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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 $
33 #ifndef _VFS_UFS_FS_H_
34 #define _VFS_UFS_FS_H_
37 * Each disk drive contains some number of filesystems.
38 * A filesystem consists of a number of cylinder groups.
39 * Each cylinder group has inodes and data.
41 * A filesystem is described by its super-block, which in turn
42 * describes the cylinder groups. The super-block is critical
43 * data and is replicated in each cylinder group to protect against
44 * catastrophic loss. This is done at `newfs' time and the critical
45 * super-block data does not change, so the copies need not be
46 * referenced further unless disaster strikes.
48 * For filesystem fs, the offsets of the various blocks of interest
49 * are given in the super block as:
50 * [fs->fs_sblkno] Super-block
51 * [fs->fs_cblkno] Cylinder group block
52 * [fs->fs_iblkno] Inode blocks
53 * [fs->fs_dblkno] Data blocks
54 * The beginning of cylinder group cg in fs, is given by
55 * the ``cgbase(fs, cg)'' macro.
57 * The first boot and super blocks are given in absolute disk addresses.
58 * The byte-offset forms are preferred, as they don't imply a sector size.
62 #define BBOFF ((off_t)(0))
63 #define SBOFF ((off_t)(BBOFF + BBSIZE))
64 #define BBLOCK ((ufs_daddr_t)(0))
67 * Addresses stored in inodes are capable of addressing fragments
68 * of `blocks'. Filesystem blocks of at most size MAXBSIZE can
69 * be optionally broken into 2, 4, or 8 pieces, each of which is
70 * addressable; these pieces may be DEV_BSIZE, or some multiple of
73 * Large files consist of exclusively large data blocks. To avoid
74 * undue wasted disk space, the last data block of a small file may be
75 * allocated as only as many fragments of a large block as are
76 * necessary. The filesystem format retains only a single pointer
77 * to such a fragment, which is a piece of a single large block that
78 * has been divided. The size of such a fragment is determinable from
79 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
81 * The filesystem records space availability at the fragment level;
82 * to determine block availability, aligned fragments are examined.
86 * MINBSIZE is the smallest allowable block size.
87 * In order to insure that it is possible to create files of size
88 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
89 * MINBSIZE must be big enough to hold a cylinder group block,
90 * thus changes to (struct cg) must keep its size within MINBSIZE.
91 * Note that super blocks are always of size SBSIZE,
92 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
97 * The path name on which the filesystem is mounted is maintained
98 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
99 * the super block for this name.
101 #define MAXMNTLEN 468
104 * The volume name for this filesystem is maintained in fs_volname.
105 * MAXVOLLEN defines the length of the buffer allocated.
110 * There is a 128-byte region in the superblock reserved for in-core
111 * pointers to summary information. Originally this included an array
112 * of pointers to blocks of struct csum; now there are just three
113 * pointers and the remaining space is padded with fs_ocsp[].
115 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
116 * is taken away to point to a contiguous array of struct csum for
117 * all cylinder groups; a second (fs_maxcluster) points to an array
118 * of cluster sizes that is computed as cylinder groups are inspected,
119 * and the third points to an array that tracks the creation of new
122 #define NOCSPTRS ((128 / sizeof(void *)) - 3)
125 * A summary of contiguous blocks of various sizes is maintained
126 * in each cylinder group. Normally this is set by the initial
127 * value of fs_maxcontig. To conserve space, a maximum summary size
128 * is set by FS_MAXCONTIG.
130 #define FS_MAXCONTIG 16
133 * MINFREE gives the minimum acceptable percentage of filesystem
134 * blocks which may be free. If the freelist drops below this level
135 * only the superuser may continue to allocate blocks. This may
136 * be set to 0 if no reserve of free blocks is deemed necessary,
137 * however throughput drops by fifty percent if the filesystem
138 * is run at between 95% and 100% full; thus the minimum default
139 * value of fs_minfree is 5%. However, to get good clustering
140 * performance, 10% is a better choice. hence we use 10% as our
141 * default value. With 10% free space, fragmentation is not a
142 * problem, so we choose to optimize for time.
145 #define DEFAULTOPT FS_OPTTIME
148 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
149 * tune the layout preferences for directories within a filesystem.
