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

Related to previously closed issue: https://github.com/linuxmint/nemo/issues/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

Start by reproducing the failure with the provided /etc/fstab NFS entry, an unavailable server, and a Nemo bookmark or desktop icon, then inspect the cinnamon and nemo-desktop journal timestamps and systemctl status output. Trace which startup accesses trigger the automount requests. Done means session registration is no longer stalled and repeated startup probes do not exhaust the automount start limit.