libnvdimm, btt: write and validate parent_uuid
When a BTT is instantiated on a namespace it must validate the namespace
uuid matches the 'parent_uuid' stored in the btt superblock. This
property enforces that changing the namespace UUID invalidates all
former BTT instances on that storage. For "IO namespaces" that don't
have a label or UUID, the parent_uuid is set to zero, and this
validation is skipped. For such cases, old BTTs have to be invalidated
by forcing the namespace to raw mode, and overwriting the BTT info
blocks.
Based on a patch by Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index 6567746..1958829 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -733,6 +733,7 @@
int ret;
struct btt_sb *super;
struct nd_btt *nd_btt = arena->nd_btt;
+ const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
ret = btt_map_init(arena);
if (ret)
@@ -748,6 +749,7 @@
strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
memcpy(super->uuid, nd_btt->uuid, 16);
+ memcpy(super->parent_uuid, parent_uuid, 16);
super->flags = cpu_to_le32(arena->flags);
super->version_major = cpu_to_le16(arena->version_major);
super->version_minor = cpu_to_le16(arena->version_minor);