xref: /csrg-svn/sbin/dump/traverse.c (revision 55288)
1 /*-
2  * Copyright (c) 1980, 1988, 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)traverse.c	5.20 (Berkeley) 07/16/92";
10 #endif /* not lint */
11 
12 #ifdef sunos
13 #include <stdio.h>
14 #include <ctype.h>
15 #include <sys/param.h>
16 #include <ufs/fs.h>
17 #else
18 #include <sys/param.h>
19 #include <ufs/ffs/fs.h>
20 #endif
21 #include <sys/time.h>
22 #include <sys/stat.h>
23 #include <ufs/ufs/dir.h>
24 #include <ufs/ufs/dinode.h>
25 #include <protocols/dumprestore.h>
26 #ifdef __STDC__
27 #include <unistd.h>
28 #include <string.h>
29 #endif
30 #include "dump.h"
31 
32 void	dmpindir();
33 #define	HASDUMPEDFILE	0x1
34 #define	HASSUBDIRS	0x2
35 
36 /*
37  * This is an estimation of the number of TP_BSIZE blocks in the file.
38  * It estimates the number of blocks in files with holes by assuming
39  * that all of the blocks accounted for by di_blocks are data blocks
40  * (when some of the blocks are usually used for indirect pointers);
41  * hence the estimate may be high.
42  */
43 long
44 blockest(dp)
45 	register struct dinode *dp;
46 {
47 	long blkest, sizeest;
48 
49 	/*
50 	 * dp->di_size is the size of the file in bytes.
51 	 * dp->di_blocks stores the number of sectors actually in the file.
52 	 * If there are more sectors than the size would indicate, this just
53 	 *	means that there are indirect blocks in the file or unused
54 	 *	sectors in the last file block; we can safely ignore these
55 	 *	(blkest = sizeest below).
56 	 * If the file is bigger than the number of sectors would indicate,
57 	 *	then the file has holes in it.	In this case we must use the
58 	 *	block count to estimate the number of data blocks used, but
59 	 *	we use the actual size for estimating the number of indirect
60 	 *	dump blocks (sizeest vs. blkest in the indirect block
61 	 *	calculation).
62 	 */
63 	blkest = howmany(dbtob(dp->di_blocks), TP_BSIZE);
64 	sizeest = howmany(dp->di_size, TP_BSIZE);
65 	if (blkest > sizeest)
66 		blkest = sizeest;
67 	if (dp->di_size > sblock->fs_bsize * NDADDR) {
68 		/* calculate the number of indirect blocks on the dump tape */
69 		blkest +=
70 			howmany(sizeest - NDADDR * sblock->fs_bsize / TP_BSIZE,
71 			TP_NINDIR);
72 	}
73 	return (blkest + 1);
74 }
75 
76 /*
77  * Dump pass 1.
78  *
79  * Walk the inode list for a filesystem to find all allocated inodes
80  * that have been modified since the previous dump time. Also, find all
81  * the directories in the filesystem.
82  */
83 mapfiles(maxino, tapesize)
84 	ino_t maxino;
85 	long *tapesize;
86 {
87 	register int mode;
88 	register ino_t ino;
89 	register struct dinode *dp;
90 	int anydirskipped = 0;
91 
92 	for (ino = 0; ino < maxino; ino++) {
93 		dp = getino(ino);
94 		if ((mode = (dp->di_mode & IFMT)) == 0)
95 			continue;
96 		SETINO(ino, usedinomap);
97 		if (mode == IFDIR)
98 			SETINO(ino, dumpdirmap);
99 		if ((dp->di_mtime.ts_sec >= spcl.c_ddate ||
100 		    dp->di_ctime.ts_sec >= spcl.c_ddate)
101 #ifndef sunos
102 		    && (dp->di_flags & NODUMP) != NODUMP
103 #endif
104 		    ) {
105 			SETINO(ino, dumpinomap);
106 			if (mode != IFREG && mode != IFDIR && mode != IFLNK) {
107 				*tapesize += 1;
108 				continue;
109 			}
110 			*tapesize += blockest(dp);
111 			continue;
112 		}
113 		if (mode == IFDIR)
114 			anydirskipped = 1;
115 	}
116 	/*
117 	 * Restore gets very upset if the root is not dumped,
118 	 * so ensure that it always is dumped.
