[PATCH RFC 3/3] nvme: delay failover by command quiesce timeout

Daniel Wagner wagi at kernel.org
Mon Mar 24 05:07:58 PDT 2025


The TP4129 mendates that the failover should be delayed by CQT.  Thus when
nvme_decide_disposition returns FAILOVER do not immediately re-queue it on
the namespace level instead queue it on the ctrl's request_list and
moved later to the namespace's requeue_list.

Signed-off-by: Daniel Wagner <wagi at kernel.org>
---
 drivers/nvme/host/core.c      | 19 ++++++++++++++++
 drivers/nvme/host/fc.c        |  4 ++++
 drivers/nvme/host/multipath.c | 52 ++++++++++++++++++++++++++++++++++++++++---
 drivers/nvme/host/nvme.h      | 15 +++++++++++++
 drivers/nvme/host/rdma.c      |  2 ++
 drivers/nvme/host/tcp.c       |  1 +
 6 files changed, 90 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 135045528ea1c79eac0d6d47d5f7f05a7c98acc4..f3155c7735e75e06c4359c26db8931142c067e1d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -239,6 +239,7 @@ static void nvme_do_delete_ctrl(struct nvme_ctrl *ctrl)
 
 	flush_work(&ctrl->reset_work);
 	nvme_stop_ctrl(ctrl);
+	nvme_flush_failover(ctrl);
 	nvme_remove_namespaces(ctrl);
 	ctrl->ops->delete_ctrl(ctrl);
 	nvme_uninit_ctrl(ctrl);
@@ -1310,6 +1311,19 @@ static void nvme_queue_keep_alive_work(struct nvme_ctrl *ctrl)
 	queue_delayed_work(nvme_wq, &ctrl->ka_work, delay);
 }
 
+void nvme_schedule_failover(struct nvme_ctrl *ctrl)
+{
+	unsigned long delay;
+
+	if (ctrl->cqt)
+		delay = msecs_to_jiffies(ctrl->cqt);
+	else
+		delay = ctrl->kato * HZ;
+
+	queue_delayed_work(nvme_wq, &ctrl->failover_work, delay);
+}
+EXPORT_SYMBOL_GPL(nvme_schedule_failover);
+
 static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
 						 blk_status_t status)
 {
@@ -1336,6 +1350,8 @@ static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
 		dev_err(ctrl->device,
 			"failed nvme_keep_alive_end_io error=%d\n",
 				status);
+
+		nvme_schedule_failover(ctrl);
 		return RQ_END_IO_NONE;
 	}
 
@@ -4716,6 +4732,7 @@ EXPORT_SYMBOL_GPL(nvme_remove_io_tag_set);
 
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl)
 {
+	nvme_schedule_failover(ctrl);
 	nvme_mpath_stop(ctrl);
 	nvme_auth_stop(ctrl);
 	nvme_stop_failfast_work(ctrl);
@@ -4842,6 +4859,8 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
 
 	INIT_DELAYED_WORK(&ctrl->ka_work, nvme_keep_alive_work);
 	INIT_DELAYED_WORK(&ctrl->failfast_work, nvme_failfast_work);
+	INIT_DELAYED_WORK(&ctrl->failover_work, nvme_failover_work);
+	INIT_LIST_HEAD(&ctrl->failover_list);
 	memset(&ctrl->ka_cmd, 0, sizeof(ctrl->ka_cmd));
 	ctrl->ka_cmd.common.opcode = nvme_admin_keep_alive;
 	ctrl->ka_last_check_time = jiffies;
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index cdc1ba277a5c23ef1afd26e6911b082f3d12b215..bd897b29cd286008b781bbcb4230e08019da6b6b 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -2553,6 +2553,8 @@ nvme_fc_error_recovery(struct nvme_fc_ctrl *ctrl, char *errmsg)
 {
 	enum nvme_ctrl_state state = nvme_ctrl_state(&ctrl->ctrl);
 
+	nvme_schedule_failover(&ctrl->ctrl);
+
 	/*
 	 * if an error (io timeout, etc) while (re)connecting, the remote
 	 * port requested terminating of the association (disconnect_ls)
@@ -3378,6 +3380,8 @@ nvme_fc_reset_ctrl_work(struct work_struct *work)
 	/* will block will waiting for io to terminate */
 	nvme_fc_delete_association(ctrl);
 
+	nvme_schedule_failover(&ctrl->ctrl);
+
 	if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING))
 		dev_err(ctrl->ctrl.device,
 			"NVME-FC{%d}: error_recovery: Couldn't change state "
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 2a7635565083046c575efe1793362ae10581defd..a14b055796b982df96609f53174a5d1334c1c0c4 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -86,9 +86,11 @@ void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
 void nvme_failover_req(struct request *req)
 {
 	struct nvme_ns *ns = req->q->queuedata;
+	struct nvme_ctrl *ctrl = nvme_req(req)->ctrl;
 	u16 status = nvme_req(req)->status & NVME_SCT_SC_MASK;
 	unsigned long flags;
 	struct bio *bio;
+	enum nvme_ctrl_state state = nvme_ctrl_state(ctrl);
 
 	nvme_mpath_clear_current_path(ns);
 
