]> git.proxmox.com Git - mirror_zfs.git/blobdiff - module/zfs/dmu_send.c
Fix typo/etc in module/zfs/zfs_ctldir.c
[mirror_zfs.git] / module / zfs / dmu_send.c
index b2d844eb42561523037f47451ff2a4a50db20c38..ad64d666bee75177c0d1128114a96f81f2780141 100644 (file)
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011 by Delphix. 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 (c) 2011, 2014 by Delphix. All rights reserved.
+ * Copyright 2014 HybridCluster. All rights reserved.
+ * Copyright 2016 RackTop Systems.
+ * Copyright (c) 2016 Actifio, Inc. All rights reserved.
  */
 
 #include <sys/dmu.h>
 #include <sys/blkptr.h>
 #include <sys/dsl_bookmark.h>
 #include <sys/zfeature.h>
+#include <sys/bqueue.h>
+#include <sys/zvol.h>
+#include <sys/policy.h>
 
 /* Set this tunable to TRUE to replace corrupt data with 0x2f5baddb10c */
 int zfs_send_corrupt_data = B_FALSE;
+int zfs_send_queue_length = SPA_MAXBLOCKSIZE;
+/* 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";
-static const char *recv_clone_name = "%recv";
+/*
+ * Use this to override the recordsize calculation for fast zfs send estimates.
+ */
+unsigned long zfs_override_estimate_recordsize = 0;
+
+#define        BP_SPAN(datablkszsec, indblkshift, level) \
+       (((uint64_t)datablkszsec) << (SPA_MINBLOCKSHIFT + \
+       (level) * (indblkshift - SPA_BLKPTRSHIFT)))
+
+struct send_thread_arg {
+       bqueue_t        q;
+       dsl_dataset_t   *ds;            /* Dataset to traverse */
+       uint64_t        fromtxg;        /* Traverse from this txg */
+       int             flags;          /* flags to pass to traverse_dataset */
+       int             error_code;
+       boolean_t       cancel;
+       zbookmark_phys_t resume;
+};
+
+struct send_block_record {
+       boolean_t               eos_marker; /* Marks the end of the stream */
+       blkptr_t                bp;
+       zbookmark_phys_t        zb;
+       uint8_t                 indblkshift;
+       uint16_t                datablkszsec;
+       bqueue_node_t           ln;
+};
 
 typedef struct dump_bytes_io {
        dmu_sendarg_t   *dbi_dsp;
@@ -67,15 +100,26 @@ typedef struct dump_bytes_io {
 } dump_bytes_io_t;
 
 static void
-dump_bytes_strategy(void *arg)
+dump_bytes_cb(void *arg)
 {
        dump_bytes_io_t *dbi = (dump_bytes_io_t *)arg;
        dmu_sendarg_t *dsp = dbi->dbi_dsp;
-       dsl_dataset_t *ds = dsp->dsa_os->os_dsl_dataset;
+       dsl_dataset_t *ds = dmu_objset_ds(dsp->dsa_os);
        ssize_t resid; /* have to get resid to get detailed errno */
-       ASSERT0(dbi->dbi_len % 8);
 
-       fletcher_4_incremental_native(dbi->dbi_buf, dbi->dbi_len, &dsp->dsa_zc);
+       /*
+        * The code does not rely on len being a multiple of 8.  We keep
+        * this assertion because of the corresponding assertion in
+        * receive_read().  Keeping this assertion ensures that we do not
+        * inadvertently break backwards compatibility (causing the assertion
+        * in receive_read() to trigger on old software). Newer feature flags
+        * (such as raw send) may break this assertion since they were
+        * introduced after the requirement was made obsolete.
+        */
+
+       ASSERT(dbi->dbi_len % 8 == 0 ||
+           (dsp->dsa_featureflags & DMU_BACKUP_FEATURE_RAW) != 0);
+
        dsp->dsa_err = vn_rdwr(UIO_WRITE, dsp->dsa_vp,
            (caddr_t)dbi->dbi_buf, dbi->dbi_len,
            0, UIO_SYSSPACE, FAPPEND, RLIM64_INFINITY, CRED(), &resid);
@@ -94,6 +138,9 @@ dump_bytes(dmu_sendarg_t *dsp, void *buf, int len)
        dbi.dbi_buf = buf;
        dbi.dbi_len = len;
 
+#if defined(HAVE_LARGE_STACKS)
+       dump_bytes_cb(&dbi);
+#else
        /*
         * The vn_rdwr() call is performed in a taskq to ensure that there is
         * always enough stack space to write safely to the target filesystem.
@@ -101,11 +148,57 @@ dump_bytes(dmu_sendarg_t *dsp, void *buf, int len)
         * them and they are used in vdev_file.c for a similar purpose.
         */
        spa_taskq_dispatch_sync(dmu_objset_spa(dsp->dsa_os), ZIO_TYPE_FREE,
-           ZIO_TASKQ_ISSUE, dump_bytes_strategy, &dbi, TQ_SLEEP);
+           ZIO_TASKQ_ISSUE, dump_bytes_cb, &dbi, TQ_SLEEP);
+#endif /* HAVE_LARGE_STACKS */
 
        return (dsp->dsa_err);
 }
 
+/*
+ * For all record types except BEGIN, fill in the checksum (overlaid in
+ * drr_u.drr_checksum.drr_checksum).  The checksum verifies everything
+ * up to the start of the checksum itself.
+ */
+static int
+dump_record(dmu_sendarg_t *dsp, void *payload, int payload_len)
+{
+       ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
+           ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
+       (void) fletcher_4_incremental_native(dsp->dsa_drr,
+           offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
+           &dsp->dsa_zc);
+       if (dsp->dsa_drr->drr_type == DRR_BEGIN) {
+               dsp->dsa_sent_begin = B_TRUE;
+       } else {
+               ASSERT(ZIO_CHECKSUM_IS_ZERO(&dsp->dsa_drr->drr_u.
+                   drr_checksum.drr_checksum));
+               dsp->dsa_drr->drr_u.drr_checksum.drr_checksum = dsp->dsa_zc;
+       }
+       if (dsp->dsa_drr->drr_type == DRR_END) {
+               dsp->dsa_sent_end = B_TRUE;
+       }
+       (void) fletcher_4_incremental_native(&dsp->dsa_drr->
+           drr_u.drr_checksum.drr_checksum,
+           sizeof (zio_cksum_t), &dsp->dsa_zc);
+       if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
+               return (SET_ERROR(EINTR));
+       if (payload_len != 0) {
+               (void) fletcher_4_incremental_native(payload, payload_len,
+                   &dsp->dsa_zc);
+               if (dump_bytes(dsp, payload, payload_len) != 0)
+                       return (SET_ERROR(EINTR));
+       }
+       return (0);
+}
+
+/*
+ * Fill in the drr_free struct, or perform aggregation if the previous record is
+ * also a free record, and the two are adjacent.
+ *
+ * Note that we send free records even for a full send, because we want to be
+ * able to receive a full send as a clone, which requires a list of all the free
+ * and freeobject records that were generated on the source.
+ */
 static int
 dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
     uint64_t length)
@@ -117,7 +210,7 @@ dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
         * that the receiving system doesn't have any dbufs in the range
         * being freed.  This is always true because there is a one-record
         * constraint: we only send one WRITE record for any given
-        * object+offset.  We know that the one-record constraint is
+        * object,offset.  We know that the one-record constraint is
         * true because we always send data in increasing order by
         * object,offset.
         *
@@ -129,18 +222,6 @@ dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
            (object == dsp->dsa_last_data_object &&
            offset > dsp->dsa_last_data_offset));
 
-       /*
-        * If we are doing a non-incremental send, then there can't
-        * be any data in the dataset we're receiving into.  Therefore
-        * a free record would simply be a no-op.  Save space by not
-        * sending it to begin with.
-        */
-       if (!dsp->dsa_incremental)
-               return (0);
-
-       if (length != -1ULL && offset + length < offset)
-               length = -1ULL;
-
        /*
         * If there is a pending op, but it's not PENDING_FREE, push it out,
         * since free block aggregation can only be done for blocks of the
@@ -150,32 +231,33 @@ dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
         */
        if (dsp->dsa_pending_op != PENDING_NONE &&
            dsp->dsa_pending_op != PENDING_FREE) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
+               if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
 
        if (dsp->dsa_pending_op == PENDING_FREE) {
                /*
-                * There should never be a PENDING_FREE if length is -1
-                * (because dump_dnode is the only place where this
-                * function is called with a -1, and only after flushing
-                * any pending record).
+                * There should never be a PENDING_FREE if length is
+                * DMU_OBJECT_END (because dump_dnode is the only place where
+                * this function is called with a DMU_OBJECT_END, and only after
+                * flushing any pending record).
                 */
-               ASSERT(length != -1ULL);
+               ASSERT(length != DMU_OBJECT_END);
                /*
                 * Check to see whether this free block can be aggregated
                 * with pending one.
                 */
                if (drrf->drr_object == object && drrf->drr_offset +
                    drrf->drr_length == offset) {
-                       drrf->drr_length += length;
+                       if (offset + length < offset)
+                               drrf->drr_length = DMU_OBJECT_END;
+                       else
+                               drrf->drr_length += length;
                        return (0);
                } else {
                        /* not a continuation.  Push out pending record */
-                       if (dump_bytes(dsp, dsp->dsa_drr,
-                           sizeof (dmu_replay_record_t)) != 0)
+                       if (dump_record(dsp, NULL, 0) != 0)
                                return (SET_ERROR(EINTR));
                        dsp->dsa_pending_op = PENDING_NONE;
                }
@@ -185,11 +267,13 @@ dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
        dsp->dsa_drr->drr_type = DRR_FREE;
        drrf->drr_object = object;
        drrf->drr_offset = offset;
-       drrf->drr_length = length;
+       if (offset + length < offset)
+               drrf->drr_length = DMU_OBJECT_END;
+       else
+               drrf->drr_length = length;
        drrf->drr_toguid = dsp->dsa_toguid;
-       if (length == -1ULL) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
+       if (length == DMU_OBJECT_END) {
+               if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
        } else {
                dsp->dsa_pending_op = PENDING_FREE;
@@ -199,9 +283,11 @@ dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
 }
 
 static int
-dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type,
-    uint64_t object, uint64_t offset, int blksz, const blkptr_t *bp, void *data)
+dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type, uint64_t object,
+    uint64_t offset, int lsize, int psize, const blkptr_t *bp, void *data)
 {
+       uint64_t payload_size;
+       boolean_t raw = (dsp->dsa_featureflags & DMU_BACKUP_FEATURE_RAW);
        struct drr_write *drrw = &(dsp->dsa_drr->drr_u.drr_write);
 
        /*
@@ -212,7 +298,7 @@ dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type,
            (object == dsp->dsa_last_data_object &&
            offset > dsp->dsa_last_data_offset));
        dsp->dsa_last_data_object = object;
-       dsp->dsa_last_data_offset = offset + blksz - 1;
+       dsp->dsa_last_data_offset = offset + lsize - 1;
 
        /*
         * If there is any kind of pending aggregation (currently either
@@ -221,40 +307,77 @@ dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type,
         * of different types.
         */
        if (dsp->dsa_pending_op != PENDING_NONE) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
+               if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
-       /* write a DATA record */
+       /* write a WRITE record */
        bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
        dsp->dsa_drr->drr_type = DRR_WRITE;
        drrw->drr_object = object;
        drrw->drr_type = type;
        drrw->drr_offset = offset;
-       drrw->drr_length = blksz;
        drrw->drr_toguid = dsp->dsa_toguid;
-       if (bp == NULL || BP_IS_EMBEDDED(bp)) {
+       drrw->drr_logical_size = lsize;
+
+       /* only set the compression fields if the buf is compressed or raw */
+       if (raw || lsize != psize) {
+               ASSERT(!BP_IS_EMBEDDED(bp));
+               ASSERT3S(psize, >, 0);
+
+               if (raw) {
+                       ASSERT(BP_IS_PROTECTED(bp));
+
+                       /*
+                        * This is a raw protected block so we need to pass
+                        * along everything the receiving side will need to
+                        * interpret this block, including the byteswap, salt,
+                        * IV, and MAC.
+                        */
+                       if (BP_SHOULD_BYTESWAP(bp))
+                               drrw->drr_flags |= DRR_RAW_BYTESWAP;
+                       zio_crypt_decode_params_bp(bp, drrw->drr_salt,
+                           drrw->drr_iv);
+                       zio_crypt_decode_mac_bp(bp, drrw->drr_mac);
+               } else {
+                       /* this is a compressed block */
+                       ASSERT(dsp->dsa_featureflags &
+                           DMU_BACKUP_FEATURE_COMPRESSED);
+                       ASSERT(!BP_SHOULD_BYTESWAP(bp));
+                       ASSERT(!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)));
+                       ASSERT3U(BP_GET_COMPRESS(bp), !=, ZIO_COMPRESS_OFF);
+                       ASSERT3S(lsize, >=, psize);
+               }
+
+               /* set fields common to compressed and raw sends */
+               drrw->drr_compressiontype = BP_GET_COMPRESS(bp);
+               drrw->drr_compressed_size = psize;
+               payload_size = drrw->drr_compressed_size;
+       } else {
+               payload_size = drrw->drr_logical_size;
+       }
+
+       if (bp == NULL || BP_IS_EMBEDDED(bp) || (BP_IS_PROTECTED(bp) && !raw)) {
                /*
-                * There's no pre-computed checksum for partial-block
-                * writes or embedded BP's, so (like
-                * fletcher4-checkummed blocks) userland will have to
-                * compute a dedup-capable checksum itself.
+                * There's no pre-computed checksum for partial-block writes,
+                * embedded BP's, or encrypted BP's that are being sent as
+                * plaintext, so (like fletcher4-checkummed blocks) userland
+                * will have to compute a dedup-capable checksum itself.
                 */
                drrw->drr_checksumtype = ZIO_CHECKSUM_OFF;
        } else {
                drrw->drr_checksumtype = BP_GET_CHECKSUM(bp);
-               if (zio_checksum_table[drrw->drr_checksumtype].ci_dedup)
-                       drrw->drr_checksumflags |= DRR_CHECKSUM_DEDUP;
+               if (zio_checksum_table[drrw->drr_checksumtype].ci_flags &
+                   ZCHECKSUM_FLAG_DEDUP)
+                       drrw->drr_flags |= DRR_CHECKSUM_DEDUP;
                DDK_SET_LSIZE(&drrw->drr_key, BP_GET_LSIZE(bp));
                DDK_SET_PSIZE(&drrw->drr_key, BP_GET_PSIZE(bp));
                DDK_SET_COMPRESS(&drrw->drr_key, BP_GET_COMPRESS(bp));
+               DDK_SET_CRYPT(&drrw->drr_key, BP_IS_PROTECTED(bp));
                drrw->drr_key.ddk_cksum = bp->blk_cksum;
        }
 
