SERVER-54922 Fix broken promises resulting from concurrency issue in BucketCatalog::clear

2 files changed, 19 insertions, 8 deletions

diff --git a/src/mongo/db/timeseries/bucket_catalog.cpp b/src/mongo/db/timeseries/bucket_catalog.cpp
index 06a9c71985d..b5b01b68631 100644
--- a/src/mongo/db/timeseries/bucket_catalog.cpp
+++ b/src/mongo/db/timeseries/bucket_catalog.cpp
@@ -320,17 +320,23 @@ void BucketCatalog::clear(const BucketId& bucketId) {
         return;
     }
 
-    while (!bucket->promises.empty()) {
-        if (auto& promise = bucket->promises.front()) {
-            promise->setError({ErrorCodes::TimeseriesBucketCleared,
-                               str::stream() << "Time-series bucket " << *bucketId << " for "
-                                             << bucket->ns << " was cleared"});
+    // Retain pointer to bucket, release so we can get an exclusive lock.
+    std::shared_ptr<Bucket> underlyingBucket{bucket};
+    bucket.release();
+    auto lk = _lockExclusive();
+
+    {
+        stdx::lock_guard blk{underlyingBucket->lock};
+        while (!underlyingBucket->promises.empty()) {
+            if (auto& promise = underlyingBucket->promises.front()) {
+                promise->setError({ErrorCodes::TimeseriesBucketCleared,
+                                   str::stream() << "Time-series bucket " << *bucketId << " for "
+                                                 << underlyingBucket->ns << " was cleared"});
+            }
+            underlyingBucket->promises.pop();
         }
-        bucket->promises.pop();
     }
 
-    bucket.release();
-    auto lk = _lockExclusive();
     _removeBucket(bucketId);
 }
 
@@ -652,6 +658,10 @@ BucketCatalog::BucketAccess::operator bool() const {
     return isLocked();
 }
 
+BucketCatalog::BucketAccess::operator std::shared_ptr<BucketCatalog::Bucket>() const {
+    return _bucket;
+}
+
 void BucketCatalog::BucketAccess::rollover(const std::function<bool(BucketAccess*)>& isBucketFull) {
     invariant(isLocked());
     invariant(_key);
diff --git a/src/mongo/db/timeseries/bucket_catalog.h b/src/mongo/db/timeseries/bucket_catalog.h
index ad7e5740d48..66f8d493cc8 100644
--- a/src/mongo/db/timeseries/bucket_catalog.h
+++ b/src/mongo/db/timeseries/bucket_catalog.h
@@ -388,6 +388,7 @@ private:
         bool isLocked() const;
         Bucket* operator->();
         operator bool() const;
+        operator std::shared_ptr<Bucket>() const;
 
         // Release the bucket lock, typically in order to reacquire the catalog lock.
         void release();