From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 237513E51FE; Wed, 26 Aug 2026 10:47:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787741263; cv=none; b=bTeV1Ue+LmuDZE3Ao3iq6R4/70GJ4AGZ8sBf8iV+745b/+qU2ZQ9qnKxscX7BAp3IGDwnxlcVieo2F5JnE7oaisxTmDoOKtUDzShwTqpc/ItugQO/UAoDsEODt/ZxGBwdnV7VdVrRsuFdLXbo8CDIG1HLkiWUxkYWUw1UwCnuBI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787741263; c=relaxed/simple; bh=EsCfNGDMAD0kqB2bJvJPVAMQnbDdNoA3cfyCUB4ulu0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qetruMOZ6KpgwsBOqSFRTsexytMLnZsbbfC+cB2C9NgY6dTIQztwg8MnFSZ2kYU54vqoGHHmV3h/DsF8WXJ/tqHEzhF5XRhfnrdYrknBe7XsIHniw5B1i5VjtTcWafpkauoVyuhfSFeV69k7KIxr947bxdCMCyXNfO31/dAT6yI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=p87huBnn; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="p87huBnn" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:In-Reply-To:References: Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description; bh=VQVWFa01CPFDyXs47ACU6VBWm1qbgJ5kbePtNrURpkQ=; b=p87huBnn0HXuiAqTqalC8qEBqZ fsBngg3Foh2e04znsjcMVyPqFknD/5UC0oQmQRaQsafZqvU8dVZ6odW/zggpHE4+W4IdtTF/fWauy KKgeoaZ7rReRnTP31YBtryKXqBpnrrLL5gaKVnQ5vOKTK5C0mwcKTM16vScHmHPmJQQ1SmvEyJiK/ xbhoat5fg1Ws0xAlLJW5vXRU7AFd+GC5VEJrfaMTeylVX2X64WZRhVHg31zzUp9hFS0M4qCpTMW8Z b6AgJfirSQZV9d2ZfQMKjJISy8NKn3N1TvstkF+6Wl/ee6utw2WbbX8s61rlN3/Ax+gDIt+sdUBYE Zg24As4g==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wzBAJ-00FA18-02; Wed, 26 Aug 2026 10:47:31 +0000 From: Breno Leitao Date: Wed, 26 Aug 2026 03:47:04 -0700 Subject: [PATCH 3/4] selftests/configfs: cover symlink and unlink Precedence: bulk X-Mailing-List: linux-fsdevel@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: <20260826-config_selftest-v1-3-e364b07e91ac@debian.org> References: <20260826-config_selftest-v1-0-e364b07e91ac@debian.org> In-Reply-To: <20260826-config_selftest-v1-0-e364b07e91ac@debian.org> To: Shuah Khan , Andreas Hindborg Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, gustavold@gmail.com, linux-fsdevel@vger.kernel.org, Breno Leitao , kernel-team@meta.com, vasilisalmpanis@gmail.com X-Mailer: b4 0.16-dev-f8e9d X-Developer-Signature: v=1; a=openpgp-sha256; l=4576; i=leitao@debian.org; h=from:subject:message-id; bh=EsCfNGDMAD0kqB2bJvJPVAMQnbDdNoA3cfyCUB4ulu0=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqjsQz/hePnaPXqpVkzcWaZVOY88OTjEBJTpz48 goLeTDxOtOJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCao7EMwAKCRA1o5Of/Hh3 bT+OD/9lFh69T1a8+mXdx2+tpIMeYAFdbcvEJeYYcC0U7UNYswF/oN/P3xYCVnB3190AfJPNwct ZPfnrpVZC6VWAAdGjlx/7wrcDFqJ+jdfp9HvNZl+eGh9nXYwyCV9KGSYt+6TJtQ5iKtHwP/ehp/ 0BXONonHJveSlLZ05zVhti/fWq6VlF/yFZVSCXC/kDzCbqKShIbmKe6BZgjCsRNi6VZ6F0VFYF2 XkXYWCrGll4wbpNJQw9ZWn7qT9STeLE+d5oEpDwPFpZ+MQOIr7O7/qGrjNaFqHJfbAWzJJT5GL0 Ut4z9FFvBFzPRn/2UnftuKLeegSdd28A6mGgfTkpm0LyQvYxoUhFsoyUm9U7NpNP6g/vVrCOHXO uZIqOMWVcnSTiQZXUnvNvXmGazjOk45V2E/3u9inm2SY3yeGW6mFCrV76UdmZG25ZiAZqXtgBbm G6s5NibSdBrGmf6vL+JS/n3bjZipn3LGt8PYSSzJIHly5Mu22NX6K/Kh20rlTnPai1dTUJu+wnM IrH4b3/xdjZURVXcGHl8u1fI5Ph9U3JFSJV06SrwKbSQ4vxPcP669f1BtYFAAN09rwffgvpk8fs rdXIvhRbXsAw4Nnoi0A8DQPEnkLJfH223FTli1bdmGPcQA8k4DMqmqGgCBdVPoR8UtB3uIGEOXq lzPcvX/FogNaYyg== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao samples/configfs had nothing to link from, so symlink(2) went untested beyond the EPERM a subsystem without ->allow_link() returns. Cover creating and removing a link, the relative body configfs stores, the count ->allow_link() and ->drop_link() keep, the busy errors both ends return, and what get_target() rejects. Signed-off-by: Breno Leitao --- .../selftests/filesystems/configfs/configfs_test.c | 85 +++++++++++++++++++++- 1 file changed, 83 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/filesystems/configfs/configfs_test.c b/tools/testing/selftests/filesystems/configfs/configfs_test.c index 072d0dcf3f96b..9b15e1fd69e5b 100644 --- a/tools/testing/selftests/filesystems/configfs/configfs_test.c +++ b/tools/testing/selftests/filesystems/configfs/configfs_test.