polkadot: remove grandpa pause support (#2511)

This was never used and we probably don't need it anyway.

cumulus/client/relay-chain-inprocess-interface/src/lib.rs

@@ -283,7 +283,6 @@ fn build_polkadot_full_node(
 		config,
 		polkadot_service::NewFullParams {
 			is_parachain_node,
-			grandpa_pause: None,
 			// Disable BEEFY. It should not be required by the internal relay chain node.
 			enable_beefy: false,
 			force_authoring_backoff: false,

polkadot/cli/src/cli.rs

@@ -82,16 +82,6 @@ pub struct RunCmd {
 	#[arg(long = "force-rococo")]
 	pub force_rococo: bool,
 
-	/// Setup a GRANDPA scheduled voting pause.
-	///
-	/// This parameter takes two values, namely a block number and a delay (in blocks).
-	///
-	/// After the given block number is finalized the GRANDPA voter will temporarily
-	/// stop voting for new blocks until the given delay has elapsed (i.e. until a
-	/// block at height `pause_block + delay` is imported).
-	#[arg(long = "grandpa-pause", num_args = 2)]
-	pub grandpa_pause: Vec<u32>,
-
 	/// Disable the BEEFY gadget.
 	///
 	/// Currently enabled by default on 'Rococo', 'Wococo' and 'Versi'.

polkadot/cli/src/command.rs

@@ -215,12 +215,6 @@ where
 
 	set_default_ss58_version(chain_spec);
 
-	let grandpa_pause = if cli.run.grandpa_pause.is_empty() {
-		None
-	} else {
-		Some((cli.run.grandpa_pause[0], cli.run.grandpa_pause[1]))
-	};
-
 	if chain_spec.is_kusama() {
 		info!("----------------------------");
 		info!("This chain is not in any way");
@@ -257,7 +251,6 @@ where
 			config,
 			service::NewFullParams {
 				is_parachain_node: service::IsParachainNode::No,
-				grandpa_pause,
 				enable_beefy,
 				force_authoring_backoff: cli.run.force_authoring_backoff,
 				jaeger_agent,

polkadot/node/service/src/grandpa_support.rs

@@ -16,8 +16,6 @@
 
 //! Polkadot-specific GRANDPA integration utilities.
 
-use std::sync::Arc;
-
 use sp_runtime::traits::{Block as BlockT, Header as _, NumberFor};
 
