[linux-cifs-client] mount.cifs and dfs referrals

Igor Mammedov niallain at gmail.com
Fri Jan 30 09:38:44 GMT 2009 

Werner Maes wrote:
> I tried Jeff Layton testkernel "kernel-2.6.18-129.el5.jtltest.60.i686.rpm" for RHEL5 with CIFS version 1.56RH but with the same results. No luck...
> 
> more log info below. what's interesting are the first two lines.
> apparently it translates the AD-DOMAIN to the dfsserver (which is good). But on the dfsserver there are dfs links that refer to shares on a NAS. And it only translates once?
> 
> AD-DOMAIN ==> DFSSERVER ==> SHARE ON NASSERVER
> 
> fs/cifs/cifs_dfs_ref.c: DFS: ref path: \AD-DOMAIN\CRD\Shares
>  fs/cifs/cifs_dfs_ref.c: DFS: node path: \dfsserver.ad.icts.kuleuven.be\Shares
>  fs/cifs/cifs_dfs_ref.c: DFS: fl: 1, srv_type: 0
>  fs/cifs/cifs_dfs_ref.c: DFS: ref_flags: 0, path_consumed: 30
>  fs/cifs/cifs_dfs_ref.c: DFS: ref path: 

Full log for this bad case may be helpful, (not just some lines from it).
And a network conversation between servers with command:
 tcpdump -s0 -w /tmp/badcase.pcap port 445