-       if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
-               return (SET_ERROR(EINTR));
-       if (dump_bytes(dsp, data, blksz) != 0)
+       if (dump_record(dsp, data, payload_size) != 0)
                return (SET_ERROR(EINTR));
        return (0);
 }
@@ -268,9 +391,8 @@ dump_write_embedded(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
            &(dsp->dsa_drr->drr_u.drr_write_embedded);
 
        if (dsp->dsa_pending_op != PENDING_NONE) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
-                       return (EINTR);
+               if (dump_record(dsp, NULL, 0) != 0)
+                       return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
 
@@ -289,21 +411,20 @@ dump_write_embedded(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
 
        decode_embedded_bp_compressed(bp, buf);
 
-       if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
-               return (EINTR);
-       if (dump_bytes(dsp, buf, P2ROUNDUP(drrw->drr_psize, 8)) != 0)
-               return (EINTR);
+       if (dump_record(dsp, buf, P2ROUNDUP(drrw->drr_psize, 8)) != 0)
+               return (SET_ERROR(EINTR));
        return (0);
 }
 
 static int
-dump_spill(dmu_sendarg_t *dsp, uint64_t object, int blksz, void *data)
+dump_spill(dmu_sendarg_t *dsp, const blkptr_t *bp, uint64_t object, void *data)
 {
        struct drr_spill *drrs = &(dsp->dsa_drr->drr_u.drr_spill);
+       uint64_t blksz = BP_GET_LSIZE(bp);
+       uint64_t payload_size = blksz;
 
        if (dsp->dsa_pending_op != PENDING_NONE) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
+               if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
@@ -315,9 +436,20 @@ dump_spill(dmu_sendarg_t *dsp, uint64_t object, int blksz, void *data)
        drrs->drr_length = blksz;
        drrs->drr_toguid = dsp->dsa_toguid;
 
-       if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)))
-               return (SET_ERROR(EINTR));
-       if (dump_bytes(dsp, data, blksz))
+       /* handle raw send fields */
+       if (dsp->dsa_featureflags & DMU_BACKUP_FEATURE_RAW) {
+               ASSERT(BP_IS_PROTECTED(bp));
+
+               if (BP_SHOULD_BYTESWAP(bp))
+                       drrs->drr_flags |= DRR_RAW_BYTESWAP;
+               drrs->drr_compressiontype = BP_GET_COMPRESS(bp);
+               drrs->drr_compressed_size = BP_GET_PSIZE(bp);
+               zio_crypt_decode_params_bp(bp, drrs->drr_salt, drrs->drr_iv);
+               zio_crypt_decode_mac_bp(bp, drrs->drr_mac);
+               payload_size = drrs->drr_compressed_size;
+       }
+
+       if (dump_record(dsp, data, payload_size) != 0)
                return (SET_ERROR(EINTR));
        return (0);
 }
@@ -326,10 +458,22 @@ static int
 dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
 {
        struct drr_freeobjects *drrfo = &(dsp->dsa_drr->drr_u.drr_freeobjects);
+       uint64_t maxobj = DNODES_PER_BLOCK *
+           (DMU_META_DNODE(dsp->dsa_os)->dn_maxblkid + 1);
 
-       /* See comment in dump_free(). */
-       if (!dsp->dsa_incremental)
-               return (0);
+       /*
+        * ZoL < 0.7 does not handle large FREEOBJECTS records correctly,
+        * leading to zfs recv never completing. to avoid this issue, don't
+        * send FREEOBJECTS records for object IDs which cannot exist on the
+        * receiving side.
+        */
+       if (maxobj > 0) {
+               if (maxobj < firstobj)
+                       return (0);
+
+               if (maxobj < firstobj + numobjs)
+                       numobjs = maxobj - firstobj;
+       }
 
        /*
         * If there is a pending op, but it's not PENDING_FREEOBJECTS,
@@ -340,8 +484,7 @@ dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
         */
        if (dsp->dsa_pending_op != PENDING_NONE &&
            dsp->dsa_pending_op != PENDING_FREEOBJECTS) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
+               if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
@@ -355,8 +498,7 @@ dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
                        return (0);
                } else {
                        /* can't be aggregated.  Push out pending record */
-                       if (dump_bytes(dsp, dsp->dsa_drr,
-                           sizeof (dmu_replay_record_t)) != 0)
+                       if (dump_record(dsp, NULL, 0) != 0)
                                return (SET_ERROR(EINTR));
                        dsp->dsa_pending_op = PENDING_NONE;
                }
@@ -375,16 +517,30 @@ dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
 }
 
 static int
-dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
+dump_dnode(dmu_sendarg_t *dsp, const blkptr_t *bp, uint64_t object,
+    dnode_phys_t *dnp)
 {
        struct drr_object *drro = &(dsp->dsa_drr->drr_u.drr_object);
+       int bonuslen;
+
+       if (object < dsp->dsa_resume_object) {
+               /*
+                * Note: when resuming, we will visit all the dnodes in
+                * the block of dnodes that we are resuming from.  In
+                * this case it's unnecessary to send the dnodes prior to
+                * the one we are resuming from.  We should be at most one
+                * block's worth of dnodes behind the resume point.
+                */
+               ASSERT3U(dsp->dsa_resume_object - object, <,
+                   1 << (DNODE_BLOCK_SHIFT - DNODE_SHIFT));
+               return (0);
+       }
 
        if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
                return (dump_freeobjects(dsp, object, 1));
 
        if (dsp->dsa_pending_op != PENDING_NONE) {
-               if (dump_bytes(dsp, dsp->dsa_drr,
-                   sizeof (dmu_replay_record_t)) != 0)
+               if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
@@ -397,6 +553,7 @@ dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
        drro->drr_bonustype = dnp->dn_bonustype;
        drro->drr_blksz = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
        drro->drr_bonuslen = dnp->dn_bonuslen;
+       drro->drr_dn_slots = dnp->dn_extra_slots + 1;
        drro->drr_checksumtype = dnp->dn_checksum;
        drro->drr_compress = dnp->dn_compress;
        drro->drr_toguid = dsp->dsa_toguid;
@@ -405,21 +562,78 @@ dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
            drro->drr_blksz > SPA_OLD_MAXBLOCKSIZE)
                drro->drr_blksz = SPA_OLD_MAXBLOCKSIZE;
 
-       if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
-               return (SET_ERROR(EINTR));
+       bonuslen = P2ROUNDUP(dnp->dn_bonuslen, 8);
+
+       if ((dsp->dsa_featureflags & DMU_BACKUP_FEATURE_RAW)) {
+               ASSERT(BP_IS_ENCRYPTED(bp));
+
+               if (BP_SHOULD_BYTESWAP(bp))
+                       drro->drr_flags |= DRR_RAW_BYTESWAP;
+
+               /* needed for reconstructing dnp on recv side */
+               drro->drr_maxblkid = dnp->dn_maxblkid;
+               drro->drr_indblkshift = dnp->dn_indblkshift;
+               drro->drr_nlevels = dnp->dn_nlevels;
+               drro->drr_nblkptr = dnp->dn_nblkptr;
+
+               /*
+                * Since we encrypt the entire bonus area, the (raw) part
+                * beyond the bonuslen is actually nonzero, so we need
+                * to send it.
+                */
+               if (bonuslen != 0) {
+                       drro->drr_raw_bonuslen = DN_MAX_BONUS_LEN(dnp);
+                       bonuslen = drro->drr_raw_bonuslen;
+               }
+       }
 
-       if (dump_bytes(dsp, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)) != 0)
+       if (dump_record(dsp, DN_BONUS(dnp), bonuslen) != 0)
                return (SET_ERROR(EINTR));
 
        /* Free anything past the end of the file. */
        if (dump_free(dsp, object, (dnp->dn_maxblkid + 1) *
-           (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL) != 0)
+           (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), DMU_OBJECT_END) != 0)
                return (SET_ERROR(EINTR));
        if (dsp->dsa_err != 0)
                return (SET_ERROR(EINTR));
        return (0);
 }
 
+static int
+dump_object_range(dmu_sendarg_t *dsp, const blkptr_t *bp, uint64_t firstobj,
+    uint64_t numslots)
+{
+       struct drr_object_range *drror =
+           &(dsp->dsa_drr->drr_u.drr_object_range);
+
+       /* we only use this record type for raw sends */
+       ASSERT(BP_IS_PROTECTED(bp));
+       ASSERT(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_RAW);
+       ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
+       ASSERT3U(BP_GET_TYPE(bp), ==, DMU_OT_DNODE);
+       ASSERT0(BP_GET_LEVEL(bp));
+
+       if (dsp->dsa_pending_op != PENDING_NONE) {
+               if (dump_record(dsp, NULL, 0) != 0)
+                       return (SET_ERROR(EINTR));
+               dsp->dsa_pending_op = PENDING_NONE;
+       }
+
+       bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
+       dsp->dsa_drr->drr_type = DRR_OBJECT_RANGE;
+       drror->drr_firstobj = firstobj;
+       drror->drr_numslots = numslots;
+       drror->drr_toguid = dsp->dsa_toguid;
+       if (BP_SHOULD_BYTESWAP(bp))
+               drror->drr_flags |= DRR_RAW_BYTESWAP;
+       zio_crypt_decode_params_bp(bp, drror->drr_salt, drror->drr_iv);
+       zio_crypt_decode_mac_bp(bp, drror->drr_mac);
+
+       if (dump_record(dsp, NULL, 0) != 0)
+               return (SET_ERROR(EINTR));
+       return (0);
+}
+
 static boolean_t
 backup_do_embed(dmu_sendarg_t *dsp, const blkptr_t *bp)
 {
@@ -430,7 +644,7 @@ backup_do_embed(dmu_sendarg_t *dsp, const blkptr_t *bp)
         * Compression function must be legacy, or explicitly enabled.
         */
        if ((BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_LEGACY_FUNCTIONS &&
-           !(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_EMBED_DATA_LZ4)))
+           !(dsp->dsa_featureflags & DMU_BACKUP_FEATURE_LZ4)))
                return (B_FALSE);
 
        /*
@@ -447,95 +661,246 @@ backup_do_embed(dmu_sendarg_t *dsp, const blkptr_t *bp)
        return (B_FALSE);
 }
 
-#define        BP_SPAN(dnp, level) \
-       (((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
-       (level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
+/*
+ * This is the callback function to traverse_dataset that acts as the worker
+ * thread for dmu_send_impl.
+ */
+/*ARGSUSED*/
+static int
+send_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
+    const zbookmark_phys_t *zb, const struct dnode_phys *dnp, void *arg)
+{
+       struct send_thread_arg *sta = arg;
+       struct send_block_record *record;
+       uint64_t record_size;
+       int err = 0;
+
+       ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
+           zb->zb_object >= sta->resume.zb_object);
+       ASSERT3P(sta->ds, !=, NULL);
 
-/* ARGSUSED */
+       if (sta->cancel)
+               return (SET_ERROR(EINTR));
+
+       if (bp == NULL) {
+               ASSERT3U(zb->zb_level, ==, ZB_DNODE_LEVEL);
+               return (0);
+       } else if (zb->zb_level < 0) {
+               return (0);
+       }
+
+       record = kmem_zalloc(sizeof (struct send_block_record), KM_SLEEP);
+       record->eos_marker = B_FALSE;
+       record->bp = *bp;
+       record->zb = *zb;
+       record->indblkshift = dnp->dn_indblkshift;
+       record->datablkszsec = dnp->dn_datablkszsec;
+       record_size = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
+       bqueue_enqueue(&sta->q, record, record_size);
+
+       return (err);
+}
+
+/*
+ * This function kicks off the traverse_dataset.  It also handles setting the
+ * error code of the thread in case something goes wrong, and pushes the End of
+ * Stream record when the traverse_dataset call has finished.  If there is no
+ * dataset to traverse, the thread immediately pushes End of Stream marker.
+ */
+static void
+send_traverse_thread(void *arg)
+{
+       struct send_thread_arg *st_arg = arg;
+       int err;
+       struct send_block_record *data;
+       fstrans_cookie_t cookie = spl_fstrans_mark();
+
+       if (st_arg->ds != NULL) {
+               err = traverse_dataset_resume(st_arg->ds,
+                   st_arg->fromtxg, &st_arg->resume,
+                   st_arg->flags, send_cb, st_arg);
+
+               if (err != EINTR)
+                       st_arg->error_code = err;
+       }
+       data = kmem_zalloc(sizeof (*data), KM_SLEEP);
+       data->eos_marker = B_TRUE;
+       bqueue_enqueue(&st_arg->q, data, 1);
+       spl_fstrans_unmark(cookie);
+       thread_exit();
+}
+
+/*
+ * This function actually handles figuring out what kind of record needs to be
+ * dumped, reading the data (which has hopefully been prefetched), and calling
+ * the appropriate helper function.
+ */
 static int
-backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
-    const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
+do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
 {
-       dmu_sendarg_t *dsp = arg;
+       dsl_dataset_t *ds = dmu_objset_ds(dsa->dsa_os);
+       const blkptr_t *bp = &data->bp;
+       const zbookmark_phys_t *zb = &data->zb;
+       uint8_t indblkshift = data->indblkshift;
+       uint16_t dblkszsec = data->datablkszsec;
+       spa_t *spa = ds->ds_dir->dd_pool->dp_spa;
        dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
        int err = 0;
 
