* feat(storage): sweep leftover empty EC .dat stubs on volume server startup
An EC volume keeps no local .dat. The pre-fix loader left empty 8-byte
superblock .dat stubs next to EC metadata (one per lone .vif). Left in
place each loads as a phantom empty volume, and the same vid's stub on
two disks of one server blocks Rust startup via the duplicate-vid check
in Store::add_location -- the prior fix stops creating new stubs but does
not clean up existing ones.
On startup, when a .dat is empty (<= a superblock, i.e. zero needles) and
its .vif marks the volume erasure-coded, remove the stub (+ empty .idx)
instead of loading it. The real data is in the EC shards, so the empty
stub holds nothing to lose. Non-EC empty .dat files (e.g. freshly
allocated volumes) are left alone.
Done in both Rust (load_existing_volumes) and Go (loadExistingVolume),
with regression tests that fail without the sweep.
* refactor(storage): extract empty EC .dat stub sweep into its own function
Move the startup stub-sweep into remove_empty_ec_dat_stub (Rust) and
removeEmptyEcDatStub + vifIsEcVolume (Go) for clearer logic, and look up
the .vif in both the data and idx directories (each read at most once) so
a stub is still found when -dir.idx is configured. Adds direct tests for
the idx-directory lookup on both engines.
Chris LuandGitHub
4f8af455bf