nvme: protect against simultaneous shutdown invocations

Signed-off-by: Keith Busch <keith.busch@intel.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Keith Busch 2015-11-26 12:21:29 +01:00 • committed by Jens Axboe
commit 77bf25ea70