Currently pids_can_attach() always returns 0 and never fails, so the
can_attach() and cancel_attach() hooks can be replaced by attach(),
since attach() is guaranteed to succeed and don't need to fallback.
Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
---
kernel/cgroup/pids.c | 25 ++-----------------------
1 file changed, 2 insertions(+), 23 deletions(-)
diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c
index 0e5ec7d59b4d..86d06f709957 100644
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -186,7 +186,7 @@ static int pids_try_charge(struct pids_cgroup *pids, int num)
return -EAGAIN;
}
-static int pids_can_attach(struct cgroup_taskset *tset)
+static void pids_attach(struct cgroup_taskset *tset)
{
struct task_struct *task;
struct cgroup_subsys_state *dst_css;
@@ -207,26 +207,6 @@ static int pids_can_attach(struct cgroup_taskset *tset)
pids_charge(pids, 1);
pids_uncharge(old_pids, 1);
}
-
- return 0;
-}
-
-static void pids_cancel_attach(struct cgroup_taskset *tset)
-{
- struct task_struct *task;
- struct cgroup_subsys_state *dst_css;
-
- cgroup_taskset_for_each(task, dst_css, tset) {
- struct pids_cgroup *pids = css_pids(dst_css);
- struct cgroup_subsys_state *old_css;
- struct pids_cgroup *old_pids;
-
- old_css = task_css(task, pids_cgrp_id);
- old_pids = css_pids(old_css);
-
- pids_charge(old_pids, 1);
- pids_uncharge(pids, 1);
- }
}
/*
@@ -374,8 +354,7 @@ static struct cftype pids_files[] = {
struct cgroup_subsys pids_cgrp_subsys = {
.css_alloc = pids_css_alloc,
.css_free = pids_css_free,
- .can_attach = pids_can_attach,
- .cancel_attach = pids_cancel_attach,
+ .attach = pids_attach,
.can_fork = pids_can_fork,
.cancel_fork = pids_cancel_fork,
.release = pids_release,
--
2.34.1
