From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zimbra.linbit.com (zimbra.linbit.com [212.69.161.123]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id 95EAB10556CC for ; Tue, 27 Sep 2011 11:34:21 +0200 (CEST) From: Philipp Reisner To: Kyle Moffett Date: Tue, 27 Sep 2011 11:34:04 +0200 References: <1316788285-17433-1-git-send-email-philipp.reisner@linbit.com> <1316788285-17433-9-git-send-email-philipp.reisner@linbit.com> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201109271134.05157.philipp.reisner@linbit.com> Cc: Jens Axboe , linux-kernel@vger.kernel.org, drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] [PATCH 08/10] drbd: Introduce protocol version 100 headers List-Id: Coordination of development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Am Freitag, 23. September 2011, 19:42:52 schrieb Kyle Moffett: > Hi! > > On Fri, Sep 23, 2011 at 10:31, Philipp Reisner > > wrote: > > From: Andreas Gruenbacher > > > > Signed-off-by: Philipp Reisner > > Signed-off-by: Lars Ellenberg > > --- > > 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 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 Signed-off-by: Lars Ellenberg Best, Phil -- : Dipl-Ing Philipp Reisner : LINBIT | Your Way to High Availability : Tel: +43-1-8178292-50, Fax: +43-1-8178292-82 : http://www.linbit.com DRBD(R) and LINBIT(R) are registered trademarks of LINBIT, Austria.