patch to fix symlink-related GPFs on Linux

[Brandon S. Allbery KF8NH]

In message <lv1hg05lr86.fsf at yakko.stacken.kth.se>, Magnus Ahltorp writes:
+-----
| > Well, the problems with 0.8 I reported seem to be gone.  However, I
| > now see lockups when trying to stat a lot of files in AFS, for
| > instance by running
| > 	ls -al /afs/athena.mit.edu/user/a/m/amu
| 
| Could you try to enable xfs debugging before doing these stats? You
+--->8

BTDT (and BTW, my earlier problems all appear to be gone).  Got a solid 
lockup (while in X => not a d*mned thing I can do about it).  As far as I 
could determine, it was a complete hang --- couldn't switch VCs, all screen 
output was frozen (including xmcd and xdaliclock), etc.  Also, my background 
mail checks halted (as determined by a lack of modem activity).

So I rebooted, forced text mode, killed syslogd/klogd and replaced it with 
"tail -f /proc/klog&" (old trick from iBCS debugging :-) and used "setdebug 
on" and "arlad -n --debug='all,-cleaner'".

I couldn't even hang it with "ls /afs/andrew.cmu.edu/usr" (don't try that it 
home, kiddies!).  Took over 5 minutes, but it didn't hang....  I did try 
various other things as well, including the one that had hung me previously 
("ls -CF /afs/ece.cmu.edu/support").

Possibly relevant:  I had additionally done the above hanging "ls -CF" when 
I didn't have a token, so I got 6 permission-denieds and a listing of the 
directory.  I then obtained a token for ece.cmu.edu and retried the "ls 
-CF"; it sent/received a number of packets and then everything hung.

Possibly also relevant:  I have packet filtering in place, although UDP 
ports 7000-7006 are permitted (as is 750, obviously since I managed to get a 
token :-)


-- 
brandon s. allbery	[os/2][linux][solaris][japh]	 allbery at kf8nh.apk.net
system administrator	     [WAY too many hats]	   allbery at ece.cmu.edu
electrical and computer engineering
carnegie mellon university			   (bsa at kf8nh is still valid.)