[PATCH v2 0/4] iomap: allow partial folio write with iomap_folio_state

[alexjlzheng@gmail.com]

From: Jinliang Zheng <alexjlzheng@tencent.com>

With iomap_folio_state, we can identify uptodate states at the block
level, and a read_folio reading can correctly handle partially
uptodate folios.

Therefore, when a partial write occurs, accept the block-aligned
partial write instead of rejecting the entire write.

This patchset has been tested by xfstests' generic and xfs group, and
there's no new failed cases compared to the lastest upstream version kernel.

Changelog:

V2: use & instead of % for 64 bit variable on m68k/xtensa, try to make them happy:
       m68k-linux-ld: fs/iomap/buffered-io.o: in function `iomap_adjust_read_range':
    >> buffered-io.c:(.text+0xa8a): undefined reference to `__moddi3'
    >> m68k-linux-ld: buffered-io.c:(.text+0xaa8): undefined reference to `__moddi3'

V1: https://lore.kernel.org/linux-fsdevel/20250810044806.3433783-1-alexjlzheng@tencent.com/

Jinliang Zheng (4):
  iomap: make sure iomap_adjust_read_range() are aligned with block_size
  iomap: move iter revert case out of the unwritten branch
  iomap: make iomap_write_end() return the number of written length again
  iomap: don't abandon the whole thing with iomap_folio_state

 fs/iomap/buffered-io.c | 68 +++++++++++++++++++++++++++++-------------
 1 file changed, 47 insertions(+), 21 deletions(-)

-- 
2.49.0