On Thu, Nov 09, 2017 at 11:52:48AM -0800, Linus Torvalds wrote: > Yes, getting rid of s_anon might involve crazy things like "let's just > walk all the dentries at umount time", but honestly, that sounds > preferable. Especially if we can just then do something like > > - set a special flag in the superblock if we ever use __d_obtain_alias() > > - only scan all the dentries on umount if that flag is set. > > Hmm? The scan would be extremely painful with our current global dcache. But then again the global dcache isn't exactly a good idea to start with. If we had a per-sb dcache using e.g. the resizable hash table the networking people seem to be fond off your idea would work really well.
