libsysprof-analyze: treat overlay as SysprofMount

This creates a synthesized SysprofMount for the overlays so that we can
process them as we walk the other mounts.

src/libsysprof-analyze/sysprof-document.c

@@ -35,6 +35,7 @@
 #include "sysprof-document-frame-private.h"
 #include "sysprof-document-jitmap.h"
 #include "sysprof-document-mmap.h"
+#include "sysprof-document-overlay.h"
 #include "sysprof-document-process-private.h"
 #include "sysprof-document-symbols-private.h"
 #include "sysprof-mount-private.h"
@@ -437,7 +438,15 @@ sysprof_document_load_overlays (SysprofDocument *self)
           SysprofProcessInfo *process_info = _sysprof_document_process_info (self, pid, TRUE);
 
           if (process_info != NULL)
-            sysprof_mount_namespace_add_overlay (process_info->mount_namespace, overlay);
+            {
+              const char *mount_point = sysprof_document_overlay_get_destination (overlay);
+              const char *host_path = sysprof_document_overlay_get_source (overlay);
+              int layer = sysprof_document_overlay_get_layer (overlay);
+              g_autoptr(SysprofMount) mount = _sysprof_mount_new_for_overlay (self->strings, mount_point, host_path, layer);
+
+              sysprof_mount_namespace_add_mount (process_info->mount_namespace,
+                                                 g_steal_pointer (&mount));
+            }
         }
       while (gtk_bitset_iter_next (&iter, &i));
     }

src/libsysprof-analyze/sysprof-mount-namespace-private.h

@@ -24,7 +24,6 @@
 
 #include "sysprof-mount-private.h"
 #include "sysprof-mount-device-private.h"
-#include "sysprof-document-overlay.h"
 
 G_BEGIN_DECLS
 
@@ -38,8 +37,6 @@ void                    sysprof_mount_namespace_add_device  (SysprofMountNamespa
                                                              SysprofMountDevice     *mount);
 void                    sysprof_mount_namespace_add_mount   (SysprofMountNamespace  *self,
                                                              SysprofMount           *mount);
-void                    sysprof_mount_namespace_add_overlay (SysprofMountNamespace  *self,
-                                                             SysprofDocumentOverlay *overlay);
 char                  **sysprof_mount_namespace_translate   (SysprofMountNamespace  *self,
                                                              const char             *path);
 

src/libsysprof-analyze/sysprof-mount-namespace.c

@@ -150,16 +150,6 @@ sysprof_mount_namespace_add_mount (SysprofMountNamespace *self,
   self->mounts_dirty = TRUE;
 }
 
-void
-sysprof_mount_namespace_add_overlay (SysprofMountNamespace  *self,
-                                     SysprofDocumentOverlay *overlay)
-{
-  g_return_if_fail (SYSPROF_IS_MOUNT_NAMESPACE (self));
-  g_return_if_fail (SYSPROF_IS_DOCUMENT_OVERLAY (overlay));
-
-  /* TODO */
-}
-
 static SysprofMountDevice *
 sysprof_mount_namespace_find_device (SysprofMountNamespace *self,
                                      SysprofMount          *mount,
@@ -196,9 +186,9 @@ sysprof_mount_namespace_find_device (SysprofMountNamespace *self,
   return NULL;
 }
 
-static gint
-sort_by_length (gconstpointer a,
-                gconstpointer b)
+static int
+compare_mount (gconstpointer a,
+               gconstpointer b)
 {
   SysprofMount *mount_a = *(SysprofMount * const *)a;
   SysprofMount *mount_b = *(SysprofMount * const *)b;
@@ -209,8 +199,13 @@ sort_by_length (gconstpointer a,
     return -1;
   else if (blen > alen)
     return 1;
-  else
-    return 0;
+
+  if (mount_a->layer < mount_b->layer)
+    return -1;
+  else if (mount_a->layer > mount_b->layer)
+    return 1;
+
+  return 0;
 }
 
 /**
@@ -237,9 +232,9 @@ sysprof_mount_namespace_translate (SysprofMountNamespace *self,
   g_return_val_if_fail (SYSPROF_IS_MOUNT_NAMESPACE (self), NULL);
   g_return_val_if_fail (file != NULL, NULL);
 
