diff --git a/app/models/folder.rb b/app/models/folder.rb
index 2a5dff9b87b..1afb670fb7c 100644
--- a/app/models/folder.rb
+++ b/app/models/folder.rb
@@ -113,9 +113,10 @@ class Folder < ActiveRecord::Base
   def default_values
     self.last_unlock_at = self.unlock_at if self.unlock_at
     self.last_lock_at = self.lock_at if self.lock_at
-    # You can't lock or hide root folders
-    if !self.parent_folder_id && (self.locked? || self.hidden? || self.protected?)
-      self.workflow_state = 'visible'
+
+    if self.parent_folder_id.blank? && ![ROOT_FOLDER_NAME, MY_FILES_FOLDER_NAME, 'files'].include?(self.name)
+      root_folder = Folder.root_folders(context).first
+      self.parent_folder_id = root_folder.id
     end
   end
   
@@ -247,25 +248,22 @@ class Folder < ActiveRecord::Base
   end
 
   def self.root_folders(context)
-    root_folders = []
-    root_folders = context.folders.active.find_all_by_parent_folder_id(nil)
     if context.is_a? Course
-      if root_folders.select{|f| f.name == ROOT_FOLDER_NAME }.empty?
-        root_folders << context.folders.create(:name => ROOT_FOLDER_NAME, :full_name => ROOT_FOLDER_NAME, :workflow_state => "visible")
-      end
+      name = ROOT_FOLDER_NAME
     elsif context.is_a? User
-      # TODO i18n 
-      t :my_files_folder_name, 'my files'
-      if root_folders.select{|f| f.name == MY_FILES_FOLDER_NAME }.empty?
-        root_folders << context.folders.create(:name => MY_FILES_FOLDER_NAME, :full_name => MY_FILES_FOLDER_NAME, :workflow_state => "visible")
-      end
+      name = MY_FILES_FOLDER_NAME
     else
-      # TODO i18n 
-      t :files_folder_name, 'files'
-      if root_folders.select{|f| f.name == "files" }.empty?
-        root_folders << context.folders.create(:name => "files", :full_name => "files", :workflow_state => "visible")
-      end
+      name = "files"
     end
+
+    root_folders = []
+
+    Folder.unique_constraint_retry do
+      root_folder = context.folders.active.find_by_parent_folder_id_and_name(nil, name)
+      root_folder ||= context.folders.create(:name => name, :full_name => name, :workflow_state => "visible")
+      root_folders = [root_folder]
+    end
+
     root_folders
   end
   
diff --git a/db/migrate/20130122193536_remove_multiple_root_folders.rb b/db/migrate/20130122193536_remove_multiple_root_folders.rb
new file mode 100644
index 00000000000..f825007e5a3
--- /dev/null
+++ b/db/migrate/20130122193536_remove_multiple_root_folders.rb
@@ -0,0 +1,17 @@
+class RemoveMultipleRootFolders < ActiveRecord::Migration
+  tag :postdeploy
+  self.transactional = false
+
+  def self.up
+    DataFixup::RemoveMultipleRootFolders.run
+    if connection.adapter_name =~ /\Apostgresql/i
+      execute("CREATE UNIQUE INDEX CONCURRENTLY index_folders_on_context_id_and_context_type_for_root_folders ON folders(context_id, context_type) WHERE parent_folder_id IS NULL AND workflow_state != 'deleted'")
+    end
+  end
+
+  def self.down
+    if connection.adapter_name =~ /\Apostgresql/i
+      execute("DROP INDEX IF EXISTS index_folders_on_context_id_and_context_type_for_root_folders")
+    end
+  end
+end
diff --git a/lib/data_fixup/remove_multiple_root_folders.rb b/lib/data_fixup/remove_multiple_root_folders.rb
new file mode 100644
index 00000000000..4d33abe0310
--- /dev/null
+++ b/lib/data_fixup/remove_multiple_root_folders.rb
@@ -0,0 +1,68 @@
+module DataFixup::RemoveMultipleRootFolders
+  def self.run(opts = {})
+
+    limit = opts[:limit] || 1000
+
+    while (folders = Folder.find(
+      :all, :conditions => ["workflow_state != ? AND parent_folder_id IS NULL", 'deleted'],
+      :select => "context_id, context_type", :having => "count(*) > 1", :group => "context_id, context_type", :limit => limit
+      )
+    ).any? do
+
+      context_types = folders.map(&:context_type).uniq
+
+      context_types.each do |context_type|
+
+        if context_type == "Course"
+          root_folder_name = Folder::ROOT_FOLDER_NAME
+        elsif context_type == "User"
+          root_folder_name = Folder::MY_FILES_FOLDER_NAME
+        else
+          root_folder_name = "files"
+        end
+
+        context_ids = folders.select{|f| f.context_type == context_type}.map(&:context_id)
+
+        root_folders = Folder.find(:all, :conditions => [
+          "context_type = ? AND context_id IN (?) AND workflow_state != ? AND parent_folder_id IS NULL",
+          context_type, context_ids, 'deleted'
+        ])
+
+        context_ids.each do |context_id|
+
+          context_root_folders = root_folders.select{|folder| folder.context_id == context_id}
+
+          main_root_folder = context_root_folders.select{|folder|
+            folder.name == root_folder_name
+          }.sort{|f1, f2|
+            f2.attachments.count + f2.sub_folders.count <=> f1.attachments.count + f1.sub_folders.count
+          }.first
+
+          if main_root_folder.nil?
