Commit
64bc06bb32ee broke buffered writes to journaled files (chattr
+j): we'll try to journal the buffer heads of the page being written to
in gfs2_iomap_journaled_page_done. However, the iomap code no longer
creates buffer heads, so we'll BUG() in gfs2_page_add_databufs. Fix
that by creating buffer heads ourself when needed.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>