xref: /freebsd/sbin/fsck_ffs/pass5.c (revision 8a4217aacf57330755501a349d0ea662d4880386)
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[] = "@(#)pass5.c	8.9 (Berkeley) 4/28/95";
35 #endif /* not lint */
36 #endif
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #define	IN_RTLD			/* So we pickup the P_OSREL defines */
41 #include <sys/param.h>
42 #include <sys/sysctl.h>
43 
44 #include <ufs/ufs/dinode.h>
45 #include <ufs/ffs/fs.h>
46 
47 #include <err.h>
48 #include <inttypes.h>
49 #include <limits.h>
50 #include <string.h>
51 #include <libufs.h>
52 
53 #include "fsck.h"
54 
55 static void check_maps(u_char *, u_char *, int, ufs2_daddr_t, const char *,
56 			int *, int, int, int);
57 static void clear_blocks(ufs2_daddr_t start, ufs2_daddr_t end);
58 
59 void
60 pass5(void)
61 {
62 	int c, i, j, blk, frags, basesize, mapsize;
63 	int inomapsize, blkmapsize;
64 	struct fs *fs = &sblock;
65 	ufs2_daddr_t d, dbase, dmax, start;
66 	int rewritecg = 0;
67 	struct csum *cs;
68 	struct csum_total cstotal;
69 	struct inodesc idesc[3];
70 	char buf[MAXBSIZE];
71 	struct cg *cg, *newcg = (struct cg *)buf;
72 	struct bufarea *cgbp;
73 
74 	inoinfo(UFS_WINO)->ino_state = USTATE;
75 	memset(newcg, 0, (size_t)fs->fs_cgsize);
76 	newcg->cg_niblk = fs->fs_ipg;
77 	if (preen == 0 && yflag == 0 && fs->fs_magic == FS_UFS2_MAGIC &&
78 	    fswritefd != -1 && (fs->fs_metackhash & CK_CYLGRP) == 0 &&
79 	    getosreldate() >= P_OSREL_CK_CYLGRP &&
80 	    reply("ADD CYLINDER GROUP CHECKSUM PROTECTION") != 0) {
81 		fs->fs_metackhash |= CK_CYLGRP;
82 		rewritecg = 1;
83 		sbdirty();
84 	}
85 	if (cvtlevel >= 3) {
86 		if (fs->fs_maxcontig < 2 && fs->fs_contigsumsize > 0) {
87 			if (preen)
88 				pwarn("DELETING CLUSTERING MAPS\n");
89 			if (preen || reply("DELETE CLUSTERING MAPS")) {
90 				fs->fs_contigsumsize = 0;
91 				rewritecg = 1;
92 				sbdirty();
93 			}
94 		}
95 		if (fs->fs_maxcontig > 1) {
96 			const char *doit = NULL;
97 
98 			if (fs->fs_contigsumsize < 1) {
99 				doit = "CREAT";
100 			} else if (fs->fs_contigsumsize < fs->fs_maxcontig &&
101 				   fs->fs_contigsumsize < FS_MAXCONTIG) {
102 				doit = "EXPAND";
103 			}
104 			if (doit) {
105 				i = fs->fs_contigsumsize;
106 				fs->fs_contigsumsize =
107 				    MIN(fs->fs_maxcontig, FS_MAXCONTIG);
108 				if (CGSIZE(fs) > (u_int)fs->fs_bsize) {
109 					pwarn("CANNOT %s CLUSTER MAPS\n", doit);
110 					fs->fs_contigsumsize = i;
111 				} else if (preen ||
112 				    reply("CREATE CLUSTER MAPS")) {
113 					if (preen)
114 						pwarn("%sING CLUSTER MAPS\n",
115 						    doit);
116 					fs->fs_cgsize =
117 					    fragroundup(fs, CGSIZE(fs));
118 					rewritecg = 1;
119 					sbdirty();
120 				}
121 			}
122 		}
123 	}
124 	basesize = &newcg->cg_space[0] - (u_char *)(&newcg->cg_firstfield);
125 	if (sblock.fs_magic == FS_UFS2_MAGIC) {
126 		newcg->cg_iusedoff = basesize;
127 	} else {
128 		/*
129 		 * We reserve the space for the old rotation summary
130 		 * tables for the benefit of old kernels, but do not
131 		 * maintain them in modern kernels. In time, they can
132 		 * go away.
