usr/src/sbin/fsck/setup.c

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
static char sccsid[] = "@(#)setup.c     5.4 (Berkeley) %G%";
#endif not lint

#define DKTYPENAMES
#include <sys/param.h>
#include <sys/inode.h>
#include <sys/fs.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/disklabel.h>
#include <sys/file.h>
#include <ctype.h>
#include "fsck.h"

#define POWEROF2(num)   (((num) & ((num) - 1)) == 0)

char    *calloc();
char    *index();

setup(dev)
        char *dev;
{
        dev_t rootdev;
        long cg, ncg, size, i, j;
        struct stat statb;
        struct fs proto;

        if (stat("/", &statb) < 0)
                errexit("Can't stat root\n");
        rootdev = statb.st_dev;
        if (stat(dev, &statb) < 0) {
                printf("Can't stat %s\n", dev);
                return (0);
        }
        rawflg = 0;
        if ((statb.st_mode & S_IFMT) == S_IFBLK)
                ;
        else if ((statb.st_mode & S_IFMT) == S_IFCHR)
                rawflg++;
        else {
                if (reply("file is not a block or character device; OK") == 0)
                        return (0);
        }
        if (rootdev == statb.st_rdev)
                hotroot++;
        if ((dfile.rfdes = open(dev, O_RDONLY)) < 0) {
                printf("Can't open %s\n", dev);
                return (0);
        }
        if (preen == 0)
                printf("** %s", dev);
        if (nflag || (dfile.wfdes = open(dev, O_WRONLY)) < 0) {
                dfile.wfdes = -1;
                if (preen)
                        pfatal("NO WRITE ACCESS");
                printf(" (NO WRITE)");
        }
        if (preen == 0)
                printf("\n");
        dfile.mod = 0;
        lfdir = 0;
        initbarea(&sblk);
        initbarea(&fileblk);
        initbarea(&inoblk);
        initbarea(&cgblk);
        /*
         * Read in the superblock, looking for alternates if necessary
         */
        if (readsb(1) == 0) {
                if (bflag || calcsb(dev, dfile.rfdes, &proto) == 0 || preen)
                        return(0);
                if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
                        return (0);
                for (cg = 0; cg < proto.fs_ncg; cg++) {
                        bflag = fsbtodb(&proto, cgsblock(&proto, cg));
                        if (readsb(0) != 0)
                                break;
                }
                if (cg >= proto.fs_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 TO SPECIFY THE",
                                "LOCATION OF AN ALTERNATE",
                                "SUPER-BLOCK TO SUPPLY NEEDED",
                                "INFORMATION; SEE fsck(8).");
                        return(0);
                }
                pwarn("USING ALTERNATE SUPERBLOCK AT %d\n", bflag);
        }
        fmax = sblock.fs_size;
        imax = sblock.fs_ncg * sblock.fs_ipg;
        /*
         * Check and potentially fix certain fields in the super block.
         */
        if (sblock.fs_optim != FS_OPTTIME && sblock.fs_optim != FS_OPTSPACE) {
                pfatal("UNDEFINED OPTIMIZATION IN SUPERBLOCK");
                if (reply("SET TO DEFAULT") == 1) {
                        sblock.fs_optim = FS_OPTTIME;
                        sbdirty();
                }
        }
        if ((sblock.fs_minfree < 0 || sblock.fs_minfree > 99)) {
                pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
                        sblock.fs_minfree);
                if (reply("SET TO DEFAULT") == 1) {
                        sblock.fs_minfree = 10;
                        sbdirty();
                }
        }
        /*
         * read in the summary info.
         */
        for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) {
                size = sblock.fs_cssize - i < sblock.fs_bsize ?
                    sblock.fs_cssize - i : sblock.fs_bsize;
                sblock.fs_csp[j] = (struct csum *)calloc(1, (unsigned)size);
                if (bread(&dfile, (char *)sblock.fs_csp[j],
                    fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag),
                    size) != 0)
                        return (0);
        }
        /*
         * allocate and initialize the necessary maps
         */
        bmapsz = roundup(howmany(fmax, NBBY), sizeof(short));
        blockmap = calloc((unsigned)bmapsz, sizeof (char));
        if (blockmap == NULL) {
                printf("cannot alloc %d bytes for blockmap\n", bmapsz);
                goto badsb;
        }
        statemap = calloc((unsigned)(imax + 1), sizeof(char));
        if (statemap == NULL) {
                printf("cannot alloc %d bytes for statemap\n", imax + 1);
                goto badsb;
        }
        lncntp = (short *)calloc((unsigned)(imax + 1), sizeof(short));
        if (lncntp == NULL) {
                printf("cannot alloc %d bytes for lncntp\n",
                    (imax + 1) * sizeof(short));
                goto badsb;
        }

