xref: /openbsd-src/sbin/dump/traverse.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1 /*	$OpenBSD: traverse.c,v 1.14 2003/07/28 06:13:26 tedu Exp $	*/
2 /*	$NetBSD: traverse.c,v 1.17 1997/06/05 11:13:27 lukem Exp $	*/
3 
4 /*-
5  * Copyright (c) 1980, 1988, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)traverse.c	8.2 (Berkeley) 9/23/93";
36 #else
37 static const char rcsid[] = "$OpenBSD: traverse.c,v 1.14 2003/07/28 06:13:26 tedu Exp $";
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/param.h>
42 #include <sys/time.h>
43 #include <sys/stat.h>
44 #ifdef sunos
45 #include <sys/vnode.h>
46 
47 #include <ufs/fs.h>
48 #include <ufs/fsdir.h>
49 #include <ufs/inode.h>
50 #else
51 #include <ufs/ffs/fs.h>
52 #include <ufs/ufs/dir.h>
53 #include <ufs/ufs/dinode.h>
54 #endif
55 
56 #include <protocols/dumprestore.h>
57 
58 #include <ctype.h>
59 #include <errno.h>
60 #include <fts.h>
61 #include <stdio.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #include "dump.h"
66 
67 #define	HASDUMPEDFILE	0x1
68 #define	HASSUBDIRS	0x2
69 
70 static	int dirindir(ino_t ino, daddr_t blkno, int level, off_t *size);
71 static	void dmpindir(ino_t ino, daddr_t blk, int level, off_t *size);
72 static	int searchdir(ino_t ino, daddr_t blkno, long size, off_t filesize);
73 
74 /*
75  * This is an estimation of the number of TP_BSIZE blocks in the file.
76  * It estimates the number of blocks in files with holes by assuming
77  * that all of the blocks accounted for by di_blocks are data blocks
78  * (when some of the blocks are usually used for indirect pointers);
79  * hence the estimate may be high.
80  */
81 off_t
82 blockest(struct dinode *dp)
83 {
84 	off_t blkest, sizeest;
85 
86 	/*
87 	 * dp->di_size is the size of the file in bytes.
88 	 * dp->di_blocks stores the number of sectors actually in the file.
89 	 * If there are more sectors than the size would indicate, this just
90 	 *	means that there are indirect blocks in the file or unused
91 	 *	sectors in the last file block; we can safely ignore these
92 	 *	(blkest = sizeest below).
93 	 * If the file is bigger than the number of sectors would indicate,
94 	 *	then the file has holes in it.	In this case we must use the
95 	 *	block count to estimate the number of data blocks used, but
96 	 *	we use the actual size for estimating the number of indirect
97 	 *	dump blocks (sizeest vs. blkest in the indirect block
98 	 *	calculation).
99 	 */
100 	blkest = howmany(dbtob((off_t)dp->di_blocks), TP_BSIZE);
101 	sizeest = howmany(dp->di_size, TP_BSIZE);
102 	if (blkest > sizeest)
103 		blkest = sizeest;
104 	if (dp->di_size > sblock->fs_bsize * NDADDR) {
105 		/* calculate the number of indirect blocks on the dump tape */
106 		blkest +=
107 			howmany(sizeest - NDADDR * sblock->fs_bsize / TP_BSIZE,
108 			TP_NINDIR);
109 	}
110 	return (blkest + 1);
111 }
112 
113 /* Auxiliary macro to pick up files changed since previous dump. */
114 #define	CHANGEDSINCE(dp, t) \
115 	((dp)->di_mtime >= (t) || (dp)->di_ctime >= (t))
116 
117 /* The WANTTODUMP macro decides whether a file should be dumped. */
118 #ifdef UF_NODUMP
119 #define	WANTTODUMP(dp) \
120 	(CHANGEDSINCE(dp, spcl.c_ddate) && \
121 	 (nonodump || ((dp)->di_flags & UF_NODUMP) != UF_NODUMP))
122 #else
123 #define	WANTTODUMP(dp) CHANGEDSINCE(dp, spcl.c_ddate)
124 #endif
125 
126 /*
127  * Determine if given inode should be dumped
128  */
129 void
130 mapfileino(ino_t ino, off_t *tapesize, int *dirskipped)
131 {
132 	int mode;
133 	struct dinode *dp;
134 
135 	dp = getino(ino);
136 	if ((mode = (dp->di_mode & IFMT)) == 0)
137 		return;
138 	SETINO(ino, usedinomap);
139 	if (mode == IFDIR)
140 		SETINO(ino, dumpdirmap);
141 	if (WANTTODUMP(dp)) {
142 		SETINO(ino, dumpinomap);
143 		if (mode != IFREG && mode != IFDIR && mode != IFLNK)
144 			*tapesize += 1;
145 		else
146 			*tapesize += blockest(dp);
147 		return;
148 	}
149 	if (mode == IFDIR)
150 		*dirskipped = 1;
151 }
152 
153 /*
154  * Dump pass 1.
