e4defrag doesn't work on root filesystem

[Ravi Pinjala <ravi@p-static.net>]

Hi,

I'm playing with e4defrag from e2frprogs git, and I've run into a bug.
When I try to defragment files on my root filesystem, it refuses to
acknowledge that the filesystem is ext4. I believe the problem is that
it checks the filesystem type by parsing /etc/mtab, but the root
filesystem shows up there like this:

rootfs on / type rootfs (rw)
/dev/root on / type ext4 (rw,noatime,barrier=1,data=ordered)

so it gets confused by the bogus first entry. It works just fine on
other ext4 filesystems I have.

(If this is the wrong mailing list, I apologize; I couldn't find one for
e2fsprogs, so I thought this was the next best thing.)

--Ravi