Any problem with mounting the hidden partition read-only in fstab? Users (even root) will not be able to change any files on the partition.

I get the idea from this file /usr/share/polkit-1/actions/org.freedesktop.udisks2.policy
Not sure why they are different, i will try to test it tonight or tomorrow.

Added
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After testing with clean -current, and trying to downgrade two packages that was changed between 14.1 and current that i think may be related to it:
udisks2-2.1.0-x86_64-1.txz -> udisks2-2.1.5-x86_64-1.txz
polkit-gnome-0.102-x86_64-1.txz -> polkit-gnome-0.102-x86_64-2.txz
There was no change in behavior, every user was able to mount internal partition that was commented in fstab.
Then i start looking into this policy file /usr/share/polkit-1/actions/org.freedesktop.udisks2.policy and /etc/polkit-1/localauthority/50-local.d/20-plugdev-group-mount-override.pkla
Second file is included in package from line 109 of polkit.SlackBuild
From my point of view this file should be removed, because it gives every user in group plugdev to much permission. Is it required for some reason ?
After removing it, users in plugdev can mount usb drives, cd and etc. but if they try to mount internal partition, root password is required.

And one more test that i made before removing 20-plugdev-group-mount-override.pkla file :
From console issuing this command from regular user:
/dev/sdX gets mounted. No password asked.
*udisksctl is from udisks2 package.
Password is requested before mounting partition.
*udisks is from udisks package.

After removing pkla file, both commands require root password.

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I think that a better solution is to edit /etc/polkit-1/localauthority/50-local.d/20-plugdev-group-mount-override.pkla

The entry
is allowing the org.freedesktop.udisks2.filesystem-mount-system action.
Also it is allowing

I suggest changing to
which restores the requirement for root authorisation for a system partition as well as prevents ejecting system media.
A member of the plugdev group can still mount, unmount and eject external media (USB devices, optical disks).

1 members found this post helpful.

I'm curious if anyone has any idea why udev's mounting protocol doesn't default to root. If one does not configure udev mounting policy Dolphin will ask for a password that doesn't exist since it is assigned to no user at all by default, that is to say that the partition is unmountable until and unless one assigns the job to root or some user. Not a big deal but I find it an odd default. Perhaps I'm missing some compelling strategy.

I can only surmise that some IMHO idiot distros disable/remove root and depend on sudo for everything.

Apologies for not responding sooner - family commitments got in the way! Still its allowed time for an interesting discussion to develop, and thanks to all who have contributed.

GazL: Yes, the behaviour is exactly the same in Xfce/Thunar, confirming that this is a system issue rather than a KDE one.

I've tried the solutions suggested both by Emsi and allend and both restore the desired behaviour - at least from my perspective. I get the feeling from the discussion that allend's solution may be the optimal one, so that's what I have left on my machine for the moment. I'm not in a position to judge for myself, as this is an area of the system outside of my experience!

I'll drop Pat an e-mail drawing his attention to this thread. I'll also leave it a couple of days before marking it "solved" to see if any more definitive conclusions can be drawn.

Thanks everybody for your contributions!

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Pete

1 members found this post helpful.

I've sent Pat an e-mail about this, and pointed him at this thread. No response, but I guess he's pretty busy right now!

I'm going to mark this as "solved" now, because the solutions offered work for me!

Many thanks, folks.

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Pete