Пример #1
0
/*
 * Get file system statistics.
 */
int
ext2fs_statvfs(struct mount *mp, struct statvfs *sbp)
{
	struct ufsmount *ump;
	struct m_ext2fs *fs;
	uint32_t overhead, overhead_per_group, ngdb;
	int i, ngroups;

	ump = VFSTOUFS(mp);
	fs = ump->um_e2fs;
	if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
		panic("ext2fs_statvfs");

	/*
	 * Compute the overhead (FS structures)
	 */
	overhead_per_group =
	    1 /* block bitmap */ +
	    1 /* inode bitmap */ +
	    fs->e2fs_itpg;
	overhead = fs->e2fs.e2fs_first_dblock +
	    fs->e2fs_ncg * overhead_per_group;
	if (EXT2F_HAS_COMPAT_FEATURE(fs, EXT2F_COMPAT_SPARSESUPER2)) {
		/*
		 * Superblock and group descriptions is in group zero,
		 * then optionally 0, 1 or 2 extra copies.
		 */
		ngroups = 1
			+ (fs->e2fs.e4fs_backup_bgs[0] ? 1 : 0)
			+ (fs->e2fs.e4fs_backup_bgs[1] ? 1 : 0);
	} else if (EXT2F_HAS_ROCOMPAT_FEATURE(fs, EXT2F_ROCOMPAT_SPARSESUPER)) {
		for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
			if (cg_has_sb(i))
				ngroups++;
		}
	} else {
		ngroups = fs->e2fs_ncg;
	}
	ngdb = fs->e2fs_ngdb;
	if (EXT2F_HAS_COMPAT_FEATURE(fs, EXT2F_COMPAT_RESIZE))
		ngdb += fs->e2fs.e2fs_reserved_ngdb;
	overhead += ngroups * (1 /* superblock */ + ngdb);

	sbp->f_bsize = fs->e2fs_bsize;
	sbp->f_frsize = MINBSIZE << fs->e2fs.e2fs_fsize;
	sbp->f_iosize = fs->e2fs_bsize;
	sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
	sbp->f_bfree = fs->e2fs.e2fs_fbcount;
	sbp->f_bresvd = fs->e2fs.e2fs_rbcount;
	if (sbp->f_bfree > sbp->f_bresvd)
		sbp->f_bavail = sbp->f_bfree - sbp->f_bresvd;
	else
		sbp->f_bavail = 0;
	sbp->f_files =  fs->e2fs.e2fs_icount;
	sbp->f_ffree = fs->e2fs.e2fs_ficount;
	sbp->f_favail = fs->e2fs.e2fs_ficount;
	sbp->f_fresvd = 0;
	copy_statvfs_info(sbp, mp);
	return 0;
}
Пример #2
0
/*
 * Get file system statistics.
 */
int
ext2fs_statvfs(struct mount *mp, struct statvfs *sbp)
{
//	printf("In file: %s, fun: %s,lineno: %d\n",__FILE__, __func__, __LINE__);
	struct ufsmount *ump;
	struct m_ext2fs *fs;
	uint32_t overhead, overhead_per_group, ngdb;
	int i, ngroups;

	ump = VFSTOUFS(mp);
	fs = ump->um_e2fs;
	if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
		panic("ext2fs_statvfs");

	/*
	 * Compute the overhead (FS structures)
	 */
	overhead_per_group =
	    1 /* block bitmap */ +
	    1 /* inode bitmap */ +
	    fs->e2fs_itpg;
	overhead = fs->e2fs.e2fs_first_dblock +
	    fs->e2fs_ncg * overhead_per_group;
	if (fs->e2fs.e2fs_rev > E2FS_REV0 &&
	    fs->e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
		for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
			if (cg_has_sb(i))
				ngroups++;
		}
	} else {
		ngroups = fs->e2fs_ncg;
	}
	ngdb = fs->e2fs_ngdb;
	if (fs->e2fs.e2fs_rev > E2FS_REV0 &&
	    fs->e2fs.e2fs_features_compat & EXT2F_COMPAT_RESIZE)
		ngdb += fs->e2fs.e2fs_reserved_ngdb;
	overhead += ngroups * (1 /* superblock */ + ngdb);

