xref: /dragonfly/sys/vfs/ufs/fs.h (revision 0ca59c34)
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: src/sys/ufs/ffs/fs.h,v 1.14.2.3 2001/09/21 19:15:22 dillon Exp $
35  * $DragonFly: src/sys/vfs/ufs/fs.h,v 1.6 2008/08/04 18:15:47 dillon Exp $
36  */
37 
38 #ifndef _VFS_UFS_FS_H_
39 #define _VFS_UFS_FS_H_
40 
41 /*
42  * Each disk drive contains some number of filesystems.
43  * A filesystem consists of a number of cylinder groups.
44  * Each cylinder group has inodes and data.
45  *
46  * A filesystem is described by its super-block, which in turn
47  * describes the cylinder groups.  The super-block is critical
48  * data and is replicated in each cylinder group to protect against
49  * catastrophic loss.  This is done at `newfs' time and the critical
50  * super-block data does not change, so the copies need not be
51  * referenced further unless disaster strikes.
52  *
53  * For filesystem fs, the offsets of the various blocks of interest
54  * are given in the super block as:
55  *	[fs->fs_sblkno]		Super-block
56  *	[fs->fs_cblkno]		Cylinder group block
57  *	[fs->fs_iblkno]		Inode blocks
58  *	[fs->fs_dblkno]		Data blocks
59  * The beginning of cylinder group cg in fs, is given by
60  * the ``cgbase(fs, cg)'' macro.
61  *
62  * The first boot and super blocks are given in absolute disk addresses.
63  * The byte-offset forms are preferred, as they don't imply a sector size.
64  */
65 #define BBSIZE		8192
66 #define SBSIZE		8192
67 #define	BBOFF		((off_t)(0))
68 #define	SBOFF		((off_t)(BBOFF + BBSIZE))
69 #define	BBLOCK		((ufs_daddr_t)(0))
70 
71 /*
72  * Addresses stored in inodes are capable of addressing fragments
73  * of `blocks'. Filesystem blocks of at most size MAXBSIZE can
74  * be optionally broken into 2, 4, or 8 pieces, each of which is
75  * addressable; these pieces may be DEV_BSIZE, or some multiple of
76  * a DEV_BSIZE unit.
77  *
78  * Large files consist of exclusively large data blocks.  To avoid
79  * undue wasted disk space, the last data block of a small file may be
80  * allocated as only as many fragments of a large block as are
81  * necessary.  The filesystem format retains only a single pointer
82  * to such a fragment, which is a piece of a single large block that
83  * has been divided.  The size of such a fragment is determinable from
84  * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
85  *
86  * The filesystem records space availability at the fragment level;
87  * to determine block availability, aligned fragments are examined.
88  */
89 
90 /*
91  * MINBSIZE is the smallest allowable block size.
92  * In order to insure that it is possible to create files of size
93  * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
94  * MINBSIZE must be big enough to hold a cylinder group block,
95  * thus changes to (struct cg) must keep its size within MINBSIZE.
96  * Note that super blocks are always of size SBSIZE,
97  * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
98  */
99 #define MINBSIZE	4096
100 
101 /*
102  * The path name on which the filesystem is mounted is maintained
103  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
104  * the super block for this name.
105  */
106 #define MAXMNTLEN	468
107 
108 /*
109  * The volume name for this filesystem is maintained in fs_volname.
110  * MAXVOLLEN defines the length of the buffer allocated.
111  */
112 #define MAXVOLLEN	32
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 filesystem
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 filesystem
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		8
150 #define DEFAULTOPT	FS_OPTTIME
151 
152 /*
153  * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
154  * tune the layout preferences for directories within a filesystem.
155  * His algorithm can be tuned by adjusting the following parameters
156  * which tell the system the average file size and the average number
157  * of files per directory. These defaults are well selected for typical
158  * filesystems, but may need to be tuned for odd cases like filesystems
159  * being used for squid caches or news spools.
160  */
161 #define AVFILESIZ      16384   /* expected average file size */
162 #define AFPDIR         64      /* expected number of files per directory */
163 
164 /*
165  * The maximum number of snapshot nodes that can be associated
166  * with each filesystem. This limit affects only the number of
167  * snapshot files that can be recorded within the superblock so
168  * that they can be found when the filesystem is mounted. However,
169  * maintaining too many will slow the filesystem performance, so
170  * having this limit is a good idea.
