From ed0ac581ad3866197fc05c7cf48e39419a51f606 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Fri, 18 Mar 2022 13:19:33 +0800
Subject: [PATCH] grub-probe: Deduplicate probed partmap output

If the target device being probed is staked on top of other physical or logical
devices, all containing device's partition map type will be printed once if
--target=partmap is used. This usually results in duplicated output as same
partition map type.

This in turn may clutter grub.cfg with many duplicated insmod part_[a-z]+ if
the /boot is RAIDed because --target=partmap output is used to producing
partmap modules required to access disk device.

Let's deduplicate that to make the grub.cfg looks better and disciplined.

Signed-off-by: Michael Chang <mchang@suse.com>
---
 util/grub-probe.c | 59 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 55 insertions(+), 4 deletions(-)

diff --git a/util/grub-probe.c b/util/grub-probe.c
index c08e46bbb..fb94f28fd 100644
--- a/util/grub-probe.c
+++ b/util/grub-probe.c
@@ -153,6 +153,50 @@ do_print (const char *x, void *data)
   grub_printf ("%s%c", x, delim);
 }
 
+static int
+check_duplicate_partmap (const char *name)
+{
+  static int alloc, used;
+  static char **partmaps;
+  int i;
+
+  if (!name)
+    {
+      if (partmaps)
+      {
+        for (i= 0; i < used; ++i)
+          free (partmaps[i]);
+        free (partmaps);
+        partmaps = NULL;
+        alloc = 0;
+        used = 0;
+      }
+      return 1;
+    }
+
+  for (i= 0; i < used; ++i)
+    if (strcmp (partmaps[i], name) == 0)
+      return 1;
+
+  if (alloc <= used)
+    {
+      alloc = (alloc) ? (alloc << 1) : 4;
+      partmaps = xrealloc (partmaps, alloc * sizeof (*partmaps));
+    }
+
+  partmaps[used++] = strdup (name);
+  return 0;
+}
+
+static void
+do_print_partmap (const char *x, void *data)
+{
+  char delim = *(const char *) data;
+  if (check_duplicate_partmap (x) != 0)
+    return;
+  grub_printf ("%s%c", x, delim);
+}
+
 static void
 probe_partmap (grub_disk_t disk, char delim)
 {
@@ -165,10 +209,14 @@ probe_partmap (grub_disk_t disk, char delim)
     }
 
   for (part = disk->partition; part; part = part->parent)
-    printf ("%s%c", part->partmap->name, delim);
+    {
+      if (check_duplicate_partmap (part->partmap->name) != 0)
+	continue;
+      printf ("%s%c", part->partmap->name, delim);
+    }
 
   if (disk->dev->id == GRUB_DISK_DEVICE_DISKFILTER_ID)
-    grub_diskfilter_get_partmap (disk, do_print, &delim);
+    grub_diskfilter_get_partmap (disk, do_print_partmap, &delim);
 
   /* In case of LVM/RAID, check the member devices as well.  */
   if (disk->dev->disk_memberlist)
@@ -674,8 +722,11 @@ probe (const char *path, char **device_names, char delim)
 	probe_cryptodisk_uuid (dev->disk, delim);
 
       else if (print == PRINT_PARTMAP)
-	/* Check if dev->disk itself is contained in a partmap.  */
-	probe_partmap (dev->disk, delim);
+	{
+	  /* Check if dev->disk itself is contained in a partmap.  */
+	  probe_partmap (dev->disk, delim);
+	  check_duplicate_partmap (NULL);
+	}
 
       else if (print == PRINT_PARTUUID)
 	{
-- 
2.35.1