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: releng/5.0/sys/ufs/ffs/fs.h 107294 2002-11-27 02:18:58Z mckusick $
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 * Depending on the architecture and the media, the superblock may
62 * reside in any one of four places. For tiny media where every block
63 * counts, it is placed at the very front of the partition. Historically,
64 * UFS1 placed it 8K from the front to leave room for the disk label and
65 * a small bootstrap. For UFS2 it got moved to 64K from the front to leave
66 * room for the disk label and a bigger bootstrap, and for really piggy
67 * systems we check at 256K from the front if the first three fail. In
68 * all cases the size of the superblock will be SBLOCKSIZE. All values are
69 * given in byte-offset form, so they do not imply a sector size. The
70 * SBLOCKSEARCH specifies the order in which the locations should be searched.
71 */
72 #define SBLOCK_FLOPPY 0
73 #define SBLOCK_UFS1 8192
74 #define SBLOCK_UFS2 65536
75 #define SBLOCK_PIGGY 262144
76 #define SBLOCKSIZE 8192
77 #define SBLOCKSEARCH \
78 { SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }
79
80 /*
81 * Max number of fragments per block. This value is NOT tweakable.
82 */
83 #define MAXFRAG 8
84
85 /*
86 * Addresses stored in inodes are capable of addressing fragments
87 * of `blocks'. File system blocks of at most size MAXBSIZE can
88 * be optionally broken into 2, 4, or 8 pieces, each of which is
89 * addressable; these pieces may be DEV_BSIZE, or some multiple of
90 * a DEV_BSIZE unit.
91 *
92 * Large files consist of exclusively large data blocks. To avoid
93 * undue wasted disk space, the last data block of a small file may be
94 * allocated as only as many fragments of a large block as are
95 * necessary. The filesystem format retains only a single pointer
96 * to such a fragment, which is a piece of a single large block that
97 * has been divided. The size of such a fragment is determinable from
98 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
99 *
100 * The filesystem records space availability at the fragment level;
101 * to determine block availability, aligned fragments are examined.
102 */
103
104 /*
105 * MINBSIZE is the smallest allowable block size.
106 * In order to insure that it is possible to create files of size
107 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
108 * MINBSIZE must be big enough to hold a cylinder group block,
109 * thus changes to (struct cg) must keep its size within MINBSIZE.
110 * Note that super blocks are always of size SBSIZE,
111 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
112 */
113 #define MINBSIZE 4096
114
115 /*
116 * The path name on which the filesystem is mounted is maintained
117 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
118 * the super block for this name.
119 */
120 #define MAXMNTLEN 512
121
122 /*
123 * There is a 128-byte region in the superblock reserved for in-core
124 * pointers to summary information. Originally this included an array
125 * of pointers to blocks of struct csum; now there are just a few
126 * pointers and the remaining space is padded with fs_ocsp[].
127 *
128 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
129 * is taken away to point to a contiguous array of struct csum for
130 * all cylinder groups; a second (fs_maxcluster) points to an array
131 * of cluster sizes that is computed as cylinder groups are inspected,
132 * and the third points to an array that tracks the creation of new
133 * directories. A fourth pointer, fs_active, is used when creating
134 * snapshots; it points to a bitmap of cylinder groups for which the
135 * free-block bitmap has changed since the snapshot operation began.
136 */
137 #define NOCSPTRS ((128 / sizeof(void *)) - 4)
138
139 /*
140 * A summary of contiguous blocks of various sizes is maintained
141 * in each cylinder group. Normally this is set by the initial
142 * value of fs_maxcontig. To conserve space, a maximum summary size
143 * is set by FS_MAXCONTIG.
144 */
145 #define FS_MAXCONTIG 16
146
147 /*
148 * MINFREE gives the minimum acceptable percentage of filesystem
149 * blocks which may be free. If the freelist drops below this level
150 * only the superuser may continue to allocate blocks. This may
151 * be set to 0 if no reserve of free blocks is deemed necessary,
152 * however throughput drops by fifty percent if the filesystem
153 * is run at between 95% and 100% full; thus the minimum default
154 * value of fs_minfree is 5%. However, to get good clustering
155 * performance, 10% is a better choice. hence we use 10% as our
156 * default value. With 10% free space, fragmentation is not a
157 * problem, so we choose to optimize for time.
158 */
159 #define MINFREE 8
160 #define DEFAULTOPT FS_OPTTIME
161
162 /*
163 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
164 * tune the layout preferences for directories within a filesystem.
