From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail01.adl2.internode.on.net ([150.101.137.133]:43881 "EHLO ipmail01.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725858AbeLCXCj (ORCPT ); Mon, 3 Dec 2018 18:02:39 -0500 Date: Tue, 4 Dec 2018 10:02:22 +1100 From: Dave Chinner Subject: Re: [PATCH 03/11] vfs: no fallback for ->copy_file_range Message-ID: <20181203230222.GH6311@dastard> References: <20181203083416.28978-1-david@fromorbit.com> <20181203083416.28978-4-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-unionfs-owner@vger.kernel.org To: Amir Goldstein Cc: linux-fsdevel , linux-xfs , Olga Kornievskaia , Linux NFS Mailing List , overlayfs , ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org List-ID: On Mon, Dec 03, 2018 at 12:22:21PM +0200, Amir Goldstein wrote: > On Mon, Dec 3, 2018 at 10:34 AM Dave Chinner wrote: > > > > From: Dave Chinner > > > > Now that we have generic_copy_file_range(), remove it as a fallback > > case when offloads fail. This puts the responsibility for executing > > fallbacks on the filesystems that implement ->copy_file_range and > > allows us to add operational validity checks to > > generic_copy_file_range(). > > > > Rework vfs_copy_file_range() to call a new do_copy_file_range() > > helper to exceute the copying callout, and move calls to > > generic_file_copy_range() into filesystem methods where they > > currently return failures. > > > > Signed-off-by: Dave Chinner > > You may add > Reviewed-by: Amir Goldstein > > After fixing the overlayfs issue below. > ... > > > diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c > > index 84dd957efa24..68736e5d6a56 100644 > > --- a/fs/overlayfs/file.c > > +++ b/fs/overlayfs/file.c > > @@ -486,8 +486,15 @@ static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in, > > struct file *file_out, loff_t pos_out, > > size_t len, unsigned int flags) > > { > > - return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags, > > + ssize_t ret; > > + > > + ret = ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags, > > OVL_COPY); > > + > > + if (ret == -EOPNOTSUPP) > > + ret = generic_copy_file_range(file_in, pos_in, file_out, > > + pos_out, len, flags); > > + return ret; > > } > > > > This is unneeded, because ovl_copyfile(OVL_COPY) is implemented > by calling vfs_copy_file_range() (on the underlying files) and it is > not possible > to get EOPNOTSUPP from vfs_copy_file_range(). Except that it is possible. e.g. If the underlying filesystem tries a copy offload, gets a "not supported" failure from the remote server and then doesn't implement a fallback. Cheers, Dave. -- Dave Chinner david@fromorbit.com