Re: [PATCH v3 1/2] ext4: Pass in DIO_SKIP_DIO_COUNT flag if inode_dio_begin() called

[Christoph Hellwig]

FYI, none of the Dax code even needs to ever touch the dio_count,
as dax I/O can't be asynchronous, and we thus don't need it to protect
against truncate.  I'd suggest to remove it and then end_io callback
from the DAX code entirely as a start and then move from there.