[PATCH v1 3/5] selftests/landlock: Add supports_filesystem() helper

Mickaël Salaün
2023-03-09T17:01:15Z

Replace supports_overlayfs() with supports_filesystem() to be able to
check several filesystems. This will be useful in a following commit.

Only check for overlay filesystem once in the setup step, and then rely
on self->skip_test.

Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20230309165455.175131-4-mic@digikod.net
---
tools/testing/selftests/landlock/fs_test.c | 36 ++++++++++++++--------
1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 0438651f61d2..c1e655fc06bb 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -107,8 +107,10 @@ static bool fgrep(FILE *const inf, const char *const str)
return false;
}

-static bool supports_overlayfs(void)
+static bool supports_filesystem(const char *const filesystem)
{
+ char str[32];
+ int len;
bool res;
FILE *const inf = fopen("/proc/filesystems", "r");

@@ -119,7 +121,12 @@ static bool supports_overlayfs(void)
if (!inf)
return true;

- res = fgrep(inf, "nodev\toverlay\n");
+ len = snprintf(str, sizeof(str), "nodev\t%s\n", filesystem);
+ if (len >= sizeof(str))
+ /* Ignores too-long filesystem names. */
+ return true;
+
+ res = fgrep(inf, str);
fclose(inf);
return res;
}
@@ -4044,14 +4051,17 @@ static const char (*merge_sub_files[])[] = {
* └── work
*/

-/* clang-format off */
-FIXTURE(layout2_overlay) {};
-/* clang-format on */
+FIXTURE(layout2_overlay)
+{
+ bool skip_test;
+};

FIXTURE_SETUP(layout2_overlay)
{
- if (!supports_overlayfs())
- SKIP(return, "overlayfs is not supported");
+ if (!supports_filesystem("overlay")) {
+ self->skip_test = true;
+ SKIP(return, "overlayfs is not supported (setup)");
+ }

prepare_layout(_metadata);

@@ -4089,8 +4099,8 @@ FIXTURE_SETUP(layout2_overlay)

FIXTURE_TEARDOWN(layout2_overlay)
{
- if (!supports_overlayfs())
- SKIP(return, "overlayfs is not supported");
+ if (self->skip_test)
+ SKIP(return, "overlayfs is not supported (teardown)");

EXPECT_EQ(0, remove_path(lower_do1_fl3));
EXPECT_EQ(0, remove_path(lower_dl1_fl2));
@@ -4123,8 +4133,8 @@ FIXTURE_TEARDOWN(layout2_overlay)

TEST_F_FORK(layout2_overlay, no_restriction)
{
- if (!supports_overlayfs())
- SKIP(return, "overlayfs is not supported");
+ if (self->skip_test)
+ SKIP(return, "overlayfs is not supported (test)");

ASSERT_EQ(0, test_open(lower_fl1, O_RDONLY));
ASSERT_EQ(0, test_open(lower_dl1, O_RDONLY));
@@ -4289,8 +4299,8 @@ TEST_F_FORK(layout2_overlay, same_content_different_file)
size_t i;
const char *path_entry;

- if (!supports_overlayfs())
- SKIP(return, "overlayfs is not supported");
+ if (self->skip_test)
+ SKIP(return, "overlayfs is not supported (test)");

/* Sets rules on base directories (i.e. outside overlay scope). */
ruleset_fd = create_ruleset(_metadata, ACCESS_RW, layer1_base);
--
2.39.2