5056 ZFS deadlock on db_mtx and dn_holds
Reviewed by: Will Andrews <willa@spectralogic.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

*** 20,29 ****
--- 20,30 ----
   */
  /*
   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
   * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
   */
  
  #ifndef _SYS_SPA_IMPL_H
  #define _SYS_SPA_IMPL_H
  
*** 142,151 ****
--- 143,155 ----
          uint64_t        spa_freeze_txg;         /* freeze pool at this txg */
          uint64_t        spa_load_max_txg;       /* best initial ub_txg */
          uint64_t        spa_claim_max_txg;      /* highest claimed birth txg */
          timespec_t      spa_loaded_ts;          /* 1st successful open time */
          objset_t        *spa_meta_objset;       /* copy of dp->dp_meta_objset */
+         kmutex_t        spa_evicting_os_lock;   /* Evicting objset list lock */
+         list_t          spa_evicting_os_list;   /* Objsets being evicted. */
+         kcondvar_t      spa_evicting_os_cv;     /* Objset Eviction Completion */
          txg_list_t      spa_vdev_txg_list;      /* per-txg dirty vdev list */
          vdev_t          *spa_root_vdev;         /* top-level vdev container */
          uint64_t        spa_config_guid;        /* config pool guid */
          uint64_t        spa_load_guid;          /* spa_load initialized guid */
          uint64_t        spa_last_synced_guid;   /* last synced guid */