Re: [RFC][PATCH v2 0/5] Experiments with overlayfs filemap

Amir Goldstein
2019-01-28T22:14:12Z

On Mon, Jan 28, 2019 at 11:22 PM Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> On Mon, Jan 28, 2019 at 10:17 PM Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> > Trying to put some code together...
>
> Very rudimentary patch attached. It doens't do direct IO yet, but
> demonstrates what I meant about achoring the upper file in the inode.
>

Code looks good, but blows up on xfstests, so I'll wait for a baked patch
before testing.

> Also found the trick to actually make writeback work:
> super_setup_bdi() call in fill_super...
>

Cool, but when adding only setup_bdi() this to my code, I still don't see any
writeback. No writeback observed with your patch as well.

Speaking of which, did you read the warning sign above
simple_write_end()? Aren't you missing the mark_inode_dirty() call?

Thanks,
Amir.