On Mon, Sep 17, 2007 at 10:37:56AM +0400, Pavel Emelyanov wrote: > J. Bruce Fields wrote: > > Is there a small chance that a lock may be applied after this check: > > > >> + mandatory = (inode->i_flock && MANDATORY_LOCK(inode)); > >> + > > > > but early enough that someone can still block on the lock while the file > > is still marked for mandatory locking? (And is the inode->i_flock check > > there really necessary?) > > There is, but as you have noticed:
OK, but why not just remove the inode->i_flock check there? I can't see how it helps anyway. > > Well, there are probably worse races in the mandatory locking code. > > ...there are. The inode->i_lock is protected with lock_kernel() only > and is not in sync with any other checks for inodes. This is sad :( > but a good locking for locks is to be done... I would also prefer a locking scheme that didn't rely on the BKL. That said, except for this race: > > (For example, my impression is that a mandatory lock can be applied just > > after the locks_mandatory_area() checks but before the io actually > > completes.) ... I'm not aware of other races in the existing file-locking code. It sounds like you might be. Could you give specific examples? --b. _______________________________________________ Devel mailing list Devel@openvz.org https://openvz.org/mailman/listinfo/devel
