[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 | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index f204c6f78b5b..df4d89aa061f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4054,6 +4054,9 @@ 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);
 	blk_cleanup_queue(ns->queue);
 
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 7fc58e1f6b09..dc9a4018f90d 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -801,6 +801,8 @@ static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl,
 
 void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
 {
+	int ret;
+
 	if (nvme_ctrl_use_ana(ns->ctrl)) {
 		struct nvme_ana_group_desc desc = {
 			.grpid = id->anagrpid,
@@ -831,6 +833,12 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
 	if (blk_queue_is_zoned(ns->queue) && ns->head->disk)
 		ns->head->disk->queue->nr_zones = ns->queue->nr_zones;
 #endif
+	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)
-- 
2.29.2