[PATCH] nvme: add namespace paths links

[Hannes Reinecke <hare@suse.de>]

It is really annoying to always have to loop through the entire
/sys/block directory just to find the namespace path links for
a single namespace in libnvme/nvme-cli.
So provide links to the namespace paths for efficient lookup.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/host/core.c      |  3 +++
 drivers/nvme/host/multipath.c | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 37b6fa746662..88933838e067 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3681,6 +3681,9 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 
 	if (!nvme_ns_head_multipath(ns->head))
 		nvme_cdev_del(&ns->cdev, &ns->cdev_device);
+	else
+		sysfs_remove_link(&disk_to_dev(ns->head->disk)->kobj,
+				  ns->disk->disk_name);
 	del_gendisk(ns->disk);
 
 	down_write(&ns->ctrl->namespaces_rwsem);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 0a88d7bdc5e3..9dd0be645dad 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -875,6 +875,16 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid)
 	if (blk_queue_is_zoned(ns->queue) && ns->head->disk)
 		ns->head->disk->nr_zones = ns->disk->nr_zones;
 #endif
+	if (ns->head->disk) {
+		int ret;
+
+		ret = sysfs_create_link(&disk_to_dev(ns->head->disk)->kobj,
+					&disk_to_dev(ns->disk)->kobj,
+					ns->disk->disk_name);
+		if (ret)
+			dev_warn(ns->ctrl->device,
+				 "failed to create namespace path link\n");
+	}
 }
 
 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head)
-- 
2.35.3