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: stable/12/sys/ufs/ffs/ffs_subr.c 371940 2022-04-10 05:02:22Z git2svn $");
36 
37 #include <sys/param.h>
38 
39 #ifndef _KERNEL
40 #include <stdio.h>
41 #include <string.h>
42 #include <stdlib.h>
43 #include <time.h>
44 #include <sys/errno.h>
45 #include <ufs/ufs/dinode.h>
46 #include <ufs/ffs/fs.h>
47 
48 struct malloc_type;
49 #define UFS_MALLOC(size, type, flags) malloc(size)
50 #define UFS_FREE(ptr, type) free(ptr)
51 #define UFS_TIME time(NULL)
52 
53 #else /* _KERNEL */
54 #include <sys/systm.h>
55 #include <sys/gsb_crc32.h>
56 #include <sys/lock.h>
57 #include <sys/malloc.h>
58 #include <sys/mount.h>
59 #include <sys/vnode.h>
60 #include <sys/bio.h>
61 #include <sys/buf.h>
62 #include <sys/ucred.h>
63 
64 #include <ufs/ufs/quota.h>
65 #include <ufs/ufs/inode.h>
66 #include <ufs/ufs/extattr.h>
67 #include <ufs/ufs/ufsmount.h>
68 #include <ufs/ufs/ufs_extern.h>
69 #include <ufs/ffs/ffs_extern.h>
70 #include <ufs/ffs/fs.h>
71 
72 #define UFS_MALLOC(size, type, flags) malloc(size, type, flags)
73 #define UFS_FREE(ptr, type) free(ptr, type)
74 #define UFS_TIME time_second
75 
76 /*
77  * Return buffer with the contents of block "offset" from the beginning of
78  * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
79  * remaining space in the directory.
80  */
81 int
ffs_blkatoff(struct vnode * vp,off_t offset,char ** res,struct buf ** bpp)82 ffs_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
83 {
84 	struct inode *ip;
85 	struct fs *fs;
86 	struct buf *bp;
87 	ufs_lbn_t lbn;
88 	int bsize, error;
89 
90 	ip = VTOI(vp);
91 	fs = ITOFS(ip);
92 	lbn = lblkno(fs, offset);
93 	bsize = blksize(fs, ip, lbn);
94 
95 	*bpp = NULL;
96 	error = bread(vp, lbn, bsize, NOCRED, &bp);
97 	if (error) {
98 		brelse(bp);
99 		return (error);
100 	}
101 	if (res)
102 		*res = (char *)bp->b_data + blkoff(fs, offset);
103 	*bpp = bp;
104 	return (0);
105 }
106 
107 /*
108  * Load up the contents of an inode and copy the appropriate pieces
109  * to the incore copy.
110  */
111 void
ffs_load_inode(struct buf * bp,struct inode * ip,struct fs * fs,ino_t ino)112 ffs_load_inode(struct buf *bp, struct inode *ip, struct fs *fs, ino_t ino)
113 {
114 
115 	if (I_IS_UFS1(ip)) {
116 		*ip->i_din1 =
117 		    *((struct ufs1_dinode *)bp->b_data + ino_to_fsbo(fs, ino));
118 		ip->i_mode = ip->i_din1->di_mode;
119 		ip->i_nlink = ip->i_din1->di_nlink;
120 		ip->i_size = ip->i_din1->di_size;
121 		ip->i_flags = ip->i_din1->di_flags;
122 		ip->i_gen = ip->i_din1->di_gen;
123 		ip->i_uid = ip->i_din1->di_uid;
124 		ip->i_gid = ip->i_din1->di_gid;
125 	} else {
126 		*ip->i_din2 =
127 		    *((struct ufs2_dinode *)bp->b_data + ino_to_fsbo(fs, ino));
128 		ip->i_mode = ip->i_din2->di_mode;
129 		ip->i_nlink = ip->i_din2->di_nlink;
130 		ip->i_size = ip->i_din2->di_size;
131 		ip->i_flags = ip->i_din2->di_flags;
132 		ip->i_gen = ip->i_din2->di_gen;
133 		ip->i_uid = ip->i_din2->di_uid;
134 		ip->i_gid = ip->i_din2->di_gid;
135 	}
136 }
137 
138 /*
139  * Verify that a filesystem block number is a valid data block.
140  * This routine is only called on untrusted filesystems.
