When a vdo is restarted after a crash, it will automatically attempt to
recover from its journals.
If a vdo encounters an unrecoverable error, it will enter read-only mode.
This mode indicates that some previously acknowledged data may have been
lost. The vdo may be instructed to rebuild as best it can in order to
return to a writable state. Although some data may be lost, this process
will ensure that the vdo's own metadata is self-consistent.
Signed-off-by: J. corwin Coburn <corwin@xxxxxxxxxx>
---
drivers/md/dm-vdo/repair.c | 1775 ++++++++++++++++++++++++++++++++++++
drivers/md/dm-vdo/repair.h | 14 +
2 files changed, 1789 insertions(+)
create mode 100644 drivers/md/dm-vdo/repair.c
create mode 100644 drivers/md/dm-vdo/repair.h
diff --git a/drivers/md/dm-vdo/repair.c b/drivers/md/dm-vdo/repair.c
new file mode 100644
index 00000000000..5b5401736f2
--- /dev/null
+++ b/drivers/md/dm-vdo/repair.c
@@ -0,0 +1,1775 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright Red Hat
+ */
+
+#include "repair.h"
+
+#include <linux/min_heap.h>
+#include <linux/minmax.h>
+
+#include "logger.h"
+#include "memory-alloc.h"
+#include "permassert.h"
+
+#include "block-map.h"
+#include "completion.h"
+#include "constants.h"
+#include "encodings.h"
+#include "int-map.h"
+#include "io-submitter.h"
+#include "recovery-journal.h"
+#include "slab-depot.h"
+#include "types.h"
+#include "vdo.h"
+#include "wait-queue.h"
+
+/*
+ * An explicitly numbered block mapping. Numbering the mappings allows them to be sorted by logical
+ * block number during repair while still preserving the relative order of journal entries with
+ * the same logical block number.
+ */
+struct numbered_block_mapping {
+ struct block_map_slot block_map_slot;
+ struct block_map_entry block_map_entry;
+ /* A serial number to use during replay */
+ u32 number;
+} __packed;
+
+/*
+ * The absolute position of an entry in the recovery journal, including the sector number and the
+ * entry number within the sector.
+ */
+struct recovery_point {
+ /* Block sequence number */
+ sequence_number_t sequence_number;
+ /* Sector number */
+ u8 sector_count;
+ /* Entry number */
+ journal_entry_count_t entry_count;
+ /* Whether or not the increment portion of the current entry has been applied */
+ bool increment_applied;
+};
+
+struct repair_completion {
+ /* The completion header */
+ struct vdo_completion completion;
+
+ /* A buffer to hold the data read off disk */
+ char *journal_data;
+
+ /* For loading the journal */
+ data_vio_count_t vio_count;
+ data_vio_count_t vios_complete;
+ struct vio *vios;
+
+ /* The number of entries to be applied to the block map */
+ size_t block_map_entry_count;
+ /* The sequence number of the first valid block for block map recovery */
+ sequence_number_t block_map_head;
+ /* The sequence number of the first valid block for slab journal replay */
+ sequence_number_t slab_journal_head;
+ /* The sequence number of the last valid block of the journal (if known) */
+ sequence_number_t tail;
+ /*
+ * The highest sequence number of the journal. During recovery (vs read-only rebuild), not
+ * the same as the tail, since the tail ignores blocks after the first hole.
+ */
+ sequence_number_t highest_tail;
+
+ /* The number of logical blocks currently known to be in use */
+ block_count_t logical_blocks_used;
+ /* The number of block map data blocks known to be allocated */
+ block_count_t block_map_data_blocks;
+
+ /* These fields are for playing the journal into the block map */
+ /* The entry data for the block map recovery */
+ struct numbered_block_mapping *entries;
+ /* The number of entries in the entry array */
+ size_t entry_count;
+ /* number of pending (non-ready) requests*/
+ page_count_t outstanding;
+ /* number of page completions */
+ page_count_t page_count;
+ bool launching;
+ /*
+ * a heap wrapping journal_entries. It re-orders and sorts journal entries in ascending LBN
+ * order, then original journal order. This permits efficient iteration over the journal
+ * entries in order.
+ */
+ struct min_heap replay_heap;
+ /* Fields tracking progress through the journal entries. */
+ struct numbered_block_mapping *current_entry;
+ struct numbered_block_mapping *current_unfetched_entry;
+ /* Current requested page's PBN */
+ physical_block_number_t pbn;
+
+ /* These fields are only used during recovery. */
+ /* A location just beyond the last valid entry of the journal */
+ struct recovery_point tail_recovery_point;
+ /* The location of the next recovery journal entry to apply */
+ struct recovery_point next_recovery_point;
+ /* The journal point to give to the next synthesized decref */
+ struct journal_point next_journal_point;
+ /* The number of entries played into slab journals */
+ size_t entries_added_to_slab_journals;
+
+ /* These fields are only used during read-only rebuild */
+ page_count_t page_to_fetch;
+ /* the number of leaf pages in the block map */
+ page_count_t leaf_pages;
+ /* the last slot of the block map */
+ struct block_map_slot last_slot;
+
+ /*
+ * The page completions used for playing the journal into the block map, and, during
+ * read-only rebuild, for rebuilding the reference counts from the block map.
+ */
+ struct vdo_page_completion page_completions[];
+};
+
+/*
+ * This is a min_heap callback function that orders numbered_block_mappings using the
+ * 'block_map_slot' field as the primary key and the mapping 'number' field as the secondary key.
+ * Using the mapping number preserves the journal order of entries for the same slot, allowing us
+ * to sort by slot while still ensuring we replay all entries with the same slot in the exact order
+ * as they appeared in the journal.
+ */
+static bool mapping_is_less_than(const void *item1, const void *item2)
+{
+ const struct numbered_block_mapping *mapping1 =
+ (const struct numbered_block_mapping *) item1;
+ const struct numbered_block_mapping *mapping2 =
+ (const struct numbered_block_mapping *) item2;
+
+ if (mapping1->block_map_slot.pbn != mapping2->block_map_slot.pbn)
+ return mapping1->block_map_slot.pbn < mapping2->block_map_slot.pbn;
+
+ if (mapping1->block_map_slot.slot != mapping2->block_map_slot.slot)
+ return mapping1->block_map_slot.slot < mapping2->block_map_slot.slot;
+
+ if (mapping1->number != mapping2->number)
+ return mapping1->number < mapping2->number;
+
+ return 0;
+}
+
+static void swap_mappings(void *item1, void *item2)
+{
+ struct numbered_block_mapping *mapping1 = item1;
+ struct numbered_block_mapping *mapping2 = item2;
+
+ swap(*mapping1, *mapping2);
+}
+
+static const struct min_heap_callbacks repair_min_heap = {
+ .elem_size = sizeof(struct numbered_block_mapping),
+ .less = mapping_is_less_than,
+ .swp = swap_mappings,
+};
+
+static struct numbered_block_mapping *
+sort_next_heap_element(struct repair_completion *repair)
+{
+ struct min_heap *heap = &repair->replay_heap;
+ struct numbered_block_mapping *last;
+
+ if (heap->nr == 0)
+ return NULL;
+
+ /*
+ * Swap the next heap element with the last one on the heap, popping it off the heap,
+ * restore the heap invariant, and return a pointer to the popped element.
+ */
+ last = &repair->entries[--heap->nr];
+ swap_mappings(heap->data, last);
+ min_heapify(heap, 0, &repair_min_heap);
+ return last;
+}
+
+/**
+ * as_repair_completion() - Convert a generic completion to a repair_completion.
+ * @completion: The completion to convert.
+ *
+ * Return: The repair_completion.
+ */
+static inline struct repair_completion * __must_check
+as_repair_completion(struct vdo_completion *completion)
+{
+ vdo_assert_completion_type(completion, VDO_REPAIR_COMPLETION);
+ return container_of(completion, struct repair_completion, completion);
+}
+
+static void prepare_repair_completion(struct repair_completion *repair,
+ vdo_action *callback,
+ enum vdo_zone_type zone_type)
+{
+ struct vdo_completion *completion = &repair->completion;
+ const struct thread_config *thread_config = &completion->vdo->thread_config;
+ thread_id_t thread_id;
+
+ /* All blockmap access is done on single thread, so use logical zone 0. */
+ thread_id = ((zone_type == VDO_ZONE_TYPE_LOGICAL) ?
