FreeBSD/Linux Kernel Cross Reference
sys/ufs/ffs/fs.h
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 three
112 * pointers and the remaining space is padded with fs_ocsp[].
113 *
114 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
115 * is taken away to point to a contiguous array of struct csum for
116 * all cylinder groups; a second (fs_maxcluster) points to an array
117 * of cluster sizes that is computed as cylinder groups are inspected,
118 * and the third points to an array that tracks the creation of new
119 * directories.
120 */
121 #define NOCSPTRS ((128 / sizeof(void *)) - 3)
122
123 /*
124 * A summary of contiguous blocks of various sizes is maintained
125 * in each cylinder group. Normally this is set by the initial
126 * value of fs_maxcontig. To conserve space, a maximum summary size
127 * is set by FS_MAXCONTIG.
128 */
129 #define FS_MAXCONTIG 16
130
131 /*
132 * MINFREE gives the minimum acceptable percentage of file system
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 file system
137 * is run at between 95% and 100% full; thus the minimum default
138 * value of fs_minfree is 5%. However, to get good clustering
139 * performance, 10% is a better choice. hence we use 10% as our
140 * default value. With 10% free space, fragmentation is not a
141 * problem, so we choose to optimize for time.
142 */
143 #define MINFREE 8
144 #define DEFAULTOPT FS_OPTTIME
145
146 /*
147 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
148 * tune the layout preferences for directories within a filesystem.
149 * His algorithm can be tuned by adjusting the following parameters
150 * which tell the system the average file size and the average number
151 * of files per directory. These defaults are well selected for typical
152 * filesystems, but may need to be tuned for odd cases like filesystems
153 * being used for squid caches or news spools.
154 */
155 #define AVFILESIZ 16384 /* expected average file size */
156 #define AFPDIR 64 /* expected number of files per directory */
157
158 /*
159 * The maximum number of snapshot nodes that can be associated
160 * with each filesystem. This limit affects only the number of
161 * snapshot files that can be recorded within the superblock so
162 * that they can be found when the filesystem is mounted. However,
163 * maintaining too many will slow the filesystem performance, so
164 * having this limit is a good idea.
165 *
166 * VALUE NOT IMPLEMENTED IN 4.x YET, RESERVED FROM -CURRENT SO SUPERBLOCKS
167 * REMAIN COMPATIBLE.
168 */
169 #define FSMAXSNAP 20
170
171 /*
172 * Per cylinder group information; summarized in blocks allocated
173 * from first cylinder group data blocks. These blocks have to be
174 * read in from fs_csaddr (size fs_cssize) in addition to the
175 * super block.
176 */
177 struct csum {
178 int32_t cs_ndir; /* number of directories */
179 int32_t cs_nbfree; /* number of free blocks */
180 int32_t cs_nifree; /* number of free inodes */
181 int32_t cs_nffree; /* number of free frags */
182 };
183
184 /*
185 * Super block for an FFS file system.
186 */
187 struct fs {
188 int32_t fs_firstfield; /* historic file system linked list, */
189 int32_t fs_unused_1; /* used for incore super blocks */
190 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
191 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
192 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
193 ufs_daddr_t fs_dblkno; /* offset of first data after cg */
194 int32_t fs_cgoffset; /* cylinder group offset in cylinder */
195 int32_t fs_cgmask; /* used to calc mod fs_ntrak */
196 time_t fs_time; /* last time written */
197 int32_t fs_size; /* number of blocks in fs */
198 int32_t fs_dsize; /* number of data blocks in fs */
199 int32_t fs_ncg; /* number of cylinder groups */
200 int32_t fs_bsize; /* size of basic blocks in fs */
201 int32_t fs_fsize; /* size of frag blocks in fs */
202 int32_t fs_frag; /* number of frags in a block in fs */
203 /* these are configuration parameters */
204 int32_t fs_minfree; /* minimum percentage of free blocks */
205 int32_t fs_rotdelay; /* num of ms for optimal next block */
206 int32_t fs_rps; /* disk revolutions per second */
207 /* these fields can be computed from the others */
208 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
209 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
