rocksdb/tools
Peter Dillinger 3b981eaa1d Fix use-after-free threading bug in ClockCache (#8261)
Summary:
In testing for https://github.com/facebook/rocksdb/issues/8225 I found cache_bench would crash with
-use_clock_cache, as well as db_bench -use_clock_cache, but not
single-threaded. Smaller cache size hits failure much faster. ASAN
reported the failuer as calling malloc_usable_size on the `key` pointer
of a ClockCache handle after it was reportedly freed. On detailed
inspection I found this bad sequence of operations for a cache entry:

state=InCache=1,refs=1
[thread 1] Start ClockCacheShard::Unref (from Release, no mutex)
[thread 1] Decrement ref count
state=InCache=1,refs=0
[thread 1] Suspend before CalcTotalCharge (no mutex)

[thread 2] Start UnsetInCache (from Insert, mutex held)
[thread 2] clear InCache bit
state=InCache=0,refs=0
[thread 2] Calls RecycleHandle (based on pre-updated state)
[thread 2] Returns to Insert which calls Cleanup which deletes `key`

[thread 1] Resume ClockCacheShard::Unref
[thread 1] Read `key` in CalcTotalCharge

To fix this, I've added a field to the handle to store the metadata
charge so that we can efficiently remember everything we need from
the handle in Unref. We must not read from the handle again if we
decrement the count to zero with InCache=1, which means we don't own
the entry and someone else could eject/overwrite it immediately.

Note before this change, on amd64 sizeof(Handle) == 56 even though there
are only 48 bytes of data. Grouping together the uint32_t fields would
cut it down to 48, but I've added another uint32_t, which takes it
back up to 56. Not a big deal.

Also fixed DisownData to cooperate with ASAN as in LRUCache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8261

Test Plan:
Manual + adding use_clock_cache to db_crashtest.py

Base performance
./cache_bench -use_clock_cache
Complete in 17.060 s; QPS = 2458513
New performance
./cache_bench -use_clock_cache
Complete in 17.052 s; QPS = 2459695

Any difference is easily buried in small noise.

Crash test shows still more bug(s) in ClockCache, so I'm expecting to
disable ClockCache from production code in a follow-up PR (if we
can't find and fix the bug(s))

