tests: add tests for renameat2(2) flags

Since mv(1) doesn't expose the RENAME_* flags we need to have our own
variation in the tests/ tree. The tests are fairly obvious functional
tests, though in the future (once we solve the d_revalidate issue) we
might also add a full-stack overlayfs integration test.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

configure.ac

@@ -226,6 +226,7 @@ AC_CONFIG_FILES([
 	tests/zfs-tests/cmd/randfree_file/Makefile
 	tests/zfs-tests/cmd/randwritecomp/Makefile
 	tests/zfs-tests/cmd/readmmap/Makefile
+	tests/zfs-tests/cmd/renameat2/Makefile
 	tests/zfs-tests/cmd/rename_dir/Makefile
 	tests/zfs-tests/cmd/rm_lnkcnt_zero_file/Makefile
 	tests/zfs-tests/cmd/send_doall/Makefile
@@ -375,6 +376,7 @@ AC_CONFIG_FILES([
 	tests/zfs-tests/tests/functional/refquota/Makefile
 	tests/zfs-tests/tests/functional/refreserv/Makefile
 	tests/zfs-tests/tests/functional/removal/Makefile
+	tests/zfs-tests/tests/functional/renameat2/Makefile
 	tests/zfs-tests/tests/functional/rename_dirs/Makefile
 	tests/zfs-tests/tests/functional/replacement/Makefile
 	tests/zfs-tests/tests/functional/reservation/Makefile

tests/runfiles/linux.run

@@ -146,6 +146,10 @@ tests = ['projectid_001_pos', 'projectid_002_pos', 'projectid_003_pos',
     'projecttree_001_pos', 'projecttree_002_pos', 'projecttree_003_neg']
 tags = ['functional', 'projectquota']
 
+[tests/functional/renameat2:Linux]
+tests = ['renameat2_noreplace', 'renameat2_exchange', 'renameat2_whiteout']
+tags = ['functional', 'renameat2']
+
 [tests/functional/rsend:Linux]
 tests = ['send_realloc_dnode_size', 'send_encrypted_files']
 tags = ['functional', 'rsend']

tests/test-runner/bin/zts-report.py.in

@@ -69,6 +69,11 @@ exec_reason = 'Test user execute permissions required for utilities'
 python_reason = 'Python v3.5 or newer required'
 python_deps_reason = 'Python modules missing: python-cffi'
 
+#
+# Some tests require that the kernel supports renameat2 syscall.
+#
+renameat2_reason = 'Kernel renameat2 support required'
+
 #
 # Some tests require the O_TMPFILE flag which was first introduced in the
 # 3.11 kernel.
@@ -234,6 +239,7 @@ maybe = {
     'redundancy/redundancy_004_neg': ['FAIL', '7290'],
     'redundancy/redundancy_draid_spare3': ['SKIP', known_reason],
     'removal/removal_condense_export': ['FAIL', known_reason],
+    'renameat2/setup': ['SKIP', renameat2_reason],
     'reservation/reservation_008_pos': ['FAIL', '7741'],
     'reservation/reservation_018_pos': ['FAIL', '5642'],
     'rsend/rsend_019_pos': ['FAIL', '6086'],

tests/zfs-tests/cmd/Makefile.am

@@ -23,6 +23,7 @@ SUBDIRS = \
 	nvlist_to_lua \
 	randwritecomp \
 	readmmap \
+	renameat2 \
 	rename_dir \
 	rm_lnkcnt_zero_file \
 	send_doall \

tests/zfs-tests/cmd/renameat2/.gitignore

@@ -0,0 +1 @@
+/renameat2

tests/zfs-tests/cmd/renameat2/Makefile.am

@@ -0,0 +1,6 @@
+include $(top_srcdir)/config/Rules.am
+
+pkgexecdir = $(datadir)/@PACKAGE@/zfs-tests/bin
+
+pkgexec_PROGRAMS = renameat2
+renameat2_SOURCES = renameat2.c