165 * His algorithm can be tuned by adjusting the following parameters
166 * which tell the system the average file size and the average number
167 * of files per directory. These defaults are well selected for typical
168 * filesystems, but may need to be tuned for odd cases like filesystems
169 * being used for sqiud caches or news spools.
170 */
171 #define AVFILESIZ 16384 /* expected average file size */
172 #define AFPDIR 64 /* expected number of files per directory */
173
174 /*
175 * The maximum number of snapshot nodes that can be associated
176 * with each filesystem. This limit affects only the number of
177 * snapshot files that can be recorded within the superblock so
178 * that they can be found when the filesystem is mounted. However,
179 * maintaining too many will slow the filesystem performance, so
180 * having this limit is a good idea.
181 */
182 #define FSMAXSNAP 20
183
184 /*
185 * Used to identify special blocks in snapshots:
186 *
187 * BLK_NOCOPY - A block that was unallocated at the time the snapshot
188 * was taken, hence does not need to be copied when written.
189 * BLK_SNAP - A block held by another snapshot that is not needed by this
190 * snapshot. When the other snapshot is freed, the BLK_SNAP entries
191 * are converted to BLK_NOCOPY. These are needed to allow fsck to
192 * identify blocks that are in use by other snapshots (which are
193 * expunged from this snapshot).
194 */
195 #define BLK_NOCOPY ((ufs2_daddr_t)(1))
196 #define BLK_SNAP ((ufs2_daddr_t)(2))
197
198 /*
199 * Sysctl values for the fast filesystem.
200 */
201 #define FFS_ADJ_REFCNT 1 /* adjust inode reference count */
202 #define FFS_ADJ_BLKCNT 2 /* adjust inode used block count */
203 #define FFS_BLK_FREE 3 /* free range of blocks in map */
204 #define FFS_DIR_FREE 4 /* free specified dir inodes in map */
205 #define FFS_FILE_FREE 5 /* free specified file inodes in map */
206 #define FFS_SET_FLAGS 6 /* set filesystem flags */
207 #define FFS_MAXID 7 /* number of valid ffs ids */
208
209 /*
210 * Command structure passed in to the filesystem to adjust filesystem values.
211 */
212 #define FFS_CMD_VERSION 0x19790518 /* version ID */
213 struct fsck_cmd {
214 int32_t version; /* version of command structure */
215 int32_t handle; /* reference to filesystem to be changed */
216 int64_t value; /* inode or block number to be affected */
217 int64_t size; /* amount or range to be adjusted */
218 int64_t spare; /* reserved for future use */
219 };
220
221 /*
222 * Per cylinder group information; summarized in blocks allocated
223 * from first cylinder group data blocks. These blocks have to be
224 * read in from fs_csaddr (size fs_cssize) in addition to the
225 * super block.
226 */
227 struct csum {
228 int32_t cs_ndir; /* number of directories */
229 int32_t cs_nbfree; /* number of free blocks */
230 int32_t cs_nifree; /* number of free inodes */
231 int32_t cs_nffree; /* number of free frags */
232 };
233 struct csum_total {
234 int64_t cs_ndir; /* number of directories */
235 int64_t cs_nbfree; /* number of free blocks */
236 int64_t cs_nifree; /* number of free inodes */
237 int64_t cs_nffree; /* number of free frags */
238 int64_t cs_numclusters; /* number of free clusters */
239 int64_t cs_spare[3]; /* future expansion */
240 };
241
242 /*
243 * Super block for an FFS filesystem.
