1 /**	$MirOS: src/sys/ufs/ffs/fs.h,v 1.7 2010/09/21 21:24:31 tg Exp $	*/
2 /*	$OpenBSD: fs.h,v 1.17 2005/03/01 13:30:50 aaron Exp $	*/
3 /*	$NetBSD: fs.h,v 1.6 1995/04/12 21:21:02 mycroft Exp $	*/
4 
5 /*
6  * Copyright (c) 1982, 1986, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. 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	8.10 (Berkeley) 10/27/94
34  */
35 
36 #ifndef	UFS_FFS_FS_H
37 #define	UFS_FFS_FS_H
38 
39 /*
40  * Each disk drive contains some number of file systems.
41  * A file system consists of a number of cylinder groups.
42  * Each cylinder group has inodes and data.
43  *
44  * A file system is described by its super-block, which in turn
45  * describes the cylinder groups.  The super-block is critical
46  * data and is replicated in each cylinder group to protect against
47  * catastrophic loss.  This is done at `newfs' time and the critical
48  * super-block data does not change, so the copies need not be
49  * referenced further unless disaster strikes.
50  *
51  * For file system fs, the offsets of the various blocks of interest
52  * are given in the super block as:
53  *	[fs->fs_sblkno]		Super-block
54  *	[fs->fs_cblkno]		Cylinder group block
55  *	[fs->fs_iblkno]		Inode blocks
56  *	[fs->fs_dblkno]		Data blocks
57  * The beginning of cylinder group cg in fs, is given by
58  * the ``cgbase(fs, cg)'' macro.
59  *
60  * The first boot and super blocks are given in absolute disk addresses.
61  * The byte-offset forms are preferred, as they don't imply a sector size.
62  */
63 #define BBSIZE		8192
64 #define SBSIZE		8192
65 #define	BBOFF		((off_t)(0))
66 #define	SBOFF		((off_t)(BBOFF + BBSIZE))
67 #define	BBLOCK		((daddr_t)(0))
68 #define	SBLOCK		((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
69 #define	SBLOCK_FLOPPY	0
70 #define	SBLOCK_UFS1	8192
71 #define	SBLOCK_UFS2	65536
72 #define	SBLOCK_PIGGY	262144
73 #define	SBLOCKSIZE	8192
74 #define	SBLOCKSEARCH \
75 	{ SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }
76 
77 /*
78  * Addresses stored in inodes are capable of addressing fragments
79  * of `blocks'. File system blocks of at most size MAXBSIZE can
80  * be optionally broken into 2, 4, or 8 pieces, each of which is
81  * addressible; these pieces may be DEV_BSIZE, or some multiple of
82  * a DEV_BSIZE unit.
83  *
84  * Large files consist of exclusively large data blocks.  To avoid
85  * undue wasted disk space, the last data block of a small file may be
86  * allocated as only as many fragments of a large block as are
87  * necessary.  The file system format retains only a single pointer
88  * to such a fragment, which is a piece of a single large block that
89  * has been divided.  The size of such a fragment is determinable from
90  * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
91  *
92  * The file system records space availability at the fragment level;
93  * to determine block availability, aligned fragments are examined.
94  */
95 
96 /*
97  * MINBSIZE is the smallest allowable block size.
98  * In order to insure that it is possible to create files of size
99  * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
100  * MINBSIZE must be big enough to hold a cylinder group block,
101  * thus changes to (struct cg) must keep its size within MINBSIZE.
102  * Note that super blocks are always of size SBSIZE,
103  * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
104  */
105 #define MINBSIZE	4096
106 
107 /*
108  * The path name on which the file system is mounted is maintained
109  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
110  * the super block for this name.
111  */
112 #define MAXMNTLEN	512
113 
114 /*
115  * There is a 128-byte region in the superblock reserved for in-core
116  * pointers to summary information. Originally this included an array
117  * of pointers to blocks of struct csum; now there are just three
118  * pointers and the remaining space is padded with fs_ocsp[].
