manifest: unref files with range keys when version refcnt is zero

compaction_test.go

@@ -2200,6 +2200,13 @@ func TestCompactionTombstones(t *testing.T) {
 				d.mu.Unlock()
 				return str
 
+			case "close":
+				if err := d.Close(); err != nil {
+					return err.Error()
+				}
+				d = nil
+				return ""
+
 			case "version":
 				d.mu.Lock()
 				s := d.mu.versions.currentVersion().String()

db.go

@@ -1316,6 +1316,12 @@ func (d *DB) Close() error {
 	d.compactionSchedulers.Wait()
 	d.mu.Lock()
 
+	// As a sanity check, ensure that there are no zombie tables. A non-zero count
+	// hints at a reference count leak.
+	if ztbls := len(d.mu.versions.zombieTables); ztbls > 0 {
+		err = firstError(err, errors.Errorf("non-zero zombie file count: %d", ztbls))
+	}
+
 	// If the options include a closer to 'close' the filesystem, close it.
 	if d.opts.private.fsCloser != nil {
 		d.opts.private.fsCloser.Close()

internal/manifest/version.go

@@ -890,6 +890,9 @@ func (v *Version) unrefFiles() []*FileMetadata {
 	for _, lm := range v.Levels {
 		obsolete = append(obsolete, lm.release()...)
 	}
+	for _, lm := range v.RangeKeyLevels {
+		obsolete = append(obsolete, lm.release()...)
+	}
 	return obsolete
 }
 

testdata/compaction_tombstones

@@ -291,3 +291,40 @@ range-deletions-bytes-estimate: 0
 maybe-compact
 ----
 (none)
+
+# Regression test for cockroachdb/cockroach#90149, exercising reference counting
+# on tables that contain a mixture of point, range dels and range keys.
+#
+# Place a table in L6 that contains a RANGEKEYDEL. Because this table is in the
+# bottom of the LSM, and there are no range keys below it, the RANGEKEYDEL is
+# eligible for elision (the RANGEDEL too). After the elision, the input table
+# should be deleted. In #90149, the table still had a reference count, and
+# therefore could not be deleted from the filesystem.
+
+define
+L6
+  rangekey:a-b:{(#1,RANGEKEYDEL)}
+  a.SET.2:a
+  b.SET.3:b
+  c.SET.4:c
+  c.RANGEDEL.5:z
+----
+6:
+  000004:[a#2,SET-z#72057594037927935,RANGEDEL]
+
+wait-pending-table-stats
+000004
+----
+num-entries: 3
+num-deletions: 1
+num-range-key-sets: 0
+point-deletions-bytes-estimate: 0
+range-deletions-bytes-estimate: 39
+
+maybe-compact
+----
+[JOB 100] compacted(elision-only) L6 [000004] (1001 B) + L6 [] (0 B) -> L6 [000005] (778 B), in 1.0s (2.0s total), output rate 778 B/s
+
+# Close the DB, asserting that the reference counts balance.
+close
+----