I have "a few" projects I'm working on / intending to work on in the near future.

Folios is the big one.  This has sub-projects:
 * MM:
  * Convert vmscan.c to folios (partly done for 5.18)
    * isolate_lru_pages()
    * alloc_demote_page()
    * reclaim_clean_pages_from_list()
    * move_pages_to_lru()
    * shrink_active_list()
    * reclaim_pages()
  * Convert filemap.c to folios
    * filemap_range_has_page()
    * __filemap_fdatawait_range()
    * filemap_range_has_writeback()
    * replace_page_cache_page()
    * page_endio()
    * find_get_pages_contig() (or can we remove it?)
    * find_get_pages_range_tag()
    * filemap_map_pmd()
    * filemap_map_pages()
    * generic_perform_write()
  * Get rid of readahead_page()
  * 
  * Move split_huge_page() to non-THP code
  * Get rid of all thp_size(), thp_order() and thp_nr_pages() calls (probably?)
 * FS:
  * Adapt NFS to use large folios
  * Adapt btrfs to use large folios
  * Adapt CIFS to use large folios
  * Convert the a_ops to take folios instead of pages (most aops done for 5.19)

Tangential to folios:
 * Phyr
 * net pool as its own type
 * pt pages as its own type
 * zspage as its own type
 * Can we make mapcount more sensible or disappear entirely?
 * Implement iomap ->writepages properly

Unrelated to folios:
 * Maple Tree (Liam is doing most of the work)
 * Shrink struct mutex (Vishal has taken this on)
 * Remove PG_private
 * Remove PG_error
 * Synchronous ->readpage
 * Broadcast readpage errors to all waiters
 * Implement ->readahead for squashfs (Hsin-Yi)
 * MatthewWilcox/ImprovedReadaheadAlgorithm
 * Slab Sevenths (Bill is attacking this one)
 * NUMA-aware zero page (Bill is working on this one too)
 * NUMA text pages in the page cache (Linus seems sceptical)
 * Usercopy for order-0 pages
   * If we check ->mapping, is that a sure sign of individual allocation?
 * Big Buckets (or integrate with Maple Tree)
 * Readahead for compressed filesystems in general
 * Fix XArray memory leak when memory allocation fails
 * Removing b_end_io (Jitendra)
 * Enable -Wshadow (needs header file cleanups)
 * Share memory when caching reflinked files
 * Make page cache better at writethrough for O_SYNC (and related)

Completed projects

 Folios:
 * MM:
  * Get large folio support in (5.18)
  * Convert GUP to folios (5.18)
  * Convert page_vma_mapped to PFNs (5.18)
  * Convert rmap to folios (5.18)
 * FS:
  * Convert XFS to large folios (5.18)
 * Remove aops->readpages (5.18)
 * Use an iov_iter in proc/vmcore (5.19)
 * Usercopy improvements (5.19)
 * Make the last argument to read_mapping_page() / read_mapping_folio() a struct file ptr (5.19)
 * Slab (Vlastimil took this over.  merged 5.17)