From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128AbeCVL6n (ORCPT ); Thu, 22 Mar 2018 07:58:43 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:35033 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266AbeCVL6m (ORCPT ); Thu, 22 Mar 2018 07:58:42 -0400 From: =?utf-8?B?5LqA5LqV5LuB5b+XIC8gS0FNRUnvvIxISVRPU0hJ?= To: Ilya Dryomov CC: Sage Weil , Alex Elder , "Ceph Development" , "linux-kernel@vger.kernel.org" Subject: RE: Re: [PATCH 0/2] rbd: thick-provision image support Thread-Topic: [!!]Re: [PATCH 0/2] rbd: thick-provision image support Thread-Index: AQHTwFSynP1gq9EPU0Sh+WFpsmRACqPcJhZQ Date: Thu, 22 Mar 2018 11:58:38 +0000 Deferred-Delivery: Thu, 22 Mar 2018 11:57:57 +0000 Message-ID: References: <5AAFA661.60103@hitachi.com> In-Reply-To: Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.232.29.202] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-TM-AS-GCONF: 00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w2MBwoBf019349 Hi Ilya, > I think it should be a map time option -- e.g. rbd map -o thick. > I don't see any reason for allowing tweaking this setting on a mapped image. I will add such option to rbd map command. The modified rbd command with the option writes "1" to sysfs file to disable discard operation at run-time. And, when user programs issue discard request to an image with the option, the patched kernel rbd driver ignores the discard request. Current kernel rbd driver always discards allocated blocks on an image when user programs issue discard operation. For example, when an rbd image is formatted by mkfs.xfs, the mkfs.xfs issues discard request and the kernel rbd driver discards allocated blocks. However, the kernel rbd driver should keep all blocks of thick/fully provisioned image. This patch allows the kernel rbd driver to ignore discard request for thick/fully provisioned image. > I looked through https://github.com/ceph/ceph/pull/18317 and I don't > see an equivalent functionality there. rbd_discard_on_zeroed_write_same > set to false makes the actual zeroes go on the wire, but I don't see > anything for ignoring discard requests. Can you point me at that? As Jason said, there is not currently an option in librbd. And the rbd command also does not have any options for this patch. I will add the option to rbd map command in the next step. And, the reason why the previous email refers to the URL is that this patch series is related to the thick/fully provisioned image described above. Regards, -- Hitoshi Kamei