Merge patch series "ns: header cleanups and initial namespace reference count improvements"

Christian Brauner <brauner@kernel.org> says:

Cleanup the namespace headers by splitting them into types and helpers.
Better separate common namepace types and functions from namespace tree
types and functions.

Fix the reference counts of initial namespaces so we don't do any
pointless cacheline ping-pong for them when we know they can never go
away. Add a bunch of asserts for both the passive and active reference
counts to catch any changes that would break it.

* patches from https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-0-e8a9264e0fb9@kernel.org:
  selftests/namespaces: fix nsid tests
  ns: drop custom reference count initialization for initial namespaces
  pid: rely on common reference count behavior
  ns: add asserts for initial namespace active reference counts
  ns: add asserts for initial namespace reference counts
  ns: make all reference counts on initial namespace a nop
  ipc: enable is_ns_init_id() assertions
  fs: use boolean to indicate anonymous mount namespace
  ns: rename is_initial_namespace()
  ns: make is_initial_namespace() argument const
  nstree: use guards for ns_tree_lock
  nstree: simplify owner list iteration
  nstree: switch to new structures
  nstree: add helper to operate on struct ns_tree_{node,root}
  nstree: move nstree types into separate header
  nstree: decouple from ns_common header
  ns: move namespace types into separate header

Link: https://patch.msgid.link/20251110-work-namespace-nstree-fixes-v1-0-e8a9264e0fb9@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 51 insertions, 56 deletions

diff --git a/tools/testing/selftests/namespaces/nsid_test.c b/tools/testing/selftests/namespaces/nsid_test.c
index e28accd74a57..527ade0a8673 100644
--- a/tools/testing/selftests/namespaces/nsid_test.c
+++ b/tools/testing/selftests/namespaces/nsid_test.c
@@ -6,6 +6,7 @@
 #include <libgen.h>
 #include <limits.h>
 #include <pthread.h>
+#include <signal.h>
 #include <string.h>
 #include <sys/mount.h>
 #include <poll.h>
@@ -14,12 +15,30 @@
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <sys/wait.h>
 #include <unistd.h>
 #include <linux/fs.h>
 #include <linux/limits.h>
 #include <linux/nsfs.h>
 #include "../kselftest_harness.h"
 
+/* Fixture for tests that create child processes */
+FIXTURE(nsid) {
+	pid_t child_pid;
+};
+
+FIXTURE_SETUP(nsid) {
+	self->child_pid = 0;
+}
+
+FIXTURE_TEARDOWN(nsid) {
+	/* Clean up any child process that may still be running */
+	if (self->child_pid > 0) {
+		kill(self->child_pid, SIGKILL);
+		waitpid(self->child_pid, NULL, 0);
+	}
+}
+
 TEST(nsid_mntns_basic)
 {
 	__u64 mnt_ns_id = 0;
@@ -44,7 +63,7 @@ TEST(nsid_mntns_basic)
 	close(fd_mntns);
 }
 
-TEST(nsid_mntns_separate)
+TEST_F(nsid, mntns_separate)
 {
 	__u64 parent_mnt_ns_id = 0;
 	__u64 child_mnt_ns_id = 0;
@@ -90,6 +109,9 @@ TEST(nsid_mntns_separate)
 		_exit(0);
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -99,8 +121,6 @@ TEST(nsid_mntns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_mntns);
 		SKIP(return, "No permission to create mount namespace");
 	}
@@ -123,10 +143,6 @@ TEST(nsid_mntns_separate)
 
 	close(fd_parent_mntns);
 	close(fd_child_mntns);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_cgroupns_basic)
@@ -153,7 +169,7 @@ TEST(nsid_cgroupns_basic)
 	close(fd_cgroupns);
 }
 
-TEST(nsid_cgroupns_separate)
+TEST_F(nsid, cgroupns_separate)
 {
 	__u64 parent_cgroup_ns_id = 0;
 	__u64 child_cgroup_ns_id = 0;
@@ -199,6 +215,9 @@ TEST(nsid_cgroupns_separate)
 		_exit(0);
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -208,8 +227,6 @@ TEST(nsid_cgroupns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_cgroupns);
 		SKIP(return, "No permission to create cgroup namespace");
 	}
@@ -232,10 +249,6 @@ TEST(nsid_cgroupns_separate)
 
 	close(fd_parent_cgroupns);
 	close(fd_child_cgroupns);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_ipcns_basic)
@@ -262,7 +275,7 @@ TEST(nsid_ipcns_basic)
 	close(fd_ipcns);
 }
 
