NVMe: Fix nvme module init when nvme_major is set

register_blkdev returns 0 when given a valid major number.

Reported-by:Ross Zwisler <ross.zwisler@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index 38b9c73f6706..46e33eec6298 100644
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -1716,9 +1716,11 @@ static int __init nvme_init(void)
         if (IS_ERR(nvme_thread))
                 return PTR_ERR(nvme_thread);
 
-        nvme_major = register_blkdev(nvme_major, "nvme");
-        if (nvme_major <= 0)
+        result = register_blkdev(nvme_major, "nvme");
+        if (result < 0)
                 goto kill_kthread;
+        else if (result > 0)
+            nvme_major = result;
 
         result = pci_register_driver(&nvme_driver);
         if (result)