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1.1 root 1: /*
2: * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
7: * Reserved. This file contains Original Code and/or Modifications of
8: * Original Code as defined in and that are subject to the Apple Public
9: * Source License Version 1.1 (the "License"). You may not use this file
10: * except in compliance with the License. Please obtain a copy of the
11: * License at http://www.apple.com/publicsource and read it before using
12: * this file.
13: *
14: * The Original Code and all software distributed under the License are
15: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
19: * License for the specific language governing rights and limitations
20: * under the License.
21: *
22: * @APPLE_LICENSE_HEADER_END@
23: */
24:
25: /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
26: /*
27: * Copyright (c) 1982, 1986, 1993
28: * The Regents of the University of California. All rights reserved.
29: *
30: * Redistribution and use in source and binary forms, with or without
31: * modification, are permitted provided that the following conditions
32: * are met:
33: * 1. Redistributions of source code must retain the above copyright
34: * notice, this list of conditions and the following disclaimer.
35: * 2. Redistributions in binary form must reproduce the above copyright
36: * notice, this list of conditions and the following disclaimer in the
37: * documentation and/or other materials provided with the distribution.
38: * 3. All advertising materials mentioning features or use of this software
39: * must display the following acknowledgement:
40: * This product includes software developed by the University of
41: * California, Berkeley and its contributors.
42: * 4. Neither the name of the University nor the names of its contributors
43: * may be used to endorse or promote products derived from this software
44: * without specific prior written permission.
45: *
46: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
47: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
50: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56: * SUCH DAMAGE.
57: *
58: * @(#)fs.h 8.13 (Berkeley) 3/21/95
59: */
60:
61: /*
62: * Each disk drive contains some number of file systems.
63: * A file system consists of a number of cylinder groups.
64: * Each cylinder group has inodes and data.
65: *
66: * A file system is described by its super-block, which in turn
67: * describes the cylinder groups. The super-block is critical
68: * data and is replicated in each cylinder group to protect against
69: * catastrophic loss. This is done at `newfs' time and the critical
70: * super-block data does not change, so the copies need not be
71: * referenced further unless disaster strikes.
72: *
73: * For file system fs, the offsets of the various blocks of interest
74: * are given in the super block as:
75: * [fs->fs_sblkno] Super-block
76: * [fs->fs_cblkno] Cylinder group block
77: * [fs->fs_iblkno] Inode blocks
78: * [fs->fs_dblkno] Data blocks
79: * The beginning of cylinder group cg in fs, is given by
80: * the ``cgbase(fs, cg)'' macro.
81: *
82: * The first boot and super blocks are given in absolute disk addresses.
83: * The byte-offset forms are preferred, as they don't imply a sector size.
84: */
85: #define BBSIZE 8192
86: #define SBSIZE 8192
87: #define BBOFF ((off_t)(0))
88: #define SBOFF ((off_t)(BBOFF + BBSIZE))
89: #define BBLOCK ((ufs_daddr_t)(0))
90: #define SBLOCK ((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
91:
92: /*
93: * Addresses stored in inodes are capable of addressing fragments
94: * of `blocks'. File system blocks of at most size MAXBSIZE can
95: * be optionally broken into 2, 4, or 8 pieces, each of which is
96: * addressible; these pieces may be DEV_BSIZE, or some multiple of
97: * a DEV_BSIZE unit.
98: *
99: * Large files consist of exclusively large data blocks. To avoid
100: * undue wasted disk space, the last data block of a small file may be
101: * allocated as only as many fragments of a large block as are
102: * necessary. The file system format retains only a single pointer
103: * to such a fragment, which is a piece of a single large block that
104: * has been divided. The size of such a fragment is determinable from
105: * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
106: *
107: * The file system records space availability at the fragment level;
108: * to determine block availability, aligned fragments are examined.
109: */
110:
111: /*
112: * MINBSIZE is the smallest allowable block size.
