From patchwork Sat Dec 19 08:18:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhen Lei X-Patchwork-Id: 11983381 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=-12.9 required=3.0 tests=BAYES_50, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 63F05C3526C for ; Sat, 19 Dec 2020 08:19:31 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (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 0AC8023BE2 for ; Sat, 19 Dec 2020 08:19:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0AC8023BE2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id ED35B100EC1FA; Sat, 19 Dec 2020 00:19:30 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=45.249.212.190; helo=szxga04-in.huawei.com; envelope-from=thunder.leizhen@huawei.com; receiver= Received: from szxga04-in.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 ml01.01.org (Postfix) with ESMTPS id 3033F100ED489 for ; Sat, 19 Dec 2020 00:19:28 -0800 (PST) Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Cydsh3D3wzksGC; Sat, 19 Dec 2020 16:18:32 +0800 (CST) Received: from thunder-town.china.huawei.com (10.174.177.9) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.498.0; Sat, 19 Dec 2020 16:19:14 +0800 From: Zhen Lei To: Dan Williams , Vishal Verma , Dave Jiang , linux-nvdimm , linux-kernel Subject: [PATCH v2 1/1] device-dax: avoid an unnecessary check in alloc_dev_dax_range() Date: Sat, 19 Dec 2020 16:18:40 +0800 Message-ID: <20201219081840.1149-2-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20201219081840.1149-1-thunder.leizhen@huawei.com> References: <20201219081840.1149-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.177.9] X-CFilter-Loop: Reflected Message-ID-Hash: KK74GCCCERUPKZSVON3MV4BYZVS5G6WI X-Message-ID-Hash: KK74GCCCERUPKZSVON3MV4BYZVS5G6WI X-MailFrom: thunder.leizhen@huawei.com X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: Zhen Lei X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Swap the calling sequence of krealloc() and __request_region(), call the latter first. In this way, the value of dev_dax->nr_range does not need to be considered when __request_region() failed. Signed-off-by: Zhen Lei --- drivers/dax/bus.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index de7b74505e75e72..359e22ece425ad2 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -772,22 +772,14 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start, return 0; } - ranges = krealloc(dev_dax->ranges, sizeof(*ranges) - * (dev_dax->nr_range + 1), GFP_KERNEL); - if (!ranges) + alloc = __request_region(res, start, size, dev_name(dev), 0); + if (!alloc) return -ENOMEM; - alloc = __request_region(res, start, size, dev_name(dev), 0); - if (!alloc) { - /* - * If this was an empty set of ranges nothing else - * will release @ranges, so do it now. - */ - if (!dev_dax->nr_range) { - kfree(ranges); - ranges = NULL; - } - dev_dax->ranges = ranges; + ranges = krealloc(dev_dax->ranges, sizeof(*ranges) + * (dev_dax->nr_range + 1), GFP_KERNEL); + if (!ranges) { + __release_region(res, alloc->start, resource_size(alloc)); return -ENOMEM; }