fs.h revision 136336
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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	@(#)fs.h	8.13 (Berkeley) 3/21/95
30 * $FreeBSD: head/sys/ufs/ffs/fs.h 136336 2004-10-09 20:16:06Z njl $
31 */
32
33#ifndef _UFS_FFS_FS_H_
34#define _UFS_FFS_FS_H_
35
36/*
37 * Each disk drive contains some number of filesystems.
38 * A filesystem consists of a number of cylinder groups.
39 * Each cylinder group has inodes and data.
40 *
41 * A filesystem is described by its super-block, which in turn
42 * describes the cylinder groups.  The super-block is critical
43 * data and is replicated in each cylinder group to protect against
44 * catastrophic loss.  This is done at `newfs' time and the critical
45 * super-block data does not change, so the copies need not be
46 * referenced further unless disaster strikes.
47 *
48 * For filesystem fs, the offsets of the various blocks of interest
49 * are given in the super block as:
50 *	[fs->fs_sblkno]		Super-block
51 *	[fs->fs_cblkno]		Cylinder group block
52 *	[fs->fs_iblkno]		Inode blocks
53 *	[fs->fs_dblkno]		Data blocks
54 * The beginning of cylinder group cg in fs, is given by
55 * the ``cgbase(fs, cg)'' macro.
56 *
57 * Depending on the architecture and the media, the superblock may
58 * reside in any one of four places. For tiny media where every block
59 * counts, it is placed at the very front of the partition. Historically,
60 * UFS1 placed it 8K from the front to leave room for the disk label and
61 * a small bootstrap. For UFS2 it got moved to 64K from the front to leave
62 * room for the disk label and a bigger bootstrap, and for really piggy
63 * systems we check at 256K from the front if the first three fail. In
64 * all cases the size of the superblock will be SBLOCKSIZE. All values are
65 * given in byte-offset form, so they do not imply a sector size. The
66 * SBLOCKSEARCH specifies the order in which the locations should be searched.
67 */
68#define SBLOCK_FLOPPY	     0
69#define SBLOCK_UFS1	  8192
70#define SBLOCK_UFS2	 65536
71#define SBLOCK_PIGGY	262144
72#define SBLOCKSIZE	  8192
73#define SBLOCKSEARCH \
74	{ SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }
75
76/*
77 * Max number of fragments per block. This value is NOT tweakable.
78 */
79#define MAXFRAG 	8
80
81/*
82 * Addresses stored in inodes are capable of addressing fragments
83 * of `blocks'. File system blocks of at most size MAXBSIZE can
84 * be optionally broken into 2, 4, or 8 pieces, each of which is
85 * addressable; these pieces may be DEV_BSIZE, or some multiple of
86 * a DEV_BSIZE unit.
87 *
88 * Large files consist of exclusively large data blocks.  To avoid
89 * undue wasted disk space, the last data block of a small file may be
90 * allocated as only as many fragments of a large block as are
91 * necessary.  The filesystem format retains only a single pointer
92 * to such a fragment, which is a piece of a single large block that
93 * has been divided.  The size of such a fragment is determinable from
94 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
95 *
96 * The filesystem records space availability at the fragment level;
97 * to determine block availability, aligned fragments are examined.
98 */
99
100/*
101 * MINBSIZE is the smallest allowable block size.
102 * In order to insure that it is possible to create files of size
103 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
104 * MINBSIZE must be big enough to hold a cylinder group block,
105 * thus changes to (struct cg) must keep its size within MINBSIZE.
106 * Note that super blocks are always of size SBSIZE,
107 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
108 */
109#define MINBSIZE	4096
110
111/*
112 * The path name on which the filesystem is mounted is maintained
113 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
114 * the super block for this name.
115 */
116#define MAXMNTLEN	468
117
118/*
119 * The volume name for this filesystem is maintained in fs_volname.
120 * MAXVOLLEN defines the length of the buffer allocated.
121 */
122#define MAXVOLLEN	32
123
124/*
125 * There is a 128-byte region in the superblock reserved for in-core
126 * pointers to summary information. Originally this included an array
127 * of pointers to blocks of struct csum; now there are just a few
128 * pointers and the remaining space is padded with fs_ocsp[].
