Bug 728878

Summary: Cannot establish connection with unix socket chardev after close several times
Product: Red Hat Enterprise Linux 6 Reporter: Shaolong Hu <shu>
Component: qemu-kvmAssignee: Amit Shah <amit.shah>
Status: CLOSED NOTABUG QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: high    
Version: 6.2CC: juzhang, michen, mkenneth, shuang, tburke, virt-maint
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-12-13 08:57:35 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Shaolong Hu 2011-08-08 09:17:08 UTC 
Description of problem:
---------------------------
Boot guest with virtio-serial, attached with a unix socket chardev, guest and host can communicate with it at beginning, after closing connection several times from host side, communication failed.  


Version-Release number of selected component (if applicable):
----------------------------------------------------------------
2.6.32-174.el6.x86_64
qemu-kvm-0.12.1.2-2.175.el6.x86_64


How reproducible:
------------------
100%


Steps to Reproduce:
---------------------
1.boot guest with:
#/usr/libexec/qemu-kvm -enable-kvm -M rhel6.2.0 -smp 4 -m 4G -name rhel6.1-64 -uuid 3f2ea5cd-3d29-48ff-aab2-23df1b6ae213 -drive file=RHEL-Server-6.1-64-virtio.qcow2,cache=none,if=none,rerror=stop,werror=stop,id=drive-virtio-disk0,format=qcow2 -device virtio-blk-pci,drive=drive-virtio-disk0,id=device-virtio-disk0 -netdev tap,script=/etc/qemu-ifup,id=netdev0 -device virtio-net-pci,netdev=netdev0,id=device-net0 -boot order=cd,menu=on -usb -device usb-tablet,id=input0 -spice disable-ticketing,port=5910 -monitor stdio -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5 -chardev socket,id=channel0,path=/tmp/foo,server,nowait -device virtserialport,chardev=channel0,name=port.0,bus=virtio-serial0.0,id=port0

2.in the host:
#nc -U /tmp/foo > a.out

3.in the guest:
#dd if=/dev/urandom of=test bs=1M count=100
#cat test > /dev/vport0p1

4.First time, it works fine, file cksum matches.

5.In host, stop nc by "ctrl+c", restart nc.

6.In guest:
#cat test > /dev/vport0p1

7.repeat 5-6

Actual results:
-----------------
After step 7 1-2 times, communicate failed.


Expected results:
------------------
Communication should work every time after step 7


Additional info:
Comment 3 Amit Shah 2011-12-09 13:00:51 UTC 
Do you wait for the transfer to finish each time before hitting Ctrl+C?

Or do you do it in the middle of the transfer?  If you do it in the middle, do you re-start transfer in guest, or do you let it continue?
Comment 4 Shaolong Hu 2011-12-13 08:57:35 UTC 
(In reply to comment #3)
> Do you wait for the transfer to finish each time before hitting Ctrl+C?
> 
> Or do you do it in the middle of the transfer?  If you do it in the middle, do
> you re-start transfer in guest, or do you let it continue?

I find when nc is terminated by "ctrl+c", its process will reside in system, and multiple nc processes cause connection failed, it's necessary to modify our test case to kill nc instead of "ctrl+c", close this as NOTABUG.