1 /**	$MirOS: src/usr.sbin/makefs/nbsrc/sys/ufs/ffs/fs.h,v 1.6 2010/09/21 21:53:24 tg Exp $ */
2 /*	$NetBSD: fs.h,v 1.55 2010/01/31 10:54:10 mlelstv Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)fs.h	8.13 (Berkeley) 3/21/95
33  */
34 
35 /*
36  * NOTE: COORDINATE ON-DISK FORMAT CHANGES WITH THE FREEBSD PROJECT.
37  */
38 
39 #ifndef	_UFS_FFS_FS_H_
40 #define	_UFS_FFS_FS_H_
41 
42 /*
43  * Each disk drive contains some number of file systems.
44  * A file system consists of a number of cylinder groups.
45  * Each cylinder group has inodes and data.
46  *
47  * A file system is described by its super-block, which in turn
48  * describes the cylinder groups.  The super-block is critical
49  * data and is replicated in each cylinder group to protect against
50  * catastrophic loss.  This is done at `newfs' time and the critical
51  * super-block data does not change, so the copies need not be
52  * referenced further unless disaster strikes.
53  *
54  * For file system fs, the offsets of the various blocks of interest
55  * are given in the super block as:
56  *	[fs->fs_sblkno]		Super-block
57  *	[fs->fs_cblkno]		Cylinder group block
58  *	[fs->fs_iblkno]		Inode blocks
59  *	[fs->fs_dblkno]		Data blocks
60  * The beginning of cylinder group cg in fs, is given by
61  * the ``cgbase(fs, cg)'' macro.
62  *
63  * Depending on the architecture and the media, the superblock may
64  * reside in any one of four places. For tiny media where every block
65  * counts, it is placed at the very front of the partition. Historically,
66  * UFS1 placed it 8K from the front to leave room for the disk label and
67  * a small bootstrap. For UFS2 it got moved to 64K from the front to leave
68  * room for the disk label and a bigger bootstrap, and for really piggy
69  * systems we check at 256K from the front if the first three fail. In
70  * all cases the size of the superblock will be SBLOCKSIZE. All values are
71  * given in byte-offset form, so they do not imply a sector size. The
72  * SBLOCKSEARCH specifies the order in which the locations should be searched.
73  *
74  * Unfortunately the UFS2/FFSv2 change was done without adequate consideration
75  * of backward compatibility.  In particular 'newfs' for a FFSv2 partition
76  * must overwrite any old FFSv1 superblock at 8k, and preferrably as many
77  * of the alternates as it can find - otherwise attempting to mount on a
78  * system that only supports FFSv1 is likely to succeed!.
79  * For a small FFSv1 filesystem, an old FFSv2 superblock can be left on
80  * the disk, and a system that tries to find an FFSv2 filesystem in preference
81  * to and FFSv1 one (as NetBSD does) can mount the old FFSv2 filesystem.
82  * As a added bonus, the 'first alternate' superblock of a FFSv1 filesystem
83  * with 64k blocks is at 64k - just where the code looks first when playing
84  * 'hunt the superblock'.
85  *
86  * The ffsv2 superblock layout (which might contain an ffsv1 filesystem)
87  * can be detected by checking for sb->fs_old_flags & FS_FLAGS_UPDATED.
88  * This is the default superblock type for NetBSD since ffsv2 support was added.
89  */
90 #define	BBSIZE		8192
91 #define	BBOFF		((off_t)(0))
92 #define	BBLOCK		((daddr_t)(0))
93 
94 #define	SBLOCK_FLOPPY      0
95 #define	SBLOCK_UFS1     8192
96 #define	SBLOCK_UFS2    65536
97 #define	SBLOCK_PIGGY  262144
98 #define	SBLOCKSIZE      8192
99 /*
100  * NB: Do not, under any circumstances, look for an ffsv1 filesystem at
101  * SBLOCK_UFS2.  Doing so will find the wrong superblock for filesystems
102  * with a 64k block size.
103  */
104 #define	SBLOCKSEARCH \
105 	{ SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }
106 
107 /*
108  * Max number of fragments per block. This value is NOT tweakable.
109  */
110 #define	MAXFRAG		8
111 
112 
113 
114 /*
115  * Addresses stored in inodes are capable of addressing fragments
116  * of `blocks'. File system blocks of at most size MAXBSIZE can
117  * be optionally broken into 2, 4, or 8 pieces, each of which is
118  * addressable; these pieces may be DEV_BSIZE, or some multiple of
119  * a DEV_BSIZE unit.
120  *
121  * Large files consist of exclusively large data blocks.  To avoid
122  * undue wasted disk space, the last data block of a small file may be
123  * allocated as only as many fragments of a large block as are
124  * necessary.  The file system format retains only a single pointer
125  * to such a fragment, which is a piece of a single large block that
126  * has been divided.  The size of such a fragment is determinable from
127  * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
128  *
129  * The file system records space availability at the fragment level;
130  * to determine block availability, aligned fragments are examined.
