On Mon, 2013-07-29 at 13:26 +0400, Askar Safin wrote:
> > But I wonder whether this configuration file is really needed for most
> > system. Couldn't we use blkid to find the swap partition automagically?
> > (The configuration file would still be necessary if there are multiple
> > swap partitions.)
> Imagine the following: there is Debian on /dev/sda1, Debian on /dev/sda2 and swap on /dev/sda3.
> Debian on sda2 configured to use sda3. Debian on sda1 doesn't use swap. Debian on sda2 suspends to sda3. Then user runs Debian on sda1.
> Initramfs from sda1 looks at the sda3 and says: "Oh! There is swap. Let's wake up from it". And initramfs performs waking up from wrong partition.
> So, don't search swap at the resume time.
In this case, sure, you wouldn't want that.
But that kind of multiboot configuration is not the *usual* case. We
should try to make the usual case 'just work' without disruption.
> > initramfs-tools has its own resume configuration file, but so far as I
> > can see the uswsusp package does not use it. So there would be no
> > reason for you to modify it - would there?
> No, "resume" file is really used. It used by early userspace.
> I just created virtual machine with fresh jessie and without swap and performed the following test:
> 1. Installed uswsusp. uswsusp said to me that I have no swap and I should add it and run "dpkg-reconfigure uswsusp".
> 2. I added swap
> 3. Rebooted
> 4. I ran "dpkg-reconfigure uswsusp". uswsusp found my swap and it was happy. It asked me a lot of questions. Then uswsusp triggered initramfs rebuilding
> 5. Rebooted
> 6. I ran "s2disk" and I could not wake up. So, this is a bug.
> 7. I created "resume" file (there was no such file before) and I put "RESUME=UUID=..." to it.
[...]
I agree this is currently needed, although the value is not used. I
assume this is done to allow overriding resume with the 'noresume' boot
parameter.
I think uswsusp should be properly integrated with initramfs-tools
handling of boot parameters by making the following changes:
1. In the initramfs build hook, write this to
$DESTDIR/conf/conf.d/resume-uswsusp:
RESUME=$(sed -rn 's/^resume device[[:space:]]+[:=][[:space:]]+// p' /etc/uswsusp.conf)
resume_offset=$(sed -rn 's/^resume offset[[:space:]]+[:=][[:space:]]+// p' /etc/uswsusp.conf)
Since this file name sorts after 'resume', it overrides the swsusp
configuration. But it can still be overridden by boot parameters.
2. In the initramfs local-premount hook, do:
/sbin/resume -r "$resume" -o "${resume_offset:-0}"
Ben.
--
Ben Hutchings
I say we take off; nuke the site from orbit. It's the only way to be sure.
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