This is an automated cherry-pick of pingcap#53690

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>

server/BUILD.bazel

@@ -237,7 +237,11 @@ go_test(
         "@com_github_tikv_client_go_v2//tikvrpc",
         "@io_etcd_go_etcd_tests_v3//integration",
         "@io_opencensus_go//stats/view",
+<<<<<<< HEAD
         "@org_golang_x_exp//slices",
+=======
+        "@org_uber_go_atomic//:atomic",
+>>>>>>> 05a1ad36ce8 (server: fix connection double close (#53690))
         "@org_uber_go_goleak//:goleak",
         "@org_uber_go_zap//:zap",
     ],

server/conn.go

@@ -336,14 +336,6 @@ func closeConn(cc *clientConn, connections int) error {
 				// This is because closeConn() might be called after a connection read-timeout.
 				logutil.Logger(context.Background()).Debug("could not close connection", zap.Error(err))
 			}
-			if cc.bufReadConn != nil {
-				err = cc.bufReadConn.Close()
-				if err != nil {
-					// We need to expect connection might have already disconnected.
-					// This is because closeConn() might be called after a connection read-timeout.
-					logutil.Logger(context.Background()).Debug("could not close connection", zap.Error(err))
-				}
-			}
 			// Close statements and session
 			// This will release advisory locks, row locks, etc.
 			if ctx := cc.getCtx(); ctx != nil {

server/conn_test.go

@@ -1692,7 +1692,7 @@ func TestMaxAllowedPacket(t *testing.T) {
 	bytes := append([]byte{0x00, 0x04, 0x00, 0x00}, []byte(fmt.Sprintf("SELECT length('%s') as len;", strings.Repeat("a", 999)))...)
 	_, err := inBuffer.Write(bytes)
 	require.NoError(t, err)
-	brc := newBufferedReadConn(&bytesConn{inBuffer})
+	brc := newBufferedReadConn(&bytesConn{b: inBuffer})
 	pkt := newPacketIO(brc)
 	pkt.setMaxAllowedPacket(maxAllowedPacket)
 	readBytes, err = pkt.readPacket()
@@ -1705,7 +1705,7 @@ func TestMaxAllowedPacket(t *testing.T) {
 	bytes = append([]byte{0x01, 0x04, 0x00, 0x00}, []byte(fmt.Sprintf("SELECT length('%s') as len;", strings.Repeat("a", 1000)))...)
 	_, err = inBuffer.Write(bytes)
 	require.NoError(t, err)
-	brc = newBufferedReadConn(&bytesConn{inBuffer})
+	brc = newBufferedReadConn(&bytesConn{b: inBuffer})
 	pkt = newPacketIO(brc)
 	pkt.setMaxAllowedPacket(maxAllowedPacket)
 	_, err = pkt.readPacket()
@@ -1717,7 +1717,7 @@ func TestMaxAllowedPacket(t *testing.T) {
 	bytes = append([]byte{0x01, 0x02, 0x00, 0x00}, []byte(fmt.Sprintf("SELECT length('%s') as len;", strings.Repeat("a", 488)))...)
 	_, err = inBuffer.Write(bytes)
 	require.NoError(t, err)
-	brc = newBufferedReadConn(&bytesConn{inBuffer})
+	brc = newBufferedReadConn(&bytesConn{b: inBuffer})
 	pkt = newPacketIO(brc)
 	pkt.setMaxAllowedPacket(maxAllowedPacket)
 	readBytes, err = pkt.readPacket()
@@ -1728,7 +1728,7 @@ func TestMaxAllowedPacket(t *testing.T) {
 	bytes = append([]byte{0x01, 0x02, 0x00, 0x01}, []byte(fmt.Sprintf("SELECT length('%s') as len;", strings.Repeat("b", 488)))...)
 	_, err = inBuffer.Write(bytes)
 	require.NoError(t, err)
-	brc = newBufferedReadConn(&bytesConn{inBuffer})
+	brc = newBufferedReadConn(&bytesConn{b: inBuffer})
 	pkt.setBufferedReadConn(brc)
 	readBytes, err = pkt.readPacket()
 	require.NoError(t, err)
@@ -1987,6 +1987,7 @@ func TestProcessInfoForExecuteCommand(t *testing.T) {
 	require.Equal(t, cc.ctx.Session.ShowProcess().Info, "select sum(col1) from t where col1 < ? and col1 > 100")
 }
 