131  */
132 
133 /*
134  * MINBSIZE is the smallest allowable block size.
135  * In order to insure that it is possible to create files of size
136  * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
137  * MINBSIZE must be big enough to hold a cylinder group block,
138  * thus changes to (struct cg) must keep its size within MINBSIZE.
139  * Note that super blocks are always of size SBSIZE,
140  * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
141  */
142 #define	MINBSIZE	4096
143 
144 /*
145  * The path name on which the file system is mounted is maintained
146  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
147  * the super block for this name.
148  */
149 #define	MAXMNTLEN	468
150 
151 /*
152  * The volume name for this filesystem is maintained in fs_volname.
153  * MAXVOLLEN defines the length of the buffer allocated.
154  * This space used to be part of of fs_fsmnt.
155  */
156 #define	MAXVOLLEN	32
157 
158 /*
159  * There is a 128-byte region in the superblock reserved for in-core
160  * pointers to summary information. Originally this included an array
161  * of pointers to blocks of struct csum; now there are just four
162  * pointers and the remaining space is padded with fs_ocsp[].
163  * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
164  * is taken away to point to a contiguous array of struct csum for
165  * all cylinder groups; a second (fs_maxcluster) points to an array
166  * of cluster sizes that is computed as cylinder groups are inspected;
167  * the third (fs_contigdirs) points to an array that tracks the
168  * creation of new directories; and the fourth (fs_active) is used
169  * by snapshots.
170  */
171 #define	NOCSPTRS	((128 / sizeof(void *)) - 4)
172 
173 /*
174  * A summary of contiguous blocks of various sizes is maintained
175  * in each cylinder group. Normally this is set by the initial
176  * value of fs_maxcontig. To conserve space, a maximum summary size
177  * is set by FS_MAXCONTIG.
178  */
179 #define	FS_MAXCONTIG	16
180 
181 /*
182  * The maximum number of snapshot nodes that can be associated
183  * with each filesystem. This limit affects only the number of
184  * snapshot files that can be recorded within the superblock so
185  * that they can be found when the filesystem is mounted. However,
186  * maintaining too many will slow the filesystem performance, so
187  * having this limit is a good idea.
188  */
189 #define	FSMAXSNAP 20
190 
191 /*
192  * Used to identify special blocks in snapshots:
193  *
194  * BLK_NOCOPY - A block that was unallocated at the time the snapshot
195  *      was taken, hence does not need to be copied when written.
196  * BLK_SNAP - A block held by another snapshot that is not needed by this
197  *      snapshot. When the other snapshot is freed, the BLK_SNAP entries
198  *      are converted to BLK_NOCOPY. These are needed to allow fsck to
199  *      identify blocks that are in use by other snapshots (which are
200  *      expunged from this snapshot).
201  */
202 #define	BLK_NOCOPY	((daddr_t)(1))
203 #define	BLK_SNAP	((daddr_t)(2))
204 
205 /*
206  * MINFREE gives the minimum acceptable percentage of file system
207  * blocks which may be free. If the freelist drops below this level
208  * only the superuser may continue to allocate blocks. This may
209  * be set to 0 if no reserve of free blocks is deemed necessary,
210  * however throughput drops by fifty percent if the file system
211  * is run at between 95% and 100% full; thus the minimum default
212  * value of fs_minfree is 5%. However, to get good clustering
213  * performance, 10% is a better choice. This value is used only
214  * when creating a file system and can be overriden from the
215  * command line. By default we choose to optimize for time.
216  */
217 #define	MINFREE		5
218 #define	DEFAULTOPT	FS_OPTTIME
219 
220 /*
221  * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
222  * tune the layout preferences for directories within a filesystem.
223  * His algorithm can be tuned by adjusting the following parameters
224  * which tell the system the average file size and the average number
225  * of files per directory. These defaults are well selected for typical
226  * filesystems, but may need to be tuned for odd cases like filesystems
227  * being used for squid caches or news spools.
228  */
229 #define	AVFILESIZ	16384	/* expected average file size */
230 #define	AFPDIR		64	/* expected number of files per directory */
231 
232 /*
233  * Per cylinder group information; summarized in blocks allocated
234  * from first cylinder group data blocks.  These blocks have to be
235  * read in from fs_csaddr (size fs_cssize) in addition to the
236  * super block.
237  */
238 struct csum {
239 	int32_t	cs_ndir;		/* number of directories */
240 	int32_t	cs_nbfree;		/* number of free blocks */
241 	int32_t	cs_nifree;		/* number of free inodes */
242 	int32_t	cs_nffree;		/* number of free frags */
243 };
244 
245 struct csum_total {
246 	int64_t cs_ndir;		/* number of directories */
247 	int64_t cs_nbfree;		/* number of free blocks */
248 	int64_t cs_nifree;		/* number of free inodes */
249 	int64_t cs_nffree;		/* number of free frags */
250 	int64_t cs_spare[4];		/* future expansion */
251 };
252 
253 
254 /*
255  * Super block for an FFS file system in memory.
