xref: /freebsd/sbin/fsck_ffs/setup.c (revision 396c556d77189a5c474d35cec6f44a762e310b7d)
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 
58 #include "fsck.h"
59 
60 struct bufarea asblk;
61 #define altsblock (*asblk.b_un.b_fs)
62 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
63 
64 static int calcsb(char *dev, int devfd, struct fs *fs);
65 static void saverecovery(int readfd, int writefd);
66 static int chkrecovery(int devfd);
67 
68 /*
69  * Read in a superblock finding an alternate if necessary.
70  * Return 1 if successful, 0 if unsuccessful, -1 if file system
71  * is already clean (ckclean and preen mode only).
72  */
73 int
74 setup(char *dev)
75 {
76 	long cg, asked, i, j;
77 	long bmapsize;
78 	struct stat statb;
79 	struct fs proto;
80 	size_t size;
81 
82 	havesb = 0;
83 	fswritefd = -1;
84 	cursnapshot = 0;
85 	if (stat(dev, &statb) < 0) {
86 		printf("Can't stat %s: %s\n", dev, strerror(errno));
87 		if (bkgrdflag) {
88 			unlink(snapname);
89 			bkgrdflag = 0;
90 		}
91 		return (0);
92 	}
93 	if ((statb.st_mode & S_IFMT) != S_IFCHR &&
94 	    (statb.st_mode & S_IFMT) != S_IFBLK) {
95 		if (bkgrdflag != 0 && (statb.st_flags & SF_SNAPSHOT) == 0) {
96 			unlink(snapname);
97 			printf("background fsck lacks a snapshot\n");
98 			exit(EEXIT);
99 		}
100 		if ((statb.st_flags & SF_SNAPSHOT) != 0 && cvtlevel == 0) {
101 			cursnapshot = statb.st_ino;
102 		} else {
103 			if (cvtlevel == 0 ||
104 			    (statb.st_flags & SF_SNAPSHOT) == 0) {
105 				if (preen && bkgrdflag) {
106 					unlink(snapname);
107 					bkgrdflag = 0;
108 				}
109 				pfatal("%s is not a disk device", dev);
110 				if (reply("CONTINUE") == 0) {
111 					if (bkgrdflag) {
112 						unlink(snapname);
113 						bkgrdflag = 0;
114 					}
115 					return (0);
116 				}
117 			} else {
118 				if (bkgrdflag) {
119 					unlink(snapname);
120 					bkgrdflag = 0;
121 				}
122 				pfatal("cannot convert a snapshot");
123 				exit(EEXIT);
124 			}
125 		}
126 	}
127 	if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
128 		if (bkgrdflag) {
129 			unlink(snapname);
130 			bkgrdflag = 0;
131 		}
132 		printf("Can't open %s: %s\n", dev, strerror(errno));
133 		return (0);
134 	}
135 	if (bkgrdflag) {
136 		unlink(snapname);
137 		size = MIBSIZE;
138 		if (sysctlnametomib("vfs.ffs.adjrefcnt", adjrefcnt, &size) < 0||
139 		    sysctlnametomib("vfs.ffs.adjblkcnt", adjblkcnt, &size) < 0||
140 		    sysctlnametomib("vfs.ffs.freefiles", freefiles, &size) < 0||
141 		    sysctlnametomib("vfs.ffs.freedirs", freedirs, &size) < 0 ||
142 		    sysctlnametomib("vfs.ffs.freeblks", freeblks, &size) < 0) {
143 			pfatal("kernel lacks background fsck support\n");
144 			exit(EEXIT);
145 		}
146 		/*
147 		 * When kernel is lack of runtime bgfsck superblock summary
148 		 * adjustment functionality, it does not mean we can not
149 		 * continue, as old kernels will recompute the summary at
150 		 * mount time.  However, it will be an unexpected softupdates
151 		 * inconsistency if it turns out that the summary is still
152 		 * incorrect.  Set a flag so subsequent operation can know
153 		 * this.
