Re: [PATCH 2/4] Remove stale archivemount support

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Apr 05, 2024 at 08:09:32PM +0200, Stefano Brivio wrote:
> On Fri, 22 Mar 2024 13:27:37 +1100
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > mbuto has two ways of building the initramfs.  One is the typical approach
> > of staging its contents in a temporary directory, then building the
> > initramfs with cpio.  The other is to create an empty initramfs, mount
> > it with archivemount, and copy things into the mounted archive.
> > 
> > However, the archivemount approach is broken.  I'm not entirely sure why,
> > but it appears not to properly unmount the archive and retrieve the final.
> > filled version.  The upshot is that if archivemount is installed, then
> > mbuto generates an empty, gzip-compressed initramfs instead of whatever it
> > was supposed to.  It looks like this has bitrotted from some earlier
> > working version.
> > 
> > The archivemount approach is not necessary, and honestly a pretty strange
> > and roundabout way of building the initramfs.  Remove it.
> 
> There were two reasons behind that: first off, I mistakenly assumed
> that the kernel could see changes made to the initramfs after boot.

Yeah, that was never going to work.

> Second, it was actually convenient for developing this tool as I could
> just make directories and copies in half-working images. I also had
> half a mind about some usage with QEMU rebooting the guest, and the
> initramfs would change across reboots without having to call mbuto
> again, for bisections or suchlike.

That's not really dependent on using archivemount in any case.  If
qemu re-reads the initrd on each boot, then you can still do this by
rebuilding the image between boots (which is all that archivemount
would do anyway).  If qemu doesn't re-read it, then this won't work
even if you are using archivemount.

> But sure, it turned out to be quite complicated to maintain, and it
> looks like it has been broken on Fedora for a while now (probably due
> to differences between fakeroot and fakeroot-ng I didn't take into
> account), so, with some regrets, I'm fine to drop this now.
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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