119  *
120  * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
121  * is taken away to point to a contiguous array of struct csum for
122  * all cylinder groups; a second (fs_maxcluster) points to an array
123  * of cluster sizes that is computed as cylinder groups are inspected,
124  * and the third points to an array that tracks the creation of new
125  * directories.
126  */
127 #define		NOCSPTRS	((128 / sizeof(void *)) - 3)
128 
129 /*
130  * A summary of contiguous blocks of various sizes is maintained
131  * in each cylinder group. Normally this is set by the initial
132  * value of fs_maxcontig. To conserve space, a maximum summary size
133  * is set by FS_MAXCONTIG.
134  */
135 #define FS_MAXCONTIG	16
136 
137 /*
138  * MINFREE gives the minimum acceptable percentage of file system
139  * blocks which may be free. If the freelist drops below this level
140  * only the superuser may continue to allocate blocks. This may
141  * be set to 0 if no reserve of free blocks is deemed necessary,
142  * however throughput drops by fifty percent if the file system
143  * is run at between 95% and 100% full; thus the minimum default
144  * value of fs_minfree is 5%. However, to get good clustering
145  * performance, 10% is a better choice. hence we use 10% as our
146  * default value. With 10% free space, fragmentation is not a
147  * problem, so we choose to optimize for time.
148  */
149 #define MINFREE		5
150 #define DEFAULTOPT	FS_OPTTIME
151 
152 /*
153  * The directory preference algorithm(dirpref) can be tuned by adjusting
154  * the following parameters which tell the system the average file size
155  * and the average number of files per directory. These defaults are well
156  * selected for typical filesystems, but may need to be tuned for odd
157  * cases like filesystems being used for sqiud caches or news spools.
158  */
159 #define AVFILESIZ	16384	/* expected average file size */
160 #define AFPDIR		64	/* expected number of files per directory */
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 struct csum {
169 	int32_t	cs_ndir;		/* number of directories */
170 	int32_t	cs_nbfree;		/* number of free blocks */
171 	int32_t	cs_nifree;		/* number of free inodes */
172 	int32_t	cs_nffree;		/* number of free frags */
173 };
174 
175 /*
176  * Super block for an FFS file system.
177  */
178 struct fs {
179 	int32_t	fs_historic_start[2];	/* used by MirBSD to store entropy */
180 #define fs_firstfield	fs_historic_start[0]	/* file system linked list, */
181 #define fs_unused_1	fs_historic_start[1]	/* used for incore superblk */
182 	int32_t	 fs_sblkno;		/* addr of super-block in filesys */
183 	int32_t	 fs_cblkno;		/* offset of cyl-block in filesys */
184 	int32_t	 fs_iblkno;		/* offset of inode-blocks in filesys */
185 	int32_t	 fs_dblkno;		/* offset of first data after cg */
186 	int32_t	 fs_cgoffset;		/* cylinder group offset in cylinder */
187 	int32_t	 fs_cgmask;		/* used to calc mod fs_ntrak */
188 	int32_t	 fs_time;		/* last time written XXX was time_t */
189 	int32_t	 fs_size;		/* number of blocks in fs */
190 	int32_t	 fs_dsize;		/* number of data blocks in fs */
191 	int32_t	 fs_ncg;		/* number of cylinder groups */
192 	int32_t	 fs_bsize;		/* size of basic blocks in fs */
193 	int32_t	 fs_fsize;		/* size of frag blocks in fs */
194 	int32_t	 fs_frag;		/* number of frags in a block in fs */
195 /* these are configuration parameters */
196 	int32_t	 fs_minfree;		/* minimum percentage of free blocks */
197 	int32_t	 fs_rotdelay;		/* num of ms for optimal next block */
198 	int32_t	 fs_rps;		/* disk revolutions per second */
199 /* these fields can be computed from the others */
200 	int32_t	 fs_bmask;		/* ``blkoff'' calc of blk offsets */
201 	int32_t	 fs_fmask;		/* ``fragoff'' calc of frag offsets */
202 	int32_t	 fs_bshift;		/* ``lblkno'' calc of logical blkno */
203 	int32_t	 fs_fshift;		/* ``numfrags'' calc number of frags */
204 /* these are configuration parameters */
205 	int32_t	 fs_maxcontig;		/* max number of contiguous blks */
206 	int32_t	 fs_maxbpg;		/* max number of blks per cyl group */
207 /* these fields can be computed from the others */
208 	int32_t	 fs_fragshift;		/* block to frag shift */