        return (1);

badsb:
        ckfini();
        return (0);
}

/*
 * Read in the super block and its summary info.
 */
readsb(listerr)
        int listerr;
{
        BUFAREA asblk;
#       define altsblock asblk.b_un.b_fs
        daddr_t super = bflag ? bflag : SBLOCK;

        initbarea(&asblk);
        if (bread(&dfile, (char *)&sblock, super, (long)SBSIZE) != 0)
                return (0);
        sblk.b_bno = super;
        sblk.b_size = SBSIZE;
        /*
         * run a few consistency checks of the super block
         */
        if (sblock.fs_magic != FS_MAGIC)
                { badsb(listerr, "MAGIC NUMBER WRONG"); return (0); }
        if (sblock.fs_ncg < 1)
                { badsb(listerr, "NCG OUT OF RANGE"); return (0); }
        if (sblock.fs_cpg < 1 || sblock.fs_cpg > MAXCPG)
                { badsb(listerr, "CPG OUT OF RANGE"); return (0); }
        if (sblock.fs_ncg * sblock.fs_cpg < sblock.fs_ncyl ||
            (sblock.fs_ncg - 1) * sblock.fs_cpg >= sblock.fs_ncyl)
                { badsb(listerr, "NCYL LESS THAN NCG*CPG"); return (0); }
        if (sblock.fs_sbsize > SBSIZE)
                { badsb(listerr, "SIZE PREPOSTEROUSLY LARGE"); return (0); }
        /*
         * 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.
         */
        if (bflag)
                return (1);
        getblk(&asblk, cgsblock(&sblock, sblock.fs_ncg - 1), sblock.fs_sbsize);
        if (asblk.b_errs != NULL)
                return (0);
        altsblock.fs_link = sblock.fs_link;
        altsblock.fs_rlink = sblock.fs_rlink;
        altsblock.fs_time = sblock.fs_time;
        altsblock.fs_cstotal = sblock.fs_cstotal;
        altsblock.fs_cgrotor = sblock.fs_cgrotor;
        altsblock.fs_fmod = sblock.fs_fmod;
        altsblock.fs_clean = sblock.fs_clean;
        altsblock.fs_ronly = sblock.fs_ronly;
        altsblock.fs_flags = sblock.fs_flags;
        altsblock.fs_maxcontig = sblock.fs_maxcontig;
        altsblock.fs_minfree = sblock.fs_minfree;
        altsblock.fs_optim = sblock.fs_optim;
        altsblock.fs_rotdelay = sblock.fs_rotdelay;
        altsblock.fs_maxbpg = sblock.fs_maxbpg;
        bcopy((char *)sblock.fs_csp, (char *)altsblock.fs_csp,
                sizeof sblock.fs_csp);
        bcopy((char *)sblock.fs_fsmnt, (char *)altsblock.fs_fsmnt,
                sizeof sblock.fs_fsmnt);
        if (bcmp((char *)&sblock, (char *)&altsblock, (int)sblock.fs_sbsize))
                { badsb(listerr, "TRASHED VALUES IN SUPER BLOCK"); return (0); }
        return (1);
#       undef altsblock
}

badsb(listerr, s)
        int listerr;
        char *s;
{

        if (!listerr)
                return;
        if (preen)
                printf("%s: ", devname);
        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!
 */
calcsb(dev, devfd, fs)
        char *dev;
        int devfd;
        register struct fs *fs;
{
        register struct disklabel *lp;
        register struct partition *pp;
        register char *cp;
        struct disklabel *getdisklabel();
        int i;

