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
           end
 
-            acc
-          end
+          @folders
         end
 
         # Prepares the settings for the NFS folders, such as setting the

lib/vagrant/hosts/bsd.rb

@@ -56,9 +56,6 @@ 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")
@@ -67,5 +64,4 @@ module Vagrant
       end
     end
   end
-  end
 end

lib/vagrant/hosts/linux.rb

@@ -52,14 +52,11 @@ 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
     end
   end
-  end
 end