From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965838AbeEXJJZ (ORCPT ); Thu, 24 May 2018 05:09:25 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:52566 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965517AbeEXJJW (ORCPT ); Thu, 24 May 2018 05:09:22 -0400 Subject: Re: BUG: scsi/qla2xxx: BUG_ON(blk_queued_rq(req) is triggered in blk_finish_request To: "Madhani, Himanshu" , Dept-Eng QLA2xxx Upstream , "jthumshirn@suse.de" Cc: "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "jejb@linux.vnet.ibm.com" , "Martin K. Petersen" , Junxiao Bi References: <5eb1eeaa-b148-7b90-eee4-e365ead49a5b@oracle.com> <8c7b011e-1379-c151-a187-94d8e0697fd9@oracle.com> From: "jianchao.wang" Message-ID: <675528c5-89d6-a4f5-e91a-6d75fdbef9af@oracle.com> Date: Thu, 24 May 2018 17:09:16 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8902 signatures=668700 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1805240111 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Himanshu Thanks god get response from your side finally :) I get qla2xxx-upstream@qlogic.com from the maintainer information of driver/scsi/qla2xxx Looks like it should be modified. Thanks Jianchao On 05/24/2018 12:21 PM, Madhani, Himanshu wrote: > Hi, > > Yes. We'll look at this issue. > > Thanks, > Himanshu > >> -----Original Message----- >> From: jianchao.wang [mailto:jianchao.w.wang@oracle.com] >> Sent: Wednesday, May 23, 2018 6:51 PM >> To: Dept-Eng QLA2xxx Upstream ; Madhani, >> Himanshu ; jthumshirn@suse.de >> Cc: linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org; >> jejb@linux.vnet.ibm.com; Martin K. Petersen ; >> Junxiao Bi >> Subject: Re: BUG: scsi/qla2xxx: BUG_ON(blk_queued_rq(req) is triggered in >> blk_finish_request >> >> Would anyone please take a look at this ? >> >> Thanks in advance >> Jianchao >> >> On 05/23/2018 11:55 AM, jianchao.wang wrote: >>> >>> >>> Hi all >>> >>> Our customer met a panic triggered by BUG_ON in blk_finish_request. >>> >From the dmesg log, the BUG_ON was triggered after command abort >> occurred many times. >>> There is a race condition in the following scenario. >>> >>> cpu A cpu B >>> kworker interrupt >>> >>> scmd_eh_abort_handler() >>> -> scsi_try_to_abort_cmd() >>> -> qla2xxx_eh_abort() >>> -> qla2x00_eh_wait_on_command() qla2x00_status_entry() >>> -> qla2x00_sp_compl() >>> -> qla2x00_sp_free_dma() >>> -> scsi_queue_insert() >>> -> __scsi_queue_insert() >>> -> blk_requeue_request() >>> -> blk_clear_rq_complete() >>> -> scsi_done >>> -> blk_complete_request >>> -> blk_mark_rq_complete >>> -> elv_requeue_request() -> __blk_complete_request() >>> -> __elv_add_request() >>> // req will be queued here >>> BLK_SOFTIRQ >>> scsi_softirq_done() >>> -> scsi_finish_command() >>> -> scsi_io_completion() >>> -> scsi_end_request() >>> -> blk_finish_request() // >> BUG_ON(blk_queued_rq(req)) !!! >>> >>> The issue will not be triggered most of time, because the request is marked as >> complete by timeout path. >>> So the scsi_done from qla2x00_sp_compl does nothing. >>> But as the scenario above, if the complete state has been cleaned by >> blk_requeue_request, we will get >>> the request both requeued and completed, and then >> BUG_ON(blk_queued_rq(req)) in blk_finish_request comes up. >>> >>> Is there any solution for this in qla2xxx driver side ? >>> >>> Thanks >>> Jianchao >>> >>>