Illumos #2703: add mechanism to report ZFS send progress

Reviewed by: Matt Ahrens <[email protected]>
Reviewed by: Robert Mustacchi <[email protected]>
Reviewed by: Richard Lowe <[email protected]>
Approved by: Eric Schrock <[email protected]>

References:
  https://www.illumos.org/issues/2703

Ported by: Martin Matuska <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>

3 files changed, 183 insertions, 123 deletions

diff --git a/module/zfs/dmu_send.c b/module/zfs/dmu_send.c
index 9f9003744..949f4d773 100644
--- a/module/zfs/dmu_send.c
+++ b/module/zfs/dmu_send.c
@@ -23,6 +23,7 @@
  * Copyright (c) 2011 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  */
 
 #include <sys/dmu.h>
@@ -52,48 +53,30 @@ int zfs_send_corrupt_data = B_FALSE;
 
 static char *dmu_recv_tag = "dmu_recv_tag";
 
-/*
- * The list of data whose inclusion in a send stream can be pending from
- * one call to backup_cb to another.  Multiple calls to dump_free() and
- * dump_freeobjects() can be aggregated into a single DRR_FREE or
- * DRR_FREEOBJECTS replay record.
- */
-typedef enum {
-	PENDING_NONE,
-	PENDING_FREE,
-	PENDING_FREEOBJECTS
-} pendop_t;
-
-struct backuparg {
-	dmu_replay_record_t *drr;
-	vnode_t *vp;
-	offset_t *off;
-	objset_t *os;
-	zio_cksum_t zc;
-	uint64_t toguid;
-	int err;
-	pendop_t pending_op;
-};
-
 static int
-dump_bytes(struct backuparg *ba, void *buf, int len)
+dump_bytes(dmu_sendarg_t *dsp, void *buf, int len)
 {
+	dsl_dataset_t *ds = dsp->dsa_os->os_dsl_dataset;
 	ssize_t resid; /* have to get resid to get detailed errno */
 	ASSERT3U(len % 8, ==, 0);
 
-	fletcher_4_incremental_native(buf, len, &ba->zc);
-	ba->err = vn_rdwr(UIO_WRITE, ba->vp,
+	fletcher_4_incremental_native(buf, len, &dsp->dsa_zc);
+	dsp->dsa_err = vn_rdwr(UIO_WRITE, dsp->dsa_vp,
 	    (caddr_t)buf, len,
 	    0, UIO_SYSSPACE, FAPPEND, RLIM64_INFINITY, CRED(), &resid);
-	*ba->off += len;
-	return (ba->err);
+
+	mutex_enter(&ds->ds_sendstream_lock);
+	*dsp->dsa_off += len;
+	mutex_exit(&ds->ds_sendstream_lock);
+
+	return (dsp->dsa_err);
 }
 
 static int
-dump_free(struct backuparg *ba, uint64_t object, uint64_t offset,
+dump_free(dmu_sendarg_t *dsp, uint64_t object, uint64_t offset,
     uint64_t length)
 {
-	struct drr_free *drrf = &(ba->drr->drr_u.drr_free);
+	struct drr_free *drrf = &(dsp->dsa_drr->drr_u.drr_free);
 
 	if (length != -1ULL && offset + length < offset)
 		length = -1ULL;
@@ -105,13 +88,15 @@ dump_free(struct backuparg *ba, uint64_t object, uint64_t offset,
 	 * other DRR_FREE records.  DRR_FREEOBJECTS records can only be
 	 * aggregated with other DRR_FREEOBJECTS records.
 	 */
-	if (ba->pending_op != PENDING_NONE && ba->pending_op != PENDING_FREE) {
-		if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dsp->dsa_pending_op != PENDING_NONE &&
+	    dsp->dsa_pending_op != PENDING_FREE) {
+		if (dump_bytes(dsp, dsp->dsa_drr,
+		    sizeof (dmu_replay_record_t)) != 0)
 			return (EINTR);
-		ba->pending_op = PENDING_NONE;
+		dsp->dsa_pending_op = PENDING_NONE;
 	}
 
