dht/dht.go | 5 ++++-
 file.go    | 2 ++

diff --git a/dht/dht.go b/dht/dht.go
index 01d2835209a7c0221bbe421087042be1acce1c72..3f4377307f99dd17fa7d35c45039b1c64229b21d 100644
--- a/dht/dht.go
+++ b/dht/dht.go
@@ -629,7 +629,10 @@ 		if n == len(b) {
 			logonce.Stderr.Printf("received dht packet exceeds buffer size")
 			continue
 		}
-		if s.ipBlocked(util.AddrIP(addr)) {
+		s.mu.Lock()
+		blocked := s.ipBlocked(util.AddrIP(addr))
+		s.mu.Unlock()
+		if blocked {
 			continue
 		}
 		s.processPacket(b[:n], newDHTAddr(addr))
diff --git a/file.go b/file.go
index 2efbaeaaf8d0149e1e0b865492d1f1470a763a8f..688fc2faa92ae6af221d706a94fe4d27461f5eb2 100644
--- a/file.go
+++ b/file.go
@@ -35,6 +35,8 @@ }
 
 // Returns the state of pieces in this file.
 func (f *File) State() (ret []FilePieceState) {
+	f.t.cl.mu.Lock()
+	defer f.t.cl.mu.Unlock()
 	pieceSize := int64(f.t.usualPieceSize())
 	off := f.offset % pieceSize
 	remaining := f.length