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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 BCD6EC64E90 for ; Tue, 1 Dec 2020 02:39:56 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E805F20809; Tue, 1 Dec 2020 02:39:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sourceforge.net header.i=@sourceforge.net header.b="XnoTUAJ6"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sf.net header.i=@sf.net header.b="RipJh1rk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E805F20809 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-f2fs-devel-bounces@lists.sourceforge.net Received: from [127.0.0.1] (helo=sfs-ml-4.v29.lw.sourceforge.com) by sfs-ml-4.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1kjva5-0003c3-Ec; Tue, 01 Dec 2020 02:39:53 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-4.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kjva3-0003bu-QT for linux-f2fs-devel@lists.sourceforge.net; Tue, 01 Dec 2020 02:39:51 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:CC:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=thfBo3DTlwV4Sn6kjtLxsEtyk/FhDuj4pX5Sisy6fyY=; b=XnoTUAJ6F6cU6IQRWrp7AW4C4C jWSg5nphm8PXLYAcm9Qns8PAgSOnhlsq/orNkft3fsJd0RsVMawu5g+DabE+FL9BB4cX1GfcLWbo+ IPzH+BDjGlQIdFeFW+RLVOAnOI+tgoCgvEvNqeMmVbWvRQpLXf7EyzS4WWqYl5ecDOv0=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=thfBo3DTlwV4Sn6kjtLxsEtyk/FhDuj4pX5Sisy6fyY=; b=RipJh1rkVgB+qN7jLGAlsI1Nrq /U4GDM3CZtBA0Li+P8BO6RGhTg9L3lzBgZbdTW4LU7VvPndIxfKwoEk1MpLe/Yarq0YUQJ2i0PBEr P8US7fs+fPgYMmZfbGtahp+L5NzJR7ZQYTrec5VpgQL8qlRhHNnCU4QqZy1edQ2RnUws=; Received: from szxga07-in.huawei.com ([45.249.212.35]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1kjvZp-008BuF-Mx for linux-f2fs-devel@lists.sourceforge.net; Tue, 01 Dec 2020 02:39:51 +0000 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4ClRB729kwz761J; Tue, 1 Dec 2020 10:38:55 +0800 (CST) Received: from [10.136.114.67] (10.136.114.67) by smtp.huawei.com (10.3.19.206) with Microsoft SMTP Server (TLS) id 14.3.487.0; Tue, 1 Dec 2020 10:39:16 +0800 To: Eric Biggers References: <20201126103709.80006-1-yuchao0@huawei.com> <7ecb947e-2f8c-abd7-c116-c82c474fded7@huawei.com> From: Chao Yu Message-ID: <11c11980-1cef-eac5-d42a-4acd4d87565c@huawei.com> Date: Tue, 1 Dec 2020 10:39:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Originating-IP: [10.136.114.67] X-CFilter-Loop: Reflected X-Headers-End: 1kjvZp-008BuF-Mx Subject: Re: [f2fs-dev] [PATCH v2] f2fs: compress: add compress_inode to cache compressed blocks X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jaegeuk@kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On 2020/12/1 2:11, Eric Biggers wrote: > On Fri, Nov 27, 2020 at 09:01:47AM +0800, Chao Yu wrote: >> On 2020/11/27 1:55, Eric Biggers wrote: >>> On Thu, Nov 26, 2020 at 06:37:09PM +0800, Chao Yu wrote: >>>> Support to use address space of inner inode to cache compressed block, >>>> in order to improve cache hit ratio of random read. >>>> >>>> Signed-off-by: Chao Yu >>> >>> If the file is also encrypted, are the compressed pages that are cached still >>> encrypted, or are they decrypted? >> >> In current implementation, they are decrypted in cache. >> > > One of the things the FS_IOC_REMOVE_ENCRYPTION key ioctl is supposed to > accomplish is evicting all the pagecache pages for all encrypted files that were > using a particular key. This happens as a consequence of the ioctl evicting the > inodes that were using that key. If the user is also using the init_on_free=1 > kernel command-line option to enable automatic zeroing of all freed memory, that > should cause those inode's pagecache pages (which contain decrypted data) to be > zeroed, so that they can't be compromised later by an online attack. > > This new filesystem-wide cache containing decrypted pages might break that. It > sounds like when an inode is evicted, its cached pages won't necessarily be > evicted from this new filesystem-wide cache. Correct. > > Can you ensure that pages get evicted from this new cache when the inode to > which they belong is evicted? Not yet with current implementation, let me consider to find a way to make sure all cached compressed pages being evicted during f2fs_evict_inode(). Thanks, > > - Eric > . > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel 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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 83164C64E90 for ; Tue, 1 Dec 2020 02:40:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CA3920857 for ; Tue, 1 Dec 2020 02:40:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727156AbgLACkC (ORCPT ); Mon, 30 Nov 2020 21:40:02 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:8892 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727041AbgLACkC (ORCPT ); Mon, 30 Nov 2020 21:40:02 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4ClRB729kwz761J; Tue, 1 Dec 2020 10:38:55 +0800 (CST) Received: from [10.136.114.67] (10.136.114.67) by smtp.huawei.com (10.3.19.206) with Microsoft SMTP Server (TLS) id 14.3.487.0; Tue, 1 Dec 2020 10:39:16 +0800 Subject: Re: [f2fs-dev] [PATCH v2] f2fs: compress: add compress_inode to cache compressed blocks To: Eric Biggers CC: , , References: <20201126103709.80006-1-yuchao0@huawei.com> <7ecb947e-2f8c-abd7-c116-c82c474fded7@huawei.com> From: Chao Yu Message-ID: <11c11980-1cef-eac5-d42a-4acd4d87565c@huawei.com> Date: Tue, 1 Dec 2020 10:39:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.136.114.67] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/12/1 2:11, Eric Biggers wrote: > On Fri, Nov 27, 2020 at 09:01:47AM +0800, Chao Yu wrote: >> On 2020/11/27 1:55, Eric Biggers wrote: >>> On Thu, Nov 26, 2020 at 06:37:09PM +0800, Chao Yu wrote: >>>> Support to use address space of inner inode to cache compressed block, >>>> in order to improve cache hit ratio of random read. >>>> >>>> Signed-off-by: Chao Yu >>> >>> If the file is also encrypted, are the compressed pages that are cached still >>> encrypted, or are they decrypted? >> >> In current implementation, they are decrypted in cache. >> > > One of the things the FS_IOC_REMOVE_ENCRYPTION key ioctl is supposed to > accomplish is evicting all the pagecache pages for all encrypted files that were > using a particular key. This happens as a consequence of the ioctl evicting the > inodes that were using that key. If the user is also using the init_on_free=1 > kernel command-line option to enable automatic zeroing of all freed memory, that > should cause those inode's pagecache pages (which contain decrypted data) to be > zeroed, so that they can't be compromised later by an online attack. > > This new filesystem-wide cache containing decrypted pages might break that. It > sounds like when an inode is evicted, its cached pages won't necessarily be > evicted from this new filesystem-wide cache. Correct. > > Can you ensure that pages get evicted from this new cache when the inode to > which they belong is evicted? Not yet with current implementation, let me consider to find a way to make sure all cached compressed pages being evicted during f2fs_evict_inode(). Thanks, > > - Eric > . >