xref: /freebsd/sys/ufs/ffs/ffs_subr.c (revision 62ff619dcc3540659a319be71c9a489f1659e14a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ffs_subr.c	8.5 (Berkeley) 3/21/95
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/limits.h>
39 
40 #ifndef _KERNEL
41 #include <stdio.h>
42 #include <string.h>
43 #include <stdlib.h>
44 #include <time.h>
45 #include <sys/errno.h>
46 #include <ufs/ufs/dinode.h>
47 #include <ufs/ffs/fs.h>
48 
49 uint32_t calculate_crc32c(uint32_t, const void *, size_t);
50 uint32_t ffs_calc_sbhash(struct fs *);
51 struct malloc_type;
52 #define UFS_MALLOC(size, type, flags) malloc(size)
53 #define UFS_FREE(ptr, type) free(ptr)
54 #define maxphys MAXPHYS
55 
56 #else /* _KERNEL */
57 #include <sys/systm.h>
58 #include <sys/gsb_crc32.h>
59 #include <sys/lock.h>
60 #include <sys/malloc.h>
61 #include <sys/mount.h>
62 #include <sys/vnode.h>
63 #include <sys/bio.h>
64 #include <sys/buf.h>
65 #include <sys/ucred.h>
66 
67 #include <ufs/ufs/quota.h>
68 #include <ufs/ufs/inode.h>
69 #include <ufs/ufs/extattr.h>
70 #include <ufs/ufs/ufsmount.h>
71 #include <ufs/ufs/ufs_extern.h>
72 #include <ufs/ffs/ffs_extern.h>
73 #include <ufs/ffs/fs.h>
74 
75 #define UFS_MALLOC(size, type, flags) malloc(size, type, flags)
76 #define UFS_FREE(ptr, type) free(ptr, type)
77 
78 #endif /* _KERNEL */
79 
80 /*
81  * Verify an inode check-hash.
82  */
83 int
84 ffs_verify_dinode_ckhash(struct fs *fs, struct ufs2_dinode *dip)
85 {
86 	uint32_t ckhash, save_ckhash;
87 
88 	/*
89 	 * Return success if unallocated or we are not doing inode check-hash.
90 	 */
91 	if (dip->di_mode == 0 || (fs->fs_metackhash & CK_INODE) == 0)
92 		return (0);
93 	/*
94 	 * Exclude di_ckhash from the crc32 calculation, e.g., always use
95 	 * a check-hash value of zero when calculating the check-hash.
96 	 */
97 	save_ckhash = dip->di_ckhash;
98 	dip->di_ckhash = 0;
99 	ckhash = calculate_crc32c(~0L, (void *)dip, sizeof(*dip));
100 	dip->di_ckhash = save_ckhash;
101 	if (save_ckhash == ckhash)
102 		return (0);
103 	return (EINVAL);
104 }
105 
106 /*
107  * Update an inode check-hash.
108  */
109 void
110 ffs_update_dinode_ckhash(struct fs *fs, struct ufs2_dinode *dip)
111 {
112 
113 	if (dip->di_mode == 0 || (fs->fs_metackhash & CK_INODE) == 0)
114 		return;
115 	/*
116 	 * Exclude old di_ckhash from the crc32 calculation, e.g., always use
117 	 * a check-hash value of zero when calculating the new check-hash.
118 	 */
119 	dip->di_ckhash = 0;
120 	dip->di_ckhash = calculate_crc32c(~0L, (void *)dip, sizeof(*dip));
121 }
122 
123 /*
124  * These are the low-level functions that actually read and write
125  * the superblock and its associated data.
126  */
127 static off_t sblock_try[] = SBLOCKSEARCH;
128 static int readsuper(void *, struct fs **, off_t, int, int,
129 	int (*)(void *, off_t, void **, int));
130 static int validate_sblock(struct fs *, int);
131 
132 /*
133  * Read a superblock from the devfd device.
134  *
135  * If an alternate superblock is specified, it is read. Otherwise the
136  * set of locations given in the SBLOCKSEARCH list is searched for a
137  * superblock. Memory is allocated for the superblock by the readfunc and
138  * is returned. If filltype is non-NULL, additional memory is allocated
139  * of type filltype and filled in with the superblock summary information.
140  * All memory is freed when any error is returned.
