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=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 08F06C433E2 for ; Tue, 15 Sep 2020 09:12:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A283D21D24 for ; Tue, 15 Sep 2020 09:12:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=zoho.com header.i=yehs2007@zoho.com header.b="oiUQAJ9q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726372AbgIOJMI (ORCPT ); Tue, 15 Sep 2020 05:12:08 -0400 Received: from sender4-pp-o92.zoho.com ([136.143.188.92]:25292 "EHLO sender4-pp-o92.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726335AbgIOJLm (ORCPT ); Tue, 15 Sep 2020 05:11:42 -0400 X-Greylist: delayed 906 seconds by postgrey-1.27 at vger.kernel.org; Tue, 15 Sep 2020 05:11:42 EDT ARC-Seal: i=1; a=rsa-sha256; t=1600160190; cv=none; d=zohomail.com; s=zohoarc; b=eMbO2pHjtI2jdc3IgYfnlHBqeuY4BZXAIWULCYsX4Nm8Cd7TEjLFyAnbWdMGQ1aMOo9bCn90l+VZbpqiHq9r3JCKzqWZhbYlHKtp9981QcUYYqxtFuhLqxOwjjSapR05lzSiB/akhpWQklg1uPXebZJBlQSsMNYYMUcK4YmBdi4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1600160190; h=Cc:Date:From:Message-ID:Subject:To; bh=3A2E2L+s1qnKc7TfNg24hR6nLEiTzDfH/1rT4r/XVXk=; b=Pf48RcKwlq8Sk8YyFd76/c9zSfc3lVm1ohL0fltZaV5+pUDQvKoRmjMuQK2+gxoFQTpAczaOAIceUO4Whx9AdS+zIvDnzeOluAm3u0g/7sPClgcL+Kh6RRiJEAcfmoU2nvx/Dst5o+G46wHm26QnU5EBFWUL5qlGSs5PWM7yfJU= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=zoho.com; spf=pass smtp.mailfrom=yehs2007@zoho.com; dmarc=pass header.from= header.from= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=from:to:cc:subject:date:message-id; b=DvdrCa2LwGY4Hi7SqqGeqrpgUEhl0KpS+MRLlHqcdfTYtZl6IEwCGvuFR1PGw3xFEUF0ukUTwDb5 XgANupyT7OMG2MwRxgQmaCJesfVcXjIBQJ5fraQPhGbbVUV2XSip DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1600160190; s=zm2020; d=zoho.com; i=yehs2007@zoho.com; h=From:To:Cc:Subject:Date:Message-Id; bh=3A2E2L+s1qnKc7TfNg24hR6nLEiTzDfH/1rT4r/XVXk=; b=oiUQAJ9q6p68bKTZY9BfTad3+MQvg5ELGy/jqKOHScobHWHg/3s1RoQZMmJKio3n ZM1r1bCQQ8WbFwTa8g0zqAlRbmeBMBgjyd2cwZsDFNzIF5QzIaGAtpRCwsofjRyCxOX nxNpm0LrPYdr/vcFp9Gn0Zc0U063G1Uc+DnlYK2w= Received: from YEHS1XPF1D05WL.lenovo.com (60.247.104.78 [60.247.104.78]) by mx.zohomail.com with SMTPS id 1600160188862947.0236886693741; Tue, 15 Sep 2020 01:56:28 -0700 (PDT) From: Huaisheng Ye To: snitzer@redhat.com, agk@redhat.com Cc: tyu1@lenovo.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org, Huaisheng Ye Subject: [PATCH] dm thin metadata: Remove unused local variable when create thin and snap Date: Tue, 15 Sep 2020 16:56:08 +0800 Message-Id: <20200915085608.13776-1-yehs2007@zoho.com> X-Mailer: git-send-email 2.17.0.windows.1 X-ZohoMailClient: External Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huaisheng Ye The local variable disk details is not used during the creating of thin & snap devices. Remove them from dm-thin-metadata, and add pointer validity check for pointer value in btree_lookup_raw. Skip memory copy when the caller doesn't need the value. Signed-off-by: Huaisheng Ye --- drivers/md/dm-thin-metadata.c | 6 ++---- drivers/md/persistent-data/dm-btree.c | 3 ++- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index b461836..6ebb212 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1051,12 +1051,11 @@ static int __create_thin(struct dm_pool_metadata *pmd, int r; dm_block_t dev_root; uint64_t key = dev; - struct disk_device_details details_le; struct dm_thin_device *td; __le64 value; r = dm_btree_lookup(&pmd->details_info, pmd->details_root, - &key, &details_le); + &key, NULL); if (!r) return -EEXIST; @@ -1129,12 +1128,11 @@ static int __create_snap(struct dm_pool_metadata *pmd, dm_block_t origin_root; uint64_t key = origin, dev_key = dev; struct dm_thin_device *td; - struct disk_device_details details_le; __le64 value; /* check this device is unused */ r = dm_btree_lookup(&pmd->details_info, pmd->details_root, - &dev_key, &details_le); + &dev_key, NULL); if (!r) return -EEXIST; diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c index 8aae062..ef6e78d 100644 --- a/drivers/md/persistent-data/dm-btree.c +++ b/drivers/md/persistent-data/dm-btree.c @@ -366,7 +366,8 @@ static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key, } while (!(flags & LEAF_NODE)); *result_key = le64_to_cpu(ro_node(s)->keys[i]); - memcpy(v, value_ptr(ro_node(s), i), value_size); + if (v) + memcpy(v, value_ptr(ro_node(s), i), value_size); return 0; } -- 1.8.3.1