Remove deduplicated send/receive code

Deduplicated send streams (i.e. `zfs send -D` and `zfs receive` of such
streams) are deprecated.  Deduplicated send streams can be received by
first converting them to non-deduplicated with the `zstream redup`
command.

This commit removes the code for sending and receiving deduplicated send
streams.  `zfs send -D` will now print a warning, ignore the `-D` flag,
and generate a regular (non-deduplicated) send stream.  `zfs receive` of
a deduplicated send stream will print an error message and fail.

The resulting code simplification (especially in the kernel's support
for receiving dedup streams) should help enable future performance
enhancements.

Several new tests are added which leverage `zstream redup`.

Reviewed-by: Paul Dagnelie <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Matthew Ahrens <[email protected]>
Issue openzfs#7887
Issue openzfs#10117
Issue openzfs#10156
Closes openzfs#10212 
(cherry picked from commit 196bee4)

cmd/zfs/zfs_main.c

@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2019 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
  * Copyright 2012 Milan Jurik. All rights reserved.
  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  * Copyright (c) 2013 Steven Hartland.  All rights reserved.
@@ -4266,7 +4266,10 @@ zfs_do_send(int argc, char **argv)
 			flags.progress = B_TRUE;
 			break;
 		case 'D':
-			flags.dedup = B_TRUE;
+			(void) fprintf(stderr,
+			    gettext("WARNING: deduplicated send is no "
+			    "longer supported.  A regular,\n"
+			    "non-deduplicated stream will be generated.\n\n"));
 			break;
 		case 'n':
 			flags.dryrun = B_TRUE;
@@ -4333,16 +4336,6 @@ zfs_do_send(int argc, char **argv)
 		}
 	}
 
-	if (flags.dedup) {
-		(void) fprintf(stderr,
-		    gettext("WARNING: deduplicated send is "
-		    "deprecated, and will be removed in a\n"
-		    "future release. (In the future, the flag will be "
-		    "accepted, but a\n"
-		    "regular, non-deduplicated stream will be "
-		    "generated.)\n\n"));
-	}
-
 	if (flags.parsable && flags.verbosity == 0)
 		flags.verbosity = 1;
 
@@ -4351,7 +4344,7 @@ zfs_do_send(int argc, char **argv)
 
 	if (resume_token != NULL) {
 		if (fromname != NULL || flags.replicate || flags.props ||
-		    flags.backup || flags.dedup || flags.holds ||
+		    flags.backup || flags.holds ||
 		    flags.saved || redactbook != NULL) {
 			(void) fprintf(stderr,
 			    gettext("invalid flags combined with -t\n"));
@@ -4375,7 +4368,7 @@ zfs_do_send(int argc, char **argv)
 
 	if (flags.saved) {
 		if (fromname != NULL || flags.replicate || flags.props ||
-		    flags.doall || flags.backup || flags.dedup ||
+		    flags.doall || flags.backup ||
 		    flags.holds || flags.largeblock || flags.embed_data ||
 		    flags.compress || flags.raw || redactbook != NULL) {
 			(void) fprintf(stderr, gettext("incompatible flags "

include/libzfs.h

@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
  * Copyright Joyent, Inc.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2016, Intel Corporation.
@@ -651,8 +651,8 @@ typedef struct sendflags {
 	/* if dataset is a clone, do incremental from its origin */
 	boolean_t fromorigin;
 
-	/* do deduplication */
-	boolean_t dedup;
+	/* field no longer used, maintained for backwards compatibility */
+	boolean_t pad;
 
 	/* send properties (ie, -p) */
 	boolean_t props;

include/libzfs_impl.h

@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
  * Copyright (c) 2018 Datto Inc.
  */
 
@@ -71,7 +71,6 @@ struct libzfs_handle {
 	int libzfs_pool_iter;
 	char libzfs_chassis_id[256];
 	boolean_t libzfs_prop_debug;
-	boolean_t libzfs_dedup_warning_printed;
 };
 
