[PATCH RFC 2/2] selftests: add F_CREATED tests

[Christian Brauner <brauner@kernel.org>]

Add simple selftests for fcntl(fd, F_CREATED, 0).

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 tools/testing/selftests/core/close_range_test.c | 39 +++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c
index 991c473e3859..3cd50246ab64 100644
--- a/tools/testing/selftests/core/close_range_test.c
+++ b/tools/testing/selftests/core/close_range_test.c
@@ -26,6 +26,10 @@
 #define F_DUPFD_QUERY (F_LINUX_SPECIFIC_BASE + 3)
 #endif
 
+#ifndef F_CREATED
+#define F_CREATED (F_LINUX_SPECIFIC_BASE + 4)
+#endif
+
 static inline int sys_close_range(unsigned int fd, unsigned int max_fd,
 				  unsigned int flags)
 {
@@ -589,4 +593,39 @@ TEST(close_range_cloexec_unshare_syzbot)
 	EXPECT_EQ(close(fd3), 0);
 }
 
+TEST(fcntl_created)
+{
+	for (int i = 0; i < 101; i++) {
+		int fd;
+		char path[PATH_MAX];
+
+		fd = open("/dev/null", O_RDONLY | O_CLOEXEC);
+		ASSERT_GE(fd, 0) {
+			if (errno == ENOENT)
+				SKIP(return,
+					   "Skipping test since /dev/null does not exist");
+		}
+
+		/* We didn't create "/dev/null". */
+		EXPECT_EQ(fcntl(fd, F_CREATED, 0), 0);
+		close(fd);
+
+		sprintf(path, "aaaa_%d", i);
+		fd = open(path, O_CREAT | O_RDONLY | O_CLOEXEC, 0600);
+		ASSERT_GE(fd, 0);
+
+		/* We created "aaaa_%d". */
+		EXPECT_EQ(fcntl(fd, F_CREATED, 0), 1);
+		close(fd);
+
+		fd = open(path, O_RDONLY | O_CLOEXEC);
+		ASSERT_GE(fd, 0);
+
+		/* We're opening it again, so no positive creation check. */
+		EXPECT_EQ(fcntl(fd, F_CREATED, 0), 0);
+		close(fd);
+		unlink(path);
+	}
+}
+
 TEST_HARNESS_MAIN

-- 
2.43.0