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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3299C19F2A for ; Thu, 4 Aug 2022 15:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237025AbiHDPzn (ORCPT ); Thu, 4 Aug 2022 11:55:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229988AbiHDPzk (ORCPT ); Thu, 4 Aug 2022 11:55:40 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 346691EC7F; Thu, 4 Aug 2022 08:55:39 -0700 (PDT) Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id C382820FE2E9; Thu, 4 Aug 2022 08:55:38 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C382820FE2E9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1659628538; bh=QXebqW0hrTf1CNPskOs0B1CdiWnWrgrHvmlsTreY3iI=; h=From:To:Subject:Date:From; b=XpAj+s7/UC4KrfmgO/5uErQKsx6pZJ8EHfMK18MyuRgk/rKSyDhrTNt03kGN/2Df/ AJjH7WkAn0wsu1icQFF7aR0A7BcOPVWeSIRIWQ4yog8Ig6L1nvLd4/uMvviZxxcHcG /yYEE/8fDSkPoaCeODHUnywF2FBS3zdc+Mz3XqDY= From: Saurabh Sengar To: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, jejb@linux.ibm.com, martin.petersen@oracle.com, linux-hyperv@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, ssengar@microsoft.com, mikelley@microsoft.com Subject: [PATCH v2] scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq Date: Thu, 4 Aug 2022 08:55:34 -0700 Message-Id: <1659628534-17539-1-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org storvsc_error_wq workqueue should not be marked as WQ_MEM_RECLAIM as it doesn't need to make forward progress under memory pressure. Marking this workqueue as WQ_MEM_RECLAIM may cause deadlock while flushing a non-WQ_MEM_RECLAIM workqueue. In the current state it causes the following warning: [ 14.506347] ------------[ cut here ]------------ [ 14.506354] workqueue: WQ_MEM_RECLAIM storvsc_error_wq_0:storvsc_remove_lun is flushing !WQ_MEM_RECLAIM events_freezable_power_:disk_events_workfn [ 14.506360] WARNING: CPU: 0 PID: 8 at <-snip->kernel/workqueue.c:2623 check_flush_dependency+0xb5/0x130 [ 14.506390] CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.4.0-1086-azure #91~18.04.1-Ubuntu [ 14.506391] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 14.506393] Workqueue: storvsc_error_wq_0 storvsc_remove_lun [ 14.506395] RIP: 0010:check_flush_dependency+0xb5/0x130 <-snip-> [ 14.506408] Call Trace: [ 14.506412] __flush_work+0xf1/0x1c0 [ 14.506414] __cancel_work_timer+0x12f/0x1b0 [ 14.506417] ? kernfs_put+0xf0/0x190 [ 14.506418] cancel_delayed_work_sync+0x13/0x20 [ 14.506420] disk_block_events+0x78/0x80 [ 14.506421] del_gendisk+0x3d/0x2f0 [ 14.506423] sr_remove+0x28/0x70 [ 14.506427] device_release_driver_internal+0xef/0x1c0 [ 14.506428] device_release_driver+0x12/0x20 [ 14.506429] bus_remove_device+0xe1/0x150 [ 14.506431] device_del+0x167/0x380 [ 14.506432] __scsi_remove_device+0x11d/0x150 [ 14.506433] scsi_remove_device+0x26/0x40 [ 14.506434] storvsc_remove_lun+0x40/0x60 [ 14.506436] process_one_work+0x209/0x400 [ 14.506437] worker_thread+0x34/0x400 [ 14.506439] kthread+0x121/0x140 [ 14.506440] ? process_one_work+0x400/0x400 [ 14.506441] ? kthread_park+0x90/0x90 [ 14.506443] ret_from_fork+0x35/0x40 [ 14.506445] ---[ end trace 2d9633159fdc6ee7 ]--- Fixes: 436ad9413353 ("scsi: storvsc: Allow only one remove lun work item to be issued per lun") Signed-off-by: Saurabh Sengar --- [v2] - s/it's/it/ - Added Fixes commit drivers/scsi/storvsc_drv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index fe000da..8ced292 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -2012,7 +2012,7 @@ static int storvsc_probe(struct hv_device *device, */ host_dev->handle_error_wq = alloc_ordered_workqueue("storvsc_error_wq_%d", - WQ_MEM_RECLAIM, + 0, host->host_no); if (!host_dev->handle_error_wq) { ret = -ENOMEM; -- 1.8.3.1