Add serialization (the usual locking code) to prevent corruption of

the .htpasswd file on ops. Note that I have disabled registration and
password changes from the twiki interface on ops for now. I'll think
about this as needed.

wiki/addwikiuser.in

@@ -6,6 +6,7 @@
 #
 use English;
 use Getopt::Std;
+use Fcntl ':flock';
 
 #
 # Add a user to the wiki on ops. Also allow update of password.
@@ -29,6 +30,7 @@ my $BOSSNODE	= "@BOSSNODE@";
 my $WIKISUPPORT = @WIKISUPPORT@;
 my $SSH         = "$TB/bin/sshtb";
 my $WIKIPROXY   = "$TB/sbin/wikiproxy";
+my $lockfile    = "/var/tmp/testbed_wikiuser_lockfile";
 
 #
 # Untaint the path
@@ -102,6 +104,70 @@ else {
     die("Bad data in user: $user.");
 }
 
+#
+# We need to serialize this script to avoid a trashed map file. Use
+# a dummy file in /var/tmp, opened for writing and flock'ed. 
+#
+if (1) {
+    open(LOCK, ">>$lockfile") || fatal("Couldn't open $lockfile\n");
+    $count = 0;
+    if (flock(LOCK, LOCK_EX|LOCK_NB) == 0) {
+	#
+	# If we don't get it the first time, we wait for:
+	# 1) The lock to become free, in which case we do our thing
+	# 2) The time on the lock to change, in which case we wait for that process
+	#    to finish
+	#
+	my $oldlocktime = (stat(LOCK))[9];
+	my $gotlock = 0;
+	while (1) {
+	    print "Another exports update in progress, ".
+		"waiting for it to finish\n";
+	    if (flock(LOCK, LOCK_EX|LOCK_NB) != 0) {
+		# OK, got the lock, we can do what we're supposed to
+		$gotlock = 1;
+		last;
+	    }
+	    $locktime = (stat(LOCK))[9];
+	    if ($locktime != $oldlocktime) {
+		$oldlocktime = $locktime;
+		last;
+	    }
+	    if ($count++ > 20)  {
+		fatal("Could not get the lock after a long time!\n");
+	    }
+	    sleep(1);
+	}
+
+	$count = 0;
+	#
+	# If we didn't get the lock, wait for the processes that did to finish
+	#
+	if (!$gotlock) {
+	    while (1) {
+		if ((stat(LOCK))[9] != $oldlocktime) {
+		    exit(0);
+		}
+		if (flock(LOCK, LOCK_EX|LOCK_NB) != 0) {
+		    close(LOCK);
+		    exit(0);
+		}
+		if ($count++ > 30)  {
+		    fatal("Process with the lock did not finish ".
+			  "after a long time!\n");
+		}
+		sleep(1); 
+	    }
+	}
+    }
+}
+
+#
+# Perl-style touch(1)
+#
+my $now = time;
+utime $now, $now, $lockfile;
+
 #
 # This script always does the right thing, so no permission checks.
 # In fact, all it does it call over to ops to run a script over there.
@@ -123,6 +189,10 @@ if (!$query_result->numrows) {
 my ($wikiname,$usr_name,$usr_email) = $query_result->fetchrow_array();
 
 if (!defined($wikiname)) {
+    # In update mode, do nothing if no wikiname.
+    exit(0)
+	if ($update);
+    
     my @tokens = split(/\s+|-/, $usr_name);
 
     #

wiki/delwikiuser.in

@@ -6,6 +6,7 @@
 #
 use English;
 use Getopt::Std;
+use Fcntl ':flock';
 
 #
 # Delete a user from the wiki
@@ -28,6 +29,7 @@ my $BOSSNODE	= "@BOSSNODE@";
 my $WIKISUPPORT = @WIKISUPPORT@;
 my $SSH         = "$TB/bin/sshtb";
 my $WIKIPROXY   = "$TB/sbin/wikiproxy";
+my $lockfile    = "/var/tmp/testbed_wikiuser_lockfile";
 
 #
 # Untaint the path
@@ -98,6 +100,70 @@ else {
     die("Bad data in user: $user.");
 }
 
+#
+# We need to serialize this script to avoid a trashed map file. Use
+# a dummy file in /var/tmp, opened for writing and flock'ed. 
+#
+if (1) {
+    open(LOCK, ">>$lockfile") || fatal("Couldn't open $lockfile\n");
+    $count = 0;
+    if (flock(LOCK, LOCK_EX|LOCK_NB) == 0) {
+	#
+	# If we don't get it the first time, we wait for:
+	# 1) The lock to become free, in which case we do our thing
+	# 2) The time on the lock to change, in which case we wait for that process
+	#    to finish
+	#
+	my $oldlocktime = (stat(LOCK))[9];
+	my $gotlock = 0;
+	while (1) {
+	    print "Another exports update in progress, ".
+		"waiting for it to finish\n";
+	    if (flock(LOCK, LOCK_EX|LOCK_NB) != 0) {
+		# OK, got the lock, we can do what we're supposed to
+		$gotlock = 1;
+		last;
+	    }
+	    $locktime = (stat(LOCK))[9];
+	    if ($locktime != $oldlocktime) {
+		$oldlocktime = $locktime;
+		last;
+	    }
+	    if ($count++ > 20)  {
+		fatal("Could not get the lock after a long time!\n");
+	    }
+	    sleep(1);
+	}
+
+	$count = 0;
+	#
+	# If we didn't get the lock, wait for the processes that did to finish
+	#
+	if (!$gotlock) {
+	    while (1) {
+		if ((stat(LOCK))[9] != $oldlocktime) {
+		    exit(0);
+		}
+		if (flock(LOCK, LOCK_EX|LOCK_NB) != 0) {
+		    close(LOCK);
+		    exit(0);
+		}
+		if ($count++ > 30)  {
+		    fatal("Process with the lock did not finish ".
+			  "after a long time!\n");
+		}
+		sleep(1); 
+	    }
+	}
+    }
+}
+
+#
+# Perl-style touch(1)
+#
+my $now = time;
+utime $now, $now, $lockfile;
+
 #
 # This script always does the right thing, so no permission checks.
 # In fact, all it does it call over to ops to run a script over there.