Re: [ANN] Squashfs 3.3 released

[Phillip Lougher <phillip@lougher.demon.co.uk>]

Christoph Hellwig wrote:
> On Wed, Nov 21, 2007 at 02:02:43PM +0000, Phillip Lougher wrote:
>> Unfortunately the move to fixed little endian filesystem will involve 
>> another filesystem layout change.  The current filesystem layout still 
>> uses packed bitfield structures, and it is impossible to swap these 
>> using the standard kernel swap macros.  Removal of my routines that can 
>> properly swap packed bitfield structures is another change demanded by 
>> the Linux kernel mailing list.
> 
> The normal way to do it is to use shift and mask after doing the endian
> conversion.  But the problem with bitfields is that they can have different
> kinds of layouts depending on the compiler or abi which is another reason
> to avoid them in ondisk/wire formats.
> 

Yes, the bitfields are packed differently on little and big endian 
architectures which mean they appear in different places in the 
structure. I want to move away from that mess when I move to little 
endian only.

Phillip