Beispiel #1
0
/*
 *  Note: if superblock is non-zero, block-size must also be non-zero.
 * 	Superblock and block_size can be zero to use the default size.
 *
 * Valid flags for ext2fs_open()
 *
 * 	EXT2_FLAG_RW	- Open the filesystem for read/write.
 * 	EXT2_FLAG_FORCE - Open the filesystem even if some of the
 *				features aren't supported.
 *	EXT2_FLAG_JOURNAL_DEV_OK - Open an ext3 journal device
 *	EXT2_FLAG_SKIP_MMP - Open without multi-mount protection check.
 *	EXT2_FLAG_64BITS - Allow 64-bit bitfields (needed for large
 *				filesystems)
 */
errcode_t ext2fs_open2(const char *name, const char *io_options,
		       int flags, int superblock,
		       unsigned int block_size, io_manager manager,
		       ext2_filsys *ret_fs)
{
	ext2_filsys	fs;
	errcode_t	retval;
	unsigned long	i, first_meta_bg;
	__u32		features;
	unsigned int	blocks_per_group, io_flags;
	blk64_t		group_block, blk;
	char		*dest, *cp;
	int		group_zero_adjust = 0;
#ifdef WORDS_BIGENDIAN
	unsigned int	groups_per_block;
	struct ext2_group_desc *gdp;
	int		j;
#endif
	char		*time_env;

	EXT2_CHECK_MAGIC(manager, EXT2_ET_MAGIC_IO_MANAGER);

	retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
	if (retval)
		return retval;

	memset(fs, 0, sizeof(struct struct_ext2_filsys));
	fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
	fs->flags = flags;
	/* don't overwrite sb backups unless flag is explicitly cleared */
	fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
	fs->umask = 022;

	time_env = getenv("E2FSPROGS_FAKE_TIME");
	if (time_env)
		fs->now = strtoul(time_env, NULL, 0);

	retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
	if (retval)
		goto cleanup;
	strcpy(fs->device_name, name);
	cp = strchr(fs->device_name, '?');
	if (!io_options && cp) {
		*cp++ = 0;
		io_options = cp;
	}

	io_flags = 0;
	if (flags & EXT2_FLAG_RW)
		io_flags |= IO_FLAG_RW;
	if (flags & EXT2_FLAG_EXCLUSIVE)
		io_flags |= IO_FLAG_EXCLUSIVE;
	if (flags & EXT2_FLAG_DIRECT_IO)
		io_flags |= IO_FLAG_DIRECT_IO;
	retval = manager->open(fs->device_name, io_flags, &fs->io);
	if (retval)
		goto cleanup;
	if (io_options &&
	    (retval = io_channel_set_options(fs->io, io_options)))
		goto cleanup;
	fs->image_io = fs->io;
	fs->io->app_data = fs;
	retval = io_channel_alloc_buf(fs->io, -SUPERBLOCK_SIZE, &fs->super);
	if (retval)
		goto cleanup;
	if (flags & EXT2_FLAG_IMAGE_FILE) {
		retval = ext2fs_get_mem(sizeof(struct ext2_image_hdr),
					&fs->image_header);
		if (retval)
			goto cleanup;
		retval = io_channel_read_blk(fs->io, 0,
					     -(int)sizeof(struct ext2_image_hdr),
					     fs->image_header);
		if (retval)
			goto cleanup;
		if (fs->image_header->magic_number != EXT2_ET_MAGIC_E2IMAGE)
			return EXT2_ET_MAGIC_E2IMAGE;
		superblock = 1;
		block_size = fs->image_header->fs_blocksize;
	}

	/*
	 * If the user specifies a specific block # for the
	 * superblock, then he/she must also specify the block size!
	 * Otherwise, read the master superblock located at offset
	 * SUPERBLOCK_OFFSET from the start of the partition.
	 *
	 * Note: we only save a backup copy of the superblock if we
	 * are reading the superblock from the primary superblock location.
	 */
	if (superblock) {
		if (!block_size) {
			retval = EXT2_ET_INVALID_ARGUMENT;
			goto cleanup;
		}
		io_channel_set_blksize(fs->io, block_size);
		group_block = superblock;
		fs->orig_super = 0;
	} else {
		io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
		superblock = 1;
		group_block = 0;
		retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &fs->orig_super);
		if (retval)
			goto cleanup;
	}
	retval = io_channel_read_blk(fs->io, superblock, -SUPERBLOCK_SIZE,
				     fs->super);
	if (retval)
		goto cleanup;
	if (fs->orig_super)
		memcpy(fs->orig_super, fs->super, SUPERBLOCK_SIZE);

	if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS)) {
		retval = 0;
		if (!ext2fs_verify_csum_type(fs, fs->super))
			retval = EXT2_ET_UNKNOWN_CSUM;
		if (!ext2fs_superblock_csum_verify(fs, fs->super))
			retval = EXT2_ET_SB_CSUM_INVALID;
	}

#ifdef WORDS_BIGENDIAN
	fs->flags |= EXT2_FLAG_SWAP_BYTES;
	ext2fs_swap_super(fs->super);
#else
	if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
		retval = EXT2_ET_UNIMPLEMENTED;
		goto cleanup;
	}
#endif

	if (fs->super->s_magic != EXT2_SUPER_MAGIC)
		retval = EXT2_ET_BAD_MAGIC;
	if (retval)
		goto cleanup;

	if (fs->super->s_rev_level > EXT2_LIB_CURRENT_REV) {
		retval = EXT2_ET_REV_TOO_HIGH;
		goto cleanup;
	}

	/*
	 * Check for feature set incompatibility
	 */
	if (!(flags & EXT2_FLAG_FORCE)) {
		features = fs->super->s_feature_incompat;
#ifdef EXT2_LIB_SOFTSUPP_INCOMPAT
		if (flags & EXT2_FLAG_SOFTSUPP_FEATURES)
			features &= ~EXT2_LIB_SOFTSUPP_INCOMPAT;
#endif
		if (features & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
			retval = EXT2_ET_UNSUPP_FEATURE;
			goto cleanup;
		}

		features = fs->super->s_feature_ro_compat;
#ifdef EXT2_LIB_SOFTSUPP_RO_COMPAT
		if (flags & EXT2_FLAG_SOFTSUPP_FEATURES)
			features &= ~EXT2_LIB_SOFTSUPP_RO_COMPAT;
#endif
		if ((flags & EXT2_FLAG_RW) &&
		    (features & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)) {
			retval = EXT2_ET_RO_UNSUPP_FEATURE;
			goto cleanup;
		}

		if (!(flags & EXT2_FLAG_JOURNAL_DEV_OK) &&
		    ext2fs_has_feature_journal_dev(fs->super)) {
			retval = EXT2_ET_UNSUPP_FEATURE;
			goto cleanup;
		}
	}

	if ((fs->super->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) >
	    EXT2_MAX_BLOCK_LOG_SIZE) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}

	/*
	 * bigalloc requires cluster-aware bitfield operations, which at the
	 * moment means we need EXT2_FLAG_64BITS.
	 */
	if (ext2fs_has_feature_bigalloc(fs->super) &&
	    !(flags & EXT2_FLAG_64BITS)) {
		retval = EXT2_ET_CANT_USE_LEGACY_BITMAPS;
		goto cleanup;
	}

	if (!ext2fs_has_feature_bigalloc(fs->super) &&
	    (fs->super->s_log_block_size != fs->super->s_log_cluster_size)) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
	if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}

