示例#1
0
static errcode_t test_open(const char *name, int flags, io_channel *channel)
{
	io_channel	io = NULL;
	struct test_private_data *data = NULL;
	errcode_t	retval;

	if (name == 0)
		return EXT2_ET_BAD_DEVICE_NAME;
	retval = ext2fs_get_mem(sizeof(struct struct_io_channel),
				(void **) &io);
	if (retval)
		return retval;
	memset(io, 0, sizeof(struct struct_io_channel));
	io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
	retval = ext2fs_get_mem(sizeof(struct test_private_data),
				(void **) &data);
	if (retval) {
		retval = EXT2_ET_NO_MEMORY;
		goto cleanup;
	}
	io->manager = test_io_manager;
	retval = ext2fs_get_mem(strlen(name)+1, (void **) &io->name);
	if (retval)
		goto cleanup;

	strcpy(io->name, name);
	io->private_data = data;
	io->block_size = 1024;
	io->read_error = 0;
	io->write_error = 0;
	io->refcount = 1;

	memset(data, 0, sizeof(struct test_private_data));
	data->magic = EXT2_ET_MAGIC_TEST_IO_CHANNEL;
	if (test_io_backing_manager) {
		retval = test_io_backing_manager->open(name, flags,
						       &data->real);
		if (retval)
			goto cleanup;
	} else
		data->real = 0;
	data->read_blk = 	test_io_cb_read_blk;
	data->write_blk = 	test_io_cb_write_blk;
	data->set_blksize = 	test_io_cb_set_blksize;
	data->write_byte = 	test_io_cb_write_byte;
	
	*channel = io;
	return 0;

cleanup:
	if (io)
		ext2fs_free_mem((void **) &io);
	if (data)
		ext2fs_free_mem((void **) &data);
	return retval;
}
示例#2
0
static errcode_t test_open(const char *name, int flags, io_channel *channel)
{
	io_channel	io = NULL;
	struct test_private_data *data = NULL;
	errcode_t	retval;
	char		*value;

	if (name == 0)
		return EXT2_ET_BAD_DEVICE_NAME;
	retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
	if (retval)
		return retval;
	memset(io, 0, sizeof(struct struct_io_channel));
	io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
	retval = ext2fs_get_mem(sizeof(struct test_private_data), &data);
	if (retval) {
		retval = EXT2_ET_NO_MEMORY;
		goto cleanup;
	}
	io->manager = test_io_manager;
	retval = ext2fs_get_mem(strlen(name)+1, &io->name);
	if (retval)
		goto cleanup;

	strcpy(io->name, name);
	io->private_data = data;
	io->block_size = 1024;
	io->read_error = 0;
	io->write_error = 0;
	io->refcount = 1;

	memset(data, 0, sizeof(struct test_private_data));
	data->magic = EXT2_ET_MAGIC_TEST_IO_CHANNEL;
	if (test_io_backing_manager) {
		retval = test_io_backing_manager->open(name, flags,
						       &data->real);
		if (retval)
			goto cleanup;
	} else
		data->real = 0;
	data->read_blk = 	test_io_cb_read_blk;
	data->write_blk = 	test_io_cb_write_blk;
	data->set_blksize = 	test_io_cb_set_blksize;
	data->write_byte = 	test_io_cb_write_byte;
	data->read_blk64 = 	test_io_cb_read_blk64;
	data->write_blk64 = 	test_io_cb_write_blk64;

	data->outfile = NULL;
	if ((value = safe_getenv("TEST_IO_LOGFILE")) != NULL)
		data->outfile = fopen(value, "w");
	if (!data->outfile)
		data->outfile = stderr;

	data->flags = 0;
	if ((value = safe_getenv("TEST_IO_FLAGS")) != NULL)
		data->flags = strtoul(value, NULL, 0);

	data->block = 0;
	if ((value = safe_getenv("TEST_IO_BLOCK")) != NULL)
		data->block = strtoul(value, NULL, 0);

	data->read_abort_count = 0;
	if ((value = safe_getenv("TEST_IO_READ_ABORT")) != NULL)
		data->read_abort_count = strtoul(value, NULL, 0);

	data->write_abort_count = 0;
	if ((value = safe_getenv("TEST_IO_WRITE_ABORT")) != NULL)
		data->write_abort_count = strtoul(value, NULL, 0);