tests/zfs-tests/cmd/renameat2/renameat2.c

@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: CDDL-1.0 OR MPL-2.0 */
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (C) 2019 Aleksa Sarai <cyphar@cyphar.com>
+ * Copyright (C) 2019 SUSE LLC
+ */
+
+/*
+ * mv(1) doesn't currently support RENAME_{EXCHANGE,WHITEOUT} so this is a very
+ * simple renameat2(2) wrapper for the OpenZFS self-tests.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/syscall.h>
+
+#ifndef SYS_renameat2
+#ifdef __NR_renameat2
+#define	SYS_renameat2 __NR_renameat2
+#elif defined(__x86_64__)
+#define	SYS_renameat2 316
+#elif defined(__i386__)
+#define	SYS_renameat2 353
+#elif defined(__arm__) || defined(__aarch64__)
+#define	SYS_renameat2 382
+#else
+#error "SYS_renameat2 not known for this architecture."
+#endif
+#endif
+
+#ifndef RENAME_NOREPLACE
+#define	RENAME_NOREPLACE	(1 << 0) /* Don't overwrite target */
+#endif
+#ifndef RENAME_EXCHANGE
+#define	RENAME_EXCHANGE		(1 << 1) /* Exchange source and dest */
+#endif
+#ifndef RENAME_WHITEOUT
+#define	RENAME_WHITEOUT		(1 << 2) /* Whiteout source */
+#endif
+
+/* glibc doesn't provide renameat2 wrapper, let's use our own */
+static int
+sys_renameat2(int olddirfd, const char *oldpath,
+    int newdirfd, const char *newpath, unsigned int flags)
+{
+	int ret = syscall(SYS_renameat2, olddirfd, oldpath, newdirfd, newpath,
+	    flags);
+	return ((ret < 0) ? -errno : ret);
+}
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage: renameat2 [-Cnwx] src dst\n");
+	exit(1);
+}
+
+static void
+check(void)
+{
+	int err = sys_renameat2(AT_FDCWD, ".", AT_FDCWD, ".", RENAME_EXCHANGE);
+	exit(err == -ENOSYS);
+}
+
+int
+main(int argc, char **argv)
+{
+	char *src, *dst;
+	int ch, err;
+	unsigned int flags = 0;
+
+	while ((ch = getopt(argc, argv, "Cnwx")) >= 0) {
+		switch (ch) {
+			case 'C':
+				check();
+				break;
+			case 'n':
+				flags |= RENAME_NOREPLACE;
+				break;
+			case 'w':
+				flags |= RENAME_WHITEOUT;
+				break;
+			case 'x':
+				flags |= RENAME_EXCHANGE;
+				break;
+			default:
+				usage();
+				break;
+		}
+	}
+
+	argc -= optind;
+	argv += optind;
+
+	if (argc != 2)
+		usage();
+	src = argv[0];
+	dst = argv[1];
+
+	err = sys_renameat2(AT_FDCWD, src, AT_FDCWD, dst, flags);
+	if (err < 0)
+		fprintf(stderr, "renameat2: %s", strerror(-err));
+	return (err != 0);
+}

tests/zfs-tests/include/commands.cfg

@@ -216,6 +216,7 @@ export ZFSTEST_FILES='badsend
     randfree_file
     randwritecomp
     readmmap
+    renameat2
     rename_dir
     rm_lnkcnt_zero_file
     send_doall

tests/zfs-tests/tests/functional/Makefile.am

@@ -62,6 +62,7 @@ SUBDIRS = \
 	refquota \
 	refreserv \
 	removal \
+	renameat2 \
 	rename_dirs \
 	replacement \
 	reservation \

tests/zfs-tests/tests/functional/renameat2/Makefile.am

@@ -0,0 +1,7 @@
+pkgdatadir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/renameat2
+dist_pkgdata_SCRIPTS = \
+	setup.ksh \
+	cleanup.ksh \
+	renameat2_noreplace.ksh \
+	renameat2_exchange.ksh \
+	renameat2_whiteout.ksh

tests/zfs-tests/tests/functional/renameat2/cleanup.ksh

@@ -0,0 +1,34 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2013 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+default_cleanup

tests/zfs-tests/tests/functional/renameat2/renameat2_exchange.ksh

@@ -0,0 +1,63 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0 OR MPL-2.0
+
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (C) 2019 Aleksa Sarai <cyphar@cyphar.com>
+# Copyright (C) 2019 SUSE LLC
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must rm -rf $TESTDIR/*
+}
+
+log_assert "ZFS supports RENAME_EXCHANGE."
+log_onexit cleanup
+
+cd $TESTDIR
+echo "foo" > foo
+echo "bar" > bar
+
+# Self-exchange is a no-op.
+log_must renameat2 -x foo foo
+log_must grep '^foo$' foo
+
+# Basic exchange.
+log_must renameat2 -x foo bar
+log_must grep '^bar$' foo
+log_must grep '^foo$' bar
+
+# And exchange back.
+log_must renameat2 -x foo bar
+log_must grep '^foo$' foo
+log_must grep '^bar$' bar
+
+# Exchange with a bad path should fail.
+log_mustnot renameat2 -x bar baz
+
+log_pass "ZFS supports RENAME_EXCHANGE as expected."

tests/zfs-tests/tests/functional/renameat2/renameat2_noreplace.ksh

@@ -0,0 +1,53 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0 OR MPL-2.0
+
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (C) 2019 Aleksa Sarai <cyphar@cyphar.com>
+# Copyright (C) 2019 SUSE LLC
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must rm -rf $TESTDIR/*
+}
+
+log_assert "ZFS supports RENAME_NOREPLACE."
+log_onexit cleanup
+
+cd $TESTDIR
+touch foo bar
+
+# Clobbers should always fail.
+log_mustnot renameat2 -n foo foo
+log_mustnot renameat2 -n foo bar
+log_mustnot renameat2 -n bar foo
+
+# Regular renames should succeed.
+log_must renameat2 -n bar baz
+
+log_pass "ZFS supports RENAME_NOREPLACE as expected."