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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 74C00C433FF for ; Thu, 1 Aug 2019 22:27:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 326172083B for ; Thu, 1 Aug 2019 22:27:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564698470; bh=cqKGC0/Mmv+kicgsvExbiyIi13wzBUDWLZxBEbE2ZDg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=z2H6iaGZ2D7zaRrDfa4yhCipyvYSne8ZFgAPBQ+i3DQFSmxm4SY4NKecufva+aYUR jqSANzmAuCzy9AmvMiYswsWSuTTWP0sH7O8a7ZaqcNJxxH3VK43ijoR6yQqhEescUu e+N2ro/PSuOB7d0by66ubl4CA8doNc/mtfr2xJGI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733056AbfHAW1t (ORCPT ); Thu, 1 Aug 2019 18:27:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:44558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732928AbfHAW1s (ORCPT ); Thu, 1 Aug 2019 18:27:48 -0400 Received: from localhost (unknown [104.132.0.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1D40B206B8; Thu, 1 Aug 2019 22:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564698467; bh=cqKGC0/Mmv+kicgsvExbiyIi13wzBUDWLZxBEbE2ZDg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OTa3yXGDnFDQ7hXFPwssvSCPLBnnvP2X0LiBOP3VPYBc9DjFg5nkiOAr4OEgQ3EnF GLC5f9kbRWoh6ZfGgRRvdq7vPB4834m7nX0TZW9h3XfNNvU4m8Vp+gtK5q/fqEbCpM jPnx2DUnIHV/nkytTmrpqo48iG8HW/M7z1BUmyfQ= Date: Thu, 1 Aug 2019 15:27:46 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org Subject: Re: [PATCH v2] f2fs: separate NOCoW and pinfile semantics Message-ID: <20190801222746.GA27597@jaegeuk-macbookpro.roam.corp.google.com> References: <20190719073903.9138-1-yuchao0@huawei.com> <20190723023640.GC60778@jaegeuk-macbookpro.roam.corp.google.com> <20190729055738.GA95664@jaegeuk-macbookpro.roam.corp.google.com> <07cd3aba-3516-9ba5-286e-277abb98e244@huawei.com> <20190730180231.GB76478@jaegeuk-macbookpro.roam.corp.google.com> <00e70eb1-c4fa-a6c9-69d7-71ff995c7d6c@huawei.com> <20190801041435.GB84433@jaegeuk-macbookpro.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/01, Chao Yu wrote: > On 2019/8/1 12:14, Jaegeuk Kim wrote: > > On 07/31, Chao Yu wrote: > >> On 2019/7/31 2:02, Jaegeuk Kim wrote: > >>> On 07/29, Chao Yu wrote: > >>>> On 2019/7/29 13:57, Jaegeuk Kim wrote: > >>>>> On 07/23, Chao Yu wrote: > >>>>>> On 2019/7/23 10:36, Jaegeuk Kim wrote: > >>>>>>> On 07/19, Chao Yu wrote: > >>>>>>>> Pinning a file is heavy, because skipping pinned files make GC > >>>>>>>> running with heavy load or no effect. > >>>>>>> > >>>>>>> Pinned file is a part of NOCOW files, so I don't think we can simply drop it > >>>>>>> for backward compatibility. > >>>>>> > >>>>>> Yes, > >>>>>> > >>>>>> But what I concerned is that pin file is too heavy, so in order to satisfy below > >>>>>> demand, how about introducing pin_file_2 flag to triggering IPU only during > >>>>>> flush/writeback. > >>>>> > >>>>> That can be done by cold files? > >>>> > >>>> Then it may inherit property of cold type file, e.g. a) goes into cold area; b) > >>>> update with very low frequency. > >>>> > >>>> Actually pin_file_2 could be used by db-wal/log file, which are updated > >>>> frequently, and should go to hot/warm area, it does not match above two property. > >>> > >>> How about considering another name like "IPU-only mode"? > >>> > >>> fallocate write Flag GC > >>> Pin_file: preallocate IPU FS_NOCOW_FL Not allowed > >>> IPU_file: Not preallocate IPU N/A Default by temperature > >> > >> One question, do we need preallocate physical block address for IPU_file as > >> Pin_file? since it can enhance db file's sequential read performance, not sure, > >> db can handle random data in preallocated blocks. > > > > db file will do atomic writes, which can not be used with this. -wal may be able > > Now WAL mode were set by default in Android, so most of db file are -wal type now. Will be back again tho. > > > to preallocate blocks, but it can eat disk space unnecessarily. > > I meant .db-wal file rather than .db. > > Yes, that's ext4 style, that would bring better performance due to less holes in > block distribution. > > I don't think we need to worry about space issue for db-wal file. I tracked > .db-wal file's update before: > - there are very frequently truncation and deletion, that means the preallocated > blocks won't exist for long time. > - and also there are very frequently append writes, I suspect there almost very > few preallocate block are not written. > - total db-wal file number is less. Sometimes it can be large enough for system. If it's from user apps and short lived, why do we need preallocation? > > > > >> > >> Other behaviors looks good to me. :) > >> > >> I plan to use last bit in inode.i_inline to store this flag. > > > > Why not using i_flag like FS_NOCOW_FL? > > Oops, as you listed in last email, I can see you don't want to break > FS_NOCOW_FL's semantics for backward compatibility. > > Flag > IPU_file N/A > > If we plan to use FS_NOCOW_FL, that's what this patch has already did, you can > merge it directly... :P > > > > >> > >>> Cold_file: Not preallocate IPU N/A Move in cold area > >>> Hot_file: Not preallocate IPU/OPU N/A Move in hot area > >> > >> Should hot file be gced to hot area? That would mix new hot data with old 'hot' > >> data which actually become cold. > > > > But, user explicitly specified this is hot. > > With current implementation, GC will migrate data from hot/warm/cold area to > cold area. > > Thanks, > > > > >> > >> Thanks, > >> > >>> > >>>> > >>>> Thank, > >>>> > >>>>> > >>>>>> > >>>>>>> > >>>>>>>> > >>>>>>>> So that this patch propose to separate nocow and pinfile semantics: > >>>>>>>> - NOCoW flag can only be set on regular file. > >>>>>>>> - NOCoW file will only trigger IPU at common writeback/flush. > >>>>>>>> - NOCow file will do OPU during GC. > >>>>>>>> > >>>>>>>> For the demand of 1) avoid fragment of file's physical block and > >>>>>>>> 2) userspace don't care about file's specific physical address, > >>>>>>>> tagging file as NOCoW will be cheaper than pinned one. > >>>>>> > >>>>>> ^^^ > >>>>>> > >>>>>> Thanks, > >>>>>> > >>>>>>>> > >>>>>>>> Signed-off-by: Chao Yu > >>>>>>>> --- > >>>>>>>> v2: > >>>>>>>> - rebase code to fix compile error. > >>>>>>>> fs/f2fs/data.c | 3 ++- > >>>>>>>> fs/f2fs/f2fs.h | 1 + > >>>>>>>> fs/f2fs/file.c | 22 +++++++++++++++++++--- > >>>>>>>> 3 files changed, 22 insertions(+), 4 deletions(-) > >>>>>>>> > >>>>>>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > >>>>>>>> index a2a28bb269bf..15fb8954c363 100644 > >>>>>>>> --- a/fs/f2fs/data.c > >>>>>>>> +++ b/fs/f2fs/data.c > >>>>>>>> @@ -1884,7 +1884,8 @@ static inline bool check_inplace_update_policy(struct inode *inode, > >>>>>>>> > >>>>>>>> bool f2fs_should_update_inplace(struct inode *inode, struct f2fs_io_info *fio) > >>>>>>>> { > >>>>>>>> - if (f2fs_is_pinned_file(inode)) > >>>>>>>> + if (f2fs_is_pinned_file(inode) || > >>>>>>>> + F2FS_I(inode)->i_flags & F2FS_NOCOW_FL) > >>>>>>>> return true; > >>>>>>>> > >>>>>>>> /* if this is cold file, we should overwrite to avoid fragmentation */ > >>>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > >>>>>>>> index 596ab3e1dd7b..f6c5a3d2e659 100644 > >>>>>>>> --- a/fs/f2fs/f2fs.h > >>>>>>>> +++ b/fs/f2fs/f2fs.h > >>>>>>>> @@ -2374,6 +2374,7 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr) > >>>>>>>> #define F2FS_NOATIME_FL 0x00000080 /* do not update atime */ > >>>>>>>> #define F2FS_INDEX_FL 0x00001000 /* hash-indexed directory */ > >>>>>>>> #define F2FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */ > >>>>>>>> +#define F2FS_NOCOW_FL 0x00800000 /* Do not cow file */ > >>>>>>>> #define F2FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ > >>>>>>>> > >>>>>>>> /* Flags that should be inherited by new inodes from their parent. */ > >>>>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > >>>>>>>> index 7ca545874060..ae0fec54cac6 100644 > >>>>>>>> --- a/fs/f2fs/file.c > >>>>>>>> +++ b/fs/f2fs/file.c > >>>>>>>> @@ -1692,6 +1692,7 @@ static const struct { > >>>>>>>> { F2FS_NOATIME_FL, FS_NOATIME_FL }, > >>>>>>>> { F2FS_INDEX_FL, FS_INDEX_FL }, > >>>>>>>> { F2FS_DIRSYNC_FL, FS_DIRSYNC_FL }, > >>>>>>>> + { F2FS_NOCOW_FL, FS_NOCOW_FL }, > >>>>>>>> { F2FS_PROJINHERIT_FL, FS_PROJINHERIT_FL }, > >>>>>>>> }; > >>>>>>>> > >>>>>>>> @@ -1715,7 +1716,8 @@ static const struct { > >>>>>>>> FS_NODUMP_FL | \ > >>>>>>>> FS_NOATIME_FL | \ > >>>>>>>> FS_DIRSYNC_FL | \ > >>>>>>>> - FS_PROJINHERIT_FL) > >>>>>>>> + FS_PROJINHERIT_FL | \ > >>>>>>>> + FS_NOCOW_FL) > >>>>>>>> > >>>>>>>> /* Convert f2fs on-disk i_flags to FS_IOC_{GET,SET}FLAGS flags */ > >>>>>>>> static inline u32 f2fs_iflags_to_fsflags(u32 iflags) > >>>>>>>> @@ -1753,8 +1755,6 @@ static int f2fs_ioc_getflags(struct file *filp, unsigned long arg) > >>>>>>>> fsflags |= FS_ENCRYPT_FL; > >>>>>>>> if (f2fs_has_inline_data(inode) || f2fs_has_inline_dentry(inode)) > >>>>>>>> fsflags |= FS_INLINE_DATA_FL; > >>>>>>>> - if (is_inode_flag_set(inode, FI_PIN_FILE)) > >>>>>>>> - fsflags |= FS_NOCOW_FL; > >>>>>>>> > >>>>>>>> fsflags &= F2FS_GETTABLE_FS_FL; > >>>>>>>> > >>>>>>>> @@ -1794,6 +1794,22 @@ static int f2fs_ioc_setflags(struct file *filp, unsigned long arg) > >>>>>>>> if (ret) > >>>>>>>> goto out; > >>>>>>>> > >>>>>>>> + if ((fsflags ^ old_fsflags) & FS_NOCOW_FL) { > >>>>>>>> + if (!S_ISREG(inode->i_mode)) { > >>>>>>>> + ret = -EINVAL; > >>>>>>>> + goto out; > >>>>>>>> + } > >>>>>>>> + > >>>>>>>> + if (f2fs_should_update_outplace(inode, NULL)) { > >>>>>>>> + ret = -EINVAL; > >>>>>>>> + goto out; > >>>>>>>> + } > >>>>>>>> + > >>>>>>>> + ret = f2fs_convert_inline_inode(inode); > >>>>>>>> + if (ret) > >>>>>>>> + goto out; > >>>>>>>> + } > >>>>>>>> + > >>>>>>>> ret = f2fs_setflags_common(inode, iflags, > >>>>>>>> f2fs_fsflags_to_iflags(F2FS_SETTABLE_FS_FL)); > >>>>>>>> out: > >>>>>>>> -- > >>>>>>>> 2.18.0.rc1 > >>>>>>> . > >>>>>>> > >>>>> . > >>>>> > >>> . > >>> > > . > >