Merge branch 'bvl-rollback-renamed-system-namespace' into 'master'

Don't rename system when migrating from 9.x -> 9.4

Closes #35525 and #36148

See merge request !13228

25 files changed, 251 insertions, 524 deletions

diff --git a/app/uploaders/personal_file_uploader.rb b/app/uploaders/personal_file_uploader.rb
index ef70871624b..3298ad104ec 100644
--- a/app/uploaders/personal_file_uploader.rb
+++ b/app/uploaders/personal_file_uploader.rb
@@ -4,7 +4,7 @@ class PersonalFileUploader < FileUploader
   end
 
   def self.base_dir
-    File.join(root_dir, 'system')
+    File.join(root_dir, '-', 'system')
   end
 
   private
diff --git a/changelogs/unreleased/bvl-rollback-renamed-system-namespace.yml b/changelogs/unreleased/bvl-rollback-renamed-system-namespace.yml
new file mode 100644
index 00000000000..a24cc7a1c43
--- /dev/null
+++ b/changelogs/unreleased/bvl-rollback-renamed-system-namespace.yml
@@ -0,0 +1,4 @@
+---
+title: Don't rename namespace called system when upgrading from 9.1.x to 9.5
+merge_request: 13228
+author:
diff --git a/config/routes/uploads.rb b/config/routes/uploads.rb
index e9c9aa8b2f9..d7bca8310e4 100644
--- a/config/routes/uploads.rb
+++ b/config/routes/uploads.rb
@@ -5,12 +5,12 @@ scope path: :uploads do
       constraints:  { model: /note|user|group|project/, mounted_as: /avatar|attachment/, filename: /[^\/]+/ }
 
   # show uploads for models, snippets (notes) available for now
-  get 'system/:model/:id/:secret/:filename',
+  get '-/system/:model/:id/:secret/:filename',
     to: 'uploads#show',
     constraints: { model: /personal_snippet/, id: /\d+/, filename: /[^\/]+/ }
 
   # show temporary uploads
-  get 'system/temp/:secret/:filename',
+  get '-/system/temp/:secret/:filename',
     to: 'uploads#show',
     constraints: { filename: /[^\/]+/ }
 
diff --git a/db/migrate/20170316163800_rename_system_namespaces.rb b/db/migrate/20170316163800_rename_system_namespaces.rb
deleted file mode 100644
index 9e9fb5ac225..00000000000
--- a/db/migrate/20170316163800_rename_system_namespaces.rb
+++ /dev/null
@@ -1,231 +0,0 @@
-# See http://doc.gitlab.com/ce/development/migration_style_guide.html
-# for more information on how to write migrations for GitLab.
-class RenameSystemNamespaces < ActiveRecord::Migration
-  include Gitlab::Database::MigrationHelpers
-  include Gitlab::ShellAdapter
-  disable_ddl_transaction!
-
-  class User < ActiveRecord::Base
-    self.table_name = 'users'
-  end
-
-  class Namespace < ActiveRecord::Base
-    self.table_name = 'namespaces'
-    belongs_to :parent, class_name: 'RenameSystemNamespaces::Namespace'
-    has_one :route, as: :source
-    has_many :children, class_name: 'RenameSystemNamespaces::Namespace', foreign_key: :parent_id
-    belongs_to :owner, class_name: 'RenameSystemNamespaces::User'
-
-    # Overridden to have the correct `source_type` for the `route` relation
-    def self.name
-      'Namespace'
-    end
-
-    def full_path
-      if route && route.path.present?
-        @full_path ||= route.path
-      else
-        update_route if persisted?
-
-        build_full_path
-      end
-    end
-
-    def build_full_path
-      if parent && path
-        parent.full_path + '/' + path
-      else
-        path
-      end
-    end
-
-    def update_route
-      prepare_route
-      route.save
-    end
-
-    def prepare_route
-      route || build_route(source: self)
-      route.path = build_full_path
-      route.name = build_full_name
-      @full_path = nil
-      @full_name = nil
-    end
-
-    def build_full_name
-      if parent && name
-        parent.human_name + ' / ' + name
-      else
-        name
-      end
-    end
-
-    def human_name
-      owner&.name
-    end
-  end
-
-  class Route < ActiveRecord::Base
-    self.table_name = 'routes'
-    belongs_to :source, polymorphic: true
-  end
-
-  class Project < ActiveRecord::Base
-    self.table_name = 'projects'
-
-    def repository_storage_path
-      Gitlab.config.repositories.storages[repository_storage]['path']
-    end
-  end
-
-  DOWNTIME = false
-
-  def up
-    return unless system_namespace
-
-    old_path = system_namespace.path
-    old_full_path = system_namespace.full_path
-    # Only remove the last occurrence of the path name to get the parent namespace path
-    namespace_path = remove_last_occurrence(old_full_path, old_path)
-    new_path = rename_path(namespace_path, old_path)
-    new_full_path = join_namespace_path(namespace_path, new_path)
-
-    Namespace.where(id: system_namespace).update_all(path: new_path) # skips callbacks & validations
-
-    replace_statement = replace_sql(Route.arel_table[:path], old_full_path, new_full_path)
-    route_matches = [old_full_path, "#{old_full_path}/%"]
-
-    update_column_in_batches(:routes, :path, replace_statement) do |table, query|
-      query.where(Route.arel_table[:path].matches_any(route_matches))
-    end
-
-    clear_cache_for_namespace(system_namespace)
-
-    # tasks here are based on `Namespace#move_dir`
-    move_repositories(system_namespace, old_full_path, new_full_path)
-    move_namespace_folders(uploads_dir, old_full_path, new_full_path) if file_storage?
-    move_namespace_folders(pages_dir, old_full_path, new_full_path)
-  end
-
-  def down
-    # nothing to do
-  end
-
-  def remove_last_occurrence(string, pattern)
-    string.reverse.sub(pattern.reverse, "").reverse
-  end
-
-  def move_namespace_folders(directory, old_relative_path, new_relative_path)
-    old_path = File.join(directory, old_relative_path)
-    return unless File.directory?(old_path)
-
-    new_path = File.join(directory, new_relative_path)
-    FileUtils.mv(old_path, new_path)
-  end
-
-  def move_repositories(namespace, old_full_path, new_full_path)
-    repo_paths_for_namespace(namespace).each do |repository_storage_path|
-      # Ensure old directory exists before moving it
-      gitlab_shell.add_namespace(repository_storage_path, old_full_path)
-
-      unless gitlab_shell.mv_namespace(repository_storage_path, old_full_path, new_full_path)
-        say "Exception moving path #{repository_storage_path} from #{old_full_path} to #{new_full_path}"
-      end
-    end
-  end
-
-  def rename_path(namespace_path, path_was)
-    counter = 0
-    path = "#{path_was}#{counter}"
-
-    while route_exists?(join_namespace_path(namespace_path, path))
-      counter += 1
-      path = "#{path_was}#{counter}"
-    end
-
-    path
-  end
-
-  def route_exists?(full_path)
-    Route.where(Route.arel_table[:path].matches(full_path)).any?
-  end
-
-  def join_namespace_path(namespace_path, path)
-    if namespace_path.present?
-      File.join(namespace_path, path)
-    else
-      path
-    end
-  end
-
-  def system_namespace
-    @system_namespace ||= Namespace.where(parent_id: nil)
-                            .where(arel_table[:path].matches(system_namespace_path))
-                            .first
-  end
-
-  def system_namespace_path
-    "system"
-  end
-
-  def clear_cache_for_namespace(namespace)
-    project_ids = projects_for_namespace(namespace).pluck(:id)
-
-    update_column_in_batches(:projects, :description_html, nil) do |table, query|
-      query.where(table[:id].in(project_ids))
-    end
-
-    update_column_in_batches(:issues, :description_html, nil) do |table, query|
-      query.where(table[:project_id].in(project_ids))
-    end
-
-    update_column_in_batches(:merge_requests, :description_html, nil) do |table, query|
-      query.where(table[:target_project_id].in(project_ids))
-    end
-
-    update_column_in_batches(:notes, :note_html, nil) do |table, query|
-      query.where(table[:project_id].in(project_ids))
-    end
-
-    update_column_in_batches(:milestones, :description_html, nil) do |table, query|
-      query.where(table[:project_id].in(project_ids))
-    end
-  end
-
-  def projects_for_namespace(namespace)
-    namespace_ids = child_ids_for_parent(namespace, ids: [namespace.id])
-    namespace_or_children = Project.arel_table[:namespace_id].in(namespace_ids)
-    Project.unscoped.where(namespace_or_children)
-  end
-
-  # This won't scale to huge trees, but it should do for a handful of namespaces
-  # called `system`.
-  def child_ids_for_parent(namespace, ids: [])
-    namespace.children.each do |child|
-      ids << child.id
-      child_ids_for_parent(child, ids: ids) if child.children.any?
-    end
-    ids
-  end
-
-  def repo_paths_for_namespace(namespace)
-    projects_for_namespace(namespace).distinct
-      .select(:repository_storage).map(&:repository_storage_path)
-  end
-
-  def uploads_dir
-    File.join(Rails.root, "public", "uploads")
-  end
-
-  def pages_dir
-    Settings.pages.path
-  end
-
-  def file_storage?
-    CarrierWave::Uploader::Base.storage == CarrierWave::Storage::File
-  end
-
-  def arel_table
-    Namespace.arel_table
-  end
-end
diff --git a/db/migrate/20170316163845_move_uploads_to_system_dir.rb b/db/migrate/20170316163845_move_uploads_to_system_dir.rb
index 564ee10b5ab..cfcb909ddaf 100644
--- a/db/migrate/20170316163845_move_uploads_to_system_dir.rb
+++ b/db/migrate/20170316163845_move_uploads_to_system_dir.rb
@@ -54,6 +54,6 @@ class MoveUploadsToSystemDir < ActiveRecord::Migration
   end
 
