NEX-16970 assertion failed: ht->ht_valid_cnt >= 0, file: ../../i86pc/vm/htable.c, line: 1204
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: Evan Layton <evan.layton@nexenta.com>
Reviewed by: Rob Gittins <rob.gittins@nexenta.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>

*** 22,31 ****
--- 22,32 ----
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  /*
   * Copyright (c) 2014 by Delphix. All rights reserved.
+  * Copyright 2019 Nexenta Systems, Inc.
   */
  
  #ifndef _VM_HAT_I86_H
  #define _VM_HAT_I86_H
  
*** 85,94 ****
--- 86,96 ----
          uint_t          hat_stats;
          pgcnt_t         hat_pages_mapped[MAX_PAGE_LEVEL + 1];
          pgcnt_t         hat_ism_pgcnt;
          cpuset_t        hat_cpus;
          uint16_t        hat_flags;
+         uint16_t        hat_unmaps;     /* stop hat being free'd during unmap */
          htable_t        *hat_htable;    /* top level htable */
          struct hat      *hat_next;
          struct hat      *hat_prev;
          uint_t          hat_num_hash;   /* number of htable hash buckets */
          htable_t        **hat_ht_hash;  /* htable hash buckets */