Add support for creating and checking 8192-byte blocksize filesystems.
We complain if you try to create such a filesystem on a system with 4096
byte PAGE_SIZE.

Add checks for valid inode size for undocumented -I option.

diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
index d8fa228..bf64c68 100644
--- a/lib/ext2fs/initialize.c
+++ b/lib/ext2fs/initialize.c
@@ -166,8 +166,8 @@
 			   EXT2_DESC_PER_BLOCK(super) - 1)
 		/ EXT2_DESC_PER_BLOCK(super);
 
-	/* n.b., fs->blocksize is <= 4096 */
-	set_field(s_inodes_count, super->s_blocks_count/(4096/fs->blocksize));
+	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