171  *
172  * VALUE NOT IMPLEMENTED IN DragonFly(and very unlikely to ever be as there are
173  * much better options such as journaling), RESERVED FROM FreeBSD 5.x SO
174  * SUPERBLOCKS REMAIN COMPATIBLE FOR THE TIME BEING. WHY ARE WE YELLING ?
175  */
176 #define FSMAXSNAP 20
177 
178 /*
179  * Per cylinder group information; summarized in blocks allocated
180  * from first cylinder group data blocks.  These blocks have to be
181  * read in from fs_csaddr (size fs_cssize) in addition to the
182  * super block.
183  */
184 struct csum {
185 	int32_t	cs_ndir;		/* number of directories */
186 	int32_t	cs_nbfree;		/* number of free blocks */
187 	int32_t	cs_nifree;		/* number of free inodes */
188 	int32_t	cs_nffree;		/* number of free frags */
189 };
190 
191 /*
192  * Super block for an FFS filesystem.
193  */
194 struct fs {
195 	int32_t	 fs_firstfield;		/* historic filesystem linked list, */
196 	int32_t	 fs_unused_1;		/*     used for incore super blocks */
197 	ufs_daddr_t fs_sblkno;		/* addr of super-block in filesys */
198 	ufs_daddr_t fs_cblkno;		/* offset of cyl-block in filesys */
199 	ufs_daddr_t fs_iblkno;		/* offset of inode-blocks in filesys */
200 	ufs_daddr_t fs_dblkno;		/* offset of first data after cg */
201 	int32_t	 fs_cgoffset;		/* cylinder group offset in cylinder */
202 	int32_t	 fs_cgmask;		/* used to calc mod fs_ntrak */
203 	ufs_time_t fs_time;		/* last time written */
204 	int32_t	 fs_size;		/* number of blocks in fs */
205 	int32_t	 fs_dsize;		/* number of data blocks in fs */
206 	int32_t	 fs_ncg;		/* number of cylinder groups */
207 	int32_t	 fs_bsize;		/* size of basic blocks in fs */
208 	int32_t	 fs_fsize;		/* size of frag blocks in fs */
209 	int32_t	 fs_frag;		/* number of frags in a block in fs */
210 /* these are configuration parameters */
211 	int32_t	 fs_minfree;		/* minimum percentage of free blocks */
212 	int32_t	 fs_rotdelay;		/* num of ms for optimal next block */
213 	int32_t	 fs_rps;		/* disk revolutions per second */
214 /* these fields can be computed from the others */
215 	int32_t	 fs_bmask;		/* ``blkoff'' calc of blk offsets */
216 	int32_t	 fs_fmask;		/* ``fragoff'' calc of frag offsets */
217 	int32_t	 fs_bshift;		/* ``lblkno'' calc of logical blkno */
218 	int32_t	 fs_fshift;		/* ``numfrags'' calc number of frags */
219 /* these are configuration parameters */
220 	int32_t	 fs_maxcontig;		/* max number of contiguous blks */
221 	int32_t	 fs_maxbpg;		/* max number of blks per cyl group */
222 /* these fields can be computed from the others */
223 	int32_t	 fs_fragshift;		/* block to frag shift */
224 	int32_t	 fs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
225 	int32_t	 fs_sbsize;		/* actual size of super block */
226 	int32_t	 fs_csmask;		/* csum block offset (now unused) */
227 	int32_t	 fs_csshift;		/* csum block number (now unused) */
228 	int32_t	 fs_nindir;		/* value of NINDIR */
229 	int32_t	 fs_inopb;		/* value of INOPB */
230 	int32_t	 fs_nspf;		/* value of NSPF */
231 /* yet another configuration parameter */
232 	int32_t	 fs_optim;		/* optimization preference, see below */
233 /* these fields are derived from the hardware */
234 	int32_t	 fs_npsect;		/* # sectors/track including spares */
235 	int32_t	 fs_interleave;		/* hardware sector interleave */
236 	int32_t	 fs_trackskew;		/* sector 0 skew, per track */
237 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
238 	int32_t	 fs_id[2];		/* unique filesystem id */
239 /* sizes determined by number of cylinder groups and their sizes */
