]> 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 2f4087a67b0e9dd64fc196081a8d1a19447a5d3e..ad64d666bee75177c0d1128114a96f81f2780141 100644 (file)
 
 /* Set this tunable to TRUE to replace corrupt data with 0x2f5baddb10c */
 int zfs_send_corrupt_data = B_FALSE;
-int zfs_send_queue_length = 16 * 1024 * 1024;
-int zfs_recv_queue_length = 16 * 1024 * 1024;
+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";
-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)))
 
-static void byteswap_record(dmu_replay_record_t *drr);
-
 struct send_thread_arg {
        bqueue_t        q;
        dsl_dataset_t   *ds;            /* Dataset to traverse */
@@ -109,18 +108,17 @@ dump_bytes_cb(void *arg)
        ssize_t resid; /* have to get resid to get detailed errno */
 
        /*
-        * The code does not rely on this (len being a multiple of 8).  We keep
+        * 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).
-        *
-        * Removing the assertions could be rolled into a new feature that uses
-        * data that isn't 8-byte aligned; if the assertions were removed, a
-        * feature flag would have to be added.
+        * 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.
         */
 
-       ASSERT0(dbi->dbi_len % 8);
+       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,
@@ -166,21 +164,26 @@ 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));
-       fletcher_4_incremental_native(dsp->dsa_drr,
+       (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) {
+       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;
        }
-       fletcher_4_incremental_native(&dsp->dsa_drr->
+       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) {
-               fletcher_4_incremental_native(payload, payload_len,
+               (void) fletcher_4_incremental_native(payload, payload_len,
                    &dsp->dsa_zc);
                if (dump_bytes(dsp, payload, payload_len) != 0)
                        return (SET_ERROR(EINTR));
@@ -219,9 +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 (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
@@ -238,19 +238,22 @@ dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
 
        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 */
@@ -264,9 +267,12 @@ 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 (length == DMU_OBJECT_END) {
                if (dump_record(dsp, NULL, 0) != 0)
                        return (SET_ERROR(EINTR));
        } else {
@@ -277,9 +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);
 
        /*
@@ -290,7 +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
@@ -309,27 +317,67 @@ dump_write(dmu_sendarg_t *dsp, dmu_object_type_t type,
        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_record(dsp, data, blksz) != 0)
+       if (dump_record(dsp, data, payload_size) != 0)
                return (SET_ERROR(EINTR));
        return (0);
 }
@@ -344,7 +392,7 @@ dump_write_embedded(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
 
        if (dsp->dsa_pending_op != PENDING_NONE) {
                if (dump_record(dsp, NULL, 0) != 0)
-                       return (EINTR);
+                       return (SET_ERROR(EINTR));
                dsp->dsa_pending_op = PENDING_NONE;
        }
 
@@ -364,14 +412,16 @@ dump_write_embedded(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
        decode_embedded_bp_compressed(bp, buf);
 
        if (dump_record(dsp, buf, P2ROUNDUP(drrw->drr_psize, 8)) != 0)
-               return (EINTR);
+               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_record(dsp, NULL, 0) != 0)
@@ -386,7 +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_record(dsp, data, blksz) != 0)
+       /* 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);
 }
@@ -395,6 +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);
+
+       /*
+        * 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,
@@ -438,9 +517,11 @@ 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) {
                /*
@@ -481,20 +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_record(dsp, DN_BONUS(dnp),
-           P2ROUNDUP(dnp->dn_bonuslen, 8)) != 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_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)
 {
@@ -505,7 +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);
 
        /*
@@ -538,6 +677,7 @@ send_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 
        ASSERT(zb->zb_object == DMU_META_DNODE_OBJECT ||
            zb->zb_object >= sta->resume.zb_object);
+       ASSERT3P(sta->ds, !=, NULL);
 
        if (sta->cancel)
                return (SET_ERROR(EINTR));
@@ -573,6 +713,7 @@ 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,
@@ -585,6 +726,8 @@ send_traverse_thread(void *arg)
        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();
 }
 
 /*
@@ -603,13 +746,24 @@ do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
        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;
-       uint64_t dnobj;
 
        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);
@@ -621,43 +775,67 @@ do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
        } else if (BP_IS_HOLE(bp)) {
                uint64_t span = BP_SPAN(dblkszsec, indblkshift, zb->zb_level);
                uint64_t offset = zb->zb_blkid * span;
-               err = dump_free(dsa, zb->zb_object, offset, 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 epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
                arc_flags_t aflags = ARC_FLAG_WAIT;
                arc_buf_t *abuf;
-               int i;
+               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;
-               dnobj = zb->zb_blkid * epb;
-               for (i = 0; i < epb; i += blk[i].dn_extra_slots + 1) {
-                       err = dump_dnode(dsa, dnobj + i, 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(dsa, zb->zb_object, blksz, abuf->b_data);
-               (void) arc_buf_remove_ref(abuf, &abuf);
+               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 = dblkszsec << SPA_MINBLOCKSHIFT;
@@ -671,19 +849,58 @@ do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
                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));
+
+               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++)
@@ -695,23 +912,24 @@ do_dump(dmu_sendarg_t *dsa, struct send_block_record *data)
 
                offset = zb->zb_blkid * blksz;
 
-               if (!(dsa->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(dsa, type, zb->zb_object,
-                                   offset, n, NULL, buf);
+                                   offset, n, n, NULL, buf);
                                offset += n;
                                buf += n;
                                blksz -= n;
                        }
                } else {
-                       err = dump_write(dsa, 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);
@@ -736,9 +954,9 @@ get_next_record(bqueue_t *bq, struct send_block_record *data)
  */
 static int
 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, int outfd,
-    uint64_t resumeobj, uint64_t resumeoff,
+    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;
@@ -758,6 +976,28 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
                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;
@@ -780,15 +1020,30 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
        }
 #endif
 
-       if (large_block_ok && to_ds->ds_feature_inuse[SPA_FEATURE_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 (to_ds->ds_feature_inuse[SPA_FEATURE_LARGE_DNODE])
+       if (dsl_dataset_feature_is_active(to_ds, SPA_FEATURE_LARGE_DNODE))
                featureflags |= DMU_BACKUP_FEATURE_LARGE_DNODE;
-       if (embedok &&
+
+       /* 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;
+       }
+
+       /* 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) {
@@ -841,20 +1096,47 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
        dsl_dataset_long_hold(to_ds, FTAG);
        dsl_pool_rele(dp, tag);
 
-       if (resumeobj != 0 || resumeoff != 0) {
-               dmu_object_info_t to_doi;
-               nvlist_t *nvl;
-               err = dmu_object_info(os, resumeobj, &to_doi);
-               if (err != 0)
-                       goto out;
-               SET_BOOKMARK(&to_arg.resume, to_ds->ds_object, resumeobj, 0,
-                   resumeoff / to_doi.doi_data_block_size);
+       /* 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);
+               }
 
