NFS bookmark/icon causes cinnamon.desktop registration timeout via automount rate-limit (mount-start-limit-hit)

[JokerGermany]

Related to previously closed issue: #3212
This report adds a fresh, more detailed reproduction on a current Mint release with precise systemd/NetworkManager journal timestamps.

Distribution

Linux Mint 22.3 (Zena), basierend auf Ubuntu 24.04 (Noble)

Package version

Nemo 6.6.3

Frequency

Always

Bug description

When an NFS share is configured in /etc/fstab with x-systemd.automount, and a Nemo bookmark or desktop icon points into that share, nemo-desktop and cinnamon repeatedly attempt to access the mount point during login. This triggers 5-6 mount attempts within about 6 seconds, hitting systemd's mount start-rate-limit (mount-start-limit-hit), which deactivates the automount unit.

As a side effect, the Cinnamon session binary itself fails to register in time:

cinnamon-session-binary: WARNING: Application 'cinnamon.desktop' failed to register before timeout
cinnamon-session-binary: CRITICAL: Unable to start session: A program required by the session failed to start. App ID: 'cinnamon.desktop'

This results in a 30+ second delay before the desktop appears, or a failed session start entirely.

Steps to reproduce

1. Configure an NFS share in /etc/fstab which is not available:

   192.168.2.10:/Raid1-1/creator /media/HDD/steamexport nfs noauto,nofail,_netdev,x-systemd.automount,x-systemd.idle-timeout=300 0 0
   

2. Create a Nemo bookmark or desktop icon pointing to a directory inside that NFS mount.
3. Ensure the NFS server is unreachable at boot time (e.g. power off the NAS, or use a network topology where the server only becomes reachable after a delay).
4. Reboot with the Ethernet connection's autoconnect enabled, and log in.
5. Observe a 30+ second delay before the Cinnamon desktop appears. Check with:

   systemctl status media-HDD-steamexport.automount
   

   Result shows mount-start-limit-hit.

Expected behavior

Nemo/Cinnamon should not repeatedly and synchronously probe network-mounted bookmarks/icons during session startup Access attempts should be asynchronous / non-blocking with respect to session registration, or throttled so they do not exhaust systemd's automount start-limit and stall cinnamon.desktop registration.

Additional information

1) NetworkManager itself completes quickly (not the bottleneck)

Aug 01 23:55:16 huppyryzen NetworkManager[1289]: <info> NetworkManager (version 1.46.0) is starting...
Aug 01 23:55:21 huppyryzen NetworkManager[1289]: <info> device (enp4s0): carrier: link connected
Aug 01 23:55:21 huppyryzen NetworkManager[1289]: <info> device (enp4s0): Activation: successful, device activated.
Aug 01 23:55:21 huppyryzen NetworkManager[1289]: <info> manager: startup complete
Aug 01 23:55:22 huppyryzen NetworkManager[1289]: <info> dhcp6 (enp4s0): state changed new lease, address=2a02:2f4:4109:8300:...

NetworkManager reaches "startup complete" only ~5 seconds after service start.

2) Gap until Cinnamon's NetworkAgent registers, and the timeout itself

Aug 01 23:55:24 huppyryzen cinnamon-session-binary[1926]: WARNING: ... autostart warnings ...
Aug 01 23:55:28 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2221 (cinnamon)
Aug 01 23:55:54 huppyryzen cinnamon-session-binary[1926]: WARNING: t+30.47765s: Application 'cinnamon.desktop' failed to register before timeout
Aug 01 23:55:54 huppyryzen cinnamon-session-binary[1926]: CRITICAL: t+30.47770s: Unable to start session: A program required by the session failed to start. App ID: 'cinnamon.desktop'.
Aug 01 23:57:00 huppyryzen NetworkManager[1289]: <info> agent-manager: agent[.../org.cinnamon.NetworkAgent/1000]: agent registered

There is a ~99 second gap between the last network-related log line and Cinnamon's NetworkAgent finally registering, directly correlating with the blocked automount access.

3) Automount rate-limit hit -- repeated access attempts by cinnamon and nemo-desktop

$ systemctl status media-HDD-steamexport.automount
○ media-HDD-steamexport.automount
    Active: inactive (dead) (Result: mount-start-limit-hit)
  Duration: 30.110s

Aug 02 01:20:30 huppyryzen systemd[1]: Set up automount media-HDD-steamexport.automount.
Aug 02 01:20:54 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2214 (cinnamon)
Aug 02 01:20:55 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2214 (cinnamon)
Aug 02 01:20:59 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2342 (nemo-desktop)
Aug 02 01:20:59 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2342 (nemo-desktop)
Aug 02 01:21:00 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2342 (nemo-desktop)
Aug 02 01:21:00 huppyryzen systemd[1]: media-HDD-steamexport.automount: Got automount request for /media/HDD/steamexport, triggered by 2342 (nemo-desktop)
Aug 02 01:21:00 huppyryzen systemd[1]: media-HDD-steamexport.automount: Failed with result 'mount-start-limit-hit'.

Both cinnamon (PID 2214/2221) and nemo-desktop (PID 2342) independently trigger repeated automount requests within a 6-second window, causing systemd's built-in start-rate-limit to trip.

4) /etc/fstab entry for the affected mount

192.168.2.10:/Raid1-1/creator /media/HDD/steamexport nfs noauto,nofail,_netdev,x-systemd.automount,x-systemd.idle-timeout=300 0 0