244 */
245 struct fs {
246 int32_t fs_firstfield; /* historic filesystem linked list, */
247 int32_t fs_unused_1; /* used for incore super blocks */
248 int32_t fs_sblkno; /* offset of super-block in filesys */
249 int32_t fs_cblkno; /* offset of cyl-block in filesys */
250 int32_t fs_iblkno; /* offset of inode-blocks in filesys */
251 int32_t fs_dblkno; /* offset of first data after cg */
252 int32_t fs_old_cgoffset; /* cylinder group offset in cylinder */
253 int32_t fs_old_cgmask; /* used to calc mod fs_ntrak */
254 int32_t fs_old_time; /* last time written */
255 int32_t fs_old_size; /* number of blocks in fs */
256 int32_t fs_old_dsize; /* number of data blocks in fs */
257 int32_t fs_ncg; /* number of cylinder groups */
258 int32_t fs_bsize; /* size of basic blocks in fs */
259 int32_t fs_fsize; /* size of frag blocks in fs */
260 int32_t fs_frag; /* number of frags in a block in fs */
261 /* these are configuration parameters */
262 int32_t fs_minfree; /* minimum percentage of free blocks */
263 int32_t fs_old_rotdelay; /* num of ms for optimal next block */
264 int32_t fs_old_rps; /* disk revolutions per second */
265 /* these fields can be computed from the others */
266 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
267 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
268 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
269 int32_t fs_fshift; /* ``numfrags'' calc number of frags */
270 /* these are configuration parameters */
271 int32_t fs_maxcontig; /* max number of contiguous blks */
272 int32_t fs_maxbpg; /* max number of blks per cyl group */
273 /* these fields can be computed from the others */
274 int32_t fs_fragshift; /* block to frag shift */
275 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
276 int32_t fs_sbsize; /* actual size of super block */
277 int32_t fs_spare1[2]; /* old fs_csmask */
278 /* old fs_csshift */
279 int32_t fs_nindir; /* value of NINDIR */
280 int32_t fs_inopb; /* value of INOPB */
281 int32_t fs_old_nspf; /* value of NSPF */
282 /* yet another configuration parameter */
283 int32_t fs_optim; /* optimization preference, see below */
284 int32_t fs_old_npsect; /* # sectors/track including spares */
285 int32_t fs_old_interleave; /* hardware sector interleave */
286 int32_t fs_old_trackskew; /* sector 0 skew, per track */
287 int32_t fs_id[2]; /* unique filesystem id */
288 /* sizes determined by number of cylinder groups and their sizes */
289 int32_t fs_old_csaddr; /* blk addr of cyl grp summary area */
290 int32_t fs_cssize; /* size of cyl grp summary area */
291 int32_t fs_cgsize; /* cylinder group size */
292 int32_t fs_spare2; /* old fs_ntrak */
293 int32_t fs_old_nsect; /* sectors per track */
294 int32_t fs_old_spc; /* sectors per cylinder */
295 int32_t fs_old_ncyl; /* cylinders in filesystem */
296 int32_t fs_old_cpg; /* cylinders per group */
297 int32_t fs_ipg; /* inodes per group */
298 int32_t fs_fpg; /* blocks per group * fs_frag */
299 /* this data must be re-computed after crashes */
300 struct csum fs_old_cstotal; /* cylinder summary information */
301 /* these fields are cleared at mount time */
302 int8_t fs_fmod; /* super block modified flag */
303 int8_t fs_clean; /* filesystem is clean flag */
304 int8_t fs_ronly; /* mounted read-only flag */
305 int8_t fs_old_flags; /* old FS_ flags */
306 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
307 /* these fields retain the current block allocation info */
308 int32_t fs_cgrotor; /* last cg searched */
309 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
310 u_int8_t *fs_contigdirs; /* # of contiguously allocated dirs */
311 struct csum *fs_csp; /* cg summary info buffer for fs_cs */
312 int32_t *fs_maxcluster; /* max cluster in each cyl group */
313 u_int *fs_active; /* used by snapshots to track fs */
314 int32_t fs_old_cpc; /* cyl per cycle in postbl */
315 int32_t fs_maxbsize; /* maximum blocking factor permitted */
316 int64_t fs_sparecon64[17]; /* old rotation block list head */
317 int64_t fs_sblockloc; /* byte offset of standard superblock */
318 struct csum_total fs_cstotal; /* cylinder summary information */
319 ufs_time_t fs_time; /* last time written */
320 int64_t fs_size; /* number of blocks in fs */
321 int64_t fs_dsize; /* number of data blocks in fs */
322 ufs2_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
323 int64_t fs_pendingblocks; /* blocks in process of being freed */
324 int32_t fs_pendinginodes; /* inodes in process of being freed */
325 int32_t fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
326 int32_t fs_avgfilesize; /* expected average file size */
327 int32_t fs_avgfpdir; /* expected # of files per directory */
328 int32_t fs_save_cgsize; /* save real cg size to use fs_bsize */
329 int32_t fs_sparecon32[26]; /* reserved for future constants */
330 int32_t fs_flags; /* see FS_ flags below */
331 int32_t fs_contigsumsize; /* size of cluster summary array */
332 int32_t fs_maxsymlinklen; /* max length of an internal symlink */
333 int32_t fs_old_inodefmt; /* format of on-disk inodes */
334 u_int64_t fs_maxfilesize; /* maximum representable file size */
335 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
336 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
337 int32_t fs_state; /* validate fs_clean field */
338 int32_t fs_old_postblformat; /* format of positional layout tables */
339 int32_t fs_old_nrpos; /* number of rotational positions */
340 int32_t fs_spare5[2]; /* old fs_postbloff */
341 /* old fs_rotbloff */
342 int32_t fs_magic; /* magic number */
343 };
344
345 /*
346 * Filesystem identification
347 */
348 #define FS_UFS1_MAGIC 0x011954 /* UFS1 fast filesystem magic number */
349 #define FS_UFS2_MAGIC 0x19540119 /* UFS2 fast filesystem magic number */
350 #define FS_OKAY 0x7c269d38 /* superblock checksum */
351 #define FS_42INODEFMT -1 /* 4.2BSD inode format */
352 #define FS_44INODEFMT 2 /* 4.4BSD inode format */
353
354 /*
355 * Preference for optimization.
