Merge patch series "iomap preliminaries for large atomic write for xfs with CoW"

Bring in the iomap changes required for xfs to support large atomic
write with CoW.

* patches from https://lore.kernel.org/r/20250303171120.2837067-1-john.g.garry@oracle.com:
  iomap: Lift blocksize restriction on atomic writes
  iomap: Support SW-based atomic writes
  iomap: Rename IOMAP_ATOMIC -> IOMAP_ATOMIC_HW

Link: https://lore.kernel.org/r/20250303171120.2837067-1-john.g.garry@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>