155  *
156  * Walk the inode list for a filesystem to find all allocated inodes
157  * that have been modified since the previous dump time. Also, find all
158  * the directories in the filesystem.
159  */
160 int
161 mapfiles(ino_t maxino, off_t *tapesize, char *disk, char * const *dirv)
162 {
163 	int anydirskipped = 0;
164 
165 	if (dirv != NULL) {
166 		char	 curdir[MAXPATHLEN];
167 		FTS	*dirh;
168 		FTSENT	*entry;
169 		int	 d;
170 
171 		if (getcwd(curdir, sizeof(curdir)) == NULL) {
172 			msg("Can't determine cwd: %s\n", strerror(errno));
173 			dumpabort(0);
174 		}
175 		if ((dirh = fts_open(dirv, FTS_PHYSICAL|FTS_SEEDOT|FTS_XDEV,
176 		    NULL)) == NULL) {
177 			msg("fts_open failed: %s\n", strerror(errno));
178 			dumpabort(0);
179 		}
180 		while ((entry = fts_read(dirh)) != NULL) {
181 			switch (entry->fts_info) {
182 			case FTS_DNR:		/* an error */
183 			case FTS_ERR:
184 			case FTS_NS:
185 				msg("Can't fts_read %s: %s\n", entry->fts_path,
186 				    strerror(errno));
187 			case FTS_DP:		/* already seen dir */
188 				continue;
189 			}
190 			mapfileino(entry->fts_statp->st_ino, tapesize,
191 			    &anydirskipped);
192 		}
193 		(void)fts_close(dirh);
194 
195 		/*
196 		 * Add any parent directories
197 		 */
198 		for (d = 0 ; dirv[d] != NULL ; d++) {
199 			char path[MAXPATHLEN];
200 
201 			if (dirv[d][0] != '/')
202 				(void)snprintf(path, sizeof(path), "%s/%s",
203 				    curdir, dirv[d]);
204 			else
205 				(void)snprintf(path, sizeof(path), "%s",
206 				    dirv[d]);
207 			while (strcmp(path, disk) != 0) {
208 				char *p;
209 				struct stat sb;
210 
211 				if (*path == '\0')
212 					break;
213 				if ((p = strrchr(path, '/')) == NULL)
214 					break;
215 				if (p == path)
216 					break;
217 				*p = '\0';
218 				if (stat(path, &sb) == -1) {
219 					msg("Can't stat %s: %s\n", path,
220 					    strerror(errno));
221 					break;
222 				}
223 				mapfileino(sb.st_ino, tapesize, &anydirskipped);
224 			}
225 		}
226 
227 		/*
228 		 * Ensure that the root inode actually appears in the
229 		 * file list for a subdir
230 		 */
231 		mapfileino(ROOTINO, tapesize, &anydirskipped);
232 	} else {
233 		ino_t ino;
234 
235 		for (ino = ROOTINO; ino < maxino; ino++) {
236 			mapfileino(ino, tapesize, &anydirskipped);
237 		}
238 	}
239 	/*
240 	 * Restore gets very upset if the root is not dumped,
241 	 * so ensure that it always is dumped.