141  *
142  * If a superblock is found, zero is returned. Otherwise one of the
143  * following error values is returned:
144  *     EIO: non-existent or truncated superblock.
145  *     EIO: error reading summary information.
146  *     ENOENT: no usable known superblock found.
147  *     ENOMEM: failed to allocate space for the superblock.
148  *     EINVAL: The previous newfs operation on this volume did not complete.
149  *         The administrator must complete newfs before using this volume.
150  */
151 int
152 ffs_sbget(void *devfd, struct fs **fsp, off_t altsblock,
153     struct malloc_type *filltype,
154     int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
155 {
156 	struct fs *fs;
157 	struct fs_summary_info *fs_si;
158 	int i, error;
159 	uint64_t size, blks;
160 	uint8_t *space;
161 	int32_t *lp;
162 	char *buf;
163 
164 	fs = NULL;
165 	*fsp = NULL;
166 	if (altsblock >= 0) {
167 		if ((error = readsuper(devfd, &fs, altsblock, 1, 0,
168 		     readfunc)) != 0) {
169 			if (fs != NULL)
170 				UFS_FREE(fs, filltype);
171 			return (error);
172 		}
173 	} else {
174 		for (i = 0; sblock_try[i] != -1; i++) {
175 			if ((error = readsuper(devfd, &fs, sblock_try[i], 0,
176 			     altsblock, readfunc)) == 0)
177 				break;
178 			if (fs != NULL) {
179 				UFS_FREE(fs, filltype);
180 				fs = NULL;
181 			}
182 			if (error == ENOENT)
183 				continue;
184 			return (error);
185 		}
186 		if (sblock_try[i] == -1)
187 			return (ENOENT);
188 	}
189 	/*
190 	 * Read in the superblock summary information.
191 	 */
192 	size = fs->fs_cssize;
193 	blks = howmany(size, fs->fs_fsize);
194 	if (fs->fs_contigsumsize > 0)
195 		size += fs->fs_ncg * sizeof(int32_t);
196 	size += fs->fs_ncg * sizeof(u_int8_t);
197 	if ((fs_si = UFS_MALLOC(sizeof(*fs_si), filltype, M_NOWAIT)) == NULL) {
198 		UFS_FREE(fs, filltype);
199 		return (ENOMEM);
200 	}
201 	bzero(fs_si, sizeof(*fs_si));
202 	fs->fs_si = fs_si;
203 	if ((space = UFS_MALLOC(size, filltype, M_NOWAIT)) == NULL) {
204 		UFS_FREE(fs->fs_si, filltype);
205 		UFS_FREE(fs, filltype);
206 		return (ENOMEM);
207 	}
208 	fs->fs_csp = (struct csum *)space;
209 	for (i = 0; i < blks; i += fs->fs_frag) {
210 		size = fs->fs_bsize;
211 		if (i + fs->fs_frag > blks)
212 			size = (blks - i) * fs->fs_fsize;
213 		buf = NULL;
214 		error = (*readfunc)(devfd,
215 		    dbtob(fsbtodb(fs, fs->fs_csaddr + i)), (void **)&buf, size);
216 		if (error) {
217 			if (buf != NULL)
218 				UFS_FREE(buf, filltype);
219 			UFS_FREE(fs->fs_csp, filltype);
220 			UFS_FREE(fs->fs_si, filltype);
221 			UFS_FREE(fs, filltype);
222 			return (error);
223 		}
224 		memcpy(space, buf, size);
225 		UFS_FREE(buf, filltype);
226 		space += size;
227 	}
228 	if (fs->fs_contigsumsize > 0) {
229 		fs->fs_maxcluster = lp = (int32_t *)space;
230 		for (i = 0; i < fs->fs_ncg; i++)
231 			*lp++ = fs->fs_contigsumsize;
232 		space = (uint8_t *)lp;
233 	}
234 	size = fs->fs_ncg * sizeof(u_int8_t);
235 	fs->fs_contigdirs = (u_int8_t *)space;
236 	bzero(fs->fs_contigdirs, size);
237 	*fsp = fs;
238 	return (0);
239 }
240 
241 /*
242  * Try to read a superblock from the location specified by sblockloc.
243  * Return zero on success or an errno on failure.