+<<<<<<< HEAD
 func TestLDAPAuthSwitch(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	cfg := newTestConfig()
@@ -2026,6 +2027,8 @@ func TestLDAPAuthSwitch(t *testing.T) {
 	require.Equal(t, []byte(mysql.AuthMySQLClearPassword), respAuthSwitch)
 }
 
+=======
+>>>>>>> 05a1ad36ce8 (server: fix connection double close (#53690))
 func TestCloseConn(t *testing.T) {
 	var outBuffer bytes.Buffer
 
@@ -2036,7 +2039,12 @@ func TestCloseConn(t *testing.T) {
 	drv := NewTiDBDriver(store)
 	server, err := NewServer(cfg, drv)
 	require.NoError(t, err)
-
+	var inBuffer bytes.Buffer
+	_, err = inBuffer.Write([]byte{0x01, 0x00, 0x00, 0x00, 0x01})
+	require.NoError(t, err)
+	// Test read one packet
+	brc := newBufferedReadConn(&bytesConn{b: inBuffer})
+	require.NoError(t, err)
 	cc := &clientConn{
 		connectionID: 0,
 		salt: []byte{
@@ -2047,11 +2055,12 @@ func TestCloseConn(t *testing.T) {
 		pkt: &packetIO{
 			bufWriter: bufio.NewWriter(&outBuffer),
 		},
-		collation:  mysql.DefaultCollationID,
-		peerHost:   "localhost",
-		alloc:      arena.NewAllocator(512),
-		chunkAlloc: chunk.NewAllocator(),
-		capability: mysql.ClientProtocol41,
+		collation:   mysql.DefaultCollationID,
+		peerHost:    "localhost",
+		alloc:       arena.NewAllocator(512),
+		chunkAlloc:  chunk.NewAllocator(),
+		capability:  mysql.ClientProtocol41,
+		bufReadConn: brc,
 	}
 
 	var wg sync.WaitGroup

server/packetio_test.go

@@ -21,8 +21,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/atomic"
 )
 
 func BenchmarkPacketIOWrite(b *testing.B) {
@@ -64,7 +66,7 @@ func TestPacketIORead(t *testing.T) {
 	_, err := inBuffer.Write([]byte{0x01, 0x00, 0x00, 0x00, 0x01})
 	require.NoError(t, err)
 	// Test read one packet
-	brc := newBufferedReadConn(&bytesConn{inBuffer})
+	brc := newBufferedReadConn(&bytesConn{b: inBuffer})
 	pkt := newPacketIO(brc)
 	readBytes, err := pkt.readPacket()
 	require.NoError(t, err)
@@ -86,7 +88,7 @@ func TestPacketIORead(t *testing.T) {
 	_, err = inBuffer.Write(buf)
 	require.NoError(t, err)
 	// Test read multiple packets
-	brc = newBufferedReadConn(&bytesConn{inBuffer})
+	brc = newBufferedReadConn(&bytesConn{b: inBuffer})
 	pkt = newPacketIO(brc)
 	readBytes, err = pkt.readPacket()
 	require.NoError(t, err)
@@ -96,7 +98,8 @@ func TestPacketIORead(t *testing.T) {
 }
 
 type bytesConn struct {
-	b bytes.Buffer
+	b      bytes.Buffer
+	closed atomic.Bool
 }
 
 func (c *bytesConn) Read(b []byte) (n int, err error) {
@@ -108,6 +111,10 @@ func (c *bytesConn) Write(b []byte) (n int, err error) {
 }
 
 func (c *bytesConn) Close() error {
+	if c.closed.Load() {
+		return errors.New("already closed")
+	}
+	c.closed.Store(true)
 	return nil
 }