Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751905AbdHAPVj (ORCPT ); Tue, 1 Aug 2017 11:21:39 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44018 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751352AbdHAPVg (ORCPT ); Tue, 1 Aug 2017 11:21:36 -0400 Subject: [PATCH] ipr: Fix scsi-mq lockdep issue To: linux-scsi Cc: Michael Ellerman , Jens Axboe , "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , Bart Van Assche , "linuxppc-dev@lists.ozlabs.org" , "James E.J. Bottomley" , Wendy Xiong References: <87a83qfosu.fsf@concordia.ellerman.id.au> <073ed79c-11ce-e86c-a905-91fd28675d47@kernel.dk> <1501166846.2516.1.camel@wdc.com> <5b85a365-faa1-3987-9b6b-270399c30686@kernel.dk> <87lgn9dqx3.fsf@concordia.ellerman.id.au> <92379297-9667-ae52-b05c-6c8a0ce4751c@kernel.dk> <5dcfe3ac-50c7-86a6-e571-fe5a1c1dc316@linux.vnet.ibm.com> <87379c6cfh.fsf@concordia.ellerman.id.au> <87a83ju6av.fsf@concordia.ellerman.id.au> From: Brian King Date: Tue, 1 Aug 2017 10:21:30 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <87a83ju6av.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17080115-0028-0000-0000-0000081F51DD X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007465; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000215; SDB=6.00896050; UDB=6.00448214; IPR=6.00676238; BA=6.00005506; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016482; XFM=3.00000015; UTC=2017-08-01 15:21:33 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17080115-0029-0000-0000-000036F11C7D Message-Id: <6d2bbcc8-3f4b-9b41-45b2-160f4817e439@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-08-01_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1708010252 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4807 Lines: 123 Fixes the following lockdep warning that can occur when scsi-mq is enabled with ipr due to ipr calling scsi_unblock_requests from irq context. The fix is to move the call to scsi_unblock_requests to ipr's existing workqueue. stack backtrace: CPU: 28 PID: 0 Comm: swapper/28 Not tainted 4.13.0-rc2-gcc6x-gf74c89b #1 Call Trace: [c000001fffe97550] [c000000000b50818] dump_stack+0xe8/0x160 (unreliable) [c000001fffe97590] [c0000000001586d0] print_usage_bug+0x2d0/0x390 [c000001fffe97640] [c000000000158f34] mark_lock+0x7a4/0x8e0 [c000001fffe976f0] [c00000000015a000] __lock_acquire+0x6a0/0x1a70 [c000001fffe97860] [c00000000015befc] lock_acquire+0xec/0x2e0 [c000001fffe97930] [c000000000b71514] _raw_spin_lock+0x44/0x70 [c000001fffe97960] [c0000000005b60f4] blk_mq_sched_dispatch_requests+0xa4/0x2a0 [c000001fffe979c0] [c0000000005acac0] __blk_mq_run_hw_queue+0x100/0x2c0 [c000001fffe97a00] [c0000000005ad478] __blk_mq_delay_run_hw_queue+0x118/0x130 [c000001fffe97a40] [c0000000005ad61c] blk_mq_start_hw_queues+0x6c/0xa0 [c000001fffe97a80] [c000000000797aac] scsi_kick_queue+0x2c/0x60 [c000001fffe97aa0] [c000000000797cf0] scsi_run_queue+0x210/0x360 [c000001fffe97b10] [c00000000079b888] scsi_run_host_queues+0x48/0x80 [c000001fffe97b40] [c0000000007b6090] ipr_ioa_bringdown_done+0x70/0x1e0 [c000001fffe97bc0] [c0000000007bc860] ipr_reset_ioa_job+0x80/0xf0 [c000001fffe97bf0] [c0000000007b4d50] ipr_reset_timer_done+0xd0/0x100 [c000001fffe97c30] [c0000000001937bc] call_timer_fn+0xdc/0x4b0 [c000001fffe97cf0] [c000000000193d08] expire_timers+0x178/0x330 [c000001fffe97d60] [c0000000001940c8] run_timer_softirq+0xb8/0x120 [c000001fffe97de0] [c000000000b726a8] __do_softirq+0x168/0x6d8 [c000001fffe97ef0] [c0000000000df2c8] irq_exit+0x108/0x150 [c000001fffe97f10] [c000000000017bf4] __do_irq+0x2a4/0x4a0 [c000001fffe97f90] [c00000000002da50] call_do_irq+0x14/0x24 [c0000007fad93aa0] [c000000000017e8c] do_IRQ+0x9c/0x140 [c0000007fad93af0] [c000000000008b98] hardware_interrupt_common+0x138/0x140 Reported-by: Michael Ellerman Signed-off-by: Brian King --- Index: linux-2.6.git/drivers/scsi/ipr.c =================================================================== --- linux-2.6.git.orig/drivers/scsi/ipr.c +++ linux-2.6.git/drivers/scsi/ipr.c @@ -3351,6 +3351,16 @@ static void ipr_worker_thread(struct wor return; } + if (ioa_cfg->scsi_unblock) { + ioa_cfg->scsi_unblock = 0; + ioa_cfg->scsi_blocked = 0; + spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags); + scsi_unblock_requests(ioa_cfg->host); + spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags); + if (ioa_cfg->scsi_blocked) + scsi_block_requests(ioa_cfg->host); + } + if (!ioa_cfg->scan_enabled) { spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags); return; @@ -7211,9 +7221,8 @@ static int ipr_ioa_bringdown_done(struct ENTER; if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) { ipr_trace; - spin_unlock_irq(ioa_cfg->host->host_lock); - scsi_unblock_requests(ioa_cfg->host); - spin_lock_irq(ioa_cfg->host->host_lock); + ioa_cfg->scsi_unblock = 1; + schedule_work(&ioa_cfg->work_q); } ioa_cfg->in_reset_reload = 0; @@ -7287,13 +7296,7 @@ static int ipr_ioa_reset_done(struct ipr list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q); wake_up_all(&ioa_cfg->reset_wait_q); - spin_unlock(ioa_cfg->host->host_lock); - scsi_unblock_requests(ioa_cfg->host); - spin_lock(ioa_cfg->host->host_lock); - - if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].allow_cmds) - scsi_block_requests(ioa_cfg->host); - + ioa_cfg->scsi_unblock = 1; schedule_work(&ioa_cfg->work_q); LEAVE; return IPR_RC_JOB_RETURN; @@ -9249,8 +9252,11 @@ static void _ipr_initiate_ioa_reset(stru spin_unlock(&ioa_cfg->hrrq[i]._lock); } wmb(); - if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) + if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) { + ioa_cfg->scsi_unblock = 0; + ioa_cfg->scsi_blocked = 1; scsi_block_requests(ioa_cfg->host); + } ipr_cmd = ipr_get_free_ipr_cmnd(ioa_cfg); ioa_cfg->reset_cmd = ipr_cmd; @@ -9306,9 +9312,8 @@ static void ipr_initiate_ioa_reset(struc wake_up_all(&ioa_cfg->reset_wait_q); if (!ioa_cfg->hrrq[IPR_INIT_HRRQ].removing_ioa) { - spin_unlock_irq(ioa_cfg->host->host_lock); - scsi_unblock_requests(ioa_cfg->host); - spin_lock_irq(ioa_cfg->host->host_lock); + ioa_cfg->scsi_unblock = 1; + schedule_work(&ioa_cfg->work_q); } return; } else { Index: linux-2.6.git/drivers/scsi/ipr.h =================================================================== --- linux-2.6.git.orig/drivers/scsi/ipr.h +++ linux-2.6.git/drivers/scsi/ipr.h @@ -1488,6 +1488,8 @@ struct ipr_ioa_cfg { u8 cfg_locked:1; u8 clear_isr:1; u8 probe_done:1; + u8 scsi_unblock:1; + u8 scsi_blocked:1; u8 revid;