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29 * @(#)fs.h 8.13 (Berkeley) 3/21/95
30 * %FreeBSD: src/sys/ufs/ffs/fs.h,v 1.14.2.3 2001/09/21 19:15:22 dillon Exp %
34 #ifndef _UFS_FFS_FS_H_
35 #define _UFS_FFS_FS_H_
38 * Each disk drive contains some number of file systems.
39 * A file system consists of a number of cylinder groups.
40 * Each cylinder group has inodes and data.
42 * A file system is described by its super-block, which in turn
43 * describes the cylinder groups. The super-block is critical
44 * data and is replicated in each cylinder group to protect against
45 * catastrophic loss. This is done at `newfs' time and the critical
46 * super-block data does not change, so the copies need not be
47 * referenced further unless disaster strikes.
49 * For file system fs, the offsets of the various blocks of interest
50 * are given in the super block as:
51 * [fs->fs_sblkno] Super-block
52 * [fs->fs_cblkno] Cylinder group block
53 * [fs->fs_iblkno] Inode blocks
54 * [fs->fs_dblkno] Data blocks
55 * The beginning of cylinder group cg in fs, is given by
56 * the ``cgbase(fs, cg)'' macro.
58 * The first boot and super blocks are given in absolute disk addresses.
59 * The byte-offset forms are preferred, as they don't imply a sector size.
63 #define BBOFF ((off_t)(0))
64 #define SBOFF ((off_t)(BBOFF + BBSIZE))
65 #define BBLOCK ((ufs_daddr_t)(0))
66 #define SBLOCK ((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
69 * Addresses stored in inodes are capable of addressing fragments
70 * of `blocks'. File system blocks of at most size MAXBSIZE can
71 * be optionally broken into 2, 4, or 8 pieces, each of which is
72 * addressable; these pieces may be DEV_BSIZE, or some multiple of
75 * Large files consist of exclusively large data blocks. To avoid
76 * undue wasted disk space, the last data block of a small file may be
77 * allocated as only as many fragments of a large block as are
78 * necessary. The file system format retains only a single pointer
79 * to such a fragment, which is a piece of a single large block that
80 * has been divided. The size of such a fragment is determinable from
81 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
83 * The file system records space availability at the fragment level;
84 * to determine block availability, aligned fragments are examined.
88 * MINBSIZE is the smallest allowable block size.
89 * In order to insure that it is possible to create files of size
90 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
91 * MINBSIZE must be big enough to hold a cylinder group block,
92 * thus changes to (struct cg) must keep its size within MINBSIZE.
93 * Note that super blocks are always of size SBSIZE,
94 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
99 * The path name on which the file system is mounted is maintained
100 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
101 * the super block for this name.
103 #define MAXMNTLEN 512
106 * There is a 128-byte region in the superblock reserved for in-core
107 * pointers to summary information. Originally this included an array
108 * of pointers to blocks of struct csum; now there are just three
109 * pointers and the remaining space is padded with fs_ocsp[].
111 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
112 * is taken away to point to a contiguous array of struct csum for
113 * all cylinder groups; a second (fs_maxcluster) points to an array
114 * of cluster sizes that is computed as cylinder groups are inspected,
115 * and the third points to an array that tracks the creation of new
118 #define NOCSPTRS ((128 / sizeof(void *)) - 3)
121 * A summary of contiguous blocks of various sizes is maintained
122 * in each cylinder group. Normally this is set by the initial
123 * value of fs_maxcontig. To conserve space, a maximum summary size
124 * is set by FS_MAXCONTIG.
126 #define FS_MAXCONTIG 16
129 * MINFREE gives the minimum acceptable percentage of file system
130 * blocks which may be free. If the freelist drops below this level
131 * only the superuser may continue to allocate blocks. This may
132 * be set to 0 if no reserve of free blocks is deemed necessary,
133 * however throughput drops by fifty percent if the file system
134 * is run at between 95% and 100% full; thus the minimum default
135 * value of fs_minfree is 5%. However, to get good clustering
136 * performance, 10% is a better choice. hence we use 10% as our
137 * default value. With 10% free space, fragmentation is not a
138 * problem, so we choose to optimize for time.
141 #define DEFAULTOPT FS_OPTTIME
144 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
145 * tune the layout preferences for directories within a filesystem.
146 * His algorithm can be tuned by adjusting the following parameters
147 * which tell the system the average file size and the average number
148 * of files per directory. These defaults are well selected for typical
149 * filesystems, but may need to be tuned for odd cases like filesystems
150 * being used for sqiud caches or news spools.