-       if (issig(JUSTLOOKING) && issig(FORREAL))
-               return (SET_ERROR(EINTR));
+       ASSERT3U(zb->zb_level, >=, 0);
+
+       ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
+           zb->zb_object >= dsa->dsa_resume_object);
+
+       /*
+        * All bps of an encrypted os should have the encryption bit set.
+        * If this is not true it indicates tampering and we report an error.
+        */
+       if (dsa->dsa_os->os_encrypted &&
+           !BP_IS_HOLE(bp) && !BP_USES_CRYPT(bp)) {
+               spa_log_error(spa, zb);
+               zfs_panic_recover("unencrypted block in encrypted "
+                   "object set %llu", ds->ds_object);
+               return (SET_ERROR(EIO));
+       }
 
        if (zb->zb_object != DMU_META_DNODE_OBJECT &&
            DMU_OBJECT_IS_SPECIAL(zb->zb_object)) {
                return (0);
-       } else if (zb->zb_level == ZB_ZIL_LEVEL) {
-               /*
-                * If we are sending a non-snapshot (which is allowed on
-                * read-only pools), it may have a ZIL, which must be ignored.
-                */
-               return (0);
        } else if (BP_IS_HOLE(bp) &&
            zb->zb_object == DMU_META_DNODE_OBJECT) {
-               uint64_t span = BP_SPAN(dnp, zb->zb_level);
+               uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
                uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
-               err = dump_freeobjects(dsp, dnobj, span >> DNODE_SHIFT);
+               err = dump_freeobjects(dsa, dnobj, span >> DNODE_SHIFT);
        } else if (BP_IS_HOLE(bp)) {
-               uint64_t span = BP_SPAN(dnp, zb->zb_level);
-               err = dump_free(dsp, zb->zb_object, zb->zb_blkid * span, span);
+               uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
+               uint64_t offset = zb->zb_blkid * span;
+               /* Don't dump free records for offsets > DMU_OBJECT_END */
+               if (zb->zb_blkid == 0 || span <= DMU_OBJECT_END / zb->zb_blkid)
+                       err = dump_free(dsa, zb->zb_object, offset, span);
        } else if (zb->zb_level > 0 || type == DMU_OT_OBJSET) {
                return (0);
        } else if (type == DMU_OT_DNODE) {
-               dnode_phys_t *blk;
-               int i;
-               int blksz = BP_GET_LSIZE(bp);
+               int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
                arc_flags_t aflags = ARC_FLAG_WAIT;
                arc_buf_t *abuf;
+               enum zio_flag zioflags = ZIO_FLAG_CANFAIL;
+
+               if (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_RAW) {
+                       ASSERT(BP_IS_ENCRYPTED(bp));
+                       ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
+                       zioflags |= ZIO_FLAG_RAW;
+               }
+
+               ASSERT0(zb->zb_level);
 
                if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
-                   ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
-                   &aflags, zb) != 0)
+                   ZIO_PRIORITY_ASYNC_READ, zioflags, &aflags, zb) != 0)
                        return (SET_ERROR(EIO));
 
-               blk = abuf->b_data;
-               for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
-                       uint64_t dnobj = (zb->zb_blkid <<
-                           (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
-                       err = dump_dnode(dsp, dnobj, blk+i);
-                       if (err != 0)
-                               break;
+               dnode_phys_t *blk = abuf->b_data;
+               uint64_t dnobj = zb->zb_blkid * epb;
+
+               /*
+                * Raw sends require sending encryption parameters for the
+                * block of dnodes. Regular sends do not need to send this
+                * info.
+                */
+               if (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_RAW) {
+                       ASSERT(arc_is_encrypted(abuf));
+                       err = dump_object_range(dsa, bp, dnobj, epb);
+               }
+
+               if (err == 0) {
+                       for (int i = 0; i < epb;
+                           i += blk[i].dn_extra_slots + 1) {
+                               err = dump_dnode(dsa, bp, dnobj + i, blk + i);
+                               if (err != 0)
+                                       break;
+                       }
                }
-               (void) arc_buf_remove_ref(abuf, &abuf);
+               arc_buf_destroy(abuf, &abuf);
        } else if (type == DMU_OT_SA) {
                arc_flags_t aflags = ARC_FLAG_WAIT;
                arc_buf_t *abuf;
-               int blksz = BP_GET_LSIZE(bp);
+               enum zio_flag zioflags = ZIO_FLAG_CANFAIL;
+
+               if (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_RAW) {
+                       ASSERT(BP_IS_PROTECTED(bp));
+                       zioflags |= ZIO_FLAG_RAW;
+               }
 
                if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
-                   ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
-                   &aflags, zb) != 0)
+                   ZIO_PRIORITY_ASYNC_READ, zioflags, &aflags, zb) != 0)
                        return (SET_ERROR(EIO));
 
-               err = dump_spill(dsp, zb->zb_object, blksz, abuf->b_data);
-               (void) arc_buf_remove_ref(abuf, &abuf);
-       } else if (backup_do_embed(dsp, bp)) {
+               err = dump_spill(dsa, bp, zb->zb_object, abuf->b_data);
+               arc_buf_destroy(abuf, &abuf);
+       } else if (backup_do_embed(dsa, bp)) {
                /* it's an embedded level-0 block of a regular object */
-               int blksz = dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
-               err = dump_write_embedded(dsp, zb->zb_object,
+               int blksz = dblkszsec << SPA_MINBLOCKSHIFT;
+               ASSERT0(zb->zb_level);
+               err = dump_write_embedded(dsa, zb->zb_object,
                    zb->zb_blkid * blksz, blksz, bp);
-       } else { /* it's a level-0 block of a regular object */
-               uint64_t offset;
+       } else {
+               /* it's a level-0 block of a regular object */
                arc_flags_t aflags = ARC_FLAG_WAIT;
                arc_buf_t *abuf;
-               int blksz = BP_GET_LSIZE(bp);
+               int blksz = dblkszsec << SPA_MINBLOCKSHIFT;
+               uint64_t offset;
+
+               /*
+                * If we have large blocks stored on disk but the send flags
+                * don't allow us to send large blocks, we split the data from
+                * the arc buf into chunks.
+                */
+               boolean_t split_large_blocks = blksz > SPA_OLD_MAXBLOCKSIZE &&
+                   !(dsa->dsa_featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS);
+
+               /*
+                * Raw sends require that we always get raw data as it exists
+                * on disk, so we assert that we are not splitting blocks here.
+                */
+               boolean_t request_raw =
+                   (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_RAW) != 0;
+
+               /*
+                * We should only request compressed data from the ARC if all
+                * the following are true:
+                *  - stream compression was requested
+                *  - we aren't splitting large blocks into smaller chunks
+                *  - the data won't need to be byteswapped before sending
+                *  - this isn't an embedded block
+                *  - this isn't metadata (if receiving on a different endian
+                *    system it can be byteswapped more easily)
+                */
+               boolean_t request_compressed =
+                   (dsa->dsa_featureflags & DMU_BACKUP_FEATURE_COMPRESSED) &&
+                   !split_large_blocks && !BP_SHOULD_BYTESWAP(bp) &&
+                   !BP_IS_EMBEDDED(bp) && !DMU_OT_IS_METADATA(BP_GET_TYPE(bp));
 
-               ASSERT3U(blksz, ==, dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT);
+               IMPLY(request_raw, !split_large_blocks);
+               IMPLY(request_raw, BP_IS_PROTECTED(bp));
                ASSERT0(zb->zb_level);
+               ASSERT(zb->zb_object > dsa->dsa_resume_object ||
+                   (zb->zb_object == dsa->dsa_resume_object &&
+                   zb->zb_blkid * blksz >= dsa->dsa_resume_offset));
+
+               ASSERT3U(blksz, ==, BP_GET_LSIZE(bp));
+
+               enum zio_flag zioflags = ZIO_FLAG_CANFAIL;
+               if (request_raw)
+                       zioflags |= ZIO_FLAG_RAW;
+               else if (request_compressed)
+                       zioflags |= ZIO_FLAG_RAW_COMPRESS;
+
                if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
-                   ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
-                   &aflags, zb) != 0) {
+                   ZIO_PRIORITY_ASYNC_READ, zioflags, &aflags, zb) != 0) {
                        if (zfs_send_corrupt_data) {
-                               uint64_t *ptr;
                                /* Send a block filled with 0x"zfs badd bloc" */
-                               abuf = arc_buf_alloc(spa, blksz, &abuf,
-                                   ARC_BUFC_DATA);
+                               abuf = arc_alloc_buf(spa, &abuf, ARC_BUFC_DATA,
+                                   blksz);
+                               uint64_t *ptr;
                                for (ptr = abuf->b_data;
                                    (char *)ptr < (char *)abuf->b_data + blksz;
                                    ptr++)
@@ -547,23 +912,24 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 
                offset = zb->zb_blkid * blksz;
 
-               if (!(dsp->dsa_featureflags &
-                   DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
-                   blksz > SPA_OLD_MAXBLOCKSIZE) {
+               if (split_large_blocks) {
+                       ASSERT0(arc_is_encrypted(abuf));
+                       ASSERT3U(arc_get_compression(abuf), ==,
+                           ZIO_COMPRESS_OFF);
                        char *buf = abuf->b_data;
                        while (blksz > 0 && err == 0) {
                                int n = MIN(blksz, SPA_OLD_MAXBLOCKSIZE);
-                               err = dump_write(dsp, type, zb->zb_object,
-                                   offset, n, NULL, buf);
+                               err = dump_write(dsa, type, zb->zb_object,
+                                   offset, n, n, NULL, buf);
                                offset += n;
                                buf += n;
                                blksz -= n;
                        }
                } else {
-                       err = dump_write(dsp, type, zb->zb_object,
-                           offset, blksz, bp, abuf->b_data);
+                       err = dump_write(dsa, type, zb->zb_object, offset,
+                           blksz, arc_buf_size(abuf), bp, abuf->b_data);
                }
-               (void) arc_buf_remove_ref(abuf, &abuf);
+               arc_buf_destroy(abuf, &abuf);
        }
 
        ASSERT(err == 0 || err == EINTR);
@@ -571,12 +937,27 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 }
 
 /*
- * Releases dp using the specified tag.
+ * Pop the new data off the queue, and free the old data.
+ */
+static struct send_block_record *
+get_next_record(bqueue_t *bq, struct send_block_record *data)
+{
+       struct send_block_record *tmp = bqueue_dequeue(bq);
+       kmem_free(data, sizeof (*data));
+       return (tmp);
+}
+
+/*
+ * Actually do the bulk of the work in a zfs send.
+ *
+ * Note: Releases dp using the specified tag.
  */
 static int
-dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *ds,
-    zfs_bookmark_phys_t *fromzb, boolean_t is_clone, boolean_t embedok,
-    boolean_t large_block_ok, int outfd, vnode_t *vp, offset_t *off)
+dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
+    zfs_bookmark_phys_t *ancestor_zb, boolean_t is_clone,
+    boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
+    boolean_t rawok, int outfd, uint64_t resumeobj, uint64_t resumeoff,
+    vnode_t *vp, offset_t *off)
 {
        objset_t *os;
        dmu_replay_record_t *drr;
@@ -584,19 +965,47 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *ds,
        int err;
        uint64_t fromtxg = 0;
        uint64_t featureflags = 0;
+       struct send_thread_arg to_arg;
+       void *payload = NULL;
+       size_t payload_len = 0;
+       struct send_block_record *to_data;
 
-       err = dmu_objset_from_ds(ds, &os);
+       err = dmu_objset_from_ds(to_ds, &os);
        if (err != 0) {
                dsl_pool_rele(dp, tag);
                return (err);
        }
 
+       /*
+        * If this is a non-raw send of an encrypted ds, we can ensure that
+        * the objset_phys_t is authenticated. This is safe because this is
+        * either a snapshot or we have owned the dataset, ensuring that
+        * it can't be modified.
+        */
+       if (!rawok && os->os_encrypted &&
+           arc_is_unauthenticated(os->os_phys_buf)) {
+               zbookmark_phys_t zb;
+
+               SET_BOOKMARK(&zb, to_ds->ds_object, ZB_ROOT_OBJECT,
+                   ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
+               err = arc_untransform(os->os_phys_buf, os->os_spa,
+                   &zb, B_FALSE);
+               if (err != 0) {
+                       dsl_pool_rele(dp, tag);
+                       return (err);
+               }
+
+               ASSERT0(arc_is_unauthenticated(os->os_phys_buf));
+       }
+
        drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
        drr->drr_type = DRR_BEGIN;
        drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
        DMU_SET_STREAM_HDRTYPE(drr->drr_u.drr_begin.drr_versioninfo,
            DMU_SUBSTREAM);
 
+       bzero(&to_arg, sizeof (to_arg));
+
 #ifdef _KERNEL
        if (dmu_objset_type(os) == DMU_OST_ZFS) {
                uint64_t version;
@@ -611,35 +1020,57 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *ds,
        }
 #endif
 
-       if (large_block_ok && ds->ds_large_blocks)
+       /* raw sends imply large_block_ok */
+       if ((large_block_ok || rawok) &&
+           dsl_dataset_feature_is_active(to_ds, SPA_FEATURE_LARGE_BLOCKS))
                featureflags |= DMU_BACKUP_FEATURE_LARGE_BLOCKS;
-       if (embedok &&
+       if (dsl_dataset_feature_is_active(to_ds, SPA_FEATURE_LARGE_DNODE))
+               featureflags |= DMU_BACKUP_FEATURE_LARGE_DNODE;
+
+       /* encrypted datasets will not have embedded blocks */
+       if ((embedok || rawok) && !os->os_encrypted &&
            spa_feature_is_active(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA)) {
                featureflags |= DMU_BACKUP_FEATURE_EMBED_DATA;
-               if (spa_feature_is_active(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
-                       featureflags |= DMU_BACKUP_FEATURE_EMBED_DATA_LZ4;
-       } else {
-               embedok = B_FALSE;
+       }
+
+       /* raw send implies compressok */
+       if (compressok || rawok)
+               featureflags |= DMU_BACKUP_FEATURE_COMPRESSED;
+       if (rawok && os->os_encrypted)
+               featureflags |= DMU_BACKUP_FEATURE_RAW;
+
+       if ((featureflags &
+           (DMU_BACKUP_FEATURE_EMBED_DATA | DMU_BACKUP_FEATURE_COMPRESSED |
+           DMU_BACKUP_FEATURE_RAW)) != 0 &&
+           spa_feature_is_active(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS)) {
+               featureflags |= DMU_BACKUP_FEATURE_LZ4;
+       }
+
+       if (resumeobj != 0 || resumeoff != 0) {
+               featureflags |= DMU_BACKUP_FEATURE_RESUMING;
        }
 
