1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/indexer/volume.h b/drivers/md/dm-vdo/indexer/volume.h
new file mode 100644
index 000000000000..8679a5e55347
--- /dev/null
+++ b/drivers/md/dm-vdo/indexer/volume.h
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef UDS_VOLUME_H
+#define UDS_VOLUME_H
+
+#include <linux/atomic.h>
+#include <linux/cache.h>
+#include <linux/dm-bufio.h>
+#include <linux/limits.h>
+
+#include "permassert.h"
+#include "thread-utils.h"
+
+#include "chapter-index.h"
+#include "config.h"
+#include "geometry.h"
+#include "indexer.h"
+#include "index-layout.h"
+#include "index-page-map.h"
+#include "radix-sort.h"
+#include "sparse-cache.h"
+
+/*
+ * The volume manages deduplication records on permanent storage. The term "volume" can also refer
+ * to the region of permanent storage where the records (and the chapters containing them) are
+ * stored. The volume handles all I/O to this region by reading, caching, and writing chapter pages
+ * as necessary.
+ */
+
+enum index_lookup_mode {
+	/* Always do lookups in all chapters normally */
+	LOOKUP_NORMAL,
+	/* Only do a subset of lookups needed when rebuilding an index */
+	LOOKUP_FOR_REBUILD,
+};
+
+struct queued_read {
+	bool invalid;
+	bool reserved;
+	u32 physical_page;
+	struct uds_request *first_request;
+	struct uds_request *last_request;
+};
+
+struct __aligned(L1_CACHE_BYTES) search_pending_counter {
+	u64 atomic_value;
+};
+
+struct cached_page {
+	/* Whether this page is currently being read asynchronously */
+	bool read_pending;
+	/* The physical page stored in this cache entry */
+	u32 physical_page;
+	/* The value of the volume clock when this page was last used */
+	s64 last_used;
+	/* The cached page buffer */
+	struct dm_buffer *buffer;
+	/* The chapter index page, meaningless for record pages */
+	struct delta_index_page index_page;
+};
+
+struct page_cache {
+	/* The number of zones */
+	unsigned int zone_count;
+	/* The number of volume pages that can be cached */
+	u32 indexable_pages;
+	/* The maximum number of simultaneously cached pages */
+	u16 cache_slots;
+	/* An index for each physical page noting where it is in the cache */
+	u16 *index;
+	/* The array of cached pages */
+	struct cached_page *cache;
+	/* A counter for each zone tracking if a search is occurring there */
+	struct search_pending_counter *search_pending_counters;
+	/* The read queue entries as a circular array */
+	struct queued_read *read_queue;
+
+	/* All entries above this point are constant after initialization. */
+
+	/*
+	 * These values are all indexes into the array of read queue entries. New entries in the
+	 * read queue are enqueued at read_queue_last. To dequeue entries, a reader thread gets the
+	 * lock and then claims the entry pointed to by read_queue_next_read and increments that
+	 * value. After the read is completed, the reader thread calls release_read_queue_entry(),
+	 * which increments read_queue_first until it points to a pending read, or is equal to
+	 * read_queue_next_read. This means that if multiple reads are outstanding,
+	 * read_queue_first might not advance until the last of the reads finishes.
+	 */
+	u16 read_queue_first;
+	u16 read_queue_next_read;
+	u16 read_queue_last;
+
+	atomic64_t clock;
+};
+
+struct volume {
+	struct index_geometry *geometry;
+	struct dm_bufio_client *client;
+	u64 nonce;
+	size_t cache_size;
+
+	/* A single page worth of records, for sorting */
+	const struct uds_volume_record **record_pointers;
+	/* Sorter for sorting records within each page */
+	struct radix_sorter *radix_sorter;
+
+	struct sparse_cache *sparse_cache;
+	struct page_cache page_cache;
+	struct index_page_map *index_page_map;
+
+	struct mutex read_threads_mutex;
+	struct cond_var read_threads_cond;
+	struct cond_var read_threads_read_done_cond;
+	struct thread **reader_threads;
+	unsigned int read_thread_count;
+	bool read_threads_exiting;
+
+	enum index_lookup_mode lookup_mode;
+	unsigned int reserved_buffers;
+};
+
+int __must_check uds_make_volume(const struct uds_configuration *config,
+				 struct index_layout *layout,
+				 struct volume **new_volume);
+
+void uds_free_volume(struct volume *volume);
+
+int __must_check uds_replace_volume_storage(struct volume *volume,
+					    struct index_layout *layout,
+					    struct block_device *bdev);
+
+int __must_check uds_find_volume_chapter_boundaries(struct volume *volume,
+						    u64 *lowest_vcn, u64 *highest_vcn,
+						    bool *is_empty);
+
+int __must_check uds_search_volume_page_cache(struct volume *volume,
+					      struct uds_request *request,
+					      bool *found);
+
+int __must_check uds_search_volume_page_cache_for_rebuild(struct volume *volume,
+							  const struct uds_record_name *name,
+							  u64 virtual_chapter,
+							  bool *found);
+
+int __must_check uds_search_cached_record_page(struct volume *volume,
+					       struct uds_request *request, u32 chapter,
+					       u16 record_page_number, bool *found);
+
+void uds_forget_chapter(struct volume *volume, u64 chapter);
+
+int __must_check uds_write_chapter(struct volume *volume,
+				   struct open_chapter_index *chapter_index,
+				   const struct uds_volume_record records[]);
+
+void uds_prefetch_volume_chapter(const struct volume *volume, u32 chapter);
+
+int __must_check uds_read_chapter_index_from_volume(const struct volume *volume,
+						    u64 virtual_chapter,
+						    struct dm_buffer *volume_buffers[],
+						    struct delta_index_page index_pages[]);
+
+int __must_check uds_get_volume_record_page(struct volume *volume, u32 chapter,
+					    u32 page_number, u8 **data_ptr);
+
+int __must_check uds_get_volume_index_page(struct volume *volume, u32 chapter,
+					   u32 page_number,
+					   struct delta_index_page **page_ptr);
+
+#endif /* UDS_VOLUME_H */