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Exercise the configfs userspace interface through the three subsystems + * Exercise the configfs userspace interface through the subsystems * registered by samples/configfs. * * Copyright (c) 2026 Meta Platforms, Inc. and affiliates @@ -10,6 +10,7 @@ #include #include +#include #include #include #include @@ -31,16 +32,24 @@ #define CHILDLESS "01-childless" #define SIMPLE "02-simple-children" #define GROUPS "03-group-children" +#define SYMLINKS "04-symlink-children" #define ITEM_A SIMPLE "/kselftest-a" #define ITEM_B SIMPLE "/kselftest-b" #define GROUP GROUPS "/kselftest-group" #define GROUP_ITEM GROUP "/kselftest-a" +#define LINK_SRC SYMLINKS "/kselftest-src" +#define LINK LINK_SRC "/kselftest-link" + +static const char * const test_links[] = { + LINK, +}; /* Deepest first, so one pass empties the tree. */ static const char * const test_dirs[] = { GROUP_ITEM, GROUP, + LINK_SRC, ITEM_A, ITEM_B, }; @@ -49,6 +58,10 @@ static void drop_test_dirs(void) { size_t i; + /* Links first: they hold both their source and their target. */ + for (i = 0; i < ARRAY_SIZE(test_links); i++) + unlink(test_links[i]); + for (i = 0; i < ARRAY_SIZE(test_dirs); i++) rmdir(test_dirs[i]); } @@ -131,7 +144,7 @@ FIXTURE_TEARDOWN(configfs) TEST_F(configfs, mount_and_subsystems) { - const char * const subsys[] = { CHILDLESS, SIMPLE, GROUPS }; + const char * const subsys[] = { CHILDLESS, SIMPLE, GROUPS, SYMLINKS }; struct statfs sfs; struct stat st; size_t i; @@ -324,6 +337,74 @@ TEST_F(configfs, symlink_without_allow_link) EXPECT_EQ(errno, EPERM); } +TEST_F(configfs, symlink_and_unlink) +{ + char buf[PATH_MAX]; + struct stat st; + ssize_t n; + + ASSERT_EQ(mkdir(ITEM_A, 0755), 0); + ASSERT_EQ(mkdir(LINK_SRC, 0755), 0); + + ASSERT_EQ(symlink(ITEM_A, LINK), 0); + + /* configfs stores its own body, a path relative to the link. */ + n = readlink(LINK, buf, sizeof(buf) - 1); + ASSERT_GT(n, 0); + buf[n] = '\0'; + EXPECT_STREQ(buf, "../../" ITEM_A); + EXPECT_EQ(stat(LINK "/storeme", &st), 0); + + /* ->allow_link() ran on the source, not on the target. */ + ASSERT_GT(read_attr(LINK_SRC "/nlinks", buf, sizeof(buf)), 0); + EXPECT_STREQ(buf, "1\n"); + + ASSERT_EQ(unlink(LINK), 0); + ASSERT_GT(read_attr(LINK_SRC "/nlinks", buf, sizeof(buf)), 0); + EXPECT_STREQ(buf, "0\n"); +} + +TEST_F(configfs, symlink_pins_both_ends) +{ + ASSERT_EQ(mkdir(ITEM_A, 0755), 0); + ASSERT_EQ(mkdir(LINK_SRC, 0755), 0); + ASSERT_EQ(symlink(ITEM_A, LINK), 0); + + /* A linked item cannot go away under the link. */ + ASSERT_EQ(rmdir(ITEM_A), -1); + EXPECT_EQ(errno, EBUSY); + + /* The link counts as a child of its source. */ + ASSERT_EQ(rmdir(LINK_SRC), -1); + EXPECT_EQ(errno, ENOTEMPTY); + + ASSERT_EQ(unlink(LINK), 0); + EXPECT_EQ(rmdir(ITEM_A), 0); +} + +TEST_F(configfs, symlink_target_outside_configfs) +{ + ASSERT_EQ(mkdir(LINK_SRC, 0755), 0); + ASSERT_EQ(symlink("/", LINK), -1); + EXPECT_EQ(errno, EPERM); +} + +TEST_F(configfs, symlink_target_missing) +{ + ASSERT_EQ(mkdir(LINK_SRC, 0755), 0); + ASSERT_EQ(symlink(SIMPLE "/kselftest-gone", LINK), -1); + EXPECT_EQ(errno, ENOENT); +} + +TEST_F(configfs, symlink_target_is_an_attribute) +{ + ASSERT_EQ(mkdir(LINK_SRC, 0755), 0); + + /* The target is resolved with LOOKUP_DIRECTORY. */ + ASSERT_EQ(symlink(CHILDLESS "/storeme", LINK), -1); + EXPECT_EQ(errno, ENOTDIR); +} + TEST_F(configfs, module_pinned_by_item) { ASSERT_EQ(mkdir(ITEM_A, 0755), 0); -- 2.53.0-Meta