-	if (ba->pending_op == PENDING_FREE) {
+	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
@@ -129,34 +114,35 @@ dump_free(struct backuparg *ba, uint64_t object, uint64_t offset,
 			return (0);
 		} else {
 			/* not a continuation.  Push out pending record */
-			if (dump_bytes(ba, ba->drr,
+			if (dump_bytes(dsp, dsp->dsa_drr,
 			    sizeof (dmu_replay_record_t)) != 0)
 				return (EINTR);
-			ba->pending_op = PENDING_NONE;
+			dsp->dsa_pending_op = PENDING_NONE;
 		}
 	}
 	/* create a FREE record and make it pending */
-	bzero(ba->drr, sizeof (dmu_replay_record_t));
-	ba->drr->drr_type = DRR_FREE;
+	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
+	dsp->dsa_drr->drr_type = DRR_FREE;
 	drrf->drr_object = object;
 	drrf->drr_offset = offset;
 	drrf->drr_length = length;
-	drrf->drr_toguid = ba->toguid;
+	drrf->drr_toguid = dsp->dsa_toguid;
 	if (length == -1ULL) {
-		if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+		if (dump_bytes(dsp, dsp->dsa_drr,
+		    sizeof (dmu_replay_record_t)) != 0)
 			return (EINTR);
 	} else {
-		ba->pending_op = PENDING_FREE;
+		dsp->dsa_pending_op = PENDING_FREE;
 	}
 
 	return (0);
 }
 
 static int
-dump_data(struct backuparg *ba, dmu_object_type_t type,
+dump_data(dmu_sendarg_t *dsp, dmu_object_type_t type,
     uint64_t object, uint64_t offset, int blksz, const blkptr_t *bp, void *data)
 {
-	struct drr_write *drrw = &(ba->drr->drr_u.drr_write);
+	struct drr_write *drrw = &(dsp->dsa_drr->drr_u.drr_write);
 
 
 	/*
@@ -165,19 +151,20 @@ dump_data(struct backuparg *ba, dmu_object_type_t type,
 	 * the stream, since aggregation can't be done across operations
 	 * of different types.
 	 */
-	if (ba->pending_op != PENDING_NONE) {
-		if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dsp->dsa_pending_op != PENDING_NONE) {
+		if (dump_bytes(dsp, dsp->dsa_drr,
+		    sizeof (dmu_replay_record_t)) != 0)
 			return (EINTR);
-		ba->pending_op = PENDING_NONE;
+		dsp->dsa_pending_op = PENDING_NONE;
 	}
 	/* write a DATA record */
-	bzero(ba->drr, sizeof (dmu_replay_record_t));
-	ba->drr->drr_type = DRR_WRITE;
+	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
+	dsp->dsa_drr->drr_type = DRR_WRITE;
 	drrw->drr_object = object;
 	drrw->drr_type = type;
 	drrw->drr_offset = offset;
 	drrw->drr_length = blksz;
-	drrw->drr_toguid = ba->toguid;
+	drrw->drr_toguid = dsp->dsa_toguid;
 	drrw->drr_checksumtype = BP_GET_CHECKSUM(bp);
 	if (zio_checksum_table[drrw->drr_checksumtype].ci_dedup)
 		drrw->drr_checksumflags |= DRR_CHECKSUM_DEDUP;
@@ -186,42 +173,43 @@ dump_data(struct backuparg *ba, dmu_object_type_t type,
 	DDK_SET_COMPRESS(&drrw->drr_key, BP_GET_COMPRESS(bp));
 	drrw->drr_key.ddk_cksum = bp->blk_cksum;
 
-	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
 		return (EINTR);
-	if (dump_bytes(ba, data, blksz) != 0)
+	if (dump_bytes(dsp, data, blksz) != 0)
 		return (EINTR);
 	return (0);
 }
 
 static int
-dump_spill(struct backuparg *ba, uint64_t object, int blksz, void *data)
+dump_spill(dmu_sendarg_t *dsp, uint64_t object, int blksz, void *data)
 {
-	struct drr_spill *drrs = &(ba->drr->drr_u.drr_spill);
+	struct drr_spill *drrs = &(dsp->dsa_drr->drr_u.drr_spill);
 
-	if (ba->pending_op != PENDING_NONE) {
-		if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dsp->dsa_pending_op != PENDING_NONE) {
+		if (dump_bytes(dsp, dsp->dsa_drr,
+		    sizeof (dmu_replay_record_t)) != 0)
 			return (EINTR);
-		ba->pending_op = PENDING_NONE;
+		dsp->dsa_pending_op = PENDING_NONE;
 	}
 
 	/* write a SPILL record */
-	bzero(ba->drr, sizeof (dmu_replay_record_t));
-	ba->drr->drr_type = DRR_SPILL;
+	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
+	dsp->dsa_drr->drr_type = DRR_SPILL;
 	drrs->drr_object = object;
 	drrs->drr_length = blksz;
-	drrs->drr_toguid = ba->toguid;
+	drrs->drr_toguid = dsp->dsa_toguid;
 
-	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
+	if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)))
 		return (EINTR);
-	if (dump_bytes(ba, data, blksz))
+	if (dump_bytes(dsp, data, blksz))
 		return (EINTR);
 	return (0);
 }
 
 static int
-dump_freeobjects(struct backuparg *ba, uint64_t firstobj, uint64_t numobjs)
+dump_freeobjects(dmu_sendarg_t *dsp, uint64_t firstobj, uint64_t numobjs)
 {
-	struct drr_freeobjects *drrfo = &(ba->drr->drr_u.drr_freeobjects);
+	struct drr_freeobjects *drrfo = &(dsp->dsa_drr->drr_u.drr_freeobjects);
 
 	/*
 	 * If there is a pending op, but it's not PENDING_FREEOBJECTS,
@@ -230,13 +218,14 @@ dump_freeobjects(struct backuparg *ba, uint64_t firstobj, uint64_t numobjs)
 	 * aggregated with other DRR_FREE records.  DRR_FREEOBJECTS records
 	 * can only be aggregated with other DRR_FREEOBJECTS records.
 	 */
-	if (ba->pending_op != PENDING_NONE &&
-	    ba->pending_op != PENDING_FREEOBJECTS) {
-		if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dsp->dsa_pending_op != PENDING_NONE &&
+	    dsp->dsa_pending_op != PENDING_FREEOBJECTS) {
+		if (dump_bytes(dsp, dsp->dsa_drr,
+		    sizeof (dmu_replay_record_t)) != 0)
 			return (EINTR);
-		ba->pending_op = PENDING_NONE;
+		dsp->dsa_pending_op = PENDING_NONE;
 	}
-	if (ba->pending_op == PENDING_FREEOBJECTS) {
+	if (dsp->dsa_pending_op == PENDING_FREEOBJECTS) {
 		/*
 		 * See whether this free object array can be aggregated
 		 * with pending one
@@ -246,42 +235,43 @@ dump_freeobjects(struct backuparg *ba, uint64_t firstobj, uint64_t numobjs)
 			return (0);
 		} else {
 			/* can't be aggregated.  Push out pending record */
-			if (dump_bytes(ba, ba->drr,
+			if (dump_bytes(dsp, dsp->dsa_drr,
 			    sizeof (dmu_replay_record_t)) != 0)
 				return (EINTR);
-			ba->pending_op = PENDING_NONE;
+			dsp->dsa_pending_op = PENDING_NONE;
 		}
 	}
 
 	/* write a FREEOBJECTS record */
-	bzero(ba->drr, sizeof (dmu_replay_record_t));
-	ba->drr->drr_type = DRR_FREEOBJECTS;
+	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
+	dsp->dsa_drr->drr_type = DRR_FREEOBJECTS;
 	drrfo->drr_firstobj = firstobj;
 	drrfo->drr_numobjs = numobjs;
-	drrfo->drr_toguid = ba->toguid;
+	drrfo->drr_toguid = dsp->dsa_toguid;
 
-	ba->pending_op = PENDING_FREEOBJECTS;
+	dsp->dsa_pending_op = PENDING_FREEOBJECTS;
 
 	return (0);
 }
 
 static int
-dump_dnode(struct backuparg *ba, uint64_t object, dnode_phys_t *dnp)
+dump_dnode(dmu_sendarg_t *dsp, uint64_t object, dnode_phys_t *dnp)
 {
-	struct drr_object *drro = &(ba->drr->drr_u.drr_object);
+	struct drr_object *drro = &(dsp->dsa_drr->drr_u.drr_object);
 
 	if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
-		return (dump_freeobjects(ba, object, 1));
+		return (dump_freeobjects(dsp, object, 1));
 
