Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 279 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/indexer/delta-index.h b/drivers/md/dm-vdo/indexer/delta-index.h
new file mode 100644
index 0000000000..53f6c6ac0b
--- /dev/null
+++ b/drivers/md/dm-vdo/indexer/delta-index.h
@@ -0,0 +1,279 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef UDS_DELTA_INDEX_H
+#define UDS_DELTA_INDEX_H
+
+#include <linux/cache.h>
+
+#include "numeric.h"
+#include "time-utils.h"
+
+#include "config.h"
+#include "io-factory.h"
+
+/*
+ * A delta index is a key-value store, where each entry maps an address (the key) to a payload (the
+ * value). The entries are sorted by address, and only the delta between successive addresses is
+ * stored in the entry. The addresses are assumed to be uniformly distributed, and the deltas are
+ * therefore exponentially distributed.
+ *
+ * A delta_index can either be mutable or immutable depending on its expected use. The immutable
+ * form of a delta index is used for the indexes of closed chapters committed to the volume. The
+ * mutable form of a delta index is used by the volume index, and also by the chapter index in an
+ * open chapter. Like the index as a whole, each mutable delta index is divided into a number of
+ * independent zones.
+ */
+
+struct delta_list {
+	/* The offset of the delta list start, in bits */
+	u64 start;
+	/* The number of bits in the delta list */
+	u16 size;
+	/* Where the last search "found" the key, in bits */
+	u16 save_offset;
+	/* The key for the record just before save_offset */
+	u32 save_key;
+};
+
+struct delta_zone {
+	/* The delta list memory */
+	u8 *memory;
+	/* The delta list headers */
+	struct delta_list *delta_lists;
+	/* Temporary starts of delta lists */
+	u64 *new_offsets;
+	/* Buffered writer for saving an index */
+	struct buffered_writer *buffered_writer;
+	/* The size of delta list memory */
+	size_t size;
+	/* Nanoseconds spent rebalancing */
+	ktime_t rebalance_time;
+	/* Number of memory rebalances */
+	u32 rebalance_count;
+	/* The number of bits in a stored value */
+	u8 value_bits;
+	/* The number of bits in the minimal key code */
+	u16 min_bits;
+	/* The number of keys used in a minimal code */
+	u32 min_keys;
+	/* The number of keys used for another code bit */
+	u32 incr_keys;
+	/* The number of records in the index */
+	u64 record_count;
+	/* The number of collision records */
+	u64 collision_count;
+	/* The number of records removed */
+	u64 discard_count;
+	/* The number of UDS_OVERFLOW errors detected */
+	u64 overflow_count;
+	/* The index of the first delta list */
+	u32 first_list;
+	/* The number of delta lists */
+	u32 list_count;
+	/* Tag belonging to this delta index */
+	u8 tag;
+} __aligned(L1_CACHE_BYTES);
+
+struct delta_list_save_info {
+	/* Tag identifying which delta index this list is in */
+	u8 tag;
+	/* Bit offset of the start of the list data */
+	u8 bit_offset;
+	/* Number of bytes of list data */
+	u16 byte_count;
+	/* The delta list number within the delta index */
+	u32 index;
+} __packed;
+
+struct delta_index {
+	/* The zones */
+	struct delta_zone *delta_zones;
+	/* The number of zones */
+	unsigned int zone_count;
+	/* The number of delta lists */
+	u32 list_count;
+	/* Maximum lists per zone */
+	u32 lists_per_zone;
+	/* Total memory allocated to this index */
+	size_t memory_size;
+	/* The number of non-empty lists at load time per zone */
+	u32 load_lists[MAX_ZONES];
+	/* True if this index is mutable */
+	bool mutable;
+	/* Tag belonging to this delta index */
+	u8 tag;
+};
+
+/*
+ * A delta_index_page describes a single page of a chapter index. The delta_index field allows the
+ * page to be treated as an immutable delta_index. We use the delta_zone field to treat the chapter
+ * index page as a single zone index, and without the need to do an additional memory allocation.
+ */
+struct delta_index_page {
+	struct delta_index delta_index;
+	/* These values are loaded from the delta_page_header */
+	u32 lowest_list_number;
+	u32 highest_list_number;
+	u64 virtual_chapter_number;
+	/* This structure describes the single zone of a delta index page. */
+	struct delta_zone delta_zone;
+};
+
+/*
+ * Notes on the delta_index_entries:
+ *
+ * The fields documented as "public" can be read by any code that uses a delta_index. The fields
+ * documented as "private" carry information between delta_index method calls and should not be
+ * used outside the delta_index module.
+ *
+ * (1) The delta_index_entry is used like an iterator when searching a delta list.
+ *
+ * (2) It is also the result of a successful search and can be used to refer to the element found
+ *     by the search.
+ *
+ * (3) It is also the result of an unsuccessful search and can be used to refer to the insertion
+ *     point for a new record.
+ *
+ * (4) If at_end is true, the delta_list entry can only be used as the insertion point for a new
+ *     record at the end of the list.
+ *
+ * (5) If at_end is false and is_collision is true, the delta_list entry fields refer to a
+ *     collision entry in the list, and the delta_list entry can be used as a reference to this
+ *     entry.
