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 filesystems. 42 * A filesystem consists of a number of cylinder groups. 43 * Each cylinder group has inodes and data. 44 * 45 * A filesystem 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 filesystem 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 size and offset of the super-block in sector-size neutral bytes. 62 */ 63 #define SBSIZE 8192 64 #define SBOFF ((off_t)(BBSIZE)) 65 #define SBLOCK ((ufs_daddr_t)(SBOFF / DEV_BSIZE)) 66 67 /* Max number of fragments per block, this is not tweakable */ 68 #define MAXFRAG 8 69 /* 70 * Addresses stored in inodes are capable of addressing fragments 71 * of `blocks'. File system blocks of at most size MAXBSIZE can 72 * be optionally broken into 2, 4, or 8 pieces, each of which is 73 * addressable; these pieces may be DEV_BSIZE, or some multiple of 74 * a DEV_BSIZE unit. 75 * 76 * Large files consist of exclusively large data blocks. To avoid 77 * undue wasted disk space, the last data block of a small file may be 78 * allocated as only as many fragments of a large block as are 79 * necessary. The filesystem format retains only a single pointer 80 * to such a fragment, which is a piece of a single large block that 81 * has been divided. The size of such a fragment is determinable from 82 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro. 83 * 84 * The filesystem records space availability at the fragment level; 85 * to determine block availability, aligned fragments are examined. 86 */ 87 88 /* 89 * MINBSIZE is the smallest allowable block size. 90 * In order to insure that it is possible to create files of size 91 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096. 92 * MINBSIZE must be big enough to hold a cylinder group block, 93 * thus changes to (struct cg) must keep its size within MINBSIZE. 94 * Note that super blocks are always of size SBSIZE, 95 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE. 96 */ 97 #define MINBSIZE 4096 98 99 /* 100 * The path name on which the filesystem is mounted is maintained 101 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in 102 * the super block for this name. 103 */ 104 #define MAXMNTLEN 512 105 106 /* 107 * There is a 128-byte region in the superblock reserved for in-core 108 * pointers to summary information. Originally this included an array 109 * of pointers to blocks of struct csum; now there are just a few 110 * pointers and the remaining space is padded with fs_ocsp[]. 111 * 112 * NOCSPTRS determines the size of this padding. One pointer (fs_csp) 113 * is taken away to point to a contiguous array of struct csum for 114 * all cylinder groups; a second (fs_maxcluster) points to an array 115 * of cluster sizes that is computed as cylinder groups are inspected, 116 * and the third points to an array that tracks the creation of new 117 * directories. A fourth pointer, fs_active, is used when creating 118 * snapshots; it points to a bitmap of cylinder groups for which the 119 * free-block bitmap has changed since the snapshot operation began. 120 */ 121 #define NOCSPTRS ((128 / sizeof(void *)) - 4) 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 sqiud 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 #define FSMAXSNAP 20 167 168 /* 169 * Used to identify special blocks in snapshots: 170 * 171 * BLK_NOCOPY - A block that was unallocated at the time the snapshot 172 * was taken, hence does not need to be copied when written. 173 * BLK_SNAP - A block held by another snapshot that is not needed by this 174 * snapshot. When the other snapshot is freed, the BLK_SNAP entries 175 * are converted to BLK_NOCOPY. These are needed to allow fsck to 176 * identify blocks that are in use by other snapshots (which are 177 * expunged from this snapshot). 178 */ 179 #define BLK_NOCOPY ((ufs_daddr_t)(1)) 180 #define BLK_SNAP ((ufs_daddr_t)(2)) 181 182 /* 183 * Sysctl values for the fast filesystem. 184 */ 185 #define FFS_ADJ_REFCNT 1 /* adjust inode reference count */ 186 #define FFS_ADJ_BLKCNT 2 /* adjust inode used block count */ 187 #define FFS_BLK_FREE 3 /* free range of blocks in map */ 188 #define FFS_DIR_FREE 4 /* free specified dir inodes in map */ 189 #define FFS_FILE_FREE 5 /* free specified file inodes in map */ 190 #define FFS_SET_FLAGS 6 /* set filesystem flags */ 191 #define FFS_MAXID 7 /* number of valid ffs ids */ 192 193 /* 194 * Command structure passed in to the filesystem to adjust filesystem values. 