-  if (self->mounts_dirty)
+  if G_UNLIKELY (self->mounts_dirty)
     {
-      g_ptr_array_sort (self->mounts, sort_by_length);
+      g_ptr_array_sort (self->mounts, compare_mount);
       self->mounts_dirty = FALSE;
     }
 
@@ -253,25 +248,21 @@ sysprof_mount_namespace_translate (SysprofMountNamespace *self,
       const char *relative;
       char *translated;
 
-      if (!(relative = _sysprof_mount_get_relative_path (mount, file)) ||
-          !(device = sysprof_mount_namespace_find_device (self, mount, relative)))
+      if (!(relative = _sysprof_mount_get_relative_path (mount, file)))
         continue;
 
-      device_mount_point = sysprof_mount_device_get_mount_point (device);
-      translated = g_build_filename (device_mount_point, relative, NULL);
+      if (!mount->is_overlay)
+        {
+          if (!(device = sysprof_mount_namespace_find_device (self, mount, relative)))
+            continue;
 
-      /* TODO: Still a bit to do here, because we need to handle overlays
-       * still as a SysprofMount. Additionally, we may need to adjust the
-       * paths a bit more based on subvolume, but I need a system such
-       * as Silverblue or GNOME OS to test that again to match or improve
-       * on existing behavior in libsysprof.
-       */
-
-      /* TODO: After we've translated to what we'd expect to see on the
-       * host system, we'll need to translate once again to what we can
-       * actually access if we're inside a container ourselves, such as
-       * Toolbox or Flatpak and use /var/run/host or similar.
-       */
+          device_mount_point = sysprof_mount_device_get_mount_point (device);
+          translated = g_build_filename (device_mount_point, relative, NULL);
+        }
+      else
+        {
+          translated = g_build_filename (mount->mount_source, relative, NULL);
+        }
 
       g_array_append_val (strv, translated);
     }

src/libsysprof-analyze/sysprof-mount-private.h

@@ -25,8 +25,28 @@
 
 G_BEGIN_DECLS
 
+struct _SysprofMount
+{
+  GObject parent_instance;
+  int mount_id;
+  int parent_mount_id;
+  int device_major;
+  int device_minor;
+  GRefString *root;
+  GRefString *mount_point;
+  GRefString *mount_source;
+  GRefString *filesystem_type;
+  GRefString *superblock_options;
+  guint is_overlay : 1;
+  guint layer : 15;
+};
+
 SysprofMount *_sysprof_mount_new_for_mountinfo (SysprofStrings *strings,
                                                 const char     *mountinfo);
+SysprofMount *_sysprof_mount_new_for_overlay   (SysprofStrings *strings,
+                                                const char     *mount_point,
+                                                const char     *host_path,
+                                                int             layer);
 const char   *_sysprof_mount_get_relative_path (SysprofMount   *self,
                                                 const char     *path);
 

src/libsysprof-analyze/sysprof-mount.c

@@ -24,20 +24,6 @@
 
 #include "sysprof-mount-private.h"
 
-struct _SysprofMount
-{
-  GObject parent_instance;
-  int mount_id;
-  int parent_mount_id;
-  int device_major;
-  int device_minor;
-  GRefString *root;
-  GRefString *mount_point;
-  GRefString *mount_source;
-  GRefString *filesystem_type;
-  GRefString *superblock_options;
-};
-
 enum {
   PROP_0,
   PROP_DEVICE_MAJOR,
@@ -239,6 +225,27 @@ finish:
   return g_steal_pointer (&self);
 }
 
+SysprofMount *
+_sysprof_mount_new_for_overlay (SysprofStrings *strings,
+                                const char     *mount_point,
+                                const char     *host_path,
+                                int             layer)
+{
+  SysprofMount *self;
+
+  g_return_val_if_fail (strings != NULL, NULL);
+  g_return_val_if_fail (mount_point != NULL, NULL);
+  g_return_val_if_fail (host_path != NULL, NULL);
+
+  self = g_object_new (SYSPROF_TYPE_MOUNT, NULL);
+  self->mount_point = sysprof_strings_get (strings, mount_point);
+  self->root = sysprof_strings_get (strings, "/");
+  self->mount_source = sysprof_strings_get (strings, host_path);
+  self->is_overlay = TRUE;
+
+  return self;
+}
+
 int
 sysprof_mount_get_device_major (SysprofMount *self)
 {