209 	int32_t	 fs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
210 	int32_t	 fs_sbsize;		/* actual size of super block */
211 	int32_t	 fs_csmask;		/* csum block offset (now unused) */
212 	int32_t	 fs_csshift;		/* csum block number (now unused) */
213 	int32_t	 fs_nindir;		/* value of NINDIR */
214 	int32_t	 fs_inopb;		/* value of INOPB */
215 	int32_t	 fs_nspf;		/* value of NSPF */
216 /* yet another configuration parameter */
217 	int32_t	 fs_optim;		/* optimization preference, see below */
218 /* these fields are derived from the hardware */
219 	int32_t	 fs_npsect;		/* # sectors/track including spares */
220 	int32_t	 fs_interleave;		/* hardware sector interleave */
221 	int32_t	 fs_trackskew;		/* sector 0 skew, per track */
222 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
223 	int32_t  fs_id[2];		/* unique filesystem id */
224 /* sizes determined by number of cylinder groups and their sizes */
225 	int32_t  fs_csaddr;		/* blk addr of cyl grp summary area */
226 	int32_t	 fs_cssize;		/* size of cyl grp summary area */
227 	int32_t	 fs_cgsize;		/* cylinder group size */
228 /* these fields are derived from the hardware */
229 	int32_t	 fs_ntrak;		/* tracks per cylinder */
230 	int32_t	 fs_nsect;		/* sectors per track */
231 	int32_t	 fs_spc;		/* sectors per cylinder */
232 /* this comes from the disk driver partitioning */
233 	int32_t	 fs_ncyl;		/* cylinders in file system */
234 /* these fields can be computed from the others */
235 	int32_t	 fs_cpg;		/* cylinders per group */
236 	int32_t	 fs_ipg;		/* inodes per group */
237 	int32_t	 fs_fpg;		/* blocks per group * fs_frag */
238 /* this data must be re-computed after crashes */
239 	struct	csum fs_cstotal;	/* cylinder summary information */
240 /* these fields are cleared at mount time */
241 	int8_t	 fs_fmod;		/* super block modified flag */
242 	int8_t	 fs_clean;		/* file system is clean flag */
243 	int8_t	 fs_ronly;		/* mounted read-only flag */
244 	int8_t	 fs_flags;		/* see FS_ below */
245 	u_char	 fs_fsmnt[MAXMNTLEN];	/* name mounted on */
246 /* these fields retain the current block allocation info */
247 	int32_t	 fs_cgrotor;		/* last cg searched */
248 	void    *fs_ocsp[NOCSPTRS];	/* padding; was list of fs_cs buffers */
249 	u_int8_t *fs_contigdirs;	/* # of contiguously allocated dirs */
250 	struct csum *fs_csp;		/* cg summary info buffer for fs_cs */
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_snapinum[20];	/* reserved for snapshot inode nums */
255 	int32_t	 fs_avgfilesize;	/* expected average file size */
256 	int32_t	 fs_avgfpdir;		/* expected # of files per directory */
257 	int32_t	 fs_sparecon[27];	/* reserved for future constants */
258 	int32_t	 fs_fscktime;		/* last time fsck(8)ed XXX was time_t */
259 	int32_t	 fs_contigsumsize;	/* size of cluster summary array */
260 	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
261 	int32_t	 fs_inodefmt;		/* format of on-disk inodes */
262 	u_int64_t fs_maxfilesize;	/* maximum representable file size */
263 	int64_t	 fs_qbmask;		/* ~fs_bmask - for use with quad size */
264 	int64_t	 fs_qfmask;		/* ~fs_fmask - for use with quad size */
265 	int32_t	 fs_state;		/* validate fs_clean field */
266 	int32_t	 fs_postblformat;	/* format of positional layout tables */
267 	int32_t	 fs_nrpos;		/* number of rotational positions */
268 	int32_t	 fs_postbloff;		/* (u_int16) rotation block list head */
269 	int32_t	 fs_rotbloff;		/* (u_int8) blocks for each rotation */
270 	int32_t	 fs_magic;		/* magic number */
271 	u_int8_t fs_space[1];		/* list of blocks for each rotation */
272 /* actually longer */
273 };
274 
275 #define	fs_opostbl_start	fs_opostbl[0][0]
276 
277 /*
278  * Filesystem identification
279  */
280 #define	FS_MAGIC	0x011954	/* the fast filesystem magic number */
281 #define	FS_UFS1_MAGIC	0x011954	/* the fast filesystem magic number */
282 #define	FS_UFS2_MAGIC	0x19540119	/* UFS fast filesystem magic number */
283 #define	FS_OKAY		0x7c269d38	/* superblock checksum */
284 #define FS_42INODEFMT	-1		/* 4.2BSD inode format */
285 #define FS_44INODEFMT	2		/* 4.4BSD inode format */
286 
287 /*
288  * Filesystem clean flags
289  */
290 #define	FS_ISCLEAN	0x01
291 #define	FS_WASCLEAN	0x02
292 
293 /*
294  * Preference for optimization.
