RFC: Should copy_file_range(2) work for shared memory objects?

Right now (as noted by PR#273962) copy_file_range(2)
fails for shared memory objects because there is no
vnode (f_vnode == NULL) for them and the code uses
vnodes (including a file system specific VOP_COPY_FILE_RANGE(9)).

Do you think copy_file_range(2) should work for shared memory objects?

This would require specific handling in kern_copy_file_range()
to work.  I do not think the patch would be a lot of work, but
I am not familiar with the f_ops and shared memory code.

rick