 #define	ZFSSHARE_MISS	0x01	/* Didn't find entry in cache */

include/sys/dmu.h

@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  * Copyright 2014 HybridCluster. All rights reserved.
@@ -864,8 +864,6 @@ int dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset,
 int dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset,
     struct arc_buf *buf, dmu_tx_t *tx);
 #define	dmu_assign_arcbuf	dmu_assign_arcbuf_by_dbuf
-void dmu_copy_from_buf(objset_t *os, uint64_t object, uint64_t offset,
-    dmu_buf_t *handle, dmu_tx_t *tx);
 #ifdef HAVE_UIO_ZEROCOPY
 int dmu_xuio_init(struct xuio *uio, int niov);
 void dmu_xuio_fini(struct xuio *uio);

include/sys/dmu_recv.h

@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2020 by Delphix. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  */
@@ -53,10 +53,8 @@ typedef struct dmu_recv_cookie {
 	boolean_t drc_raw;
 	boolean_t drc_clone;
 	boolean_t drc_spill;
-	struct avl_tree *drc_guid_to_ds_map;
 	nvlist_t *drc_keynvl;
 	uint64_t drc_fromsnapobj;
-	uint64_t drc_newsnapobj;
 	uint64_t drc_ivset_guid;
 	void *drc_owner;
 	cred_t *drc_cred;
@@ -80,13 +78,11 @@ typedef struct dmu_recv_cookie {
 	objlist_t *drc_ignore_objlist;
 } dmu_recv_cookie_t;
 
-int dmu_recv_begin(char *tofs, char *tosnap, dmu_replay_record_t *drr_begin,
-    boolean_t force, boolean_t resumable, nvlist_t *localprops,
-    nvlist_t *hidden_args, char *origin, dmu_recv_cookie_t *drc,
-    zfs_file_t *fp, offset_t *voffp);
-int dmu_recv_stream(dmu_recv_cookie_t *drc, int cleanup_fd,
-    uint64_t *action_handlep, offset_t *voffp);
-int dmu_recv_end(dmu_recv_cookie_t *drc, void *owner);
-boolean_t dmu_objset_is_receiving(objset_t *os);
+int dmu_recv_begin(char *, char *, dmu_replay_record_t *,
+    boolean_t, boolean_t, nvlist_t *, nvlist_t *, char *,
+    dmu_recv_cookie_t *, zfs_file_t *, offset_t *);
+int dmu_recv_stream(dmu_recv_cookie_t *, offset_t *);
+int dmu_recv_end(dmu_recv_cookie_t *, void *);
+boolean_t dmu_objset_is_receiving(objset_t *);
 
 #endif /* _DMU_RECV_H */

include/sys/zfs_ioctl.h

@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2020 by Delphix. All rights reserved.
  * Copyright 2016 RackTop Systems.
  * Copyright (c) 2017, Intel Corporation.
  */
@@ -111,8 +111,7 @@ typedef enum drr_headertype {
 /*
  * Mask of all supported backup features
  */
-#define	DMU_BACKUP_FEATURE_MASK	(DMU_BACKUP_FEATURE_DEDUP | \
-    DMU_BACKUP_FEATURE_DEDUPPROPS | DMU_BACKUP_FEATURE_SA_SPILL | \
+#define	DMU_BACKUP_FEATURE_MASK	(DMU_BACKUP_FEATURE_SA_SPILL | \
     DMU_BACKUP_FEATURE_EMBED_DATA | DMU_BACKUP_FEATURE_LZ4 | \
     DMU_BACKUP_FEATURE_RESUMING | DMU_BACKUP_FEATURE_LARGE_BLOCKS | \
     DMU_BACKUP_FEATURE_COMPRESSED | DMU_BACKUP_FEATURE_LARGE_DNODE | \

include/sys/zfs_onexit.h

@@ -21,6 +21,7 @@
 
 /*
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020 by Delphix. All rights reserved.
  */
 
 #ifndef	_SYS_ZFS_ONEXIT_H
@@ -54,10 +55,6 @@ extern int zfs_onexit_fd_hold(int fd, minor_t *minorp);
 extern void zfs_onexit_fd_rele(int fd);
 extern int zfs_onexit_add_cb(minor_t minor, void (*func)(void *), void *data,
     uint64_t *action_handle);
-extern int zfs_onexit_del_cb(minor_t minor, uint64_t action_handle,
-    boolean_t fire);
-extern int zfs_onexit_cb_data(minor_t minor, uint64_t action_handle,
-    void **data);
 
 #ifdef	__cplusplus
 }