xref: /csrg-svn/sbin/dump/traverse.c (revision 51605)
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	5.15 (Berkeley) 11/10/91";
10 #endif /* not lint */
11 
12 #ifdef sunos
13 #include <stdio.h>
14 #include <ctype.h>
15 #include <sys/param.h>
16 #include <sys/stat.h>
17 #include <sys/time.h>
18 #include <sys/dir.h>
19 #include <sys/vnode.h>
20 #include <ufs/inode.h>
21 #include <ufs/fs.h>
22 #else
23 #include <sys/param.h>
24 #include <ufs/ufs/dir.h>
25 #include <ufs/ufs/dinode.h>
26 #include <ufs/ffs/fs.h>
27 #endif
28 #include <protocols/dumprestore.h>
29 #ifdef __STDC__
30 #include <unistd.h>
31 #include <string.h>
32 #endif
33 #include "dump.h"
34 
35 void	dmpindir();
36 #define	HASDUMPEDFILE	0x1
37 #define	HASSUBDIRS	0x2
38 
39 /*
40  * This is an estimation of the number of TP_BSIZE blocks in the file.
41  * It estimates the number of blocks in files with holes by assuming
42  * that all of the blocks accounted for by di_blocks are data blocks
43  * (when some of the blocks are usually used for indirect pointers);
44  * hence the estimate may be high.
45  */
46 long
47 blockest(dp)
48 	register struct dinode *dp;
49 {
50 	long blkest, sizeest;
51 
52 	/*
53 	 * dp->di_size is the size of the file in bytes.
54 	 * dp->di_blocks stores the number of sectors actually in the file.
55 	 * If there are more sectors than the size would indicate, this just
56 	 *	means that there are indirect blocks in the file or unused
57 	 *	sectors in the last file block; we can safely ignore these
58 	 *	(blkest = sizeest below).
59 	 * If the file is bigger than the number of sectors would indicate,
60 	 *	then the file has holes in it.	In this case we must use the
61 	 *	block count to estimate the number of data blocks used, but
62 	 *	we use the actual size for estimating the number of indirect
63 	 *	dump blocks (sizeest vs. blkest in the indirect block
64 	 *	calculation).
65 	 */
66 	blkest = howmany(dbtob(dp->di_blocks), TP_BSIZE);
67 	sizeest = howmany(dp->di_size, TP_BSIZE);
68 	if (blkest > sizeest)
69 		blkest = sizeest;
70 	if (dp->di_size > sblock->fs_bsize * NDADDR) {
71 		/* calculate the number of indirect blocks on the dump tape */
72 		blkest +=
73 			howmany(sizeest - NDADDR * sblock->fs_bsize / TP_BSIZE,
74 			TP_NINDIR);
75 	}
76 	return (blkest + 1);
77 }
78 
79 /*
80  * Dump pass 1.
81  *
82  * Walk the inode list for a filesystem to find all allocated inodes
83  * that have been modified since the previous dump time. Also, find all
84  * the directories in the filesystem.
85  */
86 mapfiles(maxino, tapesize)
87 	ino_t maxino;
88 	long *tapesize;
89 {
90 	register int mode;
91 	register ino_t ino;
92 	register struct dinode *dp;
93 	int anydirskipped = 0;
94 
95 	for (ino = 0; ino < maxino; ino++) {
96 		dp = getino(ino);
97 		if ((mode = (dp->di_mode & IFMT)) == 0)
98 			continue;
99 		SETINO(ino, usedinomap);
100 		if (mode == IFDIR)
101 			SETINO(ino, dumpdirmap);
102 		if (dp->di_mtime >= spcl.c_ddate ||
103 		    dp->di_ctime >= spcl.c_ddate) {
104 			SETINO(ino, dumpinomap);
105 			if (mode != IFREG && mode != IFDIR && mode != IFLNK) {
106 				*tapesize += 1;
107 				continue;
108 			}
109 			*tapesize += blockest(dp);
110 			continue;
111 		}
112 		if (mode == IFDIR)
113 			anydirskipped = 1;
114 	}
115 	/*
116 	 * Restore gets very upset if the root is not dumped,
117 	 * so ensure that it always is dumped.
118 	 */
119 	SETINO(ROOTINO, dumpinomap);
120 	return (anydirskipped);
121 }
122 
123 /*
124  * Dump pass 2.
125  *
126  * Scan each directory on the filesystem to see if it has any modified
127  * files in it. If it does, and has not already been added to the dump
128  * list (because it was itself modified), then add it. If a directory
129  * has not been modified itself, contains no modified files and has no
130  * subdirectories, then it can be deleted from the dump list and from
131  * the list of directories. By deleting it from the list of directories,
132  * its parent may now qualify for the same treatment on this or a later
133  * pass using this algorithm.
