1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/indexer/config.h b/drivers/md/dm-vdo/indexer/config.h
new file mode 100644
index 000000000..08507dc2f
--- /dev/null
+++ b/drivers/md/dm-vdo/indexer/config.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef UDS_CONFIG_H
+#define UDS_CONFIG_H
+
+#include "geometry.h"
+#include "indexer.h"
+#include "io-factory.h"
+
+/*
+ * The uds_configuration records a variety of parameters used to configure a new UDS index. Some
+ * parameters are provided by the client, while others are fixed or derived from user-supplied
+ * values. It is created when an index is created, and it is recorded in the index metadata.
+ */
+
+enum {
+	DEFAULT_VOLUME_INDEX_MEAN_DELTA = 4096,
+	DEFAULT_CACHE_CHAPTERS = 7,
+	DEFAULT_SPARSE_SAMPLE_RATE = 32,
+	MAX_ZONES = 16,
+};
+
+/* A set of configuration parameters for the indexer. */
+struct uds_configuration {
+	/* Storage device for the index */
+	struct block_device *bdev;
+
+	/* The maximum allowable size of the index */
+	size_t size;
+
+	/* The offset where the index should start */
+	off_t offset;
+
+	/* Parameters for the volume */
+
+	/* The volume layout */
+	struct index_geometry *geometry;
+
+	/* Index owner's nonce */
+	u64 nonce;
+
+	/* The number of threads used to process index requests */
+	unsigned int zone_count;
+
+	/* The number of threads used to read volume pages */
+	unsigned int read_threads;
+
+	/* Size of the page cache and sparse chapter index cache in chapters */
+	u32 cache_chapters;
+
+	/* Parameters for the volume index */
+
+	/* The mean delta for the volume index */
+	u32 volume_index_mean_delta;
+
+	/* Sampling rate for sparse indexing */
+	u32 sparse_sample_rate;
+};
+
+/* On-disk structure of data for a version 8.02 index. */
+struct uds_configuration_8_02 {
+	/* Smaller (16), Small (64) or large (256) indices */
+	u32 record_pages_per_chapter;
+	/* Total number of chapters per volume */
+	u32 chapters_per_volume;
+	/* Number of sparse chapters per volume */
+	u32 sparse_chapters_per_volume;
+	/* Size of the page cache, in chapters */
+	u32 cache_chapters;
+	/* Unused field */
+	u32 unused;
+	/* The volume index mean delta to use */
+	u32 volume_index_mean_delta;
+	/* Size of a page, used for both record pages and index pages */
+	u32 bytes_per_page;
+	/* Sampling rate for sparse indexing */
+	u32 sparse_sample_rate;
+	/* Index owner's nonce */
+	u64 nonce;
+	/* Virtual chapter remapped from physical chapter 0 */
+	u64 remapped_virtual;
+	/* New physical chapter which remapped chapter was moved to */
+	u64 remapped_physical;
+} __packed;
+
+/* On-disk structure of data for a version 6.02 index. */
+struct uds_configuration_6_02 {
+	/* Smaller (16), Small (64) or large (256) indices */
+	u32 record_pages_per_chapter;
+	/* Total number of chapters per volume */
+	u32 chapters_per_volume;
+	/* Number of sparse chapters per volume */
+	u32 sparse_chapters_per_volume;
+	/* Size of the page cache, in chapters */
+	u32 cache_chapters;
+	/* Unused field */
+	u32 unused;
+	/* The volume index mean delta to use */
+	u32 volume_index_mean_delta;
+	/* Size of a page, used for both record pages and index pages */
+	u32 bytes_per_page;
+	/* Sampling rate for sparse indexing */
+	u32 sparse_sample_rate;
+	/* Index owner's nonce */
+	u64 nonce;
+} __packed;
+
+int __must_check uds_make_configuration(const struct uds_parameters *params,
+					struct uds_configuration **config_ptr);
+
+void uds_free_configuration(struct uds_configuration *config);
+
+int __must_check uds_validate_config_contents(struct buffered_reader *reader,
+					      struct uds_configuration *config);
+
+int __must_check uds_write_config_contents(struct buffered_writer *writer,
+					   struct uds_configuration *config, u32 version);
+
+void uds_log_configuration(struct uds_configuration *config);
+
+#endif /* UDS_CONFIG_H */