From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39788) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bDPbX-0005G4-1X for qemu-devel@nongnu.org; Thu, 16 Jun 2016 01:12:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bDPbV-0007IH-0g for qemu-devel@nongnu.org; Thu, 16 Jun 2016 01:12:33 -0400 Date: Thu, 16 Jun 2016 13:12:21 +0800 From: Fam Zheng Message-ID: <20160616051220.GF12178@ad.usersys.redhat.com> References: <1465939839-30097-1-git-send-email-eblake@redhat.com> <1465939839-30097-5-git-send-email-eblake@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1465939839-30097-5-git-send-email-eblake@redhat.com> Subject: Re: [Qemu-devel] [PATCH v2 04/17] nbd: Allow larger requests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: qemu-devel@nongnu.org, kwolf@redhat.com, Paolo Bonzini , qemu-block@nongnu.org, Max Reitz On Tue, 06/14 15:30, Eric Blake wrote: > The NBD layer was breaking up request at a limit of 2040 sectors > (just under 1M) to cater to old qemu-nbd. But the server limit > was raised to 32M in commit 2d8214885 to match the kernel, more > than three years ago; and the upstream NBD Protocol is proposing > documentation that without any explicit communication to state > otherwise, a client should be able to safely assume that a 32M > transaction will work. It is time to rely on the larger sizing, > and any downstream distro that cares about maximum > interoperability to older qemu-nbd servers can just tweak the > value of #define NBD_MAX_SECTORS. > > Signed-off-by: Eric Blake Reviewed-by: Fam Zheng