   def new_upload_dir
-    File.join(base_directory, "public", "uploads", "system")
+    File.join(base_directory, "public", "uploads", "-", "system")
   end
 end
diff --git a/db/migrate/20170717074009_move_system_upload_folder.rb b/db/migrate/20170717074009_move_system_upload_folder.rb
index cce31794115..d3caa53a7a4 100644
--- a/db/migrate/20170717074009_move_system_upload_folder.rb
+++ b/db/migrate/20170717074009_move_system_upload_folder.rb
@@ -15,6 +15,11 @@ class MoveSystemUploadFolder < ActiveRecord::Migration
       return
     end
 
+    if File.directory?(new_directory)
+      say "#{new_directory} already exists. No need to redo the move."
+      return
+    end
+
     FileUtils.mkdir_p(File.join(base_directory, '-'))
 
     say "Moving #{old_directory} -> #{new_directory}"
@@ -33,6 +38,11 @@ class MoveSystemUploadFolder < ActiveRecord::Migration
       return
     end
 
+    if !File.symlink?(old_directory) && File.directory?(old_directory)
+      say "#{old_directory} already exists and is not a symlink, no need to revert."
+      return
+    end
+
     if File.symlink?(old_directory)
       say "Removing #{old_directory} -> #{new_directory} symlink"
       FileUtils.rm(old_directory)
diff --git a/db/post_migrate/20170317162059_update_upload_paths_to_system.rb b/db/post_migrate/20170317162059_update_upload_paths_to_system.rb
index ca2912f8dce..92e33848bf0 100644
--- a/db/post_migrate/20170317162059_update_upload_paths_to_system.rb
+++ b/db/post_migrate/20170317162059_update_upload_paths_to_system.rb
@@ -48,7 +48,7 @@ class UpdateUploadPathsToSystem < ActiveRecord::Migration
   end
 
   def new_upload_dir
-    File.join(base_directory, "system")
+    File.join(base_directory, "-",  "system")
   end
 
   def arel_table
diff --git a/db/post_migrate/20170406111121_clean_upload_symlinks.rb b/db/post_migrate/20170406111121_clean_upload_symlinks.rb
index fc3a4acc0bb..f2ce25d4524 100644
--- a/db/post_migrate/20170406111121_clean_upload_symlinks.rb
+++ b/db/post_migrate/20170406111121_clean_upload_symlinks.rb
@@ -47,6 +47,6 @@ class CleanUploadSymlinks < ActiveRecord::Migration
   end
 