244  */
245 static int
246 readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int isaltsblk,
247     int chkhash, int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
248 {
249 	struct fs *fs;
250 	int error, res;
251 	uint32_t ckhash;
252 
253 	error = (*readfunc)(devfd, sblockloc, (void **)fsp, SBLOCKSIZE);
254 	if (error != 0)
255 		return (error);
256 	fs = *fsp;
257 	if (fs->fs_magic == FS_BAD_MAGIC)
258 		return (EINVAL);
259 	if ((error = validate_sblock(fs, isaltsblk)) != 0)
260 		return (error);
261 	/*
262 	 * If the filesystem has been run on a kernel without
263 	 * metadata check hashes, disable them.
264 	 */
265 	if ((fs->fs_flags & FS_METACKHASH) == 0)
266 		fs->fs_metackhash = 0;
267 	/*
268 	 * Clear any check-hashes that are not maintained
269 	 * by this kernel. Also clear any unsupported flags.
270 	 */
271 	fs->fs_metackhash &= CK_SUPPORTED;
272 	fs->fs_flags &= FS_SUPPORTED;
273 	if (fs->fs_ckhash != (ckhash = ffs_calc_sbhash(fs))) {
274 		if (chkhash == STDSB_NOMSG)
275 			return (EINTEGRITY);
276 		if (chkhash == STDSB_NOHASHFAIL_NOMSG)
277 			return (0);
278 #ifdef _KERNEL
279 		res = uprintf("Superblock check-hash failed: recorded "
280 		    "check-hash 0x%x != computed check-hash 0x%x%s\n",
281 		    fs->fs_ckhash, ckhash,
282 		    chkhash == STDSB_NOHASHFAIL ? " (Ignored)" : "");
283 #else
284 		res = 0;
285 #endif
286 		/*
287 		 * Print check-hash failure if no controlling terminal
288 		 * in kernel or always if in user-mode (libufs).
289 		 */
290 		if (res == 0)
291 			printf("Superblock check-hash failed: recorded "
292 			    "check-hash 0x%x != computed check-hash "
293 			    "0x%x%s\n", fs->fs_ckhash, ckhash,
294 			    chkhash == STDSB_NOHASHFAIL ?
295 			    " (Ignored)" : "");
296 		if (chkhash == STDSB)
297 			return (EINTEGRITY);
298 		/* chkhash == STDSB_NOHASHFAIL */
299 		return (0);
300 	}
301 	/* Have to set for old filesystems that predate this field */
302 	fs->fs_sblockactualloc = sblockloc;
303 	/* Not yet any summary information */
304 	fs->fs_si = NULL;
305 	return (0);
306 }
307 
308 /*
309  * Verify the filesystem values.
310  */
311 #define ILOG2(num) (fls(num) - 1)
312 
313 static int
314 validate_sblock(struct fs *fs, int isaltsblk)
315 {
316 	int i, sectorsize;
317 	u_int64_t maxfilesize, minfpg, sizepb;
318 
319 	sectorsize = dbtob(1);
320 	if (fs->fs_magic == FS_UFS2_MAGIC) {
321 		if ((!isaltsblk && (fs->fs_sblockloc != SBLOCK_UFS2 ||
322 		    fs->fs_sblockactualloc != SBLOCK_UFS2)) ||
323 		    fs->fs_maxsymlinklen != ((UFS_NDADDR + UFS_NIADDR) *
324 			sizeof(ufs2_daddr_t)) ||
325 		    fs->fs_nindir != fs->fs_bsize / sizeof(ufs2_daddr_t) ||
326 		    fs->fs_inopb != fs->fs_bsize / sizeof(struct ufs2_dinode))
327 			return (ENOENT);
328 	} else if (fs->fs_magic == FS_UFS1_MAGIC) {
329 		if ((!isaltsblk && (fs->fs_sblockloc > SBLOCK_UFS1 ||
330 		    fs->fs_sblockactualloc != SBLOCK_UFS1)) ||
331 		    fs->fs_nindir != fs->fs_bsize / sizeof(ufs1_daddr_t) ||
332 		    fs->fs_inopb != fs->fs_bsize / sizeof(struct ufs1_dinode) ||
333 		    fs->fs_maxsymlinklen != ((UFS_NDADDR + UFS_NIADDR) *
334 			sizeof(ufs1_daddr_t)) ||