195 */ 196 #define FFS_CMD_VERSION 0x05181979 /* version ID */ 197 struct fsck_cmd { 198 int version; /* version of command structure */ 199 int handle; /* reference to filesystem to be changed */ 200 off_t value; /* inode or block number to be affected */ 201 long size; /* amount or range to be adjusted */ 202 }; 203 204 /* 205 * Per cylinder group information; summarized in blocks allocated 206 * from first cylinder group data blocks. These blocks have to be 207 * read in from fs_csaddr (size fs_cssize) in addition to the 208 * super block. 209 */ 210 struct csum { 211 int32_t cs_ndir; /* number of directories */ 212 int32_t cs_nbfree; /* number of free blocks */ 213 int32_t cs_nifree; /* number of free inodes */ 214 int32_t cs_nffree; /* number of free frags */ 215 }; 216 217 /* 218 * Super block for an FFS filesystem. 219 */ 220 struct fs { 221 int32_t fs_firstfield; /* historic filesystem linked list, */ 222 int32_t fs_unused_1; /* used for incore super blocks */ 223 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */ 224 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */ 225 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */ 226 ufs_daddr_t fs_dblkno; /* offset of first data after cg */ 227 int32_t fs_cgoffset; /* cylinder group offset in cylinder */ 228 int32_t fs_cgmask; /* used to calc mod fs_ntrak */ 229 ufs_time_t fs_time; /* last time written */ 230 int32_t fs_size; /* number of blocks in fs */ 231 int32_t fs_dsize; /* number of data blocks in fs */ 232 int32_t fs_ncg; /* number of cylinder groups */ 233 int32_t fs_bsize; /* size of basic blocks in fs */ 234 int32_t fs_fsize; /* size of frag blocks in fs */ 235 int32_t fs_frag; /* number of frags in a block in fs */ 236 /* these are configuration parameters */ 237 int32_t fs_minfree; /* minimum percentage of free blocks */ 238 int32_t fs_rotdelay; /* num of ms for optimal next block */ 239 int32_t fs_rps; /* disk revolutions per second */ 240 /* these fields can be computed from the others */ 241 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ 242 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ 243 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ 244 int32_t fs_fshift; /* ``numfrags'' calc number of frags */ 245 /* these are configuration parameters */ 246 int32_t fs_maxcontig; /* max number of contiguous blks */ 247 int32_t fs_maxbpg; /* max number of blks per cyl group */ 248 /* these fields can be computed from the others */ 249 int32_t fs_fragshift; /* block to frag shift */ 250 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ 251 int32_t fs_sbsize; /* actual size of super block */ 252 int32_t fs_csmask; /* csum block offset (now unused) */ 253 int32_t fs_csshift; /* csum block number (now unused) */ 254 int32_t fs_nindir; /* value of NINDIR */ 255 int32_t fs_inopb; /* value of INOPB */ 256 int32_t fs_nspf; /* value of NSPF */ 257 /* yet another configuration parameter */ 258 int32_t fs_optim; /* optimization preference, see below */ 259 /* these fields are derived from the hardware */ 260 int32_t fs_npsect; /* # sectors/track including spares */ 261 int32_t fs_interleave; /* hardware sector interleave */ 262 int32_t fs_trackskew; /* sector 0 skew, per track */ 263 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */ 264 int32_t fs_id[2]; /* unique filesystem id */ 265 /* sizes determined by number of cylinder groups and their sizes */ 266 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ 267 int32_t fs_cssize; /* size of cyl grp summary area */ 268 int32_t fs_cgsize; /* cylinder group size */ 269 /* these fields are derived from the hardware */ 270 int32_t fs_ntrak; /* tracks per cylinder */ 271 int32_t fs_nsect; /* sectors per track */ 272 int32_t fs_spc; /* sectors per cylinder */ 273 /* this comes from the disk driver partitioning */ 274 int32_t fs_ncyl; /* cylinders in filesystem */ 275 /* these fields can be computed from the others */ 276 int32_t fs_cpg; /* cylinders per group */ 277 int32_t fs_ipg; /* inodes per group */ 278 int32_t fs_fpg; /* blocks per group * fs_frag */ 279 /* this data must be re-computed after crashes */ 280 struct csum fs_cstotal; /* cylinder summary information */ 281 /* these fields are cleared at mount time */ 282 int8_t