On Tue, Nov 14, 2023 at 04:30:25PM +0800, Ian Kent wrote: > I'll prepare a patch, the main thing that I was concerned about was > > whether the cause really was NULL root_inode but Edward more or less > > tested that. One thing: that was a massaged copy of the variant in my local tree, so this > > managed_dentry_set_managed(s->s_root); might be worth an explanation; mainline has __managed_dentry_set_managed() here, and yes, it is safe since nothing can access it yet, but... it's not worth skipping on spin_lock/spin_unlock for ->d_flags update here.