+ thread_config->logical_threads[0] :
+ thread_config->admin_thread);
+ vdo_reset_completion(completion);
+ vdo_set_completion_callback(completion, callback, thread_id);
+}
+
+static void launch_repair_completion(struct repair_completion *repair,
+ vdo_action *callback,
+ enum vdo_zone_type zone_type)
+{
+ prepare_repair_completion(repair, callback, zone_type);
+ vdo_launch_completion(&repair->completion);
+}
+
+static void uninitialize_vios(struct repair_completion *repair)
+{
+ while (repair->vio_count > 0)
+ free_vio_components(&repair->vios[--repair->vio_count]);
+
+ UDS_FREE(UDS_FORGET(repair->vios));
+}
+
+static void free_repair_completion(struct repair_completion *repair)
+{
+ if (repair == NULL)
+ return;
+
+ /*
+ * We do this here because this function is the only common bottleneck for all clean up
+ * paths.
+ */
+ repair->completion.vdo->block_map->zones[0].page_cache.rebuilding = false;
+
+ uninitialize_vios(repair);
+ UDS_FREE(UDS_FORGET(repair->journal_data));
+ UDS_FREE(UDS_FORGET(repair->entries));
+ UDS_FREE(repair);
+}
+
+static void finish_repair(struct vdo_completion *completion)
+{
+ struct vdo_completion *parent = completion->parent;
+ struct vdo *vdo = completion->vdo;
+ struct repair_completion *repair = as_repair_completion(completion);
+
+ vdo_assert_on_admin_thread(vdo, __func__);
+
+ if (vdo->load_state != VDO_REBUILD_FOR_UPGRADE)
+ vdo->states.vdo.complete_recoveries++;
+
+ vdo_initialize_recovery_journal_post_repair(vdo->recovery_journal,
+ vdo->states.vdo.complete_recoveries,
+ repair->highest_tail,
+ repair->logical_blocks_used,
+ repair->block_map_data_blocks);
+ free_repair_completion(UDS_FORGET(repair));
+
+ if (vdo_state_requires_read_only_rebuild(vdo->load_state)) {
+ uds_log_info("Read-only rebuild complete");
+ vdo_launch_completion(parent);
+ return;
+ }
+
+ /* FIXME: shouldn't this say either "recovery" or "repair"? */
+ uds_log_info("Rebuild complete");
+
+ /*
+ * Now that we've freed the repair completion and its vast array of journal entries, we
+ * can allocate refcounts.
+ */
+ vdo_continue_completion(parent, vdo_allocate_reference_counters(vdo->depot));
+}
+
+/**
+ * abort_repair() - Handle a repair error.
+ * @completion: The repair completion.
+ */
+static void abort_repair(struct vdo_completion *completion)
+{
+ struct vdo_completion *parent = completion->parent;
+ int result = completion->result;
+ struct repair_completion *repair = as_repair_completion(completion);
+
+ if (vdo_state_requires_read_only_rebuild(completion->vdo->load_state))
+ uds_log_info("Read-only rebuild aborted");
+ else
+ uds_log_warning("Recovery aborted");
+
+ free_repair_completion(UDS_FORGET(repair));
+ vdo_continue_completion(parent, result);
+}
+
+/**
+ * abort_on_error() - Abort a repair if there is an error.
+ * @result: The result to check.
+ * @repair: The repair completion.
+ *
+ * Return: true if the result was an error.
+ */
+static bool __must_check abort_on_error(int result, struct repair_completion *repair)
+{
+ if (result == VDO_SUCCESS)
+ return false;
+
+ vdo_fail_completion(&repair->completion, result);
+ return true;
+}
+
+/**
+ * drain_slab_depot() - Flush out all dirty refcounts blocks now that they have been rebuilt or
+ * recovered.
+ */
+static void drain_slab_depot(struct vdo_completion *completion)
+{
+ struct vdo *vdo = completion->vdo;
+ struct repair_completion *repair = as_repair_completion(completion);
+ const struct admin_state_code *operation;
+
+ vdo_assert_on_admin_thread(vdo, __func__);
+
+ prepare_repair_completion(repair, finish_repair, VDO_ZONE_TYPE_ADMIN);
+ if (vdo_state_requires_read_only_rebuild(vdo->load_state)) {
+ uds_log_info("Saving rebuilt state");
+ operation = VDO_ADMIN_STATE_REBUILDING;
+ } else {
+ uds_log_info("Replayed %zu journal entries into slab journals",
+ repair->entries_added_to_slab_journals);
+ operation = VDO_ADMIN_STATE_RECOVERING;
+ }
+
+ vdo_drain_slab_depot(vdo->depot, operation, completion);
+}
+
+/**
+ * flush_block_map_updates() - Flush the block map now that all the reference counts are rebuilt.
+ * @completion: The repair completion.
+ *
+ * This callback is registered in finish_if_done().
+ */
+static void flush_block_map_updates(struct vdo_completion *completion)
+{
+ vdo_assert_on_admin_thread(completion->vdo, __func__);
+
+ uds_log_info("Flushing block map changes");
+ prepare_repair_completion(as_repair_completion(completion),
+ drain_slab_depot,
+ VDO_ZONE_TYPE_ADMIN);
+ vdo_drain_block_map(completion->vdo->block_map, VDO_ADMIN_STATE_RECOVERING, completion);
+}
+
+static bool fetch_page(struct repair_completion *repair, struct vdo_completion *completion);
+
+/**
+ * handle_page_load_error() - Handle an error loading a page.
+ * @completion: The vdo_page_completion.
+ */
+static void handle_page_load_error(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = completion->parent;
+
+ repair->outstanding--;
+ vdo_set_completion_result(&repair->completion, completion->result);
+ vdo_release_page_completion(completion);
+ fetch_page(repair, completion);
+}
+
+/**
+ * unmap_entry() - Unmap an invalid entry and indicate that its page must be written out.
+ * @page: The page containing the entries
+ * @completion: The page_completion for writing the page
+ * @slot: The slot to unmap
+ */
+static void
+unmap_entry(struct block_map_page *page, struct vdo_completion *completion, slot_number_t slot)
+{
+ page->entries[slot] = vdo_pack_block_map_entry(VDO_ZERO_BLOCK, VDO_MAPPING_STATE_UNMAPPED);
+ vdo_request_page_write(completion);
+}
+
+/**
+ * remove_out_of_bounds_entries() - Unmap entries which outside the logical space.
+ * @page: The page containing the entries
+ * @completion: The page_completion for writing the page
+ * @start: The first slot to check
+ */
+static void remove_out_of_bounds_entries(struct block_map_page *page,
+ struct vdo_completion *completion,
+ slot_number_t start)
+{
+ slot_number_t slot;
+
+ for (slot = start; slot < VDO_BLOCK_MAP_ENTRIES_PER_PAGE; slot++) {
+ struct data_location mapping = vdo_unpack_block_map_entry(&page->entries[slot]);
+
+ if (vdo_is_mapped_location(&mapping))
+ unmap_entry(page, completion, slot);
+ }
+}
+
+/**
+ * process_slot() - Update the reference counts for a single entry.
+ * @page: The page containing the entries
+ * @completion: The page_completion for writing the page
+ * @slot: The slot to check
+ *
+ * Return: true if the entry was a valid mapping
+ */
+static bool
+process_slot(struct block_map_page *page, struct vdo_completion *completion, slot_number_t slot)
+{
+ struct slab_depot *depot = completion->vdo->depot;
+ int result;
+ struct data_location mapping = vdo_unpack_block_map_entry(&page->entries[slot]);
+
+ if (!vdo_is_valid_location(&mapping)) {
+ /* This entry is invalid, so remove it from the page. */
+ unmap_entry(page, completion, slot);
+ return false;
+ }
+
+ if (!vdo_is_mapped_location(&mapping))
+ return false;
+
+
+ if (mapping.pbn == VDO_ZERO_BLOCK)
+ return true;
+
+ if (!vdo_is_physical_data_block(depot, mapping.pbn)) {
+ /*
+ * This is a nonsense mapping. Remove it from the map so we're at least consistent
+ * and mark the page dirty.
