Added the flexnbd break command to stop mirroring

tests/acceptance/environment.rb

@@ -42,6 +42,10 @@ class Environment
   end
 
 
+  def break1
+    @nbd1.break
+  end
+
   def acl1( *acl )
     @nbd1.acl( *acl )
   end
@@ -111,7 +115,7 @@ class Environment
   end
 
 
-  def run_fake( name, addr, port, rebind_addr = addr, rebind_port = port )
+  def run_fake( name, addr, port, rebind_addr = addr, rebind_port = port, sock=nil )
     fakedir = File.join( File.dirname( __FILE__ ), "fakes" )
     fake = Dir[File.join( fakedir, name ) + "*"].sort.find { |fn|
       File.executable?( fn )
@@ -124,7 +128,7 @@ class Environment
     raise "no rebind_port" unless rebind_port
 
     @fake_pid = fork do
-      exec [fake, addr, port, @nbd1.pid, rebind_addr, rebind_port].map{|x| x.to_s}.join(" ")
+      exec [fake, addr, port, @nbd1.pid, rebind_addr, rebind_port, sock].map{|x| x.to_s}.join(" ")
     end
     sleep(0.5)
   end

tests/acceptance/fakes/dest/break_after_hello.rb

@@ -0,0 +1,35 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+# Open a server, accept a client, then cancel the migration by issuing
+# a break command.
+
+require 'flexnbd/fake_dest'
+include FlexNBD
+
+addr, port, src_pid, _, _, sock = *ARGV
+server = FakeDest.new( addr, port )
+client = server.accept
+
+ctrl = UNIXSocket.open( sock )
+
+Process.kill("STOP", src_pid.to_i)
+ctrl.write( "break\n" )
+ctrl.close_write
+client.write_hello
+Process.kill("CONT", src_pid.to_i)
+
+fail "Unexpected control response" unless
+  ctrl.read =~ /0: mirror stopped/
+
+client2 = nil
+begin
+  client2 = server.accept( "Expected timeout" )
+  fail "Unexpected reconnection"
+rescue Timeout::Error
+  # expected
+end
+client.close
+
+exit(0)
+

tests/acceptance/flexnbd.rb

@@ -271,6 +271,11 @@ class FlexNBD
       "#{@debug} "
   end
 
+  def break_cmd
+    "#{@bin} break "\
+      "--sock #{ctrl} "\
+      "#{@debug}"
+  end
 
   def status_cmd
     "#{@bin} status "\
@@ -416,6 +421,14 @@ class FlexNBD
   end
 
 
+  def break(timeout=nil)
+    cmd = break_cmd
+    debug( cmd )
+
+    maybe_timeout( cmd, timeout )
+  end
+
+
   def acl(*acl)
     cmd = acl_cmd( *acl )
     debug( cmd )
@@ -439,6 +452,14 @@ class FlexNBD
   end
 
 
+  def paused
+    Process.kill( "STOP", @pid )
+    yield
+  ensure
+    Process.kill( "CONT", @pid )
+  end
+
+
   protected
   def control_command(*args)
     raise "Server not running" unless @pid

tests/acceptance/test_source_error_handling.rb

@@ -90,10 +90,14 @@ class TestSourceErrorHandling < Test::Unit::TestCase
   end
 
 
+  def test_cancel_migration
+    run_fake( "dest/break_after_hello" )
+  end
+
 
   private
   def run_fake(name, opts = {})
-    @env.run_fake( name, @env.ip, @env.port2 )
+    @env.run_fake( name, @env.ip, @env.port2, @env.ip, @env.port2, @env.nbd1.ctrl )
     stdout, stderr = @env.mirror12_unchecked
     assert_success
     assert_match( opts[:err], stderr ) if opts[:err]