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-rw-r--r--drivers/md/dm-cache-metadata.h154
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diff --git a/drivers/md/dm-cache-metadata.h b/drivers/md/dm-cache-metadata.h
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+++ b/drivers/md/dm-cache-metadata.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_CACHE_METADATA_H
+#define DM_CACHE_METADATA_H
+
+#include "dm-cache-block-types.h"
+#include "dm-cache-policy-internal.h"
+#include "persistent-data/dm-space-map-metadata.h"
+
+/*----------------------------------------------------------------*/
+
+#define DM_CACHE_METADATA_BLOCK_SIZE DM_SM_METADATA_BLOCK_SIZE
+
+/* FIXME: remove this restriction */
+/*
+ * The metadata device is currently limited in size.
+ */
+#define DM_CACHE_METADATA_MAX_SECTORS DM_SM_METADATA_MAX_SECTORS
+
+/*
+ * A metadata device larger than 16GB triggers a warning.
+ */
+#define DM_CACHE_METADATA_MAX_SECTORS_WARNING (16 * (1024 * 1024 * 1024 >> SECTOR_SHIFT))
+
+/*----------------------------------------------------------------*/
+
+/*
+ * Ext[234]-style compat feature flags.
+ *
+ * A new feature which old metadata will still be compatible with should
+ * define a DM_CACHE_FEATURE_COMPAT_* flag (rarely useful).
+ *
+ * A new feature that is not compatible with old code should define a
+ * DM_CACHE_FEATURE_INCOMPAT_* flag and guard the relevant code with
+ * that flag.
+ *
+ * A new feature that is not compatible with old code accessing the
+ * metadata RDWR should define a DM_CACHE_FEATURE_RO_COMPAT_* flag and
+ * guard the relevant code with that flag.
+ *
+ * As these various flags are defined they should be added to the
+ * following masks.
+ */
+
+#define DM_CACHE_FEATURE_COMPAT_SUPP 0UL
+#define DM_CACHE_FEATURE_COMPAT_RO_SUPP 0UL
+#define DM_CACHE_FEATURE_INCOMPAT_SUPP 0UL
+
+struct dm_cache_metadata;
+
+/*
+ * Reopens or creates a new, empty metadata volume. Returns an ERR_PTR on
+ * failure. If reopening then features must match.
+ */
+struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev,
+ sector_t data_block_size,
+ bool may_format_device,
+ size_t policy_hint_size,
+ unsigned int metadata_version);
+
+void dm_cache_metadata_close(struct dm_cache_metadata *cmd);
+
+/*
+ * The metadata needs to know how many cache blocks there are. We don't
+ * care about the origin, assuming the core target is giving us valid
+ * origin blocks to map to.
+ */
+int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size);
+int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result);
+
+int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd,
+ sector_t discard_block_size,
+ dm_dblock_t new_nr_entries);
+
+typedef int (*load_discard_fn)(void *context, sector_t discard_block_size,
+ dm_dblock_t dblock, bool discarded);
+int dm_cache_load_discards(struct dm_cache_metadata *cmd,
+ load_discard_fn fn, void *context);
+
+int dm_cache_set_discard(struct dm_cache_metadata *cmd, dm_dblock_t dblock, bool discard);
+
+int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock);
+int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock, dm_oblock_t oblock);
+int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd);
+
+typedef int (*load_mapping_fn)(void *context, dm_oblock_t oblock,
+ dm_cblock_t cblock, bool dirty,
+ uint32_t hint, bool hint_valid);
+int dm_cache_load_mappings(struct dm_cache_metadata *cmd,
+ struct dm_cache_policy *policy,
+ load_mapping_fn fn,
+ void *context);
+
+int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd,
+ unsigned int nr_bits, unsigned long *bits);
+
+struct dm_cache_statistics {
+ uint32_t read_hits;
+ uint32_t read_misses;
+ uint32_t write_hits;
+ uint32_t write_misses;
+};
+
+void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd,
+ struct dm_cache_statistics *stats);
+
+/*
+ * 'void' because it's no big deal if it fails.
+ */
+void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd,
+ struct dm_cache_statistics *stats);
+
+int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown);
+
+int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd,
+ dm_block_t *result);
+
+int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd,
+ dm_block_t *result);
+
+void dm_cache_dump(struct dm_cache_metadata *cmd);
+
+/*
+ * The policy is invited to save a 32bit hint value for every cblock (eg,
+ * for a hit count). These are stored against the policy name. If
+ * policies are changed, then hints will be lost. If the machine crashes,
+ * hints will be lost.
+ *
+ * The hints are indexed by the cblock, but many policies will not
+ * necessarily have a fast way of accessing efficiently via cblock. So
+ * rather than querying the policy for each cblock, we let it walk its data
+ * structures and fill in the hints in whatever order it wishes.
+ */
+int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *p);
+
+/*
+ * Query method. Are all the blocks in the cache clean?
+ */
+int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result);
+
+int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result);
+int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd);
+void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd);
+void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd);
+int dm_cache_metadata_abort(struct dm_cache_metadata *cmd);
+
+/*----------------------------------------------------------------*/
+
+#endif /* DM_CACHE_METADATA_H */