Moritz Schulte <[EMAIL PROTECTED]> writes: > just out of curiosity: how should the yet-to-be-written unionfs > implement copy-on-write for file_chmod()? > > unionfs usually gives out ports to the underlying files; when in > copy-on-write mode, it should give out a port to which the user can > safely write without modifying the `real' data. In my understanding > this works, since unionfs notices at open time that the user intents > to write to the file (the O_WRITE flag is specified). > > But for file_chmod there is no O_WRITE needed, therefore unionfs is > not able to detect this `write'.
Well, copy-on-write is a nice idea, but it's not an inherent part of unionfs. If you want to catch file_* calls, then you really have to intervene in every call; you can't hand out the real ports at all. _______________________________________________ Bug-hurd mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-hurd
