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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
23: /*
24: * Copyright (c) 1982, 1986, 1993
25: * The Regents of the University of California. All rights reserved.
26: *
27: * Redistribution and use in source and binary forms, with or without
28: * modification, are permitted provided that the following conditions
29: * are met:
30: * 1. Redistributions of source code must retain the above copyright
31: * notice, this list of conditions and the following disclaimer.
32: * 2. Redistributions in binary form must reproduce the above copyright
33: * notice, this list of conditions and the following disclaimer in the
34: * documentation and/or other materials provided with the distribution.
35: * 3. All advertising materials mentioning features or use of this software
36: * must display the following acknowledgement:
37: * This product includes software developed by the University of
38: * California, Berkeley and its contributors.
39: * 4. Neither the name of the University nor the names of its contributors
40: * may be used to endorse or promote products derived from this software
41: * without specific prior written permission.
42: *
43: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
44: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
47: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53: * SUCH DAMAGE.
54: *
55: * @(#)fs.h 8.13 (Berkeley) 3/21/95
56: */
57: #ifndef _FFS_FS_H_
58: #define _FFS_FS_H_
59:
60: /*
61: * Each disk drive contains some number of file systems.
62: * A file system consists of a number of cylinder groups.
63: * Each cylinder group has inodes and data.
64: *
65: * A file system is described by its super-block, which in turn
66: * describes the cylinder groups. The super-block is critical
67: * data and is replicated in each cylinder group to protect against
68: * catastrophic loss. This is done at `newfs' time and the critical
69: * super-block data does not change, so the copies need not be
70: * referenced further unless disaster strikes.
71: *
72: * For file system fs, the offsets of the various blocks of interest
73: * are given in the super block as:
74: * [fs->fs_sblkno] Super-block
75: * [fs->fs_cblkno] Cylinder group block
76: * [fs->fs_iblkno] Inode blocks
77: * [fs->fs_dblkno] Data blocks
78: * The beginning of cylinder group cg in fs, is given by
79: * the ``cgbase(fs, cg)'' macro.
80: *
81: * The first boot and super blocks are given in absolute disk addresses.
82: * The byte-offset forms are preferred, as they don't imply a sector size.
83: */
84: #define BBSIZE 8192
85: #define SBSIZE 8192
86: #define BBOFF ((off_t)(0))
87: #define SBOFF ((off_t)(BBOFF + BBSIZE))
88: #define BBLOCK ((ufs_daddr_t)(0))
89: #define SBLOCK ((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
90:
91: /*
92: * Addresses stored in inodes are capable of addressing fragments
93: * of `blocks'. File system blocks of at most size MAXBSIZE can
94: * be optionally broken into 2, 4, or 8 pieces, each of which is
95: * addressible; these pieces may be DEV_BSIZE, or some multiple of
96: * a DEV_BSIZE unit.
97: *
98: * Large files consist of exclusively large data blocks. To avoid
99: * undue wasted disk space, the last data block of a small file may be
100: * allocated as only as many fragments of a large block as are
101: * necessary. The file system format retains only a single pointer
102: * to such a fragment, which is a piece of a single large block that
103: * has been divided. The size of such a fragment is determinable from
104: * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
105: *
106: * The file system records space availability at the fragment level;
107: * to determine block availability, aligned fragments are examined.
108: */
109:
110: /*
111: * MINBSIZE is the smallest allowable block size.
112: * In order to insure that it is possible to create files of size
113: * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
114: * MINBSIZE must be big enough to hold a cylinder group block,
115: * thus changes to (struct cg) must keep its size within MINBSIZE.
116: * Note that super blocks are always of size SBSIZE,
117: * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
118: */
119: #define MINBSIZE 4096
120:
121: /*
122: * The path name on which the file system is mounted is maintained
123: * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
124: * the super block for this name.
125: */
126: #define MAXMNTLEN 512
127:
128: /*
129: * The limit on the amount of summary information per file system
130: * is defined by MAXCSBUFS. It is currently parameterized for a
131: * size of 128 bytes (2 million cylinder groups on machines with
132: * 32-bit pointers, and 1 million on 64-bit machines). One pointer
133: * is taken away to point to an array of cluster sizes that is
134: * computed as cylinder groups are inspected.
