nvme: factor out a nvme_configure_metadata helper

Factor out a helper from nvme_update_ns_info that configures the
per-namespaces metadata and PI settings.  Also make sure the helpers
clear the flags explicitly instead of all of ->features to allow for
potentially reusing ->features for future non-metadata flags.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>

drivers/nvme/host/core.c

@@ -1966,6 +1966,50 @@ static int nvme_setup_streams_ns(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 	return 0;
 }
 
+static int nvme_configure_metadata(struct nvme_ns *ns, struct nvme_id_ns *id)
+{
+	struct nvme_ctrl *ctrl = ns->ctrl;
+
+	/*
+	 * The PI implementation requires the metadata size to be equal to the
+	 * t10 pi tuple size.
+	 */
+	ns->ms = le16_to_cpu(id->lbaf[id->flbas & NVME_NS_FLBAS_LBA_MASK].ms);
+	if (ns->ms == sizeof(struct t10_pi_tuple))
+		ns->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
+	else
+		ns->pi_type = 0;
+
+	ns->features &= ~(NVME_NS_METADATA_SUPPORTED | NVME_NS_EXT_LBAS);
+	if (!ns->ms || !(ctrl->ops->flags & NVME_F_METADATA_SUPPORTED))
+		return 0;
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		/*
+		 * The NVMe over Fabrics specification only supports metadata as
+		 * part of the extended data LBA.  We rely on HCA/HBA support to
+		 * remap the separate metadata buffer from the block layer.
+		 */
+		if (WARN_ON_ONCE(!(id->flbas & NVME_NS_FLBAS_META_EXT)))
+			return -EINVAL;
+		if (ctrl->max_integrity_segments)
+			ns->features |=
+				(NVME_NS_METADATA_SUPPORTED | NVME_NS_EXT_LBAS);
+	} else {
+		/*
+		 * For PCIe controllers, we can't easily remap the separate
+		 * metadata buffer from the block layer and thus require a
+		 * separate metadata buffer for block layer metadata/PI support.
+		 * We allow extended LBAs for the passthrough interface, though.
+		 */
+		if (id->flbas & NVME_NS_FLBAS_META_EXT)
+			ns->features |= NVME_NS_EXT_LBAS;
+		else
+			ns->features |= NVME_NS_METADATA_SUPPORTED;
+	}
+
+	return 0;
+}
+
 static void nvme_update_disk_info(struct gendisk *disk,
 		struct nvme_ns *ns, struct nvme_id_ns *id)
 {
@@ -2115,37 +2159,9 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
 		return -ENODEV;
 	}
 
-	ns->features = 0;
-	ns->ms = le16_to_cpu(id->lbaf[lbaf].ms);
-	/* the PI implementation requires metadata equal t10 pi tuple size */
-	if (ns->ms == sizeof(struct t10_pi_tuple))
-		ns->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
-	else
-		ns->pi_type = 0;
-
-	if (ns->ms) {
-		/*
-		 * For PCIe only the separate metadata pointer is supported,
-		 * as the block layer supplies metadata in a separate bio_vec
-		 * chain. For Fabrics, only metadata as part of extended data
-		 * LBA is supported on the wire per the Fabrics specification,
-		 * but the HBA/HCA will do the remapping from the separate
-		 * metadata buffers for us.
-		 */
-		if (id->flbas & NVME_NS_FLBAS_META_EXT) {
-			ns->features |= NVME_NS_EXT_LBAS;
-			if ((ctrl->ops->flags & NVME_F_FABRICS) &&
-			    (ctrl->ops->flags & NVME_F_METADATA_SUPPORTED) &&
-			    ctrl->max_integrity_segments)
-				ns->features |= NVME_NS_METADATA_SUPPORTED;
-		} else {
-			if (WARN_ON_ONCE(ctrl->ops->flags & NVME_F_FABRICS))
-				return -EINVAL;
-			if (ctrl->ops->flags & NVME_F_METADATA_SUPPORTED)
-				ns->features |= NVME_NS_METADATA_SUPPORTED;
-		}
-	}
-
+	ret = nvme_configure_metadata(ns, id);
+	if (ret)
+		return ret;
 	nvme_set_chunk_sectors(ns, id);
 	nvme_update_disk_info(ns->disk, ns, id);
 #ifdef CONFIG_NVME_MULTIPATH