335 		    fs->fs_old_inodefmt != FS_44INODEFMT ||
336 		    fs->fs_old_cgoffset != 0 ||
337 		    fs->fs_old_cgmask != 0xffffffff ||
338 		    fs->fs_old_size != fs->fs_size ||
339 		    fs->fs_old_rotdelay != 0 ||
340 		    fs->fs_old_rps != 60 ||
341 		    fs->fs_old_nspf != fs->fs_fsize / sectorsize ||
342 		    fs->fs_old_cpg != 1 ||
343 		    fs->fs_old_interleave != 1 ||
344 		    fs->fs_old_trackskew != 0 ||
345 		    fs->fs_old_cpc != 0 ||
346 		    fs->fs_old_postblformat != 1 ||
347 		    fs->fs_old_nrpos != 1 ||
348 		    fs->fs_old_spc != fs->fs_fpg * fs->fs_old_nspf ||
349 		    fs->fs_old_nsect != fs->fs_old_spc ||
350 		    fs->fs_old_npsect != fs->fs_old_spc ||
351 		    fs->fs_old_dsize != fs->fs_dsize ||
352 		    fs->fs_old_ncyl != fs->fs_ncg)
353 			return (ENOENT);
354 	} else {
355 		return (ENOENT);
356 	}
357 	if (fs->fs_bsize < MINBSIZE || fs->fs_bsize > MAXBSIZE ||
358 	    fs->fs_bsize < roundup(sizeof(struct fs), DEV_BSIZE) ||
359 	    fs->fs_sbsize > SBLOCKSIZE || fs->fs_sbsize < fs->fs_fsize ||
360 	    !powerof2(fs->fs_bsize))
361 		return (ENOENT);
362 	if (fs->fs_fsize < sectorsize || fs->fs_fsize > fs->fs_bsize ||
363 	    fs->fs_fsize * MAXFRAG < fs->fs_bsize || !powerof2(fs->fs_fsize))
364 		return (ENOENT);
365 	if (fs->fs_maxbsize < fs->fs_bsize || !powerof2(fs->fs_maxbsize) ||
366 	    fs->fs_maxbsize > FS_MAXCONTIG * fs->fs_bsize)
367 		return (ENOENT);
368 	if (fs->fs_bmask != ~(fs->fs_bsize - 1) ||
369 	    fs->fs_fmask != ~(fs->fs_fsize - 1) ||
370 	    fs->fs_qbmask != ~fs->fs_bmask ||
371 	    fs->fs_qfmask != ~fs->fs_fmask ||
372 	    fs->fs_bshift != ILOG2(fs->fs_bsize) ||
373 	    fs->fs_fshift != ILOG2(fs->fs_fsize) ||
374 	    fs->fs_frag != numfrags(fs, fs->fs_bsize) ||
375 	    fs->fs_fragshift != ILOG2(fs->fs_frag) ||
376 	    fs->fs_frag > MAXFRAG ||
377 	    fs->fs_fsbtodb != ILOG2(fs->fs_fsize / sectorsize))
378 		return (ENOENT);
379 	if (fs->fs_sblkno !=
380 		roundup(howmany(fs->fs_sblockloc + SBLOCKSIZE, fs->fs_fsize),
381 		    fs->fs_frag) ||
382 	    fs->fs_cblkno != fs->fs_sblkno +
383 		roundup(howmany(SBLOCKSIZE, fs->fs_fsize), fs->fs_frag) ||
384 	    fs->fs_iblkno != fs->fs_cblkno + fs->fs_frag ||
385 	    fs->fs_dblkno != fs->fs_iblkno + fs->fs_ipg / INOPF(fs) ||
386 	    fs->fs_cgsize != fragroundup(fs, CGSIZE(fs)))
387 		return (ENOENT);
388 	if (fs->fs_csaddr != cgdmin(fs, 0) ||
389 	    fs->fs_cssize !=
390 		fragroundup(fs, fs->fs_ncg * sizeof(struct csum)) ||
391 	    fs->fs_dsize != fs->fs_size - fs->fs_sblkno -
392 		fs->fs_ncg * (fs->fs_dblkno - fs->fs_sblkno) -
393 		howmany(fs->fs_cssize, fs->fs_fsize) ||
394 	    fs->fs_metaspace < 0 || fs->fs_metaspace > fs->fs_fpg / 2 ||
395 	    fs->fs_minfree > 99)
396 		return (ENOENT);
397 	maxfilesize = fs->fs_bsize * UFS_NDADDR - 1;
398 	for (sizepb = fs->fs_bsize, i = 0; i < UFS_NIADDR; i++) {
399 		sizepb *= NINDIR(fs);
400 		maxfilesize += sizepb;
401 	}
402 	if (fs->fs_maxfilesize != maxfilesize)
403 		return (ENOENT);
404 	/*
405 	 * These values have a tight interaction with each other that
406 	 * makes it hard to tightly bound them. So we can only check
407 	 * that they are within a broader possible range.
