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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 31EE0C43381 for ; Mon, 18 Feb 2019 13:45:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0144B218FC for ; Mon, 18 Feb 2019 13:45:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497525; bh=4bFnIsdXg55p+eIb1TKr2naeNkOSvdw6mjz19Cju5IQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YlzXHTHHCftFeOyl9lgLPwxT4o+/qWgLiLLHH/4tRclRTpsC7pfRP0qD6QByMAlcA svtmhF6BkFV84fXGr/l5awvgJUgOxaYKLuWlNbuEKDwFQzxGmzg7xw3EL+iWYCJzsx zANMRwrlbgE6QaEOrr61HomEmI6uzbLwIioaXCos= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731318AbfBRNpX (ORCPT ); Mon, 18 Feb 2019 08:45:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:51364 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731293AbfBRNpS (ORCPT ); Mon, 18 Feb 2019 08:45:18 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 014CF218FC; Mon, 18 Feb 2019 13:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497517; bh=4bFnIsdXg55p+eIb1TKr2naeNkOSvdw6mjz19Cju5IQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DqyFS1FBT8RHihNhJNUAKcacxClNT52/E4w8Fx9f/as+kiARQxkW7Ze0f6xXsg/nB Zi3GBo0lJNpNVTJ9RuPSVAcWCw8OhlRrCmSvlosEunIilDWwRu6sO5M5/97cKSbebF 0wbo0xukXqsQNB4teIr6PQ6O69hF0CR9LyjagZqQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Stecker , Jianchao Wang , Jens Axboe , Sasha Levin Subject: [PATCH 4.20 03/92] blk-mq: fix a hung issue when fsync Date: Mon, 18 Feb 2019 14:42:06 +0100 Message-Id: <20190218133454.948976156@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190218133454.668268457@linuxfoundation.org> References: <20190218133454.668268457@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 85bd6e61f34dffa8ec2dc75ff3c02ee7b2f1cbce ] Florian reported a io hung issue when fsync(). It should be triggered by following race condition. data + post flush a flush blk_flush_complete_seq case REQ_FSEQ_DATA blk_flush_queue_rq issued to driver blk_mq_dispatch_rq_list try to issue a flush req failed due to NON-NCQ command .queue_rq return BLK_STS_DEV_RESOURCE request completion req->end_io // doesn't check RESTART mq_flush_data_end_io case REQ_FSEQ_POSTFLUSH blk_kick_flush do nothing because previous flush has not been completed blk_mq_run_hw_queue insert rq to hctx->dispatch due to RESTART is still set, do nothing To fix this, replace the blk_mq_run_hw_queue in mq_flush_data_end_io with blk_mq_sched_restart to check and clear the RESTART flag. Fixes: bd166ef1 (blk-mq-sched: add framework for MQ capable IO schedulers) Reported-by: Florian Stecker Tested-by: Florian Stecker Signed-off-by: Jianchao Wang Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-flush.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index 8b44b86779da..87fc49daa2b4 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -424,7 +424,7 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error) blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); - blk_mq_run_hw_queue(hctx, true); + blk_mq_sched_restart(hctx); } /** -- 2.19.1