usr.sbin/makefs/ffs/mkfs.c

root/usr.sbin/makefs/ffs/mkfs.c
/*      $NetBSD: mkfs.c,v 1.22 2011/10/09 22:30:13 christos Exp $       */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2002 Networks Associates Technology, Inc.
 * All rights reserved.
 *
 * This software was developed for the FreeBSD Project by Marshall
 * Kirk McKusick and Network Associates Laboratories, the Security
 * Research Division of Network Associates, Inc. under DARPA/SPAWAR
 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
 * research program
 *
 * Copyright (c) 1980, 1989, 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. 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.
 */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/resource.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <util.h>

#include "makefs.h"
#include "ffs.h"

#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>

#include "ffs/ufs_bswap.h"
#include "ffs/ufs_inode.h"
#include "ffs/ffs_extern.h"
#include "ffs/newfs_extern.h"

#ifndef BBSIZE
#define BBSIZE  8192                    /* size of boot area, with label */
#endif

static void initcg(uint32_t, time_t, const fsinfo_t *);
static int ilog2(int);

static int count_digits(int);

/*
 * make file system for cylinder-group style file systems
 */
#define UMASK           0755
#define POWEROF2(num)   (((num) & ((num) - 1)) == 0)

/*
 * The definition of "struct cg" used to contain an extra field at the end
 * to represent the variable-length data that followed the fixed structure.
 * This had the effect of artificially limiting the number of blocks that
 * newfs would put in a CG, since newfs thought that the fixed-size header
 * was bigger than it really was.  When we started validating that the CG
 * header data actually fit into one fs block, the placeholder field caused
 * a problem because it caused struct cg to be a different size depending on
 * platform.  The placeholder field was later removed, but this caused a
 * backward compatibility problem with older binaries that still thought
 * struct cg was larger, and a new file system could fail validation if
 * viewed by the older binaries.  To avoid this compatibility problem, we
 * now artificially reduce the amount of space that the variable-length data
 * can use such that new file systems will pass validation by older binaries.
 */
#define CGSIZEFUDGE 8

static union {
        struct fs fs;
        char pad[SBLOCKSIZE];
} fsun;
#define sblock  fsun.fs

static union {
        struct cg cg;
        char pad[FFS_MAXBSIZE];
} cgun;
#define acg     cgun.cg

static char *iobuf;
static int iobufsize;

static char writebuf[FFS_MAXBSIZE];

static int     Oflag;      /* format as an 4.3BSD file system */
static int64_t fssize;     /* file system size */
static int     sectorsize;         /* bytes/sector */
static int     fsize;      /* fragment size */
static int     bsize;      /* block size */
static int     maxbsize;   /* maximum clustering */
static int     maxblkspercg;
static int     minfree;    /* free space threshold */
static int     opt;                /* optimization preference (space or time) */
static int     density;    /* number of bytes per inode */
static int     maxcontig;          /* max contiguous blocks to allocate */
static int     maxbpg;     /* maximum blocks per file in a cyl group */
static int     bbsize;     /* boot block size */
static int     sbsize;     /* superblock size */
static int     avgfilesize;        /* expected average file size */
static int     avgfpdir;           /* expected number of files per directory */

struct fs *
ffs_mkfs(const char *fsys, const fsinfo_t *fsopts, time_t tstamp)
{
        int fragsperinode, optimalfpg, origdensity, mindensity;
        int minfpg, lastminfpg;
        int32_t csfrags;
        uint32_t i, cylno;
        long long sizepb;
        ino_t maxinum;
        int minfragsperinode;   /* minimum ratio of frags to inodes */
        void *space;
        int size;
        int nprintcols, printcolwidth;
        ffs_opt_t       *ffs_opts = fsopts->fs_specific;

