Merging upstream version 6.9.7.

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

1 files changed, 601 insertions, 0 deletions

diff --git a/drivers/md/dm-vdo/slab-depot.h b/drivers/md/dm-vdo/slab-depot.h
new file mode 100644
index 0000000000..f234853501
--- /dev/null
+++ b/drivers/md/dm-vdo/slab-depot.h
@@ -0,0 +1,601 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef VDO_SLAB_DEPOT_H
+#define VDO_SLAB_DEPOT_H
+
+#include <linux/atomic.h>
+#include <linux/dm-kcopyd.h>
+#include <linux/list.h>
+
+#include "numeric.h"
+
+#include "admin-state.h"
+#include "completion.h"
+#include "data-vio.h"
+#include "encodings.h"
+#include "physical-zone.h"
+#include "priority-table.h"
+#include "recovery-journal.h"
+#include "statistics.h"
+#include "types.h"
+#include "vio.h"
+#include "wait-queue.h"
+
+/*
+ * A slab_depot is responsible for managing all of the slabs and block allocators of a VDO. It has
+ * a single array of slabs in order to eliminate the need for additional math in order to compute
+ * which physical zone a PBN is in. It also has a block_allocator per zone.
+ *
+ * Each physical zone has a single dedicated queue and thread for performing all updates to the
+ * slabs assigned to that zone. The concurrency guarantees of this single-threaded model allow the
+ * code to omit more fine-grained locking for the various slab structures. Each physical zone
+ * maintains a separate copy of the slab summary to remove the need for explicit locking on that
+ * structure as well.
+ *
+ * Load operations must be performed on the admin thread. Normal operations, such as allocations
+ * and reference count updates, must be performed on the appropriate physical zone thread. Requests
+ * from the recovery journal to commit slab journal tail blocks must be scheduled from the recovery
+ * journal thread to run on the appropriate physical zone thread. Save operations must be launched
+ * from the same admin thread as the original load operation.
+ */
+
+enum {
+	/* The number of vios in the vio pool is proportional to the throughput of the VDO. */
+	BLOCK_ALLOCATOR_VIO_POOL_SIZE = 128,
+};
+
+/*
+ * Represents the possible status of a block.
+ */
+enum reference_status {
+	RS_FREE, /* this block is free */
+	RS_SINGLE, /* this block is singly-referenced */
+	RS_SHARED, /* this block is shared */
+	RS_PROVISIONAL /* this block is provisionally allocated */
+};
+
+struct vdo_slab;
+
+struct journal_lock {
+	u16 count;
+	sequence_number_t recovery_start;
+};
+
+struct slab_journal {
+	/* A waiter object for getting a VIO pool entry */
+	struct vdo_waiter resource_waiter;
+	/* A waiter object for updating the slab summary */
+	struct vdo_waiter slab_summary_waiter;
+	/* A waiter object for getting a vio with which to flush */
+	struct vdo_waiter flush_waiter;
+	/* The queue of VIOs waiting to make an entry */
+	struct vdo_wait_queue entry_waiters;
+	/* The parent slab reference of this journal */
+	struct vdo_slab *slab;
+
+	/* Whether a tail block commit is pending */
+	bool waiting_to_commit;
+	/* Whether the journal is updating the slab summary */
+	bool updating_slab_summary;
+	/* Whether the journal is adding entries from the entry_waiters queue */
+	bool adding_entries;
+	/* Whether a partial write is in progress */
+	bool partial_write_in_progress;
+
+	/* The oldest block in the journal on disk */
+	sequence_number_t head;
+	/* The oldest block in the journal which may not be reaped */
+	sequence_number_t unreapable;
+	/* The end of the half-open interval of the active journal */
+	sequence_number_t tail;
+	/* The next journal block to be committed */
+	sequence_number_t next_commit;
+	/* The tail sequence number that is written in the slab summary */
+	sequence_number_t summarized;
+	/* The tail sequence number that was last summarized in slab summary */
+	sequence_number_t last_summarized;
+
+	/* The sequence number of the recovery journal lock */
+	sequence_number_t recovery_lock;
+
+	/*
+	 * The number of entries which fit in a single block. Can't use the constant because unit
+	 * tests change this number.
