Patch attached fixes the case where copy_file_range over an SMB3 mount tries to go beyond the end of file of the source file. This fixes xfstests generic/430 and generic/431 Amir's patches had added a similar change in the VFS layer, but presumably harmless to have the check in cifs.ko as well to ensure that we don't try to copy beyond end of the source file (otherwise SMB3 servers will return an error on copychunk rather than doing the partial copy (up to end of the source file) that copy_file_range expects). -- Thanks, Steve