150 * His algorithm can be tuned by adjusting the following parameters
151 * which tell the system the average file size and the average number
152 * of files per directory. These defaults are well selected for typical
153 * filesystems, but may need to be tuned for odd cases like filesystems
154 * being used for squid caches or news spools.
156 #define AVFILESIZ 16384 /* expected average file size */
157 #define AFPDIR 64 /* expected number of files per directory */
160 * The maximum number of snapshot nodes that can be associated
161 * with each filesystem. This limit affects only the number of
162 * snapshot files that can be recorded within the superblock so
163 * that they can be found when the filesystem is mounted. However,
164 * maintaining too many will slow the filesystem performance, so
165 * having this limit is a good idea.
167 * VALUE NOT IMPLEMENTED IN DragonFly(and very unlikely to ever be as there are
168 * much better options such as journaling), RESERVED FROM FreeBSD 5.x SO
169 * SUPERBLOCKS REMAIN COMPATIBLE FOR THE TIME BEING. WHY ARE WE YELLING ?
174 * Per cylinder group information; summarized in blocks allocated
175 * from first cylinder group data blocks. These blocks have to be
176 * read in from fs_csaddr (size fs_cssize) in addition to the
180 int32_t cs_ndir; /* number of directories */
181 int32_t cs_nbfree; /* number of free blocks */
182 int32_t cs_nifree; /* number of free inodes */
183 int32_t cs_nffree; /* number of free frags */
187 * Super block for an FFS filesystem.
190 int32_t fs_firstfield; /* historic filesystem linked list, */
191 int32_t fs_unused_1; /* used for incore super blocks */
192 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
193 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
194 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
195 ufs_daddr_t fs_dblkno; /* offset of first data after cg */
196 int32_t fs_cgoffset; /* cylinder group offset in cylinder */
197 int32_t fs_cgmask; /* used to calc mod fs_ntrak */
198 ufs_time_t fs_time; /* last time written */
199 int32_t fs_size; /* number of blocks in fs */
200 int32_t fs_dsize; /* number of data blocks in fs */
201 int32_t fs_ncg; /* number of cylinder groups */
202 int32_t fs_bsize; /* size of basic blocks in fs */
203 int32_t fs_fsize; /* size of frag blocks in fs */
204 int32_t fs_frag; /* number of frags in a block in fs */
205 /* these are configuration parameters */
206 int32_t fs_minfree; /* minimum percentage of free blocks */
207 int32_t fs_rotdelay; /* num of ms for optimal next block */
208 int32_t fs_rps; /* disk revolutions per second */
209 /* these fields can be computed from the others */
210 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
211 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
212 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
213 int32_t fs_fshift; /* ``numfrags'' calc number of frags */
214 /* these are configuration parameters */
215 int32_t fs_maxcontig; /* max number of contiguous blks */
216 int32_t fs_maxbpg; /* max number of blks per cyl group */
217 /* these fields can be computed from the others */
218 int32_t fs_fragshift; /* block to frag shift */
219 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
220 int32_t fs_sbsize; /* actual size of super block */
221 int32_t fs_csmask; /* csum block offset (now unused) */
222 int32_t fs_csshift; /* csum block number (now unused) */
223 int32_t fs_nindir; /* value of NINDIR */
224 int32_t fs_inopb; /* value of INOPB */
225 int32_t fs_nspf; /* value of NSPF */
226 /* yet another configuration parameter */
227 int32_t fs_optim; /* optimization preference, see below */
228 /* these fields are derived from the hardware */
229 int32_t fs_npsect; /* # sectors/track including spares */
230 int32_t fs_interleave; /* hardware sector interleave */
231 int32_t fs_trackskew; /* sector 0 skew, per track */
232 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
233 int32_t fs_id[2]; /* unique filesystem id */
234 /* sizes determined by number of cylinder groups and their sizes */
235 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
236 int32_t fs_cssize; /* size of cyl grp summary area */
237 int32_t fs_cgsize; /* cylinder group size */
238 /* these fields are derived from the hardware */
239 int32_t fs_ntrak; /* tracks per cylinder */
240 int32_t fs_nsect; /* sectors per track */
241 int32_t fs_spc; /* sectors per cylinder */
242 /* this comes from the disk driver partitioning */
