generic: Add a test for basic F_SETLEASE functionality

Add a new test that verifies that F_SETLEASE works as expected. The
parent opens a file and sets a lease on it and then forks. The child
then does a (possibly) conflicting open. We then verify that we get
signals as expected.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
diff --git a/src/Makefile b/src/Makefile
index c4fcf37..11190af 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -28,7 +28,7 @@
 	attr-list-by-handle-cursor-test listxattr dio-interleaved t_dir_type \
 	dio-invalidate-cache stat_test t_encrypted_d_revalidate \
 	attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \
-	fscrypt-crypt-util bulkstat_null_ocount
+	fscrypt-crypt-util bulkstat_null_ocount t_setlease
 
 SUBDIRS = log-writes perf
 
diff --git a/src/t_setlease.c b/src/t_setlease.c
new file mode 100644
index 0000000..81d46b6
--- /dev/null
+++ b/src/t_setlease.c
@@ -0,0 +1,157 @@
+/*
+ * t_setlease.c: test basic F_SETLEASE functionality
+ *
+ * Open file, set lease on it. Then fork off children that open the file with
+ * different openflags. Ensure we get signals as expected.
+ *
+ * Copyright (c) 2019: Jeff Layton <jlayton@redhat.com>
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <sys/wait.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+static volatile bool signalled;
+
+struct leasetest {
+	int	openflags;
+	int	leasetype;
+	int	conf_openflags;
+	bool	expect_signal;
+};
+
+static struct leasetest testcase[] = {
+	{ O_RDONLY, F_RDLCK, O_RDONLY, false },
+	{ O_RDONLY, F_RDLCK, O_WRONLY, true },
+	{ O_WRONLY, F_WRLCK, O_RDONLY, true },
+	{ O_WRONLY, F_WRLCK, O_WRONLY, true },
+};
+
+static void usage()
+{
+	printf("Usage: t_setlease <filename>\n");
+}
+
+static void lease_break(int signum)
+{
+	if (signum == SIGIO)
+		signalled = true;
+}
+
+/* Open/create a file, set up signal handler and set lease on file. */
+static int setlease(const char *fname, int openflags, int leasetype)
+{
+	int fd, ret;
+
+	fd = open(fname, openflags | O_CREAT, 0644);
+	if (fd < 0) {
+		perror("open");
+		return -errno;
+	}
+
+	ret = fcntl(fd, F_SETLEASE, leasetype);
+	if (ret) {
+		perror("setlease");
+		return -errno;
+	}
+	return fd;
+}
+
+static int open_conflict(const char *fname, int openflags)
+{
+	int fd;
+
+	fd = open(fname, openflags);
+	if (fd < 0) {
+		perror("open");
+		return -errno;
+	}
+	close(fd);
+	return 0;
+}
+
+static int simple_lease_break(const char *fname, struct leasetest *test)
+{
+	int fd, ret, status;
+	pid_t pid, exited;
+
+	signalled = false;
+	fd = setlease(fname, test->openflags, test->leasetype);
+	if (fd < 0)
+		return fd;
+
+	pid = fork();
+	if (pid < 0) {
+		return -errno;
+	} else if (pid == 0) {
+		/* child */
+		close(fd);
+		int ret = open_conflict(fname, test->conf_openflags);
+		exit(ret ? 1 : 0);
+	}
+
+	/* parent */
+	while (!signalled) {
+		/* Break out if child exited */
+		exited = waitpid(pid, &status, WNOHANG);
+		if (exited)
+			break;
+		usleep(1000);
+	}
+
+	fcntl(fd, F_SETLEASE, F_UNLCK);
+	close(fd);
+
+	/* If it didn't already exit, then wait now */
+	if (!exited)
+		waitpid(pid, &status, 0);
+
+	if (!WIFEXITED(status)) {
+		ret = 1;
+	} else {
+		ret = WEXITSTATUS(status);
+		if (test->expect_signal != signalled)
+			ret = 1;
+	}
+
+	return ret;
+}
+
+int main(int argc, char **argv)
+{
+	int ret, i;
+	char *fname;
+	struct sigaction sa = { .sa_handler = lease_break };
+
+	if (argc < 2) {
+		usage();
+		return 1;
+	}
+
+	fname = argv[1];
+
+	ret = sigaction(SIGIO, &sa, NULL);
+	if (ret) {
+		perror("sigaction");
+		return -1;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(testcase); ++i) {
+		struct leasetest *t = &testcase[i];
+
+		ret = simple_lease_break(fname, t);
+		if (ret) {
+			fprintf(stderr, "Test failure: openflags=%d leasetype=%d conf_openflags=%d expect_signal=%d\n", t->openflags, t->leasetype, t->conf_openflags, t->expect_signal);
+			exit(1);
+		}
+	}
+	return 0;
+}
diff --git a/tests/generic/566 b/tests/generic/566
new file mode 100755
index 0000000..abf4f6d
--- /dev/null
+++ b/tests/generic/566
@@ -0,0 +1,54 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2019 YOUR NAME HERE.  All Rights Reserved.
+#
+# FS QA Test 566
+#
+# Test basic F_SETLEASE functionality. Call the t_setlease program which
+# opens a file and sets a lease on it, and then forks a child to open the
+# same file with various openflags and verify that we get signals as expected.
+#
+# Note that kernels that lack 387e3746d01c (locks: eliminate false positive
+# conflicts for write lease) will fail this test as tasks that have the file
+# open for write are unable to get a F_WRLCK lease.
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs generic
+_supported_os Linux
+_require_test
+
+# if error
+testfile=$TEST_DIR/t_setlease-testfile
+$here/src/t_setlease $testfile
+
+# optional stuff if your test has verbose output to help resolve problems
+#echo
+#echo "If failure, check $seqres.full (this) and $seqres.full.ok (reference)"
+
+# success, all done
+status=0
+exit
diff --git a/tests/generic/566.out b/tests/generic/566.out
new file mode 100644
index 0000000..9cd099b
--- /dev/null
+++ b/tests/generic/566.out
@@ -0,0 +1 @@
+QA output created by 566
diff --git a/tests/generic/group b/tests/generic/group
index 2e4a6f7..57f85f6 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -568,3 +568,4 @@
 563 auto quick
 564 auto quick copy_range
 565 auto quick copy_range
+566 auto quick locks