Reviewed 12 of 12 files at r1, all commit messages.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @AlexTalks)

pkg/kv/kvserver/concurrency/lock/lock_waiter.proto, line 22 at r1 (raw file):

// KeyAccessType represents the type of operation that a transaction holding or
// waiting on a lock intends to carry out, once necessary locks are acquired.
enum KeyAccessType {

I think this can be replaced by the Strength enum. Currently, we only support two strengths, None (which maps to read-only here) and Exclusive (which maps to read-write here).

pkg/kv/kvserver/concurrency/lock/lock_waiter.proto, line 31 at r1 (raw file):

// LockWaiter represents a transaction (or non-transactional operation) that is
// waiting in the wait queue of readers or writers on an individual lock.
message LockWaiter {

nit: this package is called lock, so we can call this message Waiter {. There's a part of the style guide we use that talks about package name "stuttering", though I'm having trouble finding it.

pkg/kv/kvserver/concurrency/lock/locking.go, line 29 at r1 (raw file):

// SafeValue implements redact.SafeValue.
func (Durability) SafeValue() {}

Want to do the same for Strength sine you're here?

pkg/roachpb/data.proto, line 558 at r1 (raw file):

  bytes key = 2 [(gogoproto.casttype) = "Key"];
  // The metadata on the current lock holder, or nil if the lock is not held.
  LockAcquisition lock_holder = 3;

I think we decided that we should inline the txn and durability fields, since we don't need the LockAcquisition's Span and that message is used in a slightly different context. Or am I misremembering?

pkg/roachpb/data.proto, line 562 at r1 (raw file):

  google.protobuf.Duration hold_duration = 4 [(gogoproto.nullable) = false,
    (gogoproto.stdduration) = true];
  // The queue of readers and writers currently waiting on the lock.

Let's note the order of this list, or mention that the order is arbitrary.

pkg/roachpb/method.go, line 100 at r1 (raw file):

	// aborting it.
	RecoverTxn
	// QueryLocks requests the current state of concurrency control's lock table.

I don't think we meant to include this in this PR.

Sorry, didn't mean to mark this as approved quite yet 😃

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @nvanbenschoten)

pkg/roachpb/method.go, line 100 at r1 (raw file):

I did, though it was an artifact of an earlier version of the PR in which I included all API/proto updates in the same change (and running a generate build is very slow)

Reviewed 8 of 9 files at r2, 3 of 3 files at r3, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @AlexTalks)