135: */
136: #define MAXCSBUFS ((128 / sizeof(void *)) - 1)
137:
138: /*
139: * A summary of contiguous blocks of various sizes is maintained
140: * in each cylinder group. Normally this is set by the initial
141: * value of fs_maxcontig. To conserve space, a maximum summary size
142: * is set by FS_MAXCONTIG.
143: */
144: #define FS_MAXCONTIG 16
145:
146: /*
147: * MINFREE gives the minimum acceptable percentage of file system
148: * blocks which may be free. If the freelist drops below this level
149: * only the superuser may continue to allocate blocks. This may
150: * be set to 0 if no reserve of free blocks is deemed necessary,
151: * however throughput drops by fifty percent if the file system
152: * is run at between 95% and 100% full; thus the minimum default
153: * value of fs_minfree is 5%. However, to get good clustering
154: * performance, 10% is a better choice. hence we use 10% as our
155: * default value. With 10% free space, fragmentation is not a
156: * problem, so we choose to optimize for time.
157: */
158: #define MINFREE 5
159: #define DEFAULTOPT FS_OPTTIME
160:
161: /*
162: * Per cylinder group information; summarized in blocks allocated
163: * from first cylinder group data blocks. These blocks have to be
164: * read in from fs_csaddr (size fs_cssize) in addition to the
165: * super block.
166: *
167: * N.B. sizeof(struct csum) must be a power of two in order for
168: * the ``fs_cs'' macro to work (see below).
169: */
170: struct csum {
171: int32_t cs_ndir; /* number of directories */
172: int32_t cs_nbfree; /* number of free blocks */
173: int32_t cs_nifree; /* number of free inodes */
174: int32_t cs_nffree; /* number of free frags */
175: };
176:
177: /*
178: * Super block for an FFS file system.
179: */
180: struct fs {
181: int32_t fs_firstfield; /* historic file system linked list, */
182: int32_t fs_unused_1; /* used for incore super blocks */
183: ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
184: ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
185: ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
186: ufs_daddr_t fs_dblkno; /* offset of first data after cg */
187: int32_t fs_cgoffset; /* cylinder group offset in cylinder */
188: int32_t fs_cgmask; /* used to calc mod fs_ntrak */
189: time_t fs_time; /* last time written */
190: int32_t fs_size; /* number of blocks in fs */
191: int32_t fs_dsize; /* number of data blocks in fs */
192: int32_t fs_ncg; /* number of cylinder groups */
193: int32_t fs_bsize; /* size of basic blocks in fs */
194: int32_t fs_fsize; /* size of frag blocks in fs */
195: int32_t fs_frag; /* number of frags in a block in fs */
196: /* these are configuration parameters */
197: int32_t fs_minfree; /* minimum percentage of free blocks */
198: int32_t fs_rotdelay; /* num of ms for optimal next block */
199: int32_t fs_rps; /* disk revolutions per second */
200: /* these fields can be computed from the others */
201: int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
202: int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
203: int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
204: int32_t fs_fshift; /* ``numfrags'' calc number of frags */
205: /* these are configuration parameters */
206: int32_t fs_maxcontig; /* max number of contiguous blks */
207: int32_t fs_maxbpg; /* max number of blks per cyl group */
208: /* these fields can be computed from the others */
209: int32_t fs_fragshift; /* block to frag shift */
210: int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
211: int32_t fs_sbsize; /* actual size of super block */
212: int32_t fs_csmask; /* csum block offset */
213: int32_t fs_csshift; /* csum block number */
214: int32_t fs_nindir; /* value of NINDIR */
215: int32_t fs_inopb; /* value of INOPB */
216: int32_t fs_nspf; /* value of NSPF */
217: /* yet another configuration parameter */
218: int32_t fs_optim; /* optimization preference, see below */
219: /* these fields are derived from the hardware */
220: int32_t fs_npsect; /* # sectors/track including spares */
221: int32_t fs_interleave; /* hardware sector interleave */
222: int32_t fs_trackskew; /* sector 0 skew, per track */
223: int32_t fs_headswitch; /* head switch time, usec */
224: int32_t fs_trkseek; /* track-to-track seek, usec */
225: /* sizes determined by number of cylinder groups and their sizes */
226: ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
227: int32_t fs_cssize; /* size of cyl grp summary area */
