Merging upstream version 6.9.7.

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

1 files changed, 670 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/data-vio.h b/drivers/md/dm-vdo/data-vio.h
new file mode 100644
index 0000000000..25926b6cd9
--- /dev/null
+++ b/drivers/md/dm-vdo/data-vio.h
@@ -0,0 +1,670 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef DATA_VIO_H
+#define DATA_VIO_H
+
+#include <linux/atomic.h>
+#include <linux/bio.h>
+#include <linux/list.h>
+
+#include "permassert.h"
+
+#include "indexer.h"
+
+#include "block-map.h"
+#include "completion.h"
+#include "constants.h"
+#include "dedupe.h"
+#include "encodings.h"
+#include "logical-zone.h"
+#include "physical-zone.h"
+#include "types.h"
+#include "vdo.h"
+#include "vio.h"
+#include "wait-queue.h"
+
+/* Codes for describing the last asynchronous operation performed on a vio. */
+enum async_operation_number {
+	MIN_VIO_ASYNC_OPERATION_NUMBER,
+	VIO_ASYNC_OP_LAUNCH = MIN_VIO_ASYNC_OPERATION_NUMBER,
+	VIO_ASYNC_OP_ACKNOWLEDGE_WRITE,
+	VIO_ASYNC_OP_ACQUIRE_VDO_HASH_LOCK,
+	VIO_ASYNC_OP_ATTEMPT_LOGICAL_BLOCK_LOCK,
+	VIO_ASYNC_OP_LOCK_DUPLICATE_PBN,
+	VIO_ASYNC_OP_CHECK_FOR_DUPLICATION,
+	VIO_ASYNC_OP_CLEANUP,
+	VIO_ASYNC_OP_COMPRESS_DATA_VIO,
+	VIO_ASYNC_OP_FIND_BLOCK_MAP_SLOT,
+	VIO_ASYNC_OP_GET_MAPPED_BLOCK_FOR_READ,
+	VIO_ASYNC_OP_GET_MAPPED_BLOCK_FOR_WRITE,
+	VIO_ASYNC_OP_HASH_DATA_VIO,
+	VIO_ASYNC_OP_JOURNAL_REMAPPING,
+	VIO_ASYNC_OP_ATTEMPT_PACKING,
+	VIO_ASYNC_OP_PUT_MAPPED_BLOCK,
+	VIO_ASYNC_OP_READ_DATA_VIO,
+	VIO_ASYNC_OP_UPDATE_DEDUPE_INDEX,
+	VIO_ASYNC_OP_UPDATE_REFERENCE_COUNTS,
+	VIO_ASYNC_OP_VERIFY_DUPLICATION,
+	VIO_ASYNC_OP_WRITE_DATA_VIO,
+	MAX_VIO_ASYNC_OPERATION_NUMBER,
+} __packed;
+
+struct lbn_lock {
+	logical_block_number_t lbn;
+	bool locked;
+	struct vdo_wait_queue waiters;
+	struct logical_zone *zone;
+};
+
+/* A position in the arboreal block map at a specific level. */
+struct block_map_tree_slot {
+	page_number_t page_index;
+	struct block_map_slot block_map_slot;
+};
+
+/* Fields for using the arboreal block map. */
+struct tree_lock {
+	/* The current height at which this data_vio is operating */
+	height_t height;
+	/* The block map tree for this LBN */
+	root_count_t root_index;
+	/* Whether we hold a page lock */
+	bool locked;
+	/* The key for the lock map */
+	u64 key;
+	/* The queue of waiters for the page this vio is allocating or loading */
+	struct vdo_wait_queue waiters;
+	/* The block map tree slots for this LBN */
+	struct block_map_tree_slot tree_slots[VDO_BLOCK_MAP_TREE_HEIGHT + 1];
+};
+
+struct zoned_pbn {
+	physical_block_number_t pbn;
+	enum block_mapping_state state;
+	struct physical_zone *zone;
+};
+
+/*
+ * Where a data_vio is on the compression path; advance_compression_stage() depends on the order of
+ * this enum.
