dm vdo: add statistics reporting

Add data and methods to report statisics.
Co-developed-by: J. corwin Coburn <corwin@hurlbutnet.net>
Signed-off-by: J. corwin Coburn <corwin@hurlbutnet.net>
Co-developed-by: Michael Sclafani <dm-devel@lists.linux.dev>
Signed-off-by: Michael Sclafani <dm-devel@lists.linux.dev>
Co-developed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-vdo/message-stats.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef VDO_MESSAGE_STATS_H
+#define VDO_MESSAGE_STATS_H
+
+#include "types.h"
+
+int vdo_write_stats(struct vdo *vdo, char *buf, unsigned int maxlen);
+
+#endif /* VDO_MESSAGE_STATS_H */

drivers/md/dm-vdo/statistics.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2023 Red Hat
+ */
+
+#ifndef STATISTICS_H
+#define STATISTICS_H
+
+#include "types.h"
+
+enum {
+	STATISTICS_VERSION = 36,
+};
+
+struct block_allocator_statistics {
+	/** The total number of slabs from which blocks may be allocated */
+	u64 slab_count;
+	/** The total number of slabs from which blocks have ever been allocated */
+	u64 slabs_opened;
+	/** The number of times since loading that a slab has been re-opened */
+	u64 slabs_reopened;
+};
+
+/**
+ * Counters for tracking the number of items written (blocks, requests, etc.)
+ * that keep track of totals at steps in the write pipeline. Three counters
+ * allow the number of buffered, in-memory items and the number of in-flight,
+ * unacknowledged writes to be derived, while still tracking totals for
+ * reporting purposes
+ */
+struct commit_statistics {
+	/** The total number of items on which processing has started */
+	u64 started;
+	/** The total number of items for which a write operation has been issued */
+	u64 written;
+	/** The total number of items for which a write operation has completed */
+	u64 committed;
+};
+
+/** Counters for events in the recovery journal */
+struct recovery_journal_statistics {
+	/** Number of times the on-disk journal was full */
+	u64 disk_full;
+	/** Number of times the recovery journal requested slab journal commits. */
+	u64 slab_journal_commits_requested;
+	/** Write/Commit totals for individual journal entries */
+	struct commit_statistics entries;
+	/** Write/Commit totals for journal blocks */
+	struct commit_statistics blocks;
+};
+
+/** The statistics for the compressed block packer. */
+struct packer_statistics {
+	/** Number of compressed data items written since startup */
+	u64 compressed_fragments_written;
+	/** Number of blocks containing compressed items written since startup */
+	u64 compressed_blocks_written;
+	/** Number of VIOs that are pending in the packer */
+	u64 compressed_fragments_in_packer;
+};
+
+/** The statistics for the slab journals. */
+struct slab_journal_statistics {
+	/** Number of times the on-disk journal was full */
+	u64 disk_full_count;
+	/** Number of times an entry was added over the flush threshold */
+	u64 flush_count;
+	/** Number of times an entry was added over the block threshold */
+	u64 blocked_count;
+	/** Number of times a tail block was written */
+	u64 blocks_written;
+	/** Number of times we had to wait for the tail to write */
+	u64 tail_busy_count;
+};
+
+/** The statistics for the slab summary. */
+struct slab_summary_statistics {
+	/** Number of blocks written */
+	u64 blocks_written;
+};
+
+/** The statistics for the reference counts. */
+struct ref_counts_statistics {
+	/** Number of reference blocks written */
+	u64 blocks_written;
+};
+
+/** The statistics for the block map. */
+struct block_map_statistics {
+	/** number of dirty (resident) pages */
+	u32 dirty_pages;
+	/** number of clean (resident) pages */
+	u32 clean_pages;
+	/** number of free pages */
+	u32 free_pages;
+	/** number of pages in failed state */
+	u32 failed_pages;
+	/** number of pages incoming */
+	u32 incoming_pages;
+	/** number of pages outgoing */
+	u32 outgoing_pages;
+	/** how many times free page not avail */
+	u32 cache_pressure;
+	/** number of get_vdo_page() calls for read */
+	u64 read_count;
+	/** number of get_vdo_page() calls for write */
+	u64 write_count;
+	/** number of times pages failed to read */
+	u64 failed_reads;
+	/** number of times pages failed to write */
+	u64 failed_writes;
+	/** number of gets that are reclaimed */
+	u64 reclaimed;
+	/** number of gets for outgoing pages */
+	u64 read_outgoing;
+	/** number of gets that were already there */
+	u64 found_in_cache;
+	/** number of gets requiring discard */
+	u64 discard_required;
+	/** number of gets enqueued for their page */
+	u64 wait_for_page;
+	/** number of gets that have to fetch */
+	u64 fetch_required;
+	/** number of page fetches */
+	u64 pages_loaded;
+	/** number of page saves */
+	u64 pages_saved;
+	/** the number of flushes issued */
+	u64 flush_count;
+};
+
+/** The dedupe statistics from hash locks */
+struct hash_lock_statistics {
+	/** Number of times the UDS advice proved correct */
+	u64 dedupe_advice_valid;
+	/** Number of times the UDS advice proved incorrect */
