Re: [PATCH RESEND] initramfs: cleanup incomplete rootfs

From: David Engraf
Date: Tue Feb 12 2019 - 03:04:31 EST


On 12.02.19 at 01:56, Andrew Morton wrote:
On Sat, 9 Feb 2019 12:35:03 +0200 Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:

On Sat, Feb 9, 2019 at 12:08 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
On Fri, 8 Feb 2019 21:45:21 +0200 Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:
On Tue, Oct 30, 2018 at 5:22 PM David Engraf <david.engraf@xxxxxxxxx> 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?

In my case I have got "Junk in compressed archive". I don't know (I
would check if needed) which exact condition I got since there are
three places with this message.

Well that's a plain irritating screwup right there. Could someone
please cook up a patch to give us three distinct (and hopefully more
informative) error messages?

Done. BTW "invalid magic at start of compressed archive" is the error we get with the patch.

Best regards
- David