240 	ufs_daddr_t fs_csaddr;		/* blk addr of cyl grp summary area */
241 	int32_t	 fs_cssize;		/* size of cyl grp summary area */
242 	int32_t	 fs_cgsize;		/* cylinder group size */
243 /* these fields are derived from the hardware */
244 	int32_t	 fs_ntrak;		/* tracks per cylinder */
245 	int32_t	 fs_nsect;		/* sectors per track */
246 	int32_t  fs_spc;			/* sectors per cylinder */
247 /* this comes from the disk driver partitioning */
248 	int32_t	 fs_ncyl;		/* cylinders in filesystem */
249 /* these fields can be computed from the others */
250 	int32_t	 fs_cpg;			/* cylinders per group */
251 	int32_t	 fs_ipg;			/* inodes per group */
252 	int32_t	 fs_fpg;			/* blocks per group * fs_frag */
253 /* this data must be re-computed after crashes */
254 	struct	csum fs_cstotal;	/* cylinder summary information */
255 /* these fields are cleared at mount time */
256 	int8_t   fs_fmod;		/* super block modified flag */
257 	int8_t   fs_clean;		/* filesystem is clean flag */
258 	int8_t 	 fs_ronly;		/* mounted read-only flag */
259 	int8_t   fs_flags;		/* see FS_ flags below */
260 	u_char	 fs_fsmnt[MAXMNTLEN];	/* name mounted on */
261 	u_char	 fs_volname[MAXVOLLEN];	/* volume name */
262 	u_int64_t fs_swuid;		/* system-wide uid */
263 	int32_t	 fs_pad;		/* due to alignment of fs_swuid */
264 /* these fields retain the current block allocation info */
265 	int32_t	 fs_cgrotor;		/* last cg searched */
266 	void 	*fs_ocsp[NOCSPTRS];	/* padding; was list of fs_cs buffers */
267 	uint8_t *fs_contigdirs;	/* # of contiguously allocated dirs */
268 	struct csum *fs_csp;		/* cg summary info buffer for fs_cs */
269 	int32_t	*fs_maxcluster;		/* max cluster in each cyl group */
270 	int32_t	 fs_cpc;		/* cyl per cycle in postbl */
271 	int16_t	 fs_opostbl[16][8];	/* old rotation block list head */
272 	int32_t  fs_snapinum[FSMAXSNAP];/* RESERVED FROM 5.x */
273 	int32_t	 fs_avgfilesize;	/* expected average file size */
274 	int32_t  fs_avgfpdir;		/* expected # of files per directory */
275 	int32_t	 fs_sparecon[26];	/* reserved for future constants */
276 	int32_t  fs_pendingblocks;      /* RESERVED FROM 5.x */
277 	int32_t  fs_pendinginodes;      /* RESERVED FROM 5.x */
278 	int32_t	 fs_contigsumsize;	/* size of cluster summary array */
279 	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
280 	int32_t	 fs_inodefmt;		/* format of on-disk inodes */
281 	uint64_t fs_maxfilesize;	/* maximum representable file size */
282 	int64_t	 fs_qbmask;		/* ~fs_bmask for use with 64-bit size */
283 	int64_t	 fs_qfmask;		/* ~fs_fmask for use with 64-bit size */
284 	int32_t	 fs_state;		/* validate fs_clean field */
285 	int32_t	 fs_postblformat;	/* format of positional layout tables */
286 	int32_t	 fs_nrpos;		/* number of rotational positions */
287 	int32_t	 fs_postbloff;		/* (uint16) rotation block list head */
288 	int32_t	 fs_rotbloff;		/* (uint8) blocks for each rotation */
289 	int32_t	 fs_magic;		/* magic number */
290 	uint8_t fs_space[1];		/* list of blocks for each rotation */
291 /* actually longer */
292 };
293 
294 /*
295  * Filesystem identification
296  */
297 #define	FS_MAGIC	0x011954	/* the fast filesystem magic number */
298 #define	FS_OKAY		0x7c269d38	/* superblock checksum */
299 #define FS_42INODEFMT	-1		/* 4.2BSD inode format */
300 #define FS_44INODEFMT	2		/* 4.4BSD inode format */
301 
302 /*
303  * Preference for optimization.
304  */
305 #define FS_OPTTIME	0	/* minimize allocation time */
306 #define FS_OPTSPACE	1	/* minimize disk fragmentation */
307 
308 /*
309  * Filesystem flags.