        DMU_SET_FEATUREFLAGS(drr->drr_u.drr_begin.drr_versioninfo,
            featureflags);
 
        drr->drr_u.drr_begin.drr_creation_time =
-           dsl_dataset_phys(ds)->ds_creation_time;
+           dsl_dataset_phys(to_ds)->ds_creation_time;
        drr->drr_u.drr_begin.drr_type = dmu_objset_type(os);
        if (is_clone)
                drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
-       drr->drr_u.drr_begin.drr_toguid = dsl_dataset_phys(ds)->ds_guid;
-       if (dsl_dataset_phys(ds)->ds_flags & DS_FLAG_CI_DATASET)
+       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 (fromzb != NULL) {
-               drr->drr_u.drr_begin.drr_fromguid = fromzb->zbm_guid;
-               fromtxg = fromzb->zbm_creation_txg;
+       if (ancestor_zb != NULL) {
+               drr->drr_u.drr_begin.drr_fromguid =
+                   ancestor_zb->zbm_guid;
+               fromtxg = ancestor_zb->zbm_creation_txg;
        }
-       dsl_dataset_name(ds, drr->drr_u.drr_begin.drr_toname);
-       if (!ds->ds_is_snapshot) {
+       dsl_dataset_name(to_ds, drr->drr_u.drr_begin.drr_toname);
+       if (!to_ds->ds_is_snapshot) {
                (void) strlcat(drr->drr_u.drr_begin.drr_toname, "@--head--",
                    sizeof (drr->drr_u.drr_begin.drr_toname));
        }
@@ -652,29 +1083,110 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *ds,
        dsp->dsa_proc = curproc;
        dsp->dsa_os = os;
        dsp->dsa_off = off;
-       dsp->dsa_toguid = dsl_dataset_phys(ds)->ds_guid;
-       ZIO_SET_CHECKSUM(&dsp->dsa_zc, 0, 0, 0, 0);
+       dsp->dsa_toguid = dsl_dataset_phys(to_ds)->ds_guid;
        dsp->dsa_pending_op = PENDING_NONE;
-       dsp->dsa_incremental = (fromzb != NULL);
        dsp->dsa_featureflags = featureflags;
+       dsp->dsa_resume_object = resumeobj;
+       dsp->dsa_resume_offset = resumeoff;
 
-       mutex_enter(&ds->ds_sendstream_lock);
-       list_insert_head(&ds->ds_sendstreams, dsp);
-       mutex_exit(&ds->ds_sendstream_lock);
+       mutex_enter(&to_ds->ds_sendstream_lock);
+       list_insert_head(&to_ds->ds_sendstreams, dsp);
+       mutex_exit(&to_ds->ds_sendstream_lock);
 
-       dsl_dataset_long_hold(ds, FTAG);
+       dsl_dataset_long_hold(to_ds, FTAG);
        dsl_pool_rele(dp, tag);
 
-       if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0) {
+       /* handle features that require a DRR_BEGIN payload */
+       if (featureflags &
+           (DMU_BACKUP_FEATURE_RESUMING | DMU_BACKUP_FEATURE_RAW)) {
+               nvlist_t *keynvl = NULL;
+               nvlist_t *nvl = fnvlist_alloc();
+
+               if (featureflags & DMU_BACKUP_FEATURE_RESUMING) {
+                       dmu_object_info_t to_doi;
+                       err = dmu_object_info(os, resumeobj, &to_doi);
+                       if (err != 0) {
+                               fnvlist_free(nvl);
+                               goto out;
+                       }
+
+                       SET_BOOKMARK(&to_arg.resume, to_ds->ds_object,
+                           resumeobj, 0,
+                           resumeoff / to_doi.doi_data_block_size);
+
+                       fnvlist_add_uint64(nvl, "resume_object", resumeobj);
+                       fnvlist_add_uint64(nvl, "resume_offset", resumeoff);
+               }
+
+               if (featureflags & DMU_BACKUP_FEATURE_RAW) {
+                       uint64_t ivset_guid = (ancestor_zb != NULL) ?
+                           ancestor_zb->zbm_ivset_guid : 0;
+
+                       ASSERT(os->os_encrypted);
+
+                       err = dsl_crypto_populate_key_nvlist(to_ds,
+                           ivset_guid, &keynvl);
+                       if (err != 0) {
+                               fnvlist_free(nvl);
+                               goto out;
+                       }
+
+                       fnvlist_add_nvlist(nvl, "crypt_keydata", keynvl);
+               }
+
+               payload = fnvlist_pack(nvl, &payload_len);
+               drr->drr_payloadlen = payload_len;
+               fnvlist_free(keynvl);
+               fnvlist_free(nvl);
+       }
+
+       err = dump_record(dsp, payload, payload_len);
+       fnvlist_pack_free(payload, payload_len);
+       if (err != 0) {
                err = dsp->dsa_err;
                goto out;
        }
 
-       err = traverse_dataset(ds, fromtxg, TRAVERSE_PRE | TRAVERSE_PREFETCH,
-           backup_cb, dsp);
+       err = bqueue_init(&to_arg.q,
+           MAX(zfs_send_queue_length, 2 * zfs_max_recordsize),
+           offsetof(struct send_block_record, ln));
+       to_arg.error_code = 0;
+       to_arg.cancel = B_FALSE;
+       to_arg.ds = to_ds;
+       to_arg.fromtxg = fromtxg;
+       to_arg.flags = TRAVERSE_PRE | TRAVERSE_PREFETCH;
+       if (rawok)
+               to_arg.flags |= TRAVERSE_NO_DECRYPT;
+       (void) thread_create(NULL, 0, send_traverse_thread, &to_arg, 0, curproc,
+           TS_RUN, minclsyspri);
+
+       to_data = bqueue_dequeue(&to_arg.q);
+
+       while (!to_data->eos_marker && err == 0) {
+               err = do_dump(dsp, to_data);
+               to_data = get_next_record(&to_arg.q, to_data);
+               if (issig(JUSTLOOKING) && issig(FORREAL))
+                       err = EINTR;
+       }
+
+       if (err != 0) {
+               to_arg.cancel = B_TRUE;
+               while (!to_data->eos_marker) {
+                       to_data = get_next_record(&to_arg.q, to_data);
+               }
+       }
+       kmem_free(to_data, sizeof (*to_data));
+
+       bqueue_destroy(&to_arg.q);
+
+       if (err == 0 && to_arg.error_code != 0)
+               err = to_arg.error_code;
+
+       if (err != 0)
+               goto out;
 
        if (dsp->dsa_pending_op != PENDING_NONE)
-               if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0)
+               if (dump_record(dsp, NULL, 0) != 0)
                        err = SET_ERROR(EINTR);
 
        if (err != 0) {
@@ -688,80 +1200,97 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *ds,
        drr->drr_u.drr_end.drr_checksum = dsp->dsa_zc;
        drr->drr_u.drr_end.drr_toguid = dsp->dsa_toguid;
 
-       if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0) {
+       if (dump_record(dsp, NULL, 0) != 0)
                err = dsp->dsa_err;
-               goto out;
-       }
-
 out:
-       mutex_enter(&ds->ds_sendstream_lock);
-       list_remove(&ds->ds_sendstreams, dsp);
-       mutex_exit(&ds->ds_sendstream_lock);
+       mutex_enter(&to_ds->ds_sendstream_lock);
+       list_remove(&to_ds->ds_sendstreams, dsp);
+       mutex_exit(&to_ds->ds_sendstream_lock);
+
+       VERIFY(err != 0 || (dsp->dsa_sent_begin && dsp->dsa_sent_end));
 
        kmem_free(drr, sizeof (dmu_replay_record_t));
        kmem_free(dsp, sizeof (dmu_sendarg_t));
 
-       dsl_dataset_long_rele(ds, FTAG);
+       dsl_dataset_long_rele(to_ds, FTAG);
 
        return (err);
 }
 
 int
 dmu_send_obj(const char *pool, uint64_t tosnap, uint64_t fromsnap,
-    boolean_t embedok, boolean_t large_block_ok,
-    int outfd, vnode_t *vp, offset_t *off)
+    boolean_t embedok, boolean_t large_block_ok, boolean_t compressok,
+    boolean_t rawok, int outfd, vnode_t *vp, offset_t *off)
 {
        dsl_pool_t *dp;
        dsl_dataset_t *ds;
        dsl_dataset_t *fromds = NULL;
+       ds_hold_flags_t dsflags = (rawok) ? 0 : DS_HOLD_FLAG_DECRYPT;
        int err;
 
        err = dsl_pool_hold(pool, FTAG, &dp);
        if (err != 0)
                return (err);
 
-       err = dsl_dataset_hold_obj(dp, tosnap, FTAG, &ds);
+       err = dsl_dataset_hold_obj_flags(dp, tosnap, dsflags, FTAG, &ds);
        if (err != 0) {
                dsl_pool_rele(dp, FTAG);
                return (err);
        }
 
        if (fromsnap != 0) {
-               zfs_bookmark_phys_t zb;
+               zfs_bookmark_phys_t zb = { 0 };
                boolean_t is_clone;
 
                err = dsl_dataset_hold_obj(dp, fromsnap, FTAG, &fromds);
                if (err != 0) {
-                       dsl_dataset_rele(ds, FTAG);
+                       dsl_dataset_rele_flags(ds, dsflags, FTAG);
                        dsl_pool_rele(dp, FTAG);
                        return (err);
                }
-               if (!dsl_dataset_is_before(ds, fromds, 0))
+               if (!dsl_dataset_is_before(ds, fromds, 0)) {
                        err = SET_ERROR(EXDEV);
+                       dsl_dataset_rele(fromds, FTAG);
+                       dsl_dataset_rele_flags(ds, dsflags, FTAG);
+                       dsl_pool_rele(dp, FTAG);
+                       return (err);
+               }
+
                zb.zbm_creation_time =
                    dsl_dataset_phys(fromds)->ds_creation_time;
                zb.zbm_creation_txg = dsl_dataset_phys(fromds)->ds_creation_txg;
                zb.zbm_guid = dsl_dataset_phys(fromds)->ds_guid;
+
+               if (dsl_dataset_is_zapified(fromds)) {
+                       (void) zap_lookup(dp->dp_meta_objset,
+                           fromds->ds_object, DS_FIELD_IVSET_GUID, 8, 1,
+                           &zb.zbm_ivset_guid);
+               }
+
                is_clone = (fromds->ds_dir != ds->ds_dir);
                dsl_dataset_rele(fromds, FTAG);
                err = dmu_send_impl(FTAG, dp, ds, &zb, is_clone,
-                   embedok, large_block_ok, outfd, vp, off);
+                   embedok, large_block_ok, compressok, rawok, outfd,
+                   0, 0, vp, off);
        } else {
                err = dmu_send_impl(FTAG, dp, ds, NULL, B_FALSE,
-                   embedok, large_block_ok, outfd, vp, off);
+                   embedok, large_block_ok, compressok, rawok, outfd,
+                   0, 0, vp, off);
        }
-       dsl_dataset_rele(ds, FTAG);
+       dsl_dataset_rele_flags(ds, dsflags, FTAG);
        return (err);
 }
 
 int
-dmu_send(const char *tosnap, const char *fromsnap,
-    boolean_t embedok, boolean_t large_block_ok,
-    int outfd, vnode_t *vp, offset_t *off)
+dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
+    boolean_t large_block_ok, boolean_t compressok, boolean_t rawok,
+    int outfd, uint64_t resumeobj, uint64_t resumeoff, vnode_t *vp,
+    offset_t *off)
 {
        dsl_pool_t *dp;
        dsl_dataset_t *ds;
        int err;
+       ds_hold_flags_t dsflags = (rawok) ? 0 : DS_HOLD_FLAG_DECRYPT;
        boolean_t owned = B_FALSE;
 
        if (fromsnap != NULL && strpbrk(fromsnap, "@#") == NULL)
@@ -770,16 +1299,15 @@ dmu_send(const char *tosnap, const char *fromsnap,
        err = dsl_pool_hold(tosnap, FTAG, &dp);
        if (err != 0)
                return (err);
-
        if (strchr(tosnap, '@') == NULL && spa_writeable(dp->dp_spa)) {
                /*
                 * We are sending a filesystem or volume.  Ensure
                 * that it doesn't change by owning the dataset.
                 */
-               err = dsl_dataset_own(dp, tosnap, FTAG, &ds);
+               err = dsl_dataset_own(dp, tosnap, dsflags, FTAG, &ds);
                owned = B_TRUE;
        } else {
-               err = dsl_dataset_hold(dp, tosnap, FTAG, &ds);
+               err = dsl_dataset_hold_flags(dp, tosnap, dsflags, FTAG, &ds);
        }
        if (err != 0) {
                dsl_pool_rele(dp, FTAG);
@@ -787,7 +1315,7 @@ dmu_send(const char *tosnap, const char *fromsnap,
        }
 
        if (fromsnap != NULL) {
-               zfs_bookmark_phys_t zb;
+               zfs_bookmark_phys_t zb = { 0 };
                boolean_t is_clone = B_FALSE;
                int fsnamelen = strchr(tosnap, '@') - tosnap;
 
