xref: /freebsd/sbin/fsck_ffs/setup.c (revision 732a02b4e77866604a120a275c082bb6221bd2ff)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1986, 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 
32 #if 0
33 #ifndef lint
34 static const char sccsid[] = "@(#)setup.c	8.10 (Berkeley) 5/9/95";
35 #endif /* not lint */
36 #endif
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/disk.h>
42 #include <sys/stat.h>
43 #define FSTYPENAMES
44 #include <sys/disklabel.h>
45 #include <sys/file.h>
46 #include <sys/sysctl.h>
47 
48 #include <ufs/ufs/dinode.h>
49 #include <ufs/ffs/fs.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <limits.h>
55 #include <stdint.h>
56 #include <string.h>
57 #include <libufs.h>
58 
59 #include "fsck.h"
60 
61 struct inoinfo **inphead, **inpsort;
62 
63 struct uufsd disk;
64 struct bufarea asblk;
65 #define altsblock (*asblk.b_un.b_fs)
66 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
67 
68 static int calcsb(char *dev, int devfd, struct fs *fs);
69 static void saverecovery(int readfd, int writefd);
70 static int chkrecovery(int devfd);
71 
72 /*
73  * Read in a superblock finding an alternate if necessary.
74  * Return 1 if successful, 0 if unsuccessful, -1 if file system
75  * is already clean (ckclean and preen mode only).
76  */
77 int
78 setup(char *dev)
79 {
80 	long cg, asked, i, j;
81 	long bmapsize;
82 	struct stat statb;
83 	struct fs proto;
84 	size_t size;
85 
86 	havesb = 0;
87 	fswritefd = -1;
88 	cursnapshot = 0;
89 	if (stat(dev, &statb) < 0) {
90 		printf("Can't stat %s: %s\n", dev, strerror(errno));
91 		if (bkgrdflag) {
92 			unlink(snapname);
93 			bkgrdflag = 0;
94 		}
95 		return (0);
96 	}
97 	if ((statb.st_mode & S_IFMT) != S_IFCHR &&
98 	    (statb.st_mode & S_IFMT) != S_IFBLK) {
99 		if (bkgrdflag != 0 && (statb.st_flags & SF_SNAPSHOT) == 0) {
100 			unlink(snapname);
101 			printf("background fsck lacks a snapshot\n");
102 			exit(EEXIT);
103 		}
104 		if ((statb.st_flags & SF_SNAPSHOT) != 0 && cvtlevel == 0) {
105 			cursnapshot = statb.st_ino;
106 		} else {
107 			if (cvtlevel == 0 ||
108 			    (statb.st_flags & SF_SNAPSHOT) == 0) {
109 				if (preen && bkgrdflag) {
110 					unlink(snapname);
111 					bkgrdflag = 0;
112 				}
113 				pfatal("%s is not a disk device", dev);
114 				if (reply("CONTINUE") == 0) {
115 					if (bkgrdflag) {
116 						unlink(snapname);
117 						bkgrdflag = 0;
118 					}
119 					return (0);
120 				}
121 			} else {
122 				if (bkgrdflag) {
123 					unlink(snapname);
124 					bkgrdflag = 0;
125 				}
126 				pfatal("cannot convert a snapshot");
127 				exit(EEXIT);
128 			}
129 		}
130 	}
131 	if ((fsreadfd = open(dev, O_RDONLY)) < 0 ||
132 	    ufs_disk_fillout_blank(&disk, dev) < 0) {
133 		if (bkgrdflag) {
134 			unlink(snapname);
135 			bkgrdflag = 0;
136 		}
137 		printf("Can't open %s: %s\n", dev, strerror(errno));
138 		return (0);
139 	}
140 	if (bkgrdflag) {
141 		unlink(snapname);
142 		size = MIBSIZE;
143 		if (sysctlnametomib("vfs.ffs.adjrefcnt", adjrefcnt, &size) < 0||
144 		    sysctlnametomib("vfs.ffs.adjblkcnt", adjblkcnt, &size) < 0||
145 		    sysctlnametomib("vfs.ffs.setsize", setsize, &size) < 0 ||
146 		    sysctlnametomib("vfs.ffs.freefiles", freefiles, &size) < 0||
147 		    sysctlnametomib("vfs.ffs.freedirs", freedirs, &size) < 0 ||
148 		    sysctlnametomib("vfs.ffs.freeblks", freeblks, &size) < 0) {
149 			pfatal("kernel lacks background fsck support\n");
150 			exit(EEXIT);
151 		}
152 		/*
153 		 * When kernel is lack of runtime bgfsck superblock summary
154 		 * adjustment functionality, it does not mean we can not
155 		 * continue, as old kernels will recompute the summary at
156 		 * mount time.  However, it will be an unexpected softupdates
157 		 * inconsistency if it turns out that the summary is still
158 		 * incorrect.  Set a flag so subsequent operation can know
159 		 * this.