310  */
311 #define FS_UNCLEAN    0x01    /* filesystem not clean at mount */
312 #define FS_DOSOFTDEP  0x02    /* filesystem using soft dependencies */
313 
314 /*
315  * Rotational layout table format types
316  */
317 #define FS_42POSTBLFMT		-1	/* 4.2BSD rotational table format */
318 #define FS_DYNAMICPOSTBLFMT	1	/* dynamic rotational table format */
319 /*
320  * Macros for access to superblock array structures
321  */
322 #define fs_postbl(fs, cylno) \
323     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
324     ? ((fs)->fs_opostbl[cylno]) \
325     : ((int16_t *)((uint8_t *)(fs) + \
326 	(fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
327 #define fs_rotbl(fs) \
328     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
329     ? ((fs)->fs_space) \
330     : ((uint8_t *)((uint8_t *)(fs) + (fs)->fs_rotbloff)))
331 
332 /*
333  * The size of a cylinder group is calculated by CGSIZE. The maximum size
334  * is limited by the fact that cylinder groups are at most one block.
335  * Its size is derived from the size of the maps maintained in the
336  * cylinder group and the (struct cg) size.
337  */
338 #define CGSIZE(fs) \
339     /* base cg */	(sizeof(struct cg) + sizeof(int32_t) + \
340     /* blktot size */	(fs)->fs_cpg * sizeof(int32_t) + \
341     /* blks size */	(fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
342     /* inode map */	howmany((fs)->fs_ipg, NBBY) + \
343     /* block map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
344     /* if present */	((fs)->fs_contigsumsize <= 0 ? 0 : \
345     /* cluster sum */	(fs)->fs_contigsumsize * sizeof(int32_t) + \
346     /* cluster map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
347 
348 /*
349  * Convert cylinder group to base address of its global summary info.
350  */
351 #define fs_cs(fs, indx) fs_csp[indx]
352 
353 /*
354  * Cylinder group block for a filesystem.
355  */
356 #define	CG_MAGIC	0x090255
357 struct cg {
358 	int32_t	 cg_firstfield;		/* historic cyl groups linked list */
359 	int32_t	 cg_magic;		/* magic number */
360 	ufs_time_t cg_time;		/* time last written */
361 	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
362 	int16_t	 cg_ncyl;		/* number of cyl's this cg */
363 	int16_t	 cg_niblk;		/* number of inode blocks this cg */
364 	int32_t	 cg_ndblk;		/* number of data blocks this cg */
365 	struct	csum cg_cs;		/* cylinder summary information */
366 	int32_t	 cg_rotor;		/* position of last used block */
367 	int32_t	 cg_frotor;		/* position of last used frag */
368 	int32_t	 cg_irotor;		/* position of last used inode */
369 	int32_t	 cg_frsum[MAXFRAG];	/* counts of available frags */
370 	int32_t	 cg_btotoff;		/* (int32) block totals per cylinder */
371 	int32_t	 cg_boff;		/* (uint16) free block positions */
372 	int32_t	 cg_iusedoff;		/* (uint8) used inode map */
373 	int32_t	 cg_freeoff;		/* (uint8) free block map */
374 	int32_t	 cg_nextfreeoff;	/* (uint8) next available space */
375 	int32_t	 cg_clustersumoff;	/* (uint32) counts of avail clusters */
376 	int32_t	 cg_clusteroff;		/* (uint8) free cluster map */
377 	int32_t	 cg_nclusterblks;	/* number of clusters this cg */
378 	int32_t	 cg_sparecon[13];	/* reserved for future use */
379 	uint8_t cg_space[1];		/* space for cylinder group maps */
380 /* actually longer */
381 };
382 
383 /*
384  * Macros for access to cylinder group array structures
385  */
386 #define cg_blktot(cgp) \
387     (((cgp)->cg_magic != CG_MAGIC) \
388     ? (((struct ocg *)(cgp))->cg_btot) \
389     : ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_btotoff)))
390 #define cg_blks(fs, cgp, cylno) \
391     (((cgp)->cg_magic != CG_MAGIC) \
392     ? (((struct ocg *)(cgp))->cg_b[cylno]) \
393     : ((int16_t *)((uint8_t *)(cgp) + \
394 	(cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
395 #define cg_inosused(cgp) \
396     (((cgp)->cg_magic != CG_MAGIC) \
397     ? (((struct ocg *)(cgp))->cg_iused) \
398     : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_iusedoff)))
399 #define cg_blksfree(cgp) \
400     (((cgp)->cg_magic != CG_MAGIC) \
401     ? (((struct ocg *)(cgp))->cg_free) \
402     : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_freeoff)))
403 #define cg_chkmagic(cgp) \
404     ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
405 #define cg_clustersfree(cgp) \
406     ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_clusteroff))
407 #define cg_clustersum(cgp) \
408     ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_clustersumoff))
409 
410 /*
411  * The following structure is defined
412  * for compatibility with old filesystems.