129 *
130 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
131 * is taken away to point to a contiguous array of struct csum for
132 * all cylinder groups; a second (fs_maxcluster) points to an array
133 * of cluster sizes that is computed as cylinder groups are inspected,
134 * and the third points to an array that tracks the creation of new
135 * directories. A fourth pointer, fs_active, is used when creating
136 * snapshots; it points to a bitmap of cylinder groups for which the
137 * free-block bitmap has changed since the snapshot operation began.
138 */
139#define	NOCSPTRS	((128 / sizeof(void *)) - 4)
140
141/*
142 * A summary of contiguous blocks of various sizes is maintained
143 * in each cylinder group. Normally this is set by the initial
144 * value of fs_maxcontig. To conserve space, a maximum summary size
145 * is set by FS_MAXCONTIG.
146 */
147#define FS_MAXCONTIG	16
148
149/*
150 * MINFREE gives the minimum acceptable percentage of filesystem
151 * blocks which may be free. If the freelist drops below this level
152 * only the superuser may continue to allocate blocks. This may
153 * be set to 0 if no reserve of free blocks is deemed necessary,
154 * however throughput drops by fifty percent if the filesystem
155 * is run at between 95% and 100% full; thus the minimum default
156 * value of fs_minfree is 5%. However, to get good clustering
157 * performance, 10% is a better choice. hence we use 10% as our
158 * default value. With 10% free space, fragmentation is not a
159 * problem, so we choose to optimize for time.
160 */
161#define MINFREE		8
162#define DEFAULTOPT	FS_OPTTIME
163
164/*
165 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
166 * tune the layout preferences for directories within a filesystem.
167 * His algorithm can be tuned by adjusting the following parameters
168 * which tell the system the average file size and the average number
169 * of files per directory. These defaults are well selected for typical
170 * filesystems, but may need to be tuned for odd cases like filesystems
171 * being used for squid caches or news spools.
172 */
173#define AVFILESIZ	16384	/* expected average file size */
174#define AFPDIR		64	/* expected number of files per directory */
175
176/*
177 * The maximum number of snapshot nodes that can be associated
178 * with each filesystem. This limit affects only the number of
179 * snapshot files that can be recorded within the superblock so
180 * that they can be found when the filesystem is mounted. However,
181 * maintaining too many will slow the filesystem performance, so
182 * having this limit is a good idea.
183 */
184#define FSMAXSNAP 20
185
186/*
187 * Used to identify special blocks in snapshots:
188 *
189 * BLK_NOCOPY - A block that was unallocated at the time the snapshot
190 *	was taken, hence does not need to be copied when written.
191 * BLK_SNAP - A block held by another snapshot that is not needed by this
192 *	snapshot. When the other snapshot is freed, the BLK_SNAP entries
193 *	are converted to BLK_NOCOPY. These are needed to allow fsck to
194 *	identify blocks that are in use by other snapshots (which are
195 *	expunged from this snapshot).
196 */
197#define BLK_NOCOPY ((ufs2_daddr_t)(1))
198#define BLK_SNAP ((ufs2_daddr_t)(2))
199
200/*
201 * Sysctl values for the fast filesystem.
202 */
203#define	FFS_ADJ_REFCNT		 1	/* adjust inode reference count */
204#define	FFS_ADJ_BLKCNT		 2	/* adjust inode used block count */
205#define	FFS_BLK_FREE		 3	/* free range of blocks in map */
206#define	FFS_DIR_FREE		 4	/* free specified dir inodes in map */
207#define	FFS_FILE_FREE		 5	/* free specified file inodes in map */
208#define	FFS_SET_FLAGS		 6	/* set filesystem flags */
209#define	FFS_MAXID		 7	/* number of valid ffs ids */
210
211/*
212 * Command structure passed in to the filesystem to adjust filesystem values.
213 */
214#define	FFS_CMD_VERSION		0x19790518	/* version ID */
215struct fsck_cmd {
216	int32_t	version;	/* version of command structure */
217	int32_t	handle;		/* reference to filesystem to be changed */
218	int64_t	value;		/* inode or block number to be affected */
219	int64_t	size;		/* amount or range to be adjusted */
220	int64_t	spare;		/* reserved for future use */
221};
222
223/*
224 * Per cylinder group information; summarized in blocks allocated
225 * from first cylinder group data blocks.  These blocks have to be
226 * read in from fs_csaddr (size fs_cssize) in addition to the
227 * super block.
