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restore.c revision 1.13
      1 /*	$NetBSD: restore.c,v 1.13 2001/01/18 08:59:23 enami Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)restore.c	8.3 (Berkeley) 9/13/94";
     40 #else
     41 __RCSID("$NetBSD: restore.c,v 1.13 2001/01/18 08:59:23 enami Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 #include <sys/types.h>
     46 #include <sys/stat.h>
     47 
     48 #include <ufs/ufs/dinode.h>
     49 
     50 #include <stdio.h>
     51 #include <string.h>
     52 
     53 #include "restore.h"
     54 #include "extern.h"
     55 
     56 static char *keyval __P((int));
     57 
     58 /*
     59  * This implements the 't' option.
     60  * List entries on the tape.
     61  */
     62 long
     63 listfile(name, ino, type)
     64 	char *name;
     65 	ino_t ino;
     66 	int type;
     67 {
     68 	long descend = hflag ? GOOD : FAIL;
     69 
     70 	if (TSTINO(ino, dumpmap) == 0)
     71 		return (descend);
     72 	vprintf(stdout, "%s", type == LEAF ? "leaf" : "dir ");
     73 	fprintf(stdout, "%10d\t%s\n", ino, name);
     74 	return (descend);
     75 }
     76 
     77 /*
     78  * This implements the 'x' option.
     79  * Request that new entries be extracted.
     80  */
     81 long
     82 addfile(name, ino, type)
     83 	char *name;
     84 	ino_t ino;
     85 	int type;
     86 {
     87 	struct entry *ep;
     88 	long descend = hflag ? GOOD : FAIL;
     89 	char buf[100];
     90 
     91 	if (TSTINO(ino, dumpmap) == 0) {
     92 		dprintf(stdout, "%s: not on the tape\n", name);
     93 		return (descend);
     94 	}
     95 	if (ino == WINO && command == 'i' && !vflag)
     96 		return (descend);
     97 	if (!mflag) {
     98 		(void) snprintf(buf, sizeof(buf), "./%u", ino);
     99 		name = buf;
    100 		if (type == NODE) {
    101 			(void) genliteraldir(name, ino);
    102 			return (descend);
    103 		}
    104 	}
    105 	ep = lookupino(ino);
    106 	if (ep != NULL) {
    107 		if (strcmp(name, myname(ep)) == 0) {
    108 			ep->e_flags |= NEW;
    109 			return (descend);
    110 		}
    111 		type |= LINK;
    112 	}
    113 	ep = addentry(name, ino, type);
    114 	if (type == NODE)
    115 		newnode(ep);
    116 	ep->e_flags |= NEW;
    117 	return (descend);
    118 }
    119 
    120 /*
    121  * This is used by the 'i' option to undo previous requests made by addfile.
    122  * Delete entries from the request queue.
    123  */
    124 /* ARGSUSED */
    125 long
    126 deletefile(name, ino, type)
    127 	char *name;
    128 	ino_t ino;
    129 	int type;
    130 {
    131 	long descend = hflag ? GOOD : FAIL;
    132 	struct entry *ep;
    133 
    134 	if (TSTINO(ino, dumpmap) == 0)
    135 		return (descend);
    136 	ep = lookupname(name);
    137 	if (ep != NULL) {
    138 		ep->e_flags &= ~NEW;
    139 		ep->e_flags |= REMOVED;
    140 		if (ep->e_type != NODE)
    141 			freeentry(ep);
    142 	}
    143 	return (descend);
    144 }
    145 
    146 /*
    147  * The following four routines implement the incremental
    148  * restore algorithm. The first removes old entries, the second
    149  * does renames and calculates the extraction list, the third
    150  * cleans up link names missed by the first two, and the final
    151  * one deletes old directories.
    152  *
    153  * Directories cannot be immediately deleted, as they may have
    154  * other files in them which need to be moved out first. As
    155  * directories to be deleted are found, they are put on the
    156  * following deletion list. After all deletions and renames
    157  * are done, this list is actually deleted.
    158  */
    159 static struct entry *removelist;
    160 
    161 /*
    162  *	Remove invalid whiteouts from the old tree.
    163  *	Remove unneeded leaves from the old tree.
    164  *	Remove directories from the lookup chains.