	sbp->f_bsize = fs->e2fs_bsize;
	sbp->f_frsize = MINBSIZE << fs->e2fs.e2fs_fsize;
	sbp->f_iosize = fs->e2fs_bsize;
	sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
	sbp->f_bfree = fs->e2fs.e2fs_fbcount;
	sbp->f_bresvd = fs->e2fs.e2fs_rbcount;
	if (sbp->f_bfree > sbp->f_bresvd)
		sbp->f_bavail = sbp->f_bfree - sbp->f_bresvd;
	else
		sbp->f_bavail = 0;
	sbp->f_files =  fs->e2fs.e2fs_icount;
	sbp->f_ffree = fs->e2fs.e2fs_ficount;
	sbp->f_favail = fs->e2fs.e2fs_ficount;
	sbp->f_fresvd = 0;
	copy_statvfs_info(sbp, mp);
	return (0);
}
Пример #3
0
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;
}
Пример #4
0
/*
 * Get file system statistics.
 */
int
ext2_statfs(struct mount *mp, struct statfs *sbp)
{
	struct ext2mount *ump;
	struct m_ext2fs *fs;
	uint32_t overhead, overhead_per_group, ngdb;
	int i, ngroups;

	ump = VFSTOEXT2(mp);
	fs = ump->um_e2fs;
	if (fs->e2fs->e2fs_magic != E2FS_MAGIC)
		panic("ext2fs_statfs");

	/*
	 * Compute the overhead (FS structures)
	 */
	overhead_per_group =
	    1 /* block bitmap */ +
	    1 /* inode bitmap */ +
	    fs->e2fs_itpg;
	overhead = fs->e2fs->e2fs_first_dblock +
	    fs->e2fs_gcount * overhead_per_group;
	if (fs->e2fs->e2fs_rev > E2FS_REV0 &&
	    fs->e2fs->e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
		for (i = 0, ngroups = 0; i < fs->e2fs_gcount; i++) {
			if (cg_has_sb(i))
				ngroups++;
		}
	} else {
		ngroups = fs->e2fs_gcount;
	}
	ngdb = fs->e2fs_gdbcount;
	if (fs->e2fs->e2fs_rev > E2FS_REV0 &&
	    fs->e2fs->e2fs_features_compat & EXT2F_COMPAT_RESIZE)
		ngdb += fs->e2fs->e2fs_reserved_ngdb;
	overhead += ngroups * (1 /* superblock */ + ngdb);

	sbp->f_bsize = EXT2_FRAG_SIZE(fs);
	sbp->f_iosize = EXT2_BLOCK_SIZE(fs);
	sbp->f_blocks = fs->e2fs->e2fs_bcount - overhead;
	sbp->f_bfree = fs->e2fs->e2fs_fbcount;
	sbp->f_bavail = sbp->f_bfree - fs->e2fs->e2fs_rbcount;
	sbp->f_files = fs->e2fs->e2fs_icount;
	sbp->f_ffree = fs->e2fs->e2fs_ficount;
	return (0);
}
Пример #5
0
/*
 * Get file system statistics.
 */
int
ext2fs_statfs(struct mount *mp, struct statfs *sbp, struct proc *p)
{
	struct ufsmount *ump;
	struct m_ext2fs *fs;
	u_int32_t overhead, overhead_per_group;
	int i, ngroups;

	ump = VFSTOUFS(mp);
	fs = ump->um_e2fs;
	if (fs->e2fs.e2fs_magic != E2FS_MAGIC)
		panic("ext2fs_statfs");

	/*
	 * Compute the overhead (FS structures)
	 */
	overhead_per_group = 1 /* block bitmap */ + 1 /* inode bitmap */ +
	    fs->e2fs_itpg;
	overhead = fs->e2fs.e2fs_first_dblock +
	    fs->e2fs_ncg * overhead_per_group;
	if (fs->e2fs.e2fs_rev > E2FS_REV0 &&
	    fs->e2fs.e2fs_features_rocompat & EXT2F_ROCOMPAT_SPARSESUPER) {
		for (i = 0, ngroups = 0; i < fs->e2fs_ncg; i++) {
			if (cg_has_sb(i))
				ngroups++;
		}
	} else {
		ngroups = fs->e2fs_ncg;
	}
	overhead += ngroups * (1 + fs->e2fs_ngdb);

	sbp->f_bsize = fs->e2fs_bsize;
	sbp->f_iosize = fs->e2fs_bsize;
	sbp->f_blocks = fs->e2fs.e2fs_bcount - overhead;
	sbp->f_bfree = fs->e2fs.e2fs_fbcount;
	sbp->f_bavail = sbp->f_bfree - fs->e2fs.e2fs_rbcount;
	sbp->f_files =  fs->e2fs.e2fs_icount;
	sbp->f_ffree = fs->e2fs.e2fs_ficount;
	if (sbp != &mp->mnt_stat) {
		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
		memcpy(sbp->f_mntfromspec, mp->mnt_stat.f_mntfromspec, MNAMELEN);
	}
	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
	return (0);
}
Пример #6
0
/*
 * Initialize a cylinder (block) group.
 */
void
initcg(uint cylno)
{
	uint nblcg, i, j, sboff;
	struct ext2fs_dinode *dp;

