Add VTOY_MAX_SEARCH_LEVEL option in global control plugin

GRUB2/MOD_SRC/grub-2.04/grub-core/ventoy/ventoy.c

@@ -74,6 +74,7 @@ int g_ventoy_img_count = 0;
 
 grub_device_t g_enum_dev = NULL;
 grub_fs_t g_enum_fs = NULL;
+int g_img_max_search_level = -1;
 img_iterator_node g_img_iterator_head;
 img_iterator_node *g_img_iterator_tail = NULL;
 
@@ -1194,6 +1195,11 @@ static int ventoy_collect_img_files(const char *filename, const struct grub_dirh
 
     if (info->dir)
     {
+        if (node->level + 1 > g_img_max_search_level)
+        {
+            return 0;
+        }
+
         if ((len == 1 && filename[0] == '.') ||
             (len == 2 && filename[0] == '.' && filename[1] == '.'))
         {
@@ -1224,6 +1230,7 @@ static int ventoy_collect_img_files(const char *filename, const struct grub_dirh
         new_node = grub_zalloc(sizeof(img_iterator_node));
         if (new_node)
         {
+            new_node->level = node->level + 1;
             new_node->plugin_list_index = index;
             new_node->dirlen = grub_snprintf(new_node->dir, sizeof(new_node->dir), "%s%s/", node->dir, filename);
 
@@ -2054,6 +2061,16 @@ static grub_err_t ventoy_cmd_list_img(grub_extcmd_context_t ctxt, int argc, char
 
     g_img_iterator_head.tail = &tail;
 
+    if (g_img_max_search_level < 0)
+    {
+        g_img_max_search_level = GRUB_INT_MAX;
+        strdata = ventoy_get_env("VTOY_MAX_SEARCH_LEVEL");
+        if (strdata && ventoy_is_decimal(strdata))
+        {
+            g_img_max_search_level = (int)grub_strtoul(strdata, NULL, 10);
+        }
+    }
+
     for (node = &g_img_iterator_head; node; node = node->next)
     {
         fs->fs_dir(dev, node->dir, ventoy_collect_img_files, node);        

GRUB2/MOD_SRC/grub-2.04/grub-core/ventoy/ventoy_def.h

@@ -205,6 +205,7 @@ typedef struct img_iterator_node
     img_info **tail;
     char dir[400];
     int dirlen;
+    int level;
     int isocnt;
     int done;
     int select;