diff options
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 40 |
1 files changed, 33 insertions, 7 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 4fd90e129772..be45d2f6008a 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1554,7 +1554,7 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { int retval = 0; - struct cgroup_subsys *ss; + struct cgroup_subsys *ss, *failed_ss = NULL; struct cgroup *oldcgrp; struct css_set *cg; struct css_set *newcg; @@ -1568,8 +1568,16 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) for_each_subsys(root, ss) { if (ss->can_attach) { retval = ss->can_attach(ss, cgrp, tsk, false); - if (retval) - return retval; + if (retval) { + /* + * Remember on which subsystem the can_attach() + * failed, so that we only call cancel_attach() + * against the subsystems whose can_attach() + * succeeded. (See below) + */ + failed_ss = ss; + goto out; + } } } @@ -1583,14 +1591,17 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) */ newcg = find_css_set(cg, cgrp); put_css_set(cg); - if (!newcg) - return -ENOMEM; + if (!newcg) { + retval = -ENOMEM; + goto out; + } task_lock(tsk); if (tsk->flags & PF_EXITING) { task_unlock(tsk); put_css_set(newcg); - return -ESRCH; + retval = -ESRCH; + goto out; } rcu_assign_pointer(tsk->cgroups, newcg); task_unlock(tsk); @@ -1616,7 +1627,22 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) * is no longer empty. */ cgroup_wakeup_rmdir_waiter(cgrp); - return 0; +out: + if (retval) { + for_each_subsys(root, ss) { + if (ss == failed_ss) + /* + * This subsystem was the one that failed the + * can_attach() check earlier, so we don't need + * to call cancel_attach() against it or any + * remaining subsystems. + */ + break; + if (ss->cancel_attach) + ss->cancel_attach(ss, cgrp, tsk, false); + } + } + return retval; } /* |