Re: tty->count ?

Theodore Y. Ts'o (tytso@mit.edu)
Wed, 3 Jul 1996 00:20:28 -0400


From: alan@lxorguk.ukuu.org.uk (Alan Cox)
Date: Sat, 29 Jun 1996 10:39:29 +0100 (BST)

> Warning: dev (04:da) tty->count(2) != #fd's(3) in tty_open
> Warning: dev (04:da) tty->count(2) != #fd's(3) in release_dev
>

That looks like the race condition on ttys (remember the one that caused
some of the rocketport fun). Im not sure when Ted put the fix back into the
1.3.x -> 2.0 code for generic tty drivers

The standard problem here is that you have more than one device file in
/dev referring to a pty using both the old major number #4 and the new
major numbers (#2 and #3). This causes the debugging code to screw up,
since it doesn't realize that a tty could be opened from two different
sets of (major,minor) numbers.

- Ted