On Wed, Feb 18, 2026 at 10:10:38AM -0800, Bobby Eshleman wrote:
From: Bobby Eshleman <[email protected]>
Update the vsock child_ns_mode documentation to include the new the
nit: s/the new the/the new
write-once semantics of setting child_ns_mode. The semantics are
implemented in a different patch in this series.
s/different/preceding ?
IMO this can be squashed with the previous patch, but not sure netdev
policy about that. Not a strong opinion, it's fine also in this way.
Signed-off-by: Bobby Eshleman <[email protected]>
---
Documentation/admin-guide/sysctl/net.rst | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/Documentation/admin-guide/sysctl/net.rst
b/Documentation/admin-guide/sysctl/net.rst
index c10530624f1e..976a176fb451 100644
--- a/Documentation/admin-guide/sysctl/net.rst
+++ b/Documentation/admin-guide/sysctl/net.rst
@@ -581,9 +581,9 @@ The init_net mode is always ``global``.
child_ns_mode
-------------
-Controls what mode newly created child namespaces will inherit. At namespace
-creation, ``ns_mode`` is inherited from the parent's ``child_ns_mode``. The
-initial value matches the namespace's own ``ns_mode``.
+Write-once. Controls what mode newly created child namespaces will inherit. At
+namespace creation, ``ns_mode`` is inherited from the parent's
+``child_ns_mode``. The initial value matches the namespace's own ``ns_mode``.
Values:
@@ -594,6 +594,10 @@ Values:
their sockets will only be able to connect within their own
namespace.
+``child_ns_mode`` can only be written once per namespace. Writing the same
+value that is already set succeeds. Writing a different value after the first
+write returns ``-EBUSY``.
nit: instead of saying that it can only be written once, we could say
that the first write locks the value, to be closer to the actual
behavior, something like this:
The first write to ``child_ns_mode`` locks its value. Subsequent
writes of the same value succeed, but writing a different value
returns ``-EBUSY``.
Thanks,
Stefano
+
Changing ``child_ns_mode`` only affects namespaces created after the change;
it does not modify the current namespace or any existing children.
--
2.47.3
