Re: [PATCH 08/10] drbd: Introduce protocol version 100 headers

From: Philipp Reisner
Date: Tue Sep 27 2011 - 05:34:35 EST


Am Freitag, 23. September 2011, 19:42:52 schrieb Kyle Moffett:
> Hi!
>
> On Fri, Sep 23, 2011 at 10:31, Philipp Reisner
>
> <philipp.reisner@xxxxxxxxxx> wrote:
> > From: Andreas Gruenbacher <agruen@xxxxxxxxxx>
> >
> > Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
> > Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>

Best,
Phil
--
: Dipl-Ing Philipp Reisner
: LINBIT | Your Way to High Availability
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