        Oflag =         ffs_opts->version;
        fssize =        fsopts->size / fsopts->sectorsize;
        sectorsize =    fsopts->sectorsize;
        fsize =         ffs_opts->fsize;
        bsize =         ffs_opts->bsize;
        maxbsize =      ffs_opts->maxbsize;
        maxblkspercg =  ffs_opts->maxblkspercg;
        minfree =       ffs_opts->minfree;
        opt =           ffs_opts->optimization;
        density =       ffs_opts->density;
        maxcontig =     ffs_opts->maxcontig;
        maxbpg =        ffs_opts->maxbpg;
        avgfilesize =   ffs_opts->avgfilesize;
        avgfpdir =      ffs_opts->avgfpdir;
        bbsize =        BBSIZE;
        sbsize =        SBLOCKSIZE;

        strlcpy((char *)sblock.fs_volname, ffs_opts->label,
            sizeof(sblock.fs_volname));

        if (Oflag == 0) {
                sblock.fs_old_inodefmt = FS_42INODEFMT;
                sblock.fs_maxsymlinklen = 0;
                sblock.fs_old_flags = 0;
        } else {
                sblock.fs_old_inodefmt = FS_44INODEFMT;
                sblock.fs_maxsymlinklen = (Oflag == 1 ? UFS1_MAXSYMLINKLEN :
                    UFS2_MAXSYMLINKLEN);
                sblock.fs_old_flags = FS_FLAGS_UPDATED;
                sblock.fs_flags = 0;
        }
        /*
         * Validate the given file system size.
         * Verify that its last block can actually be accessed.
         * Convert to file system fragment sized units.
         */
        if (fssize <= 0) {
                printf("preposterous size %lld\n", (long long)fssize);
                exit(13);
        }
        ffs_wtfs(fssize - 1, sectorsize, (char *)&sblock, fsopts);

        /*
         * collect and verify the filesystem density info
         */
        sblock.fs_avgfilesize = avgfilesize;
        sblock.fs_avgfpdir = avgfpdir;
        if (sblock.fs_avgfilesize <= 0)
                printf("illegal expected average file size %d\n",
                    sblock.fs_avgfilesize), exit(14);
        if (sblock.fs_avgfpdir <= 0)
                printf("illegal expected number of files per directory %d\n",
                    sblock.fs_avgfpdir), exit(15);
        /*
         * collect and verify the block and fragment sizes
         */
        sblock.fs_bsize = bsize;
        sblock.fs_fsize = fsize;
        if (!POWEROF2(sblock.fs_bsize)) {
                printf("block size must be a power of 2, not %d\n",
                    sblock.fs_bsize);
                exit(16);
        }
        if (!POWEROF2(sblock.fs_fsize)) {
                printf("fragment size must be a power of 2, not %d\n",
                    sblock.fs_fsize);
                exit(17);
        }
        if (sblock.fs_fsize < sectorsize) {
                printf("fragment size %d is too small, minimum is %d\n",
                    sblock.fs_fsize, sectorsize);
                exit(18);
        }
        if (sblock.fs_bsize < MINBSIZE) {
                printf("block size %d is too small, minimum is %d\n",
                    sblock.fs_bsize, MINBSIZE);
                exit(19);
        }
        if (sblock.fs_bsize > FFS_MAXBSIZE) {
                printf("block size %d is too large, maximum is %d\n",
                    sblock.fs_bsize, FFS_MAXBSIZE);
                exit(19);
        }
        if (sblock.fs_bsize < sblock.fs_fsize) {
                printf("block size (%d) cannot be smaller than fragment size (%d)\n",
                    sblock.fs_bsize, sblock.fs_fsize);
                exit(20);
        }

        if (maxbsize < bsize || !POWEROF2(maxbsize)) {
                sblock.fs_maxbsize = sblock.fs_bsize;
                printf("Extent size set to %d\n", sblock.fs_maxbsize);
        } else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
                sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
                printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
        } else {
                sblock.fs_maxbsize = maxbsize;
        }
        sblock.fs_maxcontig = maxcontig;
        if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
                sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
                printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
        }

        if (sblock.fs_maxcontig > 1)
                sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);

        sblock.fs_bmask = ~(sblock.fs_bsize - 1);
        sblock.fs_fmask = ~(sblock.fs_fsize - 1);
        sblock.fs_qbmask = ~sblock.fs_bmask;
        sblock.fs_qfmask = ~sblock.fs_fmask;
        for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
                sblock.fs_bshift++;
        for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
                sblock.fs_fshift++;
        sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
        for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
                sblock.fs_fragshift++;
        if (sblock.fs_frag > MAXFRAG) {
                printf("fragment size %d is too small, "
                        "minimum with block size %d is %d\n",
                    sblock.fs_fsize, sblock.fs_bsize,
                    sblock.fs_bsize / MAXFRAG);
                exit(21);
        }
        sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
        sblock.fs_size = sblock.fs_providersize = fssize =
            dbtofsb(&sblock, fssize);

