Fixed a (new) test bug on Linux.

samples/interruptfs/interrupt_fs_test.go

@@ -19,6 +19,7 @@ import (
 	"os"
 	"os/exec"
 	"path"
+	"runtime"
 	"testing"
 	"time"
 
@@ -72,6 +73,18 @@ func (t *InterruptFSTest) StatFoo() {
 }
 
 func (t *InterruptFSTest) InterruptedDuringRead() {
+	// On Linux, since we have async reads enabled, the kernel sends the read and
+	// the flush ops in parallel. When the process receives SIGINT, the interrupt
+	// is delivered only for the flush, probably because that's what the process
+	// appears to be blocking on. So this test doesn't work.
+	//
+	// Note that this means that cancellation is not delivered for reads on
+	// Linux. This is unfortunate, but probably worth it due to the significant
+	// increase in performance.
+	if runtime.GOOS == "linux" {
+		return
+	}
+
 	var err error
 	t.fs.EnableReadBlocking()