jffs2_read_dnode
ret = jffs2_read_dnode(c, f, f->metadata, (char *)&jdev, 0, f->metadata->size);
ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
ret = jffs2_read_dnode(c, f, fn, mdata, 0, mdatalen);
int jffs2_read_dnode(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
ret = jffs2_read_dnode(c, f, frag->node, buf, fragofs + frag->ofs - frag->node->ofs, readlen);