PR bin/54222
Don't use portal_node_reclaim() inappropriately. It frees data we
did not allocate, but which might have been allocated by someone else.
While here, various other cleanups (avoid losing fd's if fork fails,
don't compose mangled st_mode S_IFMT values - puffs or's in what it
thinks is correct to the value we set, one case I saw was producing
0110600 for the mode, the 011 isn't any defined type at all - I'd
never seen ls print a '?' as the first char of ls -l output before!
This is still not really correct, but is I believe, better than before.
UnifiedSplitRaw