228 */
229struct csum {
230	int32_t	cs_ndir;		/* number of directories */
231	int32_t	cs_nbfree;		/* number of free blocks */
232	int32_t	cs_nifree;		/* number of free inodes */
233	int32_t	cs_nffree;		/* number of free frags */
234};
235struct csum_total {
236	int64_t	cs_ndir;		/* number of directories */
237	int64_t	cs_nbfree;		/* number of free blocks */
238	int64_t	cs_nifree;		/* number of free inodes */
239	int64_t	cs_nffree;		/* number of free frags */
240	int64_t	cs_numclusters;		/* number of free clusters */
241	int64_t	cs_spare[3];		/* future expansion */
242};
243
244/*
245 * Super block for an FFS filesystem.
246 */
247struct fs {
248	int32_t	 fs_firstfield;		/* historic filesystem linked list, */
249	int32_t	 fs_unused_1;		/*     used for incore super blocks */
250	int32_t	 fs_sblkno;		/* offset of super-block in filesys */
251	int32_t	 fs_cblkno;		/* offset of cyl-block in filesys */
252	int32_t	 fs_iblkno;		/* offset of inode-blocks in filesys */
253	int32_t	 fs_dblkno;		/* offset of first data after cg */
254	int32_t	 fs_old_cgoffset;	/* cylinder group offset in cylinder */
255	int32_t	 fs_old_cgmask;		/* used to calc mod fs_ntrak */
256	int32_t  fs_old_time;		/* last time written */
257	int32_t	 fs_old_size;		/* number of blocks in fs */
258	int32_t	 fs_old_dsize;		/* number of data blocks in fs */
259	int32_t	 fs_ncg;		/* number of cylinder groups */
260	int32_t	 fs_bsize;		/* size of basic blocks in fs */
261	int32_t	 fs_fsize;		/* size of frag blocks in fs */
262	int32_t	 fs_frag;		/* number of frags in a block in fs */
263/* these are configuration parameters */
264	int32_t	 fs_minfree;		/* minimum percentage of free blocks */
265	int32_t	 fs_old_rotdelay;	/* num of ms for optimal next block */
266	int32_t	 fs_old_rps;		/* disk revolutions per second */
267/* these fields can be computed from the others */
268	int32_t	 fs_bmask;		/* ``blkoff'' calc of blk offsets */
269	int32_t	 fs_fmask;		/* ``fragoff'' calc of frag offsets */
270	int32_t	 fs_bshift;		/* ``lblkno'' calc of logical blkno */
271	int32_t	 fs_fshift;		/* ``numfrags'' calc number of frags */
272/* these are configuration parameters */
273	int32_t	 fs_maxcontig;		/* max number of contiguous blks */
274	int32_t	 fs_maxbpg;		/* max number of blks per cyl group */
275/* these fields can be computed from the others */
276	int32_t	 fs_fragshift;		/* block to frag shift */
277	int32_t	 fs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
278	int32_t	 fs_sbsize;		/* actual size of super block */
279	int32_t	 fs_spare1[2];		/* old fs_csmask */
280					/* old fs_csshift */
281	int32_t	 fs_nindir;		/* value of NINDIR */
282	int32_t	 fs_inopb;		/* value of INOPB */
283	int32_t	 fs_old_nspf;		/* value of NSPF */
284/* yet another configuration parameter */
285	int32_t	 fs_optim;		/* optimization preference, see below */
286	int32_t	 fs_old_npsect;		/* # sectors/track including spares */
287	int32_t	 fs_old_interleave;	/* hardware sector interleave */
288	int32_t	 fs_old_trackskew;	/* sector 0 skew, per track */
289	int32_t	 fs_id[2];		/* unique filesystem id */
290/* sizes determined by number of cylinder groups and their sizes */
291	int32_t	 fs_old_csaddr;		/* blk addr of cyl grp summary area */
292	int32_t	 fs_cssize;		/* size of cyl grp summary area */
293	int32_t	 fs_cgsize;		/* cylinder group size */
294	int32_t	 fs_spare2;		/* old fs_ntrak */
295	int32_t	 fs_old_nsect;		/* sectors per track */
296	int32_t  fs_old_spc;		/* sectors per cylinder */
297	int32_t	 fs_old_ncyl;		/* cylinders in filesystem */
