ltspfsd doesn't unmount USB device

[Francis Giraldeau]

Binary package hint: ltspfs

I'm trying to use USB key with thin-client.

The key is mounted as /var/run/drives/KINGSTON and I can list the content. I tought that after 5 seconds, the mount point was unmounted. I looked to the code, and I saw that the umount should happen. So, something is going wrong, because the select timeout is never reached.

I took tcpdump to look at the network packets, and I found this :

# tcpdump -q -i eth0 port 9220
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
23:09:31.156622 IP ubuntu.local.42315 > 172.20.0.250.9220: tcp 16
23:09:31.157135 IP 172.20.0.250.9220 > ubuntu.local.42315: tcp 60
23:09:31.157155 IP ubuntu.local.42315 > 172.20.0.250.9220: tcp 0
23:09:31.656683 IP ubuntu.local.42315 > 172.20.0.250.9220: tcp 16
23:09:31.658275 IP 172.20.0.250.9220 > ubuntu.local.42315: tcp 60
23:09:31.658287 IP ubuntu.local.42315 > 172.20.0.250.9220: tcp 0

Why does the ltspfs is always sending data like this? Opened with wireshark, it seems that there is a cycle with a period of 0.5 second.

ltspfs > ltspfsd : PSH, ACK -> TCP CHECKSUM INCORRECT
ltspfsd > ltspfs : PSH, ACK
ltspfs > ltspfsd : ACK

and the cycle starts again.

Does the TCP checksum have something to do with that?

[Francis Giraldeau (francis-giraldeau)]

I'm not able to reproduce the behavior I reported yesterday. I explain that by the fact that the period of sending packets is now about 15 seconds.

I do attach the tcpdump output that is readable by wireshak.

[Oliver Grawert (ogra)]

did you check the actual mount on the client ? ltspfs's *feature* is that it unmounts the HW but keeps the visible content of the mount on teh session side persistent ... its totally fine that you see teh contentin your session as long as you see local unmounting directly on the clinet. the network mount will be removed if the device is unplugged.

[Stéphane Graber (stgraber)]

I haven't been able to reproduce that behavior with Intrepid during my tests.
Francis, can you please tell me what version of Ubuntu you were using during your tests and if whether or not it's still happening with Ubuntu ?

[Francis Giraldeau (francis-giraldeau)]

I haven't been able to reproduce that problem. If more information is available, I will reopen this issue.