cgroup/pids: Remove unreachable paths of pids_{can,cancel}_fork

According to the implementation of cgroup_css_set_fork(), it will fail
if cset cannot be found and the can_fork/cancel_fork methods will not
be called in this case, which means that the argument 'cset' for these
methods must not be NULL, so remove the unrechable paths in them.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c
index 34aa63d7c9c659ba1634148f3289a849901e88da..8f61114c36dd35a1bcb2132b857e215fc56e0662 100644 (file)
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -272,15 +272,10 @@ static void pids_event(struct pids_cgroup *pids_forking,
  */
 static int pids_can_fork(struct task_struct *task, struct css_set *cset)
 {
-       struct cgroup_subsys_state *css;
        struct pids_cgroup *pids, *pids_over_limit;
        int err;
 
-       if (cset)
-               css = cset->subsys[pids_cgrp_id];
-       else
-               css = task_css_check(current, pids_cgrp_id, true);
-       pids = css_pids(css);
+       pids = css_pids(cset->subsys[pids_cgrp_id]);
        err = pids_try_charge(pids, 1, &pids_over_limit);
        if (err)
                pids_event(pids, pids_over_limit);
@@ -290,14 +285,9 @@ static int pids_can_fork(struct task_struct *task, struct css_set *cset)
 
 static void pids_cancel_fork(struct task_struct *task, struct css_set *cset)
 {
-       struct cgroup_subsys_state *css;
        struct pids_cgroup *pids;
 
-       if (cset)
-               css = cset->subsys[pids_cgrp_id];
-       else
-               css = task_css_check(current, pids_cgrp_id, true);
-       pids = css_pids(css);
+       pids = css_pids(cset->subsys[pids_cgrp_id]);
        pids_uncharge(pids, 1);
 }