[linux-cifs-client] Re: CIFS and Windows 2003 Server shares

[Jeff Layton]

On Thu, 08 Jan 2009 15:50:06 -0500
Rob Henderson <robh at cs.indiana.edu> wrote:

> I wanted to add a 'me too' but also provide some more details about what 
> I am seeing.  Since my setup involves RHEL samba servers and RHEL cifs 
> clients it may provide a good environment for debugging.
> 
> My problem looks to be the same as Leonardo with just one slight 
> difference in that my first mount gets I/O errors rather than permission 
> denied errors after the second mount steps on it.  See below for a 
> complete transcript demonstrating the problem.
> 
> I've tested this using a diverse set of servers and clients.  I've tried 
> most combinations of the following mix of clients and servers and I have 
> yet to find any that don't fail.  It doesn't seem to matter whether I 
> have /proc/fs/cifs/MultiuserMount set to 0 or 1.
> 
> Servers:
> 
>     Red Hat EL4 running samba-3.0.28-0.el4.9 using ADS authentication 
> (security=ADS)
>     Red Hat EL5 running samba-3.0.28-1.el5_2.1 using ADS authentication 
> (security=ADS)
>     Red Hat EL5 running samba-3.0.28-1.el5_2.1 using smbpasswd 
> authentication (security=user)
>     Windows 2003 Server (R2)
> 
> Clients (with the CIFS version as reported by /proc/fs/cifs/DebugData):
> 
>     Red Hat EL4 with kernel 2.6.9-78.0.8, samba version 
> samba-3.0.28-0.el4.9, and CIFS version 1.50cRH
>     Red Hat EL5 with kernel 2.6.18-92.1.22, samba version 
> samba-3.0.28-1.el5_2.1, and CIFS version 1.50cRH
>     Red Hat EL5 with kernel 2.6.18-92.1.10, samba version 
> samba-3.0.28-1.el5_2.1, and CIFS version 1.50cRH
>     Ubuntu 8.04.1 with kernel 2.6.24-22-rt, samba version 
> 3.0.28a-1ubuntu4.7, and CIFS version 1.52
> 
> We are trying to deploy a lab of RHEL workstations that get homedirs via 
> samba+cifs from a RHEL file server with pam_mount managing the mounts at 
> login.  But, since we need to support multiple remote logins this 
> problem has us dead in the water.
> 
> I tried the equivalent patch to fs/cifs/connect.c that Leonardo 
> suggested and so far everything seems to work!  I really don't know what 
> the downside of this may be but but it _does_ seem to be working.  The 
> RHEL5 ver is a little different than the code Leonardo was dealing with 
> and here is the patch I applied:
> 
> --- fs/cifs/connect.c.orig      2009-01-08 15:05:35.000000000 -0500
> +++ fs/cifs/connect.c   2009-01-08 15:11:42.000000000 -0500
> @@ -1974,7 +1974,7 @@
>                 return -EINVAL;
>         }
>  
> -       if (srvTcp) {
> +       if (0) {
>                 cFYI(1, ("Existing tcp session with server found"));
>         } else {        /* create socket */
>                 if (volume_info.port)
> 
> 
> Please let me know if there is any further debugging information I can 
> provide.  I would also be interested to know the downside of using this 
> patch since it seems to work, albeit non-optimally.
> 

Ok,


> ======================  transcript demonstrating failure 
> ===========================
> [root at wink ~]# cat /proc/fs/cifs/MultiuserMount
> 1
> [root at wink ~]# mount -t cifs //curie.cs.indiana.edu/robh /mnt/robh -o 
> user=robh
> Password:
> [root at wink ~]# df /mnt/robh
> Filesystem           1K-blocks      Used Available Use% Mounted on
> //curie.cs.indiana.edu/robh
>                      1692109088 537737952 1068416960  34% /mnt/robh
> [root at wink ~]# cat /proc/fs/cifs/DebugData
> Display Internal CIFS Data Structures for Debugging
> ---------------------------------------------------
> CIFS Version 1.50cRH
> Active VFS Requests: 0
> Servers:
> 1) Name: 129.79.246.140  Domain: WORKGROUP Mounts: 1 OS: Unix 
>         NOS: Samba 3.0.28-1.el5_2.1     Capability: 0x80f3fd
>         SMB session status: 1   TCP status: 1
>         Local Users To Server: 1 SecMode: 0x3 Req On Wire: 0
> MIDs:
> 
> Shares:
> 1) \\curie.cs.indiana.edu\robh Uses: 1 Type: NTFS DevInfo: 0x0 
> Attributes: 0x2b
> PathComponentMax: 255 Status: 1 type: 0
> [root at wink ~]# mount -t cifs //curie.cs.indiana.edu/somebogususer 
> /mnt/somebogususer -o user=somebogususer
> Password:
> mount error 13 = Permission denied
> Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)
> 
>        -> This was just a bogus username and I just hit enter at the 
> password prompt so authentication failed
> 
> [root at wink ~]# df /mnt/robh
> df: `/mnt/robh': Input/output error
> [root at wink ~]# ls /mnt/robh
> ls: /mnt/robh: Input/output error
> [root at wink ~]# cat /proc/fs/cifs/DebugData
> Display Internal CIFS Data Structures for Debugging
> ---------------------------------------------------
> CIFS Version 1.50cRH
> Active VFS Requests: 0
> Servers:
> 1) Name: 129.79.246.140  Domain: WORKGROUP Mounts: 1 OS: Unix 
>         NOS: Samba 3.0.28-1.el5_2.1     Capability: 0x80f3fd
>         SMB session status: 2
> Shares:
> 1) \\curie.cs.indiana.edu\robh Uses: 1 Type: NTFS DevInfo: 0x0 
> Attributes: 0x2b
> PathComponentMax: 255 Status: 1 type: 0
> 
> NOTES: 
> 
>   1) It doesn't seem to matter what I do with the second mount command.  
> In this case, I just used some nonexistant username but the behavior is 
> the same if I use a real user, with or without successful authentication.
>   2) The diffs in the DebugData output show that the "SMB session 
> status" changes from 1 to 2 and the "Local Users To Server" disappears 
> as does the (empty) "MIDs:" section.
> 
> 

Rob,

Your problem sounds like a different problem from what Leonardo
described, and is probably just poor error handling in the cifs_mount
code. We've done a lot of cleanup to that code recently, so results
with more recent kernels might be better. If you have a place to test
them, please test the kernels on my people.redhat.com page and report
the results:

http://people.redhat.com/jlayton/

...they have updated CIFS code. Both the RHEL4 and RHEL5 kernels should
have the cifs_mount overhaul.

-- 
Jeff Layton <jlayton at redhat.com>