/*      $NetBSD: setup.c,v 1.39 2019/03/31 13:16:52 mlelstv Exp $       */

/*
 * Copyright (c) 1980, 1986, 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.
 */

/*
 * Copyright (c) 1997 Manuel Bouyer.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)setup.c     8.5 (Berkeley) 11/23/94";
#else
__RCSID("$NetBSD: setup.c,v 1.39 2019/03/31 13:16:52 mlelstv Exp $");
#endif
#endif /* not lint */

#define FSTYPENAMES
#include <sys/param.h>
#include <sys/time.h>
#include <sys/bitops.h>
#include <ufs/ext2fs/ext2fs_dinode.h>
#include <ufs/ext2fs/ext2fs.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/disk.h>
#include <sys/file.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include <util.h>

#include "fsck.h"
#include "extern.h"
#include "fsutil.h"
#include "partutil.h"
#include "exitvalues.h"

void badsb(int, const char *);
int calcsb(const char *, int, struct m_ext2fs *);
static int readsb(int);

/*    
 * For file systems smaller than SMALL_FSSIZE we use the S_DFL_* defaults,
 * otherwise if less than MEDIUM_FSSIZE use M_DFL_*, otherwise use 
 * L_DFL_*.
 */
#define SMALL_FSSIZE    ((4 * 1024 * 1024) / secsize)        /* 4MB */  
#define S_DFL_BSIZE     1024 
#define MEDIUM_FSSIZE   ((512 * 1024 * 1024) / secsize)      /* 512MB */
#define M_DFL_BSIZE     1024 
#define L_DFL_BSIZE     4096

int
setup(const char *dev)
{
        long cg, asked, i;
        long bmapsize;
        struct disk_geom geo;
        struct dkwedge_info dkw;
        off_t sizepb;
        struct stat statb;
        struct m_ext2fs proto;
        int doskipclean;
        u_int64_t maxfilesize;

        havesb = 0;
        fswritefd = -1;
        doskipclean = skipclean;
        if (stat(dev, &statb) < 0) {
                printf("Can't stat %s: %s\n", dev, strerror(errno));
                return 0;
        }
        if (!S_ISCHR(statb.st_mode)) {
                pfatal("%s is not a character device", dev);
                if (reply("CONTINUE") == 0)
                        return 0;
        }
        if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
                printf("Can't open %s: %s\n", dev, strerror(errno));
                return 0;
        }
        if (preen == 0)
                printf("** %s", dev);
        if (nflag || (fswritefd = open(dev, O_WRONLY)) < 0) {
                fswritefd = -1;
                if (preen)
                        pfatal("NO WRITE ACCESS");
                printf(" (NO WRITE)");
        }
        if (preen == 0)
                printf("\n");
        fsmodified = 0;
        lfdir = 0;
        initbarea(&sblk);
        initbarea(&asblk);
        sblk.b_un.b_buf = malloc(SBSIZE);
        asblk.b_un.b_buf = malloc(SBSIZE);
        if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
                errexit("cannot allocate space for superblock");
        if (getdiskinfo(dev, fsreadfd, NULL, &geo, &dkw) != -1)
                dev_bsize = secsize = geo.dg_secsize;
        else
                dev_bsize = secsize = DEV_BSIZE;
        /*
         * Read in the superblock, looking for alternates if necessary
         */
        if (readsb(1) == 0) {
                if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
                        return 0;
                if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
                        return 0;
                for (cg = 1; cg < proto.e2fs_ncg; cg++) {
                        bflag = EXT2_FSBTODB(&proto,
                            cg * proto.e2fs.e2fs_bpg +
                            proto.e2fs.e2fs_first_dblock);
                        if (readsb(0) != 0)
                                break;
                }
                if (cg >= proto.e2fs_ncg) {
                        printf("%s %s\n%s %s\n%s %s\n",
                            "SEARCH FOR ALTERNATE SUPER-BLOCK",
                            "FAILED. YOU MUST USE THE",
                            "-b OPTION TO FSCK_FFS TO SPECIFY THE",
                            "LOCATION OF AN ALTERNATE",
                            "SUPER-BLOCK TO SUPPLY NEEDED",
                            "INFORMATION; SEE fsck_ext2fs(8).");
                        return 0;
                }
                doskipclean = 0;
                pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
        }
        if (debug)
                printf("state = %d\n", sblock.e2fs.e2fs_state);
        if (sblock.e2fs.e2fs_state == E2FS_ISCLEAN) {
                if (doskipclean) {
                        pwarn("%sile system is clean; not checking\n",
                            preen ? "f" : "** F");
                        return -1;
                }
                if (!preen)
                        pwarn("** File system is already clean\n");
        }
        maxfsblock = sblock.e2fs.e2fs_bcount;
        maxino = sblock.e2fs_ncg * sblock.e2fs.e2fs_ipg;
        sizepb = sblock.e2fs_bsize;
        maxfilesize = sblock.e2fs_bsize * EXT2FS_NDADDR - 1;
        for (i = 0; i < EXT2FS_NIADDR; i++) {
                sizepb *= EXT2_NINDIR(&sblock);
                maxfilesize += sizepb;
        }
        /*
         * Check and potentially fix certain fields in the super block.
         */
        if (/* (sblock.e2fs.e2fs_rbcount < 0) || */
            (sblock.e2fs.e2fs_rbcount > sblock.e2fs.e2fs_bcount)) {
                pfatal("IMPOSSIBLE RESERVED BLOCK COUNT=%d IN SUPERBLOCK",
                    sblock.e2fs.e2fs_rbcount);
                if (reply("SET TO DEFAULT") == 1) {
                        sblock.e2fs.e2fs_rbcount =
                            sblock.e2fs.e2fs_bcount * MINFREE / 100;
                        sbdirty();
                        dirty(&asblk);
                }
        }
        if (sblock.e2fs.e2fs_bpg != sblock.e2fs.e2fs_fpg) {
                pfatal("WRONG FPG=%d (BPG=%d) IN SUPERBLOCK",
                    sblock.e2fs.e2fs_fpg, sblock.e2fs.e2fs_bpg);
                return 0;
        }
        if (asblk.b_dirty && !bflag) {
                copyback_sb(&asblk);
                flush(fswritefd, &asblk);
        }
        /*
         * read in the summary info.
         */