        if (Oflag <= 1) {
                sblock.fs_magic = FS_UFS1_MAGIC;
                sblock.fs_sblockloc = SBLOCK_UFS1;
                sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
                sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
                sblock.fs_maxsymlinklen = ((UFS_NDADDR + UFS_NIADDR) *
                    sizeof (ufs1_daddr_t));
                sblock.fs_old_inodefmt = FS_44INODEFMT;
                sblock.fs_old_cgoffset = 0;
                sblock.fs_old_cgmask = 0xffffffff;
                sblock.fs_old_size = sblock.fs_size;
                sblock.fs_old_rotdelay = 0;
                sblock.fs_old_rps = 60;
                sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
                sblock.fs_old_cpg = 1;
                sblock.fs_old_interleave = 1;
                sblock.fs_old_trackskew = 0;
                sblock.fs_old_cpc = 0;
                sblock.fs_old_postblformat = 1;
                sblock.fs_old_nrpos = 1;
        } else {
                sblock.fs_magic = FS_UFS2_MAGIC;
                sblock.fs_sblockloc = SBLOCK_UFS2;
                sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
                sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
                sblock.fs_maxsymlinklen = ((UFS_NDADDR + UFS_NIADDR) *
                    sizeof (ufs2_daddr_t));
                if (ffs_opts->softupdates == 1)
                        sblock.fs_flags |= FS_DOSOFTDEP;
        }

        sblock.fs_sblkno =
            roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
                sblock.fs_frag);
        sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
            roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag));
        sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
        sblock.fs_maxfilesize = sblock.fs_bsize * UFS_NDADDR - 1;
        for (sizepb = sblock.fs_bsize, i = 0; i < UFS_NIADDR; i++) {
                sizepb *= NINDIR(&sblock);
                sblock.fs_maxfilesize += sizepb;
        }

        /*
         * Calculate the number of blocks to put into each cylinder group.
         *
         * This algorithm selects the number of blocks per cylinder
         * group. The first goal is to have at least enough data blocks
         * in each cylinder group to meet the density requirement. Once
         * this goal is achieved we try to expand to have at least
         * 1 cylinder group. Once this goal is achieved, we pack as
         * many blocks into each cylinder group map as will fit.
         *
         * We start by calculating the smallest number of blocks that we
         * can put into each cylinder group. If this is too big, we reduce
         * the density until it fits.
         */
        maxinum = (((int64_t)(1)) << 32) - INOPB(&sblock);
        minfragsperinode = 1 + fssize / maxinum;
        mindensity = minfragsperinode * fsize;
        if (density == 0)
                density = MAX(2, minfragsperinode) * fsize;
        if (density < mindensity) {
                origdensity = density;
                density = mindensity;
                fprintf(stderr, "density increased from %d to %d\n",
                    origdensity, density);
        }
        origdensity = density;
        if (!ffs_opts->min_inodes)
                density = MIN(density, MAX(2, minfragsperinode) * fsize);
        for (;;) {
                fragsperinode = MAX(numfrags(&sblock, density), 1);
                minfpg = fragsperinode * INOPB(&sblock);
                if (minfpg > sblock.fs_size)
                        minfpg = sblock.fs_size;
                sblock.fs_ipg = INOPB(&sblock);
                sblock.fs_fpg = roundup(sblock.fs_iblkno +
                    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
                if (sblock.fs_fpg < minfpg)
                        sblock.fs_fpg = minfpg;
                sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
                    INOPB(&sblock));
                sblock.fs_fpg = roundup(sblock.fs_iblkno +
                    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
                if (sblock.fs_fpg < minfpg)
                        sblock.fs_fpg = minfpg;
                sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
                    INOPB(&sblock));
                if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize -
                    CGSIZEFUDGE)
                        break;
                density -= sblock.fs_fsize;
        }
        if (density != origdensity)
                printf("density reduced from %d to %d\n", origdensity, density);

