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=-21.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,INCLUDES_PULL_REQUEST, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 72502C49EA6 for ; Thu, 24 Jun 2021 10:33:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F61361358 for ; Thu, 24 Jun 2021 10:33:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232140AbhFXKf0 (ORCPT ); Thu, 24 Jun 2021 06:35:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:56070 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231517AbhFXKfY (ORCPT ); Thu, 24 Jun 2021 06:35:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B2E8161358; Thu, 24 Jun 2021 10:32:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624530774; bh=5veRctjnSL/jrcMhupA+suH7OAIQylpXsv4ZVHXTaUY=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=lW15ZReRIowI7E/XQoLbVPxbT9ssHWVDkyy8FUEh/bonEGlgW1ifDeWjpCGCUlSlJ hMDuRxa+Sp5y6wfNFZAoCr+EtbzaP8pn+6KYH6t39sNkj62oZ/LGJhdr0R8tL2uTab UVMOo7lEdAQDEZEiFwRaEtp2cz9AVk/TUOrWDFajAKDiSJP8nH2j/spbm7NA9YamQq Haazi0CpuGnWM625TasQsZEmAJbZMSeaj3HEKSqL17keeW3zoWS2GE6rWG8J83r69N 7m2Ak0j2zu7qeaxGsc+4C06sWGt6LXWowAs0CKHQEyyYpeM+aGfyB1BTHp6cCFLC1Z 4sg3xi7XvAaKQ== Message-ID: <1224262b5f6ec7d646b85ed43b55b64063c35ecf.camel@kernel.org> Subject: Re: [GIT PULL] netfs, afs: Fix write_begin/end From: Jeff Layton To: David Howells , torvalds@linux-foundation.org Cc: Andrew W Elble , "Matthew Wilcox (Oracle)" , Al Viro , ceph-devel@vger.kernel.org, linux-afs@lists.infradead.org, linux-cachefs@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 24 Jun 2021 06:32:51 -0400 In-Reply-To: <2842348.1624308062@warthog.procyon.org.uk> References: <2842348.1624308062@warthog.procyon.org.uk> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.40.2 (3.40.2-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2021-06-21 at 21:41 +0100, David Howells wrote: > Hi Linus, > > Could you pull this please? It includes patches to fix netfs_write_begin() > and afs_write_end() in the following ways: > > (1) In netfs_write_begin(), extract the decision about whether to skip a > page out to its own helper and have that clear around the region to be > written, but not clear that region. This requires the filesystem to > patch it up afterwards if the hole doesn't get completely filled. > > (2) Use offset_in_thp() in (1) rather than manually calculating the offset > into the page. > > (3) Due to (1), afs_write_end() now needs to handle short data write into > the page by generic_perform_write(). I've adopted an analogous > approach to ceph of just returning 0 in this case and letting the > caller go round again. > > It also adds a note that (in the future) the len parameter may extend > beyond the page allocated. This is because the page allocation is deferred > to write_begin() and that gets to decide what size of THP to allocate. > > Thanks, > David > > Link: https://lore.kernel.org/r/20210613233345.113565-1-jlayton@kernel.org/ > Link: https://lore.kernel.org/r/162367681795.460125.11729955608839747375.stgit@warthog.procyon.org.uk/ # v1 > Link: https://lore.kernel.org/r/162391823192.1173366.9740514875196345746.stgit@warthog.procyon.org.uk/ # v2 > Link: https://lore.kernel.org/r/162429000639.2770648.6368710175435880749.stgit@warthog.procyon.org.uk/ # v3 > > Changes > ======= > > ver #3: > - Drop the bits that make afs take account of len exceeding the end of > the page in afs_write_begin/end(). > > ver #2: > - Removed a var that's no longer used (spotted by the kernel test robot) > - Removed a forgotten "noinline". > > ver #1: > - Prefixed the Jeff's new helper with "netfs_". > - Don't call zero_user_segments() for a full-page write. > - Altered the beyond-last-page check to avoid a DIV. > - Removed redundant zero-length-file check. > - Added patches to fix afs. > > --- > The following changes since commit 009c9aa5be652675a06d5211e1640e02bbb1c33d: > > Linux 5.13-rc6 (2021-06-13 14:43:10 -0700) > > are available in the Git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git tags/netfs-fixes-20210621 > > for you to fetch changes up to 827a746f405d25f79560c7868474aec5aee174e1: > > netfs: fix test for whether we can skip read when writing beyond EOF (2021-06-21 21:24:07 +0100) > > ---------------------------------------------------------------- > netfslib fixes > > ---------------------------------------------------------------- > David Howells (1): > afs: Fix afs_write_end() to handle short writes > > Jeff Layton (1): > netfs: fix test for whether we can skip read when writing beyond EOF > > fs/afs/write.c | 11 +++++++++-- > fs/netfs/read_helper.c | 49 ++++++++++++++++++++++++++++++++++++------------- > 2 files changed, 45 insertions(+), 15 deletions(-) > Hi Linus, Is there some reason you haven't pulled these fixes? The netfs fix in particular fixes a data corruption bug in cephfs, so we're quite keen to get that in before v5.13 ships. Thanks, -- Jeff Layton