Add types to featureflags in zfs

The boolean featureflags in use thus far in ZFS are extremely useful,
but because they take advantage of the zap layer, more interesting data
than just a true/false value can be stored in a featureflag. In redacted
send/receive, this is used to store the list of redaction snapshots for
a redacted dataset.

This change adds the ability for ZFS to store types other than a boolean
in a featureflag. The only other implemented type is a uint64_t array.
It also modifies the interfaces around dataset features to accomodate
the new capabilities, and adds a few new functions to increase
encapsulation.

This functionality will be used by the Redacted Send/Receive feature.

Reviewed-by: Matthew Ahrens <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Paul Dagnelie <[email protected]>
Closes #7981 

1 files changed, 5 insertions, 9 deletions

diff --git a/module/zfs/dsl_destroy.c b/module/zfs/dsl_destroy.c
index b80d34672..97d7befbd 100644
--- a/module/zfs/dsl_destroy.c
+++ b/module/zfs/dsl_destroy.c
@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
  * Copyright (c) 2013 Steven Hartland. All rights reserved.
  * Copyright (c) 2013 by Joyent, Inc. All rights reserved.
  * Copyright (c) 2016 Actifio, Inc. All rights reserved.
@@ -315,10 +315,8 @@ dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
 	obj = ds->ds_object;
 
 	for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
-		if (ds->ds_feature_inuse[f]) {
-			dsl_dataset_deactivate_feature(obj, f, tx);
-			ds->ds_feature_inuse[f] = B_FALSE;
-		}
+		if (dsl_dataset_feature_is_active(ds, f))
+			dsl_dataset_deactivate_feature(ds, f, tx);
 	}
 	if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
 		ASSERT3P(ds->ds_prev, ==, NULL);
@@ -869,10 +867,8 @@ dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx)
 	obj = ds->ds_object;
 
 	for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
-		if (ds->ds_feature_inuse[f]) {
-			dsl_dataset_deactivate_feature(obj, f, tx);
-			ds->ds_feature_inuse[f] = B_FALSE;
-		}
+		if (dsl_dataset_feature_is_active(ds, f))
+			dsl_dataset_deactivate_feature(ds, f, tx);
 	}
 
 	dsl_scan_ds_destroyed(ds, tx);