+ */
+enum data_vio_compression_stage {
+	/* A data_vio which has not yet entered the compression path */
+	DATA_VIO_PRE_COMPRESSOR,
+	/* A data_vio which is in the compressor */
+	DATA_VIO_COMPRESSING,
+	/* A data_vio which is blocked in the packer */
+	DATA_VIO_PACKING,
+	/* A data_vio which is no longer on the compression path (and never will be) */
+	DATA_VIO_POST_PACKER,
+};
+
+struct data_vio_compression_status {
+	enum data_vio_compression_stage stage;
+	bool may_not_compress;
+};
+
+struct compression_state {
+	/*
+	 * The current compression status of this data_vio. This field contains a value which
+	 * consists of a data_vio_compression_stage and a flag indicating whether a request has
+	 * been made to cancel (or prevent) compression for this data_vio.
+	 *
+	 * This field should be accessed through the get_data_vio_compression_status() and
+	 * set_data_vio_compression_status() methods. It should not be accessed directly.
+	 */
+	atomic_t status;
+
+	/* The compressed size of this block */
+	u16 size;
+
+	/* The packer input or output bin slot which holds the enclosing data_vio */
+	slot_number_t slot;
+
+	/* The packer bin to which the enclosing data_vio has been assigned */
+	struct packer_bin *bin;
+
+	/* A link in the chain of data_vios which have been packed together */
+	struct data_vio *next_in_batch;
+
+	/* A vio which is blocked in the packer while holding a lock this vio needs. */
+	struct data_vio *lock_holder;
+
+	/*
+	 * The compressed block used to hold the compressed form of this block and that of any
+	 * other blocks for which this data_vio is the compressed write agent.
+	 */
+	struct compressed_block *block;
+};
+
+/* Fields supporting allocation of data blocks. */
+struct allocation {
+	/* The physical zone in which to allocate a physical block */
+	struct physical_zone *zone;
+
+	/* The block allocated to this vio */
+	physical_block_number_t pbn;
+
+	/*
+	 * If non-NULL, the pooled PBN lock held on the allocated block. Must be a write lock until
+	 * the block has been written, after which it will become a read lock.
+	 */
+	struct pbn_lock *lock;
+
+	/* The type of write lock to obtain on the allocated block */
+	enum pbn_lock_type write_lock_type;
+
+	/* The zone which was the start of the current allocation cycle */
+	zone_count_t first_allocation_zone;
+
+	/* Whether this vio should wait for a clean slab */
+	bool wait_for_clean_slab;
+};
+
+struct reference_updater {
+	enum journal_operation operation;
+	bool increment;
+	struct zoned_pbn zpbn;
+	struct pbn_lock *lock;
+	struct vdo_waiter waiter;
+};
+
+/* A vio for processing user data requests. */
+struct data_vio {
+	/* The vdo_wait_queue entry structure */
+	struct vdo_waiter waiter;
+
+	/* The logical block of this request */
+	struct lbn_lock logical;
+
+	/* The state for traversing the block map tree */
+	struct tree_lock tree_lock;
+
+	/* The current partition address of this block */
+	struct zoned_pbn mapped;
+
+	/* The hash of this vio (if not zero) */
+	struct uds_record_name record_name;
+
+	/* Used for logging and debugging */
+	enum async_operation_number last_async_operation;
+
+	/* The operations to record in the recovery and slab journals */
+	struct reference_updater increment_updater;
+	struct reference_updater decrement_updater;
+
+	u16 read : 1;
+	u16 write : 1;
+	u16 fua : 1;
+	u16 is_zero : 1;
+	u16 is_discard : 1;
+	u16 is_partial : 1;
+	u16 is_duplicate : 1;
+	u16 first_reference_operation_complete : 1;
+	u16 downgrade_allocation_lock : 1;
+
+	struct allocation allocation;
+
+	/*
+	 * Whether this vio has received an allocation. This field is examined from threads not in
+	 * the allocation zone.
