Look at the following scenario.
nvme_reset_ctrl
-> set state to RESETTING
-> queue reset_work
(scheduling)
nvme_reset_work
-> nvme_dev_disable
-> quiesce queues
-> nvme_cancel_request
on outstanding requests
-> set state to RECONNECTING
-> nvme initializing
(will issue request on adminq)
A request could expire after the ctrl state is set to RESETTING
and queue the reset_work.
- If the timeout occurs before state RECONNECTING, the expired
requests are from the previous work.
- Otherwise, the expired requests are from the controller
initializing procedure, such as sending cq/sq create commands
to adminq to setup io queues.
In current implementation, nvme_timeout only handles second case
above.
To fix this, when the state is RESETTING, handle the expired
requests as nvme_cancel_request, when the state is RECONNECTING,
handle it as the original method and discard the nvme_dev_disable
there, the nvme_reset_work will see the error and invoke itself.
Signed-off-by: Jianchao Wang <jianchao.w.w...@oracle.com>
---
drivers/nvme/host/pci.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 05344be..a9b2359 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1210,18 +1210,24 @@ static enum blk_eh_timer_return nvme_timeout(struct
request *req, bool reserved)
}
/*
- * Shutdown immediately if controller times out while starting. The
- * reset work will see the pci device disabled when it gets the forced
- * cancellation error. All outstanding requests are completed on
- * shutdown, so we return BLK_EH_HANDLED.
+ * - When the ctrl.state is NVME_CTRL_RESETTING, the expired
+ * request should come from the previous work and we handle
+ * it as nvme_cancel_request.
+ * - When the ctrl.state is NVME_CTRL_RECONNECTING, the expired
+ * request should come from the initializing procedure such as
+ * setup io queues, because all the previous outstanding
+ * requests should have been cancelled.
*/
- if (dev->ctrl.state == NVME_CTRL_RESETTING) {
- dev_warn(dev->ctrl.device,
- "I/O %d QID %d timeout, disable controller\n",
- req->tag, nvmeq->qid);
- nvme_dev_disable(dev, false);
+ switch (dev->ctrl.state) {
+ case NVME_CTRL_RESETTING:
+ nvme_req(req)->status = NVME_SC_ABORT_REQ;
+ return BLK_EH_HANDLED;
+ case NVME_CTRL_RECONNECTING:
+ WARN_ON_ONCE(nvmeq->qid);
nvme_req(req)->flags |= NVME_REQ_CANCELLED;
return BLK_EH_HANDLED;
+ default:
+ break;
}
/*
--
2.7.4
