From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luis Henriques Subject: Re: [RFC PATCH v3] ceph: add new obj copy OSD Op Date: Mon, 18 Nov 2019 14:05:51 +0000 Message-ID: <20191118140551.GA8951@hermes.olymp> References: <20191118120935.7013-1-lhenriques@suse.com> <3dc2df0ba5776fb0f7aaac3a099a938823ed0ebf.camel@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <3dc2df0ba5776fb0f7aaac3a099a938823ed0ebf.camel@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Jeff Layton Cc: Sage Weil , Ilya Dryomov , "Yan, Zheng" , Gregory Farnum , ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: ceph-devel.vger.kernel.org On Mon, Nov 18, 2019 at 08:12:39AM -0500, Jeff Layton wrote: > On Mon, 2019-11-18 at 12:09 +0000, Luis Henriques wrote: > > Hi, > > > > Before going ahead with a pull-request for ceph I would like to make sure > > we're all on the same page regarding the final fix for this problem. > > Thus, following this email, I'm sending 2 patches: one for ceph OSDs and > > the another for the kernel client. > > > > * osd: add new 'copy-from-notrunc' operation > > This patch shall be applied to ceph master after reverting commit > > ba152435fd85 ("osd: add flag to prevent truncate_seq copy in copy-from > > operation"). It adds a new operation that will be exactly the same as > > the original 'copy-from' operation, but with the extra 2 parameters > > (truncate_{seq,size}) > > > > * ceph: switch copy_file_range to 'copy-from-notrunc' operation > > This will make the kernel client use the new OSD op in > > copy_file_range. One extra thing that could probably be added is > > changing the mount options to NOCOPYFROM if the first call to > > ceph_osdc_copy_from() fails. > > > > I probably wouldn't change the mount options to be different from what > was initially specified. How about just disable copy_file_range > internally for that superblock, and then pr_notice a message that says > that copy_file_range is being autodisabled. If they mount with '-o > nocopyfrom' that will make the warning go away. Ok, that makes sense. I'll include this in the next rev, which will probably be sent only after the pull-request for ceph goes in (assuming the OSD patch won't need any major rework). > > Does this look good, or did I missed something from the previous > > discussion? > > > > (One advantage of this approach: the OSD patch can be easily backported!) > > > > Yep, I think this looks like a _much_ simpler approach to the problem. Agreed! Cheers, -- Luís