256  */
257 struct fs {
258 	int32_t	fs_historic_start[2];	/* used by MirBSD to store entropy */
259 #define fs_firstfield	fs_historic_start[0]	/* file system linked list, */
260 #define fs_unused_1	fs_historic_start[1]	/* used for incore superblk */
261 	int32_t  fs_sblkno;		/* addr of super-block in filesys */
262 	int32_t  fs_cblkno;		/* offset of cyl-block in filesys */
263 	int32_t  fs_iblkno;		/* offset of inode-blocks in filesys */
264 	int32_t  fs_dblkno;		/* offset of first data after cg */
265 	int32_t	 fs_old_cgoffset;	/* cylinder group offset in cylinder */
266 	int32_t	 fs_old_cgmask;		/* used to calc mod fs_ntrak */
267 	int32_t	 fs_old_time;		/* last time written */
268 	int32_t	 fs_old_size;		/* number of blocks in fs */
269 	int32_t	 fs_old_dsize;		/* number of data blocks in fs */
270 	int32_t	 fs_ncg;		/* number of cylinder groups */
271 	int32_t	 fs_bsize;		/* size of basic blocks in fs */
272 	int32_t	 fs_fsize;		/* size of frag blocks in fs */
273 	int32_t	 fs_frag;		/* number of frags in a block in fs */
274 /* these are configuration parameters */
275 	int32_t	 fs_minfree;		/* minimum percentage of free blocks */
276 	int32_t	 fs_old_rotdelay;	/* num of ms for optimal next block */
277 	int32_t	 fs_old_rps;		/* disk revolutions per second */
278 /* these fields can be computed from the others */
279 	int32_t	 fs_bmask;		/* ``blkoff'' calc of blk offsets */
280 	int32_t	 fs_fmask;		/* ``fragoff'' calc of frag offsets */
281 	int32_t	 fs_bshift;		/* ``lblkno'' calc of logical blkno */
282 	int32_t	 fs_fshift;		/* ``numfrags'' calc number of frags */
283 /* these are configuration parameters */
284 	int32_t	 fs_maxcontig;		/* max number of contiguous blks */
285 	int32_t	 fs_maxbpg;		/* max number of blks per cyl group */
286 /* these fields can be computed from the others */
287 	int32_t	 fs_fragshift;		/* block to frag shift */
288 	int32_t	 fs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
289 	int32_t	 fs_sbsize;		/* actual size of super block */
290 	int32_t	 fs_spare1[2];		/* old fs_csmask */
291 					/* old fs_csshift */
292 	int32_t	 fs_nindir;		/* value of NINDIR */
293 	int32_t	 fs_inopb;		/* value of INOPB */
294 	int32_t	 fs_old_nspf;		/* value of NSPF */
295 /* yet another configuration parameter */
296 	int32_t	 fs_optim;		/* optimization preference, see below */
297 /* these fields are derived from the hardware */
298 	int32_t	 fs_old_npsect;		/* # sectors/track including spares */
299 	int32_t	 fs_old_interleave;	/* hardware sector interleave */
300 	int32_t	 fs_old_trackskew;	/* sector 0 skew, per track */
301 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
302 	int32_t	 fs_id[2];		/* unique file system id */
303 /* sizes determined by number of cylinder groups and their sizes */
304 	int32_t  fs_old_csaddr;		/* blk addr of cyl grp summary area */
305 	int32_t	 fs_cssize;		/* size of cyl grp summary area */
306 	int32_t	 fs_cgsize;		/* cylinder group size */
307 /* these fields are derived from the hardware */
308 	int32_t	 fs_spare2;		/* old fs_ntrak */
309 	int32_t	 fs_old_nsect;		/* sectors per track */
310 	int32_t	 fs_old_spc;		/* sectors per cylinder */
311 	int32_t	 fs_old_ncyl;		/* cylinders in file system */
312 	int32_t	 fs_old_cpg;		/* cylinders per group */
313 	int32_t	 fs_ipg;		/* inodes per group */
314 	int32_t	 fs_fpg;		/* blocks per group * fs_frag */
315 /* this data must be re-computed after crashes */
316 	struct	csum fs_old_cstotal;	/* cylinder summary information */
317 /* these fields are cleared at mount time */
318 	int8_t	 fs_fmod;		/* super block modified flag */
319 	uint8_t	 fs_clean;		/* file system is clean flag */
320 	int8_t	 fs_ronly;		/* mounted read-only flag */
321 	uint8_t	 fs_old_flags;		/* see FS_ flags below */
322 	u_char	 fs_fsmnt[MAXMNTLEN];	/* name mounted on */
323 	u_char   fs_volname[MAXVOLLEN];	/* volume name */
324 	uint64_t fs_swuid;		/* system-wide uid */
325 	int32_t	 fs_pad;
326 /* these fields retain the current block allocation info */
327 	int32_t	 fs_cgrotor;		/* last cg searched (UNUSED) */
328 	void 	*fs_ocsp[NOCSPTRS];	/* padding; was list of fs_cs buffers */
329 	u_int8_t *fs_contigdirs;	/* # of contiguously allocated dirs */
