[PATCH] erofs: support direct IO for uncompressed file

[Christoph Hellwig]

On Wed, Dec 23, 2020 at 03:39:01AM +0800, Gao Xiang wrote:
> Hi Christoph,
> 
> On Tue, Dec 22, 2020 at 02:22:34PM +0000, Christoph Hellwig wrote:
> > Please do not add new callers of __blockdev_direct_IO and use the modern
> > iomap variant instead.
> 
> We've talked about this topic before. The current status is that iomap
> doesn't support tail-packing inline data yet (Chao once sent out a version),
> and erofs only cares about read intrastructure for now (So we don't think
> more about how to deal with tail-packing inline write path). Plus, the
> original patch was once lack of inline data regression test from gfs2 folks.

So resend Chaos prep patch as part of the series switching parts of
erofs to iomap.  We need to move things off the old infrastructure instead
of adding more users and everyone needs to help a little.