[Mageia 4] Cannot log into LightDM

[sclarckone]

Hello there,

I've got some trouble with my (almost) fresh Mageia 4 install, I can't log anymore into my Cinnamon session (it worked previously).

I usually don't have to even log in since I chose to automatically log into my graphical session with LightDM. But today, when I booted up I was asked by LightDM to type my password, which I did. Then I could see the Nvidia logo (since I use the proprietary driver) and immediately after I was thrown back to the login screen... I tried to log in as root but the problem is exactly the same.

Any idea what the problem could be ? Or which log file I should take a look at (I inspected the lightdm logs but nothing caught my attention) ?

Thanks for your help !

[tarakbumba]

Are there any clues from journalctl -b or cat .xsession-errors ?

[sclarckone]

The xsessions-errors is full of insignificant errors but it ends with a rather worrying error :

Code: Select all

XIO:  fatal IO error 4 (Interrupted system call) on X server ":0"
      after 4996 requests (4996 known processed) with 0 events remaining.

Since there are no timestamps I can't know for sure but it's the last line of the log file so it must have occurred at last boot. But the X server seems to be running fine because if I try to run the 'startx' command from another tty, I get the following message :

Code: Select all

Fatal server error : server is already active for display 0

As for the systemd journal file, I have the following entries regarding session management :

