Fix read-only open during checkpoint from reading inconsistent state#615
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ericyuanhui wants to merge 1 commit into
Open
Fix read-only open during checkpoint from reading inconsistent state#615ericyuanhui wants to merge 1 commit into
ericyuanhui wants to merge 1 commit into
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Signed-off-by: ericyuanhui <285521263@qq.com>
adsharma
reviewed
Jun 24, 2026
| tableEpochWatermarksByManager; | ||
| std::unordered_map<catalog::Catalog*, uint64_t> catalogVersionAtCheckpointByCatalog; | ||
| std::unordered_map<StorageManager*, uint64_t> pageManagerVersionAtCheckpointByManager; | ||
| std::unique_ptr<common::FileInfo> checkpointIntentLockFile; |
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Could you describe the thought process here? Why not lock the main database file instead of creating new intent/apply files?
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|
Note that DuckDB and SQLite take different approaches here: https://claude.ai/share/9ce5d5a8-bf34-46cb-87e7-9f1636491c4f |
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Summary
This change fixes a bug where opening the database in read-only mode could race with an in-progress checkpoint and end up reading inconsistent on-disk state. In that situation, recovery could observe intermediate checkpoint artifacts and continue loading from partially updated metadata, which could lead to crashes such as segmentation faults.
To address that, the fix makes checkpoint progress explicit and blocks read-only recovery from entering that unsafe window. It adds coordination around checkpoint execution so read-only opens can detect that a checkpoint is underway and fail fast instead of trying to recover from an intermediate state. It also adds defensive validation when reading checkpoint metadata so invalid or out-of-range page information is rejected with a controlled error rather than being used blindly. In addition, it cleans up a related resource-handling issue in file locking so failed lock attempts do not leak OS handles.
In short, the change turns a potentially unsafe concurrent recovery path into a safe, well-defined failure mode, and adds extra validation to prevent corrupted or partial checkpoint state from causing low-level crashes.
What Changed
Added two checkpoint lock files:*.checkpoint.intent.lock
*.checkpoint.apply.lock
Added checkpoint lock acquisition/release in Checkpointeracquire at checkpoint start
release on cleanup and rollback
Added eager creation of checkpoint lock files for non-read-only persistent databases
Added read-only recovery protection in WALReplayerif a checkpoint is in progress, opening in read-only mode now throws a RuntimeException
read-only recovery no longer proceeds through shadow file / checkpoint WAL intermediate states
Added defensive validation when reading checkpoint headersvalidate catalog page range
validate metadata page range
validate dataFileNumPages against actual file size
Fixed file descriptor / handle leaks when file locking fails in LocalFileSystem
Updated WAL testsReadOnlyRecoveryWithShadowFile now expects failure in read-only mode
added ReadOnlyRecoveryWithCheckpointWAL