408 	 *
409 	 * Calculate minfpg, the minimum number of fragments that can be
410 	 * in a cylinder group. The value 12289 is calculated in newfs(8)
411 	 * when creating the smallest block size UFS version 1 filesystem
412 	 * (4096 block size) with no fragments (4096 fragment size). That
413 	 * number may be depressed even further for very small filesystems
414 	 * since newfs(8) strives to have at least four cylinder groups.
415 	 */
416 	minfpg = MIN(12289, fs->fs_size / 4);
417 	if (fs->fs_ncg < 1 || fs->fs_ncg > (fs->fs_size / minfpg) + 1 ||
418 	    fs->fs_fpg < minfpg || fs->fs_fpg > fs->fs_size ||
419 	    fs->fs_ipg * fs->fs_ncg > (((int64_t)(1)) << 32) - INOPB(fs) ||
420 	    fs->fs_ipg > fs->fs_fpg || fs->fs_size < 8 * fs->fs_frag)
421 		return (ENOENT);
422 	if (fs->fs_size <= (fs->fs_ncg - 1) * fs->fs_fpg ||
423 	    fs->fs_size > fs->fs_ncg * fs->fs_fpg)
424 		return (ENOENT);
425 	/*
426 	 * Maxcontig sets the default for the maximum number of blocks
427 	 * that may be allocated sequentially. With file system clustering
428 	 * it is possible to allocate contiguous blocks up to the maximum
429 	 * transfer size permitted by the controller or buffering.
430 	 */
431 	if (fs->fs_maxcontig < 1 ||
432 	    fs->fs_maxcontig > MAX(1, maxphys / fs->fs_bsize))
433 		return (ENOENT);
434 	if (fs->fs_maxcontig < 0 ||
435 	    (fs->fs_maxcontig == 0 && fs->fs_contigsumsize != 0) ||
436 	    (fs->fs_maxcontig > 1 &&
437 	    fs->fs_contigsumsize != MIN(fs->fs_maxcontig, FS_MAXCONTIG)))
438 		return (ENOENT);
439 	return (0);
440 }
441 
442 /*
443  * Write a superblock to the devfd device from the memory pointed to by fs.
444  * Write out the superblock summary information if it is present.
445  *
446  * If the write is successful, zero is returned. Otherwise one of the
447  * following error values is returned:
448  *     EIO: failed to write superblock.
449  *     EIO: failed to write superblock summary information.
450  */
451 int
452 ffs_sbput(void *devfd, struct fs *fs, off_t loc,
453     int (*writefunc)(void *devfd, off_t loc, void *buf, int size))
454 {
455 	int i, error, blks, size;
456 	uint8_t *space;
457 
458 	/*
459 	 * If there is summary information, write it first, so if there
460 	 * is an error, the superblock will not be marked as clean.
461 	 */
462 	if (fs->fs_si != NULL && fs->fs_csp != NULL) {
463 		blks = howmany(fs->fs_cssize, fs->fs_fsize);
464 		space = (uint8_t *)fs->fs_csp;
465 		for (i = 0; i < blks; i += fs->fs_frag) {
466 			size = fs->fs_bsize;
467 			if (i + fs->fs_frag > blks)
468 				size = (blks - i) * fs->fs_fsize;
469 			if ((error = (*writefunc)(devfd,
470 			     dbtob(fsbtodb(fs, fs->fs_csaddr + i)),
471 			     space, size)) != 0)
472 				return (error);
473 			space += size;
474 		}
475 	}
476 	fs->fs_fmod = 0;
477 #ifndef _KERNEL
478 	{
479 		struct fs_summary_info *fs_si;
480 
481 		fs->fs_time = time(NULL);
482 		/* Clear the pointers for the duration of writing. */
483 		fs_si = fs->fs_si;
484 		fs->fs_si = NULL;
485 		fs->fs_ckhash = ffs_calc_sbhash(fs);
486 		error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize);
487 		fs->fs_si = fs_si;
488 	}
489 #else /* _KERNEL */
490 	fs->fs_time = time_second;
491 	fs->fs_ckhash = ffs_calc_sbhash(fs);
492 	error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize);
493 #endif /* _KERNEL */
494 	return (error);
495 }
496 
497 /*
498  * Calculate the check-hash for a superblock.
