mirror of
https://github.com/pezkuwichain/pezkuwi-subxt.git
synced 2026-05-07 23:38:00 +00:00
Branislav Kontur
bb8ddc46c1
I started this investigation/issue based on @liamaharon question [here](https://github.com/paritytech/polkadot-sdk/pull/1801#discussion_r1410452499). ## Problem The `pallet_balances` integrity test should correctly detect that the runtime has correct distinct `HoldReasons` variant count. I assume the same situation exists for RuntimeFreezeReason. It is not a critical problem, if we set `MaxHolds` with a sufficiently large value, everything should be ok. However, in this case, the integrity_test check becomes less useful. **Situation for "any" runtime:** - `HoldReason` enums from different pallets: ```rust /// from pallet_nis #[pallet::composite_enum] pub enum HoldReason { NftReceipt, } /// from pallet_preimage #[pallet::composite_enum] pub enum HoldReason { Preimage, } // from pallet_state-trie-migration #[pallet::composite_enum] pub enum HoldReason { SlashForContinueMigrate, SlashForMigrateCustomTop, SlashForMigrateCustomChild, } ``` - generated `RuntimeHoldReason` enum looks like: ```rust pub enum RuntimeHoldReason { #[codec(index = 32u8)] Preimage(pallet_preimage::HoldReason), #[codec(index = 38u8)] Nis(pallet_nis::HoldReason), #[codec(index = 42u8)] StateTrieMigration(pallet_state_trie_migration::HoldReason), } ``` - composite enum `RuntimeHoldReason` variant count is detected as `3` - we set `type MaxHolds = ConstU32<3>` - `pallet_balances::integrity_test` is ok with `3`(at least 3) However, the real problem can occur in a live runtime where some functionality might stop working. This is due to a total of 5 distinct hold reasons (for pallets with multi-instance support, it is even more), and not all of them can be used because of an incorrect `MaxHolds`, which is deemed acceptable according to the `integrity_test`: ``` // pseudo-code - if we try to call all of these: T::Currency::hold(&pallet_nis::HoldReason::NftReceipt.into(), &nft_owner, deposit)?; T::Currency::hold(&pallet_preimage::HoldReason::Preimage.into(), &nft_owner, deposit)?; T::Currency::hold(&pallet_state_trie_migration::HoldReason::SlashForContinueMigrate.into(), &nft_owner, deposit)?; // With `type MaxHolds = ConstU32<3>` these two will fail T::Currency::hold(&pallet_state_trie_migration::HoldReason::SlashForMigrateCustomTop.into(), &nft_owner, deposit)?; T::Currency::hold(&pallet_state_trie_migration::HoldReason::SlashForMigrateCustomChild.into(), &nft_owner, deposit)?; ``` ## Solutions A macro `#[pallet::*]` expansion is extended of `VariantCount` implementation for the `#[pallet::composite_enum]` enum type. This expansion generates the `VariantCount` implementation for pallets' `HoldReason`, `FreezeReason`, `LockId`, and `SlashReason`. Enum variants must be plain enum values without fields to ensure a deterministic count. The composite runtime enum, `RuntimeHoldReason` and `RuntimeFreezeReason`, now sets `VariantCount::VARIANT_COUNT` as the sum of pallets' enum `VariantCount::VARIANT_COUNT`: ```rust #[frame_support::pallet(dev_mode)] mod module_single_instance { #[pallet::composite_enum] pub enum HoldReason { ModuleSingleInstanceReason1, ModuleSingleInstanceReason2, } ... } #[frame_support::pallet(dev_mode)] mod module_multi_instance { #[pallet::composite_enum] pub enum HoldReason<I: 'static = ()> { ModuleMultiInstanceReason1, ModuleMultiInstanceReason2, ModuleMultiInstanceReason3, } ... } impl self::sp_api_hidden_includes_construct_runtime::hidden_include::traits::VariantCount for RuntimeHoldReason { const VARIANT_COUNT: u32 = 0 + module_single_instance::HoldReason::VARIANT_COUNT + module_multi_instance::HoldReason::<module_multi_instance::Instance1>::VARIANT_COUNT + module_multi_instance::HoldReason::<module_multi_instance::Instance2>::VARIANT_COUNT + module_multi_instance::HoldReason::<module_multi_instance::Instance3>::VARIANT_COUNT; } ``` In addition, `MaxHolds` is removed (as suggested [here](https://github.com/paritytech/polkadot-sdk/pull/2657#discussion_r1443324573)) from `pallet_balances`, and its `Holds` are now bounded to `RuntimeHoldReason::VARIANT_COUNT`. Therefore, there is no need to let the runtime specify `MaxHolds`. ## For reviewers Relevant changes can be found here: - `substrate/frame/support/procedural/src/lib.rs` - `substrate/frame/support/procedural/src/pallet/parse/composite.rs` - `substrate/frame/support/procedural/src/pallet/expand/composite.rs` - `substrate/frame/support/procedural/src/construct_runtime/expand/composite_helper.rs` - `substrate/frame/support/procedural/src/construct_runtime/expand/hold_reason.rs` - `substrate/frame/support/procedural/src/construct_runtime/expand/freeze_reason.rs` - `substrate/frame/support/src/traits/misc.rs` And the rest of the files is just about removed `MaxHolds` from `pallet_balances` ## Next steps Do the same for `MaxFreezes` https://github.com/paritytech/polkadot-sdk/issues/2997. --------- Co-authored-by: command-bot <> Co-authored-by: Bastian Köcher <git@kchr.de> Co-authored-by: Dónal Murray <donal.murray@parity.io> Co-authored-by: gupnik <nikhilgupta.iitk@gmail.com>
Identity Module
Overview
A federated naming system, allowing for multiple registrars to be added from a specified origin.
Registrars can set a fee to provide identity-verification service. Anyone can put forth a
proposed identity for a fixed deposit and ask for review by any number of registrars (paying
each of their fees). Registrar judgements are given as an enum, allowing for sophisticated,
multi-tier opinions.
Some judgements are identified as sticky, which means they cannot be removed except by complete removal of the identity, or by the registrar. Judgements are allowed to represent a portion of funds that have been reserved for the registrar.
A super-user can remove accounts and in doing so, slash the deposit.
All accounts may also have a limited number of sub-accounts which may be specified by the owner; by definition, these have equivalent ownership and each has an individual name.
The number of registrars should be limited, and the deposit made sufficiently large, to ensure no state-bloat attack is viable.
Interface
Dispatchable Functions
For general users
set_identity- Set the associated identity of an account; a small deposit is reserved if not already taken.clear_identity- Remove an account's associated identity; the deposit is returned.request_judgement- Request a judgement from a registrar, paying a fee.cancel_request- Cancel the previous request for a judgement.
For general users with sub-identities
set_subs- Set the sub-accounts of an identity.add_sub- Add a sub-identity to an identity.remove_sub- Remove a sub-identity of an identity.rename_sub- Rename a sub-identity of an identity.quit_sub- Remove a sub-identity of an identity (called by the sub-identity).
For registrars
set_fee- Set the fee required to be paid for a judgement to be given by the registrar.set_fields- Set the fields that a registrar cares about in their judgements.provide_judgement- Provide a judgement to an identity.
For super-users
add_registrar- Add a new registrar to the system.kill_identity- Forcibly remove the associated identity; the deposit is lost.
License: Apache-2.0