On Mon, Jun 23, 2025 at 12:22 PM Muhammad Usama Anjum
<usama.an...@collabora.com> wrote:
>
> On 6/20/25 7:55 PM, Chen Linxuan wrote:
> > On Fri, Jun 20, 2025 at 10:46 PM Muhammad Usama Anjum
> > <usama.an...@collabora.com> wrote:
> >>
> >> On 6/20/25 8:50 AM, Chen Linxuan wrote:
> >>> When running `make kselftest`, the following compilation warning was
> >>> encountered:
> >>>
> >>> mount-notify_test.c: In function ‘fanotify_rmdir’:
> >>> mount-notify_test.c:490:17: warning: ignoring return value of ‘chdir’
> >>> declared with attribute ‘warn_unused_result’ [-Wunused-result]
> >>> 490 | chdir("/");
> >>> | ^~~~~~~~~~
> >>>
> >>> Signed-off-by: Chen Linxuan <chenlinx...@uniontech.com>
> >>> ---
> >>> Changes in v2:
> >>> - Apply changes suggested by Shuah Khan
> >>> - Link to v1:
> >>> https://lore.kernel.org/all/20250610020758.2798787-2-chenlinx...@uniontech.com/
> >>> ---
> >>> .../filesystems/mount-notify/mount-notify_test.c | 15 ++++++++++-----
> >>> .../mount-notify/mount-notify_test_ns.c | 15 ++++++++++-----
> >>> 2 files changed, 20 insertions(+), 10 deletions(-)
> >>>
> >>> diff --git
> >>> a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> >>> b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> >>> index 5a3b0ace1a88c..f8e0c6b06e2d9 100644
> >>> --- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> >>> +++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> >>> @@ -458,12 +458,17 @@ TEST_F(fanotify, rmdir)
> >>> ASSERT_GE(ret, 0);
> >>>
> >>> if (ret == 0) {
> >>> - chdir("/");
> >>> - unshare(CLONE_NEWNS);
> >>> - mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
> >>> - umount2("/a", MNT_DETACH);
> >>> + if (chdir("/"))
> >> Please use the APIs provided by the kselftest_harness.h instead of checking
> >> return types manually. For example:
> >> use ASSERT_EQ(chdir("/", 0)).
> >
> > Are you sure？We're in a forked sub process here.
> ASSERT_* are macros. They can be used anywhere. Please give it a try.
V3:
https://lore.kernel.org/all/20250623045711.3564655-2-chenlinx...@uniontech.com/
>
> >
> >>
> >>> + exit(-1);
> >>> + if (unshare(CLONE_NEWNS))
> >>> + exit(-1);
> >>> + if (mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL))
> >>> + exit(-1);
> >>> + if (umount2("/a", MNT_DETACH))
> >>> + exit(-1);
> >>> // This triggers a detach in the other namespace
> >>> - rmdir("/a");
> >>> + if (rmdir("/a"))
> >>> + exit(-1);
> >>> exit(0);
> >>> }
> >>> wait(NULL);
> >>> diff --git
> >>> a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> >>> b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> >>> index d91946e69591a..d6a6a7ee87028 100644
> >>> ---
> >>> a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> >>> +++
> >>> b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> >>> @@ -486,12 +486,17 @@ TEST_F(fanotify, rmdir)
> >>> ASSERT_GE(ret, 0);
> >>>
> >>> if (ret == 0) {
> >>> - chdir("/");
> >>> - unshare(CLONE_NEWNS);
> >>> - mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
> >>> - umount2("/a", MNT_DETACH);
> >>> + if (chdir("/"))
> >>> + exit(-1);
> >>> + if (unshare(CLONE_NEWNS))
> >>> + exit(-1);
> >>> + if (mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL))
> >>> + exit(-1);
> >>> + if (umount2("/a", MNT_DETACH))
> >>> + exit(-1);
> >>> // This triggers a detach in the other namespace
> >>> - rmdir("/a");
> >>> + if (rmdir("/a"))
> >>> + exit(-1);
> >>> exit(0);
> >>> }
> >>> wait(NULL);
> >>
> >>
> >>
>
>
>