134  */
135 mapdirs(maxino, tapesize)
136 	ino_t maxino;
137 	long *tapesize;
138 {
139 	register struct	dinode *dp;
140 	register int i, dirty;
141 	register char *map;
142 	register ino_t ino;
143 	long filesize, blkcnt = 0;
144 	int ret, change = 0;
145 
146 	for (map = dumpdirmap, ino = 0; ino < maxino; ) {
147 		if ((ino % NBBY) == 0)
148 			dirty = *map++;
149 		else
150 			dirty >>= 1;
151 		ino++;
152 		if ((dirty & 1) == 0 || TSTINO(ino, dumpinomap))
153 			continue;
154 		dp = getino(ino);
155 		filesize = dp->di_size;
156 		for (ret = 0, i = 0; filesize > 0 && i < NDADDR; i++) {
157 			if (dp->di_db[i] != 0)
158 				ret |= searchdir(ino, dp->di_db[i],
159 					dblksize(sblock, dp, i), filesize);
160 			if (ret & HASDUMPEDFILE)
161 				filesize = 0;
162 			else
163 				filesize -= sblock->fs_bsize;
164 		}
165 		for (i = 0; filesize > 0 && i < NIADDR; i++) {
166 			if (dp->di_ib[i] == 0)
167 				continue;
168 			ret |= dirindir(ino, dp->di_ib[i], i, &filesize);
169 		}
170 		if (ret & HASDUMPEDFILE) {
171 			if (!TSTINO(ino, dumpinomap)) {
172 				SETINO(ino, dumpinomap);
173 				*tapesize += blockest(dp);
174 			}
175 			change = 1;
176 			continue;
177 		}
178 		if ((ret & HASSUBDIRS) == 0) {
179 			if (!TSTINO(ino, dumpinomap)) {
180 				CLRINO(ino, dumpdirmap);
181 				change = 1;
182 			}
183 		}
184 	}
185 	return (change);
186 }
187 
188 /*
189  * Read indirect blocks, and pass the data blocks to be searched
190  * as directories. Quit as soon as any entry is found that will
191  * require the directory to be dumped.
192  */
193 dirindir(ino, blkno, level, filesize)
194 	ino_t ino;
195 	daddr_t blkno;
196 	int level, *filesize;
197 {
198 	int ret = 0;
199 	register int i;
200 	daddr_t	idblk[MAXNINDIR];
201 
202 	bread(fsbtodb(sblock, blkno), (char *)idblk, sblock->fs_bsize);
203 	if (level <= 0) {
204 		for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
205 			blkno = idblk[i];
206 			if (blkno != 0)
207 				ret |= searchdir(ino, blkno, sblock->fs_bsize,
208 					filesize);
209 			if (ret & HASDUMPEDFILE)
210 				*filesize = 0;
211 			else
212 				*filesize -= sblock->fs_bsize;
213 		}
214 		return (ret);
215 	}
216 	level--;
217 	for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
218 		blkno = idblk[i];
219 		if (blkno != 0)
220 			ret |= dirindir(ino, blkno, level, filesize);
221 	}
222 	return (ret);
223 }
224 
225 /*
226  * Scan a disk block containing directory information looking to see if
227  * any of the entries are on the dump list and to see if the directory
228  * contains any subdirectories.
229  */
230 searchdir(ino, blkno, size, filesize)
231 	ino_t ino;
232 	daddr_t blkno;
233 	register int size;
234 	int filesize;
235 {
236 	register struct direct *dp;
237 	register long loc;
238 	char dblk[MAXBSIZE];
239 
240 	bread(fsbtodb(sblock, blkno), dblk, size);
241 	if (filesize < size)
242 		size = filesize;
243 	for (loc = 0; loc < size; ) {
244 		dp = (struct direct *)(dblk + loc);
245 		if (dp->d_reclen == 0) {
246 			msg("corrupted directory, inumber %d\n", ino);
247 			break;
248 		}
249 		loc += dp->d_reclen;
250 		if (dp->d_ino == 0)
251 			continue;
252 		if (dp->d_name[0] == '.') {
253 			if (dp->d_name[1] == '\0')
254 				continue;
255 			if (dp->d_name[1] == '.' && dp->d_name[2] == '\0')
256 				continue;
257 		}
258 		if (TSTINO(dp->d_ino, dumpinomap))
259 			return (HASDUMPEDFILE);
260 		if (TSTINO(dp->d_ino, dumpdirmap))
261 			return (HASSUBDIRS);
262 	}
263 	return (0);
264 }
265 
266 /*
267  * Dump passes 3 and 4.
