3.16.50-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Bodo Stroesser <bstroes...@ts.fujitsu.com>

commit 180efde0a3f43dbe533e4be203c2918793482d4e upstream.

If blk_queue_get() in st_probe fails, disk->queue must not be set to
SDp->request_queue, as that would result in put_disk() dropping a not
taken reference.

Thus, disk->queue should be set only after a successful blk_queue_get().

Fixes: 2b5bebccd282 ("st: Take additional queue ref in st_probe")
Signed-off-by: Bodo Stroesser <bstroes...@ts.fujitsu.com>
Acked-by: Shirish Pargaonkar <spargaon...@suse.com>
Signed-off-by: Hannes Reinecke <h...@suse.com>
Reviewed-by: Ewan D. Milne <emi...@redhat.com>
Acked-by: Kai Mäkisara <kai.makis...@kolumbus.fi>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/scsi/st.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4115,11 +4115,11 @@ static int st_probe(struct device *dev)
        kref_init(&tpnt->kref);
        tpnt->disk = disk;
        disk->private_data = &tpnt->driver;
-       disk->queue = SDp->request_queue;
        /* SCSI tape doesn't register this gendisk via add_disk().  Manually
         * take queue reference that release_disk() expects. */
-       if (!blk_get_queue(disk->queue))
+       if (!blk_get_queue(SDp->request_queue))
                goto out_put_disk;
+       disk->queue = SDp->request_queue;
        tpnt->driver = &st_template;
 
        tpnt->device = SDp;

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