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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 638A5C4363A for ; Thu, 8 Oct 2020 03:52:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22E0D2085B for ; Thu, 8 Oct 2020 03:52:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728385AbgJHDws (ORCPT ); Wed, 7 Oct 2020 23:52:48 -0400 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]:44209 "EHLO out30-133.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726469AbgJHDwn (ORCPT ); Wed, 7 Oct 2020 23:52:43 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=alimailimapcm10staff010182156082;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0UBG9jYw_1602129160; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0UBG9jYw_1602129160) by smtp.aliyun-inc.com(127.0.0.1); Thu, 08 Oct 2020 11:52:40 +0800 From: Baolin Wang To: tj@kernel.org, axboe@kernel.dk Cc: baolin.wang@linux.alibaba.com, baolin.wang7@gmail.com, linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 5/8] blk-throttle: Move the list operation after list validation Date: Thu, 8 Oct 2020 11:52:26 +0800 Message-Id: <48232fffcfb16d40aa0fedc455a0f69f1f7c45f4.1602128837.git.baolin.wang@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We should move the list operation after validation. Signed-off-by: Baolin Wang --- block/blk-throttle.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 0649bce..f1bcb5c 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -423,12 +423,13 @@ static void throtl_qnode_add_bio(struct bio *bio, struct throtl_qnode *qn, */ static struct bio *throtl_peek_queued(struct list_head *queued) { - struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); + struct throtl_qnode *qn; struct bio *bio; if (list_empty(queued)) return NULL; + qn = list_first_entry(queued, struct throtl_qnode, node); bio = bio_list_peek(&qn->bios); WARN_ON_ONCE(!bio); return bio; @@ -451,12 +452,13 @@ static struct bio *throtl_peek_queued(struct list_head *queued) static struct bio *throtl_pop_queued(struct list_head *queued, struct throtl_grp **tg_to_put) { - struct throtl_qnode *qn = list_first_entry(queued, struct throtl_qnode, node); + struct throtl_qnode *qn; struct bio *bio; if (list_empty(queued)) return NULL; + qn = list_first_entry(queued, struct throtl_qnode, node); bio = bio_list_pop(&qn->bios); WARN_ON_ONCE(!bio); -- 1.8.3.1