[systemd-devel] dev-root.device is not active, results in an umount spree

[Dimitri John Ledkov]

On 13 May 2015 at 13:43, Lennart Poettering <lennart at poettering.net> wrote:
> On Wed, 13.05.15 12:48, Dimitri John Ledkov (dimitri.j.ledkov at intel.com) wrote:
>
>> I am booting without initramfs, using a plan9 filesystem as rootfs in a kvm.
>>
>> Thus my /proc/cmdline has:
>> root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p
>>
>> # mount
>> /dev/root on / type 9p
>> (rw,relatime,sync,dirsync,rw,trans=virtio,version=9p2000.L)
>>
>> Yet, dev-root.device is dead:
>> # systemctl status dev-root.device
>> ● dev-root.device
>>    Loaded: loaded
>>    Active: inactive (dead)
>
> Yeah, this /dev/root thing is really weird in the kernel. It's not an
> actual device, it's just a weird string. We probably should filter it
> out entirely, and never ever generate a unit dependency for it.
>
> Please check if this fixes things for you:
>
> http://cgit.freedesktop.org/systemd/systemd/commit/?id=7ba2711d3fd283c389db2a1e7b9598ba9f0dac0c
>

Yeap. All good now, can this go into v219-stable tree as well please?

> That said, I figure you should backport
> 628c89cc68ab96fce2de7ebba5933725d147aecc and friends to your tree,
> which should also make this problem go away for you.
>

I have these via stable tree.

>> I am planning to locally patch mount_add_device_links to skip if what
>> is "/dev/root", to avoid a call to unit_add_node_link... But I'm not
>> sure if this is the right thing to do or not.
>
> It is, it's the change I made now, too.
>

Ok, cool.

-- 
Regards,

Dimitri.
Pura Vida!

https://clearlinux.org
Open Source Technology Center
Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ.