Re: File systems on 4k sector devices?

[mlelstv%serpens.de@localhost (Michael van Elst)]

tls%panix.com@localhost (Thor Lancelot Simon) writes:

>On Thu, Jun 07, 2012 at 11:07:31AM +0000, Michael van Elst wrote:
>> 
>> To make fsck work you need to patch the superblock to reflect reality,
>> but I fear there is no tool for that. Maybe we should invent a tunefs
>> option to adjust the superblock.

>Something very similar is needed for cgd.

cgd says:
        /*
         * XXX here we should probe the underlying device.  If we
         *     are accessing a partition of type RAW_PART, then
         *     we should populate our initial geometry with the
         *     geometry that we discover from the device.
         */

I think that is true for all partitions, not just RAW_PART. cgd
should just deliver encrypted physical blocks of the underlying
disk.

But that also means that you cannot copy an encrypted image to
a disk with different geometry. Someone has decide wether that's
worthwhile. In that case you can either build a blocking/deblocking
layer into cgd (ugly) or define that larger blocks are split into
individually encrypted chunks of 512 bytes.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."