295  */
296 #define FS_OPTTIME	0	/* minimize allocation time */
297 #define FS_OPTSPACE	1	/* minimize disk fragmentation */
298 
299 /*
300  * Filesystem flags.
301  */
302 #define FS_UNCLEAN    0x01   /* filesystem not clean at mount */
303 #define FS_DOSOFTDEP  0x02   /* filesystem using soft dependencies */
304 
305 /*
306  * Rotational layout table format types
307  */
308 #define FS_42POSTBLFMT		-1	/* 4.2BSD rotational table format */
309 #define FS_DYNAMICPOSTBLFMT	1	/* dynamic rotational table format */
310 /*
311  * Macros for access to superblock array structures
312  */
313 #define fs_postbl(fs, cylno) \
314     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
315     ? ((fs)->fs_opostbl[cylno]) \
316     : ((int16_t *)((u_int8_t *)(fs) + \
317 	(fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
318 #define fs_rotbl(fs) \
319     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
320     ? ((fs)->fs_space) \
321     : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
322 
323 /*
324  * The size of a cylinder group is calculated by CGSIZE. The maximum size
325  * is limited by the fact that cylinder groups are at most one block.
326  * Its size is derived from the size of the maps maintained in the
327  * cylinder group and the (struct cg) size.
328  */
329 #define CGSIZE(fs) \
330     /* base cg */	(sizeof(struct cg) + sizeof(int32_t) + \
331     /* blktot size */	(fs)->fs_cpg * sizeof(int32_t) + \
332     /* blks size */	(fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
333     /* inode map */	howmany((fs)->fs_ipg, NBBY) + \
334     /* block map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
335     /* if present */	((fs)->fs_contigsumsize <= 0 ? 0 : \
336     /* cluster sum */	(fs)->fs_contigsumsize * sizeof(int32_t) + \
337     /* cluster map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
338 
339 /*
340  * Convert cylinder group to base address of its global summary info.
341  */
342 #define fs_cs(fs, indx) fs_csp[indx]
343 
344 /*
345  * Cylinder group block for a file system.
