[v5] syscalls/ioprio: Add test cases for I/O priority

diff --git a/runtest/syscalls b/runtest/syscalls
index 42c20042376a..700471a2cf07 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -542,6 +542,11 @@  ioperm02 ioperm02
 iopl01 iopl01
 iopl02 iopl02
 
+ioprio_get01 ioprio_get01
+ioprio_set01 ioprio_set01
+ioprio_set02 ioprio_set02
+ioprio_set03 ioprio_set03
+
 io_cancel01 io_cancel01
 io_destroy01 io_destroy01
 io_getevents01 io_getevents01
diff --git a/testcases/kernel/syscalls/ioprio/.gitignore b/testcases/kernel/syscalls/ioprio/.gitignore
new file mode 100644
index 000000000000..373079bf2219
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/.gitignore
@@ -0,0 +1,4 @@ 
+ioprio_get01
+ioprio_set01
+ioprio_set02
+ioprio_set03
diff --git a/testcases/kernel/syscalls/ioprio/Makefile b/testcases/kernel/syscalls/ioprio/Makefile
new file mode 100644
index 000000000000..5ea7d67db123
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/Makefile
@@ -0,0 +1,6 @@ 
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/syscalls/ioprio/ioprio.h b/testcases/kernel/syscalls/ioprio/ioprio.h
new file mode 100644
index 000000000000..c74380475740
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/ioprio.h
@@ -0,0 +1,94 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2019 Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#ifndef LTP_IOPRIO_H
+#define LTP_IOPRIO_H
+
+enum {
+	IOPRIO_CLASS_NONE = 0,
+	IOPRIO_CLASS_RT,
+	IOPRIO_CLASS_BE,
+	IOPRIO_CLASS_IDLE,
+};
+
+enum {
+	IOPRIO_WHO_PROCESS = 1,
+	IOPRIO_WHO_PGRP,
+	IOPRIO_WHO_USER,
+};
+
+/* The I/O scheduler classes have 8 priorities 0..7 except for the IDLE class */
+#define IOPRIO_PRIO_NUM		8
+
+#define IOPRIO_CLASS_SHIFT	(13)
+#define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)
+
+#define IOPRIO_PRIO_CLASS(data)	((data) >> IOPRIO_CLASS_SHIFT)
+#define IOPRIO_PRIO_LEVEL(data)	((data) & IOPRIO_PRIO_MASK)
+#define IOPRIO_PRIO_VALUE(class, data)	(((class) << IOPRIO_CLASS_SHIFT) | data)
+
+static const char * const to_class_str[] = {
+	[IOPRIO_CLASS_NONE] = "NONE",
+	[IOPRIO_CLASS_RT]   = "REALTIME",
+	[IOPRIO_CLASS_BE]   = "BEST-EFFORT",
+	[IOPRIO_CLASS_IDLE] = "IDLE"
+};
+
+static inline int sys_ioprio_get(int which, int who)
+{
+	return tst_syscall(__NR_ioprio_get, which, who);
+}
+
+static inline int sys_ioprio_set(int which, int who, int ioprio)
+{
+	return tst_syscall(__NR_ioprio_set, which, who, ioprio);
+}
+
+/* Priority range from 0 (highest) to 7 (lowest) */
+static inline int prio_in_range(int prio)
+{
+	if ((prio < 0) || (prio > 7))
+		return 0;
+	return 1;
+}
+
+/* Priority range from 0 to 3 using the enum */
+static inline int class_in_range(int class)
+{
+	if ((class < IOPRIO_CLASS_NONE) || (class > IOPRIO_CLASS_IDLE))
+		return 0;
+	return 1;
+}
+
+static inline void ioprio_check_setting(int class, int prio, int report)
+{
+	int res;
+	int newclass, newprio;
+
+	res = sys_ioprio_get(IOPRIO_WHO_PROCESS, 0);
+	if (res == -1) {
+		tst_res(TFAIL | TTERRNO,
+			 "reading back prio failed");
+		return;
+	}
+
+	newclass = IOPRIO_PRIO_CLASS(res);
+	newprio = IOPRIO_PRIO_LEVEL(res);
+	if (newclass != class)
+		tst_res(TFAIL,
+			"wrong class after setting, expected %s got %s",
+			to_class_str[class],
+			to_class_str[newclass]);
+	else if (newprio != prio)
+		tst_res(TFAIL,
+			"wrong prio after setting, expected %d got %d",
+			prio, newprio);
+	else if (report)
+		tst_res(TPASS, "ioprio_set new class %s, new prio %d",
+			to_class_str[newclass],
+			newprio);
+}
+
+#endif
diff --git a/testcases/kernel/syscalls/ioprio/ioprio_get01.c b/testcases/kernel/syscalls/ioprio/ioprio_get01.c
new file mode 100644
index 000000000000..6e822434ee7f
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/ioprio_get01.c
@@ -0,0 +1,47 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Description:
+ * Basic ioprio_get() test. Gets the current process I/O priority and
+ * checks that the values are sane.
