From: Martin KaFai Lau <martin.lau@linux.dev>
To: bpf@vger.kernel.org
Cc: 'Alexei Starovoitov ' <ast@kernel.org>,
'Andrii Nakryiko ' <andrii@kernel.org>,
'Daniel Borkmann ' <daniel@iogearbox.net>,
netdev@vger.kernel.org, kernel-team@meta.com
Subject: [PATCH bpf-next 5/7] selftests/bpf: Remove the "/sys" mount and umount dance in {open,close}_netns
Date: Mon, 28 Nov 2022 23:08:58 -0800 [thread overview]
Message-ID: <20221129070900.3142427-6-martin.lau@linux.dev> (raw)
In-Reply-To: <20221129070900.3142427-1-martin.lau@linux.dev>
From: Martin KaFai Lau <martin.lau@kernel.org>
The previous patches have removed the need to do the mount and umount
dance when switching netns. In particular:
* Avoid remounting /sys/fs/bpf to have a clean start
* Avoid remounting /sys to get a ifindex of a particular netns
This patch can finally remove the mount and umount dance in
{open,close}_netns which is unnecessarily complicated and
error-prone.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
tools/testing/selftests/bpf/network_helpers.c | 51 ++-----------------
1 file changed, 5 insertions(+), 46 deletions(-)
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 1f37adff7632..01de33191226 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -390,49 +390,6 @@ struct nstoken {
int orig_netns_fd;
};
-static int setns_by_fd(int nsfd)
-{
- int err;
-
- err = setns(nsfd, CLONE_NEWNET);
- close(nsfd);
-
- if (!ASSERT_OK(err, "setns"))
- return err;
-
- /* Switch /sys to the new namespace so that e.g. /sys/class/net
- * reflects the devices in the new namespace.
- */
- err = unshare(CLONE_NEWNS);
- if (!ASSERT_OK(err, "unshare"))
- return err;
-
- /* Make our /sys mount private, so the following umount won't
- * trigger the global umount in case it's shared.
- */
- err = mount("none", "/sys", NULL, MS_PRIVATE, NULL);
- if (!ASSERT_OK(err, "remount private /sys"))
- return err;
-
- err = umount2("/sys", MNT_DETACH);
- if (!ASSERT_OK(err, "umount2 /sys"))
- return err;
-
- err = mount("sysfs", "/sys", "sysfs", 0, NULL);
- if (!ASSERT_OK(err, "mount /sys"))
- return err;
-
- err = mount("bpffs", "/sys/fs/bpf", "bpf", 0, NULL);
- if (!ASSERT_OK(err, "mount /sys/fs/bpf"))
- return err;
-
- err = mount("debugfs", "/sys/kernel/debug", "debugfs", 0, NULL);
- if (!ASSERT_OK(err, "mount /sys/kernel/debug"))
- return err;
-
- return 0;
-}
-
struct nstoken *open_netns(const char *name)
{
int nsfd;
@@ -453,8 +410,9 @@ struct nstoken *open_netns(const char *name)
if (!ASSERT_GE(nsfd, 0, "open netns fd"))
goto fail;
- err = setns_by_fd(nsfd);
- if (!ASSERT_OK(err, "setns_by_fd"))
+ err = setns(nsfd, CLONE_NEWNET);
+ close(nsfd);
+ if (!ASSERT_OK(err, "setns"))
goto fail;
return token;
@@ -465,6 +423,7 @@ struct nstoken *open_netns(const char *name)
void close_netns(struct nstoken *token)
{
- ASSERT_OK(setns_by_fd(token->orig_netns_fd), "setns_by_fd");
+ ASSERT_OK(setns(token->orig_netns_fd, CLONE_NEWNET), "setns");
+ close(token->orig_netns_fd);
free(token);
}
--
2.30.2
next prev parent reply other threads:[~2022-11-29 7:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-29 7:08 [PATCH bpf-next 0/7] selftests/bpf: Remove unnecessary mount/umount dance Martin KaFai Lau
2022-11-29 7:08 ` [PATCH bpf-next 1/7] selftests/bpf: Use if_nametoindex instead of reading the /sys/net/class/*/ifindex Martin KaFai Lau
2022-11-29 7:08 ` [PATCH bpf-next 2/7] selftests/bpf: Avoid pinning bpf prog in the tc_redirect_dtime test Martin KaFai Lau
2022-11-29 7:08 ` [PATCH bpf-next 3/7] selftests/bpf: Avoid pinning bpf prog in the tc_redirect_peer_l3 test Martin KaFai Lau
2022-11-29 7:08 ` [PATCH bpf-next 4/7] selftests/bpf: Avoid pinning bpf prog in the netns_load_bpf() callers Martin KaFai Lau
2022-11-29 7:08 ` Martin KaFai Lau [this message]
2022-11-29 7:08 ` [PATCH bpf-next 6/7] selftests/bpf: Remove serial from tests using {open,close}_netns Martin KaFai Lau
2022-11-29 7:09 ` [PATCH bpf-next 7/7] selftests/bpf: Avoid pinning prog when attaching to tc ingress in btf_skc_cls_ingress Martin KaFai Lau
2022-11-29 19:00 ` [PATCH bpf-next 0/7] selftests/bpf: Remove unnecessary mount/umount dance sdf
2022-11-30 22:00 ` patchwork-bot+netdevbpf
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