[PATCH 6/7] have ckpt_err set ctx->errno

[Serge E. Hallyn]

Quoting Oren Laadan (orenl at cs.columbia.edu):
> 
> 
> serue at us.ibm.com wrote:
> > From: Serge E. Hallyn <serue at us.ibm.com>
> > 
> > Move setting of ctx->errno into do_ckpt_msg().  We leave a small separate
> > function to notify all restarting tasks in case of failure.  We use a
> > CKPT_CTX_WOKEN bit for this.  If we always notify restarting tasks of
> > failure inside do_ckpt_msg() then we will have to be more careful about
> > when ckpt_err() is called at restart.  Only 4 instances were doing the
> 
> I don't think it is wrong to notify of errors and wakeup tasks
> "too early" or multiple times. In fact, the first one to notify
> an error (test-and-set of ctx->errno) should do that. What am I
> missing ?

ckpt_err() is called before the init_completion(&complete).  We could
just make sure that never happens.

-serge