330 	struct csum *fs_csp;		/* cg summary info buffer for fs_cs */
331 	int32_t	*fs_maxcluster;		/* max cluster in each cyl group */
332 	u_char	*fs_active;		/* used by snapshots to track fs */
333 	int32_t	 fs_old_cpc;		/* cyl per cycle in postbl */
334 /* this area is otherwise allocated unless fs_old_flags & FS_FLAGS_UPDATED */
335 	int32_t	 fs_maxbsize;		/* maximum blocking factor permitted */
336 	uint8_t	 fs_journal_version;	/* journal format version */
337 	uint8_t	 fs_journal_location;	/* journal location type */
338 	uint8_t	 fs_journal_reserved[2];/* reserved for future use */
339 	uint32_t fs_journal_flags;	/* journal flags */
340 	uint64_t fs_journallocs[4];	/* location info for journal */
341 	int64_t	 fs_sparecon64[12];	/* reserved for future use */
342 	int64_t	 fs_sblockloc;		/* byte offset of standard superblock */
343 	struct	csum_total fs_cstotal;	/* cylinder summary information */
344 	int64_t  fs_time;		/* last time written */
345 	int64_t	 fs_size;		/* number of blocks in fs */
346 	int64_t	 fs_dsize;		/* number of data blocks in fs */
347 	int64_t  fs_csaddr;		/* blk addr of cyl grp summary area */
348 	int64_t	 fs_pendingblocks;	/* blocks in process of being freed */
349 	int32_t	 fs_pendinginodes;	/* inodes in process of being freed */
350 	int32_t	 fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
351 /* back to stuff that has been around a while */
352 	int32_t	 fs_avgfilesize;	/* expected average file size */
353 	int32_t	 fs_avgfpdir;		/* expected # of files per directory */
354 	int32_t	 fs_save_cgsize;	/* save real cg size to use fs_bsize */
355 	int32_t	 fs_sparecon32[26];	/* reserved for future constants */
356 	uint32_t fs_flags;		/* see FS_ flags below */
357 /* back to stuff that has been around a while (again) */
358 	int32_t	 fs_contigsumsize;	/* size of cluster summary array */
359 	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
360 	int32_t	 fs_old_inodefmt;	/* format of on-disk inodes */
361 	u_int64_t fs_maxfilesize;	/* maximum representable file size */
362 	int64_t	 fs_qbmask;		/* ~fs_bmask for use with 64-bit size */
363 	int64_t	 fs_qfmask;		/* ~fs_fmask for use with 64-bit size */
364 	int32_t	 fs_state;		/* validate fs_clean field (UNUSED) */
365 	int32_t	 fs_old_postblformat;	/* format of positional layout tables */
366 	int32_t	 fs_old_nrpos;		/* number of rotational positions */
367 	int32_t  fs_spare5[2];		/* old fs_postbloff */
368 					/* old fs_rotbloff */
369 	int32_t	 fs_magic;		/* magic number */
370 };
371 
372 #define	fs_old_postbloff	fs_spare5[0]
373 #define	fs_old_rotbloff		fs_spare5[1]
374 #define	fs_old_postbl_start	fs_maxbsize
375 #define	fs_old_headswitch	fs_id[0]
376 #define	fs_old_trkseek	fs_id[1]
377 #define	fs_old_csmask	fs_spare1[0]
378 #define	fs_old_csshift	fs_spare1[1]
379 
380 #define	FS_42POSTBLFMT		-1	/* 4.2BSD rotational table format */
381 #define	FS_DYNAMICPOSTBLFMT	1	/* dynamic rotational table format */
382 
383 #define	old_fs_postbl(fs_, cylno, opostblsave) \
384     ((((fs_)->fs_old_postblformat == FS_42POSTBLFMT) || \
385      ((fs_)->fs_old_postbloff == offsetof(struct fs, fs_old_postbl_start))) \
386     ? ((int16_t *)(opostblsave) + (cylno) * (fs_)->fs_old_nrpos) \
387     : ((int16_t *)((uint8_t *)(fs_) + \
388 	(fs_)->fs_old_postbloff) + (cylno) * (fs_)->fs_old_nrpos))
389 #define	old_fs_rotbl(fs) \
390     (((fs)->fs_old_postblformat == FS_42POSTBLFMT) \
391     ? ((uint8_t *)(&(fs)->fs_magic+1)) \
392     : ((uint8_t *)((uint8_t *)(fs) + (fs)->fs_old_rotbloff)))
393 
394 /*
395  * File system identification
396  */
397 #define	FS_UFS1_MAGIC	0x011954	/* UFS1 fast file system magic number */
398 #define	FS_UFS2_MAGIC	0x19540119	/* UFS2 fast file system magic number */
399 #define	FS_UFS1_MAGIC_SWAPPED	0x54190100
400 #define	FS_UFS2_MAGIC_SWAPPED	0x19015419
401 #define	FS_OKAY		0x7c269d38	/* superblock checksum */
402 #define	FS_42INODEFMT	-1		/* 4.2BSD inode format */
403 #define	FS_44INODEFMT	2		/* 4.4BSD inode format */
404 
405 /*
406  * File system clean flags
407  */
408 #define	FS_ISCLEAN	0x01
409 #define	FS_WASCLEAN	0x02
410 
411 /*
412  * Preference for optimization.
