sbin/dump/dumptraverse.c

/*-
 * Copyright (c) 1980, 1988, 1991 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[] = "@(#)dumptraverse.c      5.11 (Berkeley) 3/7/91";
static char rcsid[] = "$Header: /b/source/CVS/src/sbin/dump/dumptraverse.c,v 1.5 1993/06/13 21:08:27 mycroft Exp $";
#endif /* not lint */

#include <sys/param.h>
#include <ufs/dir.h>
#include <ufs/dinode.h>
#include <ufs/fs.h>
#include <protocols/dumprestore.h>
#ifdef __STDC__
#include <unistd.h>
#include <string.h>
#endif
#include "dump.h"

void    dmpindir();
#define HASDUMPEDFILE   0x1
#define HASSUBDIRS      0x2

/*
 * 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);
}

/*
 * 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.
 */
mapfiles(maxino, tapesize)
        ino_t maxino;
        long *tapesize;
{
        register int mode;
        register ino_t ino;
        register struct dinode *dp;
        int anydirskipped = 0;

        for (ino = 0; ino <= maxino; ino++) {
                dp = getino(ino);
                if ((mode = (dp->di_mode & IFMT)) == 0)
                        continue;
                SETINO(ino, usedinomap);
                if (mode == IFDIR)
                        SETINO(ino, dumpdirmap);
                if (dp->di_mtime >= spcl.c_ddate ||
                    dp->di_ctime >= spcl.c_ddate) {
                        SETINO(ino, dumpinomap);
                        if (mode != IFREG && mode != IFDIR && mode != IFLNK) {
                                *tapesize += 1;
                                continue;
                        }
                        *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, usedinomap);
        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.
 */
mapdirs(maxino, tapesize)
        ino_t maxino;
        long *tapesize;
{
        register struct dinode *dp;
        register int i, dirty;
        register char *map;
        register ino_t ino;
        long filesize, blkcnt = 0;
        int ret, change = 0;

        for (map = dumpdirmap, ino = 0; ino < maxino; ) {
                if ((ino % NBBY) == 0)
                        dirty = *map++;
                else
                        dirty >>= 1;
                ino++;
                if ((dirty & 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],
                                        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) {
                        if (!TSTINO(ino, dumpinomap)) {
                                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.
 */
dirindir(ino, blkno, level, filesize)
        ino_t ino;
        daddr_t blkno;
        int level, *filesize;
{
        int ret = 0;
        register int i;
        daddr_t idblk[MAXNINDIR];

        bread(fsbtodb(sblock, blkno), (char *)idblk, sblock->fs_bsize);
        if (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);
        }
        level--;
        for (i = 0; *filesize > 0 && i < NINDIR(sblock); i++) {
                blkno = idblk[i];
                if (blkno != 0)
                        ret |= dirindir(ino, blkno, 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.
 */
searchdir(ino, blkno, size, filesize)
        ino_t ino;
        daddr_t blkno;
        register int size;
        int filesize;
{
        register struct direct *dp;
        register long loc;
        char dblk[MAXBSIZE];

        bread(fsbtodb(sblock, blkno), dblk, 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;
                if (dp->d_ino == 0)
                        continue;
                if (dp->d_name[0] == '.') {
                        if (dp->d_name[1] == '\0')
                                continue;
                        if (dp->d_name[1] == '.' && dp->d_name[2] == '\0')
                                continue;
                }
                if (TSTINO(dp->d_ino, dumpinomap))
                        return (HASDUMPEDFILE);
                if (TSTINO(dp->d_ino, dumpdirmap))
                        return (HASSUBDIRS);
        }
        return (0);
}

/*
 * Dump passes 3 and 4.
 *
 * Dump the contents of an inode to tape.
 */
void
dumpino(dp, ino)
        register struct dinode *dp;
        ino_t ino;
{
        int mode, level, cnt;
        long size;

        if (newtape) {
                newtape = 0;
                dumpmap(dumpinomap, TS_BITS, ino);
        }
        CLRINO(ino, dumpinomap);
        spcl.c_dinode = *dp;
        spcl.c_type = TS_INODE;
        spcl.c_count = 0;
        /*
         * Check for freed inode.
         */
        if ((mode = (dp->di_mode & IFMT)) == 0)
                return;
        if ((mode != IFDIR && mode != IFREG && mode != IFLNK) ||
            dp->di_size == 0) {
                writeheader(ino);
                return;
        }
        if (DFASTLINK(*dp)) {
                spcl.c_addr[0] = 1;
                spcl.c_count = 1;
                writeheader(ino);
                writerec(dp->di_symlink);
                return;
        }
        if (dp->di_size > NDADDR * sblock->fs_bsize)
                cnt = NDADDR * sblock->fs_frag;
        else
                cnt = howmany(dp->di_size, sblock->fs_fsize);
        blksout(&dp->di_db[0], cnt, ino);
        if ((size = dp->di_size - NDADDR * sblock->fs_bsize) <= 0)
                return;
        for (level = 0; level < NIADDR; level++) {
                dmpindir(ino, dp->di_ib[level], level, &size);
                if (size <= 0)
                        return;
        }
}