	/*
	 * Make a copy of the superblock and group descriptors.
	 */
	if (sblock.e2fs.e2fs_rev == E2FS_REV0 ||
	    (sblock.e2fs.e2fs_features_rocompat &
	     EXT2F_ROCOMPAT_SPARSESUPER) == 0 ||
	    cg_has_sb(cylno)) {
		sblock.e2fs.e2fs_block_group_nr = cylno;
		sboff = 0;
		if (cgbase(&sblock, cylno) == 0) {
			/* preserve data in bootblock in cg0 */
			sboff = SBOFF;
		}
		e2fs_sbsave(&sblock.e2fs, (struct ext2fs *)(iobuf + sboff));
		e2fs_cgsave(gd, (struct ext2_gd *)(iobuf +
		    sblock.e2fs_bsize * NBLOCK_SUPERBLOCK),
		    sizeof(struct ext2_gd) * sblock.e2fs_ncg);
		/* write superblock and group descriptor backups */
		wtfs(fsbtodb(&sblock, cgbase(&sblock, cylno)) +
		    sboff / sectorsize, iobufsize - sboff, iobuf + sboff);
	}

	/*
	 * Initialize block bitmap.
	 */
	memset(buf, 0, sblock.e2fs_bsize);
	if (cylno == (sblock.e2fs_ncg - 1)) {
		/* The last group could have less blocks than e2fs_bpg. */
		nblcg = sblock.e2fs.e2fs_bcount -
		    cgbase(&sblock, sblock.e2fs_ncg - 1);
		for (i = nblcg; i < roundup(nblcg, NBBY); i++)
			setbit(buf, i);
		memset(&buf[i / NBBY], ~0U, sblock.e2fs.e2fs_bpg - i);
	}
	/* set overhead (superblock, group descriptor etc.) blocks used */
	for (i = 0; i < cgoverhead(cylno) / NBBY; i++)
		buf[i] = ~0;
	i = i * NBBY;
	for (; i < cgoverhead(cylno); i++)
		setbit(buf, i);
	wtfs(fsbtodb(&sblock, gd[cylno].ext2bgd_b_bitmap), sblock.e2fs_bsize,
	    buf);

	/*
	 * Initialize inode bitmap.
	 *
	 *  Assume e2fs_ipg is a multiple of NBBY since
	 *  it's a multiple of e2fs_ipb (as we did above).
	 *  Note even (possibly smaller) the last group has the same e2fs_ipg.
	 */
	assert(!(sblock.e2fs.e2fs_ipg % NBBY));
	i = sblock.e2fs.e2fs_ipg / NBBY;
	memset(buf, 0, i);
	assert(sblock.e2fs_bsize >= i);
	memset(buf + i, ~0U, sblock.e2fs_bsize - i);
	if (cylno == 0) {
		/* mark reserved inodes */
		for (i = 1; i < EXT2_FIRSTINO; i++)
			setbit(buf, EXT2_INO_INDEX(i));
	}
	wtfs(fsbtodb(&sblock, gd[cylno].ext2bgd_i_bitmap), sblock.e2fs_bsize,
	    buf);

