Bug 677475

+++ This bug was initially created as a clone of Bug #676804 +++

Description of problem:

Running iscsid and tgtd on same machine 
the daemons logs semaphore errors

Version-Release number of selected component (if applicable):
scsi-target-utils-1.0.8-0.el5
iscsi-initiator-utils-6.2.0.872-6.el5

How reproducible: Everytime 

Steps to Reproduce:

1. Stop both services::

     $ service tgtd stop
     $ service iscsid stop

2. Start iscsid::

     $ service iscsid start

3. Start tgtd::

     $ service tgtd start

4. Stop iscsid::

     $ service stop iscsid

5. Stop tgtd::

     $ service tgtd stop

>> syslog error: **tgtd: semop up failed**

6. Start iscsid again::

     $ service iscsid start

7. Start tgtd again::

     $ service tgtd start

8. Stop tgtd::

     $ service tgtd stop

9. Stop iscsid::

     $ service iscsid stop

>> syslog error: **iscsid: semop down failed 22**

  
Actual results:

  Syslog Errors: tgtd: semop up failed
                 iscsid: semop down failed 22

Expected results: No Error Messages


Additional info:

Both services daemons does influence the semaphores of the other one?
Is it save to run both services on same machine at the same time?

Seen also this iscsid messages in syslog: **iscsid: semop down failed 43**
when doing iscisadm login/logout tests :-(But I can not reproduce)

Increased kernel.sem values to "1024 64000 256 1024" but
does not changed behavor.

--- Additional comment from roland.friedwagner.at on 2011-02-11 07:38:44 EST ---

Ok further testing reveals how to reproduce 
the **iscsid: semop down failed 43** error:

1. service tgtd stop
2. service iscsid restart

3. /usr/sbin/tgtd &>/dev/null
4. tgtadm --op delete --mode system
3. /usr/sbin/tgtd &>/dev/null
5. login to any iscsi target (xxx):
   iscsiadm --mode node --targetname=iqn.xxx --login
>> Syslog Error: iscsid: semop down failed 43
6. logout to any iscsi target (xxx):
   iscsiadm --mode node --targetname=iqn.xxx --logout
>> Syslog Error: iscsid: semop down failed 43

Until you did not restart iscsid you get the **iscsid: semop down failed 43**
on each login/logout of an iscsi target.

==> tgtd has brocken icsid semaphores??

Add.Info: same behavor with scsi-target-utils-0.0-6.20091205snap.el5_5.3

--- Additional comment from roland.friedwagner.at on 2011-02-11 11:25:25 EST ---

Created attachment 478273 [details]
SEMKEY clash with iscsid fix

--- Additional comment from roland.friedwagner.at on 2011-02-11 11:26:24 EST ---

Created attachment 478274 [details]
drbd control socket move2 /var/run

--- Additional comment from roland.friedwagner.at on 2011-02-11 11:27:33 EST ---

Created attachment 478275 [details]
SPEC File diff

--- Additional comment from roland.friedwagner.at on 2011-02-11 11:28:57 EST ---

The reason is a id collision with same SEMKEY in log.c used in 
scsi-target-utils-1.0.8-0.el5 and iscsi-initiator-utils-6.2.0.872-6.el5

I uploaded patch scsi-target-utils-fix-semkey-clash.patch to fix this!
It may be a very good thing that this fix makes it to RHN very soon,
because until than logging of iscid and tgtd is undefined/broken.

If Mike digs into sources, I suggest also to fix the nasty location
for the tgtd control socket being placed in /tmp but should be IMHO /var/run.
(Uploaded scsi-target-utils-namespace-socket-path.patch for this).

Kind Regards,
Roland

--- Additional comment from mchristi on 2011-02-14 17:28:25 EST ---

Hey Roland,

Thanks for both patches and problem analysis. Patches look ok to me.