traverse.c

早期freebsd实现

/*-
 * Copyright (c) 1980, 1988, 1991, 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[] = "@(#)traverse.c	8.2 (Berkeley) 9/23/93";
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#ifdef sunos
#include <sys/vnode.h>

#include <ufs/fs.h>
#include <ufs/fsdir.h>
#include <ufs/inode.h>
#else
#include <ufs/ffs/fs.h>
#include <ufs/ufs/dir.h>
#include <ufs/ufs/dinode.h>
#endif

#include <protocols/dumprestore.h>

#include <ctype.h>
#include <stdio.h>
#ifdef __STDC__
#include <string.h>
#include <unistd.h>
#endif

#include "dump.h"

#define	HASDUMPEDFILE	0x1
#define	HASSUBDIRS	0x2

#ifdef	FS_44INODEFMT
typedef	quad_t fsizeT;
#else
typedef	long fsizeT;
#endif

static	int dirindir __P((ino_t ino, daddr_t blkno, int level, long *size));
static	void dmpindir __P((ino_t ino, daddr_t blk, int level, fsizeT *size));
static	int searchdir __P((ino_t ino, daddr_t blkno, long size, long filesize));

/*
 * This is an estimation of the number of TP_BSIZE blocks in the file.
 * It estimates the number of blocks in files with holes by assuming
 * that all of the blocks accounted for by di_blocks are data blocks
 * (when some of the blocks are usually used for indirect pointers);
 * hence the estimate may be high.
 */
long
blockest(dp)
	register struct dinode *dp;
{
	long blkest, sizeest;

	/*
	 * dp->di_size is the size of the file in bytes.
	 * dp->di_blocks stores the number of sectors actually in the file.
	 * If there are more sectors than the size would indicate, this just
	 *	means that there are indirect blocks in the file or unused
	 *	sectors in the last file block; we can safely ignore these
	 *	(blkest = sizeest below).
	 * If the file is bigger than the number of sectors would indicate,
	 *	then the file has holes in it.	In this case we must use the
	 *	block count to estimate the number of data blocks used, but
	 *	we use the actual size for estimating the number of indirect
	 *	dump blocks (sizeest vs. blkest in the indirect block
	 *	calculation).
	 */
	blkest = howmany(dbtob(dp->di_blocks), TP_BSIZE);
	sizeest = howmany(dp->di_size, TP_BSIZE);
	if (blkest > sizeest)
		blkest = sizeest;
	if (dp->di_size > sblock->fs_bsize * NDADDR) {
		/* calculate the number of indirect blocks on the dump tape */
		blkest +=
			howmany(sizeest - NDADDR * sblock->fs_bsize / TP_BSIZE,
			TP_NINDIR);
	}
	return (blkest + 1);
}

/* Auxiliary macro to pick up files changed since previous dump. */
#ifdef FS_44INODEFMT
#define	CHANGEDSINCE(dp, t) \
	((dp)->di_mtime.ts_sec >= (t) || (dp)->di_ctime.ts_sec >= (t))
#else
#define	CHANGEDSINCE(dp, t) \
	((dp)->di_mtime >= (t) || (dp)->di_ctime >= (t))
#endif

/* The WANTTODUMP macro decides whether a file should be dumped. */
#ifdef UF_NODUMP
#define	WANTTODUMP(dp) \
	(CHANGEDSINCE(dp, spcl.c_ddate) && \
	 (nonodump || ((dp)->di_flags & UF_NODUMP) != UF_NODUMP))
#else
#define	WANTTODUMP(dp) CHANGEDSINCE(dp, spcl.c_ddate)
#endif

/*
 * Dump pass 1.
 *
 * Walk the inode list for a filesystem to find all allocated inodes
 * that have been modified since the previous dump time. Also, find all
 * the directories in the filesystem.
 */
int
mapfiles(maxino, tapesize)
	ino_t maxino;
	long *tapesize;
{
	register int mode;
	register ino_t ino;
	register struct dinode *dp;
	int anydirskipped = 0;

	for (ino = ROOTINO; ino < maxino; ino++) {
		dp = getino(ino);
		if ((mode = (dp->di_mode & IFMT)) == 0)
			continue;
		SETINO(ino, usedinomap);
		if (mode == IFDIR)
			SETINO(ino, dumpdirmap);
		if (WANTTODUMP(dp)) {
			SETINO(ino, dumpinomap);
			if (mode != IFREG && mode != IFDIR && mode != IFLNK)
				*tapesize += 1;
			else
				*tapesize += blockest(dp);
			continue;
		}
		if (mode == IFDIR)
			anydirskipped = 1;
	}
	/*
	 * Restore gets very upset if the root is not dumped,
	 * so ensure that it always is dumped.
	 */
	SETINO(ROOTINO, dumpinomap);
	return (anydirskipped);
}