243 int32_t fs_ncyl; /* cylinders in filesystem */
244 /* these fields can be computed from the others */
245 int32_t fs_cpg; /* cylinders per group */
246 int32_t fs_ipg; /* inodes per group */
247 int32_t fs_fpg; /* blocks per group * fs_frag */
248 /* this data must be re-computed after crashes */
249 struct csum fs_cstotal; /* cylinder summary information */
250 /* these fields are cleared at mount time */
251 int8_t fs_fmod; /* super block modified flag */
252 int8_t fs_clean; /* filesystem is clean flag */
253 int8_t fs_ronly; /* mounted read-only flag */
254 int8_t fs_flags; /* see FS_ flags below */
255 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
256 u_char fs_volname[MAXVOLLEN]; /* volume name */
257 u_int64_t fs_swuid; /* system-wide uid */
258 int32_t fs_pad; /* due to alignment of fs_swuid */
259 /* these fields retain the current block allocation info */
260 int32_t fs_cgrotor; /* last cg searched */
261 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
262 uint8_t *fs_contigdirs; /* # of contiguously allocated dirs */
263 struct csum *fs_csp; /* cg summary info buffer for fs_cs */
264 int32_t *fs_maxcluster; /* max cluster in each cyl group */
265 int32_t fs_cpc; /* cyl per cycle in postbl */
266 int16_t fs_opostbl[16][8]; /* old rotation block list head */
267 int32_t fs_snapinum[FSMAXSNAP];/* RESERVED FROM 5.x */
268 int32_t fs_avgfilesize; /* expected average file size */
269 int32_t fs_avgfpdir; /* expected # of files per directory */
270 int32_t fs_sparecon[26]; /* reserved for future constants */
271 int32_t fs_pendingblocks; /* RESERVED FROM 5.x */
272 int32_t fs_pendinginodes; /* RESERVED FROM 5.x */
273 int32_t fs_contigsumsize; /* size of cluster summary array */
274 int32_t fs_maxsymlinklen; /* max length of an internal symlink */
275 int32_t fs_inodefmt; /* format of on-disk inodes */
276 uint64_t fs_maxfilesize; /* maximum representable file size */
277 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
278 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
279 int32_t fs_state; /* validate fs_clean field */
280 int32_t fs_postblformat; /* format of positional layout tables */
281 int32_t fs_nrpos; /* number of rotational positions */
282 int32_t fs_postbloff; /* (uint16) rotation block list head */
283 int32_t fs_rotbloff; /* (uint8) blocks for each rotation */
284 int32_t fs_magic; /* magic number */
285 uint8_t fs_space[1]; /* list of blocks for each rotation */
286 /* actually longer */
290 * Filesystem identification
292 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
293 #define FS_OKAY 0x7c269d38 /* superblock checksum */
294 #define FS_42INODEFMT -1 /* 4.2BSD inode format */
295 #define FS_44INODEFMT 2 /* 4.4BSD inode format */
298 * Preference for optimization.
300 #define FS_OPTTIME 0 /* minimize allocation time */
301 #define FS_OPTSPACE 1 /* minimize disk fragmentation */
306 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */
307 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */
310 * Rotational layout table format types
312 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
313 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
315 * Macros for access to superblock array structures
317 #define fs_postbl(fs, cylno) \
318 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
319 ? ((fs)->fs_opostbl[cylno]) \
320 : ((int16_t *)((uint8_t *)(fs) + \
321 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
322 #define fs_rotbl(fs) \
323 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
325 : ((uint8_t *)((uint8_t *)(fs) + (fs)->fs_rotbloff)))
328 * The size of a cylinder group is calculated by CGSIZE. The maximum size
329 * is limited by the fact that cylinder groups are at most one block.
330 * Its size is derived from the size of the maps maintained in the
331 * cylinder group and the (struct cg) size.
334 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
335 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
336 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
337 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
338 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
339 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
340 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
341 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
344 * Convert cylinder group to base address of its global summary info.
346 #define fs_cs(fs, indx) fs_csp[indx]
349 * Cylinder group block for a filesystem.
