Re: [PATCH 16/19] nvme-multipath: add nvme_mpath_{add,delete}_ns()

[Nilay Shroff]

On 2/25/26 9:10 PM, John Garry wrote:

Add functions to call into the mpath_add_device() and mpath_delete_device()
functions.

The per-NS gendisk pointer is used as the mpath_device disk pointer, which
is used in libmultipath for references the per-path block device.

Signed-off-by: John Garry<john.g.ga...@oracle.com>
---
  drivers/nvme/host/multipath.c | 26 ++++++++++++++++++++++++++
  drivers/nvme/host/nvme.h      |  8 ++++++++
  2 files changed, 34 insertions(+)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 7ee0ad7bdfa26..bd96211123fee 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -982,6 +982,32 @@ void nvme_mpath_synchronize(struct nvme_ns_head *head)
        mpath_synchronize(mpath_disk->mpath_head);
  }

+void nvme_mpath_add_ns(struct nvme_ns *ns)

+{
+       struct nvme_ns_head *head = ns->head;
+       struct mpath_disk *mpath_disk = head->mpath_disk;
+       struct mpath_head *mpath_head;
+
+       if (!mpath_disk)
+               return;
+
+       mpath_head = mpath_disk->mpath_head;
+
+       ns->mpath_device.disk = ns->disk;
+       mpath_add_device(mpath_head, &ns->mpath_device);
+}

As we have now reference to mpath_device from struct nvme_ns
then why do we still maintain reference to ns->disk? We may
want to directly access path device disk using ns->mpath_device.disk,
makes sense?

Thanks,
--Nilay