mount of ext2fs volume stuck in "D+" state (disk uninterruptible wait)

[Joe Peterson]

New information: it looks as though this ext2fs was already mounted when
the mount was attempted.  I have reproduced the issue by simply trying
to mount the ext2fs volume more than once.  Given this, I'd expect the
mount to return an already mounted error rather than hanging, so this is
perhaps a straightforward bug.

						-Joe