+	 */
+	journal_entry_count_t entries_per_block;
+	/*
+	 * The number of full entries which fit in a single block. Can't use the constant because
+	 * unit tests change this number.
+	 */
+	journal_entry_count_t full_entries_per_block;
+
+	/* The recovery journal of the VDO (slab journal holds locks on it) */
+	struct recovery_journal *recovery_journal;
+
+	/* The statistics shared by all slab journals in our physical zone */
+	struct slab_journal_statistics *events;
+	/* A list of the VIO pool entries for outstanding journal block writes */
+	struct list_head uncommitted_blocks;
+
+	/*
+	 * The current tail block header state. This will be packed into the block just before it
+	 * is written.
+	 */
+	struct slab_journal_block_header tail_header;
+	/* A pointer to a block-sized buffer holding the packed block data */
+	struct packed_slab_journal_block *block;
+
+	/* The number of blocks in the on-disk journal */
+	block_count_t size;
+	/* The number of blocks at which to start pushing reference blocks */
+	block_count_t flushing_threshold;
+	/* The number of blocks at which all reference blocks should be writing */
+	block_count_t flushing_deadline;
+	/* The number of blocks at which to wait for reference blocks to write */
+	block_count_t blocking_threshold;
+	/* The number of blocks at which to scrub the slab before coming online */
+	block_count_t scrubbing_threshold;
+
+	/* This list entry is for block_allocator to keep a queue of dirty journals */
+	struct list_head dirty_entry;
+
+	/* The lock for the oldest unreaped block of the journal */
+	struct journal_lock *reap_lock;
+	/* The locks for each on disk block */
+	struct journal_lock *locks;
+};
+
+/*
+ * Reference_block structure
+ *
+ * Blocks are used as a proxy, permitting saves of partial refcounts.
+ */
+struct reference_block {
+	/* This block waits on the ref_counts to tell it to write */
+	struct vdo_waiter waiter;
+	/* The slab to which this reference_block belongs */
+	struct vdo_slab *slab;
+	/* The number of references in this block that represent allocations */
+	block_size_t allocated_count;
+	/* The slab journal block on which this block must hold a lock */
+	sequence_number_t slab_journal_lock;
+	/* The slab journal block which should be released when this block is committed */
+	sequence_number_t slab_journal_lock_to_release;
+	/* The point up to which each sector is accurate on disk */
+	struct journal_point commit_points[VDO_SECTORS_PER_BLOCK];
+	/* Whether this block has been modified since it was written to disk */
+	bool is_dirty;
+	/* Whether this block is currently writing */
+	bool is_writing;
+};
+
+/* The search_cursor represents the saved position of a free block search. */
+struct search_cursor {
+	/* The reference block containing the current search index */
+	struct reference_block *block;
+	/* The position at which to start searching for the next free counter */
+	slab_block_number index;
+	/* The position just past the last valid counter in the current block */
+	slab_block_number end_index;
+
+	/* A pointer to the first reference block in the slab */
+	struct reference_block *first_block;
+	/* A pointer to the last reference block in the slab */
+	struct reference_block *last_block;
+};
+
+enum slab_rebuild_status {
+	VDO_SLAB_REBUILT,
+	VDO_SLAB_REPLAYING,
+	VDO_SLAB_REQUIRES_SCRUBBING,
+	VDO_SLAB_REQUIRES_HIGH_PRIORITY_SCRUBBING,
+	VDO_SLAB_REBUILDING,
+};
+
+/*
+ * This is the type declaration for the vdo_slab type. A vdo_slab currently consists of a run of
+ * 2^23 data blocks, but that will soon change to dedicate a small number of those blocks for
+ * metadata storage for the reference counts and slab journal for the slab.
