On 2024-12-14, Greg Wooledge <g...@wooledge.org> wrote: > On Sat, Dec 14, 2024 at 10:36:55 +0100, Michel Verdier wrote: >> Let's do a small experiment to confirm it: >> >> # mount | grep steam >> portal on /var/data/steam/.cache/doc type fuse.portal >> (rw,nosuid,nodev,relatime,user_id=1001,group_id=1001) > > Curious. I have steam running, and I don't have this. I tried while > sitting at the main steam UI page with no games running, and also after > launching a game. > > hobbit:~$ mount | grep steam > hobbit:~$ sudo mount | grep steam > [sudo] password for greg: > hobbit:~$ > > I don't even have a /var/data directory in the first place. >
The behavior you're observing suggests that the specific fuse.portal mount under /var/data/steam/.cache/doc might depend on certain conditions that are not present in your setup. Here's a breakdown of potential reasons for the discrepancy and steps to investigate further: Application-Specific Behavior The fuse.portal mount you're referencing is associated with Portals, which are part of the Flatpak or sandboxed application ecosystem. Steam, when installed or run via Flatpak, uses Portals to manage file system access and other interactions with the host environment. Check Steam Installation Type: Determine if Steam is installed via Flatpak or natively through your package manager: flatpak list | grep steam If Steam doesn't appear in the Flatpak list, it is likely installed natively and won't utilize Portals in the same way. Sandbox Behavior: If using Flatpak, the /var/data/steam directory and fuse.portal mount might appear based on how Steam interacts with the sandbox. Mount Behavior The fuse.portal mount will only appear if the Portal services are being used. This might happen: When Steam accesses specific system resources. During certain game launches or configurations that require file system redirection. Inspect Running Mounts: Even if not listed under /var/data, check for any active Portal mounts elsewhere: mount | grep fuse.portal Directory Structure The /var/data/steam directory is non-standard. On most systems: Steam's default cache directory is located under ~/.steam or ~/.local/share/Steam. /var/data suggests a custom setup or an unusual configuration. Investigate Custom Paths: Check if the Steam installation or runtime environment has customized paths: steam --log Different Systems or Configurations Differences between your system and the one in the example might include: Different Linux distributions. Different Steam runtime versions. Flatpak (sandboxed) vs. native Steam installations. Different configurations for XDG (freedesktop.org standards) directories. Debugging Tips To get more context, try the following: List Active Processes: Identify the running Steam processes and their associated files: ps aux | grep steam Check Open File Descriptors: Check for mounts or directories being accessed by Steam: lsof -p $(pgrep -x steam) | grep fuse Explore Portal Logs: If you suspect a Portal interaction, check the xdg-desktop-portal logs: journalctl --user-unit xdg-desktop-portal Your environment might lack the fuse.portal mount because: Steam isn't installed via Flatpak. Steam didn't trigger any Portal interactions.Your system doesn't have /var/data or any custom configurations matching the example. If you want to reproduce the exact conditions: Ensure Steam is installed via Flatpak. Check if /var/data/steam is being used as a custom path. Explore when Portal mounts are triggered based on Steam usage.
