/*      $NetBSD: resize_lfs.c,v 1.16 2023/08/07 23:27:07 mrg Exp $      */
/*-
 * Copyright (c) 2005 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Konrad E. Schroder <perseant@hhhh.org>.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/statvfs.h>

#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_accessors.h>

#include <disktab.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>

#include "partutil.h"

static void
usage(void)
{
        errx(1, "usage: resize_lfs [-v] [-s new-size] [filesystem]");
}

int
main(int argc, char **argv)
{
        char *rdev, *fsname, buf[LFS_SBPAD];
        size_t rdevlen;
        daddr_t newsize, newnsegs;
        int devfd, rootfd;
        int ch, i, verbose;
        off_t secsize, sboff;
        struct disk_geom geo;
        struct dkwedge_info dkw;
        struct lfs *fs;
        struct statvfs vfs;

        /* Initialize and parse arguments */
        verbose = 0;
        newsize = 0;
        while ((ch = getopt(argc, argv, "s:v")) != -1) {
                switch(ch) {
                case 's':       /* New size, in sectors */
                        newsize = strtoll(optarg, NULL, 10);
                        break;
                case 'v':
                        ++verbose;
                        break;
                default:
                        usage();
                }
        }
        fsname = argv[optind];

        if (fsname == NULL)
                usage();

        /*
         * If the user did not supply a filesystem size, use the
         * length of the mounted partition.
         */
        if (statvfs(fsname, &vfs) < 0)
                err(1, "%s", fsname);
        rdevlen = strlen(vfs.f_mntfromname) + 2;
        rdev = malloc(rdevlen);
        if (getdiskrawname(rdev, rdevlen, vfs.f_mntfromname) == NULL)
                err(1, "Could not convert '%s' to raw name", vfs.f_mntfromname);
        devfd = open(rdev, O_RDONLY);
        if (devfd < 0)
                err(1, "open raw device");

        /*
         * Read the disklabel to find the sector size.  Check the
         * given size against the partition size.  We can skip some
         * error checking here since we know the fs is mountable.
         */
        if (getdiskinfo(rdev, devfd, NULL, &geo, &dkw) == -1)
                err(1, "%s: could not get info", rdev);
        secsize = geo.dg_secsize;
        if (newsize > dkw.dkw_size)
                errx(1, "new size must be <= the partition size");
        if (newsize == 0)
                newsize = dkw.dkw_size;

        /* Open the root of the filesystem so we can fcntl() it */
        rootfd = open(fsname, O_RDONLY);
        if (rootfd < 0)
                err(1, "open filesystem root");

        /* Read the superblock, finding alternates if necessary */
        fs = (struct lfs *)calloc(sizeof(*fs), 1);
        for (sboff = LFS_LABELPAD;;) {
                pread(devfd, buf, sboff, LFS_SBPAD);
                __CTASSERT(sizeof(struct dlfs) == sizeof(struct dlfs64));
                memcpy(&fs->lfs_dlfs_u, buf, sizeof(struct dlfs));
                if (sboff == LFS_LABELPAD && lfs_fsbtob(fs, 1) > LFS_LABELPAD)
                        sboff = lfs_fsbtob(fs, (off_t)lfs_sb_getsboff(fs, 0));
                else
                        break;
        }
        close(devfd);

        /* Calculate new number of segments. */
        newnsegs = (newsize * secsize) / lfs_sb_getssize(fs);
        if (newnsegs == lfs_sb_getnseg(fs)) {
                errx(0, "the filesystem is unchanged.");
        }

        /*
         * If the new filesystem is smaller than the old, we have to
         * invalidate the segments that extend beyond the new boundary.
         * Make the cleaner do this for us.
         * (XXX make the kernel able to do this instead?)
         */
        for (i = lfs_sb_getnseg(fs) - 1; i >= newnsegs; --i) {
                char cmd[128];

                /* If it's already empty, don't call the cleaner */
                if (fcntl(rootfd, LFCNINVAL, &i) == 0)
                        continue;

                snprintf(cmd, sizeof(cmd), "/libexec/lfs_cleanerd -q -i %d %s",
                         i, fsname);
                if (system(cmd) != 0)
                        err(1, "invalidating segment %d", i);
        }

        /* Tell the filesystem to resize itself. */
        if (fcntl(rootfd, LFCNRESIZE, &newnsegs) == -1) {
                err(1, "resizing");
        }

        if (verbose)
                printf("Successfully resized %s from %u to %lld segments\n",
                        fsname, lfs_sb_getnseg(fs), (long long)newnsegs);
        return 0;
}