moby/vendor/github.com/containerd/continuity/driver/driver_unix.go

// +build linux darwin freebsd solaris

/*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package driver

import (
	"errors"
	"fmt"
	"os"
	"sort"

	"github.com/containerd/continuity/devices"
	"github.com/containerd/continuity/sysx"
)

func (d *driver) Mknod(path string, mode os.FileMode, major, minor int) error {
	err := devices.Mknod(path, mode, major, minor)
	if err != nil {
		err = &os.PathError{Op: "mknod", Path: path, Err: err}
	}
	return err
}

func (d *driver) Mkfifo(path string, mode os.FileMode) error {
	if mode&os.ModeNamedPipe == 0 {
		return errors.New("mode passed to Mkfifo does not have the named pipe bit set")
	}
	// mknod with a mode that has ModeNamedPipe set creates a fifo, not a
	// device.
	err := devices.Mknod(path, mode, 0, 0)
	if err != nil {
		err = &os.PathError{Op: "mkfifo", Path: path, Err: err}
	}
	return err
}

// Getxattr returns all of the extended attributes for the file at path p.
func (d *driver) Getxattr(p string) (map[string][]byte, error) {
	xattrs, err := sysx.Listxattr(p)
	if err != nil {
		return nil, fmt.Errorf("listing %s xattrs: %v", p, err)
	}

	sort.Strings(xattrs)
	m := make(map[string][]byte, len(xattrs))

	for _, attr := range xattrs {
		value, err := sysx.Getxattr(p, attr)
		if err != nil {
			return nil, fmt.Errorf("getting %q xattr on %s: %v", attr, p, err)
		}

		// NOTE(stevvooe): This append/copy tricky relies on unique
		// xattrs. Break this out into an alloc/copy if xattrs are no
		// longer unique.
		m[attr] = append(m[attr], value...)
	}

	return m, nil
}

// Setxattr sets all of the extended attributes on file at path, following
// any symbolic links, if necessary. All attributes on the target are
// replaced by the values from attr. If the operation fails to set any
// attribute, those already applied will not be rolled back.
func (d *driver) Setxattr(path string, attrMap map[string][]byte) error {
	for attr, value := range attrMap {
		if err := sysx.Setxattr(path, attr, value, 0); err != nil {
			return fmt.Errorf("error setting xattr %q on %s: %v", attr, path, err)
		}
	}

	return nil
}

// LGetxattr returns all of the extended attributes for the file at path p
// not following symbolic links.
func (d *driver) LGetxattr(p string) (map[string][]byte, error) {
	xattrs, err := sysx.LListxattr(p)
	if err != nil {
		return nil, fmt.Errorf("listing %s xattrs: %v", p, err)
	}

	sort.Strings(xattrs)
	m := make(map[string][]byte, len(xattrs))

	for _, attr := range xattrs {
		value, err := sysx.LGetxattr(p, attr)
		if err != nil {
			return nil, fmt.Errorf("getting %q xattr on %s: %v", attr, p, err)
		}

		// NOTE(stevvooe): This append/copy tricky relies on unique
		// xattrs. Break this out into an alloc/copy if xattrs are no
		// longer unique.
		m[attr] = append(m[attr], value...)
	}

	return m, nil
}

// LSetxattr sets all of the extended attributes on file at path, not
// following any symbolic links. All attributes on the target are
// replaced by the values from attr. If the operation fails to set any
// attribute, those already applied will not be rolled back.
func (d *driver) LSetxattr(path string, attrMap map[string][]byte) error {
	for attr, value := range attrMap {
		if err := sysx.LSetxattr(path, attr, value, 0); err != nil {
			return fmt.Errorf("error setting xattr %q on %s: %v", attr, path, err)
		}
	}

	return nil
}

func (d *driver) DeviceInfo(fi os.FileInfo) (maj uint64, min uint64, err error) {
	return devices.DeviceInfo(fi)
}