268  *
269  * Dump the contents of an inode to tape.
270  */
271 void
272 dumpino(dp, ino)
273 	register struct dinode *dp;
274 	ino_t ino;
275 {
276 	int mode, level, cnt;
277 	long size;
278 
279 	if (newtape) {
280 		newtape = 0;
281 		dumpmap(dumpinomap, TS_BITS, ino);
282 	}
283 	CLRINO(ino, dumpinomap);
284 	spcl.c_dinode = *dp;
285 	spcl.c_type = TS_INODE;
286 	spcl.c_count = 0;
287 	/*
288 	 * Check for freed inode.
289 	 */
290 	if ((mode = (dp->di_mode & IFMT)) == 0)
291 		return;
292 	if ((mode != IFDIR && mode != IFREG && mode != IFLNK) ||
293 	    dp->di_size == 0) {
294 		writeheader(ino);
295 		return;
296 	}
297 	if (dp->di_size > NDADDR * sblock->fs_bsize)
298 		cnt = NDADDR * sblock->fs_frag;
299 	else
300 		cnt = howmany(dp->di_size, sblock->fs_fsize);
301 	blksout(&dp->di_db[0], cnt, ino);
302 	if ((size = dp->di_size - NDADDR * sblock->fs_bsize) <= 0)
303 		return;
304 	for (level = 0; level < NIADDR; level++) {
305 		dmpindir(ino, dp->di_ib[level], level, &size);
306 		if (size <= 0)
307 			return;
308 	}
309 }
310 
311 /*
312  * Read indirect blocks, and pass the data blocks to be dumped.
313  */
314 void
315 dmpindir(ino, blk, level, size)
316 	ino_t ino;
317 	daddr_t blk;
318 	int level;
319 	long *size;
320 {
321 	int i, cnt;
322 	daddr_t idblk[MAXNINDIR];
323 
324 	if (blk != 0)
325 		bread(fsbtodb(sblock, blk), (char *)idblk, sblock->fs_bsize);
326 	else
327 		bzero((char *)idblk, sblock->fs_bsize);
328 	if (level <= 0) {
329 		if (*size < NINDIR(sblock) * sblock->fs_bsize)
330 			cnt = howmany(*size, sblock->fs_fsize);
331 		else
332 			cnt = NINDIR(sblock) * sblock->fs_frag;
333 		*size -= NINDIR(sblock) * sblock->fs_bsize;
334 		blksout(&idblk[0], cnt, ino);
335 		return;
336 	}
337 	level--;
338 	for (i = 0; i < NINDIR(sblock); i++) {
339 		dmpindir(ino, idblk[i], level, size);
340 		if (*size <= 0)
341 			return;
342 	}
343 }
344 
345 /*
346  * Collect up the data into tape record sized buffers and output them.
347  */
348 void
349 blksout(blkp, frags, ino)
350 	daddr_t *blkp;
351 	int frags;
352 	ino_t ino;
353 {
354 	register daddr_t *bp;
355 	int i, j, count, blks, tbperdb;
356 
357 	blks = howmany(frags * sblock->fs_fsize, TP_BSIZE);
358 	tbperdb = sblock->fs_bsize >> tp_bshift;
359 	for (i = 0; i < blks; i += TP_NINDIR) {
360 		if (i + TP_NINDIR > blks)
361 			count = blks;
362 		else
363 			count = i + TP_NINDIR;
364 		for (j = i; j < count; j++)
365 			if (blkp[j / tbperdb] != 0)
366 				spcl.c_addr[j - i] = 1;
367 			else
368 				spcl.c_addr[j - i] = 0;
369 		spcl.c_count = count - i;
370 		writeheader(ino);
371 		bp = &blkp[i / tbperdb];
372 		for (j = i; j < count; j += tbperdb, bp++)
373 			if (*bp != 0)
374 				if (j + tbperdb <= count)
375 					dumpblock(*bp, sblock->fs_bsize);
376 				else
377 					dumpblock(*bp, (count - j) * TP_BSIZE);
378 		spcl.c_type = TS_ADDR;
379 	}
380 }
381 
382 /*
383  * Dump a map to the tape.