fs_fmod; /* super block modified flag */ 283 int8_t fs_clean; /* filesystem is clean flag */ 284 int8_t fs_ronly; /* mounted read-only flag */ 285 int8_t fs_flags; /* see FS_ flags below */ 286 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ 287 /* these fields retain the current block allocation info */ 288 int32_t fs_cgrotor; /* last cg searched */ 289 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */ 290 u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */ 291 struct csum *fs_csp; /* cg summary info buffer for fs_cs */ 292 int32_t *fs_maxcluster; /* max cluster in each cyl group */ 293 u_int *fs_active; /* used by snapshots to track fs */ 294 int32_t fs_cpc; /* cyl per cycle in postbl */ 295 int16_t fs_opostbl[16][8]; /* old rotation block list head */ 296 int32_t fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */ 297 int32_t fs_avgfilesize; /* expected average file size */ 298 int32_t fs_avgfpdir; /* expected # of files per directory */ 299 int32_t fs_sparecon[26]; /* reserved for future constants */ 300 int32_t fs_pendingblocks; /* blocks in process of being freed */ 301 int32_t fs_pendinginodes; /* inodes in process of being freed */ 302 int32_t fs_contigsumsize; /* size of cluster summary array */ 303 int32_t fs_maxsymlinklen; /* max length of an internal symlink */ 304 int32_t fs_inodefmt; /* format of on-disk inodes */ 305 u_int64_t fs_maxfilesize; /* maximum representable file size */ 306 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */ 307 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */ 308 int32_t fs_state; /* validate fs_clean field */ 309 int32_t fs_postblformat; /* format of positional layout tables */ 310 int32_t fs_nrpos; /* number of rotational positions */ 311 int32_t fs_postbloff; /* (u_int16) rotation block list head */ 312 int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */ 313 int32_t fs_magic; /* magic number */ 314 u_int8_t fs_space[1]; /* list of blocks for each rotation */ 315 /* actually longer */ 316 }; 317 318 /* 319 * Filesystem identification 320 */ 321 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */ 322 #define FS_OKAY 0x7c269d38 /* superblock checksum */ 323 #define FS_42INODEFMT -1 /* 4.2BSD inode format */ 324 #define FS_44INODEFMT 2 /* 4.4BSD inode format */ 325 326 /* 327 * Preference for optimization. 328 */ 329 #define FS_OPTTIME 0 /* minimize allocation time */ 330 #define FS_OPTSPACE 1 /* minimize disk fragmentation */ 331 332 /* 333 * Filesystem flags. 334 * 335 * Note that the FS_NEEDSFSCK flag is set and cleared only by the 336 * fsck utility. It is set when background fsck finds an unexpected 337 * inconsistency which requires a traditional foreground fsck to be 338 * run. Such inconsistencies should only be found after an uncorrectable 339 * disk error. A foreground fsck will clear the FS_NEEDSFSCK flag when 340 * it has successfully cleaned up the filesystem. The kernel uses this 341 * flag to enforce that inconsistent filesystems be mounted read-only. 342 */ 343 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */ 344 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */ 345 #define FS_NEEDSFSCK 0x04 /* filesystem needs sync fsck before mount */ 346 347 /* 348 * Rotational layout table format types 349 */ 350 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */ 351 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */ 352 /* 353 * Macros for access to superblock array structures 354 */ 355 #define fs_postbl(fs, cylno) \ 356 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 357 ? ((fs)->fs_opostbl[cylno]) \ 358 : ((int16_t *)((u_int8_t *)(fs) + \ 359 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos)) 360 #define fs_rotbl(fs) \ 361 (((fs)->fs_postblformat == FS_42POSTBLFMT) \ 362 ? ((fs)->fs_space) \ 363 : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff))) 364 365 /* 366 * Macros to access bits in the fs_active array. 367 */ 368 #define ACTIVECGNUM(fs, cg) ((fs)->fs_active[(cg) / (NBBY * sizeof(int))]) 369 #define ACTIVECGOFF(cg) (1 << ((cg) % (NBBY * sizeof(int)))) 370 371 /* 372 * The size of a cylinder group is calculated by CGSIZE. The maximum size 373 * is limited by the fact that cylinder groups are at most one block. 