tarfs: fix a data race condition

Fix a data race condition
WARNING: DATA RACE
Write at 0x00c000178428 by goroutine 27:
  github.com/containerd/nydus-snapshotter/pkg/remote/remotes/docker.(*httpReadSeeker).Close()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/remote/remotes/docker/httpreadseeker.go:87 +0x57
  github.com/containerd/nydus-snapshotter/pkg/tarfs.(*Manager).blobProcess.func2.1()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs.go:339 +0x48
  runtime.deferreturn()
      /opt/hostedtoolcache/go/1.20.1/x64/src/runtime/panic.go:476 +0x32
  github.com/containerd/nydus-snapshotter/pkg/tarfs.(*Manager).blobProcess.func3()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs.go:394 +0x71

Previous read at 0x00c000178428 by goroutine 40:
  github.com/containerd/nydus-snapshotter/pkg/remote/remotes/docker.(*httpReadSeeker).Read()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/remote/remotes/docker/httpreadseeker.go:48 +0x68
  bufio.(*Reader).Read()
      /opt/hostedtoolcache/go/1.20.1/x64/src/bufio/bufio.go:223 +0x2c3
  github.com/containerd/containerd/archive/compression.(*bufferedReader).Read()
      /home/runner/go/pkg/mod/github.com/containerd/[email protected]/archive/compression/compression.go:113 +0xa4
  io.copyBuffer()
      /opt/hostedtoolcache/go/1.20.1/x64/src/io/io.go:427 +0x28d
  io.Copy()
      /opt/hostedtoolcache/go/1.20.1/x64/src/io/io.go:386 +0x88
  os.genericReadFrom()
      /opt/hostedtoolcache/go/1.20.1/x64/src/os/file.go:161 +0x34
  os.(*File).ReadFrom()
      /opt/hostedtoolcache/go/1.20.1/x64/src/os/file.go:155 +0x324
  io.copyBuffer()
      /opt/hostedtoolcache/go/1.20.1/x64/src/io/io.go:413 +0x1c5
  io.Copy()
      /opt/hostedtoolcache/go/1.20.1/x64/src/io/io.go:386 +0x84
  os/exec.(*Cmd).childStdin.func1()
      /opt/hostedtoolcache/go/1.20.1/x64/src/os/exec/exec.go:511 +0x45
  os/exec.(*Cmd).Start.func2()
      /opt/hostedtoolcache/go/1.20.1/x64/src/os/exec/exec.go:717 +0x42
  os/exec.(*Cmd).Start.func3()
      /opt/hostedtoolcache/go/1.20.1/x64/src/os/exec/exec.go:729 +0x47

Goroutine 27 (running) created at:
  github.com/containerd/nydus-snapshotter/pkg/tarfs.(*Manager).blobProcess()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs.go:393 +0x9dd
  github.com/containerd/nydus-snapshotter/pkg/tarfs.(*Manager).PrepareLayer()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs.go:465 +0x444
  github.com/containerd/nydus-snapshotter/pkg/tarfs.TestPrepareLayer()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs_test.go:33 +0x188
  testing.tRunner()
      /opt/hostedtoolcache/go/1.20.1/x64/src/testing/testing.go:1576 +0x216
  testing.(*T).Run.func1()
      /opt/hostedtoolcache/go/1.20.1/x64/src/testing/testing.go:1629 +0x47

Goroutine 40 (finished) created at:
  os/exec.(*Cmd).Start()
      /opt/hostedtoolcache/go/1.20.1/x64/src/os/exec/exec.go:716 +0xf8e
  github.com/containerd/containerd/archive/compression.cmdStream()
      /home/runner/go/pkg/mod/github.com/containerd/[email protected]/archive/compression/compression.go:284 +0x36f
  github.com/containerd/containerd/archive/compression.gzipDecompress()
      /home/runner/go/pkg/mod/github.com/containerd/[email protected]/archive/compression/compression.go:272 +0x152
  github.com/containerd/containerd/archive/compression.DecompressStream()
      /home/runner/go/pkg/mod/github.com/containerd/[email protected]/archive/compression/compression.go:203 +0x3e4
  github.com/containerd/nydus-snapshotter/pkg/tarfs.(*Manager).blobProcess.func2()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs.go:341 +0x1b1
  github.com/containerd/nydus-snapshotter/pkg/tarfs.(*Manager).blobProcess.func3()
      /home/runner/work/nydus-snapshotter/nydus-snapshotter/pkg/tarfs/tarfs.go:394 +0x71
==================
    testing.go:1446: race detected during execution of test

