From b3987057c60658034e65316e06e4a00c05de6c04 Mon Sep 17 00:00:00 2001
From: Michael Kerrisk <mtk.manpages@gmail.com>
Date: Fri, 13 Aug 2021 22:48:41 +0200
Subject: [PATCH] umount.2: ERRORS: add EINVAL for case where mount is locked

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
 man2/umount.2 | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/man2/umount.2 b/man2/umount.2
index bc826776e..dae0f7e42 100644
--- a/man2/umount.2
+++ b/man2/umount.2
@@ -141,6 +141,11 @@ points outside the user address space.
 is not a mount point.
 .TP
 .B EINVAL
+.I target
+is locked; see
+.BR mount_namespaces (7).
+.TP
+.B EINVAL
 .BR umount2 ()
 was called with
 .B MNT_EXPIRE