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[23.128.96.18]) by mx.google.com with ESMTP id z7si3243696edm.477.2021.01.07.18.39.39; Thu, 07 Jan 2021 18:40:03 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@samsung.com header.s=mail20170921 header.b=hmDc5pLS; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=samsung.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727003AbhAHChy (ORCPT + 99 others); Thu, 7 Jan 2021 21:37:54 -0500 Received: from mailout2.samsung.com ([203.254.224.25]:64506 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726953AbhAHChx (ORCPT ); Thu, 7 Jan 2021 21:37:53 -0500 Received: from epcas2p2.samsung.com (unknown [182.195.41.54]) by mailout2.samsung.com (KnoxPortal) with ESMTP id 20210108023711epoutp02d0a56c8ca38e96a4eb4a5cf2d462de54~YIUFFxNpF0684206842epoutp02r for ; Fri, 8 Jan 2021 02:37:11 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.samsung.com 20210108023711epoutp02d0a56c8ca38e96a4eb4a5cf2d462de54~YIUFFxNpF0684206842epoutp02r DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1610073431; bh=l/KUfAhsFOgyUhrY21rqugRrtZWnNJOwIdHlX0ISaxg=; h=Subject:Reply-To:From:To:CC:In-Reply-To:Date:References:From; b=hmDc5pLScQNB9PGbuNSRfHVF2AaYtmKk2bY3GS9V1e1kJHfKmmAaqNnjTvp+jUpE0 jbW1RpFZ+rfxeU3qy0UmYJ0dMPen+2lJh2ggU55TPLH18CNz2X4NRniAh8ufulVE+e eiLRKD3ePDK0jMOP9UCL0A8PRfXja1kfFtMkccEE= Received: from epsnrtp4.localdomain (unknown [182.195.42.165]) by epcas2p4.samsung.com (KnoxPortal) with ESMTP id 20210108023710epcas2p4772412909ded44ae0b9d337e7e2896ed~YIUEq_vbe3132031320epcas2p4C; Fri, 8 Jan 2021 02:37:10 +0000 (GMT) Received: from epsmges2p2.samsung.com (unknown [182.195.40.182]) by epsnrtp4.localdomain (Postfix) with ESMTP id 4DBnLY1SBjz4x9Pt; Fri, 8 Jan 2021 02:37:09 +0000 (GMT) X-AuditID: b6c32a46-1efff7000000dbf8-1d-5ff7c553d592 Received: from epcas2p4.samsung.com ( [182.195.41.56]) by epsmges2p2.samsung.com (Symantec Messaging Gateway) with SMTP id 95.06.56312.355C7FF5; Fri, 8 Jan 2021 11:37:07 +0900 (KST) Mime-Version: 1.0 Subject: RE: Re: [PATCH] ext4: Remove expensive flush on fast commit Reply-To: daejun7.park@samsung.com Sender: Daejun Park From: Daejun Park To: Andreas Dilger , Daejun Park , harshad shirwadkar CC: "tytso@mit.edu" , "linux-ext4@vger.kernel.org" , "linux-kernel@vger.kernel.org" X-Priority: 3 X-Content-Kind-Code: NORMAL In-Reply-To: <8A3C241B-9536-447B-B22D-F922D64731C7@dilger.ca> X-CPGS-Detection: blocking_info_exchange X-Drm-Type: N,general X-Msg-Generator: Mail X-Msg-Type: PERSONAL X-Reply-Demand: N Message-ID: <20210108023707epcms2p32beb982610c9460e5fb08f927c52ad1d@epcms2p3> Date: Fri, 08 Jan 2021 11:37:07 +0900 X-CMS-MailID: 20210108023707epcms2p32beb982610c9460e5fb08f927c52ad1d Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpgk+LIzCtJLcpLzFFi42LZdljTQjf46Pd4g2M3bCyWnXzEZLHqQbjF ysYWJouZ8+6wWVzeNYfNorXnJ7sDm0fL5nKPnbPusns0nTnK7NG3ZRWjx+dNcgGsUTk2GamJ KalFCql5yfkpmXnptkrewfHO8aZmBoa6hpYW5koKeYm5qbZKLj4Bum6ZOUD7lRTKEnNKgUIB icXFSvp2NkX5pSWpChn5xSW2SqkFKTkFhoYFesWJucWleel6yfm5VoYGBkamQJUJORmvdqxk LNjCVrFv6lX2BsbJrF2MnBwSAiYSlyZfAbK5OIQEdjBKzLh3ia2LkYODV0BQ4u8OYZAaYQEX ifULGlhAbCEBJYn1F2exQ8T1JG49XMMIYrMJ6EhMP3EfLC4i0MQo8XNLJshMZoGFjBJdlyaw QyzjlZjR/pQFwpaW2L58K1gzp4CtxPcNnUwQcQ2JH8t6mSFsUYmbq9+yw9jvj81nhLBFJFrv nYWqEZR48HM3VFxS4tjuD1Bz6iW23vnFCHKEhEAPo8ThnbegPtaXuNaxEewIXgFfiSu35oDF WQRUJfb+vQo11EVi+pQ1YHFmAXmJ7W/nMIMChVlAU2L9Ln0QU0JAWeLILRaICj6JjsN/4V7c Me8J1AlqEut+rmeCKJeRuDUP6koPib7N+9knMCrOQgT0LCSrZiGsWsDIvIpRLLWgODc9tdio wAg5bjcxgpOiltsOxilvP+gdYmTiYDzEKMHBrCTCa3HsS7wQb0piZVVqUX58UWlOavEhRlOg JycyS4km5wPTcl5JvKGpkZmZgaWphamZkYWSOG+xwYN4IYH0xJLU7NTUgtQimD4mDk6pBqa6 qQFbVT9GMq9qZeGby7z79/dJesITtBJqOQR//zzVYZC12/6N1mL3gqJpH659+959TntjZbDV Hmued9Z2SwsZzv0sj5soZxT2ckHMUe8lRhbbWb2ebruQPH33jfjIK9ur/ZIuHjOzZudxdz90 /PeEafcs9DYpMny7sUBVqM6ivr31k8HPqBamrgMBr6aEX5mxOlX6rFDUlldMc96+vdzS0fn1 6hslt28TZ3FV8dqcuLetee3jcxdnTmvTSxEXeZvml/lzFqvc8W4tgYSmXuEH7zm+805mKp+3 vDGpUJZHSeL3r/kHfwbWb99fkOYb8nvVigjZtn0W6QXHn2zpL/npHR9j/2raBIP9iQJCuRxK LMUZiYZazEXFiQAkF7jnEwQAAA== DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20210106013242epcms2p5b6b4ed8ca86f29456fdf56aa580e74b4 References: <8A3C241B-9536-447B-B22D-F922D64731C7@dilger.ca> <20210106013242epcms2p5b6b4ed8ca86f29456fdf56aa580e74b4@epcms2p5> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > In the fast commit, it adds REQ_FUA and REQ_PREFLUSH on each fast commit > > block when barrier is enabled. However, in recovery phase, ext4 compares > > CRC value in the tail. So it is sufficient adds REQ_FUA and REQ_PREFLUSH > > on the block that has tail. > > Does the tail block *always* contain a CRC, or is that dependent on > EXT4_FEATURE_RO_COMPAT_METADATA_CSUM, JBD2_FEATURE_INCOMPAT_CSUM_V2, > or JBD2_FEATURE_INCOMPAT_CSUM_V3 being enabled? In the fast commit, the tail block always contain a CRC. > If one of those features is *required* before the FAST_COMMIT feature > can be used, then this patch looks OK. Otherwise, the CSUM feature > should be checked before the FUA is skipped for non-tail blocks. So, I think it is OK without checking other CSUM feature. Thanks, Daejun