[PATCH 4.19 18/73] scsi: zfcp: fix missing zfcp_port reference put on -EBUSY from port_remove

[Greg Kroah-Hartman]

From: Steffen Maier <maier@xxxxxxxxxxxxx>

commit d27e5e07f9c49bf2a6a4ef254ce531c1b4fb5a38 upstream.

With this early return due to zfcp_unit child(ren), we don't use the
zfcp_port reference from the earlier zfcp_get_port_by_wwpn() anymore and
need to put it.

Signed-off-by: Steffen Maier <maier@xxxxxxxxxxxxx>
Fixes: d99b601b6338 ("[SCSI] zfcp: restore refcount check on port_remove")
Cc: <stable@xxxxxxxxxxxxxxx> #3.7+
Reviewed-by: Jens Remus <jremus@xxxxxxxxxxxxx>
Reviewed-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/s390/scsi/zfcp_sysfs.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -261,6 +261,7 @@ static ssize_t zfcp_sysfs_port_remove_st
 	if (atomic_read(&port->units) > 0) {
 		retval = -EBUSY;
 		mutex_unlock(&zfcp_sysfs_port_units_mutex);
+		put_device(&port->dev); /* undo zfcp_get_port_by_wwpn() */
 		goto out;
 	}
 	/* port is about to be removed, so no more unit_add */