completion_needs_page(9)

💖 completion_needs_page(9) 💖

okay bestie, welcome to completion_needs_page(9) from the Kernel API Manual — this one is a tiny little matchmaker function and it's lowkey iconic. 🎀

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✨ NAME ✨

completion_needs_page — figure out whether a given vdo_page_completion (as a waiter) is requesting a given page number. fr fr, that's the whole vibe check. 💅

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🌸 SYNOPSIS 🌸

bool completion_needs_page (struct vdo_waiter *waiter , void *context );

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🎀 ARGUMENTS 🎀

• waiter — the page completion waiter you're checking, aka the main character being inspected. 👀
• context — a pointer to the pbn of the desired page. That's the page you're looking for, bestie. 🦋

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🫶 DESCRIPTION 🫶

This is the implementation of waiter_match_fn. That's it — that's the description. It's giving "small function, important little role," and we respect it. ✨

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🔥 RETURN 🔥

It returns true if the page completion is for the desired page number. That's the yes moment, no cap. ✅

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👑 SEE ALSO 👑

Kernel file ./drivers/md/dm-vdo/block-map.c and the whole Block map eras(9) friend group:

• Block map eras(9)
• initialize_info(9)
• allocate_cache_components(9)
• assert_on_cache_thread(9)
• get_page_state_name(9)
• update_counter(9)
• set_info_state(9)
• find_free_page(9)
• find_page(9)
• select_lru_page(9)
• complete_with_page(9)
• complete_waiter_with_error(9)
• complete_waiter_with_page(9)
• distribute_page_over_waitq(9)
• set_persistent_error(9)
• validate_completed_page(9)
• handle_load_error(9)
• page_is_loaded(9)
• handle_rebuild_read_error(9)
• launch_page_load(9)
• schedule_page_save(9)
• launch_page_save(9)
• allocate_free_page(9)
• discard_a_page(9)
• discard_page_if_needed(9)
• write_has_finished(9)
• handle_page_write_error(9)
• page_is_written_out(9)
• write_pages(9)
• vdo_release_page_completion(9)
• vdo_get_page(9)
• vdo_request_page_write(9)
• vdo_get_cached_page(9)
• vdo_invalidate_page_cache(9)
• get_tree_page_by_index(9)
• in_cyclic_range(9)
• is_not_older(9)
• add_to_dirty_lists(9)
• vdo_find_block_map_slot(9)
• make_forest(9)
• replace_forest(9)
• finish_cursor(9)
• continue_traversal(9)
• finish_traversal_load(9)
• traverse(9)
• launch_cursor(9)
• compute_boundary(9)
• vdo_traverse_forest(9)
• initialize_block_map_zone(9)
• clear_mapped_location(9)
• set_mapped_location(9)

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okay that's the page, bestie! 💅 Sign-off time: source/version is ./drivers/md/dm-vdo, dated October 2026, and the page is, of course, completion_needs_page(9). 🫶✨