[systemd-devel] Problems with rootfs over nfs

[Kay Sievers]

On Mon, May 16, 2011 at 14:27, Lennart Poettering
<lennart at poettering.net> wrote:
> On Mon, 16.05.11 13:44, Kay Sievers (kay.sievers at vrfy.org) wrote:
>
>> On Mon, May 16, 2011 at 13:39, Daniel Drake <dsd at laptop.org> wrote:
>> > On 15 May 2011 15:16, Kay Sievers <kay.sievers at vrfy.org> wrote:
>> >> Just a first quick check of an issue we ran into with ATA disks:
>> >> what's in /proc/sys/kernel/hotplug before you shut down? Or what's
>> >> CONFIG_UEVENT_HELPER in your kernel setup, it must be ="" on modern
>> >> systems, otherwise the kernel will they to exec() binaries all the
>> >> time and keep the system's rootfs busy.
>> >
>> > I'm also having trouble shutting down with systemd, and I have
>> > CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
>> > So I'll try this solution. Thanks.
>> >
>> > Just a quick question: is the same also true for Fedora 14
>> > (upstart-1.2, udev-161)? i.e. can and should that config option be
>> > cleared under that setup too? I guess so, given that /sbin/hotplug
>> > doesn't even exist.
>>
>> Yeah, /sbin/hotplug is ancient history or (broken) embedded-like
>> setups, it should always be disabled. In earlier udev/init setups we
>> used to do: echo > /proc/sys/kernel/hotplug, but we don't do it in
>> systemd setups, that's why it pops up now.
>
> I could add a taint check for this? Shall I?

Not sure, probably not. The next kernel will be fixed to disable all
usermode_helper on shutdown:
  http://git.kernel.org/?p=linux/kernel/git/gregkh/driver-core-2.6.git;a=commit;h=b50fa7c8077c625919b1e0a75fc37b825f024518

I guess, we have no real business in checking kernel config for stuff
that we don't depend on. if people want to use /sbin/hotplug, they
should be able to do it. It will slow down things, but it will not
cause any real problems after the kernel fix.

Kay