133 		 */
134 		newcg->cg_old_btotoff = basesize;
135 		newcg->cg_old_boff = newcg->cg_old_btotoff +
136 		    fs->fs_old_cpg * sizeof(int32_t);
137 		newcg->cg_iusedoff = newcg->cg_old_boff +
138 		    fs->fs_old_cpg * fs->fs_old_nrpos * sizeof(u_int16_t);
139 		memset(&newcg->cg_space[0], 0, newcg->cg_iusedoff - basesize);
140 	}
141 	inomapsize = howmany(fs->fs_ipg, CHAR_BIT);
142 	newcg->cg_freeoff = newcg->cg_iusedoff + inomapsize;
143 	blkmapsize = howmany(fs->fs_fpg, CHAR_BIT);
144 	newcg->cg_nextfreeoff = newcg->cg_freeoff + blkmapsize;
145 	if (fs->fs_contigsumsize > 0) {
146 		newcg->cg_clustersumoff = newcg->cg_nextfreeoff -
147 		    sizeof(u_int32_t);
148 		newcg->cg_clustersumoff =
149 		    roundup(newcg->cg_clustersumoff, sizeof(u_int32_t));
150 		newcg->cg_clusteroff = newcg->cg_clustersumoff +
151 		    (fs->fs_contigsumsize + 1) * sizeof(u_int32_t);
152 		newcg->cg_nextfreeoff = newcg->cg_clusteroff +
153 		    howmany(fragstoblks(fs, fs->fs_fpg), CHAR_BIT);
154 	}
155 	newcg->cg_magic = CG_MAGIC;
156 	mapsize = newcg->cg_nextfreeoff - newcg->cg_iusedoff;
157 	memset(&idesc[0], 0, sizeof idesc);
158 	for (i = 0; i < 3; i++)
159 		idesc[i].id_type = ADDR;
160 	memset(&cstotal, 0, sizeof(struct csum_total));
161 	dmax = blknum(fs, fs->fs_size + fs->fs_frag - 1);
162 	for (d = fs->fs_size; d < dmax; d++)
163 		setbmap(d);
164 	for (c = 0; c < fs->fs_ncg; c++) {
165 		if (got_siginfo) {
166 			printf("%s: phase 5: cyl group %d of %d (%d%%)\n",
167 			    cdevname, c, sblock.fs_ncg,
168 			    c * 100 / sblock.fs_ncg);
169 			got_siginfo = 0;
170 		}
171 		if (got_sigalarm) {
172 			setproctitle("%s p5 %d%%", cdevname,
173 			    c * 100 / sblock.fs_ncg);
174 			got_sigalarm = 0;
175 		}
176 		cgbp = cgget(c);
177 		cg = cgbp->b_un.b_cg;
178 		if (!cg_chkmagic(cg))
179 			pfatal("CG %d: BAD MAGIC NUMBER\n", c);
180 		newcg->cg_time = cg->cg_time;
181 		newcg->cg_old_time = cg->cg_old_time;
182 		newcg->cg_unrefs = cg->cg_unrefs;
183 		newcg->cg_cgx = c;
184 		dbase = cgbase(fs, c);
185 		dmax = dbase + fs->fs_fpg;
186 		if (dmax > fs->fs_size)
187 			dmax = fs->fs_size;
188 		newcg->cg_ndblk = dmax - dbase;
189 		if (fs->fs_magic == FS_UFS1_MAGIC) {
190 			if (c == fs->fs_ncg - 1)
191 				newcg->cg_old_ncyl = howmany(newcg->cg_ndblk,
192 				    fs->fs_fpg / fs->fs_old_cpg);
193 			else
194 				newcg->cg_old_ncyl = fs->fs_old_cpg;
195 			newcg->cg_old_niblk = fs->fs_ipg;
196 			newcg->cg_niblk = 0;
197 		}
198 		if (fs->fs_contigsumsize > 0)
199 			newcg->cg_nclusterblks = newcg->cg_ndblk / fs->fs_frag;
200 		newcg->cg_cs.cs_ndir = 0;
201 		newcg->cg_cs.cs_nffree = 0;
202 		newcg->cg_cs.cs_nbfree = 0;