141  */
142 int
ffs_check_blkno(struct mount * mp,ino_t inum,ufs2_daddr_t daddr,int blksize)143 ffs_check_blkno(struct mount *mp, ino_t inum, ufs2_daddr_t daddr, int blksize)
144 {
145 	struct fs *fs;
146 	struct ufsmount *ump;
147 	ufs2_daddr_t end_daddr;
148 	int cg, havemtx;
149 
150 	KASSERT((mp->mnt_flag & MNT_UNTRUSTED) != 0,
151 	    ("ffs_check_blkno called on a trusted file system"));
152 	ump = VFSTOUFS(mp);
153 	fs = ump->um_fs;
154 	cg = dtog(fs, daddr);
155 	end_daddr = daddr + numfrags(fs, blksize);
156 	/*
157 	 * Verify that the block number is a valid data block. Also check
158 	 * that it does not point to an inode block or a superblock. Accept
159 	 * blocks that are unalloacted (0) or part of snapshot metadata
160 	 * (BLK_NOCOPY or BLK_SNAP).
161 	 *
162 	 * Thus, the block must be in a valid range for the filesystem and
163 	 * either in the space before a backup superblock (except the first
164 	 * cylinder group where that space is used by the bootstrap code) or
165 	 * after the inode blocks and before the end of the cylinder group.
166 	 */
167 	if ((uint64_t)daddr <= BLK_SNAP ||
168 	    ((uint64_t)end_daddr <= fs->fs_size &&
169 	    ((cg > 0 && end_daddr <= cgsblock(fs, cg)) ||
170 	    (daddr >= cgdmin(fs, cg) &&
171 	    end_daddr <= cgbase(fs, cg) + fs->fs_fpg))))
172 		return (0);
173 	if ((havemtx = mtx_owned(UFS_MTX(ump))) == 0)
174 		UFS_LOCK(ump);
175 	if (ppsratecheck(&ump->um_last_integritymsg,
176 	    &ump->um_secs_integritymsg, 1)) {
177 		UFS_UNLOCK(ump);
178 		uprintf("\n%s: inode %jd, out-of-range indirect block "
179 		    "number %jd\n", mp->mnt_stat.f_mntonname, inum, daddr);
180 		if (havemtx)
181 			UFS_LOCK(ump);
182 	} else if (!havemtx)
183 		UFS_UNLOCK(ump);
184 	return (EIO);
185 }
186 #endif /* _KERNEL */
187 
188 /*
189  * These are the low-level functions that actually read and write
190  * the superblock and its associated data.
191  */
192 static off_t sblock_try[] = SBLOCKSEARCH;
193 static int readsuper(void *, struct fs **, off_t, int,
194 	int (*)(void *, off_t, void **, int));
195 
196 /*
197  * Read a superblock from the devfd device.
198  *
199  * If an alternate superblock is specified, it is read. Otherwise the
200  * set of locations given in the SBLOCKSEARCH list is searched for a
201  * superblock. Memory is allocated for the superblock by the readfunc and
202  * is returned. If filltype is non-NULL, additional memory is allocated
203  * of type filltype and filled in with the superblock summary information.
204  * All memory is freed when any error is returned.
205  *
206  * If a superblock is found, zero is returned. Otherwise one of the
207  * following error values is returned:
208  *     EIO: non-existent or truncated superblock.
209  *     EIO: error reading summary information.
210  *     ENOENT: no usable known superblock found.
211  *     ENOSPC: failed to allocate space for the superblock.
212  *     EINVAL: The previous newfs operation on this volume did not complete.
213  *         The administrator must complete newfs before using this volume.
214  */
215 int
ffs_sbget(void * devfd,struct fs ** fsp,off_t altsblock,struct malloc_type * filltype,int (* readfunc)(void * devfd,off_t loc,void ** bufp,int size))216 ffs_sbget(void *devfd, struct fs **fsp, off_t altsblock,
217     struct malloc_type *filltype,
218     int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
219 {
220 	struct fs *fs;
221 	int i, error, size, blks;
222 	uint8_t *space;
223 	int32_t *lp;
224 	char *buf;
225 
226 	fs = NULL;
227 	*fsp = NULL;
228 	if (altsblock != -1) {
229 		if ((error = readsuper(devfd, &fs, altsblock, 1,
230 		     readfunc)) != 0) {
231 			if (fs != NULL)
232 				UFS_FREE(fs, filltype);
233 			return (error);
234 		}
235 	} else {
236 		for (i = 0; sblock_try[i] != -1; i++) {
237 			if ((error = readsuper(devfd, &fs, sblock_try[i], 0,
238 			     readfunc)) == 0)
239 				break;
240 			if (fs != NULL) {
241 				UFS_FREE(fs, filltype);
242 				fs = NULL;
243 			}
244 			if (error == ENOENT)
245 				continue;
246 			return (error);
247 		}
248 		if (sblock_try[i] == -1)
249 			return (ENOENT);
250 	}
251 	/*
252 	 * Read in the superblock summary information.
