Added simple support for limiting how many machines an image can be

loaded on at once. The idea is to use this for things like rtLinux
that require a per-machine license. This mechanism is circumventable,
(for example, by simply making a second image), so it's mainly to
prevent experimenters from accidentally violating the license.

sql/database-create.sql

@@ -321,6 +321,7 @@ CREATE TABLE images (
   ezid tinyint(4) NOT NULL default '0',
   shared tinyint(4) NOT NULL default '0',
   updated datetime default NULL,
+  max_concurrent int(11) default NULL,
   PRIMARY KEY  (imagename,pid),
   KEY imageid (imageid)
 ) TYPE=MyISAM;

tbsetup/os_load.in

@@ -192,11 +192,12 @@ foreach my $node (@nodes) {
     }
     %imageid_row = $db_result->fetchhash();
 
-    my $loadpart  = $imageid_row{'loadpart'};
-    my $loadlen   = $imageid_row{'loadlength'};
-    my $imagepath = $imageid_row{'path'};
-    my $defosid   = $imageid_row{'default_osid'};
-    my $shared    = $imageid_row{'shared'};
+    my $loadpart       = $imageid_row{'loadpart'};
+    my $loadlen        = $imageid_row{'loadlength'};
+    my $imagepath      = $imageid_row{'path'};
+    my $defosid        = $imageid_row{'default_osid'};
+    my $shared         = $imageid_row{'shared'};
+    my $max_concurrent = $imageid_row{'max_concurrent'};
 
     # Check for a few errors early!
     if (!defined($imagepath)) {
@@ -208,6 +209,32 @@ foreach my $node (@nodes) {
 	    "    $imagepath does not exists or cannot be read!\n");
     }
 
+    #
+    # If there's a maxiumum number of concurrent loads listed, check to
+    # see if we'll go over the limit, by checking to see how many other
+    # nodes are currently booting thie image's default_osid. This is NOT
+    # intended to be strong enforcement of license restrictions, just a way
+    # to catch mistakes.
+    # XXX This could go outside the @nodes loop, but so could most of this
+    # stuff
+    #
+    if ($max_concurrent && !TBAdmin($UID)) {
+	# Exclude nodes in this load from the count
+	my $nodelist = join(" or ",map("node_id='$_'",@nodes));
+	if (!@nodes) {
+	    $nodelist = "1";
+	}
+	my $count_result = DBQueryFatal("select count(*) from nodes where " .
+	    "def_boot_osid='$defosid' and !($nodelist)");
+	my ($current_count) = $count_result->fetchrow();
+	if ($current_count + @nodes > $max_concurrent) {
+	    die("*** $0:\n".
+		"    This image is limited to $max_concurrent concurrent " .
+		" loads, and $current_count\nnodes are already running ".
+		" $defosid\n");
+	}
+    }
+
     #
     # Compute a maxwait time based on the image size plus a constant
     # factor for the reboot cycle. 

www/newimageid_ez.php3

@@ -345,6 +345,20 @@ function SPITFORM($formfields, $errors)
     echo "                       > Yes
               </td>
           </tr>\n";
+
+    #
+    # Maxiumum concurrent loads
+    #
+    echo "<tr>
+              <td>Maximum concurrent loads[<b>7</b>]:</td>
+              <td class=left>
+                  <input type=text
+                         name=\"formfields[max_concurrent]\"
+                         value=\"" . $formfields[max_concurrent] . "\"
+	                 size=4 maxlength=4>
+              </td>
+          </tr>\n";
+
     
     if ($isadmin) {
         #
@@ -420,6 +434,9 @@ function SPITFORM($formfields, $errors)
              <li> If you need to snapshot the entire disk (including the MBR),
                   check this option. <b>Most users will not need to check this
                   option. Please ask us first to make sure</b>.
+             <li> If your image contains software that is only licensed to run
+	  	  on a limited number of nodes at a time, you can put this
+		  number here. Most users will want to leave this option blank.
           </ol>
           </blockquote></h4>\n";
 }
@@ -620,6 +637,17 @@ if (isset($formfields[wholedisk]) &&
     $shared = 1;
 }
 
+if (isset($formfields[max_concurrent]) &&
+    strcmp($formfields[max_concurrent],"")) {
+    
+    if (!preg_match ("/^\d+$/",$formfields[max_concurrent])) {
+    	$errors["Maximum Concurrent Loads"] = "Invalid number";
+    }
+
+    $max_concurrent = "'" . $formfields[max_concurrent] . "'";
+} else {
+    $max_concurrent = "NULL";
+}
 
 #
 # If any errors, respit the form with the current values and the
@@ -693,11 +721,12 @@ if (TBValidImageID($imageid) || TBValidOSID($imageid)) {
 DBQueryFatal("INSERT INTO images ".
 	     "(imagename, imageid, ezid, description, loadpart, loadlength, ".
 	     " part" . "$bootpart" . "_osid, ".
-	     " default_osid, path, pid, shared, creator, created) ".
+	     " default_osid, path, pid, shared, creator, created, ".
+	     " max_concurrent) ".
 	     "VALUES ".
 	     "  ('$imagename', '$imageid', 1, '$description', $loadpart, ".
 	     "   $loadlen, '$imageid', '$imageid', '$path', '$pid', $shared, ".
-             "   '$uid', now())");
+             "   '$uid', now(), $max_concurrent)");
 
 DBQueryFatal("INSERT INTO os_info ".
 	     "(osname, osid, ezid, description, OS, version, path, magic, ".