linux-stable.git/mm/filemap.c, branch v5.18

tmpfs: fix regressions from wider use of ZERO_PAGE

2022-04-15T21:49:54+00:00

Chuck Lever reported fsx-based xfstests generic 075 091 112 127 failing
when 5.18-rc1 NFS server exports tmpfs: bisected to recent tmpfs change.

Whilst nfsd_splice_action() does contain some questionable handling of
repeated pages, and Chuck was able to work around there, history from
Mark Hemment makes clear that there might be similar dangers elsewhere:
it was not a good idea for me to pass ZERO_PAGE down to unknown actors.

Revert shmem_file_read_iter() to using ZERO_PAGE for holes only when
iter_is_iovec(); in other cases, use the more natural iov_iter_zero()
instead of copy_page_to_iter().

We would use iov_iter_zero() throughout, but the x86 clear_user() is not
nearly so well optimized as copy to user (dd of 1T sparse tmpfs file
takes 57 seconds rather than 44 seconds).

And now pagecache_init() does not need to SetPageUptodate(ZERO_PAGE(0)):
which had caused boot failure on arm noMMU STM32F7 and STM32H7 boards

Link: https://lkml.kernel.org/r/9a978571-8648-e830-5735-1f4748ce2e30@google.com
Fixes: 56a8c8eb1eaf ("tmpfs: do not allocate pages on read")
Signed-off-by: Hugh Dickins 
Reported-by: Patrice CHOTARD 
Reported-by: Chuck Lever III 
Tested-by: Chuck Lever III 
Cc: Mark Hemment 
Cc: Patrice CHOTARD 
Cc: Mikulas Patocka 
Cc: Lukas Czerner 
Cc: Christoph Hellwig 
Cc: "Darrick J. Wong" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: Pass an iocb to generic_perform_write()

2022-04-01T18:40:44+00:00

We can extract both the file pointer and the pos from the iocb.
This simplifies each caller as well as allowing generic_perform_write()
to see more of the iocb contents in the future.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Christian Brauner 
Reviewed-by: Al Viro 
Acked-by: Al Viro

fs: Remove ->readpages address space operation

2022-04-01T17:45:33+00:00

All filesystems have now been converted to use ->readahead, so
remove the ->readpages operation and fix all the comments that
used to refer to it.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Al Viro 
Acked-by: Al Viro

Merge tag 'write-page-prefaulting' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2

2022-03-26T19:41:52+00:00

Pull iomap fixlet from Andreas Gruenbacher:
 "Fix buffered write page prefaulting.

  I forgot to send it the previous merge window. I've only improved the
  patch description since"

* tag 'write-page-prefaulting' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  fs/iomap: Fix buffered write page prefaulting

fs/iomap: Fix buffered write page prefaulting

2022-03-25T14:14:03+00:00

When part of the user buffer passed to generic_perform_write() or
iomap_file_buffered_write() cannot be faulted in for reading, the entire
write currently fails.  The correct behavior would be to write all the
data that can be written, up to the point of failure.

Commit a6294593e8a1 ("iov_iter: Turn iov_iter_fault_in_readable into
fault_in_iov_iter_readable") gave us the information needed, so fix the
page prefaulting in generic_perform_write() and iomap_write_iter() to
only bail out when no pages could be faulted in.

We already factor in that pages that are faulted in may no longer be
resident by the time they are accessed.  Paging out pages has the same
effect as not faulting in those pages in the first place, so the code
can already deal with that.

Signed-off-by: Andreas Gruenbacher 
Reviewed-by: Catalin Marinas 
Reviewed-by: Christoph Hellwig

mm: warn on deleting redirtied only if accounted

2022-03-25T02:06:51+00:00

filemap_unaccount_folio() has a WARN_ON_ONCE(folio_test_dirty(folio)).  It
is good to warn of late dirtying on a persistent filesystem, but late
dirtying on tmpfs can only lose data which is expected to be thrown away;
and it's a pity if that warning comes ONCE on tmpfs, then hides others
which really matter.  Make it conditional on mapping_cap_writeback().

Cleanup: then folio_account_cleaned() no longer needs to check that for
itself, and so no longer needs to know the mapping.

Link: https://lkml.kernel.org/r/b5a1106c-7226-a5c6-ad41-ad4832cae1f@google.com
Signed-off-by: Hugh Dickins 
Cc: Matthew Wilcox 
Cc: Jan Kara 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: filemap_unaccount_folio() large skip mapcount fixup

2022-03-25T02:06:45+00:00

The page_mapcount_reset() when folio_mapped() while mapping_exiting() was
devised long before there were huge or compound pages in the cache.  It is
still valid for small pages, but not at all clear what's right to check
and reset on large pages.  Just don't try when folio_test_large().

