kernel/linux.git/tools/testing/selftests/namespaces/ns_active_ref_test.c, branch v6.19.12

selftests/namespace: third threaded active reference count test

2025-11-03T16:41:24+00:00

Test that namespaces become inactive after subprocess with multiple threads exits. Create a subprocess that unshares user and network namespaces, then creates two threads that share those namespaces. Verify that after all threads and subprocess exit, the namespaces are no longer listed by listns() and cannot be opened by open_by_handle_at(). Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-69-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespace: second threaded active reference count test

2025-11-03T16:41:24+00:00

Test that a namespace remains active while a thread holds an fd to it. Even after the thread exits, the namespace should remain active as long as another thread holds a file descriptor to it. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-68-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespace: first threaded active reference count test

2025-11-03T16:41:24+00:00

Test that namespace becomes inactive after thread exits. This verifies active reference counting works with threads, not just processes. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-67-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: fifteenth active reference count tests

2025-11-03T16:41:20+00:00

Test different namespace types (net, uts, ipc) all contributing active references to the same owning user namespace. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-37-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: fourteenth active reference count tests

2025-11-03T16:41:20+00:00

Test that user namespace as a child also propagates correctly. Create user_A -> user_B, verify when user_B is active that user_A is also active. This is different from non-user namespace children. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-36-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: thirteenth active reference count tests

2025-11-03T16:41:20+00:00

Test that parent stays active as long as ANY child is active. Create parent user namespace with two child net namespaces. Parent should remain active until BOTH children are inactive. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-35-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: twelth active reference count tests

2025-11-03T16:41:20+00:00

Test hierarchical propagation with deep namespace hierarchy. Create: init_user_ns -> user_A -> user_B -> net_ns When net_ns is active, both user_A and user_B should be active. This verifies the conditional recursion in __ns_ref_active_put() works. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-34-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: eleventh active reference count tests

2025-11-03T16:41:20+00:00

Test that different namespace types with same owner all contribute active references to the owning user namespace. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-33-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: tenth active reference count tests

2025-11-03T16:41:20+00:00

Test multiple children sharing same parent. Parent should stay active as long as ANY child is active. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-32-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner

selftests/namespaces: ninth active reference count tests

2025-11-03T16:41:19+00:00

Test multi-level hierarchy (3+ levels deep). Grandparent → Parent → Child When child is active, both parent AND grandparent should be active. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-31-2e6f823ebdc0@kernel.org Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner