# UNDF: UNDF-2026-000001022
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -536,6 +536,15 @@
  *   2. insert_group: linear scan of ex_groups linked list for
  *      duplicate group names, O(G) per insert = O(E*G) total.
  *
+ *   Fix: replace linked list scans with hash tables.
+ *     - lookup_or_create_elist_entry: hash table keyed by e_path
+ *     - insert_group: hash set per exportnode for group names
+ *
+ *   Impact: NFS servers with thousands of exports (common in
+ *   large HPC/enterprise deployments) experience slow MOUNT
+ *   EXPORT responses. Doubling exports quadruples response time.
+ */
+/*
  * Original code:
  *
  * static exportnode *lookup_or_create_elist_entry(exports *elist, nfs_export *exp)
@@ -558,6 +567,15 @@
  *     g->gr_next = e->ex_groups;
  *     e->ex_groups = g;
  * }
+ *
+ * Patched: use GLib hash table or POSIX hsearch_r for path lookup,
+ * and a per-exportnode hash set for group dedup.  Since mountd already
+ * links against libc, hsearch_r is available at zero dependency cost.
+ *
+ * Alternatively, since HASH_TABLE_SIZE (1021) already exists in
+ * exportfs.h for the export hash table, we can reuse the same
+ * strtoint() hash function from export.c to bucket paths, giving
+ * O(1) amortized lookup without adding new dependencies.
  */

 static exportnode *lookup_or_create_elist_entry(exports *elist, nfs_export *exp)