[PATCH bpf-next v3 0/2] Add F_SETFL for fcntl

[PATCH bpf-next v3 0/2] Add F_SETFL for fcntl

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Two fixes for test_sockmap:

Patch 1, v3 of "selftests/bpf: Add F_SETFL for fcntl":
- detect nonblock flag automaticly, then test_sockmap can run in both
block and nonblock modes.
- use continue instead of again in v2.

Patch 2, fix for umount cgroup2 error.

Geliang Tang (2):
  selftests/bpf: Add F_SETFL for fcntl in test_sockmap
  selftests/bpf: Fix umount cgroup2 error in test_sockmap

 tools/testing/selftests/bpf/test_sockmap.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

-- 
2.40.1

[PATCH bpf-next v3 1/2] selftests/bpf: Add F_SETFL for fcntl in test_sockmap

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

Incorrect arguments are passed to fcntl() in test_sockmap.c when invoking
it to set file status flags. If O_NONBLOCK is used as 2nd argument and
passed into fcntl, -EINVAL will be returned (See do_fcntl() in fs/fcntl.c).
The correct approach is to use F_SETFL as 2nd argument, and O_NONBLOCK as
3rd one.

In nonblock mode, if EWOULDBLOCK is received, continue receiving, otherwise
some subtests of test_sockmap will fail.

Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/test_sockmap.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 024a0faafb3b..4f32a5eb3864 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 		struct timeval timeout;
 		fd_set w;
 
-		fcntl(fd, fd_flags);
+		fcntl(fd, F_SETFL, fd_flags);
 		/* Account for pop bytes noting each iteration of apply will
 		 * call msg_pop_data helper so we need to account for this
 		 * by calculating the number of apply iterations. Note user
@@ -678,6 +678,9 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 					perror("recv failed()");
 					goto out_errno;
 				}
+				fd_flags = fcntl(fd, F_GETFL);
+				if (fd_flags & O_NONBLOCK)
+					continue;
 			}
 
 			s->bytes_recvd += recv;
-- 
2.40.1

[PATCH bpf-next v3 2/2] selftests/bpf: Fix umount cgroup2 error in test_sockmap

[Geliang Tang]

From: Geliang Tang <tanggeliang@kylinos.cn>

This patch fixes the following "umount cgroup2" error in test_sockmap.c:

 (cgroup_helpers.c:353: errno: Device or resource busy) umount cgroup2

Cgroup fd cg_fd should be closed before cleanup_cgroup_environment().

Fixes: 13a5f3ffd202 ("bpf: Selftests, sockmap test prog run without setting cgroup")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/test_sockmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 4f32a5eb3864..520b7d0dadda 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -2107,9 +2107,9 @@ int main(int argc, char **argv)
 		free(options.whitelist);
 	if (options.blacklist)
 		free(options.blacklist);
+	close(cg_fd);
 	if (cg_created)
 		cleanup_cgroup_environment();
-	close(cg_fd);
 	return err;
 }
 
-- 
2.40.1

Re: [PATCH bpf-next v3 0/2] Add F_SETFL for fcntl

[MPTCP CI]

Hi Geliang,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Unstable: 1 failed test(s): packetdrill_sockopts 🔴
- KVM Validation: btf (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/8593412186

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/49fb69b19ca2
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=842235


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Re: [PATCH bpf-next v3 1/2] selftests/bpf: Add F_SETFL for fcntl in test_sockmap

[Yonghong Song]

On 4/7/24 6:36 PM, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
>
> Incorrect arguments are passed to fcntl() in test_sockmap.c when invoking
> it to set file status flags. If O_NONBLOCK is used as 2nd argument and
> passed into fcntl, -EINVAL will be returned (See do_fcntl() in fs/fcntl.c).
> The correct approach is to use F_SETFL as 2nd argument, and O_NONBLOCK as
> 3rd one.
>
> In nonblock mode, if EWOULDBLOCK is received, continue receiving, otherwise
> some subtests of test_sockmap will fail.
>
> Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>

Acked-by: Yonghong Song <yonghong.song@linux.dev>

Re: [PATCH bpf-next v3 2/2] selftests/bpf: Fix umount cgroup2 error in test_sockmap

[Yonghong Song]

On 4/7/24 6:36 PM, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
>
> This patch fixes the following "umount cgroup2" error in test_sockmap.c:
>
>   (cgroup_helpers.c:353: errno: Device or resource busy) umount cgroup2
>
> Cgroup fd cg_fd should be closed before cleanup_cgroup_environment().
>
> Fixes: 13a5f3ffd202 ("bpf: Selftests, sockmap test prog run without setting cgroup")
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>

Acked-by: Yonghong Song <yonghong.song@linux.dev>

Re: [PATCH bpf-next v3 1/2] selftests/bpf: Add F_SETFL for fcntl in test_sockmap

[Martin KaFai Lau]

On 4/7/24 6:36 PM, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> Incorrect arguments are passed to fcntl() in test_sockmap.c when invoking
> it to set file status flags. If O_NONBLOCK is used as 2nd argument and
> passed into fcntl, -EINVAL will be returned (See do_fcntl() in fs/fcntl.c).
> The correct approach is to use F_SETFL as 2nd argument, and O_NONBLOCK as
> 3rd one.
> 
> In nonblock mode, if EWOULDBLOCK is received, continue receiving, otherwise
> some subtests of test_sockmap will fail.
> 
> Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
>   tools/testing/selftests/bpf/test_sockmap.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
> index 024a0faafb3b..4f32a5eb3864 100644
> --- a/tools/testing/selftests/bpf/test_sockmap.c
> +++ b/tools/testing/selftests/bpf/test_sockmap.c
> @@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
>   		struct timeval timeout;
>   		fd_set w;
>   
> -		fcntl(fd, fd_flags);
> +		fcntl(fd, F_SETFL, fd_flags);

Should it just error out here if fcntl did fail (unlikely?) ...

>   		/* Account for pop bytes noting each iteration of apply will
>   		 * call msg_pop_data helper so we need to account for this
>   		 * by calculating the number of apply iterations. Note user
> @@ -678,6 +678,9 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
>   					perror("recv failed()");
>   					goto out_errno;
>   				}
> +				fd_flags = fcntl(fd, F_GETFL);
> +				if (fd_flags & O_NONBLOCK)

... then no need to test fd_flags here?

pw-bot: cr

> +					continue;
>   			}
>   
>   			s->bytes_recvd += recv;