From fd00d9e11d9e49f9df9aaceb7ce2ae2c20ea3da8 Mon Sep 17 00:00:00 2001
From: Umang Jain <umang@endlessm.com>
Date: Wed, 21 Nov 2018 18:19:35 +0530
Subject: [PATCH] system-helper: Add CancelPull D-Bus method

If there is a pull failure in a child repo created by GetChildRepoForPull
system helper method, there is no way to go back to the system helper and
notify it to cleanup. Therefore, CancelPull is required on the pull failure
error path, so that the ongoing pull can be cleaned up nicely and prevent
any dangling mounts and subprocesses.

https://github.com/ostreedev/ostree/issues/1723
---
 data/org.freedesktop.Flatpak.xml      |  7 +++++
 system-helper/flatpak-system-helper.c | 40 ++++++++++++++++++++++++++-
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/data/org.freedesktop.Flatpak.xml b/data/org.freedesktop.Flatpak.xml
index 8e3b48ed59..435f1e1e63 100644
--- a/data/org.freedesktop.Flatpak.xml
+++ b/data/org.freedesktop.Flatpak.xml
@@ -167,6 +167,13 @@
       <arg type='s' name='repo_path' direction='out'/>
     </method>
 
+    <!-- This method cancels an ongoing pull at repo_path. The cancellation triggered
+         by the client helps to cleanup the mount setup -->
+    <method name="CancelPull">
+      <arg type='s' name='installation' direction='in'/>
+      <arg type='s' name='repo_path' direction='in'/>
+    </method>
+
   </interface>
 
 </node>
diff --git a/system-helper/flatpak-system-helper.c b/system-helper/flatpak-system-helper.c
index 66aa36820b..bd2312da58 100644
--- a/system-helper/flatpak-system-helper.c
+++ b/system-helper/flatpak-system-helper.c
@@ -1812,6 +1812,42 @@ handle_update_summary (FlatpakSystemHelper   *object,
   return TRUE;
 }
 
+static gboolean
+handle_cancel_pull (FlatpakSystemHelper   *object,
+                    GDBusMethodInvocation *invocation,
+                    const gchar           *arg_installation,
+                    const gchar           *arg_repo_path)
+{
+  g_autoptr(OngoingPull) ongoing_pull = NULL;
+  g_autoptr(FlatpakDir) system = NULL;
+  g_autoptr(GError) error = NULL;
+
+  g_debug ("CancelPull %s", arg_installation);
+
+  system = dir_get_system (arg_installation, &error);
+  if (system == NULL)
+    {
+      g_dbus_method_invocation_return_gerror (invocation, error);
+      return TRUE;
+    }
+
+  ongoing_pull = take_ongoing_pull_by_dir (arg_repo_path);
+  if (ongoing_pull != NULL)
+    {
+      ongoing_pull_teardown (ongoing_pull);
+      ongoing_pull_unref (ongoing_pull);
+    }
+  else
+    {
+      /* Should not be reached */
+      g_warning ("Cannot find ongoing pull to cancel at: %s", arg_repo_path);
+    }
+
+  flatpak_system_helper_complete_cancel_pull (object, invocation);
+
+  return TRUE;
+}
+
 static gboolean
 flatpak_authorize_method_handler (GDBusInterfaceSkeleton *interface,
                                   GDBusMethodInvocation  *invocation,
@@ -1941,7 +1977,8 @@ flatpak_authorize_method_handler (GDBusInterfaceSkeleton *interface,
            g_strcmp0 (method_name, "EnsureRepo") == 0 ||
            g_strcmp0 (method_name, "RunTriggers") == 0 ||
            g_strcmp0 (method_name, "UpdateSummary") == 0 ||
-           g_strcmp0 (method_name, "GetChildRepoForPull") == 0)
+           g_strcmp0 (method_name, "GetChildRepoForPull") == 0 ||
+           g_strcmp0 (method_name, "CancelPull") == 0)
     {
       const char *remote;
 
@@ -2013,6 +2050,7 @@ on_bus_acquired (GDBusConnection *connection,
   g_signal_connect (helper, "handle-run-triggers", G_CALLBACK (handle_run_triggers), NULL);
   g_signal_connect (helper, "handle-update-summary", G_CALLBACK (handle_update_summary), NULL);
   g_signal_connect (helper, "handle-get-child-repo-for-pull", G_CALLBACK (handle_get_child_repo_for_pull), NULL);
+  g_signal_connect (helper, "handle-cancel-pull", G_CALLBACK (handle_cancel_pull), NULL);
 
   g_signal_connect (helper, "g-authorize-method",
                     G_CALLBACK (flatpak_authorize_method_handler),