-               nvl = fnvlist_alloc();
-               fnvlist_add_uint64(nvl, "resume_object", resumeobj);
-               fnvlist_add_uint64(nvl, "resume_offset", resumeoff);
                payload = fnvlist_pack(nvl, &payload_len);
                drr->drr_payloadlen = payload_len;
+               fnvlist_free(keynvl);
                fnvlist_free(nvl);
        }
 
@@ -865,13 +1147,16 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
                goto out;
        }
 
-       err = bqueue_init(&to_arg.q, zfs_send_queue_length,
+       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);
 
@@ -917,12 +1202,13 @@ dmu_send_impl(void *tag, dsl_pool_t *dp, dsl_dataset_t *to_ds,
 
        if (dump_record(dsp, NULL, 0) != 0)
                err = dsp->dsa_err;
-
 out:
        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));
 
@@ -933,60 +1219,78 @@ out:
 
 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, 0, 0, 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, 0, 0, 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, uint64_t resumeobj, uint64_t resumeoff,
-    vnode_t *vp, offset_t *off)
+    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)
@@ -995,16 +1299,15 @@ dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
        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);
@@ -1012,7 +1315,7 @@ dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
        }
 
        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;
 
@@ -1038,59 +1341,93 @@ dmu_send(const char *tosnap, const char *fromsnap, boolean_t embedok,
                                    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,
+                   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,
+                   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;
 
@@ -1098,10 +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));
 
@@ -1120,33 +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);
 }
@@ -1158,10 +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));
 
@@ -1177,2082 +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 (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);
-       ASSERT(!(featureflags & DMU_BACKUP_FEATURE_RESUMING));
-
-       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));
-
-       if (drba->drba_cookie->drc_resumable &&
-           !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_EXTENSIBLE_DATASET))
-               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));
-
-       /*
-        * The receiving code doesn't know how to translate large dnodes
-        * to smaller ones, so the pool must have the LARGE_DNODE
-        * feature enabled if the stream has LARGE_DNODE.
-        */
-       if ((featureflags & DMU_BACKUP_FEATURE_LARGE_DNODE) &&
-           !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_LARGE_DNODE))
-               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 || drba->drba_origin) {
-                       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 ||
-                   drba->drba_origin))
-                       return (SET_ERROR(ENOENT));
-
-               /*
-                * If we're receiving a full send as a clone, and it doesn't
-                * contain all the necessary free records and freeobject
-                * records, reject it.
-                */
-               if (fromguid == 0 && drba->drba_origin &&
-                   !(flags & DRR_FLAG_FREERECORDS))
-                       return (SET_ERROR(EINVAL));
-
-               /* 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 &&
-                           fromguid != 0) {
-                               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);
-       objset_t *mos = dp->dp_meta_objset;
-       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 = 0;
-
-       if (drrb->drr_flags & DRR_FLAG_CI_DATA)
-               crflags |= DS_FLAG_CI_DATASET;
-
-       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);
-               if (drba->drba_snapobj != 0)
-                       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 (drba->drba_cookie->drc_resumable) {
-               uint64_t one = 1;
-               uint64_t zero = 0;
-
-               dsl_dataset_zapify(newds, tx);
-               if (drrb->drr_fromguid != 0) {
-                       VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_FROMGUID,
-                           8, 1, &drrb->drr_fromguid, tx));
-               }
-               VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_TOGUID,
-                   8, 1, &drrb->drr_toguid, tx));
-               VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_TONAME,
-                   1, strlen(drrb->drr_toname) + 1, drrb->drr_toname, tx));
-               VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_OBJECT,
-                   8, 1, &one, tx));
-               VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_OFFSET,
-                   8, 1, &zero, tx));
-               VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_BYTES,
-                   8, 1, &zero, tx));
-               if (DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo) &
-                   DMU_BACKUP_FEATURE_EMBED_DATA) {
-                       VERIFY0(zap_add(mos, dsobj, DS_FIELD_RESUME_EMBEDOK,
-                           8, 1, &one, tx));
-               }
-       }
-
-       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, "");
-}
-
-static int
-dmu_recv_resume_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;
-       int error;
-       uint64_t featureflags = DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo);
-       dsl_dataset_t *ds;
-       const char *tofs = drba->drba_cookie->drc_tofs;
-       char recvname[ZFS_MAXNAMELEN];
-       uint64_t val;
-
-       /* already checked */
-       ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
-       ASSERT(featureflags & DMU_BACKUP_FEATURE_RESUMING);
 
-       if (DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
-           DMU_COMPOUNDSTREAM ||
-           drrb->drr_type >= DMU_OST_NUMTYPES)
-               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 plain 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));
-
-       (void) snprintf(recvname, sizeof (recvname), "%s/%s",
-           tofs, recv_clone_name);
-
-       if (dsl_dataset_hold(dp, recvname, FTAG, &ds) != 0) {
-               /* %recv does not exist; continue in tofs */
-               error = dsl_dataset_hold(dp, tofs, FTAG, &ds);
-               if (error != 0)
-                       return (error);
-       }
+#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 */
 
-       /* check that ds is marked inconsistent */
-       if (!DS_IS_INCONSISTENT(ds)) {
-               dsl_dataset_rele(ds, FTAG);
-               return (SET_ERROR(EINVAL));
-       }
+module_param(zfs_send_corrupt_data, int, 0644);
+MODULE_PARM_DESC(zfs_send_corrupt_data, "Allow sending corrupt data");
 
