Re: [Fwd: [PATCH]: Fix crash in virtio_blk during modprobe ; rmmod ; modprobe]

[Jens Axboe <jens.axboe@oracle.com>]

On Thu, May 22 2008, Rusty Russell wrote:
> On Wednesday 21 May 2008 23:12:39 Chris Lalancette wrote:
> > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> > index 4962e62..c678ac5 100644
> > --- a/drivers/block/virtio_blk.c
> > +++ b/drivers/block/virtio_blk.c
> > @@ -294,6 +294,7 @@ static void virtblk_remove(struct virtio_device *vdev)
> >         vdev->config->reset(vdev);
> >  
> >         blk_cleanup_queue(vblk->disk->queue);
> > +       del_gendisk(vblk->disk);
> >         put_disk(vblk->disk);
> >         unregister_blkdev(major, "virtblk");
> >         mempool_destroy(vblk->pool);
> 
> Thanks Chris, it seems reasonable and I'm sure it works (kinda hard to
> test here, it's my root block dev).  Other drivers seem to do
> blk_cleanup_queue() *after* del_gendisk: does it matter?
> 
> Jens CC'd: he's gentle with my dumb questions...  Rusty.

del_gendisk() can generate IO, so it would seem safer to do that
_before_ putting the queue reference :-)

-- 
Jens Axboe