From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09E1533343C; Tue, 21 Oct 2025 11:45:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761047132; cv=none; b=DJDuNvqUIW6PT9XZ1/9SFI1Q8BgUlLv8/cfNLTzaE0bTEzUL7P80dnSoKZrg1IQbUAuWdoxzZJENOXbATY9WeoNchySw+IBuIOwYwgULRR39PewDErbHXGadS/IXN1Cs1nmNxL26gEk/CyR702lmKcDSxXFsg0+u6P3uRmP75WQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761047132; c=relaxed/simple; bh=zTxekEdjlVJZprVoI/00FXYGRRSOiQasmJAHzIPasqQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=OCJ42dUCbbbXU51sE4kd00o6MwgGzzyEf550kX5rGBwoOTRSJZLZHs/4jdDNPkeOWRoXPM2c39QG2USW0Tyq6H4yELFyebnXujPWM2/b/rhuhLjJ51ubud1EeePiXKAq93RqBVru5Urfnh6MtZKqE+z4QWgvTbxZGOkXF9YBJcs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mQ8Mx/sY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mQ8Mx/sY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A9DDAC4CEF1; Tue, 21 Oct 2025 11:45:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761047131; bh=zTxekEdjlVJZprVoI/00FXYGRRSOiQasmJAHzIPasqQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=mQ8Mx/sY+y/7NHkRcoGq+SQ6MXsnhhPoig0NxkqLdGEa2Xnktd5KVIgWHxNgrNdMm mj3ktizPR6nMI6PJmAvATb+21q7mdAQyzpV1WKqWYys4UMjB0bUGXzDTXP0/E0fbG9 d8t75GsEybF9284m7fkjn//keUsm7e+uZ4Mk1xMqhw3ftFTaNOZwZHENP5r0O/imKN XwxBPpUz4T9p9y/6InRZLOfHZXByiRErzMYdji9FdkB5EBGd7hsW0QzI4Pl0uU0m9l SmgROzbxUB4mcVaHC/12D1Gsi3o4EYlCsnpw1RGpXhA36mnGOmPoxdPEQerB4HFvb2 qAW/mAgndyJ3A== From: Christian Brauner Date: Tue, 21 Oct 2025 13:43:25 +0200 Subject: [PATCH RFC DRAFT 19/50] selftests/namespaces: first active reference count tests Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251021-work-namespace-nstree-listns-v1-19-ad44261a8a5b@kernel.org> References: <20251021-work-namespace-nstree-listns-v1-0-ad44261a8a5b@kernel.org> In-Reply-To: <20251021-work-namespace-nstree-listns-v1-0-ad44261a8a5b@kernel.org> To: linux-fsdevel@vger.kernel.org, Josef Bacik , Jeff Layton Cc: Jann Horn , Mike Yuan , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , Lennart Poettering , Daan De Meyer , Aleksa Sarai , Amir Goldstein , Tejun Heo , Johannes Weiner , Thomas Gleixner , Alexander Viro , Jan Kara , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Eric Dumazet , Jakub Kicinski , netdev@vger.kernel.org, Arnd Bergmann , Christian Brauner X-Mailer: b4 0.15-dev-96507 X-Developer-Signature: v=1; a=openpgp-sha256; l=3703; i=brauner@kernel.org; h=from:subject:message-id; bh=zTxekEdjlVJZprVoI/00FXYGRRSOiQasmJAHzIPasqQ=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWR8L3y76b9H6M1P3z2/vpCcEXH5zlMWu/7e217HxNg6V 38MfXt7TkcpC4MYF4OsmCKLQ7tJuNxynorNRpkaMHNYmUCGMHBxCsBE5hYw/NOp6f9880xaFKdg 6b1HGyetrnz3092h82Wo5uasDxfdP4Yx/BUwjFe+VLTkpGVXFUvibJE27iVTl39xzNG+t/Cllgq TMgsA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Test that initial namespaces can be reopened via file handle. Initial namespaces should always have a ref count of one from boot. Signed-off-by: Christian Brauner --- tools/testing/selftests/namespaces/.gitignore | 1 + tools/testing/selftests/namespaces/Makefile | 5 +- .../selftests/namespaces/ns_active_ref_test.c | 74 ++++++++++++++++++++++ 3 files changed, 79 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/namespaces/.gitignore b/tools/testing/selftests/namespaces/.gitignore index ccfb40837a73..100cc5bfef04 100644 --- a/tools/testing/selftests/namespaces/.gitignore +++ b/tools/testing/selftests/namespaces/.gitignore @@ -1,3 +1,4 @@ nsid_test file_handle_test init_ino_test +ns_active_ref_test diff --git a/tools/testing/selftests/namespaces/Makefile b/tools/testing/selftests/namespaces/Makefile index 5fe4b3dc07d3..5cea938cdde8 100644 --- a/tools/testing/selftests/namespaces/Makefile +++ b/tools/testing/selftests/namespaces/Makefile @@ -1,7 +1,10 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -Wall -O0 -g $(KHDR_INCLUDES) $(TOOLS_INCLUDES) +LDLIBS += -lcap -TEST_GEN_PROGS := nsid_test file_handle_test init_ino_test +TEST_GEN_PROGS := nsid_test file_handle_test init_ino_test ns_active_ref_test include ../lib.mk +$(OUTPUT)/ns_active_ref_test: ../filesystems/utils.c + diff --git a/tools/testing/selftests/namespaces/ns_active_ref_test.c b/tools/testing/selftests/namespaces/ns_active_ref_test.c new file mode 100644 index 000000000000..21514a537b26 --- /dev/null +++ b/tools/testing/selftests/namespaces/ns_active_ref_test.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "../kselftest_harness.h" +#include "../filesystems/utils.h" + +#ifndef FD_NSFS_ROOT +#define FD_NSFS_ROOT -10003 /* Root of the nsfs filesystem */ +#endif + +/* + * Test that initial namespaces can be reopened via file handle. + * Initial namespaces should have active ref count of 1 from boot. + */ +TEST(init_ns_always_active) +{ + struct file_handle *handle; + int mount_id; + int ret; + int fd1, fd2; + struct stat st1, st2; + + handle = malloc(sizeof(*handle) + MAX_HANDLE_SZ); + ASSERT_NE(handle, NULL); + + /* Open initial network namespace */ + fd1 = open("/proc/1/ns/net", O_RDONLY); + ASSERT_GE(fd1, 0); + + /* Get file handle for initial namespace */ + handle->handle_bytes = MAX_HANDLE_SZ; + ret = name_to_handle_at(fd1, "", handle, &mount_id, AT_EMPTY_PATH); + if (ret < 0 && errno == EOPNOTSUPP) { + SKIP(free(handle); close(fd1); + return, "nsfs doesn't support file handles"); + } + ASSERT_EQ(ret, 0); + + /* Close the namespace fd */ + close(fd1); + + /* Try to reopen via file handle - should succeed since init ns is always active */ + fd2 = open_by_handle_at(FD_NSFS_ROOT, handle, O_RDONLY); + if (fd2 < 0 && (errno == EINVAL || errno == EOPNOTSUPP)) { + SKIP(free(handle); + return, "open_by_handle_at with FD_NSFS_ROOT not supported"); + } + ASSERT_GE(fd2, 0); + + /* Verify we opened the same namespace */ + fd1 = open("/proc/1/ns/net", O_RDONLY); + ASSERT_GE(fd1, 0); + ASSERT_EQ(fstat(fd1, &st1), 0); + ASSERT_EQ(fstat(fd2, &st2), 0); + ASSERT_EQ(st1.st_ino, st2.st_ino); + + close(fd1); + close(fd2); + free(handle); +} + +TEST_HARNESS_MAIN -- 2.47.3