        sblock.e2fs_gd = malloc(sblock.e2fs_ngdb * sblock.e2fs_bsize);
        if (sblock.e2fs_gd == NULL)
                errexit("out of memory");
        asked = 0;
        for (i = 0; i < sblock.e2fs_ngdb; i++) {
                if (bread(fsreadfd,
                    (char *)&sblock.e2fs_gd[i * sblock.e2fs_bsize /
                    sizeof(struct ext2_gd)],
                    EXT2_FSBTODB(&sblock, ((sblock.e2fs_bsize > 1024) ? 0 : 1) +
                    i + 1),
                    sblock.e2fs_bsize) != 0 && !asked) {
                        pfatal("BAD SUMMARY INFORMATION");
                        if (reply("CONTINUE") == 0)
                                exit(FSCK_EXIT_CHECK_FAILED);
                        asked++;
                }
        }
        /*
         * allocate and initialize the necessary maps
         */
        bmapsize = roundup(howmany(maxfsblock, NBBY), sizeof(int16_t));
        blockmap = calloc((unsigned int)bmapsize, sizeof(char));
        if (blockmap == NULL) {
                printf("cannot alloc %u bytes for blockmap\n",
                    (unsigned int)bmapsize);
                goto badsblabel;
        }
        statemap = calloc((unsigned int)(maxino + 2), sizeof(char));
        if (statemap == NULL) {
                printf("cannot alloc %u bytes for statemap\n",
                    (unsigned int)(maxino + 1));
                goto badsblabel;
        }
        typemap = calloc((unsigned int)(maxino + 1), sizeof(char));
        if (typemap == NULL) {
                printf("cannot alloc %u bytes for typemap\n",
                    (unsigned int)(maxino + 1));
                goto badsblabel;
        }
        lncntp = calloc((unsigned)(maxino + 1), sizeof(int16_t));
        if (lncntp == NULL) {
                printf("cannot alloc %u bytes for lncntp\n",
                    (unsigned int)((maxino + 1) * sizeof(int16_t)));
                goto badsblabel;
        }
        for (numdirs = 0, cg = 0; cg < sblock.e2fs_ncg; cg++) {
                numdirs += fs2h16(sblock.e2fs_gd[cg].ext2bgd_ndirs);
        }
        inplast = 0;
        listmax = numdirs + 10;
        inpsort = calloc((unsigned int)listmax, sizeof(struct inoinfo *));
        inphead = calloc((unsigned int)numdirs, sizeof(struct inoinfo *));
        if (inpsort == NULL || inphead == NULL) {
                printf("cannot alloc %u bytes for inphead\n",
                    (unsigned int)(numdirs * sizeof(struct inoinfo *)));
                goto badsblabel;
        }
        bufinit();
        return 1;

badsblabel:
        ckfini(0);
        return 0;
}

/*
 * Read in the super block and its summary info, convert to host byte order.
 */
static int
readsb(int listerr)
{
        daddr_t super = bflag ? bflag : SBOFF / dev_bsize;

        if (bread(fsreadfd, (char *)sblk.b_un.b_fs, super, (long)SBSIZE) != 0)
                return 0;
        sblk.b_bno = super;
        sblk.b_size = SBSIZE;