413  */
414 #define	FS_OPTTIME	0	/* minimize allocation time */
415 #define	FS_OPTSPACE	1	/* minimize disk fragmentation */
416 
417 /*
418  * File system flags
419  */
420 #define	FS_UNCLEAN	0x001	/* file system not clean at mount (unused) */
421 #define	FS_DOSOFTDEP	0x002	/* file system using soft dependencies */
422 #define	FS_NEEDSFSCK	0x004	/* needs sync fsck (FreeBSD compat, unused) */
423 #define	FS_INDEXDIRS	0x008	/* kernel supports indexed directories */
424 #define	FS_ACLS		0x010	/* file system has ACLs enabled */
425 #define	FS_MULTILABEL	0x020	/* file system is MAC multi-label */
426 #define	FS_GJOURNAL	0x40	/* gjournaled file system */
427 #define	FS_FLAGS_UPDATED 0x80	/* flags have been moved to new location */
428 #define	FS_DOWAPBL	0x100	/* Write ahead physical block logging */
429 
430 /* File system flags that are ok for NetBSD if set in fs_flags */
431 #define	FS_KNOWN_FLAGS	(FS_DOSOFTDEP | FS_DOWAPBL)
432 
433 /*
434  * File system internal flags, also in fs_flags.
435  * (Pick highest number to avoid conflicts with others)
436  */
437 #define	FS_SWAPPED	0x80000000	/* file system is endian swapped */
438 #define	FS_INTERNAL	0x80000000	/* mask for internal flags */
439 
440 /*
441  * Macros to access bits in the fs_active array.
442  */
443 #define	ACTIVECG_SET(fs, cg)				\
444 	do {						\
445 		if ((fs)->fs_active != NULL)		\
446 			setbit((fs)->fs_active, (cg));	\
447 	} while (/*CONSTCOND*/ 0)
448 #define	ACTIVECG_CLR(fs, cg)				\
449 	do {						\
450 		if ((fs)->fs_active != NULL)		\
451 			clrbit((fs)->fs_active, (cg));	\
452 	} while (/*CONSTCOND*/ 0)
453 #define	ACTIVECG_ISSET(fs, cg)				\
454 	((fs)->fs_active != NULL && isset((fs)->fs_active, (cg)))
455 
456 /*
457  * The size of a cylinder group is calculated by CGSIZE. The maximum size
458  * is limited by the fact that cylinder groups are at most one block.
459  * Its size is derived from the size of the maps maintained in the
460  * cylinder group and the (struct cg) size.
461  */
462 #define	CGSIZE_IF(fs, ipg, fpg) \
463     /* base cg */	(sizeof(struct cg) + sizeof(int32_t) + \
464     /* old btotoff */	(fs)->fs_old_cpg * sizeof(int32_t) + \
465     /* old boff */	(fs)->fs_old_cpg * sizeof(u_int16_t) + \
466     /* inode map */	howmany((ipg), NBBY) + \
467     /* block map */	howmany((fpg), NBBY) +\
468     /* if present */	((fs)->fs_contigsumsize <= 0 ? 0 : \
469     /* cluster sum */	(fs)->fs_contigsumsize * sizeof(int32_t) + \
470     /* cluster map */	howmany(fragstoblks(fs, (fpg)), NBBY)))
471 
472 #define	CGSIZE(fs) CGSIZE_IF((fs), (fs)->fs_ipg, (fs)->fs_fpg)
473 
474 /*
475  * The minimal number of cylinder groups that should be created.
476  */
477 #define	MINCYLGRPS	4
478 
479 
480 /*
481  * Convert cylinder group to base address of its global summary info.
482  */
483 #define	fs_cs(fs, indx)	fs_csp[indx]
484 
485 /*
486  * Cylinder group block for a file system.
