From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilya Dryomov Subject: Re: [PATCH] ceph: rbd option listing and tcp_nodelay support Date: Wed, 21 Jan 2015 22:18:30 +0300 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-qg0-f52.google.com ([209.85.192.52]:44718 "EHLO mail-qg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753686AbbAUTSb (ORCPT ); Wed, 21 Jan 2015 14:18:31 -0500 Received: by mail-qg0-f52.google.com with SMTP id z107so14646573qgd.11 for ; Wed, 21 Jan 2015 11:18:30 -0800 (PST) In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Chaitanya Huilgol Cc: Ceph Development On Wed, Jan 21, 2015 at 10:00 PM, Chaitanya Huilgol wrote: > From: Chaitanya Huilgol > > Option keys supported by libceph and rbd modules is readable > as a comma separated string via /sys/bus/rbd/options read-only > interface. This will allow user app (rbd cli) to check for > supported option keys before passing options to the kernel and > remain compatible with older kernels which do not support a > particular feature. > Messenger specific options moved to messenger layer. > tcp_nodelay(default)/no_tcp_nodelay option added for setting > TCP_NODELAY on messenger socket connections. Covers both rbd > and cephfs Hi Chaitanya, Just couple high level comments - I'll take a closer look tomorrow. Option listing and tcp_nodelay should be two separate patches rbd: add option sysfs attiribute libceph: add tcp_nodelay option or something like that. The "Messenger specific options moved to messenger layer" part should probably be a separate patch as well. More importantly, I'm missing the whole point of exporting supported rbd options. Adding a new libceph option does not break compatibility in either way, as old kernels will simply fail to map/mount if a bad (unknown, let through by new rbd cli) option is encountered. Thanks, Ilya