@@ -813,57 +1341,93 @@ dmu_send(const char *tosnap, const char *fromsnap,
                                    dsl_dataset_phys(fromds)->ds_creation_txg;
                                zb.zbm_guid = dsl_dataset_phys(fromds)->ds_guid;
                                is_clone = (ds->ds_dir != fromds->ds_dir);
+
+                               if (dsl_dataset_is_zapified(fromds)) {
+                                       (void) zap_lookup(dp->dp_meta_objset,
+                                           fromds->ds_object,
+                                           DS_FIELD_IVSET_GUID, 8, 1,
+                                           &zb.zbm_ivset_guid);
+                               }
                                dsl_dataset_rele(fromds, FTAG);
                        }
                } else {
                        err = dsl_bookmark_lookup(dp, fromsnap, ds, &zb);
                }
                if (err != 0) {
-                       dsl_dataset_rele(ds, FTAG);
+                       if (owned)
+                               dsl_dataset_disown(ds, dsflags, FTAG);
+                       else
+                               dsl_dataset_rele_flags(ds, dsflags, FTAG);
+
                        dsl_pool_rele(dp, FTAG);
                        return (err);
                }
                err = dmu_send_impl(FTAG, dp, ds, &zb, is_clone,
-                   embedok, large_block_ok, outfd, vp, off);
+                   embedok, large_block_ok, compressok, rawok,
+                   outfd, resumeobj, resumeoff, vp, off);
        } else {
                err = dmu_send_impl(FTAG, dp, ds, NULL, B_FALSE,
-                   embedok, large_block_ok, outfd, vp, off);
+                   embedok, large_block_ok, compressok, rawok,
+                   outfd, resumeobj, resumeoff, vp, off);
        }
        if (owned)
-               dsl_dataset_disown(ds, FTAG);
+               dsl_dataset_disown(ds, dsflags, FTAG);
        else
-               dsl_dataset_rele(ds, FTAG);
+               dsl_dataset_rele_flags(ds, dsflags, FTAG);
+
        return (err);
 }
 
 static int
-dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t size,
-    uint64_t *sizep)
+dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t uncompressed,
+    uint64_t compressed, boolean_t stream_compressed, uint64_t *sizep)
 {
-       int err;
+       int err = 0;
+       uint64_t size;
        /*
         * Assume that space (both on-disk and in-stream) is dominated by
         * data.  We will adjust for indirect blocks and the copies property,
         * but ignore per-object space used (eg, dnodes and DRR_OBJECT records).
         */
 
+       uint64_t recordsize;
+       uint64_t record_count;
+       objset_t *os;
+       VERIFY0(dmu_objset_from_ds(ds, &os));
+
+       /* Assume all (uncompressed) blocks are recordsize. */
+       if (zfs_override_estimate_recordsize != 0) {
+               recordsize = zfs_override_estimate_recordsize;
+       } else if (os->os_phys->os_type == DMU_OST_ZVOL) {
+               err = dsl_prop_get_int_ds(ds,
+                   zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &recordsize);
+       } else {
+               err = dsl_prop_get_int_ds(ds,
+                   zfs_prop_to_name(ZFS_PROP_RECORDSIZE), &recordsize);
+       }
+       if (err != 0)
+               return (err);
+       record_count = uncompressed / recordsize;
+
+       /*
+        * If we're estimating a send size for a compressed stream, use the
+        * compressed data size to estimate the stream size. Otherwise, use the
+        * uncompressed data size.
+        */
+       size = stream_compressed ? compressed : uncompressed;
+
        /*
         * Subtract out approximate space used by indirect blocks.
         * Assume most space is used by data blocks (non-indirect, non-dnode).
-        * Assume all blocks are recordsize.  Assume ditto blocks and
-        * internal fragmentation counter out compression.
+        * Assume no ditto blocks or internal fragmentation.
         *
         * Therefore, space used by indirect blocks is sizeof(blkptr_t) per
-        * block, which we observe in practice.
+        * block.
         */
-       uint64_t recordsize;
-       err = dsl_prop_get_int_ds(ds, "recordsize", &recordsize);
-       if (err != 0)
-               return (err);
-       size -= size / recordsize * sizeof (blkptr_t);
+       size -= record_count * sizeof (blkptr_t);
 
        /* Add in the space for the record associated with each block. */
-       size += size / recordsize * sizeof (dmu_replay_record_t);
+       size += record_count * sizeof (dmu_replay_record_t);
 
        *sizep = size;
 
@@ -871,10 +1435,11 @@ dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t size,
 }
 
 int
-dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fromds, uint64_t *sizep)
+dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fromds,
+    boolean_t stream_compressed, uint64_t *sizep)
 {
        int err;
-       uint64_t size;
+       uint64_t uncomp, comp;
 
        ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
 
@@ -893,33 +1458,45 @@ dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fromds, uint64_t *sizep)
        if (fromds != NULL && !dsl_dataset_is_before(ds, fromds, 0))
                return (SET_ERROR(EXDEV));
 
-       /* Get uncompressed size estimate of changed data. */
+       /* Get compressed and uncompressed size estimates of changed data. */
        if (fromds == NULL) {
-               size = dsl_dataset_phys(ds)->ds_uncompressed_bytes;
+               uncomp = dsl_dataset_phys(ds)->ds_uncompressed_bytes;
+               comp = dsl_dataset_phys(ds)->ds_compressed_bytes;
        } else {
-               uint64_t used, comp;
+               uint64_t used;
                err = dsl_dataset_space_written(fromds, ds,
-                   &used, &comp, &size);
+                   &used, &comp, &uncomp);
                if (err != 0)
                        return (err);
        }
 
-       err = dmu_adjust_send_estimate_for_indirects(ds, size, sizep);
+       err = dmu_adjust_send_estimate_for_indirects(ds, uncomp, comp,
+           stream_compressed, sizep);
+       /*
+        * Add the size of the BEGIN and END records to the estimate.
+        */
+       *sizep += 2 * sizeof (dmu_replay_record_t);
        return (err);
 }
 
+struct calculate_send_arg {
+       uint64_t uncompressed;
+       uint64_t compressed;
+};
+
 /*
  * Simple callback used to traverse the blocks of a snapshot and sum their
- * uncompressed size
+ * uncompressed and compressed sizes.
  */
 /* ARGSUSED */
 static int
 dmu_calculate_send_traversal(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
 {
-       uint64_t *spaceptr = arg;
+       struct calculate_send_arg *space = arg;
        if (bp != NULL && !BP_IS_HOLE(bp)) {
-               *spaceptr += BP_GET_UCSIZE(bp);
+               space->uncompressed += BP_GET_UCSIZE(bp);
+               space->compressed += BP_GET_PSIZE(bp);
        }
        return (0);
 }
@@ -931,10 +1508,10 @@ dmu_calculate_send_traversal(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
  */
 int
 dmu_send_estimate_from_txg(dsl_dataset_t *ds, uint64_t from_txg,
-    uint64_t *sizep)
+    boolean_t stream_compressed, uint64_t *sizep)
 {
        int err;
-       uint64_t size = 0;
+       struct calculate_send_arg size = { 0 };
 
        ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
 
@@ -950,1325 +1527,29 @@ dmu_send_estimate_from_txg(dsl_dataset_t *ds, uint64_t from_txg,
         * traverse the blocks of the snapshot with birth times after
         * from_txg, summing their uncompressed size
         */
-       err = traverse_dataset(ds, from_txg, TRAVERSE_POST,
+       err = traverse_dataset(ds, from_txg,
+           TRAVERSE_POST | TRAVERSE_NO_DECRYPT,
            dmu_calculate_send_traversal, &size);
+
        if (err)
                return (err);
 
-       err = dmu_adjust_send_estimate_for_indirects(ds, size, sizep);
+       err = dmu_adjust_send_estimate_for_indirects(ds, size.uncompressed,
+           size.compressed, stream_compressed, sizep);
        return (err);
 }
 
-typedef struct dmu_recv_begin_arg {
-       const char *drba_origin;
-       dmu_recv_cookie_t *drba_cookie;
-       cred_t *drba_cred;
-       uint64_t drba_snapobj;
-} dmu_recv_begin_arg_t;
-
-static int
-recv_begin_check_existing_impl(dmu_recv_begin_arg_t *drba, dsl_dataset_t *ds,
-    uint64_t fromguid)
-{
-       uint64_t val;
-       int error;
-       dsl_pool_t *dp = ds->ds_dir->dd_pool;
-
-       /* temporary clone name must not exist */
-       error = zap_lookup(dp->dp_meta_objset,
-           dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, recv_clone_name,
-           8, 1, &val);
-       if (error != ENOENT)
-               return (error == 0 ? EBUSY : error);
-
-       /* new snapshot name must not exist */
-       error = zap_lookup(dp->dp_meta_objset,
-           dsl_dataset_phys(ds)->ds_snapnames_zapobj,
-           drba->drba_cookie->drc_tosnap, 8, 1, &val);
-       if (error != ENOENT)
-               return (error == 0 ? EEXIST : error);
 
-       /*
-        * Check snapshot limit before receiving. We'll recheck again at the
-        * end, but might as well abort before receiving if we're already over
-        * the limit.
-        *
-        * Note that we do not check the file system limit with
-        * dsl_dir_fscount_check because the temporary %clones don't count
-        * against that limit.
-        */
-       error = dsl_fs_ss_limit_check(ds->ds_dir, 1, ZFS_PROP_SNAPSHOT_LIMIT,
-           NULL, drba->drba_cred);
-       if (error != 0)
-               return (error);
-
-       if (fromguid != 0) {
-               dsl_dataset_t *snap;
-               uint64_t obj = dsl_dataset_phys(ds)->ds_prev_snap_obj;
-
-               /* Find snapshot in this dir that matches fromguid. */
-               while (obj != 0) {
-                       error = dsl_dataset_hold_obj(dp, obj, FTAG,
-                           &snap);
-                       if (error != 0)
-                               return (SET_ERROR(ENODEV));
-                       if (snap->ds_dir != ds->ds_dir) {
-                               dsl_dataset_rele(snap, FTAG);
-                               return (SET_ERROR(ENODEV));
-                       }
-                       if (dsl_dataset_phys(snap)->ds_guid == fromguid)
-                               break;
-                       obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
-                       dsl_dataset_rele(snap, FTAG);
-               }
-               if (obj == 0)
-                       return (SET_ERROR(ENODEV));
+#if defined(_KERNEL)
+/* BEGIN CSTYLED */
+module_param(zfs_override_estimate_recordsize, ulong, 0644);
+MODULE_PARM_DESC(zfs_override_estimate_recordsize,
+       "Record size calculation override for zfs send estimates");
+/* END CSTYLED */
 