Signed-off-by: Jiang Liu <[email protected]>

Author: jiangliu

pkg/tarfs/tarfs.go

@@ -20,6 +20,7 @@ import (
 	"strings"
 	"sync"
 	"syscall"
+	"time"
 
 	"github.com/containerd/containerd/archive/compression"
 	"github.com/containerd/containerd/log"
@@ -213,7 +214,7 @@ func (t *Manager) getBlobStream(ctx context.Context, remote *remote.Remote, ref
 }
 
 // generate tar file and layer bootstrap, return if this blob is an empty blob
-func (t *Manager) generateBootstrap(tarReader io.Reader, snapshotID, layerBlobID, upperDirPath string) (err error) {
+func (t *Manager) generateBootstrap(tarReader io.Reader, snapshotID, layerBlobID, upperDirPath string, w *sync.WaitGroup) (err error) {
 	snapshotImageDir := filepath.Join(upperDirPath, "image")
 	if err := os.MkdirAll(snapshotImageDir, 0750); err != nil {
 		return errors.Wrapf(err, "create data dir %s for tarfs snapshot", snapshotImageDir)
@@ -235,20 +236,33 @@ func (t *Manager) generateBootstrap(tarReader io.Reader, snapshotID, layerBlobID
 	defer os.Remove(layerTarFileTmp)
 
 	fifoName := filepath.Join(upperDirPath, "layer_"+snapshotID+"_"+"tar.fifo")
-	if err = syscall.Mkfifo(fifoName, 0644); err != nil {
+	if err = syscall.Mkfifo(fifoName, 0640); err != nil {
 		return err
 	}
 	defer os.Remove(fifoName)
 
+	w.Add(1)
 	go func() {
-		fifoFile, err := os.OpenFile(fifoName, os.O_WRONLY, os.ModeNamedPipe)
-		if err != nil {
-			log.L.Warnf("can not open fifo file,  err %v", err)
-			return
+		defer w.Done()
+
+		var fifoFile *os.File
+		for i := 1; i < 100 && fifoFile == nil; i++ {
+			file, err := os.OpenFile(fifoName, os.O_RDWR, os.ModeNamedPipe)
+			switch {
+			case err == nil:
+				fifoFile = file
+			case os.IsNotExist(err) || os.IsPermission(err):
+				log.L.Warnf("open fifo file, %v", err)
+				return
+			default:
+				log.L.Warnf("open fifo file, %v", err)
+				time.Sleep(time.Duration(i) * 10 * time.Millisecond)
+			}
 		}
 		defer fifoFile.Close()
+
 		if _, err := io.Copy(fifoFile, io.TeeReader(tarReader, tarFile)); err != nil {
-			log.L.Warnf("tar stream copy err %v", err)
+			log.L.Warnf("tar stream copy, %v", err)
 		}
 	}()
 
@@ -338,6 +352,9 @@ func (t *Manager) blobProcess(ctx context.Context, snapshotID, ref string,
 	process := func(rc io.ReadCloser, remote *remote.Remote) error {
 		defer rc.Close()
 
+		var w sync.WaitGroup
+		defer w.Wait()
+
 		ds, err := compression.DecompressStream(rc)
 		if err != nil {
 			return epilog(err, "unpack layer blob stream for tarfs")
@@ -351,7 +368,7 @@ func (t *Manager) blobProcess(ctx context.Context, snapshotID, ref string,
 			}
 			digester := digest.Canonical.Digester()
 			dr := io.TeeReader(ds, digester.Hash())
-			err = t.generateBootstrap(dr, snapshotID, layerBlobID, upperDirPath)
+			err = t.generateBootstrap(dr, snapshotID, layerBlobID, upperDirPath, &w)
 			switch {
 			case err != nil && !errdefs.IsAlreadyExists(err):
 				return epilog(err, "generate tarfs from image layer blob")
@@ -362,7 +379,7 @@ func (t *Manager) blobProcess(ctx context.Context, snapshotID, ref string,
 				return epilog(nil, msg)
 			}
 		} else {
-			err = t.generateBootstrap(ds, snapshotID, layerBlobID, upperDirPath)
+			err = t.generateBootstrap(ds, snapshotID, layerBlobID, upperDirPath, &w)
 			if err != nil && !errdefs.IsAlreadyExists(err) {
 				return epilog(err, "generate tarfs data from image layer blob")
 			}