From 84c5c9aab15896e1c55c3febfa1fac5ed2009069 Mon Sep 17 00:00:00 2001 From: Sagar Vemuri Date: Wed, 3 Jul 2019 18:36:08 -0700 Subject: [PATCH] Fix a bug in compaction reads causing checksum mismatches and asan errors (#5531) Summary: Fixed a bug in compaction reads due to which incorrect number of bytes were being read/utilized. The bug was introduced in https://github.com/facebook/rocksdb/issues/5498 , resulting in "Corruption: block checksum mismatch" and "heap-buffer-overflow" asan errors in our tests. https://github.com/facebook/rocksdb/issues/5498 was introduced recently and is not in any released versions. ASAN: ``` > ==2280939==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6250005e83da at pc 0x000000d57f62 bp 0x7f954f483770 sp 0x7f954f482f20 > === How to use this, how to get the raw stack trace, and more: fburl.com/ASAN === > READ of size 4 at 0x6250005e83da thread T4 > SCARINESS: 27 (4-byte-read-heap-buffer-overflow-far-from-bounds) > #0 tests+0xd57f61 __asan_memcpy > https://github.com/facebook/rocksdb/issues/1 rocksdb/src/util/coding.h:124 rocksdb::DecodeFixed32(char const*) > https://github.com/facebook/rocksdb/issues/2 rocksdb/src/table/block_fetcher.cc:39 rocksdb::BlockFetcher::CheckBlockChecksum() > https://github.com/facebook/rocksdb/issues/3 rocksdb/src/table/block_fetcher.cc:99 rocksdb::BlockFetcher::TryGetFromPrefetchBuffer() > https://github.com/facebook/rocksdb/issues/4 rocksdb/src/table/block_fetcher.cc:209 rocksdb::BlockFetcher::ReadBlockContents() > https://github.com/facebook/rocksdb/issues/5 rocksdb/src/table/block_based/block_based_table_reader.cc:93 rocksdb::(anonymous namespace)::ReadBlockFromFile(rocksdb::RandomAccessFileReader*, rocksdb::FilePrefetchBuffer*, rocksdb::Footer const&, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, std::unique_ptr<...>*, rocksdb::ImmutableCFOptions const&, bool, bool, rocksdb::UncompressionDict const&, rocksdb::PersistentCacheOptions const&, unsigned long, unsigned long, rocksdb::MemoryAllocator*, bool) > https://github.com/facebook/rocksdb/issues/6 rocksdb/src/table/block_based/block_based_table_reader.cc:2331 rocksdb::BlockBasedTable::RetrieveBlock(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, rocksdb::CachableEntry<...>*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, bool) const > https://github.com/facebook/rocksdb/issues/7 rocksdb/src/table/block_based/block_based_table_reader.cc:2090 rocksdb::DataBlockIter* rocksdb::BlockBasedTable::NewDataBlockIterator<...>(rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::DataBlockIter*, rocksdb::BlockType, bool, bool, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::Status, rocksdb::FilePrefetchBuffe r*, bool) const > https://github.com/facebook/rocksdb/issues/8 rocksdb/src/table/block_based/block_based_table_reader.cc:2720 rocksdb::BlockBasedTableIterator<...>::InitDataBlock() > https://github.com/facebook/rocksdb/issues/9 rocksdb/src/table/block_based/block_based_table_reader.cc:2607 rocksdb::BlockBasedTableIterator<...>::SeekToFirst() > https://github.com/facebook/rocksdb/issues/10 rocksdb/src/table/iterator_wrapper.h:83 rocksdb::IteratorWrapperBase<...>::SeekToFirst() > https://github.com/facebook/rocksdb/issues/11 rocksdb/src/table/merging_iterator.cc:100 rocksdb::MergingIterator::SeekToFirst() > https://github.com/facebook/rocksdb/issues/12 rocksdb/compaction/compaction_job.cc:877 rocksdb::CompactionJob::ProcessKeyValueCompaction(rocksdb::CompactionJob::SubcompactionState*) > https://github.com/facebook/rocksdb/issues/13 rocksdb/compaction/compaction_job.cc:590 rocksdb::CompactionJob::Run() > https://github.com/facebook/rocksdb/issues/14 rocksdb/db_impl/db_impl_compaction_flush.cc:2689 rocksdb::DBImpl::BackgroundCompaction(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) > https://github.com/facebook/rocksdb/issues/15 rocksdb/db_impl/db_impl_compaction_flush.cc:2248 rocksdb::DBImpl::BackgroundCallCompaction(rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) > https://github.com/facebook/rocksdb/issues/16 rocksdb/db_impl/db_impl_compaction_flush.cc:2024 rocksdb::DBImpl::BGWorkCompaction(void*) > https://github.com/facebook/rocksdb/issues/23 rocksdb/src/util/threadpool_imp.cc:266 rocksdb::ThreadPoolImpl::Impl::BGThread(unsigned long) > https://github.com/facebook/rocksdb/issues/24 rocksdb/src/util/threadpool_imp.cc:307 rocksdb::ThreadPoolImpl::Impl::BGThreadWrapper(void*) ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/5531 Test Plan: Verified that this fixes the fb-internal Logdevice test which caught the issue. Differential Revision: D16109702 Pulled By: sagar0 fbshipit-source-id: 1fc08549cf7b553e338a133ae11eb9f4d5011914 --- util/file_reader_writer.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/util/file_reader_writer.cc b/util/file_reader_writer.cc index f49866d13..db16e82ae 100644 --- a/util/file_reader_writer.cc +++ b/util/file_reader_writer.cc @@ -842,7 +842,7 @@ bool FilePrefetchBuffer::TryReadFromCache(uint64_t offset, size_t n, assert(max_readahead_size_ >= readahead_size_); Status s; if (for_compaction) { - s = Prefetch(file_reader_, offset, readahead_size_, for_compaction); + s = Prefetch(file_reader_, offset, std::max(n, readahead_size_), for_compaction); } else { s = Prefetch(file_reader_, offset, n + readahead_size_, for_compaction); }