read_pnode: error -22 reading pnode at XX:YYYYY

[Rick Johnson]

Hi Artem,

Thanks for your advice!  We were finally able to reproduce the problem.

> 1. Validate the pnode before packing, do the same validate_pnode() does.
> May be you'll catch the place where it we write incorrect pnode. Because
> what you see is a result of an error which might have happend long
> before you hit it.

We did validate_pnode() before the pnode was packed and have this output 
from dbg_dump_pnode():

(pid 6298) dumping pnode:
	address c631d380 parent c6005720 cnext c6005720
	flags 3 iip 3 level 0 num -969086448
	0: free 0 dirty 127984 flags 1 lnum 514
	1: free 129024 dirty 0 flags 4 lnum 515
	2: free 0 dirty 127920 flags 1 lnum 516
	3: free 129024 dirty 0 flags 4 lnum 517


It looks like 'num' is not valid.  Also, is it normal for 'parent' to be 
equal to 'cnext'?

We'll continue to look into this, but I thought it wouldn't hurt to get 
your opinion on the above debug.

Thanks!
Rick