cgroup: relocate setting of CGRP_DEAD

In cgroup_destroy_locked(), move setting of CGRP_DEAD above
invocations of kill_css().  This doesn't make any visible behavior
difference now but will be used to inhibit manipulating controller
enable states of a dying cgroup on the unified hierarchy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 306ad0ed19ef..b604c7e0cfc6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3868,6 +3868,15 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
                 return -EBUSY;
 
         /*
+         * Mark @cgrp dead.  This prevents further task migration and child
+         * creation by disabling cgroup_lock_live_group().  Note that
+         * CGRP_DEAD assertion is depended upon by css_next_child() to
+         * resume iteration after dropping RCU read lock.  See
+         * css_next_child() for details.
+         */
+        set_bit(CGRP_DEAD, &cgrp->flags);
+
+        /*
          * Initiate massacre of all css's.  cgroup_destroy_css_killed()
          * will be invoked to perform the rest of destruction once the
          * percpu refs of all css's are confirmed to be killed.  This
@@ -3878,15 +3887,6 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
                 kill_css(css);
         mutex_lock(&cgroup_mutex);
 
-        /*
-         * Mark @cgrp dead.  This prevents further task migration and child
-         * creation by disabling cgroup_lock_live_group().  Note that
-         * CGRP_DEAD assertion is depended upon by css_next_child() to
-         * resume iteration after dropping RCU read lock.  See
-         * css_next_child() for details.
-         */
-        set_bit(CGRP_DEAD, &cgrp->flags);
-
         /* CGRP_DEAD is set, remove from ->release_list for the last time */
         raw_spin_lock(&release_list_lock);
         if (!list_empty(&cgrp->release_list))