210 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
211 int32_t fs_fshift; /* ``numfrags'' calc number of frags */
212 /* these are configuration parameters */
213 int32_t fs_maxcontig; /* max number of contiguous blks */
214 int32_t fs_maxbpg; /* max number of blks per cyl group */
215 /* these fields can be computed from the others */
216 int32_t fs_fragshift; /* block to frag shift */
217 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
218 int32_t fs_sbsize; /* actual size of super block */
219 int32_t fs_csmask; /* csum block offset (now unused) */
220 int32_t fs_csshift; /* csum block number (now unused) */
221 int32_t fs_nindir; /* value of NINDIR */
222 int32_t fs_inopb; /* value of INOPB */
223 int32_t fs_nspf; /* value of NSPF */
224 /* yet another configuration parameter */
225 int32_t fs_optim; /* optimization preference, see below */
226 /* these fields are derived from the hardware */
227 int32_t fs_npsect; /* # sectors/track including spares */
228 int32_t fs_interleave; /* hardware sector interleave */
229 int32_t fs_trackskew; /* sector 0 skew, per track */
230 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
231 int32_t fs_id[2]; /* unique filesystem id */
232 /* sizes determined by number of cylinder groups and their sizes */
233 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
234 int32_t fs_cssize; /* size of cyl grp summary area */
235 int32_t fs_cgsize; /* cylinder group size */
236 /* these fields are derived from the hardware */
237 int32_t fs_ntrak; /* tracks per cylinder */
238 int32_t fs_nsect; /* sectors per track */
239 int32_t fs_spc; /* sectors per cylinder */
240 /* this comes from the disk driver partitioning */
241 int32_t fs_ncyl; /* cylinders in file system */
242 /* these fields can be computed from the others */
243 int32_t fs_cpg; /* cylinders per group */
244 int32_t fs_ipg; /* inodes per group */
245 int32_t fs_fpg; /* blocks per group * fs_frag */
246 /* this data must be re-computed after crashes */
247 struct csum fs_cstotal; /* cylinder summary information */
248 /* these fields are cleared at mount time */
249 int8_t fs_fmod; /* super block modified flag */
250 int8_t fs_clean; /* file system is clean flag */
251 int8_t fs_ronly; /* mounted read-only flag */
252 int8_t fs_flags; /* see FS_ flags below */
253 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
254 /* these fields retain the current block allocation info */
255 int32_t fs_cgrotor; /* last cg searched */
256 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
257 u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */
258 struct csum *fs_csp; /* cg summary info buffer for fs_cs */
259 int32_t *fs_maxcluster; /* max cluster in each cyl group */
260 int32_t fs_cpc; /* cyl per cycle in postbl */
261 int16_t fs_opostbl[16][8]; /* old rotation block list head */
262 int32_t fs_snapinum[FSMAXSNAP];/* RESERVED FROM 5.x */
263 int32_t fs_avgfilesize; /* expected average file size */
264 int32_t fs_avgfpdir; /* expected # of files per directory */
265 int32_t fs_sparecon[26]; /* reserved for future constants */
266 int32_t fs_pendingblocks; /* RESERVED FROM 5.x */
267 int32_t fs_pendinginodes; /* RESERVED FROM 5.x */
268 int32_t fs_contigsumsize; /* size of cluster summary array */
269 int32_t fs_maxsymlinklen; /* max length of an internal symlink */
270 int32_t fs_inodefmt; /* format of on-disk inodes */
271 u_int64_t fs_maxfilesize; /* maximum representable file size */
272 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
273 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
274 int32_t fs_state; /* validate fs_clean field */
275 int32_t fs_postblformat; /* format of positional layout tables */
276 int32_t fs_nrpos; /* number of rotational positions */
277 int32_t fs_postbloff; /* (u_int16) rotation block list head */
278 int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */
279 int32_t fs_magic; /* magic number */
280 u_int8_t fs_space[1]; /* list of blocks for each rotation */
281 /* actually longer */
282 };
283
284 /*
285 * Filesystem identification
286 */
287 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
288 #define FS_OKAY 0x7c269d38 /* superblock checksum */
289 #define FS_42INODEFMT -1 /* 4.2BSD inode format */
290 #define FS_44INODEFMT 2 /* 4.4BSD inode format */
291
292 /*
293 * Preference for optimization.
