb) 463 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb) 464 465 /* 466 * Cylinder group macros to locate things in cylinder groups. 467 * They calc file system addresses of cylinder group data structures. 468 */ 469 #define cgbase(fs, c) ((daddr_t)(fs)->fs_fpg * (c)) 470 #define cgdata(fs, c) (cgdmin(fs, c) + (fs)->fs_minfree) /* data zone */ 471 #define cgmeta(fs, c) (cgdmin(fs, c)) /* meta data */ 472 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */ 473 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */ 474 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */ 475 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */ 476 #define cgstart(fs, c) \ 477 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask))) 478 479 /* 480 * Macros for handling inode numbers: 481 * inode number to file system block offset. 482 * inode number to cylinder group number. 483 * inode number to file system block address. 484 */ 485 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg) 486 #define ino_to_fsba(fs, x) \ 487 ((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \ 488 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs)))))) 489 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs)) 490 491 /* 492 * Give cylinder group number for a file system block. 493 * Give frag block number in cylinder group for a file system block. 494 */ 495 #define dtog(fs, d) ((d) / (fs)->fs_fpg) 496 #define dtogd(fs, d) ((d) % (fs)->fs_fpg) 497 498 /* 499 * Extract the bits for a block from a map. 500 * Compute the cylinder and rotational position of a cyl block addr. 501 */ 502 #define blkmap(fs, map, loc) \ 503 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag))) 504 #define cbtocylno(fs, bno) \ 505 (fsbtodb(fs, bno) / (fs)->fs_spc) 506 #define cbtorpos(fs, bno) \ 507 ((fs)->fs_nrpos <= 1 ? 0 : \ 508 (fsbtodb(fs, bno) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \ 509 fsbtodb(fs, bno) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \ 510 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect) 511 512 /* 513 * The following macros optimize certain frequently calculated 514 * quantities by using shifts and masks in place of divisions 515 * modulos and multiplications. 516 */ 517 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \ 518 ((loc) & (fs)->fs_qbmask) 519 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \ 520 ((loc) & (fs)->fs_qfmask) 521 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \ 522 ((off_t)(blk) << (fs)->fs_bshift) 523 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ 524 ((loc) >> (fs)->fs_bshift) 525 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ 526 ((loc) >> (fs)->fs_fshift) 527 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \ 528 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask) 529 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ 530 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) 531 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \ 532 ((frags) >> (fs)->fs_fragshift) 533 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \ 534 ((blks) << (fs)->fs_fragshift) 535 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \ 536 ((fsb) & ((fs)->fs_frag - 1)) 537 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \ 538 ((fsb) &~ ((fs)->fs_frag - 1)) 539 540 /* 541 * Determine the number of available frags given a 542 * percentage to hold in reserve. 543 */ 544 #define freespace(fs, percentreserved) \ 545 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \ 546 (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100)) 547 548 /* 549 * Determining the size of a file block in the file system. 550 */ 551 #define blksize(fs, ip, lbn) \ 552 (((lbn) >= NDADDR || DIP((ip), size) >= ((lbn) + 1) << (fs)->fs_bshift) \ 553 ? (u_int64_t)(fs)->fs_bsize \ 554 : (fragroundup(fs, blkoff(fs, DIP((ip), size))))) 555 #define dblksize(fs, dip, lbn) \ 556 (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \ 557 ? (u_int64_t)(fs)->fs_bsize \ 558 : (fragroundup(fs, blkoff(fs, (dip)->di_size)))) 559 560 #define sblksize(fs, size, lbn) \ 561 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \ 562 ? (u_int64_t)(fs)->fs_bsize \ 563 : (fragroundup(fs, blkoff(fs, (size))))) 564 565 566 /* 567 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte 568 * sector size. 569 */ 570 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift) 571 #define NSPF(fs) ((fs)->fs_nspf) 572 573 /* Number of inodes per file system block (fs->fs_bsize) */ 574 #define INOPB(fs) ((fs)->fs_inopb) 575 /* Number of inodes per file system fragment (fs->fs_fsize) */ 576 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift) 577 578 /* 579 * Number of indirects in a file system block. 580 */ 581 #define NINDIR(fs) ((fs)->fs_nindir) 582 583 /* Maximum file size the kernel allows. 584 * Even though ffs can handle files up to 16TB, we do limit the max file 585 * to 2^31 pages to prevent overflow of a 32-bit unsigned int. The buffer 586 * cache has its own checks but a little added paranoia never hurts. 587 */ 588 #define FS_KERNMAXFILESIZE(pgsiz, fs) ((u_int64_t)0x80000000 * \ 589 MIN((pgsiz), (fs)->fs_bsize) - 1) 590 591 extern const int inside[], around[]; 592 extern const u_char *fragtbl[]; 593