+            main_root_folder = Folder.create!(
+              :context_type => context_type, :context_id => context_id,
+              :name => root_folder_name, :full_name => root_folder_name, :workflow_state => "visible")
+            context_root_folders << main_root_folder
+          end
+
+          if context_root_folders.count > 1
+            context_root_folders.each do |folder|
+              unless folder.id == main_root_folder.id
+                Folder.transaction do
+                  if folder.attachments.count > 0 || folder.sub_folders.count > 0
+                    Folder.update_all({:parent_folder_id => main_root_folder.id}, {:id => folder.id})
+                  else
+                    Folder.update_all({:workflow_state => 'deleted'}, {:id => folder.id})
+                  end
+                end
+              end
+            end
+          end
+
+        end
+
+      end
+    end
+
+  end
+end
\ No newline at end of file
diff --git a/spec/migrations/remove_multiple_root_folders_spec.rb b/spec/migrations/remove_multiple_root_folders_spec.rb
new file mode 100644
index 00000000000..9168826787c
--- /dev/null
+++ b/spec/migrations/remove_multiple_root_folders_spec.rb
@@ -0,0 +1,214 @@
+require File.expand_path(File.dirname(__FILE__) + '/../spec_helper.rb')
+require 'db/migrate/20130122193536_remove_multiple_root_folders'
+
+
+describe 'DataFixup::RemoveMultipleRootFolders' do
+  self.use_transactional_fixtures = false
+
+  def get_root_folder_name(context)
+    if context.is_a? Course
+      root_folder_name = Folder::ROOT_FOLDER_NAME
+    elsif context.is_a? User
+      root_folder_name = Folder::MY_FILES_FOLDER_NAME
+    else
+      root_folder_name = "files"
+    end
+    root_folder_name
+  end
+
+  before :each do
+    RemoveMultipleRootFolders.down
+
+    @contexts = []
+
+    12.times do |x|
+      case x % 4
+        when 0
+          context = course
+        when 1
+          context = user
+        when 2
+          context = group
+        when 3
+          context = Account.create!
+      end
+      @contexts << context
+    end
+  end
+
+  after :each do
+    @contexts.each do |c|
+      c.folders.each do |f|
+        f.attachments.delete_all
+      end
+      Folder.delete_all(:id => c.folders.map(&:id))
+      c.delete
+    end
+    RemoveMultipleRootFolders.up
+  end
+
+  it "should remove extra root folders if they are empty" do
+    empty_folders = []
+
+    @contexts.each do |context|
+      Folder.root_folders(context)
+      empty_folders << context.folders.create!(:name => "name1")
+      empty_folders << context.folders.create!(:name => "name2")
+      empty_folders << context.folders.create!(:name => "name3")
+
+      Folder.update_all({:parent_folder_id => nil}, {:context_type => context.class.to_s, :context_id => context.id})
+
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+        context.class.to_s, context.id, 'deleted']
+      ).should == 4
+    end
+
+    DataFixup::RemoveMultipleRootFolders.run(:limit => 2)
+
+    @contexts.each do |c|
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+        c.class.to_s, c.id, 'deleted']
+      ).should == 1
+    end
+
+    empty_folders.each do |folder|
+      folder.reload
+      folder.workflow_state.should == 'deleted'
+    end
+  end
+
+  it "should move extra root folders to one root folder if they are not empty (either a sub-folder or attachment)" do
+    extra_folders = []
+
+    @contexts.each do |context|
+      Folder.root_folders(context)
+      extra_folder1 = context.folders.create!(:name => "name1")
+      extra_folders << extra_folder1
+      extra_folder1.sub_folders.create!(:name => "name2", :context => context)
+
+      extra_folder2 = context.folders.create!(:name => "name1")
+      extra_folders << extra_folder2
+      a = extra_folder2.active_file_attachments.build
+      a.context = context
+      a.uploaded_data = default_uploaded_data
+      a.save!