+ */
+ unmap_entry(page, completion, slot);
+ return false;
+ }
+
+ result = vdo_adjust_reference_count_for_rebuild(depot,
+ mapping.pbn,
+ VDO_JOURNAL_DATA_REMAPPING);
+ if (result == VDO_SUCCESS)
+ return true;
+
+ uds_log_error_strerror(result,
+ "Could not adjust reference count for PBN %llu, slot %u mapped to PBN %llu",
+ (unsigned long long) vdo_get_block_map_page_pbn(page),
+ slot,
+ (unsigned long long) mapping.pbn);
+ unmap_entry(page, completion, slot);
+ return false;
+}
+
+/**
+ * rebuild_reference_counts_from_page() - Rebuild reference counts from a block map page.
+ * @repair: The repair completion.
+ * @completion: The page completion holding the page.
+ */
+static void rebuild_reference_counts_from_page(struct repair_completion *repair,
+ struct vdo_completion *completion)
+{
+ slot_number_t slot, last_slot;
+ struct block_map_page *page;
+ int result;
+
+ result = vdo_get_cached_page(completion, &page);
+ if (result != VDO_SUCCESS) {
+ vdo_set_completion_result(&repair->completion, result);
+ return;
+ }
+
+ if (!page->header.initialized)
+ return;
+
+ /* Remove any bogus entries which exist beyond the end of the logical space. */
+ if (vdo_get_block_map_page_pbn(page) == repair->last_slot.pbn) {
+ last_slot = repair->last_slot.slot;
+ remove_out_of_bounds_entries(page, completion, last_slot);
+ } else {
+ last_slot = VDO_BLOCK_MAP_ENTRIES_PER_PAGE;
+ }
+
+ /* Inform the slab depot of all entries on this page. */
+ for (slot = 0; slot < last_slot; slot++) {
+ if (process_slot(page, completion, slot))
+ repair->logical_blocks_used++;
+ }
+}
+
+/**
+ * page_loaded() - Process a page which has just been loaded.
+ * @completion: The vdo_page_completion for the fetched page.
+ *
+ * This callback is registered by fetch_page().
+ */
+static void page_loaded(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = completion->parent;
+
+ repair->outstanding--;
+ rebuild_reference_counts_from_page(repair, completion);
+ vdo_release_page_completion(completion);
+
+ /* Advance progress to the next page, and fetch the next page we haven't yet requested. */
+ fetch_page(repair, completion);
+}
+
+static physical_block_number_t
+get_pbn_to_fetch(struct repair_completion *repair, struct block_map *block_map)
+{
+ physical_block_number_t pbn = VDO_ZERO_BLOCK;
+
+ if (repair->completion.result != VDO_SUCCESS)
+ return VDO_ZERO_BLOCK;
+
+ while ((pbn == VDO_ZERO_BLOCK) && (repair->page_to_fetch < repair->leaf_pages))
+ pbn = vdo_find_block_map_page_pbn(block_map, repair->page_to_fetch++);
+
+ if (vdo_is_physical_data_block(repair->completion.vdo->depot, pbn))
+ return pbn;
+
+ vdo_set_completion_result(&repair->completion, VDO_BAD_MAPPING);
+ return VDO_ZERO_BLOCK;
+}
+
+/**
+ * fetch_page() - Fetch a page from the block map.
+ * @repair: The repair_completion.
+ * @completion: The page completion to use.
+ *
+ * Return true if the rebuild is complete
+ */
+static bool fetch_page(struct repair_completion *repair, struct vdo_completion *completion)
+{
+ struct vdo_page_completion *page_completion = (struct vdo_page_completion *) completion;
+ struct block_map *block_map = repair->completion.vdo->block_map;
+ physical_block_number_t pbn = get_pbn_to_fetch(repair, block_map);
+
+ if (pbn != VDO_ZERO_BLOCK) {
+ repair->outstanding++;
+ /*
+ * We must set the requeue flag here to ensure that we don't blow the stack if all
+ * the requested pages are already in the cache or get load errors.
+ */
+ vdo_get_page(page_completion,
+ &block_map->zones[0],
+ pbn,
+ true,
+ repair,
+ page_loaded,
+ handle_page_load_error,
+ true);
+ }
+
+ if (repair->outstanding > 0)
+ return false;
+
+ launch_repair_completion(repair, flush_block_map_updates, VDO_ZONE_TYPE_ADMIN);
+ return true;
+}
+
+/**
+ * rebuild_from_leaves() - Rebuild reference counts from the leaf block map pages.
+ * @completion: The repair completion.
+ *
+ * Rebuilds reference counts from the leaf block map pages now that reference counts have been
+ * rebuilt from the interior tree pages (which have been loaded in the process). This callback is
+ * registered in rebuild_reference_counts().
+ */
+static void rebuild_from_leaves(struct vdo_completion *completion)
+{
+ page_count_t i;
+ struct repair_completion *repair = as_repair_completion(completion);
+ struct block_map *map = completion->vdo->block_map;
+
+ repair->logical_blocks_used = 0;
+
+ /*
+ * The PBN calculation doesn't work until the tree pages have been loaded, so we can't set
+ * this value at the start of repair.
+ */
+ repair->leaf_pages = vdo_compute_block_map_page_count(map->entry_count);
+ repair->last_slot = (struct block_map_slot) {
+ .slot = map->entry_count % VDO_BLOCK_MAP_ENTRIES_PER_PAGE,
+ .pbn = vdo_find_block_map_page_pbn(map, repair->leaf_pages - 1),
+ };
+ if (repair->last_slot.slot == 0)
+ repair->last_slot.slot = VDO_BLOCK_MAP_ENTRIES_PER_PAGE;
+
+ for (i = 0; i < repair->page_count; i++) {
+ if (fetch_page(repair, &repair->page_completions[i].completion))
+ /*
+ * The rebuild has already moved on, so it isn't safe nor is there a need
+ * to launch any more fetches.
+ */
+ return;
+ }
+}
+
+/**
+ * process_entry() - Process a single entry from the block map tree.
+ * @pbn: A pbn which holds a block map tree page.
+ * @completion: The parent completion of the traversal.
+ *
+ * Implements vdo_entry_callback.
+ *
+ * Return: VDO_SUCCESS or an error.
+ */
+static int process_entry(physical_block_number_t pbn, struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion);
+ struct slab_depot *depot = completion->vdo->depot;
+ int result;
+
+ if ((pbn == VDO_ZERO_BLOCK) || !vdo_is_physical_data_block(depot, pbn))
+ return uds_log_error_strerror(VDO_BAD_CONFIGURATION,
+ "PBN %llu out of range",
+ (unsigned long long) pbn);
+
+ result = vdo_adjust_reference_count_for_rebuild(depot,
+ pbn,
+ VDO_JOURNAL_BLOCK_MAP_REMAPPING);
+ if (result != VDO_SUCCESS)
+ return uds_log_error_strerror(result,
+ "Could not adjust reference count for block map tree PBN %llu",
+ (unsigned long long) pbn);
+
+ repair->block_map_data_blocks++;
+ return VDO_SUCCESS;
+}
+
+static void rebuild_reference_counts(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion);
+ struct vdo *vdo = completion->vdo;
+ struct vdo_page_cache *cache = &vdo->block_map->zones[0].page_cache;
+
+ /* We must allocate ref_counts before we can rebuild them. */
+ if (abort_on_error(vdo_allocate_reference_counters(vdo->depot), repair))
+ return;
+
+ /*
+ * Completion chaining from page cache hits can lead to stack overflow during the rebuild,
+ * so clear out the cache before this rebuild phase.
+ */
+ if (abort_on_error(vdo_invalidate_page_cache(cache), repair))
+ return;
+
+ prepare_repair_completion(repair, rebuild_from_leaves, VDO_ZONE_TYPE_LOGICAL);
+ vdo_traverse_forest(vdo->block_map, process_entry, completion);
+}
+
+/**
+ * increment_recovery_point() - Move the given recovery point forward by one entry.
+ */
+static void increment_recovery_point(struct recovery_point *point)
+{
+ if (++point->entry_count < RECOVERY_JOURNAL_ENTRIES_PER_SECTOR)
+ return;
+
+ point->entry_count = 0;
+ if (point->sector_count < (VDO_SECTORS_PER_BLOCK - 1)) {
+ point->sector_count++;
+ return;
+ }
+
+ point->sequence_number++;
+ point->sector_count = 1;
+}
+
+/**
+ * advance_points() - Advance the current recovery and journal points.
