Always clear NFS exports for the VM booting [GH-529]

lib/vagrant/action/vm/nfs.rb

@@ -60,19 +60,19 @@ module Vagrant
         # task.
         def extract_folders
           # Load the NFS enabled shared folders
-          @folders = @env[:vm].config.vm.shared_folders.inject({}) do |acc, data|
-            key, opts = data
-
+          @folders = {}
+          @env[:vm].config.vm.shared_folders.each do |name, opts|
             if opts[:nfs]
               # Duplicate the options, set the hostpath, and set disabled on the original
               # options so the ShareFolders middleware doesn't try to mount it.
-              acc[key] = opts.dup
-              acc[key][:hostpath] = File.expand_path(opts[:hostpath], @env[:root_path])
+              opts = opts.dup
+              opts[:hostpath] = File.expand_path(opts[:hostpath], @env[:root_path])
               opts[:disabled] = true
+              @folders[key] = opts
             end
-
-            acc
           end
+
+          @folders
         end
 
         # Prepares the settings for the NFS folders, such as setting the

lib/vagrant/hosts/bsd.rb

@@ -56,14 +56,10 @@ module Vagrant
         return if !File.exist?("/etc/exports")
 
         retryable(:tries => 10, :on => TypeError) do
-          system("cat /etc/exports | grep 'VAGRANT-BEGIN: #{id}' > /dev/null 2>&1")
-
-          if $?.to_i == 0
-            # Use sed to just strip out the block of code which was inserted
-            # by Vagrant, and restart NFS.
-            system("sudo sed -e '/^# VAGRANT-BEGIN: #{id}/,/^# VAGRANT-END: #{id}/ d' -ibak /etc/exports")
-            system(@nfs_restart_command)
-          end
+          # Use sed to just strip out the block of code which was inserted
+          # by Vagrant, and restart NFS.
+          system("sudo sed -e '/^# VAGRANT-BEGIN: #{id}/,/^# VAGRANT-END: #{id}/ d' -ibak /etc/exports")
+          system(@nfs_restart_command)
         end
       end
     end

lib/vagrant/hosts/linux.rb

@@ -52,13 +52,10 @@ module Vagrant
 
       def nfs_cleanup(id)
         return if !File.exist?("/etc/exports")
-        system("cat /etc/exports | grep 'VAGRANT-BEGIN: #{id}' > /dev/null 2>&1")
 
-        if $?.to_i == 0
-          # Use sed to just strip out the block of code which was inserted
-          # by Vagrant
-          system("sudo sed -e '/^# VAGRANT-BEGIN: #{id}/,/^# VAGRANT-END: #{id}/ d' -ibak /etc/exports")
-        end
+        # Use sed to just strip out the block of code which was inserted
+        # by Vagrant
+        system("sudo sed -e '/^# VAGRANT-BEGIN: #{id}/,/^# VAGRANT-END: #{id}/ d' -ibak /etc/exports")
       end
     end
   end