[systemd-devel] sd 221 regression: login - nonexistent sessions via lightdm

[poma]

On 07.07.2015 19:48, David Herrmann wrote:
> Hi
> 
> On Tue, Jul 7, 2015 at 7:10 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
>> Hi
>>
>> On Tue, Jul 7, 2015 at 6:55 PM, Martin Pitt <martin.pitt at ubuntu.com> wrote:
>>> Hey David,
>>>
>>> David Herrmann [2015-07-07 18:31 +0200]:
>>>>> Revert "login: re-use VT-sessions if they already exist" - commit 0204c4b
>>>>> http://cgit.freedesktop.org/systemd/systemd/commit/?id=0204c4b
>>>>
>>>> Can someone elaborate what exactly lightdm does here? We really want
>>>> to prevent multiple sessions on the same VT. This is just nasty and
>>>> never made any sense. So I'm really interested why lightdm doesn't
>>>> kill it's manager-session before it starts the new session. Any
>>>> particular reason here?
>>>
>>> I'll let Robert answer with the details, but something I noticed:
>>>
>>> It's not that simple to reproduce, but sometimes it seems the lightdm
>>> "greeter" session (running as user lightdm, where you select user/type
>>> password and so on) doesn't completely terminate, but some processes
>>> stay around in it. Thus the greeter session stays around in state
>>> "Closing", and then the "real" session starts on the same VT.
>>>
>>> I asked the reporter of https://launchpad.net/bugs/1472259 to attach
>>> systemd-cgls, so that we can see what's running in the session.
>>
>> So it might indeed just be a race in lightdm. Hmm..
>> Anyway, this patch here should also fix the issue (if it does, I'll
>> commit something proper).
> 
> Ok, I pushed this to -git now. Should be fixed. Can you guys verify?
> 
> Thanks
> David
> 

$ loginctl list-sessions 
   SESSION        UID USER             SEAT            
         1       1001 test             seat0           
        c1        989 lightdm          seat0           

2 sessions listed.

$ loginctl show-session c1 
Id=c1
Name=lightdm
Timestamp=Tue 2015-07-07 21:44:41 CEST
TimestampMonotonic=51125373
VTNr=1
Display=:0
Remote=no
Service=lightdm-greeter
Scope=session-c1.scope
Leader=1346
Audit=0
Type=x11
Class=greeter
Active=no
State=closing
IdleHint=no
IdleSinceHint=0
IdleSinceHintMonotonic=0

$ loginctl show-session 1
Id=1
Name=test
Timestamp=Tue 2015-07-07 21:56:10 CEST
TimestampMonotonic=739928248
VTNr=1
Display=:0
Remote=no
Service=lightdm
Desktop=xfce
Scope=session-1.scope
Leader=1983
Audit=1
Type=x11
Class=user
Active=yes
State=active
IdleHint=no
IdleSinceHint=0
IdleSinceHintMonotonic=0

$ rpm -q systemd lightdm lightdm-gtk
systemd-222-2.fc23.x86_64
lightdm-1.15.0-2.fc23.x86_64
lightdm-gtk-2.0.1-2.fc23.x86_64

It's OK.