294 */
295 #define FS_OPTTIME 0 /* minimize allocation time */
296 #define FS_OPTSPACE 1 /* minimize disk fragmentation */
297
298 /*
299 * Filesystem flags.
300 */
301 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */
302 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */
303
304 /*
305 * Rotational layout table format types
306 */
307 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
308 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
309 /*
310 * Macros for access to superblock array structures
311 */
312 #define fs_postbl(fs, cylno) \
313 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
314 ? ((fs)->fs_opostbl[cylno]) \
315 : ((int16_t *)((u_int8_t *)(fs) + \
316 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
317 #define fs_rotbl(fs) \
318 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
319 ? ((fs)->fs_space) \
320 : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
321
322 /*
323 * The size of a cylinder group is calculated by CGSIZE. The maximum size
324 * is limited by the fact that cylinder groups are at most one block.
325 * Its size is derived from the size of the maps maintained in the
326 * cylinder group and the (struct cg) size.
327 */
328 #define CGSIZE(fs) \
329 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
330 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
331 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
332 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
333 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
334 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
335 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
336 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
337
338 /*
339 * Convert cylinder group to base address of its global summary info.
340 */
341 #define fs_cs(fs, indx) fs_csp[indx]
342
343 /*
344 * Cylinder group block for a file system.
345 */
346 #define CG_MAGIC 0x090255
347 struct cg {
348 int32_t cg_firstfield; /* historic cyl groups linked list */
349 int32_t cg_magic; /* magic number */
350 time_t cg_time; /* time last written */
351 int32_t cg_cgx; /* we are the cgx'th cylinder group */
352 int16_t cg_ncyl; /* number of cyl's this cg */
353 int16_t cg_niblk; /* number of inode blocks this cg */
354 int32_t cg_ndblk; /* number of data blocks this cg */
355 struct csum cg_cs; /* cylinder summary information */
356 int32_t cg_rotor; /* position of last used block */
357 int32_t cg_frotor; /* position of last used frag */
358 int32_t cg_irotor; /* position of last used inode */
359 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
360 int32_t cg_btotoff; /* (int32) block totals per cylinder */
361 int32_t cg_boff; /* (u_int16) free block positions */
362 int32_t cg_iusedoff; /* (u_int8) used inode map */
363 int32_t cg_freeoff; /* (u_int8) free block map */
364 int32_t cg_nextfreeoff; /* (u_int8) next available space */
365 int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */
366 int32_t cg_clusteroff; /* (u_int8) free cluster map */
367 int32_t cg_nclusterblks; /* number of clusters this cg */
368 int32_t cg_sparecon[13]; /* reserved for future use */
369 u_int8_t cg_space[1]; /* space for cylinder group maps */
370 /* actually longer */
371 };
372
373 /*
374 * Macros for access to cylinder group array structures
375 */
376 #define cg_blktot(cgp) \
377 (((cgp)->cg_magic != CG_MAGIC) \
378 ? (((struct ocg *)(cgp))->cg_btot) \
379 : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
380 #define cg_blks(fs, cgp, cylno) \
381 (((cgp)->cg_magic != CG_MAGIC) \
382 ? (((struct ocg *)(cgp))->cg_b[cylno]) \
383 : ((int16_t *)((u_int8_t *)(cgp) + \
384 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
385 #define cg_inosused(cgp) \
386 (((cgp)->cg_magic != CG_MAGIC) \
387 ? (((struct ocg *)(cgp))->cg_iused) \
388 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
389 #define cg_blksfree(cgp) \
390 (((cgp)->cg_magic != CG_MAGIC) \
391 ? (((struct ocg *)(cgp))->cg_free) \
392 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff)))
393 #define cg_chkmagic(cgp) \
394 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
395 #define cg_clustersfree(cgp) \
396 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
397 #define cg_clustersum(cgp) \
398 ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
399
400 /*
401 * The following structure is defined
402 * for compatibility with old file systems.
