Page cache for 5.17

The following changes since commit 2a987e65025e2b79c6d453b78cb5985ac6e5eb26:

Merge tag 'perf-tools-fixes-for-v5.16-2021-12-07' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux (2021-12-07 15:36:45 -0800)

are available in the Git repository at:

git://git.infradead.org/users/willy/pagecache.git tags/folio-5.17

for you to fetch changes up to 6b24ca4a1a8d4ee3221d6d44ddbb99f542e4bda3:

mm: Use multi-index entries in the page cache (2022-01-08 00:28:41 -0500)

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Convert much of the page cache to use folios

This patchset stops just short of actually enabling large folios. It converts everything that I noticed needs to be converted, but there may still be places I've overlooked which still have page size assumptions. The big change here is using large entries in the page cache XArray instead of many small entries. That only affects shmem for now, but it's a pretty big change for shmem since it changes where memory needs to be allocated (at split time instead of insertion).

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Matthew Wilcox (Oracle) (49):
filemap: Remove PageHWPoison check from next_uptodate_page() fs/writeback: Convert inode_switch_wbs_work_fn to folios mm/doc: Add documentation for folio_test_uptodate mm/writeback: Improve __folio_mark_dirty() comment
pagevec: Add folio_batch
iov_iter: Add copy_folio_to_iter()
iov_iter: Convert iter_xarray to use folios
mm: Add folio_test_pmd_mappable()
filemap: Add folio_put_wait_locked()
filemap: Convert page_cache_delete to take a folio
filemap: Add filemap_unaccount_folio()
filemap: Convert tracing of page cache operations to folio
filemap: Add filemap_remove_folio and __filemap_remove_folio
filemap: Convert find_get_entry to return a folio
filemap: Remove thp_contains()
filemap: Convert filemap_get_read_batch to use folios
filemap: Convert find_get_pages_contig to folios
filemap: Convert filemap_read_page to take a folio
filemap: Convert filemap_create_page to folio
filemap: Convert filemap_range_uptodate to folios
readahead: Convert page_cache_async_ra() to take a folio
readahead: Convert page_cache_ra_unbounded to folios
filemap: Convert do_async_mmap_readahead to take a folio
filemap: Convert filemap_fault to folio
filemap: Add read_cache_folio and read_mapping_folio
filemap: Drop the refcount while waiting for page lock
filemap: Convert filemap_get_pages to use folios
filemap: Convert page_cache_delete_batch to folios
filemap: Use folios in next_uptodate_page
filemap: Use a folio in filemap_map_pages
filemap: Use a folio in filemap_page_mkwrite
filemap: Add filemap_release_folio()
truncate: Add truncate_cleanup_folio()
mm: Add unmap_mapping_folio()
shmem: Convert part of shmem_undo_range() to use a folio truncate,shmem: Add truncate_inode_folio()
truncate: Skip known-truncated indices
truncate: Convert invalidate_inode_pages2_range() to use a folio
truncate: Add invalidate_complete_folio2()
filemap: Convert filemap_read() to use a folio
filemap: Convert filemap_get_read_batch() to use a folio_batch
filemap: Return only folios from find_get_entries()
mm: Convert find_lock_entries() to use a folio_batch
mm: Remove pagevec_remove_exceptionals()
fs: Convert vfs_dedupe_file_range_compare to folios
truncate: Convert invalidate_inode_pages2_range to folios truncate,shmem: Handle truncates that split large folios
XArray: Add xas_advance()
mm: Use multi-index entries in the page cache

 fs/f2fs/f2fs.h                 |    2 +
 fs/fs-writeback.c              |   24 +-
 fs/remap_range.c               |  116 +++--
 include/linux/huge_mm.h        |   14 +
 include/linux/mm.h             |   68 +--
 include/linux/page-flags.h     |   13 +-
 include/linux/pagemap.h        |   59 +--
 include/linux/pagevec.h        |   67 ++-
 include/linux/uio.h            |    7 +
 include/linux/xarray.h         |   18 +
 include/trace/events/filemap.h |   32 +-
 lib/iov_iter.c                 |   30 +-
 lib/xarray.c                   |    6 +-
 mm/filemap.c                   | 1006 +++++++++++++++++++---------------------
 mm/folio-compat.c              |   11 +
 mm/huge_memory.c               |   18 +-
 mm/internal.h                  |   14 +-
 mm/khugepaged.c                |   12 +-
 mm/memory.c                    |   49 +-
 mm/migrate.c                   |   29 +-
 mm/page-writeback.c            |    6 +-
 mm/readahead.c                 |   24 +-
 mm/shmem.c                     |  174 ++++---
 mm/swap.c                      |   26 +-
 mm/truncate.c                  |  304 ++++++------
 25 files changed, 1114 insertions(+), 1015 deletions(-)

So I note that you tend to still sometimes use 'page' in the commit messages and leave them in the comments.

For example:

or the comment (and function name) in next_uptodate_page():

                /* Has the page moved or been split? */

and obviously also function names for first_map_page()/next_map_page().

I don't mind, but it's an odd kind of inconsistency, where the code all uses 'folio', but then the function name and comment wasn't updated.

Sometimes you _do_ update the function name, sometimes you don't. Maybe there's a pattern I'm not seeing.

Anyway, regardless of that small nit - pulled.

Linus