   def new_upload_dir
-    File.join(base_directory, "public", "uploads", "system")
+    File.join(base_directory, "public", "uploads", "-", "system")
   end
 end
diff --git a/db/post_migrate/20170606202615_move_appearance_to_system_dir.rb b/db/post_migrate/20170606202615_move_appearance_to_system_dir.rb
index 561de59ec69..07935ab8a52 100644
--- a/db/post_migrate/20170606202615_move_appearance_to_system_dir.rb
+++ b/db/post_migrate/20170606202615_move_appearance_to_system_dir.rb
@@ -52,6 +52,6 @@ class MoveAppearanceToSystemDir < ActiveRecord::Migration
   end
 
   def new_upload_dir
-    File.join(base_directory, "public", "uploads", "system")
+    File.join(base_directory, "public", "uploads", "-", "system")
   end
 end
diff --git a/db/post_migrate/20170612071012_move_personal_snippets_files.rb b/db/post_migrate/20170612071012_move_personal_snippets_files.rb
index 33043364bde..2b79a87ccd8 100644
--- a/db/post_migrate/20170612071012_move_personal_snippets_files.rb
+++ b/db/post_migrate/20170612071012_move_personal_snippets_files.rb
@@ -10,7 +10,7 @@ class MovePersonalSnippetsFiles < ActiveRecord::Migration
     return unless file_storage?
 
     @source_relative_location = File.join('/uploads', 'personal_snippet')
-    @destination_relative_location = File.join('/uploads', 'system', 'personal_snippet')
+    @destination_relative_location = File.join('/uploads', '-', 'system', 'personal_snippet')
 
     move_personal_snippet_files
   end
@@ -18,7 +18,7 @@ class MovePersonalSnippetsFiles < ActiveRecord::Migration
   def down
     return unless file_storage?
 
-    @source_relative_location = File.join('/uploads', 'system', 'personal_snippet')
+    @source_relative_location = File.join('/uploads', '-', 'system', 'personal_snippet')
     @destination_relative_location = File.join('/uploads', 'personal_snippet')
 
     move_personal_snippet_files
diff --git a/db/post_migrate/20170807190736_move_personal_snippet_files_into_correct_folder.rb b/db/post_migrate/20170807190736_move_personal_snippet_files_into_correct_folder.rb
new file mode 100644
index 00000000000..e3d2446b897
--- /dev/null
+++ b/db/post_migrate/20170807190736_move_personal_snippet_files_into_correct_folder.rb
@@ -0,0 +1,29 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class MovePersonalSnippetFilesIntoCorrectFolder < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+  disable_ddl_transaction!
+
+  DOWNTIME = false
+  NEW_DIRECTORY = File.join('/uploads', '-', 'system', 'personal_snippet')
+  OLD_DIRECTORY = File.join('/uploads', 'system', 'personal_snippet')
+
+  def up
+    return unless file_storage?
+
+    BackgroundMigrationWorker.perform_async('MovePersonalSnippetFiles',
+                                            [OLD_DIRECTORY, NEW_DIRECTORY])
+  end
+
+  def down
+    return unless file_storage?
+
+    BackgroundMigrationWorker.perform_async('MovePersonalSnippetFiles',
+                                            [NEW_DIRECTORY, OLD_DIRECTORY])
+  end
+
+  def file_storage?
+    CarrierWave::Uploader::Base.storage == CarrierWave::Storage::File
+  end
+end
diff --git a/lib/gitlab/background_migration/move_personal_snippet_files.rb b/lib/gitlab/background_migration/move_personal_snippet_files.rb
new file mode 100644
index 00000000000..07cec96bcc3
--- /dev/null
+++ b/lib/gitlab/background_migration/move_personal_snippet_files.rb
@@ -0,0 +1,79 @@
+module Gitlab
+  module BackgroundMigration
+    class MovePersonalSnippetFiles
+      delegate :select_all, :execute, :quote_string, to: :connection
+
+      def perform(relative_source, relative_destination)
+        @source_relative_location = relative_source
+        @destination_relative_location = relative_destination
+
+        move_personal_snippet_files
+      end
+
+      def move_personal_snippet_files
+        query = "SELECT uploads.path, uploads.model_id FROM uploads "\
+                "INNER JOIN snippets ON snippets.id = uploads.model_id WHERE uploader = 'PersonalFileUploader'"
+        select_all(query).each do |upload|
+          secret = upload['path'].split('/')[0]
+          file_name = upload['path'].split('/')[1]
+
+          move_file(upload['model_id'], secret, file_name)
+          update_markdown(upload['model_id'], secret, file_name)
+        end
+      end
+
+      def move_file(snippet_id, secret, file_name)
+        source_dir = File.join(base_directory, @source_relative_location, snippet_id.to_s, secret)
+        destination_dir = File.join(base_directory, @destination_relative_location, snippet_id.to_s, secret)
+
+        source_file_path = File.join(source_dir, file_name)
+        destination_file_path = File.join(destination_dir, file_name)
+
+        unless File.exist?(source_file_path)
+          say "Source file `#{source_file_path}` doesn't exist. Skipping."
+          return
+        end
+
+        say "Moving file #{source_file_path} -> #{destination_file_path}"
+
+        FileUtils.mkdir_p(destination_dir)
+        FileUtils.move(source_file_path, destination_file_path)
+      end
+
+      def update_markdown(snippet_id, secret, file_name)
+        source_markdown_path = File.join(@source_relative_location, snippet_id.to_s, secret, file_name)
+        destination_markdown_path = File.join(@destination_relative_location, snippet_id.to_s, secret, file_name)
+
+        source_markdown = "](#{source_markdown_path})"
+        destination_markdown = "](#{destination_markdown_path})"
+        quoted_source = quote_string(source_markdown)
+        quoted_destination = quote_string(destination_markdown)
+
+        execute("UPDATE snippets "\
+                "SET description = replace(snippets.description, '#{quoted_source}', '#{quoted_destination}'), description_html = NULL "\
+                "WHERE id = #{snippet_id}")
+
+        query = "SELECT id, note FROM notes WHERE noteable_id = #{snippet_id} "\
+                "AND noteable_type = 'Snippet' AND note IS NOT NULL"
+        select_all(query).each do |note|
+          text = note['note'].gsub(source_markdown, destination_markdown)
+          quoted_text = quote_string(text)
+
+          execute("UPDATE notes SET note = '#{quoted_text}', note_html = NULL WHERE id = #{note['id']}")
+        end
+      end
+
+      def base_directory
+        File.join(Rails.root, 'public')
+      end
+
+      def connection
+        ActiveRecord::Base.connection
+      end
+
+      def say(message)
+        Rails.logger.debug(message)
+      end
+    end
+  end
+end
diff --git a/spec/controllers/snippets_controller_spec.rb b/spec/controllers/snippets_controller_spec.rb
index 475ceda11fe..7c5d059760f 100644
--- a/spec/controllers/snippets_controller_spec.rb
+++ b/spec/controllers/snippets_controller_spec.rb
@@ -186,8 +186,8 @@ describe SnippetsController do
     end
 