-       /* check that there is resuming data, and that the toguid matches */
-       if (!dsl_dataset_is_zapified(ds)) {
-               dsl_dataset_rele(ds, FTAG);
-               return (SET_ERROR(EINVAL));
-       }
-       error = zap_lookup(dp->dp_meta_objset, ds->ds_object,
-           DS_FIELD_RESUME_TOGUID, sizeof (val), 1, &val);
-       if (error != 0 || drrb->drr_toguid != val) {
-               dsl_dataset_rele(ds, FTAG);
-               return (SET_ERROR(EINVAL));
-       }
-
-       /*
-        * Check if the receive is still running.  If so, it will be owned.
-        * Note that nothing else can own the dataset (e.g. after the receive
-        * fails) because it will be marked inconsistent.
-        */
-       if (dsl_dataset_has_owner(ds)) {
-               dsl_dataset_rele(ds, FTAG);
-               return (SET_ERROR(EBUSY));
-       }
-
-       /* There should not be any snapshots of this fs yet. */
-       if (ds->ds_prev != NULL && ds->ds_prev->ds_dir == ds->ds_dir) {
-               dsl_dataset_rele(ds, FTAG);
-               return (SET_ERROR(EINVAL));
-       }
-
-       /*
-        * Note: resume point will be checked when we process the first WRITE
-        * record.
-        */
-
-       /* check that the origin matches */
-       val = 0;
-       (void) zap_lookup(dp->dp_meta_objset, ds->ds_object,
-           DS_FIELD_RESUME_FROMGUID, sizeof (val), 1, &val);
-       if (drrb->drr_fromguid != val) {
-               dsl_dataset_rele(ds, FTAG);
-               return (SET_ERROR(EINVAL));
-       }
-
-       dsl_dataset_rele(ds, FTAG);
-       return (0);
-}
-
-static void
-dmu_recv_resume_begin_sync(void *arg, dmu_tx_t *tx)
-{
-       dmu_recv_begin_arg_t *drba = arg;
-       dsl_pool_t *dp = dmu_tx_pool(tx);
-       const char *tofs = drba->drba_cookie->drc_tofs;
-       dsl_dataset_t *ds;
-       uint64_t dsobj;
-       char recvname[ZFS_MAXNAMELEN];
-
-       (void) snprintf(recvname, sizeof (recvname), "%s/%s",
-           tofs, recv_clone_name);
-
-       if (dsl_dataset_hold(dp, recvname, FTAG, &ds) != 0) {
-               /* %recv does not exist; continue in tofs */
-               VERIFY0(dsl_dataset_hold(dp, tofs, FTAG, &ds));
-               drba->drba_cookie->drc_newfs = B_TRUE;
-       }
-
-       /* clear the inconsistent flag so that we can own it */
-       ASSERT(DS_IS_INCONSISTENT(ds));
-       dmu_buf_will_dirty(ds->ds_dbuf, tx);
-       dsl_dataset_phys(ds)->ds_flags &= ~DS_FLAG_INCONSISTENT;
-       dsobj = ds->ds_object;
-       dsl_dataset_rele(ds, FTAG);
-
-       VERIFY0(dsl_dataset_own_obj(dp, dsobj, dmu_recv_tag, &ds));
-
-       dmu_buf_will_dirty(ds->ds_dbuf, tx);
-       dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT;
-
-       ASSERT(!BP_IS_HOLE(dsl_dataset_get_blkptr(ds)));
-
-       drba->drba_cookie->drc_ds = ds;
-
-       spa_history_log_internal_ds(ds, "resume 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, dmu_replay_record_t *drr_begin,
-    boolean_t force, boolean_t resumable, char *origin, dmu_recv_cookie_t *drc)
-{
-       dmu_recv_begin_arg_t drba = { 0 };
-
-       bzero(drc, sizeof (dmu_recv_cookie_t));
-       drc->drc_drr_begin = drr_begin;
-       drc->drc_drrb = &drr_begin->drr_u.drr_begin;
-       drc->drc_tosnap = tosnap;
-       drc->drc_tofs = tofs;
-       drc->drc_force = force;
-       drc->drc_resumable = resumable;
-       drc->drc_cred = CRED();
-
-       if (drc->drc_drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC)) {
-               drc->drc_byteswap = B_TRUE;
-               fletcher_4_incremental_byteswap(drr_begin,
-                   sizeof (dmu_replay_record_t), &drc->drc_cksum);
-               byteswap_record(drr_begin);
-       } else if (drc->drc_drrb->drr_magic == DMU_BACKUP_MAGIC) {
-               fletcher_4_incremental_native(drr_begin,
-                   sizeof (dmu_replay_record_t), &drc->drc_cksum);
-       } else {
-               return (SET_ERROR(EINVAL));
-       }
-
-       drba.drba_origin = origin;
-       drba.drba_cookie = drc;
-       drba.drba_cred = CRED();
-
-       if (DMU_GET_FEATUREFLAGS(drc->drc_drrb->drr_versioninfo) &
-           DMU_BACKUP_FEATURE_RESUMING) {
-               return (dsl_sync_task(tofs,
-                   dmu_recv_resume_begin_check, dmu_recv_resume_begin_sync,
-                   &drba, 5, ZFS_SPACE_CHECK_NORMAL));
-       } else  {
-               return (dsl_sync_task(tofs,
-                   dmu_recv_begin_check, dmu_recv_begin_sync,
-                   &drba, 5, ZFS_SPACE_CHECK_NORMAL));
-       }
-}
-
-struct receive_record_arg {
-       dmu_replay_record_t header;
-       void *payload; /* Pointer to a buffer containing the payload */
-       /*
-        * If the record is a write, pointer to the arc_buf_t containing the
-        * payload.
-        */
-       arc_buf_t *write_buf;
-       int payload_size;
-       uint64_t bytes_read; /* bytes read from stream when record created */
-       boolean_t eos_marker; /* Marks the end of the stream */
-       bqueue_node_t node;
-};
-
-struct receive_writer_arg {
-       objset_t *os;
-       boolean_t byteswap;
-       bqueue_t q;
-
-       /*
-        * These three args are used to signal to the main thread that we're
-        * done.
-        */
-       kmutex_t mutex;
-       kcondvar_t cv;
-       boolean_t done;
-
-       int err;
-       /* A map from guid to dataset to help handle dedup'd streams. */
-       avl_tree_t *guid_to_ds_map;
-       boolean_t resumable;
-       uint64_t last_object, last_offset;
-       uint64_t bytes_read; /* bytes read when current record created */
-};
-
-struct objlist {
-       list_t list; /* List of struct receive_objnode. */
-       /*
-        * Last object looked up. Used to assert that objects are being looked
-        * up in ascending order.
-        */
-       uint64_t last_lookup;
-};
-
-struct receive_objnode {
-       list_node_t node;
-       uint64_t object;
-};
-
-struct receive_arg  {
-       objset_t *os;
-       vnode_t *vp; /* The vnode to read the stream from */
-       uint64_t voff; /* The current offset in the stream */
-       uint64_t bytes_read;
-       /*
-        * A record that has had its payload read in, but hasn't yet been handed
-        * off to the worker thread.
-        */
-       struct receive_record_arg *rrd;
-       /* A record that has had its header read in, but not its payload. */
-       struct receive_record_arg *next_rrd;
-       zio_cksum_t cksum;
-       zio_cksum_t prev_cksum;
-       int err;
-       boolean_t byteswap;
-       /* Sorted list of objects not to issue prefetches for. */
-       struct objlist ignore_objlist;
-};
-
-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 int
-receive_read(struct receive_arg *ra, int len, void *buf)
-{
-       int done = 0;
-
-       /*