242 	 */
243 	SETINO(ROOTINO, dumpinomap);
244 	return (anydirskipped);
245 }
246 
247 /*
248  * Dump pass 2.
249  *
250  * Scan each directory on the filesystem to see if it has any modified
251  * files in it. If it does, and has not already been added to the dump
252  * list (because it was itself modified), then add it. If a directory
253  * has not been modified itself, contains no modified files and has no
254  * subdirectories, then it can be deleted from the dump list and from
255  * the list of directories. By deleting it from the list of directories,
256  * its parent may now qualify for the same treatment on this or a later
257  * pass using this algorithm.
258  */
259 int
260 mapdirs(ino_t maxino, off_t *tapesize)
261 {
262 	struct	dinode *dp;
263 	int i, isdir;
264 	char *map;
265 	ino_t ino;
266 	off_t filesize;
267 	int ret, change = 0;
268 
269 	isdir = 0;		/* XXX just to get gcc to shut up */
270 	for (map = dumpdirmap, ino = 1; ino < maxino; ino++) {
271 		if (((ino - 1) % NBBY) == 0)	/* map is offset by 1 */
272 			isdir = *map++;
273 		else
274 			isdir >>= 1;
275 		if ((isdir & 1) == 0 || TSTINO(ino, dumpinomap))
276 			continue;
277 		dp = getino(ino);
278 		filesize = dp->di_size;
279 		for (ret = 0, i = 0; filesize > 0 && i < NDADDR; i++) {
280 			if (dp->di_db[i] != 0)
281 				ret |= searchdir(ino, dp->di_db[i],
282 				    dblksize(sblock, dp, i), filesize);
283 			if (ret & HASDUMPEDFILE)
284 				filesize = 0;
285 			else
286 				filesize -= sblock->fs_bsize;
287 		}
288 		for (i = 0; filesize > 0 && i < NIADDR; i++) {
289 			if (dp->di_ib[i] == 0)
290 				continue;
291 			ret |= dirindir(ino, dp->di_ib[i], i, &filesize);
292 		}
293 		if (ret & HASDUMPEDFILE) {
294 			SETINO(ino, dumpinomap);
295 			*tapesize += blockest(dp);
296 			change = 1;
297 			continue;
298 		}
299 		if ((ret & HASSUBDIRS) == 0) {
300 			if (!TSTINO(ino, dumpinomap)) {
301 				CLRINO(ino, dumpdirmap);
302 				change = 1;
303 			}
304 		}
305 	}
306 	return (change);
307 }
308 
309 /*
310  * Read indirect blocks, and pass the data blocks to be searched
311  * as directories. Quit as soon as any entry is found that will
312  * require the directory to be dumped.
313  */
314 static int
315 dirindir(ino_t ino, daddr_t blkno, int ind_level, off_t *filesize)
316 {
317 	int ret = 0;
318 	int i;
319 	daddr_t	idblk[MAXNINDIR];
320 
321 	bread(fsbtodb(sblock, blkno), (char *)idblk, (int)sblock->fs_bsize);
322 	if (ind_level <= 0) {
323 		for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
324 			blkno = idblk[i];
325 			if (blkno != 0)
326 				ret |= searchdir(ino, blkno, sblock->fs_bsize,
327 					*filesize);
328 			if (ret & HASDUMPEDFILE)
329 				*filesize = 0;
330 			else
331 				*filesize -= sblock->fs_bsize;
332 		}
333 		return (ret);
334 	}
335 	ind_level--;
336 	for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
337 		blkno = idblk[i];
338 		if (blkno != 0)
339 			ret |= dirindir(ino, blkno, ind_level, filesize);
340 	}
341 	return (ret);
342 }
343 
344 /*
345  * Scan a disk block containing directory information looking to see if
346  * any of the entries are on the dump list and to see if the directory
347  * contains any subdirectories.
