Re: [overlayfs]: Overlayfs questions

Re: [overlayfs]: Overlayfs questions

[Amir Goldstein]

On Wed, Jul 28, 2021 at 4:18 AM www <ouyangxuan10@163.com> wrote:
>
> Dear Miklos Szeredi , Amir Goldstein and Kevin,
>
> I would like to ask some question in overlayfs：
> 1.  in overlayfs, where is the code for obtaining directory or file attributes?
>
> 2. Where is the code that combines lowerdir and Upper Dir into a visual part?
>
> thanks，
> Byron
>

Those are very broad questions.

In a very narrow sense the answers are
1. ovl_getattr()
2. ovl_iterate() and ovl_lookup()

This is the most up to date documentation:
https://www.kernel.org/doc/Documentation/filesystems/overlayfs.rst

For anything beyond that, you'll need to read the code:
https://elixir.bootlin.com/linux/latest/source/fs/overlayfs

Thanks,
Amir.