356 */
357 #define FS_OPTTIME 0 /* minimize allocation time */
358 #define FS_OPTSPACE 1 /* minimize disk fragmentation */
359
360 /*
361 * Filesystem flags.
362 *
363 * The FS_UNCLEAN flag is set by the kernel when the filesystem was
364 * mounted with fs_clean set to zero. The FS_DOSOFTDEP flag indicates
365 * that the filesystem should be managed by the soft updates code.
366 * Note that the FS_NEEDSFSCK flag is set and cleared only by the
367 * fsck utility. It is set when background fsck finds an unexpected
368 * inconsistency which requires a traditional foreground fsck to be
369 * run. Such inconsistencies should only be found after an uncorrectable
370 * disk error. A foreground fsck will clear the FS_NEEDSFSCK flag when
371 * it has successfully cleaned up the filesystem. The kernel uses this
372 * flag to enforce that inconsistent filesystems be mounted read-only.
373 * The FS_INDEXDIRS flag when set indicates that the kernel maintains
374 * on-disk auxiliary indexes (such as B-trees) for speeding directory
375 * accesses. Kernels that do not support auxiliary indicies clear the
376 * flag to indicate that the indicies need to be rebuilt (by fsck) before
377 * they can be used.
378 *
379 * FS_ACLS indicates that ACLs are administratively enabled for the
380 * file system, so they should be loaded from extended attributes,
381 * observed for access control purposes, and be administered by object
382 * owners. FS_MULTILABEL indicates that the TrustedBSD MAC Framework
383 * should attempt to back MAC labels into extended attributes on the
384 * file system rather than maintain a single mount label for all
385 * objects.
386 */
387 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */
388 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */
389 #define FS_NEEDSFSCK 0x04 /* filesystem needs sync fsck before mount */
390 #define FS_INDEXDIRS 0x08 /* kernel supports indexed directories */
391 #define FS_ACLS 0x10 /* file system has ACLs enabled */
392 #define FS_MULTILABEL 0x20 /* file system is MAC multi-label */
393 #define FS_FLAGS_UPDATED 0x80 /* flags have been moved to new location */
394
395 /*
396 * Macros to access bits in the fs_active array.
397 */
398 #define ACTIVECGNUM(fs, cg) ((fs)->fs_active[(cg) / (NBBY * sizeof(int))])
399 #define ACTIVECGOFF(cg) (1 << ((cg) % (NBBY * sizeof(int))))
400
401 /*
402 * The size of a cylinder group is calculated by CGSIZE. The maximum size
403 * is limited by the fact that cylinder groups are at most one block.
404 * Its size is derived from the size of the maps maintained in the
405 * cylinder group and the (struct cg) size.
406 */
407 #define CGSIZE(fs) \
408 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
409 /* old btotoff */ (fs)->fs_old_cpg * sizeof(int32_t) + \
410 /* old boff */ (fs)->fs_old_cpg * sizeof(u_int16_t) + \
411 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
412 /* block map */ howmany((fs)->fs_fpg, NBBY) +\
413 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
414 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
415 /* cluster map */ howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY)))
416
417 /*
418 * The minimal number of cylinder groups that should be created.
419 */
420 #define MINCYLGRPS 4
421
422 /*
423 * Convert cylinder group to base address of its global summary info.
424 */
425 #define fs_cs(fs, indx) fs_csp[indx]
426
427 /*
428 * Cylinder group block for a filesystem.
