[gnome-disk-utility] Detect and convey MD-RAID split-brain syndrome

[David Zeuthen <davidz src gnome org>]

commit 2e6adb16edecf757bf87e5737e96f1c7c98ceedf
Author: David Zeuthen <zeuthen gmail com>
Date:   Thu Nov 29 12:06:58 2012 -0500

    Detect and convey MD-RAID split-brain syndrome
    
    See this udisks commit for more information about the syndrome
    
     http://cgit.freedesktop.org/udisks/commit/?id=301ab668ff65c4e9f28037251bedba26543b6024
    
    The fact that Linux / mdadm allows you to end up in a split-brain
    situation in the _first_ place is pretty horrific (that's the price
    you pay for flexibility, loosely coupled systems etc. etc.).
    
    Anyway, in Disks, we cope with the situation by conveying the device
    files in question and a link to Wikipedia. It looks like this
    
     http://people.freedesktop.org/~david/gnome-disks-mdraid-split-brain.png
    
    Ideally there would be a page on the Linux RAID wiki at
    
     https://raid.wiki.kernel.org/index.php/Linux_Raid
    
    but that is not how things work right now.
    
    Signed-off-by: David Zeuthen <zeuthen gmail com>

 src/disks/gduwindow.c |   43 +++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 41 insertions(+), 2 deletions(-)
---
diff --git a/src/disks/gduwindow.c b/src/disks/gduwindow.c
index dce9338..22f11a2 100644
--- a/src/disks/gduwindow.c
+++ b/src/disks/gduwindow.c
@@ -2133,6 +2133,7 @@ update_device_page_for_mdraid (GduWindow      *window,
   gchar *s = NULL, *s2, *s3;
   gchar *desc = NULL;
   gchar *device_desc = NULL;
+  GList *all_blocks = NULL;
   UDisksBlock *block = NULL;
   guint64 size = 0;
   guint num_devices = 0;
@@ -2157,6 +2158,7 @@ update_device_page_for_mdraid (GduWindow      *window,
   size = udisks_mdraid_get_size (mdraid);
   num_devices = udisks_mdraid_get_num_devices (mdraid);
   block = udisks_client_get_block_for_mdraid (window->client, mdraid);
+  all_blocks = udisks_client_get_all_blocks_for_mdraid (window->client, mdraid);
   members = udisks_client_get_members_for_mdraid (window->client, mdraid);
   degraded = udisks_mdraid_get_degraded (mdraid);
   sync_action = udisks_mdraid_get_sync_action (mdraid);
@@ -2181,9 +2183,21 @@ update_device_page_for_mdraid (GduWindow      *window,
 
   update_grid_for_mdraid (window, mdraid);
 
-  if (block != NULL)
+  if (all_blocks != NULL)
     {
-      device_desc = get_device_file_for_display (block);
+      GString *str;
+      GList *l;
+      str = g_string_new (NULL);
+      for (l = all_blocks; l != NULL; l = l->next)
+        {
+          UDisksBlock *mdraid_block = UDISKS_BLOCK (l->data);
+          if (str->len > 0)
+            g_string_append_c (str, ' ');
+          s = get_device_file_for_display (mdraid_block);
+          g_string_append (str, s);
+          g_free (s);
+        }
+      device_desc = g_string_free (str, FALSE);
       show_flags->drive_buttons |= SHOW_FLAGS_DRIVE_BUTTONS_RAID_STOP;
       show_flags->drive_menu |= SHOW_FLAGS_DRIVE_MENU_MDRAID_DISKS;
     }
@@ -2417,6 +2431,30 @@ update_device_page_for_mdraid (GduWindow      *window,
         }
     }
 
+  /* If we've detected a split-brain situation, this is more important
+   * to convey than the actual array state
+   */
+  if (g_list_length (all_blocks) > 1)
+    {
+      s = g_strdup_printf ("<span foreground=\"#ff0000\"><b>%s</b></span>",
+                           /* Translators: String for conveying the raid array is misconfigured */
+                           C_("raid-split-brain", "RAID ARRAY IS MISCONFIGURED"));
+      s2 = g_strdup_printf ("<a href='http://en.wikipedia.org/wiki/Split-brain_(computing)'>%s</a>",
+                           /* Translators: The specific type of misconfiguration, see
+                            * http://en.wikipedia.org/wiki/Split-brain_(computing)
+                            * for more details
+                            */
+                            C_("raid-split-brain", "Split-brain syndrome"));
+      g_free (raid_state_upper);
+      /* Translators: Combiner for the RAID split-brain strings.
+       *              The first %s is "SYSTEM IS MISCONFIGURED".
+       *              The second %s is "Split-brain syndrome" as a hyperlink.
+       */
+      raid_state_upper = g_strdup_printf (C_("raid-split-brain", "%s (%s)"), s, s2);
+      g_free (s2);
+      g_free (s);
+    }
+
   gtk_widget_show (window->devtab_drive_raid_state_value_label);
   gtk_label_set_markup (GTK_LABEL (window->devtab_drive_raid_state_value_label), raid_state_upper);
 
@@ -2482,6 +2520,7 @@ update_device_page_for_mdraid (GduWindow      *window,
   g_clear_object (&info);
 
   g_clear_object (&block);
+  g_list_free_full (all_blocks, g_object_unref);
 }
 
 /* ---------------------------------------------------------------------------------------------------- */