119 	 */
120 	SETINO(ROOTINO, dumpinomap);
121 	return (anydirskipped);
122 }
123 
124 /*
125  * Dump pass 2.
126  *
127  * Scan each directory on the filesystem to see if it has any modified
128  * files in it. If it does, and has not already been added to the dump
129  * list (because it was itself modified), then add it. If a directory
130  * has not been modified itself, contains no modified files and has no
131  * subdirectories, then it can be deleted from the dump list and from
132  * the list of directories. By deleting it from the list of directories,
133  * its parent may now qualify for the same treatment on this or a later
134  * pass using this algorithm.
135  */
136 mapdirs(maxino, tapesize)
137 	ino_t maxino;
138 	long *tapesize;
139 {
140 	register struct	dinode *dp;
141 	register int i, dirty;
142 	register char *map;
143 	register ino_t ino;
144 	long filesize;
145 	int ret, change = 0;
146 
147 	for (map = dumpdirmap, ino = 0; ino < maxino; ) {
148 		if ((ino % NBBY) == 0)
149 			dirty = *map++;
150 		else
151 			dirty >>= 1;
152 		ino++;
153 		if ((dirty & 1) == 0 || TSTINO(ino, dumpinomap))
154 			continue;
155 		dp = getino(ino);
156 		filesize = dp->di_size;
157 		for (ret = 0, i = 0; filesize > 0 && i < NDADDR; i++) {
158 			if (dp->di_db[i] != 0)
159 				ret |= searchdir(ino, dp->di_db[i],
160 					dblksize(sblock, dp, i), filesize);
161 			if (ret & HASDUMPEDFILE)
162 				filesize = 0;
163 			else
164 				filesize -= sblock->fs_bsize;
165 		}
166 		for (i = 0; filesize > 0 && i < NIADDR; i++) {
167 			if (dp->di_ib[i] == 0)
168 				continue;
169 			ret |= dirindir(ino, dp->di_ib[i], i, &filesize);
170 		}
171 		if (ret & HASDUMPEDFILE) {
172 			if (!TSTINO(ino, dumpinomap)) {
173 				SETINO(ino, dumpinomap);
174 				*tapesize += blockest(dp);
175 			}
176 			change = 1;
177 			continue;
178 		}
179 		if ((ret & HASSUBDIRS) == 0) {
180 			if (!TSTINO(ino, dumpinomap)) {
181 				CLRINO(ino, dumpdirmap);
182 				change = 1;
183 			}
184 		}
185 	}
186 	return (change);
187 }
188 
189 /*
190  * Read indirect blocks, and pass the data blocks to be searched
191  * as directories. Quit as soon as any entry is found that will
192  * require the directory to be dumped.
193  */
194 dirindir(ino, blkno, ind_level, filesize)
195 	ino_t ino;
196 	daddr_t blkno;
197 	int ind_level;
198 	long *filesize;
199 {
200 	int ret = 0;
201 	register int i;
202 	daddr_t	idblk[MAXNINDIR];
203 
204 	bread(fsbtodb(sblock, blkno), (char *)idblk, (int)sblock->fs_bsize);
205 	if (ind_level <= 0) {
206 		for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
207 			blkno = idblk[i];
208 			if (blkno != 0)
209 				ret |= searchdir(ino, blkno, sblock->fs_bsize,
210 					*filesize);
211 			if (ret & HASDUMPEDFILE)
212 				*filesize = 0;
213 			else
214 				*filesize -= sblock->fs_bsize;
215 		}
216 		return (ret);
217 	}
218 	ind_level--;
219 	for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
220 		blkno = idblk[i];
221 		if (blkno != 0)
222 			ret |= dirindir(ino, blkno, ind_level, filesize);
223 	}
224 	return (ret);
225 }
226 
227 /*
228  * Scan a disk block containing directory information looking to see if
229  * any of the entries are on the dump list and to see if the directory
230  * contains any subdirectories.