+	 */
+	bool allocation_succeeded;
+
+	/* The new partition address of this block after the vio write completes */
+	struct zoned_pbn new_mapped;
+
+	/* The hash zone responsible for the name (NULL if is_zero_block) */
+	struct hash_zone *hash_zone;
+
+	/* The lock this vio holds or shares with other vios with the same data */
+	struct hash_lock *hash_lock;
+
+	/* All data_vios sharing a hash lock are kept in a list linking these list entries */
+	struct list_head hash_lock_entry;
+
+	/* The block number in the partition of the UDS deduplication advice */
+	struct zoned_pbn duplicate;
+
+	/*
+	 * The sequence number of the recovery journal block containing the increment entry for
+	 * this vio.
+	 */
+	sequence_number_t recovery_sequence_number;
+
+	/* The point in the recovery journal where this write last made an entry */
+	struct journal_point recovery_journal_point;
+
+	/* The list of vios in user initiated write requests */
+	struct list_head write_entry;
+
+	/* The generation number of the VDO that this vio belongs to */
+	sequence_number_t flush_generation;
+
+	/* The completion to use for fetching block map pages for this vio */
+	struct vdo_page_completion page_completion;
+
+	/* The user bio that initiated this VIO */
+	struct bio *user_bio;
+
+	/* partial block support */
+	block_size_t offset;
+
+	/*
+	 * The number of bytes to be discarded. For discards, this field will always be positive,
+	 * whereas for non-discards it will always be 0. Hence it can be used to determine whether
+	 * a data_vio is processing a discard, even after the user_bio has been acknowledged.
+	 */
+	u32 remaining_discard;
+
+	struct dedupe_context *dedupe_context;
+
+	/* Fields beyond this point will not be reset when a pooled data_vio is reused. */
+
+	struct vio vio;
+
+	/* The completion for making reference count decrements */
+	struct vdo_completion decrement_completion;
+
+	/* All of the fields necessary for the compression path */
+	struct compression_state compression;
+
+	/* A block used as output during compression or uncompression */
+	char *scratch_block;
+
+	struct list_head pool_entry;
+};
+
+static inline struct data_vio *vio_as_data_vio(struct vio *vio)
+{
+	VDO_ASSERT_LOG_ONLY((vio->type == VIO_TYPE_DATA), "vio is a data_vio");
+	return container_of(vio, struct data_vio, vio);
+}
+
+static inline struct data_vio *as_data_vio(struct vdo_completion *completion)
+{
+	return vio_as_data_vio(as_vio(completion));
+}
+
+static inline struct data_vio *vdo_waiter_as_data_vio(struct vdo_waiter *waiter)
+{
+	if (waiter == NULL)
+		return NULL;
+
+	return container_of(waiter, struct data_vio, waiter);
+}
+
+static inline struct data_vio *data_vio_from_reference_updater(struct reference_updater *updater)
+{
+	if (updater->increment)
+		return container_of(updater, struct data_vio, increment_updater);
+
+	return container_of(updater, struct data_vio, decrement_updater);
+}
+
+static inline bool data_vio_has_flush_generation_lock(struct data_vio *data_vio)
+{
+	return !list_empty(&data_vio->write_entry);
+}
+
+static inline struct vdo *vdo_from_data_vio(struct data_vio *data_vio)
+{
+	return data_vio->vio.completion.vdo;
+}
+
+static inline bool data_vio_has_allocation(struct data_vio *data_vio)
+{
+	return (data_vio->allocation.pbn != VDO_ZERO_BLOCK);
+}
+
+struct data_vio_compression_status __must_check
+advance_data_vio_compression_stage(struct data_vio *data_vio);
+struct data_vio_compression_status __must_check
+get_data_vio_compression_status(struct data_vio *data_vio);
+bool cancel_data_vio_compression(struct data_vio *data_vio);
+
+struct data_vio_pool;
+
+int make_data_vio_pool(struct vdo *vdo, data_vio_count_t pool_size,
+		       data_vio_count_t discard_limit, struct data_vio_pool **pool_ptr);
+void free_data_vio_pool(struct data_vio_pool *pool);
+void vdo_launch_bio(struct data_vio_pool *pool, struct bio *bio);
+void drain_data_vio_pool(struct data_vio_pool *pool, struct vdo_completion *completion);
+void resume_data_vio_pool(struct data_vio_pool *pool, struct vdo_completion *completion);
+
+void dump_data_vio_pool(struct data_vio_pool *pool, bool dump_vios);
+data_vio_count_t get_data_vio_pool_active_discards(struct data_vio_pool *pool);
+data_vio_count_t get_data_vio_pool_discard_limit(struct data_vio_pool *pool);
+data_vio_count_t get_data_vio_pool_maximum_discards(struct data_vio_pool *pool);
+int __must_check set_data_vio_pool_discard_limit(struct data_vio_pool *pool,
+						 data_vio_count_t limit);
+data_vio_count_t get_data_vio_pool_active_requests(struct data_vio_pool *pool);
+data_vio_count_t get_data_vio_pool_request_limit(struct data_vio_pool *pool);
+data_vio_count_t get_data_vio_pool_maximum_requests(struct data_vio_pool *pool);
+
+void complete_data_vio(struct vdo_completion *completion);
+void handle_data_vio_error(struct vdo_completion *completion);
+
+static inline void continue_data_vio(struct data_vio *data_vio)
+{
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+/**
+ * continue_data_vio_with_error() - Set an error code and then continue processing a data_vio.