-               if (drba->drba_cookie->drc_force) {
-                       drba->drba_snapobj = obj;
-               } else {
-                       /*
-                        * If we are not forcing, there must be no
-                        * changes since fromsnap.
-                        */
-                       if (dsl_dataset_modified_since_snap(ds, snap)) {
-                               dsl_dataset_rele(snap, FTAG);
-                               return (SET_ERROR(ETXTBSY));
-                       }
-                       drba->drba_snapobj = ds->ds_prev->ds_object;
-               }
-
-               dsl_dataset_rele(snap, FTAG);
-       } else {
-               /* if full, then must be forced */
-               if (!drba->drba_cookie->drc_force)
-                       return (SET_ERROR(EEXIST));
-               /* start from $ORIGIN@$ORIGIN, if supported */
-               drba->drba_snapobj = dp->dp_origin_snap != NULL ?
-                   dp->dp_origin_snap->ds_object : 0;
-       }
-
-       return (0);
-
-}
-
-static int
-dmu_recv_begin_check(void *arg, dmu_tx_t *tx)
-{
-       dmu_recv_begin_arg_t *drba = arg;
-       dsl_pool_t *dp = dmu_tx_pool(tx);
-       struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
-       uint64_t fromguid = drrb->drr_fromguid;
-       int flags = drrb->drr_flags;
-       int error;
-       uint64_t featureflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
-       dsl_dataset_t *ds;
-       const char *tofs = drba->drba_cookie->drc_tofs;
-
-       /* already checked */
-       ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
-
-       if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
-           DMU_COMPOUNDSTREAM ||
-           drrb->drr_type >= DMU_OST_NUMTYPES ||
-           ((flags & DRR_FLAG_CLONE) && drba->drba_origin == NULL))
-               return (SET_ERROR(EINVAL));
-
-       /* Verify pool version supports SA if SA_SPILL feature set */
-       if ((featureflags & DMU_BACKUP_FEATURE_SA_SPILL) &&
-           spa_version(dp->dp_spa) < SPA_VERSION_SA)
-               return (SET_ERROR(ENOTSUP));
-
-       /*
-        * The receiving code doesn't know how to translate a WRITE_EMBEDDED
-        * record to a plan WRITE record, so the pool must have the
-        * EMBEDDED_DATA feature enabled if the stream has WRITE_EMBEDDED
-        * records.  Same with WRITE_EMBEDDED records that use LZ4 compression.
-        */
-       if ((featureflags & DMU_BACKUP_FEATURE_EMBED_DATA) &&
-           !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EMBEDDED_DATA))
-               return (SET_ERROR(ENOTSUP));
-       if ((featureflags & DMU_BACKUP_FEATURE_EMBED_DATA_LZ4) &&
-           !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LZ4_COMPRESS))
-               return (SET_ERROR(ENOTSUP));
-
-       /*
-        * The receiving code doesn't know how to translate large blocks
-        * to smaller ones, so the pool must have the LARGE_BLOCKS
-        * feature enabled if the stream has LARGE_BLOCKS.
-        */
-       if ((featureflags & DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
-           !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS))
-               return (SET_ERROR(ENOTSUP));
-
-       error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
-       if (error == 0) {
-               /* target fs already exists; recv into temp clone */
-
-               /* Can't recv a clone into an existing fs */
-               if (flags & DRR_FLAG_CLONE) {
-                       dsl_dataset_rele(ds, FTAG);
-                       return (SET_ERROR(EINVAL));
-               }
-
-               error = recv_begin_check_existing_impl(drba, ds, fromguid);
-               dsl_dataset_rele(ds, FTAG);
-       } else if (error == ENOENT) {
-               /* target fs does not exist; must be a full backup or clone */
-               char buf[MAXNAMELEN];
-
-               /*
-                * If it's a non-clone incremental, we are missing the
-                * target fs, so fail the recv.
-                */
-               if (fromguid != 0 && !(flags & DRR_FLAG_CLONE))
-                       return (SET_ERROR(ENOENT));
-
-               /* Open the parent of tofs */
-               ASSERT3U(strlen(tofs), <, MAXNAMELEN);
-               (void) strlcpy(buf, tofs, strrchr(tofs, '/') - tofs + 1);
-               error = dsl_dataset_hold(dp, buf, FTAG, &ds);
-               if (error != 0)
-                       return (error);
-
-               /*
-                * Check filesystem and snapshot limits before receiving. We'll
-                * recheck snapshot limits again at the end (we create the
-                * filesystems and increment those counts during begin_sync).
-                */
-               error = dsl_fs_ss_limit_check(ds->ds_dir, 1,
-                   ZFS_PROP_FILESYSTEM_LIMIT, NULL, drba->drba_cred);
-               if (error != 0) {
-                       dsl_dataset_rele(ds, FTAG);
-                       return (error);
-               }
-
-               error = dsl_fs_ss_limit_check(ds->ds_dir, 1,
-                   ZFS_PROP_SNAPSHOT_LIMIT, NULL, drba->drba_cred);
-               if (error != 0) {
-                       dsl_dataset_rele(ds, FTAG);
-                       return (error);
-               }
-
-               if (drba->drba_origin != NULL) {
-                       dsl_dataset_t *origin;
-                       error = dsl_dataset_hold(dp, drba->drba_origin,
-                           FTAG, &origin);
-                       if (error != 0) {
-                               dsl_dataset_rele(ds, FTAG);
-                               return (error);
-                       }
-                       if (!origin->ds_is_snapshot) {
-                               dsl_dataset_rele(origin, FTAG);
-                               dsl_dataset_rele(ds, FTAG);
-                               return (SET_ERROR(EINVAL));
-                       }
-                       if (dsl_dataset_phys(origin)->ds_guid != fromguid) {
-                               dsl_dataset_rele(origin, FTAG);
-                               dsl_dataset_rele(ds, FTAG);
-                               return (SET_ERROR(ENODEV));
-                       }
-                       dsl_dataset_rele(origin, FTAG);
-               }
-               dsl_dataset_rele(ds, FTAG);
-               error = 0;
-       }
-       return (error);
-}
-
-static void
-dmu_recv_begin_sync(void *arg, dmu_tx_t *tx)
-{
-       dmu_recv_begin_arg_t *drba = arg;
-       dsl_pool_t *dp = dmu_tx_pool(tx);
-       struct drr_begin *drrb = drba->drba_cookie->drc_drrb;
-       const char *tofs = drba->drba_cookie->drc_tofs;
-       dsl_dataset_t *ds, *newds;
-       uint64_t dsobj;
-       int error;
-       uint64_t crflags;
-
-       crflags = (drrb->drr_flags & DRR_FLAG_CI_DATA) ?
-           DS_FLAG_CI_DATASET : 0;
-
-       error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
-       if (error == 0) {
-               /* create temporary clone */
-               dsl_dataset_t *snap = NULL;
-               if (drba->drba_snapobj != 0) {
-                       VERIFY0(dsl_dataset_hold_obj(dp,
-                           drba->drba_snapobj, FTAG, &snap));
-               }
-               dsobj = dsl_dataset_create_sync(ds->ds_dir, recv_clone_name,
-                   snap, crflags, drba->drba_cred, tx);
-               dsl_dataset_rele(snap, FTAG);
-               dsl_dataset_rele(ds, FTAG);
-       } else {
-               dsl_dir_t *dd;
-               const char *tail;
-               dsl_dataset_t *origin = NULL;
-
-               VERIFY0(dsl_dir_hold(dp, tofs, FTAG, &dd, &tail));
-
-               if (drba->drba_origin != NULL) {
-                       VERIFY0(dsl_dataset_hold(dp, drba->drba_origin,
-                           FTAG, &origin));
-               }
-
-               /* Create new dataset. */
-               dsobj = dsl_dataset_create_sync(dd,
-                   strrchr(tofs, '/') + 1,
-                   origin, crflags, drba->drba_cred, tx);
-               if (origin != NULL)
-                       dsl_dataset_rele(origin, FTAG);
-               dsl_dir_rele(dd, FTAG);
-               drba->drba_cookie->drc_newfs = B_TRUE;
-       }
-       VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &newds));
-
-       if ((DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
-           DMU_BACKUP_FEATURE_LARGE_BLOCKS) &&
-           !newds->ds_large_blocks) {
-               dsl_dataset_activate_large_blocks_sync_impl(dsobj, tx);
-               newds->ds_large_blocks = B_TRUE;
-       }
-
-       dmu_buf_will_dirty(newds->ds_dbuf, tx);
-       dsl_dataset_phys(newds)->ds_flags |= DS_FLAG_INCONSISTENT;
-
-       /*
-        * If we actually created a non-clone, we need to create the
-        * objset in our new dataset.
-        */
-       if (BP_IS_HOLE(dsl_dataset_get_blkptr(newds))) {
-               (void) dmu_objset_create_impl(dp->dp_spa,
-                   newds, dsl_dataset_get_blkptr(newds), drrb->drr_type, tx);
-       }
-
-       drba->drba_cookie->drc_ds = newds;
-
-       spa_history_log_internal_ds(newds, "receive", tx, "");
-}
-
-/*
- * NB: callers *MUST* call dmu_recv_stream() if dmu_recv_begin()
- * succeeds; otherwise we will leak the holds on the datasets.
- */
-int
-dmu_recv_begin(char *tofs, char *tosnap, struct drr_begin *drrb,
-    boolean_t force, char *origin, dmu_recv_cookie_t *drc)
-{
-       dmu_recv_begin_arg_t drba = { 0 };
-       dmu_replay_record_t *drr;
-
-       bzero(drc, sizeof (dmu_recv_cookie_t));
-       drc->drc_drrb = drrb;
-       drc->drc_tosnap = tosnap;
-       drc->drc_tofs = tofs;
-       drc->drc_force = force;
-       drc->drc_cred = CRED();
-
-       if (drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC))
-               drc->drc_byteswap = B_TRUE;
-       else if (drrb->drr_magic != DMU_BACKUP_MAGIC)
-               return (SET_ERROR(EINVAL));
-
-       drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
-       drr->drr_type = DRR_BEGIN;
-       drr->drr_u.drr_begin = *drc->drc_drrb;
-       if (drc->drc_byteswap) {
-               fletcher_4_incremental_byteswap(drr,
-                   sizeof (dmu_replay_record_t), &drc->drc_cksum);
-       } else {
-               fletcher_4_incremental_native(drr,
-                   sizeof (dmu_replay_record_t), &drc->drc_cksum);
-       }
-       kmem_free(drr, sizeof (dmu_replay_record_t));
-
-       if (drc->drc_byteswap) {
-               drrb->drr_magic = BSWAP_64(drrb->drr_magic);
-               drrb->drr_versioninfo = BSWAP_64(drrb->drr_versioninfo);
-               drrb->drr_creation_time = BSWAP_64(drrb->drr_creation_time);
-               drrb->drr_type = BSWAP_32(drrb->drr_type);
-               drrb->drr_toguid = BSWAP_64(drrb->drr_toguid);
-               drrb->drr_fromguid = BSWAP_64(drrb->drr_fromguid);
-       }
-
-       drba.drba_origin = origin;
-       drba.drba_cookie = drc;
-       drba.drba_cred = CRED();
-
-       return (dsl_sync_task(tofs, dmu_recv_begin_check, dmu_recv_begin_sync,
-           &drba, 5, ZFS_SPACE_CHECK_NORMAL));
-}
-
-struct restorearg {
-       int err;
-       boolean_t byteswap;
-       vnode_t *vp;
-       char *buf;
-       uint64_t voff;
-       int bufsize; /* amount of memory allocated for buf */
-       zio_cksum_t cksum;
-       avl_tree_t *guid_to_ds_map;
-};
-
-typedef struct guid_map_entry {
-       uint64_t        guid;
-       dsl_dataset_t   *gme_ds;
-       avl_node_t      avlnode;
-} guid_map_entry_t;
-
-static int
-guid_compare(const void *arg1, const void *arg2)
-{
-       const guid_map_entry_t *gmep1 = arg1;
-       const guid_map_entry_t *gmep2 = arg2;
-
-       if (gmep1->guid < gmep2->guid)
-               return (-1);
-       else if (gmep1->guid > gmep2->guid)
-               return (1);
-       return (0);
-}
-
-static void
-free_guid_map_onexit(void *arg)
-{
-       avl_tree_t *ca = arg;
-       void *cookie = NULL;
-       guid_map_entry_t *gmep;
-
-       while ((gmep = avl_destroy_nodes(ca, &cookie)) != NULL) {
-               dsl_dataset_long_rele(gmep->gme_ds, gmep);
-               dsl_dataset_rele(gmep->gme_ds, gmep);
-               kmem_free(gmep, sizeof (guid_map_entry_t));
-       }
-       avl_destroy(ca);
-       kmem_free(ca, sizeof (avl_tree_t));
-}
-
-static void *
-restore_read(struct restorearg *ra, int len, char *buf)
-{
-       int done = 0;
-
-       if (buf == NULL)
-               buf = ra->buf;
-
-       /* some things will require 8-byte alignment, so everything must */
-       ASSERT0(len % 8);
-       ASSERT3U(len, <=, ra->bufsize);
-
-       while (done < len) {
-               ssize_t resid;
-
-               ra->err = vn_rdwr(UIO_READ, ra->vp,
-                   buf + done, len - done,
-                   ra->voff, UIO_SYSSPACE, FAPPEND,
-                   RLIM64_INFINITY, CRED(), &resid);
-
-               if (resid == len - done)
-                       ra->err = SET_ERROR(EINVAL);
-               ra->voff += len - done - resid;
-               done = len - resid;
-               if (ra->err != 0)
-                       return (NULL);
-       }
-
-       ASSERT3U(done, ==, len);
-       if (ra->byteswap)
-               fletcher_4_incremental_byteswap(buf, len, &ra->cksum);
-       else
-               fletcher_4_incremental_native(buf, len, &ra->cksum);
-       return (buf);
-}
-
-noinline static void
-backup_byteswap(dmu_replay_record_t *drr)
-{
-#define        DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
-#define        DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
-       drr->drr_type = BSWAP_32(drr->drr_type);
-       drr->drr_payloadlen = BSWAP_32(drr->drr_payloadlen);
-       switch (drr->drr_type) {
-       case DRR_BEGIN:
-               DO64(drr_begin.drr_magic);
-               DO64(drr_begin.drr_versioninfo);
-               DO64(drr_begin.drr_creation_time);
-               DO32(drr_begin.drr_type);
-               DO32(drr_begin.drr_flags);
-               DO64(drr_begin.drr_toguid);
-               DO64(drr_begin.drr_fromguid);
-               break;
-       case DRR_OBJECT:
-               DO64(drr_object.drr_object);
-               DO32(drr_object.drr_type);
-               DO32(drr_object.drr_bonustype);
-               DO32(drr_object.drr_blksz);
-               DO32(drr_object.drr_bonuslen);
-               DO64(drr_object.drr_toguid);
-               break;
-       case DRR_FREEOBJECTS:
-               DO64(drr_freeobjects.drr_firstobj);
-               DO64(drr_freeobjects.drr_numobjs);
-               DO64(drr_freeobjects.drr_toguid);
-               break;
-       case DRR_WRITE:
-               DO64(drr_write.drr_object);
-               DO32(drr_write.drr_type);
-               DO64(drr_write.drr_offset);
-               DO64(drr_write.drr_length);
-               DO64(drr_write.drr_toguid);
-               DO64(drr_write.drr_key.ddk_cksum.zc_word[0]);
-               DO64(drr_write.drr_key.ddk_cksum.zc_word[1]);
-               DO64(drr_write.drr_key.ddk_cksum.zc_word[2]);
