rootlessport: fix potential hang
write to the error pipe only in case of an error.  Otherwise we may
end up in a race condition in the select statement below as the read
from errChan happens before initComplete and the function returns
immediately nil.
Closes:
@@ -122,6 +122,7 @@ func parent() error {
logrus.WithError(driverErr).Warn("parent driver exited")
}
errCh <- driverErr
+ close(errCh)
}()
opaque := driver.OpaqueForChild()
logrus.Infof("opaque=%+v", opaque)
@@ -142,7 +143,7 @@ func parent() error {
}()
// reexec the child process in the child netns
- cmd := exec.Command(fmt.Sprintf("/proc/%d/exe", os.Getpid()))
+ cmd := exec.Command("/proc/self/exe")
cmd.Args = []string{reexecChildKey}
cmd.Stdin = childQuitR
cmd.Stdout = &logrusWriter{prefix: "child"}
@@ -164,12 +165,19 @@ func parent() error {
logrus.Info("waiting for initComplete")
// wait for the child to connect to the parent
+outer:
+ for {
select {
case <-initComplete:
logrus.Infof("initComplete is closed; parent and child established the communication channel")
+ break outer
case err := <-errCh:
+ if err != nil {
return err
}
+ }
+ }
+
defer func() {
logrus.Info("stopping parent driver")
quit <- struct{}{}