487  */
488 #define	CG_MAGIC	0x090255
489 struct cg {
490 	int32_t	 cg_firstfield;		/* historic cyl groups linked list */
491 	int32_t	 cg_magic;		/* magic number */
492 	int32_t	 cg_old_time;		/* time last written */
493 	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
494 	int16_t	 cg_old_ncyl;		/* number of cyl's this cg */
495 	int16_t	 cg_old_niblk;		/* number of inode blocks this cg */
496 	int32_t	 cg_ndblk;		/* number of data blocks this cg */
497 	struct	csum cg_cs;		/* cylinder summary information */
498 	int32_t	 cg_rotor;		/* position of last used block */
499 	int32_t	 cg_frotor;		/* position of last used frag */
500 	int32_t	 cg_irotor;		/* position of last used inode */
501 	int32_t	 cg_frsum[MAXFRAG];	/* counts of available frags */
502 	int32_t	 cg_old_btotoff;	/* (int32) block totals per cylinder */
503 	int32_t	 cg_old_boff;		/* (u_int16) free block positions */
504 	int32_t	 cg_iusedoff;		/* (u_int8) used inode map */
505 	int32_t	 cg_freeoff;		/* (u_int8) free block map */
506 	int32_t	 cg_nextfreeoff;	/* (u_int8) next available space */
507 	int32_t	 cg_clustersumoff;	/* (u_int32) counts of avail clusters */
508 	int32_t	 cg_clusteroff;		/* (u_int8) free cluster map */
509 	int32_t	 cg_nclusterblks;	/* number of clusters this cg */
510 	int32_t  cg_niblk;		/* number of inode blocks this cg */
511 	int32_t  cg_initediblk;		/* last initialized inode */
512 	int32_t	 cg_sparecon32[3];	/* reserved for future use */
513 	int64_t  cg_time;		/* time last written */
514 	int64_t  cg_sparecon64[3];	/* reserved for future use */
515 	u_int8_t cg_space[1];		/* space for cylinder group maps */
516 /* actually longer */
517 };
518 
519 /*
520  * The following structure is defined
521  * for compatibility with old file systems.
522  */
523 struct ocg {
524 	int32_t  cg_firstfield;		/* historic linked list of cyl groups */
525 	int32_t  cg_unused_1;		/*     used for incore cyl groups */
526 	int32_t  cg_time;		/* time last written */
527 	int32_t  cg_cgx;		/* we are the cgx'th cylinder group */
528 	int16_t  cg_ncyl;		/* number of cyl's this cg */
529 	int16_t  cg_niblk;		/* number of inode blocks this cg */
530 	int32_t  cg_ndblk;		/* number of data blocks this cg */
531 	struct  csum cg_cs;		/* cylinder summary information */
532 	int32_t  cg_rotor;		/* position of last used block */
533 	int32_t  cg_frotor;		/* position of last used frag */
534 	int32_t  cg_irotor;		/* position of last used inode */
535 	int32_t  cg_frsum[8];		/* counts of available frags */
536 	int32_t  cg_btot[32];		/* block totals per cylinder */
537 	int16_t  cg_b[32][8];		/* positions of free blocks */
538 	u_int8_t cg_iused[256];		/* used inode map */
539 	int32_t  cg_magic;		/* magic number */
540 	u_int8_t cg_free[1];		/* free block map */
541 /* actually longer */
542 };
543 
544 
545 /*
546  * Macros for access to cylinder group array structures.
547  */
548 #define	old_cg_blktot_old(cgp, ns) \
549     (((struct ocg *)(cgp))->cg_btot)
550 #define	old_cg_blks_old(fs, cgp, cylno, ns) \
551     (((struct ocg *)(cgp))->cg_b[cylno])
552 
553 #define	old_cg_blktot_new(cgp, ns) \
554     ((int32_t *)((u_int8_t *)(cgp) + \
555 	ufs_rw32((cgp)->cg_old_btotoff, (ns))))
556 #define	old_cg_blks_new(fs, cgp, cylno, ns) \
557     ((int16_t *)((u_int8_t *)(cgp) + \
558 	ufs_rw32((cgp)->cg_old_boff, (ns))) + (cylno) * (fs)->fs_old_nrpos)
559 
560 #define	old_cg_blktot(cgp, ns) \
561     ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \
562       old_cg_blktot_old(cgp, ns) : old_cg_blktot_new(cgp, ns))
563 #define	old_cg_blks(fs, cgp, cylno, ns) \
564     ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \
565       old_cg_blks_old(fs, cgp, cylno, ns) : old_cg_blks_new(fs, cgp, cylno, ns))
566 
567 #define	cg_inosused_new(cgp, ns) \
568     ((u_int8_t *)((u_int8_t *)(cgp) + \
569 	ufs_rw32((cgp)->cg_iusedoff, (ns))))
570 #define	cg_blksfree_new(cgp, ns) \