346  */
347 #define	CG_MAGIC	0x090255
348 struct cg {
349 	int32_t	 cg_firstfield;		/* historic cyl groups linked list */
350 	int32_t	 cg_magic;		/* magic number */
351 	int32_t	 cg_time;		/* time last written XXX was time_t */
352 	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
353 	int16_t	 cg_ncyl;		/* number of cyl's this cg */
354 	int16_t	 cg_niblk;		/* number of inode blocks this cg */
355 	int32_t	 cg_ndblk;		/* number of data blocks this cg */
356 	struct	csum cg_cs;		/* cylinder summary information */
357 	int32_t	 cg_rotor;		/* position of last used block */
358 	int32_t	 cg_frotor;		/* position of last used frag */
359 	int32_t	 cg_irotor;		/* position of last used inode */
360 	int32_t	 cg_frsum[MAXFRAG];	/* counts of available frags */
361 	int32_t	 cg_btotoff;		/* (int32) block totals per cylinder */
362 	int32_t	 cg_boff;		/* (u_int16) free block positions */
363 	int32_t	 cg_iusedoff;		/* (u_int8) used inode map */
364 	int32_t	 cg_freeoff;		/* (u_int8) free block map */
365 	int32_t	 cg_nextfreeoff;	/* (u_int8) next available space */
366 	int32_t	 cg_clustersumoff;	/* (u_int32) counts of avail clusters */
367 	int32_t	 cg_clusteroff;		/* (u_int8) free cluster map */
368 	int32_t	 cg_nclusterblks;	/* number of clusters this cg */
369 	int32_t	 cg_ffs2_niblk;		/* number of inode blocks this cg */
370 	int32_t	 cg_initediblk;		/* last initialized inode */
371 	int32_t	 cg_sparecon32[3];	/* reserved for future use */
372 	int64_t	 cg_ffs2_time;		/* time last written */
373 	int64_t	 cg_sparecon64[3];	/* reserved for future use */
374 	u_int8_t cg_space[1];		/* space for cylinder group maps */
375 /* actually longer */
376 };
377 
378 /*
379  * Macros for access to cylinder group array structures
380  */
381 #define cg_blktot(cgp) \
382     (((cgp)->cg_magic != CG_MAGIC) \
383     ? (((struct ocg *)(cgp))->cg_btot) \
384     : ((int32_t *)((u_int8_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 *)((u_int8_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     : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
394 #define cg_blksfree(cgp) \
395     (((cgp)->cg_magic != CG_MAGIC) \
396     ? (((struct ocg *)(cgp))->cg_free) \
397     : ((u_int8_t *)((u_int8_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     ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
402 #define cg_clustersum(cgp) \
403     ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
404 
405 /*
406  * The following structure is defined
407  * for compatibility with old file systems.
408  */
409 struct ocg {
410 	int32_t	 cg_firstfield;		/* historic linked list of cyl groups */
411 	int32_t	 cg_unused_1;		/*     used for incore cyl groups */
412 	int32_t	 cg_time;		/* time last written XXX was time_t */
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 	u_int8_t cg_iused[256];		/* used inode map */
425 	int32_t	 cg_magic;		/* magic number */
426 	u_int8_t cg_free[1];		/* free block map */
427 /* actually longer */
428 };
429 
430 /*
431  * Turn file system block numbers into disk block addresses.
432  * This maps file system blocks to device size blocks.
433  */
434 #define fsbtodb(fs, b)	((b) << (fs)->fs_fsbtodb)
435 #define	dbtofsb(fs, b)	((b) >> (fs)->fs_fsbtodb)
436 
437 /*
438  * Cylinder group macros to locate things in cylinder groups.
439  * They calc file system addresses of cylinder group data structures.
440  */
441 #define	cgbase(fs, c)	((daddr_t)((fs)->fs_fpg * (c)))
442 #define	cgdmin(fs, c)	(cgstart(fs, c) + (fs)->fs_dblkno)	/* 1st data */
443 #define	cgimin(fs, c)	(cgstart(fs, c) + (fs)->fs_iblkno)	/* inode blk */
444 #define	cgsblock(fs, c)	(cgstart(fs, c) + (fs)->fs_sblkno)	/* super blk */
445 #define	cgtod(fs, c)	(cgstart(fs, c) + (fs)->fs_cblkno)	/* cg block */
446 #define cgstart(fs, c)							\
447 	(cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
448 
449 /*
450  * Macros for handling inode numbers:
451  *     inode number to file system block offset.
452  *     inode number to cylinder group number.
453  *     inode number to file system block address.
454  */
455 #define	ino_to_cg(fs, x)	((x) / (fs)->fs_ipg)
456 #define	ino_to_fsba(fs, x)						\
457 	((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) +			\
458 	    (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
459 #define	ino_to_fsbo(fs, x)	((x) % INOPB(fs))
460 
461 /*
462  * Give cylinder group number for a file system block.
463  * Give cylinder group block number for a file system block.