298	int32_t	 fs_old_cpg;		/* cylinders per group */
299	int32_t	 fs_ipg;		/* inodes per group */
300	int32_t	 fs_fpg;		/* blocks per group * fs_frag */
301/* this data must be re-computed after crashes */
302	struct	csum fs_old_cstotal;	/* cylinder summary information */
303/* these fields are cleared at mount time */
304	int8_t   fs_fmod;		/* super block modified flag */
305	int8_t   fs_clean;		/* filesystem is clean flag */
306	int8_t 	 fs_ronly;		/* mounted read-only flag */
307	int8_t   fs_old_flags;		/* old FS_ flags */
308	u_char	 fs_fsmnt[MAXMNTLEN];	/* name mounted on */
309	u_char	 fs_volname[MAXVOLLEN];	/* volume name */
310	u_int64_t fs_swuid;		/* system-wide uid */
311	int32_t  fs_pad;		/* due to alignment of fs_swuid */
312/* these fields retain the current block allocation info */
313	int32_t	 fs_cgrotor;		/* last cg searched */
314	void 	*fs_ocsp[NOCSPTRS];	/* padding; was list of fs_cs buffers */
315	u_int8_t *fs_contigdirs;	/* # of contiguously allocated dirs */
316	struct	csum *fs_csp;		/* cg summary info buffer for fs_cs */
317	int32_t	*fs_maxcluster;		/* max cluster in each cyl group */
318	u_int	*fs_active;		/* used by snapshots to track fs */
319	int32_t	 fs_old_cpc;		/* cyl per cycle in postbl */
320	int32_t	 fs_maxbsize;		/* maximum blocking factor permitted */
321	int64_t	 fs_sparecon64[17];	/* old rotation block list head */
322	int64_t	 fs_sblockloc;		/* byte offset of standard superblock */
323	struct	csum_total fs_cstotal;	/* cylinder summary information */
324	ufs_time_t fs_time;		/* last time written */
325	int64_t	 fs_size;		/* number of blocks in fs */
326	int64_t	 fs_dsize;		/* number of data blocks in fs */
327	ufs2_daddr_t fs_csaddr;		/* blk addr of cyl grp summary area */
328	int64_t	 fs_pendingblocks;	/* blocks in process of being freed */
329	int32_t	 fs_pendinginodes;	/* inodes in process of being freed */
330	int32_t	 fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
331	int32_t	 fs_avgfilesize;	/* expected average file size */
332	int32_t	 fs_avgfpdir;		/* expected # of files per directory */
333	int32_t	 fs_save_cgsize;	/* save real cg size to use fs_bsize */
334	int32_t	 fs_sparecon32[26];	/* reserved for future constants */
335	int32_t  fs_flags;		/* see FS_ flags below */
336	int32_t	 fs_contigsumsize;	/* size of cluster summary array */
337	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
338	int32_t	 fs_old_inodefmt;	/* format of on-disk inodes */
339	u_int64_t fs_maxfilesize;	/* maximum representable file size */
340	int64_t	 fs_qbmask;		/* ~fs_bmask for use with 64-bit size */
341	int64_t	 fs_qfmask;		/* ~fs_fmask for use with 64-bit size */
342	int32_t	 fs_state;		/* validate fs_clean field */
343	int32_t	 fs_old_postblformat;	/* format of positional layout tables */
344	int32_t	 fs_old_nrpos;		/* number of rotational positions */
345	int32_t	 fs_spare5[2];		/* old fs_postbloff */
346					/* old fs_rotbloff */
347	int32_t	 fs_magic;		/* magic number */
348};
349
350/* Sanity checking. */
351#ifdef CTASSERT
352CTASSERT(sizeof(struct fs) == 1376);
353#endif
354
355/*
356 * Filesystem identification
357 */
358#define	FS_UFS1_MAGIC	0x011954	/* UFS1 fast filesystem magic number */
359#define	FS_UFS2_MAGIC	0x19540119	/* UFS2 fast filesystem magic number */
360#define	FS_BAD_MAGIC	0x19960408	/* UFS incomplete newfs magic number */
361#define	FS_OKAY		0x7c269d38	/* superblock checksum */
362#define FS_42INODEFMT	-1		/* 4.2BSD inode format */
363#define FS_44INODEFMT	2		/* 4.4BSD inode format */
364
365/*
366 * Preference for optimization.
