find_free_block(9)

okay bestie, welcome to the find_free_block(9) page from the Kernel API Manual 💖 this one is short and sweet: it's the little helper that looks for the first block with a reference count of zero in the specified range of reference counter indexes. lowkey iconic.

🌸 NAME 🌸

find_free_block — find the first block with a reference count of zero in the specified range of reference counter indexes. periodt. ✨

✨ SYNOPSIS ✨

here's the exact signature, bestie — don't let the *s scare you:

bool find_free_block (const struct vdo_slab *slab , slab_block_number
       *index_ptr );

💅 ARGUMENTS 💅

• slab — the slab counters you're scanning. that's the target, bestie.
• index_ptr — a pointer meant to hold the array index of the free block. it's where the answer goes. 🎀

🎀 RETURN 🎀

True if a free block was found in the specified range. that's the whole return vibe. ✅

🦋 SEE ALSO 🦋

and now the group chat — the kernel file ./drivers/md/dm-vdo/slab-depot.c and literally every function reference from the original SEE ALSO list, no skips, no cap:

Kernel file ./drivers/md/dm-vdo/slab-depot.c get_lock(9),
must_make_entries_to_flush(9), is_reaping(9), initialize_tail_block(9),
initialize_journal_state(9), block_is_full(9), is_slab_journal_blank(9),
mark_slab_journal_dirty(9), compute_fullness_hint(9),
check_summary_drain_complete(9), notify_summary_waiters(9),
finish_updating_slab_summary_block(9), finish_update(9),
handle_write_error(9), launch_write(9), update_slab_summary_entry(9),
finish_reaping(9), complete_reaping(9), handle_flush_error(9),
flush_for_reaping(9), reap_slab_journal(9),
adjust_slab_journal_block_reference(9), release_journal_locks(9),
update_tail_block_location(9), reopen_slab_journal(9),
complete_write(9), write_slab_journal_block(9), commit_tail(9),
encode_slab_journal_entry(9), expand_journal_point(9), add_entry(9),
vdo_attempt_replay_into_slab(9), requires_reaping(9),
launch_reference_block_write(9), finish_reference_block_write(9),
get_reference_counters_for_block(9), pack_reference_block(9),
handle_io_error(9), write_reference_block(9),
reference_count_to_status(9), dirty_block(9), get_reference_block(9),
slab_block_number_from_pbn(9), get_reference_counter(9),
adjust_free_block_count(9), increment_for_data(9),
decrement_for_data(9), increment_for_block_map(9),
update_reference_count(9), add_entry_from_waiter(9),
is_next_entry_a_block_map_increment(9), add_entries(9),
reset_search_cursor(9), advance_search_cursor(9),
vdo_adjust_reference_count_for_rebuild(9),
replay_reference_count_change(9), find_zero_byte_in_word(9),
search_current_reference_block(9), search_reference_blocks(9),
make_provisional_reference(9), dirty_all_reference_blocks(9),
match_bytes(9), count_valid_references(9), unpack_reference_block(9),
finish_reference_block_load(9), load_reference_block_group(9),
load_reference_blocks(9), drain_slab(9), read_slab_journal_tail(9),
load_slab_journal(9), get_next_slab(9), has_slabs_to_scrub(9),
uninitialize_scrubber_vio(9), finish_scrubbing(9), slab_scrubbed(9),
abort_scrubbing(9), handle_scrubber_error(9), apply_block_entries(9),
apply_journal_entries(9), start_scrubbing(9), scrub_next_slab(9),
scrub_slabs(9), get_depot_slab_iterator(9), next_slab(9),
abort_waiter(9), vdo_acquire_provisional_reference(9), open_slab(9),
vdo_enqueue_clean_slab_waiter(9), vdo_modify_reference_count(9),
vdo_notify_slab_journals_are_recovered(9), make_slab(9),
allocate_slabs(9), vdo_abandon_new_slabs(9),
release_recovery_journal_lock(9), prepare_for_tail_block_commit(9),
schedule_tail_block_commit(9), initialize_slab_scrubber(9),
initialize_slab_summary_block(9), vdo_decode_slab_depot(9),
vdo_free_slab_depot(9), vdo_record_slab_depot(9),
vdo_allocate_reference_counters(9), get_slab_number(9), vdo_get_slab(9),
vdo_get_increment_limit(9), vdo_is_physical_data_block(9),
vdo_get_slab_depot_allocated_blocks(9),
vdo_get_slab_depot_data_blocks(9), finish_combining_zones(9),
combine_summaries(9), finish_loading_summary(9), load_slab_summary(9),
vdo_load_slab_depot(9), vdo_prepare_slab_depot_to_allocate(9),
vdo_update_slab_depot_size(9), vdo_prepare_to_grow_slab_depot(9),
finish_registration(9), vdo_use_new_slabs(9), stop_scrubbing(9),
vdo_drain_slab_depot(9), resume_scrubbing(9), vdo_resume_slab_depot(9),
vdo_commit_oldest_slab_journal_tail_blocks(9),
vdo_scrub_all_unrecovered_slabs(9), get_block_allocator_statistics(9),
get_ref_counts_statistics(9), get_slab_journal_statistics(9),
vdo_get_slab_depot_statistics(9), vdo_dump_slab_depot(9)

okay that's the page, bestie 💖 source/version vibe: ./drivers/md/dm-vdo, date: October 2026, page: find_free_block(9). periodt. 🌈