take the targets of /proc/*/ns/* symlinks to separate fs

[linux-2.6-block.git] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 9dfb4cac0c41db8c6cdf833b130ccf70f494040f..30df6e7dd80720ddb261c8f80d5e0f4df3e34e5d 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1569,8 +1569,8 @@ SYSCALL_DEFINE1(oldumount, char __user *, name)
 static bool is_mnt_ns_file(struct dentry *dentry)
 {
        /* Is this a proxy for a mount namespace? */
-       struct inode *inode = dentry->d_inode;
-       return proc_ns_inode(inode) && dentry->d_fsdata == &mntns_operations;
+       return dentry->d_op == &ns_dentry_operations &&
+              dentry->d_fsdata == &mntns_operations;
 }
 
 struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
@@ -2016,7 +2016,10 @@ static int do_loopback(struct path *path, const char *old_name,
        if (IS_MNT_UNBINDABLE(old))
                goto out2;
 
-       if (!check_mnt(parent) || !check_mnt(old))
+       if (!check_mnt(parent))
+               goto out2;
+
+       if (!check_mnt(old) && old_path.dentry->d_op != &ns_dentry_operations)
                goto out2;
 
        if (!recurse && has_locked_children(old, old_path.dentry))