+ * @repair: The repair_completion whose points are to be advanced.
+ * @entries_per_block: The number of entries in a recovery journal block.
+ */
+static void
+advance_points(struct repair_completion *repair, journal_entry_count_t entries_per_block)
+{
+ if (!repair->next_recovery_point.increment_applied) {
+ repair->next_recovery_point.increment_applied = true;
+ return;
+ }
+
+ increment_recovery_point(&repair->next_recovery_point);
+ vdo_advance_journal_point(&repair->next_journal_point, entries_per_block);
+ repair->next_recovery_point.increment_applied = false;
+}
+
+/**
+ * before_recovery_point() - Check whether the first point precedes the second point.
+ * @first: The first recovery point.
+ * @second: The second recovery point.
+ *
+ * Return: true if the first point precedes the second point.
+ */
+static bool __must_check
+before_recovery_point(const struct recovery_point *first, const struct recovery_point *second)
+{
+ if (first->sequence_number < second->sequence_number)
+ return true;
+
+ if (first->sequence_number > second->sequence_number)
+ return false;
+
+ if (first->sector_count < second->sector_count)
+ return true;
+
+ return ((first->sector_count == second->sector_count) &&
+ (first->entry_count < second->entry_count));
+}
+
+static struct packed_journal_sector * __must_check
+get_sector(struct recovery_journal *journal,
+ char *journal_data,
+ sequence_number_t sequence,
+ u8 sector_number)
+{
+ off_t offset;
+
+ offset = ((vdo_get_recovery_journal_block_number(journal, sequence) * VDO_BLOCK_SIZE) +
+ (VDO_SECTOR_SIZE * sector_number));
+ return (struct packed_journal_sector *) (journal_data + offset);
+}
+
+/**
+ * get_entry() - Unpack the recovery journal entry associated with the given recovery point.
+ * @repair: The repair completion.
+ * @point: The recovery point.
+ *
+ * Return: The unpacked contents of the matching recovery journal entry.
+ */
+static struct recovery_journal_entry
+get_entry(const struct repair_completion *repair, const struct recovery_point *point)
+{
+ struct packed_journal_sector *sector;
+
+ sector = get_sector(repair->completion.vdo->recovery_journal,
+ repair->journal_data,
+ point->sequence_number,
+ point->sector_count);
+ return vdo_unpack_recovery_journal_entry(§or->entries[point->entry_count]);
+}
+
+/**
+ * validate_recovery_journal_entry() - Validate a recovery journal entry.
+ * @vdo: The vdo.
+ * @entry: The entry to validate.
+ *
+ * Return: VDO_SUCCESS or an error.
+ */
+static int
+validate_recovery_journal_entry(const struct vdo *vdo, const struct recovery_journal_entry *entry)
+{
+ if ((entry->slot.pbn >= vdo->states.vdo.config.physical_blocks) ||
+ (entry->slot.slot >= VDO_BLOCK_MAP_ENTRIES_PER_PAGE) ||
+ !vdo_is_valid_location(&entry->mapping) ||
+ !vdo_is_valid_location(&entry->unmapping) ||
+ !vdo_is_physical_data_block(vdo->depot, entry->mapping.pbn) ||
+ !vdo_is_physical_data_block(vdo->depot, entry->unmapping.pbn))
+ return uds_log_error_strerror(VDO_CORRUPT_JOURNAL,
+ "Invalid entry: %s (%llu, %u) from %llu to %llu is not within bounds",
+ vdo_get_journal_operation_name(entry->operation),
+ (unsigned long long) entry->slot.pbn,
+ entry->slot.slot,
+ (unsigned long long) entry->unmapping.pbn,
+ (unsigned long long) entry->mapping.pbn);
+
+ if ((entry->operation == VDO_JOURNAL_BLOCK_MAP_REMAPPING) &&
+ (vdo_is_state_compressed(entry->mapping.state) ||
+ (entry->mapping.pbn == VDO_ZERO_BLOCK) ||
+ (entry->unmapping.state != VDO_MAPPING_STATE_UNMAPPED) ||
+ (entry->unmapping.pbn != VDO_ZERO_BLOCK)))
+ return uds_log_error_strerror(VDO_CORRUPT_JOURNAL,
+ "Invalid entry: %s (%llu, %u) from %llu to %llu is not a valid tree mapping",
+ vdo_get_journal_operation_name(entry->operation),
+ (unsigned long long) entry->slot.pbn,
+ entry->slot.slot,
+ (unsigned long long) entry->unmapping.pbn,
+ (unsigned long long) entry->mapping.pbn);
+
+ return VDO_SUCCESS;
+}
+
+/**
+ * add_slab_journal_entries() - Replay recovery journal entries into the slab journals of the
+ * allocator currently being recovered.
+ * @completion: The allocator completion.
+ *
+ * Waits for slab journal tailblock space when necessary. This method is its own callback.
+ */
+static void add_slab_journal_entries(struct vdo_completion *completion)
+{
+ struct recovery_point *recovery_point;
+ struct repair_completion *repair = completion->parent;
+ struct vdo *vdo = completion->vdo;
+ struct recovery_journal *journal = vdo->recovery_journal;
+ struct block_allocator *allocator = vdo_as_block_allocator(completion);
+
+ /* Get ready in case we need to enqueue again. */
+ vdo_prepare_completion(completion,
+ add_slab_journal_entries,
+ vdo_notify_slab_journals_are_recovered,
+ completion->callback_thread_id,
+ repair);
+ for (recovery_point = &repair->next_recovery_point;
+ before_recovery_point(recovery_point, &repair->tail_recovery_point);
+ advance_points(repair, journal->entries_per_block)) {
+ int result;
+ physical_block_number_t pbn;
+ struct vdo_slab *slab;
+ struct recovery_journal_entry entry = get_entry(repair, recovery_point);
+ bool increment = !repair->next_recovery_point.increment_applied;
+
+ if (increment) {
+ result = validate_recovery_journal_entry(vdo, &entry);
+ if (result != VDO_SUCCESS) {
+ vdo_enter_read_only_mode(vdo, result);
+ vdo_fail_completion(completion, result);
+ return;
+ }
+
+ pbn = entry.mapping.pbn;
+ } else {
+ pbn = entry.unmapping.pbn;
+ }
+
+ if (pbn == VDO_ZERO_BLOCK)
+ continue;
+
+ slab = vdo_get_slab(vdo->depot, pbn);
+ if (slab->allocator != allocator)
+ continue;
+
+ if (!vdo_attempt_replay_into_slab(slab,
+ pbn,
+ entry.operation,
+ increment,
+ &repair->next_journal_point,
+ completion))
+ return;
+
+ repair->entries_added_to_slab_journals++;
+ }
+
+ vdo_notify_slab_journals_are_recovered(completion);
+}
+
+/**
+ * vdo_replay_into_slab_journals() - Replay recovery journal entries in the slab journals of slabs
+ * owned by a given block_allocator.
+ * @allocator: The allocator whose slab journals are to be recovered.
+ * @context: The slab depot load context supplied by a recovery when it loads the depot.