Code: Select all

Mar 13 21:22:37 localhost systemd[1]: Starting User Manager for 500...
Mar 13 21:22:37 localhost systemd[1]: Starting Session 1 of user sclarckone.
Mar 13 21:22:37 localhost systemd-logind[961]: New session 1 of user sclarckone.
Mar 13 21:22:37 localhost systemd-logind[961]: Linked /tmp/.X11-unix/X0 to /run/user/500/X11-display.
Mar 13 21:22:37 localhost systemd[1389]: pam_tcb(systemd-user:session): Session opened for sclarckone by (uid=0)
Mar 13 21:22:37 localhost systemd[1]: Started Session 1 of user sclarckone.
Mar 13 21:22:37 localhost systemd[1389]: Failed to open private bus connection: Failed to connect to socket /run/user/500/dbus/user_bus_socket: No such file or directory
Mar 13 21:22:37 localhost systemd[1]: Stopping Session 1 of user sclarckone.
Mar 13 21:22:37 localhost systemd[1]: Stopped Session 1 of user sclarckone.
Mar 13 21:22:37 localhost systemd[1389]: Starting Default.
Mar 13 21:22:37 localhost systemd[1389]: Reached target Default.
Mar 13 21:22:37 localhost systemd[1389]: Startup finished in 21ms.
Mar 13 21:22:37 localhost systemd[1]: Started User Manager for 500.
Mar 13 21:22:37 localhost systemd-logind[961]: Removed session 1.
Mar 13 21:22:37 localhost systemd[1]: Stopping User Manager for 500...
Mar 13 21:22:37 localhost lightdm[1385]: pam_tcb(lightdm-autologin:session): Session opened for sclarckone by sclarckone(uid=0)
Mar 13 21:22:37 localhost systemd[1394]: pam_tcb(systemd-user:session): Session opened for sclarckone by (uid=0)
Mar 13 21:22:37 localhost systemd[1395]: pam_tcb(systemd-user:session): Session closed for sclarckone
Mar 13 21:22:37 localhost systemd[1389]: Stopping Default.
Mar 13 21:22:37 localhost systemd[1389]: Stopped target Default.
Mar 13 21:22:37 localhost systemd[1389]: Starting Shutdown.
Mar 13 21:22:37 localhost systemd[1389]: Reached target Shutdown.
Mar 13 21:22:37 localhost systemd[1389]: Starting Exit the Session...
Mar 13 21:22:37 localhost systemd[1389]: Received SIGRTMIN+24 from PID 1397 (kill).
Mar 13 21:22:37 localhost systemd[1]: Stopped User Manager for 500.
Mar 13 21:22:37 localhost systemd[1]: Stopping user-500.slice.
Mar 13 21:22:37 localhost systemd[1]: Removed slice user-500.slice.
Mar 13 21:22:37 localhost systemd[1390]: pam_tcb(systemd-user:session): Session closed for sclarckone
Mar 13 21:22:41 localhost systemd[1]: Starting user-488.slice.
Mar 13 21:22:41 localhost systemd[1]: Created slice user-488.slice.
Mar 13 21:22:41 localhost systemd[1]: Starting User Manager for 488...
Mar 13 21:22:41 localhost systemd[1553]: pam_tcb(systemd-user:session): Session opened for lightdm by (uid=0)
Mar 13 21:22:42 localhost systemd[1]: Starting Session c1 of user lightdm.
Mar 13 21:22:42 localhost systemd[1]: Started Session c1 of user lightdm.
Mar 13 21:22:42 localhost systemd-logind[961]: New session c1 of user lightdm.
Mar 13 21:22:42 localhost systemd-logind[961]: Linked /tmp/.X11-unix/X0 to /run/user/488/X11-display.
Mar 13 21:22:42 localhost systemd[1553]: Failed to open private bus connection: Failed to connect to socket /run/user/488/dbus/user_bus_socket: No such file or directory
Mar 13 21:22:42 localhost systemd[1553]: Starting Default.
Mar 13 21:22:42 localhost systemd[1553]: Reached target Default.
Mar 13 21:22:42 localhost systemd[1553]: Startup finished in 15ms.
Mar 13 21:22:42 localhost systemd[1]: Started User Manager for 488.
Mar 13 21:22:42 localhost lightdm[1534]: pam_tcb(lightdm-greeter:session): Session opened for lightdm by (uid=0)
Mar 13 21:22:42 localhost lightdm[1598]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "sclarckone"
Mar 13 21:22:48 localhost lightdm[1598]: pam_tcb(lightdm:auth): Authentication passed for sclarckone from (uid=0)
Mar 13 21:22:48 localhost lightdm[1534]: pam_tcb(lightdm-greeter:session): Session closed for lightdm
Mar 13 21:22:48 localhost systemd-logind[961]: Removed session c1.
Mar 13 21:22:48 localhost systemd[1]: Stopping User Manager for 488...
Mar 13 21:22:48 localhost systemd[2677]: pam_tcb(systemd-user:session): Session opened for lightdm by (uid=0)
Mar 13 21:22:48 localhost systemd[1553]: Stopping Default.
Mar 13 21:22:48 localhost systemd[1553]: Stopped target Default.
Mar 13 21:22:48 localhost systemd[1553]: Starting Shutdown.
Mar 13 21:22:48 localhost systemd[1553]: Reached target Shutdown.
Mar 13 21:22:48 localhost systemd[1553]: Starting Exit the Session...
Mar 13 21:22:48 localhost systemd[1553]: Received SIGRTMIN+24 from PID 2679 (kill).
Mar 13 21:22:48 localhost systemd[1]: Stopped User Manager for 488.
Mar 13 21:22:48 localhost systemd[1]: Stopping user-488.slice.
Mar 13 21:22:48 localhost systemd[1]: Removed slice user-488.slice.
Mar 13 21:22:48 localhost systemd[1554]: pam_tcb(systemd-user:session): Session closed for lightdm
Mar 13 21:22:48 localhost systemd[1]: Starting user-500.slice.
Mar 13 21:22:48 localhost systemd[1]: Created slice user-500.slice.
Mar 13 21:22:48 localhost systemd[1]: Starting User Manager for 500...
Mar 13 21:22:48 localhost systemd[2682]: pam_tcb(systemd-user:session): Session opened for sclarckone by (uid=0)
Mar 13 21:22:48 localhost systemd[1]: Starting Session 2 of user sclarckone.
