Re: RFC: iomap write invalidation

Christoph Hellwig
2020-07-21T16:01:48Z

On Tue, Jul 21, 2020 at 08:59:25AM -0700, Darrick J. Wong wrote:
> In the comment that precedes iomap_dio_rw() for the iomap version,

maybe let's just do that..

> ``direct_IO``
> called by the generic read/write routines to perform direct_IO -
> that is IO requests which bypass the page cache and transfer
> data directly between the storage and the application's address
> space. This function can return -ENOTBLK to signal that it is
> necessary to fallback to buffered IO. Note that
> blockdev_direct_IO and variants can also return -ENOTBLK.

->direct_IO is not used for iomap and various other implementations.
In fact it is a horrible hack that I've been trying to get rid of
for a while.