Moved directory walk, compare file code to it's own function

plugins/ipam/host-local/backend/disk/backend.go

@@ -26,6 +26,7 @@ import (
 )
 
 const lastIPFilePrefix = "last_reserved_ip."
+const LineBreak = "\r\n"
 
 var defaultDataDir = "/var/lib/cni/networks"
 
@@ -65,7 +66,7 @@ func (s *Store) Reserve(id string, ifname string, ip net.IP, rangeID string) (bo
  if err != nil {
  return false, err
  }
- if _, err := f.WriteString(strings.TrimSpace(id) + "\n" + ifname); err != nil {
+ if _, err := f.WriteString(strings.TrimSpace(id) + LineBreak + ifname); err != nil {
  f.Close()
  os.Remove(f.Name())
  return false, err
@@ -97,10 +98,7 @@ func (s *Store) Release(ip net.IP) error {
  return os.Remove(GetEscapedPath(s.dataDir, ip.String()))
 }
 
-// N.B. This function eats errors to be tolerant and
-// release as much as possible
-func (s *Store) ReleaseByID(id string, ifname string) error {
-
+func (s *Store) ReleaseByKey(id string, ifname string, match string) (bool, error) {
  found := false
  err := filepath.Walk(s.dataDir, func(path string, info os.FileInfo, err error) error {
  if err != nil || info.IsDir() {
@@ -110,35 +108,29 @@ func (s *Store) ReleaseByID(id string, ifname string) error {
  if err != nil {
  return nil
  }
- if strings.TrimSpace(string(data)) == (strings.TrimSpace(id) + "\n" + ifname) {
+ if strings.TrimSpace(string(data)) == match {
  if err := os.Remove(path); err != nil {
  return nil
  }
  found = true
  }
  return nil
  })
+ return found, err
 
- if (!found) && (err == nil) {
- err = filepath.Walk(s.dataDir, func(path string, info os.FileInfo, err error) error {
- if err != nil || info.IsDir() {
- return nil
- }
- data, err := ioutil.ReadFile(path)
- if err != nil {
- return nil
- }
- isCurrent := strings.Contains(string(data), "\n")
-
- if !isCurrent {
- if strings.TrimSpace(string(data)) == (strings.TrimSpace(id)) {
- if err := os.Remove(path); err != nil {
- return nil
- }
- }
- }
- return nil
- })
+}
+
+// N.B. This function eats errors to be tolerant and
+// release as much as possible
+func (s *Store) ReleaseByID(id string, ifname string) error {
+ found := false
+ match := strings.TrimSpace(id) + LineBreak + ifname
+ found, err := s.ReleaseByKey(id, ifname, match)
+
+ // For backwards compatibility, look for files written by a previous version
+ if !found && err == nil {
+ match := strings.TrimSpace(id)
+ found, err = s.ReleaseByKey(id, ifname, match)
  }
  return err
 }