+ */
+void vdo_replay_into_slab_journals(struct block_allocator *allocator, void *context)
+{
+ struct vdo_completion *completion = &allocator->completion;
+ struct repair_completion *repair = context;
+ struct vdo *vdo = completion->vdo;
+
+ vdo_assert_on_physical_zone_thread(vdo, allocator->zone_number, __func__);
+ if (repair->entry_count == 0) {
+ /* there's nothing to replay */
+ repair->logical_blocks_used = vdo->recovery_journal->logical_blocks_used;
+ repair->block_map_data_blocks = vdo->recovery_journal->block_map_data_blocks;
+ vdo_notify_slab_journals_are_recovered(completion);
+ return;
+ }
+
+ repair->next_recovery_point = (struct recovery_point) {
+ .sequence_number = repair->slab_journal_head,
+ .sector_count = 1,
+ .entry_count = 0,
+ };
+
+ repair->next_journal_point = (struct journal_point) {
+ .sequence_number = repair->slab_journal_head,
+ .entry_count = 0,
+ };
+
+ uds_log_info("Replaying entries into slab journals for zone %u", allocator->zone_number);
+ completion->parent = repair;
+ add_slab_journal_entries(completion);
+}
+
+static void load_slab_depot(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion);
+ const struct admin_state_code *operation;
+
+ vdo_assert_on_admin_thread(completion->vdo, __func__);
+
+ if (vdo_state_requires_read_only_rebuild(completion->vdo->load_state)) {
+ prepare_repair_completion(repair, rebuild_reference_counts, VDO_ZONE_TYPE_LOGICAL);
+ operation = VDO_ADMIN_STATE_LOADING_FOR_REBUILD;
+ } else {
+ prepare_repair_completion(repair, drain_slab_depot, VDO_ZONE_TYPE_ADMIN);
+ operation = VDO_ADMIN_STATE_LOADING_FOR_RECOVERY;
+ }
+
+ vdo_load_slab_depot(completion->vdo->depot, operation, completion, repair);
+}
+
+static void flush_block_map(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion);
+ const struct admin_state_code *operation;
+
+ vdo_assert_on_admin_thread(completion->vdo, __func__);
+
+ uds_log_info("Flushing block map changes");
+ prepare_repair_completion(repair, load_slab_depot, VDO_ZONE_TYPE_ADMIN);
+ operation = (vdo_state_requires_read_only_rebuild(completion->vdo->load_state) ?
+ VDO_ADMIN_STATE_REBUILDING :
+ VDO_ADMIN_STATE_RECOVERING);
+ vdo_drain_block_map(completion->vdo->block_map, operation, completion);
+}
+
+static bool finish_if_done(struct repair_completion *repair)
+{
+ /* Pages are still being launched or there is still work to do */
+ if (repair->launching || (repair->outstanding > 0))
+ return false;
+
+ if (repair->completion.result != VDO_SUCCESS) {
+ page_count_t i;
+
+ for (i = 0; i < repair->page_count; i++) {
+ struct vdo_page_completion *page_completion =
+ &repair->page_completions[i];
+
+ if (page_completion->ready)
+ vdo_release_page_completion(&page_completion->completion);
+ }
+
+ vdo_launch_completion(&repair->completion);
+ return true;
+ }
+
+ if (repair->current_entry >= repair->entries)
+ return false;
+
+ launch_repair_completion(repair, flush_block_map, VDO_ZONE_TYPE_ADMIN);
+ return true;
+}
+
+static void abort_block_map_recovery(struct repair_completion *repair, int result)
+{
+ vdo_set_completion_result(&repair->completion, result);
+ finish_if_done(repair);
+}
+
+/**
+ * find_entry_starting_next_page() - Find the first journal entry after a given entry which is not
+ * on the same block map page.
+ * @current_entry: The entry to search from.
+ * @needs_sort: Whether sorting is needed to proceed.
+ *
+ * Return: Pointer to the first later journal entry on a different block map page, or a pointer to
+ * just before the journal entries if no subsequent entry is on a different block map page.
+ */
+static struct numbered_block_mapping *
+find_entry_starting_next_page(struct repair_completion *repair,
+ struct numbered_block_mapping *current_entry,
+ bool needs_sort)
+{
+ size_t current_page;
+
+ /* If current_entry is invalid, return immediately. */
+ if (current_entry < repair->entries)
+ return current_entry;
+
+ current_page = current_entry->block_map_slot.pbn;
+
+ /* Decrement current_entry until it's out of bounds or on a different page. */
+ while ((current_entry >= repair->entries) &&
+ (current_entry->block_map_slot.pbn == current_page)) {
+ if (needs_sort) {
+ struct numbered_block_mapping *just_sorted_entry =
+ sort_next_heap_element(repair);
+ ASSERT_LOG_ONLY(just_sorted_entry < current_entry,
+ "heap is returning elements in an unexpected order");
+ }
+
+ current_entry--;
+ }
+
+ return current_entry;
+}
+
+/*
+ * Apply a range of journal entries [starting_entry, ending_entry) journal
+ * entries to a block map page.
+ */
+static void apply_journal_entries_to_page(struct block_map_page *page,
+ struct numbered_block_mapping *starting_entry,
+ struct numbered_block_mapping *ending_entry)
+{
+ struct numbered_block_mapping *current_entry = starting_entry;
+
+ while (current_entry != ending_entry) {
+ page->entries[current_entry->block_map_slot.slot] = current_entry->block_map_entry;
+ current_entry--;
+ }
+}
+
+static void recover_ready_pages(struct repair_completion *repair,
+ struct vdo_completion *completion);
+
+static void block_map_page_loaded(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion->parent);
+
+ repair->outstanding--;
+ if (!repair->launching)
+ recover_ready_pages(repair, completion);
+}
+
+static void handle_block_map_page_load_error(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion->parent);
+
+ repair->outstanding--;
+ abort_block_map_recovery(repair, completion->result);
+}
+
+static void fetch_block_map_page(struct repair_completion *repair,
+ struct vdo_completion *completion)
+{
+ physical_block_number_t pbn;
+
+ if (repair->current_unfetched_entry < repair->entries)
+ /* Nothing left to fetch. */
+ return;
+
+ /* Fetch the next page we haven't yet requested. */
+ pbn = repair->current_unfetched_entry->block_map_slot.pbn;
+ repair->current_unfetched_entry =
+ find_entry_starting_next_page(repair, repair->current_unfetched_entry, true);
+ repair->outstanding++;
+ vdo_get_page(((struct vdo_page_completion *) completion),
+ &repair->completion.vdo->block_map->zones[0],
+ pbn,
+ true,
+ &repair->completion,
+ block_map_page_loaded,
+ handle_block_map_page_load_error,
+ false);
+}
+
+static struct vdo_page_completion *
+get_next_page_completion(struct repair_completion *repair, struct vdo_page_completion *completion)
+{
+ completion++;
+ if (completion == (&repair->page_completions[repair->page_count]))
+ completion = &repair->page_completions[0];
+ return completion;
+}
+
+static void recover_ready_pages(struct repair_completion *repair,
+ struct vdo_completion *completion)
+{
+ struct vdo_page_completion *page_completion = (struct vdo_page_completion *) completion;
+
+ if (finish_if_done(repair))
+ return;
+
+ if (repair->pbn != page_completion->pbn)
+ return;
+
+ while (page_completion->ready) {
+ struct numbered_block_mapping *start_of_next_page;
+ struct block_map_page *page;
+ int result;
+
+ result = vdo_get_cached_page(completion, &page);
+ if (result != VDO_SUCCESS) {
+ abort_block_map_recovery(repair, result);
+ return;
+ }
+
+ start_of_next_page =
+ find_entry_starting_next_page(repair, repair->current_entry, false);
+ apply_journal_entries_to_page(page, repair->current_entry, start_of_next_page);
+ repair->current_entry = start_of_next_page;
+ vdo_request_page_write(completion);
+ vdo_release_page_completion(completion);
+
+ if (finish_if_done(repair))
+ return;
+
+ repair->pbn = repair->current_entry->block_map_slot.pbn;
+ fetch_block_map_page(repair, completion);
+ page_completion = get_next_page_completion(repair, page_completion);
+ completion = &page_completion->completion;
+ }
+}
+
+static void recover_block_map(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = as_repair_completion(completion);
+ struct vdo *vdo = completion->vdo;
+ struct numbered_block_mapping *first_sorted_entry;
+ page_count_t i;
+
+ vdo_assert_on_logical_zone_thread(vdo, 0, __func__);
+
+ /* Suppress block map errors. */
+ vdo->block_map->zones[0].page_cache.rebuilding =
+ vdo_state_requires_read_only_rebuild(vdo->load_state);
+
+ if (repair->block_map_entry_count == 0) {
+ uds_log_info("Replaying 0 recovery entries into block map");
+ UDS_FREE(UDS_FORGET(repair->journal_data));
+ launch_repair_completion(repair, load_slab_depot, VDO_ZONE_TYPE_ADMIN);
+ return;
+ }
+
+ /*
+ * Organize the journal entries into a binary heap so we can iterate over them in sorted
+ * order incrementally, avoiding an expensive sort call.