203 		newcg->cg_cs.cs_nifree = fs->fs_ipg;
204 		if (cg->cg_rotor >= 0 && cg->cg_rotor < newcg->cg_ndblk)
205 			newcg->cg_rotor = cg->cg_rotor;
206 		else
207 			newcg->cg_rotor = 0;
208 		if (cg->cg_frotor >= 0 && cg->cg_frotor < newcg->cg_ndblk)
209 			newcg->cg_frotor = cg->cg_frotor;
210 		else
211 			newcg->cg_frotor = 0;
212 		if (cg->cg_irotor >= 0 && cg->cg_irotor < fs->fs_ipg)
213 			newcg->cg_irotor = cg->cg_irotor;
214 		else
215 			newcg->cg_irotor = 0;
216 		if (fs->fs_magic == FS_UFS1_MAGIC) {
217 			newcg->cg_initediblk = 0;
218 		} else {
219 			if ((unsigned)cg->cg_initediblk > fs->fs_ipg)
220 				newcg->cg_initediblk = fs->fs_ipg;
221 			else
222 				newcg->cg_initediblk = cg->cg_initediblk;
223 		}
224 		memset(&newcg->cg_frsum[0], 0, sizeof newcg->cg_frsum);
225 		memset(cg_inosused(newcg), 0, (size_t)(mapsize));
226 		j = fs->fs_ipg * c;
227 		for (i = 0; i < inostathead[c].il_numalloced; j++, i++) {
228 			switch (inoinfo(j)->ino_state) {
229 
230 			case USTATE:
231 				break;
232 
233 			case DSTATE:
234 			case DCLEAR:
235 			case DFOUND:
236 			case DZLINK:
237 				newcg->cg_cs.cs_ndir++;
238 				/* FALLTHROUGH */
239 
240 			case FSTATE:
241 			case FCLEAR:
242 			case FZLINK:
243 				newcg->cg_cs.cs_nifree--;
244 				setbit(cg_inosused(newcg), i);
245 				break;
246 
247 			default:
248 				if (j < (int)UFS_ROOTINO)
249 					break;
250 				errx(EEXIT, "BAD STATE %d FOR INODE I=%d",
251 				    inoinfo(j)->ino_state, j);
252 			}
253 		}
254 		if (c == 0)
255 			for (i = 0; i < (int)UFS_ROOTINO; i++) {
256 				setbit(cg_inosused(newcg), i);
257 				newcg->cg_cs.cs_nifree--;
258 			}
259 		start = -1;
260 		for (i = 0, d = dbase;
261 		     d < dmax;
262 		     d += fs->fs_frag, i += fs->fs_frag) {
263 			frags = 0;
264 			for (j = 0; j < fs->fs_frag; j++) {
265 				if (testbmap(d + j)) {
266 					if ((Eflag || Zflag) && start != -1) {
267 						clear_blocks(start, d + j - 1);
268 						start = -1;
269 					}
270 					continue;
271 				}
272 				if (start == -1)
273 					start = d + j;
274 				setbit(cg_blksfree(newcg), i + j);
275 				frags++;
276 			}
277 			if (frags == fs->fs_frag) {
278 				newcg->cg_cs.cs_nbfree++;
279 				if (fs->fs_contigsumsize > 0)
280 					setbit(cg_clustersfree(newcg),
281 					    i / fs->fs_frag);
282 			} else if (frags > 0) {
283 				newcg->cg_cs.cs_nffree += frags;
284 				blk = blkmap(fs, cg_blksfree(newcg), i);
285 				ffs_fragacct(fs, blk, newcg->cg_frsum, 1);
286 			}
287 		}
288 		if ((Eflag || Zflag) && start != -1)
289 			clear_blocks(start, d - 1);
290 		if (fs->fs_contigsumsize > 0) {
291 			int32_t *sump = cg_clustersum(newcg);
292 			u_char *mapp = cg_clustersfree(newcg);
