diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
index 4586fa9b3b67..bfd8e2d7c9ac 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
@@ -449,7 +449,7 @@ dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp)
  * and can induce severe lock contention when writing to several files
  * whose dnodes are in the same block.
  */
-static int
+int
 dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
     boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags)
 {
@@ -1321,7 +1321,7 @@ xuio_stat_wbuf_nocopy(void)
 }
 
 #ifdef _KERNEL
-static int
+int
 dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size)
 {
 	dmu_buf_t **dbp;
@@ -1437,7 +1437,7 @@ dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size)
 	return (err);
 }
 
-static int
+int
 dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx)
 {
 	dmu_buf_t **dbp;
@@ -1881,22 +1881,17 @@ dmu_return_arcbuf(arc_buf_t *buf)
  * dmu_write().
  */
 void
-dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
+dmu_assign_arcbuf_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf,
     dmu_tx_t *tx)
 {
-	dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
-	dnode_t *dn;
 	dmu_buf_impl_t *db;
 	uint32_t blksz = (uint32_t)arc_buf_lsize(buf);
 	uint64_t blkid;
 
-	DB_DNODE_ENTER(dbuf);
-	dn = DB_DNODE(dbuf);
 	rw_enter(&dn->dn_struct_rwlock, RW_READER);
 	blkid = dbuf_whichblock(dn, 0, offset);
 	VERIFY((db = dbuf_hold(dn, blkid, FTAG)) != NULL);
 	rw_exit(&dn->dn_struct_rwlock);
-	DB_DNODE_EXIT(dbuf);
 
 	/*
 	 * We can only assign if the offset is aligned, the arc buf is the
@@ -1924,11 +1919,8 @@ dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
 		ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF);
 		ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED));
 
-		DB_DNODE_ENTER(dbuf);
-		dn = DB_DNODE(dbuf);
 		os = dn->dn_objset;
 		object = dn->dn_object;
-		DB_DNODE_EXIT(dbuf);
 
 		dbuf_rele(db, FTAG);
 		dmu_write(os, object, offset, blksz, buf->b_data, tx);
@@ -1937,6 +1929,17 @@ dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
 	}
 }
 
+void
+dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf,
+    dmu_tx_t *tx)
+{
+	dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle;
+
+	DB_DNODE_ENTER(dbuf);
+	dmu_assign_arcbuf_dnode(DB_DNODE(dbuf), offset, buf, tx);
+	DB_DNODE_EXIT(dbuf);
+}
+
 typedef struct {
 	dbuf_dirty_record_t	*dsa_dr;
 	dmu_sync_cb_t		*dsa_done;
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h
index 9c542baf5809..9bba698828fd 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h
@@ -519,6 +519,9 @@ uint64_t dmu_buf_refcount(dmu_buf_t *db);
 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
     uint64_t length, boolean_t read, void *tag,
     int *numbufsp, dmu_buf_t ***dbpp);
+int dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length,
+    boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp,
+    uint32_t flags);
 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
 
 typedef void dmu_buf_evict_func_t(void *user_ptr);
@@ -757,10 +760,13 @@ void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
 	dmu_tx_t *tx);
 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size);
+int dmu_read_uio_dnode(dnode_t *dn, struct uio *uio, uint64_t size);
 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
     dmu_tx_t *tx);
 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size,
     dmu_tx_t *tx);
+int dmu_write_uio_dnode(dnode_t *dn, struct uio *uio, uint64_t size,
+    dmu_tx_t *tx);
 #ifdef _KERNEL
 #ifdef illumos
 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
@@ -774,6 +780,8 @@ int dmu_read_pages(objset_t *os, uint64_t object, vm_page_t *ma, int count,
 #endif
 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size);
 void dmu_return_arcbuf(struct arc_buf *buf);
+void dmu_assign_arcbuf_dnode(dnode_t *handle, uint64_t offset,
+    struct arc_buf *buf, dmu_tx_t *tx);
 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf,
     dmu_tx_t *tx);
 int dmu_xuio_init(struct xuio *uio, int niov);
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
index 805c63d09a01..3c7f669a351a 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c
@@ -174,7 +174,7 @@ typedef struct zvol_state {
 	zilog_t		*zv_zilog;	/* ZIL handle */
 	list_t		zv_extents;	/* List of extents for dump */
 	znode_t		zv_znode;	/* for range locking */
-	dmu_buf_t	*zv_dbuf;	/* bonus handle */
+	dnode_t		*zv_dn;		/* dnode hold */
 #ifndef illumos
 	int		zv_state;
 	int		zv_volmode;	/* Provide GEOM or cdev */
@@ -868,7 +868,7 @@ zvol_first_open(zvol_state_t *zv)
 	}
 	zv->zv_volblocksize = doi.doi_data_block_size;
 