367 */
368#define FS_OPTTIME	0	/* minimize allocation time */
369#define FS_OPTSPACE	1	/* minimize disk fragmentation */
370
371/*
372 * Filesystem flags.
373 *
374 * The FS_UNCLEAN flag is set by the kernel when the filesystem was
375 * mounted with fs_clean set to zero. The FS_DOSOFTDEP flag indicates
376 * that the filesystem should be managed by the soft updates code.
377 * Note that the FS_NEEDSFSCK flag is set and cleared only by the
378 * fsck utility. It is set when background fsck finds an unexpected
379 * inconsistency which requires a traditional foreground fsck to be
380 * run. Such inconsistencies should only be found after an uncorrectable
381 * disk error. A foreground fsck will clear the FS_NEEDSFSCK flag when
382 * it has successfully cleaned up the filesystem. The kernel uses this
383 * flag to enforce that inconsistent filesystems be mounted read-only.
384 * The FS_INDEXDIRS flag when set indicates that the kernel maintains
385 * on-disk auxiliary indexes (such as B-trees) for speeding directory
386 * accesses. Kernels that do not support auxiliary indicies clear the
387 * flag to indicate that the indicies need to be rebuilt (by fsck) before
388 * they can be used.
389 *
390 * FS_ACLS indicates that ACLs are administratively enabled for the
391 * file system, so they should be loaded from extended attributes,
392 * observed for access control purposes, and be administered by object
393 * owners.  FS_MULTILABEL indicates that the TrustedBSD MAC Framework
394 * should attempt to back MAC labels into extended attributes on the
395 * file system rather than maintain a single mount label for all
396 * objects.
397 */
398#define FS_UNCLEAN    0x01	/* filesystem not clean at mount */
399#define FS_DOSOFTDEP  0x02	/* filesystem using soft dependencies */
400#define FS_NEEDSFSCK  0x04	/* filesystem needs sync fsck before mount */
401#define FS_INDEXDIRS  0x08	/* kernel supports indexed directories */
402#define FS_ACLS       0x10	/* file system has ACLs enabled */
403#define FS_MULTILABEL 0x20	/* file system is MAC multi-label */
404#define FS_FLAGS_UPDATED 0x80	/* flags have been moved to new location */
405
406/*
407 * Macros to access bits in the fs_active array.
408 */
409#define	ACTIVECGNUM(fs, cg)	((fs)->fs_active[(cg) / (NBBY * sizeof(int))])
410#define	ACTIVECGOFF(cg)		(1 << ((cg) % (NBBY * sizeof(int))))
411
412/*
413 * The size of a cylinder group is calculated by CGSIZE. The maximum size
414 * is limited by the fact that cylinder groups are at most one block.
415 * Its size is derived from the size of the maps maintained in the
416 * cylinder group and the (struct cg) size.
417 */
418#define CGSIZE(fs) \
419    /* base cg */	(sizeof(struct cg) + sizeof(int32_t) + \
420    /* old btotoff */	(fs)->fs_old_cpg * sizeof(int32_t) + \
421    /* old boff */	(fs)->fs_old_cpg * sizeof(u_int16_t) + \
422    /* inode map */	howmany((fs)->fs_ipg, NBBY) + \
423    /* block map */	howmany((fs)->fs_fpg, NBBY) +\
424    /* if present */	((fs)->fs_contigsumsize <= 0 ? 0 : \
425    /* cluster sum */	(fs)->fs_contigsumsize * sizeof(int32_t) + \
426    /* cluster map */	howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY)))
427
428/*
429 * The minimal number of cylinder groups that should be created.