293 			int map = *mapp++;
294 			int bit = 1;
295 			int run = 0;
296 
297 			for (i = 0; i < newcg->cg_nclusterblks; i++) {
298 				if ((map & bit) != 0) {
299 					run++;
300 				} else if (run != 0) {
301 					if (run > fs->fs_contigsumsize)
302 						run = fs->fs_contigsumsize;
303 					sump[run]++;
304 					run = 0;
305 				}
306 				if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
307 					bit <<= 1;
308 				} else {
309 					map = *mapp++;
310 					bit = 1;
311 				}
312 			}
313 			if (run != 0) {
314 				if (run > fs->fs_contigsumsize)
315 					run = fs->fs_contigsumsize;
316 				sump[run]++;
317 			}
318 		}
319 		if ((fs->fs_metackhash & CK_CYLGRP) != 0) {
320 			newcg->cg_ckhash = 0;
321 			newcg->cg_ckhash =
322 			    calculate_crc32c(~0L, (void *)newcg, fs->fs_cgsize);
323 		}
324 
325 		if (bkgrdflag != 0) {
326 			cstotal.cs_nffree += cg->cg_cs.cs_nffree;
327 			cstotal.cs_nbfree += cg->cg_cs.cs_nbfree;
328 			cstotal.cs_nifree += cg->cg_cs.cs_nifree;
329 			cstotal.cs_ndir += cg->cg_cs.cs_ndir;
330 		} else {
331 			cstotal.cs_nffree += newcg->cg_cs.cs_nffree;
332 			cstotal.cs_nbfree += newcg->cg_cs.cs_nbfree;
333 			cstotal.cs_nifree += newcg->cg_cs.cs_nifree;
334 			cstotal.cs_ndir += newcg->cg_cs.cs_ndir;
335 		}
336 		cs = &fs->fs_cs(fs, c);
337 		if (cursnapshot == 0 &&
338 		    memcmp(&newcg->cg_cs, cs, sizeof *cs) != 0 &&
339 		    dofix(&idesc[0], "FREE BLK COUNT(S) WRONG IN SUPERBLK")) {
340 			memmove(cs, &newcg->cg_cs, sizeof *cs);
341 			sbdirty();
342 		}
343 		if (rewritecg) {
344 			memmove(cg, newcg, (size_t)fs->fs_cgsize);
345 			dirty(cgbp);
346 			continue;
347 		}
348 		if (cursnapshot == 0 &&
349 		    memcmp(newcg, cg, basesize) != 0 &&
350 		    dofix(&idesc[2], "SUMMARY INFORMATION BAD")) {
351 			memmove(cg, newcg, (size_t)basesize);
352 			dirty(cgbp);
353 		}
354 		if (bkgrdflag != 0 || usedsoftdep || debug)
355 			update_maps(cg, newcg, bkgrdflag);
356 		if (cursnapshot == 0 &&
357 		    memcmp(cg_inosused(newcg), cg_inosused(cg), mapsize) != 0 &&
358 		    dofix(&idesc[1], "BLK(S) MISSING IN BIT MAPS")) {
359 			memmove(cg_inosused(cg), cg_inosused(newcg),
360 			      (size_t)mapsize);
361 			dirty(cgbp);
362 		}
363 	}
364 	if (cursnapshot == 0 &&
365 	    memcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal) != 0
366 	    && dofix(&idesc[0], "SUMMARY BLK COUNT(S) WRONG IN SUPERBLK")) {
367 		memmove(&fs->fs_cstotal, &cstotal, sizeof cstotal);
368 		fs->fs_ronly = 0;
369 		fs->fs_fmod = 0;
370 		sbdirty();
371 	}
372 
373 	/*
374 	 * When doing background fsck on a snapshot, figure out whether
375 	 * the superblock summary is inaccurate and correct it when
376 	 * necessary.
