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=unavailable 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 8CA90C3F2CD for ; Tue, 3 Mar 2020 09:52:28 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 4E5AE214D8 for ; Tue, 3 Mar 2020 09:52:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4E5AE214D8 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-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 48WskG6vbrzDqbl for ; Tue, 3 Mar 2020 20:52:22 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.190; helo=huawei.com; envelope-from=yuchao0@huawei.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from huawei.com (szxga04-in.huawei.com [45.249.212.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 48Wsgl0PdvzDqHp for ; Tue, 3 Mar 2020 20:50:10 +1100 (AEDT) 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 , 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 X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lasse Collin , Miao Xie , LKML Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" 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,