	*channel = io;
	return 0;

cleanup:
	if (io)
		ext2fs_free_mem(&io);
	if (data)
		ext2fs_free_mem(&data);
	return retval;
}
示例#3
0
文件: util.c 项目: guaneryu/e2fsprogs
blk64_t get_backup_sb(e2fsck_t ctx, ext2_filsys fs, const char *name,
		      io_manager manager)
{
	struct ext2_super_block *sb;
	io_channel		io = NULL;
	void			*buf = NULL;
	int			blocksize;
	blk64_t			superblock, ret_sb = 8193;

	if (fs && fs->super) {
		ret_sb = (fs->super->s_blocks_per_group +
			  fs->super->s_first_data_block);
		if (ctx) {
			ctx->superblock = ret_sb;
			ctx->blocksize = fs->blocksize;
		}
		return ret_sb;
	}

	if (ctx) {
		if (ctx->blocksize) {
			ret_sb = ctx->blocksize * 8;
			if (ctx->blocksize == 1024)
				ret_sb++;
			ctx->superblock = ret_sb;
			return ret_sb;
		}
		ctx->superblock = ret_sb;
		ctx->blocksize = 1024;
	}

	if (!name || !manager)
		goto cleanup;

	if (manager->open(name, 0, &io) != 0)
		goto cleanup;

	if (ext2fs_get_mem(SUPERBLOCK_SIZE, &buf))
		goto cleanup;
	sb = (struct ext2_super_block *) buf;

	for (blocksize = EXT2_MIN_BLOCK_SIZE;
	     blocksize <= EXT2_MAX_BLOCK_SIZE ; blocksize *= 2) {
		superblock = blocksize*8;
		if (blocksize == 1024)
			superblock++;
		io_channel_set_blksize(io, blocksize);
		if (io_channel_read_blk64(io, superblock,
					-SUPERBLOCK_SIZE, buf))
			continue;
#ifdef WORDS_BIGENDIAN
		if (sb->s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC))
			ext2fs_swap_super(sb);
#endif
		if ((sb->s_magic == EXT2_SUPER_MAGIC) &&
		    (EXT2_BLOCK_SIZE(sb) == blocksize)) {
			ret_sb = superblock;
			if (ctx) {
				ctx->superblock = superblock;
				ctx->blocksize = blocksize;
			}
			break;
		}
	}

cleanup:
	if (io)
		io_channel_close(io);
	if (buf)
		ext2fs_free_mem(&buf);
	return (ret_sb);
}
示例#4
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;
}
示例#5
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_manager manager,
		       ext2_filsys *ret_fs)
{
	ext2_filsys	fs;
	errcode_t	retval;
	unsigned long	i, first_meta_bg;
	__u32		features;
	int		groups_per_block, blocks_per_group, io_flags;
	blk_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->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_mem(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);

#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->fragsize = EXT2_FRAG_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 >= fs->super->s_blocks_count) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->group_desc_count = ext2fs_div_ceil(fs->super->s_blocks_count -
					       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++)
			ext2fs_swap_group_desc(gdp++);
#endif
		dest += fs->blocksize*first_meta_bg;
	}
	for (i=first_meta_bg ; i < fs->desc_blocks; i++) {
		blk = ext2fs_descriptor_block_loc(fs, group_block, i);
		retval = io_channel_read_blk(fs->io, blk, 1, dest);
		if (retval)
			goto cleanup;
#ifdef WORDS_BIGENDIAN
		gdp = (struct ext2_group_desc *) dest;
		for (j=0; j < groups_per_block; j++)
			ext2fs_swap_group_desc(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)) {
		struct ext2_group_desc *gd;
		for (i = 0, gd = fs->group_desc; i < fs->group_desc_count;
		     i++, gd++) {
			gd->bg_flags &= ~EXT2_BG_BLOCK_UNINIT;
			gd->bg_flags &= ~EXT2_BG_INODE_UNINIT;
			gd->bg_itable_unused = 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;
}
示例#6
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;
    int		frags_per_block;
    unsigned int	rem;
    unsigned int	overhead = 0;
    unsigned int	ipg;
    dgrp_t		i;
    blk_t		numblocks;
    int		rsv_gdt;
    int		io_flags;
    char		*buf;
    char		c;

    if (!param || !param->s_blocks_count)
        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;
#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;
    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))

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

    set_field(s_log_block_size, 0);	/* default blocksize: 1024 bytes */
    set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
    set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
    set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
    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_first_meta_bg, 0);
    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);
    }

    set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
    super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL);

    super->s_creator_os = CREATOR_OS;

    fs->blocksize = EXT2_BLOCK_SIZE(super);
    fs->fragsize = EXT2_FRAG_SIZE(super);
    frags_per_block = fs->blocksize / fs->fragsize;

    /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */
    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_frags_per_group = super->s_blocks_per_group * frags_per_block;

    super->s_blocks_count = param->s_blocks_count;
    super->s_r_blocks_count = param->s_r_blocks_count;
    if (super->s_r_blocks_count >= param->s_blocks_count) {
        retval = EXT2_ET_INVALID_ARGUMENT;
        goto cleanup;
    }