+ *
+ * This will not mask older errors. This function can be called with a success code, but it is more
+ * efficient to call continue_data_vio() if the caller knows the result was a success.
+ */
+static inline void continue_data_vio_with_error(struct data_vio *data_vio, int result)
+{
+	vdo_continue_completion(&data_vio->vio.completion, result);
+}
+
+const char * __must_check get_data_vio_operation_name(struct data_vio *data_vio);
+
+static inline void assert_data_vio_in_hash_zone(struct data_vio *data_vio)
+{
+	thread_id_t expected = data_vio->hash_zone->thread_id;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+	/*
+	 * It's odd to use the LBN, but converting the record name to hex is a bit clunky for an
+	 * inline, and the LBN better than nothing as an identifier.
+	 */
+	VDO_ASSERT_LOG_ONLY((expected == thread_id),
+			    "data_vio for logical block %llu on thread %u, should be on hash zone thread %u",
+			    (unsigned long long) data_vio->logical.lbn, thread_id, expected);
+}
+
+static inline void set_data_vio_hash_zone_callback(struct data_vio *data_vio,
+						   vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    data_vio->hash_zone->thread_id);
+}
+
+/**
+ * launch_data_vio_hash_zone_callback() - Set a callback as a hash zone operation and invoke it
+ *					  immediately.
+ */
+static inline void launch_data_vio_hash_zone_callback(struct data_vio *data_vio,
+						      vdo_action_fn callback)
+{
+	set_data_vio_hash_zone_callback(data_vio, callback);
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+static inline void assert_data_vio_in_logical_zone(struct data_vio *data_vio)
+{
+	thread_id_t expected = data_vio->logical.zone->thread_id;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((expected == thread_id),
+			    "data_vio for logical block %llu on thread %u, should be on thread %u",
+			    (unsigned long long) data_vio->logical.lbn, thread_id, expected);
+}
+
+static inline void set_data_vio_logical_callback(struct data_vio *data_vio,
+						 vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    data_vio->logical.zone->thread_id);
+}
+
+/**
+ * launch_data_vio_logical_callback() - Set a callback as a logical block operation and invoke it
+ *					immediately.
+ */
+static inline void launch_data_vio_logical_callback(struct data_vio *data_vio,
+						    vdo_action_fn callback)
+{
+	set_data_vio_logical_callback(data_vio, callback);
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+static inline void assert_data_vio_in_allocated_zone(struct data_vio *data_vio)
+{
+	thread_id_t expected = data_vio->allocation.zone->thread_id;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((expected == thread_id),
+			    "struct data_vio for allocated physical block %llu on thread %u, should be on thread %u",
+			    (unsigned long long) data_vio->allocation.pbn, thread_id,
+			    expected);
+}
+
+static inline void set_data_vio_allocated_zone_callback(struct data_vio *data_vio,
+							vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    data_vio->allocation.zone->thread_id);
+}
+
+/**
+ * launch_data_vio_allocated_zone_callback() - Set a callback as a physical block operation in a
+ *					       data_vio's allocated zone and queue the data_vio and
+ *					       invoke it immediately.
