[LTP] [PATCH v3] unlink: Add error tests for EPERM and EROFS

[Yang Xu]

Add negative cases for unlink(), when errno is EPERM or EROFS.

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
 runtest/syscalls                            |   1 +
 testcases/kernel/syscalls/unlink/.gitignore |   1 +
 testcases/kernel/syscalls/unlink/unlink09.c | 102 ++++++++++++++++++++
 3 files changed, 104 insertions(+)
 create mode 100644 testcases/kernel/syscalls/unlink/unlink09.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 010a1a752..000c9e536 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1651,6 +1651,7 @@ unlink01 symlink01 -T unlink01
 unlink05 unlink05
 unlink07 unlink07
 unlink08 unlink08
+unlink09 unlink09
 
 #unlinkat test cases
 unlinkat01 unlinkat01
diff --git a/testcases/kernel/syscalls/unlink/.gitignore b/testcases/kernel/syscalls/unlink/.gitignore
index 2e783580d..6038cc29d 100644
--- a/testcases/kernel/syscalls/unlink/.gitignore
+++ b/testcases/kernel/syscalls/unlink/.gitignore
@@ -1,3 +1,4 @@
 /unlink05
 /unlink07
 /unlink08
+/unlink09
diff --git a/testcases/kernel/syscalls/unlink/unlink09.c b/testcases/kernel/syscalls/unlink/unlink09.c
new file mode 100644
index 000000000..cc4b4a07e
--- /dev/null
+++ b/testcases/kernel/syscalls/unlink/unlink09.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2024 FUJITSU LIMITED. All Rights Reserved.
+ * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that unlink(2) fails with
+ *
+ * - EPERM when target file is marked as immutable or append-only
+ * - EROFS when target file is on a read-only filesystem.
+ */
+
+#include <sys/ioctl.h>
+#include "tst_test.h"
+#include "lapi/fs.h"
+
+#define TEST_EPERM_IMMUTABLE "test_eperm_immutable"
+#define TEST_EPERM_APPEND_ONLY "test_eperm_append_only"
+#define DIR_EROFS "erofs"
+#define TEST_EROFS "erofs/test_erofs"
+
+static int fd_immutable;
+static int fd_append_only;
+
+static struct test_case_t {
+	char *filename;
+	int *fd;
+	int flag;
+	int expected_errno;
+	char *desc;
+} tcases[] = {
+	{TEST_EPERM_IMMUTABLE, &fd_immutable, FS_IMMUTABLE_FL, EPERM,
+		"target file is immutable"},
+	{TEST_EPERM_APPEND_ONLY, &fd_append_only, FS_APPEND_FL, EPERM,
+		"target file is append-only"},
+	{TEST_EROFS, NULL, 0, EROFS, "target file in read-only filesystem"},
+};
+
+static void setup(void)
+{
+	int attr;
+
+	fd_immutable = SAFE_OPEN(TEST_EPERM_IMMUTABLE, O_CREAT, 0600);
+	SAFE_IOCTL(fd_immutable, FS_IOC_GETFLAGS, &attr);
+	attr |= FS_IMMUTABLE_FL;
+	SAFE_IOCTL(fd_immutable, FS_IOC_SETFLAGS, &attr);
+
+	fd_append_only = SAFE_OPEN(TEST_EPERM_APPEND_ONLY, O_CREAT, 0600);
+	SAFE_IOCTL(fd_append_only, FS_IOC_GETFLAGS, &attr);
+	attr |= FS_APPEND_FL;
+	SAFE_IOCTL(fd_append_only, FS_IOC_SETFLAGS, &attr);
+}
+
+static void cleanup(void)
+{
+	int attr;
+
+	SAFE_IOCTL(fd_immutable, FS_IOC_GETFLAGS, &attr);
+	attr &= ~FS_IMMUTABLE_FL;
+	SAFE_IOCTL(fd_immutable, FS_IOC_SETFLAGS, &attr);
+	SAFE_CLOSE(fd_immutable);
+
+	SAFE_IOCTL(fd_append_only, FS_IOC_GETFLAGS, &attr);
+	attr &= ~FS_APPEND_FL;
+	SAFE_IOCTL(fd_append_only, FS_IOC_SETFLAGS, &attr);
+	SAFE_CLOSE(fd_append_only);
+}
+
+static void verify_unlink(unsigned int i)
+{
+	struct test_case_t *tc = &tcases[i];
+	int attr;
+
+	TST_EXP_FAIL(unlink(tc->filename), tc->expected_errno, "%s", tc->desc);
+
+	/* If unlink() succeeded unexpectedly, test file should be restored. */
+	if (!TST_RET) {
+		if (tc->fd) {
+			*(tc->fd) = SAFE_OPEN(tc->filename, O_CREAT, 0600);
+			if (tc->flag) {
+				SAFE_IOCTL(*(tc->fd), FS_IOC_GETFLAGS, &attr);
+				attr |= tc->flag;
+				SAFE_IOCTL(*(tc->fd), FS_IOC_SETFLAGS, &attr);
+			}
+		} else {
+			SAFE_TOUCH(tc->filename, 0600, 0);
+		}
+	}
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.tcnt = ARRAY_SIZE(tcases),
+	.cleanup = cleanup,
+	.test = verify_unlink,
+	.needs_rofs = 1,
+	.mntpoint = DIR_EROFS,
+	.needs_root = 1,
+};
-- 
2.39.3