113: * In order to insure that it is possible to create files of size
114: * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
115: * MINBSIZE must be big enough to hold a cylinder group block,
116: * thus changes to (struct cg) must keep its size within MINBSIZE.
117: * Note that super blocks are always of size SBSIZE,
118: * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
119: */
120: #define MINBSIZE 4096
121:
122: /*
123: * The path name on which the file system is mounted is maintained
124: * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
125: * the super block for this name.
126: */
127: #define MAXMNTLEN 512
128:
129: /*
130: * The limit on the amount of summary information per file system
131: * is defined by MAXCSBUFS. It is currently parameterized for a
132: * size of 128 bytes (2 million cylinder groups on machines with
133: * 32-bit pointers, and 1 million on 64-bit machines). One pointer
134: * is taken away to point to an array of cluster sizes that is
135: * computed as cylinder groups are inspected.
136: */
137: #define MAXCSBUFS ((128 / sizeof(void *)) - 1)
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 file system
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 file system
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 5
160: #define DEFAULTOPT FS_OPTTIME
161:
162: /*
163: * Per cylinder group information; summarized in blocks allocated
164: * from first cylinder group data blocks. These blocks have to be
165: * read in from fs_csaddr (size fs_cssize) in addition to the
166: * super block.
167: *
168: * N.B. sizeof(struct csum) must be a power of two in order for
169: * the ``fs_cs'' macro to work (see below).
170: */
171: struct csum {
172: int32_t cs_ndir; /* number of directories */
173: int32_t cs_nbfree; /* number of free blocks */
174: int32_t cs_nifree; /* number of free inodes */
175: int32_t cs_nffree; /* number of free frags */
176: };
177:
178: /*
179: * Super block for an FFS file system.
180: */
181: struct fs {
182: int32_t fs_firstfield; /* historic file system linked list, */
183: int32_t fs_unused_1; /* used for incore super blocks */
184: ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
185: ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
186: ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
187: ufs_daddr_t fs_dblkno; /* offset of first data after cg */
188: int32_t fs_cgoffset; /* cylinder group offset in cylinder */
189: int32_t fs_cgmask; /* used to calc mod fs_ntrak */
190: time_t fs_time; /* last time written */
191: int32_t fs_size; /* number of blocks in fs */
192: int32_t fs_dsize; /* number of data blocks in fs */
193: int32_t fs_ncg; /* number of cylinder groups */
194: int32_t fs_bsize; /* size of basic blocks in fs */
195: int32_t fs_fsize; /* size of frag blocks in fs */
196: int32_t fs_frag; /* number of frags in a block in fs */
197: /* these are configuration parameters */
198: int32_t fs_minfree; /* minimum percentage of free blocks */
199: int32_t fs_rotdelay; /* num of ms for optimal next block */
200: int32_t fs_rps; /* disk revolutions per second */
201: /* these fields can be computed from the others */
202: int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
203: int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
204: int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
205: int32_t fs_fshift; /* ``numfrags'' calc number of frags */
206: /* these are configuration parameters */
207: int32_t fs_maxcontig; /* max number of contiguous blks */
208: int32_t fs_maxbpg; /* max number of blks per cyl group */
209: /* these fields can be computed from the others */
210: int32_t fs_fragshift; /* block to frag shift */
211: int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
212: int32_t fs_sbsize; /* actual size of super block */
213: int32_t fs_csmask; /* csum block offset */
214: int32_t fs_csshift; /* csum block number */
215: int32_t fs_nindir; /* value of NINDIR */
216: int32_t fs_inopb; /* value of INOPB */
217: int32_t fs_nspf; /* value of NSPF */
218: /* yet another configuration parameter */
219: int32_t fs_optim; /* optimization preference, see below */