> So I do mount.cifs directly on the dfsserver I get (and this works):
> 
> fs/cifs/cifs_dfs_ref.c: DFS: ref path: \dfdserver.ad.icts.kuleuven.be\Shares\
>  fs/cifs/cifs_dfs_ref.c: DFS: node path: \nasserver.ad.icts.kuleuven.be\CRD_SHARES$\
>  fs/cifs/cifs_dfs_ref.c: DFS: fl: 2, srv_type: 0
>  fs/cifs/cifs_dfs_ref.c: DFS: ref_flags: 0, path_consumed: 52
>  fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: nasserver.ad.icts.kuleuven.be to a.b.c.d (ipadress)
>  fs/cifs/cifsfs.c: Devname: \\nasserver.ad.icts.kuleuven.be\CRD_SHARES$ flags: 0 
>  fs/cifs/connect.c: CIFS VFS: in cifs_mount as Xid: 128 with uid: 0
>  fs/cifs/connect.c: Domain name set
>  fs/cifs/connect.c: prefix path /sharepoint-03
>  fs/cifs/connect.c: Username: xxxxxx
>  fs/cifs/connect.c: UNC: \\nasserver.ad.icts.kuleuven.be\CRD_SHARES$ ip: a.b.c.d
>  fs/cifs/connect.c: Socket created
> 
>  
> 
>> -----Original Message-----
>> From: Werner Maes
>> Sent: donderdag 29 januari 2009 21:07
>> To: Q (Igor Mammedov)
>> Cc: linux-cifs-client at lists.samba.org
>> Subject: RE: [linux-cifs-client] mount.cifs and dfs referrals
>>
>> What exactly do you need?
>>
>> ________________________________________
>> Van: Q (Igor Mammedov) [niallain at gmail.com]
>> Verzonden: donderdag 29 januari 2009 20:29
>> Aan: Werner Maes
>> CC: linux-cifs-client at lists.samba.org
>> Onderwerp: Re: [linux-cifs-client] mount.cifs and dfs referrals
>>
>> It is hard to comment on issue, without log and dump of the packets.
>>
>> On Thu, Jan 29, 2009 at 8:23 PM, Werner Maes
>> <Werner.Maes at icts.kuleuven.be> wrote:
>>> yes
>>>
>>> I had configured it:
>>>
>>> # cat /etc/request-key.conf
>>> create cifs.spnego * * /usr/sbin/cifs.upcall %k
>>> create dns_resolver * * /usr/sbin/cifs.upcall %k
>>>
>>> this resolved some issues e.g:
>>> I can now follow a dfs link in this mounted share:
>>>
>>> mount.cifs //dfsserver.icts.kuleuven.be/shares /mnt -o ... (dfs root
>> level)
>>> this share on the dfs-server contains dfs links and they work.
>>>
>>> HOWEVER:
>>>
>>> what does not work if I access it through the domain level e.g.:
>>>
>>> mount.cifs //AD-DOMAIN/shares /mnt
>>>
>>> the mount works without kernel failures but I can't follow the link
>>>
>>> [root at fedora10 Users]# ls
>>> ls: reading directory .: Object is remote
>>>
>>> Jan 29 17:52:43 localhost kernel: Status code returned 0xc0000257
>> NT_STATUS_PATH_NOT_COVERED
>>> (Users being a dfs link)
>>>
>>> I enabled some error logging with echo 7 > /proc/fs/cifs/cifsFYI
>>> but I can't work out what's wrong..
>>> maybe some issues with Active Directory??
>>>
>>> werner
>>>
>>>> -----Original Message-----
>>>> From: Igor Mammedov [mailto:niallain at gmail.com]
>>>> Sent: donderdag 29 januari 2009 17:56
>>>> To: Werner Maes
>>>> Cc: 'linux-cifs-client at lists.samba.org'
>>>> Subject: Re: [linux-cifs-client] mount.cifs and dfs referrals
>>>>
>>>> Werner Maes wrote:
>>>>> I also get this message
>>>>>
>>>>> CIFS VFS: dns_resolve_server_name_to_ip: unable to resolve:
>>>> xxx.icts.kuleuven.be
>>>>> CIFS VFS: compose_mount_options: Failed to resolve server part of
>>>> \\xxx.icts.kuleuven.be\share to IP
>>>>> which seems strange since I can ping the server name in question.
>>>> Check if your samba package have cifs.upcall program.
>>>> Then add into /etc/request-key.conf a line like this:
>>>>
>>>> create dns_resolver     *       *     /bla/bla/cifs.upcall %k
>>>>
>>>>
>>>>
>>>>> what does mount.cifs use for name resolution?
>>>>>
>>>>> werner
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Igor Mammedov [mailto:niallain at gmail.com]
>>>>>> Sent: donderdag 29 januari 2009 14:16
>>>>>> To: Werner Maes
>>>>>> Cc: 'linux-cifs-client at lists.samba.org'
>>>>>> Subject: Re: [linux-cifs-client] mount.cifs and dfs referrals
>>>>>>
