Fix segfault in Iterator::Refresh() #10739
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LGTM. Thanks @cbi42 for the fix.
Maybe note that in order to reproduce, ASAN build is needed?
Thanks for the review. ASAN build is not needed for repro since it was a double free bug. |
Oh, I thought some allocators may not necessarily fail, but never mind. :) |
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@cbi42 has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
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@cbi42 has updated the pull request. You must reimport the pull request before landing. |
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@cbi42 has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
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@cbi42 has updated the pull request. You must reimport the pull request before landing. |
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@cbi42 has updated the pull request. You must reimport the pull request before landing. |
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@cbi42 has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
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@cbi42 has updated the pull request. You must reimport the pull request before landing. |
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@cbi42 has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
Summary: when a new internal iterator is constructed during iterator refresh, pointer to the previous memtable range tombstone iterator was not cleared. This could cause segfault for future `Refresh()` calls when they try to free the memtable range tombstones. This PR fixes this issue. Pull Request resolved: #10739 Test Plan: added a unit test in db_range_del_test.cc to reproduce this issue. Reviewed By: ajkr, riversand963 Differential Revision: D39825283 Pulled By: cbi42 fbshipit-source-id: 3b59a2b73865aed39e28cdd5c1b57eed7991b94c
Summary: added calls to `Iterator::Refresh()` in `NonBatchedOpsStressTest::TestIterateAgainstExpected()`. The testing key range is locked in `TestIterateAgainstExpected` so I do not expect this change to provide thorough stress test to `Iterator::Refresh()`. However, it can still be helpful for catching bugs like #10739. Will add calls to refresh in `TestIterate` once we support iterator refresh with snapshots. Pull Request resolved: #10766 Test Plan: `python3 tools/db_crashtest.py whitebox --simple --verify_iterator_with_expected_state_one_in=2` Reviewed By: ajkr Differential Revision: D40008320 Pulled By: ajkr fbshipit-source-id: cec93b07f915ef6476d41c1fee9b23c115188085
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Hi @ajkr @riversand963 , does this PR can be cherry-picked to branch 6.29.fb? |
The bug this PR fixed was introduced in 7.7, it may not apply to 6.29.fb. |
Summary: when a new internal iterator is constructed during iterator refresh, pointer to the previous memtable range tombstone iterator was not cleared. This could cause segfault for future
Refresh()calls when they try to free the memtable range tombstones. This PR fixes this issue.Test plan: added a unit test in db_range_del_test.cc to reproduce this issue.