253 	 */
254 	size = fs->fs_cssize;
255 	blks = howmany(size, fs->fs_fsize);
256 	if (fs->fs_contigsumsize > 0)
257 		size += fs->fs_ncg * sizeof(int32_t);
258 	size += fs->fs_ncg * sizeof(u_int8_t);
259 	/* When running in libufs or libsa, UFS_MALLOC may fail */
260 	if ((space = UFS_MALLOC(size, filltype, M_WAITOK)) == NULL) {
261 		UFS_FREE(fs, filltype);
262 		return (ENOSPC);
263 	}
264 	fs->fs_csp = (struct csum *)space;
265 	for (i = 0; i < blks; i += fs->fs_frag) {
266 		size = fs->fs_bsize;
267 		if (i + fs->fs_frag > blks)
268 			size = (blks - i) * fs->fs_fsize;
269 		buf = NULL;
270 		error = (*readfunc)(devfd,
271 		    dbtob(fsbtodb(fs, fs->fs_csaddr + i)), (void **)&buf, size);
272 		if (error) {
273 			if (buf != NULL)
274 				UFS_FREE(buf, filltype);
275 			UFS_FREE(fs->fs_csp, filltype);
276 			UFS_FREE(fs, filltype);
277 			return (error);
278 		}
279 		memcpy(space, buf, size);
280 		UFS_FREE(buf, filltype);
281 		space += size;
282 	}
283 	if (fs->fs_contigsumsize > 0) {
284 		fs->fs_maxcluster = lp = (int32_t *)space;
285 		for (i = 0; i < fs->fs_ncg; i++)
286 			*lp++ = fs->fs_contigsumsize;
287 		space = (uint8_t *)lp;
288 	}
289 	size = fs->fs_ncg * sizeof(u_int8_t);
290 	fs->fs_contigdirs = (u_int8_t *)space;
291 	bzero(fs->fs_contigdirs, size);
292 	*fsp = fs;
293 	return (0);
294 }
295 
296 /*
297  * Try to read a superblock from the location specified by sblockloc.
298  * Return zero on success or an errno on failure.
299  */
300 static int
readsuper(void * devfd,struct fs ** fsp,off_t sblockloc,int isaltsblk,int (* readfunc)(void * devfd,off_t loc,void ** bufp,int size))301 readsuper(void *devfd, struct fs **fsp, off_t sblockloc, int isaltsblk,
302     int (*readfunc)(void *devfd, off_t loc, void **bufp, int size))
303 {
304 	struct fs *fs;
305 	int error;
306 
307 	error = (*readfunc)(devfd, sblockloc, (void **)fsp, SBLOCKSIZE);
308 	if (error != 0)
309 		return (error);
310 	fs = *fsp;
311 	if (fs->fs_magic == FS_BAD_MAGIC)
312 		return (EINVAL);
313 	if (((fs->fs_magic == FS_UFS1_MAGIC && (isaltsblk ||
314 	      sblockloc <= SBLOCK_UFS1)) ||
315 	     (fs->fs_magic == FS_UFS2_MAGIC && (isaltsblk ||
316 	      sblockloc == fs->fs_sblockloc))) &&
317 	    fs->fs_ncg >= 1 &&
318 	    fs->fs_bsize >= MINBSIZE &&
319 	    fs->fs_bsize <= MAXBSIZE &&
320 	    fs->fs_bsize >= roundup(sizeof(struct fs), DEV_BSIZE) &&
321 	    fs->fs_sbsize <= SBLOCKSIZE) {
322 		/*
323 		 * If the filesystem has been run on a kernel without
324 		 * metadata check hashes, disable them.
325 		 */
326 		if ((fs->fs_flags & FS_METACKHASH) == 0)
327 			fs->fs_metackhash = 0;
328 		/*
329 		 * Clear any check-hashes that are not maintained
330 		 * by this kernel. Also clear any unsupported flags.
331 		 */
332 		fs->fs_metackhash &= CK_SUPPORTED;
333 		fs->fs_flags &= FS_SUPPORTED;
334 		/* Have to set for old filesystems that predate this field */
335 		fs->fs_sblockactualloc = sblockloc;
336 		/* Not yet any summary information */
337 		fs->fs_csp = NULL;
338 		return (0);
339 	}
340 	return (ENOENT);
341 }
342 
343 /*
344  * Write a superblock to the devfd device from the memory pointed to by fs.
345  * Write out the superblock summary information if it is present.
