xfs_buf_get
error = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, &bp);
error = xfs_buf_get(xfbt->target, xfbno_to_daddr(bno), XFBNO_BBSIZE,
error = xfs_buf_get(mp->m_ddev_targp,
DEFINE_BUF_FLAGS_EVENT(xfs_buf_get);