kvserver: disable latch assertions further down

pkg/kv/kvserver/batcheval/cmd_export.go

@@ -76,11 +76,6 @@ func declareKeysExport(
 		return err
 	}
 	latchSpans.AddNonMVCC(spanset.SpanReadOnly, roachpb.Span{Key: keys.RangeGCThresholdKey(header.RangeID)})
-	// Export requests will usually not hold latches during their evaluation.
-	//
-	// See call to `AssertAllowed()` in GetGCThreshold() to understand why we need
-	// to disable these assertions for export requests.
-	latchSpans.DisableUndeclaredAccessAssertions()
 	return nil
 }
 
@@ -96,6 +91,12 @@ func evalExport(
 	ctx, evalExportSpan := tracing.ChildSpan(ctx, "evalExport")
 	defer evalExportSpan.Finish()
 
+	// Export requests will usually not hold latches during their evaluation.
+	//
+	// See call to `AssertAllowed()` in GetGCThreshold() to understand why we need
+	// to disable these assertions for export requests.
+	reader = spanset.DisableReaderAssertions(reader)
+
 	// Table's marked to be excluded from backup are expected to be configured
 	// with a short GC TTL. Additionally, backup excludes such table's from being
 	// protected from GC when writing ProtectedTimestamp records. The

pkg/kv/kvserver/batcheval/cmd_gc.go

@@ -106,7 +106,6 @@ func declareKeysGC(
 	latchSpans.AddNonMVCC(spanset.SpanReadOnly, roachpb.Span{Key: keys.RangeDescriptorKey(rs.GetStartKey())})
 	// Needed for updating optional GC hint.
 	latchSpans.AddNonMVCC(spanset.SpanReadWrite, roachpb.Span{Key: keys.RangeGCHintKey(rs.GetRangeID())})
-	latchSpans.DisableUndeclaredAccessAssertions()
 	return nil
 }
 
@@ -139,6 +138,9 @@ func GC(
 	args := cArgs.Args.(*kvpb.GCRequest)
 	h := cArgs.Header
 
+	// TODO(pav-kv): find out why and comment.
+	readWriter = spanset.DisableReadWriterAssertions(readWriter)
+
 	// We do not allow GC requests to bump the GC threshold at the same time that
 	// they GC individual keys. This is because performing both of these actions
 	// at the same time could lead to a race where a read request is allowed to

pkg/kv/kvserver/batcheval/cmd_lease_request.go

@@ -23,18 +23,17 @@ func init() {
 }
 
 func declareKeysRequestLease(
-	rs ImmutableRangeState,
+	_ ImmutableRangeState,
 	_ *kvpb.Header,
 	_ kvpb.Request,
-	latchSpans *spanset.SpanSet,
+	_ *spanset.SpanSet,
 	_ *lockspanset.LockSpanSet,
 	_ time.Duration,
 ) error {
 	// NOTE: RequestLease is run on replicas that do not hold the lease, so
 	// acquiring latches would not help synchronize with other requests. As
 	// such, the request does not declare latches. See also
 	// concurrency.shouldIgnoreLatches().
-	latchSpans.DisableUndeclaredAccessAssertions()
 	return nil
 }
 
@@ -54,6 +53,9 @@ func RequestLease(
 	prevLease := args.PrevLease
 	newLease := args.Lease
 
+	// RequestLease does not hold latches by design.
+	readWriter = spanset.DisableReadWriterAssertions(readWriter)
+
 	// If this check is removed at some point, the filtering of learners on the
 	// sending side would have to be removed as well.
 	// TODO(nvanbenschoten): move this into leases.Verify.

pkg/kv/kvserver/batcheval/cmd_recompute_stats.go

@@ -51,8 +51,6 @@ func declareKeysRecomputeStats(
 	rdKey := keys.RangeDescriptorKey(rs.GetStartKey())
 	latchSpans.AddNonMVCC(spanset.SpanReadOnly, roachpb.Span{Key: rdKey})
 	latchSpans.AddNonMVCC(spanset.SpanReadWrite, roachpb.Span{Key: keys.TransactionKey(rdKey, uuid.Nil)})
-	// Disable the assertions which check that all reads were previously declared.
-	latchSpans.DisableUndeclaredAccessAssertions()
 	return nil
 }
 
@@ -72,9 +70,12 @@ func RecomputeStats(
 		return result.Result{}, RecomputeStatsMismatchError
 	}
 	dryRun := args.DryRun
-
 	args = nil // avoid accidental use below
 
+	// Disable the assertions which check that all reads were previously declared.
+	// TODO(pav-kv): find out why we can do that.
+	reader = spanset.DisableReaderAssertions(reader)
+
 	actualMS, err := rditer.ComputeStatsForRange(ctx, desc, reader, cArgs.Header.Timestamp.WallTime)
 	if err != nil {
 		return result.Result{}, err

pkg/kv/kvserver/spanset/spanset.go

@@ -83,8 +83,7 @@ type Span struct {
 // The Span slice for a particular access and scope contains non-overlapping
 // spans in increasing key order after calls to SortAndDedup.
 type SpanSet struct {
-	spans           [NumSpanAccess][NumSpanScope][]Span
-	allowUndeclared bool
+	spans [NumSpanAccess][NumSpanScope][]Span
 }
 
 var spanSetPool = sync.Pool{
@@ -113,7 +112,6 @@ func (s *SpanSet) Release() {
 			s.spans[sa][ss] = recycle
 		}
 	}
-	s.allowUndeclared = false
 	spanSetPool.Put(s)
 }
 
@@ -155,7 +153,6 @@ func (s *SpanSet) Copy() *SpanSet {
 			n.spans[sa][ss] = append(n.spans[sa][ss], s.spans[sa][ss]...)
 		}
 	}
-	n.allowUndeclared = s.allowUndeclared
 	return n
 }
 
@@ -208,7 +205,6 @@ func (s *SpanSet) Merge(s2 *SpanSet) {
 			s.spans[sa][ss] = append(s.spans[sa][ss], s2.spans[sa][ss]...)
 		}
 	}
-	s.allowUndeclared = s2.allowUndeclared
 	s.SortAndDedup()
 }
 
@@ -331,12 +327,6 @@ func (s *SpanSet) CheckAllowedAt(
 func (s *SpanSet) checkAllowed(
 	access SpanAccess, span roachpb.Span, check func(SpanAccess, Span) bool,
 ) error {
-	if s.allowUndeclared {
-		// If the request has specified that undeclared spans are allowed, do
-		// nothing.
-		return nil
-	}
-
 	scope := SpanGlobal
 	if (span.Key != nil && keys.IsLocal(span.Key)) ||
 		(span.EndKey != nil && keys.IsLocal(span.EndKey)) {
@@ -389,10 +379,3 @@ func (s *SpanSet) Validate() error {
 
 	return nil
 }
-
-// DisableUndeclaredAccessAssertions disables the assertions that prevent
-// undeclared access to spans. This is generally set by requests that rely on
-// other forms of synchronization for correctness (e.g. GCRequest).
-func (s *SpanSet) DisableUndeclaredAccessAssertions() {
-	s.allowUndeclared = true
-}