231  */
232 searchdir(ino, blkno, size, filesize)
233 	ino_t ino;
234 	daddr_t blkno;
235 	register long size;
236 	long filesize;
237 {
238 	register struct direct *dp;
239 	register long loc;
240 	char dblk[MAXBSIZE];
241 
242 	bread(fsbtodb(sblock, blkno), dblk, (int)size);
243 	if (filesize < size)
244 		size = filesize;
245 	for (loc = 0; loc < size; ) {
246 		dp = (struct direct *)(dblk + loc);
247 		if (dp->d_reclen == 0) {
248 			msg("corrupted directory, inumber %d\n", ino);
249 			break;
250 		}
251 		loc += dp->d_reclen;
252 		if (dp->d_ino == 0)
253 			continue;
254 		if (dp->d_name[0] == '.') {
255 			if (dp->d_name[1] == '\0')
256 				continue;
257 			if (dp->d_name[1] == '.' && dp->d_name[2] == '\0')
258 				continue;
259 		}
260 		if (TSTINO(dp->d_ino, dumpinomap))
261 			return (HASDUMPEDFILE);
262 		if (TSTINO(dp->d_ino, dumpdirmap))
263 			return (HASSUBDIRS);
264 	}
265 	return (0);
266 }
267 
268 /*
269  * Dump passes 3 and 4.
270  *
271  * Dump the contents of an inode to tape.
272  */
273 void
274 dumpino(dp, ino)
275 	register struct dinode *dp;
276 	ino_t ino;
277 {
278 	int ind_level, cnt;
279 	long size;
280 	char buf[TP_BSIZE];
281 
282 	if (newtape) {
283 		newtape = 0;
284 		dumpmap(dumpinomap, TS_BITS, ino);
285 	}
286 	CLRINO(ino, dumpinomap);
287 	spcl.c_dinode = *dp;
288 	spcl.c_type = TS_INODE;
289 	spcl.c_count = 0;
290 	switch (IFTODT(dp->di_mode)) {
291 
292 	case DT_UNKNOWN:
293 		/*
294 		 * Freed inode.
295 		 */
296 		return;
297 
298 	case DT_LNK:
299 		/*
300 		 * Check for short symbolic link.
301 		 */
302 		if (dp->di_size > 0 &&
303 		    dp->di_size < sblock->fs_maxsymlinklen) {
304 			spcl.c_addr[0] = 1;
305 			spcl.c_count = 1;
306 			writeheader(ino);
307 			bcopy((caddr_t)dp->di_shortlink, buf,
308 			    (u_long)dp->di_size);
309 			buf[dp->di_size] = '\0';
310 			writerec(buf, 0);
311 			return;
312 		}
313 		/* fall through */
314 
315 	case DT_DIR:
316 	case DT_REG:
317 		if (dp->di_size > 0)
318 			break;
319 		/* fall through */
320 
321 	case DT_FIFO:
322 	case DT_SOCK:
323 	case DT_CHR:
324 	case DT_BLK:
325 		writeheader(ino);
326 		return;
327 
328 	default:
329 		msg("Warning: undefined file type 0%o\n", dp->di_mode & IFMT);
330 		return;
331 	}
332 	if (dp->di_size > NDADDR * sblock->fs_bsize)
333 		cnt = NDADDR * sblock->fs_frag;
334 	else
335 		cnt = howmany(dp->di_size, sblock->fs_fsize);
336 	blksout(&dp->di_db[0], cnt, ino);
337 	if ((size = dp->di_size - NDADDR * sblock->fs_bsize) <= 0)
338 		return;
339 	for (ind_level = 0; ind_level < NIADDR; ind_level++) {
340 		dmpindir(ino, dp->di_ib[ind_level], ind_level, &size);
341 		if (size <= 0)
342 			return;
343 	}
344 }
345 
346 /*
347  * Read indirect blocks, and pass the data blocks to be dumped.
