Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:
 "During v4.6-rc1 cgroup namespace support was merged.  There is an
  issue where it's impossible to tell whether a given cgroup mount point
  is bind mounted or namespaced.  Serge has been working on the issue
  but it took longer than expected to resolve, so the late pull request.

  Given that it's a completely new feature and the patches don't touch
  anything else, the risk seems acceptable.  However, if this is too
  late, an alternative is plugging new cgroup ns creation for v4.6 and
  retrying for v4.7"

* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix compile warning
  kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call
  cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces
  kernfs_path_from_node_locked: don't overwrite nlen

2 files changed, 18 insertions, 3 deletions

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 03b688d19f69..37f9678ae4df 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -153,9 +153,9 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to,
 	p = buf + len + nlen;
 	*p = '\0';
 	for (kn = kn_to; kn != common; kn = kn->parent) {
-		nlen = strlen(kn->name);
-		p -= nlen;
-		memcpy(p, kn->name, nlen);
+		size_t tmp = strlen(kn->name);
+		p -= tmp;
+		memcpy(p, kn->name, tmp);
 		*(--p) = '/';
 	}
 
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index f73541fbe7af..3d670a3678f2 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/namei.h>
+#include <linux/seq_file.h>
 
 #include "kernfs-internal.h"
 
@@ -40,6 +41,19 @@ static int kernfs_sop_show_options(struct seq_file *sf, struct dentry *dentry)
 	return 0;
 }
 
+static int kernfs_sop_show_path(struct seq_file *sf, struct dentry *dentry)
+{
+	struct kernfs_node *node = dentry->d_fsdata;
+	struct kernfs_root *root = kernfs_root(node);
+	struct kernfs_syscall_ops *scops = root->syscall_ops;
+
+	if (scops && scops->show_path)
+		return scops->show_path(sf, node, root);
+
+	seq_dentry(sf, dentry, " \t\n\\");
+	return 0;
+}
+
 const struct super_operations kernfs_sops = {
 	.statfs		= simple_statfs,
 	.drop_inode	= generic_delete_inode,
@@ -47,6 +61,7 @@ const struct super_operations kernfs_sops = {
 
 	.remount_fs	= kernfs_sop_remount_fs,
 	.show_options	= kernfs_sop_show_options,
+	.show_path	= kernfs_sop_show_path,
 };
 
 /**