1 files changed, 34 insertions, 0 deletions
diff --git a/fs/pnode.c b/fs/pnode.c
index 18e56fc4a88c..c35d03d42902 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -411,3 +411,37 @@ int propagate_umount(struct hlist_head *list)
 		__propagate_umount(mnt);
 	return 0;
 }
+
+/*
+ *  Iterates over all slaves, and slaves of slaves.
+ */
+static struct mount *next_descendent(struct mount *root, struct mount *cur)
+{
+	if (!IS_MNT_NEW(cur) && !list_empty(&cur->mnt_slave_list))
+		return first_slave(cur);
+	do {
+		struct mount *master = cur->mnt_master;
+
+		if (!master || cur->mnt_slave.next != &master->mnt_slave_list) {
+			struct mount *next = next_slave(cur);
+
+			return (next == root) ? NULL : next;
+		}
+		cur = master;
+	} while (cur != root);
+	return NULL;
+}
+
+void propagate_remount(struct mount *mnt)
+{
+	struct mount *m = mnt;
+	struct super_block *sb = mnt->mnt.mnt_sb;
+
+	if (sb->s_op->copy_mnt_data) {
+		m = next_descendent(mnt, m);
+		while (m) {
+			sb->s_op->copy_mnt_data(m->mnt.data, mnt->mnt.data);
+			m = next_descendent(mnt, m);
+		}
+	}
+}