On 06/23/2015 06:07 PM, Jan Olszak wrote:
On 06/23/2015 03:23 PM, David Howells wrote:
Jan Olszak <j.olszak@xxxxxxxxxxx> wrote:
Why not just say: "rename causes copy" and leave everything as it is
now.
That's another option - but your whole proposal was that we
specifically don't
copy up these files IIRC.
Yes, so let's modify the proposal:
Overlayfs checks xattr "trusted.overlay.cow" to switch COW off
whenever it's possible.
1. This would be an optimization/convenience option, not a security
option
2. By default overlayfs uses COW like it does now
3. trusted.overlay.cow=="n" means:
- Unlink, open, setattr etc. use the original inode from lowerdir
- Unmodifying operations also use inode from lowerdir
- Other operations (rename) may copy the file if it's required by the
implementation of overlayfs
So does it sound upstreamable?
Jan
--
To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