384  */
385 void
386 dumpmap(map, type, ino)
387 	char *map;
388 	int type;
389 	ino_t ino;
390 {
391 	register int i;
392 	char *cp;
393 
394 	spcl.c_type = type;
395 	spcl.c_count = howmany(mapsize * sizeof(char), TP_BSIZE);
396 	writeheader(ino);
397 	for (i = 0, cp = map; i < spcl.c_count; i++, cp += TP_BSIZE)
398 		writerec(cp);
399 }
400 
401 /*
402  * Write a header record to the dump tape.
403  */
404 void
405 writeheader(ino)
406 	ino_t ino;
407 {
408 	register long sum, cnt, *lp;
409 
410 	spcl.c_inumber = ino;
411 	spcl.c_magic = NFS_MAGIC;
412 	spcl.c_checksum = 0;
413 	lp = (long *)&spcl;
414 	sum = 0;
415 	cnt = sizeof(union u_spcl) / (4 * sizeof(long));
416 	while (--cnt >= 0) {
417 		sum += *lp++;
418 		sum += *lp++;
419 		sum += *lp++;
420 		sum += *lp++;
421 	}
422 	spcl.c_checksum = CHECKSUM - sum;
423 	writerec((char *)&spcl);
424 }
425 
426 struct dinode *
427 getino(inum)
428 	ino_t inum;
429 {
430 	static daddr_t minino, maxino;
431 	static struct dinode inoblock[MAXINOPB];
432 
433 	curino = inum;
434 	if (inum >= minino && inum < maxino)
435 		return (&inoblock[inum - minino]);
436 	bread(fsbtodb(sblock, itod(sblock, inum)), inoblock, sblock->fs_bsize);
437 	minino = inum - (inum % INOPB(sblock));
438 	maxino = minino + INOPB(sblock);
439 	return (&inoblock[inum - minino]);
440 }
441 
442 /*
443  * Read a chunk of data from the disk.
444  * Try to recover from hard errors by reading in sector sized pieces.
445  * Error recovery is attempted at most BREADEMAX times before seeking
446  * consent from the operator to continue.
447  */
448 int	breaderrors = 0;
449 #define	BREADEMAX 32
450 
451 void
452 bread(blkno, buf, size)
453 	daddr_t blkno;
454 	char *buf;
455 	int size;
456 {
457 	int cnt, i;
458 	extern int errno;
459 
460 loop:
461 	if (lseek(diskfd, (long)(blkno << dev_bshift), 0) < 0)
462 		msg("bread: lseek fails\n");
463 	if ((cnt = read(diskfd, buf, size)) == size)
464 		return;
465 	if (blkno + (size / dev_bsize) > fsbtodb(sblock, sblock->fs_size)) {
466 		/*
467 		 * Trying to read the final fragment.
468 		 *
469 		 * NB - dump only works in TP_BSIZE blocks, hence
470 		 * rounds `dev_bsize' fragments up to TP_BSIZE pieces.
471 		 * It should be smarter about not actually trying to
472 		 * read more than it can get, but for the time being
473 		 * we punt and scale back the read only when it gets
474 		 * us into trouble. (mkm 9/25/83)
475 		 */
476 		size -= dev_bsize;
477 		goto loop;
478 	}
479 	if (cnt == -1)
480 		msg("read error from %s: %s: [block %d]: count=%d\n",
481 			disk, strerror(errno), blkno, size);
482 	else
483 		msg("short read error from %s: [block %d]: count=%d, got=%d\n",
484 			disk, blkno, size, cnt);
485 	if (++breaderrors > BREADEMAX) {
486 		msg("More than %d block read errors from %d\n",
487 			BREADEMAX, disk);
488 		broadcast("DUMP IS AILING!\n");
489 		msg("This is an unrecoverable error.\n");
490 		if (!query("Do you want to attempt to continue?")){
491 			dumpabort();
492 			/*NOTREACHED*/
493 		} else
494 			breaderrors = 0;
495 	}
496 	/*
497 	 * Zero buffer, then try to read each sector of buffer separately.
498 	 */
499 	bzero(buf, size);
500 	for (i = 0; i < size; i += dev_bsize, buf += dev_bsize, blkno++) {
501 		if (lseek(diskfd, (long)(blkno << dev_bshift), 0) < 0)
502 			msg("bread: lseek2 fails!\n");
503 		if ((cnt = read(diskfd, buf, dev_bsize)) == dev_bsize)
504 			continue;
505 		if (cnt == -1) {
506 			msg("read error from %s: %s: [sector %d]: count=%d\n",
507 				disk, strerror(errno), blkno, dev_bsize);
508 			continue;
509 		}
510 		msg("short read error from %s: [sector %d]: count=%d, got=%d\n",
511 			disk, blkno, dev_bsize, cnt);
512 	}
513 }
514