My notes on making encrypted filesystems 'Just Work(tm)'

W. Michael Petullo mike at
Thu Dec 16 12:46:14 PST 2004

>> Finally, since the hal daemon understands the clear text block
>> devices, /dev/dm-0 and onwards, provided by dm and hal must knows how to
>> add hal device objects for these. Thus, if /dev/dm-0 is really the
>> decrypted version of /dev/sda1 then hald must create a hal device object
>> representing /dev/dm-0. This device object will be a sibling to the
>> device object representing /dev/sda1 and will have the same storage
>> device as a parent.

> The current code in hal for dm detection is really ugly imho. I think the
> right way (tm) is to push the kernel people to put some more info in
> sysfs for dm devices. (I'm currently playing with the code to see how i
> can do that).

> And obviously i'm interested in your sesame code :), so lemme know if the
> starts of it are available somewhere..

For what its worth, I did make a post on the Linux kernel mailing list
about this.  See:

The subject was "Dm-crypt, device-mapper and sysfs."

I never got a response but I'm pretty low on the totem pole -- actually
I'm probably not even on the totem pole.


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