linux-kernel - Re: [PATCH RESEND] initramfs: cleanup incomplete rootfs

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Message-Id: <20190208140810.76ef6c25825a5644d9625f0a@linux-foundation.org>
Date:   Fri, 8 Feb 2019 14:08:10 -0800
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
Cc:     David Engraf <david.engraf@...go.com>,
        Dominik Brodowski <linux@...inikbrodowski.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Philippe Ombredanne <pombredanne@...b.com>,
        Arnd Bergmann <arnd@...db.de>,
        Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH RESEND] initramfs: cleanup incomplete rootfs

On Fri, 8 Feb 2019 21:45:21 +0200 Andy Shevchenko <andy.shevchenko@...il.com> wrote:

> On Tue, Oct 30, 2018 at 5:22 PM David Engraf <david.engraf@...go.com> wrote:
> >
> > Unpacking an external initrd may fail e.g. not enough memory. This leads
> > to an incomplete rootfs because some files might be extracted already.
> > Fixed by cleaning the rootfs so the kernel is not using an incomplete
> > rootfs.
> 
> This breaks my setup where I have U-boot provided more size of
> initramfs than needed. This allows a bit of flexibility to increase or
> decrease initramfs compressed image without taking care of bootloader.
> The proper solution is to do this if we sure that we didn't get enough
> memory, otherwise I can't consider the error fatal to clean up rootfs.

OK, thanks.  Maybe David can suggest a fix - I'll queue up a revert
meanwhile.

I don't really understand the failure.  Why does an oversized initramfs
cause unpack_to_rootfs() to fail?