        /* Copy the superblock in memory */
        e2fs_sbload(sblk.b_un.b_fs, &sblock.e2fs);
        
        /*
         * run a few consistency checks of the super block
         */
        if (sblock.e2fs.e2fs_magic != E2FS_MAGIC) {
                badsb(listerr, "MAGIC NUMBER WRONG");
                return 0;
        }
        if (sblock.e2fs.e2fs_log_bsize > 2) {
                badsb(listerr, "BAD LOG_BSIZE");
                return 0;
        }
        if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
            (!powerof2(sblock.e2fs.e2fs_inode_size) ||
             sblock.e2fs.e2fs_inode_size < EXT2_REV0_DINODE_SIZE ||
             sblock.e2fs.e2fs_inode_size >
              (1024 << sblock.e2fs.e2fs_log_bsize))) {
                badsb(listerr, "BAD INODE_SIZE");
                return 0;
        }

        /* compute the dynamic fields of the in-memory sb */
        /* compute dynamic sb infos */
        sblock.e2fs_ncg =
            howmany(sblock.e2fs.e2fs_bcount - sblock.e2fs.e2fs_first_dblock,
            sblock.e2fs.e2fs_bpg);
        sblock.e2fs_fsbtodb = sblock.e2fs.e2fs_log_bsize + ilog2(1024 / dev_bsize);
        sblock.e2fs_bsize = 1024 << sblock.e2fs.e2fs_log_bsize;
        sblock.e2fs_bshift = LOG_MINBSIZE + sblock.e2fs.e2fs_log_bsize;
        sblock.e2fs_qbmask = sblock.e2fs_bsize - 1;
        sblock.e2fs_bmask = ~sblock.e2fs_qbmask;
        sblock.e2fs_ngdb = howmany(sblock.e2fs_ncg,
            sblock.e2fs_bsize / sizeof(struct ext2_gd));
        sblock.e2fs_ipb = sblock.e2fs_bsize / EXT2_DINODE_SIZE(&sblock);
        sblock.e2fs_itpg = howmany(sblock.e2fs.e2fs_ipg, sblock.e2fs_ipb);

        /*
         * Compute block size that the filesystem is based on,
         * according to fsbtodb, and adjust superblock block number
         * so we can tell if this is an alternate later.
         */
        super *= dev_bsize;
        dev_bsize = sblock.e2fs_bsize / EXT2_FSBTODB(&sblock, 1);
        sblk.b_bno = super / dev_bsize;

        if (sblock.e2fs_ncg == 1) {
                /* no alternate superblock; assume it's okay */
                havesb = 1;
                return 1;
        }
        getblk(&asblk, 1 * sblock.e2fs.e2fs_bpg + sblock.e2fs.e2fs_first_dblock,
                (long)SBSIZE);
        if (asblk.b_errs)
                return 0;
        if (bflag) {
                havesb = 1;
                return 1;
        }