-	if (ba->pending_op != PENDING_NONE) {
-		if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dsp->dsa_pending_op != PENDING_NONE) {
+		if (dump_bytes(dsp, dsp->dsa_drr,
+		    sizeof (dmu_replay_record_t)) != 0)
 			return (EINTR);
-		ba->pending_op = PENDING_NONE;
+		dsp->dsa_pending_op = PENDING_NONE;
 	}
 
 	/* write an OBJECT record */
-	bzero(ba->drr, sizeof (dmu_replay_record_t));
-	ba->drr->drr_type = DRR_OBJECT;
+	bzero(dsp->dsa_drr, sizeof (dmu_replay_record_t));
+	dsp->dsa_drr->drr_type = DRR_OBJECT;
 	drro->drr_object = object;
 	drro->drr_type = dnp->dn_type;
 	drro->drr_bonustype = dnp->dn_bonustype;
@@ -289,19 +279,19 @@ dump_dnode(struct backuparg *ba, uint64_t object, dnode_phys_t *dnp)
 	drro->drr_bonuslen = dnp->dn_bonuslen;
 	drro->drr_checksumtype = dnp->dn_checksum;
 	drro->drr_compress = dnp->dn_compress;
-	drro->drr_toguid = ba->toguid;
+	drro->drr_toguid = dsp->dsa_toguid;
 
-	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dump_bytes(dsp, dsp->dsa_drr, sizeof (dmu_replay_record_t)) != 0)
 		return (EINTR);
 
-	if (dump_bytes(ba, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)) != 0)
+	if (dump_bytes(dsp, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)) != 0)
 		return (EINTR);
 
 	/* free anything past the end of the file */
-	if (dump_free(ba, object, (dnp->dn_maxblkid + 1) *
+	if (dump_free(dsp, object, (dnp->dn_maxblkid + 1) *
 	    (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL))
 		return (EINTR);
-	if (ba->err)
+	if (dsp->dsa_err)
 		return (EINTR);
 	return (0);
 }
@@ -315,7 +305,7 @@ static int
 backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
 {
-	struct backuparg *ba = arg;
+	dmu_sendarg_t *dsp = arg;
 	dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
 	int err = 0;
 
@@ -328,10 +318,10 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
 	} else if (bp == NULL && zb->zb_object == DMU_META_DNODE_OBJECT) {
 		uint64_t span = BP_SPAN(dnp, zb->zb_level);
 		uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
-		err = dump_freeobjects(ba, dnobj, span >> DNODE_SHIFT);
+		err = dump_freeobjects(dsp, dnobj, span >> DNODE_SHIFT);
 	} else if (bp == NULL) {
 		uint64_t span = BP_SPAN(dnp, zb->zb_level);
-		err = dump_free(ba, zb->zb_object, zb->zb_blkid * span, span);
+		err = dump_free(dsp, zb->zb_object, zb->zb_blkid * span, span);
 	} else if (zb->zb_level > 0 || type == DMU_OT_OBJSET) {
 		return (0);
 	} else if (type == DMU_OT_DNODE) {
@@ -350,7 +340,7 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
 		for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
 			uint64_t dnobj = (zb->zb_blkid <<
 			    (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
-			err = dump_dnode(ba, dnobj, blk+i);
+			err = dump_dnode(dsp, dnobj, blk+i);
 			if (err)
 				break;
 		}
@@ -365,7 +355,7 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
 		    ZIO_FLAG_CANFAIL, &aflags, zb) != 0)
 			return (EIO);
 
-		err = dump_spill(ba, zb->zb_object, blksz, abuf->b_data);
+		err = dump_spill(dsp, zb->zb_object, blksz, abuf->b_data);
 		(void) arc_buf_remove_ref(abuf, &abuf);
 	} else { /* it's a level-0 block of a regular object */
 		uint32_t aflags = ARC_WAIT;
@@ -389,7 +379,7 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
 			}
 		}
 
-		err = dump_data(ba, type, zb->zb_object, zb->zb_blkid * blksz,
+		err = dump_data(dsp, type, zb->zb_object, zb->zb_blkid * blksz,
 		    blksz, bp, abuf->b_data);
 		(void) arc_buf_remove_ref(abuf, &abuf);
 	}
@@ -399,13 +389,13 @@ backup_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
 }
 
 int
-dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
-    vnode_t *vp, offset_t *off)
+dmu_send(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
+    int outfd, vnode_t *vp, offset_t *off)
 {
 	dsl_dataset_t *ds = tosnap->os_dsl_dataset;
 	dsl_dataset_t *fromds = fromsnap ? fromsnap->os_dsl_dataset : NULL;
 	dmu_replay_record_t *drr;
-	struct backuparg ba;
+	dmu_sendarg_t *dsp;
 	int err;
 	uint64_t fromtxg = 0;
 