>>>>>> At the present moment cifs is able to follow DFS links only
>> inside
>>>>>> mounted share.
>>>>>> You are attempting to mount share that itself is remote, and cifs
>>>> can't
>>>>>> do it now.
>>>>>> However there is workaround, you can find out what server works
>> as a
>>>>>> real storage
>>>>>> for your share and mount it.
>>>>>>
>>>>>> Werner Maes wrote:
>>>>>>> hello
>>>>>>>
>>>>>>> I wanted to know whether mount.cifs is able to follow dfs
>>>> referrals.
>>>>>>> On my system I get a kernel failure if I try this
>>>>>>>
>>>>>>> mount.cifs //AD-DOMAIN/DFS /mnt -o username="AD\user"
>>>>>>>
>>>>>>> /mnt seems to be mounted
>>>>>>> //xx.yy.KULEUVEN.BE/xx/ on /mnt type cifs (rw,mand)
>>>>>>>
>>>>>>> but if I do ll /mnt, I get a segmentation fault and this appears
>> in
>>>>>> dmesg (see below):
>>>>>>> so my question is: is mount.cifs able to follow dfs links like
>>>>>> smbclient can?
>>>>>>> kind regards
>>>>>>>
>>>>>>> werner
>>>>>>>
>>>>>>> kernel BUG at fs/cifs/cifs_dfs_ref.c:274!
>>>>>>> invalid opcode: 0000 [#1] SMP
>>>>>>> Modules linked in: nls_utf8 cifs fuse sunrpc ipv6 dm_multipath
>>>> uinput
>>>>>> ppdev floppy pcspkr i2c_piix4 pcnet32 mii parport_pc i2c_core
>>>> parport
>>>>>> BusLogic [last unloaded: microcode]
>>>>>>> Pid: 5110, comm: ls Not tainted (2.6.27.12-170.2.5.fc10.i686 #1)
>>>>>>> EIP: 0060:[<d09d6ef1>] EFLAGS: 00010246 CPU: 0
>>>>>>> EIP is at cifs_dfs_follow_mountpoint+0x3b/0x627 [cifs]
>>>>>>> EAX: c68ce7f8 EBX: c68ce7f8 ECX: d09ec7dc EDX: cfb85f38
>>>>>>> ESI: cfb85f38 EDI: ce5d3000 EBP: cfb85e88 ESP: cfb85e3c
>>>>>>>  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
>>>>>>> Process ls (pid: 5110, ti=cfb85000 task=c1613340
>> task.ti=cfb85000)
>>>>>>> Stack: cfb85e58 cfb85f38 cf84af68 cf84af00 ce5d3000 cfb85e70
>>>> c04a4a55
>>>>>> c06a9411
>>>>>>>        cf0565d8 cfb85edc cfb85f38 cfb85edc ce5d3000 cfb85e78
>>>> 00000000
>>>>>> 00000000
>>>>>>>        00000000 cfb85f38 ce5d3000 cfb85eb4 c049941c cfb85edc
>>>> cfb85edc
>>>>>> c68ce7f8
>>>>>>> Call Trace:
>>>>>>>  [<c04a4a55>] ? mntput_no_expire+0x1a/0xf7
>>>>>>>  [<c06a9411>] ? _spin_lock+0x8/0xb
>>>>>>>  [<c049941c>] ? do_follow_link+0xdb/0x272
>>>>>>>  [<c0499110>] ? __link_path_walk+0x5b2/0x6b5
>>>>>>>  [<c04995ff>] ? path_walk+0x4c/0x9b
>>>>>>>  [<c04997fb>] ? do_path_lookup+0x12d/0x175
>>>>>>>  [<c049a8fa>] ? user_path_at+0x3c/0x62
>>>>>>>  [<c04a4a55>] ? mntput_no_expire+0x1a/0xf7
>>>>>>>  [<c0497986>] ? mntput+0x13/0x15
>>>>>>>  [<c04a9021>] ? sys_getxattr+0x1e/0x49
>>>>>>>  [<c051edbc>] ? trace_hardirqs_on_thunk+0xc/0x10
>>>>>>>  [<c0403c6e>] ? syscall_call+0x7/0xb
>>>>>>>  =======================
>>>>>>> Code: d0 01 89 55 b8 c7 45 f0 00 00 00 00 c7 45 ec 00 00 00 00
>> 74
>>>> 11
>>>>>> 68 94 a6 9d d0 68 2f 64 9e d0 e8 82 08 cd ef 59 5e 3b 5b 18 75 04
>>>> <0f>
>>>>>> 0b eb fe e8 20 7c ff ff f6 05 00 da 9e d0 01 89 45 bc 74 21
>>>>>>> EIP: [<d09d6ef1>] cifs_dfs_follow_mountpoint+0x3b/0x627 [cifs]
>>>> SS:ESP
>>>>>> 0068:cfb85e3c
>>>>>>>
>>>>>>> Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> linux-cifs-client mailing list
>>>>>>> linux-cifs-client at lists.samba.org
>>>>>>> https://lists.samba.org/mailman/listinfo/linux-cifs-client
>>>>>> --
>>>>>>
>>>>>> Best regards,
>>>>>>
>>>>>> -------------------------
>>>>>> Igor Mammedov,
>>>>>> niallain "at" gmail.com
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>> Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
>>>>>
>>>> --
>>>>
>>>> Best regards,
>>>>
>>>> -------------------------
>>>> Igor Mammedov,
>>>> niallain "at" gmail.com
>>>>
>>>>
>>>>
>>>
>>> Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
>>>
>>>
> 
> Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
> 

-- 

Best regards,

-------------------------
Igor Mammedov,
niallain "at" gmail.com

More information about the linux-cifs-client mailing list