From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C7B2C433DB for ; Wed, 24 Feb 2021 10:23:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A72360C3E for ; Wed, 24 Feb 2021 10:23:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234344AbhBXKXP (ORCPT ); Wed, 24 Feb 2021 05:23:15 -0500 Received: from mx2.suse.de ([195.135.220.15]:51778 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234650AbhBXKXD (ORCPT ); Wed, 24 Feb 2021 05:23:03 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 92C26B03A; Wed, 24 Feb 2021 10:22:20 +0000 (UTC) Received: from localhost (brahms [local]) by brahms (OpenSMTPD) with ESMTPA id 4d05c3a6; Wed, 24 Feb 2021 10:23:26 +0000 (UTC) Date: Wed, 24 Feb 2021 10:23:25 +0000 From: Luis Henriques To: Olga Kornievskaia Cc: Amir Goldstein , Jeff Layton , Steve French , Miklos Szeredi , Trond Myklebust , Anna Schumaker , Alexander Viro , "Darrick J. Wong" , Dave Chinner , Greg KH , Nicolas Boichat , Ian Lance Taylor , Luis Lozano , Andreas Dilger , Christoph Hellwig , ceph-devel , linux-kernel , CIFS , samba-technical , linux-fsdevel , linux-nfs Subject: Re: [PATCH v8] vfs: fix copy_file_range regression in cross-fs copies Message-ID: References: <20210221195833.23828-1-lhenriques@suse.de> <20210222102456.6692-1-lhenriques@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Tue, Feb 23, 2021 at 08:00:54PM -0500, Olga Kornievskaia wrote: > On Mon, Feb 22, 2021 at 5:25 AM Luis Henriques wrote: > > > > A regression has been reported by Nicolas Boichat, found while using the > > copy_file_range syscall to copy a tracefs file. Before commit > > 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices") the > > kernel would return -EXDEV to userspace when trying to copy a file across > > different filesystems. After this commit, the syscall doesn't fail anymore > > and instead returns zero (zero bytes copied), as this file's content is > > generated on-the-fly and thus reports a size of zero. > > > > This patch restores some cross-filesystem copy restrictions that existed > > prior to commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across > > devices"). Filesystems are still allowed to fall-back to the VFS > > generic_copy_file_range() implementation, but that has now to be done > > explicitly. > > > > nfsd is also modified to fall-back into generic_copy_file_range() in case > > vfs_copy_file_range() fails with -EOPNOTSUPP or -EXDEV. > > > > Fixes: 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices") > > Link: https://lore.kernel.org/linux-fsdevel/20210212044405.4120619-1-drinkcat@chromium.org/ > > Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@mail.gmail.com/ > > Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/ > > Reported-by: Nicolas Boichat > > Signed-off-by: Luis Henriques > > I tested v8 and I believe it works for NFS. Thanks a lot for the testing. And to everyone else for reviews, feedback,... and patience. I'll now go look into the manpage and see what needs to be changed. Cheers, -- Luís