fix(files): keep the root filesystem among the volumes

files/tests/volume_manager_test.cpp

@@ -444,11 +444,11 @@ TEST(VolumeManagerTest, SystemMountPointsAreLeftOut)
 
     using files::testing::waitFor;
 
-    ASSERT_TRUE(waitFor(loop, [&] { return manager.volumes().size() == 4; }));
+    ASSERT_TRUE(waitFor(loop, [&] { return manager.volumes().size() == 5; }));
     std::vector<std::string> names;
     for (const Volume& volume : manager.volumes())
         names.push_back(volume.name);
-    EXPECT_EQ(names, (std::vector<std::string>{"data", "USB", "stick", "windows"}));
+    EXPECT_EQ(names, (std::vector<std::string>{"data", "root", "USB", "stick", "windows"}));
     // A Windows partition stays: it takes an administrator to mount, nothing more.
     EXPECT_TRUE(manager.volume(root + "/block_devices/windows").system);
     EXPECT_FALSE(manager.volume(root + "/block_devices/stick").system);

files/volume_manager.cpp

@@ -42,6 +42,8 @@ static bool isSet(const ObjectPath& path)
 
 static bool isSystemMountPoint(const std::string& path)
 {
+    if (path == "/")
+        return false;
     for (const std::string prefix : {"/media/", "/run/media/", "/mnt/"}) {
         if (path.starts_with(prefix))
             return false;

files/volume_manager.h

@@ -45,9 +45,9 @@ struct Volume
 };
 
 // UDisks2's block devices, kept up to date from its signals, and mounting,
-// unmounting and ejecting them. Calls never block. Blocks mounted outside
+// unmounting and ejecting them. Calls never block. Blocks mounted outside /,
-// /media, /run/media and /mnt (the root, home and boot filesystems) are left
+// /media, /run/media and /mnt (the home and boot filesystems) are left out,
-// out, and an unlocked encrypted volume stands for its cleartext block.
+// and an unlocked encrypted volume stands for its cleartext block.
 class VolumeManager
 {
 public: