dm thin: generate event when metadata threshold passed
Generate a dm event when the amount of remaining thin pool metadata
space falls below a certain level.
The threshold is taken to be a quarter of the size of the metadata
device with a minimum threshold of 4MB.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index ef8dd70..845ebbe 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -8,6 +8,7 @@
#define DM_THIN_METADATA_H
#include "persistent-data/dm-block-manager.h"
+#include "persistent-data/dm-space-map.h"
#define THIN_METADATA_BLOCK_SIZE 4096
@@ -193,6 +194,11 @@
*/
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd);
+int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
+ dm_block_t threshold,
+ dm_sm_threshold_fn fn,
+ void *context);
+
/*----------------------------------------------------------------*/
#endif