Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...

[karo-tx-linux.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 0f3527d6184a1597fb81f00a878df15eeab0ecf8..72fcd3069a909064529f1eb730e4985d16cef006 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -896,10 +896,13 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
                mutex_unlock(&cgroup_mutex);
 
                /*
-                * Drop the active superblock reference that we took when we
-                * created the cgroup
+                * 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().
                 */
-               deactivate_super(cgrp->root->sb);
+               dentry->d_fsdata = cgroup_diput;
 
                /*
                 * if we're getting rid of the cgroup, refcount should ensure
@@ -925,6 +928,13 @@ 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);
@@ -1532,6 +1542,7 @@ 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 =