499  */
500 uint32_t
501 ffs_calc_sbhash(struct fs *fs)
502 {
503 	uint32_t ckhash, save_ckhash;
504 
505 	/*
506 	 * A filesystem that was using a superblock ckhash may be moved
507 	 * to an older kernel that does not support ckhashes. The
508 	 * older kernel will clear the FS_METACKHASH flag indicating
509 	 * that it does not update hashes. When the disk is moved back
510 	 * to a kernel capable of ckhashes it disables them on mount:
511 	 *
512 	 *	if ((fs->fs_flags & FS_METACKHASH) == 0)
513 	 *		fs->fs_metackhash = 0;
514 	 *
515 	 * This leaves (fs->fs_metackhash & CK_SUPERBLOCK) == 0) with an
516 	 * old stale value in the fs->fs_ckhash field. Thus the need to
517 	 * just accept what is there.
518 	 */
519 	if ((fs->fs_metackhash & CK_SUPERBLOCK) == 0)
520 		return (fs->fs_ckhash);
521 
522 	save_ckhash = fs->fs_ckhash;
523 	fs->fs_ckhash = 0;
524 	/*
525 	 * If newly read from disk, the caller is responsible for
526 	 * verifying that fs->fs_sbsize <= SBLOCKSIZE.
527 	 */
528 	ckhash = calculate_crc32c(~0L, (void *)fs, fs->fs_sbsize);
529 	fs->fs_ckhash = save_ckhash;
530 	return (ckhash);
531 }
532 
533 /*
534  * Update the frsum fields to reflect addition or deletion
535  * of some frags.
536  */
537 void
538 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
539 {
540 	int inblk;
541 	int field, subfield;
542 	int siz, pos;
543 
544 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
545 	fragmap <<= 1;
546 	for (siz = 1; siz < fs->fs_frag; siz++) {
547 		if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
548 			continue;
549 		field = around[siz];
550 		subfield = inside[siz];
551 		for (pos = siz; pos <= fs->fs_frag; pos++) {
552 			if ((fragmap & field) == subfield) {
553 				fraglist[siz] += cnt;
554 				pos += siz;
555 				field <<= siz;
556 				subfield <<= siz;
557 			}
558 			field <<= 1;
559 			subfield <<= 1;
560 		}
561 	}
562 }
563 
564 /*
565  * block operations
566  *
567  * check if a block is available
568  */
569 int
570 ffs_isblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
571 {
572 	unsigned char mask;
573 
574 	switch ((int)fs->fs_frag) {
575 	case 8:
576 		return (cp[h] == 0xff);
577 	case 4:
578 		mask = 0x0f << ((h & 0x1) << 2);
579 		return ((cp[h >> 1] & mask) == mask);
580 	case 2:
581 		mask = 0x03 << ((h & 0x3) << 1);
582 		return ((cp[h >> 2] & mask) == mask);
583 	case 1:
584 		mask = 0x01 << (h & 0x7);
585 		return ((cp[h >> 3] & mask) == mask);
586 	default:
587 #ifdef _KERNEL
588 		panic("ffs_isblock");
589 #endif
590 		break;
591 	}
592 	return (0);
593 }
594 
595 /*
596  * check if a block is free
597  */
598 int
599 ffs_isfreeblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
600 {
601 
602 	switch ((int)fs->fs_frag) {
603 	case 8:
604 		return (cp[h] == 0);
605 	case 4:
606 		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
607 	case 2:
608 		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
609 	case 1:
610 		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
611 	default:
612 #ifdef _KERNEL
613 		panic("ffs_isfreeblock");
614 #endif
615 		break;
616 	}
617 	return (0);
618 }
619 
620 /*
621  * take a block out of the map
622  */
623 void
624 ffs_clrblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
