From 255aefb6287031af678ee2539cf6289dea3b7942 Mon Sep 17 00:00:00 2001
From: jsteemann <jsteemann@users.noreply.github.com>
Date: Fri, 7 Jan 2022 18:08:50 -0800
Subject: [PATCH] Add filename to several Corruption messages (#9239)

Summary:
This change adds the filename of the offending filen to several place that produce Status objects with code `kCorruption`.
This is not an attempt to have every Corruption message in the codebase extended with the filename, but it is a start.
The motivation for the change was to quickly diagnose which file is corrupted when a large database is openend and there is not option to copy it offsite for analysis, run strace or install the ldb tool.
In the particular case in question, the error message improved from a mere
```
Corruption: checksum mismatch
```
to
```
Corruption: checksum mismatch in file /path/to/db/engine-rocksdb/MANIFEST-000171
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9239

Reviewed By: jay-zhuang

Differential Revision: D33237742

Pulled By: riversand963

fbshipit-source-id: bd42559cfbf786a0a674d091671d1a2bf07bdd31
---
 db/version_edit_handler.cc | 21 +++++++++++++++++++++
 db/version_set_test.cc     |  4 ++++
 2 files changed, 25 insertions(+)

diff --git a/db/version_edit_handler.cc b/db/version_edit_handler.cc
index c944a46ca..3fc25a010 100644
--- a/db/version_edit_handler.cc
+++ b/db/version_edit_handler.cc
@@ -10,6 +10,7 @@
 #include "db/version_edit_handler.h"
 
 #include <cinttypes>
+#include <sstream>
 
 #include "db/blob/blob_file_cache.h"
 #include "db/blob/blob_file_reader.h"
@@ -68,6 +69,26 @@ void VersionEditHandlerBase::Iterate(log::Reader& reader,
   CheckIterationResult(reader, &s);
 
   if (!s.ok()) {
+    if (s.IsCorruption()) {
+      // when we find a Corruption error, something is
+      // wrong with the underlying file. in this case we
+      // want to report the filename, so in here we append
+      // the filename to the Corruption message
+      assert(reader.file());
+
+      // build a new error message
+      std::stringstream message;
+      // append previous dynamic state message
+      const char* state = s.getState();
+      if (state != nullptr) {
+        message << state;
+        message << ' ';
+      }
+      // append the filename to the corruption message
+      message << "in file " << reader.file()->file_name();
+      // overwrite the status with the extended status
+      s = Status(s.code(), s.subcode(), s.severity(), message.str());
+    }
     status_ = s;
   }
   TEST_SYNC_POINT_CALLBACK("VersionEditHandlerBase::Iterate:Finish",
diff --git a/db/version_set_test.cc b/db/version_set_test.cc
index 9f5bd272e..bb3df039b 100644
--- a/db/version_set_test.cc
+++ b/db/version_set_test.cc
@@ -2629,6 +2629,7 @@ TEST_P(VersionSetTestEmptyDb, OpenFromIncompleteManifest0) {
   if (iter == cf_names.end()) {
     ASSERT_TRUE(s.IsInvalidArgument());
   } else {
+    ASSERT_NE(s.ToString().find(manifest_path), std::string::npos);
     ASSERT_TRUE(s.IsCorruption());
   }
 }
@@ -2670,6 +2671,7 @@ TEST_P(VersionSetTestEmptyDb, OpenFromIncompleteManifest1) {
   if (iter == cf_names.end()) {
     ASSERT_TRUE(s.IsInvalidArgument());
   } else {
+    ASSERT_NE(s.ToString().find(manifest_path), std::string::npos);
     ASSERT_TRUE(s.IsCorruption());
   }
 }
@@ -2716,6 +2718,7 @@ TEST_P(VersionSetTestEmptyDb, OpenFromInCompleteManifest2) {
   if (iter == cf_names.end()) {
     ASSERT_TRUE(s.IsInvalidArgument());
   } else {
+    ASSERT_NE(s.ToString().find(manifest_path), std::string::npos);
     ASSERT_TRUE(s.IsCorruption());
   }
 }
@@ -2773,6 +2776,7 @@ TEST_P(VersionSetTestEmptyDb, OpenManifestWithUnknownCF) {
   if (iter == cf_names.end()) {
     ASSERT_TRUE(s.IsInvalidArgument());
   } else {
+    ASSERT_NE(s.ToString().find(manifest_path), std::string::npos);
     ASSERT_TRUE(s.IsCorruption());
   }
 }