-        * The code doesn't rely on this (lengths being multiples of 8).  See
-        * comment in dump_bytes.
-        */
-       ASSERT0(len % 8);
-
-       while (done < len) {
-               ssize_t resid;
-
-               ra->err = vn_rdwr(UIO_READ, ra->vp,
-                   (char *)buf + done, len - done,
-                   ra->voff, UIO_SYSSPACE, FAPPEND,
-                   RLIM64_INFINITY, CRED(), &resid);
-
-               if (resid == len - done) {
-                       /*
-                        * Note: ECKSUM indicates that the receive
-                        * was interrupted and can potentially be resumed.
-                        */
-                       ra->err = SET_ERROR(ECKSUM);
-               }
-               ra->voff += len - done - resid;
-               done = len - resid;
-               if (ra->err != 0)
-                       return (ra->err);
-       }
-
-       ra->bytes_read += len;
-
-       ASSERT3U(done, ==, len);
-       return (0);
-}
-
-noinline static void
-byteswap_record(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);
-               ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_write.drr_key.ddk_cksum);
-               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);
-               ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_write_byref.
-                   drr_key.ddk_cksum);
-               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_toguid);
-               ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_end.drr_checksum);
-               break;
-       default:
-               break;
-       }
-
-       if (drr->drr_type != DRR_BEGIN) {
-               ZIO_CHECKSUM_BSWAP(&drr->drr_u.drr_checksum.drr_checksum);
-       }
-
-#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_OLD_MAX_BONUSLEN -
-                   MIN(DN_OLD_MAX_BONUSLEN, bonus_size)) >> SPA_BLKPTRSHIFT));
-       }
-}
-
-static void
-save_resume_state(struct receive_writer_arg *rwa,
-    uint64_t object, uint64_t offset, dmu_tx_t *tx)
-{
-       int txgoff = dmu_tx_get_txg(tx) & TXG_MASK;
-
-       if (!rwa->resumable)
-               return;
-
-       /*
-        * We use ds_resume_bytes[] != 0 to indicate that we need to
-        * update this on disk, so it must not be 0.
-        */
-       ASSERT(rwa->bytes_read != 0);
-
-       /*
-        * We only resume from write records, which have a valid
-        * (non-meta-dnode) object number.
-        */
-       ASSERT(object != 0);
-
-       /*
-        * For resuming to work correctly, we must receive records in order,
-        * sorted by object,offset.  This is checked by the callers, but
-        * assert it here for good measure.
-        */
-       ASSERT3U(object, >=, rwa->os->os_dsl_dataset->ds_resume_object[txgoff]);
-       ASSERT(object != rwa->os->os_dsl_dataset->ds_resume_object[txgoff] ||
-           offset >= rwa->os->os_dsl_dataset->ds_resume_offset[txgoff]);
-       ASSERT3U(rwa->bytes_read, >=,
-           rwa->os->os_dsl_dataset->ds_resume_bytes[txgoff]);
-
-       rwa->os->os_dsl_dataset->ds_resume_object[txgoff] = object;
-       rwa->os->os_dsl_dataset->ds_resume_offset[txgoff] = offset;
-       rwa->os->os_dsl_dataset->ds_resume_bytes[txgoff] = rwa->bytes_read;
-}
-
-noinline static int
-receive_object(struct receive_writer_arg *rwa, struct drr_object *drro,
-       void *data)
-{
-       dmu_object_info_t doi;
-       dmu_tx_t *tx;
-       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(rwa->os)) ||
-           drro->drr_bonuslen >
-           DN_BONUS_SIZE(spa_maxdnodesize(dmu_objset_spa(rwa->os)))) {
-               return (SET_ERROR(EINVAL));
-       }
-
-       err = dmu_object_info(rwa->os, drro->drr_object, &doi);
-
-       if (err != 0 && err != ENOENT)
-               return (SET_ERROR(EINVAL));
-       object = err == 0 ? drro->drr_object : DMU_NEW_OBJECT;
-
-       /*
-        * 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(rwa->os, drro->drr_object,
-                           0, DMU_OBJECT_END);
-                       if (err != 0)
-                               return (SET_ERROR(EINVAL));
-               }
-       }
-
-       tx = dmu_tx_create(rwa->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_dnsize(rwa->os, drro->drr_object,
-                   drro->drr_type, drro->drr_blksz,
-                   drro->drr_bonustype, drro->drr_bonuslen,
-                   drro->drr_dn_slots << DNODE_SHIFT, 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(rwa->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(rwa->os, drro->drr_object,
-           drro->drr_checksumtype, tx);
-       dmu_object_set_compress(rwa->os, drro->drr_object,
-           drro->drr_compress, tx);
-
-       if (data != NULL) {
-               dmu_buf_t *db;
-
-               VERIFY0(dmu_bonus_hold(rwa->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 (rwa->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
-receive_freeobjects(struct receive_writer_arg *rwa,
-    struct drr_freeobjects *drrfo)
-{
-       uint64_t obj;
-       int next_err = 0;
-
-       if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
-               return (SET_ERROR(EINVAL));
-
-       for (obj = drrfo->drr_firstobj == 0 ? 1 : drrfo->drr_firstobj;
-           obj < drrfo->drr_firstobj + drrfo->drr_numobjs && next_err == 0;
-           next_err = dmu_object_next(rwa->os, &obj, FALSE, 0)) {
-               dmu_object_info_t doi;
-               int err;
-
-               err = dmu_object_info(rwa->os, obj, &doi);
-               if (err == ENOENT) {
-                       obj++;
-                       continue;
-               } else if (err != 0) {
-                       return (err);
-               }
-
-               err = dmu_free_long_object(rwa->os, obj);
-               if (err != 0)
-                       return (err);
-       }
-       if (next_err != ESRCH)
-               return (next_err);
-       return (0);
-}
-
-noinline static int
-receive_write(struct receive_writer_arg *rwa, struct drr_write *drrw,
-       arc_buf_t *abuf)
-{
-       dmu_tx_t *tx;
-       dmu_buf_t *bonus;
-       int err;
-
-       if (drrw->drr_offset + drrw->drr_length < drrw->drr_offset ||
-           !DMU_OT_IS_VALID(drrw->drr_type))
-               return (SET_ERROR(EINVAL));
-
-       /*
-        * For resuming to work, records must be in increasing order
-        * by (object, offset).
-        */
-       if (drrw->drr_object < rwa->last_object ||
-           (drrw->drr_object == rwa->last_object &&
-           drrw->drr_offset < rwa->last_offset)) {
-               return (SET_ERROR(EINVAL));
-       }
-       rwa->last_object = drrw->drr_object;
-       rwa->last_offset = drrw->drr_offset;
-
-       if (dmu_object_info(rwa->os, drrw->drr_object, NULL) != 0)
