Re: [PATCH 4/4] ovl: alllow remote upper

On Thu, Feb 20, 2020 at 10:00 PM Amir Goldstein [off-list ref] wrote:

On Thu, Feb 20, 2020 at 9:52 AM Amir Goldstein [off-list ref] wrote:

quoted

On Tue, Feb 4, 2020 at 7:02 PM Amir Goldstein [off-list ref] wrote:

quoted

On Tue, Feb 4, 2020 at 6:17 PM Miklos Szeredi [off-list ref] wrote:

quoted

On Tue, Feb 4, 2020 at 3:59 PM Vivek Goyal [off-list ref] wrote:

quoted

On Fri, Jan 31, 2020 at 12:50:04PM +0100, Miklos Szeredi wrote:

quoted

No reason to prevent upper layer being a remote filesystem.  Do the
revalidation in that case, just as we already do for lower layers.

This lets virtiofs be used as upper layer, which appears to be a real use
case.

Hi Miklos,

I have couple of very basic questions.

- So with this change, we will allow NFS to be upper layer also?

I haven't tested, but I think it will fail on the d_type test.

But we do not fail mount on no d_type support...
Besides, I though you were going to add the RENAME_WHITEOUT
test to avert untested network fs as upper.

Pushed strict remote upper check to:
https://github.com/amir73il/linux/commits/ovl-strict-upper

Vivek,

Could you please make sure that the code in ovl-strict-upper branch
works as expected for virtio as upper fs?
I have rebased it on latest overlayfs-next merge into current master.

I would very much prefer that the code merged to v5.7-rc1 will be more
restrictive than the current overlayfs-next.

Thanks,
Amir.