        if (maxblkspercg <= 0 || maxblkspercg >= fssize)
                maxblkspercg = fssize - 1;
        /*
         * Start packing more blocks into the cylinder group until
         * it cannot grow any larger, the number of cylinder groups
         * drops below 1, or we reach the size requested.
         */
        for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
                sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
                    INOPB(&sblock));
                if (sblock.fs_size / sblock.fs_fpg < 1)
                        break;
                if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize -
                    CGSIZEFUDGE)
                        continue;
                if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize -
                    CGSIZEFUDGE)
                        break;
                sblock.fs_fpg -= sblock.fs_frag;
                sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
                    INOPB(&sblock));
                break;
        }
        /*
         * Check to be sure that the last cylinder group has enough blocks
         * to be viable. If it is too small, reduce the number of blocks
         * per cylinder group which will have the effect of moving more
         * blocks into the last cylinder group.
         */
        optimalfpg = sblock.fs_fpg;
        for (;;) {
                sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
                lastminfpg = roundup(sblock.fs_iblkno +
                    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
                if (sblock.fs_size < lastminfpg) {
                        printf("Filesystem size %lld < minimum size of %d\n",
                            (long long)sblock.fs_size, lastminfpg);
                        exit(28);
                }
                if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
                    sblock.fs_size % sblock.fs_fpg == 0)
                        break;
                sblock.fs_fpg -= sblock.fs_frag;
                sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
                    INOPB(&sblock));
        }
        if (optimalfpg != sblock.fs_fpg)
                printf("Reduced frags per cylinder group from %d to %d %s\n",
                   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
        sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
        sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
        if (Oflag <= 1) {
                sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
                sblock.fs_old_nsect = sblock.fs_old_spc;
                sblock.fs_old_npsect = sblock.fs_old_spc;
                sblock.fs_old_ncyl = sblock.fs_ncg;
        }

        /*
         * fill in remaining fields of the super block
         */
        sblock.fs_csaddr = cgdmin(&sblock, 0);
        sblock.fs_cssize =
            fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));

        /*
         * Setup memory for temporary in-core cylgroup summaries.
         * Cribbed from ffs_mountfs().
         */
        size = sblock.fs_cssize;
        if (sblock.fs_contigsumsize > 0)
                size += sblock.fs_ncg * sizeof(int32_t);
        space = ecalloc(1, size);
        sblock.fs_si = ecalloc(1, sizeof(struct fs_summary_info));
        sblock.fs_csp = space;
        space = (char *)space + sblock.fs_cssize;
        if (sblock.fs_contigsumsize > 0) {
                int32_t *lp;

                sblock.fs_maxcluster = lp = space;
                for (i = 0; i < sblock.fs_ncg; i++)
                *lp++ = sblock.fs_contigsumsize;
        }

        sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
        if (sblock.fs_sbsize > SBLOCKSIZE)
                sblock.fs_sbsize = SBLOCKSIZE;
        sblock.fs_minfree = minfree;
        sblock.fs_maxcontig = maxcontig;
        sblock.fs_maxbpg = maxbpg;
        sblock.fs_optim = opt;
        sblock.fs_cgrotor = 0;
        sblock.fs_pendingblocks = 0;
        sblock.fs_pendinginodes = 0;
        sblock.fs_cstotal.cs_ndir = 0;
        sblock.fs_cstotal.cs_nbfree = 0;
        sblock.fs_cstotal.cs_nifree = 0;
        sblock.fs_cstotal.cs_nffree = 0;
        sblock.fs_fmod = 0;
        sblock.fs_ronly = 0;
        sblock.fs_state = 0;
        sblock.fs_clean = FS_ISCLEAN;
        sblock.fs_ronly = 0;
        sblock.fs_id[0] = tstamp;
        sblock.fs_id[1] = random();
        sblock.fs_fsmnt[0] = '\0';
        csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
        sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
            sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
        sblock.fs_cstotal.cs_nbfree =
            fragstoblks(&sblock, sblock.fs_dsize) -
            howmany(csfrags, sblock.fs_frag);
        sblock.fs_cstotal.cs_nffree =
            fragnum(&sblock, sblock.fs_size) +
            (fragnum(&sblock, csfrags) > 0 ?
            sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
        sblock.fs_cstotal.cs_nifree =
            sblock.fs_ncg * sblock.fs_ipg - UFS_ROOTINO;
        sblock.fs_cstotal.cs_ndir = 0;
        sblock.fs_dsize -= csfrags;
        sblock.fs_time = tstamp;
        if (Oflag <= 1) {
                sblock.fs_old_time = tstamp;
                sblock.fs_old_dsize = sblock.fs_dsize;
                sblock.fs_old_csaddr = sblock.fs_csaddr;
                sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
                sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
                sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
                sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
        }
        /*
         * Dump out summary information about file system.
         */
#define B2MBFACTOR (1 / (1024.0 * 1024.0))
        printf("%s: %.1fMB (%lld sectors) block size %d, "
               "fragment size %d\n",
            fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
            (long long)fsbtodb(&sblock, sblock.fs_size),
            sblock.fs_bsize, sblock.fs_fsize);
        printf("\tusing %d cylinder groups of %.2fMB, %d blks, "
               "%d inodes.\n",
            sblock.fs_ncg,
            (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
            sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
#undef B2MBFACTOR
        /*
         * Now determine how wide each column will be, and calculate how
         * many columns will fit in a 76 char line. 76 is the width of the
         * subwindows in sysinst.
         */
        printcolwidth = count_digits(
                        fsbtodb(&sblock, cgsblock(&sblock, sblock.fs_ncg -1)));
        nprintcols = 76 / (printcolwidth + 2);