     context 'when the snippet description contains a file' do
-      let(:picture_file) { '/system/temp/secret56/picture.jpg' }
-      let(:text_file) { '/system/temp/secret78/text.txt' }
+      let(:picture_file) { '/-/system/temp/secret56/picture.jpg' }
+      let(:text_file) { '/-/system/temp/secret78/text.txt' }
       let(:description) do
         "Description with picture: ![picture](/uploads#{picture_file}) and "\
         "text: [text.txt](/uploads#{text_file})"
@@ -208,8 +208,8 @@ describe SnippetsController do
         snippet = subject
 
         expected_description = "Description with picture: "\
-          "![picture](/uploads/system/personal_snippet/#{snippet.id}/secret56/picture.jpg) and "\
-          "text: [text.txt](/uploads/system/personal_snippet/#{snippet.id}/secret78/text.txt)"
+          "![picture](/uploads/-/system/personal_snippet/#{snippet.id}/secret56/picture.jpg) and "\
+          "text: [text.txt](/uploads/-/system/personal_snippet/#{snippet.id}/secret78/text.txt)"
 
         expect(snippet.description).to eq(expected_description)
       end
diff --git a/spec/controllers/uploads_controller_spec.rb b/spec/controllers/uploads_controller_spec.rb
index b3a40f5d15c..b29f3d861be 100644
--- a/spec/controllers/uploads_controller_spec.rb
+++ b/spec/controllers/uploads_controller_spec.rb
@@ -102,7 +102,7 @@ describe UploadsController do
           subject
 
           expect(response.body).to match '\"alt\":\"rails_sample\"'
-          expect(response.body).to match "\"url\":\"/uploads/system/temp"
+          expect(response.body).to match "\"url\":\"/uploads/-/system/temp"
         end
 
         it 'does not create an Upload record' do
@@ -119,7 +119,7 @@ describe UploadsController do
           subject
 
           expect(response.body).to match '\"alt\":\"doc_sample.txt\"'
-          expect(response.body).to match "\"url\":\"/uploads/system/temp"
+          expect(response.body).to match "\"url\":\"/uploads/-/system/temp"
         end
 
         it 'does not create an Upload record' do
diff --git a/spec/features/snippets/user_creates_snippet_spec.rb b/spec/features/snippets/user_creates_snippet_spec.rb
index a919f5fa20b..d732383a1e1 100644
--- a/spec/features/snippets/user_creates_snippet_spec.rb
+++ b/spec/features/snippets/user_creates_snippet_spec.rb
@@ -41,7 +41,7 @@ feature 'User creates snippet', :js do
       expect(page).to have_content('My Snippet')
 
       link = find('a.no-attachment-icon img[alt="banana_sample"]')['src']
-      expect(link).to match(%r{/uploads/system/temp/\h{32}/banana_sample\.gif\z})
+      expect(link).to match(%r{/uploads/-/system/temp/\h{32}/banana_sample\.gif\z})
 
       visit(link)
       expect(page.status_code).to eq(200)
@@ -59,7 +59,7 @@ feature 'User creates snippet', :js do
     wait_for_requests
 
     link = find('a.no-attachment-icon img[alt="banana_sample"]')['src']
-    expect(link).to match(%r{/uploads/system/personal_snippet/#{Snippet.last.id}/\h{32}/banana_sample\.gif\z})
+    expect(link).to match(%r{/uploads/-/system/personal_snippet/#{Snippet.last.id}/\h{32}/banana_sample\.gif\z})
 
     visit(link)
     expect(page.status_code).to eq(200)
@@ -84,7 +84,7 @@ feature 'User creates snippet', :js do
     end
     expect(page).to have_content('Hello World!')
     link = find('a.no-attachment-icon img[alt="banana_sample"]')['src']
-    expect(link).to match(%r{/uploads/system/personal_snippet/#{Snippet.last.id}/\h{32}/banana_sample\.gif\z})
+    expect(link).to match(%r{/uploads/-/system/personal_snippet/#{Snippet.last.id}/\h{32}/banana_sample\.gif\z})
 
     visit(link)
     expect(page.status_code).to eq(200)
diff --git a/spec/features/snippets/user_edits_snippet_spec.rb b/spec/features/snippets/user_edits_snippet_spec.rb
index 26070e508e2..71de6b6bd1c 100644
--- a/spec/features/snippets/user_edits_snippet_spec.rb
+++ b/spec/features/snippets/user_edits_snippet_spec.rb
@@ -33,7 +33,7 @@ feature 'User edits snippet', :js do
     wait_for_requests
 
     link = find('a.no-attachment-icon img[alt="banana_sample"]')['src']
-    expect(link).to match(%r{/uploads/system/personal_snippet/#{snippet.id}/\h{32}/banana_sample\.gif\z})
+    expect(link).to match(%r{/uploads/-/system/personal_snippet/#{snippet.id}/\h{32}/banana_sample\.gif\z})
   end
 
