A small object whose data shards are inlined in xl.meta can be reassembled
straight from the already-resolved metadata, skipping the Erasure reconstruct
pipeline. The fast path existed but was opt-in
(`RUSTFS_GET_SMALL_OBJECT_DIRECT_MEMORY`, default off), so every deployment
paid the full shard-read fan-out for eligible small GETs by default.
- Flip `DEFAULT_RUSTFS_GET_SMALL_OBJECT_DIRECT_MEMORY` to `true`. The path is
correctness-neutral on a miss: `try_get_object_direct_data_shards_*` returns
None when the inline reassembly cannot satisfy the read, and the GET then
proceeds through the normal shard-read pipeline. The env stays as a kill
switch (`=false` restores the legacy path).
- Drop the bucket-level `versioned` / `version_suspended` exclusions. The
decision is made on `fi` — the already-resolved target version — so
reassembling its inlined data is correct on a versioned bucket too. An
explicit versionId GET still falls back (`opts.version_id`), and a
delete-marker latest is still rejected. The two now-unused fallback reasons
and their metric labels are removed.
- Tests updated: a versioned latest-version object is now eligible / `Use`
(covers the newly allowed path); the removed reasons' label assertions are
dropped.
cargo check --lib --tests and the direct_memory unit tests pass on macOS
(the change is fully cross-platform).
Co-authored-by: heihutu <[email protected]>