160 		 */
161 		bkgrdsumadj = 1;
162 		if (sysctlnametomib("vfs.ffs.adjndir", adjndir, &size) < 0 ||
163 		    sysctlnametomib("vfs.ffs.adjnbfree", adjnbfree, &size) < 0 ||
164 		    sysctlnametomib("vfs.ffs.adjnifree", adjnifree, &size) < 0 ||
165 		    sysctlnametomib("vfs.ffs.adjnffree", adjnffree, &size) < 0 ||
166 		    sysctlnametomib("vfs.ffs.adjnumclusters", adjnumclusters, &size) < 0) {
167 			bkgrdsumadj = 0;
168 			pwarn("kernel lacks runtime superblock summary adjustment support");
169 		}
170 		cmd.version = FFS_CMD_VERSION;
171 		cmd.handle = fsreadfd;
172 		fswritefd = -1;
173 	}
174 	if (preen == 0)
175 		printf("** %s", dev);
176 	if (bkgrdflag == 0 &&
177 	    (nflag || ufs_disk_write(&disk) < 0 ||
178 	     (fswritefd = dup(disk.d_fd)) < 0)) {
179 		fswritefd = -1;
180 		if (preen)
181 			pfatal("NO WRITE ACCESS");
182 		printf(" (NO WRITE)");
183 	}
184 	if (preen == 0)
185 		printf("\n");
186 	/*
187 	 * Read in the superblock, looking for alternates if necessary
188 	 */
189 	if (readsb(1) == 0) {
190 		skipclean = 0;
191 		if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
192 			return(0);
193 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
194 			return (0);
195 		for (cg = 0; cg < proto.fs_ncg; cg++) {
196 			bflag = fsbtodb(&proto, cgsblock(&proto, cg));
197 			if (readsb(0) != 0)
198 				break;
199 		}
200 		if (cg >= proto.fs_ncg) {
201 			printf("%s %s\n%s %s\n%s %s\n",
202 				"SEARCH FOR ALTERNATE SUPER-BLOCK",
203 				"FAILED. YOU MUST USE THE",
204 				"-b OPTION TO FSCK TO SPECIFY THE",
205 				"LOCATION OF AN ALTERNATE",
206 				"SUPER-BLOCK TO SUPPLY NEEDED",
207 				"INFORMATION; SEE fsck_ffs(8).");
208 			bflag = 0;
209 			return(0);
210 		}
211 		pwarn("USING ALTERNATE SUPERBLOCK AT %jd\n", bflag);
212 		bflag = 0;
213 	}
214 	/* Save copy of things needed by libufs */
215 	memcpy(&disk.d_fs, &sblock, sblock.fs_sbsize);
216 	disk.d_ufs = (sblock.fs_magic == FS_UFS1_MAGIC) ? 1 : 2;
217 	disk.d_bsize = sblock.fs_fsize / fsbtodb(&sblock, 1);
218 	disk.d_sblock = sblock.fs_sblockloc / disk.d_bsize;
219 	disk.d_sbcsum = sblock.fs_csp;
220 
221 	if (skipclean && ckclean && sblock.fs_clean) {
222 		pwarn("FILE SYSTEM CLEAN; SKIPPING CHECKS\n");
223 		return (-1);
224 	}
225 	maxfsblock = sblock.fs_size;
226 	maxino = sblock.fs_ncg * sblock.fs_ipg;
227 	/*
228 	 * Check and potentially fix certain fields in the super block.