+	u64 dedupe_advice_stale;
+	/** Number of writes with the same data as another in-flight write */
+	u64 concurrent_data_matches;
+	/** Number of writes whose hash collided with an in-flight write */
+	u64 concurrent_hash_collisions;
+	/** Current number of dedupe queries that are in flight */
+	u32 curr_dedupe_queries;
+};
+
+/** Counts of error conditions in VDO. */
+struct error_statistics {
+	/** number of times VDO got an invalid dedupe advice PBN from UDS */
+	u64 invalid_advice_pbn_count;
+	/** number of times a VIO completed with a VDO_NO_SPACE error */
+	u64 no_space_error_count;
+	/** number of times a VIO completed with a VDO_READ_ONLY error */
+	u64 read_only_error_count;
+};
+
+struct bio_stats {
+	/** Number of REQ_OP_READ bios */
+	u64 read;
+	/** Number of REQ_OP_WRITE bios with data */
+	u64 write;
+	/** Number of bios tagged with REQ_PREFLUSH and containing no data */
+	u64 empty_flush;
+	/** Number of REQ_OP_DISCARD bios */
+	u64 discard;
+	/** Number of bios tagged with REQ_PREFLUSH */
+	u64 flush;
+	/** Number of bios tagged with REQ_FUA */
+	u64 fua;
+};
+
+struct memory_usage {
+	/** Tracked bytes currently allocated. */
+	u64 bytes_used;
+	/** Maximum tracked bytes allocated. */
+	u64 peak_bytes_used;
+};
+
+/** UDS index statistics */
+struct index_statistics {
+	/** Number of records stored in the index */
+	u64 entries_indexed;
+	/** Number of post calls that found an existing entry */
+	u64 posts_found;
+	/** Number of post calls that added a new entry */
+	u64 posts_not_found;
+	/** Number of query calls that found an existing entry */
+	u64 queries_found;
+	/** Number of query calls that added a new entry */
+	u64 queries_not_found;
+	/** Number of update calls that found an existing entry */
+	u64 updates_found;
+	/** Number of update calls that added a new entry */
+	u64 updates_not_found;
+	/** Number of entries discarded */
+	u64 entries_discarded;
+};
+
+/** The statistics of the vdo service. */
+struct vdo_statistics {
+	u32 version;
+	/** Number of blocks used for data */
+	u64 data_blocks_used;
+	/** Number of blocks used for VDO metadata */
+	u64 overhead_blocks_used;
+	/** Number of logical blocks that are currently mapped to physical blocks */
+	u64 logical_blocks_used;
+	/** number of physical blocks */
+	block_count_t physical_blocks;
+	/** number of logical blocks */
+	block_count_t logical_blocks;
+	/** Size of the block map page cache, in bytes */
+	u64 block_map_cache_size;
+	/** The physical block size */
+	u64 block_size;
+	/** Number of times the VDO has successfully recovered */
+	u64 complete_recoveries;
+	/** Number of times the VDO has recovered from read-only mode */
+	u64 read_only_recoveries;
+	/** String describing the operating mode of the VDO */
+	char mode[15];
+	/** Whether the VDO is in recovery mode */
+	bool in_recovery_mode;
+	/** What percentage of recovery mode work has been completed */
+	u8 recovery_percentage;
+	/** The statistics for the compressed block packer */
+	struct packer_statistics packer;
+	/** Counters for events in the block allocator */
+	struct block_allocator_statistics allocator;
+	/** Counters for events in the recovery journal */
+	struct recovery_journal_statistics journal;
+	/** The statistics for the slab journals */
+	struct slab_journal_statistics slab_journal;
+	/** The statistics for the slab summary */
+	struct slab_summary_statistics slab_summary;
+	/** The statistics for the reference counts */
+	struct ref_counts_statistics ref_counts;
+	/** The statistics for the block map */
+	struct block_map_statistics block_map;
+	/** The dedupe statistics from hash locks */
+	struct hash_lock_statistics hash_lock;
+	/** Counts of error conditions */
+	struct error_statistics errors;
+	/** The VDO instance */
+	u32 instance;
+	/** Current number of active VIOs */
+	u32 current_vios_in_progress;
+	/** Maximum number of active VIOs */
+	u32 max_vios;
+	/** Number of times the UDS index was too slow in responding */
+	u64 dedupe_advice_timeouts;
+	/** Number of flush requests submitted to the storage device */
+	u64 flush_out;
+	/** Logical block size */
+	u64 logical_block_size;
+	/** Bios submitted into VDO from above */
+	struct bio_stats bios_in;
+	struct bio_stats bios_in_partial;
+	/** Bios submitted onward for user data */
+	struct bio_stats bios_out;
+	/** Bios submitted onward for metadata */
+	struct bio_stats bios_meta;
+	struct bio_stats bios_journal;
+	struct bio_stats bios_page_cache;
+	struct bio_stats bios_out_completed;
+	struct bio_stats bios_meta_completed;
+	struct bio_stats bios_journal_completed;
+	struct bio_stats bios_page_cache_completed;
+	struct bio_stats bios_acknowledged;
+	struct bio_stats bios_acknowledged_partial;
+	/** Current number of bios in progress */
+	struct bio_stats bios_in_progress;
+	/** Memory usage stats. */
+	struct memory_usage memory_usage;
+	/** The statistics for the UDS index */
+	struct index_statistics index;
+};
+
+#endif /* not STATISTICS_H */