Manual Para Lock (#5451)

* remove para lock check for now

* fmt

* manual para lock

* expose schedule_code_upgrade and set_current_head

* extrinsics and benchmarks

* use zero

* add weights

* fix variable name

* add and fix comments

* fix weights

* add back default lock

Co-authored-by: parity-processbot <>

polkadot/runtime/parachains/src/lib.rs

@@ -50,7 +50,8 @@ mod mock;
 
 pub use origin::{ensure_parachain, Origin};
 pub use paras::ParaLifecycle;
-use primitives::v2::Id as ParaId;
+use primitives::v2::{HeadData, Id as ParaId, ValidationCode};
+use sp_runtime::DispatchResult;
 
 /// Schedule a para to be initialized at the start of the next session with the given genesis data.
 ///
@@ -78,3 +79,20 @@ pub fn schedule_parathread_upgrade<T: paras::Config>(id: ParaId) -> Result<(), (
 pub fn schedule_parachain_downgrade<T: paras::Config>(id: ParaId) -> Result<(), ()> {
 	paras::Pallet::<T>::schedule_parachain_downgrade(id).map_err(|_| ())
 }
+
+/// Schedules a validation code upgrade to a parachain with the given id.
+///
+/// This simply calls [`crate::paras::Pallet::schedule_code_upgrade_external`].
+pub fn schedule_code_upgrade<T: paras::Config>(
+	id: ParaId,
+	new_code: ValidationCode,
+) -> DispatchResult {
+	paras::Pallet::<T>::schedule_code_upgrade_external(id, new_code)
+}
+
+/// Sets the current parachain head with the given id.
+///
+/// This simply calls [`crate::paras::Pallet::set_current_head`].
+pub fn set_current_head<T: paras::Config>(id: ParaId, new_head: HeadData) {
+	paras::Pallet::<T>::set_current_head(id, new_head)
+}

polkadot/runtime/parachains/src/paras/mod.rs

@@ -118,7 +118,7 @@ use primitives::v2::{
 use scale_info::TypeInfo;
 use sp_core::RuntimeDebug;
 use sp_runtime::{
-	traits::{AppVerify, One},
+	traits::{AppVerify, One, Saturating},
 	DispatchResult, SaturatedConversion,
 };
 use sp_std::{cmp, mem, prelude::*};
@@ -535,6 +535,8 @@ pub mod pallet {
 		/// The PVF pre-checking statement cannot be included since the PVF pre-checking mechanism
 		/// is disabled.
 		PvfCheckDisabled,
+		/// Parachain cannot currently schedule a code upgrade.
+		CannotUpgradeCode,
 	}
 
 	/// All currently active PVF pre-checking votes.
@@ -752,8 +754,7 @@ pub mod pallet {
 			new_head: HeadData,
 		) -> DispatchResult {
 			ensure_root(origin)?;
-			<Self as Store>::Heads::insert(&para, new_head);
-			Self::deposit_event(Event::CurrentHeadUpdated(para));
+			Self::set_current_head(para, new_head);
 			Ok(())
 		}
 
@@ -1050,6 +1051,31 @@ const INVALID_TX_DOUBLE_VOTE: u8 = 3;
 const INVALID_TX_PVF_CHECK_DISABLED: u8 = 4;
 
 impl<T: Config> Pallet<T> {
+	/// This is a call to schedule code upgrades for parachains which is safe to be called
+	/// outside of this module. That means this function does all checks necessary to ensure
+	/// that some external code is allowed to trigger a code upgrade. We do not do auth checks,
+	/// that should be handled by whomever calls this function.
+	pub(crate) fn schedule_code_upgrade_external(
+		id: ParaId,
+		new_code: ValidationCode,
+	) -> DispatchResult {
+		// Check that we can schedule an upgrade at all.
+		ensure!(Self::can_upgrade_validation_code(id), Error::<T>::CannotUpgradeCode);
+		let config = configuration::Pallet::<T>::config();
+		let current_block = frame_system::Pallet::<T>::block_number();
+		// Schedule the upgrade with a delay just like if a parachain triggered the upgrade.
+		let upgrade_block = current_block.saturating_add(config.validation_upgrade_delay);
+		Self::schedule_code_upgrade(id, new_code, upgrade_block, &config);
+		Self::deposit_event(Event::CodeUpgradeScheduled(id));
+		Ok(())
+	}
+
+	/// Set the current head of a parachain.
+	pub(crate) fn set_current_head(para: ParaId, new_head: HeadData) {
+		<Self as Store>::Heads::insert(&para, new_head);
+		Self::deposit_event(Event::CurrentHeadUpdated(para));
+	}
+
 	/// Called by the initializer to initialize the paras pallet.
 	pub(crate) fn initializer_initialize(now: T::BlockNumber) -> Weight {
 		let weight = Self::prune_old_code(now);