Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932341AbdCINMI (ORCPT ); Thu, 9 Mar 2017 08:12:08 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:33490 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932250AbdCINMG (ORCPT ); Thu, 9 Mar 2017 08:12:06 -0500 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig Cc: Yi Zhang , Ming Lei , Tejun Heo Subject: [PATCH 2/2] blk-mq: start to freeze queue just after setting dying Date: Thu, 9 Mar 2017 21:02:58 +0800 Message-Id: <1489064578-17305-4-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489064578-17305-1-git-send-email-tom.leiming@gmail.com> References: <1489064578-17305-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1293 Lines: 41 Before commit 780db2071a(blk-mq: decouble blk-mq freezing from generic bypassing), the dying flag is checked before entering queue, and Tejun converts the checking into .mq_freeze_depth, and assumes the counter is increased just after dying flag is set. Unfortunately we doesn't do that in blk_set_queue_dying(). This patch calls blk_mq_freeze_queue_start() for blk-mq in blk_set_queue_dying(), so that we can block new I/O coming once the queue is set as dying. Given blk_set_queue_dying() is always called in remove path of block device, and queue will be cleaned up later, we don't need to worry about undo of the counter. Cc: Tejun Heo Signed-off-by: Ming Lei --- block/blk-core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 0eeb99ef654f..559487e58296 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -500,9 +500,12 @@ void blk_set_queue_dying(struct request_queue *q) queue_flag_set(QUEUE_FLAG_DYING, q); spin_unlock_irq(q->queue_lock); - if (q->mq_ops) + if (q->mq_ops) { blk_mq_wake_waiters(q); - else { + + /* block new I/O coming */ + blk_mq_freeze_queue_start(q); + } else { struct request_list *rl; spin_lock_irq(q->queue_lock); -- 2.7.4