    165  */
    166 void
    167 removeoldleaves()
    168 {
    169 	struct entry *ep, *nextep;
    170 	ino_t i, mydirino;
    171 
    172 	vprintf(stdout, "Mark entries to be removed.\n");
    173 	if ((ep = lookupino(WINO)) != NULL) {
    174 		vprintf(stdout, "Delete whiteouts\n");
    175 		for ( ; ep != NULL; ep = nextep) {
    176 			nextep = ep->e_links;
    177 			mydirino = ep->e_parent->e_ino;
    178 			/*
    179 			 * We remove all whiteouts that are in directories
    180 			 * that have been removed or that have been dumped.
    181 			 */
    182 			if (TSTINO(mydirino, usedinomap) &&
    183 			    !TSTINO(mydirino, dumpmap))
    184 				continue;
    185 			delwhiteout(ep);
    186 			freeentry(ep);
    187 		}
    188 	}
    189 	for (i = ROOTINO + 1; i < maxino; i++) {
    190 		ep = lookupino(i);
    191 		if (ep == NULL)
    192 			continue;
    193 		if (TSTINO(i, usedinomap))
    194 			continue;
    195 		for ( ; ep != NULL; ep = ep->e_links) {
    196 			dprintf(stdout, "%s: REMOVE\n", myname(ep));
    197 			if (ep->e_type == LEAF) {
    198 				removeleaf(ep);
    199 				freeentry(ep);
    200 			} else {
    201 				mktempname(ep);
    202 				deleteino(ep->e_ino);
    203 				ep->e_next = removelist;
    204 				removelist = ep;
    205 			}
    206 		}
    207 	}
    208 }
    209 
    210 /*
    211  *	For each directory entry on the incremental tape, determine which
    212  *	category it falls into as follows:
    213  *	KEEP - entries that are to be left alone.
    214  *	NEW - new entries to be added.
    215  *	EXTRACT - files that must be updated with new contents.
    216  *	LINK - new links to be added.
    217  *	Renames are done at the same time.
    218  */
    219 long
    220 nodeupdates(name, ino, type)
    221 	char *name;
    222 	ino_t ino;
    223 	int type;
    224 {
    225 	struct entry *ep, *np, *ip;
    226 	long descend = GOOD;
    227 	int lookuptype = 0;
    228 	int key = 0;
    229 		/* key values */
    230 #		define ONTAPE	0x1	/* inode is on the tape */
    231 #		define INOFND	0x2	/* inode already exists */
    232 #		define NAMEFND	0x4	/* name already exists */
    233 #		define MODECHG	0x8	/* mode of inode changed */
    234 
    235 	/*
    236 	 * This routine is called once for each element in the
    237 	 * directory hierarchy, with a full path name.
    238 	 * The "type" value is incorrectly specified as LEAF for
    239 	 * directories that are not on the dump tape.
    240 	 *
    241 	 * Check to see if the file is on the tape.
    242 	 */
    243 	if (TSTINO(ino, dumpmap))
    244 		key |= ONTAPE;
    245 	/*
    246 	 * Check to see if the name exists, and if the name is a link.
    247 	 */
    248 	np = lookupname(name);
    249 	if (np != NULL) {
    250 		key |= NAMEFND;
    251 		ip = lookupino(np->e_ino);
    252 		if (ip == NULL)
    253 			panic("corrupted symbol table\n");
    254 		if (ip != np)
    255 			lookuptype = LINK;
    256 	}
    257 	/*
    258 	 * Check to see if the inode exists, and if one of its links
    259 	 * corresponds to the name (if one was found).
    260 	 */
    261 	ip = lookupino(ino);
    262 	if (ip != NULL) {
    263 		key |= INOFND;
    264 		for (ep = ip->e_links; ep != NULL; ep = ep->e_links) {
    265 			if (ep == np) {
    266 				ip = ep;
    267 				break;
    268 			}
    269 		}
    270 	}
    271 	/*
    272 	 * If both a name and an inode are found, but they do not
    273 	 * correspond to the same file, then both the inode that has
    274 	 * been found and the inode corresponding to the name that
    275 	 * has been found need to be renamed. The current pathname
    276 	 * is the new name for the inode that has been found. Since
    277 	 * all files to be deleted have already been removed, the
    278 	 * named file is either a now unneeded link, or it must live
    279 	 * under a new name in this dump level. If it is a link, it
    280 	 * can be removed. If it is not a link, it is given a
    281 	 * temporary name in anticipation that it will be renamed
    282 	 * when it is later found by inode number.