430 */
431#define MINCYLGRPS	4
432
433/*
434 * Convert cylinder group to base address of its global summary info.
435 */
436#define fs_cs(fs, indx) fs_csp[indx]
437
438/*
439 * Cylinder group block for a filesystem.
440 */
441#define	CG_MAGIC	0x090255
442struct cg {
443	int32_t	 cg_firstfield;		/* historic cyl groups linked list */
444	int32_t	 cg_magic;		/* magic number */
445	int32_t  cg_old_time;		/* time last written */
446	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
447	int16_t	 cg_old_ncyl;		/* number of cyl's this cg */
448	int16_t  cg_old_niblk;		/* number of inode blocks this cg */
449	int32_t	 cg_ndblk;		/* number of data blocks this cg */
450	struct	csum cg_cs;		/* cylinder summary information */
451	int32_t	 cg_rotor;		/* position of last used block */
452	int32_t	 cg_frotor;		/* position of last used frag */
453	int32_t	 cg_irotor;		/* position of last used inode */
454	int32_t	 cg_frsum[MAXFRAG];	/* counts of available frags */
455	int32_t	 cg_old_btotoff;	/* (int32) block totals per cylinder */
456	int32_t	 cg_old_boff;		/* (u_int16) free block positions */
457	int32_t	 cg_iusedoff;		/* (u_int8) used inode map */
458	int32_t	 cg_freeoff;		/* (u_int8) free block map */
459	int32_t	 cg_nextfreeoff;	/* (u_int8) next available space */
460	int32_t	 cg_clustersumoff;	/* (u_int32) counts of avail clusters */
461	int32_t	 cg_clusteroff;		/* (u_int8) free cluster map */
462	int32_t	 cg_nclusterblks;	/* number of clusters this cg */
463	int32_t  cg_niblk;		/* number of inode blocks this cg */
464	int32_t	 cg_initediblk;		/* last initialized inode */
465	int32_t	 cg_sparecon32[3];	/* reserved for future use */
466	ufs_time_t cg_time;		/* time last written */
467	int64_t	 cg_sparecon64[3];	/* reserved for future use */
468	u_int8_t cg_space[1];		/* space for cylinder group maps */
469/* actually longer */
470};
471
472/*
473 * Macros for access to cylinder group array structures
474 */
475#define cg_chkmagic(cgp) ((cgp)->cg_magic == CG_MAGIC)
476#define cg_inosused(cgp) \
477    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))
478#define cg_blksfree(cgp) \
479    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))
480#define cg_clustersfree(cgp) \
481    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
482#define cg_clustersum(cgp) \
483    ((int32_t *)((uintptr_t)(cgp) + (cgp)->cg_clustersumoff))
484
485/*
486 * Turn filesystem block numbers into disk block addresses.
487 * This maps filesystem blocks to device size blocks.
488 */
489#define	fsbtodb(fs, b)	((daddr_t)(b) << (fs)->fs_fsbtodb)
490#define	dbtofsb(fs, b)	((b) >> (fs)->fs_fsbtodb)
491
492/*
493 * Cylinder group macros to locate things in cylinder groups.
494 * They calc filesystem addresses of cylinder group data structures.
495 */
496#define	cgbase(fs, c)	(((ufs2_daddr_t)(fs)->fs_fpg) * (c))
497#define	cgdmin(fs, c)	(cgstart(fs, c) + (fs)->fs_dblkno)	/* 1st data */
498#define	cgimin(fs, c)	(cgstart(fs, c) + (fs)->fs_iblkno)	/* inode blk */
499#define	cgsblock(fs, c)	(cgstart(fs, c) + (fs)->fs_sblkno)	/* super blk */
500#define	cgtod(fs, c)	(cgstart(fs, c) + (fs)->fs_cblkno)	/* cg block */
501#define cgstart(fs, c)							\
502       ((fs)->fs_magic == FS_UFS2_MAGIC ? cgbase(fs, c) :		\
503       (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask))))
504
505/*
506 * Macros for handling inode numbers:
507 *     inode number to filesystem block offset.
508 *     inode number to cylinder group number.
509 *     inode number to filesystem block address.
