I encountered a similar problem in Gentoo - e2fsck 1.42.5 can't check read-only mounted FS with an external journal. Ted Ts'o just wrote a fix: http://www.spinics.net/lists/linux-ext4/msg38096.html
That fixes the problem for me; it should for you as well. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org