+ *
+ * A reference count is maintained for each physical block number. The vast majority of blocks have
+ * a very small reference count (usually 0 or 1). For references less than or equal to MAXIMUM_REFS
+ * (254) the reference count is stored in counters[pbn].
+ */
+struct vdo_slab {
+	/* A list entry to queue this slab in a block_allocator list */
+	struct list_head allocq_entry;
+
+	/* The struct block_allocator that owns this slab */
+	struct block_allocator *allocator;
+
+	/* The journal for this slab */
+	struct slab_journal journal;
+
+	/* The slab number of this slab */
+	slab_count_t slab_number;
+	/* The offset in the allocator partition of the first block in this slab */
+	physical_block_number_t start;
+	/* The offset of the first block past the end of this slab */
+	physical_block_number_t end;
+	/* The starting translated PBN of the slab journal */
+	physical_block_number_t journal_origin;
+	/* The starting translated PBN of the reference counts */
+	physical_block_number_t ref_counts_origin;
+
+	/* The administrative state of the slab */
+	struct admin_state state;
+	/* The status of the slab */
+	enum slab_rebuild_status status;
+	/* Whether the slab was ever queued for scrubbing */
+	bool was_queued_for_scrubbing;
+
+	/* The priority at which this slab has been queued for allocation */
+	u8 priority;
+
+	/* Fields beyond this point are the reference counts for the data blocks in this slab. */
+	/* The size of the counters array */
+	u32 block_count;
+	/* The number of free blocks */
+	u32 free_blocks;
+	/* The array of reference counts */
+	vdo_refcount_t *counters; /* use vdo_allocate() to align data ptr */
+
+	/* The saved block pointer and array indexes for the free block search */
+	struct search_cursor search_cursor;
+
+	/* A list of the dirty blocks waiting to be written out */
+	struct vdo_wait_queue dirty_blocks;
+	/* The number of blocks which are currently writing */
+	size_t active_count;
+
+	/* A waiter object for updating the slab summary */
+	struct vdo_waiter summary_waiter;
+
+	/* The latest slab journal for which there has been a reference count update */
+	struct journal_point slab_journal_point;
+
+	/* The number of reference count blocks */
+	u32 reference_block_count;
+	/* reference count block array */
+	struct reference_block *reference_blocks;
+};
+
+enum block_allocator_drain_step {
+	VDO_DRAIN_ALLOCATOR_START,
+	VDO_DRAIN_ALLOCATOR_STEP_SCRUBBER,
+	VDO_DRAIN_ALLOCATOR_STEP_SLABS,
+	VDO_DRAIN_ALLOCATOR_STEP_SUMMARY,
+	VDO_DRAIN_ALLOCATOR_STEP_FINISHED,
+};
+
+struct slab_scrubber {
+	/* The queue of slabs to scrub first */
+	struct list_head high_priority_slabs;
+	/* The queue of slabs to scrub once there are no high_priority_slabs */
+	struct list_head slabs;
+	/* The queue of VIOs waiting for a slab to be scrubbed */
+	struct vdo_wait_queue waiters;
+
+	/*
+	 * The number of slabs that are unrecovered or being scrubbed. This field is modified by
+	 * the physical zone thread, but is queried by other threads.
+	 */
+	slab_count_t slab_count;
+
+	/* The administrative state of the scrubber */
+	struct admin_state admin_state;
+	/* Whether to only scrub high-priority slabs */
+	bool high_priority_only;
+	/* The slab currently being scrubbed */
+	struct vdo_slab *slab;
+	/* The vio for loading slab journal blocks */
+	struct vio vio;
+};
+
+/* A sub-structure for applying actions in parallel to all an allocator's slabs. */
+struct slab_actor {
+	/* The number of slabs performing a slab action */
+	slab_count_t slab_action_count;
+	/* The method to call when a slab action has been completed by all slabs */
+	vdo_action_fn callback;
+};
+
+/* A slab_iterator is a structure for iterating over a set of slabs. */
+struct slab_iterator {
+	struct vdo_slab **slabs;
+	struct vdo_slab *next;
+	slab_count_t end;
+	slab_count_t stride;
+};
+
+/*
+ * The slab_summary provides hints during load and recovery about the state of the slabs in order
+ * to avoid the need to read the slab journals in their entirety before a VDO can come online.
+ *
+ * The information in the summary for each slab includes the rough number of free blocks (which is
+ * used to prioritize scrubbing), the cleanliness of a slab (so that clean slabs containing free
+ * space will be used on restart), and the location of the tail block of the slab's journal.
+ *
+ * The slab_summary has its own partition at the end of the volume which is sized to allow for a
+ * complete copy of the summary for each of up to 16 physical zones.
+ *
+ * During resize, the slab_summary moves its backing partition and is saved once moved; the
+ * slab_summary is not permitted to overwrite the previous recovery journal space.
+ *
+ * The slab_summary does not have its own version information, but relies on the VDO volume version
+ * number.
+ */
+
+/*
+ * A slab status is a very small structure for use in determining the ordering of slabs in the
+ * scrubbing process.
+ */
+struct slab_status {
+	slab_count_t slab_number;
+	bool is_clean;
+	u8 emptiness;
+};
+
+struct slab_summary_block {
+	/* The block_allocator to which this block belongs */
+	struct block_allocator *allocator;
+	/* The index of this block in its zone's summary */
+	block_count_t index;
+	/* Whether this block has a write outstanding */
+	bool writing;
+	/* Ring of updates waiting on the outstanding write */
+	struct vdo_wait_queue current_update_waiters;
+	/* Ring of updates waiting on the next write */
+	struct vdo_wait_queue next_update_waiters;
+	/* The active slab_summary_entry array for this block */
+	struct slab_summary_entry *entries;
+	/* The vio used to write this block */
+	struct vio vio;
+	/* The packed entries, one block long, backing the vio */
+	char *outgoing_entries;
+};
+
+/*
+ * The statistics for all the slab summary zones owned by this slab summary. These fields are all
+ * mutated only by their physical zone threads, but are read by other threads when gathering
+ * statistics for the entire depot.
+ */
+struct atomic_slab_summary_statistics {
+	/* Number of blocks written */
+	atomic64_t blocks_written;
+};
+
+struct block_allocator {
+	struct vdo_completion completion;
+	/* The slab depot for this allocator */
+	struct slab_depot *depot;
+	/* The nonce of the VDO */
+	nonce_t nonce;
+	/* The physical zone number of this allocator */
+	zone_count_t zone_number;
+	/* The thread ID for this allocator's physical zone */
+	thread_id_t thread_id;
+	/* The number of slabs in this allocator */
+	slab_count_t slab_count;
+	/* The number of the last slab owned by this allocator */
+	slab_count_t last_slab;
+	/* The reduced priority level used to preserve unopened slabs */
+	unsigned int unopened_slab_priority;
+	/* The state of this allocator */
+	struct admin_state state;
+	/* The actor for applying an action to all slabs */
+	struct slab_actor slab_actor;
+
+	/* The slab from which blocks are currently being allocated */
+	struct vdo_slab *open_slab;
+	/* A priority queue containing all slabs available for allocation */
+	struct priority_table *prioritized_slabs;
+	/* The slab scrubber */
+	struct slab_scrubber scrubber;
+	/* What phase of the close operation the allocator is to perform */
+	enum block_allocator_drain_step drain_step;
+
+	/*
+	 * These statistics are all mutated only by the physical zone thread, but are read by other
+	 * threads when gathering statistics for the entire depot.
+	 */
+	/*
+	 * The count of allocated blocks in this zone. Not in block_allocator_statistics for
+	 * historical reasons.