+ */
+#include <sys/types.h>
+#include <sys/syscall.h>
+
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+#include "ioprio.h"
+
+static void run(void)
+{
+	int prio, class;
+
+	/* Get the I/O priority for the current process */
+	TEST(sys_ioprio_get(IOPRIO_WHO_PROCESS, 0));
+
+	if (TST_RET == -1) {
+		tst_res(TFAIL | TTERRNO, "ioprio_get failed");
+		return;
+	}
+
+	class = IOPRIO_PRIO_CLASS(TST_RET);
+	prio = IOPRIO_PRIO_LEVEL(TST_RET);
+
+	if (!prio_in_range(prio)) {
+		tst_res(TFAIL, "ioprio out of range (%d)", prio);
+		return;
+	}
+
+	if (!class_in_range(class)) {
+		tst_res(TFAIL, "ioprio class of range (%d)", class);
+		return;
+	}
+
+	tst_res(TPASS, "ioprio_get returned class %s prio %d",
+		to_class_str[class], prio);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+};
diff --git a/testcases/kernel/syscalls/ioprio/ioprio_set01.c b/testcases/kernel/syscalls/ioprio/ioprio_set01.c
new file mode 100644
index 000000000000..24bf8a9caea9
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/ioprio_set01.c
@@ -0,0 +1,63 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Description:
+ * Basic ioprio_set() test. Gets the current process I/O priority and
+ * bumps it up one notch, then down two notches and checks that the
+ * new priority is reported back correctly.
+ */
+#include <sys/types.h>
+#include <sys/syscall.h>
+
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+#include "ioprio.h"
+
+static void run(void)
+{
+	int class, prio;
+
+	/* Get the I/O priority for the current process */
+	TEST(sys_ioprio_get(IOPRIO_WHO_PROCESS, 0));
+
+	if (TST_RET == -1)
+		tst_brk(TBROK | TTERRNO, "ioprio_get failed");
+
+	class = IOPRIO_PRIO_CLASS(TST_RET);
+	prio = IOPRIO_PRIO_LEVEL(TST_RET);
+	tst_res(TINFO, "ioprio_get returned class %s prio %d",
+		to_class_str[class], prio);
+
+	/* Bump prio to what it was + 1 */
+	class = IOPRIO_CLASS_BE;
+	if (!prio_in_range(prio + 1)) {
+		tst_res(TFAIL, "ioprio increase out of range (%d)", prio + 1);
+		return;
+	}
+	prio = (prio + 1);
+
+	TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+			    IOPRIO_PRIO_VALUE(class, prio)));
+	if (TST_RET == -1)
+		tst_res(TFAIL | TTERRNO, "ioprio_set failed");
+	else
+		ioprio_check_setting(class, prio, 1);
+
+	/* Bump prio down two notches */
+	if (!prio_in_range(prio - 2)) {
+		tst_res(TFAIL, "ioprio increase out of range (%d)", prio - 2);
+		return;
+	}
+	prio = (prio - 2);
+	TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+			    IOPRIO_PRIO_VALUE(class, prio)));
+	if (TST_RET == -1)
+		tst_res(TFAIL | TTERRNO, "ioprio_set failed");
+	else
+		ioprio_check_setting(class, prio, 1);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+};
diff --git a/testcases/kernel/syscalls/ioprio/ioprio_set02.c b/testcases/kernel/syscalls/ioprio/ioprio_set02.c
new file mode 100644
index 000000000000..6a655394845c
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/ioprio_set02.c
@@ -0,0 +1,67 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Description:
+ * Extended ioprio_set() test.
+ * Tests to set all 8 priority levels for best effort priority, then
+ * switches to test all 8 priority levels for idle priority. Also test
+ * some non-working priorities to make sure they don't work.
