[PATCH v3 0/4] iomap: zero range flush fixes

[Brian Foster <bfoster@redhat.com>]

Hi all,

Here's v3 of the change to improve zero range performance in the case of
frequent size extensions leading to excessive flushing. The main
differences from v2 are the addition of patch 1 to replace the need for
an iter reinit helper, some minor cleanups, and the addition of patch 4
to detect unexpected uses of zero range now that it no longer updates
i_size.

Thoughts, reviews, flames appreciated.

Brian

v3:
- Added new patch 1 to always reset per-iter state in iomap_iter.
- Dropped iomap_iter_init() helper.
- Misc. cleanups.
- Appended patch 4 to warn on zeroing beyond EOF.
v2: https://lore.kernel.org/linux-fsdevel/20241031140449.439576-1-bfoster@redhat.com/
- Added patch 1 to lift zeroed mapping handling code into caller.
- Split unaligned start range handling at the top level.
- Retain existing conditional flush behavior (vs. unconditional flush)
  for the remaining range.
v1: https://lore.kernel.org/linux-fsdevel/20241023143029.11275-1-bfoster@redhat.com/

Brian Foster (4):
  iomap: reset per-iter state on non-error iter advances
  iomap: lift zeroed mapping handling into iomap_zero_range()
  iomap: elide flush from partial eof zero range
  iomap: warn on zero range of a post-eof folio

 fs/iomap/buffered-io.c | 89 ++++++++++++++++++++++--------------------
 fs/iomap/iter.c        | 11 +++---
 2 files changed, 51 insertions(+), 49 deletions(-)

-- 
2.47.0