xref: /freebsd/sys/ufs/ffs/ffs_subr.c (revision a765ac11c50bb20a64905e365b05b010533f26d3)
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 #undef CHK
313 #define CHK(lhs, op, rhs, fmt)						\
314 	if (lhs op rhs) {						\
315 		printf("UFS%d superblock failed: %s (" #fmt ") %s %s ("	\
316 		    #fmt ")\n", fs->fs_magic == FS_UFS1_MAGIC ? 1 : 2,	\
317 		    #lhs, (intmax_t)lhs, #op, #rhs, (intmax_t)rhs);	\
318 		return (ENOENT);					\
319 	}
320 #define CHK2(lhs1, op1, rhs1, lhs2, op2, rhs2, fmt)			\
321 	if (lhs1 op1 rhs1 && lhs2 op2 rhs2) {				\
322 		printf("UFS%d superblock failed: %s (" #fmt ") %s %s ("	\
323 		    #fmt ") && %s (" #fmt ") %s %s (" #fmt ")\n",	\
324 		    fs->fs_magic == FS_UFS1_MAGIC ? 1 : 2, #lhs1, 	\
325 		    (intmax_t)lhs1, #op1, #rhs1, (intmax_t)rhs1, #lhs2,	\
326 		    (intmax_t)lhs2, #op2, #rhs2, (intmax_t)rhs2);	\
327 		return (ENOENT);					\
328 	}
329 
330 static int
331 validate_sblock(struct fs *fs, int isaltsblk)
332 {
333 	int i, sectorsize;
334 	u_int64_t maxfilesize, minfpg, sizepb;
335 
336 	sectorsize = dbtob(1);
337 	if (fs->fs_magic == FS_UFS2_MAGIC) {
338 		if (!isaltsblk) {
339 			CHK(fs->fs_sblockloc, !=, SBLOCK_UFS2, %#jx);
340 			CHK2(fs->fs_sblockactualloc, !=, SBLOCK_UFS2,
341 			    fs->fs_sblockactualloc, !=, 0, %jd);
342 		}
343 		CHK(fs->fs_maxsymlinklen, !=, ((UFS_NDADDR + UFS_NIADDR) *
344 			sizeof(ufs2_daddr_t)), %jd);
345 		CHK(fs->fs_nindir, !=, fs->fs_bsize / sizeof(ufs2_daddr_t),
346 		    %jd);
347 		CHK(fs->fs_inopb, !=, fs->fs_bsize / sizeof(struct ufs2_dinode),
348 		    %jd);
349 	} else if (fs->fs_magic == FS_UFS1_MAGIC) {
350 		if (!isaltsblk) {
351 			CHK(fs->fs_sblockloc, >, SBLOCK_UFS1, %#jx);
352 			CHK2(fs->fs_sblockactualloc, !=, SBLOCK_UFS1,
353 			    fs->fs_sblockactualloc, !=, 0, %jd);
354 		}
355 		CHK(fs->fs_nindir, !=, fs->fs_bsize / sizeof(ufs1_daddr_t),
356 		    %jd);
357 		CHK(fs->fs_inopb, !=, fs->fs_bsize / sizeof(struct ufs1_dinode),
358 		    %jd);
359 		CHK(fs->fs_maxsymlinklen, !=, ((UFS_NDADDR + UFS_NIADDR) *
360 			sizeof(ufs1_daddr_t)), %jd);
361 		CHK(fs->fs_old_inodefmt, !=, FS_44INODEFMT, %jd);
362 		CHK(fs->fs_old_cgoffset, !=, 0, %jd);
363 		CHK(fs->fs_old_cgmask, !=, 0xffffffff, %#jx);
364 		CHK(fs->fs_old_rotdelay, !=, 0, %jd);
365 		CHK(fs->fs_old_rps, !=, 60, %jd);
366 		CHK(fs->fs_old_nspf, !=, fs->fs_fsize / sectorsize, %jd);
367 		CHK(fs->fs_old_cpg, !=, 1, %jd);
368 		CHK(fs->fs_old_interleave, !=, 1, %jd);
369 		CHK(fs->fs_old_trackskew, !=, 0, %jd);
370 		CHK(fs->fs_old_cpc, !=, 0, %jd);
371 		CHK(fs->fs_old_postblformat, !=, 1, %jd);
372 		CHK(fs->fs_old_nrpos, !=, 1, %jd);
373 		CHK(fs->fs_old_spc, !=, fs->fs_fpg * fs->fs_old_nspf, %jd);