+	 */
+	u64 allocated_blocks;
+	/* Statistics for this block allocator */
+	struct block_allocator_statistics statistics;
+	/* Cumulative statistics for the slab journals in this zone */
+	struct slab_journal_statistics slab_journal_statistics;
+	/* Cumulative statistics for the reference counters in this zone */
+	struct ref_counts_statistics ref_counts_statistics;
+
+	/*
+	 * This is the head of a queue of slab journals which have entries in their tail blocks
+	 * which have not yet started to commit. When the recovery journal is under space pressure,
+	 * slab journals which have uncommitted entries holding a lock on the recovery journal head
+	 * are forced to commit their blocks early. This list is kept in order, with the tail
+	 * containing the slab journal holding the most recent recovery journal lock.
+	 */
+	struct list_head dirty_slab_journals;
+
+	/* The vio pool for reading and writing block allocator metadata */
+	struct vio_pool *vio_pool;
+	/* The dm_kcopyd client for erasing slab journals */
+	struct dm_kcopyd_client *eraser;
+	/* Iterator over the slabs to be erased */
+	struct slab_iterator slabs_to_erase;
+
+	/* The portion of the slab summary managed by this allocator */
+	/* The state of the slab summary */
+	struct admin_state summary_state;
+	/* The number of outstanding summary writes */
+	block_count_t summary_write_count;
+	/* The array (owned by the blocks) of all entries */
+	struct slab_summary_entry *summary_entries;
+	/* The array of slab_summary_blocks */
+	struct slab_summary_block *summary_blocks;
+};
+
+enum slab_depot_load_type {
+	VDO_SLAB_DEPOT_NORMAL_LOAD,
+	VDO_SLAB_DEPOT_RECOVERY_LOAD,
+	VDO_SLAB_DEPOT_REBUILD_LOAD
+};
+
+struct slab_depot {
+	zone_count_t zone_count;
+	zone_count_t old_zone_count;
+	struct vdo *vdo;
+	struct slab_config slab_config;
+	struct action_manager *action_manager;
+
+	physical_block_number_t first_block;
+	physical_block_number_t last_block;
+	physical_block_number_t origin;
+
+	/* slab_size == (1 << slab_size_shift) */
+	unsigned int slab_size_shift;
+
+	/* Determines how slabs should be queued during load */
+	enum slab_depot_load_type load_type;
+
+	/* The state for notifying slab journals to release recovery journal */
+	sequence_number_t active_release_request;
+	sequence_number_t new_release_request;
+
+	/* State variables for scrubbing complete handling */
+	atomic_t zones_to_scrub;
+
+	/* Array of pointers to individually allocated slabs */
+	struct vdo_slab **slabs;
+	/* The number of slabs currently allocated and stored in 'slabs' */
+	slab_count_t slab_count;
+
+	/* Array of pointers to a larger set of slabs (used during resize) */
+	struct vdo_slab **new_slabs;
+	/* The number of slabs currently allocated and stored in 'new_slabs' */
+	slab_count_t new_slab_count;
+	/* The size that 'new_slabs' was allocated for */
+	block_count_t new_size;
+
+	/* The last block before resize, for rollback */
+	physical_block_number_t old_last_block;
+	/* The last block after resize, for resize */
+	physical_block_number_t new_last_block;
+
+	/* The statistics for the slab summary */
+	struct atomic_slab_summary_statistics summary_statistics;
+	/* The start of the slab summary partition */
+	physical_block_number_t summary_origin;
+	/* The number of bits to shift to get a 7-bit fullness hint */
+	unsigned int hint_shift;
+	/* The slab summary entries for all of the zones the partition can hold */
+	struct slab_summary_entry *summary_entries;
+
+	/* The block allocators for this depot */
+	struct block_allocator allocators[];
+};
+
+struct reference_updater;
+
+bool __must_check vdo_attempt_replay_into_slab(struct vdo_slab *slab,
