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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62DE1C433EF for ; Sat, 28 May 2022 01:42:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347634AbiE1Bmk (ORCPT ); Fri, 27 May 2022 21:42:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231386AbiE1Bmk (ORCPT ); Fri, 27 May 2022 21:42:40 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58CD913C1DE; Fri, 27 May 2022 18:42:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 172B2B82649; Sat, 28 May 2022 01:42:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ADD6BC34113; Sat, 28 May 2022 01:42:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653702156; bh=j+FxAMoUxjrnMrkR7+D1UfkLzawirXG78XCfbEzPawQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R0J7/2/Z1LOYV6ZvC1PmKypkWwchOrYxwuMKAaqcXJCLnOBI88CcuguJD/eVPIiD2 IsG0nubaNWnNBM8znoo03xQnRefWQPH9rizLT2ZwJdACppyXUh7yWz/5eLaZxwIWl2 h+v2nxcdpsZoXSTlMZ//vPxAFjloY8TS3atKPXPvMRZfNrtEbZPq0O5NN9lqDtR/mk dvzcW2qG5BE8/0LnkGXadkRLYjyZ4FIoeMgRP9u0Uz+wf3xJzt+2zQGV5JvClIkEYu 1uvQaMaphfvDY5ijvLX149ZhOgdk68QXAS3j4+vz7lWkVsRGywmr7bQgwTh0QPBn3E x/DziNugDCEPQ== Date: Fri, 27 May 2022 18:42:36 -0700 From: "Darrick J. Wong" To: Jaegeuk Kim Cc: Eric Biggers , linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-block@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH] f2fs: add sysfs entry to avoid FUA Message-ID: References: <20220527205955.3251982-1-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, May 27, 2022 at 06:06:08PM -0700, Jaegeuk Kim wrote: > On 05/27, Eric Biggers wrote: > > [+Cc linux-block for FUA, and linux-xfs for iomap] > > > > On Fri, May 27, 2022 at 01:59:55PM -0700, Jaegeuk Kim wrote: > > > Some UFS storage gives slower performance on FUA than write+cache_flush. > > > Let's give a way to manage it. > > > > > > Signed-off-by: Jaegeuk Kim > > > > Should the driver even be saying that it has FUA support in this case? If the > > driver didn't claim FUA support, that would also solve this problem. > > I think there's still some benefit to use FUA such as small chunk writes > for checkpoint. > > > > > > --- > > > Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++++++ > > > fs/f2fs/data.c | 2 ++ > > > fs/f2fs/f2fs.h | 1 + > > > fs/f2fs/sysfs.c | 2 ++ > > > 4 files changed, 12 insertions(+) > > > > > > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs > > > index 9b583dd0298b..cd96b09d7182 100644 > > > --- a/Documentation/ABI/testing/sysfs-fs-f2fs > > > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs > > > @@ -434,6 +434,7 @@ Date: April 2020 > > > Contact: "Daeho Jeong" > > > Description: Give a way to change iostat_period time. 3secs by default. > > > The new iostat trace gives stats gap given the period. > > > + > > > What: /sys/fs/f2fs//max_io_bytes > > > Date: December 2020 > > > Contact: "Jaegeuk Kim" > > > @@ -442,6 +443,12 @@ Description: This gives a control to limit the bio size in f2fs. > > > whereas, if it has a certain bytes value, f2fs won't submit a > > > bio larger than that size. > > > > > > +What: /sys/fs/f2fs//no_fua_dio > > > +Date: May 2022 > > > +Contact: "Jaegeuk Kim" > > > +Description: This gives a signal to iomap, which should not use FUA for > > > + direct IOs. Default: 0. > > > > iomap is an implementation detail, so it shouldn't be mentioned in UAPI > > documentation. UAPI documentation should describe user-visible behavior only. > > Ok. > > > > > > + > > > What: /sys/fs/f2fs//stat/sb_status > > > Date: December 2020 > > > Contact: "Chao Yu" > > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > > > index f5f2b7233982..23486486eab2 100644 > > > --- a/fs/f2fs/data.c > > > +++ b/fs/f2fs/data.c > > > @@ -4153,6 +4153,8 @@ static int f2fs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > > > if ((inode->i_state & I_DIRTY_DATASYNC) || > > > offset + length > i_size_read(inode)) > > > iomap->flags |= IOMAP_F_DIRTY; > > > + if (F2FS_I_SB(inode)->no_fua_dio) > > > + iomap->flags |= IOMAP_F_DIRTY; > > > > This is overloading the IOMAP_F_DIRTY flag to mean something other than dirty. > > Perhaps this flag needs to be renamed, or a new flag should be added? > > I'm not sure it's acceptable to add another flag for f2fs only. I think Al and willy have been throwing around patches to tell iomap_dio_rw or someone that the caller will handle cache flushes and that it shouldn't initiate them on its own; would that help here? --D > > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > > index e10838879538..c2400ea0080b 100644 > > > --- a/fs/f2fs/f2fs.h > > > +++ b/fs/f2fs/f2fs.h > > > @@ -1671,6 +1671,7 @@ struct f2fs_sb_info { > > > int dir_level; /* directory level */ > > > int readdir_ra; /* readahead inode in readdir */ > > > u64 max_io_bytes; /* max io bytes to merge IOs */ > > > + int no_fua_dio; /* avoid FUA in DIO */ > > > > Make this a bool? > > Done. > > > > > > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c > > > index 4c50aedd5144..24d628ca92cc 100644 > > > --- a/fs/f2fs/sysfs.c > > > +++ b/fs/f2fs/sysfs.c > > > @@ -771,6 +771,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_period_ms, iostat_period_ms); > > > #endif > > > F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra); > > > F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_io_bytes, max_io_bytes); > > > +F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, no_fua_dio, no_fua_dio); > > > F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold); > > > F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list); > > > #ifdef CONFIG_F2FS_FAULT_INJECTION > > > @@ -890,6 +891,7 @@ static struct attribute *f2fs_attrs[] = { > > > #endif > > > ATTR_LIST(readdir_ra), > > > ATTR_LIST(max_io_bytes), > > > + ATTR_LIST(no_fua_dio), > > > > Where is it validated that only valid values (0 or 1) can be written to this > > file? > > Added. > > > > > - Eric