Re: [PATCH] cifs: Fix oops due to uncleared server->smbd_conn in reconnect

[Tom Talpey <tom@talpey.com>]

On 1/26/2023 10:20 AM, David Howells wrote:
> Tom Talpey <tom@talpey.com> wrote:
> 
>> Do you have any logging from the softRoCE runs? I'd suspect some
>> kind of RDMA-specific scatter/gather overflow which might be
>> server-side as easily as client-side.
>>
>> On client, try:
>>    echo 0x1ff >/sys/module/cifs/parameters/smbd_logging_class
>>
>> On server:
>>     ksmbd.control -d conn
>>     ksmbd.control -d rdma
> 
> Okay, on -rc5 without my patches, using:
> 
> # rdma link add rxe0 type rxe netdev enp6s0 # andromeda, softRoCE
> # mount //192.168.6.1/test /xfstest.test -o user=shares,pass=foobar,rdma
> # dd if=/dev/zero of=/xfstest.test/hello2 bs=16k count=1 oflag=direct conv=notrunc seek=2
> 
> the dd hangs.  I've captured the client and server logging you requested plus
> a pcap file on the server (see attached).
> 
> Note also I tried md5summing a 1MiB file and that produced a different MD5 sum
> each time.  I couldn't see enough data being transferred in the pcap to
> indicate that that was happening.

It looks like the server is seeing transmit timeouts on its responses,
there are 7 of these in server-log.txt:

[3700697.936899] ksmbd: smb_direct: read/write error. opcode = 0, status 
= transport retry counter exceeded(12)
[3700697.937043] ksmbd: Failed to send message: -107

Maybe this is a softiWARP issue?