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Date:   Fri, 6 Apr 2018 21:03:34 -0400
From:   Wakko Warner <wakko@animx.eu.org>
To:     Bart Van Assche <Bart.VanAssche@wdc.com>
Cc:     "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "richard.weinberger@gmail.com" <richard.weinberger@gmail.com>,
        "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Subject: Re: 4.15.14 crash with iscsi target and dvd
Message-ID: <20180407010334.GA11092@animx.eu.org>
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Bart Van Assche wrote:
> On Thu, 2018-04-05 at 22:06 -0400, Wakko Warner wrote:
> > I know now why scsi_print_command isn't doing anything.  cmd->cmnd is null.
> > I added a dev_printk in scsi_print_command where the 2 if statements return.
> > Logs:
> > [  29.866415] sr 3:0:0:0: cmd->cmnd is NULL
> 
> That's something that should never happen. As one can see in
> scsi_setup_scsi_cmnd() and scsi_setup_fs_cmnd() both functions initialize
> that pointer. Since I have not yet been able to reproduce myself what you
> reported, would it be possible for you to bisect this issue? You will need
> to follow something like the following procedure (see also
> https://git-scm.com/docs/git-bisect):
> 
> git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git bisect start
> git bisect bad v4.10
> git bisect good v4.9
> 
> and then build the kernel, install it, boot the kernel and test it.
> Depending on the result, run either git bisect bad or git bisect good and
> keep going until git bisect comes to a conclusion. This can take an hour or
> more.

I have 1 question.  Should make clean be done between tests?  My box
compiles the whole kernel in 2 minutes.

-- 
 Microsoft has beaten Volkswagen's world record.  Volkswagen only created 22
 million bugs.