libnvdimm, pfn: add parent uuid validation

Track and check the uuid of the namespace hosting a pfn instance.  This
forces the pfn info block to be invalidated if the namespace is
re-configured with a different uuid.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 95ecd7b0fab3..f9b674bc49db 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -273,10 +273,11 @@ struct device *nd_pfn_create(struct nd_region *nd_region)
 
 int nd_pfn_validate(struct nd_pfn *nd_pfn)
 {
-        struct nd_namespace_common *ndns = nd_pfn->ndns;
-        struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
-        struct nd_namespace_io *nsio;
         u64 checksum, offset;
+        struct nd_namespace_io *nsio;
+        struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+        struct nd_namespace_common *ndns = nd_pfn->ndns;
+        const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 
         if (!pfn_sb || !ndns)
                 return -ENODEV;
@@ -296,6 +297,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                 return -ENODEV;
         pfn_sb->checksum = cpu_to_le64(checksum);
 
+        if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
+                return -ENODEV;
+
         switch (le32_to_cpu(pfn_sb->mode)) {
         case PFN_MODE_RAM:
                 break;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 5ba351e4f26a..dc6866734f70 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -270,6 +270,7 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
         pfn_sb->npfns = cpu_to_le64(npfns);
         memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
         memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
+        memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
         pfn_sb->version_major = cpu_to_le16(1);
         checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
         pfn_sb->checksum = cpu_to_le64(checksum);