        /*
         * allocate space for superblock, cylinder group map, and
         * two sets of inode blocks.
         */
        if (sblock.fs_bsize < SBLOCKSIZE)
                iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
        else
                iobufsize = 4 * sblock.fs_bsize;
        iobuf = ecalloc(1, iobufsize);
        /*
         * Make a copy of the superblock into the buffer that we will be
         * writing out in each cylinder group.
         */
        memcpy(writebuf, &sblock, sbsize);
        if (fsopts->needswap)
                ffs_sb_swap(&sblock, (struct fs*)writebuf);
        memcpy(iobuf, writebuf, SBLOCKSIZE);

        printf("super-block backups (for fsck -b #) at:");
        for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
                initcg(cylno, tstamp, fsopts);
                if (cylno % nprintcols == 0)
                        printf("\n");
                printf(" %*lld%s", printcolwidth,
                    (long long)fsbtodb(&sblock, cgsblock(&sblock, cylno)),
                    cylno == sblock.fs_ncg - 1 ? "" : ",");
                fflush(stdout);
        }
        printf("\n");

        /*
         * Now construct the initial file system,
         * then write out the super-block.
         */
        sblock.fs_time = tstamp;
        if (Oflag <= 1) {
                sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
                sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
                sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
                sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
        }
        if (fsopts->needswap)
                sblock.fs_flags |= FS_SWAPPED;
        ffs_write_superblock(&sblock, fsopts);
        return (&sblock);
}

/*
 * Write out the superblock and its duplicates,
 * and the cylinder group summaries
 */
void
ffs_write_superblock(struct fs *fs, const fsinfo_t *fsopts)
{
        int size, blks, i, saveflag;
        uint32_t cylno;
        void *info, *space;
        char *wrbuf;

        saveflag = fs->fs_flags & FS_INTERNAL;
        fs->fs_flags &= ~FS_INTERNAL;

        /*
         * Write out the superblock.  Blank out the summary info field, as it's
         * a random pointer that would make the resulting image unreproducible.
         */
        info = fs->fs_si;
        fs->fs_si = NULL;
        memcpy(writebuf, fs, sbsize);
        fs->fs_si = info;

        if (fsopts->needswap)
                ffs_sb_swap(fs, (struct fs*)writebuf);
        ffs_wtfs(fs->fs_sblockloc / sectorsize, sbsize, writebuf, fsopts);

        /* Write out the duplicate super blocks */
        for (cylno = 0; cylno < fs->fs_ncg; cylno++)
                ffs_wtfs(fsbtodb(fs, cgsblock(fs, cylno)),
                    sbsize, writebuf, fsopts);

        /* Write out the cylinder group summaries */
        size = fs->fs_cssize;
        blks = howmany(size, fs->fs_fsize);
        space = (void *)fs->fs_csp;
        wrbuf = emalloc(size);
        for (i = 0; i < blks; i+= fs->fs_frag) {
                size = fs->fs_bsize;
                if (i + fs->fs_frag > blks)
                        size = (blks - i) * fs->fs_fsize;
                if (fsopts->needswap)
                        ffs_csum_swap((struct csum *)space,
                            (struct csum *)wrbuf, size);
                else
                        memcpy(wrbuf, space, (u_int)size);
                ffs_wtfs(fsbtodb(fs, fs->fs_csaddr + i), size, wrbuf, fsopts);
                space = (char *)space + size;
        }
        free(wrbuf);
        fs->fs_flags |= saveflag;
}

