17.12 bdwrite (4836)
This procedure is called by “writei” (6311) and “bmap” (6443, 6449, 6485, 6500 and 6501 !).
4844:
Don’t delay the write if the device is a magnetic tape drive ... keep everything in order;
4847:
Set the “B_DONE”, “B_DELWRI” flags and call “brelse” to link the buffer into the “av”-list.