	/* Enforce the block group descriptor size */
	if (ext2fs_has_feature_64bit(fs->super)) {
		if (fs->super->s_desc_size < EXT2_MIN_DESC_SIZE_64BIT) {
			retval = EXT2_ET_BAD_DESC_SIZE;
			goto cleanup;
		}
	} else {
		if (fs->super->s_desc_size &&
		    fs->super->s_desc_size != EXT2_MIN_DESC_SIZE) {
			retval = EXT2_ET_BAD_DESC_SIZE;
			goto cleanup;
		}
	}

	fs->cluster_ratio_bits = fs->super->s_log_cluster_size -
		fs->super->s_log_block_size;
	if (EXT2_BLOCKS_PER_GROUP(fs->super) !=
	    EXT2_CLUSTERS_PER_GROUP(fs->super) << fs->cluster_ratio_bits) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->inode_blocks_per_group = ((EXT2_INODES_PER_GROUP(fs->super) *
				       EXT2_INODE_SIZE(fs->super) +
				       EXT2_BLOCK_SIZE(fs->super) - 1) /
				      EXT2_BLOCK_SIZE(fs->super));
	if (block_size) {
		if (block_size != fs->blocksize) {
			retval = EXT2_ET_UNEXPECTED_BLOCK_SIZE;
			goto cleanup;
		}
	}
	/*
	 * Set the blocksize to the filesystem's blocksize.
	 */
	io_channel_set_blksize(fs->io, fs->blocksize);

	/*
	 * If this is an external journal device, don't try to read
	 * the group descriptors, because they're not there.
	 */
	if (ext2fs_has_feature_journal_dev(fs->super)) {
		fs->group_desc_count = 0;
		*ret_fs = fs;
		return 0;
	}

	if (EXT2_INODES_PER_GROUP(fs->super) == 0) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	/* Precompute the FS UUID to seed other checksums */
	ext2fs_init_csum_seed(fs);

	/*
	 * Read group descriptors
	 */
	blocks_per_group = EXT2_BLOCKS_PER_GROUP(fs->super);
	if (blocks_per_group == 0 ||
	    blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(fs->super) ||
	    fs->inode_blocks_per_group > EXT2_MAX_INODES_PER_GROUP(fs->super) ||
           EXT2_DESC_PER_BLOCK(fs->super) == 0 ||
           fs->super->s_first_data_block >= ext2fs_blocks_count(fs->super)) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
						 fs->super->s_first_data_block,
						 blocks_per_group);
	if (fs->group_desc_count * EXT2_INODES_PER_GROUP(fs->super) !=
	    fs->super->s_inodes_count) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
					  EXT2_DESC_PER_BLOCK(fs->super));
	retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
				&fs->group_desc);
	if (retval)
		goto cleanup;
	if (!group_block)
		group_block = fs->super->s_first_data_block;
	/*
	 * On a FS with a 1K blocksize, block 0 is reserved for bootloaders
	 * so we must increment block numbers to any group 0 items.
	 *
	 * However, we cannot touch group_block directly because in the meta_bg
	 * case, the ext2fs_descriptor_block_loc2() function will interpret
	 * group_block != s_first_data_block to mean that we want to access the
	 * backup group descriptors.  This is not what we want if the caller
	 * set superblock == 0 (i.e. auto-detect the superblock), which is
	 * what's going on here.
	 */
	if (group_block == 0 && fs->blocksize == 1024)
		group_zero_adjust = 1;
	dest = (char *) fs->group_desc;
#ifdef WORDS_BIGENDIAN
	groups_per_block = EXT2_DESC_PER_BLOCK(fs->super);
#endif
	if (ext2fs_has_feature_meta_bg(fs->super)) {
		first_meta_bg = fs->super->s_first_meta_bg;
		if (first_meta_bg > fs->desc_blocks)
			first_meta_bg = fs->desc_blocks;
	} else
		first_meta_bg = fs->desc_blocks;
	if (first_meta_bg) {
		retval = io_channel_read_blk(fs->io, group_block +
					     group_zero_adjust + 1,
					     first_meta_bg, dest);
		if (retval)
			goto cleanup;
#ifdef WORDS_BIGENDIAN
		gdp = (struct ext2_group_desc *) dest;
		for (j=0; j < groups_per_block*first_meta_bg; j++) {
			gdp = ext2fs_group_desc(fs, fs->group_desc, j);
			ext2fs_swap_group_desc2(fs, gdp);
		}
#endif
		dest += fs->blocksize*first_meta_bg;
	}
	for (i=first_meta_bg ; i < fs->desc_blocks; i++) {
		blk = ext2fs_descriptor_block_loc2(fs, group_block, i);
		retval = io_channel_read_blk64(fs->io, blk, 1, dest);
		if (retval)
			goto cleanup;
#ifdef WORDS_BIGENDIAN
		for (j=0; j < groups_per_block; j++) {
			gdp = ext2fs_group_desc(fs, fs->group_desc,
						i * groups_per_block + j);
			ext2fs_swap_group_desc2(fs, gdp);
		}
#endif
		dest += fs->blocksize;
	}

	fs->stride = fs->super->s_raid_stride;

	/*
	 * If recovery is from backup superblock, Clear _UNININT flags &
	 * reset bg_itable_unused to zero
	 */
	if (superblock > 1 && ext2fs_has_group_desc_csum(fs)) {
		dgrp_t group;

		for (group = 0; group < fs->group_desc_count; group++) {
			ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
			ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
			ext2fs_bg_itable_unused_set(fs, group, 0);
			/* The checksum will be reset later, but fix it here
			 * anyway to avoid printing a lot of spurious errors. */
			ext2fs_group_desc_csum_set(fs, group);
		}
		if (fs->flags & EXT2_FLAG_RW)
			ext2fs_mark_super_dirty(fs);
	}

	if (ext2fs_has_feature_mmp(fs->super) &&
	    !(flags & EXT2_FLAG_SKIP_MMP) &&
	    (flags & (EXT2_FLAG_RW | EXT2_FLAG_EXCLUSIVE))) {
		retval = ext2fs_mmp_start(fs);
		if (retval) {
			fs->flags |= EXT2_FLAG_SKIP_MMP; /* just do cleanup */
			ext2fs_mmp_stop(fs);
			goto cleanup;
		}
	}

	if (fs->flags & EXT2_FLAG_SHARE_DUP) {
		fs->block_sha_map = ext2fs_hashmap_create(ext2fs_djb2_hash,
					block_sha_map_free_entry, 4096);
		if (!fs->block_sha_map) {
			retval = EXT2_ET_NO_MEMORY;
			goto cleanup;
		}
		ext2fs_set_feature_shared_blocks(fs->super);
	}

	fs->flags &= ~EXT2_FLAG_NOFREE_ON_ERROR;
	*ret_fs = fs;

	return 0;
cleanup:
	if (!(flags & EXT2_FLAG_NOFREE_ON_ERROR)) {
		ext2fs_free(fs);
		fs = NULL;
	}
	*ret_fs = fs;
	return retval;
}
Beispiel #2
0
/*
 *  Note: if superblock is non-zero, block-size must also be non-zero.
 * 	Superblock and block_size can be zero to use the default size.
 *
 * Valid flags for ext2fs_open()
 *
 * 	EXT2_FLAG_RW	- Open the filesystem for read/write.
 * 	EXT2_FLAG_FORCE - Open the filesystem even if some of the
 *				features aren't supported.
 *	EXT2_FLAG_JOURNAL_DEV_OK - Open an ext3 journal device
 */
errcode_t ext2fs_open2(const char *name, const char *io_options,
		       int flags, int superblock,
		       unsigned int block_size, io_channel * io,
		       ext2_filsys *ret_fs)
{
	ext2_filsys	fs;
	io_manager manager = (*io)->manager;
	errcode_t	retval;
	unsigned long	i, first_meta_bg;
	__u32		features;
	int		groups_per_block, blocks_per_group, io_flags;
	blk64_t		group_block, blk;
	char		*dest, *cp;
#ifdef WORDS_BIGENDIAN
	struct ext2_group_desc *gdp;
	int		j;
#endif