374 		CHK(fs->fs_old_nsect, !=, fs->fs_old_spc, %jd);
375 		CHK(fs->fs_old_npsect, !=, fs->fs_old_spc, %jd);
376 		CHK(fs->fs_old_ncyl, !=, fs->fs_ncg, %jd);
377 	} else {
378 		/* Bad magic number, so assume not a superblock */
379 		return (ENOENT);
380 	}
381 	CHK(fs->fs_bsize, <, MINBSIZE, %jd);
382 	CHK(fs->fs_bsize, >, MAXBSIZE, %jd);
383 	CHK(fs->fs_bsize, <, roundup(sizeof(struct fs), DEV_BSIZE), %jd);
384 	CHK(fs->fs_sbsize, >, SBLOCKSIZE, %jd);
385 	CHK(fs->fs_sbsize, <, fs->fs_fsize, %jd);
386 	CHK(powerof2(fs->fs_bsize), ==, 0, %jd);
387 	CHK(fs->fs_fsize, <, sectorsize, %jd);
388 	CHK(fs->fs_fsize, >, fs->fs_bsize, %jd);
389 	CHK(fs->fs_fsize * MAXFRAG, <, fs->fs_bsize, %jd);
390 	CHK(powerof2(fs->fs_fsize), ==, 0, %jd);
391 	CHK(fs->fs_maxbsize, <, fs->fs_bsize, %jd);
392 	CHK(powerof2(fs->fs_maxbsize), ==, 0, %jd);
393 	CHK(fs->fs_maxbsize, >, FS_MAXCONTIG * fs->fs_bsize, %jd);
394 	CHK(fs->fs_bmask, !=, ~(fs->fs_bsize - 1), %#jx);
395 	CHK(fs->fs_fmask, !=, ~(fs->fs_fsize - 1), %#jx);
396 	CHK(fs->fs_qbmask, !=, ~fs->fs_bmask, %#jx);
397 	CHK(fs->fs_qfmask, !=, ~fs->fs_fmask, %#jx);
398 	CHK(fs->fs_bshift, !=, ILOG2(fs->fs_bsize), %jd);
399 	CHK(fs->fs_fshift, !=, ILOG2(fs->fs_fsize), %jd);
400 	CHK(fs->fs_frag, !=, numfrags(fs, fs->fs_bsize), %jd);
401 	CHK(fs->fs_fragshift, !=, ILOG2(fs->fs_frag), %jd);
402 	CHK(fs->fs_frag, >, MAXFRAG, %jd);
403 	CHK(fs->fs_fsbtodb, !=, ILOG2(fs->fs_fsize / sectorsize), %jd);
404 	CHK(fs->fs_sblkno, !=, roundup(
405 	    howmany(fs->fs_sblockloc + SBLOCKSIZE, fs->fs_fsize),
406 	    fs->fs_frag), %jd);
407 	CHK(fs->fs_cblkno, !=, fs->fs_sblkno +
408 	    roundup(howmany(SBLOCKSIZE, fs->fs_fsize), fs->fs_frag), %jd);
409 	CHK(fs->fs_iblkno, !=, fs->fs_cblkno + fs->fs_frag, %jd);
410 	CHK(fs->fs_dblkno, !=, fs->fs_iblkno + fs->fs_ipg / INOPF(fs), %jd);
411 	CHK(fs->fs_cgsize, >, fs->fs_bsize, %jd);
412 	CHK(fs->fs_csaddr, !=, cgdmin(fs, 0), %jd);
413 	CHK(fs->fs_cssize, !=,
414 		fragroundup(fs, fs->fs_ncg * sizeof(struct csum)), %jd);
415 	CHK(fs->fs_dsize, !=, fs->fs_size - fs->fs_sblkno -
416 		fs->fs_ncg * (fs->fs_dblkno - fs->fs_sblkno) -
417 		howmany(fs->fs_cssize, fs->fs_fsize), %jd);
418 	CHK(fs->fs_metaspace, <, 0, %jd);
419 	CHK(fs->fs_metaspace, >, fs->fs_fpg / 2, %jd);
420 	CHK(fs->fs_minfree, >, 99, %jd%%);
421 	maxfilesize = fs->fs_bsize * UFS_NDADDR - 1;
422 	for (sizepb = fs->fs_bsize, i = 0; i < UFS_NIADDR; i++) {
423 		sizepb *= NINDIR(fs);
424 		maxfilesize += sizepb;
425 	}
426 	CHK(fs->fs_maxfilesize, !=, maxfilesize, %jd);
427 	/*
428 	 * These values have a tight interaction with each other that
429 	 * makes it hard to tightly bound them. So we can only check
430 	 * that they are within a broader possible range.
