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-rw-r--r--drivers/md/dm-vdo/physical-zone.h115
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/physical-zone.h b/drivers/md/dm-vdo/physical-zone.h
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index 0000000000..47d874fd5a
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+++ b/drivers/md/dm-vdo/physical-zone.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef VDO_PHYSICAL_ZONE_H
+#define VDO_PHYSICAL_ZONE_H
+
+#include <linux/atomic.h>
+
+#include "types.h"
+
+/*
+ * The type of a PBN lock.
+ */
+enum pbn_lock_type {
+ VIO_READ_LOCK,
+ VIO_WRITE_LOCK,
+ VIO_BLOCK_MAP_WRITE_LOCK,
+};
+
+struct pbn_lock_implementation;
+
+/*
+ * A PBN lock.
+ */
+struct pbn_lock {
+ /* The implementation of the lock */
+ const struct pbn_lock_implementation *implementation;
+
+ /* The number of VIOs holding or sharing this lock */
+ data_vio_count_t holder_count;
+ /*
+ * The number of compressed block writers holding a share of this lock while they are
+ * acquiring a reference to the PBN.
+ */
+ u8 fragment_locks;
+
+ /* Whether the locked PBN has been provisionally referenced on behalf of the lock holder. */
+ bool has_provisional_reference;
+
+ /*
+ * For read locks, the number of references that were known to be available on the locked
+ * block at the time the lock was acquired.
+ */
+ u8 increment_limit;
+
+ /*
+ * For read locks, the number of data_vios that have tried to claim one of the available
+ * increments during the lifetime of the lock. Each claim will first increment this
+ * counter, so it can exceed the increment limit.
+ */
+ atomic_t increments_claimed;
+};
+
+struct physical_zone {
+ /* Which physical zone this is */
+ zone_count_t zone_number;
+ /* The thread ID for this zone */
+ thread_id_t thread_id;
+ /* In progress operations keyed by PBN */
+ struct int_map *pbn_operations;
+ /* Pool of unused pbn_lock instances */
+ struct pbn_lock_pool *lock_pool;
+ /* The block allocator for this zone */
+ struct block_allocator *allocator;
+ /* The next zone from which to attempt an allocation */
+ struct physical_zone *next;
+};
+
+struct physical_zones {
+ /* The number of zones */
+ zone_count_t zone_count;
+ /* The physical zones themselves */
+ struct physical_zone zones[];
+};
+
+bool __must_check vdo_is_pbn_read_lock(const struct pbn_lock *lock);
+void vdo_downgrade_pbn_write_lock(struct pbn_lock *lock, bool compressed_write);
+bool __must_check vdo_claim_pbn_lock_increment(struct pbn_lock *lock);
+
+/**
+ * vdo_pbn_lock_has_provisional_reference() - Check whether a PBN lock has a provisional reference.
+ * @lock: The PBN lock.
+ */
+static inline bool vdo_pbn_lock_has_provisional_reference(struct pbn_lock *lock)
+{
+ return ((lock != NULL) && lock->has_provisional_reference);
+}
+
+void vdo_assign_pbn_lock_provisional_reference(struct pbn_lock *lock);
+void vdo_unassign_pbn_lock_provisional_reference(struct pbn_lock *lock);
+
+int __must_check vdo_make_physical_zones(struct vdo *vdo,
+ struct physical_zones **zones_ptr);
+
+void vdo_free_physical_zones(struct physical_zones *zones);
+
+struct pbn_lock * __must_check vdo_get_physical_zone_pbn_lock(struct physical_zone *zone,
+ physical_block_number_t pbn);
+
+int __must_check vdo_attempt_physical_zone_pbn_lock(struct physical_zone *zone,
+ physical_block_number_t pbn,
+ enum pbn_lock_type type,
+ struct pbn_lock **lock_ptr);
+
+bool __must_check vdo_allocate_block_in_zone(struct data_vio *data_vio);
+
+void vdo_release_physical_zone_pbn_lock(struct physical_zone *zone,
+ physical_block_number_t locked_pbn,
+ struct pbn_lock *lock);
+
+void vdo_dump_physical_zone(const struct physical_zone *zone);
+
+#endif /* VDO_PHYSICAL_ZONE_H */