+ *
+ * (6) If at_end is false and is_collision is false, the delta_list entry fields refer to a
+ *     non-collision entry in the list. Such delta_list entries can be used as a reference to a
+ *     found entry, or an insertion point for a non-collision entry before this entry, or an
+ *     insertion point for a collision entry that collides with this entry.
+ */
+struct delta_index_entry {
+	/* Public fields */
+	/* The key for this entry */
+	u32 key;
+	/* We are after the last list entry */
+	bool at_end;
+	/* This record is a collision */
+	bool is_collision;
+
+	/* Private fields */
+	/* This delta list overflowed */
+	bool list_overflow;
+	/* The number of bits used for the value */
+	u8 value_bits;
+	/* The number of bits used for the entire entry */
+	u16 entry_bits;
+	/* The delta index zone */
+	struct delta_zone *delta_zone;
+	/* The delta list containing the entry */
+	struct delta_list *delta_list;
+	/* The delta list number */
+	u32 list_number;
+	/* Bit offset of this entry within the list */
+	u16 offset;
+	/* The delta between this and previous entry */
+	u32 delta;
+	/* Temporary delta list for immutable indices */
+	struct delta_list temp_delta_list;
+};
+
+struct delta_index_stats {
+	/* Number of bytes allocated */
+	size_t memory_allocated;
+	/* Nanoseconds spent rebalancing */
+	ktime_t rebalance_time;
+	/* Number of memory rebalances */
+	u32 rebalance_count;
+	/* The number of records in the index */
+	u64 record_count;
+	/* The number of collision records */
+	u64 collision_count;
+	/* The number of records removed */
+	u64 discard_count;
+	/* The number of UDS_OVERFLOW errors detected */
+	u64 overflow_count;
+	/* The number of delta lists */
+	u32 list_count;
+};
+
+int __must_check uds_initialize_delta_index(struct delta_index *delta_index,
+					    unsigned int zone_count, u32 list_count,
+					    u32 mean_delta, u32 payload_bits,
+					    size_t memory_size, u8 tag);
+
+int __must_check uds_initialize_delta_index_page(struct delta_index_page *delta_index_page,
+						 u64 expected_nonce, u32 mean_delta,
+						 u32 payload_bits, u8 *memory,
+						 size_t memory_size);
+
+void uds_uninitialize_delta_index(struct delta_index *delta_index);
+
+void uds_reset_delta_index(const struct delta_index *delta_index);
+
+int __must_check uds_pack_delta_index_page(const struct delta_index *delta_index,
+					   u64 header_nonce, u8 *memory,
+					   size_t memory_size,
+					   u64 virtual_chapter_number, u32 first_list,
+					   u32 *list_count);
+
+int __must_check uds_start_restoring_delta_index(struct delta_index *delta_index,
+						 struct buffered_reader **buffered_readers,
+						 unsigned int reader_count);
+
+int __must_check uds_finish_restoring_delta_index(struct delta_index *delta_index,
+						  struct buffered_reader **buffered_readers,
+						  unsigned int reader_count);
+
+int __must_check uds_check_guard_delta_lists(struct buffered_reader **buffered_readers,
+					     unsigned int reader_count);
+
+int __must_check uds_start_saving_delta_index(const struct delta_index *delta_index,
+					      unsigned int zone_number,
+					      struct buffered_writer *buffered_writer);
+
+int __must_check uds_finish_saving_delta_index(const struct delta_index *delta_index,
+					       unsigned int zone_number);
+
+int __must_check uds_write_guard_delta_list(struct buffered_writer *buffered_writer);
+
+size_t __must_check uds_compute_delta_index_save_bytes(u32 list_count,
+						       size_t memory_size);
+
+int __must_check uds_start_delta_index_search(const struct delta_index *delta_index,
+					      u32 list_number, u32 key,
+					      struct delta_index_entry *iterator);
+
+int __must_check uds_next_delta_index_entry(struct delta_index_entry *delta_entry);
+
+int __must_check uds_remember_delta_index_offset(const struct delta_index_entry *delta_entry);
+
+int __must_check uds_get_delta_index_entry(const struct delta_index *delta_index,
+					   u32 list_number, u32 key, const u8 *name,
+					   struct delta_index_entry *delta_entry);
+
+int __must_check uds_get_delta_entry_collision(const struct delta_index_entry *delta_entry,
+					       u8 *name);
+
+u32 __must_check uds_get_delta_entry_value(const struct delta_index_entry *delta_entry);
+
+int __must_check uds_set_delta_entry_value(const struct delta_index_entry *delta_entry, u32 value);
+
+int __must_check uds_put_delta_index_entry(struct delta_index_entry *delta_entry, u32 key,
+					   u32 value, const u8 *name);
+
+int __must_check uds_remove_delta_index_entry(struct delta_index_entry *delta_entry);
+
+void uds_get_delta_index_stats(const struct delta_index *delta_index,
+			       struct delta_index_stats *stats);
+
+size_t __must_check uds_compute_delta_index_size(u32 entry_count, u32 mean_delta,
+						 u32 payload_bits);
+
+u32 uds_get_delta_index_page_count(u32 entry_count, u32 list_count, u32 mean_delta,
+				   u32 payload_bits, size_t bytes_per_page);
+
+void uds_log_delta_index_entry(struct delta_index_entry *delta_entry);
+
+#endif /* UDS_DELTA_INDEX_H */