1 files changed, 18 insertions, 18 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 72fcd3069a90..b303dfc7dce0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -255,12 +255,17 @@ int cgroup_lock_is_held(void)
 
 EXPORT_SYMBOL_GPL(cgroup_lock_is_held);
 
+static int css_unbias_refcnt(int refcnt)
+{
+        return refcnt >= 0 ? refcnt : refcnt - CSS_DEACT_BIAS;
+}
+
 /* the current nr of refs, always >= 0 whether @css is deactivated or not */
 static int css_refcnt(struct cgroup_subsys_state *css)
 {
         int v = atomic_read(&css->refcnt);
 
-        return v >= 0 ? v : v - CSS_DEACT_BIAS;
+        return css_unbias_refcnt(v);
 }
 
 /* convenient tests for these bits */
@@ -896,13 +901,10 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
                 mutex_unlock(&cgroup_mutex);
 
                 /*
-                 * We want to drop the active superblock reference from the
-                 * cgroup creation after all the dentry refs are gone -
-                 * kill_sb gets mighty unhappy otherwise.  Mark
-                 * dentry->d_fsdata with cgroup_diput() to tell
-                 * cgroup_d_release() to call deactivate_super().
+                 * Drop the active superblock reference that we took when we
+                 * created the cgroup
                  */
-                dentry->d_fsdata = cgroup_diput;
+                deactivate_super(cgrp->root->sb);
 
                 /*
                  * if we're getting rid of the cgroup, refcount should ensure
@@ -928,13 +930,6 @@ static int cgroup_delete(const struct dentry *d)
         return 1;
 }
 
-static void cgroup_d_release(struct dentry *dentry)
-{
-        /* did cgroup_diput() tell me to deactivate super? */
-        if (dentry->d_fsdata == cgroup_diput)
-                deactivate_super(dentry->d_sb);
-}
-
 static void remove_dir(struct dentry *d)
 {
         struct dentry *parent = dget(d->d_parent);
@@ -1542,7 +1537,6 @@ static int cgroup_get_rootdir(struct super_block *sb)
         static const struct dentry_operations cgroup_dops = {
                 .d_iput = cgroup_diput,
                 .d_delete = cgroup_delete,
-                .d_release = cgroup_d_release,
         };
 
         struct inode *inode =
@@ -3889,8 +3883,12 @@ static void css_dput_fn(struct work_struct *work)
 {
         struct cgroup_subsys_state *css =
                 container_of(work, struct cgroup_subsys_state, dput_work);
+        struct dentry *dentry = css->cgroup->dentry;
+        struct super_block *sb = dentry->d_sb;
 
-        dput(css->cgroup->dentry);
+        atomic_inc(&sb->s_active);
+        dput(dentry);
+        deactivate_super(sb);
 }
 
 static void init_cgroup_css(struct cgroup_subsys_state *css,
@@ -4982,10 +4980,12 @@ EXPORT_SYMBOL_GPL(__css_tryget);
 void __css_put(struct cgroup_subsys_state *css)
 {
         struct cgroup *cgrp = css->cgroup;
+        int v;
 
         rcu_read_lock();
-        atomic_dec(&css->refcnt);
-        switch (css_refcnt(css)) {
+        v = css_unbias_refcnt(atomic_dec_return(&css->refcnt));
+
+        switch (v) {
         case 1:
                 if (notify_on_release(cgrp)) {
                         set_bit(CGRP_RELEASABLE, &cgrp->flags);