154 		 */
155 		bkgrdsumadj = 1;
156 		if (sysctlnametomib("vfs.ffs.adjndir", adjndir, &size) < 0 ||
157 		    sysctlnametomib("vfs.ffs.adjnbfree", adjnbfree, &size) < 0 ||
158 		    sysctlnametomib("vfs.ffs.adjnifree", adjnifree, &size) < 0 ||
159 		    sysctlnametomib("vfs.ffs.adjnffree", adjnffree, &size) < 0 ||
160 		    sysctlnametomib("vfs.ffs.adjnumclusters", adjnumclusters, &size) < 0) {
161 			bkgrdsumadj = 0;
162 			pwarn("kernel lacks runtime superblock summary adjustment support");
163 		}
164 		cmd.version = FFS_CMD_VERSION;
165 		cmd.handle = fsreadfd;
166 		fswritefd = -1;
167 	}
168 	if (preen == 0)
169 		printf("** %s", dev);
170 	if (bkgrdflag == 0 &&
171 	    (nflag || (fswritefd = open(dev, O_WRONLY)) < 0)) {
172 		fswritefd = -1;
173 		if (preen)
174 			pfatal("NO WRITE ACCESS");
175 		printf(" (NO WRITE)");
176 	}
177 	if (preen == 0)
178 		printf("\n");
179 	/*
180 	 * Read in the superblock, looking for alternates if necessary
181 	 */
182 	if (readsb(1) == 0) {
183 		skipclean = 0;
184 		if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
185 			return(0);
186 		if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
187 			return (0);
188 		for (cg = 0; cg < proto.fs_ncg; cg++) {
189 			bflag = fsbtodb(&proto, cgsblock(&proto, cg));
190 			if (readsb(0) != 0)
191 				break;
192 		}
193 		if (cg >= proto.fs_ncg) {
194 			printf("%s %s\n%s %s\n%s %s\n",
195 				"SEARCH FOR ALTERNATE SUPER-BLOCK",
196 				"FAILED. YOU MUST USE THE",
197 				"-b OPTION TO FSCK TO SPECIFY THE",
198 				"LOCATION OF AN ALTERNATE",
199 				"SUPER-BLOCK TO SUPPLY NEEDED",
200 				"INFORMATION; SEE fsck_ffs(8).");
201 			bflag = 0;
202 			return(0);
203 		}
204 		pwarn("USING ALTERNATE SUPERBLOCK AT %jd\n", bflag);
205 		bflag = 0;
206 	}
207 	if (skipclean && ckclean && sblock.fs_clean) {
208 		pwarn("FILE SYSTEM CLEAN; SKIPPING CHECKS\n");
209 		return (-1);
210 	}
211 	maxfsblock = sblock.fs_size;
212 	maxino = sblock.fs_ncg * sblock.fs_ipg;
213 	/*
214 	 * Check and potentially fix certain fields in the super block.
215 	 */
216 	if (sblock.fs_optim != FS_OPTTIME && sblock.fs_optim != FS_OPTSPACE) {
217 		pfatal("UNDEFINED OPTIMIZATION IN SUPERBLOCK");
218 		if (reply("SET TO DEFAULT") == 1) {
219 			sblock.fs_optim = FS_OPTTIME;
220 			sbdirty();
221 		}
222 	}
223 	if ((sblock.fs_minfree < 0 || sblock.fs_minfree > 99)) {
224 		pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
225 			sblock.fs_minfree);
226 		if (reply("SET TO DEFAULT") == 1) {
227 			sblock.fs_minfree = 10;
228 			sbdirty();
229 		}
230 	}
231 	if (sblock.fs_magic == FS_UFS1_MAGIC &&
232 	    sblock.fs_old_inodefmt < FS_44INODEFMT) {
233 		pwarn("Format of file system is too old.\n");
234 		pwarn("Must update to modern format using a version of fsck\n");
235 		pfatal("from before 2002 with the command ``fsck -c 2''\n");
236 		exit(EEXIT);
237 	}
238 	if (asblk.b_dirty && !bflag) {
239 		memmove(&altsblock, &sblock, (size_t)sblock.fs_sbsize);
240 		flush(fswritefd, &asblk);
241 	}
242 	if (preen == 0 && yflag == 0 && sblock.fs_magic == FS_UFS2_MAGIC &&
243 	    fswritefd != -1 && chkrecovery(fsreadfd) == 0 &&
244 	    reply("SAVE DATA TO FIND ALTERNATE SUPERBLOCKS") != 0)
245 		saverecovery(fsreadfd, fswritefd);
246 	/*
247 	 * read in the summary info.
