Re: Why I cannot reconnect blk backend

[Wayne Gong <wayne.gong@oracle.com>]

> All I can suggest is that your turn on the logging in xenstore and watch
> what happens - looking for differences between what happens then xenvbd
> first starts up and when it resumes.
blkback: ring-ref 335, event-channel 5, protocol 1 (unspecified, 
assuming native)
vbd vbd-3-768: 1 mapping ring-ref 335 port 5
blkback: ring-ref 335, event-channel 5, protocol 1 (unspecified, 
assuming native)
vbd vbd-3-768: 1 mapping ring-ref 335 port 5
blkback: ring-ref 335, event-channel 5, protocol 1 (unspecified, 
assuming native)
vbd vbd-3-768: 1 mapping ring-ref 335 port 5

What's this mean?
I guess when vbd device resume, I use a mapped ring-ref to initialize 
device. When vbd device resume, I allocate some new memory and call 
SHARED_RING_INIT to init them and then save the ring-ref to xenstore. 
After that, xenstore pops a warning as above. How can I release that 
ring-ref when suspend vbd device, or how to reallocate a new ring-ref 
for vbd device?

Thanks
Wayne