[PATCH] cgroup: simplify code for cgroup_subtree_control_write()

[Peng Wang]

Process "enable" and "disable" earlier to simplify code.

Signed-off-by: Peng Wang <rock...@whu.edu.cn>
---
 kernel/cgroup/cgroup.c | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index bf9dbffd46b1..e49b8bde5c99 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3269,23 +3269,21 @@ static ssize_t cgroup_subtree_control_write(struct 
kernfs_open_file *of,
        if (!cgrp)
                return -ENODEV;
 
+       enable &= ~(cgrp->subtree_control);
+       disable &= cgrp->subtree_control;
+
+       if (!enable && !disable) {
+               ret = 0;
+               goto out_unlock;
+       }
+
        for_each_subsys(ss, ssid) {
                if (enable & (1 << ssid)) {
-                       if (cgrp->subtree_control & (1 << ssid)) {
-                               enable &= ~(1 << ssid);
-                               continue;
-                       }
-
                        if (!(cgroup_control(cgrp) & (1 << ssid))) {
                                ret = -ENOENT;
                                goto out_unlock;
                        }
                } else if (disable & (1 << ssid)) {
-                       if (!(cgrp->subtree_control & (1 << ssid))) {
-                               disable &= ~(1 << ssid);
-                               continue;
-                       }
-
                        /* a child has it enabled? */
                        cgroup_for_each_live_child(child, cgrp) {
                                if (child->subtree_control & (1 << ssid)) {
@@ -3296,11 +3294,6 @@ static ssize_t cgroup_subtree_control_write(struct 
kernfs_open_file *of,
                }
        }
 
-       if (!enable && !disable) {
-               ret = 0;
-               goto out_unlock;
-       }
-
        ret = cgroup_vet_subtree_control_enable(cgrp, enable);
        if (ret)
                goto out_unlock;
-- 
2.19.1