+ */
+#include <sys/types.h>
+#include <sys/syscall.h>
+
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+#include "ioprio.h"
+
+static void run(void)
+{
+	int class, prio;
+	int fail_in_loop;
+
+	/* Bump to best effort scheduling, all 8 priorities */
+	class = IOPRIO_CLASS_BE;
+
+	fail_in_loop = 0;
+	for (prio = 0; prio < IOPRIO_PRIO_NUM; prio++) {
+		TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+				    IOPRIO_PRIO_VALUE(class, prio)));
+		if (TST_RET == -1) {
+			tst_res(TFAIL | TTERRNO, "ioprio_set IOPRIO_CLASS_BE prio %d failed", prio);
+			fail_in_loop = 1;
+		}
+	}
+	if (!fail_in_loop)
+		tst_res(TPASS, "tested all prios in class %s",
+			 to_class_str[class]);
+
+	/* Bump down to idle scheduling */
+	class = IOPRIO_CLASS_IDLE;
+
+	fail_in_loop = 0;
+	for (prio = 0; prio < IOPRIO_PRIO_NUM; prio++) {
+		TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+				    IOPRIO_PRIO_VALUE(class, prio)));
+		if (TST_RET == -1) {
+			tst_res(TFAIL | TTERRNO, "ioprio_set IOPRIO_CLASS_IDLE prio %d failed", prio);
+			fail_in_loop = 1;
+		}
+	}
+	if (!fail_in_loop)
+		tst_res(TPASS, "tested all prios in class %s",
+			 to_class_str[class]);
+
+	/* Test NONE scheduling */
+	class = IOPRIO_CLASS_NONE;
+	TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+			    IOPRIO_PRIO_VALUE(class, 0)));
+	if (TST_RET == -1)
+		tst_res(TFAIL | TTERRNO, "ioprio_set IOPRIO_CLASS_NONE failed");
+	else
+		ioprio_check_setting(class, 0, 1);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+};
diff --git a/testcases/kernel/syscalls/ioprio/ioprio_set03.c b/testcases/kernel/syscalls/ioprio/ioprio_set03.c
new file mode 100644
index 000000000000..b2c962a6f0a5
--- /dev/null
+++ b/testcases/kernel/syscalls/ioprio/ioprio_set03.c
@@ -0,0 +1,61 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Description:
+ * Negative ioprio_set() test. Test some non-working priorities to make
+ * sure they don't work.
+ */
+#include <sys/types.h>
+#include <sys/syscall.h>
+
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+#include "ioprio.h"
+
+static void run(void)
+{
+	int class;
+
+	class = IOPRIO_CLASS_BE;
+
+	/*
+	 * Test to fail with prio 8, first set prio 4 so we know what it
+	 * should still be after failure, i.e. we check that the priority
+	 * didn't change as a side effect of setting an invalid priority.
+	 */
+	sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+		       IOPRIO_PRIO_VALUE(class, 4));
+	TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+			    IOPRIO_PRIO_VALUE(class, 8)));
+	if (TST_RET == -1) {
+		ioprio_check_setting(class, 4, 1);
+		if (errno == EINVAL)
+			tst_res(TPASS | TTERRNO, "returned correct error for wrong prio");
+		else
+			tst_res(TFAIL, "ioprio_set returns wrong errno %d",
+				TST_ERR);
+	} else {
+		tst_res(TFAIL, "ioprio_set IOPRIO_CLASS_BE prio 8 should not work");
+	}
+
+	/* Any other prio than 0 should not work with NONE */
+	class = IOPRIO_CLASS_NONE;
+	TEST(sys_ioprio_set(IOPRIO_WHO_PROCESS, 0,
+			    IOPRIO_PRIO_VALUE(class, 4)));
+	if (TST_RET == -1) {
+		tst_res(TINFO, "tested illegal priority with class %s",
+			to_class_str[class]);
+		if (errno == EINVAL)
+			tst_res(TPASS | TTERRNO, "returned correct error for wrong prio");
+		else
+			tst_res(TFAIL, "ioprio_set returns wrong errno %d",
+				TST_ERR);
+	} else {
+		tst_res(TFAIL, "ioprio_set IOPRIO_CLASS_NONE should fail");
+	}
+}
+
+static struct tst_test test = {
+	.test_all = run,
+};