Ensure `note_min_gas_price_target` updated in a block once

[hackfisher]

• [x] For inherent call, the weight might need to be DispatchClass::Mandatory, refer timestamp pallet.

  #[pallet::weight((
          T::WeightInfo::set(),
          DispatchClass::Mandatory
      ))]

• [x] Inherent and Unsigned Transaction are both verified by ensure_none? Does Unsigned Transaction require extra validation for those calls use ensure_none?

[AurevoirXavier]

For the second question:

https://crates.parity.io/frame_support/inherent/trait.ProvideInherent.html#tymethod.is_inherent https://github.com/paritytech/substrate/blob/master/frame/timestamp/src/lib.rs

[boundless-forest]

Inherent and Unsigned Transaction are both verified by ensure_none?

As far as I understand it, Inherent is a special unsigned transaction. Therefore, you must ensure ensure_none().

For inherent, you can add extra InherentData validation by using check_inherent(). For general unsigned transaction, checked by validate_unsigned().

Does Unsigned Transaction require extra validation for those calls use ensure_none?

Sometimes it is necessary.

With extra validation examples:

1. https://github.com/darwinia-network/darwinia-common/blob/master/frame/claims/src/lib.rs#L418
2. https://github.com/darwinia-network/darwinia-common/blob/master/frame/claims/src/lib.rs#L418

No extra validation examples:

1. https://github.com/paritytech/substrate/blob/master/frame/authorship/src/lib.rs#L220
2. https://github.com/paritytech/substrate/blob/master/frame/timestamp/src/lib.rs#L190

[hackfisher]

Just as the timestamp pallet from substrate, which validates the timestamp must be updated only once in the block.

Refer:

https://github.com/paritytech/substrate/blob/a019b577163ec354d2776178fbdb922b0e77dea9/frame/timestamp/src/lib.rs#L191

The dvm dynamic fee might be better to do the same check to avoid corner cases of including multiple such note_min_gas_price_target, one from block producer, others might from tx pool, ordered and included by block producer by accident.

https://github.com/darwinia-network/darwinia-common/blob/93f8d4b7b3e9f616ddc0728477bd6347908bd615/frame/dvm-dynamic-fee/src/lib.rs#L79

[boundless-forest]

https://substrate.dev/docs/en/knowledgebase/runtime/fees#mandatory-dispatches

[boundless-forest]

https://github.com/paritytech/frontier/pull/435

[AurevoirXavier]

Any update? @AsceticBear

[boundless-forest]

Waiting for the next DVM update

[hackfisher]

others might from tx pool, ordered and included by block producer by accident.

It is not possible to be include by block producer if it uses transaction pool

https://github.com/paritytech/substrate/blob/master/primitives/runtime/src/generic/checked_extrinsic.rs#L51-L66

Inherent does not pass through the transaction pool, so it will not be checked out of NoUnsignedValidator by validate_unsigned, but the Unsigned Extrinsic sent by users outside the block producer will be checked out of the transaction pool and will be checked out of NoUnsignedValidator

[hackfisher]

Multiple inherent inclusion is fixing by https://github.com/darwinia-network/darwinia-common/pull/817