runc/libcontainer/cgroups/fscommon/fscommon.go

61 lines
1.3 KiB
Go

// +build linux
package fscommon
import (
"io/ioutil"
"os"
"syscall"
securejoin "github.com/cyphar/filepath-securejoin"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
func WriteFile(dir, file, data string) error {
if dir == "" {
return errors.Errorf("no directory specified for %s", file)
}
path, err := securejoin.SecureJoin(dir, file)
if err != nil {
return err
}
if err := retryingWriteFile(path, []byte(data), 0700); err != nil {
return errors.Wrapf(err, "failed to write %q to %q", data, path)
}
return nil
}
func ReadFile(dir, file string) (string, error) {
if dir == "" {
return "", errors.Errorf("no directory specified for %s", file)
}
path, err := securejoin.SecureJoin(dir, file)
if err != nil {
return "", err
}
data, err := ioutil.ReadFile(path)
return string(data), err
}
func retryingWriteFile(filename string, data []byte, perm os.FileMode) error {
for {
err := ioutil.WriteFile(filename, data, perm)
if isInterruptedWriteFile(err) {
logrus.Infof("interrupted while writing %s to %s", string(data), filename)
continue
}
return err
}
}
func isInterruptedWriteFile(err error) bool {
if patherr, ok := err.(*os.PathError); ok {
errno, ok2 := patherr.Err.(syscall.Errno)
if ok2 && errno == syscall.EINTR {
return true
}
}
return false
}