248 	 */
249 	asked = 0;
250 	sblock.fs_csp = Calloc(1, sblock.fs_cssize);
251 	if (sblock.fs_csp == NULL) {
252 		printf("cannot alloc %u bytes for cg summary info\n",
253 		    (unsigned)sblock.fs_cssize);
254 		goto badsb;
255 	}
256 	for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) {
257 		size = MIN(sblock.fs_cssize - i, sblock.fs_bsize);
258 		readcnt[sblk.b_type]++;
259 		if (blread(fsreadfd, (char *)sblock.fs_csp + i,
260 		    fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag),
261 		    size) != 0 && !asked) {
262 			pfatal("BAD SUMMARY INFORMATION");
263 			if (reply("CONTINUE") == 0) {
264 				ckfini(0);
265 				exit(EEXIT);
266 			}
267 			asked++;
268 		}
269 	}
270 	/*
271 	 * allocate and initialize the necessary maps
272 	 */
273 	bmapsize = roundup(howmany(maxfsblock, CHAR_BIT), sizeof(short));
274 	blockmap = Calloc((unsigned)bmapsize, sizeof (char));
275 	if (blockmap == NULL) {
276 		printf("cannot alloc %u bytes for blockmap\n",
277 		    (unsigned)bmapsize);
278 		goto badsb;
279 	}
280 	inostathead = Calloc(sblock.fs_ncg, sizeof(struct inostatlist));
281 	if (inostathead == NULL) {
282 		printf("cannot alloc %u bytes for inostathead\n",
283 		    (unsigned)(sizeof(struct inostatlist) * (sblock.fs_ncg)));
284 		goto badsb;
285 	}
286 	numdirs = MAX(sblock.fs_cstotal.cs_ndir, 128);
287 	dirhash = numdirs;
288 	inplast = 0;
289 	listmax = numdirs + 10;
290 	inpsort = (struct inoinfo **)Calloc(listmax, sizeof(struct inoinfo *));
291 	inphead = (struct inoinfo **)Calloc(numdirs, sizeof(struct inoinfo *));
292 	if (inpsort == NULL || inphead == NULL) {
293 		printf("cannot alloc %ju bytes for inphead\n",
294 		    (uintmax_t)numdirs * sizeof(struct inoinfo *));
295 		goto badsb;
296 	}
297 	bufinit();
298 	if (sblock.fs_flags & FS_DOSOFTDEP)
299 		usedsoftdep = 1;
300 	else
301 		usedsoftdep = 0;
302 	return (1);
303 
304 badsb:
305 	ckfini(0);
306 	return (0);
307 }
308 
309 /*
310  * Possible superblock locations ordered from most to least likely.
311  */
312 static int sblock_try[] = SBLOCKSEARCH;
313 
314 #define BAD_MAGIC_MSG \
315 "The previous newfs operation on this volume did not complete.\n" \
316 "You must complete newfs before mounting this volume.\n"
317 
318 /*
319  * Read in the super block and its summary info.
320  */
321 int
322 readsb(int listerr)
323 {
324 	ufs2_daddr_t super;
325 	int i, bad;
326 
327 	if (bflag) {
328 		super = bflag;
329 		readcnt[sblk.b_type]++;
330 		if ((blread(fsreadfd, (char *)&sblock, super, (long)SBLOCKSIZE)))
331 			return (0);
332 		if (sblock.fs_magic == FS_BAD_MAGIC) {
333 			fprintf(stderr, BAD_MAGIC_MSG);
334 			exit(11);
335 		}
336 		if (sblock.fs_magic != FS_UFS1_MAGIC &&
337 		    sblock.fs_magic != FS_UFS2_MAGIC) {
338 			fprintf(stderr, "%jd is not a file system superblock\n",
339 			    bflag);
340 			return (0);
341 		}
342 	} else {
343 		for (i = 0; sblock_try[i] != -1; i++) {
344 			super = sblock_try[i] / dev_bsize;
345 			readcnt[sblk.b_type]++;
346 			if ((blread(fsreadfd, (char *)&sblock, super,
347 			    (long)SBLOCKSIZE)))
348 				return (0);
349 			if (sblock.fs_magic == FS_BAD_MAGIC) {
350 				fprintf(stderr, BAD_MAGIC_MSG);
351 				exit(11);
352 			}
353 			if ((sblock.fs_magic == FS_UFS1_MAGIC ||
354 			     (sblock.fs_magic == FS_UFS2_MAGIC &&
355 			      sblock.fs_sblockloc == sblock_try[i])) &&
356 			    sblock.fs_ncg >= 1 &&
357 			    sblock.fs_bsize >= MINBSIZE &&
358 			    sblock.fs_sbsize >= roundup(sizeof(struct fs), dev_bsize))
359 				break;
360 		}
361 		if (sblock_try[i] == -1) {
362 			fprintf(stderr, "Cannot find file system superblock\n");
363 			return (0);
364 		}
365 	}
366 	/*
367 	 * Compute block size that the file system is based on,
368 	 * according to fsbtodb, and adjust superblock block number
369 	 * so we can tell if this is an alternate later.
