1 files changed, 37 insertions, 9 deletions

diff --git a/app/uploaders/object_storage.rb b/app/uploaders/object_storage.rb
index 23b3dcf84c0..b8ecfc4ee2b 100644
--- a/app/uploaders/object_storage.rb
+++ b/app/uploaders/object_storage.rb
@@ -10,6 +10,17 @@ module ObjectStorage
   UnknownStoreError = Class.new(StandardError)
   ObjectStorageUnavailable = Class.new(StandardError)
 
+  class ExclusiveLeaseTaken < StandardError
+    def initialize(lease_key)
+      @lease_key = lease_key
+    end
+
+    def message
+      *lease_key_group, _ = *@lease_key.split(":")
+      "Exclusive lease for #{lease_key_group.join(':')} is already taken."
+    end
+  end
+
   TMP_UPLOAD_PATH = 'tmp/uploads'.freeze
 
   module Store
@@ -29,7 +40,7 @@ module ObjectStorage
       end
 
       def retrieve_from_store!(identifier)
-        paths = store_dirs.map { |store, path| File.join(path, identifier) }
+        paths = upload_paths(identifier)
 
         unless current_upload_satisfies?(paths, model)
           # the upload we already have isn't right, find the correct one
@@ -62,6 +73,15 @@ module ObjectStorage
                                                 upload.id)
       end
 
+      def exclusive_lease_key
+        # For FileUploaders, model may have many uploaders. In that case
+        # we want to use exclusive key per upload, not per model to allow
+        # parallel migration
+        key_object = upload || model
+
+        "object_storage_migrate:#{key_object.class}:#{key_object.id}"
+      end
+
       private
 
       def current_upload_satisfies?(paths, model)
@@ -261,7 +281,7 @@ module ObjectStorage
     end
 
     def delete_migrated_file(migrated_file)
-      migrated_file.delete if exists?
+      migrated_file.delete
     end
 
     def exists?
@@ -279,6 +299,13 @@ module ObjectStorage
       }
     end
 
+    # Returns all the possible paths for an upload.
+    # the `upload.path` is a lookup parameter, and it may change
+    # depending on the `store` param.
+    def upload_paths(identifier)
+      store_dirs.map { |store, path| File.join(path, identifier) }
+    end
+
     def cache!(new_file = sanitized_file)
       # We intercept ::UploadedFile which might be stored on remote storage
       # We use that for "accelerated" uploads, where we store result on remote storage
@@ -298,6 +325,10 @@ module ObjectStorage
       super
     end
 
+    def exclusive_lease_key
+      "object_storage_migrate:#{model.class}:#{model.id}"
+    end
+
     private
 
     def schedule_background_upload?
@@ -364,17 +395,14 @@ module ObjectStorage
       end
     end
 
-    def exclusive_lease_key
-      "object_storage_migrate:#{model.class}:#{model.id}"
-    end
-
     def with_exclusive_lease
-      uuid = Gitlab::ExclusiveLease.new(exclusive_lease_key, timeout: 1.hour.to_i).try_obtain
-      raise 'exclusive lease already taken' unless uuid
+      lease_key = exclusive_lease_key
+      uuid = Gitlab::ExclusiveLease.new(lease_key, timeout: 1.hour.to_i).try_obtain
+      raise ExclusiveLeaseTaken.new(lease_key) unless uuid
 
       yield uuid
     ensure
-      Gitlab::ExclusiveLease.cancel(exclusive_lease_key, uuid)
+      Gitlab::ExclusiveLease.cancel(lease_key, uuid)
     end
 
     #