@@ -446,8 +436,10 @@ dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
 #ifdef _KERNEL
 	if (dmu_objset_type(tosnap) == DMU_OST_ZFS) {
 		uint64_t version;
-		if (zfs_get_zplprop(tosnap, ZFS_PROP_VERSION, &version) != 0)
+		if (zfs_get_zplprop(tosnap, ZFS_PROP_VERSION, &version) != 0) {
+			kmem_free(drr, sizeof (dmu_replay_record_t));
 			return (EINVAL);
+		}
 		if (version == ZPL_VERSION_SA) {
 			DMU_SET_FEATUREFLAGS(
 			    drr->drr_u.drr_begin.drr_versioninfo,
@@ -474,46 +466,59 @@ dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
 	if (fromorigin)
 		dsl_dataset_rele(fromds, FTAG);
 
-	ba.drr = drr;
-	ba.vp = vp;
-	ba.os = tosnap;
-	ba.off = off;
-	ba.toguid = ds->ds_phys->ds_guid;
-	ZIO_SET_CHECKSUM(&ba.zc, 0, 0, 0, 0);
-	ba.pending_op = PENDING_NONE;
-
-	if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t)) != 0) {
-		kmem_free(drr, sizeof (dmu_replay_record_t));
-		return (ba.err);
+	dsp = kmem_zalloc(sizeof (dmu_sendarg_t), KM_SLEEP);
+
+	dsp->dsa_drr = drr;
+	dsp->dsa_vp = vp;
+	dsp->dsa_outfd = outfd;
+	dsp->dsa_proc = curproc;
+	dsp->dsa_os = tosnap;
+	dsp->dsa_off = off;
+	dsp->dsa_toguid = ds->ds_phys->ds_guid;
+	ZIO_SET_CHECKSUM(&dsp->dsa_zc, 0, 0, 0, 0);
+	dsp->dsa_pending_op = PENDING_NONE;
+
+	mutex_enter(&ds->ds_sendstream_lock);
+	list_insert_head(&ds->ds_sendstreams, dsp);
+	mutex_exit(&ds->ds_sendstream_lock);
+
+	if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0) {
+		err = dsp->dsa_err;
+		goto out;
 	}
 
 	err = traverse_dataset(ds, fromtxg, TRAVERSE_PRE | TRAVERSE_PREFETCH,
-	    backup_cb, &ba);
+	    backup_cb, dsp);
 
-	if (ba.pending_op != PENDING_NONE)
-		if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t)) != 0)
+	if (dsp->dsa_pending_op != PENDING_NONE)
+		if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0)
 			err = EINTR;
 
 	if (err) {
-		if (err == EINTR && ba.err)
-			err = ba.err;
-		kmem_free(drr, sizeof (dmu_replay_record_t));
-		return (err);
+		if (err == EINTR && dsp->dsa_err)
+			err = dsp->dsa_err;
+		goto out;
 	}
 
 	bzero(drr, sizeof (dmu_replay_record_t));
 	drr->drr_type = DRR_END;
-	drr->drr_u.drr_end.drr_checksum = ba.zc;
-	drr->drr_u.drr_end.drr_toguid = ba.toguid;
+	drr->drr_u.drr_end.drr_checksum = dsp->dsa_zc;
+	drr->drr_u.drr_end.drr_toguid = dsp->dsa_toguid;
 
-	if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t)) != 0) {
-		kmem_free(drr, sizeof (dmu_replay_record_t));
-		return (ba.err);
+	if (dump_bytes(dsp, drr, sizeof (dmu_replay_record_t)) != 0) {
+		err = dsp->dsa_err;
+		goto out;
 	}
 
+out:
+	mutex_enter(&ds->ds_sendstream_lock);
+	list_remove(&ds->ds_sendstreams, dsp);
+	mutex_exit(&ds->ds_sendstream_lock);
+
 	kmem_free(drr, sizeof (dmu_replay_record_t));
+	kmem_free(dsp, sizeof (dmu_sendarg_t));
 
