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Date:   Thu, 24 Oct 2019 06:14:32 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     Michal =?iso-8859-1?Q?Such=E1nek?= <msuchanek@suse.de>
Cc:     Christoph Hellwig <hch@infradead.org>, linux-scsi@vger.kernel.org,
        Jonathan Corbet <corbet@lwn.net>, Jens Axboe <axboe@kernel.dk>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Eric Biggers <ebiggers@google.com>,
        "J. Bruce Fields" <bfields@redhat.com>,
        Benjamin Coddington <bcodding@redhat.com>,
        Hannes Reinecke <hare@suse.com>,
        Omar Sandoval <osandov@fb.com>, Ming Lei <ming.lei@redhat.com>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Tejun Heo <tj@kernel.org>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 8/8] scsi: sr: wait for the medium to become ready
Message-ID: <20191024131432.GF2963@bombadil.infradead.org>
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 <20191024022406.GD11485@infradead.org>
 <20191024085136.GG938@kitsune.suse.cz>
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On Thu, Oct 24, 2019 at 10:51:36AM +0200, Michal Such?nek wrote:
> On Wed, Oct 23, 2019 at 07:24:06PM -0700, Christoph Hellwig wrote:
> > On Wed, Oct 23, 2019 at 02:52:47PM +0200, Michal Suchanek wrote:
> > > +static int sr_block_open_finish(struct block_device *bdev, fmode_t mode,
> > > +				int ret)
> > > +{
> > > +	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
> > > +
> > > +	/* wait for drive to get ready */
> > > +	if ((ret == -ENOMEDIUM) && !(mode & FMODE_NDELAY)) {
> > > +		struct scsi_device *sdev = cd->device;
> > > +		/*
> > > +		 * Cannot use sr_block_ioctl because it locks sr_mutex blocking
> > > +		 * out any processes trying to access the drive
> > > +		 */
> > > +		scsi_autopm_get_device(sdev);
> > > +		cdrom_ioctl(&cd->cdi, bdev, mode, CDROM_AUTOCLOSE, 0);
> > > +		ret = __sr_block_open(bdev, mode);
> > > +		scsi_autopm_put_device(sdev);
> > 
> > Ioctls should never be used from kernel space.  We have a few leftovers,
> > but we need to get rid of that and not add more.
> 
> What is the alternative?

Call the function that would be called by the ioctl instead.