Re: [PATCH 4/4] scsi: core: only put parent device if host state isn't in SHOST_CREATED

[Ming Lei <ming.lei@redhat.com>]

On Mon, Jun 07, 2021 at 01:41:36PM +0200, Hannes Reinecke wrote:
> On 6/2/21 3:30 PM, Ming Lei wrote:
> > get_device(shost->shost_gendev.parent) is called after host state is
> > changed to SHOST_RUNNING. So scsi_host_dev_release() shouldn't release
> > the parent device if host state is still SHOST_CREATED.
> > 
> > Cc: Bart Van Assche <bvanassche@acm.org>
> > Cc: John Garry <john.garry@huawei.com>
> > Cc: Hannes Reinecke <hare@suse.de>
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> >  drivers/scsi/hosts.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
> > index 7049844adb6b..34db5be7a562 100644
> > --- a/drivers/scsi/hosts.c
> > +++ b/drivers/scsi/hosts.c
> > @@ -350,7 +350,7 @@ static void scsi_host_dev_release(struct device *dev)
> >  
> >  	ida_simple_remove(&host_index_ida, shost->host_no);
> >  
> > -	if (parent)
> > +	if (shost->shost_state != SHOST_CREATED)
> >  		put_device(parent);
> >  	kfree(shost);
> >  }
> > 
> What happened to the check 'if (parent)'?

put_device() is just like kfree(), and it will handle null 'parent'.

Thanks,
Ming