-               return (SET_ERROR(EINVAL));
-
-       tx = dmu_tx_create(rwa->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_tx_abort(tx);
-               return (err);
-       }
-       if (rwa->byteswap) {
-               dmu_object_byteswap_t byteswap =
-                   DMU_OT_BYTESWAP(drrw->drr_type);
-               dmu_ot_byteswap[byteswap].ob_func(abuf->b_data,
-                   drrw->drr_length);
-       }
-
-       if (dmu_bonus_hold(rwa->os, drrw->drr_object, FTAG, &bonus) != 0)
-               return (SET_ERROR(EINVAL));
-       dmu_assign_arcbuf(bonus, drrw->drr_offset, abuf, tx);
-
-       /*
-        * Note: If the receive fails, we want the resume stream to start
-        * with the same record that we last successfully received (as opposed
-        * to the next record), so that we can verify that we are
-        * resuming from the correct location.
-        */
-       save_resume_state(rwa, drrw->drr_object, drrw->drr_offset, 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
-receive_write_byref(struct receive_writer_arg *rwa,
-    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(rwa->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 = rwa->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(rwa->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(rwa->os, drrwbr->drr_object,
-           drrwbr->drr_offset, drrwbr->drr_length, dbp->db_data, tx);
-       dmu_buf_rele(dbp, FTAG);
-
-       /* See comment in restore_write. */
-       save_resume_state(rwa, drrwbr->drr_object, drrwbr->drr_offset, tx);
-       dmu_tx_commit(tx);
-       return (0);
-}
-
-static int
-receive_write_embedded(struct receive_writer_arg *rwa,
-    struct drr_write_embedded *drrwe, void *data)
-{
-       dmu_tx_t *tx;
-       int err;
-
-       if (drrwe->drr_offset + drrwe->drr_length < drrwe->drr_offset)
-               return (EINVAL);
-
-       if (drrwe->drr_psize > BPE_PAYLOAD_SIZE)
-               return (EINVAL);
-
-       if (drrwe->drr_etype >= NUM_BP_EMBEDDED_TYPES)
-               return (EINVAL);
-       if (drrwe->drr_compression >= ZIO_COMPRESS_FUNCTIONS)
-               return (EINVAL);
-
-       tx = dmu_tx_create(rwa->os);
-
-       dmu_tx_hold_write(tx, drrwe->drr_object,
-           drrwe->drr_offset, drrwe->drr_length);
-       err = dmu_tx_assign(tx, TXG_WAIT);
-       if (err != 0) {
-               dmu_tx_abort(tx);
-               return (err);
-       }
-
-       dmu_write_embedded(rwa->os, drrwe->drr_object,
-           drrwe->drr_offset, data, drrwe->drr_etype,
-           drrwe->drr_compression, drrwe->drr_lsize, drrwe->drr_psize,
-           rwa->byteswap ^ ZFS_HOST_BYTEORDER, tx);
-
-       /* See comment in restore_write. */
-       save_resume_state(rwa, drrwe->drr_object, drrwe->drr_offset, tx);
-       dmu_tx_commit(tx);
-       return (0);
-}
-
-static int
-receive_spill(struct receive_writer_arg *rwa, struct drr_spill *drrs,
-    void *data)
-{
-       dmu_tx_t *tx;
-       dmu_buf_t *db, *db_spill;
-       int err;
-
-       if (drrs->drr_length < SPA_MINBLOCKSIZE ||
-           drrs->drr_length > spa_maxblocksize(dmu_objset_spa(rwa->os)))
-               return (SET_ERROR(EINVAL));
-
-       if (dmu_object_info(rwa->os, drrs->drr_object, NULL) != 0)
-               return (SET_ERROR(EINVAL));
-
-       VERIFY0(dmu_bonus_hold(rwa->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(rwa->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
-receive_free(struct receive_writer_arg *rwa, 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(rwa->os, drrf->drr_object, NULL) != 0)
-               return (SET_ERROR(EINVAL));
-
-       err = dmu_free_long_range(rwa->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)
-{
-       if (drc->drc_resumable) {
-               /* wait for our resume state to be written to disk */
-               txg_wait_synced(drc->drc_ds->ds_dir->dd_pool, 0);
-               dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
-       } else {
-               char name[MAXNAMELEN];
-               dsl_dataset_name(drc->drc_ds, name);
-               dsl_dataset_disown(drc->drc_ds, dmu_recv_tag);
-               (void) dsl_destroy_head(name);
-       }
-}
-
-static void
-receive_cksum(struct receive_arg *ra, int len, void *buf)
-{
-       if (ra->byteswap) {
-               fletcher_4_incremental_byteswap(buf, len, &ra->cksum);
-       } else {
-               fletcher_4_incremental_native(buf, len, &ra->cksum);
-       }
-}
-
-/*
- * Read the payload into a buffer of size len, and update the current record's
- * payload field.
- * Allocate ra->next_rrd and read the next record's header into
- * ra->next_rrd->header.
- * Verify checksum of payload and next record.
- */
-static int
-receive_read_payload_and_next_header(struct receive_arg *ra, int len, void *buf)
-{
-       int err;
-       zio_cksum_t cksum_orig;
-       zio_cksum_t *cksump;
-
-       if (len != 0) {
-               ASSERT3U(len, <=, SPA_MAXBLOCKSIZE);
-               err = receive_read(ra, len, buf);
-               if (err != 0)
-                       return (err);
-               receive_cksum(ra, len, buf);
-
-               /* note: rrd is NULL when reading the begin record's payload */
-               if (ra->rrd != NULL) {
-                       ra->rrd->payload = buf;
-                       ra->rrd->payload_size = len;
-                       ra->rrd->bytes_read = ra->bytes_read;
-               }
-       }
-
-       ra->prev_cksum = ra->cksum;
-
-       ra->next_rrd = kmem_zalloc(sizeof (*ra->next_rrd), KM_SLEEP);
-       err = receive_read(ra, sizeof (ra->next_rrd->header),
-           &ra->next_rrd->header);
-       ra->next_rrd->bytes_read = ra->bytes_read;
-       if (err != 0) {
-               kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
-               ra->next_rrd = NULL;
-               return (err);
-       }
-       if (ra->next_rrd->header.drr_type == DRR_BEGIN) {
-               kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
-               ra->next_rrd = NULL;
-               return (SET_ERROR(EINVAL));
-       }
-
-       /*
-        * Note: checksum is of everything up to but not including the
-        * checksum itself.
-        */
-       ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
-           ==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
-       receive_cksum(ra,
-           offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
-           &ra->next_rrd->header);
-
-       cksum_orig = ra->next_rrd->header.drr_u.drr_checksum.drr_checksum;
-       cksump = &ra->next_rrd->header.drr_u.drr_checksum.drr_checksum;
-
-       if (ra->byteswap)
-               byteswap_record(&ra->next_rrd->header);
-
-       if ((!ZIO_CHECKSUM_IS_ZERO(cksump)) &&
-           !ZIO_CHECKSUM_EQUAL(ra->cksum, *cksump)) {
