From patchwork Fri Feb 21 13:13:15 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 13985528 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 633BB111A8 for ; Fri, 21 Feb 2025 13:14:07 +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=1740143647; cv=none; b=SrBLgNPc+QcDvxbpR4w6h1VagnEcOCEpx+v/PSbASMZVE/7168zC3WL0va1kEnd1g8FWQEE9Ku5LG2qPHESO7Y+KPxDKfI0OIjm4bZ1wUHoKHUMRVtlmYBS2CHNeCWQk17gNBX5Bb4WcB593Xq6qlOO9p0h8WdYK2mbKs4QCj/g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740143647; c=relaxed/simple; bh=1clxT3Zpmz6FTLemMwi5prQ4u2yWEBWniWHuv5h5jfg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qPweQekzVnS/XbA00CQ/wXaXVJ3b9Dfu5BrkefT3/NiXhsbs1hLom+7ntrPRiorWG3IIuW0EpAGaQtUwtXeZWUh8cShn0v+Q8+akGG4o81LDeqfR0YRP/2UcfJY+mV/z9jCspide781bxoFSrORUZPldaJZAIX7/shenrWB3LVo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VvW9l7hn; 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="VvW9l7hn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D493C4CEE6; Fri, 21 Feb 2025 13:14:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740143646; bh=1clxT3Zpmz6FTLemMwi5prQ4u2yWEBWniWHuv5h5jfg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=VvW9l7hn7oRsjVbePc8HdtcZQJedS9L/XiO97bRFhX5JuE3KI7DsR9M1Y8AtQh5fY r1nn97ZJAnf6FLglrfx4dlkvG9C7mBA966Xe9jGPIpPkCY+v3URwH5cT9f7prMRvyO 6s2sGiwEoMr6XbxyUEVLGUC3em8fqTxqwXNxV6WlmFnMXJIBupzWIAmFYIPZqUkJu4 YbWBeJtBODwJjuUmTGF3niAbAbpdLTi1WlPxQ+d30Xb4f00SY07W1m69T8s0cTN4Fz JMfojlaiols/7KsLXSlTxidkgwqo1v3Y8AUfrz9ZR+rLrCmxiA0t/nEFYZrspDdji4 d4GGD7K5kMXMg== From: Christian Brauner Date: Fri, 21 Feb 2025 14:13:15 +0100 Subject: [PATCH RFC 16/16] selftests: seventh test for mounting detached mounts onto detached mounts Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250221-brauner-open_tree-v1-16-dbcfcb98c676@kernel.org> References: <20250221-brauner-open_tree-v1-0-dbcfcb98c676@kernel.org> In-Reply-To: <20250221-brauner-open_tree-v1-0-dbcfcb98c676@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Al Viro , Miklos Szeredi , Jeff Layton , Josef Bacik , Seth Forshee , Christian Brauner X-Mailer: b4 0.15-dev-d23a9 X-Developer-Signature: v=1; a=openpgp-sha256; l=1961; i=brauner@kernel.org; h=from:subject:message-id; bh=1clxT3Zpmz6FTLemMwi5prQ4u2yWEBWniWHuv5h5jfg=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaTvqP496Vhc6vNGRYm7Lsq/rL785Dh/95pb6pzi/1tE9 YyXGIc87ChlYRDjYpAVU2RxaDcJl1vOU7HZKFMDZg4rE8gQBi5OAZjI8mCG/0FdFxql9d5/fvZ6 8nMmm4di/XH/A9s/bEtQM7ef6G3afIzhn/1945OSH6x53/p77vFI2R61g3Um7yWdBau6FKy5tr9 W4QQA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Add a test to verify that detached mounts behave correctly. Signed-off-by: Christian Brauner --- .../selftests/mount_setattr/mount_setattr_test.c | 36 ++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c index d2bf8b77df3f..1e0508cb5c2d 100644 --- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c +++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c @@ -2061,4 +2061,40 @@ TEST_F(mount_setattr, two_detached_mounts_referring_to_same_anonymous_mount_name ASSERT_NE(move_mount(fd_tree1, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0); } +TEST_F(mount_setattr, two_detached_subtrees_of_same_anonymous_mount_namespace) +{ + int fd_tree1 = -EBADF, fd_tree2 = -EBADF; + + /* + * Copy the following mount tree: + * + * |-/mnt/A testing tmpfs + * `-/mnt/A/AA testing tmpfs + * `-/mnt/A/AA/B testing tmpfs + * `-/mnt/A/AA/B/BB testing tmpfs + */ + fd_tree1 = sys_open_tree(-EBADF, "/mnt/A", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + AT_RECURSIVE | OPEN_TREE_CLOEXEC | + OPEN_TREE_CLONE); + ASSERT_GE(fd_tree1, 0); + + /* + * Create an O_PATH file descriptors with a separate struct file that + * refers to a subtree of the same detached mount tree as @fd_tree1 + */ + fd_tree2 = sys_open_tree(fd_tree1, "AA", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + AT_EMPTY_PATH | OPEN_TREE_CLOEXEC); + ASSERT_GE(fd_tree2, 0); + + /* + * This must fail as it is only possible to attach the root of a + * detached mount tree. + */ + ASSERT_NE(move_mount(fd_tree2, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0); + + ASSERT_EQ(move_mount(fd_tree1, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0); +} + TEST_HARNESS_MAIN