Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753680Ab1E0Fnm (ORCPT ); Fri, 27 May 2011 01:43:42 -0400 Received: from mx1.fusionio.com ([66.114.96.30]:60610 "EHLO mx1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751525Ab1E0Fnk (ORCPT ); Fri, 27 May 2011 01:43:40 -0400 X-ASG-Debug-ID: 1306475019-03d6a512ab0dbb0001-xx1T2L X-Barracuda-Envelope-From: JAxboe@fusionio.com Message-ID: <4DDF3A07.7040106@fusionio.com> Date: Fri, 27 May 2011 07:43:35 +0200 From: Jens Axboe MIME-Version: 1.0 To: James Bottomley CC: Parag Warudkar , Linus Torvalds , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , Linux SCSI List Subject: Re: [PATCH] SCSI IOCTL: Check for device deletion [was Re: __elv_add_request OOPS] References: <4DDB8BF6.2000304@fusionio.com> <4DDCB1C8.7040708@fusionio.com> <4DDD5240.2060308@fusionio.com> <4DDD55D6.1080909@fusionio.com> <1306356735.1641.61.camel@mulgrave.site> <1306468385.4048.73.camel@mulgrave.site> X-ASG-Orig-Subj: Re: [PATCH] SCSI IOCTL: Check for device deletion [was Re: __elv_add_request OOPS] In-Reply-To: <1306468385.4048.73.camel@mulgrave.site> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Barracuda-Connect: mail1.int.fusionio.com[10.101.1.21] X-Barracuda-Start-Time: 1306475019 X-Barracuda-URL: http://10.101.1.180:8000/cgi-mod/mark.cgi X-Barracuda-Spam-Score: 0.00 X-Barracuda-Spam-Status: No, SCORE=0.00 using per-user scores of TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=9.0 tests= X-Barracuda-Spam-Report: Code version 3.2, rules version 3.2.2.64786 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------------------------- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1572 Lines: 44 On 2011-05-27 05:53, James Bottomley wrote: > On Wed, 2011-05-25 at 15:52 -0500, James Bottomley wrote: >> On Wed, 2011-05-25 at 16:42 -0400, Parag Warudkar wrote: >>> Yeah - that makes sense. By that logic, looks like we can only disallow >>> for SDEV_DEL (if we decide to do that check here). >> >> I don't think this is the root cause. I think q is non-NULL but has >> already been released, so we're just getting a NULL deref on the actual >> list head. >> >> Does this fix it? It adds the refcounting at approximately the correct >> places. Of course, we'll now be trying elevator operations on an extant >> queue but one whose elevator functions have been destroyed, so there are >> probably additional state guards to place. >> >> James >> >> --- >> >> diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c >> index 58584dc..44e8ca3 100644 >> --- a/drivers/scsi/scsi_scan.c >> +++ b/drivers/scsi/scsi_scan.c >> @@ -297,7 +297,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, >> kfree(sdev); >> goto out; >> } >> - >> + blk_get_queue(sdev->request_queue); > > Apparently we can't do this because blk_[put|get]_queue aren't exported > for use in modules (and SCSI can be modular), so this caused a build > failure in linux-next. I'll just export them. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/