152 #define AVFILESIZ 16384 /* expected average file size */
153 #define AFPDIR 64 /* expected number of files per directory */
156 * The maximum number of snapshot nodes that can be associated
157 * with each filesystem. This limit affects only the number of
158 * snapshot files that can be recorded within the superblock so
159 * that they can be found when the filesystem is mounted. However,
160 * maintaining too many will slow the filesystem performance, so
161 * having this limit is a good idea.
163 * VALUE NOT IMPLEMENTED IN 4.x YET, RESERVED FROM -CURRENT SO SUPERBLOCKS
169 * Per cylinder group information; summarized in blocks allocated
170 * from first cylinder group data blocks. These blocks have to be
171 * read in from fs_csaddr (size fs_cssize) in addition to the
175 int32_t cs_ndir; /* number of directories */
176 int32_t cs_nbfree; /* number of free blocks */
177 int32_t cs_nifree; /* number of free inodes */
178 int32_t cs_nffree; /* number of free frags */
182 * Super block for an FFS file system.
185 int32_t fs_firstfield; /* historic file system linked list, */
186 int32_t fs_unused_1; /* used for incore super blocks */
187 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
188 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
189 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
190 ufs_daddr_t fs_dblkno; /* offset of first data after cg */
191 int32_t fs_cgoffset; /* cylinder group offset in cylinder */
192 int32_t fs_cgmask; /* used to calc mod fs_ntrak */
193 time_t fs_time; /* last time written */
194 int32_t fs_size; /* number of blocks in fs */
195 int32_t fs_dsize; /* number of data blocks in fs */
196 int32_t fs_ncg; /* number of cylinder groups */
197 int32_t fs_bsize; /* size of basic blocks in fs */
198 int32_t fs_fsize; /* size of frag blocks in fs */
199 int32_t fs_frag; /* number of frags in a block in fs */
200 /* these are configuration parameters */
201 int32_t fs_minfree; /* minimum percentage of free blocks */
202 int32_t fs_rotdelay; /* num of ms for optimal next block */
203 int32_t fs_rps; /* disk revolutions per second */
204 /* these fields can be computed from the others */
205 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
206 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
207 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
208 int32_t fs_fshift; /* ``numfrags'' calc number of frags */
209 /* these are configuration parameters */
210 int32_t fs_maxcontig; /* max number of contiguous blks */
211 int32_t fs_maxbpg; /* max number of blks per cyl group */
212 /* these fields can be computed from the others */
213 int32_t fs_fragshift; /* block to frag shift */
214 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
215 int32_t fs_sbsize; /* actual size of super block */
216 int32_t fs_csmask; /* csum block offset (now unused) */
217 int32_t fs_csshift; /* csum block number (now unused) */
218 int32_t fs_nindir; /* value of NINDIR */
219 int32_t fs_inopb; /* value of INOPB */
220 int32_t fs_nspf; /* value of NSPF */
221 /* yet another configuration parameter */
222 int32_t fs_optim; /* optimization preference, see below */
223 /* these fields are derived from the hardware */
224 int32_t fs_npsect; /* # sectors/track including spares */
225 int32_t fs_interleave; /* hardware sector interleave */
226 int32_t fs_trackskew; /* sector 0 skew, per track */
227 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
228 int32_t fs_id[2]; /* unique filesystem id */
229 /* sizes determined by number of cylinder groups and their sizes */
230 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
231 int32_t fs_cssize; /* size of cyl grp summary area */
232 int32_t fs_cgsize; /* cylinder group size */
233 /* these fields are derived from the hardware */
234 int32_t fs_ntrak; /* tracks per cylinder */
235 int32_t fs_nsect; /* sectors per track */
236 int32_t fs_spc; /* sectors per cylinder */
237 /* this comes from the disk driver partitioning */
238 int32_t fs_ncyl; /* cylinders in file system */
239 /* these fields can be computed from the others */
240 int32_t fs_cpg; /* cylinders per group */
241 int32_t fs_ipg; /* inodes per group */
242 int32_t fs_fpg; /* blocks per group * fs_frag */
243 /* this data must be re-computed after crashes */
244 struct csum fs_cstotal; /* cylinder summary information */
245 /* these fields are cleared at mount time */
246 int8_t fs_fmod; /* super block modified flag */
247 int8_t fs_clean; /* file system is clean flag */
248 int8_t fs_ronly; /* mounted read-only flag */
249 int8_t fs_flags; /* see FS_ flags below */
250 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
251 /* these fields retain the current block allocation info */
252 int32_t fs_cgrotor; /* last cg searched */
253 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
254 u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */
255 struct csum *fs_csp; /* cg summary info buffer for fs_cs */
256 int32_t *fs_maxcluster; /* max cluster in each cyl group */
257 int32_t fs_cpc; /* cyl per cycle in postbl */
258 int16_t fs_opostbl[16][8]; /* old rotation block list head */
259 int32_t fs_snapinum[FSMAXSNAP];/* RESERVED FROM 5.x */
260 int32_t fs_avgfilesize; /* expected average file size */
261 int32_t fs_avgfpdir; /* expected # of files per directory */
262 int32_t fs_sparecon[26]; /* reserved for future constants */
