Fix race condition when using cgroups.Paths

hqhq · hqhq · commit 6ecb469b2b98 · 2016-08-02T15:43:04.000+08:00
Signed-off-by: Qiang Huang &lt;h.huangqiang@huawei.com&gt;
diff --git a/libcontainer/cgroups/fs/apply_raw.go b/libcontainer/cgroups/fs/apply_raw.go
@@ -104,6 +104,8 @@ func (m *Manager) Apply(pid int) (err error) {
 	if m.Cgroups == nil {
 		return nil
 	}
+	m.mu.Lock()
+	defer m.mu.Unlock()
 
 	var c = m.Cgroups
 
@@ -128,8 +130,6 @@ func (m *Manager) Apply(pid int) (err error) {
 		return cgroups.EnterPid(m.Paths, pid)
 	}
 
-	m.mu.Lock()
-	defer m.mu.Unlock()
 	paths := make(map[string]string)
 	for _, sys := range subsystems {
 		if err := sys.Apply(d); err != nil {

Original file line number	Diff line number	Diff line change
`@@ -104,6 +104,8 @@ func (m *Manager) Apply(pid int) (err error) {`
`104`	`104`	`if m.Cgroups == nil {`
`105`	`105`	`return nil`
`106`	`106`	`}`
	`107`	`+ m.mu.Lock()`
	`108`	`+ defer m.mu.Unlock()`
`107`	`109`
`108`	`110`	`var c = m.Cgroups`
`109`	`111`
`@@ -128,8 +130,6 @@ func (m *Manager) Apply(pid int) (err error) {`
`128`	`130`	`return cgroups.EnterPid(m.Paths, pid)`
`129`	`131`	`}`
`130`	`132`
`131`		`- m.mu.Lock()`
`132`		`- defer m.mu.Unlock()`
`133`	`133`	`paths := make(map[string]string)`
`134`	`134`	`for _, sys := range subsystems {`
`135`	`135`	`if err := sys.Apply(d); err != nil {`