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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 5FC81C3526C for ; Sat, 19 Dec 2020 08:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1997823BED for ; Sat, 19 Dec 2020 08:20:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726439AbgLSIUL (ORCPT ); Sat, 19 Dec 2020 03:20:11 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:9231 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726346AbgLSIUK (ORCPT ); Sat, 19 Dec 2020 03:20:10 -0500 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 CC: Zhen Lei 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 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.177.9] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; } -- 2.26.0.106.g9fadedd