Re: [PATCH 1/1] Char: tty_io, fix closecount counting

[Jiri Slaby <jirislaby@gmail.com>]

Jiri Slaby napsal(a):
> Jiri Slaby napsal(a):
>> This is probably a fix for an issue first reported in 2.6.18.1:
>> http://lkml.org/lkml/2006/10/20/301
>> and
>> http://marc.info/?l=linux-mips&m=118797256328587
> 
> Alan, I know, you already stated some time ago, that you don't have a 
> clue what could have caused this. Haven't you found anything since that 
> time as I think the hangup path is the only possible cause of this problem?
> 
> I've found an other one from 2.6.17-rc4:
> http://readlist.com/lists/vger.kernel.org/linux-kernel/44/220050.html
> and from 2.6.22+suse_stuff:
> http://lists.opensuse.org/opensuse-bugs/2008-04/msg05628.html
> 
> It is ever vcs1, which is /dev/console and it is the only treated 
> separately (otherwise I think we would have more (and distinct) reports 
> like this). When the console is HUPped? And what should happen with 
> openers? The 2.6.22+suse happened when sulogin /dev/console was invoked. 
> Any ideas how to track this down?
> 
>> --- a/drivers/char/tty_io.c
>> +++ b/drivers/char/tty_io.c
>> @@ -1434,9 +1434,9 @@ static void do_tty_hangup(struct work_struct *work)
>>      list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) {
>>          if (filp->f_op->write == redirected_tty_write)
>>              cons_filp = filp;
>> +        closecount++;
>>          if (filp->f_op->write != tty_write)
>>              continue;
>> -        closecount++;
>>          tty_fasync(-1, filp, 0);    /* can't block */
>>          filp->f_op = &hung_up_tty_fops;
>>      }

(Ah, btw, I've uttered this change as wrong.)