On Mon, Sep 18, 2017 at 04:14:52PM -0700, Christoph Hellwig wrote:

Introduce a new struct nvme_ns_head [1] that holds information about
an actual namespace, unlike struct nvme_ns, which only holds the
per-controller namespace information.  For private namespaces there
is a 1:1 relation of the two, but for shared namespaces this lets us
discover all the paths to it.  For now only the identifiers are moved
to the new structure, but most of the information in struct nvme_ns
should eventually move over.

To allow lockless path lookup the list of nvme_ns structures per
nvme_ns_head is protected by SRCU, which requires freeing the nvme_ns
structure through call_srcu.

[1] comments welcome if you have a better name for it, the current one is
    horrible.  One idea would be to rename the current struct nvme_ns
    to struct nvme_ns_link or similar and use the nvme_ns name for the
    new structure.  But that would involve a lot of churn.

Being one of the persons who has to backport a lot of NVMe code to older
kernels I'm not a huge fan of renaming nmve_ns.

That said, I don't have a better name for nvme_ns_head (yet) but I'll try to
think of one as well. OTOH looking at nvme_ns_head it actaully is the list
head of the nvme_ns list.

Byte,
	Johannes
-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
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