625 {
626 
627 	switch ((int)fs->fs_frag) {
628 	case 8:
629 		cp[h] = 0;
630 		return;
631 	case 4:
632 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
633 		return;
634 	case 2:
635 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
636 		return;
637 	case 1:
638 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
639 		return;
640 	default:
641 #ifdef _KERNEL
642 		panic("ffs_clrblock");
643 #endif
644 		break;
645 	}
646 }
647 
648 /*
649  * put a block into the map
650  */
651 void
652 ffs_setblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
653 {
654 
655 	switch ((int)fs->fs_frag) {
656 	case 8:
657 		cp[h] = 0xff;
658 		return;
659 	case 4:
660 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
661 		return;
662 	case 2:
663 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
664 		return;
665 	case 1:
666 		cp[h >> 3] |= (0x01 << (h & 0x7));
667 		return;
668 	default:
669 #ifdef _KERNEL
670 		panic("ffs_setblock");
671 #endif
672 		break;
673 	}
674 }
675 
676 /*
677  * Update the cluster map because of an allocation or free.
678  *
679  * Cnt == 1 means free; cnt == -1 means allocating.
680  */
681 void
682 ffs_clusteracct(struct fs *fs, struct cg *cgp, ufs1_daddr_t blkno, int cnt)
683 {
684 	int32_t *sump;
685 	int32_t *lp;
686 	u_char *freemapp, *mapp;
687 	int i, start, end, forw, back, map;
688 	u_int bit;
689 
690 	if (fs->fs_contigsumsize <= 0)
691 		return;
692 	freemapp = cg_clustersfree(cgp);
693 	sump = cg_clustersum(cgp);
694 	/*
695 	 * Allocate or clear the actual block.
696 	 */
697 	if (cnt > 0)
698 		setbit(freemapp, blkno);
699 	else
700 		clrbit(freemapp, blkno);
701 	/*
702 	 * Find the size of the cluster going forward.
703 	 */
704 	start = blkno + 1;
705 	end = start + fs->fs_contigsumsize;
706 	if (end >= cgp->cg_nclusterblks)
707 		end = cgp->cg_nclusterblks;
708 	mapp = &freemapp[start / NBBY];
709 	map = *mapp++;
710 	bit = 1U << (start % NBBY);
711 	for (i = start; i < end; i++) {
712 		if ((map & bit) == 0)
713 			break;
714 		if ((i & (NBBY - 1)) != (NBBY - 1)) {
715 			bit <<= 1;
716 		} else {
717 			map = *mapp++;
718 			bit = 1;
719 		}
720 	}
721 	forw = i - start;
722 	/*
723 	 * Find the size of the cluster going backward.
724 	 */
725 	start = blkno - 1;
726 	end = start - fs->fs_contigsumsize;
727 	if (end < 0)
728 		end = -1;
729 	mapp = &freemapp[start / NBBY];
730 	map = *mapp--;
731 	bit = 1U << (start % NBBY);
732 	for (i = start; i > end; i--) {
733 		if ((map & bit) == 0)
734 			break;
735 		if ((i & (NBBY - 1)) != 0) {
736 			bit >>= 1;
737 		} else {
738 			map = *mapp--;
739 			bit = 1U << (NBBY - 1);
740 		}
741 	}
742 	back = start - i;
743 	/*
744 	 * Account for old cluster and the possibly new forward and
745 	 * back clusters.
746 	 */
747 	i = back + forw + 1;
748 	if (i > fs->fs_contigsumsize)
749 		i = fs->fs_contigsumsize;
750 	sump[i] += cnt;
751 	if (back > 0)
752 		sump[back] -= cnt;
753 	if (forw > 0)
754 		sump[forw] -= cnt;
755 	/*
756 	 * Update cluster summary information.
757 	 */
758 	lp = &sump[fs->fs_contigsumsize];
759 	for (i = fs->fs_contigsumsize; i > 0; i--)
760 		if (*lp-- > 0)
761 			break;
762 	fs->fs_maxcluster[cgp->cg_cgx] = i;
763 }
764