libbe: recursively promote deep BE datasets

beadm will recursively promote deep BE datasets. In order to match the
beadm behavior, we need to recursively iterate over child filesystems
and promote them along the way.

This patch further refines the work from D40903, completing the fix for
promotion.

Reviewed by:	kevans, rew
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D40972

lib/libbe/be.c

@@ -1266,12 +1266,38 @@ be_deactivate(libbe_handle_t *lbh, const char *ds, bool temporary)
 	return (0);
 }
 
+static int
+be_zfs_promote_cb(zfs_handle_t *zhp, void *data)
+{
+	char origin[BE_MAXPATHLEN];
+	bool *found_origin = (bool *)data;
+	int err;
+
+	if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, sizeof(origin),
+	    NULL, NULL, 0, true) == 0) {
+		*found_origin = true;
+		err = zfs_promote(zhp);
+		if (err)
+			return (err);
+	}
+
+	return (zfs_iter_filesystems(zhp, be_zfs_promote_cb, data));
+}
+
+static int
+be_zfs_promote(zfs_handle_t *zhp, bool *found_origin)
+{
+	*found_origin = false;
+	return (be_zfs_promote_cb(zhp, (void *)found_origin));
+}
+
 int
 be_activate(libbe_handle_t *lbh, const char *bootenv, bool temporary)
 {
-	char be_path[BE_MAXPATHLEN], origin[BE_MAXPATHLEN];
+	char be_path[BE_MAXPATHLEN];
 	zfs_handle_t *zhp;
 	int err;
+	bool found_origin;
 
 	be_root_concat(lbh, bootenv, be_path);
 
@@ -1297,19 +1323,15 @@ be_activate(libbe_handle_t *lbh, const char *bootenv, bool temporary)
 			if (zhp == NULL)
 				return (-1);
 
-			if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, sizeof(origin),
-				NULL, NULL, 0, 1) != 0) {
-				zfs_close(zhp);
-				break;
-			}
+			err = be_zfs_promote(zhp, &found_origin);
 
-			err = zfs_promote(zhp);
 			zfs_close(zhp);
-			if (err)
+			if (!found_origin)
 				break;
+			if (err)
+				return (err);
 		}
 
-
 		if (err)
 			return (-1);
 	}

sbin/bectl/tests/bectl_test.sh

@@ -528,7 +528,6 @@ bectl_jail_cleanup()
 atf_test_case bectl_promotion cleanup
 bectl_promotion_head()
 {
-
 	atf_set "descr" "Check bectl promotion upon activation"
 	atf_set "require.user" root
 }
@@ -550,7 +549,7 @@ bectl_promotion_body()
 	mount=${cwd}/mnt
 	root=${mount}/root
 
-	bectl_create_setup ${zpool} ${disk} ${mount}
+	bectl_create_deep_setup ${zpool} ${disk} ${mount}
 	atf_check mkdir -p ${root}
 
 	# Sleeps interspersed to workaround some naming quirks; notably,
@@ -560,23 +559,22 @@ bectl_promotion_body()
 	# with the same name, and the promotion will fail.
 	atf_check bectl -r ${zpool}/ROOT rename default A
 	sleep 1
-	atf_check bectl -r ${zpool}/ROOT create -e A B
+	atf_check bectl -r ${zpool}/ROOT create -r -e A B
 	sleep 1
-	atf_check bectl -r ${zpool}/ROOT create -e B C
+	atf_check bectl -r ${zpool}/ROOT create -r -e B C
 
 	# C should be a clone of B to start with
-	atf_check -o not-inline:"-" zfs list -H -o origin ${zpool}/ROOT/C
+	atf_check -o not-inline:"-" zfs list -Hr -o origin ${zpool}/ROOT/C
 
 	# Activating it should then promote it all the way out of clone-hood.
 	# This entails two promotes internally, as the first would promote it to
 	# a snapshot of A before finally promoting it the second time out of
 	# clone status.
 	atf_check -o not-empty bectl -r ${zpool}/ROOT activate C
-	atf_check -o inline:"-\n" zfs list -H -o origin ${zpool}/ROOT/C
+	atf_check -o inline:"-\n-\n" zfs list -Hr -o origin ${zpool}/ROOT/C
 }
 bectl_promotion_cleanup()
 {
-
 	bectl_cleanup $(get_zpool_name)
 }