> > doesn't it break EEXIST cases?
> 
> What do you mean specifically?  Trying to create a node which already
> exists on a readonly nfs mount?  Yes, I think might now return EROFS
> instead of EEXIST.  I'll revert that part.  thanks.

yes, it's what i meant.
i think it can be even worse for non-exclusive create.

YAMAMOTO Takashi