From 39ff0ed013102542292f3270ed99babe3964c2a8 Mon Sep 17 00:00:00 2001
From: yangjiaqi <yangjiaqi16@huawei.com>
Date: Fri, 11 Aug 2023 14:47:05 +0800
Subject: [PATCH] use file locks to avoid remounting the sharepath/master dir
Signed-off-by: yangjiaqi <yangjiaqi16@huawei.com>
---
utils/transfer.go | 40 +++++++++++++++++++++++++++++++++++-----
1 file changed, 35 insertions(+), 5 deletions(-)
diff --git a/utils/transfer.go b/utils/transfer.go
index 9c6d527..789cb99 100644
--- a/utils/transfer.go
+++ b/utils/transfer.go
@@ -20,17 +20,20 @@ import (
"path/filepath"
"syscall"
- mymount "isula.org/syscontainer-tools/pkg/mount"
"github.com/docker/docker/pkg/mount"
+ "github.com/sirupsen/logrus"
+ "golang.org/x/sys/unix"
+ hconfig "isula.org/syscontainer-tools/config"
+ mymount "isula.org/syscontainer-tools/pkg/mount"
"isula.org/syscontainer-tools/types"
- "github.com/sirupsen/logrus"
)
const (
masterPath = "/.sharedpath/master"
midTransferPath = "/.sharedpath/midpath"
slavePath = "/.sharedpath"
+ lockFile = "master_locker"
)
/* Add path to container when it is running
@@ -171,17 +174,44 @@ func GetSlavePath() string {
// PrepareHostPath prepare host path
func PrepareHostPath(id string) error {
+ lockFile := filepath.Join(hconfig.IsuladToolsDir, lockFile)
+ // get lock file handler
+ f, err := os.OpenFile(lockFile, os.O_RDONLY|os.O_CREATE, 0600)
+ if err != nil {
+ return err
+ }
+ defer f.Close()
- if err := os.MkdirAll(masterPath, 0600); err != nil {
- return fmt.Errorf("create host shared path failed, err: %s", err)
+ // lock
+ if err := unix.Flock(int(f.Fd()), unix.LOCK_EX); err != nil {
+ return fmt.Errorf("fail to lock file %v: %v", f.Name(), err)
}
- if m, _ := mount.Mounted(masterPath); m != true {
+ mountErr := func() error {
+ mounted, err := mount.Mounted(masterPath)
+ if err != nil {
+ return fmt.Errorf("fail to know whether %v is mounted: %v", masterPath, err)
+ }
+ // has mounted
+ if mounted {
+ return nil
+ }
+ // do nothing if the directory has already been existed
+ if err := os.MkdirAll(masterPath, 0600); err != nil {
+ return fmt.Errorf("create host shared path failed, err: %s", err)
+ }
if err := mount.Mount("none", masterPath, "tmpfs", "size=16m"); err != nil {
return fmt.Errorf("mount host shared path failed:, %s", err)
}
if err := syscall.Mount("none", masterPath, "none", syscall.MS_SHARED|syscall.MS_REC, ""); err != nil {
return fmt.Errorf("failed to make mountpoint shared, err: %s", err)
}
+ return nil
+ }()
+ if unlockErr := unix.Flock(int(f.Fd()), unix.LOCK_UN); unlockErr != nil {
+ logrus.Errorf("failed to unlock %v : %v", f.Name(), unlockErr)
+ }
+ if mountErr != nil {
+ return mountErr
}
if err := os.MkdirAll(filepath.Join(masterPath, id), 0600); err != nil {
--
2.30.0