220: /* these fields are derived from the hardware */
221: int32_t fs_npsect; /* # sectors/track including spares */
222: int32_t fs_interleave; /* hardware sector interleave */
223: int32_t fs_trackskew; /* sector 0 skew, per track */
224: int32_t fs_headswitch; /* head switch time, usec */
225: int32_t fs_trkseek; /* track-to-track seek, usec */
226: /* sizes determined by number of cylinder groups and their sizes */
227: ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
228: int32_t fs_cssize; /* size of cyl grp summary area */
229: int32_t fs_cgsize; /* cylinder group size */
230: /* these fields are derived from the hardware */
231: int32_t fs_ntrak; /* tracks per cylinder */
232: int32_t fs_nsect; /* sectors per track */
233: int32_t fs_spc; /* sectors per cylinder */
234: /* this comes from the disk driver partitioning */
235: int32_t fs_ncyl; /* cylinders in file system */
236: /* these fields can be computed from the others */
237: int32_t fs_cpg; /* cylinders per group */
238: int32_t fs_ipg; /* inodes per group */
239: int32_t fs_fpg; /* blocks per group * fs_frag */
240: /* this data must be re-computed after crashes */
241: struct csum fs_cstotal; /* cylinder summary information */
242: /* these fields are cleared at mount time */
243: int8_t fs_fmod; /* super block modified flag */
244: int8_t fs_clean; /* file system is clean flag */
245: int8_t fs_ronly; /* mounted read-only flag */
246: int8_t fs_flags; /* currently unused flag */
247: u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
248: /* these fields retain the current block allocation info */
249: int32_t fs_cgrotor; /* last cg searched */
250: struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
251: int32_t *fs_maxcluster; /* max cluster in each cyl group */
252: int32_t fs_cpc; /* cyl per cycle in postbl */
253: int16_t fs_opostbl[16][8]; /* old rotation block list head */
254: int32_t fs_sparecon[50]; /* reserved for future constants */
255: int32_t fs_contigsumsize; /* size of cluster summary array */
256: int32_t fs_maxsymlinklen; /* max length of an internal symlink */
257: int32_t fs_inodefmt; /* format of on-disk inodes */
258: u_int64_t fs_maxfilesize; /* maximum representable file size */
259: int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
260: int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
261: int32_t fs_state; /* validate fs_clean field */
262: int32_t fs_postblformat; /* format of positional layout tables */
263: int32_t fs_nrpos; /* number of rotational positions */
264: int32_t fs_postbloff; /* (u_int16) rotation block list head */
265: int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */
266: int32_t fs_magic; /* magic number */
267: u_int8_t fs_space[1]; /* list of blocks for each rotation */
268: /* actually longer */
269: };
270:
271: /*
272: * Filesystem identification
273: */
274: #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
275: #define FS_OKAY 0x7c269d38 /* superblock checksum */
276: #define FS_42INODEFMT -1 /* 4.2BSD inode format */
277: #define FS_44INODEFMT 2 /* 4.4BSD inode format */
278: /*
279: * Preference for optimization.
280: */
281: #define FS_OPTTIME 0 /* minimize allocation time */
282: #define FS_OPTSPACE 1 /* minimize disk fragmentation */
283:
284: /*
285: * Rotational layout table format types
286: */
287: #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
288: #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
289: /*
290: * Macros for access to superblock array structures
291: */
292: #define fs_postbl(fs, cylno) \
293: (((fs)->fs_postblformat == FS_42POSTBLFMT) \
294: ? ((fs)->fs_opostbl[cylno]) \
295: : ((int16_t *)((u_int8_t *)(fs) + \
296: (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
297: #define fs_rotbl(fs) \
298: (((fs)->fs_postblformat == FS_42POSTBLFMT) \
299: ? ((fs)->fs_space) \
300: : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
301:
302: /*
303: * The size of a cylinder group is calculated by CGSIZE. The maximum size
304: * is limited by the fact that cylinder groups are at most one block.
305: * Its size is derived from the size of the maps maintained in the
306: * cylinder group and the (struct cg) size.
