Re: [Linux-cachefs] [PATCH v6 0/2] mm, netfs, fscache: Stop read optimisation when folio removed from pagecache

[David Wysochanski <dwysocha@redhat.com>]

On Thu, Feb 16, 2023 at 10:07 AM David Howells <dhowells@redhat.com> wrote:
>
> Hi Willy,
>
> Is this okay by you?  You said you wanted to look at the remaining uses of
> page_has_private(), of which there are then three after these patches, not
> counting folio_has_private():
>
>         arch/s390/kernel/uv.c:          if (page_has_private(page))
>         mm/khugepaged.c:                    1 + page_mapcount(page) + page_has_private(page)) {
>         mm/migrate_device.c:            extra += 1 + page_has_private(page);
>
> --
> I've split the folio_has_private()/filemap_release_folio() call pair
> merging into its own patch, separate from the actual bugfix and pulled out
> the folio_needs_release() function into mm/internal.h and made
> filemap_release_folio() use it.  I've also got rid of the bit clearances
> from the network filesystem evict_inode functions as they doesn't seem to
> be necessary.
>
> Note that the last vestiges of try_to_release_page() got swept away, so I
> rebased and dealt with that.  One comment remained, which is removed by the
> first patch.
>
> David
>
> Changes:
> ========
> ver #6)
>  - Drop the third patch which removes a duplicate check in vmscan().
>
> ver #5)
>  - Rebased on linus/master.  try_to_release_page() has now been entirely
>    replaced by filemap_release_folio(), barring one comment.
>  - Cleaned up some pairs in ext4.
>
> ver #4)
>  - Split has_private/release call pairs into own patch.
>  - Moved folio_needs_release() to mm/internal.h and removed open-coded
>    version from filemap_release_folio().
>  - Don't need to clear AS_RELEASE_ALWAYS in ->evict_inode().
>  - Added experimental patch to reduce shrink_folio_list().
>
> ver #3)
>  - Fixed mapping_clear_release_always() to use clear_bit() not set_bit().
>  - Moved a '&&' to the correct line.
>
> ver #2)
>  - Rewrote entirely according to Willy's suggestion[1].
>
> Link: https://lore.kernel.org/r/Yk9V/03wgdYi65Lb@casper.infradead.org/ [1]
> Link: https://lore.kernel.org/r/164928630577.457102.8519251179327601178.stgit@warthog.procyon.org.uk/ # v1
> Link: https://lore.kernel.org/r/166844174069.1124521.10890506360974169994.stgit@warthog.procyon.org.uk/ # v2
> Link: https://lore.kernel.org/r/166869495238.3720468.4878151409085146764.stgit@warthog.procyon.org.uk/ # v3
> Link: https://lore.kernel.org/r/1459152.1669208550@warthog.procyon.org.uk/ # v3 also
> Link: https://lore.kernel.org/r/166924370539.1772793.13730698360771821317.stgit@warthog.procyon.org.uk/ # v4
> Link: https://lore.kernel.org/r/167172131368.2334525.8569808925687731937.stgit@warthog.procyon.org.uk/ # v5
> ---
> %(shortlog)s
> %(diffstat)s
>
> David Howells (2):
>   mm: Merge folio_has_private()/filemap_release_folio() call pairs
>   mm, netfs, fscache: Stop read optimisation when folio removed from
>     pagecache
>
>  fs/9p/cache.c           |  2 ++
>  fs/afs/internal.h       |  2 ++
>  fs/cachefiles/namei.c   |  2 ++
>  fs/ceph/cache.c         |  2 ++
>  fs/cifs/fscache.c       |  2 ++
>  fs/ext4/move_extent.c   | 12 ++++--------
>  fs/splice.c             |  3 +--
>  include/linux/pagemap.h | 16 ++++++++++++++++
>  mm/filemap.c            |  2 ++
>  mm/huge_memory.c        |  3 +--
>  mm/internal.h           | 11 +++++++++++
>  mm/khugepaged.c         |  3 +--
>  mm/memory-failure.c     |  8 +++-----
>  mm/migrate.c            |  3 +--
>  mm/truncate.c           |  6 ++----
>  mm/vmscan.c             |  8 ++++----
>  16 files changed, 56 insertions(+), 29 deletions(-)
>
> --
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> Linux-cachefs@redhat.com
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>

Willy, and David,

Can this series move forward?
This just got mentioned again [1] after Chris tested the NFS netfs
patches that were merged in 6.4-rc1

[1] https://lore.kernel.org/linux-nfs/CAAmbk-f_U8CPcTQM866L572uUHdK4p5iWKnUQs4r8fkW=6RW9g@mail.gmail.com/