-               kmem_free(ra->next_rrd, sizeof (*ra->next_rrd));
-               ra->next_rrd = NULL;
-               return (SET_ERROR(ECKSUM));
-       }
-
-       receive_cksum(ra, sizeof (cksum_orig), &cksum_orig);
-
-       return (0);
-}
-
-static void
-objlist_create(struct objlist *list)
-{
-       list_create(&list->list, sizeof (struct receive_objnode),
-           offsetof(struct receive_objnode, node));
-       list->last_lookup = 0;
-}
-
-static void
-objlist_destroy(struct objlist *list)
-{
-       struct receive_objnode *n;
-
-       for (n = list_remove_head(&list->list);
-           n != NULL; n = list_remove_head(&list->list)) {
-               kmem_free(n, sizeof (*n));
-       }
-       list_destroy(&list->list);
-}
-
-/*
- * This function looks through the objlist to see if the specified object number
- * is contained in the objlist.  In the process, it will remove all object
- * numbers in the list that are smaller than the specified object number.  Thus,
- * any lookup of an object number smaller than a previously looked up object
- * number will always return false; therefore, all lookups should be done in
- * ascending order.
- */
-static boolean_t
-objlist_exists(struct objlist *list, uint64_t object)
-{
-       struct receive_objnode *node = list_head(&list->list);
-       ASSERT3U(object, >=, list->last_lookup);
-       list->last_lookup = object;
-       while (node != NULL && node->object < object) {
-               VERIFY3P(node, ==, list_remove_head(&list->list));
-               kmem_free(node, sizeof (*node));
-               node = list_head(&list->list);
-       }
-       return (node != NULL && node->object == object);
-}
-
-/*
- * The objlist is a list of object numbers stored in ascending order.  However,
- * the insertion of new object numbers does not seek out the correct location to
- * store a new object number; instead, it appends it to the list for simplicity.
- * Thus, any users must take care to only insert new object numbers in ascending
- * order.
- */
-static void
-objlist_insert(struct objlist *list, uint64_t object)
-{
-       struct receive_objnode *node = kmem_zalloc(sizeof (*node), KM_SLEEP);
-       node->object = object;
-#ifdef ZFS_DEBUG
-       {
-       struct receive_objnode *last_object = list_tail(&list->list);
-       uint64_t last_objnum = (last_object != NULL ? last_object->object : 0);
-       ASSERT3U(node->object, >, last_objnum);
-       }
-#endif
-       list_insert_tail(&list->list, node);
-}
-
-/*
- * Issue the prefetch reads for any necessary indirect blocks.
- *
- * We use the object ignore list to tell us whether or not to issue prefetches
- * for a given object.  We do this for both correctness (in case the blocksize
- * of an object has changed) and performance (if the object doesn't exist, don't
- * needlessly try to issue prefetches).  We also trim the list as we go through
- * the stream to prevent it from growing to an unbounded size.
- *
- * The object numbers within will always be in sorted order, and any write
- * records we see will also be in sorted order, but they're not sorted with
- * respect to each other (i.e. we can get several object records before
- * receiving each object's write records).  As a result, once we've reached a
- * given object number, we can safely remove any reference to lower object
- * numbers in the ignore list. In practice, we receive up to 32 object records
- * before receiving write records, so the list can have up to 32 nodes in it.
- */
-/* ARGSUSED */
-static void
-receive_read_prefetch(struct receive_arg *ra,
-    uint64_t object, uint64_t offset, uint64_t length)
-{
-       if (!objlist_exists(&ra->ignore_objlist, object)) {
-               dmu_prefetch(ra->os, object, 1, offset, length,
-                   ZIO_PRIORITY_SYNC_READ);
-       }
-}
-
-/*
- * Read records off the stream, issuing any necessary prefetches.
- */
-static int
-receive_read_record(struct receive_arg *ra)
-{
-       int err;
-
-       switch (ra->rrd->header.drr_type) {
-       case DRR_OBJECT:
-       {
-               struct drr_object *drro = &ra->rrd->header.drr_u.drr_object;
-               uint32_t size = P2ROUNDUP(drro->drr_bonuslen, 8);
-               void *buf = kmem_zalloc(size, KM_SLEEP);
-               dmu_object_info_t doi;
-               err = receive_read_payload_and_next_header(ra, size, buf);
-               if (err != 0) {
-                       kmem_free(buf, size);
-                       return (err);
-               }
-               err = dmu_object_info(ra->os, drro->drr_object, &doi);
-               /*
-                * See receive_read_prefetch for an explanation why we're
-                * storing this object in the ignore_obj_list.
-                */
-               if (err == ENOENT ||
-                   (err == 0 && doi.doi_data_block_size != drro->drr_blksz)) {
-                       objlist_insert(&ra->ignore_objlist, drro->drr_object);
-                       err = 0;
-               }
-               return (err);
-       }
-       case DRR_FREEOBJECTS:
-       {
-               err = receive_read_payload_and_next_header(ra, 0, NULL);
-               return (err);
-       }
-       case DRR_WRITE:
-       {
-               struct drr_write *drrw = &ra->rrd->header.drr_u.drr_write;
-               arc_buf_t *abuf = arc_loan_buf(dmu_objset_spa(ra->os),
-                   drrw->drr_length);
-
-               err = receive_read_payload_and_next_header(ra,
-                   drrw->drr_length, abuf->b_data);
-               if (err != 0) {
-                       dmu_return_arcbuf(abuf);
-                       return (err);
-               }
-               ra->rrd->write_buf = abuf;
-               receive_read_prefetch(ra, drrw->drr_object, drrw->drr_offset,
-                   drrw->drr_length);
-               return (err);
-       }
-       case DRR_WRITE_BYREF:
-       {
-               struct drr_write_byref *drrwb =
-                   &ra->rrd->header.drr_u.drr_write_byref;
-               err = receive_read_payload_and_next_header(ra, 0, NULL);
-               receive_read_prefetch(ra, drrwb->drr_object, drrwb->drr_offset,
-                   drrwb->drr_length);
-               return (err);
-       }
-       case DRR_WRITE_EMBEDDED:
-       {
-               struct drr_write_embedded *drrwe =
-                   &ra->rrd->header.drr_u.drr_write_embedded;
-               uint32_t size = P2ROUNDUP(drrwe->drr_psize, 8);
-               void *buf = kmem_zalloc(size, KM_SLEEP);
-
-               err = receive_read_payload_and_next_header(ra, size, buf);
-               if (err != 0) {
-                       kmem_free(buf, size);
-                       return (err);
-               }
-
-               receive_read_prefetch(ra, drrwe->drr_object, drrwe->drr_offset,