+ */
+static inline void launch_data_vio_allocated_zone_callback(struct data_vio *data_vio,
+							   vdo_action_fn callback)
+{
+	set_data_vio_allocated_zone_callback(data_vio, callback);
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+static inline void assert_data_vio_in_duplicate_zone(struct data_vio *data_vio)
+{
+	thread_id_t expected = data_vio->duplicate.zone->thread_id;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((expected == thread_id),
+			    "data_vio for duplicate physical block %llu on thread %u, should be on thread %u",
+			    (unsigned long long) data_vio->duplicate.pbn, thread_id,
+			    expected);
+}
+
+static inline void set_data_vio_duplicate_zone_callback(struct data_vio *data_vio,
+							vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    data_vio->duplicate.zone->thread_id);
+}
+
+/**
+ * launch_data_vio_duplicate_zone_callback() - Set a callback as a physical block operation in a
+ *					       data_vio's duplicate zone and queue the data_vio and
+ *					       invoke it immediately.
+ */
+static inline void launch_data_vio_duplicate_zone_callback(struct data_vio *data_vio,
+							   vdo_action_fn callback)
+{
+	set_data_vio_duplicate_zone_callback(data_vio, callback);
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+static inline void assert_data_vio_in_mapped_zone(struct data_vio *data_vio)
+{
+	thread_id_t expected = data_vio->mapped.zone->thread_id;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((expected == thread_id),
+			    "data_vio for mapped physical block %llu on thread %u, should be on thread %u",
+			    (unsigned long long) data_vio->mapped.pbn, thread_id, expected);
+}
+
+static inline void set_data_vio_mapped_zone_callback(struct data_vio *data_vio,
+						     vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    data_vio->mapped.zone->thread_id);
+}
+
+static inline void assert_data_vio_in_new_mapped_zone(struct data_vio *data_vio)
+{
+	thread_id_t expected = data_vio->new_mapped.zone->thread_id;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((expected == thread_id),
+			    "data_vio for new_mapped physical block %llu on thread %u, should be on thread %u",
+			    (unsigned long long) data_vio->new_mapped.pbn, thread_id,
+			    expected);
+}
+
+static inline void set_data_vio_new_mapped_zone_callback(struct data_vio *data_vio,
+							 vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    data_vio->new_mapped.zone->thread_id);
+}
+
+static inline void assert_data_vio_in_journal_zone(struct data_vio *data_vio)
+{
+	thread_id_t journal_thread = vdo_from_data_vio(data_vio)->thread_config.journal_thread;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((journal_thread == thread_id),
+			    "data_vio for logical block %llu on thread %u, should be on journal thread %u",
+			    (unsigned long long) data_vio->logical.lbn, thread_id,
+			    journal_thread);
+}
+
+static inline void set_data_vio_journal_callback(struct data_vio *data_vio,
+						 vdo_action_fn callback)
+{
+	thread_id_t journal_thread = vdo_from_data_vio(data_vio)->thread_config.journal_thread;
+
+	vdo_set_completion_callback(&data_vio->vio.completion, callback, journal_thread);
+}
+
+/**
+ * launch_data_vio_journal_callback() - Set a callback as a journal operation and invoke it
+ *					immediately.
+ */
+static inline void launch_data_vio_journal_callback(struct data_vio *data_vio,
+						    vdo_action_fn callback)
+{
+	set_data_vio_journal_callback(data_vio, callback);
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+static inline void assert_data_vio_in_packer_zone(struct data_vio *data_vio)
+{
+	thread_id_t packer_thread = vdo_from_data_vio(data_vio)->thread_config.packer_thread;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((packer_thread == thread_id),
+			    "data_vio for logical block %llu on thread %u, should be on packer thread %u",
+			    (unsigned long long) data_vio->logical.lbn, thread_id,
+			    packer_thread);
+}
+
+static inline void set_data_vio_packer_callback(struct data_vio *data_vio,
+						vdo_action_fn callback)
+{
+	thread_id_t packer_thread = vdo_from_data_vio(data_vio)->thread_config.packer_thread;
+
+	vdo_set_completion_callback(&data_vio->vio.completion, callback, packer_thread);
+}
+
+/**
+ * launch_data_vio_packer_callback() - Set a callback as a packer operation and invoke it
+ *				       immediately.
