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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 3DFC3C3F2CD for ; Tue, 3 Mar 2020 09:50:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B37020848 for ; Tue, 3 Mar 2020 09:50:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728328AbgCCJuI (ORCPT ); Tue, 3 Mar 2020 04:50:08 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:11137 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727912AbgCCJuH (ORCPT ); Tue, 3 Mar 2020 04:50:07 -0500 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id AE1EDB7AAA038C916A33; Tue, 3 Mar 2020 17:50:04 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.207) with Microsoft SMTP Server (TLS) id 14.3.439.0; Tue, 3 Mar 2020 17:49:55 +0800 Subject: Re: [PATCH 2/3] erofs: use LZ4_decompress_safe() for full decoding To: Gao Xiang , CC: LKML , Miao Xie , "Lasse Collin" References: <20200226023011.103798-1-gaoxiang25@huawei.com> <20200226023011.103798-2-gaoxiang25@huawei.com> From: Chao Yu Message-ID: <8c1a119e-7f3d-a42d-3208-d30b476baf73@huawei.com> Date: Tue, 3 Mar 2020 17:49:54 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200226023011.103798-2-gaoxiang25@huawei.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/2/26 10:30, Gao Xiang wrote: > As Lasse pointed out, "EROFS uses LZ4_decompress_safe_partial > for both partial and full blocks. Thus when it is decoding a > full block, it doesn't know if the LZ4 decoder actually decoded > all the input. The real uncompressed size could be bigger than > the value stored in the file system metadata. > > Using LZ4_decompress_safe instead of _safe_partial when > decompressing a full block would help to detect errors." > > So it's reasonable to use _safe in case of corrupted images and > it might have some speed gain as well although I didn't observe > much difference. > > Cc: Lasse Collin > Signed-off-by: Gao Xiang Reviewed-by: Chao Yu Thanks,