Re: [PATCH RESEND] initramfs: cleanup incomplete rootfs

[David Engraf <david.engraf@sysgo.com>]

On 09.02.19 at 11:35, Andy Shevchenko wrote:
> On Sat, Feb 9, 2019 at 12:08 AM Andrew Morton <akpm@linux-foundation.org> wrote:
>> On Fri, 8 Feb 2019 21:45:21 +0200 Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>>> On Tue, Oct 30, 2018 at 5:22 PM David Engraf <david.engraf@sysgo.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?
> 
> 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. The file itself smaller than the size
> passed through bootparam. So, when decomression is finished
> (successfully!) we still have a garbarge in the memory which is not
> related to archive. Message per se is okay to have, though I consider
> this non-fatal.

I can reproduce this special case. The unpacking decompresses the whole 
size instead of checking the archive size. I will have a look how to get 
the real archive size.

Best regards
- David