1. Return zero on zero length read and writes
2. For a too large write return -EFBIG as defined in man write(2)
EFBIG An attempt was made to write a file that
exceeds the implementation-defined maximum
file size or the process's file size limit,
or to write at a position past the maximum
allowed offset.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>