[PATCH v2 2/2] nvme: enable generic interface (/dev/ngXnY) for unknown command sets

[Joel Granados]

Extend nvme_alloc_ns() and nvme_validate_ns() for unknown command-set as
well. Both are made to use a new helper (nvme_update_ns_info_cs_indep)
which is similar to nvme_update_ns_info but performs fewer operations
to get the generic interface up.

Suggested-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Joel Granados <j.granados at samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
---
 drivers/nvme/host/core.c | 83 ++++++++++++++++++++++++++++++++++------
 1 file changed, 72 insertions(+), 11 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 06b9718b0540..c7eb92480fad 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1912,6 +1912,33 @@ static void nvme_set_chunk_sectors(struct nvme_ns *ns, struct nvme_id_ns *id)
 	blk_queue_chunk_sectors(ns->queue, iob);
 }
 
+static int nvme_update_ns_info_cs_indep(struct nvme_ns *ns,
+				struct nvme_id_ns_cs_indep *id)
+{
+	blk_mq_freeze_queue(ns->disk->queue);
+	nvme_set_queue_limits(ns->ctrl, ns->queue);
+	set_disk_ro(ns->disk, (id->nsattr & NVME_NS_ATTR_RO) ||
+		test_bit(NVME_NS_FORCE_RO, &ns->flags));
+	blk_mq_unfreeze_queue(ns->disk->queue);
+
+	if (nvme_ns_head_multipath(ns->head)) {
+		blk_mq_freeze_queue(ns->head->disk->queue);
+		set_disk_ro(ns->head->disk,
+			    (id->nsattr & NVME_NS_ATTR_RO) ||
+				    test_bit(NVME_NS_FORCE_RO, &ns->flags));
+		nvme_mpath_revalidate_paths(ns);
+		blk_stack_limits(&ns->head->disk->queue->limits,
+				 &ns->queue->limits, 0);
+		blk_mq_unfreeze_queue(ns->head->disk->queue);
+	}
+
+	/* Hide the block-interface for these devices */
+	ns->disk->flags |= GENHD_FL_HIDDEN;
+	set_bit(NVME_NS_READY, &ns->flags);
+
+	return 0;
+}
+
 static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
 {
 	unsigned lbaf = nvme_lbaf_index(id->flbas);
@@ -3953,15 +3980,27 @@ static void nvme_ns_add_to_ctrl_list(struct nvme_ns *ns)
 	list_add(&ns->list, &ns->ctrl->namespaces);
 }
 
+static inline bool nvme_ns_indep(struct nvme_ns_ids *ids)
+{
+	return ids->csi != NVME_CSI_NVM && ids->csi != NVME_CSI_ZNS;
+}
+
 static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 		struct nvme_ns_ids *ids)
 {
+	int ret = 0;
 	struct nvme_ns *ns;
 	struct gendisk *disk;
 	struct nvme_id_ns *id;
+	struct nvme_id_ns_cs_indep *indep_id;
 	int node = ctrl->numa_node;
+	bool cs_indep = nvme_ns_indep(ids);
 
-	if (nvme_identify_ns(ctrl, nsid, ids, &id))
+	if (cs_indep)
+		ret = nvme_identify_ns_cs_indep(ctrl, nsid, &indep_id);
+	else
+		ret = nvme_identify_ns(ctrl, nsid, ids, &id);
+	if (ret)
 		return;
 
 	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
@@ -3987,7 +4026,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 	ns->ctrl = ctrl;
 	kref_init(&ns->kref);
 
-	if (nvme_init_ns_head(ns, nsid, ids, id->nmic & NVME_NS_NMIC_SHARED))
+	if (nvme_init_ns_head(ns, nsid, ids,
+			      (cs_indep ? indep_id->nmic : id->nmic) & NVME_NS_NMIC_SHARED))
 		goto out_cleanup_disk;
 
 	/*
@@ -4013,7 +4053,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 			ns->head->instance);
 	}
 
-	if (nvme_update_ns_info(ns, id))
+	if (cs_indep)
+		ret = nvme_update_ns_info_cs_indep(ns, indep_id);
+	else
+		ret = nvme_update_ns_info(ns, id);
+	if (ret)
 		goto out_unlink_ns;
 
 	down_write(&ctrl->namespaces_rwsem);
@@ -4027,9 +4071,12 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 	if (!nvme_ns_head_multipath(ns->head))
 		nvme_add_ns_cdev(ns);
 
-	nvme_mpath_add_disk(ns, id->anagrpid);
+	nvme_mpath_add_disk(ns, cs_indep ? indep_id->anagrpid : id->anagrpid);
 	nvme_fault_inject_init(&ns->fault_inject, ns->disk->disk_name);
-	kfree(id);
+	if (cs_indep)
+		kfree(indep_id);
+	else
+		kfree(id);
 
 	return;
 
@@ -4050,7 +4097,10 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
  out_free_ns:
 	kfree(ns);
  out_free_id:
-	kfree(id);
+	if (cs_indep)
+		kfree(indep_id);
+	else
+		kfree(id);
 }
 
 static void nvme_ns_remove(struct nvme_ns *ns)
@@ -4112,12 +4162,17 @@ static void nvme_ns_remove_by_nsid(struct nvme_ctrl *ctrl, u32 nsid)
 static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
 {
 	struct nvme_id_ns *id;
+	struct nvme_id_ns_cs_indep *indep_id;
 	int ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
+	bool cs_indep = nvme_ns_indep(ids);
 
 	if (test_bit(NVME_NS_DEAD, &ns->flags))
 		goto out;
 
-	ret = nvme_identify_ns(ns->ctrl, ns->head->ns_id, ids, &id);
+	if (cs_indep)
+		ret = nvme_identify_ns_cs_indep(ns->ctrl, ns->head->ns_id, &indep_id);
+	else
+		ret = nvme_identify_ns(ns->ctrl, ns->head->ns_id, ids, &id);
 	if (ret)
 		goto out;
 
@@ -4128,10 +4183,16 @@ static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
 		goto out_free_id;
 	}
 
-	ret = nvme_update_ns_info(ns, id);
+	if (cs_indep)
+		ret = nvme_update_ns_info_cs_indep(ns, indep_id);
+	else
+		ret = nvme_update_ns_info(ns, id);
 
 out_free_id:
-	kfree(id);
+	if (cs_indep)
+		kfree(indep_id);
+	else
+		kfree(id);
 out:
 	/*
 	 * Only remove the namespace if we got a fatal error back from the
@@ -4193,8 +4254,8 @@ static void nvme_validate_or_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 		nvme_alloc_ns(ctrl, nsid, &ids);
 		break;
 	default:
-		dev_warn(ctrl->device, "unknown csi %u for nsid %u\n",
-			ids.csi, nsid);
+		/* required to enable char-interface for unknown command sets*/
+		nvme_alloc_ns(ctrl, nsid, &ids);
 		break;
 	}
 }
-- 
2.30.2