431 	 *
432 	 * Calculate minfpg, the minimum number of fragments that can be
433 	 * in a cylinder group. The value 12289 is calculated in newfs(8)
434 	 * when creating the smallest block size UFS version 1 filesystem
435 	 * (4096 block size) with no fragments (4096 fragment size). That
436 	 * number may be depressed even further for very small filesystems
437 	 * since newfs(8) strives to have at least four cylinder groups.
438 	 */
439 	minfpg = MIN(12289, fs->fs_size / 4);
440 	CHK(fs->fs_ncg, <, 1, %jd);
441 	CHK(fs->fs_ncg, >, (fs->fs_size / minfpg) + 1, %jd);
442 	CHK(fs->fs_fpg, <, minfpg, %jd);
443 	CHK(fs->fs_fpg, >, fs->fs_size, %jd);
444 	CHK(fs->fs_ipg * fs->fs_ncg, >, (((int64_t)(1)) << 32) - INOPB(fs),
445 	    %jd);
446 	CHK(fs->fs_ipg, >, fs->fs_fpg, %jd);
447 	CHK(fs->fs_size, <, 8 * fs->fs_frag, %jd);
448 	CHK(fs->fs_size, <=, (fs->fs_ncg - 1) * fs->fs_fpg, %jd);
449 	CHK(fs->fs_size, >, fs->fs_ncg * fs->fs_fpg, %jd);
450 	/*
451 	 * With file system clustering it is possible to allocate
452 	 * many contiguous blocks. The kernel variable maxphys defines
453 	 * the maximum transfer size permitted by the controller and/or
454 	 * buffering. The fs_maxcontig parameter controls the maximum
455 	 * number of blocks that the filesystem will read or write
456 	 * in a single transfer. It is calculated when the filesystem
457 	 * is created as maxphys / fs_bsize. The loader uses a maxphys
458 	 * of 128K even when running on a system that supports larger
459 	 * values. If the filesystem was built on a system that supports
460 	 * a larger maxphys (1M is typical) it will have configured
461 	 * fs_maxcontig for that larger system. So we bound the upper
462 	 * allowable limit for fs_maxconfig to be able to at least
463 	 * work with a 1M maxphys on the smallest block size filesystem:
464 	 * 1M / 4096 == 256. There is no harm in allowing the mounting of
465 	 * filesystems that make larger than maxphys I/O requests because
466 	 * those (mostly 32-bit machines) can (very slowly) handle I/O
467 	 * requests that exceed maxphys.
468 	 */
469 	CHK(fs->fs_maxcontig, <, 1, %jd);
470 	CHK(fs->fs_maxcontig, >, MAX(256, maxphys / fs->fs_bsize), %jd);
471 	CHK(fs->fs_maxcontig, <, 0, %jd);
472 	CHK2(fs->fs_maxcontig, ==, 0, fs->fs_contigsumsize, !=, 0, %jd);
473 	CHK2(fs->fs_maxcontig, >, 1, fs->fs_contigsumsize, !=,
474 	    MIN(fs->fs_maxcontig, FS_MAXCONTIG), %jd);
475 	return (0);
476 }
477 
478 /*
479  * Write a superblock to the devfd device from the memory pointed to by fs.
480  * Write out the superblock summary information if it is present.
481  *
482  * If the write is successful, zero is returned. Otherwise one of the
483  * following error values is returned:
484  *     EIO: failed to write superblock.
485  *     EIO: failed to write superblock summary information.
486  */
487 int
488 ffs_sbput(void *devfd, struct fs *fs, off_t loc,
489     int (*writefunc)(void *devfd, off_t loc, void *buf, int size))
490 {
491 	int i, error, blks, size;
492 	uint8_t *space;
493 
494 	/*
495 	 * If there is summary information, write it first, so if there
496 	 * is an error, the superblock will not be marked as clean.