-                   drrwe->drr_length);
-               return (err);
-       }
-       case DRR_FREE:
-       {
-               /*
-                * It might be beneficial to prefetch indirect blocks here, but
-                * we don't really have the data to decide for sure.
-                */
-               err = receive_read_payload_and_next_header(ra, 0, NULL);
-               return (err);
-       }
-       case DRR_END:
-       {
-               struct drr_end *drre = &ra->rrd->header.drr_u.drr_end;
-               if (!ZIO_CHECKSUM_EQUAL(ra->prev_cksum, drre->drr_checksum))
-                       return (SET_ERROR(ECKSUM));
-               return (0);
-       }
-       case DRR_SPILL:
-       {
-               struct drr_spill *drrs = &ra->rrd->header.drr_u.drr_spill;
-               void *buf = kmem_zalloc(drrs->drr_length, KM_SLEEP);
-               err = receive_read_payload_and_next_header(ra, drrs->drr_length,
-                   buf);
-               if (err != 0)
-                       kmem_free(buf, drrs->drr_length);
-               return (err);
-       }
-       default:
-               return (SET_ERROR(EINVAL));
-       }
-}
-
-/*
- * Commit the records to the pool.
- */
-static int
-receive_process_record(struct receive_writer_arg *rwa,
-    struct receive_record_arg *rrd)
-{
-       int err;
-
-       /* Processing in order, therefore bytes_read should be increasing. */
-       ASSERT3U(rrd->bytes_read, >=, rwa->bytes_read);
-       rwa->bytes_read = rrd->bytes_read;
-
-       switch (rrd->header.drr_type) {
-       case DRR_OBJECT:
-       {
-               struct drr_object *drro = &rrd->header.drr_u.drr_object;
-               err = receive_object(rwa, drro, rrd->payload);
-               kmem_free(rrd->payload, rrd->payload_size);
-               rrd->payload = NULL;
-               return (err);
-       }
-       case DRR_FREEOBJECTS:
-       {
-               struct drr_freeobjects *drrfo =
-                   &rrd->header.drr_u.drr_freeobjects;
-               return (receive_freeobjects(rwa, drrfo));
-       }
-       case DRR_WRITE:
-       {
-               struct drr_write *drrw = &rrd->header.drr_u.drr_write;
-               err = receive_write(rwa, drrw, rrd->write_buf);
-               /* if receive_write() is successful, it consumes the arc_buf */
-               if (err != 0)
-                       dmu_return_arcbuf(rrd->write_buf);
-               rrd->write_buf = NULL;
-               rrd->payload = NULL;
-               return (err);
-       }
-       case DRR_WRITE_BYREF:
-       {
-               struct drr_write_byref *drrwbr =
-                   &rrd->header.drr_u.drr_write_byref;
-               return (receive_write_byref(rwa, drrwbr));
-       }
-       case DRR_WRITE_EMBEDDED:
-       {
-               struct drr_write_embedded *drrwe =
-                   &rrd->header.drr_u.drr_write_embedded;
-               err = receive_write_embedded(rwa, drrwe, rrd->payload);
-               kmem_free(rrd->payload, rrd->payload_size);
-               rrd->payload = NULL;
-               return (err);
-       }
-       case DRR_FREE:
-       {
-               struct drr_free *drrf = &rrd->header.drr_u.drr_free;
-               return (receive_free(rwa, drrf));
-       }
-       case DRR_SPILL:
-       {
-               struct drr_spill *drrs = &rrd->header.drr_u.drr_spill;
-               err = receive_spill(rwa, drrs, rrd->payload);
-               kmem_free(rrd->payload, rrd->payload_size);
-               rrd->payload = NULL;
-               return (err);
-       }
-       default:
-               return (SET_ERROR(EINVAL));
-       }
-}
-
-/*
- * dmu_recv_stream's worker thread; pull records off the queue, and then call
- * receive_process_record  When we're done, signal the main thread and exit.
- */
-static void
-receive_writer_thread(void *arg)
-{
-       struct receive_writer_arg *rwa = arg;
-       struct receive_record_arg *rrd;
-       for (rrd = bqueue_dequeue(&rwa->q); !rrd->eos_marker;
-           rrd = bqueue_dequeue(&rwa->q)) {
-               /*
-                * If there's an error, the main thread will stop putting things
-                * on the queue, but we need to clear everything in it before we
-                * can exit.
-                */
-               if (rwa->err == 0) {
-                       rwa->err = receive_process_record(rwa, rrd);
-               } else if (rrd->write_buf != NULL) {
-                       dmu_return_arcbuf(rrd->write_buf);
-                       rrd->write_buf = NULL;
-                       rrd->payload = NULL;
-               } else if (rrd->payload != NULL) {
-                       kmem_free(rrd->payload, rrd->payload_size);
-                       rrd->payload = NULL;
-               }
-               kmem_free(rrd, sizeof (*rrd));
-       }
-       kmem_free(rrd, sizeof (*rrd));
-       mutex_enter(&rwa->mutex);
-       rwa->done = B_TRUE;
-       cv_signal(&rwa->cv);
-       mutex_exit(&rwa->mutex);
-}
-
-static int
-resume_check(struct receive_arg *ra, nvlist_t *begin_nvl)
-{
-       uint64_t val;
-       objset_t *mos = dmu_objset_pool(ra->os)->dp_meta_objset;
-       uint64_t dsobj = dmu_objset_id(ra->os);
-       uint64_t resume_obj, resume_off;
-
-       if (nvlist_lookup_uint64(begin_nvl,
-           "resume_object", &resume_obj) != 0 ||
-           nvlist_lookup_uint64(begin_nvl,
-           "resume_offset", &resume_off) != 0) {
-               return (SET_ERROR(EINVAL));
-       }
-       VERIFY0(zap_lookup(mos, dsobj,
-           DS_FIELD_RESUME_OBJECT, sizeof (val), 1, &val));
-       if (resume_obj != val)
-               return (SET_ERROR(EINVAL));
-       VERIFY0(zap_lookup(mos, dsobj,
-           DS_FIELD_RESUME_OFFSET, sizeof (val), 1, &val));
-       if (resume_off != val)
-               return (SET_ERROR(EINVAL));
-
-       return (0);
-}
-
-/*
- * Read in the stream's records, one by one, and apply them to the pool.  There
- * are two threads involved; the thread that calls this function will spin up a
- * worker thread, read the records off the stream one by one, and issue
- * prefetches for any necessary indirect blocks.  It will then push the records
- * onto an internal blocking queue.  The worker thread will pull the records off
- * the queue, and actually write the data into the DMU.  This way, the worker
- * thread doesn't have to wait for reads to complete, since everything it needs
- * (the indirect blocks) will be prefetched.
- *
- * 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)
-{
-       int err = 0;
-       struct receive_arg *ra;
-       struct receive_writer_arg *rwa;
-       int featureflags;
-       uint32_t payloadlen;
-       void *payload;
-       nvlist_t *begin_nvl = NULL;
-
-       ra = kmem_zalloc(sizeof (*ra), KM_SLEEP);