348  */
349 static int
350 searchdir(ino_t ino, daddr_t blkno, long size, off_t filesize)
351 {
352 	struct direct *dp;
353 	long loc;
354 	char dblk[MAXBSIZE];
355 	int ret = 0;
356 
357 	bread(fsbtodb(sblock, blkno), dblk, (int)size);
358 	if (filesize < size)
359 		size = filesize;
360 	for (loc = 0; loc < size; ) {
361 		dp = (struct direct *)(dblk + loc);
362 		if (dp->d_reclen == 0) {
363 			msg("corrupted directory, inumber %d\n", ino);
364 			break;
365 		}
366 		loc += dp->d_reclen;
367 		if (dp->d_ino == 0)
368 			continue;
369 		if (dp->d_name[0] == '.') {
370 			if (dp->d_name[1] == '\0')
371 				continue;
372 			if (dp->d_name[1] == '.' && dp->d_name[2] == '\0')
373 				continue;
374 		}
375 		if (TSTINO(dp->d_ino, dumpinomap)) {
376 			ret |= HASDUMPEDFILE;
377 			if (ret & HASSUBDIRS)
378 				break;
379 		}
380 		if (TSTINO(dp->d_ino, dumpdirmap)) {
381 			ret |= HASSUBDIRS;
382 			if (ret & HASDUMPEDFILE)
383 				break;
384 		}
385 	}
386 	return (ret);
387 }
388 
389 /*
390  * Dump passes 3 and 4.
391  *
392  * Dump the contents of an inode to tape.
393  */
394 void
395 dumpino(struct dinode *dp, ino_t ino)
396 {
397 	int ind_level, cnt;
398 	off_t size;
399 	char buf[TP_BSIZE];
400 
401 	if (newtape) {
402 		newtape = 0;
403 		dumpmap(dumpinomap, TS_BITS, ino);
404 	}
405 	CLRINO(ino, dumpinomap);
406 	spcl.c_dinode = *dp;
407 	spcl.c_type = TS_INODE;
408 	spcl.c_count = 0;
409 	switch (dp->di_mode & IFMT) {
410 
411 	case 0:
412 		/*
413 		 * Freed inode.
414 		 */
415 		return;
416 
417 	case IFLNK:
418 		/*
419 		 * Check for short symbolic link.
420 		 */
421 		if (dp->di_size > 0 &&
422 #ifdef FS_44INODEFMT
423 		    (dp->di_size < sblock->fs_maxsymlinklen ||
424 		     (sblock->fs_maxsymlinklen == 0 && dp->di_blocks == 0))) {
425 #else
426 		    dp->di_blocks == 0) {
427 #endif
428 			spcl.c_addr[0] = 1;
429 			spcl.c_count = 1;
430 			writeheader(ino);
431 			memcpy(buf, dp->di_shortlink, (u_long)dp->di_size);
432 			buf[dp->di_size] = '\0';
433 			writerec(buf, 0);
434 			return;
435 		}
436 		/* fall through */
437 
438 	case IFDIR:
439 	case IFREG:
440 		if (dp->di_size > 0)
441 			break;
442 		/* fall through */
443 
444 	case IFIFO:
445 	case IFSOCK:
446 	case IFCHR:
447 	case IFBLK:
448 		writeheader(ino);
449 		return;
450 
451 	default:
452 		msg("Warning: undefined file type 0%o\n", dp->di_mode & IFMT);
453 		return;
454 	}
455 	if (dp->di_size > NDADDR * sblock->fs_bsize)
456 		cnt = NDADDR * sblock->fs_frag;
457 	else
458 		cnt = howmany(dp->di_size, sblock->fs_fsize);
459 	blksout(&dp->di_db[0], cnt, ino);
460 	if ((size = dp->di_size - NDADDR * sblock->fs_bsize) <= 0)
461 		return;
462 	for (ind_level = 0; ind_level < NIADDR; ind_level++) {
463 		dmpindir(ino, dp->di_ib[ind_level], ind_level, &size);
464 		if (size <= 0)
465 			return;
466 	}
467 }
468 
469 /*
470  * Read indirect blocks, and pass the data blocks to be dumped.