+ */
+ repair->replay_heap = (struct min_heap) {
+ .data = repair->entries,
+ .nr = repair->block_map_entry_count,
+ .size = repair->block_map_entry_count,
+ };
+ min_heapify_all(&repair->replay_heap, &repair_min_heap);
+
+ uds_log_info("Replaying %zu recovery entries into block map",
+ repair->block_map_entry_count);
+
+ repair->current_entry = &repair->entries[repair->block_map_entry_count - 1];
+ first_sorted_entry = sort_next_heap_element(repair);
+ ASSERT_LOG_ONLY(first_sorted_entry == repair->current_entry,
+ "heap is returning elements in an unexpected order");
+
+ /* Prevent any page from being processed until all pages have been launched. */
+ repair->launching = true;
+ repair->pbn = repair->current_entry->block_map_slot.pbn;
+ repair->current_unfetched_entry = repair->current_entry;
+ for (i = 0; i < repair->page_count; i++) {
+ if (repair->current_unfetched_entry < repair->entries)
+ break;
+
+ fetch_block_map_page(repair, &repair->page_completions[i].completion);
+ }
+ repair->launching = false;
+
+ /* Process any ready pages. */
+ recover_ready_pages(repair, &repair->page_completions[0].completion);
+}
+
+/**
+ * get_recovery_journal_block_header() - Get the block header for a block at a position in the
+ * journal data and unpack it.
+ * @journal: The recovery journal.
+ * @data: The recovery journal data.
+ * @sequence: The sequence number.
+ *
+ * Return: The unpacked header.
+ */
+static struct recovery_block_header __must_check
+get_recovery_journal_block_header(struct recovery_journal *journal,
+ char *data,
+ sequence_number_t sequence)
+{
+ physical_block_number_t pbn = vdo_get_recovery_journal_block_number(journal, sequence);
+ char *header = &data[pbn * VDO_BLOCK_SIZE];
+
+ return vdo_unpack_recovery_block_header((struct packed_journal_header *) header);
+}
+
+/**
+ * is_valid_recovery_journal_block() - Determine whether the given header describes a valid block
+ * for the given journal.
+ * @journal: The journal to use.
+ * @header: The unpacked block header to check.
+ * @old_ok: Whether an old format header is valid.
+ *
+ * A block is not valid if it is unformatted, or if it is older than the last successful recovery
+ * or reformat.
+ *
+ * Return: True if the header is valid.
+ */
+static bool __must_check
+is_valid_recovery_journal_block(const struct recovery_journal *journal,
+ const struct recovery_block_header *header,
+ bool old_ok)
+{
+ if ((header->nonce != journal->nonce) ||
+ (header->recovery_count != journal->recovery_count))
+ return false;
+
+ if (header->metadata_type == VDO_METADATA_RECOVERY_JOURNAL_2)
+ return (header->entry_count <= journal->entries_per_block);
+
+ return (old_ok &&
+ (header->metadata_type == VDO_METADATA_RECOVERY_JOURNAL) &&
+ (header->entry_count <= RECOVERY_JOURNAL_1_ENTRIES_PER_BLOCK));
+}
+
+/**
+ * is_exact_recovery_journal_block() - Determine whether the given header describes the exact block
+ * indicated.
+ * @journal: The journal to use.
+ * @header: The unpacked block header to check.
+ * @sequence: The expected sequence number.
+ * @type: The expected metadata type.
+ *
+ * Return: True if the block matches.
+ */
+static bool __must_check
+is_exact_recovery_journal_block(const struct recovery_journal *journal,
+ const struct recovery_block_header *header,
+ sequence_number_t sequence,
+ enum vdo_metadata_type type)
+{
+ return ((header->metadata_type == type) &&
+ (header->sequence_number == sequence) &&
+ (is_valid_recovery_journal_block(journal, header, true)));
+}
+
+/**
+ * find_recovery_journal_head_and_tail() - Find the tail and head of the journal.
+ *
+ * Return: True if there were valid journal blocks.
+ */
+static bool find_recovery_journal_head_and_tail(struct repair_completion *repair)
+{
+ struct recovery_journal *journal = repair->completion.vdo->recovery_journal;
+ bool found_entries = false;
+ physical_block_number_t i;
+
+ /*
+ * Ensure that we don't replay old entries since we know the tail recorded in the super
+ * block must be a lower bound. Not doing so can result in extra data loss by setting the
+ * tail too early.
+ */
+ repair->highest_tail = journal->tail;
+ for (i = 0; i < journal->size; i++) {
+ struct recovery_block_header header =
+ get_recovery_journal_block_header(journal, repair->journal_data, i);
+
+ if (!is_valid_recovery_journal_block(journal, &header, true))
+ /* This block is old or incorrectly formatted */
+ continue;
+
+ if (vdo_get_recovery_journal_block_number(journal, header.sequence_number) != i)
+ /* This block is in the wrong location */
+ continue;
+
+ if (header.sequence_number >= repair->highest_tail) {
+ found_entries = true;
+ repair->highest_tail = header.sequence_number;
+ }
+
+ if (!found_entries)
+ continue;
+
+ if (header.block_map_head > repair->block_map_head)
+ repair->block_map_head = header.block_map_head;
+
+ if (header.slab_journal_head > repair->slab_journal_head)
+ repair->slab_journal_head = header.slab_journal_head;
+ }
+
+ return found_entries;
+}
+
+/**
+ * unpack_entry() - Unpack a recovery journal entry in either format.
+ * @vdo: The vdo.
+ * @packed: The entry to unpack.
+ * @format: The expected format of the entry.
+ * @entry: The unpacked entry.
+ *
+ * Return: true if the entry should be applied.3
+ */
+static bool unpack_entry(struct vdo *vdo,
+ char *packed,
+ enum vdo_metadata_type format,
+ struct recovery_journal_entry *entry)
+{
+ if (format == VDO_METADATA_RECOVERY_JOURNAL_2) {
+ struct packed_recovery_journal_entry *packed_entry =
+ (struct packed_recovery_journal_entry *) packed;
+
+ *entry = vdo_unpack_recovery_journal_entry(packed_entry);
+ } else {
+ physical_block_number_t low32, high4;
+
+ struct packed_recovery_journal_entry_1 *packed_entry =
+ (struct packed_recovery_journal_entry_1 *) packed;
+
+ if (packed_entry->operation == VDO_JOURNAL_DATA_INCREMENT)
+ entry->operation = VDO_JOURNAL_DATA_REMAPPING;
+ else if (packed_entry->operation == VDO_JOURNAL_BLOCK_MAP_INCREMENT)
+ entry->operation = VDO_JOURNAL_BLOCK_MAP_REMAPPING;
+ else
+ return false;
+
+ low32 = __le32_to_cpu(packed_entry->pbn_low_word);
+ high4 = packed_entry->pbn_high_nibble;
+ entry->slot = (struct block_map_slot) {
+ .pbn = ((high4 << 32) | low32),
+ .slot = (packed_entry->slot_low | (packed_entry->slot_high << 6)),
+ };
+ entry->mapping = vdo_unpack_block_map_entry(&packed_entry->block_map_entry);
+ entry->unmapping = (struct data_location) {
+ .pbn = VDO_ZERO_BLOCK,
+ .state = VDO_MAPPING_STATE_UNMAPPED,
+ };
+ }
+
+ return (validate_recovery_journal_entry(vdo, entry) == VDO_SUCCESS);
+}
+
+/**
+ * append_sector_entries() - Append an array of recovery journal entries from a journal block
+ * sector to the array of numbered mappings in the repair completion,
+ * numbering each entry in the order they are appended.
+ * @repair: The repair completion.
+ * @entries: The entries in the sector.
+ * @format: The format of the sector.
+ * @entry_count: The number of entries to append.
