From 7e5ad817ec297f91a2fa5c423a39a458a4701bca Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Thu, 28 Oct 2021 10:47:24 +0100 Subject: [PATCH] selftests/bpf: Test RENAME_EXCHANGE and RENAME_NOREPLACE on bpffs Add tests to exercise the behaviour of RENAME_EXCHANGE and RENAME_NOREPLACE on bpffs. The former checks that after an exchange the inode of two directories has changed. The latter checks that the source still exists after a failed rename. Generally, having support for renameat2(RENAME_EXCHANGE) in bpffs fixes atomic upgrades of our sk_lookup control plane. Signed-off-by: Lorenz Bauer Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211028094724.59043-5-lmb@cloudflare.com --- .../testing/selftests/bpf/prog_tests/test_bpffs.c | 65 +++++++++++++++++++++- 1 file changed, 64 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c index 533e3f3..d29ebfe 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c +++ b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2020 Facebook */ #define _GNU_SOURCE +#include #include #include #include @@ -29,7 +30,8 @@ static int read_iter(char *file) static int fn(void) { - int err; + struct stat a, b, c; + int err, map; err = unshare(CLONE_NEWNS); if (!ASSERT_OK(err, "unshare")) @@ -67,6 +69,67 @@ static int fn(void) err = read_iter(TDIR "/fs2/progs.debug"); if (!ASSERT_OK(err, "reading " TDIR "/fs2/progs.debug")) goto out; + + err = mkdir(TDIR "/fs1/a", 0777); + if (!ASSERT_OK(err, "creating " TDIR "/fs1/a")) + goto out; + err = mkdir(TDIR "/fs1/a/1", 0777); + if (!ASSERT_OK(err, "creating " TDIR "/fs1/a/1")) + goto out; + err = mkdir(TDIR "/fs1/b", 0777); + if (!ASSERT_OK(err, "creating " TDIR "/fs1/b")) + goto out; + + map = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 4, 1, 0); + if (!ASSERT_GT(map, 0, "create_map(ARRAY)")) + goto out; + err = bpf_obj_pin(map, TDIR "/fs1/c"); + if (!ASSERT_OK(err, "pin map")) + goto out; + close(map); + + /* Check that RENAME_EXCHANGE works for directories. */ + err = stat(TDIR "/fs1/a", &a); + if (!ASSERT_OK(err, "stat(" TDIR "/fs1/a)")) + goto out; + err = renameat2(0, TDIR "/fs1/a", 0, TDIR "/fs1/b", RENAME_EXCHANGE); + if (!ASSERT_OK(err, "renameat2(/fs1/a, /fs1/b, RENAME_EXCHANGE)")) + goto out; + err = stat(TDIR "/fs1/b", &b); + if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)")) + goto out; + if (!ASSERT_EQ(a.st_ino, b.st_ino, "b should have a's inode")) + goto out; + err = access(TDIR "/fs1/b/1", F_OK); + if (!ASSERT_OK(err, "access(" TDIR "/fs1/b/1)")) + goto out; + + /* Check that RENAME_EXCHANGE works for mixed file types. */ + err = stat(TDIR "/fs1/c", &c); + if (!ASSERT_OK(err, "stat(" TDIR "/fs1/map)")) + goto out; + err = renameat2(0, TDIR "/fs1/c", 0, TDIR "/fs1/b", RENAME_EXCHANGE); + if (!ASSERT_OK(err, "renameat2(/fs1/c, /fs1/b, RENAME_EXCHANGE)")) + goto out; + err = stat(TDIR "/fs1/b", &b); + if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)")) + goto out; + if (!ASSERT_EQ(c.st_ino, b.st_ino, "b should have c's inode")) + goto out; + err = access(TDIR "/fs1/c/1", F_OK); + if (!ASSERT_OK(err, "access(" TDIR "/fs1/c/1)")) + goto out; + + /* Check that RENAME_NOREPLACE works. */ + err = renameat2(0, TDIR "/fs1/b", 0, TDIR "/fs1/a", RENAME_NOREPLACE); + if (!ASSERT_ERR(err, "renameat2(RENAME_NOREPLACE)")) { + err = -EINVAL; + goto out; + } + err = access(TDIR "/fs1/b", F_OK); + if (!ASSERT_OK(err, "access(" TDIR "/fs1/b)")) + goto out; + out: umount(TDIR "/fs1"); umount(TDIR "/fs2"); -- 2.7.4