| Message ID | 20220104121030.138216-1-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5e22dd18626726028a93ff1350a8a71a00fd843d |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf/selftests: Fix namespace mount setup in tc_redirect | expand |
| Context | Check | Description |
|---|---|---|
| bpf/vmtest-bpf-next | success | VM_Test |
| bpf/vmtest-bpf-next-PR | success | PR summary |
| netdev/tree_selection | success | Not a local patch |
Hello: This patch was applied to bpf/bpf-next.git (master) by Daniel Borkmann <daniel@iogearbox.net>: On Tue, 4 Jan 2022 13:10:30 +0100 you wrote: > The tc_redirect umounts /sys in the new namespace, which can be > mounted as shared and cause global umount. The lazy umount also > takes down mounted trees under /sys like debugfs, which won't be > available after sysfs mounts again and could cause fails in other > tests. > > # cat /proc/self/mountinfo | grep debugfs > 34 23 0:7 / /sys/kernel/debug rw,nosuid,nodev,noexec,relatime shared:14 - debugfs debugfs rw > # cat /proc/self/mountinfo | grep sysfs > 23 86 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw > # mount | grep debugfs > debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) > > [...] Here is the summary with links: - bpf/selftests: Fix namespace mount setup in tc_redirect https://git.kernel.org/bpf/bpf-next/c/5e22dd186267 You are awesome, thank you!
On Tue, Jan 4, 2022 at 4:10 AM Jiri Olsa <jolsa@redhat.com> wrote: > > The tc_redirect umounts /sys in the new namespace, which can be > mounted as shared and cause global umount. The lazy umount also > takes down mounted trees under /sys like debugfs, which won't be > available after sysfs mounts again and could cause fails in other > tests. > > # cat /proc/self/mountinfo | grep debugfs > 34 23 0:7 / /sys/kernel/debug rw,nosuid,nodev,noexec,relatime shared:14 - debugfs debugfs rw > # cat /proc/self/mountinfo | grep sysfs > 23 86 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw > # mount | grep debugfs > debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) > > # ./test_progs -t tc_redirect > #164 tc_redirect:OK > Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED > > # mount | grep debugfs > # cat /proc/self/mountinfo | grep debugfs > # cat /proc/self/mountinfo | grep sysfs > 25 86 0:22 / /sys rw,relatime shared:2 - sysfs sysfs rw > > Making the sysfs private under the new namespace so the umount won't > trigger the global sysfs umount. Hey Jiri, Thanks for the fix. Did you try making tc_redirect non-serial again (s/serial_test_tc_redirect/test_tc_redirect/) and doing parallelized test_progs run (./test_progs -j) in a tight loop for a while? I suspect this might have been an issue forcing us to make this test serial in the first place, so now that it's fixed, we can make parallel test_progs a bit faster. > > Cc: Jussi Maki <joamaki@gmail.com> > Reported-by: Hangbin Liu <haliu@redhat.com> > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > tools/testing/selftests/bpf/prog_tests/tc_redirect.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c > index 4b18b73df10b..c2426df58e17 100644 > --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c > +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c > @@ -105,6 +105,13 @@ static int setns_by_fd(int nsfd) > 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; > -- > 2.33.1 >
On Wed, Jan 05, 2022 at 12:40:34PM -0800, Andrii Nakryiko wrote: > On Tue, Jan 4, 2022 at 4:10 AM Jiri Olsa <jolsa@redhat.com> wrote: > > > > The tc_redirect umounts /sys in the new namespace, which can be > > mounted as shared and cause global umount. The lazy umount also > > takes down mounted trees under /sys like debugfs, which won't be > > available after sysfs mounts again and could cause fails in other > > tests. > > > > # cat /proc/self/mountinfo | grep debugfs > > 34 23 0:7 / /sys/kernel/debug rw,nosuid,nodev,noexec,relatime shared:14 - debugfs debugfs rw > > # cat /proc/self/mountinfo | grep sysfs > > 23 86 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw > > # mount | grep debugfs > > debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) > > > > # ./test_progs -t tc_redirect > > #164 tc_redirect:OK > > Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED > > > > # mount | grep debugfs > > # cat /proc/self/mountinfo | grep debugfs > > # cat /proc/self/mountinfo | grep sysfs > > 25 86 0:22 / /sys rw,relatime shared:2 - sysfs sysfs rw > > > > Making the sysfs private under the new namespace so the umount won't > > trigger the global sysfs umount. > > Hey Jiri, > > Thanks for the fix. Did you try making tc_redirect non-serial again > (s/serial_test_tc_redirect/test_tc_redirect/) and doing parallelized > test_progs run (./test_progs -j) in a tight loop for a while? I > suspect this might have been an issue forcing us to make this test > serial in the first place, so now that it's fixed, we can make > parallel test_progs a bit faster. hi, right, will try jirka > > > > > Cc: Jussi Maki <joamaki@gmail.com> > > Reported-by: Hangbin Liu <haliu@redhat.com> > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > > --- > > tools/testing/selftests/bpf/prog_tests/tc_redirect.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c > > index 4b18b73df10b..c2426df58e17 100644 > > --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c > > +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c > > @@ -105,6 +105,13 @@ static int setns_by_fd(int nsfd) > > 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; > > -- > > 2.33.1 > > >
