From patchwork Sun Sep 20 09:14:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 11787397 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1B916618 for ; Sun, 20 Sep 2020 09:14:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E3F1216C4 for ; Sun, 20 Sep 2020 09:14:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726353AbgITJOh (ORCPT ); Sun, 20 Sep 2020 05:14:37 -0400 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:46992 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726255AbgITJOf (ORCPT ); Sun, 20 Sep 2020 05:14:35 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R131e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04420;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0U9TYh0l_1600593271; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0U9TYh0l_1600593271) by smtp.aliyun-inc.com(127.0.0.1); Sun, 20 Sep 2020 17:14:31 +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 4/4] blk-throttle: Fix IO hang for a corner case Date: Sun, 20 Sep 2020 17:14:27 +0800 Message-Id: <605f98f527761d79dea4345976e57566c03afcd4.1600592693.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-block@vger.kernel.org It can not scale up in throtl_adjusted_limit() if we set bps or iops is 1, which will cause IO hang when enable low limit. Thus we should treat 1 as a illegal value to avoid this issue. Signed-off-by: Baolin Wang --- block/blk-throttle.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index b0d8f7c..0649bce 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1687,13 +1687,13 @@ static ssize_t tg_set_limit(struct kernfs_open_file *of, goto out_finish; ret = -EINVAL; - if (!strcmp(tok, "rbps")) + if (!strcmp(tok, "rbps") && val > 1) v[0] = val; - else if (!strcmp(tok, "wbps")) + else if (!strcmp(tok, "wbps") && val > 1) v[1] = val; - else if (!strcmp(tok, "riops")) + else if (!strcmp(tok, "riops") && val > 1) v[2] = min_t(u64, val, UINT_MAX); - else if (!strcmp(tok, "wiops")) + else if (!strcmp(tok, "wiops") && val > 1) v[3] = min_t(u64, val, UINT_MAX); else if (off == LIMIT_LOW && !strcmp(tok, "idle")) idle_time = val;