+ */
+static inline void launch_data_vio_packer_callback(struct data_vio *data_vio,
+						   vdo_action_fn callback)
+{
+	set_data_vio_packer_callback(data_vio, callback);
+	vdo_launch_completion(&data_vio->vio.completion);
+}
+
+static inline void assert_data_vio_on_cpu_thread(struct data_vio *data_vio)
+{
+	thread_id_t cpu_thread = vdo_from_data_vio(data_vio)->thread_config.cpu_thread;
+	thread_id_t thread_id = vdo_get_callback_thread_id();
+
+	VDO_ASSERT_LOG_ONLY((cpu_thread == thread_id),
+			    "data_vio for logical block %llu on thread %u, should be on cpu thread %u",
+			    (unsigned long long) data_vio->logical.lbn, thread_id,
+			    cpu_thread);
+}
+
+static inline void set_data_vio_cpu_callback(struct data_vio *data_vio,
+					     vdo_action_fn callback)
+{
+	thread_id_t cpu_thread = vdo_from_data_vio(data_vio)->thread_config.cpu_thread;
+
+	vdo_set_completion_callback(&data_vio->vio.completion, callback, cpu_thread);
+}
+
+/**
+ * launch_data_vio_cpu_callback() - Set a callback to run on the CPU queues and invoke it
+ *				    immediately.
+ */
+static inline void launch_data_vio_cpu_callback(struct data_vio *data_vio,
+						vdo_action_fn callback,
+						enum vdo_completion_priority priority)
+{
+	set_data_vio_cpu_callback(data_vio, callback);
+	vdo_launch_completion_with_priority(&data_vio->vio.completion, priority);
+}
+
+static inline void set_data_vio_bio_zone_callback(struct data_vio *data_vio,
+						  vdo_action_fn callback)
+{
+	vdo_set_completion_callback(&data_vio->vio.completion, callback,
+				    get_vio_bio_zone_thread_id(&data_vio->vio));
+}
+
+/**
+ * launch_data_vio_bio_zone_callback() - Set a callback as a bio zone operation and invoke it
+ *					 immediately.
+ */
+static inline void launch_data_vio_bio_zone_callback(struct data_vio *data_vio,
+						     vdo_action_fn callback)
+{
+	set_data_vio_bio_zone_callback(data_vio, callback);
+	vdo_launch_completion_with_priority(&data_vio->vio.completion,
+					    BIO_Q_DATA_PRIORITY);
+}
+
+/**
+ * launch_data_vio_on_bio_ack_queue() - If the vdo uses a bio_ack queue, set a callback to run on
+ *					it and invoke it immediately, otherwise, just run the
+ *					callback on the current thread.
+ */
+static inline void launch_data_vio_on_bio_ack_queue(struct data_vio *data_vio,
+						    vdo_action_fn callback)
+{
+	struct vdo_completion *completion = &data_vio->vio.completion;
+	struct vdo *vdo = completion->vdo;
+
+	if (!vdo_uses_bio_ack_queue(vdo)) {
+		callback(completion);
+		return;
+	}
+
+	vdo_set_completion_callback(completion, callback,
+				    vdo->thread_config.bio_ack_thread);
+	vdo_launch_completion_with_priority(completion, BIO_ACK_Q_ACK_PRIORITY);
+}
+
+void data_vio_allocate_data_block(struct data_vio *data_vio,
+				  enum pbn_lock_type write_lock_type,
+				  vdo_action_fn callback, vdo_action_fn error_handler);
+
+void release_data_vio_allocation_lock(struct data_vio *data_vio, bool reset);
+
+int __must_check uncompress_data_vio(struct data_vio *data_vio,
+				     enum block_mapping_state mapping_state,
+				     char *buffer);
+
+void update_metadata_for_data_vio_write(struct data_vio *data_vio,
+					struct pbn_lock *lock);
+void write_data_vio(struct data_vio *data_vio);
+void launch_compress_data_vio(struct data_vio *data_vio);
+void continue_data_vio_with_block_map_slot(struct vdo_completion *completion);
+
+#endif /* DATA_VIO_H */