 use crate::HeaderProvider;
@@ -59,55 +57,6 @@ where
 	}
 }
 
-/// A custom GRANDPA voting rule that "pauses" voting (i.e. keeps voting for the
-/// same last finalized block) after a given block at height `N` has been
-/// finalized and for a delay of `M` blocks, i.e. until the best block reaches
-/// `N` + `M`, the voter will keep voting for block `N`.
-#[derive(Clone)]
-pub(crate) struct PauseAfterBlockFor<N>(pub(crate) N, pub(crate) N);
-
-impl<Block, B> grandpa::VotingRule<Block, B> for PauseAfterBlockFor<NumberFor<Block>>
-where
-	Block: BlockT,
-	B: sp_blockchain::HeaderBackend<Block> + 'static,
-{
-	fn restrict_vote(
-		&self,
-		backend: Arc<B>,
-		base: &Block::Header,
-		best_target: &Block::Header,
-		current_target: &Block::Header,
-	) -> grandpa::VotingRuleResult<Block> {
-		let aux = || {
-			// only restrict votes targeting a block higher than the block
-			// we've set for the pause
-			if *current_target.number() > self.0 {
-				// if we're past the pause period (i.e. `self.0 + self.1`)
-				// then we no longer need to restrict any votes
-				if *best_target.number() > self.0 + self.1 {
-					return None
-				}
-
-				// if we've finalized the pause block, just keep returning it
-				// until best number increases enough to pass the condition above
-				if *base.number() >= self.0 {
-					return Some((base.hash(), *base.number()))
-				}
-
-				// otherwise find the target header at the pause block
-				// to vote on
-				return walk_backwards_to_target_block(&*backend, self.0, current_target).ok()
-			}
-
-			None
-		};
-
-		let target = aux();
-
-		Box::pin(async move { target })
-	}
-}
-
 /// GRANDPA hard forks due to borked migration of session keys after a runtime
 /// upgrade (at #1491596), the signaled authority set changes were invalid
 /// (blank keys) and were impossible to finalize. The authorities for these
@@ -214,130 +163,3 @@ pub(crate) fn kusama_hard_forks() -> Vec<grandpa::AuthoritySetHardFork<Block>> {
 		})
 		.collect()
 }
-
-#[cfg(test)]
-mod tests {
-	use consensus_common::BlockOrigin;
-	use grandpa::VotingRule;
-	use polkadot_test_client::{
-		ClientBlockImportExt, DefaultTestClientBuilderExt, InitPolkadotBlockBuilder,
-		TestClientBuilder, TestClientBuilderExt,
-	};
-	use sp_blockchain::HeaderBackend;
-	use sp_runtime::traits::Header;
-	use std::sync::Arc;
-
-	#[test]
-	fn grandpa_pause_voting_rule_works() {
-		let _ = env_logger::try_init();
-
-		let client = Arc::new(TestClientBuilder::new().build());
-		let mut hashes = vec![];
-		hashes.push(client.info().genesis_hash);
-
-		let mut push_blocks = {
-			let mut client = client.clone();
-
-			move |hashes: &mut Vec<_>, n| {
-				for _ in 0..n {
-					let block = client.init_polkadot_block_builder().build().unwrap().block;
-					hashes.push(block.header.hash());
-					futures::executor::block_on(client.import(BlockOrigin::Own, block)).unwrap();
-				}
-			}
-		};
-
-		let get_header = {
-			let client = client.clone();
-			move |n| client.expect_header(n).unwrap()
-		};
-
-		// the rule should filter all votes after block #20
-		// is finalized until block #50 is imported.
-		let voting_rule = super::PauseAfterBlockFor(20, 30);
-
-		// add 10 blocks
-		push_blocks(&mut hashes, 10);
-		assert_eq!(client.info().best_number, 10);
-
-		// we have not reached the pause block
-		// therefore nothing should be restricted
-		assert_eq!(
-			futures::executor::block_on(voting_rule.restrict_vote(
-				client.clone(),
-				&get_header(hashes[0]),
-				&get_header(hashes[10]),
-				&get_header(hashes[10])
-			)),
-			None,
-		);
-
-		// add 15 more blocks
-		// best block: #25
-		push_blocks(&mut hashes, 15);
-
-		// we are targeting the pause block,
-		// the vote should not be restricted
-		assert_eq!(
-			futures::executor::block_on(voting_rule.restrict_vote(
-				client.clone(),
-				&get_header(hashes[10]),
-				&get_header(hashes[20]),
-				&get_header(hashes[20])
-			)),
-			None,
-		);
-
-		// we are past the pause block, votes should
-		// be limited to the pause block.
-		let pause_block = get_header(hashes[20]);
-		assert_eq!(
-			futures::executor::block_on(voting_rule.restrict_vote(
-				client.clone(),
-				&get_header(hashes[10]),
-				&get_header(hashes[21]),
-				&get_header(hashes[21])
-			)),
-			Some((pause_block.hash(), *pause_block.number())),
-		);
-
-		// we've finalized the pause block, so we'll keep
-		// restricting our votes to it.
-		assert_eq!(
-			futures::executor::block_on(voting_rule.restrict_vote(
-				client.clone(),
-				&pause_block, // #20
-				&get_header(hashes[21]),
-				&get_header(hashes[21]),
-			)),
-			Some((pause_block.hash(), *pause_block.number())),
-		);
-
-		// add 30 more blocks
-		// best block: #55
-		push_blocks(&mut hashes, 30);
-
-		// we're at the last block of the pause, this block
-		// should still be considered in the pause period
-		assert_eq!(
-			futures::executor::block_on(voting_rule.restrict_vote(
-				client.clone(),
-				&pause_block, // #20
-				&get_header(hashes[50]),
-				&get_header(hashes[50]),
-			)),
-			Some((pause_block.hash(), *pause_block.number())),
-		);
-
-		// we're past the pause period, no votes should be filtered
-		assert_eq!(
-			futures::executor::block_on(voting_rule.restrict_vote(
-				client.clone(),
-				&pause_block, // #20
-				&get_header(hashes[51]),
-				&get_header(hashes[51]),
-			)),
-			None,
-		);
-	}
-}