+ */
+static void append_sector_entries(struct repair_completion *repair,
+ char *entries,
+ enum vdo_metadata_type format,
+ journal_entry_count_t entry_count)
+{
+ journal_entry_count_t i;
+ struct vdo *vdo = repair->completion.vdo;
+ off_t increment = ((format == VDO_METADATA_RECOVERY_JOURNAL_2)
+ ? sizeof(struct packed_recovery_journal_entry)
+ : sizeof(struct packed_recovery_journal_entry_1));
+
+ for (i = 0; i < entry_count; i++, entries += increment) {
+ struct recovery_journal_entry entry;
+
+ if (!unpack_entry(vdo, entries, format, &entry))
+ /* When recovering from read-only mode, ignore damaged entries. */
+ continue;
+
+ repair->entries[repair->block_map_entry_count] =
+ (struct numbered_block_mapping) {
+ .block_map_slot = entry.slot,
+ .block_map_entry = vdo_pack_block_map_entry(entry.mapping.pbn,
+ entry.mapping.state),
+ .number = repair->block_map_entry_count,
+ };
+ repair->block_map_entry_count++;
+ }
+}
+
+static journal_entry_count_t entries_per_sector(enum vdo_metadata_type format, u8 sector_number)
+{
+ if (format == VDO_METADATA_RECOVERY_JOURNAL_2)
+ return RECOVERY_JOURNAL_ENTRIES_PER_SECTOR;
+
+ return ((sector_number == (VDO_SECTORS_PER_BLOCK - 1))
+ ? RECOVERY_JOURNAL_1_ENTRIES_IN_LAST_SECTOR
+ : RECOVERY_JOURNAL_1_ENTRIES_PER_SECTOR);
+}
+
+static void extract_entries_from_block(struct repair_completion *repair,
+ struct recovery_journal *journal,
+ sequence_number_t sequence,
+ enum vdo_metadata_type format,
+ journal_entry_count_t entries)
+{
+ sector_count_t i;
+ struct recovery_block_header header =
+ get_recovery_journal_block_header(journal, repair->journal_data, sequence);
+
+ if (!is_exact_recovery_journal_block(journal, &header, sequence, format))
+ /* This block is invalid, so skip it. */
+ return;
+
+ entries = min(entries, header.entry_count);
+ for (i = 1; i < VDO_SECTORS_PER_BLOCK; i++) {
+ struct packed_journal_sector *sector =
+ get_sector(journal, repair->journal_data, sequence, i);
+ journal_entry_count_t sector_entries = min(entries, entries_per_sector(format, i));
+
+ if (vdo_is_valid_recovery_journal_sector(&header, sector, i)) {
+ /* Only extract as many as the block header calls for. */
+ append_sector_entries(repair,
+ (char *) sector->entries,
+ format,
+ min_t(journal_entry_count_t,
+ sector->entry_count,
+ sector_entries));
+ }
+
+ /*
+ * Even if the sector wasn't full, count it as full when counting up to the
+ * entry count the block header claims.
+ */
+ entries -= sector_entries;
+ }
+}
+
+static int parse_journal_for_rebuild(struct repair_completion *repair)
+{
+ int result;
+ sequence_number_t i;
+ block_count_t count;
+ enum vdo_metadata_type format;
+ struct vdo *vdo = repair->completion.vdo;
+ struct recovery_journal *journal = vdo->recovery_journal;
+ journal_entry_count_t entries_per_block = journal->entries_per_block;
+
+ format = get_recovery_journal_block_header(journal,
+ repair->journal_data,
+ repair->highest_tail).metadata_type;
+ if (format == VDO_METADATA_RECOVERY_JOURNAL)
+ entries_per_block = RECOVERY_JOURNAL_1_ENTRIES_PER_BLOCK;
+
+ /*
+ * Allocate an array of numbered_block_mapping structures large enough to transcribe every
+ * packed_recovery_journal_entry from every valid journal block.
+ */
+ count = ((repair->highest_tail - repair->block_map_head + 1) * entries_per_block);
+ result = UDS_ALLOCATE(count, struct numbered_block_mapping, __func__, &repair->entries);
+ if (result != VDO_SUCCESS)
+ return result;
+
+ for (i = repair->block_map_head; i <= repair->highest_tail; i++)
+ extract_entries_from_block(repair, journal, i, format, entries_per_block);
+
+ return VDO_SUCCESS;
+}
+
+static int validate_heads(struct repair_completion *repair)
+{
+ /* Both reap heads must be behind the tail. */
+ if ((repair->block_map_head <= repair->tail) &&
+ (repair->slab_journal_head <= repair->tail))
+ return VDO_SUCCESS;
+
+
+ return uds_log_error_strerror(VDO_CORRUPT_JOURNAL,
+ "Journal tail too early. block map head: %llu, slab journal head: %llu, tail: %llu",
+ (unsigned long long) repair->block_map_head,
+ (unsigned long long) repair->slab_journal_head,
+ (unsigned long long) repair->tail);
+}
+
+/**
+ * extract_new_mappings() - Find all valid new mappings to be applied to the block map.
+ *
+ * The mappings are extracted from the journal and stored in a sortable array so that all of the
+ * mappings to be applied to a given block map page can be done in a single page fetch.
+ */
+static int extract_new_mappings(struct repair_completion *repair)
+{
+ int result;
+ struct vdo *vdo = repair->completion.vdo;
+ struct recovery_point recovery_point = {
+ .sequence_number = repair->block_map_head,
+ .sector_count = 1,
+ .entry_count = 0,
+ };
+
+ /*
+ * Allocate an array of numbered_block_mapping structs just large enough to transcribe
+ * every packed_recovery_journal_entry from every valid journal block.
+ */
+ result = UDS_ALLOCATE(repair->entry_count,
+ struct numbered_block_mapping,
+ __func__,
+ &repair->entries);
+ if (result != VDO_SUCCESS)
+ return result;
+
+ for (; before_recovery_point(&recovery_point, &repair->tail_recovery_point);
+ increment_recovery_point(&recovery_point)) {
+ struct recovery_journal_entry entry = get_entry(repair, &recovery_point);
+
+ result = validate_recovery_journal_entry(vdo, &entry);
+ if (result != VDO_SUCCESS) {
+ vdo_enter_read_only_mode(vdo, result);
+ return result;
+ }
+
+ repair->entries[repair->block_map_entry_count] =
+ (struct numbered_block_mapping) {
+ .block_map_slot = entry.slot,
+ .block_map_entry = vdo_pack_block_map_entry(entry.mapping.pbn,
+ entry.mapping.state),
+ .number = repair->block_map_entry_count,
+ };
+ repair->block_map_entry_count++;
+ }
+
+ result = ASSERT((repair->block_map_entry_count <= repair->entry_count),
+ "approximate entry count is an upper bound");
+ if (result != VDO_SUCCESS)
+ vdo_enter_read_only_mode(vdo, result);
+
+ return result;
+}
+
+/**
+ * compute_usages() - Compute the lbns in use and block map data blocks counts from the tail of
+ * the journal.
+ */
+static noinline int compute_usages(struct repair_completion *repair)
+{
+ /*
+ * VDO-5182: function is declared noinline to avoid what is likely a spurious valgrind
+ * error about this structure being uninitialized.
