[Samba] File locking problem involving Samba, Clearcase, and Cygwin

[Kathy]

We are having some problems in our company's test group that did not
exist when our Clearcase 2003.06 server existed on a Solaris 8
machine.  Now we are running on RHEL 5.2 with Clearcase 7.0.1.3 with
Samba 3.0.28 (despite the fact that IBM has only blessed up to 3.0.24)
and running into some file locking issues with some scripts our test
group runs.  I am hoping that someone might have some ideas.

The environment is this:  Our test group has a PC that runs VMWare
virtual machines (Windows XP).  They log into one of the virtual Win
XP machines and pop several Cygwin windows running bash.  They have
several Clearcase views that they might use at the same time but each
view used is in a different Cygwin window.  The views are located on a
RHEL 5.2 Clearcase server named Flint running Samba 3.0.28.  So, in
each Cygwin window, they will "cd
//flint/views/<view_name>/vobs/c2test/C2Testsuite"  and in there they
run some scripts that write to logs called magellan.log and
magellan.sum.  They are essentially using the views as a file server
for their test scripts.

They often run these scripts from different views at the same time,
and each script that runs runs multiple sequential tests.  Inside the
master script (simple bourne shell), after a test is complete, it
closes out the magellan.log (and .sum) files and does a "mv" to rename
the file so the next iteration can use the same name for the log file.
 (Yeah, it would be easier to just make them unique names for each
run, but this is old legacy stuff that would be a pain in the kazoo to
change, so for the moment we're trying to just fix it before
redesigning it all).

What's happening is at random times, the mv command fails and they get
permission denied because another process is holding on to the script
and sometimes in the Samba log I will see NT_STATUS_SHARING_VIOLATION,
which can make sense if another process has a lock on the file.  In
our smb.conf file, I have oplocks turned off because IBM requires this
for Clearcase:

# first statement is old and may not be obsolete but we still keep it
just in case
oplocks = no
kernel oplocks = no
level2 oplocks = no

However, as shown below, we're seeing oplocks reported and I have no
idea whether this is normal or not.  I asked a Clearcase support guy
and he did not know (sigh).  So hence I'm hoping someone here has some
experience with this.  Again, we ran this same sort of set up before
with a Solaris Clearcase/Samba server and we didn't see these
problems.  This may not be related to Clearcase at all and simply and
issue of how file locking is working between RHEL 5.2 and Samba.  What
exactly is a LEVEL_II oplock and why am I seeing these if I have Samba
oplocks turned off?

Other than this, Clearcase is operating normally and Samba is
operating normally on Flint for all other applications.  It's just
this situation where we're running these sequential scripts sitting in
side the Clearcase view via Samba.

Thanks for any insight --



Kathy





Locked files:

Pid          Uid        DenyMode   Access      R/W        Oplock           Share

Path   Name   Time

--------------------------------------------------------------------------------

------------------

12825        20191      DENY_NONE  0x20196     WRONLY     NONE             /view

   turboS_verification_1/vobs/c2test/C2Testsuite/magellan.log   Thu Jan 15 04:40

:30 2009

12825        20191      DENY_NONE  0x20196     WRONLY     EXCLUSIVE+BATCH  /view

   turboS_verification_2/vobs/c2test/C2Testsuite/cozushell.cvf   Thu Jan 15 05:1

5:59 2009

12825        20191      DENY_NONE  0x20089     RDONLY     NONE
    /view   turboS_verification_4/vobs/c2test/C2Testsuite/magellan.she

ll/S6_PU   Wed Jan 14 18:00:20 2009

12825        20191      DENY_NONE  0x20089     RDONLY     NONE
    /view   turboS_verification_1/vobs/c2test/C2Testsuite/magellan.she

ll/TURBOS_TESTSUITE   Wed Jan 14 17:54:21 2009

12825        20191      DENY_NONE  0x20089     RDONLY     LEVEL_II
    /view   turboS_verification_1/vobs/c2test/C2Testsuite/magellan.she

ll/TURBOS_TESTSUITE   Wed Jan 14 17:56:41 2009

12825        20191      DENY_NONE  0x20089     RDONLY     LEVEL_II
    /view   turboS_verification_1/vobs/c2test/C2Testsuite/magellan.she

ll/TURBOS_TESTSUITE   Wed Jan 14 17:57:23 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_4/vobs/c2test/C2Testsuite/cozushell.cv

f   Thu Jan 15 04:29:34 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_4/vobs/c2test/C2Testsuite/magellan.sum

   Thu Jan 15 04:29:34 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_1/vobs/c2test/C2Testsuite/magellan.sum

   Thu Jan 15 04:40:30 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_2/vobs/c2test/C2Testsuite/magellan.log

   Thu Jan 15 05:15:59 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_4/vobs/c2test/C2Testsuite/magellan.log

   Thu Jan 15 04:29:34 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_2/vobs/c2test/C2Testsuite/magellan.sum

   Thu Jan 15 05:15:59 2009

12825        20191      DENY_NONE  0x20196     WRONLY
EXCLUSIVE+BATCH  /view
turboS_verification_3/vobs/c2test/C2Testsuite/cozushell.cv

f   Thu Jan 15 06:30:22 2009

12825        20191      DENY_NONE  0x20196     WRONLY     LEVEL_II
    /view   turboS_verification_3/vobs/c2test/C2Testsuite/magellan.sum

   Thu Jan 15 06:30:22 2009

12825        20191      DENY_NONE  0x20196     WRONLY     LEVEL_II
    /view   turboS_verification_3/vobs/c2test/C2Testsuite/magellan.sum

   Thu Jan 15 04:40:31 2009

12825        20191      DENY_NONE  0x20196     WRONLY     NONE
    /view   turboS_verification_3/vobs/c2test/C2Testsuite/magellan.log

   Thu Jan 15 06:30:22 2009