For XCM instructions which are unable to avoid any state changes on an error, use a storage transaction to ensure that changes are rolled back in the case of an error after changes have been made. Instructions which need this are:

• WithdrawAsset
• ReserveAssetDeposited
• TransferAsset
• TransferReserveAsset
• ReceiveTeleportedAsset
• DepositAsset
• DepositReserveAsset
• InitiateReserveWithdraw
• InitiateTeleport
• BuyExecution
• ClaimAsset
• ExportMessage
• LockAsset
• UnlockAsset
• RequestUnlock

Each should have their implementations in XcmExecutor::process_instruction be wrapped in a storage transaction which reverts any changes in case an Err value is returned.