1 files changed, 61 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/indexer/chapter-index.h b/drivers/md/dm-vdo/indexer/chapter-index.h
new file mode 100644
index 000000000000..be8bf2b675b1
--- /dev/null
+++ b/drivers/md/dm-vdo/indexer/chapter-index.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef UDS_CHAPTER_INDEX_H
+#define UDS_CHAPTER_INDEX_H
+
+#include <linux/limits.h>
+
+#include "delta-index.h"
+#include "geometry.h"
+
+/*
+ * A chapter index for an open chapter is a mutable structure that tracks all the records that have
+ * been added to the chapter. A chapter index for a closed chapter is similar except that it is
+ * immutable because the contents of a closed chapter can never change, and the immutable structure
+ * is more efficient. Both types of chapter index are implemented with a delta index.
+ */
+
+/* The value returned when no entry is found in the chapter index. */
+#define NO_CHAPTER_INDEX_ENTRY U16_MAX
+
+struct open_chapter_index {
+	const struct index_geometry *geometry;
+	struct delta_index delta_index;
+	u64 virtual_chapter_number;
+	u64 volume_nonce;
+	size_t memory_size;
+};
+
+int __must_check uds_make_open_chapter_index(struct open_chapter_index **chapter_index,
+					     const struct index_geometry *geometry,
+					     u64 volume_nonce);
+
+void uds_free_open_chapter_index(struct open_chapter_index *chapter_index);
+
+void uds_empty_open_chapter_index(struct open_chapter_index *chapter_index,
+				  u64 virtual_chapter_number);
+
+int __must_check uds_put_open_chapter_index_record(struct open_chapter_index *chapter_index,
+						   const struct uds_record_name *name,
+						   u32 page_number);
+
+int __must_check uds_pack_open_chapter_index_page(struct open_chapter_index *chapter_index,
+						  u8 *memory, u32 first_list,
+						  bool last_page, u32 *lists_packed);
+
+int __must_check uds_initialize_chapter_index_page(struct delta_index_page *index_page,
+						   const struct index_geometry *geometry,
+						   u8 *page_buffer, u64 volume_nonce);
+
+int __must_check uds_validate_chapter_index_page(const struct delta_index_page *index_page,
+						 const struct index_geometry *geometry);
+
+int __must_check uds_search_chapter_index_page(struct delta_index_page *index_page,
+					       const struct index_geometry *geometry,
+					       const struct uds_record_name *name,
+					       u16 *record_page_ptr);
+
+#endif /* UDS_CHAPTER_INDEX_H */