[PATCH] fix d_absolute_path() interplay with fsmount()

stuff in anon namespace should be treated as unattached.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/d_path.c

@@ -116,8 +116,10 @@ static int prepend_path(const struct path *path,
 				vfsmnt = &mnt->mnt;
 				continue;
 			}
-			if (!error)
-				error = is_mounted(vfsmnt) ? 1 : 2;
+			if (is_mounted(vfsmnt) && !is_anon_ns(mnt->mnt_ns))
+				error = 1;	// absolute root
+			else
+				error = 2;	// detached or not attached yet
 			break;
 		}
 		parent = dentry->d_parent;