-               DO64(drr_write.drr_key.ddk_cksum.zc_word[3]);
-               DO64(drr_write.drr_key.ddk_prop);
-               break;
-       case DRR_WRITE_BYREF:
-               DO64(drr_write_byref.drr_object);
-               DO64(drr_write_byref.drr_offset);
-               DO64(drr_write_byref.drr_length);
-               DO64(drr_write_byref.drr_toguid);
-               DO64(drr_write_byref.drr_refguid);
-               DO64(drr_write_byref.drr_refobject);
-               DO64(drr_write_byref.drr_refoffset);
-               DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[0]);
-               DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[1]);
-               DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[2]);
-               DO64(drr_write_byref.drr_key.ddk_cksum.zc_word[3]);
-               DO64(drr_write_byref.drr_key.ddk_prop);
-               break;
-       case DRR_WRITE_EMBEDDED:
-               DO64(drr_write_embedded.drr_object);
-               DO64(drr_write_embedded.drr_offset);
-               DO64(drr_write_embedded.drr_length);
-               DO64(drr_write_embedded.drr_toguid);
-               DO32(drr_write_embedded.drr_lsize);
-               DO32(drr_write_embedded.drr_psize);
-               break;
-       case DRR_FREE:
-               DO64(drr_free.drr_object);
-               DO64(drr_free.drr_offset);
-               DO64(drr_free.drr_length);
-               DO64(drr_free.drr_toguid);
-               break;
-       case DRR_SPILL:
-               DO64(drr_spill.drr_object);
-               DO64(drr_spill.drr_length);
-               DO64(drr_spill.drr_toguid);
-               break;
-       case DRR_END:
-               DO64(drr_end.drr_checksum.zc_word[0]);
-               DO64(drr_end.drr_checksum.zc_word[1]);
-               DO64(drr_end.drr_checksum.zc_word[2]);
-               DO64(drr_end.drr_checksum.zc_word[3]);
-               DO64(drr_end.drr_toguid);
-               break;
-       default:
-               break;
-       }
-#undef DO64
-#undef DO32
-}
-
-static inline uint8_t
-deduce_nblkptr(dmu_object_type_t bonus_type, uint64_t bonus_size)
-{
-       if (bonus_type == DMU_OT_SA) {
-               return (1);
-       } else {
-               return (1 +
-                   ((DN_MAX_BONUSLEN - bonus_size) >> SPA_BLKPTRSHIFT));
-       }
-}
-
-noinline static int
-restore_object(struct restorearg *ra, objset_t *os, struct drr_object *drro)
-{
-       dmu_object_info_t doi;
-       dmu_tx_t *tx;
-       void *data = NULL;
-       uint64_t object;
-       int err;
-
-       if (drro->drr_type == DMU_OT_NONE ||
-           !DMU_OT_IS_VALID(drro->drr_type) ||
-           !DMU_OT_IS_VALID(drro->drr_bonustype) ||
-           drro->drr_checksumtype >= ZIO_CHECKSUM_FUNCTIONS ||
-           drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
-           P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
-           drro->drr_blksz < SPA_MINBLOCKSIZE ||
-           drro->drr_blksz > spa_maxblocksize(dmu_objset_spa(os)) ||
-           drro->drr_bonuslen > DN_MAX_BONUSLEN) {
-               return (SET_ERROR(EINVAL));
-       }
-
-       err = dmu_object_info(os, drro->drr_object, &doi);
-
-       if (err != 0 && err != ENOENT)
-               return (SET_ERROR(EINVAL));
-       object = err == 0 ? drro->drr_object : DMU_NEW_OBJECT;
-
-       if (drro->drr_bonuslen) {
-               data = restore_read(ra, P2ROUNDUP(drro->drr_bonuslen, 8), NULL);
-               if (ra->err != 0)
-                       return (ra->err);
-       }
-
-       /*
-        * If we are losing blkptrs or changing the block size this must
-        * be a new file instance.  We must clear out the previous file
-        * contents before we can change this type of metadata in the dnode.
-        */
-       if (err == 0) {
-               int nblkptr;
-
-               nblkptr = deduce_nblkptr(drro->drr_bonustype,
-                   drro->drr_bonuslen);
-
-               if (drro->drr_blksz != doi.doi_data_block_size ||
-                   nblkptr < doi.doi_nblkptr) {
-                       err = dmu_free_long_range(os, drro->drr_object,
-                           0, DMU_OBJECT_END);
-                       if (err != 0)
-                               return (SET_ERROR(EINVAL));
-               }
-       }
-
-       tx = dmu_tx_create(os);
-       dmu_tx_hold_bonus(tx, object);
-       err = dmu_tx_assign(tx, TXG_WAIT);
-       if (err != 0) {
-               dmu_tx_abort(tx);
-               return (err);
-       }
-
-       if (object == DMU_NEW_OBJECT) {
-               /* currently free, want to be allocated */
-               err = dmu_object_claim(os, drro->drr_object,
-                   drro->drr_type, drro->drr_blksz,
-                   drro->drr_bonustype, drro->drr_bonuslen, tx);
-       } else if (drro->drr_type != doi.doi_type ||
-           drro->drr_blksz != doi.doi_data_block_size ||
-           drro->drr_bonustype != doi.doi_bonus_type ||
-           drro->drr_bonuslen != doi.doi_bonus_size) {
-               /* currently allocated, but with different properties */
-               err = dmu_object_reclaim(os, drro->drr_object,
-                   drro->drr_type, drro->drr_blksz,
-                   drro->drr_bonustype, drro->drr_bonuslen, tx);
-       }
-       if (err != 0) {
-               dmu_tx_commit(tx);
-               return (SET_ERROR(EINVAL));
-       }
-
-       dmu_object_set_checksum(os, drro->drr_object, drro->drr_checksumtype,
-           tx);
-       dmu_object_set_compress(os, drro->drr_object, drro->drr_compress, tx);
-
-       if (data != NULL) {
-               dmu_buf_t *db;
-
-               VERIFY(0 == dmu_bonus_hold(os, drro->drr_object, FTAG, &db));
-               dmu_buf_will_dirty(db, tx);
-
-               ASSERT3U(db->db_size, >=, drro->drr_bonuslen);
-               bcopy(data, db->db_data, drro->drr_bonuslen);
-               if (ra->byteswap) {
-                       dmu_object_byteswap_t byteswap =
-                           DMU_OT_BYTESWAP(drro->drr_bonustype);
-                       dmu_ot_byteswap[byteswap].ob_func(db->db_data,
-                           drro->drr_bonuslen);
-               }
-               dmu_buf_rele(db, FTAG);
-       }
-       dmu_tx_commit(tx);
-       return (0);
-}
-
-/* ARGSUSED */
-noinline static int
-restore_freeobjects(struct restorearg *ra, objset_t *os,
-    struct drr_freeobjects *drrfo)
-{
-       uint64_t obj;
-
-       if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
-               return (SET_ERROR(EINVAL));
-
-       for (obj = drrfo->drr_firstobj;
-           obj < drrfo->drr_firstobj + drrfo->drr_numobjs;
-           (void) dmu_object_next(os, &obj, FALSE, 0)) {
-               int err;
-
-               if (dmu_object_info(os, obj, NULL) != 0)
-                       continue;
-
-               err = dmu_free_long_object(os, obj);
-               if (err != 0)
-                       return (err);
-       }
-       return (0);
-}
-
-noinline static int
-restore_write(struct restorearg *ra, objset_t *os,
-    struct drr_write *drrw)
-{
-       dmu_tx_t *tx;
-       dmu_buf_t *bonus;
-       arc_buf_t *abuf;
-       void *data;
-       int err;
-
-       if (drrw->drr_offset + drrw->drr_length < drrw->drr_offset ||
-           !DMU_OT_IS_VALID(drrw->drr_type))
-               return (SET_ERROR(EINVAL));
-
-       if (dmu_object_info(os, drrw->drr_object, NULL) != 0)
-               return (SET_ERROR(EINVAL));
-
-       if (dmu_bonus_hold(os, drrw->drr_object, FTAG, &bonus) != 0)
-               return (SET_ERROR(EINVAL));
-
-       abuf = dmu_request_arcbuf(bonus, drrw->drr_length);
-
-       data = restore_read(ra, drrw->drr_length, abuf->b_data);
-       if (data == NULL) {
-               dmu_return_arcbuf(abuf);
-               dmu_buf_rele(bonus, FTAG);
-               return (ra->err);
-       }
-
-       tx = dmu_tx_create(os);
-
-       dmu_tx_hold_write(tx, drrw->drr_object,
-           drrw->drr_offset, drrw->drr_length);
-       err = dmu_tx_assign(tx, TXG_WAIT);
-       if (err != 0) {
-               dmu_return_arcbuf(abuf);
-               dmu_buf_rele(bonus, FTAG);
-               dmu_tx_abort(tx);
-               return (err);
-       }
-       if (ra->byteswap) {
-               dmu_object_byteswap_t byteswap =
-                   DMU_OT_BYTESWAP(drrw->drr_type);
-               dmu_ot_byteswap[byteswap].ob_func(data, drrw->drr_length);
-       }
-       dmu_assign_arcbuf(bonus, drrw->drr_offset, abuf, tx);
-       dmu_tx_commit(tx);
-       dmu_buf_rele(bonus, FTAG);
-       return (0);
-}
-
-/*
- * Handle a DRR_WRITE_BYREF record.  This record is used in dedup'ed
- * streams to refer to a copy of the data that is already on the
- * system because it came in earlier in the stream.  This function
- * finds the earlier copy of the data, and uses that copy instead of
- * data from the stream to fulfill this write.
- */
-static int
-restore_write_byref(struct restorearg *ra, objset_t *os,
-    struct drr_write_byref *drrwbr)
-{
-       dmu_tx_t *tx;
-       int err;
-       guid_map_entry_t gmesrch;
-       guid_map_entry_t *gmep;
-       avl_index_t where;
-       objset_t *ref_os = NULL;
-       dmu_buf_t *dbp;
-
-       if (drrwbr->drr_offset + drrwbr->drr_length < drrwbr->drr_offset)
-               return (SET_ERROR(EINVAL));
-
-       /*
-        * If the GUID of the referenced dataset is different from the
-        * GUID of the target dataset, find the referenced dataset.
-        */
-       if (drrwbr->drr_toguid != drrwbr->drr_refguid) {
-               gmesrch.guid = drrwbr->drr_refguid;
-               if ((gmep = avl_find(ra->guid_to_ds_map, &gmesrch,
-                   &where)) == NULL) {
-                       return (SET_ERROR(EINVAL));
-               }
-               if (dmu_objset_from_ds(gmep->gme_ds, &ref_os))
-                       return (SET_ERROR(EINVAL));
-       } else {
-               ref_os = os;
-       }
-
-       err = dmu_buf_hold(ref_os, drrwbr->drr_refobject,
-           drrwbr->drr_refoffset, FTAG, &dbp, DMU_READ_PREFETCH);
-       if (err != 0)
-               return (err);
-
-       tx = dmu_tx_create(os);
-
-       dmu_tx_hold_write(tx, drrwbr->drr_object,
-           drrwbr->drr_offset, drrwbr->drr_length);
-       err = dmu_tx_assign(tx, TXG_WAIT);
-       if (err != 0) {
-               dmu_tx_abort(tx);
-               return (err);
-       }
-       dmu_write(os, drrwbr->drr_object,
-           drrwbr->drr_offset, drrwbr->drr_length, dbp->db_data, tx);
-       dmu_buf_rele(dbp, FTAG);
-       dmu_tx_commit(tx);
-       return (0);
-}
-
-static int
-restore_write_embedded(struct restorearg *ra, objset_t *os,
-    struct drr_write_embedded *drrwnp)
-{
-       dmu_tx_t *tx;
-       int err;
-       void *data;
-
-       if (drrwnp->drr_offset + drrwnp->drr_length < drrwnp->drr_offset)
-               return (EINVAL);
-
-       if (drrwnp->drr_psize > BPE_PAYLOAD_SIZE)
-               return (EINVAL);
-
-       if (drrwnp->drr_etype >= NUM_BP_EMBEDDED_TYPES)
-               return (EINVAL);
-       if (drrwnp->drr_compression >= ZIO_COMPRESS_FUNCTIONS)
-               return (EINVAL);
-
-       data = restore_read(ra, P2ROUNDUP(drrwnp->drr_psize, 8), NULL);
-       if (data == NULL)
-               return (ra->err);
-
-       tx = dmu_tx_create(os);
-
-       dmu_tx_hold_write(tx, drrwnp->drr_object,
-           drrwnp->drr_offset, drrwnp->drr_length);
-       err = dmu_tx_assign(tx, TXG_WAIT);
-       if (err != 0) {
-               dmu_tx_abort(tx);
-               return (err);
-       }
-
-       dmu_write_embedded(os, drrwnp->drr_object,
-           drrwnp->drr_offset, data, drrwnp->drr_etype,
-           drrwnp->drr_compression, drrwnp->drr_lsize, drrwnp->drr_psize,
-           ra->byteswap ^ ZFS_HOST_BYTEORDER, tx);
-
-       dmu_tx_commit(tx);
-       return (0);
-}
-
-static int
-restore_spill(struct restorearg *ra, objset_t *os, struct drr_spill *drrs)
-{
-       dmu_tx_t *tx;
-       void *data;
-       dmu_buf_t *db, *db_spill;
-       int err;
-
-       if (drrs->drr_length < SPA_MINBLOCKSIZE ||
-           drrs->drr_length > spa_maxblocksize(dmu_objset_spa(os)))
-               return (SET_ERROR(EINVAL));
-
-       data = restore_read(ra, drrs->drr_length, NULL);
-       if (data == NULL)
-               return (ra->err);
-
-       if (dmu_object_info(os, drrs->drr_object, NULL) != 0)
-               return (SET_ERROR(EINVAL));
-
-       VERIFY(0 == dmu_bonus_hold(os, drrs->drr_object, FTAG, &db));
-       if ((err = dmu_spill_hold_by_bonus(db, FTAG, &db_spill)) != 0) {
-               dmu_buf_rele(db, FTAG);
-               return (err);
-       }
-
-       tx = dmu_tx_create(os);
-
-       dmu_tx_hold_spill(tx, db->db_object);
-
-       err = dmu_tx_assign(tx, TXG_WAIT);
-       if (err != 0) {
-               dmu_buf_rele(db, FTAG);
-               dmu_buf_rele(db_spill, FTAG);
-               dmu_tx_abort(tx);
-               return (err);
-       }
-       dmu_buf_will_dirty(db_spill, tx);
-
-       if (db_spill->db_size < drrs->drr_length)
-               VERIFY(0 == dbuf_spill_set_blksz(db_spill,
-                   drrs->drr_length, tx));
-       bcopy(data, db_spill->db_data, drrs->drr_length);
-
-       dmu_buf_rele(db, FTAG);
-       dmu_buf_rele(db_spill, FTAG);
-
-       dmu_tx_commit(tx);
-       return (0);
-}
-
-/* ARGSUSED */
-noinline static int
-restore_free(struct restorearg *ra, objset_t *os,
-    struct drr_free *drrf)
-{
-       int err;
-
-       if (drrf->drr_length != -1ULL &&
-           drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
-               return (SET_ERROR(EINVAL));
-
-       if (dmu_object_info(os, drrf->drr_object, NULL) != 0)
-               return (SET_ERROR(EINVAL));
-
-       err = dmu_free_long_range(os, drrf->drr_object,
-           drrf->drr_offset, drrf->drr_length);
-       return (err);
-}
-
-/* used to destroy the drc_ds on error */
-static void
-dmu_recv_cleanup_ds(dmu_recv_cookie_t *drc)
-{
-       char name[MAXNAMELEN];
-       dsl_dataset_name(drc->drc_ds, name);
-       dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
-       (void) dsl_destroy_head(name);
-}
-
-/*
- * NB: callers *must* call dmu_recv_end() if this succeeds.
- */
-int
-dmu_recv_stream(dmu_recv_cookie_t *drc, vnode_t *vp, offset_t *voffp,
-    int cleanup_fd, uint64_t *action_handlep)
-{
-       struct restorearg ra = { 0 };
-       dmu_replay_record_t *drr;
-       objset_t *os;
-       zio_cksum_t pcksum;
-       int featureflags;
-
-       ra.byteswap = drc->drc_byteswap;
-       ra.cksum = drc->drc_cksum;
-       ra.vp = vp;
-       ra.voff = *voffp;
-       ra.bufsize = SPA_MAXBLOCKSIZE;
-       ra.buf = vmem_alloc(ra.bufsize, KM_SLEEP);
-
-       /* these were verified in dmu_recv_begin */
-       ASSERT3U(DMU_GET_STREAM_HDRTYPE(drc->drc_drrb->drr_versioninfo), ==,
-           DMU_SUBSTREAM);
-       ASSERT3U(drc->drc_drrb->drr_type, <, DMU_OST_NUMTYPES);
-
-       /*
-        * Open the objset we are modifying.
-        */
-       VERIFY0(dmu_objset_from_ds(drc->drc_ds, &os));
