From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030200AbbCMPQO (ORCPT ); Fri, 13 Mar 2015 11:16:14 -0400 Received: from smtprelay0141.hostedemail.com ([216.40.44.141]:33604 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932192AbbCMPPX (ORCPT ); Fri, 13 Mar 2015 11:15:23 -0400 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,,::::::::::::::::,RULES_HIT:355:379:871:988:989:1183:1260:1277:1312:1313:1314:1345:1516:1518:1519:1522:1534:1593:1594:1595:1596:1692:1730:1747:1777:1792:2392:2393:2559:2562:2828:3138:3139:3140:3141:3142:3876:3877:5007:6114:6261:6642:6748:7281:7901:10004:10848:11604:11914:12517:12519:13895:14394:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: pets52_68ac873db2b10 X-Filterd-Recvd-Size: 4747 Message-Id: <20150313151518.657974370@goodmis.org> User-Agent: quilt/0.61-1 Date: Fri, 13 Mar 2015 11:15:16 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Subject: [PATCH RT 22/31] sas-ata/isci: dontt disable interrupts in qc_issue handler References: <20150313151454.809081378@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0022-sas-ata-isci-dont-t-disable-interrupts-in-qc_issue-h.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10.70-rt75-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Gortmaker On 3.14-rt we see the following trace on Canoe Pass for SCSI_ISCI "Intel(R) C600 Series Chipset SAS Controller" when the sas qc_issue handler is run: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:905 in_atomic(): 0, irqs_disabled(): 1, pid: 432, name: udevd CPU: 11 PID: 432 Comm: udevd Not tainted 3.14.28-rt22 #2 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.02.01.0002.082220131453 08/22/2013 ffff880fab500000 ffff880fa9f239c0 ffffffff81a2d273 0000000000000000 ffff880fa9f239d8 ffffffff8107f023 ffff880faac23dc0 ffff880fa9f239f0 ffffffff81a33cc0 ffff880faaeb1400 ffff880fa9f23a40 ffffffff815de891 Call Trace: [] dump_stack+0x4e/0x7a [] __might_sleep+0xe3/0x160 [] rt_spin_lock+0x20/0x50 [] isci_task_execute_task+0x171/0x2f0 <----- [] sas_ata_qc_issue+0x25b/0x2a0 [] ata_qc_issue+0x1f3/0x370 [] ? ata_scsi_invalid_field+0x40/0x40 [] ata_scsi_translate+0xa5/0x1b0 [] ata_sas_queuecmd+0x86/0x280 [] sas_queuecommand+0x196/0x230 [] ? get_parent_ip+0xd/0x50 [] scsi_dispatch_cmd+0xb4/0x210 [] scsi_request_fn+0x314/0x530 and gdb shows: (gdb) list * isci_task_execute_task+0x171 0xffffffff815ddfb1 is in isci_task_execute_task (drivers/scsi/isci/task.c:138). 133 dev_dbg(&ihost->pdev->dev, "%s: num=%d\n", __func__, num); 134 135 for_each_sas_task(num, task) { 136 enum sci_status status = SCI_FAILURE; 137 138 spin_lock_irqsave(&ihost->scic_lock, flags); <----- 139 idev = isci_lookup_device(task->dev); 140 io_ready = isci_device_io_ready(idev, task); 141 tag = isci_alloc_tag(ihost); 142 spin_unlock_irqrestore(&ihost->scic_lock, flags); (gdb) In addition to the scic_lock, the function also contains locking of the task_state_lock -- which is clearly not a candidate for raw lock conversion. As can be seen by the comment nearby, we really should be running the qc_issue code with interrupts enabled anyway. Cc: stable-rt@vger.kernel.org Signed-off-by: Paul Gortmaker Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt --- drivers/scsi/libsas/sas_ata.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c index d2895836f9fa..c85e07ab51e4 100644 --- a/drivers/scsi/libsas/sas_ata.c +++ b/drivers/scsi/libsas/sas_ata.c @@ -191,7 +191,7 @@ static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc) /* TODO: audit callers to ensure they are ready for qc_issue to * unconditionally re-enable interrupts */ - local_irq_save(flags); + local_irq_save_nort(flags); spin_unlock(ap->lock); /* If the device fell off, no sense in issuing commands */ @@ -261,7 +261,7 @@ static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc) out: spin_lock(ap->lock); - local_irq_restore(flags); + local_irq_restore_nort(flags); return ret; } -- 2.1.4