571     ((u_int8_t *)((u_int8_t *)(cgp) + \
572 	ufs_rw32((cgp)->cg_freeoff, (ns))))
573 #define	cg_chkmagic_new(cgp, ns) \
574     (ufs_rw32((cgp)->cg_magic, (ns)) == CG_MAGIC)
575 
576 #define	cg_inosused_old(cgp, ns) \
577     (((struct ocg *)(cgp))->cg_iused)
578 #define	cg_blksfree_old(cgp, ns) \
579     (((struct ocg *)(cgp))->cg_free)
580 #define	cg_chkmagic_old(cgp, ns) \
581     (ufs_rw32(((struct ocg *)(cgp))->cg_magic, (ns)) == CG_MAGIC)
582 
583 #define	cg_inosused(cgp, ns) \
584     ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \
585       cg_inosused_old(cgp, ns) : cg_inosused_new(cgp, ns))
586 #define	cg_blksfree(cgp, ns) \
587     ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \
588       cg_blksfree_old(cgp, ns) : cg_blksfree_new(cgp, ns))
589 #define	cg_chkmagic(cgp, ns) \
590     (cg_chkmagic_new(cgp, ns) || cg_chkmagic_old(cgp, ns))
591 
592 #define	cg_clustersfree(cgp, ns) \
593     ((u_int8_t *)((u_int8_t *)(cgp) + \
594 	ufs_rw32((cgp)->cg_clusteroff, (ns))))
595 #define	cg_clustersum(cgp, ns) \
596     ((int32_t *)((u_int8_t *)(cgp) + \
597 	ufs_rw32((cgp)->cg_clustersumoff, (ns))))
598 
599 
600 /*
601  * Turn file system block numbers into disk block addresses.
602  * This maps file system blocks to device size blocks.
603  */
604 #if defined (_KERNEL)
605 #define	fsbtodb(fs, b)	((b) << ((fs)->fs_fshift - DEV_BSHIFT))
606 #define	dbtofsb(fs, b)	((b) >> ((fs)->fs_fshift - DEV_BSHIFT))
607 #else
608 #define	fsbtodb(fs, b)	((b) << (fs)->fs_fsbtodb)
609 #define	dbtofsb(fs, b)	((b) >> (fs)->fs_fsbtodb)
610 #endif
611 
612 /*
613  * Cylinder group macros to locate things in cylinder groups.
614  * They calc file system addresses of cylinder group data structures.
615  */
616 #define	cgbase(fs, c)	(((daddr_t)(fs)->fs_fpg) * (c))
617 #define	cgstart_ufs1(fs, c) \
618     (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask)))
619 #define	cgstart_ufs2(fs, c) cgbase((fs), (c))
620 #define	cgstart(fs, c) ((fs)->fs_magic == FS_UFS2_MAGIC \
621 			    ? cgstart_ufs2((fs), (c)) : cgstart_ufs1((fs), (c)))
622 #define	cgdmin(fs, c)	(cgstart(fs, c) + (fs)->fs_dblkno)	/* 1st data */
623 #define	cgimin(fs, c)	(cgstart(fs, c) + (fs)->fs_iblkno)	/* inode blk */
624 #define	cgsblock(fs, c)	(cgstart(fs, c) + (fs)->fs_sblkno)	/* super blk */
625 #define	cgtod(fs, c)	(cgstart(fs, c) + (fs)->fs_cblkno)	/* cg block */
626 
627 /*
628  * Macros for handling inode numbers:
629  *     inode number to file system block offset.
630  *     inode number to cylinder group number.
631  *     inode number to file system block address.
632  */
633 #define	ino_to_cg(fs, x)	((x) / (fs)->fs_ipg)
634 #define	ino_to_fsba(fs, x)						\
635 	((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) +			\
636 	    (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
637 #define	ino_to_fsbo(fs, x)	((x) % INOPB(fs))
638 
639 /*
640  * Give cylinder group number for a file system block.
641  * Give cylinder group block number for a file system block.
642  */
643 #define	dtog(fs, d)	((d) / (fs)->fs_fpg)
644 #define	dtogd(fs, d)	((d) % (fs)->fs_fpg)
645 
646 /*
647  * Extract the bits for a block from a map.
648  * Compute the cylinder and rotational position of a cyl block addr.
649  */
650 #define	blkmap(fs, map, loc) \
651     (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
652 #define	old_cbtocylno(fs, bno) \
653     (fsbtodb(fs, bno) / (fs)->fs_old_spc)
654 #define	old_cbtorpos(fs, bno) \
655     ((fs)->fs_old_nrpos <= 1 ? 0 : \
656      (fsbtodb(fs, bno) % (fs)->fs_old_spc / (fs)->fs_old_nsect * (fs)->fs_old_trackskew + \
657       fsbtodb(fs, bno) % (fs)->fs_old_spc % (fs)->fs_old_nsect * (fs)->fs_old_interleave) % \
658      (fs)->fs_old_nsect * (fs)->fs_old_nrpos / (fs)->fs_old_npsect)
659 
660 /*
661  * The following macros optimize certain frequently calculated
662  * quantities by using shifts and masks in place of divisions
663  * modulos and multiplications.