429 */
430 #define CG_MAGIC 0x090255
431 struct cg {
432 int32_t cg_firstfield; /* historic cyl groups linked list */
433 int32_t cg_magic; /* magic number */
434 int32_t cg_old_time; /* time last written */
435 int32_t cg_cgx; /* we are the cgx'th cylinder group */
436 int16_t cg_old_ncyl; /* number of cyl's this cg */
437 int16_t cg_old_niblk; /* number of inode blocks this cg */
438 int32_t cg_ndblk; /* number of data blocks this cg */
439 struct csum cg_cs; /* cylinder summary information */
440 int32_t cg_rotor; /* position of last used block */
441 int32_t cg_frotor; /* position of last used frag */
442 int32_t cg_irotor; /* position of last used inode */
443 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
444 int32_t cg_old_btotoff; /* (int32) block totals per cylinder */
445 int32_t cg_old_boff; /* (u_int16) free block positions */
446 int32_t cg_iusedoff; /* (u_int8) used inode map */
447 int32_t cg_freeoff; /* (u_int8) free block map */
448 int32_t cg_nextfreeoff; /* (u_int8) next available space */
449 int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */
450 int32_t cg_clusteroff; /* (u_int8) free cluster map */
451 int32_t cg_nclusterblks; /* number of clusters this cg */
452 int32_t cg_niblk; /* number of inode blocks this cg */
453 int32_t cg_initediblk; /* last initialized inode */
454 int32_t cg_sparecon32[3]; /* reserved for future use */
455 ufs_time_t cg_time; /* time last written */
456 int64_t cg_sparecon64[3]; /* reserved for future use */
457 u_int8_t cg_space[1]; /* space for cylinder group maps */
458 /* actually longer */
459 };
460
461 /*
462 * Macros for access to cylinder group array structures
463 */
464 #define cg_chkmagic(cgp) ((cgp)->cg_magic == CG_MAGIC)
465 #define cg_inosused(cgp) \
466 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))
467 #define cg_blksfree(cgp) \
468 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))
469 #define cg_clustersfree(cgp) \
470 ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
471 #define cg_clustersum(cgp) \
472 ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
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) ((ufs2_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 ((fs)->fs_magic == FS_UFS2_MAGIC ? cgbase(fs, c) : \
492 (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask))))
493
494 /*
495 * Macros for handling inode numbers:
496 * inode number to filesystem block offset.
497 * inode number to cylinder group number.
498 * inode number to filesystem block address.
499 */
500 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
501 #define ino_to_fsba(fs, x) \
502 ((ufs2_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
503 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
504 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
505
506 /*
507 * Give cylinder group number for a filesystem block.
508 * Give cylinder group block number for a filesystem block.
509 */
510 #define dtog(fs, d) ((d) / (fs)->fs_fpg)
511 #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
512
513 /*
514 * Extract the bits for a block from a map.
515 * Compute the cylinder and rotational position of a cyl block addr.
516 */
517 #define blkmap(fs, map, loc) \
518 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
519
520 /*
521 * The following macros optimize certain frequently calculated
522 * quantities by using shifts and masks in place of divisions
523 * modulos and multiplications.
524 */
525 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
526 ((loc) & (fs)->fs_qbmask)
527 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
528 ((loc) & (fs)->fs_qfmask)
529 #define lfragtosize(fs, frag) /* calculates ((off_t)frag * fs->fs_fsize) */ \
530 ((off_t)(frag) << (fs)->fs_fshift)
531 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \
532 ((off_t)(blk) << (fs)->fs_bshift)
533 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */
534 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
535 ((blk) << (fs)->fs_bshift)
536 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
537 ((loc) >> (fs)->fs_bshift)
538 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
539 ((loc) >> (fs)->fs_fshift)
540 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
541 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
542 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
543 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
544 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
545 ((frags) >> (fs)->fs_fragshift)
546 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
547 ((blks) << (fs)->fs_fragshift)
548 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
549 ((fsb) & ((fs)->fs_frag - 1))
550 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
551 ((fsb) &~ ((fs)->fs_frag - 1))
552
553 /*
554 * Determine the number of available frags given a
555 * percentage to hold in reserve.
556 */
557 #define freespace(fs, percentreserved) \
558 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
559 (fs)->fs_cstotal.cs_nffree - \
560 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100))
561
562 /*
563 * Determining the size of a file block in the filesystem.
564 */
565 #define blksize(fs, ip, lbn) \
566 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
567 ? (fs)->fs_bsize \
568 : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
569 #define sblksize(fs, size, lbn) \
570 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
571 ? (fs)->fs_bsize \
572 : (fragroundup(fs, blkoff(fs, (size)))))
573
574
575 /*
576 * Number of inodes in a secondary storage block/fragment.
577 */
578 #define INOPB(fs) ((fs)->fs_inopb)
579 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
580
581 /*
582 * Number of indirects in a filesystem block.
583 */
584 #define NINDIR(fs) ((fs)->fs_nindir)
585
586 extern int inside[], around[];
587 extern u_char *fragtbl[];
588
589 #endif
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