413  */
414 struct ocg {
415 	int32_t	 cg_firstfield;		/* historic linked list of cyl groups */
416 	int32_t	 cg_unused_1;		/*     used for incore cyl groups */
417 	ufs_time_t cg_time;		/* time last written */
418 	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
419 	int16_t	 cg_ncyl;		/* number of cyl's this cg */
420 	int16_t	 cg_niblk;		/* number of inode blocks this cg */
421 	int32_t	 cg_ndblk;		/* number of data blocks this cg */
422 	struct	csum cg_cs;		/* cylinder summary information */
423 	int32_t	 cg_rotor;		/* position of last used block */
424 	int32_t	 cg_frotor;		/* position of last used frag */
425 	int32_t	 cg_irotor;		/* position of last used inode */
426 	int32_t	 cg_frsum[8];		/* counts of available frags */
427 	int32_t	 cg_btot[32];		/* block totals per cylinder */
428 	int16_t	 cg_b[32][8];		/* positions of free blocks */
429 	uint8_t cg_iused[256];		/* used inode map */
430 	int32_t	 cg_magic;		/* magic number */
431 	uint8_t cg_free[1];		/* free block map */
432 /* actually longer */
433 };
434 
435 /*
436  * Turn filesystem block numbers into disk block addresses.
437  * This maps filesystem blocks to device size blocks.
438  */
439 #define fsbtodb(fs, b)	((b) << (fs)->fs_fsbtodb)
440 #define	dbtofsb(fs, b)	((b) >> (fs)->fs_fsbtodb)
441 #define	btofsb(fs, b)	((daddr_t)((b) >> ((fs)->fs_fsbtodb + DEV_BSHIFT)))
442 
443 /*
444  * Cylinder group macros to locate things in cylinder groups.
445  * They calc filesystem addresses of cylinder group data structures.
446  */
447 #define	cgbase(fs, c)	((ufs_daddr_t)((fs)->fs_fpg * (c)))
448 #define	cgdmin(fs, c)	(cgstart(fs, c) + (fs)->fs_dblkno)	/* 1st data */
449 #define	cgimin(fs, c)	(cgstart(fs, c) + (fs)->fs_iblkno)	/* inode blk */
450 #define	cgsblock(fs, c)	(cgstart(fs, c) + (fs)->fs_sblkno)	/* super blk */
451 #define	cgtod(fs, c)	(cgstart(fs, c) + (fs)->fs_cblkno)	/* cg block */
452 #define cgstart(fs, c)							\
453 	(cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
454 
455 /*
456  * Macros for handling inode numbers:
457  *     inode number to filesystem block offset.
458  *     inode number to cylinder group number.
459  *     inode number to filesystem block address.
460  */
461 #define	ino_to_cg(fs, x)	((x) / (fs)->fs_ipg)
462 #define	ino_to_fsba(fs, x)						\
463 	((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) +			\
464 	    (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
465 #define	ino_to_fsbo(fs, x)	((x) % INOPB(fs))
466 
467 /*
468  * Give cylinder group number for a filesystem block.
469  * Give cylinder group block number for a filesystem block.
470  */
471 #define	dtog(fs, d)	((d) / (fs)->fs_fpg)
472 #define	dtogd(fs, d)	((d) % (fs)->fs_fpg)
473 
474 /*
475  * Extract the bits for a block from a map.
476  * Compute the cylinder and rotational position of a cyl block addr.
477  */
478 #define blkmap(fs, map, loc) \
479     (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
480 #define cbtocylno(fs, bno) \
481     ((bno) * NSPF(fs) / (fs)->fs_spc)
482 #define cbtorpos(fs, bno) \
483     (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
484      (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
485      (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
486 
487 /*
488  * The following macros optimize certain frequently calculated
489  * quantities by using shifts and masks in place of divisions
490  * modulos and multiplications.
