Re: [patch 01/22] update ctime and mtime for mmaped write

[Peter Staubach]

Miklos Szeredi wrote:
> > What happens if the application overwrites what it had written some
> > time later?  Nothing.  The page is already read-write, the pte dirty,
> > so even though the file was clearly modified, there's absolutely no
> > way in which this can be used to force an update to the timestamp.
> >     
>
> Which, I realize now, actually means, that the patch is wrong.  Msync
> will have to write protect the page table entries, so that later
> dirtyings may have an effect on the timestamp.

I thought that PeterZ's changes were to write-protect the page after
cleaning it so that future modifications could be detected and tracked
accordingly?  Does the right thing not happen already?

   Thanx...

      ps
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