NFS4_FF_MIRROR_STAT_AVAIL
if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL,
set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);