	/*
	 * Initialize inode tables.
	 *
	 *  Just initialize generation numbers for NFS security.
	 *  XXX: sys/ufs/ext2fs/ext2fs_alloc.c:ext2fs_valloc() seems
	 *       to override these generated numbers.
	 */
	memset(buf, 0, sblock.e2fs_bsize);
	for (i = 0; i < sblock.e2fs_itpg; i++) {
		for (j = 0; j < sblock.e2fs_ipb; j++) {
			dp = (struct ext2fs_dinode *)(buf + inodesize * j);
			/* h2fs32() just for consistency */
			dp->e2di_gen = h2fs32(arc4random());
		}
		wtfs(fsbtodb(&sblock, gd[cylno].ext2bgd_i_tables + i),
		    sblock.e2fs_bsize, buf);
	}
}
Пример #7
0
void
mke2fs(const char *fsys, int fi, int fo)
{
	struct timeval tv;
	int64_t minfssize;
	uint bcount, fbcount, ficount;
	uint blocks_gd, blocks_per_cg, inodes_per_cg, iblocks_per_cg;
	uint minblocks_per_cg, blocks_lastcg;
	uint ncg, cylno, sboff;
	uuid_t uuid;
	uint32_t uustat;
	int i, len, col, delta, fld_width, max_cols;
	struct winsize winsize;

	gettimeofday(&tv, NULL);
	fsi = fi;
	fso = fo;

	/*
	 * collect and verify the block and fragment sizes
	 */
	if (!powerof2(bsize)) {
		errx(EXIT_FAILURE,
		    "block size must be a power of 2, not %u\n",
		    bsize);
	}
	if (!powerof2(fsize)) {
		errx(EXIT_FAILURE,
		    "fragment size must be a power of 2, not %u\n",
		    fsize);
	}
	if (fsize < sectorsize) {
		errx(EXIT_FAILURE,
		    "fragment size %u is too small, minimum is %u\n",
		    fsize, sectorsize);
	}
	if (bsize < MINBSIZE) {
		errx(EXIT_FAILURE,
		    "block size %u is too small, minimum is %u\n",
		    bsize, MINBSIZE);
	}
	if (bsize > EXT2_MAXBSIZE) {
		errx(EXIT_FAILURE,
		    "block size %u is too large, maximum is %u\n",
		    bsize, MAXBSIZE);
	}
	if (bsize != fsize) {
		/*
		 * There is no fragment support on current ext2fs (yet?),
		 * but some kernel code refers fsize or fpg as bsize or bpg
		 * and Linux seems to set the same values to them.
		 */
		errx(EXIT_FAILURE,
		    "block size (%u) can't be different from "
		    "fragment size (%u)\n",
		    bsize, fsize);
	}

	/* variable inodesize is REV1 feature */
	if (Oflag == 0 && inodesize != EXT2_REV0_DINODE_SIZE) {
		errx(EXIT_FAILURE, "GOOD_OLD_REV file system format"
		    " doesn't support %d byte inode\n", inodesize);
	}

	sblock.e2fs.e2fs_log_bsize = ilog2(bsize) - LOG_MINBSIZE;
	/* Umm, why not e2fs_log_fsize? */
	sblock.e2fs.e2fs_fsize = ilog2(fsize) - LOG_MINBSIZE;

	sblock.e2fs_bsize = bsize;
	sblock.e2fs_bshift = sblock.e2fs.e2fs_log_bsize + LOG_MINBSIZE;
	sblock.e2fs_qbmask = sblock.e2fs_bsize - 1;
	sblock.e2fs_bmask = ~sblock.e2fs_qbmask;
	sblock.e2fs_fsbtodb = ilog2(sblock.e2fs_bsize) - ilog2(sectorsize);
	sblock.e2fs_ipb = sblock.e2fs_bsize / inodesize;

	/*
	 * Ext2fs preserves BBSIZE (1024 bytes) space at the top for
	 * bootloader (though it is not enough at all for our bootloader).
	 * If bsize == BBSIZE we have to preserve one block.
	 * If bsize > BBSIZE, the first block already contains BBSIZE space
	 * before superblock because superblock is allocated at SBOFF and
	 * bsize is a power of two (i.e. 2048 bytes or more).
	 */
	sblock.e2fs.e2fs_first_dblock = (sblock.e2fs_bsize > BBSIZE) ? 0 : 1;
	minfssize = fsbtodb(&sblock,
	    sblock.e2fs.e2fs_first_dblock +
	    NBLOCK_SUPERBLOCK +
	    1 /* at least one group descriptor */ +
	    NBLOCK_BLOCK_BITMAP	+
	    NBLOCK_INODE_BITMAP +
	    1 /* at least one inode table block */ +
	    1 /* at least one data block for rootdir */ +
	    1 /* at least one data block for data */
	    );			/* XXX and more? */

	if (fssize < minfssize)
		errx(EXIT_FAILURE, "Filesystem size %" PRId64
		    " < minimum size of %" PRId64 "\n", fssize, minfssize);

	bcount = dbtofsb(&sblock, fssize);