307: */
308: #define CGSIZE(fs) \
309: /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
310: /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
311: /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
312: /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
313: /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
314: /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
315: /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
316: /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
317:
318: /*
319: * Convert cylinder group to base address of its global summary info.
320: *
321: * N.B. This macro assumes that sizeof(struct csum) is a power of two.
322: */
323: #define fs_cs(fs, indx) \
324: fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
325:
326: /*
327: * Cylinder group block for a file system.
328: */
329: #define CG_MAGIC 0x090255
330: struct cg {
331: int32_t cg_firstfield; /* historic cyl groups linked list */
332: int32_t cg_magic; /* magic number */
333: time_t cg_time; /* time last written */
334: int32_t cg_cgx; /* we are the cgx'th cylinder group */
335: int16_t cg_ncyl; /* number of cyl's this cg */
336: int16_t cg_niblk; /* number of inode blocks this cg */
337: int32_t cg_ndblk; /* number of data blocks this cg */
338: struct csum cg_cs; /* cylinder summary information */
339: int32_t cg_rotor; /* position of last used block */
340: int32_t cg_frotor; /* position of last used frag */
341: int32_t cg_irotor; /* position of last used inode */
342: int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
343: int32_t cg_btotoff; /* (int32) block totals per cylinder */
344: int32_t cg_boff; /* (u_int16) free block positions */
345: int32_t cg_iusedoff; /* (u_int8) used inode map */
346: int32_t cg_freeoff; /* (u_int8) free block map */
347: int32_t cg_nextfreeoff; /* (u_int8) next available space */
348: int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */
349: int32_t cg_clusteroff; /* (u_int8) free cluster map */
350: int32_t cg_nclusterblks; /* number of clusters this cg */
351: int32_t cg_sparecon[13]; /* reserved for future use */
352: u_int8_t cg_space[1]; /* space for cylinder group maps */
353: /* actually longer */
354: };
355:
356: /*
357: * Macros for access to cylinder group array structures
358: */
359: #define cg_blktot(cgp) \
360: (((cgp)->cg_magic != CG_MAGIC) \
361: ? (((struct ocg *)(cgp))->cg_btot) \
362: : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
363: #define cg_blks(fs, cgp, cylno) \
364: (((cgp)->cg_magic != CG_MAGIC) \
365: ? (((struct ocg *)(cgp))->cg_b[cylno]) \
366: : ((int16_t *)((u_int8_t *)(cgp) + \
367: (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
368: #define cg_inosused(cgp) \
369: (((cgp)->cg_magic != CG_MAGIC) \
370: ? (((struct ocg *)(cgp))->cg_iused) \
371: : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
372: #define cg_blksfree(cgp) \
373: (((cgp)->cg_magic != CG_MAGIC) \
374: ? (((struct ocg *)(cgp))->cg_free) \
375: : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff)))
376: #define cg_chkmagic(cgp) \
377: ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
378: #define cg_clustersfree(cgp) \
379: ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
380: #define cg_clustersum(cgp) \
381: ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
382:
383: /*
384: * The following structure is defined
385: * for compatibility with old file systems.
386: */
387: struct ocg {
388: int32_t cg_firstfield; /* historic linked list of cyl groups */
389: int32_t cg_unused_1; /* used for incore cyl groups */
390: time_t cg_time; /* time last written */
391: int32_t cg_cgx; /* we are the cgx'th cylinder group */
392: int16_t cg_ncyl; /* number of cyl's this cg */
393: int16_t cg_niblk; /* number of inode blocks this cg */
394: int32_t cg_ndblk; /* number of data blocks this cg */
395: struct csum cg_cs; /* cylinder summary information */
396: int32_t cg_rotor; /* position of last used block */
397: int32_t cg_frotor; /* position of last used frag */
398: int32_t cg_irotor; /* position of last used inode */
399: int32_t cg_frsum[8]; /* counts of available frags */
400: int32_t cg_btot[32]; /* block totals per cylinder */
401: int16_t cg_b[32][8]; /* positions of free blocks */
402: u_int8_t cg_iused[256]; /* used inode map */
403: int32_t cg_magic; /* magic number */
404: u_int8_t cg_free[1]; /* free block map */
405: /* actually longer */
406: };
407:
408: /*
409: * Turn file system block numbers into disk block addresses.
