samba - Aug 2000 - shm_open (667) & locking_init(174), not 2.3.xx kernel

This weekend, we upgraded our server to Linux-Mandrake 7.1, which uses
a (slightly customized by Mandrake) 2.2.15 kernel. Since then, users are
unable to log in, and log.smb shows

locking/shmem_sysv_shm_open(667). Can't create or use use IPC area. Error
was File exists
locking/locking.c:locking_init(174). ERROR: Failed to initialise share
modes

There have been several messages posted about this, but all have been by
people who have upgraded to 2.3.xxx kernels, which apparently use a shm
filesystem.

I've tried the advice offered to these people (mount the shm filesystem at
/var/shm), however, this does not work--our kernel does not seem to have
been compiled to recognize/use that filesystem.

Possible thought:
. we are using Linux-Mandrake in the more "secure" mode, which locks
down
some directory/processes, etc. (for examples, users can't ps a to see
other processes, file creation modes are strict, etc.) Is it possible that
somehow samba process is unable to change the shared memory b/c of too
strict security measures?

We are using samba-2.0.7

I am *not* subscribed to that list (in the middle of this crisis right
now.) Please cc any help to joel@scw.org. *Thanks* for any timely help
with this.

[Joel Burton <joel@scw.org>]
> This weekend, we upgraded our server to Linux-Mandrake 7.1, which
> uses a (slightly customized by Mandrake) 2.2.15 kernel. Since then,
> users are unable to log in, and log.smb shows
> 
> locking/shmem_sysv_shm_open(667). Can't create or use use IPC area.
Error
> was File exists
> locking/locking.c:locking_init(174). ERROR: Failed to initialise share
> modes
Hmmmmmmmm.  You're right, this has nothing to do with the 2.3.x problem
you've heard about.  (That problem is very specific to 2.3/2.4, a side
effect of Al Viro's recent reorganization of half the VFS.)

According to `man shmget',

       EEXIST      is   returned  if  IPC_CREAT  |  IPC_EXCL  was
                   specified and the segment exists.

This is happening in `locking/shmem_sysv.c' where it fails to create
the shm segment after it has failed to open an existing one.

My guess is that the segment exists.  Stop Samba, type `ipcs' and see
if shared memory segment 0x280267 is sitting around.  If so, remove it
with `ipcrm 0x280267'.  Then restart Samba.

Peter