374 * Its size is derived from the size of the maps maintained in the 375 * cylinder group and the (struct cg) size. 376 */ 377 #define CGSIZE(fs) \ 378 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \ 379 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \ 380 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \ 381 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \ 382 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\ 383 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \ 384 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \ 385 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY))) 386 387 /* 388 * Convert cylinder group to base address of its global summary info. 389 */ 390 #define fs_cs(fs, indx) fs_csp[indx] 391 392 /* 393 * Cylinder group block for a filesystem. 394 */ 395 #define CG_MAGIC 0x090255 396 struct cg { 397 int32_t cg_firstfield; /* historic cyl groups linked list */ 398 int32_t cg_magic; /* magic number */ 399 ufs_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[MAXFRAG]; /* counts of available frags */ 409 int32_t cg_btotoff; /* (int32) block totals per cylinder */ 410 int32_t cg_boff; /* (u_int16) free block positions */ 411 int32_t cg_iusedoff; /* (u_int8) used inode map */ 412 int32_t cg_freeoff; /* (u_int8) free block map */ 413 int32_t cg_nextfreeoff; /* (u_int8) next available space */ 414 int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */ 415 int32_t cg_clusteroff; /* (u_int8) free cluster map */ 416 int32_t cg_nclusterblks; /* number of clusters this cg */ 417 int32_t cg_sparecon[13]; /* reserved for future use */ 418 u_int8_t cg_space[1]; /* space for cylinder group maps */ 419 /* actually longer */ 420 }; 421 422 /* 423 * Macros for access to cylinder group array structures 424 */ 425 #define cg_blktot(cgp) \ 426 (((cgp)->cg_magic != CG_MAGIC) \ 427 ? (((struct ocg *)(cgp))->cg_btot) \ 428 : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff))) 429 #define cg_blks(fs, cgp, cylno) \ 430 (((cgp)->cg_magic != CG_MAGIC) \ 431 ? (((struct ocg *)(cgp))->cg_b[cylno]) \ 432 : ((int16_t *)((u_int8_t *)(cgp) + \ 433 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos)) 434 #define cg_inosused(cgp) \ 435 (((cgp)->cg_magic != CG_MAGIC) \ 436 ? (((struct ocg *)(cgp))->cg_iused) \ 437 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))) 438 #define cg_blksfree(cgp) \ 439 (((cgp)->cg_magic != CG_MAGIC) \ 440 ? (((struct ocg *)(cgp))->cg_free) \ 441 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))) 442 #define cg_chkmagic(cgp) \ 443 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC) 444 #define cg_clustersfree(cgp) \ 445 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff)) 446 #define cg_clustersum(cgp) \ 447 ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff)) 448 449 /* 450 * The following structure is defined 451 * for compatibility with old filesystems. 452 */ 453 struct ocg { 454 int32_t cg_firstfield; /* historic linked list of cyl groups */ 455 int32_t cg_unused_1; /* used for incore cyl groups */ 456 ufs_time_t cg_time; /* time last written */ 457 int32_t cg_cgx; /* we are the cgx'th cylinder group */ 458 int16_t cg_ncyl; /* number of cyl's this cg */ 459 int16_t cg_niblk; /* number of inode blocks this cg */ 460 int32_t cg_ndblk; /* number of data blocks this cg */ 461 struct csum cg_cs; /* cylinder summary information */ 462 int32_t cg_rotor; /* position of last used block */ 463 int32_t cg_frotor; /* position of last used frag */ 464 int32_t cg_irotor; /* position of last used inode */ 465 int32_t cg_frsum[8]; /* counts of available frags */ 466 int32_t cg_btot[32]; /* block totals per cylinder */ 467 int16_t cg_b[32][8]; /* positions of free blocks */ 468 u_int8_t cg_iused[256]; /* used inode map */ 469 int32_t cg_magic; /* magic number */ 470 u_int8_t cg_free[1]; /* free block map */ 471 /* actually longer */ 472 }; 473 474 /* 475 * Turn filesystem block numbers into disk block addresses. 476 * This maps filesystem blocks to device size blocks. 477 */ 478 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb) 479 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb) 480 481 /* 482 * Cylinder group macros to locate things in cylinder groups. 483 * They calc filesystem addresses of cylinder group data structures. 