497 	 */
498 	if (fs->fs_si != NULL && fs->fs_csp != NULL) {
499 		blks = howmany(fs->fs_cssize, fs->fs_fsize);
500 		space = (uint8_t *)fs->fs_csp;
501 		for (i = 0; i < blks; i += fs->fs_frag) {
502 			size = fs->fs_bsize;
503 			if (i + fs->fs_frag > blks)
504 				size = (blks - i) * fs->fs_fsize;
505 			if ((error = (*writefunc)(devfd,
506 			     dbtob(fsbtodb(fs, fs->fs_csaddr + i)),
507 			     space, size)) != 0)
508 				return (error);
509 			space += size;
510 		}
511 	}
512 	fs->fs_fmod = 0;
513 #ifndef _KERNEL
514 	{
515 		struct fs_summary_info *fs_si;
516 
517 		fs->fs_time = time(NULL);
518 		/* Clear the pointers for the duration of writing. */
519 		fs_si = fs->fs_si;
520 		fs->fs_si = NULL;
521 		fs->fs_ckhash = ffs_calc_sbhash(fs);
522 		error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize);
523 		fs->fs_si = fs_si;
524 	}
525 #else /* _KERNEL */
526 	fs->fs_time = time_second;
527 	fs->fs_ckhash = ffs_calc_sbhash(fs);
528 	error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize);
529 #endif /* _KERNEL */
530 	return (error);
531 }
532 
533 /*
534  * Calculate the check-hash for a superblock.
535  */
536 uint32_t
537 ffs_calc_sbhash(struct fs *fs)
538 {
539 	uint32_t ckhash, save_ckhash;
540 
541 	/*
542 	 * A filesystem that was using a superblock ckhash may be moved
543 	 * to an older kernel that does not support ckhashes. The
544 	 * older kernel will clear the FS_METACKHASH flag indicating
545 	 * that it does not update hashes. When the disk is moved back
546 	 * to a kernel capable of ckhashes it disables them on mount:
547 	 *
548 	 *	if ((fs->fs_flags & FS_METACKHASH) == 0)
549 	 *		fs->fs_metackhash = 0;
550 	 *
551 	 * This leaves (fs->fs_metackhash & CK_SUPERBLOCK) == 0) with an
552 	 * old stale value in the fs->fs_ckhash field. Thus the need to
553 	 * just accept what is there.
554 	 */
555 	if ((fs->fs_metackhash & CK_SUPERBLOCK) == 0)
556 		return (fs->fs_ckhash);
557 
558 	save_ckhash = fs->fs_ckhash;
559 	fs->fs_ckhash = 0;
560 	/*
561 	 * If newly read from disk, the caller is responsible for
562 	 * verifying that fs->fs_sbsize <= SBLOCKSIZE.
563 	 */
564 	ckhash = calculate_crc32c(~0L, (void *)fs, fs->fs_sbsize);
565 	fs->fs_ckhash = save_ckhash;
566 	return (ckhash);
567 }
568 
569 /*
570  * Update the frsum fields to reflect addition or deletion
571  * of some frags.
572  */
573 void
574 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
575 {
576 	int inblk;
577 	int field, subfield;
578 	int siz, pos;
579 
580 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
581 	fragmap <<= 1;
582 	for (siz = 1; siz < fs->fs_frag; siz++) {
583 		if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
584 			continue;
585 		field = around[siz];
586 		subfield = inside[siz];
587 		for (pos = siz; pos <= fs->fs_frag; pos++) {
588 			if ((fragmap & field) == subfield) {
589 				fraglist[siz] += cnt;
590 				pos += siz;
591 				field <<= siz;
592 				subfield <<= siz;
593 			}
594 			field <<= 1;
595 			subfield <<= 1;
596 		}
597 	}
598 }
599 
600 /*
601  * block operations
602  *
603  * check if a block is available
604  */
605 int
606 ffs_isblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
607 {
608 	unsigned char mask;
609 
610 	switch ((int)fs->fs_frag) {
611 	case 8:
612 		return (cp[h] == 0xff);
613 	case 4:
614 		mask = 0x0f << ((h & 0x1) << 2);
615 		return ((cp[h >> 1] & mask) == mask);
616 	case 2:
617 		mask = 0x03 << ((h & 0x3) << 1);
618 		return ((cp[h >> 2] & mask) == mask);
619 	case 1:
620 		mask = 0x01 << (h & 0x7);
621 		return ((cp[h >> 3] & mask) == mask);
622 	default:
623 #ifdef _KERNEL
624 		panic("ffs_isblock");
625 #endif
626 		break;
627 	}
628 	return (0);
629 }
630 
631 /*
632  * check if a block is free
633  */
634 int
