Re: Fixes to loop.c et al. for DES,IDEA,stego now done

Ian Goldberg (
Thu, 8 Aug 1996 17:23:17 -0700


In article <Pine.LNX.3.91.890918054255.204A-100000@HellSpawn>,
Damien Lucifer <root@hellspawn.Berkeley.EDU> wrote:
>On Tue, 6 Aug 1996, Ian Goldberg wrote:
>> This directory contains patches to the Linux kernel to enable encryption and
>> steganography of filesystems. Encryption allows you to have a scrambled
>> partition or file that, with the proper pass phrase, you can mount, just
>> like a normal filesystem. Steganography allows you to hide a filesystem in
>> the low bits of, say, an audio file. You can even combine these two to hide
>> a scrambled filesystem in the low bits of an audio file (see the example,
>> below).
>So the question on my mind, is can the loop device(s) be
>multi-threaded? I decided to be clever one evening and moved all my home
>directories to cfs directories.. unfortunatly when two instances of the
>same user try to hit their CFS home directory at once, the whole machine
>goes flubflub and and needs to be rebooted. Single threading didnt seem
>like such a terrible thing when I installed cfs, but lately its become
>rather restrictive and ugly to deal with. Please tell me theres a better
>way. :)

Well, unlike CFS, loop.c is part of the Linux kernel, which is single-threaded,
so I guess loop.c is also single-threaded. However, I took care that deadlocks
be avoided (mounting a loop device as another loop device (for example,
hiding an encrypted filesystem as stego) caused me to think a bit, but I'm
fairly confident that it works now).

- Ian

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