ntfs_ib_read
err = ntfs_ib_read(icx, old_vcn, ib);
ret = ntfs_ib_read(icx, ntfs_icx_parent_vcn(icx), ib);
ret = ntfs_ib_read(icx, vcn, ib);
if (!ntfs_ib_read(ictx, vcn, ictx->ib)) {
if (!ntfs_ib_read(ictx, vcn, ictx->ib)) {
if (ntfs_ib_read(icx, vcn, ib)) {