484 */ 485 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c))) 486 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */ 487 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */ 488 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */ 489 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */ 490 #define cgstart(fs, c) \ 491 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask))) 492 493 /* 494 * Macros for handling inode numbers: 495 * inode number to filesystem block offset. 496 * inode number to cylinder group number. 497 * inode number to filesystem block address. 498 */ 499 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg) 500 #define ino_to_fsba(fs, x) \ 501 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \ 502 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs)))))) 503 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs)) 504 505 /* 506 * Give cylinder group number for a filesystem block. 507 * Give cylinder group block number for a filesystem block. 508 */ 509 #define dtog(fs, d) ((d) / (fs)->fs_fpg) 510 #define dtogd(fs, d) ((d) % (fs)->fs_fpg) 511 512 /* 513 * Extract the bits for a block from a map. 514 * Compute the cylinder and rotational position of a cyl block addr. 515 */ 516 #define blkmap(fs, map, loc) \ 517 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag))) 518 #define cbtocylno(fs, bno) \ 519 ((bno) * NSPF(fs) / (fs)->fs_spc) 520 #define cbtorpos(fs, bno) \ 521 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \ 522 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \ 523 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect) 524 525 /* 526 * The following macros optimize certain frequently calculated 527 * quantities by using shifts and masks in place of divisions 528 * modulos and multiplications. 529 */ 530 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \ 531 ((loc) & (fs)->fs_qbmask) 532 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \ 533 ((loc) & (fs)->fs_qfmask) 534 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \ 535 ((off_t)(blk) << (fs)->fs_bshift) 536 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */ 537 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \ 538 ((blk) << (fs)->fs_bshift) 539 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \ 540 ((loc) >> (fs)->fs_bshift) 541 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \ 542 ((loc) >> (fs)->fs_fshift) 543 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \ 544 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask) 545 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \ 546 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask) 547 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \ 548 ((frags) >> (fs)->fs_fragshift) 549 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \ 550 ((blks) << (fs)->fs_fragshift) 551 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \ 552 ((fsb) & ((fs)->fs_frag - 1)) 553 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \ 554 ((fsb) &~ ((fs)->fs_frag - 1)) 555 556 /* 557 * Determine the number of available frags given a 558 * percentage to hold in reserve. 559 */ 560 #define freespace(fs, percentreserved) \ 561 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \ 562 (fs)->fs_cstotal.cs_nffree - \ 563 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100)) 564 565 /* 566 * Determining the size of a file block in the filesystem. 567 */ 568 #define blksize(fs, ip, lbn) \ 569 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \ 570 ? (fs)->fs_bsize \ 571 : (fragroundup(fs, blkoff(fs, (ip)->i_size)))) 572 #define dblksize(fs, dip, lbn) \ 573 (((lbn) >= NDADDR || \ 574 (dip)->di_size >= (u_int64_t)smalllblktosize(fs, (lbn) + 1)) \ 575 ? (fs)->fs_bsize \ 576 : (fragroundup(fs, blkoff(fs, (dip)->di_size)))) 577 #define sblksize(fs, size, lbn) \ 578 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \ 579 ? (fs)->fs_bsize \ 580 : (fragroundup(fs, blkoff(fs, (size))))) 581 582 583 /* 584 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte 585 * sector size. 586 */ 587 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift) 588 #define NSPF(fs) ((fs)->fs_nspf) 589 590 /* 591 * Number of inodes in a secondary storage block/fragment. 592 */ 593 #define INOPB(fs) ((fs)->fs_inopb) 594 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift) 595 596 /* 597 * Number of indirects in a filesystem block. 598 */ 599 #define NINDIR(fs) ((fs)->fs_nindir) 600 601 extern int inside[], around[]; 602 extern u_char *fragtbl[]; 603 604 #endif 605