On Mon, 14 Dec 2009, David Howells wrote:

 config EXT4_USE_FOR_EXT23
 	bool "Use ext4 for ext2/ext3 file systems"
-	depends on EXT3_FS=n || EXT2_FS=n
+	depends on EXT4_FS && (EXT3_FS=n || EXT2_FS=n)

Side note: I think we should actively avoid complex config dependency 
expressions.

The above can be written with simpler expressions by just splitting it in 
two, and I think it makes it more readable:

	depends on EXT4_FS
	depends on EXT3_FS=n || EXT2_FS=n

since the two expressions are logically totally unrelated: one is just the 
obvious "this kconfig doesn't make sense without ext4" thing that was 
missing before, and the other is a totally unrelated "if you already have 
selected ext2 and ext3, then you clearly don't want ext4 to deal with 
them".

			Linus