connhelper: fix cmd.Wait() race
Fix
@@ -82,6 +82,7 @@ func newCommandConn(ctx context.Context, cmd string, args ...string) (net.Conn,
// commandConn implements net.Conn
type commandConn struct {
cmd *exec.Cmd
+ cmdMutex sync.Mutex
stdin io.WriteCloser
stdout io.ReadCloser
stderrMu sync.Mutex
@@ -102,6 +103,7 @@ func (c *commandConn) killIfStdioClosed() error {
return nil
}
var err error
+ c.cmdMutex.Lock()
// NOTE: maybe already killed here
if err = c.cmd.Process.Kill(); err == nil {
err = c.cmd.Wait()
@@ -113,11 +115,14 @@ func (c *commandConn) killIfStdioClosed() error {
err = nil
}
}
+ c.cmdMutex.Unlock()
return err
}
func (c *commandConn) onEOF(eof error) error {
+ c.cmdMutex.Lock()
werr := c.cmd.Wait()
+ c.cmdMutex.Unlock()
if werr == nil {
return eof
}
@@ -131,6 +136,7 @@ func ignorableCloseError(err error) bool {
errS := err.Error()
ss := []string{
os.ErrClosed.Error(),
+ "process already finished",
}
for _, s := range ss {
if strings.Contains(errS, s) {
@@ -148,7 +154,10 @@ func (c *commandConn) CloseRead() error {
c.stdioClosedMu.Lock()
c.stdoutClosed = true
c.stdioClosedMu.Unlock()
- return c.killIfStdioClosed()
+ if err := c.killIfStdioClosed(); err != nil && !ignorableCloseError(err) {
+ logrus.Warnf("commandConn.CloseRead: %v", err)
+ }
+ return nil
}
func (c *commandConn) Read(p []byte) (int, error) {
@@ -167,7 +176,10 @@ func (c *commandConn) CloseWrite() error {
c.stdioClosedMu.Lock()
c.stdinClosed = true
c.stdioClosedMu.Unlock()
- return c.killIfStdioClosed()
+ if err := c.killIfStdioClosed(); err != nil && !ignorableCloseError(err) {
+ logrus.Warnf("commandConn.CloseWrite: %v", err)
+ }
+ return nil
}
func (c *commandConn) Write(p []byte) (int, error) {