229 	 */
230 	if (sblock.fs_optim != FS_OPTTIME && sblock.fs_optim != FS_OPTSPACE) {
231 		pfatal("UNDEFINED OPTIMIZATION IN SUPERBLOCK");
232 		if (reply("SET TO DEFAULT") == 1) {
233 			sblock.fs_optim = FS_OPTTIME;
234 			sbdirty();
235 		}
236 	}
237 	if ((sblock.fs_minfree < 0 || sblock.fs_minfree > 99)) {
238 		pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
239 			sblock.fs_minfree);
240 		if (reply("SET TO DEFAULT") == 1) {
241 			sblock.fs_minfree = 10;
242 			sbdirty();
243 		}
244 	}
245 	if (sblock.fs_magic == FS_UFS1_MAGIC &&
246 	    sblock.fs_old_inodefmt < FS_44INODEFMT) {
247 		pwarn("Format of file system is too old.\n");
248 		pwarn("Must update to modern format using a version of fsck\n");
249 		pfatal("from before 2002 with the command ``fsck -c 2''\n");
250 		exit(EEXIT);
251 	}
252 	if (asblk.b_dirty && !bflag) {
253 		memmove(&altsblock, &sblock, (size_t)sblock.fs_sbsize);
254 		flush(fswritefd, &asblk);
255 	}
256 	if (preen == 0 && yflag == 0 && sblock.fs_magic == FS_UFS2_MAGIC &&
257 	    fswritefd != -1 && chkrecovery(fsreadfd) == 0 &&
258 	    reply("SAVE DATA TO FIND ALTERNATE SUPERBLOCKS") != 0)
259 		saverecovery(fsreadfd, fswritefd);
260 	/*
261 	 * read in the summary info.
262 	 */
263 	asked = 0;
264 	sblock.fs_csp = Calloc(1, sblock.fs_cssize);
265 	if (sblock.fs_csp == NULL) {
266 		printf("cannot alloc %u bytes for cg summary info\n",
267 		    (unsigned)sblock.fs_cssize);
268 		goto badsb;
269 	}
270 	for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) {
271 		size = MIN(sblock.fs_cssize - i, sblock.fs_bsize);
272 		readcnt[sblk.b_type]++;
273 		if (blread(fsreadfd, (char *)sblock.fs_csp + i,
274 		    fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag),
275 		    size) != 0 && !asked) {
276 			pfatal("BAD SUMMARY INFORMATION");
277 			if (reply("CONTINUE") == 0) {
278 				ckfini(0);
279 				exit(EEXIT);
280 			}
281 			asked++;
282 		}
283 	}
284 	/*
285 	 * allocate and initialize the necessary maps
286 	 */
287 	bmapsize = roundup(howmany(maxfsblock, CHAR_BIT), sizeof(short));
288 	blockmap = Calloc((unsigned)bmapsize, sizeof (char));
289 	if (blockmap == NULL) {
290 		printf("cannot alloc %u bytes for blockmap\n",
291 		    (unsigned)bmapsize);
292 		goto badsb;
293 	}
294 	inostathead = Calloc(sblock.fs_ncg, sizeof(struct inostatlist));
295 	if (inostathead == NULL) {
296 		printf("cannot alloc %u bytes for inostathead\n",
297 		    (unsigned)(sizeof(struct inostatlist) * (sblock.fs_ncg)));
298 		goto badsb;
299 	}
300 	numdirs = MAX(sblock.fs_cstotal.cs_ndir, 128);
301 	dirhash = numdirs;
302 	inplast = 0;
303 	listmax = numdirs + 10;
304 	inpsort = (struct inoinfo **)Calloc(listmax, sizeof(struct inoinfo *));
305 	inphead = (struct inoinfo **)Calloc(numdirs, sizeof(struct inoinfo *));
306 	if (inpsort == NULL || inphead == NULL) {
307 		printf("cannot alloc %ju bytes for inphead\n",
308 		    (uintmax_t)numdirs * sizeof(struct inoinfo *));
309 		goto badsb;
310 	}
311 	bufinit();
312 	if (sblock.fs_flags & FS_DOSOFTDEP)
313 		usedsoftdep = 1;
314 	else
315 		usedsoftdep = 0;
316 	return (1);
317 
318 badsb:
319 	ckfini(0);
320 	return (0);
321 }
322 
323 /*
324  * Read in the super block and its summary info.
325  */
326 int
327 readsb(int listerr)
328 {
329 	off_t super;
330 	int bad, ret;
331 	struct fs *fs;
332 
333 	super = bflag ? bflag * dev_bsize : STDSB;
334 	readcnt[sblk.b_type]++;
335 	if ((ret = sbget(fsreadfd, &fs, super)) != 0) {
336 		switch (ret) {
337 		case EINVAL:
338 			/* Superblock check-hash failed */
339 			return (0);
340 		case ENOENT:
341 			if (bflag)
342 				fprintf(stderr, "%jd is not a file system "
343 				    "superblock\n", super / dev_bsize);
344 			else
345 				fprintf(stderr, "Cannot find file system "
346 				    "superblock\n");
347 			return (0);
348 		case EIO:
349 		default:
350 			fprintf(stderr, "I/O error reading %jd\n",
351 			    super / dev_bsize);
352 			return (0);
353 		}
354 	}
355 	memcpy(&sblock, fs, fs->fs_sbsize);
356 	free(fs);
357 	/*
358 	 * Compute block size that the file system is based on,
359 	 * according to fsbtodb, and adjust superblock block number
360 	 * so we can tell if this is an alternate later.