/*
 * Initialize a cylinder group.
 */
static void
initcg(uint32_t cylno, time_t utime, const fsinfo_t *fsopts)
{
        daddr_t cbase, dmax;
        int32_t blkno;
        uint32_t i, j, d, dlower, dupper;
        struct ufs1_dinode *dp1;
        struct ufs2_dinode *dp2;
        int start;

        /*
         * Determine block bounds for cylinder group.
         * Allow space for super block summary information in first
         * cylinder group.
         */
        cbase = cgbase(&sblock, cylno);
        dmax = cbase + sblock.fs_fpg;
        if (dmax > sblock.fs_size)
                dmax = sblock.fs_size;
        dlower = cgsblock(&sblock, cylno) - cbase;
        dupper = cgdmin(&sblock, cylno) - cbase;
        if (cylno == 0)
                dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
        memset(&acg, 0, sblock.fs_cgsize);
        acg.cg_time = utime;
        acg.cg_magic = CG_MAGIC;
        acg.cg_cgx = cylno;
        acg.cg_niblk = sblock.fs_ipg;
        acg.cg_initediblk = MIN(sblock.fs_ipg, 2 * INOPB(&sblock));
        acg.cg_ndblk = dmax - cbase;
        if (sblock.fs_contigsumsize > 0)
                acg.cg_nclusterblks = acg.cg_ndblk >> sblock.fs_fragshift;
        start = sizeof(acg);
        if (Oflag == 2) {
                acg.cg_iusedoff = start;
        } else {
                if (cylno == sblock.fs_ncg - 1)
                        acg.cg_old_ncyl = howmany(acg.cg_ndblk,
                            sblock.fs_fpg / sblock.fs_old_cpg);
                else
                        acg.cg_old_ncyl = sblock.fs_old_cpg;
                acg.cg_old_time = acg.cg_time;
                acg.cg_time = 0;
                acg.cg_old_niblk = acg.cg_niblk;
                acg.cg_niblk = 0;
                acg.cg_initediblk = 0;
                acg.cg_old_btotoff = start;
                acg.cg_old_boff = acg.cg_old_btotoff +
                    sblock.fs_old_cpg * sizeof(int32_t);
                acg.cg_iusedoff = acg.cg_old_boff +
                    sblock.fs_old_cpg * sizeof(u_int16_t);
        }
        acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
        if (sblock.fs_contigsumsize <= 0) {
                acg.cg_nextfreeoff = acg.cg_freeoff +
                   howmany(sblock.fs_fpg, CHAR_BIT);
        } else {
                acg.cg_clustersumoff = acg.cg_freeoff +
                    howmany(sblock.fs_fpg, CHAR_BIT) - sizeof(int32_t);
                acg.cg_clustersumoff =
                    roundup(acg.cg_clustersumoff, sizeof(int32_t));
                acg.cg_clusteroff = acg.cg_clustersumoff +
                    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
                acg.cg_nextfreeoff = acg.cg_clusteroff +
                    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
        }
        if (acg.cg_nextfreeoff > (uint32_t)sblock.fs_cgsize) {
                printf("Panic: cylinder group too big\n");
                exit(37);
        }
        acg.cg_cs.cs_nifree += sblock.fs_ipg;
        if (cylno == 0)
                for (i = 0; i < UFS_ROOTINO; i++) {
                        setbit(cg_inosused_swap(&acg, 0), i);
                        acg.cg_cs.cs_nifree--;
                }
        if (cylno > 0) {
                /*
                 * In cylno 0, beginning space is reserved
                 * for boot and super blocks.
                 */
                for (d = 0, blkno = 0; d < dlower;) {
                        ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
                        if (sblock.fs_contigsumsize > 0)
                                setbit(cg_clustersfree_swap(&acg, 0), blkno);
                        acg.cg_cs.cs_nbfree++;
                        d += sblock.fs_frag;
                        blkno++;
                }
        }
        if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
                acg.cg_frsum[sblock.fs_frag - i]++;
                for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
                        setbit(cg_blksfree_swap(&acg, 0), dupper);
                        acg.cg_cs.cs_nffree++;
                }
        }
        for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
             d + sblock.fs_frag <= acg.cg_ndblk; ) {
                ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
                if (sblock.fs_contigsumsize > 0)
                        setbit(cg_clustersfree_swap(&acg, 0), blkno);
                acg.cg_cs.cs_nbfree++;
                d += sblock.fs_frag;
                blkno++;
        }
        if (d < acg.cg_ndblk) {
                acg.cg_frsum[acg.cg_ndblk - d]++;
                for (; d < acg.cg_ndblk; d++) {
                        setbit(cg_blksfree_swap(&acg, 0), d);
                        acg.cg_cs.cs_nffree++;
                }
        }
        if (sblock.fs_contigsumsize > 0) {
                int32_t *sump = cg_clustersum_swap(&acg, 0);
                u_char *mapp = cg_clustersfree_swap(&acg, 0);
                int map = *mapp++;
                int bit = 1;
                int run = 0;

