swim3_readbit
if (swim3_readbit(fs, SEEK_COMPLETE))
ret = swim3_readbit(fs, SEEK_COMPLETE) == 0
|| swim3_readbit(fs, DISK_IN) == 0;
fs->write_prot = swim3_readbit(fs, WRITE_PROT);
if (swim3_readbit(fs, TRACK_ZERO)) {
if (swim3_readbit(fs, SEEK_COMPLETE)) {
if (swim3_readbit(fs, DISK_IN) == 0)
if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
|| swim3_readbit(fs, DISK_IN) == 0))
fs->write_prot = swim3_readbit(fs, WRITE_PROT);