471  */
472 static void
473 dmpindir(ino_t ino, daddr_t blk, int ind_level, off_t *size)
474 {
475 	int i, cnt;
476 	daddr_t idblk[MAXNINDIR];
477 
478 	if (blk != 0)
479 		bread(fsbtodb(sblock, blk), (char *)idblk, (int) sblock->fs_bsize);
480 	else
481 		memset(idblk, 0, (int)sblock->fs_bsize);
482 	if (ind_level <= 0) {
483 		if (*size < NINDIR(sblock) * sblock->fs_bsize)
484 			cnt = howmany(*size, sblock->fs_fsize);
485 		else
486 			cnt = NINDIR(sblock) * sblock->fs_frag;
487 		*size -= NINDIR(sblock) * sblock->fs_bsize;
488 		blksout(&idblk[0], cnt, ino);
489 		return;
490 	}
491 	ind_level--;
492 	for (i = 0; i < NINDIR(sblock); i++) {
493 		dmpindir(ino, idblk[i], ind_level, size);
494 		if (*size <= 0)
495 			return;
496 	}
497 }
498 
499 /*
500  * Collect up the data into tape record sized buffers and output them.
501  */
502 void
503 blksout(daddr_t *blkp, int frags, ino_t ino)
504 {
505 	daddr_t *bp;
506 	int i, j, count, blks, tbperdb;
507 
508 	blks = howmany(frags * sblock->fs_fsize, TP_BSIZE);
509 	tbperdb = sblock->fs_bsize >> tp_bshift;
510 	for (i = 0; i < blks; i += TP_NINDIR) {
511 		if (i + TP_NINDIR > blks)
512 			count = blks;
513 		else
514 			count = i + TP_NINDIR;
515 		for (j = i; j < count; j++)
516 			if (blkp[j / tbperdb] != 0)
517 				spcl.c_addr[j - i] = 1;
518 			else
519 				spcl.c_addr[j - i] = 0;
520 		spcl.c_count = count - i;
521 		writeheader(ino);
522 		bp = &blkp[i / tbperdb];
523 		for (j = i; j < count; j += tbperdb, bp++)
524 			if (*bp != 0) {
525 				if (j + tbperdb <= count)
526 					dumpblock(*bp, (int)sblock->fs_bsize);
527 				else
528 					dumpblock(*bp, (count - j) * TP_BSIZE);
529 			}
530 		spcl.c_type = TS_ADDR;
531 	}
532 }
533 
534 /*
535  * Dump a map to the tape.
536  */
537 void
538 dumpmap(map, type, ino)
539 	char *map;
540 	int type;
541 	ino_t ino;
542 {
543 	int i;
544 	char *cp;
545 
546 	spcl.c_type = type;
547 	spcl.c_count = howmany(mapsize * sizeof(char), TP_BSIZE);
548 	writeheader(ino);
549 	for (i = 0, cp = map; i < spcl.c_count; i++, cp += TP_BSIZE)
550 		writerec(cp, 0);
551 }
552 
553 /*
554  * Write a header record to the dump tape.
