Fix race condition in SstFileManagerImpl error recovery code #9435
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Summary: There is a race in SstFileManagerImpl between the ClearError() function and CancelErrorRecovery(). The race can cause ClearError() to deref the file system pointer after it has been freed. This is likely to occur during process shutdown, when the order of destruction of the DB/Env/FileSystem and SstFileManagerImpl is not deterministic. Test Plan: Reproduce the crash in a TSAN build by introducing sleeps in the code, and verify with the fix. Reviewers: Subscribers: Tasks: Tags:
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@anand1976 has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
siying
approved these changes
Jan 25, 2022
| @@ -256,7 +256,7 @@ void SstFileManagerImpl::ClearError() { | |||
| while (true) { | |||
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If this can be reproduced, we can try to add a unit test with a sync point here to reproduce this sequence.
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Hmm... this is hard since this happens in test cleaning up phase. If it is too hard, then forget about it. We can have it here and see whether the test failure still h appends in the future.
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Yeah, I couldn't figure out a repro using sync points. Ended up with sleeps in the SstFileManagerImpl destructor and ClearError to repro.
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Summary:
There is a race in SstFileManagerImpl between the ClearError() function
and CancelErrorRecovery(). The race can cause ClearError() to deref the
file system pointer after it has been freed. This is likely to occur
during process shutdown, when the order of destruction of the
DB/Env/FileSystem and SstFileManagerImpl is not deterministic.
Test Plan:
Reproduce the crash in a TSAN build by introducing sleeps in the code, and verify with
the fix.