[Drbd-dev] [PATCH 08/10] drbd: Introduce protocol version 100 headers

[Philipp Reisner]

Am Freitag, 23. September 2011, 19:42:52 schrieb Kyle Moffett:
> Hi!
> 
> On Fri, Sep 23, 2011 at 10:31, Philipp Reisner
> 
> <philipp.reisner at linbit.com> wrote:
> > From: Andreas Gruenbacher <agruen at linbit.com>
> > 
> > Signed-off-by: Philipp Reisner <philipp.reisner at linbit.com>
> > Signed-off-by: Lars Ellenberg <lars.ellenberg at linbit.com>
> > ---
> >  drivers/block/drbd/drbd_int.h      |    8 ++++++++
> >  drivers/block/drbd/drbd_main.c     |   31
> > +++++++++++++++++++++++++------ drivers/block/drbd/drbd_receiver.c |  
> > 14 ++++++++++++--
> >  include/linux/drbd.h               |    1 +
> >  4 files changed, 46 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/block/drbd/drbd_int.h
> > b/drivers/block/drbd/drbd_int.h index 9868518..7d679c5 100644
> > --- a/drivers/block/drbd/drbd_int.h
> > +++ b/drivers/block/drbd/drbd_int.h
> > @@ -307,6 +307,14 @@ struct p_header95 {
> >        u32       vol_n_len;    /* big endian: high byte = volume;
> > remaining 24 bit = length */ } __packed;
> > 
> > +struct p_header100 {
> > +       u32       magic;
> > +       u16       volume;
> > +       u16       command;
> > +       u32       length;
> > +       u32       pad;
> > +} __packed;
> > +
> 
> This commit also needs additional log message text,
> specifically something that indicates what is new and
> different between the protocol 95 and protocol 100
> headers.  (IE: Why was the change made?)
> 

I merged patch 10/10 to this one. The updated, and merged
commit message is:

Author: Andreas Gruenbacher <agruen at linbit.com>
Date:   Wed Mar 30 16:00:17 2011 +0200

    drbd: Introduce protocol version 100 headers
    
    The 8 byte header finally becomes too small. With the protocol 100 header we
    have 16 bit for the volume number, proper 32 bit for the data length, and
    32 bit for further extensions in the future.
    
    Previous versions of drbd are using version 80 headers for all packets
    short enough for protocol 80.  They support both header versions in
    worker context, but only version 80 headers in asynchronous context.
    For backwards compatibility, continue to use version 80 headers for
    short packets before protocol version 100.
    
    From protocol version 100 on, use the same header version for all
    packets.
    
    Signed-off-by: Philipp Reisner <philipp.reisner at linbit.com>
    Signed-off-by: Lars Ellenberg <lars.ellenberg at linbit.com>

Best,
 Phil
-- 
: Dipl-Ing Philipp Reisner
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