        /*
         * Set all possible fields that could differ, then do check
         * of whole super block against an alternate super block.
         * When an alternate super-block is specified this check is skipped.
         */
        asblk.b_un.b_fs->e2fs_rbcount = sblk.b_un.b_fs->e2fs_rbcount;
        asblk.b_un.b_fs->e2fs_fbcount = sblk.b_un.b_fs->e2fs_fbcount;
        asblk.b_un.b_fs->e2fs_ficount = sblk.b_un.b_fs->e2fs_ficount;
        asblk.b_un.b_fs->e2fs_mtime = sblk.b_un.b_fs->e2fs_mtime;
        asblk.b_un.b_fs->e2fs_wtime = sblk.b_un.b_fs->e2fs_wtime;
        asblk.b_un.b_fs->e2fs_mnt_count = sblk.b_un.b_fs->e2fs_mnt_count;
        asblk.b_un.b_fs->e2fs_max_mnt_count =
            sblk.b_un.b_fs->e2fs_max_mnt_count;
        asblk.b_un.b_fs->e2fs_state = sblk.b_un.b_fs->e2fs_state;
        asblk.b_un.b_fs->e2fs_beh = sblk.b_un.b_fs->e2fs_beh;
        asblk.b_un.b_fs->e2fs_lastfsck = sblk.b_un.b_fs->e2fs_lastfsck;
        asblk.b_un.b_fs->e2fs_fsckintv = sblk.b_un.b_fs->e2fs_fsckintv;
        asblk.b_un.b_fs->e2fs_ruid = sblk.b_un.b_fs->e2fs_ruid;
        asblk.b_un.b_fs->e2fs_rgid = sblk.b_un.b_fs->e2fs_rgid;
        asblk.b_un.b_fs->e2fs_block_group_nr =
            sblk.b_un.b_fs->e2fs_block_group_nr;
        asblk.b_un.b_fs->e2fs_features_rocompat &= ~EXT2F_ROCOMPAT_LARGEFILE;
        asblk.b_un.b_fs->e2fs_features_rocompat |=
            sblk.b_un.b_fs->e2fs_features_rocompat & EXT2F_ROCOMPAT_LARGEFILE;
        memcpy(asblk.b_un.b_fs->e2fs_fsmnt, sblk.b_un.b_fs->e2fs_fsmnt,
            sizeof(asblk.b_un.b_fs->e2fs_fsmnt));
        asblk.b_un.b_fs->e4fs_kbytes_written =
            sblk.b_un.b_fs->e4fs_kbytes_written;
        if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
            ((sblock.e2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP_FSCK) ||
            (sblock.e2fs.e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP_FSCK))) {
                if (debug) {
                        printf("compat 0x%08x, incompat 0x%08x, compat_ro "
                            "0x%08x\n",
                            sblock.e2fs.e2fs_features_compat,
                            sblock.e2fs.e2fs_features_incompat,
                            sblock.e2fs.e2fs_features_rocompat);

                        if ((sblock.e2fs.e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP_FSCK)) {
                                char buf[512];

                                snprintb(buf, sizeof(buf), EXT2F_ROCOMPAT_BITS,
                                        sblock.e2fs.e2fs_features_rocompat & ~EXT2F_ROCOMPAT_SUPP_FSCK);
                                printf("unsupported rocompat features: %s\n", buf);
                        }
                        if ((sblock.e2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP_FSCK)) {
                                char buf[512];

                                snprintb(buf, sizeof(buf), EXT2F_INCOMPAT_BITS,
                                        sblock.e2fs.e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP_FSCK);
                                printf("unsupported incompat features: %s\n", buf);
                        }
                }
                badsb(listerr, "INCOMPATIBLE FEATURE BITS IN SUPER BLOCK");
                return 0;
        }
        if (memcmp(sblk.b_un.b_fs, asblk.b_un.b_fs, SBSIZE)) {
                if (debug) {
                        u_int32_t *nlp, *olp, *endlp;

                        printf("superblock mismatches\n");
                        nlp = (u_int32_t *)asblk.b_un.b_fs;
                        olp = (u_int32_t *)sblk.b_un.b_fs;
                        endlp = olp + (SBSIZE / sizeof(*olp));
                        for ( ; olp < endlp; olp++, nlp++) {
                                if (*olp == *nlp)
                                        continue;
                                printf("offset %ld, original %ld, "
                                    "alternate %ld\n",
                                    (long)(olp - (u_int32_t *)sblk.b_un.b_fs),
                                    (long)fs2h32(*olp),
                                    (long)fs2h32(*nlp));
                        }
                }
                badsb(listerr,
                    "VALUES IN SUPER BLOCK DISAGREE WITH "
                    "THOSE IN FIRST ALTERNATE");
                return 0;
        }
        havesb = 1;
        return 1;
}