370 	 */
371 	super *= dev_bsize;
372 	dev_bsize = sblock.fs_fsize / fsbtodb(&sblock, 1);
373 	sblk.b_bno = super / dev_bsize;
374 	sblk.b_size = SBLOCKSIZE;
375 	/*
376 	 * Compare all fields that should not differ in alternate super block.
377 	 * When an alternate super-block is specified this check is skipped.
378 	 */
379 	if (bflag)
380 		goto out;
381 	getblk(&asblk, cgsblock(&sblock, sblock.fs_ncg - 1), sblock.fs_sbsize);
382 	if (asblk.b_errs)
383 		return (0);
384 	bad = 0;
385 #define CHK(x, y)				\
386 	if (altsblock.x != sblock.x) {		\
387 		bad++;				\
388 		if (listerr && debug)		\
389 			printf("SUPER BLOCK VS ALTERNATE MISMATCH %s: " y " vs " y "\n", \
390 			    #x, (intmax_t)sblock.x, (intmax_t)altsblock.x); \
391 	}
392 	CHK(fs_sblkno, "%jd");
393 	CHK(fs_cblkno, "%jd");
394 	CHK(fs_iblkno, "%jd");
395 	CHK(fs_dblkno, "%jd");
396 	CHK(fs_ncg, "%jd");
397 	CHK(fs_bsize, "%jd");
398 	CHK(fs_fsize, "%jd");
399 	CHK(fs_frag, "%jd");
400 	CHK(fs_bmask, "%#jx");
401 	CHK(fs_fmask, "%#jx");
402 	CHK(fs_bshift, "%jd");
403 	CHK(fs_fshift, "%jd");
404 	CHK(fs_fragshift, "%jd");
405 	CHK(fs_fsbtodb, "%jd");
406 	CHK(fs_sbsize, "%jd");
407 	CHK(fs_nindir, "%jd");
408 	CHK(fs_inopb, "%jd");
409 	CHK(fs_cssize, "%jd");
410 	CHK(fs_ipg, "%jd");
411 	CHK(fs_fpg, "%jd");
412 	CHK(fs_magic, "%#jx");
413 #undef CHK
414 	if (bad) {
415 		if (listerr == 0)
416 			return (0);
417 		if (preen)
418 			printf("%s: ", cdevname);
419 		printf(
420 		    "VALUES IN SUPER BLOCK LSB=%jd DISAGREE WITH THOSE IN\n"
421 		    "LAST ALTERNATE LSB=%jd\n",
422 		    sblk.b_bno, asblk.b_bno);
423 		if (reply("IGNORE ALTERNATE SUPER BLOCK") == 0)
424 			return (0);
425 	}
426 out:
427 	/*
428 	 * If not yet done, update UFS1 superblock with new wider fields.
429 	 */
430 	if (sblock.fs_magic == FS_UFS1_MAGIC &&
431 	    sblock.fs_maxbsize != sblock.fs_bsize) {
432 		sblock.fs_maxbsize = sblock.fs_bsize;
433 		sblock.fs_time = sblock.fs_old_time;
434 		sblock.fs_size = sblock.fs_old_size;
435 		sblock.fs_dsize = sblock.fs_old_dsize;
436 		sblock.fs_csaddr = sblock.fs_old_csaddr;
437 		sblock.fs_cstotal.cs_ndir = sblock.fs_old_cstotal.cs_ndir;
438 		sblock.fs_cstotal.cs_nbfree = sblock.fs_old_cstotal.cs_nbfree;
439 		sblock.fs_cstotal.cs_nifree = sblock.fs_old_cstotal.cs_nifree;
440 		sblock.fs_cstotal.cs_nffree = sblock.fs_old_cstotal.cs_nffree;
441 	}
442 	havesb = 1;
443 	return (1);
444 }
445 
446 void
447 sblock_init(void)
448 {
449 
450 	fswritefd = -1;
451 	fsmodified = 0;
452 	lfdir = 0;
453 	initbarea(&sblk, BT_SUPERBLK);
454 	initbarea(&asblk, BT_SUPERBLK);
455 	sblk.b_un.b_buf = Malloc(SBLOCKSIZE);
456 	asblk.b_un.b_buf = Malloc(SBLOCKSIZE);
457 	if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
458 		errx(EEXIT, "cannot allocate space for superblock");
459 	dev_bsize = secsize = DEV_BSIZE;
460 }
461 
462 /*
463  * Calculate a prototype superblock based on information in the boot area.
