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

[Kathy]

I wanted to post again with the results of using Samba 3.2.8.  Looks
like this did not solve our "locking" problem.  We are still getting
permission denied errors when we try to do a "mv" of a log file inside
a Clearcase view via a Samba share to a different location.  Again,
this is inside a Cygwin window on a WindowsXP virtual machine.  It is
referencing a Clearcase dynamic view via Samba on
//server/<view_name>.   It does not matter if you try to move it to
another Clearcase view (i.e. //server/views/<ccase_view_name/<dir>) or
if you try to move it to a Windows share or even to the local drive.
Below is a snippet of what the Samba log shows when these two files
can't be moved.  ProcessExplorer program on the Windows XP machine did
not show file handle holding on to either of these files.  Smbstatus
on the RHEL 5.2 Clearcase/Samba server reported NONE for oplocks,
WRONLY for R/W, and DENY_NONE on DenyMode.

We are now running new tests where the scripts are writing the logs to
a Samba share, but not to a share that is also a Clearcase view.  And
if we still have issues we are going to then have the logs write to a
local drive, leaving Samba completely out of it for the part of
writing logs.  (They will still be inside the CC view via Samba when
firing off their scripts.)

Kathy

[2009/02/10 09:09:31,  3] smbd/sec_ctx.c:set_sec_ctx(324)

  setting sec ctx (20191, 1600) - sec_ctx_stack_ndx = 0

[2009/02/10 09:09:31,  3] smbd/dosmode.c:unix_mode(124)

  unix_mode(turbo_verification_2/vobs/c2test/C2Testsuite/magellan.sum)
returning 0664

[2009/02/10 09:09:31,  3] smbd/error.c:error_packet_set(61)

  error packet at smbd/nttrans.c(532) cmd=162 (SMBntcreateX)
NT_STATUS_SHARING_VIOLATION

[2009/02/10 09:09:31,  3] smbd/process.c:process_smb(1550)

  Transaction 29647671 of length 238 (0 toread)

[2009/02/10 09:09:31,  3] smbd/process.c:switch_message(1361)

  switch message SMBtrans2 (pid 5039) conn 0x927e338

[2009/02/10 09:09:31,  3] smbd/trans2.c:call_trans2qfilepathinfo(3929)

  call_trans2qfilepathinfo: TRANSACT2_QPATHINFO: level = 1004

[2009/02/10 09:09:31,  3] smbd/trans2.c:call_trans2qfilepathinfo(4043)

  call_trans2qfilepathinfo
turbo_verification_3/vobs/c2test/C2Testsuite/mModeBasicMsrmnt_C25_ICT_NTSC.sum
(fnum = -1) level=1004 call=5 total_data=0

[2009/02/10 09:09:31,  3] smbd/process.c:process_smb(1550)

  Transaction 29647672 of length 238 (0 toread)

[2009/02/10 09:09:31,  3] smbd/process.c:switch_message(1361)

  switch message SMBtrans2 (pid 5039) conn 0x927e338

[2009/02/10 09:09:31,  3] smbd/trans2.c:call_trans2qfilepathinfo(3929)

  call_trans2qfilepathinfo: TRANSACT2_QPATHINFO: level = 1004

[2009/02/10 09:09:31,  3] smbd/trans2.c:call_trans2qfilepathinfo(4043)

  call_trans2qfilepathinfo
turbo_verification_3/vobs/c2test/C2Testsuite/mModeBasicMsrmnt_C25_ICT_NTSC.sum
(fnum = -1) level=1004 call=5 total_data=0

[2009/02/10 09:09:31,  3] smbd/process.c:process_smb(1550)

<snip>

[2009/02/10 09:09:33,  3] smbd/dosmode.c:unix_mode(124)

  unix_mode(turbo_verification_3/vobs/c2test/C2Testsuite/mModeBasicMsrmnt_C25_ICT_NTSC.sum)
returning 0664

[2009/02/10 09:09:33,  3] smbd/error.c:error_packet_set(61)

  error packet at smbd/nttrans.c(532) cmd=162 (SMBntcreateX)
NT_STATUS_SHARING_VIOLATION

[2009/02/10 09:09:33,  3] smbd/process.c:process_smb(1550)

  Transaction 29647927 of length 206 (0 toread)

[2009/02/10 09:09:33,  3] smbd/process.c:switch_message(1361)

  switch message SMBntcreateX (pid 5039) conn 0x927e338

[2009/02/10 09:09:33,  3] smbd/dosmode.c:unix_mode(124)



>
> On 2/6/09, Brian Cowan <brcowan at gmail.com> wrote:
> > Kathy, I work in ClearCase support, and this construct is not supported by
> > IBM. It's not a tested configuration. There is a mechanism -- export_mvfs --
> > that allows hosts that do not have ClearCase installed to access files in
> > dynamic views via NFS. You are trying to accomplish the same thing by
> > sharing the MVFS root (/view -- translation for non-CC people: Think
> > "path=/net"). Is there a pressing reason for doing this? Wouldn't it be
> > simpler to install ClearCase on the PC's and access the files through the
> > Windows-Native MVFS (which in turn would access the VOBs on your VOB
> > server)?
> >
> > That being said, I doubt that it's the MVFS confusing Samba, but it is
> > possible. If this turns out to be a load-related issue, the MVFS may show
> > this issue more often because it does a lot more under the hood than most
> > filesystems (version selection, getting cleartext constructed, etc). I would
> > recommend testing to see if you can make the same thing happen with files
> > in:
> > 1) A local filesystem
> > 2) a remote NFS-mounted filesystem.
> >
> > You may need to increase the load on the Samba server 2-fold or more to get
> > it to "fall over" in the same way, but definitely try. If so, then ClearCase
> > has been eliminated from the picture and you can start trying various
> > debugging tricks to see why Samba thinks some users have oplocks when they
> > shouldn't.
> >
> > By the way, I suspect that you have a case open with us about this issue, if
> > so, can you send me the PMR number?
> >
>