555  */
556 void
557 writeheader(ino)
558 	ino_t ino;
559 {
560 	int32_t sum, cnt, *lp;
561 
562 	spcl.c_inumber = ino;
563 	spcl.c_magic = NFS_MAGIC;
564 	spcl.c_checksum = 0;
565 	lp = (int32_t *)&spcl;
566 	sum = 0;
567 	cnt = sizeof(union u_spcl) / (4 * sizeof(int32_t));
568 	while (--cnt >= 0) {
569 		sum += *lp++;
570 		sum += *lp++;
571 		sum += *lp++;
572 		sum += *lp++;
573 	}
574 	spcl.c_checksum = CHECKSUM - sum;
575 	writerec((char *)&spcl, 1);
576 }
577 
578 struct dinode *
579 getino(ino_t inum)
580 {
581 	static daddr_t minino, maxino;
582 	static struct dinode inoblock[MAXINOPB];
583 
584 	curino = inum;
585 	if (inum >= minino && inum < maxino)
586 		return (&inoblock[inum - minino]);
587 	bread(fsbtodb(sblock, ino_to_fsba(sblock, inum)), (char *)inoblock,
588 	    (int)sblock->fs_bsize);
589 	minino = inum - (inum % INOPB(sblock));
590 	maxino = minino + INOPB(sblock);
591 	return (&inoblock[inum - minino]);
592 }
593 
594 /*
595  * Read a chunk of data from the disk.
596  * Try to recover from hard errors by reading in sector sized pieces.
597  * Error recovery is attempted at most BREADEMAX times before seeking
598  * consent from the operator to continue.
599  */
600 int	breaderrors = 0;
601 #define	BREADEMAX 32
602 
603 void
604 bread(daddr_t blkno, char *buf, int size)
605 {
606 	int cnt, i;
607 
608 loop:
609 	if (lseek(diskfd, ((off_t)blkno << dev_bshift), 0) < 0)
610 		msg("bread: lseek fails\n");
611 	if ((cnt = read(diskfd, buf, size)) == size)
612 		return;
613 	if (blkno + (size / dev_bsize) > fsbtodb(sblock, sblock->fs_size)) {
614 		/*
615 		 * Trying to read the final fragment.
616 		 *
617 		 * NB - dump only works in TP_BSIZE blocks, hence
618 		 * rounds `dev_bsize' fragments up to TP_BSIZE pieces.
619 		 * It should be smarter about not actually trying to
620 		 * read more than it can get, but for the time being
621 		 * we punt and scale back the read only when it gets
622 		 * us into trouble. (mkm 9/25/83)
623 		 */
624 		size -= dev_bsize;
625 		goto loop;
626 	}
627 	if (cnt == -1)
628 		msg("read error from %s: %s: [block %d]: count=%d\n",
629 			disk, strerror(errno), blkno, size);
630 	else
631 		msg("short read error from %s: [block %d]: count=%d, got=%d\n",
632 			disk, blkno, size, cnt);
633 	if (++breaderrors > BREADEMAX) {
634 		msg("More than %d block read errors from %s\n",
635 			BREADEMAX, disk);
636 		broadcast("DUMP IS AILING!\n");
637 		msg("This is an unrecoverable error.\n");
638 		if (!query("Do you want to attempt to continue?")){
639 			dumpabort(0);
640 			/*NOTREACHED*/
641 		} else
642 			breaderrors = 0;
643 	}
644 	/*
645 	 * Zero buffer, then try to read each sector of buffer separately.
646 	 */
647 	memset(buf, 0, size);
648 	for (i = 0; i < size; i += dev_bsize, buf += dev_bsize, blkno++) {
649 		if (lseek(diskfd, ((off_t)blkno << dev_bshift), 0) < 0)
650 			msg("bread: lseek2 fails!\n");
651 		if ((cnt = read(diskfd, buf, (int)dev_bsize)) == dev_bsize)
652 			continue;
653 		if (cnt == -1) {
654 			msg("read error from %s: %s: [sector %d]: count=%d\n",
655 				disk, strerror(errno), blkno, dev_bsize);
656 			continue;
657 		}
658 		msg("short read error from %s: [sector %d]: count=%d, got=%d\n",
659 			disk, blkno, dev_bsize, cnt);
660 	}
661 }
662