-
-       ASSERT(dsl_dataset_phys(drc->drc_ds)->ds_flags & DS_FLAG_INCONSISTENT);
-
-       featureflags = DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo);
-
-       /* if this stream is dedup'ed, set up the avl tree for guid mapping */
-       if (featureflags & DMU_BACKUP_FEATURE_DEDUP) {
-               minor_t minor;
-
-               if (cleanup_fd == -1) {
-                       ra.err = SET_ERROR(EBADF);
-                       goto out;
-               }
-               ra.err = zfs_onexit_fd_hold(cleanup_fd, &minor);
-               if (ra.err != 0) {
-                       cleanup_fd = -1;
-                       goto out;
-               }
-
-               if (*action_handlep == 0) {
-                       ra.guid_to_ds_map =
-                           kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
-                       avl_create(ra.guid_to_ds_map, guid_compare,
-                           sizeof (guid_map_entry_t),
-                           offsetof(guid_map_entry_t, avlnode));
-                       ra.err = zfs_onexit_add_cb(minor,
-                           free_guid_map_onexit, ra.guid_to_ds_map,
-                           action_handlep);
-                       if (ra.err != 0)
-                               goto out;
-               } else {
-                       ra.err = zfs_onexit_cb_data(minor, *action_handlep,
-                           (void **)&ra.guid_to_ds_map);
-                       if (ra.err != 0)
-                               goto out;
-               }
-
-               drc->drc_guid_to_ds_map = ra.guid_to_ds_map;
-       }
-
-       /*
-        * Read records and process them.
-        */
-       pcksum = ra.cksum;
-       while (ra.err == 0 &&
-           NULL != (drr = restore_read(&ra, sizeof (*drr), NULL))) {
-               if (issig(JUSTLOOKING) && issig(FORREAL)) {
-                       ra.err = SET_ERROR(EINTR);
-                       goto out;
-               }
-
-               if (ra.byteswap)
-                       backup_byteswap(drr);
-
-               switch (drr->drr_type) {
-               case DRR_OBJECT:
-               {
-                       /*
-                        * We need to make a copy of the record header,
-                        * because restore_{object,write} may need to
-                        * restore_read(), which will invalidate drr.
-                        */
-                       struct drr_object drro = drr->drr_u.drr_object;
-                       ra.err = restore_object(&ra, os, &drro);
-                       break;
-               }
-               case DRR_FREEOBJECTS:
-               {
-                       struct drr_freeobjects drrfo =
-                           drr->drr_u.drr_freeobjects;
-                       ra.err = restore_freeobjects(&ra, os, &drrfo);
-                       break;
-               }
-               case DRR_WRITE:
-               {
-                       struct drr_write drrw = drr->drr_u.drr_write;
-                       ra.err = restore_write(&ra, os, &drrw);
-                       break;
-               }
-               case DRR_WRITE_BYREF:
-               {
-                       struct drr_write_byref drrwbr =
-                           drr->drr_u.drr_write_byref;
-                       ra.err = restore_write_byref(&ra, os, &drrwbr);
-                       break;
-               }
-               case DRR_WRITE_EMBEDDED:
-               {
-                       struct drr_write_embedded drrwe =
-                           drr->drr_u.drr_write_embedded;
-                       ra.err = restore_write_embedded(&ra, os, &drrwe);
-                       break;
-               }
-               case DRR_FREE:
-               {
-                       struct drr_free drrf = drr->drr_u.drr_free;
-                       ra.err = restore_free(&ra, os, &drrf);
-                       break;
-               }
-               case DRR_END:
-               {
-                       struct drr_end drre = drr->drr_u.drr_end;
-                       /*
-                        * We compare against the *previous* checksum
-                        * value, because the stored checksum is of
-                        * everything before the DRR_END record.
-                        */
-                       if (!ZIO_CHECKSUM_EQUAL(drre.drr_checksum, pcksum))
-                               ra.err = SET_ERROR(ECKSUM);
-                       goto out;
-               }
-               case DRR_SPILL:
-               {
-                       struct drr_spill drrs = drr->drr_u.drr_spill;
-                       ra.err = restore_spill(&ra, os, &drrs);
-                       break;
-               }
-               default:
-                       ra.err = SET_ERROR(EINVAL);
-                       goto out;
-               }
-               pcksum = ra.cksum;
-       }
-       ASSERT(ra.err != 0);
-
-out:
-       if ((featureflags & DMU_BACKUP_FEATURE_DEDUP) && (cleanup_fd != -1))
-               zfs_onexit_fd_rele(cleanup_fd);
-
-       if (ra.err != 0) {
-               /*
-                * destroy what we created, so we don't leave it in the
-                * inconsistent restoring state.
-                */
-               dmu_recv_cleanup_ds(drc);
-       }
-
-       vmem_free(ra.buf, ra.bufsize);
-       *voffp = ra.voff;
-       return (ra.err);
-}
-
-static int
-dmu_recv_end_check(void *arg, dmu_tx_t *tx)
-{
-       dmu_recv_cookie_t *drc = arg;
-       dsl_pool_t *dp = dmu_tx_pool(tx);
-       int error;
-
-       ASSERT3P(drc->drc_ds->ds_owner, ==, dmu_recv_tag);
-
-       if (!drc->drc_newfs) {
-               dsl_dataset_t *origin_head;
-
-               error = dsl_dataset_hold(dp, drc->drc_tofs, FTAG, &origin_head);
-               if (error != 0)
-                       return (error);
-               if (drc->drc_force) {
-                       /*
-                        * We will destroy any snapshots in tofs (i.e. before
-                        * origin_head) that are after the origin (which is
-                        * the snap before drc_ds, because drc_ds can not
-                        * have any snaps of its own).
-                        */
-                       uint64_t obj;
-
-                       obj = dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
-                       while (obj !=
-                           dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj) {
-                               dsl_dataset_t *snap;
-                               error = dsl_dataset_hold_obj(dp, obj, FTAG,
-                                   &snap);
-                               if (error != 0)
-                                       break;
-                               if (snap->ds_dir != origin_head->ds_dir)
-                                       error = SET_ERROR(EINVAL);
-                               if (error == 0)  {
-                                       error = dsl_destroy_snapshot_check_impl(
-                                           snap, B_FALSE);
-                               }
-                               obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
-                               dsl_dataset_rele(snap, FTAG);
-                               if (error != 0)
-                                       break;
-                       }
-                       if (error != 0) {
-                               dsl_dataset_rele(origin_head, FTAG);
-                               return (error);
-                       }
-               }
-               error = dsl_dataset_clone_swap_check_impl(drc->drc_ds,
-                   origin_head, drc->drc_force, drc->drc_owner, tx);
-               if (error != 0) {
-                       dsl_dataset_rele(origin_head, FTAG);
-                       return (error);
-               }
-               error = dsl_dataset_snapshot_check_impl(origin_head,
-                   drc->drc_tosnap, tx, B_TRUE, 1, drc->drc_cred);
-               dsl_dataset_rele(origin_head, FTAG);
-               if (error != 0)
-                       return (error);
-
-               error = dsl_destroy_head_check_impl(drc->drc_ds, 1);
-       } else {
-               error = dsl_dataset_snapshot_check_impl(drc->drc_ds,
-                   drc->drc_tosnap, tx, B_TRUE, 1, drc->drc_cred);
-       }
-       return (error);
-}
-
-static void
-dmu_recv_end_sync(void *arg, dmu_tx_t *tx)
-{
-       dmu_recv_cookie_t *drc = arg;
-       dsl_pool_t *dp = dmu_tx_pool(tx);
-
-       spa_history_log_internal_ds(drc->drc_ds, "finish receiving",
-           tx, "snap=%s", drc->drc_tosnap);
-
-       if (!drc->drc_newfs) {
-               dsl_dataset_t *origin_head;
-
-               VERIFY0(dsl_dataset_hold(dp, drc->drc_tofs, FTAG,
-                   &origin_head));
-
-               if (drc->drc_force) {
-                       /*
-                        * Destroy any snapshots of drc_tofs (origin_head)
-                        * after the origin (the snap before drc_ds).
-                        */
-                       uint64_t obj;
-
-                       obj = dsl_dataset_phys(origin_head)->ds_prev_snap_obj;
-                       while (obj !=
-                           dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj) {
-                               dsl_dataset_t *snap;
-                               VERIFY0(dsl_dataset_hold_obj(dp, obj, FTAG,
-                                   &snap));
-                               ASSERT3P(snap->ds_dir, ==, origin_head->ds_dir);
-                               obj = dsl_dataset_phys(snap)->ds_prev_snap_obj;
-                               dsl_destroy_snapshot_sync_impl(snap,
-                                   B_FALSE, tx);
-                               dsl_dataset_rele(snap, FTAG);
-                       }
-               }
-               VERIFY3P(drc->drc_ds->ds_prev, ==,
-                   origin_head->ds_prev);
-
-               dsl_dataset_clone_swap_sync_impl(drc->drc_ds,
-                   origin_head, tx);
-               dsl_dataset_snapshot_sync_impl(origin_head,
-                   drc->drc_tosnap, tx);
-
-               /* set snapshot's creation time and guid */
-               dmu_buf_will_dirty(origin_head->ds_prev->ds_dbuf, tx);
-               dsl_dataset_phys(origin_head->ds_prev)->ds_creation_time =
-                   drc->drc_drrb->drr_creation_time;
-               dsl_dataset_phys(origin_head->ds_prev)->ds_guid =
-                   drc->drc_drrb->drr_toguid;
-               dsl_dataset_phys(origin_head->ds_prev)->ds_flags &=
-                   ~DS_FLAG_INCONSISTENT;
-
-               dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
-               dsl_dataset_phys(origin_head)->ds_flags &=
-                   ~DS_FLAG_INCONSISTENT;
-
-               dsl_dataset_rele(origin_head, FTAG);
-               dsl_destroy_head_sync_impl(drc->drc_ds, tx);
-
-               if (drc->drc_owner != NULL)
-                       VERIFY3P(origin_head->ds_owner, ==, drc->drc_owner);
-       } else {
-               dsl_dataset_t *ds = drc->drc_ds;
-
-               dsl_dataset_snapshot_sync_impl(ds, drc->drc_tosnap, tx);
-
-               /* set snapshot's creation time and guid */
-               dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
-               dsl_dataset_phys(ds->ds_prev)->ds_creation_time =
-                   drc->drc_drrb->drr_creation_time;
-               dsl_dataset_phys(ds->ds_prev)->ds_guid =
-                   drc->drc_drrb->drr_toguid;
-               dsl_dataset_phys(ds->ds_prev)->ds_flags &=
-                   ~DS_FLAG_INCONSISTENT;
-
-               dmu_buf_will_dirty(ds->ds_dbuf, tx);
-               dsl_dataset_phys(ds)->ds_flags &= ~DS_FLAG_INCONSISTENT;
-       }
-       drc->drc_newsnapobj = dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj;
-       /*
-        * Release the hold from dmu_recv_begin.  This must be done before
-        * we return to open context, so that when we free the dataset's dnode,
-        * we can evict its bonus buffer.
-        */
-       dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
-       drc->drc_ds = NULL;
-}
-
-static int
-add_ds_to_guidmap(const char *name, avl_tree_t *guid_map, uint64_t snapobj)
-{
-       dsl_pool_t *dp;
-       dsl_dataset_t *snapds;
-       guid_map_entry_t *gmep;
-       int err;
-
-       ASSERT(guid_map != NULL);
-
-       err = dsl_pool_hold(name, FTAG, &dp);
-       if (err != 0)
-               return (err);
-       gmep = kmem_alloc(sizeof (*gmep), KM_SLEEP);
-       err = dsl_dataset_hold_obj(dp, snapobj, gmep, &snapds);
-       if (err == 0) {
-               gmep->guid = dsl_dataset_phys(snapds)->ds_guid;
-               gmep->gme_ds = snapds;
-               avl_add(guid_map, gmep);
-               dsl_dataset_long_hold(snapds, gmep);
-       } else {
-               kmem_free(gmep, sizeof (*gmep));
-       }
-
-       dsl_pool_rele(dp, FTAG);
-       return (err);
-}
-
-static int dmu_recv_end_modified_blocks = 3;
-
-static int
-dmu_recv_existing_end(dmu_recv_cookie_t *drc)
-{
-       int error;
-
-#ifdef _KERNEL
-       char *name;
-
-       /*
-        * We will be destroying the ds; make sure its origin is unmounted if
-        * necessary.
-        */
-       name = kmem_alloc(MAXNAMELEN, KM_SLEEP);
-       dsl_dataset_name(drc->drc_ds, name);
-       zfs_destroy_unmount_origin(name);
-       kmem_free(name, MAXNAMELEN);
-#endif
-
-       error = dsl_sync_task(drc->drc_tofs,
-           dmu_recv_end_check, dmu_recv_end_sync, drc,
-           dmu_recv_end_modified_blocks, ZFS_SPACE_CHECK_NORMAL);
-
-       if (error != 0)
-               dmu_recv_cleanup_ds(drc);
-       return (error);
-}
-
-static int
-dmu_recv_new_end(dmu_recv_cookie_t *drc)
-{
-       int error;
-
-       error = dsl_sync_task(drc->drc_tofs,
-           dmu_recv_end_check, dmu_recv_end_sync, drc,
-           dmu_recv_end_modified_blocks, ZFS_SPACE_CHECK_NORMAL);
-
-       if (error != 0) {
-               dmu_recv_cleanup_ds(drc);
-       } else if (drc->drc_guid_to_ds_map != NULL) {
-               (void) add_ds_to_guidmap(drc->drc_tofs,
-                   drc->drc_guid_to_ds_map,
-                   drc->drc_newsnapobj);
-       }
-       return (error);
-}
-
-int
-dmu_recv_end(dmu_recv_cookie_t *drc, void *owner)
-{
-       drc->drc_owner = owner;
-
-       if (drc->drc_newfs)
-               return (dmu_recv_new_end(drc));
-       else
-               return (dmu_recv_existing_end(drc));
-}
-
-/*
- * Return TRUE if this objset is currently being received into.
- */
-boolean_t
-dmu_objset_is_receiving(objset_t *os)
-{
-       return (os->os_dsl_dataset != NULL &&
-           os->os_dsl_dataset->ds_owner == dmu_recv_tag);
-}
-
-#if defined(_KERNEL)
 module_param(zfs_send_corrupt_data, int, 0644);
 MODULE_PARM_DESC(zfs_send_corrupt_data, "Allow sending corrupt data");
+
+module_param(zfs_send_queue_length, int, 0644);
+MODULE_PARM_DESC(zfs_send_queue_length, "Maximum send queue length");
 #endif