> >> Here's a further version of the patch, against 2.6.26rc2, with the > >> 2008-05-19 git changes you sent me applied. This patch is based on > >> the draft patch you sent me. I've tested this version of the patch, > >> and it works as for all cases except the one mentioned below. But > >> note the following points: > >> > >> 1) I didn't make use of the code in notify_change() that checks > >> IS_IMMUTABLE() and IS_APPEND() (i.e., I did not add > >> ATTR_OWNER_CHECK to the mask in the controlling if statement). > >> Doing this can't easily be made to work for the > >> do_futimes() case without reworking the arguments passed to > >> notify_change(). Actually, I'm inclined to doubt whether it > >> is a good idea to try to roll that check into notify_change() -- > >> at least for utimensat() it seems simpler to not do so. > > > > Ugh... Could we just omit this part (the if !times and write error > > then check owner)? I know it was my idea, but > > > > a) my ideas are often stupid > > b) one patch should ideally do just one thing > > > > After we fixed the original issue, we can still think about this other > > thing :) > > Okay, by now quite a bit of my time has been wasted, and my patience > is starting to get a little thin. I understand your frustration, but actually I did say this the last time as well: "Sorry, that was just an idea, but since it's not as simple as it should be, I guess we should leave that till later. My main objection was against introducing more is_owner_or_cap() checks. Just doing the times == NULL case with ATTR_OWNER_CHECK should be fine." Yeah, I may have been more explicit... > The relevant interfaces here are: > > utimensat() > futimesat() > utime() > utimes() > futimens() -- because implemented in glibc via utimensat() with path==NULL. > > * utime() and utimes() can't be affected by this point: they don't use > file descriptors. OK, you're right. I've overlooked this point. So as long as we believe that nobody is using the futime*() interfaces in the way you described, which is highly probable, then we can fix that as well. Which is actually a nice thing, because it means the permission checking for the times == NULL case can move from both do_utimes_name() and do_futimes() into utimes_common(). So let's make two patches, and let's forget about the write_error thing for now: 1) - turn UTIME_NOW/UTIME_NOW into times = NULL - for times != NULL set ATTR_OWNER_CHECK 2) - move times == NULL permission check into utimes_common. For 2) you can just use permission() instead of vfs_permission() which is exactly the same in this case (and consolidated into a common function later in the vfs-cleanups tree). OK? Thanks, Miklos -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