+ */
+ struct recovery_point recovery_point = {
+ .sequence_number = repair->tail,
+ .sector_count = 1,
+ .entry_count = 0,
+ };
+
+ struct vdo *vdo = repair->completion.vdo;
+ struct recovery_journal *journal = vdo->recovery_journal;
+ struct recovery_block_header header =
+ get_recovery_journal_block_header(journal, repair->journal_data, repair->tail);
+
+ repair->logical_blocks_used = header.logical_blocks_used;
+ repair->block_map_data_blocks = header.block_map_data_blocks;
+
+ for (; before_recovery_point(&recovery_point, &repair->tail_recovery_point);
+ increment_recovery_point(&recovery_point)) {
+ struct recovery_journal_entry entry = get_entry(repair, &recovery_point);
+ int result;
+
+ result = validate_recovery_journal_entry(vdo, &entry);
+ if (result != VDO_SUCCESS) {
+ vdo_enter_read_only_mode(vdo, result);
+ return result;
+ }
+
+ if (entry.operation == VDO_JOURNAL_BLOCK_MAP_REMAPPING) {
+ repair->block_map_data_blocks++;
+ continue;
+ }
+
+ if (vdo_is_mapped_location(&entry.mapping))
+ repair->logical_blocks_used++;
+
+ if (vdo_is_mapped_location(&entry.unmapping))
+ repair->logical_blocks_used--;
+ }
+
+ return VDO_SUCCESS;
+}
+
+static int parse_journal_for_recovery(struct repair_completion *repair)
+{
+ int result;
+ sequence_number_t i, head;
+ bool found_entries = false;
+ struct recovery_journal *journal = repair->completion.vdo->recovery_journal;
+
+ head = min(repair->block_map_head, repair->slab_journal_head);
+ for (i = head; i <= repair->highest_tail; i++) {
+ struct recovery_block_header header;
+ journal_entry_count_t block_entries;
+ u8 j;
+
+ repair->tail = i;
+ repair->tail_recovery_point = (struct recovery_point) {
+ .sequence_number = i,
+ .sector_count = 0,
+ .entry_count = 0,
+ };
+
+ header = get_recovery_journal_block_header(journal, repair->journal_data, i);
+ if (header.metadata_type == VDO_METADATA_RECOVERY_JOURNAL) {
+ /* This is an old format block, so we need to upgrade */
+ uds_log_error_strerror(VDO_UNSUPPORTED_VERSION,
+ "Recovery journal is in the old format, a read-only rebuild is required.");
+ vdo_enter_read_only_mode(repair->completion.vdo, VDO_UNSUPPORTED_VERSION);
+ return VDO_UNSUPPORTED_VERSION;
+ }
+
+ if (!is_exact_recovery_journal_block(journal,
+ &header,
+ i,
+ VDO_METADATA_RECOVERY_JOURNAL_2))
+ /* A bad block header was found so this must be the end of the journal. */
+ break;
+
+ block_entries = header.entry_count;
+
+ /* Examine each sector in turn to determine the last valid sector. */
+ for (j = 1; j < VDO_SECTORS_PER_BLOCK; j++) {
+ struct packed_journal_sector *sector =
+ get_sector(journal, repair->journal_data, i, j);
+ journal_entry_count_t sector_entries =
+ min_t(journal_entry_count_t, sector->entry_count, block_entries);
+
+ /* A bad sector means that this block was torn. */
+ if (!vdo_is_valid_recovery_journal_sector(&header, sector, j))
+ break;
+
+ if (sector_entries > 0) {
+ found_entries = true;
+ repair->tail_recovery_point.sector_count++;
+ repair->tail_recovery_point.entry_count = sector_entries;
+ block_entries -= sector_entries;
+ repair->entry_count += sector_entries;
+ }
+
+ /* If this sector is short, the later sectors can't matter. */
+ if ((sector_entries < RECOVERY_JOURNAL_ENTRIES_PER_SECTOR) ||
+ (block_entries == 0))
+ break;
+ }
+
+ /* If this block was not filled, or if it tore, no later block can matter. */
+ if ((header.entry_count != journal->entries_per_block) || (block_entries > 0))
+ break;
+ }
+
+ if (!found_entries)
+ return validate_heads(repair);
+
+ /* Set the tail to the last valid tail block, if there is one. */
+ if (repair->tail_recovery_point.sector_count == 0)
+ repair->tail--;
+
+ result = validate_heads(repair);
+ if (result != VDO_SUCCESS)
+ return result;
+
+ uds_log_info("Highest-numbered recovery journal block has sequence number %llu, and the highest-numbered usable block is %llu",
+ (unsigned long long) repair->highest_tail,
+ (unsigned long long) repair->tail);
+
+ result = extract_new_mappings(repair);
+ if (result != VDO_SUCCESS)
+ return result;
+
+ return compute_usages(repair);
+}
+
+static int parse_journal(struct repair_completion *repair)
+{
+ if (!find_recovery_journal_head_and_tail(repair))
+ return VDO_SUCCESS;
+
+ return (vdo_state_requires_read_only_rebuild(repair->completion.vdo->load_state) ?
+ parse_journal_for_rebuild(repair) :
+ parse_journal_for_recovery(repair));
+}
+
+static void finish_journal_load(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = completion->parent;
+
+ if (++repair->vios_complete != repair->vio_count)
+ return;
+
+ uds_log_info("Finished reading recovery journal");
+ uninitialize_vios(repair);
+ prepare_repair_completion(repair, recover_block_map, VDO_ZONE_TYPE_LOGICAL);
+ vdo_continue_completion(&repair->completion, parse_journal(repair));
+}
+
+static void handle_journal_load_error(struct vdo_completion *completion)
+{
+ struct repair_completion *repair = completion->parent;
+
+ /* Preserve the error */
+ vdo_set_completion_result(&repair->completion, completion->result);
+ vio_record_metadata_io_error(as_vio(completion));
+ completion->callback(completion);
+}
+
+static void read_journal_endio(struct bio *bio)
+{
+ struct vio *vio = bio->bi_private;
+ struct vdo *vdo = vio->completion.vdo;
+
+ continue_vio_after_io(vio, finish_journal_load, vdo->thread_config.admin_thread);
+}
+
+/**
+ * vdo_repair() - Load the recovery journal and then recover or rebuild a vdo.
+ * @parent: The completion to notify when the operation is complete
+ */
+void vdo_repair(struct vdo_completion *parent)
+{
+ int result;
+ char *ptr;
+ struct repair_completion *repair;
+ struct vdo *vdo = parent->vdo;
+ struct recovery_journal *journal = vdo->recovery_journal;
+ physical_block_number_t pbn = journal->origin;
+ block_count_t remaining = journal->size;
+ block_count_t vio_count = DIV_ROUND_UP(remaining, MAX_BLOCKS_PER_VIO);
+ page_count_t page_count = min_t(page_count_t,
+ vdo->device_config->cache_size >> 1,
+ MAXIMUM_SIMULTANEOUS_VDO_BLOCK_MAP_RESTORATION_READS);
+
+ vdo_assert_on_admin_thread(vdo, __func__);
+
+ if (vdo->load_state == VDO_FORCE_REBUILD) {
+ uds_log_warning("Rebuilding reference counts to clear read-only mode");
+ vdo->states.vdo.read_only_recoveries++;
+ } else if (vdo->load_state == VDO_REBUILD_FOR_UPGRADE) {
+ uds_log_warning("Rebuilding reference counts for upgrade");
+ } else {
+ uds_log_warning("Device was dirty, rebuilding reference counts");
+ }
+
+ result = UDS_ALLOCATE_EXTENDED(struct repair_completion,
+ page_count,
+ struct vdo_page_completion,
+ __func__,
+ &repair);
+ if (result != VDO_SUCCESS) {
+ vdo_fail_completion(parent, result);
+ return;
+ }
+
+ vdo_initialize_completion(&repair->completion, vdo, VDO_REPAIR_COMPLETION);
+ repair->completion.error_handler = abort_repair;
+ repair->completion.parent = parent;
+ prepare_repair_completion(repair, finish_repair, VDO_ZONE_TYPE_ADMIN);
+ repair->page_count = page_count;
+
+ result = UDS_ALLOCATE(remaining * VDO_BLOCK_SIZE, char, __func__, &repair->journal_data);
+ if (abort_on_error(result, repair))
+ return;
+
+ result = UDS_ALLOCATE(vio_count, struct vio, __func__, &repair->vios);
+ if (abort_on_error(result, repair))
+ return;
+
+ ptr = repair->journal_data;
+ for (repair->vio_count = 0; repair->vio_count < vio_count; repair->vio_count++) {
+ block_count_t blocks = min_t(block_count_t, remaining, MAX_BLOCKS_PER_VIO);
+
+ result = allocate_vio_components(vdo,
+ VIO_TYPE_RECOVERY_JOURNAL,
+ VIO_PRIORITY_METADATA,
+ repair,
+ blocks,
+ ptr,
+ &repair->vios[repair->vio_count]);
+ if (abort_on_error(result, repair))
+ return;
+
+ ptr += (blocks * VDO_BLOCK_SIZE);
+ remaining -= blocks;
+ }
+
+ for (vio_count = 0;
+ vio_count < repair->vio_count;
+ vio_count++, pbn += MAX_BLOCKS_PER_VIO)
+ submit_metadata_vio(&repair->vios[vio_count],
+ pbn,
+ read_journal_endio,
+ handle_journal_load_error,
+ REQ_OP_READ);
+}
diff --git a/drivers/md/dm-vdo/repair.h b/drivers/md/dm-vdo/repair.h
new file mode 100644
index 00000000000..a28637d0a05
--- /dev/null
+++ b/drivers/md/dm-vdo/repair.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright Red Hat
+ */
+
+#ifndef VDO_REPAIR_H
+#define VDO_REPAIR_H
+
+#include "types.h"
+
+void vdo_replay_into_slab_journals(struct block_allocator *allocator, void *context);
+void vdo_repair(struct vdo_completion *parent);
+
+#endif /* VDO_REPAIR_H */
--
2.40.1
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/dm-devel