    283 	 */
    284 	if (((key & (INOFND|NAMEFND)) == (INOFND|NAMEFND)) && ip != np) {
    285 		if (lookuptype == LINK) {
    286 			removeleaf(np);
    287 			freeentry(np);
    288 		} else {
    289 			dprintf(stdout, "name/inode conflict, mktempname %s\n",
    290 				myname(np));
    291 			mktempname(np);
    292 		}
    293 		np = NULL;
    294 		key &= ~NAMEFND;
    295 	}
    296 	if ((key & ONTAPE) &&
    297 	  (((key & INOFND) && ip->e_type != type) ||
    298 	   ((key & NAMEFND) && np->e_type != type)))
    299 		key |= MODECHG;
    300 
    301 	/*
    302 	 * Decide on the disposition of the file based on its flags.
    303 	 * Note that we have already handled the case in which
    304 	 * a name and inode are found that correspond to different files.
    305 	 * Thus if both NAMEFND and INOFND are set then ip == np.
    306 	 */
    307 	switch (key) {
    308 
    309 	/*
    310 	 * A previously existing file has been found.
    311 	 * Mark it as KEEP so that other links to the inode can be
    312 	 * detected, and so that it will not be reclaimed by the search
    313 	 * for unreferenced names.
    314 	 */
    315 	case INOFND|NAMEFND:
    316 		ip->e_flags |= KEEP;
    317 		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
    318 			flagvalues(ip));
    319 		break;
    320 
    321 	/*
    322 	 * A file on the tape has a name which is the same as a name
    323 	 * corresponding to a different file in the previous dump.
    324 	 * Since all files to be deleted have already been removed,
    325 	 * this file is either a now unneeded link, or it must live
    326 	 * under a new name in this dump level. If it is a link, it
    327 	 * can simply be removed. If it is not a link, it is given a
    328 	 * temporary name in anticipation that it will be renamed
    329 	 * when it is later found by inode number (see INOFND case
    330 	 * below). The entry is then treated as a new file.
    331 	 */
    332 	case ONTAPE|NAMEFND:
    333 	case ONTAPE|NAMEFND|MODECHG:
    334 		if (lookuptype == LINK) {
    335 			removeleaf(np);
    336 			freeentry(np);
    337 		} else {
    338 			mktempname(np);
    339 		}
    340 		/* fall through */
    341 
    342 	/*
    343 	 * A previously non-existent file.
    344 	 * Add it to the file system, and request its extraction.
    345 	 * If it is a directory, create it immediately.
    346 	 * (Since the name is unused there can be no conflict)
    347 	 */
    348 	case ONTAPE:
    349 		ep = addentry(name, ino, type);
    350 		if (type == NODE)
    351 			newnode(ep);
    352 		ep->e_flags |= NEW|KEEP;
    353 		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
    354 			flagvalues(ep));
    355 		break;
    356 
    357 	/*
    358 	 * A file with the same inode number, but a different
    359 	 * name has been found. If the other name has not already
    360 	 * been found (indicated by the KEEP flag, see above) then
    361 	 * this must be a new name for the file, and it is renamed.
    362 	 * If the other name has been found then this must be a
    363 	 * link to the file. Hard links to directories are not
    364 	 * permitted, and are either deleted or converted to
    365 	 * symbolic links. Finally, if the file is on the tape,
    366 	 * a request is made to extract it.
    367 	 */
    368 	case ONTAPE|INOFND:
    369 		if (type == LEAF && (ip->e_flags & KEEP) == 0)
    370 			ip->e_flags |= EXTRACT;
    371 		/* fall through */
    372 	case INOFND:
    373 		if ((ip->e_flags & KEEP) == 0) {
    374 			renameit(myname(ip), name);
    375 			moveentry(ip, name);
    376 			ip->e_flags |= KEEP;
    377 			dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
    378 				flagvalues(ip));
    379 			break;
    380 		}
    381 		if (ip->e_type == NODE) {
    382 			descend = FAIL;
    383 			fprintf(stderr,
    384 				"deleted hard link %s to directory %s\n",
    385 				name, myname(ip));
    386 			break;
    387 		}
    388 		ep = addentry(name, ino, type|LINK);
    389 		ep->e_flags |= NEW;
    390 		dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
    391 			flagvalues(ep));
    392 		break;
    393 
    394 	/*
    395 	 * A previously known file which is to be updated. If it is a link,
    396 	 * then all names referring to the previous file must be removed
    397 	 * so that the subset of them that remain can be recreated.
