Re: [Nfs-ganesha-devel] NFSv4 referrals not working with ganesha.

* Re: [Nfs-ganesha-devel] NFSv4 referrals not working with ganesha.
       [not found]         ` <CAD8zhTDK-x+UmHnqvKm+5hnoYmob+rOGW1XxFt37-JsDm-Px2w@mail.gmail.com>
@ 2017-11-01 14:53           ` Pradeep
  2017-11-01 15:49             ` Chuck Lever
  0 siblings, 1 reply; 4+ messages in thread
From: Pradeep @ 2017-11-01 14:53 UTC (permalink / raw)
  To: Frank Filz; +Cc: nfs-ganesha-devel, ssaurabh.wisc, linux-nfs

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Adding linux-nfs (did not work last couple of times because of email format).

 Is this supposed to work with Linux NFS clients (see the problem
description at the end of this email)?

The NFSv4 referrals with Linux clients does not work with 'stat', 'ls'
etc., But linux client follows referrals after a 'cd'. Is this the
expected behavior?

tcpdump is attached.

>>
>> On Mon, Oct 30, 2017 at 3:24 PM, Frank Filz <ffilzlnx@mindspring.com>
>> wrote:
>>>
>>> Oh, I had forgotten about that patch…
>>>
>>>
>>>
>>> Can you try any other clients? This may be a client issue (I did see some
>>> suspicious code in the client).
>>>
>>>
>>>
>>> It may also be that you need a fully qualified path (starting with a /).
>>>
>>>
>>>
>>> It looks like Ganesha is doing the right thing though.
>>>
>>>
>>>
>>> Frank
>>>
>>>
>>>
>>> From: Pradeep [mailto:pradeep.thomas@gmail.com]
>>> Sent: Monday, October 30, 2017 2:21 PM
>>> To: Frank Filz <ffilzlnx@mindspring.com>
>>> Cc: nfs-ganesha-devel <nfs-ganesha-devel@lists.sourceforge.net>;
>>> ssaurabh.wisc@gmail.com
>>> Subject: Re: [Nfs-ganesha-devel] NFSv4 referrals not working with
>>> ganesha.
>>>
>>>
>>>
>>> Hi Frank,
>>>
>>>
>>>
>>> This is with latest version of Ganesha. The referral support is already
>>> in VFS: https://review.gerrithub.io/c/353684
>>>
>>>
>>>
>>> tcpdump is attached. From the tcpdump, we can see that the stat sent a
>>> LOOKUP for the remote export and received a moved error. It also sent back
>>> the fs_locations. But the client (CentOS 7.3) never followed that with a
>>> LOOKUP to the remote server.
>>>
>>>
>>>
>>> You can see that packet #41 has the correct FS locations. But client does
>>> not do another lookup to get the correct attributes.
>>>
>>>
>>>
>>> $ stat /mnt/nfs_d1
>>>
>>>   File: ‘/mnt/nfs_d1’
>>>
>>>   Size: 0               Blocks: 0          IO Block: 1048576 directory
>>>
>>> Device: 28h/40d Inode: 1           Links: 2
>>>
>>> Access: (0555/dr-xr-xr-x)  Uid: (4294967294/ UNKNOWN)   Gid: (4294967294/
>>> UNKNOWN)
>>>
>>> Context: system_u:object_r:nfs_t:s0
>>>
>>> Access: 1969-12-31 16:00:00.000000000 -0800
>>>
>>> Modify: 1969-12-31 16:00:00.000000000 -0800
>>>
>>> Change: 1969-12-31 16:00:00.000000000 -0800
>>>
>>>  Birth: -
>>>
>>>
>>>
>>>
>>>
>>> On Mon, Oct 30, 2017 at 12:13 PM, Frank Filz <ffilzlnx@mindspring.com>
>>> wrote:
>>>
>>> What version of Ganesha? I assume by “native” FSAL, you mean FSAL_VFS?
>>> Did you add the fs locations XATTR support? FSAL_GPFS currently has the only
>>> in-tree referral support and I’m not sure it necessarily works, but I’m
>>> unable to test it.
>>>
>>>
>>>
>>> If you have code for FSAL_VFS to add the fs locations attribute, go ahead
>>> and post it and I could poke at it.
>>>
>>>
>>>
>>> Also, tcpdump traces might help understand what is going wrong.
>>>
>>>
>>>
>>> Frank
>>>
>>>
>>>
>>> From: Pradeep [mailto:pradeep.thomas@gmail.com]
>>> Sent: Monday, October 30, 2017 11:45 AM
>>> To: nfs-ganesha-devel <nfs-ganesha-devel@lists.sourceforge.net>
>>> Cc: ssaurabh.wisc@gmail.com
>>> Subject: [Nfs-ganesha-devel] NFSv4 referrals not working with ganesha.
>>>
>>>
>>>
>>> Hi all,
>>>
>>>
>>>
>>> We are testing NFSv4 referral for Linux CentOS 7 with nfs-ganesha and are
>>> running
>>>
>>> into some serious issues.
>>>
>>>
>>>
>>> Although, we were able to set up NFSv4 referral using the native Ganesha
>>> FSAL,
>>>
>>> we could not get it fully functional for all Linux client system calls.
>>>
>>> Basically, the NFSv4 spec suggests to return a NFS4ERR_MOVED on a
>>>
>>> LOOKUP done for a remote export. However, this breaks the `stat` system
>>> call on
>>>
>>> Linux CentOS 7 (stat’ results in a LOOKUP,GETFH,GETATTR compound). An
>>> easy way to
>>>
>>> reproduce the broken behavior is:
>>>
>>> 1) mount the root of the pseudo file system and
>>>
>>> 2) issue a `stat` command on the remote export.
>>>
>>> The stat returned are corrupt.
>>>
>>>
>>>
>>> After digging into the CentOS 7 client code, we realized that the stat
>>> operation
>>>
>>> is never expected to follow the referral. However, switching to returning
>>> NFS4_OK
>>>
>>> for stat, then breaks `cd` or a `ls -l` command, because now we don't
>>> know when
>>>
>>> to follow the referral.
>>>
>>>
>>>
>>> Does anyone have a successful experience in setting up the NFSv4
>>> referrals that
>>>
>>> they could share? Or, if some suggestions on what we might be doing
>>> wrong?
>>>
>>>
>>>
>>> Thanks
>>>
>>>
>>>
>>> Virus-free. www.avast.com
>>>
>>>
>>
>>
>

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