From: Hannes Reinecke <hare@suse.de>
Date: Tue, 7 Aug 2018 12:43:42 +0200
Subject: [PATCH] nvme: fixup crash on failed discovery
Git-commit: 8f220c418d070a097f7d292cf6b37f88d67845ad
References: bsc#1103920
Patch-Mainline: v4.19-rc1

When the initial discovery fails the subsystem hasn't been setup yet
in nvme_mpath_stop, and we can't dereference ctrl->subsys.

Fixes: 0d0b660f ("nvme: add ANA support")
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/multipath.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index c643872f8dac..5a9562881d4e 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -22,7 +22,7 @@ MODULE_PARM_DESC(multipath,
 
 inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
 {
-	return multipath && (ctrl->subsys->cmic & (1 << 3));
+	return multipath && ctrl->subsys && (ctrl->subsys->cmic & (1 << 3));
 }
 
 /*
-- 
2.12.3