nvme: check for duplicate identifiers earlier

Lift the check for duplicate identifiers into nvme_init_ns_head, which
avoids pointless error unwinding in case they don't match, and also
matches where we check identifier validity for the multipath case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

drivers/nvme/host/core.c

@@ -3782,13 +3782,6 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
 	head->ids = *ids;
 	kref_init(&head->ref);
 
-	ret = nvme_subsys_check_duplicate_ids(ctrl->subsys, &head->ids);
-	if (ret) {
-		dev_err(ctrl->device,
-			"duplicate IDs for nsid %d\n", nsid);
-		goto out_cleanup_srcu;
-	}
-
 	if (head->ids.csi) {
 		ret = nvme_get_effects_log(ctrl, head->ids.csi, &head->effects);
 		if (ret)
@@ -3827,6 +3820,12 @@ static int nvme_init_ns_head(struct nvme_ns *ns, unsigned nsid,
 	mutex_lock(&ctrl->subsys->lock);
 	head = nvme_find_ns_head(ctrl->subsys, nsid);
 	if (!head) {
+		ret = nvme_subsys_check_duplicate_ids(ctrl->subsys, ids);
+		if (ret) {
+			dev_err(ctrl->device,
+				"duplicate IDs for nsid %d\n", nsid);
+			goto out_unlock;
+		}
 		head = nvme_alloc_ns_head(ctrl, nsid, ids);
 		if (IS_ERR(head)) {
 			ret = PTR_ERR(head);