routableWriteOwner no longer excludes object-lock buckets, so a versioned PUT
(which creates a new version, never overwriting a locked one) and a
non-versioned overwrite (WORM-checked gateway-side before dispatch) route to the
owner filer like any other write.
routedObjectOwner still excludes object-lock: an unversioned object-lock delete
enforces WORM under the lock, so it stays there rather than routing past the
check. Version-specific deletes likewise stay on the lock — routing them needs
the WORM check (on the version entry) and the latest-pointer recompute (on the
object) under one transaction, which the current single condition target cannot
express.
s3: route versioned PutObject finalize off the distributed lock
A versioned write's finalize (flip the .versions pointer to the newest version,
demote the prior latest) now runs as a single RECOMPUTE_LATEST ObjectTransaction
on the object's owner filer, under its per-path lock, instead of the unserialized
updateLatestVersionInDirectory. The version file is written first; the owner
re-derives the pointer by scanning the directory.
RECOMPUTE_LATEST gains size_to_key / mtime_to_key to cache the chosen version's
size and mtime on the pointer, and demote_key / demote_value to stamp the
displaced prior latest (NoncurrentSinceNs for lifecycle) when the pointer moves.
Falls back to updateLatestVersionInDirectory when no owner is known yet.
s3: route non-versioned object PUT and DELETE off the distributed lock
A non-versioned, non-object-lock object write now goes straight to the key's
owner filer as a single-mutation ObjectTransaction, which serializes it with the
owner's per-path lock and evaluates the precondition, instead of taking a
cluster-wide lock. PUT and DELETE use the object's full path as the lock key, so
a concurrent create and delete of the same key serialize against each other.
The fast path is taken only when the precondition reduces to clauses the filer
can evaluate (existence and a single strong-ETag match); time-based conditions,
ETag lists, weak ETags, post-create hooks, and an unknown owner fall back to the
lock. A routed mutation error other than a failed precondition also falls back,
so the lock path stays the authority for the cases it alone covers.
PrimaryForKey returns "" until the ring view arrives, keeping writes on the lock
until routing is known.
Chris Lu