-	error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
+	error = dnode_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dn);
 	if (error) {
 		dmu_objset_disown(os, zvol_tag);
 		return (error);
@@ -893,8 +893,8 @@ zvol_last_close(zvol_state_t *zv)
 	zil_close(zv->zv_zilog);
 	zv->zv_zilog = NULL;
 
-	dmu_buf_rele(zv->zv_dbuf, zvol_tag);
-	zv->zv_dbuf = NULL;
+	dnode_rele(zv->zv_dn, zvol_tag);
+	zv->zv_dn = NULL;
 
 	/*
 	 * Evict cached data
@@ -1342,8 +1342,6 @@ static int
 zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
 {
 	zvol_state_t *zv = arg;
-	objset_t *os = zv->zv_objset;
-	uint64_t object = ZVOL_OBJ;
 	uint64_t offset = lr->lr_offset;
 	uint64_t size = lr->lr_length;	/* length of user data */
 	dmu_buf_t *db;
@@ -1367,7 +1365,7 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
 	if (buf != NULL) { /* immediate write */
 		zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size,
 		    RL_READER);
-		error = dmu_read(os, object, offset, size, buf,
+		error = dmu_read_by_dnode(zv->zv_dn, offset, size, buf,
 		    DMU_READ_NO_PREFETCH);
 	} else { /* indirect write */
 		/*
@@ -1380,7 +1378,7 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
 		offset = P2ALIGN(offset, size);
 		zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size,
 		    RL_READER);
-		error = dmu_buf_hold(os, object, offset, zgd, &db,
+		error = dmu_buf_hold_by_dnode(zv->zv_dn, offset, zgd, &db,
 		    DMU_READ_NO_PREFETCH);
 		if (error == 0) {
 			blkptr_t *bp = &lr->lr_blkptr;
@@ -1451,8 +1449,8 @@ zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
 		itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
 		    (wr_state == WR_COPIED ? len : 0));
 		lr = (lr_write_t *)&itx->itx_lr;
-		if (wr_state == WR_COPIED && dmu_read(zv->zv_objset,
-		    ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
+		if (wr_state == WR_COPIED && dmu_read_by_dnode(zv->zv_dn,
+		    off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
 			zil_itx_destroy(itx);
 			itx = zil_itx_create(TX_WRITE, sizeof (*lr));
 			lr = (lr_write_t *)&itx->itx_lr;
@@ -1874,7 +1872,7 @@ zvol_read(struct cdev *dev, struct uio *uio, int ioflag)
 		if (bytes > volsize - uio->uio_loffset)
 			bytes = volsize - uio->uio_loffset;
 
-		error =  dmu_read_uio_dbuf(zv->zv_dbuf, uio, bytes);
+		error =  dmu_read_uio_dnode(zv->zv_dn, uio, bytes);
 		if (error) {
 			/* convert checksum errors into IO errors */
 			if (error == ECKSUM)
@@ -1946,7 +1944,7 @@ zvol_write(struct cdev *dev, struct uio *uio, int ioflag)
 			dmu_tx_abort(tx);
 			break;
 		}
-		error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
+		error = dmu_write_uio_dnode(zv->zv_dn, uio, bytes, tx);
 		if (error == 0)
 			zvol_log_write(zv, tx, off, bytes, sync);
 		dmu_tx_commit(tx);
@@ -2028,7 +2026,7 @@ zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
 int
 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
     uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
-    void **rl_hdl, void **bonus_hdl)
+    void **rl_hdl, void **dnode_hdl)
 {
 	zvol_state_t *zv;
 
@@ -2039,7 +2037,7 @@ zvol_get_volume_params(minor_t minor, uint64_t *blksize,
 		return (SET_ERROR(ENXIO));
 
 	ASSERT(blksize && max_xfer_len && minor_hdl &&
-	    objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
+	    objset_hdl && zil_hdl && rl_hdl && dnode_hdl);
 
 	*blksize = zv->zv_volblocksize;
 	*max_xfer_len = (uint64_t)zvol_maxphys;
@@ -2047,7 +2045,7 @@ zvol_get_volume_params(minor_t minor, uint64_t *blksize,
 	*objset_hdl = zv->zv_objset;
 	*zil_hdl = zv->zv_zilog;
 	*rl_hdl = &zv->zv_znode;
-	*bonus_hdl = zv->zv_dbuf;
+	*dnode_hdl = zv->zv_dn;
 	return (0);
 }