377 	 */
378 	if (cursnapshot != 0) {
379 		cmd.size = 1;
380 
381 		cmd.value = cstotal.cs_ndir - fs->fs_cstotal.cs_ndir;
382 		if (cmd.value != 0) {
383 			if (debug)
384 				printf("adjndir by %+" PRIi64 "\n", cmd.value);
385 			if (bkgrdsumadj == 0 || sysctl(adjndir, MIBSIZE, 0, 0,
386 			    &cmd, sizeof cmd) == -1)
387 				rwerror("ADJUST NUMBER OF DIRECTORIES", cmd.value);
388 		}
389 
390 		cmd.value = cstotal.cs_nbfree - fs->fs_cstotal.cs_nbfree;
391 		if (cmd.value != 0) {
392 			if (debug)
393 				printf("adjnbfree by %+" PRIi64 "\n", cmd.value);
394 			if (bkgrdsumadj == 0 || sysctl(adjnbfree, MIBSIZE, 0, 0,
395 			    &cmd, sizeof cmd) == -1)
396 				rwerror("ADJUST NUMBER OF FREE BLOCKS", cmd.value);
397 		}
398 
399 		cmd.value = cstotal.cs_nifree - fs->fs_cstotal.cs_nifree;
400 		if (cmd.value != 0) {
401 			if (debug)
402 				printf("adjnifree by %+" PRIi64 "\n", cmd.value);
403 			if (bkgrdsumadj == 0 || sysctl(adjnifree, MIBSIZE, 0, 0,
404 			    &cmd, sizeof cmd) == -1)
405 				rwerror("ADJUST NUMBER OF FREE INODES", cmd.value);
406 		}
407 
408 		cmd.value = cstotal.cs_nffree - fs->fs_cstotal.cs_nffree;
409 		if (cmd.value != 0) {
410 			if (debug)
411 				printf("adjnffree by %+" PRIi64 "\n", cmd.value);
412 			if (bkgrdsumadj == 0 || sysctl(adjnffree, MIBSIZE, 0, 0,
413 			    &cmd, sizeof cmd) == -1)
414 				rwerror("ADJUST NUMBER OF FREE FRAGS", cmd.value);
415 		}
416 
417 		cmd.value = cstotal.cs_numclusters - fs->fs_cstotal.cs_numclusters;
418 		if (cmd.value != 0) {
419 			if (debug)
420 				printf("adjnumclusters by %+" PRIi64 "\n", cmd.value);
421 			if (bkgrdsumadj == 0 || sysctl(adjnumclusters, MIBSIZE, 0, 0,
422 			    &cmd, sizeof cmd) == -1)
423 				rwerror("ADJUST NUMBER OF FREE CLUSTERS", cmd.value);
424 		}
425 	}
426 }
427 
428 /*
429  * Compare the original cylinder group inode and block bitmaps with the
430  * updated cylinder group inode and block bitmaps. Free inodes and blocks
431  * that have been added. Complain if any previously freed inodes blocks
432  * are now allocated.
433  */
434 void
435 update_maps(
436 	struct cg *oldcg,	/* cylinder group of claimed allocations */
437 	struct cg *newcg,	/* cylinder group of determined allocations */
438 	int usesysctl)		/* 1 => use sysctl interface to update maps */
439 {
440 	int inomapsize, excessdirs;
441 	struct fs *fs = &sblock;
442 
443 	inomapsize = howmany(fs->fs_ipg, CHAR_BIT);
444 	excessdirs = oldcg->cg_cs.cs_ndir - newcg->cg_cs.cs_ndir;
445 	if (excessdirs < 0) {
446 		pfatal("LOST %d DIRECTORIES\n", -excessdirs);
447 		excessdirs = 0;
448 	}
449 	if (excessdirs > 0)
450 		check_maps(cg_inosused(newcg), cg_inosused(oldcg), inomapsize,
451 		    oldcg->cg_cgx * (ufs2_daddr_t)fs->fs_ipg, "DIR", freedirs,
452 		    0, excessdirs, usesysctl);
453 	check_maps(cg_inosused(newcg), cg_inosused(oldcg), inomapsize,
454 	    oldcg->cg_cgx * (ufs2_daddr_t)fs->fs_ipg, "FILE", freefiles,
455 	    excessdirs, fs->fs_ipg, usesysctl);
456 	check_maps(cg_blksfree(oldcg), cg_blksfree(newcg),
457 	    howmany(fs->fs_fpg, CHAR_BIT),
458 	    oldcg->cg_cgx * (ufs2_daddr_t)fs->fs_fpg, "FRAG",
459 	    freeblks, 0, fs->fs_fpg, usesysctl);
460 }
461 
462 static void
463 check_maps(
464 	u_char *map1,	/* map of claimed allocations */
465 	u_char *map2,	/* map of determined allocations */
466 	int mapsize,	/* size of above two maps */
467 	ufs2_daddr_t startvalue, /* resource value for first element in map */
468 	const char *name,	/* name of resource found in maps */
469 	int *opcode,	/* sysctl opcode to free resource */
470 	int skip,	/* number of entries to skip before starting to free */
471 	int limit,	/* limit on number of entries to free */
