Hi everyone: I have met this problem when I try to test udp6 for nfs connection, my environment is:
Server: kernel: 4.1.15 IP:xxxx::36/64 MTU:1500 Setting: /etc/exports:/home/nfs *(rw,sync,no_subtree_check,no_root_squash) Client: kernel: 4.1.18 IP:xxxx::90/64 MTU:1500 command: mount -t nfs -o vers=3,proto=udp6,rsize=4096,wsize=4096 [xxxx::36]:/home/nfs /home/tmp I check the nfs parameter configuration, it looks fine and could work well for proto=tcp6. Then I have mount correctly and try to run the command "ls", it hang. When I use the rsize=1024 and wsize=1024 to mount, the problem disappeared, so I guess it is the problem for GSO or GRO for UDP。 Then I try to debug the problem, first I tcpdump the package from cline to server, and found that the client have send readdirplus message to server correctly, and then the Server send a 4k package to client(the big package will frag to 4 package by GSO), till now it looks fine, and the Client Nic could receive the 4 skb then send to upper stack to ipv6 and udp, I found the incoming 4 package has been merged to one and send to upper stack just like sunrpc, but I try to open the rpc_debug, it looks that the rpc could not receive message. I built a simple demo to test the udp stack, use the client socket to send big package to server socket, it work well, so I think the udp is fine, maybe the bug is in sunrpc. The test is very simple, does any body met the same problem like me, thanks for any suggestion. Ding
