Re: [Drbd-dev] [DRBD][PATCH] drbd_bitfild_endian.patch

[Philipp Reisner <philipp.reisner@linbit.com>]

On Tuesday 27 November 2007 11:55:12 Lars Ellenberg wrote:
> On Tue, Nov 27, 2007 at 12:51:44PM +0000, Maxim Uvarov wrote:
> > By the way, Lars,  don't  use if defined(__LITTLE_ENDIAN) condition
> > because  __LITTLE_ENDIAN and __BIG_ENDIAN are always defined :)
>
> in userland, yes.
> in kernel, no.
>
> in kernel there is no "if BYTE_ORDER == __LITTLE_ENDIAN",
> there is only "ifdef __LITTLE_ENDIAN".
>
> unless you prove me wrong.

Hi,

I have decided to go with Maxim's initial approach == Lars' approach.

I decided for that because according to GCC's documentation the
layout of bit-fields is part of the platform's ABI. It is not
compiler version dependant...

Please review commit 
d43cf82288b7cbd703aa0b587c4ab32605fb97c5

Thanks!

Changing the protocol is not an option for drbd-8.0. The protocol
is frozen (for little endian).

That breaks of course rolling upgrades for users of existing
clusters on bit-endian machines.... if there are any.

BTW: If we really want we could even fix this, since we know
     that _pad is always 0 .... but it is not worth the effort
     when there are no users out there.

-phil
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