   it 'updates the snippet to make it internal' do
diff --git a/spec/lib/gitlab/background_migration/move_personal_snippet_files_spec.rb b/spec/lib/gitlab/background_migration/move_personal_snippet_files_spec.rb
new file mode 100644
index 00000000000..ee60e498b59
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/move_personal_snippet_files_spec.rb
@@ -0,0 +1,72 @@
+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::MovePersonalSnippetFiles do
+  let(:test_dir) { File.join(Rails.root, 'tmp', 'tests', 'move_snippet_files_test') }
+  let(:old_uploads_dir) { File.join('uploads', 'system', 'personal_snippet') }
+  let(:new_uploads_dir) { File.join('uploads', '-', 'system', 'personal_snippet') }
+  let(:snippet) do
+    snippet = create(:personal_snippet)
+    create_upload_for_snippet(snippet)
+    snippet.update_attributes!(description: markdown_linking_file(snippet))
+    snippet
+  end
+
+  let(:migration) { described_class.new }
+
+  before do
+    allow(migration).to receive(:base_directory) { test_dir }
+  end
+
+  describe '#perform' do
+    it 'moves the file on the disk'  do
+      expected_path = File.join(test_dir, new_uploads_dir, snippet.id.to_s, "secret#{snippet.id}", 'upload.txt')
+
+      migration.perform(old_uploads_dir, new_uploads_dir)
+
+      expect(File.exist?(expected_path)).to be_truthy
+    end
+
+    it 'updates the markdown of the snippet' do
+      expected_path = File.join(new_uploads_dir, snippet.id.to_s, "secret#{snippet.id}", 'upload.txt')
+      expected_markdown = "[an upload](#{expected_path})"
+
+      migration.perform(old_uploads_dir, new_uploads_dir)
+
+      expect(snippet.reload.description).to eq(expected_markdown)
+    end
+
+    it 'updates the markdown of notes' do
+      expected_path = File.join(new_uploads_dir, snippet.id.to_s, "secret#{snippet.id}", 'upload.txt')
+      expected_markdown = "with [an upload](#{expected_path})"
+
+      note = create(:note_on_personal_snippet, noteable: snippet, note: "with #{markdown_linking_file(snippet)}")
+
+      migration.perform(old_uploads_dir, new_uploads_dir)
+
+      expect(note.reload.note).to eq(expected_markdown)
+    end
+  end
+
+  def create_upload_for_snippet(snippet)
+    snippet_path = path_for_file_in_snippet(snippet)
+    path = File.join(old_uploads_dir, snippet.id.to_s, snippet_path)
+    absolute_path = File.join(test_dir, path)
+
+    FileUtils.mkdir_p(File.dirname(absolute_path))
+    FileUtils.touch(absolute_path)
+
+    create(:upload, model: snippet, path: snippet_path, uploader: PersonalFileUploader)
+  end
+
+  def path_for_file_in_snippet(snippet)
+    secret = "secret#{snippet.id}"
+    filename = 'upload.txt'
+
+    File.join(secret, filename)
+  end
+
+  def markdown_linking_file(snippet)
+    path = File.join(old_uploads_dir, snippet.id.to_s, path_for_file_in_snippet(snippet))
+    "[an upload](#{path})"
+  end
+end
diff --git a/spec/migrations/clean_upload_symlinks_spec.rb b/spec/migrations/clean_upload_symlinks_spec.rb
index cecb3ddac53..26653b9c008 100644
--- a/spec/migrations/clean_upload_symlinks_spec.rb
+++ b/spec/migrations/clean_upload_symlinks_spec.rb
@@ -5,7 +5,7 @@ describe CleanUploadSymlinks do
   let(:migration) { described_class.new }
   let(:test_dir) { File.join(Rails.root, "tmp", "tests", "move_uploads_test") }
   let(:uploads_dir) { File.join(test_dir, "public", "uploads") }
-  let(:new_uploads_dir) { File.join(uploads_dir, "system") }
+  let(:new_uploads_dir) { File.join(uploads_dir, "-", "system") }
   let(:original_path) { File.join(new_uploads_dir, 'user') }
   let(:symlink_path) { File.join(uploads_dir, 'user') }
 
diff --git a/spec/migrations/move_personal_snippets_files_spec.rb b/spec/migrations/move_personal_snippets_files_spec.rb
index 8505c7bf3e3..1a319eccc0d 100644
--- a/spec/migrations/move_personal_snippets_files_spec.rb
+++ b/spec/migrations/move_personal_snippets_files_spec.rb
@@ -5,7 +5,7 @@ describe MovePersonalSnippetsFiles do
   let(:migration) { described_class.new }
   let(:test_dir) { File.join(Rails.root, "tmp", "tests", "move_snippet_files_test") }
   let(:uploads_dir) { File.join(test_dir, 'uploads') }
-  let(:new_uploads_dir) { File.join(uploads_dir, 'system') }
+  let(:new_uploads_dir) { File.join(uploads_dir, '-', 'system') }
 
   before do
     allow(CarrierWave).to receive(:root).and_return(test_dir)
@@ -42,7 +42,7 @@ describe MovePersonalSnippetsFiles do
     describe 'updating the markdown' do
       it 'includes the new path when the file exists' do
         secret = "secret#{snippet.id}"
-        file_location = "/uploads/system/personal_snippet/#{snippet.id}/#{secret}/picture.jpg"
+        file_location = "/uploads/-/system/personal_snippet/#{snippet.id}/#{secret}/picture.jpg"
 
         migration.up
 
@@ -60,7 +60,7 @@ describe MovePersonalSnippetsFiles do
 
       it 'updates the note markdown' do
         secret = "secret#{snippet.id}"
-        file_location = "/uploads/system/personal_snippet/#{snippet.id}/#{secret}/picture.jpg"
+        file_location = "/uploads/-/system/personal_snippet/#{snippet.id}/#{secret}/picture.jpg"
         markdown = markdown_linking_file('picture.jpg', snippet)
         note = create(:note_on_personal_snippet, noteable: snippet, note: "with #{markdown}")
 