263 int32_t fs_pendingblocks; /* RESERVED FROM 5.x */
264 int32_t fs_pendinginodes; /* RESERVED FROM 5.x */
265 int32_t fs_contigsumsize; /* size of cluster summary array */
266 int32_t fs_maxsymlinklen; /* max length of an internal symlink */
267 int32_t fs_inodefmt; /* format of on-disk inodes */
268 u_int64_t fs_maxfilesize; /* maximum representable file size */
269 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
270 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
271 int32_t fs_state; /* validate fs_clean field */
272 int32_t fs_postblformat; /* format of positional layout tables */
273 int32_t fs_nrpos; /* number of rotational positions */
274 int32_t fs_postbloff; /* (u_int16) rotation block list head */
275 int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */
276 int32_t fs_magic; /* magic number */
277 u_int8_t fs_space[1]; /* list of blocks for each rotation */
278 /* actually longer */
282 * Filesystem identification
284 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
285 #define FS_OKAY 0x7c269d38 /* superblock checksum */
286 #define FS_42INODEFMT -1 /* 4.2BSD inode format */
287 #define FS_44INODEFMT 2 /* 4.4BSD inode format */
290 * Preference for optimization.
292 #define FS_OPTTIME 0 /* minimize allocation time */
293 #define FS_OPTSPACE 1 /* minimize disk fragmentation */
298 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */
299 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */
302 * Rotational layout table format types
304 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
305 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
307 * Macros for access to superblock array structures
309 #define fs_postbl(fs, cylno) \
310 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
311 ? ((fs)->fs_opostbl[cylno]) \
312 : ((int16_t *)((u_int8_t *)(fs) + \
313 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
314 #define fs_rotbl(fs) \
315 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
317 : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
320 * The size of a cylinder group is calculated by CGSIZE. The maximum size
321 * is limited by the fact that cylinder groups are at most one block.
322 * Its size is derived from the size of the maps maintained in the
323 * cylinder group and the (struct cg) size.
326 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
327 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
328 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
329 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
330 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
331 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
332 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
333 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
336 * Convert cylinder group to base address of its global summary info.
338 #define fs_cs(fs, indx) fs_csp[indx]
341 * Cylinder group block for a file system.
343 #define CG_MAGIC 0x090255
345 int32_t cg_firstfield; /* historic cyl groups linked list */
346 int32_t cg_magic; /* magic number */
347 time_t cg_time; /* time last written */
348 int32_t cg_cgx; /* we are the cgx'th cylinder group */
349 int16_t cg_ncyl; /* number of cyl's this cg */
350 int16_t cg_niblk; /* number of inode blocks this cg */
351 int32_t cg_ndblk; /* number of data blocks this cg */
352 struct csum cg_cs; /* cylinder summary information */
353 int32_t cg_rotor; /* position of last used block */
354 int32_t cg_frotor; /* position of last used frag */
355 int32_t cg_irotor; /* position of last used inode */
356 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
357 int32_t cg_btotoff; /* (int32) block totals per cylinder */
358 int32_t cg_boff; /* (u_int16) free block positions */
359 int32_t cg_iusedoff; /* (u_int8) used inode map */
360 int32_t cg_freeoff; /* (u_int8) free block map */
361 int32_t cg_nextfreeoff; /* (u_int8) next available space */
362 int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */
363 int32_t cg_clusteroff; /* (u_int8) free cluster map */
364 int32_t cg_nclusterblks; /* number of clusters this cg */
365 int32_t cg_sparecon[13]; /* reserved for future use */
366 u_int8_t cg_space[1]; /* space for cylinder group maps */
367 /* actually longer */
371 * Macros for access to cylinder group array structures
373 #define cg_blktot(cgp) \
374 (((cgp)->cg_magic != CG_MAGIC) \
375 ? (((struct ocg *)(cgp))->cg_btot) \
376 : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
377 #define cg_blks(fs, cgp, cylno) \
378 (((cgp)->cg_magic != CG_MAGIC) \
379 ? (((struct ocg *)(cgp))->cg_b[cylno]) \
380 : ((int16_t *)((u_int8_t *)(cgp) + \
381 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
382 #define cg_inosused(cgp) \
383 (((cgp)->cg_magic != CG_MAGIC) \
384 ? (((struct ocg *)(cgp))->cg_iused) \
385 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
386 #define cg_blksfree(cgp) \
387 (((cgp)->cg_magic != CG_MAGIC) \
388 ? (((struct ocg *)(cgp))->cg_free) \
389 : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff)))
390 #define cg_chkmagic(cgp) \
391 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
392 #define cg_clustersfree(cgp) \
393 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
394 #define cg_clustersum(cgp) \
395 ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
398 * The following structure is defined
399 * for compatibility with old file systems.
