SERVER-37796 Always salvage WiredTiger metadata regardless of error code when starting with repair

(cherry picked from commit c7553b861796c1581c85b3cbc4e55dcc9666aa0f)
(cherry picked from commit eae0b57705a7b18362b7028c6fcb7c2469043ef4)
(cherry picked from commit 13950ba0c4dfe22de28d1a7ec724d102ad69b949)

2 files changed, 53 insertions, 14 deletions

diff --git a/jstests/disk/wt_repair_corrupt_metadata.js b/jstests/disk/wt_repair_corrupt_metadata.js
index 16c12ac9bd7..a8240e97fe0 100644
--- a/jstests/disk/wt_repair_corrupt_metadata.js
+++ b/jstests/disk/wt_repair_corrupt_metadata.js
@@ -26,7 +26,8 @@
         // Unfortunately using --nojournal triggers a WT_PANIC and aborts in debug builds, which the
         // following test case can exercise.
         // TODO: This return can be removed once WT-4310 is completed.
-        if (db.adminCommand('buildInfo').debug && mongodOptions.hasOwnProperty('nojournal')) {
+        let isDebug = db.adminCommand('buildInfo').debug;
+        if (isDebug && mongodOptions.hasOwnProperty('nojournal')) {
             jsTestLog(
                 "Skipping test case because this is a debug build and --nojournal was provided.");
             return;
@@ -65,13 +66,47 @@
         mongod = startMongodOnExistingPath(dbpath, mongodOptions);
         testColl = mongod.getDB(baseName)[collName];
 
-        // The collection exists depite using an older turtle file because salvage is able to find
+        // The collection exists despite using an older turtle file because salvage is able to find
         // the table in the WiredTiger.wt file.
         assert(testColl.exists());
         // We can assert that the data exists because the salvage only took place on the metadata,
         // not the data.
         assert.eq(testColl.find({}).itcount(), 1);
         MongoRunner.stopMongod(mongod);
+
+        // Corrupt the .turtle file in a very specific way such that the log sequence numbers are
+        // invalid.
+        if (mongodOptions.hasOwnProperty('journal')) {
+            // TODO: This return can be removed once WT-4459 is completed.
+            if (_isAddressSanitizerActive()) {
+                jsTestLog("Skipping log file corruption because the address sanitizer is active.");
+                return;
+            }
+
+            jsTestLog("Corrupting log file metadata");
+
+            let data = cat(turtleFile, true /* useBinaryMode */);
+            let re = /checkpoint_lsn=\(([0-9,]+)\)/g;
+            let newData = data.replace(re, "checkpoint_lsn=(1,2)");
+
+            print('writing data to new turtle file: \n' + newData);
+            removeFile(turtleFile);
+            writeFile(turtleFile, newData, true /* useBinaryMode */);
+
+            assertRepairSucceeds(dbpath, mongod.port, mongodOptions);
+
+            mongod = startMongodOnExistingPath(dbpath, mongodOptions);
+            testColl = mongod.getDB(baseName)[collName];
+
+            // The collection exists despite using a salvaged turtle file because salvage is able to
+            // find the table in the WiredTiger.wt file.
+            assert(testColl.exists());
+
+            // We can assert that the data exists because the salvage only took place on the
+            // metadata, not the data.
+            assert.eq(testColl.find({}).itcount(), 1);
+            MongoRunner.stopMongod(mongod);
+        }
     };
 
     // Repair may behave differently with journaling enabled or disabled, but the end result should
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp
index edf280200c0..fbd5f6ad3fe 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp
@@ -631,22 +631,26 @@ void WiredTigerKVEngine::_openWiredTiger(const std::string& path, const std::str
             severe() << kWTRepairMsg;
             fassertFailedNoTrace(50944);
         }
+    }
 
-        warning() << "Attempting to salvage WiredTiger metadata";
-        configStr = wtOpenConfig + ",salvage=true";
-        ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn);
-        if (!ret) {
-            StorageRepairObserver::get(getGlobalServiceContext())
-                ->onModification("WiredTiger metadata salvaged");
-            return;
-        }
+    severe() << "Reason: " << wtRCToStatus(ret).reason();
+    if (!_inRepairMode) {
+        fassertFailedNoTrace(28595);
+    }
 
-        severe() << "Failed to salvage WiredTiger metadata: " + wtRCToStatus(ret).reason();
-        fassertFailedNoTrace(50947);
+    // Always attempt to salvage metadata regardless of error code when in repair mode.
+
+    warning() << "Attempting to salvage WiredTiger metadata";
+    configStr = wtOpenConfig + ",salvage=true";
+    ret = wiredtiger_open(path.c_str(), wtEventHandler, configStr.c_str(), &_conn);
+    if (!ret) {
+        StorageRepairObserver::get(getGlobalServiceContext())
+            ->onModification("WiredTiger metadata salvaged");
+        return;
     }
 
-    severe() << "Reason: " << wtRCToStatus(ret).reason();
-    fassertFailedNoTrace(28595);
+    severe() << "Failed to salvage WiredTiger metadata: " + wtRCToStatus(ret).reason();
+    fassertFailedNoTrace(50947);
 }
 
 void WiredTigerKVEngine::cleanShutdown() {