	EXT2_CHECK_MAGIC(manager, EXT2_ET_MAGIC_IO_MANAGER);

	retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
	if (retval)
		return retval;

	memset(fs, 0, sizeof(struct struct_ext2_filsys));
	fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
	fs->io = *io;
	fs->flags = flags;
	/* don't overwrite sb backups unless flag is explicitly cleared */
	fs->flags |= EXT2_FLAG_MASTER_SB_ONLY;
	fs->umask = 022;
	retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
	if (retval)
		goto cleanup;
	strcpy(fs->device_name, name);
	cp = strchr(fs->device_name, '?');
	if (!io_options && cp) {
		*cp++ = 0;
		io_options = cp;
	}

	io_flags = 0;
	if (flags & EXT2_FLAG_RW)
		io_flags |= IO_FLAG_RW;
	if (flags & EXT2_FLAG_EXCLUSIVE)
		io_flags |= IO_FLAG_EXCLUSIVE;
	if (flags & EXT2_FLAG_DIRECT_IO)
		io_flags |= IO_FLAG_DIRECT_IO;
	retval = manager->open(fs->device_name, io_flags, &fs->io);
	if (retval)
		goto cleanup;
	if (io_options &&
	    (retval = io_channel_set_options(fs->io, io_options)))
		goto cleanup;
	fs->image_io = fs->io;
	fs->io->app_data = fs;
	retval = ext2fs_get_memalign(SUPERBLOCK_SIZE, 512, &fs->super);
	if (retval)
		goto cleanup;
	if (flags & EXT2_FLAG_IMAGE_FILE) {
		retval = ext2fs_get_mem(sizeof(struct ext2_image_hdr),
					&fs->image_header);
		if (retval)
			goto cleanup;
		retval = io_channel_read_blk(fs->io, 0,
					     -(int)sizeof(struct ext2_image_hdr),
					     fs->image_header);
		if (retval)
			goto cleanup;
		if (fs->image_header->magic_number != EXT2_ET_MAGIC_E2IMAGE)
			return EXT2_ET_MAGIC_E2IMAGE;
		superblock = 1;
		block_size = fs->image_header->fs_blocksize;
	}

	/*
	 * If the user specifies a specific block # for the
	 * superblock, then he/she must also specify the block size!
	 * Otherwise, read the master superblock located at offset
	 * SUPERBLOCK_OFFSET from the start of the partition.
	 *
	 * Note: we only save a backup copy of the superblock if we
	 * are reading the superblock from the primary superblock location.
	 */
	if (superblock) {
		if (!block_size) {
			retval = EXT2_ET_INVALID_ARGUMENT;
			goto cleanup;
		}
		io_channel_set_blksize(fs->io, block_size);
		group_block = superblock;
		fs->orig_super = 0;
	} else {
		io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
		superblock = 1;
		group_block = 0;
		retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &fs->orig_super);
		if (retval)
			goto cleanup;
	}
	retval = io_channel_read_blk(fs->io, superblock, -SUPERBLOCK_SIZE,
				     fs->super);
	if (retval)
		goto cleanup;
	if (fs->orig_super)
		memcpy(fs->orig_super, fs->super, SUPERBLOCK_SIZE);

#ifdef WORDS_BIGENDIAN
	fs->flags |= EXT2_FLAG_SWAP_BYTES;
	ext2fs_swap_super(fs->super);
#else
	if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
		retval = EXT2_ET_UNIMPLEMENTED;
		goto cleanup;
	}
#endif

	if (fs->super->s_magic != EXT2_SUPER_MAGIC) {
		retval = EXT2_ET_BAD_MAGIC;
		goto cleanup;
	}
	if (fs->super->s_rev_level > EXT2_LIB_CURRENT_REV) {
		retval = EXT2_ET_REV_TOO_HIGH;
		goto cleanup;
	}

	/*
	 * Check for feature set incompatibility
	 */
	if (!(flags & EXT2_FLAG_FORCE)) {
		features = fs->super->s_feature_incompat;
#ifdef EXT2_LIB_SOFTSUPP_INCOMPAT
		if (flags & EXT2_FLAG_SOFTSUPP_FEATURES)
			features &= !EXT2_LIB_SOFTSUPP_INCOMPAT;
#endif
		if (features & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
			retval = EXT2_ET_UNSUPP_FEATURE;
			goto cleanup;
		}

		features = fs->super->s_feature_ro_compat;
#ifdef EXT2_LIB_SOFTSUPP_RO_COMPAT
		if (flags & EXT2_FLAG_SOFTSUPP_FEATURES)
			features &= !EXT2_LIB_SOFTSUPP_RO_COMPAT;
#endif
		if ((flags & EXT2_FLAG_RW) &&
		    (features & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)) {
			retval = EXT2_ET_RO_UNSUPP_FEATURE;
			goto cleanup;
		}

		if (!(flags & EXT2_FLAG_JOURNAL_DEV_OK) &&
		    (fs->super->s_feature_incompat &
		     EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)) {
			retval = EXT2_ET_UNSUPP_FEATURE;
			goto cleanup;
		}
	}

	if ((fs->super->s_log_block_size + EXT2_MIN_BLOCK_LOG_SIZE) >
	    EXT2_MAX_BLOCK_LOG_SIZE) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
	if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->clustersize = EXT2_CLUSTER_SIZE(fs->super);
	fs->inode_blocks_per_group = ((EXT2_INODES_PER_GROUP(fs->super) *
				       EXT2_INODE_SIZE(fs->super) +
				       EXT2_BLOCK_SIZE(fs->super) - 1) /
				      EXT2_BLOCK_SIZE(fs->super));
	if (block_size) {
		if (block_size != fs->blocksize) {
			retval = EXT2_ET_UNEXPECTED_BLOCK_SIZE;
			goto cleanup;
		}
	}
	/*
	 * Set the blocksize to the filesystem's blocksize.
	 */
	io_channel_set_blksize(fs->io, fs->blocksize);

	/*
	 * If this is an external journal device, don't try to read
	 * the group descriptors, because they're not there.
	 */
	if (fs->super->s_feature_incompat &
	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
		fs->group_desc_count = 0;
		*ret_fs = fs;
		return 0;
	}

	if (EXT2_INODES_PER_GROUP(fs->super) == 0) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}