361 	 */
362 	dev_bsize = sblock.fs_fsize / fsbtodb(&sblock, 1);
363 	sblk.b_bno = sblock.fs_sblockactualloc / dev_bsize;
364 	sblk.b_size = SBLOCKSIZE;
365 	/*
366 	 * Compare all fields that should not differ in alternate super block.
367 	 * When an alternate super-block is specified this check is skipped.
368 	 */
369 	if (bflag)
370 		goto out;
371 	getblk(&asblk, cgsblock(&sblock, sblock.fs_ncg - 1), sblock.fs_sbsize);
372 	if (asblk.b_errs)
373 		return (0);
374 	bad = 0;
375 #define CHK(x, y)				\
376 	if (altsblock.x != sblock.x) {		\
377 		bad++;				\
378 		if (listerr && debug)		\
379 			printf("SUPER BLOCK VS ALTERNATE MISMATCH %s: " y " vs " y "\n", \
380 			    #x, (intmax_t)sblock.x, (intmax_t)altsblock.x); \
381 	}
382 	CHK(fs_sblkno, "%jd");
383 	CHK(fs_cblkno, "%jd");
384 	CHK(fs_iblkno, "%jd");
385 	CHK(fs_dblkno, "%jd");
386 	CHK(fs_ncg, "%jd");
387 	CHK(fs_bsize, "%jd");
388 	CHK(fs_fsize, "%jd");
389 	CHK(fs_frag, "%jd");
390 	CHK(fs_bmask, "%#jx");
391 	CHK(fs_fmask, "%#jx");
392 	CHK(fs_bshift, "%jd");
393 	CHK(fs_fshift, "%jd");
394 	CHK(fs_fragshift, "%jd");
395 	CHK(fs_fsbtodb, "%jd");
396 	CHK(fs_sbsize, "%jd");
397 	CHK(fs_nindir, "%jd");
398 	CHK(fs_inopb, "%jd");
399 	CHK(fs_cssize, "%jd");
400 	CHK(fs_ipg, "%jd");
401 	CHK(fs_fpg, "%jd");
402 	CHK(fs_magic, "%#jx");
403 #undef CHK
404 	if (bad) {
405 		if (listerr == 0)
406 			return (0);
407 		if (preen)
408 			printf("%s: ", cdevname);
409 		printf(
410 		    "VALUES IN SUPER BLOCK LSB=%jd DISAGREE WITH THOSE IN\n"
411 		    "LAST ALTERNATE LSB=%jd\n",
412 		    sblk.b_bno, asblk.b_bno);
413 		if (reply("IGNORE ALTERNATE SUPER BLOCK") == 0)
414 			return (0);
415 	}
416 out:
417 	/*
418 	 * If not yet done, update UFS1 superblock with new wider fields.
419 	 */
420 	if (sblock.fs_magic == FS_UFS1_MAGIC &&
421 	    sblock.fs_maxbsize != sblock.fs_bsize) {
422 		sblock.fs_maxbsize = sblock.fs_bsize;
423 		sblock.fs_time = sblock.fs_old_time;
424 		sblock.fs_size = sblock.fs_old_size;
425 		sblock.fs_dsize = sblock.fs_old_dsize;
426 		sblock.fs_csaddr = sblock.fs_old_csaddr;
427 		sblock.fs_cstotal.cs_ndir = sblock.fs_old_cstotal.cs_ndir;
428 		sblock.fs_cstotal.cs_nbfree = sblock.fs_old_cstotal.cs_nbfree;
429 		sblock.fs_cstotal.cs_nifree = sblock.fs_old_cstotal.cs_nifree;
430 		sblock.fs_cstotal.cs_nffree = sblock.fs_old_cstotal.cs_nffree;
431 	}
432 	havesb = 1;
433 	return (1);
434 }
435 
436 void
437 sblock_init(void)
438 {
439 
440 	fswritefd = -1;
441 	fsmodified = 0;
442 	lfdir = 0;
443 	initbarea(&sblk, BT_SUPERBLK);
444 	initbarea(&asblk, BT_SUPERBLK);
445 	sblk.b_un.b_buf = Malloc(SBLOCKSIZE);
446 	asblk.b_un.b_buf = Malloc(SBLOCKSIZE);
447 	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
448 		errx(EEXIT, "cannot allocate space for superblock");
449 	dev_bsize = secsize = DEV_BSIZE;
450 }
451 
452 /*
453  * Calculate a prototype superblock based on information in the boot area.
