From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2295815CE; Wed, 19 Jun 2024 00:24:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718756685; cv=none; b=Z0A922BnpELk8SVFB7i+v7kiCrjegXELqcvHJO0hndP4WM3PeIce66U8oCG1WYvBGFuy2ULtGSXzI4zED24JOfskAmuHPy916QbIhjIGO0i8PIEfELdulKGI6cioZIzXrP7xMqnEhP0R78iv1jEJc/hj3JuQY/cp7y31V76E+bM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718756685; c=relaxed/simple; bh=o7V1HvxMcu/Vb4/1j0DAzvXV9PZEBwsKo7jyvsnWr0I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iDxcMk6lWirb2zk/f1FXucZiZwcI+rwNznVTYrFIg0AC5P/1Q5brbjch3EVeY61HEyVOL+BzzxLoeFLFseN/QSGF8JeT9UYcToArVjuwqkxIQERVgm820xrmTxnVk+9N7G8sA4Y/3u0ET+NfNdu2z05zGz52MVTvzDpg7L5qe+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eFARj+oK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eFARj+oK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4CE2C3277B; Wed, 19 Jun 2024 00:24:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718756684; bh=o7V1HvxMcu/Vb4/1j0DAzvXV9PZEBwsKo7jyvsnWr0I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eFARj+oKSVgku84ZhIsLmAJo1V54cM+nw1tCZrdiwttnL65nAqnmQvdwvHZir4SFb WLoENeWrnMas+HclEEattz5nvzOCNXq7Cpb7QZo5JNg4yHwftoZ9BPmbXo0E7IxqwV /rztxscSSQDNd9BMd+CcAk4upFUTNBEbrFT6VZf9VUSFYAKc8H5PdMBHP8ZEfTBaMU u/k+3BnvOdpin6rQQZYKn+V6wpSq5DYPGRWcv2yKnztdmlA3q2p401rmGrQ/6aIaTV pGByh3u3S5nJbsH7q5uZv9KkkjYRyrBQGLa6agdcQ4RHBtONbIGYRvcMqQWnz/fbHI FbBiwijxQl1Xg== Date: Tue, 18 Jun 2024 17:24:44 -0700 From: "Darrick J. Wong" To: Zhang Yi Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, brauner@kernel.org, david@fromorbit.com, chandanbabu@kernel.org, jack@suse.cz, yi.zhang@huawei.com, chengzhihao1@huawei.com, yukuai3@huawei.com Subject: Re: [PATCH -next v6 0/2] iomap/xfs: fix stale data exposure when truncating realtime inodes Message-ID: <20240619002444.GH103034@frogsfrogsfrogs> References: <20240618142112.1315279-1-yi.zhang@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240618142112.1315279-1-yi.zhang@huaweicloud.com> On Tue, Jun 18, 2024 at 10:21:10PM +0800, Zhang Yi wrote: > Changes since v5: > - Drop all the code about zeroing out the whole allocation unitsize > on truncate down in xfs_setattr_size() as Christoph suggested, let's > just fix this issue for RT file by converting tail blocks to > unwritten now, and we could think about forced aligned extent and > atomic write later until it needs, so only pick patch 6 and 8 in > previous version, do some minor git log changes. This mostly makes sense, let's see how it fares with overnight fstests. For now, this is a provisional Reviewed-by: Darrick J. Wong --D > Changes since v4: > - Drop the first patch in v4 "iomap: zeroing needs to be pagecache > aware" since this series is not strongly depends on it, that patch > still needs furtuer analyse and also should add to handle the case of > a pending COW extent that extends over a data fork hole. This is a > big job, so let's fix the exposure stale data issue and brings back > the changes in iomap_write_end() first, don't block the ext4 buffered > iomap conversion. > - In patch 1, drop the 'ifndef rem_u64'. > - In patch 4, factor out a helper xfs_setattr_truncate_data() to handle > the zero out, update i_size, write back and drop pagecache on > truncate. > - In patch 5, switch to use xfs_inode_alloc_unitsize() in > xfs_itruncate_extents_flags(). > - In patch 6, changes to reserve blocks for rtextsize > 1 realtime > inodes on truncate down. > - In patch 7, drop the unwritten convert threshold, always convert tail > blocks to unwritten on truncate down realtime inodes. > - Add patch 8 to bring back 'commit 943bc0882ceb ("iomap: don't > increase i_size if it's not a write operation")'. > > Changes since v3: > - Factor out a new helper to get the remainder in math64.h as Darrick > suggested. > - Adjust the truncating order to prevent too much redundant blocking > writes as Dave suggested. > - Improve to convert the tail extent to unwritten when truncating down > an inode with large rtextsize as Darrick and Dave suggested. > > Since 'commit 943bc0882ceb ("iomap: don't increase i_size if it's not a > write operation")' merged, Chandan reported a stale data exposure issue > when running fstests generic/561 on xfs with realtime device [1]. This > issue has been fix in 6.10 by revert this commit through commit > '0841ea4a3b41 ("iomap: keep on increasing i_size in iomap_write_end()")', > but the real problem is xfs_setattr_size() doesn't zero out enough range > when truncate down a realtime inode. So this series fix this problem by > just converting the tail blocks to unwritten when truncate down realtime > inodes, then we could bring commit 943bc0882ceb back. > > I've tested this series on fstests (1) with reflink=0, (2) with > reflink=1, (3) with 28K RT device, no new failures detected, and it > passed generic/561 on RT device over 300+ rounds, please let me know if > we need any other test. > > [1] https://lore.kernel.org/linux-xfs/87ttj8ircu.fsf@debian-BULLSEYE-live-builder-AMD64/ > > Thanks, > Yi. > > Zhang Yi (2): > xfs: reserve blocks for truncating large realtime inode > iomap: don't increase i_size in iomap_write_end() > > fs/iomap/buffered-io.c | 53 +++++++++++++++++++++++------------------- > fs/xfs/xfs_iops.c | 15 +++++++++++- > 2 files changed, 43 insertions(+), 25 deletions(-) > > -- > 2.39.2 > >