libnvdimm: pmem label sets and namespace instantiation.

A complete label set is a PMEM-label per-dimm per-interleave-set where
all the UUIDs match and the interleave set cookie matches the hosting
interleave set.

Present sysfs attributes for manipulation of a PMEM-namespace's
'alt_name', 'uuid', and 'size' attributes.  A later patch will make
these settings persistent by writing back the label.

Note that PMEM allocations grow forwards from the start of an interleave
set (lowest dimm-physical-address (DPA)).  BLK-namespaces that alias
with a PMEM interleave set will grow allocations backward from the
highest DPA.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 1b627b109360..c130972e08c4 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -41,10 +41,20 @@ typedef int (*ndctl_fn)(struct nvdimm_bus_descriptor *nd_desc,
                 struct nvdimm *nvdimm, unsigned int cmd, void *buf,
                 unsigned int buf_len);
 
+struct nd_namespace_label;
+struct nvdimm_drvdata;
 struct nd_mapping {
         struct nvdimm *nvdimm;
+        struct nd_namespace_label **labels;
         u64 start;
         u64 size;
+        /*
+         * @ndd is for private use at region enable / disable time for
+         * get_ndd() + put_ndd(), all other nd_mapping to ndd
+         * conversions use to_ndd() which respects enabled state of the
+         * nvdimm.
+         */
+        struct nvdimm_drvdata *ndd;
 };
 
 struct nvdimm_bus_descriptor {