228: int32_t fs_cgsize; /* cylinder group size */
229: /* these fields are derived from the hardware */
230: int32_t fs_ntrak; /* tracks per cylinder */
231: int32_t fs_nsect; /* sectors per track */
232: int32_t fs_spc; /* sectors per cylinder */
233: /* this comes from the disk driver partitioning */
234: int32_t fs_ncyl; /* cylinders in file system */
235: /* these fields can be computed from the others */
236: int32_t fs_cpg; /* cylinders per group */
237: int32_t fs_ipg; /* inodes per group */
238: int32_t fs_fpg; /* blocks per group * fs_frag */
239: /* this data must be re-computed after crashes */
240: struct csum fs_cstotal; /* cylinder summary information */
241: /* these fields are cleared at mount time */
242: int8_t fs_fmod; /* super block modified flag */
243: int8_t fs_clean; /* file system is clean flag */
244: int8_t fs_ronly; /* mounted read-only flag */
245: int8_t fs_flags; /* currently unused flag */
246: u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
247: /* these fields retain the current block allocation info */
248: int32_t fs_cgrotor; /* last cg searched */
249: struct csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
250: int32_t *fs_maxcluster; /* max cluster in each cyl group */
251: int32_t fs_cpc; /* cyl per cycle in postbl */
252: int16_t fs_opostbl[16][8]; /* old rotation block list head */
253: int32_t fs_sparecon[50]; /* reserved for future constants */
254: int32_t fs_contigsumsize; /* size of cluster summary array */
255: int32_t fs_maxsymlinklen; /* max length of an internal symlink */
256: int32_t fs_inodefmt; /* format of on-disk inodes */
257: u_int64_t fs_maxfilesize; /* maximum representable file size */
258: int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
259: int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
260: int32_t fs_state; /* validate fs_clean field */
261: int32_t fs_postblformat; /* format of positional layout tables */
262: int32_t fs_nrpos; /* number of rotational positions */
263: int32_t fs_postbloff; /* (u_int16) rotation block list head */
264: int32_t fs_rotbloff; /* (u_int8) blocks for each rotation */
265: int32_t fs_magic; /* magic number */
266: u_int8_t fs_space[1]; /* list of blocks for each rotation */
267: /* actually longer */
268: };
269:
270: /*
271: * Filesystem identification
272: */
273: #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
274: #define FS_OKAY 0x7c269d38 /* superblock checksum */
275: #define FS_42INODEFMT -1 /* 4.2BSD inode format */
276: #define FS_44INODEFMT 2 /* 4.4BSD inode format */
277: /*
278: * Preference for optimization.
279: */
280: #define FS_OPTTIME 0 /* minimize allocation time */
281: #define FS_OPTSPACE 1 /* minimize disk fragmentation */
282:
283: /*
284: * Rotational layout table format types
285: */
286: #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
287: #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
288: /*
289: * Macros for access to superblock array structures
290: */
291: #define fs_postbl(fs, cylno) \
292: (((fs)->fs_postblformat == FS_42POSTBLFMT) \
293: ? ((fs)->fs_opostbl[cylno]) \
294: : ((int16_t *)((u_int8_t *)(fs) + \
295: (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
296: #define fs_rotbl(fs) \
297: (((fs)->fs_postblformat == FS_42POSTBLFMT) \
298: ? ((fs)->fs_space) \
299: : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
300:
301: /*
302: * The size of a cylinder group is calculated by CGSIZE. The maximum size
303: * is limited by the fact that cylinder groups are at most one block.
304: * Its size is derived from the size of the maps maintained in the
305: * cylinder group and the (struct cg) size.
306: */
307: #define CGSIZE(fs) \
308: /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
309: /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
310: /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
311: /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
312: /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
313: /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
314: /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
315: /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
316:
317: /*
318: * Convert cylinder group to base address of its global summary info.
319: *
320: * N.B. This macro assumes that sizeof(struct csum) is a power of two.
321: */
322: #define fs_cs(fs, indx) \
323: fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
324:
325: /*
326: * Cylinder group block for a file system.