472 	int usesysctl)	/* 1 => use sysctl interface to update maps */
473 {
474 #	define BUFSIZE 16
475 	char buf[BUFSIZE];
476 	long i, j, k, l, m, size;
477 	ufs2_daddr_t n, astart, aend, ustart, uend;
478 	void (*msg)(const char *fmt, ...);
479 
480 	if (usesysctl)
481 		msg = pfatal;
482 	else
483 		msg = pwarn;
484 	astart = ustart = aend = uend = -1;
485 	for (i = 0; i < mapsize; i++) {
486 		j = *map1++;
487 		k = *map2++;
488 		if (j == k)
489 			continue;
490 		for (m = 0, l = 1; m < CHAR_BIT; m++, l <<= 1) {
491 			if ((j & l) == (k & l))
492 				continue;
493 			n = startvalue + i * CHAR_BIT + m;
494 			if ((j & l) != 0) {
495 				if (astart == -1) {
496 					astart = aend = n;
497 					continue;
498 				}
499 				if (aend + 1 == n) {
500 					aend = n;
501 					continue;
502 				}
503 				if (astart == aend)
504 					(*msg)("ALLOCATED %s %" PRId64
505 					    " MARKED FREE\n",
506 					    name, astart);
507 				else
508 					(*msg)("%s %sS %" PRId64 "-%" PRId64
509 					    " MARKED FREE\n",
510 					    "ALLOCATED", name, astart, aend);
511 				astart = aend = n;
512 			} else {
513 				if (ustart == -1) {
514 					ustart = uend = n;
515 					continue;
516 				}
517 				if (uend + 1 == n) {
518 					uend = n;
519 					continue;
520 				}
521 				size = uend - ustart + 1;
522 				if (size <= skip) {
523 					skip -= size;
524 					ustart = uend = n;
525 					continue;
526 				}
527 				if (skip > 0) {
528 					ustart += skip;
529 					size -= skip;
530 					skip = 0;
531 				}
532 				if (size > limit)
533 					size = limit;
534 				if (debug && size == 1)
535 					pwarn("%s %s %" PRId64
536 					    " MARKED USED\n",
537 					    "UNALLOCATED", name, ustart);
538 				else if (debug)
539 					pwarn("%s %sS %" PRId64 "-%" PRId64
540 					    " MARKED USED\n",
541 					    "UNALLOCATED", name, ustart,
542 					    ustart + size - 1);
543 				if (usesysctl != 0) {
544 					cmd.value = ustart;
545 					cmd.size = size;
546 					if (sysctl(opcode, MIBSIZE, 0, 0,
547 					    &cmd, sizeof cmd) == -1) {
548 						snprintf(buf, BUFSIZE,
549 						    "FREE %s", name);
550 						rwerror(buf, cmd.value);
551 					}
552 				}
553 				limit -= size;
554 				if (limit <= 0)
555 					return;
556 				ustart = uend = n;
557 			}
558 		}
559 	}
560 	if (astart != -1) {
561 		if (astart == aend)
562 			(*msg)("ALLOCATED %s %" PRId64
563 			    " MARKED FREE\n", name, astart);
564 		else
565 			(*msg)("ALLOCATED %sS %" PRId64 "-%" PRId64
566 			    " MARKED FREE\n",
567 			    name, astart, aend);
568 	}
569 	if (ustart != -1) {
570 		size = uend - ustart + 1;
571 		if (size <= skip)
572 			return;
573 		if (skip > 0) {
574 			ustart += skip;
575 			size -= skip;
576 		}
577 		if (size > limit)
578 			size = limit;
579 		if (debug) {
580 			if (size == 1)
581 				pwarn("UNALLOCATED %s %" PRId64
582 				    " MARKED USED\n",
583 				    name, ustart);
584 			else
585 				pwarn("UNALLOCATED %sS %" PRId64 "-%" PRId64
586 				    " MARKED USED\n",
587 				    name, ustart, ustart + size - 1);
588 		}
589 		if (usesysctl != 0) {
590 			cmd.value = ustart;
591 			cmd.size = size;
592 			if (sysctl(opcode, MIBSIZE, 0, 0, &cmd,
593 			    sizeof cmd) == -1) {
594 				snprintf(buf, BUFSIZE, "FREE %s", name);
595 				rwerror(buf, cmd.value);
596 			}
597 		}
598 	}
599 }
600 
601 static void
602 clear_blocks(ufs2_daddr_t start, ufs2_daddr_t end)
603 {
604 
605 	if (debug)
606 		printf("Zero frags %jd to %jd\n", start, end);
607 	if (Zflag)
608 		blzero(fswritefd, fsbtodb(&sblock, start),
609 		    lfragtosize(&sblock, end - start + 1));
610 	if (Eflag)
611 		blerase(fswritefd, fsbtodb(&sblock, start),
612 		    lfragtosize(&sblock, end - start + 1));
613 }
614