@@ -121,9 +123,53 @@ void nvme_failover_req(struct request *req)
 	blk_steal_bios(&ns->head->requeue_list, req);
 	spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
 
-	nvme_req(req)->status = 0;
-	nvme_end_req(req);
-	kblockd_schedule_work(&ns->head->requeue_work);
+	spin_lock_irqsave(&ctrl->lock, flags);
+	list_add_tail(&req->queuelist, &ctrl->failover_list);
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	if (state == NVME_CTRL_DELETING) {
+		/*
+		 * request which fail over in the DELETING state were
+		 * canceled and blk_mq_tagset_wait_completed_request will
+		 * block until they have been proceed. Though
+		 * nvme_failover_work is already stopped. Thus schedule
+		 * a failover; it's still necessary to delay these commands
+		 * by CQT.
+		 */
+		nvme_schedule_failover(ctrl);
+	}
+}
+
+void nvme_flush_failover(struct nvme_ctrl *ctrl)
+{
+	LIST_HEAD(failover_list);
+	struct request *rq;
+	bool kick = false;
+
+	spin_lock_irq(&ctrl->lock);
+	list_splice_init(&ctrl->failover_list, &failover_list);
+	spin_unlock_irq(&ctrl->lock);
+
+	while (!list_empty(&failover_list)) {
+		rq = list_entry(failover_list.next,
+				struct request, queuelist);
+		list_del_init(&rq->queuelist);
+
+		nvme_req(rq)->status = 0;
+		nvme_end_req(rq);
+		kick = true;
+	}
+
+	if (kick)
+		nvme_kick_requeue_lists(ctrl);
+}
+
+void nvme_failover_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl = container_of(to_delayed_work(work),
+					struct nvme_ctrl, failover_work);
+
+	nvme_flush_failover(ctrl);
 }
 
 void nvme_mpath_start_request(struct request *rq)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 7563332b5b7b76fc6165ec8c6f2d144737d4fe85..10eb323bdaf139526959180c1e66ab4579bb145d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -411,6 +411,9 @@ struct nvme_ctrl {
 
 	enum nvme_ctrl_type cntrltype;
 	enum nvme_dctype dctype;
+
+	struct delayed_work failover_work;
+	struct list_head failover_list;
 };
 
 static inline enum nvme_ctrl_state nvme_ctrl_state(struct nvme_ctrl *ctrl)
@@ -954,6 +957,9 @@ void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys);
 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys);
 void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys);
 void nvme_failover_req(struct request *req);
+void nvme_failover_work(struct work_struct *work);
+void nvme_schedule_failover(struct nvme_ctrl *ctrl);
+void nvme_flush_failover(struct nvme_ctrl *ctrl);
 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head);
 void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid);
@@ -996,6 +1002,15 @@ static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
 static inline void nvme_failover_req(struct request *req)
 {
 }
+static inline void nvme_failover_work(struct work_struct *work)
+{
+}
+static inline void nvme_schedule_failover(struct nvme_ctrl *ctrl)
+{
+}
+static inline void nvme_flush_failover(struct nvme_ctrl *ctrl)
+{
+}
 static inline void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
 {
 }
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 86a2891d9bcc7a990cd214a7fe93fa5c55b292c7..9bee376f881b4c3ebe5502abf23a8e76829780ff 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1127,6 +1127,7 @@ static void nvme_rdma_error_recovery_work(struct work_struct *work)
 
 	nvme_stop_keep_alive(&ctrl->ctrl);
 	flush_work(&ctrl->ctrl.async_event_work);
+	nvme_schedule_failover(&ctrl->ctrl);
 	nvme_rdma_teardown_io_queues(ctrl, false);
 	nvme_unquiesce_io_queues(&ctrl->ctrl);
 	nvme_rdma_teardown_admin_queue(ctrl, false);
@@ -2153,6 +2154,7 @@ static const struct blk_mq_ops nvme_rdma_admin_mq_ops = {
 
 static void nvme_rdma_shutdown_ctrl(struct nvme_rdma_ctrl *ctrl, bool shutdown)
 {
+	nvme_schedule_failover(&ctrl->ctrl);
 	nvme_rdma_teardown_io_queues(ctrl, shutdown);
 	nvme_quiesce_admin_queue(&ctrl->ctrl);
 	nvme_disable_ctrl(&ctrl->ctrl, shutdown);
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index d0023bcfd8a79a193adf2807a24481c8c164a174..3a6c1d3febaf233996e4dcf684793327b5d1412f 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2345,6 +2345,7 @@ static void nvme_tcp_error_recovery_work(struct work_struct *work)
 
 	nvme_stop_keep_alive(ctrl);
 	flush_work(&ctrl->async_event_work);
+	nvme_schedule_failover(ctrl);
 	nvme_tcp_teardown_io_queues(ctrl, false);
 	/* unquiesce to fail fast pending requests */
 	nvme_unquiesce_io_queues(ctrl);

-- 
2.48.1




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