Patch "nvme/core: Fix race kicking freed request_queue" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    nvme/core: Fix race kicking freed request_queue

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nvme-core-fix-race-kicking-freed-request_queue.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f33447b90e96076483525b21cc4e0a8977cdd07c Mon Sep 17 00:00:00 2001
From: Keith Busch <keith.busch@intel.com>
Date: Fri, 10 Feb 2017 18:15:51 -0500
Subject: nvme/core: Fix race kicking freed request_queue

From: Keith Busch <keith.busch@intel.com>

commit f33447b90e96076483525b21cc4e0a8977cdd07c upstream.

If a namespace has already been marked dead, we don't want to kick the
request_queue again since we may have just freed it from another thread.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/nvme/host/core.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2057,9 +2057,9 @@ void nvme_kill_queues(struct nvme_ctrl *
 		 * Revalidating a dead namespace sets capacity to 0. This will
 		 * end buffered writers dirtying pages that can't be synced.
 		 */
-		if (ns->disk && !test_and_set_bit(NVME_NS_DEAD, &ns->flags))
-			revalidate_disk(ns->disk);
-
+		if (!ns->disk || test_and_set_bit(NVME_NS_DEAD, &ns->flags))
+			continue;
+		revalidate_disk(ns->disk);
 		blk_set_queue_dying(ns->queue);
 		blk_mq_abort_requeue_list(ns->queue);
 		blk_mq_start_stopped_hw_queues(ns->queue, true);


Patches currently in stable-queue which might be from keith.busch@intel.com are

queue-4.9/nvme-pci-disable-on-removal-when-disconnected.patch
queue-4.9/nvme-core-fix-race-kicking-freed-request_queue.patch