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1562524e63
Summary: Fix db_stress failure in async_io in FilePrefetchBuffer. From the logs, assertion was caused when - prev_offset_ = offset but somehow prev_len != 0 and explicit_prefetch_submitted_ = true. That scenario is when we send async request to prefetch buffer during seek but in second seek that data is found in cache. prev_offset_ and prev_len_ get updated but we were not setting explicit_prefetch_submitted_ = false because of which buffers were getting out of sync. It's possible a read by another thread might have loaded the block into the cache in the meantime. Particular assertion example: ``` prev_offset: 0, prev_len_: 8097 , offset: 0, length: 8097, actual_length: 8097 , actual_offset: 0 , curr_: 0, bufs_[curr_].offset_: 4096 ,bufs_[curr_].CurrentSize(): 48541 , async_len_to_read: 278528, bufs_[curr_].async_in_progress_: false second: 1, bufs_[second].offset_: 282624 ,bufs_[second].CurrentSize(): 0, async_len_to_read: 262144 ,bufs_[second].async_in_progress_: true , explicit_prefetch_submitted_: true , copy_to_third_buffer: false ``` As we can see curr_ was expected to read 278528 but it read 48541. Also buffers are out of sync. Also `explicit_prefetch_submitted_` is set true but prev_len not 0. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10949 Test Plan: - Ran db_bench for regression to make sure there is no regression; - Ran db_stress failing without this fix, - Ran build-linux-mini-crashtest 7- 8 times locally + CircleCI Reviewed By: anand1976 Differential Revision: D41257786 Pulled By: akankshamahajan15 fbshipit-source-id: 1d100f94f8c06bbbe4cc76ca27f1bbc820c2494f |
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| .. | ||
| delete_scheduler.cc | ||
| delete_scheduler.h | ||
| delete_scheduler_test.cc | ||
| file_prefetch_buffer.cc | ||
| file_prefetch_buffer.h | ||
| file_util.cc | ||
| file_util.h | ||
| filename.cc | ||
| filename.h | ||
| line_file_reader.cc | ||
| line_file_reader.h | ||
| prefetch_test.cc | ||
| random_access_file_reader.cc | ||
| random_access_file_reader.h | ||
| random_access_file_reader_test.cc | ||
| read_write_util.cc | ||
| read_write_util.h | ||
| readahead_file_info.h | ||
| readahead_raf.cc | ||
| readahead_raf.h | ||
| sequence_file_reader.cc | ||
| sequence_file_reader.h | ||
| sst_file_manager_impl.cc | ||
| sst_file_manager_impl.h | ||
| writable_file_writer.cc | ||
| writable_file_writer.h | ||