On Thu, Jan 06, 2022 at 08:35:18AM +0100, Jiri Olsa wrote: > On Wed, Jan 05, 2022 at 12:40:34PM -0800, Andrii Nakryiko wrote: > > On Tue, Jan 4, 2022 at 4:10 AM Jiri Olsa <jolsa@redhat.com> wrote: > > > > > > The tc_redirect umounts /sys in the new namespace, which can be > > > mounted as shared and cause global umount. The lazy umount also > > > takes down mounted trees under /sys like debugfs, which won't be > > > available after sysfs mounts again and could cause fails in other > > > tests. > > > > > > # cat /proc/self/mountinfo | grep debugfs > > > 34 23 0:7 / /sys/kernel/debug rw,nosuid,nodev,noexec,relatime shared:14 - debugfs debugfs rw > > > # cat /proc/self/mountinfo | grep sysfs > > > 23 86 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw > > > # mount | grep debugfs > > > debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) > > > > > > # ./test_progs -t tc_redirect > > > #164 tc_redirect:OK > > > Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED > > > > > > # mount | grep debugfs > > > # cat /proc/self/mountinfo | grep debugfs > > > # cat /proc/self/mountinfo | grep sysfs > > > 25 86 0:22 / /sys rw,relatime shared:2 - sysfs sysfs rw > > > > > > Making the sysfs private under the new namespace so the umount won't > > > trigger the global sysfs umount. > > > > Hey Jiri, > > > > Thanks for the fix. Did you try making tc_redirect non-serial again > > (s/serial_test_tc_redirect/test_tc_redirect/) and doing parallelized > > test_progs run (./test_progs -j) in a tight loop for a while? I > > suspect this might have been an issue forcing us to make this test > > serial in the first place, so now that it's fixed, we can make > > parallel test_progs a bit faster. > > hi, > right, will try so I can't reproduce the issue in the first place - that means without my fix and with reverted serial_test_tc_redirect change - by running parallelized test_progs, could you guys try it? jirka
On Mon, Jan 17, 2022 at 11:25 AM Jiri Olsa <jolsa@redhat.com> wrote: > > On Thu, Jan 06, 2022 at 08:35:18AM +0100, Jiri Olsa wrote: > > On Wed, Jan 05, 2022 at 12:40:34PM -0800, Andrii Nakryiko wrote: > > > On Tue, Jan 4, 2022 at 4:10 AM Jiri Olsa <jolsa@redhat.com> wrote: > > > > > > > > The tc_redirect umounts /sys in the new namespace, which can be > > > > mounted as shared and cause global umount. The lazy umount also > > > > takes down mounted trees under /sys like debugfs, which won't be > > > > available after sysfs mounts again and could cause fails in other > > > > tests. > > > > > > > > # cat /proc/self/mountinfo | grep debugfs > > > > 34 23 0:7 / /sys/kernel/debug rw,nosuid,nodev,noexec,relatime shared:14 - debugfs debugfs rw > > > > # cat /proc/self/mountinfo | grep sysfs > > > > 23 86 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw > > > > # mount | grep debugfs > > > > debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) > > > > > > > > # ./test_progs -t tc_redirect > > > > #164 tc_redirect:OK > > > > Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED > > > > > > > > # mount | grep debugfs > > > > # cat /proc/self/mountinfo | grep debugfs > > > > # cat /proc/self/mountinfo | grep sysfs > > > > 25 86 0:22 / /sys rw,relatime shared:2 - sysfs sysfs rw > > > > > > > > Making the sysfs private under the new namespace so the umount won't > > > > trigger the global sysfs umount. > > > > > > Hey Jiri, > > > > > > Thanks for the fix. Did you try making tc_redirect non-serial again > > > (s/serial_test_tc_redirect/test_tc_redirect/) and doing parallelized > > > test_progs run (./test_progs -j) in a tight loop for a while? I > > > suspect this might have been an issue forcing us to make this test > > > serial in the first place, so now that it's fixed, we can make > > > parallel test_progs a bit faster. > > > > hi, > > right, will try > > so I can't reproduce the issue in the first place - that means without my > fix and with reverted serial_test_tc_redirect change - by running parallelized > test_progs, could you guys try it? > I tried it for a bunch of iterations and didn't repro it either. Doesn't mean much as CI's environment is different, but I think it might be worth making it parallel again and see if it reproes in CI again. > jirka >
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c index 4b18b73df10b..c2426df58e17 100644 --- a/tools/testing/selftests/bpf/prog_tests/tc_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/tc_redirect.c @@ -105,6 +105,13 @@ static int setns_by_fd(int nsfd) 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;
The tc_redirect umounts /sys in the new namespace, which can be mounted as shared and cause global umount. The lazy umount also takes down mounted trees under /sys like debugfs, which won't be available after sysfs mounts again and could cause fails in other tests. # cat /proc/self/mountinfo | grep debugfs 34 23 0:7 / /sys/kernel/debug rw,nosuid,nodev,noexec,relatime shared:14 - debugfs debugfs rw # cat /proc/self/mountinfo | grep sysfs 23 86 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw # mount | grep debugfs debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime) # ./test_progs -t tc_redirect #164 tc_redirect:OK Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED # mount | grep debugfs # cat /proc/self/mountinfo | grep debugfs # cat /proc/self/mountinfo | grep sysfs 25 86 0:22 / /sys rw,relatime shared:2 - sysfs sysfs rw Making the sysfs private under the new namespace so the umount won't trigger the global sysfs umount. Cc: Jussi Maki <joamaki@gmail.com> Reported-by: Hangbin Liu <haliu@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/testing/selftests/bpf/prog_tests/tc_redirect.c | 7 +++++++ 1 file changed, 7 insertions(+)