	/*
	 * While many people claim that ext2fs is a (bad) clone of ufs/ffs,
	 * it isn't actual ffs so maybe we should call it "block group"
	 * as their native name rather than ffs derived "cylinder group."
	 * But we'll use the latter here since other kernel sources use it.
	 * (I also agree "cylinder" based allocation is obsolete though)
	 */

	/* maybe "simple is the best" */
	blocks_per_cg = sblock.e2fs_bsize * NBBY;

	ncg = howmany(bcount - sblock.e2fs.e2fs_first_dblock, blocks_per_cg);
	blocks_gd = howmany(sizeof(struct ext2_gd) * ncg, bsize);

	/* check range of inode number */
	if (num_inodes < EXT2_FIRSTINO)
		num_inodes = EXT2_FIRSTINO;	/* needs reserved inodes + 1 */
	if (num_inodes > UINT16_MAX * ncg)
		num_inodes = UINT16_MAX * ncg;	/* ext2bgd_nifree is uint16_t */

	inodes_per_cg = num_inodes / ncg;
	iblocks_per_cg = howmany(inodesize * inodes_per_cg, bsize);

	/* Check that the last cylinder group has enough space for inodes */
	minblocks_per_cg =
	    NBLOCK_BLOCK_BITMAP +
	    NBLOCK_INODE_BITMAP +
	    iblocks_per_cg +
	    1;	/* at least one data block */
	if (Oflag == 0 || cg_has_sb(ncg - 1) != 0)
		minblocks_per_cg += NBLOCK_SUPERBLOCK + blocks_gd;

	blocks_lastcg = bcount - sblock.e2fs.e2fs_first_dblock -
	    blocks_per_cg * (ncg - 1);
	if (blocks_lastcg < minblocks_per_cg) {
		/*
		 * Since we make all the cylinder groups the same size, the
		 * last will only be small if there are more than one
		 * cylinder groups. If the last one is too small to store
		 * filesystem data, just kill it.
		 *
		 * XXX: Does fsck_ext2fs(8) properly handle this case?
		 */
		bcount -= blocks_lastcg;
		ncg--;
		blocks_lastcg = blocks_per_cg;
		blocks_gd = howmany(sizeof(struct ext2_gd) * ncg, bsize);
		inodes_per_cg = num_inodes / ncg;
	}
	/* roundup inodes_per_cg to make it use whole inode table blocks */
	inodes_per_cg = roundup(inodes_per_cg, sblock.e2fs_ipb);
	num_inodes = inodes_per_cg * ncg;
	iblocks_per_cg = inodes_per_cg / sblock.e2fs_ipb;

	/* XXX: probably we should check these adjusted values again */

	sblock.e2fs.e2fs_bcount = bcount;
	sblock.e2fs.e2fs_icount = num_inodes;

	sblock.e2fs_ncg = ncg;
	sblock.e2fs_ngdb = blocks_gd;
	sblock.e2fs_itpg = iblocks_per_cg;

	sblock.e2fs.e2fs_rbcount = sblock.e2fs.e2fs_bcount * minfree / 100;
	/* e2fs_fbcount will be accounted later */
	/* e2fs_ficount will be accounted later */

	sblock.e2fs.e2fs_bpg = blocks_per_cg;
	sblock.e2fs.e2fs_fpg = blocks_per_cg;

	sblock.e2fs.e2fs_ipg = inodes_per_cg;

	sblock.e2fs.e2fs_mtime = 0;
	sblock.e2fs.e2fs_wtime = tv.tv_sec;
	sblock.e2fs.e2fs_mnt_count = 0;
	/* XXX: should add some entropy to avoid checking all fs at once? */
	sblock.e2fs.e2fs_max_mnt_count = EXT2_DEF_MAX_MNT_COUNT;

	sblock.e2fs.e2fs_magic = E2FS_MAGIC;
	sblock.e2fs.e2fs_state = E2FS_ISCLEAN;
	sblock.e2fs.e2fs_beh = E2FS_BEH_DEFAULT;
	sblock.e2fs.e2fs_minrev = 0;
	sblock.e2fs.e2fs_lastfsck = tv.tv_sec;
	sblock.e2fs.e2fs_fsckintv = EXT2_DEF_FSCKINTV;