664  */
665 #define	blkoff(fs, loc)		/* calculates (loc % fs->fs_bsize) */ \
666 	((loc) & (fs)->fs_qbmask)
667 #define	fragoff(fs, loc)	/* calculates (loc % fs->fs_fsize) */ \
668 	((loc) & (fs)->fs_qfmask)
669 #define	lfragtosize(fs, frag)	/* calculates ((off_t)frag * fs->fs_fsize) */ \
670 	(((off_t)(frag)) << (fs)->fs_fshift)
671 #define	lblktosize(fs, blk)	/* calculates ((off_t)blk * fs->fs_bsize) */ \
672 	(((off_t)(blk)) << (fs)->fs_bshift)
673 #define	lblkno(fs, loc)		/* calculates (loc / fs->fs_bsize) */ \
674 	((loc) >> (fs)->fs_bshift)
675 #define	numfrags(fs, loc)	/* calculates (loc / fs->fs_fsize) */ \
676 	((loc) >> (fs)->fs_fshift)
677 #define	blkroundup(fs, size)	/* calculates roundup(size, fs->fs_bsize) */ \
678 	(((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
679 #define	fragroundup(fs, size)	/* calculates roundup(size, fs->fs_fsize) */ \
680 	(((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
681 #define	fragstoblks(fs, frags)	/* calculates (frags / fs->fs_frag) */ \
682 	((frags) >> (fs)->fs_fragshift)
683 #define	blkstofrags(fs, blks)	/* calculates (blks * fs->fs_frag) */ \
684 	((blks) << (fs)->fs_fragshift)
685 #define	fragnum(fs, fsb)	/* calculates (fsb % fs->fs_frag) */ \
686 	((fsb) & ((fs)->fs_frag - 1))
687 #define	blknum(fs, fsb)		/* calculates rounddown(fsb, fs->fs_frag) */ \
688 	((fsb) &~ ((fs)->fs_frag - 1))
689 
690 /*
691  * Determine the number of available frags given a
692  * percentage to hold in reserve.
693  */
694 #define	freespace(fs, percentreserved) \
695 	(blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
696 	(fs)->fs_cstotal.cs_nffree - \
697 	(((off_t)((fs)->fs_dsize)) * (percentreserved) / 100))
698 
699 /*
700  * Determining the size of a file block in the file system.
701  */
702 #define	blksize(fs, ip, lbn) \
703 	(((lbn) >= NDADDR || (off_t)(ip)->i_size >= lblktosize(fs, (lbn) + 1)) \
704 	    ? (int32_t)(fs)->fs_bsize \
705 	    : (int32_t)(fragroundup(fs, blkoff(fs, (ip)->i_size))))
706 
707 #define	sblksize(fs, size, lbn) \
708 	(((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
709 	  ? (fs)->fs_bsize \
710 	  : (fragroundup(fs, blkoff(fs, (size)))))
711 
712 
713 /*
714  * Number of inodes in a secondary storage block/fragment.
715  */
716 #define	INOPB(fs)	((fs)->fs_inopb)
717 #define	INOPF(fs)	((fs)->fs_inopb >> (fs)->fs_fragshift)
718 
719 /*
720  * Number of indirects in a file system block.
721  */
722 #define	NINDIR(fs)	((fs)->fs_nindir)
723 
724 /*
725  * Apple UFS Label:
726  *  We check for this to decide to use APPLEUFS_DIRBLKSIZ
727  */
728 #define	APPLEUFS_LABEL_MAGIC		0x4c41424c /* LABL */
729 #define	APPLEUFS_LABEL_SIZE		1024
730 #define	APPLEUFS_LABEL_OFFSET	(BBSIZE - APPLEUFS_LABEL_SIZE) /* located at 7k */
731 #define	APPLEUFS_LABEL_VERSION	1
732 #define	APPLEUFS_MAX_LABEL_NAME	512
733 
734 struct appleufslabel {
735 	u_int32_t	ul_magic;
736 	u_int16_t	ul_checksum;
737 	u_int16_t	ul_unused0;
738 	u_int32_t	ul_version;
739 	u_int32_t	ul_time;
740 	u_int16_t	ul_namelen;
741 	u_char	ul_name[APPLEUFS_MAX_LABEL_NAME]; /* Warning: may not be null terminated */
742 	u_int16_t	ul_unused1;
743 	u_int64_t	ul_uuid;	/* Note this is only 4 byte aligned */
744 	u_char	ul_reserved[24];
745 	u_char	ul_unused[460];
746 } __packed;
747 
748 
749 #endif /* !_UFS_FFS_FS_H_ */
750