@@ -108,7 +108,7 @@ describe MovePersonalSnippetsFiles do
 
       it 'keeps the markdown as is when the file is missing' do
         secret = "secret#{snippet_with_missing_file.id}"
-        file_location = "/uploads/system/personal_snippet/#{snippet_with_missing_file.id}/#{secret}/picture.jpg"
+        file_location = "/uploads/-/system/personal_snippet/#{snippet_with_missing_file.id}/#{secret}/picture.jpg"
 
         migration.down
 
@@ -167,7 +167,7 @@ describe MovePersonalSnippetsFiles do
   def markdown_linking_file(filename, snippet, in_new_path: false)
     markdown =  "![#{filename.split('.')[0]}]"
     markdown += '(/uploads'
-    markdown += '/system' if in_new_path
+    markdown += '/-/system' if in_new_path
     markdown += "/#{model_file_path(filename, snippet)})"
     markdown
   end
diff --git a/spec/migrations/move_system_upload_folder_spec.rb b/spec/migrations/move_system_upload_folder_spec.rb
index b622b4e9536..d3180477db3 100644
--- a/spec/migrations/move_system_upload_folder_spec.rb
+++ b/spec/migrations/move_system_upload_folder_spec.rb
@@ -33,6 +33,15 @@ describe MoveSystemUploadFolder do
       expect(File.symlink?(File.join(test_base, 'system'))).to be_truthy
       expect(File.exist?(File.join(test_base, 'system', 'file'))).to be_truthy
     end
+
+    it 'does not move if the target directory already exists' do
+      FileUtils.mkdir_p(File.join(test_base, '-', 'system'))
+
+      expect(FileUtils).not_to receive(:mv)
+      expect(migration).to receive(:say).with(/already exists. No need to redo the move/)
+
+      migration.up
+    end
   end
 
   describe '#down' do
@@ -58,5 +67,14 @@ describe MoveSystemUploadFolder do
       expect(File.directory?(File.join(test_base, 'system'))).to be_truthy
       expect(File.symlink?(File.join(test_base, 'system'))).to be_falsey
     end
+
+    it 'does not move if the old directory already exists' do
+      FileUtils.mkdir_p(File.join(test_base, 'system'))
+
+      expect(FileUtils).not_to receive(:mv)
+      expect(migration).to receive(:say).with(/already exists and is not a symlink, no need to revert/)
+
+      migration.down
+    end
   end
 end
diff --git a/spec/migrations/move_uploads_to_system_dir_spec.rb b/spec/migrations/move_uploads_to_system_dir_spec.rb
index 37d66452447..ca11a2004c5 100644
--- a/spec/migrations/move_uploads_to_system_dir_spec.rb
+++ b/spec/migrations/move_uploads_to_system_dir_spec.rb
@@ -5,7 +5,7 @@ describe MoveUploadsToSystemDir do
   let(:migration) { described_class.new }
   let(:test_dir) { File.join(Rails.root, "tmp", "move_uploads_test") }
   let(:uploads_dir) { File.join(test_dir, "public", "uploads") }
-  let(:new_uploads_dir) { File.join(uploads_dir, "system") }
+  let(:new_uploads_dir) { File.join(uploads_dir, "-", "system") }
 
