iomap: buffered io changes

This series is on top of commit 267652e9d474 ("Merge branch 'vfs-6.18.async'
into vfs.all") and patches [1][2][3] in Christian's vfs.all tree.

Patches 8 and 9 (using find_next_bit() for bitmap scanning) were pulled from
another patchset [4]. Patch 8 includes Darrick's nifty
'for_each_clean_block()' macro suggestion and includes expliciting handling
the "if (start_blk == end_blk)" case in ifs_find_dirty_range() to make it less
confusing, per Brian's feedback.

This series was run through fstests on fuse passthrough_hp as a sanity-check.

Thanks,
Joanne

[1] https://lore.kernel.org/linux-fsdevel/20250919214250.4144...
[2] https://lore.kernel.org/linux-fsdevel/20250922180042.1775...
[3] https://lore.kernel.org/linux-fsdevel/20250926002609.1302...
[4] https://lore.kernel.org/linux-fsdevel/20250829233942.3607...


Joanne Koong (9):
  iomap: account for unaligned end offsets when truncating read range
  docs: document iomap writeback's iomap_finish_folio_write()
    requirement
  iomap: optimize pending async writeback accounting
  iomap: simplify ->read_folio_range() error handling for reads
  iomap: simplify when reads can be skipped for writes
  iomap: optimize reads for non-block-aligned writes
  iomap: use loff_t for file positions and offsets in writeback code
  iomap: use find_next_bit() for dirty bitmap scanning
  iomap: use find_next_bit() for uptodate bitmap scanning

 .../filesystems/iomap/operations.rst          |  10 +-
 fs/fuse/file.c                                |  18 +-
 fs/iomap/buffered-io.c                        | 281 ++++++++++++------
 fs/iomap/ioend.c                              |   2 -
 fs/xfs/xfs_aops.c                             |   8 +-
 include/linux/iomap.h                         |  15 +-
 6 files changed, 208 insertions(+), 126 deletions(-)

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2.47.3