Eliah RusinandClaude Fable 5.1 7dbbdac030 rust volume: keep the EC shard-location map, its refresh time and stale mark under one lock (#11356) ...

The per-EcVolume shard-location cache was three fields under three locks:
an RwLock<HashMap> for the map, a Mutex<Option<Instant>> for the time it
was last refreshed, and a Mutex<bool> for the stale mark. Nothing tied
them together. merge_shard_locations published the merged map, released
the write lock, and only then stamped the refresh time; both readers
(scrub_ec_volume_distributed's snapshot and build_snapshot) took the two
guards one after the other. A reader landing between the two writes
paired a freshly merged map with the previous lookup's timestamp -- and
that pair is exactly what needs_refresh judges, so a read went back to
the master for a map that had just been refreshed. Go keeps the same
state in one struct behind one ShardLocationsLock. replace_shard_locations
documented itself as "a single observable step" while being two.

Fold the three fields into one ShardLocationCache behind a single RwLock.
merge_shard_locations upserts and stamps in one write section,
shard_locations_snapshot returns the map and its time from one read
section, and mark_shard_locations_stale / claim_shard_locations_refresh
move the mark's read-and-consume onto the cache. The three zero-caller
accessors -- set_shard_locations, replace_shard_locations,
get_shard_locations -- are deleted, and the field is now private, so the
invariant cannot be sidestepped from outside the module. The two test
seeding sites go through merge_shard_locations, which already produces
the state they were writing by hand.

Unchanged: the freshness rule. needs_refresh keeps its thresholds and
still judges the caller's snapshot -- the map that caller will actually
read from, not whatever is cached by the time the claim runs -- so only
the stale mark is read from under the new lock. The master lookup, the
completeness guard in write_back_shard_locations and the per-shard upsert
semantics are untouched.

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

2026-09-20 13:30:15 -07:00

..

erasure_coding

rust volume: keep the EC shard-location map, its refresh time and stale mark under one lock (#11356)

2026-09-20 13:30:15 -07:00

idx

rust: cargo fmt both crates, with a commented-out fmt --check CI step (#11329)

2026-09-15 09:29:22 -07:00

needle

fix(volume): reject negative Size, recover poisoned store lock (#11345)

2026-09-16 08:12:11 -07:00

needle_map

rust volume: typed errors for store compaction so gRPC can answer NotFound (#11355)

2026-09-20 13:30:02 -07:00

disk_location.rs

rust volume: document every unsafe block and stop mutating the process env in tests (#11352)

2026-09-20 13:29:07 -07:00

io.rs

rust volume: one positional read helper; never seek a dup'd handle on Windows (#11342)

2026-09-17 11:47:38 -07:00

mod.rs

rust volume: one positional read helper; never seek a dup'd handle on Windows (#11342)

2026-09-17 11:47:38 -07:00

needle_map.rs

rust volume: typed errors for store compaction so gRPC can answer NotFound (#11355)

2026-09-20 13:30:02 -07:00

store_ec_mirror.rs

rust: cargo fmt both crates, with a commented-out fmt --check CI step (#11329)

2026-09-15 09:29:22 -07:00

store_ec_reconcile.rs

fix(ec): validate ShardId at gRPC boundary, reject >=32 (#11346)

2026-09-16 08:33:22 -07:00

store.rs

rust volume: typed errors for store compaction so gRPC can answer NotFound (#11355)

2026-09-20 13:30:02 -07:00

super_block.rs

Rust volume server implementation with CI (#8539)

2026-03-26 17:24:35 -07:00

types.rs

rust: clippy-clean both crates and adopt the std APIs the 1.91 MSRV allows (#11312)

2026-09-14 11:29:29 -07:00

volume_idx_rebuild.rs

rust: cargo fmt both crates, with a commented-out fmt --check CI step (#11329)

2026-09-15 09:29:22 -07:00

volume_idx_repair.rs

fix(volume): stop ScanVolumeFileFrom at a header it cannot advance past (#11398)

2026-09-19 22:26:56 -07:00

volume_open.rs

volume: open volume files with O_NOATIME (#11055)

2026-08-31 21:41:50 -07:00

volume_report_hash.rs

rust: clippy-clean both crates and adopt the std APIs the 1.91 MSRV allows (#11312)

2026-09-14 11:29:29 -07:00

volume_report.rs

volume: cut idle memory at high volume counts (#10861)

2026-08-21 13:04:56 -07:00

volume.rs

rust volume: typed errors for store compaction so gRPC can answer NotFound (#11355)

2026-09-20 13:30:02 -07:00