    398 	 */
    399 	case ONTAPE|INOFND|NAMEFND:
    400 		if (lookuptype == LINK) {
    401 			removeleaf(np);
    402 			freeentry(np);
    403 			ep = addentry(name, ino, type|LINK);
    404 			if (type == NODE)
    405 			        newnode(ep);
    406 			ep->e_flags |= NEW|KEEP;
    407 			dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
    408 				flagvalues(ep));
    409 			break;
    410 		}
    411 		if (type == LEAF && lookuptype != LINK)
    412 			np->e_flags |= EXTRACT;
    413 		np->e_flags |= KEEP;
    414 		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
    415 			flagvalues(np));
    416 		break;
    417 
    418 	/*
    419 	 * An inode is being reused in a completely different way.
    420 	 * Normally an extract can simply do an "unlink" followed
    421 	 * by a "creat". Here we must do effectively the same
    422 	 * thing. The complications arise because we cannot really
    423 	 * delete a directory since it may still contain files
    424 	 * that we need to rename, so we delete it from the symbol
    425 	 * table, and put it on the list to be deleted eventually.
    426 	 * Conversely if a directory is to be created, it must be
    427 	 * done immediately, rather than waiting until the
    428 	 * extraction phase.
    429 	 */
    430 	case ONTAPE|INOFND|MODECHG:
    431 	case ONTAPE|INOFND|NAMEFND|MODECHG:
    432 		if (ip->e_flags & KEEP) {
    433 			badentry(ip, "cannot KEEP and change modes");
    434 			break;
    435 		}
    436 		if (ip->e_type == LEAF) {
    437 			/* changing from leaf to node */
    438 			for ( ; ip != NULL; ip = ip->e_links) {
    439 				if (ip->e_type != LEAF)
    440 					badentry(ip,
    441 					    "NODE and LEAF links to same inode");
    442 				removeleaf(ip);
    443 				freeentry(ip);
    444 			}
    445 			ip = addentry(name, ino, type);
    446 			newnode(ip);
    447 		} else {
    448 			/* changing from node to leaf */
    449 			if ((ip->e_flags & TMPNAME) == 0)
    450 				mktempname(ip);
    451 			deleteino(ip->e_ino);
    452 			ip->e_next = removelist;
    453 			removelist = ip;
    454 			ip = addentry(name, ino, type);
    455 		}
    456 		ip->e_flags |= NEW|KEEP;
    457 		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
    458 			flagvalues(ip));
    459 		break;
    460 
    461 	/*
    462 	 * A hard link to a diirectory that has been removed.
    463 	 * Ignore it.
    464 	 */
    465 	case NAMEFND:
    466 		dprintf(stdout, "[%s] %s: Extraneous name\n", keyval(key),
    467 			name);
    468 		descend = FAIL;
    469 		break;
    470 
    471 	/*
    472 	 * If we find a directory entry for a file that is not on
    473 	 * the tape, then we must have found a file that was created
    474 	 * while the dump was in progress. Since we have no contents
    475 	 * for it, we discard the name knowing that it will be on the
    476 	 * next incremental tape.
    477 	 */
    478 	case NULL:
    479 		fprintf(stderr, "%s: (inode %d) not found on tape\n",
    480 			name, ino);
    481 		break;
    482 
    483 	/*
    484 	 * If any of these arise, something is grievously wrong with
    485 	 * the current state of the symbol table.
    486 	 */
    487 	case INOFND|NAMEFND|MODECHG:
    488 	case NAMEFND|MODECHG:
    489 	case INOFND|MODECHG:
    490 		fprintf(stderr, "[%s] %s: inconsistent state\n", keyval(key),
    491 			name);
    492 		break;
    493 
    494 	/*
    495 	 * These states "cannot" arise for any state of the symbol table.
    496 	 */
    497 	case ONTAPE|MODECHG:
    498 	case MODECHG:
    499 	default:
    500 		panic("[%s] %s: impossible state\n", keyval(key), name);
    501 		break;
    502 	}
    503 	return (descend);
    504 }
    505 
    506 /*
    507  * Calculate the active flags in a key.
