NEX-6859 TX-commit callback that is registered in sync-ctx causes system panic
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>

@@ -21,10 +21,11 @@
 /*
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 /*
+ * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
  */
 
 #ifndef _SYS_TXG_H
 #define _SYS_TXG_H

@@ -72,10 +73,12 @@
 extern void txg_sync_stop(struct dsl_pool *dp);
 extern uint64_t txg_hold_open(struct dsl_pool *dp, txg_handle_t *txghp);
 extern void txg_rele_to_quiesce(txg_handle_t *txghp);
 extern void txg_rele_to_sync(txg_handle_t *txghp);
 extern void txg_register_callbacks(txg_handle_t *txghp, list_t *tx_callbacks);
+extern void txg_register_callbacks_sync(struct dsl_pool *dp,
+    uint64_t txg, list_t *tx_callbacks);
 
 extern void txg_delay(struct dsl_pool *dp, uint64_t txg, hrtime_t delta,
     hrtime_t resolution);
 extern void txg_kick(struct dsl_pool *dp);