348  */
349 void
350 dmpindir(ino, blk, ind_level, size)
351 	ino_t ino;
352 	daddr_t blk;
353 	int ind_level;
354 	long *size;
355 {
356 	int i, cnt;
357 	daddr_t idblk[MAXNINDIR];
358 
359 	if (blk != 0)
360 		bread(fsbtodb(sblock, blk), (char *)idblk, (int) sblock->fs_bsize);
361 	else
362 		bzero((char *)idblk, (int)sblock->fs_bsize);
363 	if (ind_level <= 0) {
364 		if (*size < NINDIR(sblock) * sblock->fs_bsize)
365 			cnt = howmany(*size, sblock->fs_fsize);
366 		else
367 			cnt = NINDIR(sblock) * sblock->fs_frag;
368 		*size -= NINDIR(sblock) * sblock->fs_bsize;
369 		blksout(&idblk[0], cnt, ino);
370 		return;
371 	}
372 	ind_level--;
373 	for (i = 0; i < NINDIR(sblock); i++) {
374 		dmpindir(ino, idblk[i], ind_level, size);
375 		if (*size <= 0)
376 			return;
377 	}
378 }
379 
380 /*
381  * Collect up the data into tape record sized buffers and output them.
382  */
383 void
384 blksout(blkp, frags, ino)
385 	daddr_t *blkp;
386 	int frags;
387 	ino_t ino;
388 {
389 	register daddr_t *bp;
390 	int i, j, count, blks, tbperdb;
391 
392 	blks = howmany(frags * sblock->fs_fsize, TP_BSIZE);
393 	tbperdb = sblock->fs_bsize >> tp_bshift;
394 	for (i = 0; i < blks; i += TP_NINDIR) {
395 		if (i + TP_NINDIR > blks)
396 			count = blks;
397 		else
398 			count = i + TP_NINDIR;
399 		for (j = i; j < count; j++)
400 			if (blkp[j / tbperdb] != 0)
401 				spcl.c_addr[j - i] = 1;
402 			else
403 				spcl.c_addr[j - i] = 0;
404 		spcl.c_count = count - i;
405 		writeheader(ino);
406 		bp = &blkp[i / tbperdb];
407 		for (j = i; j < count; j += tbperdb, bp++)
408 			if (*bp != 0)
409 				if (j + tbperdb <= count)
410 					dumpblock(*bp, (int)sblock->fs_bsize);
411 				else
412 					dumpblock(*bp, (count - j) * TP_BSIZE);
413 		spcl.c_type = TS_ADDR;
414 	}
415 }
416 
417 /*
418  * Dump a map to the tape.
419  */
420 void
421 dumpmap(map, type, ino)
422 	char *map;
423 	int type;
424 	ino_t ino;
425 {
426 	register int i;
427 	char *cp;
428 
429 	spcl.c_type = type;
430 	spcl.c_count = howmany(mapsize * sizeof(char), TP_BSIZE);
431 	writeheader(ino);
432 	for (i = 0, cp = map; i < spcl.c_count; i++, cp += TP_BSIZE)
433 		writerec(cp, 0);
434 }
435 
436 /*
437  * Write a header record to the dump tape.