    508  */
    509 static char *
    510 keyval(key)
    511 	int key;
    512 {
    513 	static char keybuf[32];
    514 
    515 	(void) strcpy(keybuf, "|NIL");
    516 	keybuf[0] = '\0';
    517 	if (key & ONTAPE)
    518 		(void) strcat(keybuf, "|ONTAPE");
    519 	if (key & INOFND)
    520 		(void) strcat(keybuf, "|INOFND");
    521 	if (key & NAMEFND)
    522 		(void) strcat(keybuf, "|NAMEFND");
    523 	if (key & MODECHG)
    524 		(void) strcat(keybuf, "|MODECHG");
    525 	return (&keybuf[1]);
    526 }
    527 
    528 /*
    529  * Find unreferenced link names.
    530  */
    531 void
    532 findunreflinks()
    533 {
    534 	struct entry *ep, *np;
    535 	ino_t i;
    536 
    537 	vprintf(stdout, "Find unreferenced names.\n");
    538 	for (i = ROOTINO; i < maxino; i++) {
    539 		ep = lookupino(i);
    540 		if (ep == NULL || ep->e_type == LEAF || TSTINO(i, dumpmap) == 0)
    541 			continue;
    542 		for (np = ep->e_entries; np != NULL; np = np->e_sibling) {
    543 			if (np->e_flags == 0) {
    544 				dprintf(stdout,
    545 				    "%s: remove unreferenced name\n",
    546 				    myname(np));
    547 				removeleaf(np);
    548 				freeentry(np);
    549 			}
    550 		}
    551 	}
    552 	/*
    553 	 * Any leaves remaining in removed directories is unreferenced.
    554 	 */
    555 	for (ep = removelist; ep != NULL; ep = ep->e_next) {
    556 		for (np = ep->e_entries; np != NULL; np = np->e_sibling) {
    557 			if (np->e_type == LEAF) {
    558 				if (np->e_flags != 0)
    559 					badentry(np, "unreferenced with flags");
    560 				dprintf(stdout,
    561 				    "%s: remove unreferenced name\n",
    562 				    myname(np));
    563 				removeleaf(np);
    564 				freeentry(np);
    565 			}
    566 		}
    567 	}
    568 }
    569 
    570 /*
    571  * Remove old nodes (directories).
    572  * Note that this routine runs in O(N*D) where:
    573  *	N is the number of directory entries to be removed.
    574  *	D is the maximum depth of the tree.
    575  * If N == D this can be quite slow. If the list were
    576  * topologically sorted, the deletion could be done in
    577  * time O(N).
    578  */
    579 void
    580 removeoldnodes()
    581 {
    582 	struct entry *ep, **prev;
    583 	long change;
    584 
    585 	vprintf(stdout, "Remove old nodes (directories).\n");
    586 	do	{
    587 		change = 0;
    588 		prev = &removelist;
    589 		for (ep = removelist; ep != NULL; ep = *prev) {
    590 			if (ep->e_entries != NULL) {
    591 				prev = &ep->e_next;
    592 				continue;
    593 			}
    594 			*prev = ep->e_next;
    595 			removenode(ep);
    596 			freeentry(ep);
    597 			change++;
    598 		}
    599 	} while (change);
    600 	for (ep = removelist; ep != NULL; ep = ep->e_next)
    601 		badentry(ep, "cannot remove, non-empty");
    602 }
    603 
    604 /*
    605  * This is the routine used to extract files for the 'r' command.
    606  * Extract new leaves.
    607  */
    608 void
    609 createleaves(symtabfile)
    610 	char *symtabfile;
    611 {
    612 	struct entry *ep;
    613 	ino_t first;
    614 	long curvol;
    615 
    616 	if (command == 'R') {
    617 		vprintf(stdout, "Continue extraction of new leaves\n");
    618 	} else {
    619 		vprintf(stdout, "Extract new leaves.\n");
    620 		dumpsymtable(symtabfile, volno);
    621 	}
    622 	first = lowerbnd(ROOTINO);
    623 	curvol = volno;
    624 	while (curfile.ino < maxino) {
    625 		first = lowerbnd(first);
    626 		/*
    627 		 * If the next available file is not the one which we
    628 		 * expect then we have missed one or more files. Since
    629 		 * we do not request files that were not on the tape,
    630 		 * the lost files must have been due to a tape read error,
    631 		 * or a file that was removed while the dump was in progress.