510 */
511#define	ino_to_cg(fs, x)	((x) / (fs)->fs_ipg)
512#define	ino_to_fsba(fs, x)						\
513	((ufs2_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) +			\
514	    (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
515#define	ino_to_fsbo(fs, x)	((x) % INOPB(fs))
516
517/*
518 * Give cylinder group number for a filesystem block.
519 * Give cylinder group block number for a filesystem block.
520 */
521#define	dtog(fs, d)	((d) / (fs)->fs_fpg)
522#define	dtogd(fs, d)	((d) % (fs)->fs_fpg)
523
524/*
525 * Extract the bits for a block from a map.
526 * Compute the cylinder and rotational position of a cyl block addr.
527 */
528#define blkmap(fs, map, loc) \
529    (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
530
531/*
532 * The following macros optimize certain frequently calculated
533 * quantities by using shifts and masks in place of divisions
534 * modulos and multiplications.
535 */
536#define blkoff(fs, loc)		/* calculates (loc % fs->fs_bsize) */ \
537	((loc) & (fs)->fs_qbmask)
538#define fragoff(fs, loc)	/* calculates (loc % fs->fs_fsize) */ \
539	((loc) & (fs)->fs_qfmask)
540#define lfragtosize(fs, frag)	/* calculates ((off_t)frag * fs->fs_fsize) */ \
541	(((off_t)(frag)) << (fs)->fs_fshift)
542#define lblktosize(fs, blk)	/* calculates ((off_t)blk * fs->fs_bsize) */ \
543	(((off_t)(blk)) << (fs)->fs_bshift)
544/* Use this only when `blk' is known to be small, e.g., < NDADDR. */
545#define smalllblktosize(fs, blk)    /* calculates (blk * fs->fs_bsize) */ \
546	((blk) << (fs)->fs_bshift)
547#define lblkno(fs, loc)		/* calculates (loc / fs->fs_bsize) */ \
548	((loc) >> (fs)->fs_bshift)
549#define numfrags(fs, loc)	/* calculates (loc / fs->fs_fsize) */ \
550	((loc) >> (fs)->fs_fshift)
551#define blkroundup(fs, size)	/* calculates roundup(size, fs->fs_bsize) */ \
552	(((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
553#define fragroundup(fs, size)	/* calculates roundup(size, fs->fs_fsize) */ \
554	(((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
555#define fragstoblks(fs, frags)	/* calculates (frags / fs->fs_frag) */ \
556	((frags) >> (fs)->fs_fragshift)
557#define blkstofrags(fs, blks)	/* calculates (blks * fs->fs_frag) */ \
558	((blks) << (fs)->fs_fragshift)
559#define fragnum(fs, fsb)	/* calculates (fsb % fs->fs_frag) */ \
560	((fsb) & ((fs)->fs_frag - 1))
561#define blknum(fs, fsb)		/* calculates rounddown(fsb, fs->fs_frag) */ \
562	((fsb) &~ ((fs)->fs_frag - 1))
563
564/*
565 * Determine the number of available frags given a
566 * percentage to hold in reserve.
567 */
568#define freespace(fs, percentreserved) \
569	(blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
570	(fs)->fs_cstotal.cs_nffree - \
571	(((off_t)((fs)->fs_dsize)) * (percentreserved) / 100))
572
573/*
574 * Determining the size of a file block in the filesystem.
575 */
576#define blksize(fs, ip, lbn) \
577	(((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
578	    ? (fs)->fs_bsize \
579	    : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
580#define sblksize(fs, size, lbn) \
581	(((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
582	  ? (fs)->fs_bsize \
583	  : (fragroundup(fs, blkoff(fs, (size)))))
584
585
586/*
587 * Number of inodes in a secondary storage block/fragment.
588 */
589#define	INOPB(fs)	((fs)->fs_inopb)
590#define	INOPF(fs)	((fs)->fs_inopb >> (fs)->fs_fragshift)
591
592/*
593 * Number of indirects in a filesystem block.
594 */
595#define	NINDIR(fs)	((fs)->fs_nindir)
596
597extern int inside[], around[];
598extern u_char *fragtbl[];
599
600#endif
601