[PATCH v8 5/5] docs: proc: add documentation about relaxing visibility restrictions

[Alexey Gladkov <legion@kernel.org>]

Signed-off-by: Alexey Gladkov <legion@kernel.org>
---
 Documentation/filesystems/proc.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index c8864fcbdec7..3acf178c1202 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -2417,7 +2417,8 @@ so will give an `-EBUSY` error).
 If user namespaces are in use, the kernel additionally checks the instances of
 procfs available to the mounter and will not allow procfs to be mounted if:
 
-  1. This mount is not fully visible.
+  1. This mount is not fully visible unless the new procfs is going to be
+     mounted with subset=pid option.
 
      a. It's root directory is not the root directory of the filesystem.
      b. If any file or non-empty procfs directory is hidden by another mount.
-- 
2.53.0