1 files changed, 30 insertions, 6 deletions

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index ba5c80903efe..bafdf86b0497 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -56,22 +56,38 @@ static int __init mount_param(char *str)
 }
 __setup("devtmpfs.mount=", mount_param);
 
+static struct vfsmount *mnt;
+
+static struct dentry *public_dev_mount(struct file_system_type *fs_type, int flags,
+		      const char *dev_name, void *data)
+{
+	struct super_block *s = mnt->mnt_sb;
+	atomic_inc(&s->s_active);
+	down_write(&s->s_umount);
+	return dget(s->s_root);
+}
+
 static struct dentry *dev_mount(struct file_system_type *fs_type, int flags,
 		      const char *dev_name, void *data)
 {
 #ifdef CONFIG_TMPFS
-	return mount_single(fs_type, flags, data, shmem_fill_super);
+	return mount_nodev(fs_type, flags, data, shmem_fill_super);
 #else
-	return mount_single(fs_type, flags, data, ramfs_fill_super);
+	return ramfs_mount(fs_type, flags, dev_name, data);
 #endif
 }
 
-static struct file_system_type dev_fs_type = {
+static struct file_system_type internal_fs_type = {
 	.name = "devtmpfs",
 	.mount = dev_mount,
 	.kill_sb = kill_litter_super,
 };
 
+static struct file_system_type dev_fs_type = {
+	.name = "devtmpfs",
+	.mount = public_dev_mount,
+};
+
 #ifdef CONFIG_BLOCK
 static inline int is_blockdev(struct device *dev)
 {
@@ -378,12 +394,11 @@ static int handle(const char *name, umode_t mode, kuid_t uid, kgid_t gid,
 
 static int devtmpfsd(void *p)
 {
-	char options[] = "mode=0755";
 	int *err = p;
 	*err = ksys_unshare(CLONE_NEWNS);
 	if (*err)
 		goto out;
-	*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
+	*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, NULL);
 	if (*err)
 		goto out;
 	ksys_chdir("/.."); /* will traverse into overmounted root */
@@ -420,7 +435,16 @@ out:
  */
 int __init devtmpfs_init(void)
 {
-	int err = register_filesystem(&dev_fs_type);
+	char opts[] = "mode=0755";
+	int err;
+
+	mnt = vfs_kern_mount(&internal_fs_type, 0, "devtmpfs", opts);
+	if (IS_ERR(mnt)) {
+		printk(KERN_ERR "devtmpfs: unable to create devtmpfs %ld\n",
+				PTR_ERR(mnt));
+		return PTR_ERR(mnt);
+	}
+	err = register_filesystem(&dev_fs_type);
 	if (err) {
 		printk(KERN_ERR "devtmpfs: unable to register devtmpfs "
 		       "type %i\n", err);