464  * When done the cgsblock macro can be calculated and the fs_ncg field
465  * can be used. Do NOT attempt to use other macros without verifying that
466  * their needed information is available!
467  */
468 static int
469 calcsb(char *dev, int devfd, struct fs *fs)
470 {
471 	struct fsrecovery *fsr;
472 	char *fsrbuf;
473 	u_int secsize;
474 
475 	/*
476 	 * We need fragments-per-group and the partition-size.
477 	 *
478 	 * Newfs stores these details at the end of the boot block area
479 	 * at the start of the filesystem partition. If they have been
480 	 * overwritten by a boot block, we fail. But usually they are
481 	 * there and we can use them.
482 	 */
483 	if (ioctl(devfd, DIOCGSECTORSIZE, &secsize) == -1)
484 		return (0);
485 	fsrbuf = Malloc(secsize);
486 	if (fsrbuf == NULL)
487 		errx(EEXIT, "calcsb: cannot allocate recovery buffer");
488 	if (blread(devfd, fsrbuf,
489 	    (SBLOCK_UFS2 - secsize) / dev_bsize, secsize) != 0)
490 		return (0);
491 	fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
492 	if (fsr->fsr_magic != FS_UFS2_MAGIC)
493 		return (0);
494 	memset(fs, 0, sizeof(struct fs));
495 	fs->fs_fpg = fsr->fsr_fpg;
496 	fs->fs_fsbtodb = fsr->fsr_fsbtodb;
497 	fs->fs_sblkno = fsr->fsr_sblkno;
498 	fs->fs_magic = fsr->fsr_magic;
499 	fs->fs_ncg = fsr->fsr_ncg;
500 	free(fsrbuf);
501 	return (1);
502 }
503 
504 /*
505  * Check to see if recovery information exists.
506  * Return 1 if it exists or cannot be created.
507  * Return 0 if it does not exist and can be created.
508  */
509 static int
510 chkrecovery(int devfd)
511 {
512 	struct fsrecovery *fsr;
513 	char *fsrbuf;
514 	u_int secsize;
515 
516 	/*
517 	 * Could not determine if backup material exists, so do not
518 	 * offer to create it.
519 	 */
520 	if (ioctl(devfd, DIOCGSECTORSIZE, &secsize) == -1 ||
521 	    (fsrbuf = Malloc(secsize)) == NULL ||
522 	    blread(devfd, fsrbuf, (SBLOCK_UFS2 - secsize) / dev_bsize,
523 	      secsize) != 0)
524 		return (1);
525 	/*
526 	 * Recovery material has already been created, so do not
527 	 * need to create it again.
528 	 */
529 	fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
530 	if (fsr->fsr_magic == FS_UFS2_MAGIC) {
531 		free(fsrbuf);
532 		return (1);
533 	}
534 	/*
535 	 * Recovery material has not been created and can be if desired.
536 	 */
537 	free(fsrbuf);
538 	return (0);
539 }
540 
541 /*
542  * Read the last sector of the boot block, replace the last
543  * 20 bytes with the recovery information, then write it back.
544  * The recovery information only works for UFS2 filesystems.
545  */
546 static void
547 saverecovery(int readfd, int writefd)
548 {
549 	struct fsrecovery *fsr;
550 	char *fsrbuf;
551 	u_int secsize;
552 
553 	if (sblock.fs_magic != FS_UFS2_MAGIC ||
554 	    ioctl(readfd, DIOCGSECTORSIZE, &secsize) == -1 ||
555 	    (fsrbuf = Malloc(secsize)) == NULL ||
556 	    blread(readfd, fsrbuf, (SBLOCK_UFS2 - secsize) / dev_bsize,
557 	      secsize) != 0) {
558 		printf("RECOVERY DATA COULD NOT BE CREATED\n");
559 		return;
560 	}
561 	fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
562 	fsr->fsr_magic = sblock.fs_magic;
563 	fsr->fsr_fpg = sblock.fs_fpg;
564 	fsr->fsr_fsbtodb = sblock.fs_fsbtodb;
565 	fsr->fsr_sblkno = sblock.fs_sblkno;
566 	fsr->fsr_ncg = sblock.fs_ncg;
567 	blwrite(writefd, fsrbuf, (SBLOCK_UFS2 - secsize) / secsize, secsize);
568 	free(fsrbuf);
569 }
570