454  * When done the cgsblock macro can be calculated and the fs_ncg field
455  * can be used. Do NOT attempt to use other macros without verifying that
456  * their needed information is available!
457  */
458 static int
459 calcsb(char *dev, int devfd, struct fs *fs)
460 {
461 	struct fsrecovery *fsr;
462 	char *fsrbuf;
463 	u_int secsize;
464 
465 	/*
466 	 * We need fragments-per-group and the partition-size.
467 	 *
468 	 * Newfs stores these details at the end of the boot block area
469 	 * at the start of the filesystem partition. If they have been
470 	 * overwritten by a boot block, we fail. But usually they are
471 	 * there and we can use them.
472 	 */
473 	if (ioctl(devfd, DIOCGSECTORSIZE, &secsize) == -1)
474 		return (0);
475 	fsrbuf = Malloc(secsize);
476 	if (fsrbuf == NULL)
477 		errx(EEXIT, "calcsb: cannot allocate recovery buffer");
478 	if (blread(devfd, fsrbuf,
479 	    (SBLOCK_UFS2 - secsize) / dev_bsize, secsize) != 0) {
480 		free(fsrbuf);
481 		return (0);
482 	}
483 	fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
484 	if (fsr->fsr_magic != FS_UFS2_MAGIC) {
485 		free(fsrbuf);
486 		return (0);
487 	}
488 	memset(fs, 0, sizeof(struct fs));
489 	fs->fs_fpg = fsr->fsr_fpg;
490 	fs->fs_fsbtodb = fsr->fsr_fsbtodb;
491 	fs->fs_sblkno = fsr->fsr_sblkno;
492 	fs->fs_magic = fsr->fsr_magic;
493 	fs->fs_ncg = fsr->fsr_ncg;
494 	free(fsrbuf);
495 	return (1);
496 }
497 
498 /*
499  * Check to see if recovery information exists.
500  * Return 1 if it exists or cannot be created.
501  * Return 0 if it does not exist and can be created.
502  */
503 static int
504 chkrecovery(int devfd)
505 {
506 	struct fsrecovery *fsr;
507 	char *fsrbuf;
508 	u_int secsize;
509 
510 	/*
511 	 * Could not determine if backup material exists, so do not
512 	 * offer to create it.
513 	 */
514 	fsrbuf = NULL;
515 	if (ioctl(devfd, DIOCGSECTORSIZE, &secsize) == -1 ||
516 	    (fsrbuf = Malloc(secsize)) == NULL ||
517 	    blread(devfd, fsrbuf, (SBLOCK_UFS2 - secsize) / dev_bsize,
518 	      secsize) != 0) {
519 		free(fsrbuf);
520 		return (1);
521 	}
522 	/*
523 	 * Recovery material has already been created, so do not
524 	 * need to create it again.
525 	 */
526 	fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
527 	if (fsr->fsr_magic == FS_UFS2_MAGIC) {
528 		free(fsrbuf);
529 		return (1);
530 	}
531 	/*
532 	 * Recovery material has not been created and can be if desired.
533 	 */
534 	free(fsrbuf);
535 	return (0);
536 }
537 
538 /*
539  * Read the last sector of the boot block, replace the last
540  * 20 bytes with the recovery information, then write it back.
541  * The recovery information only works for UFS2 filesystems.
542  */
543 static void
544 saverecovery(int readfd, int writefd)
545 {
546 	struct fsrecovery *fsr;
547 	char *fsrbuf;
548 	u_int secsize;
549 
550 	fsrbuf = NULL;
551 	if (sblock.fs_magic != FS_UFS2_MAGIC ||
552 	    ioctl(readfd, DIOCGSECTORSIZE, &secsize) == -1 ||
553 	    (fsrbuf = Malloc(secsize)) == NULL ||
554 	    blread(readfd, fsrbuf, (SBLOCK_UFS2 - secsize) / dev_bsize,
555 	      secsize) != 0) {
556 		printf("RECOVERY DATA COULD NOT BE CREATED\n");
557 		free(fsrbuf);
558 		return;
559 	}
560 	fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
561 	fsr->fsr_magic = sblock.fs_magic;
562 	fsr->fsr_fpg = sblock.fs_fpg;
563 	fsr->fsr_fsbtodb = sblock.fs_fsbtodb;
564 	fsr->fsr_sblkno = sblock.fs_sblkno;
565 	fsr->fsr_ncg = sblock.fs_ncg;
566 	blwrite(writefd, fsrbuf, (SBLOCK_UFS2 - secsize) / secsize, secsize);
567 	free(fsrbuf);
568 }
569