    632 		 */
    633 		while (first < curfile.ino) {
    634 			ep = lookupino(first);
    635 			if (ep == NULL)
    636 				panic("%d: bad first\n", first);
    637 			fprintf(stderr, "%s: not found on tape\n", myname(ep));
    638 			ep->e_flags &= ~(NEW|EXTRACT);
    639 			first = lowerbnd(first);
    640 		}
    641 		/*
    642 		 * If we find files on the tape that have no corresponding
    643 		 * directory entries, then we must have found a file that
    644 		 * was created while the dump was in progress. Since we have
    645 		 * no name for it, we discard it knowing that it will be
    646 		 * on the next incremental tape.
    647 		 */
    648 		if (first != curfile.ino) {
    649 			fprintf(stderr, "expected next file %d, got %d\n",
    650 				first, curfile.ino);
    651 			skipfile();
    652 			goto next;
    653 		}
    654 		ep = lookupino(curfile.ino);
    655 		if (ep == NULL)
    656 			panic("unknown file on tape\n");
    657 		if ((ep->e_flags & (NEW|EXTRACT)) == 0)
    658 			badentry(ep, "unexpected file on tape");
    659 		/*
    660 		 * If the file is to be extracted, then the old file must
    661 		 * be removed since its type may change from one leaf type
    662 		 * to another (eg "file" to "character special").
    663 		 */
    664 		if ((ep->e_flags & EXTRACT) != 0) {
    665 			removeleaf(ep);
    666 			ep->e_flags &= ~REMOVED;
    667 		}
    668 		(void) extractfile(myname(ep));
    669 		ep->e_flags &= ~(NEW|EXTRACT);
    670 		/*
    671 		 * We checkpoint the restore after every tape reel, so
    672 		 * as to simplify the amount of work re quired by the
    673 		 * 'R' command.
    674 		 */
    675 	next:
    676 		if (curvol != volno) {
    677 			dumpsymtable(symtabfile, volno);
    678 			skipmaps();
    679 			curvol = volno;
    680 		}
    681 	}
    682 }
    683 
    684 /*
    685  * This is the routine used to extract files for the 'x' and 'i' commands.
    686  * Efficiently extract a subset of the files on a tape.
    687  */
    688 void
    689 createfiles()
    690 {
    691 	ino_t first, next, last;
    692 	struct entry *ep;
    693 	long curvol;
    694 
    695 	vprintf(stdout, "Extract requested files\n");
    696 	curfile.action = SKIP;
    697 	getvol((long)1);
    698 	skipmaps();
    699 	skipdirs();
    700 	first = lowerbnd(ROOTINO);
    701 	last = upperbnd(maxino - 1);
    702 
    703 new_volume:
    704 	/*
    705 	 * Decide on the next inode needed in this volume.
    706 	 */
    707 	next = lowerbnd(curfile.ino);
    708 	for (;;) {
    709 		first = lowerbnd(first);
    710 		last = upperbnd(last);
    711 		/*
    712 		 * Check to see if any files remain to be extracted
    713 		 */
    714 		if (first > last)
    715 			return;
    716 		/*
    717 		 * Reject any volumes with inodes greater
    718 		 * than the last one needed
    719 		 */
    720 		if (curfile.ino > last) {
    721 			do {
    722 				curfile.action = SKIP;
    723 				getvol((long)0);
    724 				skipmaps();
    725 				skipdirs();
    726 			} while (curfile.ino > last);
    727 			goto new_volume;
    728 		}
    729 		/*
    730 		 * Skip across the inodes until the next inode is found
    731 		 * or an out of order volume change is encountered
    732 		 */
    733 		do {
    734 			curvol = volno;
    735 			while (next > curfile.ino && volno == curvol)
    736 				skipfile();
    737 			skipmaps();
    738 			skipdirs();
    739 		} while (volno == curvol + 1);
    740 		/*
    741 		 * If volume change out of order occurred the
    742 		 * current state must be recalculated
    743 		 */
    744 		if (volno != curvol)
    745 			goto new_volume;
    746 		/*
    747 		 * If the current inode is greater than the one we were
    748 		 * looking for then we missed the one we were looking for.
    749 		 * Since we only attempt to extract files listed in the
    750 		 * dump map, the lost files must have been due to a tape
    751 		 * read error, or a file that was removed while the dump
    752 		 * was in progress. Thus we report all requested files
    753 		 * between the one we were looking for, and the one we
    754 		 * found as missing, and delete their request flags.
