restore.c

早期freebsd实现

/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char sccsid[] = "@(#)restore.c	8.1 (Berkeley) 6/5/93";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>

#include <ufs/ufs/dinode.h>

#include <stdio.h>
#include <string.h>

#include "restore.h"
#include "extern.h"

static char *keyval __P((int));

/*
 * This implements the 't' option.
 * List entries on the tape.
 */
long
listfile(name, ino, type)
	char *name;
	ino_t ino;
	int type;
{
	long descend = hflag ? GOOD : FAIL;

	if (TSTINO(ino, dumpmap) == 0)
		return (descend);
	vprintf(stdout, "%s", type == LEAF ? "leaf" : "dir ");
	fprintf(stdout, "%10d\t%s\n", ino, name);
	return (descend);
}

/*
 * This implements the 'x' option.
 * Request that new entries be extracted.
 */
long
addfile(name, ino, type)
	char *name;
	ino_t ino;
	int type;
{
	register struct entry *ep;
	long descend = hflag ? GOOD : FAIL;
	char buf[100];

	if (TSTINO(ino, dumpmap) == 0) {
		dprintf(stdout, "%s: not on the tape\n", name);
		return (descend);
	}
	if (!mflag) {
		(void) sprintf(buf, "./%u", ino);
		name = buf;
		if (type == NODE) {
			(void) genliteraldir(name, ino);
			return (descend);
		}
	}
	ep = lookupino(ino);
	if (ep != NULL) {
		if (strcmp(name, myname(ep)) == 0) {
			ep->e_flags |= NEW;
			return (descend);
		}
		type |= LINK;
	}
	ep = addentry(name, ino, type);
	if (type == NODE)
		newnode(ep);
	ep->e_flags |= NEW;
	return (descend);
}

/*
 * This is used by the 'i' option to undo previous requests made by addfile.
 * Delete entries from the request queue.
 */
/* ARGSUSED */
long
deletefile(name, ino, type)
	char *name;
	ino_t ino;
	int type;
{
	long descend = hflag ? GOOD : FAIL;
	struct entry *ep;

	if (TSTINO(ino, dumpmap) == 0)
		return (descend);
	ep = lookupino(ino);
	if (ep != NULL)
		ep->e_flags &= ~NEW;
	return (descend);
}

/* 
 * The following four routines implement the incremental
 * restore algorithm. The first removes old entries, the second
 * does renames and calculates the extraction list, the third
 * cleans up link names missed by the first two, and the final
 * one deletes old directories.
 *
 * Directories cannot be immediately deleted, as they may have
 * other files in them which need to be moved out first. As
 * directories to be deleted are found, they are put on the 
 * following deletion list. After all deletions and renames
 * are done, this list is actually deleted.
 */
static struct entry *removelist;

/*
 *	Remove unneeded leaves from the old tree.
 *	Remove directories from the lookup chains.
 */
void
removeoldleaves()
{
	register struct entry *ep;
	register ino_t i;

	vprintf(stdout, "Mark entries to be removed.\n");
	for (i = ROOTINO + 1; i < maxino; i++) {
		ep = lookupino(i);
		if (ep == NULL)
			continue;
		if (TSTINO(i, clrimap))
			continue;
		for ( ; ep != NULL; ep = ep->e_links) {
			dprintf(stdout, "%s: REMOVE\n", myname(ep));
			if (ep->e_type == LEAF) {
				removeleaf(ep);
				freeentry(ep);
			} else {
				mktempname(ep);
				deleteino(ep->e_ino);
				ep->e_next = removelist;
				removelist = ep;
			}
		}
	}
}

/*
 *	For each directory entry on the incremental tape, determine which
 *	category it falls into as follows:
 *	KEEP - entries that are to be left alone.
 *	NEW - new entries to be added.
 *	EXTRACT - files that must be updated with new contents.
 *	LINK - new links to be added.
 *	Renames are done at the same time.
 */
long
nodeupdates(name, ino, type)
	char *name;
	ino_t ino;
	int type;
{
	register struct entry *ep, *np, *ip;
	long descend = GOOD;
	int lookuptype = 0;
	int key = 0;
		/* key values */
#		define ONTAPE	0x1	/* inode is on the tape */
#		define INOFND	0x2	/* inode already exists */
#		define NAMEFND	0x4	/* name already exists */
#		define MODECHG	0x8	/* mode of inode changed */

	/*
	 * This routine is called once for each element in the 
	 * directory hierarchy, with a full path name.
	 * The "type" value is incorrectly specified as LEAF for
	 * directories that are not on the dump tape.
	 *
	 * Check to see if the file is on the tape.
	 */
	if (TSTINO(ino, dumpmap))
		key |= ONTAPE;
	/*
	 * Check to see if the name exists, and if the name is a link.
	 */
	np = lookupname(name);
	if (np != NULL) {
		key |= NAMEFND;
		ip = lookupino(np->e_ino);
		if (ip == NULL)
			panic("corrupted symbol table\n");
		if (ip != np)
			lookuptype = LINK;
	}
	/*
	 * Check to see if the inode exists, and if one of its links
	 * corresponds to the name (if one was found).
	 */
	ip = lookupino(ino);
	if (ip != NULL) {
		key |= INOFND;
		for (ep = ip->e_links; ep != NULL; ep = ep->e_links) {
			if (ep == np) {
				ip = ep;
				break;
			}
		}
	}
	/*
	 * If both a name and an inode are found, but they do not
	 * correspond to the same file, then both the inode that has
	 * been found and the inode corresponding to the name that
	 * has been found need to be renamed. The current pathname
	 * is the new name for the inode that has been found. Since
	 * all files to be deleted have already been removed, the
	 * named file is either a now unneeded link, or it must live
	 * under a new name in this dump level. If it is a link, it
	 * can be removed. If it is not a link, it is given a
	 * temporary name in anticipation that it will be renamed
	 * when it is later found by inode number.
	 */
	if (((key & (INOFND|NAMEFND)) == (INOFND|NAMEFND)) && ip != np) {
		if (lookuptype == LINK) {
			removeleaf(np);
			freeentry(np);
		} else {
			dprintf(stdout, "name/inode conflict, mktempname %s\n",
				myname(np));
			mktempname(np);
		}
		np = NULL;
		key &= ~NAMEFND;
	}
	if ((key & ONTAPE) &&
	  (((key & INOFND) && ip->e_type != type) ||
	   ((key & NAMEFND) && np->e_type != type)))
		key |= MODECHG;

