From 3f6eb96d6e44fa774370e2e31238872885c4024b Mon Sep 17 00:00:00 2001
From: Brooks Prumo <brooks@solana.com>
Date: Mon, 13 Sep 2021 08:27:50 -0500
Subject: [PATCH] Call `Bank::update_accounts_hash()` before taking bank
 snapshot (#19765)

This is a bugfix.

When `load_frozen_forks()` called `snapshot_bank()`, the accounts hash
was not computed.  So then when a snapshot archive was eventually
created, its hash would be all 1s, which is clearly wrong.  The fix is
to update the bank's accounts hash before taking the bank snapshot.
---
 ledger/src/blockstore_processor.rs | 6 ++++++
 runtime/src/snapshot_config.rs     | 8 ++++++++
 validator/src/main.rs              | 2 ++
 3 files changed, 16 insertions(+)

diff --git a/ledger/src/blockstore_processor.rs b/ledger/src/blockstore_processor.rs
index a66d76f4b9..190f09d117 100644
--- a/ledger/src/blockstore_processor.rs
+++ b/ledger/src/blockstore_processor.rs
@@ -1192,8 +1192,14 @@ fn load_frozen_forks(
                         block_height,
                         snapshot_config.full_snapshot_archive_interval_slots,
                     ) {
+                        info!("Taking snapshot of new root bank that has crossed the full snapshot interval! slot: {}", *root);
                         *last_full_snapshot_slot = Some(*root);
                         new_root_bank.clean_accounts(true, true, *last_full_snapshot_slot);
+                        new_root_bank.update_accounts_hash_with_index_option(
+                            snapshot_config.accounts_hash_use_index,
+                            snapshot_config.accounts_hash_debug_verify,
+                            Some(new_root_bank.epoch_schedule().slots_per_epoch),
+                        );
                         snapshot_utils::snapshot_bank(
                             new_root_bank,
                             new_root_bank.src.slot_deltas(&new_root_bank.src.roots()),
diff --git a/runtime/src/snapshot_config.rs b/runtime/src/snapshot_config.rs
index 2e834fd829..215231e0c3 100644
--- a/runtime/src/snapshot_config.rs
+++ b/runtime/src/snapshot_config.rs
@@ -29,6 +29,12 @@ pub struct SnapshotConfig {
     /// Maximum number of incremental snapshot archives to retain
     /// NOTE: Incremental snapshots will only be kept for the latest full snapshot
     pub maximum_incremental_snapshot_archives_to_retain: usize,
+
+    /// This is the `use_index` parameter to use when calling `update_accounts_hash()`
+    pub accounts_hash_use_index: bool,
+
+    /// This is the `debug_verify` parameter to use when calling `update_accounts_hash()`
+    pub accounts_hash_debug_verify: bool,
 }
 
 impl Default for SnapshotConfig {
@@ -46,6 +52,8 @@ impl Default for SnapshotConfig {
                 snapshot_utils::DEFAULT_MAX_FULL_SNAPSHOT_ARCHIVES_TO_RETAIN,
             maximum_incremental_snapshot_archives_to_retain:
                 snapshot_utils::DEFAULT_MAX_INCREMENTAL_SNAPSHOT_ARCHIVES_TO_RETAIN,
+            accounts_hash_use_index: false,
+            accounts_hash_debug_verify: false,
         }
     }
 }
diff --git a/validator/src/main.rs b/validator/src/main.rs
index c3849d688a..ae880f69f0 100644
--- a/validator/src/main.rs
+++ b/validator/src/main.rs
@@ -2751,6 +2751,8 @@ pub fn main() {
         snapshot_version,
         maximum_full_snapshot_archives_to_retain,
         maximum_incremental_snapshot_archives_to_retain,
+        accounts_hash_use_index: validator_config.accounts_db_use_index_hash_calculation,
+        accounts_hash_debug_verify: validator_config.accounts_db_test_hash_calculation,
     });
 
     validator_config.accounts_hash_interval_slots =