+
+      Folder.update_all({:parent_folder_id => nil}, {:id => [extra_folder1.id, extra_folder2.id]})
+
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+        context.class.to_s, context.id, 'deleted']
+      ).should == 3
+    end
+
+    DataFixup::RemoveMultipleRootFolders.run(:limit => 2)
+
+    @contexts.each do |c|
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+        c.class.to_s, c.id, 'deleted']
+      ).should == 1
+    end
+
+    extra_folders.each do |folder|
+      folder.reload
+      folder.workflow_state.should_not == 'deleted'
+      folder.parent_folder_id.should == Folder.root_folders(folder.context).first.id
+    end
+  end
+
+  it "should move extra root folders to the root folder with the most content" do
+    extra_folders = []
+
+    empty_root_folder_ids = []
+    root_folder_ids_with_content = []
+
+    @contexts.each do |context|
+      root_folder_name = get_root_folder_name(context)
+
+      empty_root_folder = context.folders.create!(:name => root_folder_name)
+      empty_root_folder_ids << empty_root_folder.id
+
+      root_folder_with_content = context.folders.create!(:name => root_folder_name)
+      root_folder_with_content.sub_folders.create!(:name => "name2", :context => context)
+      root_folder_ids_with_content << root_folder_with_content.id
+
+      extra_folder1 = context.folders.create!(:name => "name1")
+      extra_folders << extra_folder1
+      extra_folder1.sub_folders.create!(:name => "name2", :context => context)
+
+      extra_folder2 = context.folders.create!(:name => "name1")
+      extra_folders << extra_folder2
+      a = extra_folder2.active_file_attachments.build
+      a.context = context
+      a.uploaded_data = default_uploaded_data
+      a.save!
+
+      Folder.update_all({:parent_folder_id => nil}, {:id => [extra_folder1.id, extra_folder2.id]})
+
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+                                   context.class.to_s, context.id, 'deleted']
+      ).should == 4
+    end
+
+    DataFixup::RemoveMultipleRootFolders.run(:limit => 2)
+
+    @contexts.each do |c|
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+                                   c.class.to_s, c.id, 'deleted']
+      ).should == 1
+    end
+
+    extra_folders.each do |folder|
+      folder.reload
+      folder.workflow_state.should_not == 'deleted'
+      folder.parent_folder_id.should == Folder.root_folders(folder.context).first.id
+      empty_root_folder_ids.include?(folder.parent_folder_id).should be_false
+      root_folder_ids_with_content.include?(folder.parent_folder_id).should be_true
+    end
+  end
+
+  it "should create a new root folder with the proper name if it doesn't exist already" do
+    extra_folders = []
+
+    @contexts.each do |context|
+      root_folder_name = get_root_folder_name(context)
+      context.folders.find_by_name(root_folder_name).should be_nil
+
+      extra_folder1 = context.folders.create!(:name => "name1")
+      extra_folders << extra_folder1
+      extra_folder1.sub_folders.create!(:name => "name2", :context => context)
+
+      extra_folder2 = context.folders.create!(:name => "name1")
+      extra_folders << extra_folder2
+      a = extra_folder2.active_file_attachments.build
+      a.context = context
+      a.uploaded_data = default_uploaded_data
+      a.save!
