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Michael Renner
ea9b1a2309
Since #17567, FS.ChildAUMs scans and decodes every active AUM file. Authority reconstruction and compaction call it repeatedly, making filesystem work quadratic in the number of AUMs. Build per-FS indexes of active AUM hashes and parent-to-child relationships in one scan. Use the indexes for graph queries while continuing to decode returned AUM values from disk. Invalidate the indexes after mutations, but retain them for empty purges. A production-sized 825-AUM benchmark improves from 124 seconds to 4 seconds on macOS with Defender and from 5.9 seconds to 34 milliseconds on Linux ext3. The checked-in benchmark exercises the 2,000-AUM maximum linear history accepted by the traversal guardrail. RELNOTE: Avoid Tailnet Lock startup failures with large authority histories. Fixes #20735 Change-Id: I088136bc2e9d1b6bfdecb223c069d42400c9f63d Signed-off-by: Michael Renner <terrorobe@github.com>