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) 2012, 2014 by Delphix. All rights reserved.
   * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
+  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
   */
  
  /* Portions Copyright 2010 Robert Milkowski */
  
  #ifndef _SYS_DMU_OBJSET_H
*** 72,97 ****
          struct dsl_dataset *os_dsl_dataset;
          spa_t *os_spa;
          arc_buf_t *os_phys_buf;
          objset_phys_t *os_phys;
          /*
!          * The following "special" dnodes have no parent and are exempt from
!          * dnode_move(), but they root their descendents in this objset using
!          * handles anyway, so that all access to dnodes from dbufs consistently
!          * uses handles.
           */
          dnode_handle_t os_meta_dnode;
          dnode_handle_t os_userused_dnode;
          dnode_handle_t os_groupused_dnode;
          zilog_t *os_zil;
  
          /* can change, under dsl_dir's locks: */
          enum zio_checksum os_checksum;
          enum zio_compress os_compress;
          uint8_t os_copies;
          enum zio_checksum os_dedup_checksum;
          boolean_t os_dedup_verify;
          zfs_logbias_op_t os_logbias;
          zfs_cache_type_t os_primary_cache;
          zfs_cache_type_t os_secondary_cache;
          zfs_sync_type_t os_sync;
          zfs_redundant_metadata_type_t os_redundant_metadata;
--- 73,101 ----
          struct dsl_dataset *os_dsl_dataset;
          spa_t *os_spa;
          arc_buf_t *os_phys_buf;
          objset_phys_t *os_phys;
          /*
!          * The following "special" dnodes have no parent, are exempt
!          * from dnode_move(), and are not recorded in os_dnodes, but they
!          * root their descendents in this objset using handles anyway, so
!          * that all access to dnodes from dbufs consistently uses handles.
           */
          dnode_handle_t os_meta_dnode;
          dnode_handle_t os_userused_dnode;
          dnode_handle_t os_groupused_dnode;
          zilog_t *os_zil;
  
+         list_node_t os_evicting_node;
+ 
          /* can change, under dsl_dir's locks: */
          enum zio_checksum os_checksum;
          enum zio_compress os_compress;
          uint8_t os_copies;
          enum zio_checksum os_dedup_checksum;
          boolean_t os_dedup_verify;
+         boolean_t os_evicting;
          zfs_logbias_op_t os_logbias;
          zfs_cache_type_t os_primary_cache;
          zfs_cache_type_t os_secondary_cache;
          zfs_sync_type_t os_sync;
          zfs_redundant_metadata_type_t os_redundant_metadata;
*** 168,177 ****
--- 172,183 ----
  boolean_t dmu_objset_userused_enabled(objset_t *os);
  int dmu_objset_userspace_upgrade(objset_t *os);
  boolean_t dmu_objset_userspace_present(objset_t *os);
  int dmu_fsname(const char *snapname, char *buf);
  
+ void dmu_objset_evict_done(objset_t *os);
+ 
  void dmu_objset_init(void);
  void dmu_objset_fini(void);
  
  #ifdef  __cplusplus
  }