From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Sender: Tejun Heo Date: Thu, 8 Feb 2018 09:54:51 -0800 From: "tj@kernel.org" To: Bart Van Assche Cc: "hch@lst.de" , "linux-block@vger.kernel.org" , "axboe@kernel.dk" Subject: Re: [PATCH v2] blk-mq: Fix race between resetting the timer and completion handling Message-ID: <20180208175451.GS695913@devbig577.frc2.facebook.com> References: <1518047297.2870.80.camel@wdc.com> <1518052193.2870.90.camel@wdc.com> <20180208153940.GM695913@devbig577.frc2.facebook.com> <1518107501.3611.19.camel@wdc.com> <20180208170010.GP695913@devbig577.frc2.facebook.com> <1518109843.3611.25.camel@wdc.com> <20180208171934.GQ695913@devbig577.frc2.facebook.com> <1518111465.3611.36.camel@wdc.com> <20180208174017.GR695913@devbig577.frc2.facebook.com> <1518112111.3611.42.camel@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1518112111.3611.42.camel@wdc.com> List-ID: On Thu, Feb 08, 2018 at 05:48:32PM +0000, Bart Van Assche wrote: > On Thu, 2018-02-08 at 09:40 -0800, tj@kernel.org wrote: > > Heh, sorry about not being clear. What I'm trying to say is that > > scmd->device != NULL && device->host == NULL. Or was this what you > > were saying all along? > > What I agree with is that the request pointer (req argument) is stored in %rdi > and that mov 0x1b0(%rdi),%rax loads scmd->device into %rax. Since RIP == > scsi_times_out+0x17, since the instruction at that address tries to dereference > %rax and since the register dump shows that %rax == NULL I think that means that > scmd->device == NULL. Ah, I was completely confused about which one had to be NULL. You're absolutely right. Let's continue earlier in the thread. Thanks. -- tejun