[LTP] [PATCH v4] Add rename15 test

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

This test has been extracted from symlink01 and it verifies that
rename() is working correctly on symlink() generated files, renaming
symbolic link and checking if stat() information are preserved.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
Reviewed-by: Li Wang <liwang@redhat.com>
---
use lstat to make sure symlink exist and it has been created
check if files are still there or they have been removed

 runtest/syscalls                            |   1 +
 testcases/kernel/syscalls/rename/.gitignore |   1 +
 testcases/kernel/syscalls/rename/rename15.c | 126 ++++++++++++++++++++
 3 files changed, 128 insertions(+)
 create mode 100644 testcases/kernel/syscalls/rename/rename15.c

diff --git a/runtest/syscalls b/runtest/syscalls
index a9fc8c432..bc99e8272 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1196,6 +1196,7 @@ rename11 rename11
 rename12 rename12
 rename13 rename13
 rename14 rename14
+rename15 rename15
 
 #renameat test cases
 renameat01 renameat01
diff --git a/testcases/kernel/syscalls/rename/.gitignore b/testcases/kernel/syscalls/rename/.gitignore
index f95cf7d21..d17b80f09 100644
--- a/testcases/kernel/syscalls/rename/.gitignore
+++ b/testcases/kernel/syscalls/rename/.gitignore
@@ -11,3 +11,4 @@
 /rename12
 /rename13
 /rename14
+/rename15
diff --git a/testcases/kernel/syscalls/rename/rename15.c b/testcases/kernel/syscalls/rename/rename15.c
new file mode 100644
index 000000000..aad01dee9
--- /dev/null
+++ b/testcases/kernel/syscalls/rename/rename15.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
+ *    Authors: David Fenner, Jon Hendrickson
+ * Copyright (C) 2024 Andrea Cervesato andrea.cervesato@suse.com
+ */
+
+/*\
+ * [Description]
+ *
+ * This test suite validates the behavior of the `rename()` system call on
+ * symbolic links under three scenarios:
+ *
+ * - rename a symlink pointing to an existing file and verifies that the
+ *   symlink's inode and device number remain unchanged.
+ *
+ * - rename a symlink pointing to a non-existent path, ensuring that the
+ *   original symlink remains unaffected.
+ *
+ * - rename a symlink pointing to a created file, confirming that the new
+ *   symlink points to the correct file.
+ */
+
+#include "tst_test.h"
+#include "tst_tmpdir.h"
+
+#define MNTPOINT "mnt"
+#define OLDNAME MNTPOINT"/msymlink0"
+#define NEWNAME MNTPOINT"/asymlink0"
+#define OBJNAME MNTPOINT"/object"
+
+static char *tmpdir;
+static char *oldname;
+static char *newname;
+static char *objname;
+
+static void test_existing(void)
+{
+	tst_res(TINFO, "Test rename() on symlink pointing to an existent path");
+
+	struct stat sym_stat;
+	struct stat oldsym_stat;
+	struct stat newsym_stat;
+
+	SAFE_SYMLINK(tmpdir, oldname);
+	TST_EXP_PASS(lstat(oldname, &sym_stat));
+	SAFE_STAT(oldname, &oldsym_stat);
+
+	SAFE_RENAME(oldname, newname);
+	SAFE_STAT(newname, &newsym_stat);
+
+	TST_EXP_EQ_LI(oldsym_stat.st_ino, newsym_stat.st_ino);
+	TST_EXP_EQ_LI(oldsym_stat.st_dev, newsym_stat.st_dev);
+	TST_EXP_FAIL(access(oldname, F_OK), ENOENT);
+
+	SAFE_UNLINK(newname);
+}
+
+static void test_non_existing(void)
+{
+	tst_res(TINFO, "Test rename() on symlink pointing to a non-existent path");
+
+	struct stat path_stat;
+
+	SAFE_SYMLINK("this_path_doesnt_exist", oldname);
+	TST_EXP_FAIL(stat(oldname, &path_stat), ENOENT);
+
+	SAFE_RENAME(oldname, newname);
+	TST_EXP_FAIL(stat(newname, &path_stat), ENOENT);
+	TST_EXP_FAIL(access(oldname, F_OK), ENOENT);
+
+	SAFE_UNLINK(newname);
+}
+
+static void test_creat(void)
+{
+
+	tst_res(TINFO, "Test rename() on symlink pointing to a path created lately");
+
+	struct stat sym_stat;
+	struct stat path_stat;
+
+	SAFE_SYMLINK(objname, oldname);
+	TST_EXP_PASS(lstat(oldname, &sym_stat));
+	TST_EXP_FAIL(stat(oldname, &path_stat), ENOENT);
+
+	tst_res(TINFO, "Create object file");
+
+	int fd;
+
+	fd = SAFE_CREAT(objname, 0700);
+	if (fd >= 0)
+		SAFE_CLOSE(fd);
+
+	SAFE_RENAME(oldname, newname);
+	TST_EXP_PASS(stat(newname, &path_stat));
+	TST_EXP_FAIL(access(oldname, F_OK), ENOENT);
+	TST_EXP_PASS(access(objname, F_OK));
+
+	SAFE_UNLINK(objname);
+	SAFE_UNLINK(newname);
+}
+
+static void run(void)
+{
+	test_existing();
+	test_creat();
+	test_non_existing();
+}
+
+static void setup(void)
+{
+	tmpdir = tst_tmpdir_path();
+	oldname = tst_tmpdir_mkpath(OLDNAME);
+	newname = tst_tmpdir_mkpath(NEWNAME);
+	objname = tst_tmpdir_mkpath(OBJNAME);
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.test_all = run,
+	.all_filesystems = 1,
+	.mntpoint = MNTPOINT,
+	.format_device = 1,
+	.needs_root = 1,
+};
-- 
2.43.0