	/*
	 * Read group descriptors
	 */
	blocks_per_group = EXT2_BLOCKS_PER_GROUP(fs->super);
	if (blocks_per_group == 0 ||
	    blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(fs->super) ||
	    fs->inode_blocks_per_group > EXT2_MAX_INODES_PER_GROUP(fs->super) ||
           EXT2_DESC_PER_BLOCK(fs->super) == 0 ||
           fs->super->s_first_data_block >= ext2fs_blocks_count(fs->super)) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->group_desc_count = ext2fs_div64_ceil(ext2fs_blocks_count(fs->super) -
						 fs->super->s_first_data_block,
						 blocks_per_group);
	if (fs->group_desc_count * EXT2_INODES_PER_GROUP(fs->super) !=
	    fs->super->s_inodes_count) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
					  EXT2_DESC_PER_BLOCK(fs->super));
	retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
				&fs->group_desc);
	if (retval)
		goto cleanup;
	if (!group_block)
		group_block = fs->super->s_first_data_block;
	dest = (char *) fs->group_desc;
	groups_per_block = EXT2_DESC_PER_BLOCK(fs->super);
	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
		first_meta_bg = fs->super->s_first_meta_bg;
	else
		first_meta_bg = fs->desc_blocks;
	if (first_meta_bg) {
		retval = io_channel_read_blk(fs->io, group_block+1,
					     first_meta_bg, dest);
		if (retval)
			goto cleanup;
#ifdef WORDS_BIGENDIAN
		gdp = (struct ext2_group_desc *) dest;
		for (j=0; j < groups_per_block*first_meta_bg; j++) {
			gdp = ext2fs_group_desc(fs, fs->group_desc, j);
			ext2fs_swap_group_desc2(fs, gdp);
		}
#endif
		dest += fs->blocksize*first_meta_bg;
	}
	for (i=first_meta_bg ; i < fs->desc_blocks; i++) {
		blk = ext2fs_descriptor_block_loc2(fs, group_block, i);
		retval = io_channel_read_blk64(fs->io, blk, 1, dest);
		if (retval)
			goto cleanup;
#ifdef WORDS_BIGENDIAN
		for (j=0; j < groups_per_block; j++) {
			/* The below happens to work... be careful. */
			gdp = ext2fs_group_desc(fs, fs->group_desc, j);
			ext2fs_swap_group_desc2(fs, gdp);
		}
#endif
		dest += fs->blocksize;
	}

	fs->stride = fs->super->s_raid_stride;

	/*
	 * If recovery is from backup superblock, Clear _UNININT flags &
	 * reset bg_itable_unused to zero
	 */
	if (superblock > 1 && EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
					EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
		dgrp_t group;

		for (group = 0; group < fs->group_desc_count; group++) {
			ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
			ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
			ext2fs_bg_itable_unused_set(fs, group, 0);
		}
		ext2fs_mark_super_dirty(fs);
	}

	fs->flags &= ~EXT2_FLAG_NOFREE_ON_ERROR;
	*ret_fs = fs;
	return 0;
cleanup:
	if (flags & EXT2_FLAG_NOFREE_ON_ERROR)
		*ret_fs = fs;
	else
		ext2fs_free(fs);
	return retval;
}
Beispiel #3
0
static int check_dir_block(ext2_filsys fs,
			   struct ext2_db_entry2 *db,
			   void *priv_data)
{
 	struct dx_dir_info	*dx_dir;
#ifdef ENABLE_HTREE
	struct dx_dirblock_info	*dx_db = 0;
#endif /* ENABLE_HTREE */
	struct ext2_dir_entry 	*dirent, *prev;
	ext2_dirhash_t		hash;
	unsigned int		offset = 0;
	int			dir_modified = 0;
	int			dot_state;
	unsigned int		rec_len;
	blk64_t			block_nr = db->blk;
	ext2_ino_t 		ino = db->ino;
	ext2_ino_t 		subdir_parent;
	__u16			links;
	struct check_dir_struct	*cd;
	char 			*buf;
	e2fsck_t		ctx;
	int			problem;
	struct ext2_dx_root_info *root;
	struct ext2_dx_countlimit *limit;
	static dict_t de_dict;
	struct problem_context	pctx;
	int	dups_found = 0;
	int	ret;
	int	dx_csum_size = 0, de_csum_size = 0;
	int	failed_csum = 0;
	int	is_leaf = 1;

	cd = (struct check_dir_struct *) priv_data;
	buf = cd->buf;
	ctx = cd->ctx;

	if (ctx->flags & E2F_FLAG_SIGNAL_MASK || ctx->flags & E2F_FLAG_RESTART)
		return DIRENT_ABORT;

	if (ctx->progress && (ctx->progress)(ctx, 2, cd->count++, cd->max))
		return DIRENT_ABORT;

	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
		dx_csum_size = sizeof(struct ext2_dx_tail);
		de_csum_size = sizeof(struct ext2_dir_entry_tail);
	}

	/*
	 * Make sure the inode is still in use (could have been
	 * deleted in the duplicate/bad blocks pass.
	 */
	if (!(ext2fs_test_inode_bitmap2(ctx->inode_used_map, ino)))
		return 0;

	cd->pctx.ino = ino;
	cd->pctx.blk = block_nr;
	cd->pctx.blkcount = db->blockcnt;
	cd->pctx.ino2 = 0;
	cd->pctx.dirent = 0;
	cd->pctx.num = 0;

	if (db->blk == 0) {
		if (allocate_dir_block(ctx, db, buf, &cd->pctx))
			return 0;
		block_nr = db->blk;
	}

	if (db->blockcnt)
		dot_state = 2;
	else
		dot_state = 0;

	if (ctx->dirs_to_hash &&
	    ext2fs_u32_list_test(ctx->dirs_to_hash, ino))
		dups_found++;

#if 0
	printf("In process_dir_block block %lu, #%d, inode %lu\n", block_nr,
	       db->blockcnt, ino);
#endif

	ehandler_operation(_("reading directory block"));
	cd->pctx.errcode = ext2fs_read_dir_block4(fs, block_nr, buf, 0, ino);
	ehandler_operation(0);
	if (cd->pctx.errcode == EXT2_ET_DIR_CORRUPTED)
		cd->pctx.errcode = 0; /* We'll handle this ourselves */
	else if (cd->pctx.errcode == EXT2_ET_DIR_CSUM_INVALID) {
		cd->pctx.errcode = 0; /* We'll handle this ourselves */
		failed_csum = 1;
	}
	if (cd->pctx.errcode) {
		char *buf2;
		if (!fix_problem(ctx, PR_2_READ_DIRBLOCK, &cd->pctx)) {
			ctx->flags |= E2F_FLAG_ABORT;
			return DIRENT_ABORT;
		}
		ext2fs_new_dir_block(fs, db->blockcnt == 0 ? ino : 0,
				     EXT2_ROOT_INO, &buf2);
		memcpy(buf, buf2, fs->blocksize);
		ext2fs_free_mem(&buf2);
	}
#ifdef ENABLE_HTREE
	dx_dir = e2fsck_get_dx_dir_info(ctx, ino);
	if (dx_dir && dx_dir->numblocks) {
		if (db->blockcnt >= dx_dir->numblocks) {
			if (fix_problem(ctx, PR_2_UNEXPECTED_HTREE_BLOCK,
					&pctx)) {
				clear_htree(ctx, ino);
				dx_dir->numblocks = 0;
				dx_db = 0;
				goto out_htree;
			}
			fatal_error(ctx, _("Can not continue."));
		}
		dx_db = &dx_dir->dx_block[db->blockcnt];
		dx_db->type = DX_DIRBLOCK_LEAF;
		dx_db->phys = block_nr;
		dx_db->min_hash = ~0;
		dx_db->max_hash = 0;

