[PATCH v8 8/8] nvme-multipath: queue-depth support for marginal paths

[Bryan Gurney <bgurney@redhat.com>]

From: John Meneghini <jmeneghi@redhat.com>

Exclude marginal paths from queue-depth io policy. In the case where all
paths are marginal and no optimized or non-optimized path is found, we
fall back to __nvme_find_path which selects the best marginal path.

Tested-by: Bryan Gurney <bgurney@redhat.com>
Signed-off-by: John Meneghini <jmeneghi@redhat.com>
---
 drivers/nvme/host/multipath.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 8d4e54bb4261..767583e8454b 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -420,6 +420,9 @@ static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
 		if (nvme_path_is_disabled(ns))
 			continue;
 
+		if (nvme_ctrl_is_marginal(ns->ctrl))
+			continue;
+
 		depth = atomic_read(&ns->ctrl->nr_active);
 
 		switch (ns->ana_state) {
@@ -443,7 +446,9 @@ static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
 			return best_opt;
 	}
 
-	return best_opt ? best_opt : best_nonopt;
+	best_opt = (best_opt) ? best_opt : best_nonopt;
+
+	return best_opt ? best_opt : __nvme_find_path(head, numa_node_id());
 }
 
 static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
-- 
2.50.0