346  *
347  * If the write is successful, zero is returned. Otherwise one of the
348  * following error values is returned:
349  *     EIO: failed to write superblock.
350  *     EIO: failed to write superblock summary information.
351  */
352 int
ffs_sbput(void * devfd,struct fs * fs,off_t loc,int (* writefunc)(void * devfd,off_t loc,void * buf,int size))353 ffs_sbput(void *devfd, struct fs *fs, off_t loc,
354     int (*writefunc)(void *devfd, off_t loc, void *buf, int size))
355 {
356 	int i, error, blks, size;
357 	uint8_t *space;
358 
359 	/*
360 	 * If there is summary information, write it first, so if there
361 	 * is an error, the superblock will not be marked as clean.
362 	 */
363 	if (fs->fs_csp != NULL) {
364 		blks = howmany(fs->fs_cssize, fs->fs_fsize);
365 		space = (uint8_t *)fs->fs_csp;
366 		for (i = 0; i < blks; i += fs->fs_frag) {
367 			size = fs->fs_bsize;
368 			if (i + fs->fs_frag > blks)
369 				size = (blks - i) * fs->fs_fsize;
370 			if ((error = (*writefunc)(devfd,
371 			     dbtob(fsbtodb(fs, fs->fs_csaddr + i)),
372 			     space, size)) != 0)
373 				return (error);
374 			space += size;
375 		}
376 	}
377 	fs->fs_fmod = 0;
378 	fs->fs_time = UFS_TIME;
379 	if ((error = (*writefunc)(devfd, loc, fs, fs->fs_sbsize)) != 0)
380 		return (error);
381 	return (0);
382 }
383 
384 /*
385  * Update the frsum fields to reflect addition or deletion
386  * of some frags.
387  */
388 void
ffs_fragacct(struct fs * fs,int fragmap,int32_t fraglist[],int cnt)389 ffs_fragacct(struct fs *fs, int fragmap, int32_t fraglist[], int cnt)
390 {
391 	int inblk;
392 	int field, subfield;
393 	int siz, pos;
394 
395 	inblk = (int)(fragtbl[fs->fs_frag][fragmap]) << 1;
396 	fragmap <<= 1;
397 	for (siz = 1; siz < fs->fs_frag; siz++) {
398 		if ((inblk & (1 << (siz + (fs->fs_frag % NBBY)))) == 0)
399 			continue;
400 		field = around[siz];
401 		subfield = inside[siz];
402 		for (pos = siz; pos <= fs->fs_frag; pos++) {
403 			if ((fragmap & field) == subfield) {
404 				fraglist[siz] += cnt;
405 				pos += siz;
406 				field <<= siz;
407 				subfield <<= siz;
408 			}
409 			field <<= 1;
410 			subfield <<= 1;
411 		}
412 	}
413 }
414 
415 /*
416  * block operations
417  *
418  * check if a block is available
419  */
420 int
ffs_isblock(struct fs * fs,unsigned char * cp,ufs1_daddr_t h)421 ffs_isblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
422 {
423 	unsigned char mask;
424 
425 	switch ((int)fs->fs_frag) {
426 	case 8:
427 		return (cp[h] == 0xff);
428 	case 4:
429 		mask = 0x0f << ((h & 0x1) << 2);
430 		return ((cp[h >> 1] & mask) == mask);
431 	case 2:
432 		mask = 0x03 << ((h & 0x3) << 1);
433 		return ((cp[h >> 2] & mask) == mask);
434 	case 1:
435 		mask = 0x01 << (h & 0x7);
436 		return ((cp[h >> 3] & mask) == mask);
437 	default:
438 #ifdef _KERNEL
439 		panic("ffs_isblock");
440 #endif
441 		break;
442 	}
443 	return (0);
444 }
445 
446 /*
447  * check if a block is free
448  */
449 int
ffs_isfreeblock(struct fs * fs,u_char * cp,ufs1_daddr_t h)450 ffs_isfreeblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
451 {
452 
453 	switch ((int)fs->fs_frag) {
454 	case 8:
455 		return (cp[h] == 0);
456 	case 4:
457 		return ((cp[h >> 1] & (0x0f << ((h & 0x1) << 2))) == 0);
458 	case 2:
459 		return ((cp[h >> 2] & (0x03 << ((h & 0x3) << 1))) == 0);
460 	case 1:
461 		return ((cp[h >> 3] & (0x01 << (h & 0x7))) == 0);
462 	default:
463 #ifdef _KERNEL
464 		panic("ffs_isfreeblock");
465 #endif
466 		break;
467 	}
468 	return (0);
469 }
470 