	/*
	 * Maybe we can use E2FS_OS_FREEBSD here and it would be more proper,
	 * but the purpose of this newfs_ext2fs(8) command is to provide
	 * a filesystem which can be recognized by firmware on some
	 * Linux based appliances that can load bootstrap files only from
	 * (their native) ext2fs, and anyway we will (and should) try to
	 * act like them as much as possible.
	 *
	 * Anyway, I hope that all newer such boxes will keep their support
	 * for the "GOOD_OLD_REV" ext2fs.
	 */
	sblock.e2fs.e2fs_creator = E2FS_OS_LINUX;

	if (Oflag == 0) {
		sblock.e2fs.e2fs_rev = E2FS_REV0;
		sblock.e2fs.e2fs_features_compat   = 0;
		sblock.e2fs.e2fs_features_incompat = 0;
		sblock.e2fs.e2fs_features_rocompat = 0;
	} else {
		sblock.e2fs.e2fs_rev = E2FS_REV1;
		/*
		 * e2fsprogs say "REV1" is "dynamic" so
		 * it isn't quite a version and maybe it means
		 * "extended from REV0 so check compat features."
		 *
		 * XXX: We don't have any native tool to activate
		 *      the EXT2F_COMPAT_RESIZE feature and
		 *      fsck_ext2fs(8) might not fix structures for it.
		 */
		sblock.e2fs.e2fs_features_compat   = EXT2F_COMPAT_RESIZE;
		sblock.e2fs.e2fs_features_incompat = EXT2F_INCOMPAT_FTYPE;
		sblock.e2fs.e2fs_features_rocompat =
		    EXT2F_ROCOMPAT_SPARSESUPER | EXT2F_ROCOMPAT_LARGEFILE;
	}

	sblock.e2fs.e2fs_ruid = geteuid();
	sblock.e2fs.e2fs_rgid = getegid();

	sblock.e2fs.e2fs_first_ino = EXT2_FIRSTINO;
	sblock.e2fs.e2fs_inode_size = inodesize;

	/* e2fs_block_group_nr is set on writing superblock to each group */

	uuid_create(&uuid, &uustat);
	if (uustat != uuid_s_ok)
		errx(EXIT_FAILURE, "Failed to generate uuid\n");
	uuid_enc_le(sblock.e2fs.e2fs_uuid, &uuid);
	if (volname != NULL) {
		if (strlen(volname) > sizeof(sblock.e2fs.e2fs_vname))
			errx(EXIT_FAILURE, "Volume name is too long");
		strlcpy(sblock.e2fs.e2fs_vname, volname,
		    sizeof(sblock.e2fs.e2fs_vname));
	}

	sblock.e2fs.e2fs_fsmnt[0] = '\0';
	sblock.e2fs_fsmnt[0] = '\0';

	sblock.e2fs.e2fs_algo = 0;		/* XXX unsupported? */
	sblock.e2fs.e2fs_prealloc = 0;		/* XXX unsupported? */
	sblock.e2fs.e2fs_dir_prealloc = 0;	/* XXX unsupported? */

	/* calculate blocks for reserved group descriptors for resize */
	sblock.e2fs.e2fs_reserved_ngdb = 0;
	if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
	    (sblock.e2fs.e2fs_features_compat & EXT2F_COMPAT_RESIZE) != 0) {
		uint64_t target_blocks;
		uint target_ncg, target_ngdb, reserved_ngdb;

		/* reserve descriptors for size as 1024 times as current */
		target_blocks =
		    (sblock.e2fs.e2fs_bcount - sblock.e2fs.e2fs_first_dblock)
		    * 1024ULL;
		/* number of blocks must be in uint32_t */
		if (target_blocks > UINT32_MAX)
			target_blocks = UINT32_MAX;
		target_ncg = howmany(target_blocks, sblock.e2fs.e2fs_bpg);
		target_ngdb = howmany(sizeof(struct ext2_gd) * target_ncg,
		    sblock.e2fs_bsize);
		/*
		 * Reserved group descriptor blocks are preserved as
		 * the second level double indirect reference blocks in
		 * the EXT2_RESIZEINO inode, so the maximum number of
		 * the blocks is NINDIR(fs).
		 * (see also descriptions in init_resizeino() function)
		 *
		 * We check a number including current e2fs_ngdb here
		 * because they will be moved into reserved gdb on
		 * possible future size shrink, though e2fsprogs don't
		 * seem to care about it.
		 */
		if (target_ngdb > NINDIR(&sblock))
			target_ngdb = NINDIR(&sblock);

		reserved_ngdb = target_ngdb - sblock.e2fs_ngdb;

