1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/md/dm-cache-background-tracker.h b/drivers/md/dm-cache-background-tracker.h
new file mode 100644
index 000000000000..27ab90dbc275
--- /dev/null
+++ b/drivers/md/dm-cache-background-tracker.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2017 Red Hat. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_CACHE_BACKGROUND_WORK_H
+#define DM_CACHE_BACKGROUND_WORK_H
+
+#include <linux/vmalloc.h>
+#include "dm-cache-policy.h"
+
+/*----------------------------------------------------------------*/
+
+struct background_work;
+struct background_tracker;
+
+/*
+ * FIXME: discuss lack of locking in all methods.
+ */
+struct background_tracker *btracker_create(unsigned max_work);
+void btracker_destroy(struct background_tracker *b);
+
+unsigned btracker_nr_writebacks_queued(struct background_tracker *b);
+unsigned btracker_nr_demotions_queued(struct background_tracker *b);
+
+/*
+ * returns -EINVAL iff the work is already queued.  -ENOMEM if the work
+ * couldn't be queued for another reason.
+ */
+int btracker_queue(struct background_tracker *b,
+		   struct policy_work *work,
+		   struct policy_work **pwork);
+
+/*
+ * Returns -ENODATA if there's no work.
+ */
+int btracker_issue(struct background_tracker *b, struct policy_work **work);
+void btracker_complete(struct background_tracker *b,
+		       struct policy_work *op);
+bool btracker_promotion_already_present(struct background_tracker *b,
+					dm_oblock_t oblock);
+
+/*----------------------------------------------------------------*/
+
+#endif