On Mon, Jan 8, 2018 at 4:13 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > On Sat, Jan 06, 2018 at 09:38:07AM +0200, Amir Goldstein wrote: >> On Wed, Nov 29, 2017 at 5:54 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: >> > Hi, >> > >> > Please find attached V9 of the patches. Minor changes to take care of >> > Amir's comments. I have also dropped RFC tag. If there are no concerns, >> > then I would like these patches to be included. >> > >> >> Sorry Vivek, just realized some issues: >> >> 1. Considering Miklos' commit >> 438c84c2f0c7 ovl: don't follow redirects if redirect_dir=off >> It is probably not a good idea to allow lookup of metacopy unless >> metacopy=on. Is that already the behavior in V9? > > Hi Amir, > > Hmm.., no, that's not the behavior in V9. Remember, we wanted to follow > metacopy origin even if metacopy=off. That way a user can mount a > overlayfs with metacopy=off (which was previously mounted as metacopy=on) > and not be broken. > User can also mount with redirect_dir=nofollow after previously mounting with redirect_dir=on. It's the exact same thing. > If we follow metacopy only if metacopy=on, then we really need some > mechanism which can atleast warn user that this overlay mount was > mounted with metacopy=on in the past and expect some unexpected results > if mounted with metacopy=off. > > Has there been any agreement on what mechanism to use to remember what > features have been turned on existing overlay mount. > There is no agreement, but there is code in upstream that "allows" the user to make the same with redirect_dir. The consequences of this configuration is -EPERM on lookup. You actually have to allow this configuration for security reasons, the only question is whether metacopy will have 3 modes (off/follow/on) or just on/off where off implies nofollow. Amir. -- 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
