mirror of https://github.com/k3s-io/k3s
53 lines
1.5 KiB
Go
53 lines
1.5 KiB
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 continuity
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
// hardlinkKey provides a tuple-key for managing hardlinks. This is system-
|
|
// specific.
|
|
type hardlinkKey struct {
|
|
dev uint64
|
|
inode uint64
|
|
}
|
|
|
|
// newHardlinkKey returns a hardlink key for the provided file info. If the
|
|
// resource does not represent a possible hardlink, errNotAHardLink will be
|
|
// returned.
|
|
func newHardlinkKey(fi os.FileInfo) (hardlinkKey, error) {
|
|
sys, ok := fi.Sys().(*syscall.Stat_t)
|
|
if !ok {
|
|
return hardlinkKey{}, fmt.Errorf("cannot resolve (*syscall.Stat_t) from os.FileInfo")
|
|
}
|
|
|
|
if sys.Nlink < 2 {
|
|
// NOTE(stevvooe): This is not always true for all filesystems. We
|
|
// should somehow detect this and provided a slow "polyfill" that
|
|
// leverages os.SameFile if we detect a filesystem where link counts
|
|
// is not really supported.
|
|
return hardlinkKey{}, errNotAHardLink
|
|
}
|
|
|
|
return hardlinkKey{dev: uint64(sys.Dev), inode: uint64(sys.Ino)}, nil
|
|
}
|