[glib/wip/oholy/bind-mounts: 2/2] gunixmounts: Mark mounts as system internal instead of filtering out

[Ondrej Holy <oholy src gnome org>]

commit 4ffad004ed2afc128bd28e7f2f3c222cee5da779
Author: Ondrej Holy <oholy redhat com>
Date:   Thu Apr 26 16:22:36 2018 +0200

    gunixmounts: Mark mounts as system internal instead of filtering out
    
    mntent-based implementation filter out mounts with device path that was
    repeated. Consequently, it is not possible to show such mounts in UI even
    with x-gvfs-show, because they are not returned from g_unix_mounts_get.
    libmount-based implementation currently doesn't filter out any mounts
    which causes issues to our volume monitors. Let's rather mark mounts
    which don't point into fs root as system_internal. This approach won't be
    affected by mount order as is mntent-based implementation. It will mark
    more mounts as system_internal than it is filtered out with mntend-based
    implementation, but there will be always possibility to show them in UI
    over x-gvfs-show, which was not possible with mntend-based. We can
    probably introduce some improvements later to not mark unique mounts as
    system internal even if they don't point into fs root...
    
    https://bugzilla.gnome.org/show_bug.cgi?id=782814

 gio/gunixmounts.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
---
diff --git a/gio/gunixmounts.c b/gio/gunixmounts.c
index 452b686d5..6b50f58b1 100644
--- a/gio/gunixmounts.c
+++ b/gio/gunixmounts.c
@@ -389,8 +389,9 @@ g_unix_is_system_device_path (const char *device_path)
 
 static gboolean
 guess_system_internal (const char *mountpoint,
-                      const char *fs,
-                      const char *device)
+                       const char *fs,
+                       const char *device,
+                       const char *root)
 {
   if (g_unix_is_system_fs_type (fs))
     return TRUE;
@@ -400,7 +401,14 @@ guess_system_internal (const char *mountpoint,
 
   if (g_unix_is_mount_path_system_internal (mountpoint))
     return TRUE;
-  
+
+  /* Mounts created by bind operation, or btrfs subvolumes just usually
+   * duplicate content of other mounts, so let's mark them as system internal
+   * by default.
+   */
+  if (root != NULL && g_strcmp0 (root, "/") != 0)
+    return TRUE;
+
   return FALSE;
 }
 
@@ -427,7 +435,9 @@ create_unix_mount_entry (const char *device_path,
   mount_entry->is_system_internal =
     guess_system_internal (mount_entry->mount_path,
                            mount_entry->filesystem_type,
-                           mount_entry->device_path);
+                           mount_entry->device_path,
+                           mount_entry->root_path);
+
   return mount_entry;
 }