327: */
328: #define CG_MAGIC 0x090255
329: struct cg {
330: int32_t cg_firstfield; /* historic cyl groups linked list */
331: int32_t cg_magic; /* magic number */
332: time_t cg_time; /* time last written */
333: int32_t cg_cgx; /* we are the cgx'th cylinder group */
334: int16_t cg_ncyl; /* number of cyl's this cg */
335: int16_t cg_niblk; /* number of inode blocks this cg */
336: int32_t cg_ndblk; /* number of data blocks this cg */
337: struct csum cg_cs; /* cylinder summary information */
338: int32_t cg_rotor; /* position of last used block */
339: int32_t cg_frotor; /* position of last used frag */
340: int32_t cg_irotor; /* position of last used inode */
341: int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
342: int32_t cg_btotoff; /* (int32) block totals per cylinder */
343: int32_t cg_boff; /* (u_int16) free block positions */
344: int32_t cg_iusedoff; /* (u_int8) used inode map */
345: int32_t cg_freeoff; /* (u_int8) free block map */
346: int32_t cg_nextfreeoff; /* (u_int8) next available space */
347: int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */
348: int32_t cg_clusteroff; /* (u_int8) free cluster map */
349: int32_t cg_nclusterblks; /* number of clusters this cg */
350: int32_t cg_sparecon[13]; /* reserved for future use */
351: u_int8_t cg_space[1]; /* space for cylinder group maps */
352: /* actually longer */
353: };
354:
355: /*
356: * Macros for access to cylinder group array structures
357: */
358: #define cg_blktot(cgp) \
359: (((cgp)->cg_magic != CG_MAGIC) \
360: ? (((struct ocg *)(cgp))->cg_btot) \
361: : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
362: #define cg_blks(fs, cgp, cylno) \
363: (((cgp)->cg_magic != CG_MAGIC) \
364: ? (((struct ocg *)(cgp))->cg_b[cylno]) \
365: : ((int16_t *)((u_int8_t *)(cgp) + \
366: (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
367: #define cg_inosused(cgp) \
368: (((cgp)->cg_magic != CG_MAGIC) \
369: ? (((struct ocg *)(cgp))->cg_iused) \
370: : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
371: #define cg_blksfree(cgp) \
372: (((cgp)->cg_magic != CG_MAGIC) \
373: ? (((struct ocg *)(cgp))->cg_free) \
374: : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff)))
375: #define cg_chkmagic(cgp) \
376: ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
377: #define cg_clustersfree(cgp) \
378: ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
379: #define cg_clustersum(cgp) \
380: ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
381:
382: /*
383: * The following structure is defined
384: * for compatibility with old file systems.
385: */
386: struct ocg {
387: int32_t cg_firstfield; /* historic linked list of cyl groups */
388: int32_t cg_unused_1; /* used for incore cyl groups */
389: time_t cg_time; /* time last written */
390: int32_t cg_cgx; /* we are the cgx'th cylinder group */
391: int16_t cg_ncyl; /* number of cyl's this cg */
392: int16_t cg_niblk; /* number of inode blocks this cg */
393: int32_t cg_ndblk; /* number of data blocks this cg */
394: struct csum cg_cs; /* cylinder summary information */
395: int32_t cg_rotor; /* position of last used block */
396: int32_t cg_frotor; /* position of last used frag */
397: int32_t cg_irotor; /* position of last used inode */
398: int32_t cg_frsum[8]; /* counts of available frags */
399: int32_t cg_btot[32]; /* block totals per cylinder */
400: int16_t cg_b[32][8]; /* positions of free blocks */
401: u_int8_t cg_iused[256]; /* used inode map */
402: int32_t cg_magic; /* magic number */
403: u_int8_t cg_free[1]; /* free block map */
404: /* actually longer */
405: };
406:
407: /*
408: * Turn file system block numbers into disk block addresses.
409: * This maps file system blocks to device size blocks.
410: */
411: #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
412: #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
413:
414: /*
415: * Cylinder group macros to locate things in cylinder groups.
416: * They calc file system addresses of cylinder group data structures.
417: */
418: #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c)))
419: #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
420: #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
421: #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
422: #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
423: #define cgstart(fs, c) \
424: (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
425:
426: /*
427: * Macros for handling inode numbers:
428: * inode number to file system block offset.
429: * inode number to cylinder group number.
430: * inode number to file system block address.