        cp = index(dev, '\0') - 1;
        if (cp == (char *)-1 || (*cp < 'a' || *cp > 'h') && !isdigit(*cp)) {
                pfatal("%s: CANNOT FIGURE OUT FILE SYSTEM PARTITION\n", dev);
                return (0);
        }
        lp = getdisklabel(dev, devfd);
        if (isdigit(*cp))
                pp = &lp->d_partitions[0];
        else
                pp = &lp->d_partitions[*cp - 'a'];
        if (pp->p_fstype != FS_BSDFFS) {
                pfatal("%s: NOT FORMATTED AS A BSD FILE SYSTEM (%s)\n",
                        dev, pp->p_fstype < FSMAXTYPES ?
                        fstypenames[pp->p_fstype] : "unknown");
                return (0);
        }
        bzero(fs, sizeof(struct fs));
        fs->fs_fsize = pp->p_fsize;
        fs->fs_frag = pp->p_frag;
        fs->fs_cpg = pp->p_cpg;
        fs->fs_size = pp->p_size;
        fs->fs_ntrak = lp->d_ntracks;
        fs->fs_nsect = lp->d_nsectors;
        fs->fs_spc = lp->d_secpercyl;
        fs->fs_nspf = fs->fs_fsize / lp->d_secsize;
        fs->fs_sblkno = roundup(
                howmany(lp->d_bbsize + lp->d_sbsize, fs->fs_fsize),
                fs->fs_frag);
        fs->fs_cgmask = 0xffffffff;
        for (i = fs->fs_ntrak; i > 1; i >>= 1)
                fs->fs_cgmask <<= 1;
        if (!POWEROF2(fs->fs_ntrak))
                fs->fs_cgmask <<= 1;
        fs->fs_cgoffset = roundup(
                howmany(fs->fs_nsect, NSPF(fs)), fs->fs_frag);
        fs->fs_fpg = (fs->fs_cpg * fs->fs_spc) / NSPF(fs);
        fs->fs_ncg = howmany(fs->fs_size / fs->fs_spc, fs->fs_cpg);
        for (fs->fs_fsbtodb = 0, i = NSPF(fs); i > 1; i >>= 1)
                fs->fs_fsbtodb++;
        return (1);
}

#ifdef byioctl
struct disklabel *
getdisklabel(s, fd)
        char *s;
        int     fd;
{
        static struct disklabel lab;

        if (ioctl(fd, DIOCGDINFO, (char *)&lab) < 0) {
                perror("ioctl (GDINFO)");
                fatal("%s: can't read disk label", s);
        }
        return (&lab);
}
#else byioctl
char specname[64];
char boot[BBSIZE];

struct disklabel *
getdisklabel(s, fd)
        char *s;
        int     fd;
{
        char *cp;
        u_long magic = htonl(DISKMAGIC);
        register struct disklabel *lp;
        int cfd;

        /*
         * Make name for 'c' partition.
         */
        strcpy(specname, s);
        cp = specname + strlen(specname) - 1;
        if (!isdigit(*cp))
                *cp = 'c';
        cfd = open(specname, O_RDONLY);
        if (cfd < 0) {
                perror(specname);
                exit(2);
        }

        if (read(cfd, boot, BBSIZE) < BBSIZE) {
                perror(specname);
                exit(2);
        }
        close(cfd);
        for (lp = (struct disklabel *)(boot + LABELOFFSET);
            lp <= (struct disklabel *)(boot + BBSIZE -
            sizeof(struct disklabel));
            lp = (struct disklabel *)((char *)lp + 128))
                if (lp->d_magic == magic && lp->d_magic2 == magic)
                        break;
        if (lp > (struct disklabel *)(boot + BBSIZE -
            sizeof(struct disklabel)) ||
            lp->d_magic != magic || lp->d_magic2 != magic ||
            dkcksum(lp) != 0) {
                printf("Bad pack magic number %s\n",
                        "(label is damaged, or pack is unlabeled)");
                exit(1);
        }
#if ENDIAN != BIG
        swablabel(lp);
#endif
        return (lp);
}
#endif byioctl