491  */
492 #define blkoff(fs, loc)		/* calculates (loc % fs->fs_bsize) */ \
493 	((loc) & (fs)->fs_qbmask)
494 #define fragoff(fs, loc)	/* calculates (loc % fs->fs_fsize) */ \
495 	((loc) & (fs)->fs_qfmask)
496 #define lblktosize(fs, blk)	/* calculates ((off_t)blk * fs->fs_bsize) */ \
497 	((off_t)(blk) << (fs)->fs_bshift)
498 /*
499  * These functions convert filesystem logical block numbers (typ 8K),
500  * filesystem block numbers (typ 1K), and disk block numbers to 64 bit
501  * offsets for the purposes of bread(), getblk(), etc.
502  *
503  * note: fs_nspf = number of sectors per fragment.  For some reason
504  * completely lost to me the superblock doesn't actually store the disk
505  * block size.
506  */
507 #define lblktodoff(fs, blk)	((off_t)(blk) << (fs)->fs_bshift)
508 #define fsbtodoff(fs, b)	((off_t)(b) << (fs)->fs_fshift)
509 #define dbtodoff(fs, b)		((off_t)(b) * ((fs)->fs_fsize / (fs)->fs_nspf))
510 #define dofftofsb(fs, b)	((ufs_daddr_t)((b) >> (fs)->fs_fshift))
511 
512 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */
513 #define smalllblktosize(fs, blk)    /* calculates (blk * fs->fs_bsize) */ \
514 	((blk) << (fs)->fs_bshift)
515 #define lblkno(fs, loc)		/* calculates (loc / fs->fs_bsize) */ \
516 	((loc) >> (fs)->fs_bshift)
517 #define numfrags(fs, loc)	/* calculates (loc / fs->fs_fsize) */ \
518 	((loc) >> (fs)->fs_fshift)
519 #define blkroundup(fs, size)	/* calculates roundup(size, fs->fs_bsize) */ \
520 	(((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
521 #define fragroundup(fs, size)	/* calculates roundup(size, fs->fs_fsize) */ \
522 	(((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
523 #define fragstoblks(fs, frags)	/* calculates (frags / fs->fs_frag) */ \
524 	((frags) >> (fs)->fs_fragshift)
525 #define blkstofrags(fs, blks)	/* calculates (blks * fs->fs_frag) */ \
526 	((blks) << (fs)->fs_fragshift)
527 #define fragnum(fs, fsb)	/* calculates (fsb % fs->fs_frag) */ \
528 	((fsb) & ((fs)->fs_frag - 1))
529 #define blknum(fs, fsb)		/* calculates rounddown(fsb, fs->fs_frag) */ \
530 	((fsb) &~ ((fs)->fs_frag - 1))
531 
532 /*
533  * Determine the number of available frags given a
534  * percentage to hold in reserve.
535  */
536 #define freespace(fs, percentreserved) \
537 	(blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
538 	(fs)->fs_cstotal.cs_nffree - \
539 	((off_t)((fs)->fs_dsize) * (percentreserved) / 100))
540 
541 /*
542  * Determining the size of a file block in the filesystem.
543  */
544 #define blksize(fs, ip, lbn) \
545 	(((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
546 	    ? (fs)->fs_bsize \
547 	    : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
548 #define dblksize(fs, dip, lbn) \
549 	(((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
550 	    ? (fs)->fs_bsize \
551 	    : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
552 #define sblksize(fs, size, lbn) \
553 	(((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
554 	  ? (fs)->fs_bsize \
555 	  : (fragroundup(fs, blkoff(fs, (size)))))
556 
557 /*
558  * Extract the block size for the buffer cache buffer at offset (loc)
559  * relative to the current ip->i_size, or relative to a specific ip->i_size.
560  */
561 #define blkoffsize(fs, ip, loc)	blksize(fs, ip, lblkno(fs, loc))
562 #define blkoffresize(fs, loc) sblksize(fs, loc, lblkno(fs, loc))
563 
564 /*
565  * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
566  * sector size.
567  */
568 #define	NSPB(fs)	((fs)->fs_nspf << (fs)->fs_fragshift)
569 #define	NSPF(fs)	((fs)->fs_nspf)
570 
571 /*
572  * Number of inodes in a secondary storage block/fragment.
573  */
574 #define	INOPB(fs)	((fs)->fs_inopb)
575 #define	INOPF(fs)	((fs)->fs_inopb >> (fs)->fs_fragshift)
576 
577 /*
578  * Number of indirects in a filesystem block.
579  */
580 #define	NINDIR(fs)	((fs)->fs_nindir)
581 
582 extern int inside[], around[];
583 extern u_char *fragtbl[];
584 
585 #endif /* !_VFS_UFS_FS_H_ */
586