On Sat, 22 Feb 2025, Al Viro wrote: > On Fri, Feb 21, 2025 at 10:36:30AM +1100, NeilBrown wrote: > > > +In general, filesystems which use d_instantiate_new() to install the new > > +inode can safely return NULL. Filesystems which may not have an I_NEW inode > > +should use d_drop();d_splice_alias() and return the result of the latter. > > IMO that's a bad pattern, _especially_ if you want to go for "in-update" > kind of stuff later. Agreed. I have a draft patch to change d_splice_alias() and d_exact_alias() to work on hashed dentrys. I thought it should go after these mkdir patches rather than before. Thanks, NeilBrown > > That's pretty much the same thing as d_drop()/d_rehash() window. > > We'd be better off dropping that BUG_ON() in d_splice_alias() and teaching > __d_add() to handle the "it's a hashed negative" case. >