402 int32_t cg_firstfield; /* historic linked list of cyl groups */
403 int32_t cg_unused_1; /* used for incore cyl groups */
404 time_t cg_time; /* time last written */
405 int32_t cg_cgx; /* we are the cgx'th cylinder group */
406 int16_t cg_ncyl; /* number of cyl's this cg */
407 int16_t cg_niblk; /* number of inode blocks this cg */
408 int32_t cg_ndblk; /* number of data blocks this cg */
409 struct csum cg_cs; /* cylinder summary information */
410 int32_t cg_rotor; /* position of last used block */
411 int32_t cg_frotor; /* position of last used frag */
412 int32_t cg_irotor; /* position of last used inode */
413 int32_t cg_frsum[8]; /* counts of available frags */
414 int32_t cg_btot[32]; /* block totals per cylinder */
415 int16_t cg_b[32][8]; /* positions of free blocks */
416 u_int8_t cg_iused[256]; /* used inode map */
417 int32_t cg_magic; /* magic number */
418 u_int8_t cg_free[1]; /* free block map */
419 /* actually longer */
423 * Turn file system block numbers into disk block addresses.
424 * This maps file system blocks to device size blocks.
426 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
427 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
430 * Cylinder group macros to locate things in cylinder groups.
431 * They calc file system addresses of cylinder group data structures.
433 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c)))
434 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
435 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
436 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
437 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
438 #define cgstart(fs, c) \
439 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
442 * Macros for handling inode numbers:
443 * inode number to file system block offset.
444 * inode number to cylinder group number.
445 * inode number to file system block address.
447 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
448 #define ino_to_fsba(fs, x) \
449 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
450 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
451 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
454 * Give cylinder group number for a file system block.
455 * Give cylinder group block number for a file system block.
457 #define dtog(fs, d) ((d) / (fs)->fs_fpg)
458 #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
461 * Extract the bits for a block from a map.
462 * Compute the cylinder and rotational position of a cyl block addr.
464 #define blkmap(fs, map, loc) \
465 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
466 #define cbtocylno(fs, bno) \
467 ((bno) * NSPF(fs) / (fs)->fs_spc)
468 #define cbtorpos(fs, bno) \
469 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
470 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
471 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
474 * The following macros optimize certain frequently calculated
475 * quantities by using shifts and masks in place of divisions
476 * modulos and multiplications.
478 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
479 ((loc) & (fs)->fs_qbmask)
480 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
481 ((loc) & (fs)->fs_qfmask)
482 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \
483 ((off_t)(blk) << (fs)->fs_bshift)
484 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */
485 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
486 ((blk) << (fs)->fs_bshift)
487 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
488 ((loc) >> (fs)->fs_bshift)
489 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
490 ((loc) >> (fs)->fs_fshift)
491 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
492 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
493 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
494 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
495 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
496 ((frags) >> (fs)->fs_fragshift)
497 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
498 ((blks) << (fs)->fs_fragshift)
499 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
500 ((fsb) & ((fs)->fs_frag - 1))
501 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
502 ((fsb) &~ ((fs)->fs_frag - 1))
505 * Determine the number of available frags given a
506 * percentage to hold in reserve.
508 #define freespace(fs, percentreserved) \
509 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
510 (fs)->fs_cstotal.cs_nffree - \
511 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100))
514 * Determining the size of a file block in the file system.
516 #define blksize(fs, ip, lbn) \
517 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
519 : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
520 #define dblksize(fs, dip, lbn) \
521 (((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
523 : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
524 #define sblksize(fs, size, lbn) \
525 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
527 : (fragroundup(fs, blkoff(fs, (size)))))
531 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
534 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
535 #define NSPF(fs) ((fs)->fs_nspf)
538 * Number of inodes in a secondary storage block/fragment.
540 #define INOPB(fs) ((fs)->fs_inopb)
541 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
544 * Number of indirects in a file system block.
546 #define NINDIR(fs) ((fs)->fs_nindir)
548 extern int inside[], around[];
549 extern u_char *fragtbl[];