Merge patch series "iomap/fuse: add helper to keep uptodate bitmap in sync"

Joanne Koong <joannelkoong@gmail.com> says:

iomap/fuse: add helper to keep uptodate bitmap in sync

Filesystems that use iomap normally mark folios uptodate through the iomap
read/write paths, which keep iomap's internal uptodate bitmap in sync.
However, some filesystems need to write data directly into the page cache
outside of those paths (eg fuse, which may need to write server-pushed data
straight into the page cache for servicing notify stores). These filesystems
need a way to mark a folio uptodate that also updates the iomap bitmap so
they're kept in sync.

This series adds iomap_folio_mark_uptodate() for filesystems to do that and
updates the relevant fuse call paths to use this. This is needed before fuse
can enable large folios.

Patch 1 ("fuse: don't clear folio uptodate on writethrough errors") was
originally submitted to the fuse tree [1] but patch 3 ("fuse: use iomap helper
to mark folio uptodate") has a dependency on it, so to make cross-coordination
between trees easier, patch 1 is now part of this series and submitted to the
vfs tree.

[1] https://lore.kernel.org/fuse-devel/20260624205201.842714-1-joannelkoong@gmail.com/

* patches from https://patch.msgid.link/20260707220450.1200943-1-joannelkoong@gmail.com:
  fuse: use iomap helper to mark folio uptodate
  iomap: add helper to mark folio uptodate
  fuse: don't clear folio uptodate on writethrough errors

Link: https://patch.msgid.link/20260707220450.1200943-1-joannelkoong@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>