Fwd: NFS4.0 rdma with referal

[gaurav gangalwar <gaurav.gangalwar@xxxxxxxxx>]

Hi,

I had one query with NFS rdma support, details mentioned in the mail, but couldn't reach out to nfs-rdma-devel@xxxxxxxxxxxxxxxxxxxxx

Please check if this is the right mailing list to ask this question, else point me to the correct mailing list.

Thanks,

Gaurav Gangalwar

---------- Forwarded message ---------
From: gaurav gangalwar <gaurav.gangalwar@xxxxxxxxx>
Date: Fri, Jan 26, 2024 at 3:14 PM
Subject: NFS4.0 rdma with referal
To: <nfs-rdma-devel@xxxxxxxxxxxxxxxxxxxxx>

Hello,

I was experimenting with Linux nfs kernel rdma with nfsref.

With direct mount NFSv4.0 it works fine with rdma

But when I add a referral using nfsref, it uses tcp for referral mount.

[root@uvm-ca102ba ~]# sudo mount -vvv -o rdma,port=20049,vers=4.0 10.53.65.28:/expdir rdma-kernel

mount.nfs: timeout set for Fri Jan 26 01:28:40 2024

mount.nfs: trying text-based options 'rdma,port=20049,vers=4.0,addr=10.53.65.28,clientaddr=10.51.43.103'

[root@uvm-ca102ba ~]# cd rdma-kernel

[root@uvm-ca102ba rdma-kernel]# find .

.

./expdir1

[root@uvm-ca102ba rdma-kernel]# nfsstat -m

/root/rdma-kernel from 10.53.65.28:/expdir

 Flags: rw,relatime,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,hard,proto=rdma,port=20049,timeo=600,retrans=2,sec=sys,clientaddr=10.51.43.103,local_lock=none,addr=10.53.65.28

/root/rdma-kernel/expdir1 from 10.53.65.36:/expdir1

 Flags: rw,relatime,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=20049,timeo=600,retrans=2,sec=sys,clientaddr=10.51.43.103,local_lock=none,addr=10.53.65.36

I am using SoftROCE and both the ips have a rdma port added for nfs.

~$ cat /proc/fs/nfsd/portlist

rdma 20049

rdma 20049

udp 2049

tcp 2049

udp 2049

tcp 2049

Attaching tcpdump also for same

Why is the client not using rdma to mount referral fs location?

Attachment: linux_kernel_40_referal.pcap
Description: Binary data