351 #define CG_MAGIC 0x090255
353 int32_t cg_firstfield; /* historic cyl groups linked list */
354 int32_t cg_magic; /* magic number */
355 ufs_time_t cg_time; /* time last written */
356 int32_t cg_cgx; /* we are the cgx'th cylinder group */
357 int16_t cg_ncyl; /* number of cyl's this cg */
358 int16_t cg_niblk; /* number of inode blocks this cg */
359 int32_t cg_ndblk; /* number of data blocks this cg */
360 struct csum cg_cs; /* cylinder summary information */
361 int32_t cg_rotor; /* position of last used block */
362 int32_t cg_frotor; /* position of last used frag */
363 int32_t cg_irotor; /* position of last used inode */
364 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
365 int32_t cg_btotoff; /* (int32) block totals per cylinder */
366 int32_t cg_boff; /* (uint16) free block positions */
367 int32_t cg_iusedoff; /* (uint8) used inode map */
368 int32_t cg_freeoff; /* (uint8) free block map */
369 int32_t cg_nextfreeoff; /* (uint8) next available space */
370 int32_t cg_clustersumoff; /* (uint32) counts of avail clusters */
371 int32_t cg_clusteroff; /* (uint8) free cluster map */
372 int32_t cg_nclusterblks; /* number of clusters this cg */
373 int32_t cg_sparecon[13]; /* reserved for future use */
374 uint8_t cg_space[1]; /* space for cylinder group maps */
375 /* actually longer */
379 * Macros for access to cylinder group array structures
381 #define cg_blktot(cgp) \
382 (((cgp)->cg_magic != CG_MAGIC) \
383 ? (((struct ocg *)(cgp))->cg_btot) \
384 : ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_btotoff)))
385 #define cg_blks(fs, cgp, cylno) \
386 (((cgp)->cg_magic != CG_MAGIC) \
387 ? (((struct ocg *)(cgp))->cg_b[cylno]) \
388 : ((int16_t *)((uint8_t *)(cgp) + \
389 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
390 #define cg_inosused(cgp) \
391 (((cgp)->cg_magic != CG_MAGIC) \
392 ? (((struct ocg *)(cgp))->cg_iused) \
393 : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_iusedoff)))
394 #define cg_blksfree(cgp) \
395 (((cgp)->cg_magic != CG_MAGIC) \
396 ? (((struct ocg *)(cgp))->cg_free) \
397 : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_freeoff)))
398 #define cg_chkmagic(cgp) \
399 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
400 #define cg_clustersfree(cgp) \
401 ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_clusteroff))
402 #define cg_clustersum(cgp) \
403 ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_clustersumoff))
406 * The following structure is defined
407 * for compatibility with old filesystems.
410 int32_t cg_firstfield; /* historic linked list of cyl groups */
411 int32_t cg_unused_1; /* used for incore cyl groups */
412 ufs_time_t cg_time; /* time last written */
413 int32_t cg_cgx; /* we are the cgx'th cylinder group */
414 int16_t cg_ncyl; /* number of cyl's this cg */
415 int16_t cg_niblk; /* number of inode blocks this cg */
416 int32_t cg_ndblk; /* number of data blocks this cg */
417 struct csum cg_cs; /* cylinder summary information */
418 int32_t cg_rotor; /* position of last used block */
419 int32_t cg_frotor; /* position of last used frag */
420 int32_t cg_irotor; /* position of last used inode */
421 int32_t cg_frsum[8]; /* counts of available frags */
422 int32_t cg_btot[32]; /* block totals per cylinder */
423 int16_t cg_b[32][8]; /* positions of free blocks */
424 uint8_t cg_iused[256]; /* used inode map */
425 int32_t cg_magic; /* magic number */
426 uint8_t cg_free[1]; /* free block map */
427 /* actually longer */
431 * Turn filesystem block numbers into disk block addresses.
432 * This maps filesystem blocks to device size blocks.
434 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
435 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
436 #define btofsb(fs, b) ((daddr_t)((b) >> ((fs)->fs_fsbtodb + DEV_BSHIFT)))
439 * Cylinder group macros to locate things in cylinder groups.
440 * They calc filesystem addresses of cylinder group data structures.
