[PATCH 6/6] nvme: track shared namespaces in a siblings list

[Sagi Grimberg]

>> General question, Would it make sense to invoke this search from the
>> block layer as part of adding a new disk (a new block_device operation)?
>> And should the sibling association maybe move up to struct block_device?
>> (we could cache nvme_id_ns in nvme_ns for that to happen)?
> 
> For the block/nvme multipath code I need to expose the relationship
> to the block layer.  But the locking is already complicated enough as
> is, so I want to keep the NVMe list as well with that.

Not sure what you mean, but I didn't mean to change any locking scheme,
just have the sibling list exist in struct block_device and call
nvme_ns_find_siblings as a fops callout when the bdev is created, driver
stays responsible for locking.