On Wed, Jul 03, 2019 at 02:43:07PM +0800, Hillf Danton wrote: > > This is very much *NOT* fine. > > 1) trylock can fail from any number of reasons, starting > > with "somebody is going through the hash chain doing a lookup on > > something completely unrelated" > > They are also a red light that we need to bail out of spiraling up > the directory hierarchy imho. Translation: "let's leak the reference to parent, shall we?" > > 2) whoever had been holding the lock and whatever they'd > > been doing might be over right after we get the return value from > > spin_trylock(). > > Or after we send a mail using git. I don't know. > > > 3) even had that been really somebody adding children in > > the same parent *AND* even if they really kept doing that, rather > > than unlocking and buggering off, would you care to explain why > > dentry_unlist() called by __dentry_kill() and removing the victim > > from the list of children would be safe to do in parallel with that? > > > My bad. I have to walk around that unsafety. WHAT unsafety? Can you explain what are you seeing and how to reproduce it, whatever it is?