+
+      Folder.update_all({:parent_folder_id => nil}, {:id => [extra_folder1.id, extra_folder2.id]})
+
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+                                   context.class.to_s, context.id, 'deleted']
+      ).should == 3
+    end
+
+    DataFixup::RemoveMultipleRootFolders.run(:limit => 2)
+
+    @contexts.each do |c|
+      Folder.count(:conditions => ["context_type = ? AND context_id = ? AND workflow_state != ? AND parent_folder_id IS NULL",
+                                   c.class.to_s, c.id, 'deleted']
+      ).should == 1
+
+      root_folder_name = get_root_folder_name(c)
+      c.folders.find_by_name(root_folder_name).should_not be_nil
+    end
+
+    extra_folders.each do |folder|
+      folder.reload
+      folder.workflow_state.should_not == 'deleted'
+      folder.parent_folder_id.should_not be_nil
+
+      root_folder_name = get_root_folder_name(folder.context)
+      folder.parent_folder.name.should == root_folder_name
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/models/folder_spec.rb b/spec/models/folder_spec.rb
index 1ef04d69bdf..dffbef3d531 100644
--- a/spec/models/folder_spec.rb
+++ b/spec/models/folder_spec.rb
@@ -28,30 +28,28 @@ describe Folder do
   end
   
   it "should infer its full name if it has a parent folder" do
-    f = @course.folders.create!(:name => "root")
-    f.full_name.should eql("root")
+    f = Folder.root_folders(@course).first
+    f.full_name.should eql("course files")
     child = f.active_sub_folders.build(:name => "child")
     child.context = @course
     child.save!
     child.parent_folder.should eql(f)
-    child.full_name.should eql("root/child")
+    child.full_name.should eql("course files/child")
     grandchild = child.sub_folders.build(:name => "grandchild")
     grandchild.context = @course
     grandchild.save!
-    grandchild.full_name.should eql("root/child/grandchild")
+    grandchild.full_name.should eql("course files/child/grandchild")
     great_grandchild = grandchild.sub_folders.build(:name => "great_grandchild")
     great_grandchild.context = @course
     great_grandchild.save!
-    great_grandchild.full_name.should eql("root/child/grandchild/great_grandchild")
-    child.parent_folder = nil
-    child.save!
-    child.reload
-    child.parent_folder.should be_nil
-    child.full_name.should eql("child")
+    great_grandchild.full_name.should eql("course files/child/grandchild/great_grandchild")
+
+    grandchild.parent_folder = f
+    grandchild.save!
     grandchild.reload
-    grandchild.full_name.should eql("child/grandchild")
+    grandchild.full_name.should eql("course files/grandchild")
     great_grandchild.reload
-    great_grandchild.full_name.should eql("child/grandchild/great_grandchild")
+    great_grandchild.full_name.should eql("course files/grandchild/great_grandchild")
   end
 
   it "should not allow recursive folder structures" do
@@ -100,10 +98,10 @@ describe Folder do
 
   it "should implement the not_locked scope correctly" do
     not_locked = [
-      @course.folders.create!(:name => "not locked 1"),
-      @course.folders.create!(:name => "not locked 2", :locked => false),
-      @course.folders.create!(:name => "not locked 3", :lock_at => 1.days.from_now),
-      @course.folders.create!(:name => "not locked 4", :lock_at => 2.days.ago, :unlock_at => 1.days.ago)
+      Folder.root_folders(@course).first,
+      @course.folders.create!(:name => "not locked 1", :locked => false),
+      @course.folders.create!(:name => "not locked 2", :lock_at => 1.days.from_now),
+      @course.folders.create!(:name => "not locked 3", :lock_at => 2.days.ago, :unlock_at => 1.days.ago)
     ]
     locked = [
       @course.folders.create!(:name => "locked 1", :locked => true),
@@ -113,4 +111,14 @@ describe Folder do
     @course.folders.map(&:id).sort.should == (not_locked + locked).map(&:id).sort
     @course.folders.not_locked.map(&:id).sort.should == (not_locked).map(&:id).sort
   end
+
+  it "should not create multiple root folders for a course" do
+    pending('spec requires postgres index') unless Folder.connection.adapter_name == 'PostgreSQL'
+
+    @course.folders.create!(:name => Folder::ROOT_FOLDER_NAME, :full_name => Folder::ROOT_FOLDER_NAME, :workflow_state => 'visible')
+    lambda { @course.folders.create!(:name => Folder::ROOT_FOLDER_NAME, :full_name => Folder::ROOT_FOLDER_NAME, :workflow_state => 'visible') }.should raise_error
+
+    @course.reload
+    @course.folders.count.should == 1
+  end
 end