   before do
     FileUtils.remove_dir(test_dir) if File.directory?(test_dir)
diff --git a/spec/migrations/rename_system_namespaces_spec.rb b/spec/migrations/rename_system_namespaces_spec.rb
deleted file mode 100644
index 747694cbe33..00000000000
--- a/spec/migrations/rename_system_namespaces_spec.rb
+++ /dev/null
@@ -1,254 +0,0 @@
-require "spec_helper"
-require Rails.root.join("db", "migrate", "20170316163800_rename_system_namespaces.rb")
-
-describe RenameSystemNamespaces, truncate: true do
-  let(:migration) { described_class.new }
-  let(:test_dir) { File.join(Rails.root, "tmp", "tests", "rename_namespaces_test") }
-  let(:uploads_dir) { File.join(test_dir, "public", "uploads") }
-  let(:system_namespace) do
-    namespace = build(:namespace, path: "system")
-    namespace.save(validate: false)
-    namespace
-  end
-
-  def save_invalid_routable(routable)
-    routable.__send__(:prepare_route)
-    routable.save(validate: false)
-  end
-
-  before do
-    FileUtils.remove_dir(test_dir) if File.directory?(test_dir)
-    FileUtils.mkdir_p(uploads_dir)
-    FileUtils.remove_dir(TestEnv.repos_path) if File.directory?(TestEnv.repos_path)
-    allow(migration).to receive(:say)
-    allow(migration).to receive(:uploads_dir).and_return(uploads_dir)
-  end
-
-  describe "#system_namespace" do
-    it "only root namespaces called with path `system`" do
-      system_namespace
-      system_namespace_with_parent = build(:namespace, path: 'system', parent: create(:namespace))
-      system_namespace_with_parent.save(validate: false)
-
-      expect(migration.system_namespace.id).to eq(system_namespace.id)
-    end
-  end
-
-  describe "#up" do
-    before do
-      system_namespace
-    end
-
-    it "doesn't break if there are no namespaces called system" do
-      Namespace.delete_all
-
-      migration.up
-    end
-
-    it "renames namespaces called system" do
-      migration.up
-
-      expect(system_namespace.reload.path).to eq("system0")
-    end
-
-    it "renames the route to the namespace" do
-      migration.up
-
-      expect(system_namespace.reload.full_path).to eq("system0")
-    end
-
-    it "renames the route for projects of the namespace" do
-      project = build(:project, :repository, path: "project-path", namespace: system_namespace)
-      save_invalid_routable(project)
-
-      migration.up
-
-      expect(project.route.reload.path).to eq("system0/project-path")
-    end
-
-    it "doesn't touch routes of namespaces that look like system" do
-      namespace = create(:group, path: 'systemlookalike')
-      project = create(:project, :repository, namespace: namespace, path: 'the-project')
-
-      migration.up
-
-      expect(project.route.reload.path).to eq('systemlookalike/the-project')
-      expect(namespace.route.reload.path).to eq('systemlookalike')
-    end
-
-    it "moves the the repository for a project in the namespace" do
-      project = build(:project, :repository, namespace: system_namespace, path: "system-project")
-      save_invalid_routable(project)
-      TestEnv.copy_repo(project,
-                        bare_repo: TestEnv.factory_repo_path_bare,
-                        refs: TestEnv::BRANCH_SHA)
-      expected_repo = File.join(TestEnv.repos_path, "system0", "system-project.git")
-
-      migration.up
-
-      expect(File.directory?(expected_repo)).to be(true)
-    end
-
-    it "moves the uploads for the namespace" do
-      allow(migration).to receive(:move_namespace_folders).with(Settings.pages.path, "system", "system0")
-      expect(migration).to receive(:move_namespace_folders).with(uploads_dir, "system", "system0")
-
-      migration.up
-    end
-
-    it "moves the pages for the namespace" do
-      allow(migration).to receive(:move_namespace_folders).with(uploads_dir, "system", "system0")
-      expect(migration).to receive(:move_namespace_folders).with(Settings.pages.path, "system", "system0")
-
-      migration.up
-    end
-
-    describe "clears the markdown cache for projects in the system namespace" do
-      let!(:project) do
-        project = build(:project, :repository, namespace: system_namespace)
-        save_invalid_routable(project)
-        project
-      end
-
-      it 'removes description_html from projects' do
-        migration.up
-
-        expect(project.reload.description_html).to be_nil
-      end
-
-      it 'removes issue descriptions' do
-        issue = create(:issue, project: project, description_html: 'Issue description')
-
-        migration.up
-
-        expect(issue.reload.description_html).to be_nil
-      end
-
-      it 'removes merge request descriptions' do
-        merge_request = create(:merge_request,
-                               source_project: project,
-                               target_project: project,
-                               description_html: 'MergeRequest description')
-
-        migration.up
-
-        expect(merge_request.reload.description_html).to be_nil
-      end
-
-      it 'removes note html' do
-        note = create(:note,
-                      project: project,
-                      noteable: create(:issue, project: project),
-                      note_html: 'note description')
-
-        migration.up
-
-        expect(note.reload.note_html).to be_nil
-      end
-
-      it 'removes milestone description' do
-        milestone = create(:milestone,
-                           project: project,
-                           description_html: 'milestone description')
-
-        migration.up
-
-        expect(milestone.reload.description_html).to be_nil
-      end
-    end
-
-    context "system namespace -> subgroup -> system0 project" do
-      it "updates the route of the project correctly" do
-        subgroup = build(:group, path: "subgroup", parent: system_namespace)
-        save_invalid_routable(subgroup)
-        project = build(:project, :repository, path: "system0", namespace: subgroup)
-        save_invalid_routable(project)
-
-        migration.up
-
-        expect(project.route.reload.path).to eq("system0/subgroup/system0")
-      end
-    end
-  end
-
-  describe "#move_repositories" do
-    let(:namespace) { create(:group, name: "hello-group") }
-    it "moves a project for a namespace" do
-      create(:project, :repository, namespace: namespace, path: "hello-project")
-      expected_path = File.join(TestEnv.repos_path, "bye-group", "hello-project.git")
-
-      migration.move_repositories(namespace, "hello-group", "bye-group")
-
-      expect(File.directory?(expected_path)).to be(true)
-    end
-
-    it "moves a namespace in a subdirectory correctly" do
-      child_namespace = create(:group, name: "sub-group", parent: namespace)
-      create(:project, :repository, namespace: child_namespace, path: "hello-project")
-
-      expected_path = File.join(TestEnv.repos_path, "hello-group", "renamed-sub-group", "hello-project.git")
-
-      migration.move_repositories(child_namespace, "hello-group/sub-group", "hello-group/renamed-sub-group")
-
-      expect(File.directory?(expected_path)).to be(true)
-    end
-
-    it "moves a parent namespace with subdirectories" do
-      child_namespace = create(:group, name: "sub-group", parent: namespace)
-      create(:project, :repository, namespace: child_namespace, path: "hello-project")
-      expected_path = File.join(TestEnv.repos_path, "renamed-group", "sub-group", "hello-project.git")
-
-      migration.move_repositories(child_namespace, "hello-group", "renamed-group")
-
-      expect(File.directory?(expected_path)).to be(true)
-    end
-  end
-
-  describe "#move_namespace_folders" do
-    it "moves a namespace with files" do
-      source = File.join(uploads_dir, "parent-group", "sub-group")
-      FileUtils.mkdir_p(source)
-      destination = File.join(uploads_dir, "parent-group", "moved-group")
-      FileUtils.touch(File.join(source, "test.txt"))
-      expected_file = File.join(destination, "test.txt")
-
-      migration.move_namespace_folders(uploads_dir, File.join("parent-group", "sub-group"), File.join("parent-group", "moved-group"))
-
-      expect(File.exist?(expected_file)).to be(true)
-    end
-
-    it "moves a parent namespace uploads" do
-      source = File.join(uploads_dir, "parent-group", "sub-group")
-      FileUtils.mkdir_p(source)
-      destination = File.join(uploads_dir, "moved-parent", "sub-group")
-      FileUtils.touch(File.join(source, "test.txt"))
-      expected_file = File.join(destination, "test.txt")
-
-      migration.move_namespace_folders(uploads_dir, "parent-group", "moved-parent")
-
-      expect(File.exist?(expected_file)).to be(true)
-    end
-  end
-
-  describe "#child_ids_for_parent" do
-    it "collects child ids for all levels" do
-      parent = create(:group)
-      first_child = create(:group, parent: parent)
-      second_child = create(:group, parent: parent)
-      third_child = create(:group, parent: second_child)
-      all_ids = [parent.id, first_child.id, second_child.id, third_child.id]
-
-      collected_ids = migration.child_ids_for_parent(parent, ids: [parent.id])
-
-      expect(collected_ids).to contain_exactly(*all_ids)
-    end
-  end
-
-  describe "#remove_last_ocurrence" do
-    it "removes only the last occurance of a string" do
-      input = "this/is/system/namespace/with/system"
-
-      expect(migration.remove_last_occurrence(input, "system")).to eq("this/is/system/namespace/with/")
-    end
-  end
-end
diff --git a/spec/migrations/update_upload_paths_to_system_spec.rb b/spec/migrations/update_upload_paths_to_system_spec.rb
index 11412005b72..0a45c5ea32d 100644
--- a/spec/migrations/update_upload_paths_to_system_spec.rb
+++ b/spec/migrations/update_upload_paths_to_system_spec.rb
@@ -11,7 +11,7 @@ describe UpdateUploadPathsToSystem do
   describe "#uploads_to_switch_to_new_path" do
     it "contains only uploads with the old path for the correct models" do
       _upload_for_other_type = create(:upload, model: create(:ci_pipeline), path: "uploads/ci_pipeline/avatar.jpg")
-      _upload_with_system_path = create(:upload, model: create(:project), path: "uploads/system/project/avatar.jpg")
+      _upload_with_system_path = create(:upload, model: create(:project), path: "uploads/-/system/project/avatar.jpg")
       _upload_with_other_path = create(:upload, model: create(:project), path: "thelongsecretforafileupload/avatar.jpg")
       old_upload = create(:upload, model: create(:project), path: "uploads/project/avatar.jpg")
       group_upload = create(:upload, model: create(:group), path: "uploads/group/avatar.jpg")
@@ -23,7 +23,7 @@ describe UpdateUploadPathsToSystem do
   describe "#uploads_to_switch_to_old_path" do
     it "contains only uploads with the new path for the correct models" do
       _upload_for_other_type = create(:upload, model: create(:ci_pipeline), path: "uploads/ci_pipeline/avatar.jpg")
-      upload_with_system_path = create(:upload, model: create(:project), path: "uploads/system/project/avatar.jpg")
+      upload_with_system_path = create(:upload, model: create(:project), path: "uploads/-/system/project/avatar.jpg")
       _upload_with_other_path = create(:upload, model: create(:project), path: "thelongsecretforafileupload/avatar.jpg")
       _old_upload = create(:upload, model: create(:project), path: "uploads/project/avatar.jpg")
 
