+static int ext3_valid_block_bitmap(struct super_block *sb,
+ struct ext3_group_desc *desc,
+ unsigned int block_group,
+ struct buffer_head *bh)
+{
+ ext3_grpblk_t offset;
+ ext3_grpblk_t next_zero_bit;
+ ext3_fsblk_t bitmap_blk;
+ ext3_fsblk_t group_first_block;
+
+ group_first_block = ext3_group_first_block_no(sb, block_group);
+
+ /* check whether block bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode table block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+ offset = bitmap_blk - group_first_block;
+ next_zero_bit = ext3_find_next_zero_bit(bh->b_data,
+ offset + EXT3_SB(sb)->s_itb_per_group,
+ offset);
+ if (next_zero_bit >= offset + EXT3_SB(sb)->s_itb_per_group)
+ /* good bitmap for inode tables */
+ return 1;
+
+err_out:
+ ext3_error(sb, __func__,
+ "Invalid block bitmap - "
+ "block_group = %d, block = %lu",
+ block_group, bitmap_blk);
+ return 0;
+}
+