dm: add persistent data library

The persistent-data library offers a re-usable framework for the storage
and management of on-disk metadata in device-mapper targets.

It's used by the thin-provisioning target in the next patch and in an
upcoming hierarchical storage target.

For further information, please read
Documentation/device-mapper/persistent-data.txt

Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/md/persistent-data/Kconfig b/drivers/md/persistent-data/Kconfig
new file mode 100644
index 000000000000..ceb359050a59
--- /dev/null
+++ b/drivers/md/persistent-data/Kconfig
@@ -0,0 +1,8 @@
+config DM_PERSISTENT_DATA
+       tristate
+       depends on BLK_DEV_DM && EXPERIMENTAL
+       select LIBCRC32C
+       select DM_BUFIO
+       ---help---
+         Library providing immutable on-disk data structure support for
+         device-mapper targets such as the thin provisioning target.