                for (i = 0; i < acg.cg_nclusterblks; i++) {
                        if ((map & bit) != 0) {
                                run++;
                        } else if (run != 0) {
                                if (run > sblock.fs_contigsumsize)
                                        run = sblock.fs_contigsumsize;
                                sump[run]++;
                                run = 0;
                        }
                        if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
                                bit <<= 1;
                        } else {
                                map = *mapp++;
                                bit = 1;
                        }
                }
                if (run != 0) {
                        if (run > sblock.fs_contigsumsize)
                                run = sblock.fs_contigsumsize;
                        sump[run]++;
                }
        }
        sblock.fs_cs(&sblock, cylno) = acg.cg_cs;
        /*
         * Write out the duplicate super block, the cylinder group map
         * and two blocks worth of inodes in a single write.
         */
        start = MAX(sblock.fs_bsize, SBLOCKSIZE);
        memcpy(&iobuf[start], &acg, sblock.fs_cgsize);
        if (fsopts->needswap)
                ffs_cg_swap(&acg, (struct cg*)&iobuf[start], &sblock);
        start += sblock.fs_bsize;
        dp1 = (struct ufs1_dinode *)(&iobuf[start]);
        dp2 = (struct ufs2_dinode *)(&iobuf[start]);
        for (i = 0; i < acg.cg_initediblk; i++) {
                if (sblock.fs_magic == FS_UFS1_MAGIC) {
                        /* No need to swap, it'll stay random */
                        dp1->di_gen = random();
                        dp1++;
                } else {
                        dp2->di_gen = random();
                        dp2++;
                }
        }
        ffs_wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf,
            fsopts);
        /*
         * For the old file system, we have to initialize all the inodes.
         */
        if (Oflag <= 1) {
                for (i = 2 * sblock.fs_frag;
                     i < sblock.fs_ipg / INOPF(&sblock);
                     i += sblock.fs_frag) {
                        dp1 = (struct ufs1_dinode *)(&iobuf[start]);
                        for (j = 0; j < INOPB(&sblock); j++) {
                                dp1->di_gen = random();
                                dp1++;
                        }
                        ffs_wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
                            sblock.fs_bsize, &iobuf[start], fsopts);
                }
        }
}

/*
 * read a block from the file system
 */
void
ffs_rdfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
{
        int n;
        off_t offset;

        offset = (off_t)bno * fsopts->sectorsize + fsopts->offset;
        if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
                err(1, "%s: seek error for sector %lld", __func__,
                    (long long)bno);
        n = read(fsopts->fd, bf, size);
        if (n == -1) {
                abort();
                err(1, "%s: read error bno %lld size %d", __func__,
                    (long long)bno, size);
        }
        else if (n != size)
                errx(1, "%s: read error for sector %lld", __func__,
                    (long long)bno);
}

/*
 * write a block to the file system
 */
void
ffs_wtfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
{
        int n;
        off_t offset;

        offset = (off_t)bno * fsopts->sectorsize + fsopts->offset;
        if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
                err(1, "%s: seek error for sector %lld", __func__,
                    (long long)bno);
        n = write(fsopts->fd, bf, size);
        if (n == -1)
                err(1, "%s: write error for sector %lld", __func__,
                    (long long)bno);
        else if (n != size)
                errx(1, "%s: write error for sector %lld", __func__,
                    (long long)bno);
}


/* Determine how many digits are needed to print a given integer */
static int
count_digits(int num)
{
        int ndig;

        for(ndig = 1; num > 9; num /=10, ndig++);

        return (ndig);
}

static int
ilog2(int val)
{
        u_int n;

        for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
                if (1 << n == val)
                        return (n);
        errx(1, "%s: %d is not a power of 2", __func__, val);
}