		dirent = (struct ext2_dir_entry *) buf;
		(void) ext2fs_get_rec_len(fs, dirent, &rec_len);
		limit = (struct ext2_dx_countlimit *) (buf+8);
		if (db->blockcnt == 0) {
			root = (struct ext2_dx_root_info *) (buf + 24);
			dx_db->type = DX_DIRBLOCK_ROOT;
			dx_db->flags |= DX_FLAG_FIRST | DX_FLAG_LAST;
			if ((root->reserved_zero ||
			     root->info_length < 8 ||
			     root->indirect_levels > 1) &&
			    fix_problem(ctx, PR_2_HTREE_BAD_ROOT, &cd->pctx)) {
				clear_htree(ctx, ino);
				dx_dir->numblocks = 0;
				dx_db = 0;
			}
			dx_dir->hashversion = root->hash_version;
			if ((dx_dir->hashversion <= EXT2_HASH_TEA) &&
			    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
				dx_dir->hashversion += 3;
			dx_dir->depth = root->indirect_levels + 1;
		} else if ((dirent->inode == 0) &&
			   (rec_len == fs->blocksize) &&
			   (dirent->name_len == 0) &&
			   (ext2fs_le16_to_cpu(limit->limit) ==
			    ((fs->blocksize - (8 + dx_csum_size)) /
			     sizeof(struct ext2_dx_entry))))
			dx_db->type = DX_DIRBLOCK_NODE;
		is_leaf = 0;
	}
out_htree:
#endif /* ENABLE_HTREE */

	/* Verify checksum. */
	if (is_leaf && de_csum_size) {
		/* No space for csum?  Rebuild dirs in pass 3A. */
		if (!ext2fs_dirent_has_tail(fs, (struct ext2_dir_entry *)buf)) {
			de_csum_size = 0;
			if (e2fsck_dir_will_be_rehashed(ctx, ino))
				goto skip_checksum;
			if (!fix_problem(cd->ctx, PR_2_LEAF_NODE_MISSING_CSUM,
					 &cd->pctx))
				goto skip_checksum;
			e2fsck_rehash_dir_later(ctx, ino);
			goto skip_checksum;
		}
		if (failed_csum) {
			char *buf2;
			if (!fix_problem(cd->ctx, PR_2_LEAF_NODE_CSUM_INVALID,
					 &cd->pctx))
				goto skip_checksum;
			ext2fs_new_dir_block(fs,
					     db->blockcnt == 0 ? ino : 0,
					     EXT2_ROOT_INO, &buf2);
			memcpy(buf, buf2, fs->blocksize);
			ext2fs_free_mem(&buf2);
			dir_modified++;
			failed_csum = 0;
		}
	}
	/* htree nodes don't use fake dirents to store checksums */
	if (!is_leaf)
		de_csum_size = 0;

skip_checksum:
	dict_init(&de_dict, DICTCOUNT_T_MAX, dict_de_cmp);
	prev = 0;
	do {
		int group;
		ext2_ino_t first_unused_inode;

		problem = 0;
		dirent = (struct ext2_dir_entry *) (buf + offset);
		(void) ext2fs_get_rec_len(fs, dirent, &rec_len);
		cd->pctx.dirent = dirent;
		cd->pctx.num = offset;
		if (((offset + rec_len) > fs->blocksize) ||
		    (rec_len < 12) ||
		    ((rec_len % 4) != 0) ||
		    (((dirent->name_len & (unsigned) 0xFF)+8) > rec_len)) {
			if (fix_problem(ctx, PR_2_DIR_CORRUPTED, &cd->pctx)) {
				salvage_directory(fs, dirent, prev, &offset);
				dir_modified++;
				continue;
			} else
				goto abort_free_dict;
		}

		if (dot_state == 0) {
			if (check_dot(ctx, dirent, ino, &cd->pctx))
				dir_modified++;
		} else if (dot_state == 1) {
			ret = check_dotdot(ctx, dirent, ino, &cd->pctx);
			if (ret < 0)
				goto abort_free_dict;
			if (ret)
				dir_modified++;
		} else if (dirent->inode == ino) {
			problem = PR_2_LINK_DOT;
			if (fix_problem(ctx, PR_2_LINK_DOT, &cd->pctx)) {
				dirent->inode = 0;
				dir_modified++;
				goto next;
			}
		}
		if (!dirent->inode)
			goto next;

		/*
		 * Make sure the inode listed is a legal one.
		 */
		if (((dirent->inode != EXT2_ROOT_INO) &&
		     (dirent->inode < EXT2_FIRST_INODE(fs->super))) ||
		    (dirent->inode > fs->super->s_inodes_count)) {
			problem = PR_2_BAD_INO;
		} else if (ctx->inode_bb_map &&
			   (ext2fs_test_inode_bitmap2(ctx->inode_bb_map,
						     dirent->inode))) {
			/*
			 * If the inode is in a bad block, offer to
			 * clear it.
			 */
			problem = PR_2_BB_INODE;
		} else if ((dot_state > 1) &&
			   ((dirent->name_len & 0xFF) == 1) &&
			   (dirent->name[0] == '.')) {
			/*
			 * If there's a '.' entry in anything other
			 * than the first directory entry, it's a
			 * duplicate entry that should be removed.
			 */
			problem = PR_2_DUP_DOT;
		} else if ((dot_state > 1) &&
			   ((dirent->name_len & 0xFF) == 2) &&
			   (dirent->name[0] == '.') &&
			   (dirent->name[1] == '.')) {
			/*
			 * If there's a '..' entry in anything other
			 * than the second directory entry, it's a
			 * duplicate entry that should be removed.
			 */
			problem = PR_2_DUP_DOT_DOT;
		} else if ((dot_state > 1) &&
			   (dirent->inode == EXT2_ROOT_INO)) {
			/*
			 * Don't allow links to the root directory.
			 * We check this specially to make sure we
			 * catch this error case even if the root
			 * directory hasn't been created yet.
			 */
			problem = PR_2_LINK_ROOT;
		} else if ((dot_state > 1) &&
			   (dirent->name_len & 0xFF) == 0) {
			/*
			 * Don't allow zero-length directory names.
			 */
			problem = PR_2_NULL_NAME;
		}

		if (problem) {
			if (fix_problem(ctx, problem, &cd->pctx)) {
				dirent->inode = 0;
				dir_modified++;
				goto next;
			} else {
				ext2fs_unmark_valid(fs);
				if (problem == PR_2_BAD_INO)
					goto next;
			}
		}

		/*
		 * If the inode was marked as having bad fields in
		 * pass1, process it and offer to fix/clear it.
		 * (We wait until now so that we can display the
		 * pathname to the user.)
		 */
		if (ctx->inode_bad_map &&
		    ext2fs_test_inode_bitmap2(ctx->inode_bad_map,
					     dirent->inode)) {
			if (e2fsck_process_bad_inode(ctx, ino,
						     dirent->inode,
						     buf + fs->blocksize)) {
				dirent->inode = 0;
				dir_modified++;
				goto next;
			}
			if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
				return DIRENT_ABORT;
		}

		group = ext2fs_group_of_ino(fs, dirent->inode);
		first_unused_inode = group * fs->super->s_inodes_per_group +
					1 + fs->super->s_inodes_per_group -
					ext2fs_bg_itable_unused(fs, group);
		cd->pctx.group = group;

