HISTORY.md

 # Rocksdb Change Log
 > NOTE: Entries for next release do not go here. Follow instructions in `unreleased_history/README.txt`
 
+## 8.4.4 (09/01/2023)
+### Bug Fixes
+* Fix a bug where if there is an error reading from offset 0 of a file from L1+ and that the file is not the first file in the sorted run, data can be lost in compaction and read/scan can return incorrect results.
+* Fix a bug where iterator may return incorrect result for DeleteRange() users if there was an error reading from a file.
+* Fixed a race condition in `GenericRateLimiter` that could cause it to stop granting requests
+
 ## 8.4.3 (07/27/2023)
 ### Bug Fixes
 * Fix use_after_free bug in async_io MultiReads when underlying FS enabled kFSBuffer. kFSBuffer is when underlying FS pass their own buffer instead of using RocksDB scratch in FSReadRequest.

include/rocksdb/version.h

@@ -13,7 +13,7 @@
 // minor or major version number planned for release.
 #define ROCKSDB_MAJOR 8
 #define ROCKSDB_MINOR 4
-#define ROCKSDB_PATCH 3
+#define ROCKSDB_PATCH 4
 
 // Do not use these. We made the mistake of declaring macros starting with
 // double underscore. Now we have to live with our choice. We'll deprecate these

table/compaction_merging_iterator.cc

@@ -329,6 +329,7 @@ void CompactionMergingIterator::FindNextVisibleKey() {
       assert(current->iter.status().ok());
       minHeap_.replace_top(current);
     } else {
+      considerStatus(current->iter.status());
       minHeap_.pop();
     }
     if (range_tombstone_iters_[current->level]) {

table/merging_iterator.cc

@@ -308,6 +308,7 @@ class MergingIterator : public InternalIterator {
     // holds after this call, and minHeap_.top().iter points to the
     // first key >= target among children_ that is not covered by any range
     // tombstone.
+    status_ = Status::OK();
     SeekImpl(target);
     FindNextVisibleKey();
 
@@ -321,6 +322,7 @@ class MergingIterator : public InternalIterator {
   void SeekForPrev(const Slice& target) override {
     assert(range_tombstone_iters_.empty() ||
            range_tombstone_iters_.size() == children_.size());
+    status_ = Status::OK();
     SeekForPrevImpl(target);
     FindPrevVisibleKey();
 
@@ -798,7 +800,6 @@ void MergingIterator::SeekImpl(const Slice& target, size_t starting_level,
     active_.erase(active_.lower_bound(starting_level), active_.end());
   }
 
-  status_ = Status::OK();
   IterKey current_search_key;
   current_search_key.SetInternalKey(target, false /* copy */);
   // Seek target might change to some range tombstone end key, so
@@ -931,6 +932,7 @@ bool MergingIterator::SkipNextDeleted() {
       InsertRangeTombstoneToMinHeap(current->level, true /* start_key */,
                                     true /* replace_top */);
     } else {
+      // TruncatedRangeDelIterator does not have status
       minHeap_.pop();
     }
     return true /* current key deleted */;
@@ -988,6 +990,9 @@ bool MergingIterator::SkipNextDeleted() {
     if (current->iter.Valid()) {
       assert(current->iter.status().ok());
       minHeap_.push(current);
+    } else {
+      // TODO(cbi): check status and early return if non-ok.
+      considerStatus(current->iter.status());
     }
     // Invariants (rti) and (phi)
     if (range_tombstone_iters_[current->level] &&
@@ -1027,6 +1032,7 @@ bool MergingIterator::SkipNextDeleted() {
         if (current->iter.Valid()) {
           minHeap_.replace_top(current);
         } else {
+          considerStatus(current->iter.status());
           minHeap_.pop();
         }
         return true /* current key deleted */;
@@ -1078,7 +1084,6 @@ void MergingIterator::SeekForPrevImpl(const Slice& target,
     active_.erase(active_.lower_bound(starting_level), active_.end());
   }
 
-  status_ = Status::OK();
   IterKey current_search_key;
   current_search_key.SetInternalKey(target, false /* copy */);
   // Seek target might change to some range tombstone end key, so
@@ -1199,6 +1204,8 @@ bool MergingIterator::SkipPrevDeleted() {
     if (current->iter.Valid()) {
       assert(current->iter.status().ok());
       maxHeap_->push(current);
+    } else {
+      considerStatus(current->iter.status());
     }
 
     if (range_tombstone_iters_[current->level] &&
@@ -1241,6 +1248,7 @@ bool MergingIterator::SkipPrevDeleted() {
         if (current->iter.Valid()) {
           maxHeap_->replace_top(current);
         } else {
+          considerStatus(current->iter.status());
           maxHeap_->pop();
         }
         return true /* current key deleted */;

util/rate_limiter.cc

@@ -179,16 +179,16 @@ void GenericRateLimiter::Request(int64_t bytes, const Env::IOPriority pri,
       // Whichever thread reaches here first performs duty (2) as described
       // above.
       RefillBytesAndGrantRequestsLocked();
-      if (r.request_bytes == 0) {
-        // If there is any remaining requests, make sure there exists at least
-        // one candidate is awake for future duties by signaling a front request
-        // of a queue.
-        for (int i = Env::IO_TOTAL - 1; i >= Env::IO_LOW; --i) {
-          std::deque<Req*> queue = queue_[i];
-          if (!queue.empty()) {
-            queue.front()->cv.Signal();
-            break;
-          }
+    }
+    if (r.request_bytes == 0) {
+      // If there is any remaining requests, make sure there exists at least
+      // one candidate is awake for future duties by signaling a front request
+      // of a queue.
+      for (int i = Env::IO_TOTAL - 1; i >= Env::IO_LOW; --i) {
+        auto& queue = queue_[i];
+        if (!queue.empty()) {
+          queue.front()->cv.Signal();
+          break;
         }
       }
     }