464  */
465 #define	dtog(fs, d)	((d) / (fs)->fs_fpg)
466 #define	dtogd(fs, d)	((d) % (fs)->fs_fpg)
467 
468 /*
469  * Extract the bits for a block from a map.
470  * Compute the cylinder and rotational position of a cyl block addr.
471  */
472 #define blkmap(fs, map, loc) \
473     (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
474 #define cbtocylno(fs, bno) \
475     ((bno) * NSPF(fs) / (fs)->fs_spc)
476 #define cbtorpos(fs, bno) \
477     (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
478      (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
479      (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
480 
481 /*
482  * The following macros optimize certain frequently calculated
483  * quantities by using shifts and masks in place of divisions
484  * modulos and multiplications.
485  */
486 #define blkoff(fs, loc)		/* calculates (loc % fs->fs_bsize) */ \
487 	((loc) & (fs)->fs_qbmask)
488 #define fragoff(fs, loc)	/* calculates (loc % fs->fs_fsize) */ \
489 	((loc) & (fs)->fs_qfmask)
490 #define lblktosize(fs, blk)	/* calculates ((off_t)blk * fs->fs_bsize) */ \
491 	((off_t)(blk) << (fs)->fs_bshift)
492 #define lblkno(fs, loc)		/* calculates (loc / fs->fs_bsize) */ \
493 	((loc) >> (fs)->fs_bshift)
494 #define numfrags(fs, loc)	/* calculates (loc / fs->fs_fsize) */ \
495 	((loc) >> (fs)->fs_fshift)
496 #define blkroundup(fs, size)	/* calculates roundup(size, fs->fs_bsize) */ \
497 	(((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
498 #define fragroundup(fs, size)	/* calculates roundup(size, fs->fs_fsize) */ \
499 	(((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
500 #define fragstoblks(fs, frags)	/* calculates (frags / fs->fs_frag) */ \
501 	((frags) >> (fs)->fs_fragshift)
502 #define blkstofrags(fs, blks)	/* calculates (blks * fs->fs_frag) */ \
503 	((blks) << (fs)->fs_fragshift)
504 #define fragnum(fs, fsb)	/* calculates (fsb % fs->fs_frag) */ \
505 	((fsb) & ((fs)->fs_frag - 1))
506 #define blknum(fs, fsb)		/* calculates rounddown(fsb, fs->fs_frag) */ \
507 	((fsb) &~ ((fs)->fs_frag - 1))
508 
509 /*
510  * Determine the number of available frags given a
511  * percentage to hold in reserve.
512  */
513 #define freespace(fs, percentreserved) \
514 	(blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
515 	(fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
516 
517 /*
518  * Determining the size of a file block in the file system.
519  */
520 #define blksize(fs, ip, lbn) \
521 	(((lbn) >= NDADDR || (ip)->i_ffs_size >= ((lbn) + 1) << (fs)->fs_bshift) \
522 	    ? (fs)->fs_bsize \
523 	    : (fragroundup(fs, blkoff(fs, (ip)->i_ffs_size))))
524 #define dblksize(fs, dip, lbn) \
525 	(((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
526 	    ? (fs)->fs_bsize \
527 	    : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
528 
529 #define sblksize(fs, size, lbn) \
530         (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
531             ? (fs)->fs_bsize \
532             : (fragroundup(fs, blkoff(fs, (size)))))
533 
534 
535 /*
536  * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
537  * sector size.
538  */
539 #define	NSPB(fs)	((fs)->fs_nspf << (fs)->fs_fragshift)
540 #define	NSPF(fs)	((fs)->fs_nspf)
541 
542 /*
543  * Number of inodes in a secondary storage block/fragment.
544  */
545 #define	INOPB(fs)	((fs)->fs_inopb)
546 #define	INOPF(fs)	((fs)->fs_inopb >> (fs)->fs_fragshift)
547 
548 /*
549  * Number of indirects in a file system block.
550  */
551 #define	NINDIR(fs)	((fs)->fs_nindir)
552 
553 extern const int inside[], around[];
554 extern const u_char *fragtbl[];
555 
556 #endif /* notdef UFS_FFS_FS_H */
557