dm persistent data: add threshold callback to space map
Add a threshold callback function to the persistent data space map
interface for a subsequent patch to use.
dm-thin and dm-cache are interested in knowing when they're getting
low on metadata or data blocks. This patch introduces a new method
for registering a callback against a threshold.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index 51ca9ed..883b465 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -391,7 +391,8 @@
.new_block = sm_metadata_new_block,
.commit = sm_metadata_commit,
.root_size = sm_metadata_root_size,
- .copy_root = sm_metadata_copy_root
+ .copy_root = sm_metadata_copy_root,
+ .register_threshold_callback = NULL
};
/*----------------------------------------------------------------*/
@@ -513,7 +514,8 @@
.new_block = sm_bootstrap_new_block,
.commit = sm_bootstrap_commit,
.root_size = sm_bootstrap_root_size,
- .copy_root = sm_bootstrap_copy_root
+ .copy_root = sm_bootstrap_copy_root,
+ .register_threshold_callback = NULL
};
/*----------------------------------------------------------------*/