containerd/core/diff/apply/apply_linux.go
Sebastiaan van Stijn 9776047243
migrate to github.com/moby/sys/userns
Commit 8437c567d8 migrated the use of the
userns package to the github.com/moby/sys/user module.

After further discussion with maintainers, it was decided to move the
userns package to a separate module, as it has no direct relation with
"user" operations (other than having "user" in its name).

This patch migrates our code to use the new module.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2024-08-08 12:48:54 +02:00

106 lines
2.7 KiB
Go

/*
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 apply
import (
"context"
"fmt"
"io"
"os"
"strings"
"github.com/moby/sys/userns"
"golang.org/x/sys/unix"
"github.com/containerd/containerd/v2/core/mount"
"github.com/containerd/containerd/v2/pkg/archive"
"github.com/containerd/errdefs"
)
func apply(ctx context.Context, mounts []mount.Mount, r io.Reader, sync bool) (retErr error) {
switch {
case len(mounts) == 1 && mounts[0].Type == "overlay":
// OverlayConvertWhiteout (mknod c 0 0) doesn't work in userns.
// https://github.com/containerd/containerd/issues/3762
if userns.RunningInUserNS() {
break
}
path, parents, err := getOverlayPath(mounts[0].Options)
if err != nil {
if errdefs.IsInvalidArgument(err) {
break
}
return err
}
opts := []archive.ApplyOpt{
archive.WithConvertWhiteout(archive.OverlayConvertWhiteout),
}
if len(parents) > 0 {
opts = append(opts, archive.WithParents(parents))
}
_, err = archive.Apply(ctx, path, r, opts...)
if err == nil && sync {
err = doSyncFs(path)
}
return err
case sync && len(mounts) == 1 && mounts[0].Type == "bind":
defer func() {
if retErr != nil {
return
}
retErr = doSyncFs(mounts[0].Source)
}()
}
return mount.WithTempMount(ctx, mounts, func(root string) error {
_, err := archive.Apply(ctx, root, r)
return err
})
}
func getOverlayPath(options []string) (upper string, lower []string, err error) {
const upperdirPrefix = "upperdir="
const lowerdirPrefix = "lowerdir="
for _, o := range options {
if strings.HasPrefix(o, upperdirPrefix) {
upper = strings.TrimPrefix(o, upperdirPrefix)
} else if strings.HasPrefix(o, lowerdirPrefix) {
lower = strings.Split(strings.TrimPrefix(o, lowerdirPrefix), ":")
}
}
if upper == "" {
return "", nil, fmt.Errorf("upperdir not found: %w", errdefs.ErrInvalidArgument)
}
return
}
func doSyncFs(file string) error {
fd, err := os.Open(file)
if err != nil {
return fmt.Errorf("failed to open %s: %w", file, err)
}
defer fd.Close()
err = unix.Syncfs(int(fd.Fd()))
if err != nil {
return fmt.Errorf("failed to syncfs for %s: %w", file, err)
}
return nil
}