442 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c)))
443 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
444 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
445 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
446 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
447 #define cgstart(fs, c) \
448 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
451 * Macros for handling inode numbers:
452 * inode number to filesystem block offset.
453 * inode number to cylinder group number.
454 * inode number to filesystem block address.
456 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
457 #define ino_to_fsba(fs, x) \
458 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
459 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
460 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
463 * Give cylinder group number for a filesystem block.
464 * Give cylinder group block number for a filesystem block.
466 #define dtog(fs, d) ((d) / (fs)->fs_fpg)
467 #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
470 * Extract the bits for a block from a map.
471 * Compute the cylinder and rotational position of a cyl block addr.
473 #define blkmap(fs, map, loc) \
474 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
475 #define cbtocylno(fs, bno) \
476 ((bno) * NSPF(fs) / (fs)->fs_spc)
477 #define cbtorpos(fs, bno) \
478 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
479 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
480 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
483 * The following macros optimize certain frequently calculated
484 * quantities by using shifts and masks in place of divisions
485 * modulos and multiplications.
487 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
488 ((loc) & (fs)->fs_qbmask)
489 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
490 ((loc) & (fs)->fs_qfmask)
491 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \
492 ((off_t)(blk) << (fs)->fs_bshift)
494 * These functions convert filesystem logical block numbers (typ 8K),
495 * filesystem block numbers (typ 1K), and disk block numbers to 64 bit
496 * offsets for the purposes of bread(), getblk(), etc.
498 * note: fs_nspf = number of sectors per fragment. For some reason
499 * completely lost to me the superblock doesn't actually store the disk
502 #define lblktodoff(fs, blk) ((off_t)(blk) << (fs)->fs_bshift)
503 #define fsbtodoff(fs, b) ((off_t)(b) << (fs)->fs_fshift)
504 #define dbtodoff(fs, b) ((off_t)(b) * ((fs)->fs_fsize / (fs)->fs_nspf))
505 #define dofftofsb(fs, b) ((ufs_daddr_t)((b) >> (fs)->fs_fshift))
507 /* Use this only when `blk' is known to be small, e.g., < UFS_NDADDR. */
508 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
509 ((blk) << (fs)->fs_bshift)
510 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
511 ((loc) >> (fs)->fs_bshift)
512 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
513 ((loc) >> (fs)->fs_fshift)
514 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
515 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
516 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
517 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
518 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
519 ((frags) >> (fs)->fs_fragshift)
520 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
521 ((blks) << (fs)->fs_fragshift)
522 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
523 ((fsb) & ((fs)->fs_frag - 1))
524 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
525 ((fsb) &~ ((fs)->fs_frag - 1))
528 * Determine the number of available frags given a
529 * percentage to hold in reserve.
531 #define freespace(fs, percentreserved) \
532 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
533 (fs)->fs_cstotal.cs_nffree - \
534 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100))
537 * Determining the size of a file block in the filesystem.
539 #define blksize(fs, ip, lbn) \
540 (((lbn) >= UFS_NDADDR || \
541 (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
543 : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
544 #define dblksize(fs, dip, lbn) \
545 (((lbn) >= UFS_NDADDR || \
546 (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
548 : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
549 #define sblksize(fs, size, lbn) \
550 (((lbn) >= UFS_NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
552 : (fragroundup(fs, blkoff(fs, (size)))))
555 * Extract the block size for the buffer cache buffer at offset (loc)
556 * relative to the current ip->i_size, or relative to a specific ip->i_size.
558 #define blkoffsize(fs, ip, loc) blksize(fs, ip, lblkno(fs, loc))
559 #define blkoffresize(fs, loc) sblksize(fs, loc, lblkno(fs, loc))
562 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
565 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
566 #define NSPF(fs) ((fs)->fs_nspf)
569 * Number of inodes in a secondary storage block/fragment.
571 #define INOPB(fs) ((fs)->fs_inopb)
572 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
575 * Number of indirects in a filesystem block.
577 #define NINDIR(fs) ((fs)->fs_nindir)
579 extern int inside[], around[];
580 extern u_char *fragtbl[];
582 #endif /* !_VFS_UFS_FS_H_ */