xrep_bufscan_advance
while ((bp = xrep_bufscan_advance(mp, &scan)) != NULL) {
while ((bp = xrep_bufscan_advance(mp, &scan)) != NULL) {
while ((bp = xrep_bufscan_advance(mp, &scan)) != NULL) {
struct xfs_buf *xrep_bufscan_advance(struct xfs_mount *mp,