ext3 support as mkfs.ext3, mke2fs, fsck?

[Denys Vlasenko]

On Tue, Aug 16, 2011 at 11:33 AM, Tomasz Czapiewski <xeros at irc.pl> wrote:
> Hi,
> Would you add ext3 filesystem support in mkfs and fsck applets?

mkfs: yes, it's possible.

fsck: busybox does not implement filesystem-specific fsck's,
it only has a driver fsck program.

It's way better and safer to leave creation and maintaining of
filesystem-specific fsck to people who specialize on the filesystem
in question.

> I'm using platform where kernel was built with ext3 fs support but ext2 was
> disabled.
> Currently I'm using binary mke2fs but I'd like to be able to use BusyBox
> applet for that.
>
> Flashing recompiled kernel is quite risky on the platform I'm writing to and
> additional ext2.ko module takes too much space.
>
> '-j' argument is simply ignored by BusyBox mke2fs applet and such ext2
> filesystem is not mountable there.

Adding ext3 support to mke2fs entails mke3fs'ing an image,
looking at it with hex editor, reading docs,
and trying to reproduce the same image with bbox code.
Repeat this until bbox generates the same images as upstream
for all image sizes from ~100k to ~2G and you're done :)
Of course, reading upstream code helps a lot.

-- 
vda