hede | # 1 | 2013-10-18, 22:14 | Report

I encrypted my /home/user/MyDocs via cryptsetup luks. Works fine, except the camera doesn't want to take pictures because it thinks it has no permission to do so.

But if I loop-mount the _same_ filesystem everything is fine.

=> camera complains: NO PERMISSIONS! I cannot take a photo.

=> everything is fine. I can take a photo.

wtf!?

Where does the camera gets its permission status from? Definitively not by checking the real permissions, because they must be absolutely identical!

Anyone using luks encryption and the camera?

Mentalist Traceur | # 2 | 2013-10-18, 22:26 | Report

I've got no useful info for you, but I am curious in case it is relevant for anyone who would know, is this with the normal N900 camera, or the open source recode by Nicolai (or whatever his username was) which is part of the CSSU (or at least used to be part of CSSU, there was some complaints about it being included and I'm not sure if current CSSU stable installs it by default)?

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Last edited by Mentalist Traceur; 2013-10-18 at 22:27. Reason: Typo: s/.$/?/

pichlo | # 3 | 2013-10-18, 23:48 | Report

I don't really know what I'm talking about and may be talking BS but... different user context? Mapper doesn't allow user write access but loopback does, and by the time the I/O reaches mapper through loopback, it is done at elevated privileges? What differences are there between the permissions of /dev/mapper/mydocs_luks and /dev/loop4?

hede | # 4 | 2013-10-19, 06:30 | Report

Thanks for your answers.

camera-ui (and the whole camera thing) is the one with stable CSSU or if CSSU didn't change it, it should be the original one from Nokia. I didn't touch it.

The permissions of the block devices /dev/mapper/mydocs_luks and /dev/loop4 differ. But it doesn't matter if I mount /dev/dm-1, which is the same major/minor than /dev/mapper/mydocs_luks but with the same owner/group/permissions as /dev/loop4. (Or if I change the permissions on /dev/mapper/mydocs_luks)

No luck so far.

hede | # 5 | 2013-10-19, 08:12 | Report

I installed the alternate camera-ui from cssu-testing and it works. There's some bug in the original camera-ui!

btw. my system seams to be broken anyway. Or maybe maemo at all(?), because I do have two N900s and both are affected.

I tried to reformat: and I get:
I can even use some shell in /etc/init.d/rcS, so most of the maemo userland is not loaded. And I can "luksClose" the device and manually "luksOpen" it with another different name, no chance. mkfs still complains it is mounted... but it's definetely NOT mounted.
(PS: not mounted and there's no entry in /proc/mounts not in /etc/mtab)

I hate it, when computers think to be smarter than humans. They're not! (At least up to the present ;-) )

But this bug doesn't matter. I exported the device via mass storage mode and reformatted at my pc.

It works now, even with ext3 (at one device) and ext4 (at the other).

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Last edited by hede; 2013-10-19 at 08:31. Reason: PS: ...

misterc | # 6 | 2013-10-19, 08:59 | Report

glad to hear / read that you were able to fix your... N900s
personally i recently configured my 2nd N900 w/ CSSU-Thumb 2 and can't help feeling that it is far less stable then the original N900...
anyway...

is LUKS part of the original Maemo freemantle?
nope, thus you broke your N900s by adding it...

hede | # 7 | 2013-10-19, 15:48 | Report

Yes, I triggered the bug. But the bug itself is in Maemos original camera-ui.

Either you have a general purpose operating system or you have a phone with fixed functions. And I thought Maemo would be a general purpose operating system featuring flexibility?

There are so many Bugs closed at the old Maemo Bugtracker by Nokia with reason "not part of maemos fixed feature set" (not exactly with these words, but to imply)... that reminds me more on simple feature phones or even old dumb phones than on anything like iOS or Android.

I love Maemo, it's a fine thing and - at the moment - I don't want to change to iOS or Android or anything else, precisely because Maemo is a flexible extendable general purpose operating system. And if Bugs get triggered, they get triggered and aren't non-resistant. They even are existent if they don't get triggered in regular use. (Think of Security bugs like buffer overflows. They also don't get triggered in regular use cases, but it's better to fix them.)

And I think it's great if people like Nikolai Hess not only extend "feature complete" software, but even remove nonexistent bugs. *scnr*
Many thanks to him and to all those other people still working on Maemo for N900.

Sorry - just my 2¢


ps, btw: I've written some password prompt in bootmenu/backupmenu style (kind of derived work). It's a little fancier than the small cryptsetup-prompt most people seem to use for early decryption in early boot stage!? Maybe I should post/publish it here? It's a really simple thing.

pichlo | # 8 | 2013-10-19, 15:57 | Report

Wonderfully put, absolutely agree.

Yes, please!

Mentalist Traceur | # 9 | 2013-10-19, 16:18 | Report

Well that's interesting. I was just shooting in the dark about the open source alternative camera UI being different in this regard (though it intuitively makes sense because often times any 'clever' hackish 'features' like weird permissions handling can go unnoticed in open source recodes of closed source stuff). I'm glad to hear it turned out to be a correct guess.

My argument would be to just continue using the alternative camera-ui. It's essentially a feature-complete recode (I think there were some obscure bugs some people found, but those may well have all been fixed by now), and by nature of it being open source, it's either better in every way or has the potential to be better in any way that it's not better in yet, so yeah.

Frankly, I have no idea what caused the stable CSSU to not feature it, seeing as how one of the initial ideas behind the CSSU as I recall was that it would replace the closed source bits with open source ones.

It is, at the core, held back only by the various closed source parts that keep the rest of the software locked to this hardware and to old versions of itself. Of course various bugs in the Nokia bug tracker are closed and dismissed by Nokia as not fitting its limited feature set, but that's the nature of companies making phones - they made a phone, with a given supported set of features. It has the potential to be way more and we were fortunate that they didn't artificially limit that potential, but they can't be bothered to spend the resources to fix bugs that don't affect their particular official feature set.

hede | # 10 | 2013-10-19, 17:21 | Report

The wiki says the new one has still some regression. All in all the new one may be better, but if someone who is using the missing feature is automatically updated... can be very annoying. Maybe it's ok to leave it in testing.

yes - I agree.