make allocpool check the allocations file

as sometimes people change allocations, but not the contents of the pool
directory or the other way around. Make it check both, to ensure
someones running mkcloud is not replaced.

scripts/mkcloudhost/allocpool

@@ -5,6 +5,7 @@ use Time::HiRes qw(sleep);
 use Fcntl qw(:DEFAULT :flock);
 
 my $pooldir="$ENV{HOME}/pool";
+my $allocationsfile="$ENV{HOME}/allocations";
 my $allocname="tmpqueuesched.pid";
 # Take the oldest directory
 my @dirs= sort { (stat("$a/$allocname"))[9] <=>
@@ -19,6 +20,19 @@ sleep(rand(2)); # reduce chance of collisions with make -j
 # lock+select testdir
 my $found=0;
 foreach my $d (@dirs) {
+        # check that allocations isn't out of sync with pool
+        open my $fha, $allocationsfile or die "Error: cant read $allocationsfile";
+        my $allocationfound=0;
+        my $n=$d;
+        $n=~ s/$pooldir\///;
+        while(my $line=<$fha>) {
+                if($line =~ /^[a-z]*$n jenkins$/) {
+                        $allocationfound=1;
+                        last;
+                }
+        }
+        if(!$allocationfound) {die "Error: cant find in $allocationsfile: $n jenkins"}
+        close($fha);
         # use own allocation lock protocol
         my $a="$d/$allocname";
         sysopen my $fh, $a, O_RDWR|O_CREAT or die "cant create $a";