nfsclient: flush dirty pages of the vnode before ncl_flush() when done to ensure that the server sees our cached data. Convert LK_SHARED invp lock into LK_EXCLUSIVE if needed to call vm_object_page_clean(). Otherwise server-side copy makes the client cache inconsistent with the server data.
nfsclient copy_file_range(): flush dst vnode data Otherwise server-side copy makes the client cache inconsistent with the server data.