410: * This maps file system blocks to device size blocks.
411: */
412: #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
413: #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
414:
415: /*
416: * Cylinder group macros to locate things in cylinder groups.
417: * They calc file system addresses of cylinder group data structures.
418: */
419: #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c)))
420: #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
421: #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
422: #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
423: #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
424: #define cgstart(fs, c) \
425: (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
426:
427: /*
428: * Macros for handling inode numbers:
429: * inode number to file system block offset.
430: * inode number to cylinder group number.
431: * inode number to file system block address.
432: */
433: #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
434: #define ino_to_fsba(fs, x) \
435: ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
436: (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
437: #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
438:
439: /*
440: * Give cylinder group number for a file system block.
441: * Give cylinder group block number for a file system block.
442: */
443: #define dtog(fs, d) ((d) / (fs)->fs_fpg)
444: #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
445:
446: /*
447: * Extract the bits for a block from a map.
448: * Compute the cylinder and rotational position of a cyl block addr.
449: */
450: #define blkmap(fs, map, loc) \
451: (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
452: #define cbtocylno(fs, bno) \
453: ((bno) * NSPF(fs) / (fs)->fs_spc)
454: #define cbtorpos(fs, bno) \
455: (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
456: (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
457: (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
458:
459: /*
460: * The following macros optimize certain frequently calculated
461: * quantities by using shifts and masks in place of divisions
462: * modulos and multiplications.
463: */
464: #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
465: ((loc) & (fs)->fs_qbmask)
466: #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
467: ((loc) & (fs)->fs_qfmask)
468: #define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
469: ((blk) << (fs)->fs_bshift)
470: #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
471: ((loc) >> (fs)->fs_bshift)
472: #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
473: ((loc) >> (fs)->fs_fshift)
474: #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
475: (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
476: #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
477: (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
478: #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
479: ((frags) >> (fs)->fs_fragshift)
480: #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
481: ((blks) << (fs)->fs_fragshift)
482: #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
483: ((fsb) & ((fs)->fs_frag - 1))
484: #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
485: ((fsb) &~ ((fs)->fs_frag - 1))
486:
487: /*
488: * Determine the number of available frags given a
489: * percentage to hold in reserve.
490: */
491: #define freespace(fs, percentreserved) \
492: (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
493: (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
494:
495: /*
496: * Determining the size of a file block in the file system.
497: */
498: #define blksize(fs, ip, lbn) \
499: (((lbn) >= NDADDR || (ip)->i_size >= ((lbn) + 1) << (fs)->fs_bshift) \
500: ? (fs)->fs_bsize \
501: : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
502: #define dblksize(fs, dip, lbn) \
503: (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
504: ? (fs)->fs_bsize \
505: : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
506:
507: /*
508: * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
509: * sector size.
510: */
511: #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
512: #define NSPF(fs) ((fs)->fs_nspf)
513:
514: /*
515: * Number of inodes in a secondary storage block/fragment.
516: */
517: #define INOPB(fs) ((fs)->fs_inopb)
518: #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
519:
520: /*
521: * Number of indirects in a file system block.
522: */
523: #define NINDIR(fs) ((fs)->fs_nindir)
524:
525: /*
526: * This macro controls whether the file system format is byte swapped or not.
527: * At NeXT, all little endian machines read and write big endian file systems.
528: */
529: #define BIG_ENDIAN_FS (__LITTLE_ENDIAN__)
530:
531: extern int inside[], around[];
532: extern u_char *fragtbl[];
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