Mar 13 21:22:48 localhost systemd-logind[961]: New session 2 of user sclarckone.
Mar 13 21:22:48 localhost systemd-logind[961]: Linked /tmp/.X11-unix/X0 to /run/user/500/X11-display.
Mar 13 21:22:48 localhost systemd[2682]: Failed to open private bus connection: Failed to connect to socket /run/user/500/dbus/user_bus_socket: No such file or directory
Mar 13 21:22:48 localhost systemd[1]: Started Session 2 of user sclarckone.
Mar 13 21:22:48 localhost lightdm[1598]: pam_tcb(lightdm:session): Session opened for sclarckone by sclarckone(uid=0)
Mar 13 21:22:48 localhost systemd[2682]: Starting Default.
Mar 13 21:22:48 localhost systemd[2682]: Reached target Default.
Mar 13 21:22:48 localhost systemd[2682]: Startup finished in 15ms.
Mar 13 21:22:48 localhost systemd[1]: Started User Manager for 500.
Mar 13 21:22:48 localhost systemd[1]: Stopping Session 2 of user sclarckone.
Mar 13 21:22:48 localhost systemd[1]: Stopped Session 2 of user sclarckone.
Mar 13 21:22:48 localhost systemd-logind[961]: Removed session 2.
Mar 13 21:22:48 localhost systemd[1]: Stopping User Manager for 500...
Mar 13 21:22:48 localhost systemd[2688]: pam_tcb(systemd-user:session): Session opened for sclarckone by (uid=0)
Mar 13 21:22:48 localhost systemd[2689]: pam_tcb(systemd-user:session): Session closed for sclarckone
Mar 13 21:22:48 localhost systemd[2682]: Stopping Default.
Mar 13 21:22:48 localhost systemd[2682]: Stopped target Default.
Mar 13 21:22:48 localhost systemd[2682]: Starting Shutdown.
Mar 13 21:22:48 localhost systemd[2682]: Reached target Shutdown.
Mar 13 21:22:48 localhost systemd[2682]: Starting Exit the Session...
Mar 13 21:22:48 localhost systemd[2682]: Received SIGRTMIN+24 from PID 2691 (kill).
Mar 13 21:22:48 localhost systemd[1]: Stopped User Manager for 500.
Mar 13 21:22:48 localhost systemd[1]: Stopping user-500.slice.
Mar 13 21:22:48 localhost systemd[1]: Removed slice user-500.slice.
Mar 13 21:22:48 localhost systemd[2683]: pam_tcb(systemd-user:session): Session closed for sclarckone
ar 13 21:22:52 localhost systemd[1]: Starting user-488.slice.
Mar 13 21:22:52 localhost systemd[1]: Created slice user-488.slice.
Mar 13 21:22:52 localhost systemd[1]: Starting User Manager for 488...
Mar 13 21:22:52 localhost systemd[1]: Starting Session c2 of user lightdm.
Mar 13 21:22:52 localhost systemd[2701]: pam_tcb(systemd-user:session): Session opened for lightdm by (uid=0)
Mar 13 21:22:52 localhost systemd-logind[961]: New session c2 of user lightdm.
Mar 13 21:22:52 localhost systemd-logind[961]: Linked /tmp/.X11-unix/X0 to /run/user/488/X11-display.
Mar 13 21:22:52 localhost systemd[1]: Started Session c2 of user lightdm.
Mar 13 21:22:52 localhost systemd[2701]: Failed to open private bus connection: Failed to connect to socket /run/user/488/dbus/user_bus_socket: No such file or directory
Mar 13 21:22:52 localhost lightdm[2699]: pam_tcb(lightdm-greeter:session): Session opened for lightdm by (uid=0)
Mar 13 21:22:52 localhost systemd[2701]: Starting Default.
Mar 13 21:22:52 localhost systemd[2701]: Reached target Default.
Mar 13 21:22:52 localhost systemd[2701]: Startup finished in 9ms.
Mar 13 21:22:52 localhost systemd[1]: Started User Manager for 488.
Mar 13 21:22:52 localhost lightdm[2709]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "sclarckone"
Mar 13 21:26:18 localhost systemd[1]: Starting Getty on tty2...
Mar 13 21:26:18 localhost systemd[1]: Started Getty on tty2.
Mar 13 21:26:20 localhost acpid[977]: client 2694[0:0] has disconnected
Mar 13 21:26:20 localhost acpid[977]: client 2694[0:0] has disconnected
Mar 13 21:26:22 localhost login[2725]: pam_tcb(login:auth): Authentication passed for root from LOGIN(uid=0)
Mar 13 21:26:22 localhost systemd[1]: Starting user-0.slice.
Mar 13 21:26:22 localhost systemd[1]: Created slice user-0.slice.
Mar 13 21:26:22 localhost systemd[1]: Starting User Manager for 0...
Mar 13 21:26:22 localhost systemd[1]: Starting Session 3 of user root.
Mar 13 21:26:22 localhost systemd-logind[961]: New session 3 of user root.
Mar 13 21:26:22 localhost systemd[1]: Started Session 3 of user root.
Mar 13 21:26:22 localhost systemd[2726]: pam_tcb(systemd-user:session): Session opened for root by (uid=0)
Mar 13 21:26:22 localhost systemd[2726]: Failed to open private bus connection: Failed to connect to socket /run/user/0/dbus/user_bus_socket: No such file or directory
Mar 13 21:26:22 localhost login[2725]: pam_tcb(login:session): Session opened for root by root(uid=0)
Mar 13 21:26:22 localhost login[2725]: ROOT LOGIN ON tty2
Mar 13 21:26:22 localhost systemd[2726]: Starting Default.
Mar 13 21:26:22 localhost systemd[2726]: Reached target Default.
Mar 13 21:26:22 localhost systemd[2726]: Startup finished in 7ms.

The last part is my successful attempt to log in as root on tty2.

I don't get why there are several attempts made to log in as user "sclarckone" whereas I've only tried once... Maybe some automatic retries made by systemd itself ?

Otherwise, the only difference I can notice is that the target Default (systemd targets appear to be similar to SysV runlevels) is stopped but it doesn't say why.

Any idea ?