Merge pull request #8580 from influxdata/sgc-8500-deadlock

Free RLock prior to returning

CHANGELOG.md

@@ -23,6 +23,7 @@
 ### Bugfixes
 
 - [#8559](https://github.com/influxdata/influxdb/issues/8559): Ensure temporary TSM files get cleaned up when compaction aborted.
+- [#8500](https://github.com/influxdata/influxdb/issues/8500): InfluxDB goes unresponsive
 
 
 ## v1.3.0 [2017-06-21]

tsdb/index/inmem/meta.go

@@ -330,11 +330,13 @@ func (m *Measurement) TagSets(shardID uint64, opt influxql.IteratorOptions) ([]*
 		// Abort if the query was killed
 		select {
 		case <-opt.InterruptCh:
+			m.mu.RUnlock()
 			return nil, influxql.ErrQueryInterrupted
 		default:
 		}
 
 		if opt.MaxSeriesN > 0 && seriesN > opt.MaxSeriesN {
+			m.mu.RUnlock()
 			return nil, fmt.Errorf("max-select-series limit exceeded: (%d/%d)", seriesN, opt.MaxSeriesN)
 		}