+					       physical_block_number_t pbn,
+					       enum journal_operation operation,
+					       bool increment,
+					       struct journal_point *recovery_point,
+					       struct vdo_completion *parent);
+
+int __must_check vdo_adjust_reference_count_for_rebuild(struct slab_depot *depot,
+							physical_block_number_t pbn,
+							enum journal_operation operation);
+
+static inline struct block_allocator *vdo_as_block_allocator(struct vdo_completion *completion)
+{
+	vdo_assert_completion_type(completion, VDO_BLOCK_ALLOCATOR_COMPLETION);
+	return container_of(completion, struct block_allocator, completion);
+}
+
+int __must_check vdo_acquire_provisional_reference(struct vdo_slab *slab,
+						   physical_block_number_t pbn,
+						   struct pbn_lock *lock);
+
+int __must_check vdo_allocate_block(struct block_allocator *allocator,
+				    physical_block_number_t *block_number_ptr);
+
+int vdo_enqueue_clean_slab_waiter(struct block_allocator *allocator,
+				  struct vdo_waiter *waiter);
+
+void vdo_modify_reference_count(struct vdo_completion *completion,
+				struct reference_updater *updater);
+
+int __must_check vdo_release_block_reference(struct block_allocator *allocator,
+					     physical_block_number_t pbn);
+
+void vdo_notify_slab_journals_are_recovered(struct vdo_completion *completion);
+
+void vdo_dump_block_allocator(const struct block_allocator *allocator);
+
+int __must_check vdo_decode_slab_depot(struct slab_depot_state_2_0 state,
+				       struct vdo *vdo,
+				       struct partition *summary_partition,
+				       struct slab_depot **depot_ptr);
+
+void vdo_free_slab_depot(struct slab_depot *depot);
+
+struct slab_depot_state_2_0 __must_check vdo_record_slab_depot(const struct slab_depot *depot);
+
+int __must_check vdo_allocate_reference_counters(struct slab_depot *depot);
+
+struct vdo_slab * __must_check vdo_get_slab(const struct slab_depot *depot,
+					    physical_block_number_t pbn);
+
+u8 __must_check vdo_get_increment_limit(struct slab_depot *depot,
+					physical_block_number_t pbn);
+
+bool __must_check vdo_is_physical_data_block(const struct slab_depot *depot,
+					     physical_block_number_t pbn);
+
+block_count_t __must_check vdo_get_slab_depot_allocated_blocks(const struct slab_depot *depot);
+
+block_count_t __must_check vdo_get_slab_depot_data_blocks(const struct slab_depot *depot);
+
+void vdo_get_slab_depot_statistics(const struct slab_depot *depot,
+				   struct vdo_statistics *stats);
+
+void vdo_load_slab_depot(struct slab_depot *depot,
+			 const struct admin_state_code *operation,
+			 struct vdo_completion *parent, void *context);
+
+void vdo_prepare_slab_depot_to_allocate(struct slab_depot *depot,
+					enum slab_depot_load_type load_type,
+					struct vdo_completion *parent);
+
+void vdo_update_slab_depot_size(struct slab_depot *depot);
+
+int __must_check vdo_prepare_to_grow_slab_depot(struct slab_depot *depot,
+						const struct partition *partition);
+
+void vdo_use_new_slabs(struct slab_depot *depot, struct vdo_completion *parent);
+
+void vdo_abandon_new_slabs(struct slab_depot *depot);
+
+void vdo_drain_slab_depot(struct slab_depot *depot,
+			  const struct admin_state_code *operation,
+			  struct vdo_completion *parent);
+
+void vdo_resume_slab_depot(struct slab_depot *depot, struct vdo_completion *parent);
+
+void vdo_commit_oldest_slab_journal_tail_blocks(struct slab_depot *depot,
+						sequence_number_t recovery_block_number);
+
+void vdo_scrub_all_unrecovered_slabs(struct slab_depot *depot,
+				     struct vdo_completion *parent);
+
+void vdo_dump_slab_depot(const struct slab_depot *depot);
+
+#endif /* VDO_SLAB_DEPOT_H */