6536 zfs send: want a way to disable setting of DRR_FLAG_FREERECORDS
Reviewed by: Anil Vijarnia <avijarnia@racktopsystems.com>
Reviewed by: Kim Shrier <kshrier@racktopsystems.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>

@@ -22,10 +22,11 @@
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
  * Copyright (c) 2014, Joyent, Inc. All rights reserved.
  * Copyright 2014 HybridCluster. All rights reserved.
+ * Copyright 2016 RackTop Systems.
  */
 
 #include <sys/dmu.h>
 #include <sys/dmu_impl.h>
 #include <sys/dmu_tx.h>

@@ -56,10 +57,12 @@
 
 /* Set this tunable to TRUE to replace corrupt data with 0x2f5baddb10c */
 int zfs_send_corrupt_data = B_FALSE;
 int zfs_send_queue_length = 16 * 1024 * 1024;
 int zfs_recv_queue_length = 16 * 1024 * 1024;
+/* Set this tunable to FALSE to disable setting of DRR_FLAG_FREERECORDS */
+int zfs_send_set_freerecords_bit = B_TRUE;
 
 static char *dmu_recv_tag = "dmu_recv_tag";
 const char *recv_clone_name = "%recv";
 
 #define BP_SPAN(datablkszsec, indblkshift, level) \

@@ -743,10 +746,11 @@
         if (is_clone)
                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
         drr->drr_u.drr_begin.drr_toguid = dsl_dataset_phys(to_ds)->ds_guid;
         if (dsl_dataset_phys(to_ds)->ds_flags & DS_FLAG_CI_DATASET)
                 drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CI_DATA;
+        if (zfs_send_set_freerecords_bit)
         drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_FREERECORDS;
 
         if (ancestor_zb != NULL) {
                 drr->drr_u.drr_begin.drr_fromguid =
                     ancestor_zb->zbm_guid;