[PATCH 2/3] Revert "UBUNTU: SAUCE: (noup) cgroup namespaces: add a 'nsroot=' mountinfo field"

[Serge Hallyn]

This reverts commit d5e333e38ae8db3c355dee0a3d49c362df250420.
---
 fs/kernfs/mount.c      |  2 +-
 include/linux/kernfs.h |  3 +--
 kernel/cgroup.c        | 29 +----------------------------
 3 files changed, 3 insertions(+), 31 deletions(-)

diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index 6d178f2..ac44f27 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -36,7 +36,7 @@ static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry)
 	struct kernfs_syscall_ops *scops = root->syscall_ops;
 
 	if (scops && scops->show_options)
-		return scops->show_options(sf, dentry, root);
+		return scops->show_options(sf, root);
 	return 0;
 }
 
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index d8bb68f..307e1a6 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -145,8 +145,7 @@ struct kernfs_node {
  */
 struct kernfs_syscall_ops {
 	int (*remount_fs)(struct kernfs_root *root, int *flags, char *data);
-	int (*show_options)(struct seq_file *sf, struct dentry *dentry,
-			    struct kernfs_root *root);
+	int (*show_options)(struct seq_file *sf, struct kernfs_root *root);
 
 	int (*mkdir)(struct kernfs_node *parent, const char *name,
 		     umode_t mode);
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8a4408f..a50b707 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1589,32 +1589,7 @@ static int rebind_subsystems(struct cgroup_root *dst_root,
 	return 0;
 }
 
-static void cgroup_show_nsroot(struct seq_file *seq, struct dentry *dentry,
-			       struct kernfs_root *kf_root)
-{
-	struct kernfs_node *d_kn = dentry->d_fsdata;
-	char *nsroot;
-	int len, ret;
-
-	if (!kf_root)
-		return;
-	len = kernfs_path_from_node(d_kn, kf_root->kn, NULL, 0);
-	if (len <= 0)
-		return;
-	nsroot = kzalloc(len + 1, GFP_ATOMIC);
-	if (!nsroot)
-		return;
-	ret = kernfs_path_from_node(d_kn, kf_root->kn, nsroot, len + 1);
-	if (ret <= 0 || ret > len)
-		goto out;
-
-	seq_show_option(seq, "nsroot", nsroot);
-
-out:
-	kfree(nsroot);
-}
-
-static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry,
+static int cgroup_show_options(struct seq_file *seq,
 			       struct kernfs_root *kf_root)
 {
 	struct cgroup_root *root = cgroup_root_from_kf(kf_root);
@@ -1640,8 +1615,6 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry,
 		seq_puts(seq, ",clone_children");
 	if (strlen(root->name))
 		seq_show_option(seq, "name", root->name);
-	cgroup_show_nsroot(seq, dentry, kf_root);
-
 	return 0;
 }
 
-- 
2.7.0