[Cluster-devel] Question on LVB when the node that held EX lock crash

[Eric Ren]

On 11/16/2016 04:29 PM, Eric Ren wrote:
> Hi David and all,
>
> I am debugging an issue of ocfs2 that relates to LVB value. I will try to make it a pure 
> DLM question:
>
> Two nodes (N1, N2) try to truncate the same file(R1) concurrently.
>
> N1                                         N2
> lock(R1, EX)
> changing LVB: x
>                                               lock(R1, EX)
> convert(R1, NULL)
> flush LVB
>                                               changing LVB: x -> y
>                                               crash

Hmm, here should be a long story of DLM recovery;-)

Eric
> convert(R1, EX)
> get LVB
> Qustion: what is the LVB then? x or y?
> ======
>
> Is this a valid question? or am I missing something?
>
> Looking forward your help;-)
>
> Thanks,
> Eric