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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 BAA2CC10F0E for ; Thu, 18 Apr 2019 10:00:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BF2121479 for ; Thu, 18 Apr 2019 10:00:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388524AbfDRKAa (ORCPT ); Thu, 18 Apr 2019 06:00:30 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:35670 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1733049AbfDRKAa (ORCPT ); Thu, 18 Apr 2019 06:00:30 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 0AF69772A36535CE5C0A; Thu, 18 Apr 2019 18:00:28 +0800 (CST) Received: from localhost.localdomain (10.67.212.75) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.408.0; Thu, 18 Apr 2019 18:00:17 +0800 From: Zhou Wang To: , CC: , , Zhou Wang Subject: [PATCH] lib: scatterlist: Fix to support no mapped sg Date: Thu, 18 Apr 2019 17:50:06 +0800 Message-ID: <1555581006-153458-1-git-send-email-wangzhou1@hisilicon.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In function sg_split, the second sg_calculate_split will return -EINVAL when in_mapped_nents is 0. Indeed there is no need to do second sg_calculate_split and sg_split_mapped when in_mapped_nents is 0, as in_mapped_nents indicates no mapped entry in original sgl. Signed-off-by: Zhou Wang --- lib/sg_split.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/lib/sg_split.c b/lib/sg_split.c index b063410..d4181c8 100644 --- a/lib/sg_split.c +++ b/lib/sg_split.c @@ -178,11 +178,13 @@ int sg_split(struct scatterlist *in, const int in_mapped_nents, * The order of these 3 calls is important and should be kept. */ sg_split_phys(splitters, nb_splits); - ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip, - split_sizes, splitters, true); - if (ret < 0) - goto err; - sg_split_mapped(splitters, nb_splits); + if (in_mapped_nents) { + ret = sg_calculate_split(in, in_mapped_nents, nb_splits, skip, + split_sizes, splitters, true); + if (ret < 0) + goto err; + sg_split_mapped(splitters, nb_splits); + } for (i = 0; i < nb_splits; i++) { out[i] = splitters[i].out_sg; -- 2.8.1