4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 86880d646122240596d6719b642fee3213239994 ]
Delete operations are seeing NULL pointer references in call_timer_fn. Tracking these back, the timer appears to be the keep alive timer.
nvme_keep_alive_work() which is tied to the timer that is cancelled by nvme_stop_keep_alive(), simply starts the keep alive io but doesn't wait for it's completion. So nvme_stop_keep_alive() only stops a timer when it's pending. When a keep alive is in flight, there is no timer running and the nvme_stop_keep_alive() will have no affect on the keep alive io. Thus, if the io completes successfully, the keep alive timer will be rescheduled. In the failure case, delete is called, the controller state is changed, the nvme_stop_keep_alive() is called while the io is outstanding, and the delete path continues on. The keep alive happens to successfully complete before the delete paths mark it as aborted as part of the queue termination, so the timer is restarted. The delete paths then tear down the controller, and later on the timer code fires and the timer entry is now corrupt.
Fix by validating the controller state before rescheduling the keep alive. Testing with the fix has confirmed the condition above was hit.
Signed-off-by: James Smart jsmart2021@gmail.com Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index b7b2659e02fa..e5bddae16ed4 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -831,6 +831,8 @@ static int nvme_submit_user_cmd(struct request_queue *q, static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status) { struct nvme_ctrl *ctrl = rq->end_io_data; + unsigned long flags; + bool startka = false;
blk_mq_free_request(rq);
@@ -841,7 +843,13 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status) return; }
- schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + spin_lock_irqsave(&ctrl->lock, flags); + if (ctrl->state == NVME_CTRL_LIVE || + ctrl->state == NVME_CTRL_CONNECTING) + startka = true; + spin_unlock_irqrestore(&ctrl->lock, flags); + if (startka) + schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); }
static int nvme_keep_alive(struct nvme_ctrl *ctrl)