void
copyback_sb(struct bufarea *bp)
{
        /* Copy the in-memory superblock back to buffer */
        bp->b_un.b_fs->e2fs_icount = h2fs32(sblock.e2fs.e2fs_icount);
        bp->b_un.b_fs->e2fs_bcount = h2fs32(sblock.e2fs.e2fs_bcount);
        bp->b_un.b_fs->e2fs_rbcount = h2fs32(sblock.e2fs.e2fs_rbcount);
        bp->b_un.b_fs->e2fs_fbcount = h2fs32(sblock.e2fs.e2fs_fbcount);
        bp->b_un.b_fs->e2fs_ficount = h2fs32(sblock.e2fs.e2fs_ficount);
        bp->b_un.b_fs->e2fs_first_dblock =
            h2fs32(sblock.e2fs.e2fs_first_dblock);
        bp->b_un.b_fs->e2fs_log_bsize = h2fs32(sblock.e2fs.e2fs_log_bsize);
        bp->b_un.b_fs->e2fs_fsize = h2fs32(sblock.e2fs.e2fs_fsize);
        bp->b_un.b_fs->e2fs_bpg = h2fs32(sblock.e2fs.e2fs_bpg);
        bp->b_un.b_fs->e2fs_fpg = h2fs32(sblock.e2fs.e2fs_fpg);
        bp->b_un.b_fs->e2fs_ipg = h2fs32(sblock.e2fs.e2fs_ipg);
        bp->b_un.b_fs->e2fs_mtime = h2fs32(sblock.e2fs.e2fs_mtime);
        bp->b_un.b_fs->e2fs_wtime = h2fs32(sblock.e2fs.e2fs_wtime);
        bp->b_un.b_fs->e2fs_lastfsck = h2fs32(sblock.e2fs.e2fs_lastfsck);
        bp->b_un.b_fs->e2fs_fsckintv = h2fs32(sblock.e2fs.e2fs_fsckintv);
        bp->b_un.b_fs->e2fs_creator = h2fs32(sblock.e2fs.e2fs_creator);
        bp->b_un.b_fs->e2fs_rev = h2fs32(sblock.e2fs.e2fs_rev);
        bp->b_un.b_fs->e2fs_mnt_count = h2fs16(sblock.e2fs.e2fs_mnt_count);
        bp->b_un.b_fs->e2fs_max_mnt_count =
            h2fs16(sblock.e2fs.e2fs_max_mnt_count);
        bp->b_un.b_fs->e2fs_magic = h2fs16(sblock.e2fs.e2fs_magic);
        bp->b_un.b_fs->e2fs_state = h2fs16(sblock.e2fs.e2fs_state);
        bp->b_un.b_fs->e2fs_beh = h2fs16(sblock.e2fs.e2fs_beh);
        bp->b_un.b_fs->e2fs_ruid = h2fs16(sblock.e2fs.e2fs_ruid);
        bp->b_un.b_fs->e2fs_rgid = h2fs16(sblock.e2fs.e2fs_rgid);
}

void
badsb(int listerr, const char *s)
{

        if (!listerr)
                return;
        if (preen)
                printf("%s: ", cdevname());
        pfatal("BAD SUPER BLOCK: %s\n", s);
}

/*
 * Calculate a prototype superblock based on information in the disk label.
 * When done the cgsblock macro can be calculated and the fs_ncg field
 * can be used. Do NOT attempt to use other macros without verifying that
 * their needed information is available!
 */

int
calcsb(const char *dev, int devfd, struct m_ext2fs *fs)
{
        struct dkwedge_info dkw;
        struct disk_geom geo;

        if (getdiskinfo(dev, devfd, NULL, &geo, &dkw) == -1)
                pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
        if (dkw.dkw_parent[0] == '\0') {
                pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
                return 0;
        }

        memset(fs, 0, sizeof(struct m_ext2fs));

        if (dkw.dkw_size < (uint64_t)SMALL_FSSIZE)
                fs->e2fs_bsize = S_DFL_BSIZE;
        else if (dkw.dkw_size < (uint64_t)MEDIUM_FSSIZE)
                fs->e2fs_bsize = M_DFL_BSIZE;
        else
                fs->e2fs_bsize = L_DFL_BSIZE;

        fs->e2fs.e2fs_log_bsize = ilog2(fs->e2fs_bsize / 1024);
        fs->e2fs.e2fs_bcount = (fs->e2fs_bsize * DEV_BSIZE) / fs->e2fs_bsize;
        fs->e2fs.e2fs_first_dblock = (fs->e2fs.e2fs_log_bsize == 0) ? 1 : 0;
        fs->e2fs.e2fs_bpg = fs->e2fs_bsize * NBBY;
        fs->e2fs_bshift = LOG_MINBSIZE + fs->e2fs.e2fs_log_bsize;
        fs->e2fs_qbmask = fs->e2fs_bsize - 1;
        fs->e2fs_bmask = ~fs->e2fs_qbmask;
        fs->e2fs_ncg =
            howmany(fs->e2fs.e2fs_bcount - fs->e2fs.e2fs_first_dblock,
            fs->e2fs.e2fs_bpg);
        fs->e2fs_fsbtodb = fs->e2fs.e2fs_log_bsize + 1;
        fs->e2fs_ngdb = howmany(fs->e2fs_ncg,
            fs->e2fs_bsize / sizeof(struct ext2_gd));

        return 1;
}

daddr_t
cgoverhead(int c)
{
        int overh;
        overh =
            1 /* block bitmap */ +
            1 /* inode bitmap */ +
            sblock.e2fs_itpg;
        if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
            sblock.e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
                if (cg_has_sb(c) == 0)
                        return overh;
        }
        overh += 1 /* superblock */ + sblock.e2fs_ngdb;
        return overh;
}