431: */
432: #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
433: #define ino_to_fsba(fs, x) \
434: ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
435: (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
436: #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
437:
438: /*
439: * Give cylinder group number for a file system block.
440: * Give cylinder group block number for a file system block.
441: */
442: #define dtog(fs, d) ((d) / (fs)->fs_fpg)
443: #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
444:
445: /*
446: * Extract the bits for a block from a map.
447: * Compute the cylinder and rotational position of a cyl block addr.
448: */
449: #define blkmap(fs, map, loc) \
450: (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
451: #define cbtocylno(fs, bno) \
452: ((bno) * NSPF(fs) / (fs)->fs_spc)
453: #define cbtorpos(fs, bno) \
454: (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
455: (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
456: (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
457:
458: /*
459: * The following macros optimize certain frequently calculated
460: * quantities by using shifts and masks in place of divisions
461: * modulos and multiplications.
462: */
463: #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
464: ((loc) & (fs)->fs_qbmask)
465: #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
466: ((loc) & (fs)->fs_qfmask)
467: #define lblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
468: ((blk) << (fs)->fs_bshift)
469: #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
470: ((loc) >> (fs)->fs_bshift)
471: #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
472: ((loc) >> (fs)->fs_fshift)
473: #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
474: (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
475: #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
476: (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
477: #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
478: ((frags) >> (fs)->fs_fragshift)
479: #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
480: ((blks) << (fs)->fs_fragshift)
481: #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
482: ((fsb) & ((fs)->fs_frag - 1))
483: #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
484: ((fsb) &~ ((fs)->fs_frag - 1))
485:
486: /*
487: * Determine the number of available frags given a
488: * percentage to hold in reserve.
489: */
490: #define freespace(fs, percentreserved) \
491: (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
492: (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
493:
494: /*
495: * Determining the size of a file block in the file system.
496: */
497: #define blksize(fs, ip, lbn) \
498: (((lbn) >= NDADDR || (ip)->i_size >= ((lbn) + 1) << (fs)->fs_bshift) \
499: ? (fs)->fs_bsize \
500: : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
501: #define dblksize(fs, dip, lbn) \
502: (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
503: ? (fs)->fs_bsize \
504: : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
505:
506: /*
507: * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
508: * sector size.
509: */
510: #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
511: #define NSPF(fs) ((fs)->fs_nspf)
512:
513: /*
514: * Number of inodes in a secondary storage block/fragment.
515: */
516: #define INOPB(fs) ((fs)->fs_inopb)
517: #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
518:
519: /*
520: * Number of indirects in a file system block.
521: */
522: #define NINDIR(fs) ((fs)->fs_nindir)
523:
524: /*
525: * This macro controls whether the file system format is byte swapped or not.
526: * At NeXT, all little endian machines read and write big endian file systems.
527: */
528: #define BIG_ENDIAN_FS (__LITTLE_ENDIAN__)
529:
530: extern int inside[], around[];
531: extern u_char *fragtbl[];
532:
533:
534: /*
535: * UFS Label:
536: * The purpose of this label is to name a UFS/FFS filesystem. The label
537: * is located at offset 7K (BBSIZE=8K - UFS_LABEL_SIZE=1K = 7K) of the
538: * partition. The first 7K is still available for boot blocks.
539: */
540:
541: #define UFS_LABEL_MAGIC { 'L', 'A', 'B', 'L' }
542: #define UFS_LABEL_SIZE 1024
543: #define UFS_LABEL_OFFSET (BBSIZE - UFS_LABEL_SIZE) /* top 1K */
544: #define UFS_LABEL_VERSION 1
545: #define UFS_MAX_LABEL_NAME 512
546:
547: struct ufslabel {
548: u_int32_t ul_magic;
549: u_int16_t ul_checksum; /* checksum over entire label*/
550: u_int32_t ul_version; /* label version */
551: u_int32_t ul_time; /* creation time */
552: u_int16_t ul_namelen; /* filesystem name length */
553: u_char ul_name[UFS_MAX_LABEL_NAME]; /* filesystem name */
554: u_char ul_reserved[32];/* reserved for future use */
555: u_char ul_unused[460]; /* pad out to 1K */
556: };
557:
558: #endif /* ! _FFS_FS_H_ */
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