635 ffs_isfreeblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
636 {
637 
638 	switch ((int)fs->fs_frag) {
639 	case 8:
640 		return (cp[h] == 0);
641 	case 4:
642 		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
643 	case 2:
644 		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
645 	case 1:
646 		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
647 	default:
648 #ifdef _KERNEL
649 		panic("ffs_isfreeblock");
650 #endif
651 		break;
652 	}
653 	return (0);
654 }
655 
656 /*
657  * take a block out of the map
658  */
659 void
660 ffs_clrblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
661 {
662 
663 	switch ((int)fs->fs_frag) {
664 	case 8:
665 		cp[h] = 0;
666 		return;
667 	case 4:
668 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
669 		return;
670 	case 2:
671 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
672 		return;
673 	case 1:
674 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
675 		return;
676 	default:
677 #ifdef _KERNEL
678 		panic("ffs_clrblock");
679 #endif
680 		break;
681 	}
682 }
683 
684 /*
685  * put a block into the map
686  */
687 void
688 ffs_setblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
689 {
690 
691 	switch ((int)fs->fs_frag) {
692 	case 8:
693 		cp[h] = 0xff;
694 		return;
695 	case 4:
696 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
697 		return;
698 	case 2:
699 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
700 		return;
701 	case 1:
702 		cp[h >> 3] |= (0x01 << (h & 0x7));
703 		return;
704 	default:
705 #ifdef _KERNEL
706 		panic("ffs_setblock");
707 #endif
708 		break;
709 	}
710 }
711 
712 /*
713  * Update the cluster map because of an allocation or free.
714  *
715  * Cnt == 1 means free; cnt == -1 means allocating.
716  */
717 void
718 ffs_clusteracct(struct fs *fs, struct cg *cgp, ufs1_daddr_t blkno, int cnt)
719 {
720 	int32_t *sump;
721 	int32_t *lp;
722 	u_char *freemapp, *mapp;
723 	int i, start, end, forw, back, map;
724 	u_int bit;
725 
726 	if (fs->fs_contigsumsize <= 0)
727 		return;
728 	freemapp = cg_clustersfree(cgp);
729 	sump = cg_clustersum(cgp);
730 	/*
731 	 * Allocate or clear the actual block.
732 	 */
733 	if (cnt > 0)
734 		setbit(freemapp, blkno);
735 	else
736 		clrbit(freemapp, blkno);
737 	/*
738 	 * Find the size of the cluster going forward.
739 	 */
740 	start = blkno + 1;
741 	end = start + fs->fs_contigsumsize;
742 	if (end >= cgp->cg_nclusterblks)
743 		end = cgp->cg_nclusterblks;
744 	mapp = &freemapp[start / NBBY];
745 	map = *mapp++;
746 	bit = 1U << (start % NBBY);
747 	for (i = start; i < end; i++) {
748 		if ((map & bit) == 0)
749 			break;
750 		if ((i & (NBBY - 1)) != (NBBY - 1)) {
751 			bit <<= 1;
752 		} else {
753 			map = *mapp++;
754 			bit = 1;
755 		}
756 	}
757 	forw = i - start;
758 	/*
759 	 * Find the size of the cluster going backward.
760 	 */
761 	start = blkno - 1;
762 	end = start - fs->fs_contigsumsize;
763 	if (end < 0)
764 		end = -1;
765 	mapp = &freemapp[start / NBBY];
766 	map = *mapp--;
767 	bit = 1U << (start % NBBY);
768 	for (i = start; i > end; i--) {
769 		if ((map & bit) == 0)
770 			break;
771 		if ((i & (NBBY - 1)) != 0) {
772 			bit >>= 1;
773 		} else {
774 			map = *mapp--;
775 			bit = 1U << (NBBY - 1);
776 		}
777 	}
778 	back = start - i;
779 	/*
780 	 * Account for old cluster and the possibly new forward and
781 	 * back clusters.
782 	 */
783 	i = back + forw + 1;
784 	if (i > fs->fs_contigsumsize)
785 		i = fs->fs_contigsumsize;
786 	sump[i] += cnt;
787 	if (back > 0)
788 		sump[back] -= cnt;
789 	if (forw > 0)
790 		sump[forw] -= cnt;
791 	/*
792 	 * Update cluster summary information.
793 	 */
794 	lp = &sump[fs->fs_contigsumsize];
795 	for (i = fs->fs_contigsumsize; i > 0; i--)
796 		if (*lp-- > 0)
797 			break;
798 	fs->fs_maxcluster[cgp->cg_cgx] = i;
799 }
800