/*
 * Read indirect blocks, and pass the data blocks to be dumped.
 */
void
dmpindir(ino, blk, level, size)
        ino_t ino;
        daddr_t blk;
        int level;
        long *size;
{
        int i, cnt;
        daddr_t idblk[MAXNINDIR];

        if (blk != 0)
                bread(fsbtodb(sblock, blk), (char *)idblk, sblock->fs_bsize);
        else
                bzero((char *)idblk, sblock->fs_bsize);
        if (level <= 0) {
                if (*size < NINDIR(sblock) * sblock->fs_bsize)
                        cnt = howmany(*size, sblock->fs_fsize);
                else
                        cnt = NINDIR(sblock) * sblock->fs_frag;
                *size -= NINDIR(sblock) * sblock->fs_bsize;
                blksout(&idblk[0], cnt, ino);
                return;
        }
        level--;
        for (i = 0; i < NINDIR(sblock); i++) {
                dmpindir(ino, idblk[i], level, size);
                if (*size <= 0)
                        return;
        }
}

/*
 * Collect up the data into tape record sized buffers and output them.
 */
void
blksout(blkp, frags, ino)
        daddr_t *blkp;
        int frags;
        ino_t ino;
{
        register daddr_t *bp;
        int i, j, count, blks, tbperdb;

        blks = howmany(frags * sblock->fs_fsize, TP_BSIZE);
        tbperdb = sblock->fs_bsize >> tp_bshift;
        for (i = 0; i < blks; i += TP_NINDIR) {
                if (i + TP_NINDIR > blks)
                        count = blks;
                else
                        count = i + TP_NINDIR;
                for (j = i; j < count; j++)
                        if (blkp[j / tbperdb] != 0)
                                spcl.c_addr[j - i] = 1;
                        else
                                spcl.c_addr[j - i] = 0;
                spcl.c_count = count - i;
                writeheader(ino);
                bp = &blkp[i / tbperdb];
                for (j = i; j < count; j += tbperdb, bp++)
                        if (*bp != 0)
                                if (j + tbperdb <= count)
                                        dumpblock(*bp, sblock->fs_bsize);
                                else
                                        dumpblock(*bp, (count - j) * TP_BSIZE);
                spcl.c_type = TS_ADDR;
        }
}

/*
 * Dump a map to the tape.
 */
void
dumpmap(map, type, ino)
        char *map;
        int type;
        ino_t ino;
{
        register int i;
        char *cp;

        spcl.c_type = type;
        spcl.c_count = howmany(mapsize * sizeof(char), TP_BSIZE);
        writeheader(ino);
        for (i = 0, cp = map; i < spcl.c_count; i++, cp += TP_BSIZE)
                writerec(cp);
}

/*
 * Write a header record to the dump tape.
 */
void
writeheader(ino)
        ino_t ino;
{
        register long sum, cnt, *lp;

        spcl.c_inumber = ino;
        spcl.c_magic = NFS_MAGIC;
        spcl.c_checksum = 0;
        lp = (long *)&spcl;
        sum = 0;
        cnt = sizeof(union u_spcl) / (4 * sizeof(long));
        while (--cnt >= 0) {
                sum += *lp++;
                sum += *lp++;
                sum += *lp++;
                sum += *lp++;
        }
        spcl.c_checksum = CHECKSUM - sum;
        writerec((char *)&spcl);
}

struct dinode *
getino(inum)
        ino_t inum;
{
        static daddr_t minino, maxino;
        static struct dinode inoblock[MAXINOPB];

        curino = inum;
        if (inum >= minino && inum < maxino)
                return (&inoblock[inum - minino]);
        bread(fsbtodb(sblock, itod(sblock, inum)), inoblock, sblock->fs_bsize);
        minino = inum - (inum % INOPB(sblock));
        maxino = minino + INOPB(sblock);
        return (&inoblock[inum - minino]);
}

/*
 * Read a chunk of data from the disk.
 * Try to recover from hard errors by reading in sector sized pieces.
 * Error recovery is attempted at most BREADEMAX times before seeking
 * consent from the operator to continue.
 */
int     breaderrors = 0;
#define BREADEMAX 32

void
bread(blkno, buf, size)
        daddr_t blkno;
        char *buf;
        int size;
{
        int cnt, i;
        extern int errno;

loop:
        if (lseek(diskfd, (long)(blkno << dev_bshift), 0) < 0)
                msg("bread: lseek fails\n");
        if ((cnt = read(diskfd, buf, size)) == size)
                return;
        if (blkno + (size / dev_bsize) > fsbtodb(sblock, sblock->fs_size)) {
                /*
                 * Trying to read the final fragment.
                 *
                 * NB - dump only works in TP_BSIZE blocks, hence
                 * rounds `dev_bsize' fragments up to TP_BSIZE pieces.
                 * It should be smarter about not actually trying to
                 * read more than it can get, but for the time being
                 * we punt and scale back the read only when it gets
                 * us into trouble. (mkm 9/25/83)
                 */
                size -= dev_bsize;
                goto loop;
        }
        msg("read error from %s [block %d]: count=%d, got=%d, errno=%d (%s)\n",
                disk, blkno, size, cnt, errno, strerror(errno));
        if (++breaderrors > BREADEMAX) {
                msg("More than %d block read errors from %d\n",
                        BREADEMAX, disk);
                broadcast("DUMP IS AILING!\n");
                msg("This is an unrecoverable error.\n");
                if (!query("Do you want to attempt to continue?")){
                        dumpabort();
                        /*NOTREACHED*/
                } else
                        breaderrors = 0;
        }
        /*
         * Zero buffer, then try to read each sector of buffer separately.
         */
        bzero(buf, size);
        for (i = 0; i < size; i += dev_bsize, buf += dev_bsize, blkno++) {
                if (lseek(diskfd, (long)(blkno << dev_bshift), 0) < 0)
                        msg("bread: lseek2 fails!\n");
                if ((cnt = read(diskfd, buf, dev_bsize)) != dev_bsize)
                        msg("    read error from %s [sector %d, errno %d]\n",
                            disk, blkno, errno);
        }
}