/*
 * Dump pass 2.
 *
 * Scan each directory on the filesystem to see if it has any modified
 * files in it. If it does, and has not already been added to the dump
 * list (because it was itself modified), then add it. If a directory
 * has not been modified itself, contains no modified files and has no
 * subdirectories, then it can be deleted from the dump list and from
 * the list of directories. By deleting it from the list of directories,
 * its parent may now qualify for the same treatment on this or a later
 * pass using this algorithm.
 */
int
mapdirs(maxino, tapesize)
	ino_t maxino;
	long *tapesize;
{
	register struct	dinode *dp;
	register int i, isdir;
	register char *map;
	register ino_t ino;
	long filesize;
	int ret, change = 0;

	isdir = 0;		/* XXX just to get gcc to shut up */
	for (map = dumpdirmap, ino = 1; ino < maxino; ino++) {
		if (((ino - 1) % NBBY) == 0)	/* map is offset by 1 */
			isdir = *map++;
		else
			isdir >>= 1;
		if ((isdir & 1) == 0 || TSTINO(ino, dumpinomap))
			continue;
		dp = getino(ino);
		filesize = dp->di_size;
		for (ret = 0, i = 0; filesize > 0 && i < NDADDR; i++) {
			if (dp->di_db[i] != 0)
				ret |= searchdir(ino, dp->di_db[i],
					(long)dblksize(sblock, dp, i),
					filesize);
			if (ret & HASDUMPEDFILE)
				filesize = 0;
			else
				filesize -= sblock->fs_bsize;
		}
		for (i = 0; filesize > 0 && i < NIADDR; i++) {
			if (dp->di_ib[i] == 0)
				continue;
			ret |= dirindir(ino, dp->di_ib[i], i, &filesize);
		}
		if (ret & HASDUMPEDFILE) {
			SETINO(ino, dumpinomap);
			*tapesize += blockest(dp);
			change = 1;
			continue;
		}
		if ((ret & HASSUBDIRS) == 0) {
			if (!TSTINO(ino, dumpinomap)) {
				CLRINO(ino, dumpdirmap);
				change = 1;
			}
		}
	}
	return (change);
}

/*
 * Read indirect blocks, and pass the data blocks to be searched
 * as directories. Quit as soon as any entry is found that will
 * require the directory to be dumped.
 */
static int
dirindir(ino, blkno, ind_level, filesize)
	ino_t ino;
	daddr_t blkno;
	int ind_level;
	long *filesize;
{
	int ret = 0;
	register int i;
	daddr_t	idblk[MAXNINDIR];

	bread(fsbtodb(sblock, blkno), (char *)idblk, (int)sblock->fs_bsize);
	if (ind_level <= 0) {
		for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
			blkno = idblk[i];
			if (blkno != 0)
				ret |= searchdir(ino, blkno, sblock->fs_bsize,
					*filesize);
			if (ret & HASDUMPEDFILE)
				*filesize = 0;
			else
				*filesize -= sblock->fs_bsize;
		}
		return (ret);
	}
	ind_level--;
	for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
		blkno = idblk[i];
		if (blkno != 0)
			ret |= dirindir(ino, blkno, ind_level, filesize);
	}
	return (ret);
}

/*
 * Scan a disk block containing directory information looking to see if
 * any of the entries are on the dump list and to see if the directory
 * contains any subdirectories.
 */
static int
searchdir(ino, blkno, size, filesize)
	ino_t ino;
	daddr_t blkno;
	register long size;
	long filesize;
{
	register struct direct *dp;
	register long loc, ret = 0;
	char dblk[MAXBSIZE];

	bread(fsbtodb(sblock, blkno), dblk, (int)size);
	if (filesize < size)
		size = filesize;
	for (loc = 0; loc < size; ) {
		dp = (struct direct *)(dblk + loc);
		if (dp->d_reclen == 0) {
			msg("corrupted directory, inumber %d\n", ino);
			break;
		}
		loc += dp->d_reclen;