[PATCH 03/34] VFS: Add CL_NO_SLAVE flag to clone_mnt()/copy_tree()

[Valerie Aurora <vaurora@redhat.com>]

Passing the CL_NO_SLAVE flag to clone_mnt() causes the clone
to fail if the source mnt is a slave.

Signed-off-by: Valerie Aurora <vaurora@redhat.com>
---
 fs/namespace.c |    3 +++
 fs/pnode.h     |    1 +
 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index eeb4c22..6956062 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -565,6 +565,9 @@ static struct vfsmount *clone_mnt(struct vfsmount *old, struct dentry *root,
 	if ((flag & CL_NO_SHARED) && (IS_MNT_SHARED(old)))
 		return ERR_PTR(-EINVAL);
 
+	if ((flag & CL_NO_SLAVE) && (IS_MNT_SLAVE(old)))
+		return ERR_PTR(-EINVAL);
+
 	mnt = alloc_vfsmnt(old->mnt_devname);
 	if (!mnt)
 		return ERR_PTR(-ENOMEM);
diff --git a/fs/pnode.h b/fs/pnode.h
index bcb3c47..8920e47 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -23,6 +23,7 @@
 #define CL_MAKE_SHARED 		0x08
 #define CL_PRIVATE 		0x10
 #define CL_NO_SHARED 		0x20
+#define CL_NO_SLAVE 		0x40
 
 static inline void set_mnt_shared(struct vfsmount *mnt)
 {
-- 
1.6.3.3