[PATCH] nvme: don't reference NS after unlocking in nvme_ns_head_ctrl_ioctl()

In nvme_ns_head_ctrl_ioctl(), once we drop the SRCU read lock we should
not reference the NS to lookup the controller, so use the available
controller pointer directly.

Signed-off-by: John Garry <[email protected]>

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 664216eece4a6..d5a8f375953bc 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -699,7 +699,7 @@ static int nvme_ns_head_ctrl_ioctl(struct nvme_ns *ns, unsigned int cmd,
 
 	nvme_get_ctrl(ns->ctrl);
 	srcu_read_unlock(&head->srcu, srcu_idx);
-	ret = nvme_ctrl_ioctl(ns->ctrl, cmd, argp, open_for_write);
+	ret = nvme_ctrl_ioctl(ctrl, cmd, argp, open_for_write);
 
 	nvme_put_ctrl(ctrl);
 	return ret;
-- 
2.43.7