Re: two questiones about overlayfs

[Vivek Goyal <vgoyal@redhat.com>]

On Wed, Aug 16, 2017 at 12:19:22PM +0200, Miklos Szeredi wrote:
> On Tue, Aug 15, 2017 at 6:16 PM, Amir Goldstein <amir73il@gmail.com> wrote:
> > On Tue, Aug 15, 2017 at 5:56 PM, Vivek Goyal <vgoyal@redhat.com> wrote:
> 
> >> IIUC, so now "chattr -p <id>" will fail on overlayfs (assume file has not
> >> been copied up yet).
> >>
> >
> > Yap.
> >
> >> IOW, on overlayfs, will it be responsibility of user space to make
> >> sure file has been copied up, for chattr operation to succeed? Does that
> >> mean we need to modify chattr to open file for WRITE instead of READ.
> >>
> >
> > I guess that would make sense.
> > I only wonder what was the reason for chattr to open RDONLY in
> > the first place (cc Ted)??
> 
> What about copy up of flags?  Should we?  Does reflink copy the flags?

Oh yes, copy up of flags seem to be an issue too. I have a file on lower
with project id 123 and once that file gets copied up, project id goes
back to 0.

[merged]# lsattr -p foo.txt 
  123 ------------------- foo.txt

[merged]# touch foo.txt

[merged]# lsattr -p foo.txt 
    0 ------------------- foo.txt

Vivek