    /*
     * 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 = ext2fs_div_ceil(super->s_blocks_count -
                                           super->s_first_data_block,
                                           EXT2_BLOCKS_PER_GROUP(super));
    if (fs->group_desc_count == 0) {
        retval = EXT2_ET_TOOSMALL;
        goto cleanup;
    }
    fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
                                      EXT2_DESC_PER_BLOCK(super));

    i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
    set_field(s_inodes_count, super->s_blocks_count / 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 (super->s_blocks_per_group >= 256) {
            /* Try again with slightly different parameters */
            super->s_blocks_per_group -= 8;
            super->s_blocks_count = param->s_blocks_count;
            super->s_frags_per_group = super->s_blocks_per_group *
                                       frags_per_block;
            goto retry;
        } else
            return EXT2_ET_TOO_MANY_INODES;
    }

    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.
     */
    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;
    }

    /*
     * Overhead is the number of bookkeeping blocks per group.  It
     * includes the superblock backup, the group descriptor
     * backups, the inode bitmap, the block bitmap, and the inode
     * table.
     */

    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;

    /* This can only happen if the user requested too many inodes */
    if (overhead > super->s_blocks_per_group)
        return EXT2_ET_TOO_MANY_INODES;

    /*
     * See if the last group is big enough to support the
     * necessary data structures.  If not, we need to get rid of
     * it.
     */
    rem = ((super->s_blocks_count - super->s_first_data_block) %
           super->s_blocks_per_group);
    if ((fs->group_desc_count == 1) && rem && (rem < overhead))
        return EXT2_ET_TOOSMALL;
    if (rem && (rem < overhead+50)) {
        super->s_blocks_count -= rem;
        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.
     */

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

    sprintf(buf, "block bitmap for %s", fs->device_name);
    retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
    if (retval)
        goto cleanup;

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

    ext2fs_free_mem(&buf);

    retval = ext2fs_get_mem((size_t) 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.
     */
    super->s_free_blocks_count = 0;
    for (i = 0; i < fs->group_desc_count; i++) {
        numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);

        super->s_free_blocks_count += numblocks;
        fs->group_desc[i].bg_free_blocks_count = numblocks;
        fs->group_desc[i].bg_free_inodes_count =
            fs->super->s_inodes_per_group;
        fs->group_desc[i].bg_used_dirs_count = 0;
    }

    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:
    ext2fs_free(fs);
    return retval;
}
示例#7
0
文件: openfs.c 项目: K0T0LI/busybox
/*
 *  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_manager manager, 
		       ext2_filsys *ret_fs)
{
	ext2_filsys	fs;
	errcode_t	retval;
	unsigned long	i;
	int		groups_per_block, blocks_per_group;
	blk_t		group_block, blk;
	char		*dest, *cp;
#ifdef EXT2FS_ENABLE_SWAPFS
	int j;
	struct ext2_group_desc *gdp;
#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->flags = flags;
	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;
	}
		
	retval = manager->open(fs->device_name, 
			       (flags & EXT2_FLAG_RW) ? IO_FLAG_RW : 0,
			       &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_mem(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);

#ifdef EXT2FS_ENABLE_SWAPFS
	if ((fs->super->s_magic == ext2fs_swab16(EXT2_SUPER_MAGIC)) ||
	    (fs->flags & EXT2_FLAG_SWAP_BYTES)) {
		fs->flags |= EXT2_FLAG_SWAP_BYTES;

		ext2fs_swap_super(fs->super);
	}
#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)) {
		if (fs->super->s_feature_incompat &
		    ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
			retval = EXT2_ET_UNSUPP_FEATURE;
			goto cleanup;
		}
		if ((flags & EXT2_FLAG_RW) &&
		    (fs->super->s_feature_ro_compat &
		     ~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;
		}
	}
	
	fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
	if (fs->blocksize == 0) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->fragsize = EXT2_FRAG_SIZE(fs->super);
	fs->inode_blocks_per_group = ((fs->super->s_inodes_per_group *
				       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;
	}
	
	/*
	 * 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)) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->group_desc_count = (fs->super->s_blocks_count -
				fs->super->s_first_data_block +
				blocks_per_group - 1) / blocks_per_group;
	fs->desc_blocks = (fs->group_desc_count +
			   EXT2_DESC_PER_BLOCK(fs->super) - 1)
		/ EXT2_DESC_PER_BLOCK(fs->super);
	retval = ext2fs_get_mem(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 = fs->blocksize / sizeof(struct ext2_group_desc);
	for (i=0 ; i < fs->desc_blocks; i++) {
		blk = ext2fs_descriptor_block_loc(fs, group_block, i);
		retval = io_channel_read_blk(fs->io, blk, 1, dest);
		if (retval)
			goto cleanup;
#ifdef EXT2FS_ENABLE_SWAPFS
		if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
			gdp = (struct ext2_group_desc *) dest;
			for (j=0; j < groups_per_block; j++)
				ext2fs_swap_group_desc(gdp++);
		}
#endif
		dest += fs->blocksize;
	}

	*ret_fs = fs;
	return 0;
cleanup:
	ext2fs_free(fs);
	return retval;
}
示例#8
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;
}