-	return (0);
+	return (err);
 }
 
 int
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c
index e7cbc5138..10e9b19d6 100644
--- a/module/zfs/dsl_dataset.c
+++ b/module/zfs/dsl_dataset.c
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  */
 
 #include <sys/dmu_objset.h>
@@ -29,6 +30,7 @@
 #include <sys/dsl_prop.h>
 #include <sys/dsl_synctask.h>
 #include <sys/dmu_traverse.h>
+#include <sys/dmu_impl.h>
 #include <sys/dmu_tx.h>
 #include <sys/arc.h>
 #include <sys/zio.h>
@@ -399,6 +401,8 @@ dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
 		mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
 		mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
 		mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
+		mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
+
 		rw_init(&ds->ds_rwlock, NULL, RW_DEFAULT, NULL);
 		cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
 
@@ -406,6 +410,9 @@ dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
 		dsl_deadlist_open(&ds->ds_deadlist,
 		    mos, ds->ds_phys->ds_deadlist_obj);
 
+		list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
+		    offsetof(dmu_sendarg_t, dsa_link));
+
 		if (err == 0) {
 			err = dsl_dir_open_obj(dp,
 			    ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 7a27f70bb..aeac01496 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -25,6 +25,7 @@
  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  */
 
 #include <sys/types.h>
@@ -53,6 +54,7 @@
 #include <sys/dsl_prop.h>
 #include <sys/dsl_deleg.h>
 #include <sys/dmu_objset.h>
+#include <sys/dmu_impl.h>
 #include <sys/ddi.h>
 #include <sys/sunddi.h>
 #include <sys/sunldi.h>
@@ -3890,8 +3892,8 @@ zfs_ioc_send(zfs_cmd_t *zc)
 		}
 
 		off = fp->f_offset;
-		error = dmu_sendbackup(tosnap, fromsnap, zc->zc_obj,
-		    fp->f_vnode, &off);
+		error = dmu_send(tosnap, fromsnap, zc->zc_obj,
+		    zc->zc_cookie, fp->f_vnode, &off);
 
 		if (VOP_SEEK(fp->f_vnode, fp->f_offset, &off, NULL) == 0)
 			fp->f_offset = off;
@@ -3903,6 +3905,50 @@ zfs_ioc_send(zfs_cmd_t *zc)
 	return (error);
 }
 
+/*
+ * inputs:
+ * zc_name	name of snapshot on which to report progress
+ * zc_cookie	file descriptor of send stream
+ *
+ * outputs:
+ * zc_cookie	number of bytes written in send stream thus far
+ */
+static int
+zfs_ioc_send_progress(zfs_cmd_t *zc)
+{
+	dsl_dataset_t *ds;
+	dmu_sendarg_t *dsp = NULL;
+	int error;
+
+	if ((error = dsl_dataset_hold(zc->zc_name, FTAG, &ds)) != 0)
+		return (error);
+
+	mutex_enter(&ds->ds_sendstream_lock);
+
+	/*
+	 * Iterate over all the send streams currently active on this dataset.
+	 * If there's one which matches the specified file descriptor _and_ the
+	 * stream was started by the current process, return the progress of
+	 * that stream.
+	 */
+
+	for (dsp = list_head(&ds->ds_sendstreams); dsp != NULL;
+	    dsp = list_next(&ds->ds_sendstreams, dsp)) {
+		if (dsp->dsa_outfd == zc->zc_cookie &&
+		    dsp->dsa_proc->group_leader == curproc->group_leader)
+			break;
+	}
+
+	if (dsp != NULL)
+		zc->zc_cookie = *(dsp->dsa_off);
+	else
+		error = ENOENT;
+
+	mutex_exit(&ds->ds_sendstream_lock);
+	dsl_dataset_rele(ds, FTAG);
+	return (error);
+}
+
 static int
 zfs_ioc_inject_fault(zfs_cmd_t *zc)
 {
@@ -4849,6 +4895,8 @@ static zfs_ioc_vec_t zfs_ioc_vec[] = {
 	    POOL_CHECK_SUSPENDED },
 	{ zfs_ioc_pool_reopen, zfs_secpolicy_config, POOL_NAME, B_TRUE,
 	    POOL_CHECK_SUSPENDED },
+	{ zfs_ioc_send_progress, zfs_secpolicy_read, DATASET_NAME, B_FALSE,
+	    POOL_CHECK_NONE }
 };
 
 int