[PATCHv3] nvme: skip noiob for zoned devices

[Keith Busch]

Zoned block devices reuse the chunk_sectors queue limit to define zone
boundaries. If a such a device happens to also report an optimal
boundary, log a warning of the conflicting attributes and do not use
that to define the chunk_sectors as that may intermittently interfere
with io splitting and zone size queries.

Signed-off-by: Keith Busch <kbusch at kernel.org>
---
v2 -> v3:

 Emit a warning on the initial validation if a zoned device reports an
 optimal boundary.

 drivers/nvme/host/core.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 88cff309d8e4..10cf40d2cfef 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2075,8 +2075,13 @@ static int __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id)
 		}
 	}
 
-	if (iob)
-		blk_queue_chunk_sectors(ns->queue, rounddown_pow_of_two(iob));
+	if (iob) {
+		if (!blk_queue_is_zoned(disk->queue))
+			blk_queue_chunk_sectors(ns->queue, rounddown_pow_of_two(iob));
+		else if (!(disk->flags & GENHD_FL_UP))
+			pr_warn("%s: zone namespace has unused IO boundary:%u\n",
+				disk->disk_name, iob);
+	}
 	nvme_update_disk_info(disk, ns, id);
 #ifdef CONFIG_NVME_MULTIPATH
 	if (ns->head->disk) {
-- 
2.24.1