freezer_cg: simplify freezer_change_state()

Just call unfreeze_cgroup() if goal_state == THAWED, and call
try_to_freeze_cgroup() if goal_state == FROZEN.

No behavior has been changed.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 12 deletions

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 5e6d26b66e88..7fa476f01d05 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -296,27 +296,22 @@ static int freezer_change_state(struct cgroup *cgroup,
         int retval = 0;
 
         freezer = cgroup_freezer(cgroup);
+
         spin_lock_irq(&freezer->lock);
+
         update_freezer_state(cgroup, freezer);
         if (goal_state == freezer->state)
                 goto out;
-        switch (freezer->state) {
+
+        switch (goal_state) {
         case CGROUP_THAWED:
-                retval = try_to_freeze_cgroup(cgroup, freezer);
+                unfreeze_cgroup(cgroup, freezer);
                 break;
-        case CGROUP_FREEZING:
-                if (goal_state == CGROUP_FROZEN) {
-                        /* Userspace is retrying after
-                         * "/bin/echo FROZEN > freezer.state" returned -EBUSY */
-                        retval = try_to_freeze_cgroup(cgroup, freezer);
-                        break;
-                }
-                /* state == FREEZING and goal_state == THAWED, so unfreeze */
         case CGROUP_FROZEN:
-                unfreeze_cgroup(cgroup, freezer);
+                retval = try_to_freeze_cgroup(cgroup, freezer);
                 break;
         default:
-                break;
+                BUG();
         }
 out:
         spin_unlock_irq(&freezer->lock);