[comp.dcom.lans] fuser bug/problem on AT&T STARLAN 10

norm@cfctech.UUCP (Norm Meluch) (01/28/89)

	Recent use of the fuser command on our UNIX Sys V rel 3.2 machines
(3B2/600, and 6386E WGS) has shown a problem killing starlan users.  If the
user logs into the system via a starlan device (/dev/slan??) the system
administrator cannot kill that user properly with the fuser -k /dev/slan??
command.  If this command is used the processes are killed off, and the process
table is fine, however the user still appears in the who command because
/etc/utmp is not updated properly, and they still own the device!  As far
as the user's concerned they get kicked off and all is well for them.
Furthermore, when another user logs in if they get exact same device
the who becomes fine (because the /etc/utmp table is correctly
updated) and all seems to go fine for the session.  However when they logout
the /dev/slan?? device is returned to the id of the killed user!  Not root.

	AT&T said this is a result of the fuser command kill(-9)ing the ttysrv 
parent process first before the children.  There are reportedly checks for 
some server processes (which makes the command kill child processes first)
in the fuser code just not for the ttysrv process.  Until a fix is issued
the suggested procedure is to kill all child processes of the ttysrv program
(namely /bin/sh or the like) and let the ttysrv program clean up after itself
when it detectes that the child dies. 

	Thanks for your support.


|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Norman J. Meluch ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
| Mail:uunet!sharkey!cfctech!norm                      Voice: (313) 244-1809   |
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
| Note: The opinions expressed here are in no way to be confused with valid    |
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