setupLoop()'s Autoclear (LO_FLAGS_AUTOCLEAR) will destruct the loopback device when all associated file descriptors are closed. However this behavior didn't work before since setupLoop() was returning a file name. The looppack device was destructed at the end of the function when LoopParams had Autoclear = true. Fixes #4969. Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
		
			
				
	
	
		
			118 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			118 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// +build linux
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/*
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   Copyright The containerd Authors.
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   Licensed under the Apache License, Version 2.0 (the "License");
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   you may not use this file except in compliance with the License.
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   You may obtain a copy of the License at
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       http://www.apache.org/licenses/LICENSE-2.0
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   Unless required by applicable law or agreed to in writing, software
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   distributed under the License is distributed on an "AS IS" BASIS,
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   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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   See the License for the specific language governing permissions and
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   limitations under the License.
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*/
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package mount
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import (
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	"io/ioutil"
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	"os"
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	"testing"
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	"github.com/containerd/continuity/testutil"
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)
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var randomData = []byte("randomdata")
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func createTempFile(t *testing.T) string {
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	t.Helper()
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	f, err := ioutil.TempFile("", "losetup")
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	if err != nil {
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		t.Fatal(err)
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	}
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	defer f.Close()
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	if err = f.Truncate(512); err != nil {
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		t.Fatal(err)
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	}
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	return f.Name()
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}
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func TestNonExistingLoop(t *testing.T) {
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	testutil.RequiresRoot(t)
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	backingFile := "setup-loop-test-no-such-file"
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	_, err := setupLoop(backingFile, LoopParams{})
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	if err == nil {
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		t.Fatalf("setupLoop with non-existing file should fail")
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	}
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}
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func TestRoLoop(t *testing.T) {
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	testutil.RequiresRoot(t)
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	backingFile := createTempFile(t)
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	defer func() {
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		if err := os.Remove(backingFile); err != nil {
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			t.Fatal(err)
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		}
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	}()
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	file, err := setupLoop(backingFile, LoopParams{Readonly: true, Autoclear: true})
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	if err != nil {
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		t.Fatal(err)
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	}
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	defer file.Close()
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	if _, err := file.Write(randomData); err == nil {
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		t.Fatalf("writing to readonly loop device should fail")
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	}
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}
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func TestRwLoop(t *testing.T) {
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	testutil.RequiresRoot(t)
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	backingFile := createTempFile(t)
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	defer func() {
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		if err := os.Remove(backingFile); err != nil {
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			t.Fatal(err)
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		}
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	}()
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	file, err := setupLoop(backingFile, LoopParams{Autoclear: false})
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	if err != nil {
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		t.Fatal(err)
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	}
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	defer file.Close()
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	if _, err := file.Write(randomData); err != nil {
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		t.Fatal(err)
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	}
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}
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func TestAttachDetachLoopDevice(t *testing.T) {
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	testutil.RequiresRoot(t)
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	path := createTempFile(t)
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	defer func() {
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		if err := os.Remove(path); err != nil {
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			t.Fatal(err)
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		}
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	}()
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	dev, err := AttachLoopDevice(path)
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	if err != nil {
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		t.Fatal(err)
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	}
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	if err = DetachLoopDevice(dev); err != nil {
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		t.Fatal(err)
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	}
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}
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