438  */
439 void
440 writeheader(ino)
441 	ino_t ino;
442 {
443 	register long sum, cnt, *lp;
444 
445 	spcl.c_inumber = ino;
446 	spcl.c_magic = NFS_MAGIC;
447 	spcl.c_checksum = 0;
448 	lp = (long *)&spcl;
449 	sum = 0;
450 	cnt = sizeof(union u_spcl) / (4 * sizeof(long));
451 	while (--cnt >= 0) {
452 		sum += *lp++;
453 		sum += *lp++;
454 		sum += *lp++;
455 		sum += *lp++;
456 	}
457 	spcl.c_checksum = CHECKSUM - sum;
458 	writerec((char *)&spcl, 1);
459 }
460 
461 struct dinode *
462 getino(inum)
463 	ino_t inum;
464 {
465 	static daddr_t minino, maxino;
466 	static struct dinode inoblock[MAXINOPB];
467 
468 	curino = inum;
469 	if (inum >= minino && inum < maxino)
470 		return (&inoblock[inum - minino]);
471 	bread(fsbtodb(sblock, itod(sblock, inum)), (char *)inoblock,
472 	    (int)sblock->fs_bsize);
473 	minino = inum - (inum % INOPB(sblock));
474 	maxino = minino + INOPB(sblock);
475 	return (&inoblock[inum - minino]);
476 }
477 
478 /*
479  * Read a chunk of data from the disk.
480  * Try to recover from hard errors by reading in sector sized pieces.
481  * Error recovery is attempted at most BREADEMAX times before seeking
482  * consent from the operator to continue.
483  */
484 int	breaderrors = 0;
485 #define	BREADEMAX 32
486 
487 void
488 bread(blkno, buf, size)
489 	daddr_t blkno;
490 	char *buf;
491 	int size;
492 {
493 	int cnt, i;
494 	extern int errno;
495 
496 loop:
497 	if ((int)lseek(diskfd, ((off_t)blkno << dev_bshift), 0) < 0)
498 		msg("bread: lseek fails\n");
499 	if ((cnt = read(diskfd, buf, size)) == size)
500 		return;
501 	if (blkno + (size / dev_bsize) > fsbtodb(sblock, sblock->fs_size)) {
502 		/*
503 		 * Trying to read the final fragment.
504 		 *
505 		 * NB - dump only works in TP_BSIZE blocks, hence
506 		 * rounds `dev_bsize' fragments up to TP_BSIZE pieces.
507 		 * It should be smarter about not actually trying to
508 		 * read more than it can get, but for the time being
509 		 * we punt and scale back the read only when it gets
510 		 * us into trouble. (mkm 9/25/83)
511 		 */
512 		size -= dev_bsize;
513 		goto loop;
514 	}
515 	if (cnt == -1)
516 		msg("read error from %s: %s: [block %d]: count=%d\n",
517 			disk, strerror(errno), blkno, size);
518 	else
519 		msg("short read error from %s: [block %d]: count=%d, got=%d\n",
520 			disk, blkno, size, cnt);
521 	if (++breaderrors > BREADEMAX) {
522 		msg("More than %d block read errors from %d\n",
523 			BREADEMAX, disk);
524 		broadcast("DUMP IS AILING!\n");
525 		msg("This is an unrecoverable error.\n");
526 		if (!query("Do you want to attempt to continue?")){
527 			dumpabort(0);
528 			/*NOTREACHED*/
529 		} else
530 			breaderrors = 0;
531 	}
532 	/*
533 	 * Zero buffer, then try to read each sector of buffer separately.
534 	 */
535 	bzero(buf, size);
536 	for (i = 0; i < size; i += dev_bsize, buf += dev_bsize, blkno++) {
537 		if ((int)lseek(diskfd, ((off_t)blkno << dev_bshift), 0) < 0)
538 			msg("bread: lseek2 fails!\n");
539 		if ((cnt = read(diskfd, buf, (int)dev_bsize)) == dev_bsize)
540 			continue;
541 		if (cnt == -1) {
542 			msg("read error from %s: %s: [sector %d]: count=%d\n",
543 				disk, strerror(errno), blkno, dev_bsize);
544 			continue;
545 		}
546 		msg("short read error from %s: [sector %d]: count=%d, got=%d\n",
547 			disk, blkno, dev_bsize, cnt);
548 	}
549 }
550