[SERVER-53142] Data race on CollectionImpl::_committed Created: 01/Dec/20 Updated: 29/Oct/23 Resolved: 10/Dec/20 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | 4.9.0 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Henrik Edin | Assignee: | Henrik Edin |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||
| Operating System: | ALL | ||||
| Sprint: | Execution Team 2020-12-14 | ||||
| Participants: | |||||
| Linked BF Score: | 16 | ||||
| Description |
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When UncommittedCollections commit a collection we install the new collection in the catalog here: https://github.com/mongodb/mongo/blob/1e6d0a856a9c9858552cdbdec889be14f4964b61/src/mongo/db/catalog/uncommitted_collections.cpp#L150-L151 And later we set the committed flag in a commit handler: https://github.com/mongodb/mongo/blob/1e6d0a856a9c9858552cdbdec889be14f4964b61/src/mongo/db/catalog/uncommitted_collections.cpp#L161 While still holding on to the MODE_IX lock. However, a lock-free reader may access this collection instance on a different thread and check CollectionImpl::_committed, causing a data race as this is not an atomic variable. |
| Comments |
| Comment by Githook User [ 10/Dec/20 ] |
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Author: {'name': 'Henrik Edin', 'email': 'henrik.edin@mongodb.com', 'username': 'henrikedin'}Message: |