    755 		 */
    756 		while (next < curfile.ino) {
    757 			ep = lookupino(next);
    758 			if (ep == NULL)
    759 				panic("corrupted symbol table\n");
    760 			fprintf(stderr, "%s: not found on tape\n", myname(ep));
    761 			ep->e_flags &= ~NEW;
    762 			next = lowerbnd(next);
    763 		}
    764 		/*
    765 		 * The current inode is the one that we are looking for,
    766 		 * so extract it per its requested name.
    767 		 */
    768 		if (next == curfile.ino && next <= last) {
    769 			ep = lookupino(next);
    770 			if (ep == NULL)
    771 				panic("corrupted symbol table\n");
    772 			(void) extractfile(myname(ep));
    773 			ep->e_flags &= ~NEW;
    774 			if (volno != curvol) {
    775 				skipmaps();
    776 				goto new_volume;
    777 			}
    778 			/*
    779 			 * Decide the next inode.  Note that curfile.ino
    780 			 * already updated to the next file on the tape,
    781 			 * and we can't used it since it may be greater
    782 			 * than `next'.
    783 			 */
    784 			next = lowerbnd(next);
    785 		}
    786 	}
    787 }
    788 
    789 /*
    790  * Add links.
    791  */
    792 void
    793 createlinks()
    794 {
    795 	struct entry *np, *ep;
    796 	ino_t i;
    797 	char name[BUFSIZ];
    798 
    799 	if ((ep = lookupino(WINO)) != NULL) {
    800 		vprintf(stdout, "Add whiteouts\n");
    801 		for ( ; ep != NULL; ep = ep->e_links) {
    802 			if ((ep->e_flags & NEW) == 0)
    803 				continue;
    804 			(void) addwhiteout(myname(ep));
    805 			ep->e_flags &= ~NEW;
    806 		}
    807 	}
    808 	vprintf(stdout, "Add links\n");
    809 	for (i = ROOTINO; i < maxino; i++) {
    810 		ep = lookupino(i);
    811 		if (ep == NULL)
    812 			continue;
    813 		for (np = ep->e_links; np != NULL; np = np->e_links) {
    814 			if ((np->e_flags & NEW) == 0)
    815 				continue;
    816 			(void) strcpy(name, myname(ep));
    817 			if (ep->e_type == NODE) {
    818 				(void) linkit(name, myname(np), SYMLINK);
    819 			} else {
    820 				(void) linkit(name, myname(np), HARDLINK);
    821 			}
    822 			np->e_flags &= ~NEW;
    823 		}
    824 	}
    825 }
    826 
    827 /*
    828  * Check the symbol table.
    829  * We do this to insure that all the requested work was done, and
    830  * that no temporary names remain.
    831  */
    832 void
    833 checkrestore()
    834 {
    835 	struct entry *ep;
    836 	ino_t i;
    837 
    838 	vprintf(stdout, "Check the symbol table.\n");
    839 	for (i = WINO; i < maxino; i++) {
    840 		for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
    841 			ep->e_flags &= ~KEEP;
    842 			if (ep->e_type == NODE)
    843 				ep->e_flags &= ~(NEW|EXISTED);
    844 			if (ep->e_flags != 0)
    845 				badentry(ep, "incomplete operations");
    846 		}
    847 	}
    848 }
    849 
    850 /*
    851  * Compare with the directory structure on the tape
    852  * A paranoid check that things are as they should be.
    853  */
    854 long
    855 verifyfile(name, ino, type)
    856 	char *name;
    857 	ino_t ino;
    858 	int type;
    859 {
    860 	struct entry *np, *ep;
    861 	long descend = GOOD;
    862 
    863 	ep = lookupname(name);
    864 	if (ep == NULL) {
    865 		fprintf(stderr, "Warning: missing name %s\n", name);
    866 		return (FAIL);
    867 	}
    868 	np = lookupino(ino);
    869 	if (np != ep)
    870 		descend = FAIL;
    871 	for ( ; np != NULL; np = np->e_links)
    872 		if (np == ep)
    873 			break;
    874 	if (np == NULL)
    875 		panic("missing inumber %d\n", ino);
    876 	if (ep->e_type == LEAF && type != LEAF)
    877 		badentry(ep, "type should be LEAF");
    878 	return (descend);
    879 }
    880