-TEST(nsid_ipcns_separate)
+TEST_F(nsid, ipcns_separate)
 {
 	__u64 parent_ipc_ns_id = 0;
 	__u64 child_ipc_ns_id = 0;
@@ -308,6 +321,9 @@ TEST(nsid_ipcns_separate)
 		_exit(0);
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -317,8 +333,6 @@ TEST(nsid_ipcns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_ipcns);
 		SKIP(return, "No permission to create IPC namespace");
 	}
@@ -341,10 +355,6 @@ TEST(nsid_ipcns_separate)
 
 	close(fd_parent_ipcns);
 	close(fd_child_ipcns);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_utsns_basic)
@@ -371,7 +381,7 @@ TEST(nsid_utsns_basic)
 	close(fd_utsns);
 }
 
-TEST(nsid_utsns_separate)
+TEST_F(nsid, utsns_separate)
 {
 	__u64 parent_uts_ns_id = 0;
 	__u64 child_uts_ns_id = 0;
@@ -417,6 +427,9 @@ TEST(nsid_utsns_separate)
 		_exit(0);
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -426,8 +439,6 @@ TEST(nsid_utsns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_utsns);
 		SKIP(return, "No permission to create UTS namespace");
 	}
@@ -450,10 +461,6 @@ TEST(nsid_utsns_separate)
 
 	close(fd_parent_utsns);
 	close(fd_child_utsns);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_userns_basic)
@@ -480,7 +487,7 @@ TEST(nsid_userns_basic)
 	close(fd_userns);
 }
 
-TEST(nsid_userns_separate)
+TEST_F(nsid, userns_separate)
 {
 	__u64 parent_user_ns_id = 0;
 	__u64 child_user_ns_id = 0;
@@ -526,6 +533,9 @@ TEST(nsid_userns_separate)
 		_exit(0);
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -535,8 +545,6 @@ TEST(nsid_userns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_userns);
 		SKIP(return, "No permission to create user namespace");
 	}
@@ -559,10 +567,6 @@ TEST(nsid_userns_separate)
 
 	close(fd_parent_userns);
 	close(fd_child_userns);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_timens_basic)
@@ -591,7 +595,7 @@ TEST(nsid_timens_basic)
 	close(fd_timens);
 }
 
-TEST(nsid_timens_separate)
+TEST_F(nsid, timens_separate)
 {
 	__u64 parent_time_ns_id = 0;
 	__u64 child_time_ns_id = 0;
@@ -652,6 +656,9 @@ TEST(nsid_timens_separate)
 		}
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -660,8 +667,6 @@ TEST(nsid_timens_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_timens);
 		close(pipefd[0]);
 		SKIP(return, "Cannot create time namespace");
@@ -689,10 +694,6 @@ TEST(nsid_timens_separate)
 
 	close(fd_parent_timens);
 	close(fd_child_timens);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_pidns_basic)
@@ -719,7 +720,7 @@ TEST(nsid_pidns_basic)
 	close(fd_pidns);
 }
 
-TEST(nsid_pidns_separate)
+TEST_F(nsid, pidns_separate)
 {
 	__u64 parent_pid_ns_id = 0;
 	__u64 child_pid_ns_id = 0;
@@ -776,6 +777,9 @@ TEST(nsid_pidns_separate)
 		}
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -784,8 +788,6 @@ TEST(nsid_pidns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_pidns);
 		close(pipefd[0]);
 		SKIP(return, "No permission to create PID namespace");
@@ -813,10 +815,6 @@ TEST(nsid_pidns_separate)
 
 	close(fd_parent_pidns);
 	close(fd_child_pidns);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST(nsid_netns_basic)
@@ -860,7 +858,7 @@ TEST(nsid_netns_basic)
 	close(fd_netns);
 }
 
-TEST(nsid_netns_separate)
+TEST_F(nsid, netns_separate)
 {
 	__u64 parent_net_ns_id = 0;
 	__u64 parent_netns_cookie = 0;
@@ -920,6 +918,9 @@ TEST(nsid_netns_separate)
 		_exit(0);
 	}
 
+	/* Track child for cleanup */
+	self->child_pid = pid;
+
 	/* Parent process */
 	close(pipefd[1]);
 
@@ -929,8 +930,6 @@ TEST(nsid_netns_separate)
 
 	if (buf == 'S') {
 		/* Child couldn't create namespace, skip test */
-		kill(pid, SIGTERM);
-		waitpid(pid, NULL, 0);
 		close(fd_parent_netns);
 		close(parent_sock);
 		SKIP(return, "No permission to create network namespace");
@@ -977,10 +976,6 @@ TEST(nsid_netns_separate)
 	close(fd_parent_netns);
 	close(fd_child_netns);
 	close(parent_sock);
-
-	/* Clean up child process */
-	kill(pid, SIGTERM);
-	waitpid(pid, NULL, 0);
 }
 
 TEST_HARNESS_MAIN