1 files changed, 30 insertions, 27 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 1d2b6ceea95d..d9d5648f3cdc 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -265,7 +265,7 @@ list_for_each_entry(_root, &roots, root_list)
 /* the list of cgroups eligible for automatic release. Protected by
  * release_list_lock */
 static LIST_HEAD(release_list);
-static DEFINE_SPINLOCK(release_list_lock);
+static DEFINE_RAW_SPINLOCK(release_list_lock);
 static void cgroup_release_agent(struct work_struct *work);
 static DECLARE_WORK(release_agent_work, cgroup_release_agent);
 static void check_for_release(struct cgroup *cgrp);
@@ -2027,7 +2027,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
                 goto out_free_group_list;
 
         /* prevent changes to the threadgroup list while we take a snapshot. */
-        rcu_read_lock();
+        read_lock(&tasklist_lock);
         if (!thread_group_leader(leader)) {
                 /*
                  * a race with de_thread from another thread's exec() may strip
@@ -2036,7 +2036,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
                  * throw this task away and try again (from cgroup_procs_write);
                  * this is "double-double-toil-and-trouble-check locking".
                  */
-                rcu_read_unlock();
+                read_unlock(&tasklist_lock);
                 retval = -EAGAIN;
                 goto out_free_group_list;
         }
@@ -2057,7 +2057,7 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
         } while_each_thread(leader, tsk);
         /* remember the number of threads in the array for later. */
         group_size = i;
-        rcu_read_unlock();
+        read_unlock(&tasklist_lock);
 
         /*
          * step 1: check that we can legitimately attach to the cgroup.
@@ -2135,14 +2135,17 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
                 oldcgrp = task_cgroup_from_root(tsk, root);
                 if (cgrp == oldcgrp)
                         continue;
-                /* attach each task to each subsystem */
-                for_each_subsys(root, ss) {
-                        if (ss->attach_task)
-                                ss->attach_task(cgrp, tsk);
-                }
                 /* if the thread is PF_EXITING, it can just get skipped. */
                 retval = cgroup_task_migrate(cgrp, oldcgrp, tsk, true);
-                BUG_ON(retval != 0 && retval != -ESRCH);
+                if (retval == 0) {
+                        /* attach each task to each subsystem */
+                        for_each_subsys(root, ss) {
+                                if (ss->attach_task)
+                                        ss->attach_task(cgrp, tsk);
+                        }
+                } else {
+                        BUG_ON(retval != -ESRCH);
+                }
         }
         /* nothing is sensitive to fork() after this point. */
 
@@ -4014,11 +4017,11 @@ again:
         finish_wait(&cgroup_rmdir_waitq, &wait);
         clear_bit(CGRP_WAIT_ON_RMDIR, &cgrp->flags);
 
-        spin_lock(&release_list_lock);
+        raw_spin_lock(&release_list_lock);
         set_bit(CGRP_REMOVED, &cgrp->flags);
         if (!list_empty(&cgrp->release_list))
                 list_del_init(&cgrp->release_list);
-        spin_unlock(&release_list_lock);
+        raw_spin_unlock(&release_list_lock);
 
         cgroup_lock_hierarchy(cgrp->root);
         /* delete this cgroup from parent->children */
@@ -4671,13 +4674,13 @@ static void check_for_release(struct cgroup *cgrp)
                  * already queued for a userspace notification, queue
                  * it now */
                 int need_schedule_work = 0;
-                spin_lock(&release_list_lock);
+                raw_spin_lock(&release_list_lock);
                 if (!cgroup_is_removed(cgrp) &&
                     list_empty(&cgrp->release_list)) {
                         list_add(&cgrp->release_list, &release_list);
                         need_schedule_work = 1;
                 }
-                spin_unlock(&release_list_lock);
+                raw_spin_unlock(&release_list_lock);
                 if (need_schedule_work)
                         schedule_work(&release_agent_work);
         }
@@ -4729,7 +4732,7 @@ static void cgroup_release_agent(struct work_struct *work)
 {
         BUG_ON(work != &release_agent_work);
         mutex_lock(&cgroup_mutex);
-        spin_lock(&release_list_lock);
+        raw_spin_lock(&release_list_lock);
         while (!list_empty(&release_list)) {
                 char *argv[3], *envp[3];
                 int i;
@@ -4738,7 +4741,7 @@ static void cgroup_release_agent(struct work_struct *work)
                                                     struct cgroup,
                                                     release_list);
                 list_del_init(&cgrp->release_list);
-                spin_unlock(&release_list_lock);
+                raw_spin_unlock(&release_list_lock);
                 pathbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
                 if (!pathbuf)
                         goto continue_free;
@@ -4768,9 +4771,9 @@ static void cgroup_release_agent(struct work_struct *work)
  continue_free:
                 kfree(pathbuf);
                 kfree(agentbuf);
-                spin_lock(&release_list_lock);
+                raw_spin_lock(&release_list_lock);
         }
-        spin_unlock(&release_list_lock);
+        raw_spin_unlock(&release_list_lock);
         mutex_unlock(&cgroup_mutex);
 }
 
@@ -4880,9 +4883,9 @@ void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css)
 
         rcu_assign_pointer(id->css, NULL);
         rcu_assign_pointer(css->id, NULL);
-        spin_lock(&ss->id_lock);
+        write_lock(&ss->id_lock);
         idr_remove(&ss->idr, id->id);
-        spin_unlock(&ss->id_lock);
+        write_unlock(&ss->id_lock);
         kfree_rcu(id, rcu_head);
 }
 EXPORT_SYMBOL_GPL(free_css_id);
@@ -4908,10 +4911,10 @@ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
                 error = -ENOMEM;
                 goto err_out;
         }
-        spin_lock(&ss->id_lock);
+        write_lock(&ss->id_lock);
         /* Don't use 0. allocates an ID of 1-65535 */
         error = idr_get_new_above(&ss->idr, newid, 1, &myid);
-        spin_unlock(&ss->id_lock);
+        write_unlock(&ss->id_lock);
 
         /* Returns error when there are no free spaces for new ID.*/
         if (error) {
@@ -4926,9 +4929,9 @@ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
         return newid;
 remove_idr:
         error = -ENOSPC;
-        spin_lock(&ss->id_lock);
+        write_lock(&ss->id_lock);
         idr_remove(&ss->idr, myid);
-        spin_unlock(&ss->id_lock);
+        write_unlock(&ss->id_lock);
 err_out:
         kfree(newid);
         return ERR_PTR(error);
@@ -4940,7 +4943,7 @@ static int __init_or_module cgroup_init_idr(struct cgroup_subsys *ss,
 {
         struct css_id *newid;
 
-        spin_lock_init(&ss->id_lock);
+        rwlock_init(&ss->id_lock);
         idr_init(&ss->idr);
 
         newid = get_new_cssid(ss, 0);
@@ -5035,9 +5038,9 @@ css_get_next(struct cgroup_subsys *ss, int id,
                  * scan next entry from bitmap(tree), tmpid is updated after
                  * idr_get_next().
                  */
-                spin_lock(&ss->id_lock);
+                read_lock(&ss->id_lock);
                 tmp = idr_get_next(&ss->idr, &tmpid);
-                spin_unlock(&ss->id_lock);
+                read_unlock(&ss->id_lock);
 
                 if (!tmp)
                         break;