		/*
		 * Check if the inode was missed out because
		 * _INODE_UNINIT flag was set or bg_itable_unused was
		 * incorrect.  If so, clear the _INODE_UNINIT flag and
		 * restart e2fsck.  In the future it would be nice if
		 * we could call a function in pass1.c that checks the
		 * newly visible inodes.
		 */
		if (ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)) {
			pctx.num = dirent->inode;
			if (fix_problem(ctx, PR_2_INOREF_BG_INO_UNINIT,
					&cd->pctx)){
				ext2fs_bg_flags_clear(fs, group,
						      EXT2_BG_INODE_UNINIT);
				ext2fs_mark_super_dirty(fs);
				ctx->flags |= E2F_FLAG_RESTART_LATER;
			} else {
				ext2fs_unmark_valid(fs);
				if (problem == PR_2_BAD_INO)
					goto next;
			}
		} else if (dirent->inode >= first_unused_inode) {
			pctx.num = dirent->inode;
			if (fix_problem(ctx, PR_2_INOREF_IN_UNUSED, &cd->pctx)){
				ext2fs_bg_itable_unused_set(fs, group, 0);
				ext2fs_mark_super_dirty(fs);
				ctx->flags |= E2F_FLAG_RESTART_LATER;
			} else {
				ext2fs_unmark_valid(fs);
				if (problem == PR_2_BAD_INO)
					goto next;
			}
		}

		/* 
		 * Offer to clear unused inodes; if we are going to be
		 * restarting the scan due to bg_itable_unused being
		 * wrong, then don't clear any inodes to avoid zapping
		 * inodes that were skipped during pass1 due to an
		 * incorrect bg_itable_unused; we'll get any real
		 * problems after we restart.
		 */
		if (!(ctx->flags & E2F_FLAG_RESTART_LATER) &&
		    !(ext2fs_test_inode_bitmap2(ctx->inode_used_map,
						dirent->inode)))
			problem = PR_2_UNUSED_INODE;

		if (problem) {
			if (fix_problem(ctx, problem, &cd->pctx)) {
				dirent->inode = 0;
				dir_modified++;
				goto next;
			} else {
				ext2fs_unmark_valid(fs);
				if (problem == PR_2_BAD_INO)
					goto next;
			}
		}

		if (check_name(ctx, dirent, ino, &cd->pctx))
			dir_modified++;

		if (check_filetype(ctx, dirent, ino, &cd->pctx))
			dir_modified++;

#ifdef ENABLE_HTREE
		if (dx_db) {
			ext2fs_dirhash(dx_dir->hashversion, dirent->name,
				       (dirent->name_len & 0xFF),
				       fs->super->s_hash_seed, &hash, 0);
			if (hash < dx_db->min_hash)
				dx_db->min_hash = hash;
			if (hash > dx_db->max_hash)
				dx_db->max_hash = hash;
		}
#endif

		/*
		 * If this is a directory, then mark its parent in its
		 * dir_info structure.  If the parent field is already
		 * filled in, then this directory has more than one
		 * hard link.  We assume the first link is correct,
		 * and ask the user if he/she wants to clear this one.
		 */
		if ((dot_state > 1) &&
		    (ext2fs_test_inode_bitmap2(ctx->inode_dir_map,
					      dirent->inode))) {
			if (e2fsck_dir_info_get_parent(ctx, dirent->inode,
						       &subdir_parent)) {
				cd->pctx.ino = dirent->inode;
				fix_problem(ctx, PR_2_NO_DIRINFO, &cd->pctx);
				goto abort_free_dict;
			}
			if (subdir_parent) {
				cd->pctx.ino2 = subdir_parent;
				if (fix_problem(ctx, PR_2_LINK_DIR,
						&cd->pctx)) {
					dirent->inode = 0;
					dir_modified++;
					goto next;
				}
				cd->pctx.ino2 = 0;
			} else {
				(void) e2fsck_dir_info_set_parent(ctx,
						  dirent->inode, ino);
			}
		}

		if (dups_found) {
			;
		} else if (dict_lookup(&de_dict, dirent)) {
			clear_problem_context(&pctx);
			pctx.ino = ino;
			pctx.dirent = dirent;
			fix_problem(ctx, PR_2_REPORT_DUP_DIRENT, &pctx);
			e2fsck_rehash_dir_later(ctx, ino);
			dups_found++;
		} else
			dict_alloc_insert(&de_dict, dirent, dirent);

		ext2fs_icount_increment(ctx->inode_count, dirent->inode,
					&links);
		if (links > 1)
			ctx->fs_links_count++;
		ctx->fs_total_count++;
	next:
		prev = dirent;
		if (dir_modified)
			(void) ext2fs_get_rec_len(fs, dirent, &rec_len);
		offset += rec_len;
		dot_state++;
	} while (offset < fs->blocksize - de_csum_size);
#if 0
	printf("\n");
#endif
#ifdef ENABLE_HTREE
	if (dx_db) {
#ifdef DX_DEBUG
		printf("db_block %d, type %d, min_hash 0x%0x, max_hash 0x%0x\n",
		       db->blockcnt, dx_db->type,
		       dx_db->min_hash, dx_db->max_hash);
#endif
		cd->pctx.dir = cd->pctx.ino;
		if ((dx_db->type == DX_DIRBLOCK_ROOT) ||
		    (dx_db->type == DX_DIRBLOCK_NODE))
			parse_int_node(fs, db, cd, dx_dir, buf, failed_csum);
	}
#endif /* ENABLE_HTREE */

	if (offset != fs->blocksize - de_csum_size) {
		cd->pctx.num = rec_len - (fs->blocksize - de_csum_size) +
			       offset;
		if (fix_problem(ctx, PR_2_FINAL_RECLEN, &cd->pctx)) {
			dirent->rec_len = cd->pctx.num;
			dir_modified++;
		}
	}
	if (dir_modified) {
		/* leaf block with no tail?  Rehash dirs later. */
		if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
				EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
		    is_leaf &&
		    !ext2fs_dirent_has_tail(fs, (struct ext2_dir_entry *)buf))
			e2fsck_rehash_dir_later(ctx, ino);

write_and_fix:
		if (e2fsck_dir_will_be_rehashed(ctx, ino))
			ctx->fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
		cd->pctx.errcode = ext2fs_write_dir_block4(fs, block_nr, buf,
							   0, ino);
		if (e2fsck_dir_will_be_rehashed(ctx, ino))
			ctx->fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
		if (cd->pctx.errcode) {
			if (!fix_problem(ctx, PR_2_WRITE_DIRBLOCK,
					 &cd->pctx))
				goto abort_free_dict;
		}
		ext2fs_mark_changed(fs);
	} else if (is_leaf && failed_csum && !dir_modified) {
		/*
		 * If a leaf node that fails csum makes it this far without
		 * alteration, ask the user if the checksum should be fixed.
		 */
		if (fix_problem(ctx, PR_2_LEAF_NODE_ONLY_CSUM_INVALID,
				&cd->pctx))
			goto write_and_fix;
	}
	dict_free_nodes(&de_dict);
	return 0;
abort_free_dict:
	ctx->flags |= E2F_FLAG_ABORT;
	dict_free_nodes(&de_dict);
	return DIRENT_ABORT;
}
Beispiel #4
0
errcode_t ext2fs_initialize(const char *name, int flags,
			    struct ext2_super_block *param,
			    io_manager manager, ext2_filsys *ret_fs)
{
	ext2_filsys	fs;
	errcode_t	retval;
	struct ext2_super_block *super;
	unsigned int	rem;
	unsigned int	overhead = 0;
	unsigned int	ipg;
	dgrp_t		i;
	blk64_t		free_blocks;
	blk_t		numblocks;
	int		rsv_gdt;
	int		csum_flag;
	int		bigalloc_flag;
	int		io_flags;
	unsigned	reserved_inos;
	char		*buf = 0;
	char		c;
	double		reserved_ratio;