Reviewed By: mrambacher

Differential Revision: D28207358

Pulled By: pdillinger

fbshipit-source-id: aa7a9322afc6f18f30e462c75dbbe4a1206eb294
2021-05-04 22:18:00 -07:00
..
advisor remediation of S205607 2020-07-17 17:20:49 -07:00
block_cache_analyzer Use SystemClock* instead of std::shared_ptr<SystemClock> in lower level routines (#8033) 2021-03-15 04:34:11 -07:00
dump Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
rdb Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
analyze_txn_stress_test.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
auto_sanity_test.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
backup_db.sh Revamp check_format_compatible.sh (#8012) 2021-03-02 11:42:27 -08:00
benchmark_leveldb.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
benchmark.sh Fixed typo in benchmark.sh (#6434) 2020-02-19 17:08:02 -08:00
blob_dump.cc Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
check_all_python.py Allow missing "unversioned" python, as in CentOS 8 (#6883) 2020-05-29 11:29:23 -07:00
check_format_compatible.sh Add 6.18, 6.19 and 6.20 to check_format_compatible.sh (#8236) 2021-04-27 10:24:27 -07:00
CMakeLists.txt Mark dependencies as PRIVATE and fix missing dependencies in tools. (#6790) 2020-05-12 21:07:55 -07:00
db_bench_tool_test.cc Add support for the integrated BlobDB to db_bench (#7956) 2021-02-17 11:10:18 -08:00
db_bench_tool.cc Hint temperature of bottommost level files to FileSystem (#8222) 2021-05-03 13:34:04 -07:00
db_bench.cc Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
db_crashtest.py Fix use-after-free threading bug in ClockCache (#8261) 2021-05-04 22:18:00 -07:00
db_repl_stress.cc Migrate away from Travis+Linux+amd64 (#7791) 2020-12-22 00:20:57 -08:00
db_sanity_test.cc Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
dbench_monitor Fix /bin/bash shebangs 2017-08-03 15:56:46 -07:00
Dockerfile adding docker build script and dockerfile 2015-05-22 16:03:39 -07:00
generate_random_db.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
ingest_external_sst.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
io_tracer_parser_test.cc Add request_id in IODebugContext. (#8045) 2021-04-01 13:14:51 -07:00
io_tracer_parser_tool.cc Add request_id in IODebugContext. (#8045) 2021-04-01 13:14:51 -07:00
io_tracer_parser_tool.h Add IO Tracer Parser (#7333) 2020-09-23 15:50:26 -07:00
io_tracer_parser.cc Add IO Tracer Parser (#7333) 2020-09-23 15:50:26 -07:00
ldb_cmd_impl.h Add support for custom file systems to ldb and sst_dump (#8010) 2021-03-09 20:49:15 -08:00
ldb_cmd_test.cc Extend file_checksum_dump ldb command and DB::GetLiveFilesChecksumInfo to blob files (#8179) 2021-04-15 09:38:13 -07:00
ldb_cmd.cc Check and handle failure in ldb (#8072) 2021-03-18 14:43:34 -07:00
ldb_test.py aggregated-table-properties with GetMapProperty (#7779) 2020-12-19 08:00:14 -08:00
ldb_tool.cc Add support for custom file systems to ldb and sst_dump (#8010) 2021-03-09 20:49:15 -08:00
ldb.cc Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
pflag Fix /bin/bash shebangs 2017-08-03 15:56:46 -07:00
reduce_levels_test.cc Add more tests for assert status checked (#7524) 2020-12-22 23:45:58 -08:00
regression_test.sh Update internal build script (#7957) 2021-02-11 14:55:43 -08:00
report_lite_binary_size.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
restore_db.sh Revamp check_format_compatible.sh (#8012) 2021-03-02 11:42:27 -08:00
rocksdb_dump_test.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
run_flash_bench.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
run_leveldb.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
sample-dump.dmp First version of rocksdb_dump and rocksdb_undump. 2015-06-19 16:24:36 -07:00
simulated_hybrid_file_system.cc Hint temperature of bottommost level files to FileSystem (#8222) 2021-05-03 13:34:04 -07:00
simulated_hybrid_file_system.h Hint temperature of bottommost level files to FileSystem (#8222) 2021-05-03 13:34:04 -07:00
sst_dump_test.cc Add more LSM info to FilterBuildingContext (#8246) 2021-04-30 13:50:13 -07:00
sst_dump_tool.cc Add support for custom file systems to ldb and sst_dump (#8010) 2021-03-09 20:49:15 -08:00
sst_dump.cc Implement a new subcommand "identify" for sst_dump (#6943) 2020-06-08 13:58:28 -07:00
trace_analyzer_test.cc Refactor: add LineFileReader and Status::MustCheck (#8026) 2021-03-09 20:12:38 -08:00
trace_analyzer_tool.cc Refactor: add LineFileReader and Status::MustCheck (#8026) 2021-03-09 20:12:38 -08:00
trace_analyzer_tool.h Introduce a new trace file format (v 0.2) for better extension (#7977) 2021-02-18 23:05:35 -08:00
trace_analyzer.cc Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433) 2020-02-20 12:09:57 -08:00
verify_random_db.sh Add copyright headers per FB open-source checkup tool. (#5199) 2019-04-18 10:55:01 -07:00
write_external_sst.sh Revamp check_format_compatible.sh (#8012) 2021-03-02 11:42:27 -08:00
write_stress_runner.py Allow missing "unversioned" python, as in CentOS 8 (#6883) 2020-05-29 11:29:23 -07:00
write_stress.cc Add a SystemClock class to capture the time functions of an Env (#7858) 2021-01-25 22:09:11 -08:00