471 /*
472  * take a block out of the map
473  */
474 void
ffs_clrblock(struct fs * fs,u_char * cp,ufs1_daddr_t h)475 ffs_clrblock(struct fs *fs, u_char *cp, ufs1_daddr_t h)
476 {
477 
478 	switch ((int)fs->fs_frag) {
479 	case 8:
480 		cp[h] = 0;
481 		return;
482 	case 4:
483 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
484 		return;
485 	case 2:
486 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
487 		return;
488 	case 1:
489 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
490 		return;
491 	default:
492 #ifdef _KERNEL
493 		panic("ffs_clrblock");
494 #endif
495 		break;
496 	}
497 }
498 
499 /*
500  * put a block into the map
501  */
502 void
ffs_setblock(struct fs * fs,unsigned char * cp,ufs1_daddr_t h)503 ffs_setblock(struct fs *fs, unsigned char *cp, ufs1_daddr_t h)
504 {
505 
506 	switch ((int)fs->fs_frag) {
507 
508 	case 8:
509 		cp[h] = 0xff;
510 		return;
511 	case 4:
512 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
513 		return;
514 	case 2:
515 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
516 		return;
517 	case 1:
518 		cp[h >> 3] |= (0x01 << (h & 0x7));
519 		return;
520 	default:
521 #ifdef _KERNEL
522 		panic("ffs_setblock");
523 #endif
524 		break;
525 	}
526 }
527 
528 /*
529  * Update the cluster map because of an allocation or free.
530  *
531  * Cnt == 1 means free; cnt == -1 means allocating.
532  */
533 void
ffs_clusteracct(struct fs * fs,struct cg * cgp,ufs1_daddr_t blkno,int cnt)534 ffs_clusteracct(struct fs *fs, struct cg *cgp, ufs1_daddr_t blkno, int cnt)
535 {
536 	int32_t *sump;
537 	int32_t *lp;
538 	u_char *freemapp, *mapp;
539 	int i, start, end, forw, back, map;
540 	u_int bit;
541 
542 	if (fs->fs_contigsumsize <= 0)
543 		return;
544 	freemapp = cg_clustersfree(cgp);
545 	sump = cg_clustersum(cgp);
546 	/*
547 	 * Allocate or clear the actual block.
548 	 */
549 	if (cnt > 0)
550 		setbit(freemapp, blkno);
551 	else
552 		clrbit(freemapp, blkno);
553 	/*
554 	 * Find the size of the cluster going forward.
555 	 */
556 	start = blkno + 1;
557 	end = start + fs->fs_contigsumsize;
558 	if (end >= cgp->cg_nclusterblks)
559 		end = cgp->cg_nclusterblks;
560 	mapp = &freemapp[start / NBBY];
561 	map = *mapp++;
562 	bit = 1U << (start % NBBY);
563 	for (i = start; i < end; i++) {
564 		if ((map & bit) == 0)
565 			break;
566 		if ((i & (NBBY - 1)) != (NBBY - 1)) {
567 			bit <<= 1;
568 		} else {
569 			map = *mapp++;
570 			bit = 1;
571 		}
572 	}
573 	forw = i - start;
574 	/*
575 	 * Find the size of the cluster going backward.
576 	 */
577 	start = blkno - 1;
578 	end = start - fs->fs_contigsumsize;
579 	if (end < 0)
580 		end = -1;
581 	mapp = &freemapp[start / NBBY];
582 	map = *mapp--;
583 	bit = 1U << (start % NBBY);
584 	for (i = start; i > end; i--) {
585 		if ((map & bit) == 0)
586 			break;
587 		if ((i & (NBBY - 1)) != 0) {
588 			bit >>= 1;
589 		} else {
590 			map = *mapp--;
591 			bit = 1U << (NBBY - 1);
592 		}
593 	}
594 	back = start - i;
595 	/*
596 	 * Account for old cluster and the possibly new forward and
597 	 * back clusters.
598 	 */
599 	i = back + forw + 1;
600 	if (i > fs->fs_contigsumsize)
601 		i = fs->fs_contigsumsize;
602 	sump[i] += cnt;
603 	if (back > 0)
604 		sump[back] -= cnt;
605 	if (forw > 0)
606 		sump[forw] -= cnt;
607 	/*
608 	 * Update cluster summary information.
609 	 */
610 	lp = &sump[fs->fs_contigsumsize];
611 	for (i = fs->fs_contigsumsize; i > 0; i--)
612 		if (*lp-- > 0)
613 			break;
614 	fs->fs_maxcluster[cgp->cg_cgx] = i;
615 }
616