	if (!param || !ext2fs_blocks_count(param))
		return EXT2_ET_INVALID_ARGUMENT;

	retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
	if (retval)
		return retval;

	memset(fs, 0, sizeof(struct struct_ext2_filsys));
	fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
	fs->flags = flags | EXT2_FLAG_RW;
	fs->umask = 022;
	fs->default_bitmap_type = EXT2FS_BMAP64_RBTREE;
#ifdef WORDS_BIGENDIAN
	fs->flags |= EXT2_FLAG_SWAP_BYTES;
#endif
	io_flags = IO_FLAG_RW;
	if (flags & EXT2_FLAG_EXCLUSIVE)
		io_flags |= IO_FLAG_EXCLUSIVE;
	if (flags & EXT2_FLAG_DIRECT_IO)
		io_flags |= IO_FLAG_DIRECT_IO;
	retval = manager->open(name, io_flags, &fs->io);
	if (retval)
		goto cleanup;
	fs->image_io = fs->io;
	fs->io->app_data = fs;
	retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
	if (retval)
		goto cleanup;

	strcpy(fs->device_name, name);
	retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
	if (retval)
		goto cleanup;
	fs->super = super;

	memset(super, 0, SUPERBLOCK_SIZE);

#define set_field(field, default) (super->field = param->field ? \
				   param->field : (default))
#define assign_field(field)	(super->field = param->field)

	super->s_magic = EXT2_SUPER_MAGIC;
	super->s_state = EXT2_VALID_FS;

	bigalloc_flag = EXT2_HAS_RO_COMPAT_FEATURE(param,
				   EXT4_FEATURE_RO_COMPAT_BIGALLOC);

	assign_field(s_log_block_size);

	if (bigalloc_flag) {
		set_field(s_log_cluster_size, super->s_log_block_size+4);
		if (super->s_log_block_size > super->s_log_cluster_size) {
			retval = EXT2_ET_INVALID_ARGUMENT;
			goto cleanup;
		}
	} else
		super->s_log_cluster_size = super->s_log_block_size;

	set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1);
	set_field(s_max_mnt_count, 0);
	set_field(s_errors, EXT2_ERRORS_DEFAULT);
	set_field(s_feature_compat, 0);
	set_field(s_feature_incompat, 0);
	set_field(s_feature_ro_compat, 0);
	set_field(s_default_mount_opts, 0);
	set_field(s_first_meta_bg, 0);
	set_field(s_raid_stride, 0);		/* default stride size: 0 */
	set_field(s_raid_stripe_width, 0);	/* default stripe width: 0 */
	set_field(s_log_groups_per_flex, 0);
	set_field(s_flags, 0);
	assign_field(s_backup_bgs[0]);
	assign_field(s_backup_bgs[1]);
	if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
		retval = EXT2_ET_UNSUPP_FEATURE;
		goto cleanup;
	}
	if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
		retval = EXT2_ET_RO_UNSUPP_FEATURE;
		goto cleanup;
	}

	set_field(s_rev_level, EXT2_GOOD_OLD_REV);
	if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
		set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
		set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
		if (super->s_inode_size >= sizeof(struct ext2_inode_large)) {
			int extra_isize = sizeof(struct ext2_inode_large) -
				EXT2_GOOD_OLD_INODE_SIZE;
			set_field(s_min_extra_isize, extra_isize);
			set_field(s_want_extra_isize, extra_isize);
		}
	} else {
		super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
		super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
	}

	set_field(s_checkinterval, 0);
	super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL);

	super->s_creator_os = CREATOR_OS;

	fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super);
	fs->cluster_ratio_bits = super->s_log_cluster_size -
		super->s_log_block_size;

	if (bigalloc_flag) {
		unsigned long long bpg;

		if (param->s_blocks_per_group &&
		    param->s_clusters_per_group &&
		    ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) !=
		     param->s_blocks_per_group)) {
			retval = EXT2_ET_INVALID_ARGUMENT;
			goto cleanup;
		}
		if (param->s_clusters_per_group)
			assign_field(s_clusters_per_group);
		else if (param->s_blocks_per_group)
			super->s_clusters_per_group = 
				param->s_blocks_per_group /
				EXT2FS_CLUSTER_RATIO(fs);
		else if (super->s_log_cluster_size + 15 < 32)
			super->s_clusters_per_group = fs->blocksize * 8;
		else
			super->s_clusters_per_group = (fs->blocksize - 1) * 8;
		if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super))
			super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super);
		bpg = EXT2FS_C2B(fs,
			(unsigned long long) super->s_clusters_per_group);
		if (bpg >= (((unsigned long long) 1) << 32)) {
			retval = EXT2_ET_INVALID_ARGUMENT;
			goto cleanup;
		}
		super->s_blocks_per_group = bpg;
	} else {
		set_field(s_blocks_per_group, fs->blocksize * 8);
		if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
			super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
		super->s_clusters_per_group = super->s_blocks_per_group;
	}

	ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) &
				~((blk64_t) EXT2FS_CLUSTER_MASK(fs)));
	ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param));
	if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) {
		retval = EXT2_ET_INVALID_ARGUMENT;
		goto cleanup;
	}

	set_field(s_mmp_update_interval, 0);

	/*
	 * If we're creating an external journal device, we don't need
	 * to bother with the rest.
	 */
	if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
		fs->group_desc_count = 0;
		ext2fs_mark_super_dirty(fs);
		*ret_fs = fs;
		return 0;
	}

retry:
	fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil(
		ext2fs_blocks_count(super) - super->s_first_data_block,
		EXT2_BLOCKS_PER_GROUP(super));
	if (fs->group_desc_count == 0) {
		retval = EXT2_ET_TOOSMALL;
		goto cleanup;
	}

	set_field(s_desc_size,
		  super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
		  EXT2_MIN_DESC_SIZE_64BIT : 0);

	fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
					  EXT2_DESC_PER_BLOCK(super));

	i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;

	if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT &&
	    (ext2fs_blocks_count(super) / i) > (1ULL << 32))
		set_field(s_inodes_count, ~0U);
	else
		set_field(s_inodes_count, ext2fs_blocks_count(super) / i);

	/*
	 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
	 * that we have enough inodes for the filesystem(!)
	 */
	if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
		super->s_inodes_count = EXT2_FIRST_INODE(super)+1;

	/*
	 * There should be at least as many inodes as the user
	 * requested.  Figure out how many inodes per group that
	 * should be.  But make sure that we don't allocate more than
	 * one bitmap's worth of inodes each group.
	 */
	ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count);
	if (ipg > fs->blocksize * 8) {
		if (!bigalloc_flag && super->s_blocks_per_group >= 256) {
			/* Try again with slightly different parameters */
			super->s_blocks_per_group -= 8;
			ext2fs_blocks_count_set(super,
						ext2fs_blocks_count(param));
			super->s_clusters_per_group = super->s_blocks_per_group;
			goto retry;
		} else {
			retval = EXT2_ET_TOO_MANY_INODES;
			goto cleanup;
		}
	}

	if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
		ipg = EXT2_MAX_INODES_PER_GROUP(super);

ipg_retry:
	super->s_inodes_per_group = ipg;