Link: https://lkml.kernel.org/r/879c4426-4122-da9c-1a86-697f2c9a083@google.com
Signed-off-by: Hugh Dickins 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: delete __ClearPageWaiters()

2022-03-25T02:06:45+00:00

The PG_waiters bit is not included in PAGE_FLAGS_CHECK_AT_FREE, and
vmscan.c's free_unref_page_list() callers rely on that not to generate
bad_page() alerts.  So __page_cache_release(), put_pages_list() and
release_pages() (and presumably copy-and-pasted free_zone_device_page())
are redundant and misleading to make a special point of clearing it (as
the "__" implies, it could only safely be used on the freeing path).

Delete __ClearPageWaiters().  Remark on this in one of the "possible"
comments in folio_wake_bit(), and delete the superfluous comments.

Link: https://lkml.kernel.org/r/3eafa969-5b1a-accf-88fe-318784c791a@google.com
Signed-off-by: Hugh Dickins 
Tested-by: Yu Zhao 
Reviewed-by: Yang Shi 
Reviewed-by: David Hildenbrand 
Cc: Matthew Wilcox 
Cc: Nicholas Piggin 
Cc: Yu Zhao 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache

2022-03-23T01:26:56+00:00

Pull filesystem folio updates from Matthew Wilcox:
 "Primarily this series converts some of the address_space operations to
  take a folio instead of a page.

  Notably:

   - a_ops->is_partially_uptodate() takes a folio instead of a page and
     changes the type of the 'from' and 'count' arguments to make it
     obvious they're bytes.

   - a_ops->invalidatepage() becomes ->invalidate_folio() and has a
     similar type change.

   - a_ops->launder_page() becomes ->launder_folio()

   - a_ops->set_page_dirty() becomes ->dirty_folio() and adds the
     address_space as an argument.

  There are a couple of other misc changes up front that weren't worth
  separating into their own pull request"

* tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits)
  fs: Remove aops ->set_page_dirty
  fb_defio: Use noop_dirty_folio()
  fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
  fs: Convert __set_page_dirty_buffers to block_dirty_folio
  nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio()
  mm: Convert swap_set_page_dirty() to swap_dirty_folio()
  ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio
  f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio
  f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio
  f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio
  afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio()
  btrfs: Convert extent_range_redirty_for_io() to use folios
  fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio
  btrfs: Convert from set_page_dirty to dirty_folio
  fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
  fs: Add aops->dirty_folio
  fs: Remove aops->launder_page
  orangefs: Convert launder_page to launder_folio
  nfs: Convert from launder_page to launder_folio
  fuse: Convert from launder_page to launder_folio
  ...

Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache

2022-03-23T00:03:12+00:00

Pull folio updates from Matthew Wilcox:

 - Rewrite how munlock works to massively reduce the contention on
   i_mmap_rwsem (Hugh Dickins):

     https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/

 - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph
   Hellwig):

     https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/

 - Convert GUP to use folios and make pincount available for order-1
   pages. (Matthew Wilcox)

 - Convert a few more truncation functions to use folios (Matthew
   Wilcox)

 - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew
   Wilcox)

 - Convert rmap_walk to use folios (Matthew Wilcox)

 - Convert most of shrink_page_list() to use a folio (Matthew Wilcox)

 - Add support for creating large folios in readahead (Matthew Wilcox)

* tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits)
  mm/damon: minor cleanup for damon_pa_young
  selftests/vm/transhuge-stress: Support file-backed PMD folios
  mm/filemap: Support VM_HUGEPAGE for file mappings
  mm/readahead: Switch to page_cache_ra_order
  mm/readahead: Align file mappings for non-DAX
  mm/readahead: Add large folio readahead
  mm: Support arbitrary THP sizes
  mm: Make large folios depend on THP
  mm: Fix READ_ONLY_THP warning
  mm/filemap: Allow large folios to be added to the page cache
  mm: Turn can_split_huge_page() into can_split_folio()
  mm/vmscan: Convert pageout() to take a folio
  mm/vmscan: Turn page_check_references() into folio_check_references()
  mm/vmscan: Account large folios correctly
  mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios
  mm/vmscan: Free non-shmem folios without splitting them
  mm/rmap: Constify the rmap_walk_control argument
  mm/rmap: Convert rmap_walk() to take a folio
  mm: Turn page_anon_vma() into folio_anon_vma()
  mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
  ...