nvme: find numa distance only if controller has valid numa id

PATCH Applied Nilay Shroff 5 participants 5 messages Apr 16, 2024 NVMe

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Nilay Shroff

author

2024-04-16 08:22 UTC #0 lore raw

PATCH v3 1/1 nvme: find numa distance only if controller has valid numa id

On system where native nvme multipath is configured and iopolicy is set to numa but the nvme controller numa node id is undefined or -1 (NUMA_NO_NODE) then avoid calculating node distance for finding optimal io path. In such case we may access numa distance table with invalid index and that may potentially refer to incorrect memory. So this patch ensures that if the nvme controller numa node id is -1 then instead of calculating node distance for finding optimal io path, we set the numa node distance of such controller to default 10 (LOCAL_DISTANCE).

Link https://lore.kernel.org/all/[email protected]/ open here

Signed-off-by Nilay Shroff <[email protected]>

---
Changes from v2:
Formatting cleanups to avoid overshooting 80 chars width (Chaitanya)
Changes from v1:
Formatting cleanups (Christoph)

 drivers/nvme/host/multipath.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

drivers/nvme/host/multipath.c +2 -1

index 5397fb428b24..d16e976ae1a4 100644
@@ -247,7 +247,8 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
 		if (nvme_path_is_disabled(ns))
 			continue;
 
-		if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
+		if (ns->ctrl->numa_node != NUMA_NO_NODE &&
+		    READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
 			distance = node_distance(node, ns->ctrl->numa_node);
 		else
 			distance = LOCAL_DISTANCE;

Signature · 1 line

2.44.0

Chaitanya Kulkarni

Reviewed-by on v3 1/1

2024-04-16 09:07 UTC #1 lore raw

Quoted 10 lines · Nilay Shroff

On system where native nvme multipath is configured and iopolicy is set to numa but the nvme controller numa node id is undefined or -1 (NUMA_NO_NODE) then avoid calculating node distance for finding optimal io path. In such case we may access numa distance table with invalid index and that may potentially refer to incorrect memory. So this patch ensures that if the nvme controller numa node id is -1 then instead of calculating node distance for finding optimal io path, we set the numa node distance of such controller to default 10 (LOCAL_DISTANCE).

Quoted 2 lines

Link https://lore.kernel.org/all/[email protected]/ open here
Signed-off-by Nilay Shroff<[email protected]>

Reviewed-by Chaitanya Kulkarni <[email protected]>

-ck

Sagi Grimberg

maintainer Reviewed-by on v3 1/1

2024-04-16 09:44 UTC #2 lore raw

In reply to Nilay Shroff

Reviewed-by Sagi Grimberg <[email protected]>

Christoph Hellwig

maintainer Reviewed-by on v3 1/1

2024-04-16 15:14 UTC #3 lore raw

In reply to Nilay Shroff

Looks good:

Reviewed-by Christoph Hellwig <[email protected]>

Keith Busch

maintainer Applied

2024-04-16 16:44 UTC #4 lore raw

In reply to Nilay Shroff

Quoted 9 lines · Nilay Shroff

On system where native nvme multipath is configured and iopolicy is set to numa but the nvme controller numa node id is undefined or -1 (NUMA_NO_NODE) then avoid calculating node distance for finding optimal io path. In such case we may access numa distance table with invalid index and that may potentially refer to incorrect memory. So this patch ensures that if the nvme controller numa node id is -1 then instead of calculating node distance for finding optimal io path, we set the numa node distance of such controller to default 10 (LOCAL_DISTANCE).

Thanks, applied to nvme-6.9.