		/* make sure reserved_ngdb fits in the last cg */
		if (reserved_ngdb >= blocks_lastcg - cgoverhead(ncg - 1))
			reserved_ngdb = blocks_lastcg - cgoverhead(ncg - 1);
		if (reserved_ngdb == 0) {
			/* if no space for reserved gdb, disable the feature */
			sblock.e2fs.e2fs_features_compat &=
			    ~EXT2F_COMPAT_RESIZE;
		}
		sblock.e2fs.e2fs_reserved_ngdb = reserved_ngdb;
	}

	/*
	 * Initialize group descriptors
	 */
	gd = malloc(sblock.e2fs_ngdb * bsize);
	if (gd == NULL)
		errx(EXIT_FAILURE, "Can't allocate descriptors buffer");
	memset(gd, 0, sblock.e2fs_ngdb * bsize);

	fbcount = 0;
	ficount = 0;
	for (cylno = 0; cylno < ncg; cylno++) {
		uint boffset;

		boffset = cgbase(&sblock, cylno);
		if (sblock.e2fs.e2fs_rev == E2FS_REV0 ||
		    (sblock.e2fs.e2fs_features_rocompat &
		     EXT2F_ROCOMPAT_SPARSESUPER) == 0 ||
		    cg_has_sb(cylno)) {
			boffset += NBLOCK_SUPERBLOCK + sblock.e2fs_ngdb;
			if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
			    (sblock.e2fs.e2fs_features_compat &
			     EXT2F_COMPAT_RESIZE) != 0)
				boffset += sblock.e2fs.e2fs_reserved_ngdb;
		}
		gd[cylno].ext2bgd_b_bitmap = boffset;
		boffset += NBLOCK_BLOCK_BITMAP;
		gd[cylno].ext2bgd_i_bitmap = boffset;
		boffset += NBLOCK_INODE_BITMAP;
		gd[cylno].ext2bgd_i_tables = boffset;
		if (cylno == (ncg - 1))
			gd[cylno].ext2bgd_nbfree =
			    blocks_lastcg - cgoverhead(cylno);
		else
			gd[cylno].ext2bgd_nbfree =
			    sblock.e2fs.e2fs_bpg - cgoverhead(cylno);
		fbcount += gd[cylno].ext2bgd_nbfree;
		gd[cylno].ext2bgd_nifree = sblock.e2fs.e2fs_ipg;
		if (cylno == 0) {
			/* take reserved inodes off nifree */
			gd[cylno].ext2bgd_nifree -= EXT2_RESERVED_INODES;
		}
		ficount += gd[cylno].ext2bgd_nifree;
		gd[cylno].ext2bgd_ndirs = 0;
	}
	sblock.e2fs.e2fs_fbcount = fbcount;
	sblock.e2fs.e2fs_ficount = ficount;

	/*
	 * Dump out summary information about file system.
	 */
	if (verbosity > 0) {
		printf("%s: %u.%1uMB (%" PRId64 " sectors) "
		    "block size %u, fragment size %u\n",
		    fsys,
		    (uint)(((uint64_t)bcount * bsize) / (1024 * 1024)),
		    (uint)((uint64_t)bcount * bsize -
		    rounddown((uint64_t)bcount * bsize, 1024 * 1024))
		    / 1024 / 100,
		    fssize, bsize, fsize);
		printf("\tusing %u block groups of %u.0MB, %u blks, "
		    "%u inodes.\n",
		    ncg, bsize * sblock.e2fs.e2fs_bpg / (1024 * 1024),
		    sblock.e2fs.e2fs_bpg, sblock.e2fs.e2fs_ipg);
	}

	/*
	 * allocate space for superblock and group descriptors
	 */
	iobufsize = (NBLOCK_SUPERBLOCK + sblock.e2fs_ngdb) * sblock.e2fs_bsize;
	iobuf = mmap(0, iobufsize, PROT_READ|PROT_WRITE,
	    MAP_ANON|MAP_PRIVATE, -1, 0);
	if (iobuf == NULL)
		errx(EXIT_FAILURE, "Cannot allocate I/O buffer\n");
	memset(iobuf, 0, iobufsize);

