From 937299d72b5060fd3e98527b0a4268c549a94d3f Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@dell.com>
Date: Tue, 13 Mar 2018 22:08:39 -0500
Subject: [PATCH] uefi: Check that EFI system partition is mounted (Fixes:
 #436)

If the ESP isn't mounted it's possible that the update may look
succesful on the Linux side, but certain to fail later.
---
 plugins/uefi/fu-plugin-uefi.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/plugins/uefi/fu-plugin-uefi.c b/plugins/uefi/fu-plugin-uefi.c
index f587c1d41..c089a7e37 100644
--- a/plugins/uefi/fu-plugin-uefi.c
+++ b/plugins/uefi/fu-plugin-uefi.c
@@ -377,6 +377,30 @@ fu_plugin_uefi_update_splash (GError **error)
 	return fu_plugin_uefi_update_resource (re, 0, image_bmp, error);
 }
 
+static gboolean
+fu_plugin_uefi_esp_mounted (FuPlugin *plugin, GError **error)
+{
+	FuPluginData *data = fu_plugin_get_data (plugin);
+	g_autofree gchar *contents = NULL;
+	g_auto(GStrv) lines = NULL;
+	gsize length;
+
+	if (!g_file_get_contents ("/proc/mounts", &contents, &length, error))
+		return FALSE;
+	lines = g_strsplit (contents, "\n", 0);
+
+	for (guint i = 0; lines[i] != NULL; i++) {
+		if (lines[i] != NULL && g_strrstr (lines[i], data->esp_path))
+			return TRUE;
+	}
+	g_set_error (error,
+		     FWUPD_ERROR,
+		     FWUPD_ERROR_NOT_SUPPORTED,
+		     "EFI System partition %s is not mounted",
+		     data->esp_path);
+	return FALSE;
+}
+
 gboolean
 fu_plugin_update (FuPlugin *plugin,
 		  FuDevice *device,
@@ -403,6 +427,10 @@ fu_plugin_update (FuPlugin *plugin,
 	str = _("Installing firmware update…");
 	g_assert (str != NULL);
 
+	/* make sure that the ESP is mounted */
+	if (!fu_plugin_uefi_esp_mounted (plugin, error))
+		return FALSE;
+
 	/* perform the update */
 	g_debug ("Performing UEFI capsule update");
 	fu_device_set_status (device, FWUPD_STATUS_SCHEDULING);