From ec380135ed8cf57a70501542081dad51d2d11fa8 Mon Sep 17 00:00:00 2001
From: Tomas Bzatek <tbzatek@redhat.com>
Date: Thu, 6 Jan 2022 20:45:45 +0100
Subject: [PATCH] udiskslinuxprovider: Only update related objects on utab
 changes

Updating all existing block objects on any utab change
was unnecessary and overly expensive. With the UDisksUtabMonitor
providing specific utab entry, update just block objects
with matching device file.

Note that there is a room for similar optimization in fstab
and crypttab monitoring.
---
 src/udiskslinuxprovider.c | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/udiskslinuxprovider.c b/src/udiskslinuxprovider.c
index cfc6a330..4231a33c 100644
--- a/src/udiskslinuxprovider.c
+++ b/src/udiskslinuxprovider.c
@@ -39,6 +39,7 @@
 #include "udisksmoduleobject.h"
 #include "udisksdaemonutil.h"
 #include "udisksconfigmanager.h"
+#include "udisksutabentry.h"
 
 /**
  * SECTION:udiskslinuxprovider
@@ -1559,7 +1560,7 @@ on_housekeeping_timeout (gpointer user_data)
 /* ---------------------------------------------------------------------------------------------------- */
 
 static void
-update_all_block_objects (UDisksLinuxProvider *provider)
+update_block_objects (UDisksLinuxProvider *provider, const gchar *device_path)
 {
   GList *objects;
   GList *l;
@@ -1572,18 +1573,36 @@ update_all_block_objects (UDisksLinuxProvider *provider)
   for (l = objects; l != NULL; l = l->next)
     {
       UDisksLinuxBlockObject *object = UDISKS_LINUX_BLOCK_OBJECT (l->data);
-      udisks_linux_block_object_uevent (object, "change", NULL);
+
+      if (device_path == NULL)
+        udisks_linux_block_object_uevent (object, "change", NULL);
+      else
+        {
+          gchar *block_dev;
+          gboolean match;
+
+          block_dev = udisks_linux_block_object_get_device_file (object);
+          match = g_strcmp0 (block_dev, device_path) == 0;
+          g_free (block_dev);
+          if (match)
+            {
+              udisks_linux_block_object_uevent (object, "change", NULL);
+              break;
+            }
+        }
     }
 
   g_list_free_full (objects, g_object_unref);
 }
 
+/* fstab monitoring */
 static void
 mount_monitor_on_mountpoints_changed (GUnixMountMonitor *monitor,
                                       gpointer           user_data)
 {
   UDisksLinuxProvider *provider = UDISKS_LINUX_PROVIDER (user_data);
-  update_all_block_objects (provider);
+  /* TODO: compare differences and only update relevant objects */
+  update_block_objects (provider, NULL);
 }
 
 static void
@@ -1592,7 +1611,7 @@ crypttab_monitor_on_entry_added (UDisksCrypttabMonitor *monitor,
                                  gpointer               user_data)
 {
   UDisksLinuxProvider *provider = UDISKS_LINUX_PROVIDER (user_data);
-  update_all_block_objects (provider);
+  update_block_objects (provider, NULL);
 }
 
 static void
@@ -1601,7 +1620,7 @@ crypttab_monitor_on_entry_removed (UDisksCrypttabMonitor *monitor,
                                    gpointer               user_data)
 {
   UDisksLinuxProvider *provider = UDISKS_LINUX_PROVIDER (user_data);
-  update_all_block_objects (provider);
+  update_block_objects (provider, NULL);
 }
 
 #ifdef HAVE_LIBMOUNT_UTAB
@@ -1611,7 +1630,7 @@ utab_monitor_on_entry_added (UDisksUtabMonitor *monitor,
                              gpointer           user_data)
 {
   UDisksLinuxProvider *provider = UDISKS_LINUX_PROVIDER (user_data);
-  update_all_block_objects (provider);
+  update_block_objects (provider, udisks_utab_entry_get_source (entry));
 }
 
 static void
@@ -1620,6 +1639,6 @@ utab_monitor_on_entry_removed (UDisksUtabMonitor *monitor,
                                gpointer           user_data)
 {
   UDisksLinuxProvider *provider = UDISKS_LINUX_PROVIDER (user_data);
-  update_all_block_objects (provider);
+  update_block_objects (provider, udisks_utab_entry_get_source (entry));
 }
 #endif
-- 
2.38.1