On Mon 06-12-21 18:52:28, Matthew Wilcox wrote: > On Mon, Dec 06, 2021 at 10:35:03AM -0800, Suren Baghdasaryan wrote: > > > Other than that looks OK to me. Maybe we want to add an explicit note > > > that vm_ops::close cannot take mmap_sem in any form. The changelog > > > should also mention that you have considered remove_vma and its previous > > > no MM locking assumption. You can argue that fput is async and close > > > callback shouldn't really need mmap_sem. > > > > Should I post another version of this patch with the patch description > > clarifying these points and additional comments as you suggested? > > fyi, vm_ops->close() is already called with the mmap_sem held for write > in __split_vma(). If that needs to be documented, it's a separate patch > because it's absolutely not a consequence of this patch. Agreed! We definitely want to document that. -- Michal Hocko SUSE Labs
