[PATCH 3/4] nvme: ANA transition timeout handling

[hare@suse.de (Hannes Reinecke)]

Add a timer for tracking ANA transition timeout, and reset the
controller once the timeout expires.

Signed-off-by: Hannes Reinecke <hare at suse.com>
---
 drivers/nvme/host/core.c      |  3 +++
 drivers/nvme/host/multipath.c | 34 ++++++++++++++++++++++++++++------
 drivers/nvme/host/nvme.h      |  6 ++++++
 3 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e62de51209b2..3b578ae62cb5 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2378,6 +2378,7 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 	ctrl->kas = le16_to_cpu(id->kas);
 	ctrl->max_namespaces = le32_to_cpu(id->mnan);
 	ctrl->anacap = id->anacap;
+	ctrl->anatt = id->anatt;
 	ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);
 	ctrl->anagrpmax = le32_to_cpu(id->anagrpmax);
 
@@ -3025,6 +3026,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue);
 	ns->queue->queuedata = ns;
 	ns->ctrl = ctrl;
+	timer_setup(&ns->anatt_timer, nvme_anatt_timedout, 0);
 
 	kref_init(&ns->kref);
 	ns->lba_shift = 9; /* set to a default value for 512 until disk is validated */
@@ -3113,6 +3115,7 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 			blk_integrity_unregister(ns->disk);
 	}
 
+	del_timer_sync(&ns->anatt_timer);
 	mutex_lock(&ns->ctrl->subsys->lock);
 	nvme_mpath_clear_current_path(ns);
 	list_del_rcu(&ns->siblings);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index d30229a21c97..7a37f5959ad4 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -62,13 +62,12 @@ void nvme_failover_req(struct request *req)
 	 */
 	switch (nvme_req(req)->status & 0x7ff) {
 	case NVME_SC_ANA_TRANSITION:
-		/*
-		 * XXX: We should verify the controller doesn't die on during
-		 * the transition.  But that means we per-group timeout from
-		 * when we first hit the change state, so this won't be
-		 * entirely trivial..
-		 */
 		nvme_update_ana_state(ns, NVME_ANA_CHANGE);
+		if (!timer_pending(&ns->anatt_timer)) {
+			ns->anatt_timer.expires =
+				ns->ctrl->anatt * HZ + jiffies;
+			add_timer(&ns->anatt_timer);
+		}
 		break;
 	case NVME_SC_ANA_PERSISTENT_LOSS:
 		nvme_update_ana_state(ns, NVME_ANA_PERSISTENT_LOSS);
@@ -390,11 +389,34 @@ static int nvme_process_ana_log(struct nvme_ctrl *ctrl, bool groups_only)
 static void nvme_ana_work(struct work_struct *work)
 {
 	struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work);
+	struct nvme_ns *ns;
 
 	nvme_process_ana_log(ctrl, false);
+	down_write(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list) {
+		enum nvme_ana_state state = nvme_ns_ana_state(ns);
+
+		if (timer_pending(&ns->anatt_timer) &&
+		    state != NVME_ANA_CHANGE)
+			del_timer_sync(&ns->anatt_timer);
+		if (!timer_pending(&ns->anatt_timer) &&
+		    state == NVME_ANA_CHANGE) {
+			ns->anatt_timer.expires =
+				ns->ctrl->anatt * HZ + jiffies;
+			add_timer(&ns->anatt_timer);
+		}
+	}
+	up_write(&ctrl->namespaces_rwsem);
 	nvme_kick_requeue_lists(ctrl);
 }
 
+void nvme_anatt_timedout(struct timer_list *t)
+{
+	struct nvme_ns *ns = from_timer(ns, t, anatt_timer);
+
+	nvme_reset_ctrl(ns->ctrl);
+}
+
 int nvme_configure_ana(struct nvme_ctrl *ctrl)
 {
 	int error;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index be2585576bad..d059b5522993 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -200,6 +200,7 @@ struct nvme_ctrl {
 
 	/* asymmetric namespace access: */
 	u8 anacap;
+	u8 anatt;
 	u32 anagrpmax;
 	u32 nanagrpid;
 	enum nvme_ana_state *ana_state;
@@ -301,6 +302,7 @@ struct nvme_ns {
 	struct nvm_dev *ndev;
 	struct kref kref;
 	struct nvme_ns_head *head;
+	struct timer_list anatt_timer;
 
 	int lba_shift;
 	u16 ms;
@@ -469,6 +471,7 @@ void nvme_mpath_add_disk(struct nvme_ns *ns);
 void nvme_mpath_remove_disk(struct nvme_ns_head *head);
 int nvme_configure_ana(struct nvme_ctrl *ctrl);
 void nvme_deconfigure_ana(struct nvme_ctrl *ctrl);
+void nvme_anatt_timedout(struct timer_list *t);
 
 static inline void nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
@@ -531,6 +534,9 @@ static inline int nvme_configure_ana(struct nvme_ctrl *ctrl)
 static inline void nvme_deconfigure_ana(struct nvme_ctrl *ctrl)
 {
 }
+void nvme_anatt_timedout(struct timer_list *t)
+{
+}
 #endif /* CONFIG_NVME_MULTIPATH */
 
 #ifdef CONFIG_NVM
-- 
2.12.3