From 935e06f8f1c0ecb638cf88e1f6285a1bc6055343 Mon Sep 17 00:00:00 2001
From: steviez <steven@solana.com>
Date: Wed, 29 Nov 2023 17:20:27 -0600
Subject: [PATCH] Output BankHashDetails file when leader drops its' own block
 (#34256)

Currently, the file is generated when a node drops a block that was
produced by another node. However, it would also be beneficial to see
the account state when a node drops its' own block.

Output the file in this additional failure codepath
---
 core/src/replay_stage.rs              | 26 +++++++++++++++++++-------
 ledger-tool/src/main.rs               |  6 +++++-
 runtime/src/bank/bank_hash_details.rs | 10 +++-------
 3 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/core/src/replay_stage.rs b/core/src/replay_stage.rs
index 4c546307e..fbf97d13e 100644
--- a/core/src/replay_stage.rs
+++ b/core/src/replay_stage.rs
@@ -1349,14 +1349,22 @@ impl ReplayStage {
                         );
                     }
 
-
                     // Should not dump slots for which we were the leader
                     if Some(*my_pubkey) == leader_schedule_cache.slot_leader_at(*duplicate_slot, None) {
-                            panic!("We are attempting to dump a block that we produced. \
-                                This indicates that we are producing duplicate blocks, \
-                                or that there is a bug in our runtime/replay code which \
-                                causes us to compute different bank hashes than the rest of the cluster. \
-                                We froze slot {duplicate_slot} with hash {frozen_hash:?} while the cluster hash is {correct_hash}");
+                        if let Some(bank) = bank_forks.read().unwrap().get(*duplicate_slot) {
+                            bank_hash_details::write_bank_hash_details_file(&bank)
+                                .map_err(|err| {
+                                    warn!("Unable to write bank hash details file: {err}");
+                                })
+                                .ok();
+                        } else {
+                            warn!("Unable to get bank for slot {duplicate_slot} from bank forks");
+                        }
+                        panic!("We are attempting to dump a block that we produced. \
+                            This indicates that we are producing duplicate blocks, \
+                            or that there is a bug in our runtime/replay code which \
+                            causes us to compute different bank hashes than the rest of the cluster. \
+                            We froze slot {duplicate_slot} with hash {frozen_hash:?} while the cluster hash is {correct_hash}");
                     }
 
                     let attempt_no = purge_repair_slot_counter
@@ -1507,7 +1515,11 @@ impl ReplayStage {
                     let bank = w_bank_forks
                         .remove(*slot)
                         .expect("BankForks should not have been purged yet");
-                    let _ = bank_hash_details::write_bank_hash_details_file(&bank);
+                    bank_hash_details::write_bank_hash_details_file(&bank)
+                        .map_err(|err| {
+                            warn!("Unable to write bank hash details file: {err}");
+                        })
+                        .ok();
                     ((*slot, bank.bank_id()), bank)
                 })
                 .unzip()
diff --git a/ledger-tool/src/main.rs b/ledger-tool/src/main.rs
index 3cd4153bd..053656990 100644
--- a/ledger-tool/src/main.rs
+++ b/ledger-tool/src/main.rs
@@ -2695,7 +2695,11 @@ fn main() {
                 }
                 if write_bank_file {
                     let working_bank = bank_forks.read().unwrap().working_bank();
-                    let _ = bank_hash_details::write_bank_hash_details_file(&working_bank);
+                    bank_hash_details::write_bank_hash_details_file(&working_bank)
+                        .map_err(|err| {
+                            warn!("Unable to write bank hash_details file: {err}");
+                        })
+                        .ok();
                 }
                 exit_signal.store(true, Ordering::Relaxed);
                 system_monitor_service.join().unwrap();
diff --git a/runtime/src/bank/bank_hash_details.rs b/runtime/src/bank/bank_hash_details.rs
index a1b4fa74f..6b40e7aef 100644
--- a/runtime/src/bank/bank_hash_details.rs
+++ b/runtime/src/bank/bank_hash_details.rs
@@ -216,14 +216,10 @@ pub fn write_bank_hash_details_file(bank: &Bank) -> std::result::Result<(), Stri
         // path does not exist. So, call std::fs_create_dir_all first.
         // https://doc.rust-lang.org/std/fs/fn.write.html
         _ = std::fs::create_dir_all(parent_dir);
-        let file = std::fs::File::create(&path).map_err(|err| {
-            format!(
-                "Unable to create bank hash file at {}: {err}",
-                path.display()
-            )
-        })?;
+        let file = std::fs::File::create(&path)
+            .map_err(|err| format!("Unable to create file at {}: {err}", path.display()))?;
         serde_json::to_writer_pretty(file, &details)
-            .map_err(|err| format!("Unable to write bank hash file contents: {err}"))?;
+            .map_err(|err| format!("Unable to write file at {}: {err}", path.display()))?;
     }
     Ok(())
 }