Custom sensors in sensors.d/ can never pass the -x check because the directory lives on the flash boot device

[shomilsaini]

Custom sensors in sensors.d/ can never pass the -x check because the directory lives on the flash boot device

Description

aux_sensors.sh reads custom sensor scripts from fcp_custom_sensor_dir, which defaults to /boot/config/plugins/fanctrlplus2/sensors.d:

fcp_custom_sensor_dir="${fcp_custom_sensor_dir:-/boot/config/plugins/fanctrlplus2/sensors.d}"

Before running a candidate script, it gates on a real executable bit:

[[ "${BASH_REMATCH[1]}" == .* || ! -x "$script" ]] && return 0

Unraid's flash boot device is FAT32, and since ~2020 Unraid has deliberately disabled setting the execute permission on files stored there as a flash-drive security hardening measure (chmod +x reports success but is silently a no-op; ls -la confirms the file stays -rw-------). This means [[ -x "$script" ]] will always evaluate false for any file placed in the documented sensors.d/ path, so custom sensors can never appear as selectable, regardless of what the user does with permissions.

Steps to reproduce

1. Place an executable shell script in /boot/config/plugins/fanctrlplus2/sensors.d/ per the plugin's own docs.
2. chmod +x the file (reports no error).
3. ls -la the directory — permissions show -rw-------, not -rwxr-xr-x.
4. The sensor never appears as selectable in the plugin UI, and [[ -x "$script" ]] in aux_sensors.sh will always be false for this path.

Expected

A correctly-written script dropped in sensors.d/ per the documented contract (prints Celsius, exits non-zero on error) becomes a selectable sensor.

Actual

The sensor never appears, silently, with no error surfaced to the user — because the exec-bit test can never pass on a flash-resident file.

Suggested fix

Either:

• (a) drop the -x requirement and just attempt to run the file directly with bash "$script" / sh "$script" regardless of its permission bits, since the shebang/interpreter can be invoked without an exec bit, or
• (b) have the plugin sync sensors.d/ into a writable runtime location (e.g. under /usr/local/emhttp/plugins/fanctrlplus2/, where the rest of the plugin's scripts already live with real -rwxr-xr-x permissions) at service start, and read from there instead of directly off /boot.

Environment

• Unraid version: [v7.3.2]
• FanCtrl Plus 2 version: [v1.8.3]
• Custom sensor script location: /boot/config/plugins/fanctrlplus2/sensors.d/