On Fri, Feb 02, 2024 at 01:03:57PM +0100, Jan Kara wrote: > On Fri 26-01-24 21:08:28, Kent Overstreet wrote: > > *_lock_nested() is fundamentally broken; lockdep needs to check lock > > ordering, but we cannot device a total ordering on an unbounded number > > of elements with only a few subclasses. > > > > the replacement is to define lock ordering with a proper comparison > > function. > > > > fs/pipe.c was already doing everything correctly otherwise, nothing > > much changes here. > > > > Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> > > Cc: Christian Brauner <brauner@xxxxxxxxxx> > > Cc: Jan Kara <jack@xxxxxxx> > > Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx> > > I had to digest for a while what this new lockdep lock ordering feature is > about. I have one pending question - what is the motivation of this > conversion of pipe code? AFAIU we don't have any problems with lockdep > annotations on pipe->mutex because there are always only two subclasses? It's one of the easier conversions to do, and ideally /all/ users of subclasses would go away. Start with the easier ones, figure out those patterns, then the harder...