	/*
	 * We now start writing to the filesystem
	 */

	if (!Nflag) {
		static const uint pbsize[] = { 1024, 2048, 4096, 0 };
		uint pblock, epblock;
		/*
		 * 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)
			errx(EXIT_FAILURE, "Preposterous size %" PRId64 "\n",
			    fssize);
		wtfs(fssize - 1, sectorsize, iobuf);

		/*
		 * Ensure there is nothing that looks like a filesystem
		 * superblock anywhere other than where ours will be.
		 * If fsck_ext2fs finds the wrong one all hell breaks loose!
		 *
		 * XXX: needs to check how fsck_ext2fs programs even
		 *      on other OSes determine alternate superblocks
		 */
		for (i = 0; pbsize[i] != 0; i++) {
			epblock = (uint64_t)bcount * bsize / pbsize[i];
			for (pblock = ((pbsize[i] == SBSIZE) ? 1 : 0);
			    pblock < epblock;
			    pblock += pbsize[i] * NBBY /* bpg */)
				zap_old_sblock((daddr_t)pblock *
				    pbsize[i] / sectorsize);
		}
	}

	if (verbosity >= 3)
		printf("super-block backups (for fsck_ext2fs -b #) at:\n");
	/* If we are printing more than one line of numbers, line up columns */
	fld_width = verbosity < 4 ? 1 : snprintf(NULL, 0, "%" PRIu64,
	    (uint64_t)cgbase(&sblock, ncg - 1));
	/* Get terminal width */
	if (ioctl(fileno(stdout), TIOCGWINSZ, &winsize) == 0)
		max_cols = winsize.ws_col;
	else
		max_cols = 80;
	if (Nflag && verbosity == 3)
		/* Leave space to add " ..." after one row of numbers */
		max_cols -= 4;
#define BASE 0x10000	/* For some fixed-point maths */
	col = 0;
	delta = verbosity > 2 ? 0 : max_cols * BASE / ncg;
	for (cylno = 0; cylno < ncg; cylno++) {
		fflush(stdout);
		initcg(cylno);
		if (verbosity < 2)
			continue;
		/* the first one is a master, not backup */
		if (cylno == 0)
			continue;
		/* skip if this cylinder doesn't have a backup */
		if (sblock.e2fs.e2fs_rev > E2FS_REV0 &&
		    (sblock.e2fs.e2fs_features_rocompat &
		     EXT2F_ROCOMPAT_SPARSESUPER) != 0 &&
		    cg_has_sb(cylno) == 0)
			continue;

		if (delta > 0) {
			if (Nflag)
				/* No point doing dots for -N */
				break;
			/* Print dots scaled to end near RH margin */
			for (col += delta; col > BASE; col -= BASE)
				printf(".");
			continue;
		}
		/* Print superblock numbers */
		len = printf(" %*" PRIu64 "," + !col, fld_width,
		    (uint64_t)cgbase(&sblock, cylno));
		col += len;
		if (col + len < max_cols)
			/* Next number fits */
			continue;
		/* Next number won't fit, need a newline */
		if (verbosity <= 3) {
			/* Print dots for subsequent cylinder groups */
			delta = sblock.e2fs_ncg - cylno - 1;
			if (delta != 0) {
				if (Nflag) {
					printf(" ...");
					break;
				}
				delta = max_cols * BASE / delta;
			}
		}
		col = 0;
		printf("\n");
	}
#undef BASE
	if (col > 0)
		printf("\n");
	if (Nflag)
		return;

	/*
	 * Now construct the initial file system,
	 */
	if (fsinit(&tv) == 0)
		errx(EXIT_FAILURE, "Error making filesystem");
	/*
	 * Write out the superblock and group descriptors
	 */
	sblock.e2fs.e2fs_block_group_nr = 0;
	sboff = 0;
	if (cgbase(&sblock, 0) == 0) {
		/*
		 * If the first block contains the boot block sectors,
		 * (i.e. in case of sblock.e2fs.e2fs_bsize > BBSIZE)
		 * we have to preserve data in it.
		 */
		sboff = SBOFF;
	}
	e2fs_sbsave(&sblock.e2fs, (struct ext2fs *)(iobuf + sboff));
	e2fs_cgsave(gd, (struct ext2_gd *)(iobuf + sblock.e2fs_bsize),
	   sizeof(struct ext2_gd) * sblock.e2fs_ncg);
	wtfs(fsbtodb(&sblock, cgbase(&sblock, 0)) + sboff / sectorsize,
	    iobufsize - sboff, iobuf + sboff);

	munmap(iobuf, iobufsize);
}