-       rwa = kmem_zalloc(sizeof (*rwa), KM_SLEEP);
-
-       ra->byteswap = drc->drc_byteswap;
-       ra->cksum = drc->drc_cksum;
-       ra->vp = vp;
-       ra->voff = *voffp;
-
-       if (dsl_dataset_is_zapified(drc->drc_ds)) {
-               (void) zap_lookup(drc->drc_ds->ds_dir->dd_pool->dp_meta_objset,
-                   drc->drc_ds->ds_object, DS_FIELD_RESUME_BYTES,
-                   sizeof (ra->bytes_read), 1, &ra->bytes_read);
-       }
-
-       objlist_create(&ra->ignore_objlist);
-
-       /* 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, &ra->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) {
-                       rwa->guid_to_ds_map =
-                           kmem_alloc(sizeof (avl_tree_t), KM_SLEEP);
-                       avl_create(rwa->guid_to_ds_map, guid_compare,
-                           sizeof (guid_map_entry_t),
-                           offsetof(guid_map_entry_t, avlnode));
-                       err = zfs_onexit_add_cb(minor,
-                           free_guid_map_onexit, rwa->guid_to_ds_map,
-                           action_handlep);
-                       if (ra->err != 0)
-                               goto out;
-               } else {
-                       err = zfs_onexit_cb_data(minor, *action_handlep,
-                           (void **)&rwa->guid_to_ds_map);
-                       if (ra->err != 0)
-                               goto out;
-               }
-
-               drc->drc_guid_to_ds_map = rwa->guid_to_ds_map;
-       }
-
-       payloadlen = drc->drc_drr_begin->drr_payloadlen;
-       payload = NULL;
-       if (payloadlen != 0)
-               payload = kmem_alloc(payloadlen, KM_SLEEP);
-
-       err = receive_read_payload_and_next_header(ra, payloadlen, payload);
-       if (err != 0) {
-               if (payloadlen != 0)
-                       kmem_free(payload, payloadlen);
-               goto out;
-       }
-       if (payloadlen != 0) {
-               err = nvlist_unpack(payload, payloadlen, &begin_nvl, KM_SLEEP);
-               kmem_free(payload, payloadlen);
-               if (err != 0)
-                       goto out;
-       }
-
-       if (featureflags & DMU_BACKUP_FEATURE_RESUMING) {
-               err = resume_check(ra, begin_nvl);
-               if (err != 0)
-                       goto out;
-       }
-
-       (void) bqueue_init(&rwa->q, zfs_recv_queue_length,
-           offsetof(struct receive_record_arg, node));
-       cv_init(&rwa->cv, NULL, CV_DEFAULT, NULL);
-       mutex_init(&rwa->mutex, NULL, MUTEX_DEFAULT, NULL);
-       rwa->os = ra->os;
-       rwa->byteswap = drc->drc_byteswap;
-       rwa->resumable = drc->drc_resumable;
-
-       (void) thread_create(NULL, 0, receive_writer_thread, rwa, 0, curproc,
-           TS_RUN, minclsyspri);
-       /*
-        * We're reading rwa->err without locks, which is safe since we are the
-        * only reader, and the worker thread is the only writer.  It's ok if we
-        * miss a write for an iteration or two of the loop, since the writer
-        * thread will keep freeing records we send it until we send it an eos
-        * marker.
-        *
-        * We can leave this loop in 3 ways:  First, if rwa->err is
-        * non-zero.  In that case, the writer thread will free the rrd we just
-        * pushed.  Second, if  we're interrupted; in that case, either it's the
-        * first loop and ra->rrd was never allocated, or it's later and ra->rrd
-        * has been handed off to the writer thread who will free it.  Finally,
-        * if receive_read_record fails or we're at the end of the stream, then
-        * we free ra->rrd and exit.
-        */
-       while (rwa->err == 0) {
-               if (issig(JUSTLOOKING) && issig(FORREAL)) {
-                       err = SET_ERROR(EINTR);
-                       break;
-               }
-
-               ASSERT3P(ra->rrd, ==, NULL);
-               ra->rrd = ra->next_rrd;
-               ra->next_rrd = NULL;
-               /* Allocates and loads header into ra->next_rrd */
-               err = receive_read_record(ra);
-
-               if (ra->rrd->header.drr_type == DRR_END || err != 0) {
-                       kmem_free(ra->rrd, sizeof (*ra->rrd));
-                       ra->rrd = NULL;
-                       break;
-               }
-
-               bqueue_enqueue(&rwa->q, ra->rrd,
-                   sizeof (struct receive_record_arg) + ra->rrd->payload_size);
-               ra->rrd = NULL;
-       }
-       if (ra->next_rrd == NULL)
-               ra->next_rrd = kmem_zalloc(sizeof (*ra->next_rrd), KM_SLEEP);
-       ra->next_rrd->eos_marker = B_TRUE;
-       bqueue_enqueue(&rwa->q, ra->next_rrd, 1);
-
-       mutex_enter(&rwa->mutex);
-       while (!rwa->done) {
-               cv_wait(&rwa->cv, &rwa->mutex);
-       }
-       mutex_exit(&rwa->mutex);
-
-       cv_destroy(&rwa->cv);
-       mutex_destroy(&rwa->mutex);
-       bqueue_destroy(&rwa->q);
-       if (err == 0)
-               err = rwa->err;
-
-out:
-       nvlist_free(begin_nvl);
-       if ((featureflags & DMU_BACKUP_FEATURE_DEDUP) && (cleanup_fd != -1))
-               zfs_onexit_fd_rele(cleanup_fd);
-
-       if (err != 0) {
-               /*
-                * Clean up references. If receive is not resumable,
-                * destroy what we created, so we don't leave it in
-                * the inconsistent state.
-                */
-               dmu_recv_cleanup_ds(drc);
-       }
-
-       *voffp = ra->voff;
-       objlist_destroy(&ra->ignore_objlist);
-       kmem_free(ra, sizeof (*ra));
-       kmem_free(rwa, sizeof (*rwa));
-       return (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;
-               if (dsl_dataset_has_resume_receive_state(ds)) {
-                       (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
-                           DS_FIELD_RESUME_FROMGUID, tx);
-                       (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
-                           DS_FIELD_RESUME_OBJECT, tx);
-                       (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
-                           DS_FIELD_RESUME_OFFSET, tx);
-                       (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
-                           DS_FIELD_RESUME_BYTES, tx);
-                       (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
-                           DS_FIELD_RESUME_TOGUID, tx);
-                       (void) zap_remove(dp->dp_meta_objset, ds->ds_object,
-                           DS_FIELD_RESUME_TONAME, tx);
-               }
-       }
-       drc->drc_newsnapobj = dsl_dataset_phys(drc->drc_ds)->ds_prev_snap_obj;
-       zvol_create_minors(dp->dp_spa, drc->drc_tofs, B_TRUE);
-       /*
-        * 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