	/*
	 * Decide on the disposition of the file based on its flags.
	 * Note that we have already handled the case in which
	 * a name and inode are found that correspond to different files.
	 * Thus if both NAMEFND and INOFND are set then ip == np.
	 */
	switch (key) {

	/*
	 * A previously existing file has been found.
	 * Mark it as KEEP so that other links to the inode can be
	 * detected, and so that it will not be reclaimed by the search
	 * for unreferenced names.
	 */
	case INOFND|NAMEFND:
		ip->e_flags |= KEEP;
		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
			flagvalues(ip));
		break;

	/*
	 * A file on the tape has a name which is the same as a name
	 * corresponding to a different file in the previous dump.
	 * Since all files to be deleted have already been removed,
	 * this file is either a now unneeded link, or it must live
	 * under a new name in this dump level. If it is a link, it
	 * can simply be removed. If it is not a link, it is given a
	 * temporary name in anticipation that it will be renamed
	 * when it is later found by inode number (see INOFND case
	 * below). The entry is then treated as a new file.
	 */
	case ONTAPE|NAMEFND:
	case ONTAPE|NAMEFND|MODECHG:
		if (lookuptype == LINK) {
			removeleaf(np);
			freeentry(np);
		} else {
			mktempname(np);
		}
		/* fall through */

	/*
	 * A previously non-existent file.
	 * Add it to the file system, and request its extraction.
	 * If it is a directory, create it immediately.
	 * (Since the name is unused there can be no conflict)
	 */
	case ONTAPE:
		ep = addentry(name, ino, type);
		if (type == NODE)
			newnode(ep);
		ep->e_flags |= NEW|KEEP;
		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
			flagvalues(ep));
		break;

	/*
	 * A file with the same inode number, but a different
	 * name has been found. If the other name has not already
	 * been found (indicated by the KEEP flag, see above) then
	 * this must be a new name for the file, and it is renamed.
	 * If the other name has been found then this must be a
	 * link to the file. Hard links to directories are not
	 * permitted, and are either deleted or converted to
	 * symbolic links. Finally, if the file is on the tape,
	 * a request is made to extract it.
	 */
	case ONTAPE|INOFND:
		if (type == LEAF && (ip->e_flags & KEEP) == 0)
			ip->e_flags |= EXTRACT;
		/* fall through */
	case INOFND:
		if ((ip->e_flags & KEEP) == 0) {
			renameit(myname(ip), name);
			moveentry(ip, name);
			ip->e_flags |= KEEP;
			dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
				flagvalues(ip));
			break;
		}
		if (ip->e_type == NODE) {
			descend = FAIL;
			fprintf(stderr,
				"deleted hard link %s to directory %s\n",
				name, myname(ip));
			break;
		}
		ep = addentry(name, ino, type|LINK);
		ep->e_flags |= NEW;
		dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
			flagvalues(ep));
		break;

	/*
	 * A previously known file which is to be updated. If it is a link,
	 * then all names referring to the previous file must be removed
	 * so that the subset of them that remain can be recreated.
	 */
	case ONTAPE|INOFND|NAMEFND:
		if (lookuptype == LINK) {
			removeleaf(np);
			freeentry(np);
			ep = addentry(name, ino, type|LINK);
			if (type == NODE)
			        newnode(ep);
			ep->e_flags |= NEW|KEEP;
			dprintf(stdout, "[%s] %s: %s|LINK\n", keyval(key), name,
				flagvalues(ep));
			break;
		}
		if (type == LEAF && lookuptype != LINK)
			np->e_flags |= EXTRACT;
		np->e_flags |= KEEP;
		dprintf(stdout, "[%s] %s: %s\n", keyval(key), name,
			flagvalues(np));
		break;

	/*
	 * An inode is being reused in a completely different way.
	 * Normally an extract can simply do an "unlink" followed
	 * by a "creat". Here we must do effectively the same
	 * thing. The complications arise because we cannot really
	 * delete a directory since it may still contain files
	 * that we need to rename, so we delete it from the symbol
	 * table, and put it on the list to be deleted eventually.
	 * Conversely if a directory is to be created, it must be
	 * done immediately, rather than waiting until the 
	 * extraction phase.
	 */
	case ONTAPE|INOFND|MODECHG:
	case ONTAPE|INOFND|NAMEFND|MODECHG:
		if (ip->e_flags & KEEP) {
			badentry(ip, "cannot KEEP and change modes");
			break;
		}
		if (ip->e_type == LEAF) {
			/* changing from leaf to node */
			removeleaf(ip);
			freeentry(ip);
			ip = addentry(name, ino, type);