403 */
404 struct ocg {
405 int32_t cg_firstfield; /* historic linked list of cyl groups */
406 int32_t cg_unused_1; /* used for incore cyl groups */
407 time_t cg_time; /* time last written */
408 int32_t cg_cgx; /* we are the cgx'th cylinder group */
409 int16_t cg_ncyl; /* number of cyl's this cg */
410 int16_t cg_niblk; /* number of inode blocks this cg */
411 int32_t cg_ndblk; /* number of data blocks this cg */
412 struct csum cg_cs; /* cylinder summary information */
413 int32_t cg_rotor; /* position of last used block */
414 int32_t cg_frotor; /* position of last used frag */
415 int32_t cg_irotor; /* position of last used inode */
416 int32_t cg_frsum[8]; /* counts of available frags */
417 int32_t cg_btot[32]; /* block totals per cylinder */
418 int16_t cg_b[32][8]; /* positions of free blocks */
419 u_int8_t cg_iused[256]; /* used inode map */
420 int32_t cg_magic; /* magic number */
421 u_int8_t cg_free[1]; /* free block map */
422 /* actually longer */
423 };
424
425 /*
426 * Turn file system block numbers into disk block addresses.
427 * This maps file system blocks to device size blocks.
428 */
429 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
430 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
431
432 /*
433 * Cylinder group macros to locate things in cylinder groups.
434 * They calc file system addresses of cylinder group data structures.
435 */
436 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c)))
437 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
438 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
439 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
440 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
441 #define cgstart(fs, c) \
442 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
443
444 /*
445 * Macros for handling inode numbers:
446 * inode number to file system block offset.
447 * inode number to cylinder group number.
448 * inode number to file system block address.
449 */
450 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
451 #define ino_to_fsba(fs, x) \
452 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
453 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
454 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
455
456 /*
457 * Give cylinder group number for a file system block.
458 * Give cylinder group block number for a file system block.
459 */
460 #define dtog(fs, d) ((d) / (fs)->fs_fpg)
461 #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
462
463 /*
464 * Extract the bits for a block from a map.
465 * Compute the cylinder and rotational position of a cyl block addr.
466 */
467 #define blkmap(fs, map, loc) \
468 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
469 #define cbtocylno(fs, bno) \
470 ((bno) * NSPF(fs) / (fs)->fs_spc)
471 #define cbtorpos(fs, bno) \
472 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
473 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
474 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
475
476 /*
477 * The following macros optimize certain frequently calculated
478 * quantities by using shifts and masks in place of divisions
479 * modulos and multiplications.
480 */
481 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
482 ((loc) & (fs)->fs_qbmask)
483 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
484 ((loc) & (fs)->fs_qfmask)
485 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \
486 ((off_t)(blk) << (fs)->fs_bshift)
487 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */
488 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
489 ((blk) << (fs)->fs_bshift)
490 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
491 ((loc) >> (fs)->fs_bshift)
492 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
493 ((loc) >> (fs)->fs_fshift)
494 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
495 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
496 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
497 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
498 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
499 ((frags) >> (fs)->fs_fragshift)
500 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
501 ((blks) << (fs)->fs_fragshift)
502 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
503 ((fsb) & ((fs)->fs_frag - 1))
504 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
505 ((fsb) &~ ((fs)->fs_frag - 1))
506
507 /*
508 * Determine the number of available frags given a
509 * percentage to hold in reserve.
510 */
511 #define freespace(fs, percentreserved) \
512 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
513 (fs)->fs_cstotal.cs_nffree - \
514 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100))
515
516 /*
517 * Determining the size of a file block in the file system.
518 */
519 #define blksize(fs, ip, lbn) \
520 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
521 ? (fs)->fs_bsize \
522 : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
523 #define dblksize(fs, dip, lbn) \
524 (((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
525 ? (fs)->fs_bsize \
526 : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
527 #define sblksize(fs, size, lbn) \
528 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
529 ? (fs)->fs_bsize \
530 : (fragroundup(fs, blkoff(fs, (size)))))
531
532
533 /*
534 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
535 * sector size.
536 */
537 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
538 #define NSPF(fs) ((fs)->fs_nspf)
539
540 /*
541 * Number of inodes in a secondary storage block/fragment.
542 */
543 #define INOPB(fs) ((fs)->fs_inopb)
544 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
545
546 /*
547 * Number of indirects in a file system block.
548 */
549 #define NINDIR(fs) ((fs)->fs_nindir)
550
551 extern int inside[], around[];
552 extern u_char *fragtbl[];
553
554 #endif
Cache object: 8ed14410a170b9ed8083217dfcc1f06d
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