	/*
	 * Make sure the number of inodes per group completely fills
	 * the inode table blocks in the descriptor.  If not, add some
	 * additional inodes/group.  Waste not, want not...
	 */
	fs->inode_blocks_per_group = (((super->s_inodes_per_group *
					EXT2_INODE_SIZE(super)) +
				       EXT2_BLOCK_SIZE(super) - 1) /
				      EXT2_BLOCK_SIZE(super));
	super->s_inodes_per_group = ((fs->inode_blocks_per_group *
				      EXT2_BLOCK_SIZE(super)) /
				     EXT2_INODE_SIZE(super));
	/*
	 * Finally, make sure the number of inodes per group is a
	 * multiple of 8.  This is needed to simplify the bitmap
	 * splicing code.
	 */
	if (super->s_inodes_per_group < 8)
		super->s_inodes_per_group = 8;
	super->s_inodes_per_group &= ~7;
	fs->inode_blocks_per_group = (((super->s_inodes_per_group *
					EXT2_INODE_SIZE(super)) +
				       EXT2_BLOCK_SIZE(super) - 1) /
				      EXT2_BLOCK_SIZE(super));

	/*
	 * adjust inode count to reflect the adjusted inodes_per_group
	 */
	if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) {
		ipg--;
		goto ipg_retry;
	}
	super->s_inodes_count = super->s_inodes_per_group *
		fs->group_desc_count;
	super->s_free_inodes_count = super->s_inodes_count;

	/*
	 * check the number of reserved group descriptor table blocks
	 */
	if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
		rsv_gdt = calc_reserved_gdt_blocks(fs);
	else
		rsv_gdt = 0;
	set_field(s_reserved_gdt_blocks, rsv_gdt);
	if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
		retval = EXT2_ET_RES_GDT_BLOCKS;
		goto cleanup;
	}

	/*
	 * Calculate the maximum number of bookkeeping blocks per
	 * group.  It includes the superblock, the block group
	 * descriptors, the block bitmap, the inode bitmap, the inode
	 * table, and the reserved gdt blocks.
	 */
	overhead = (int) (3 + fs->inode_blocks_per_group +
			  fs->desc_blocks + super->s_reserved_gdt_blocks);

	/* This can only happen if the user requested too many inodes */
	if (overhead > super->s_blocks_per_group) {
		retval = EXT2_ET_TOO_MANY_INODES;
		goto cleanup;
	}

	/*
	 * See if the last group is big enough to support the
	 * necessary data structures.  If not, we need to get rid of
	 * it.  We need to recalculate the overhead for the last block
	 * group, since it might or might not have a superblock
	 * backup.
	 */
	overhead = (int) (2 + fs->inode_blocks_per_group);
	if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
		overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
	rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) %
	       super->s_blocks_per_group);
	if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
		retval = EXT2_ET_TOOSMALL;
		goto cleanup;
	}
	if (rem && (rem < overhead+50)) {
		ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) -
					rem);
		/*
		 * If blocks count is changed, we need to recalculate
		 * reserved blocks count not to exceed 50%.
		 */
		reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) /
			ext2fs_blocks_count(param);
		ext2fs_r_blocks_count_set(super, reserved_ratio *
			ext2fs_blocks_count(super) / 100.0);

		goto retry;
	}

	/*
	 * At this point we know how big the filesystem will be.  So
	 * we can do any and all allocations that depend on the block
	 * count.
	 */

	/* Set up the locations of the backup superblocks */
	if (super->s_feature_compat & EXT4_FEATURE_COMPAT_SPARSE_SUPER2) {
		if (super->s_backup_bgs[0] >= fs->group_desc_count)
			super->s_backup_bgs[0] = fs->group_desc_count - 1;
		if (super->s_backup_bgs[1] >= fs->group_desc_count)
			super->s_backup_bgs[1] = fs->group_desc_count - 1;
		if (super->s_backup_bgs[0] == super->s_backup_bgs[1])
			super->s_backup_bgs[1] = 0;
		if (super->s_backup_bgs[0] > super->s_backup_bgs[1]) {
			__u32 t = super->s_backup_bgs[0];
			super->s_backup_bgs[0] = super->s_backup_bgs[1];
			super->s_backup_bgs[1] = t;
		}
	}

	retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
	if (retval)
		goto cleanup;

	strcpy(buf, "block bitmap for ");
	strcat(buf, fs->device_name);
	retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map);
	if (retval)
		goto cleanup;

	strcpy(buf, "inode bitmap for ");
	strcat(buf, fs->device_name);
	retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
	if (retval)
		goto cleanup;

	ext2fs_free_mem(&buf);

	retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
				&fs->group_desc);
	if (retval)
		goto cleanup;

	memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);

	/*
	 * Reserve the superblock and group descriptors for each
	 * group, and fill in the correct group statistics for group.
	 * Note that although the block bitmap, inode bitmap, and
	 * inode table have not been allocated (and in fact won't be
	 * by this routine), they are accounted for nevertheless.
	 *
	 * If FLEX_BG meta-data grouping is used, only account for the
	 * superblock and group descriptors (the inode tables and
	 * bitmaps will be accounted for when allocated).
	 */
	free_blocks = 0;
	csum_flag = ext2fs_has_group_desc_csum(fs);
	reserved_inos = super->s_first_ino;
	for (i = 0; i < fs->group_desc_count; i++) {
		/*
		 * Don't set the BLOCK_UNINIT group for the last group
		 * because the block bitmap needs to be padded.
		 */
		if (csum_flag) {
			if (i != fs->group_desc_count - 1)
				ext2fs_bg_flags_set(fs, i,
						    EXT2_BG_BLOCK_UNINIT);
			ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
			numblocks = super->s_inodes_per_group;
			if (reserved_inos) {
				if (numblocks > reserved_inos) {
					numblocks -= reserved_inos;
					reserved_inos = 0;
				} else {
					reserved_inos -= numblocks;
					numblocks = 0;
				}
			}
			ext2fs_bg_itable_unused_set(fs, i, numblocks);
		}
		numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
		if (fs->super->s_log_groups_per_flex)
			numblocks += 2 + fs->inode_blocks_per_group;

		free_blocks += numblocks;
		ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
		ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group);
		ext2fs_bg_used_dirs_count_set(fs, i, 0);
		ext2fs_group_desc_csum_set(fs, i);
	}
	free_blocks &= ~EXT2FS_CLUSTER_MASK(fs);
	ext2fs_free_blocks_count_set(super, free_blocks);

	c = (char) 255;
	if (((int) c) == -1) {
		super->s_flags |= EXT2_FLAGS_SIGNED_HASH;
	} else {
		super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
	}

	ext2fs_mark_super_dirty(fs);
	ext2fs_mark_bb_dirty(fs);
	ext2fs_mark_ib_dirty(fs);

	io_channel_set_blksize(fs->io, fs->blocksize);

	*ret_fs = fs;
	return 0;
cleanup:
	free(buf);
	ext2fs_free(fs);
	return retval;
}