Re: [RFC V2] init: support device of major:minor:offset format

[Yu Chen <yu.c.chen@intel.com>]

Hi, Geert

On 05/07/2015 12:49 AM, Geert Uytterhoeven wrote:
> On Wed, May 6, 2015 at 2:24 AM, Chen Yu <yu.c.chen@intel.com> wrote:
>> Distribution like Ubuntu uses klibc rather than uswsusp to resume
>> system from hibernation, which will treat swap partition/file in
>> the form of major:minor:offset. For example, 8:3:0 represents a
>> swap partition in klibc, and klibc's resume process in initrd will
>> finally echo 8:3:0 to /sys/power/resume for manually restoring.
>> However in current implementation, 8:3:0 will be treated as an invalid
>
> Why can't klibc write the same information as uswsusp?
I agree. However it seems that klibc treats all device/file as such
fixed format when dealing with hibernation, I guess that might be
easier for it to implement?

> Why should the kernel adapt to a specific piece of userspace?
>
>> device format, and it is found that manual resumming from hibernation
>> will fail on lastest kernel.
>
> Is this a regression, perhaps introduced by commit 283e7ad024115571
> ("init: stricter checking of major:minor root= values")? If that is the case,
> please say so.
>
yes, it is. I think there's a modified patch for it at:

https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=cb31ef485dd4c6a205d1064b42027f82076d00c8


Thanks

Best Regards,
Yu

> Gr{oetje,eeting}s,
>
>                          Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds
>