Add ksft_exit_fail_msg() return value checks for fchdir() & chroot()
to address the selftests statmount test compile warnings

statmount_test.c:127:2: warning: ignoring return value of ‘fchdir’,
declared with attribute warn_unused_result [-Wunused-result]
  127 |  fchdir(orig_root);
      |  ^~~~~~~~~~~~~~~~~
statmount_test.c:128:2: warning: ignoring return value of ‘chroot’,
declared with attribute warn_unused_result [-Wunused-result]
  128 |  chroot(".");
      |  ^~~~~~~~~~~

Signed-off-by: Abhinav Jain <jain.abhinav177@gmail.com>
---
 .../filesystems/statmount/statmount_test.c          | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/filesystems/statmount/statmount_test.c b/tools/testing/selftests/filesystems/statmount/statmount_test.c
index e6d7c4f1c85b..b5e1247233b6 100644
--- a/tools/testing/selftests/filesystems/statmount/statmount_test.c
+++ b/tools/testing/selftests/filesystems/statmount/statmount_test.c
@@ -125,8 +125,17 @@ static uint32_t old_root_id, old_parent_id;
 
 static void cleanup_namespace(void)
 {
-	fchdir(orig_root);
-	chroot(".");
+	int ret;
+
+	ret = fchdir(orig_root);
+	if (ret == -1)
+		ksft_exit_fail_msg("changing current directory: %s\n",
+				strerror(errno));
+
+	ret = chroot(".");
+	if (ret == -1)
+		ksft_exit_fail_msg("chroot: %s\n", strerror(errno));
+
 	umount2(root_mntpoint, MNT_DETACH);
 	rmdir(root_mntpoint);
 }
-- 
2.34.1

On 6/10/24 14:09, Abhinav Jain wrote:
> Add ksft_exit_fail_msg() return value checks for fchdir() & chroot()
> to address the selftests statmount test compile warnings
> 
> statmount_test.c:127:2: warning: ignoring return value of ‘fchdir’,
> declared with attribute warn_unused_result [-Wunused-result]
>    127 |  fchdir(orig_root);
>        |  ^~~~~~~~~~~~~~~~~
> statmount_test.c:128:2: warning: ignoring return value of ‘chroot’,
> declared with attribute warn_unused_result [-Wunused-result]
>    128 |  chroot(".");
>        |  ^~~~~~~~~~~
> 
> Signed-off-by: Abhinav Jain <jain.abhinav177@gmail.com>
> ---
>   .../filesystems/statmount/statmount_test.c          | 13 +++++++++++--
>   1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/filesystems/statmount/statmount_test.c b/tools/testing/selftests/filesystems/statmount/statmount_test.c
> index e6d7c4f1c85b..b5e1247233b6 100644
> --- a/tools/testing/selftests/filesystems/statmount/statmount_test.c
> +++ b/tools/testing/selftests/filesystems/statmount/statmount_test.c
> @@ -125,8 +125,17 @@ static uint32_t old_root_id, old_parent_id;
>   
>   static void cleanup_namespace(void)
>   {
> -	fchdir(orig_root);
> -	chroot(".");
> +	int ret;
> +
> +	ret = fchdir(orig_root);
> +	if (ret == -1)
> +		ksft_exit_fail_msg("changing current directory: %s\n",
> +				strerror(errno));
> +
> +	ret = chroot(".");
> +	if (ret == -1)
> +		ksft_exit_fail_msg("chroot: %s\n", strerror(errno));
> +
>   	umount2(root_mntpoint, MNT_DETACH);
>   	rmdir(root_mntpoint);
>   }


There is another prior patch that fixes the problem
https://patchwork.kernel.org/project/linux-kselftest/patch/20240417184913.74734-1-amer.shanawany@gmail.com/

thanks,
-- Shuah