polkadot/node/service/src/lib.rs

@@ -623,7 +623,6 @@ where
 #[cfg(feature = "full-node")]
 pub struct NewFullParams<OverseerGenerator: OverseerGen> {
 	pub is_parachain_node: IsParachainNode,
-	pub grandpa_pause: Option<(u32, u32)>,
 	pub enable_beefy: bool,
 	/// Whether to enable the block authoring backoff on production networks
 	/// where it isn't enabled by default.
@@ -717,7 +716,6 @@ pub fn new_full<OverseerGenerator: OverseerGen>(
 	mut config: Configuration,
 	NewFullParams {
 		is_parachain_node,
-		grandpa_pause,
 		enable_beefy,
 		force_authoring_backoff,
 		jaeger_agent,
@@ -1248,32 +1246,14 @@ pub fn new_full<OverseerGenerator: OverseerGen>(
 		// provide better guarantees of block and vote data availability than
 		// the observer.
 
-		// add a custom voting rule to temporarily stop voting for new blocks
+		let mut voting_rules_builder = grandpa::VotingRulesBuilder::default();
-		// after the given pause block is finalized and restarting after the
-		// given delay.
-		let mut builder = grandpa::VotingRulesBuilder::default();
 
 		#[cfg(not(feature = "malus"))]
 		let _malus_finality_delay = None;
 
 		if let Some(delay) = _malus_finality_delay {
 			info!(?delay, "Enabling malus finality delay",);
-			builder = builder.add(grandpa::BeforeBestBlockBy(delay));
+			voting_rules_builder = voting_rules_builder.add(grandpa::BeforeBestBlockBy(delay));
-		};
-
-		let voting_rule = match grandpa_pause {
-			Some((block, delay)) => {
-				info!(
-					block_number = %block,
-					delay = %delay,
-					"GRANDPA scheduled voting pause set for block #{} with a duration of {} blocks.",
-					block,
-					delay,
-				);
-
-				builder.add(grandpa_support::PauseAfterBlockFor(block, delay)).build()
-			},
-			None => builder.build(),
 		};
 
 		let grandpa_config = grandpa::GrandpaParams {
@@ -1281,7 +1261,7 @@ pub fn new_full<OverseerGenerator: OverseerGen>(
 			link: link_half,
 			network: network.clone(),
 			sync: sync_service.clone(),
-			voting_rule,
+			voting_rule: voting_rules_builder.build(),
 			prometheus_registry: prometheus_registry.clone(),
 			shared_voter_state,
 			telemetry: telemetry.as_ref().map(|x| x.handle()),

polkadot/node/test/service/src/lib.rs

@@ -80,7 +80,6 @@ pub fn new_full(
 		config,
 		polkadot_service::NewFullParams {
 			is_parachain_node,
-			grandpa_pause: None,
 			enable_beefy: true,
 			force_authoring_backoff: false,
 			jaeger_agent: None,

polkadot/parachain/test-parachains/adder/collator/src/main.rs

@@ -62,7 +62,6 @@ fn main() -> Result<()> {
 						is_parachain_node: polkadot_service::IsParachainNode::Collator(
 							collator.collator_key(),
 						),
-						grandpa_pause: None,
 						enable_beefy: false,
 						force_authoring_backoff: false,
 						jaeger_agent: None,

polkadot/parachain/test-parachains/undying/collator/src/main.rs

@@ -82,7 +82,6 @@ fn main() -> Result<()> {
 						is_parachain_node: polkadot_service::IsParachainNode::Collator(
 							collator.collator_key(),
 						),
-						grandpa_pause: None,
 						enable_beefy: false,
 						force_authoring_backoff: false,
 						jaeger_agent: None,