@@ -37,13 +37,13 @@ describe UpdateUploadPathsToSystem do
 
       migration.up
 
-      expect(old_upload.reload.path).to eq("uploads/system/project/avatar.jpg")
+      expect(old_upload.reload.path).to eq("uploads/-/system/project/avatar.jpg")
     end
   end
 
   describe "#down", truncate: true do
     it "updates the new system patsh to the old paths" do
-      new_upload = create(:upload, model: create(:project), path: "uploads/system/project/avatar.jpg")
+      new_upload = create(:upload, model: create(:project), path: "uploads/-/system/project/avatar.jpg")
 
       migration.down
 
diff --git a/spec/uploaders/file_mover_spec.rb b/spec/uploaders/file_mover_spec.rb
index d7c1b390f9a..0cf462e9553 100644
--- a/spec/uploaders/file_mover_spec.rb
+++ b/spec/uploaders/file_mover_spec.rb
@@ -4,11 +4,11 @@ describe FileMover do
   let(:filename) { 'banana_sample.gif' }
   let(:file) { fixture_file_upload(Rails.root.join('spec', 'fixtures', filename)) }
   let(:temp_description) do
-    'test ![banana_sample](/uploads/system/temp/secret55/banana_sample.gif) same ![banana_sample]'\
-    '(/uploads/system/temp/secret55/banana_sample.gif)'
+    'test ![banana_sample](/uploads/-/system/temp/secret55/banana_sample.gif) same ![banana_sample]'\
+    '(/uploads/-/system/temp/secret55/banana_sample.gif)'
   end
   let(:temp_file_path) { File.join('secret55', filename).to_s }
-  let(:file_path) { File.join('uploads', 'system', 'personal_snippet', snippet.id.to_s, 'secret55', filename).to_s }
+  let(:file_path) { File.join('uploads', '-', 'system', 'personal_snippet', snippet.id.to_s, 'secret55', filename).to_s }
 
   let(:snippet) { create(:personal_snippet, description: temp_description) }
 
@@ -28,8 +28,8 @@ describe FileMover do
 
         expect(snippet.reload.description)
           .to eq(
-            "test ![banana_sample](/uploads/system/personal_snippet/#{snippet.id}/secret55/banana_sample.gif)"\
-            " same ![banana_sample](/uploads/system/personal_snippet/#{snippet.id}/secret55/banana_sample.gif)"
+            "test ![banana_sample](/uploads/-/system/personal_snippet/#{snippet.id}/secret55/banana_sample.gif)"\
+            " same ![banana_sample](/uploads/-/system/personal_snippet/#{snippet.id}/secret55/banana_sample.gif)"
           )
       end
 
@@ -50,8 +50,8 @@ describe FileMover do
 
         expect(snippet.reload.description)
           .to eq(
-            "test ![banana_sample](/uploads/system/temp/secret55/banana_sample.gif)"\
-            " same ![banana_sample](/uploads/system/temp/secret55/banana_sample.gif)"
+            "test ![banana_sample](/uploads/-/system/temp/secret55/banana_sample.gif)"\
+            " same ![banana_sample](/uploads/-/system/temp/secret55/banana_sample.gif)"
           )
       end
 
diff --git a/spec/uploaders/personal_file_uploader_spec.rb b/spec/uploaders/personal_file_uploader_spec.rb
index e505edc75ce..cbafa9f478d 100644
--- a/spec/uploaders/personal_file_uploader_spec.rb
+++ b/spec/uploaders/personal_file_uploader_spec.rb
@@ -10,7 +10,7 @@ describe PersonalFileUploader do
 
       dynamic_segment = "personal_snippet/#{snippet.id}"
 
-      expect(described_class.absolute_path(upload)).to end_with("/system/#{dynamic_segment}/secret/foo.jpg")
+      expect(described_class.absolute_path(upload)).to end_with("/-/system/#{dynamic_segment}/secret/foo.jpg")
     end
   end
 
@@ -19,7 +19,7 @@ describe PersonalFileUploader do
       uploader = described_class.new(snippet, 'secret')
 
       allow(uploader).to receive(:file).and_return(double(extension: 'txt', filename: 'file_name'))
-      expected_url = "/uploads/system/personal_snippet/#{snippet.id}/secret/file_name"
+      expected_url = "/uploads/-/system/personal_snippet/#{snippet.id}/secret/file_name"
 
       expect(uploader.to_h).to eq(
         alt: 'file_name',