[LTP] [PATCH v1 4/4] syscalls/ioctl_loop09: Add LOOP_CONFIGURE ioctl test with direct I/O flag

[Yang Xu]

Since kernel commit 3448914e8cc5("loop: Add LOOP_CONFIGURE ioctl"),
it can explicitly request direct I/O mode by setting LO_FLAGS_DIRECT_IO
in loop_config.info.lo_flags.

Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
---
 runtest/syscalls                              |   1 +
 testcases/kernel/syscalls/ioctl/.gitignore    |   1 +
 .../kernel/syscalls/ioctl/ioctl_loop09.c      | 151 ++++++++++++++++++
 3 files changed, 153 insertions(+)
 create mode 100644 testcases/kernel/syscalls/ioctl/ioctl_loop09.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 7259f2a92..df99a0600 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -537,6 +537,7 @@ ioctl_loop05 ioctl_loop05
 ioctl_loop06 ioctl_loop06
 ioctl_loop07 ioctl_loop07
 ioctl_loop08 ioctl_loop08
+ioctl_loop09 ioctl_loop09
 
 ioctl_ns01 ioctl_ns01
 ioctl_ns02 ioctl_ns02
diff --git a/testcases/kernel/syscalls/ioctl/.gitignore b/testcases/kernel/syscalls/ioctl/.gitignore
index 97134aa0b..0decf6ea1 100644
--- a/testcases/kernel/syscalls/ioctl/.gitignore
+++ b/testcases/kernel/syscalls/ioctl/.gitignore
@@ -14,6 +14,7 @@
 /ioctl_loop06
 /ioctl_loop07
 /ioctl_loop08
+/ioctl_loop09
 /ioctl_ns01
 /ioctl_ns02
 /ioctl_ns03
diff --git a/testcases/kernel/syscalls/ioctl/ioctl_loop09.c b/testcases/kernel/syscalls/ioctl/ioctl_loop09.c
new file mode 100644
index 000000000..c291afeb6
--- /dev/null
+++ b/testcases/kernel/syscalls/ioctl/ioctl_loop09.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@cn.jujitsu.com>
+ *
+ * This is a basic ioctl test about loopdevice. It sets LO_FLAGS_DIRECT_IO
+ * in loop_config.info.lo_flags by using LOOP_CONFIGURE instead of using
+ * LOOP_SET_DIRECT_IO. It is similar with ioctl_loop05.c.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include "lapi/loop.h"
+#include "tst_test.h"
+#include "tst_safe_stdio.h"
+
+#define DIO_MESSAGE "In dio mode"
+#define NON_DIO_MESSAGE "In non dio mode"
+
+static char dev_path[1024], sys_loop_diopath[1024];
+static int dev_num, dev_fd, file_fd, block_devfd, logical_block_size;
+static struct loop_config loopconfig;
+static struct tcase {
+	int multi; /*logical_block_size / 2 as unit */
+	int dio_value;
+	char *message;
+} tcases[] = {
+	{0, 1, "Without setting lo_offset or sizelimit"},
+	{2, 1, "With offset equal to logical_block_size"},
+	{1, 0, "less than logical_block_size"},
+};
+
+static void check_dio_value(int flag)
+{
+	struct loop_info loopinfoget;
+
+	memset(&loopinfoget, 0, sizeof(loopinfoget));
+
+	SAFE_IOCTL(dev_fd, LOOP_GET_STATUS, &loopinfoget);
+	tst_res(TINFO, "%s", flag ? DIO_MESSAGE : NON_DIO_MESSAGE);
+
+	if (loopinfoget.lo_flags & LO_FLAGS_DIRECT_IO)
+		tst_res(flag ? TPASS : TFAIL, "lo_flags has LO_FLAGS_DIRECT_IO flag");
+	else
+		tst_res(flag ? TFAIL : TPASS, "lo_flags doesn't have LO_FLAGS_DIRECT_IO flag");
+
+	TST_ASSERT_INT(sys_loop_diopath, flag);
+}
+
+static void find_backing_bdpath(char *buf)
+{
+	const char *const df_cmd[] = {"df", "-T", ".", NULL};
+	char line[PATH_MAX];
+	FILE *file;
+
+	SAFE_CMD(df_cmd, "1.txt", NULL);
+	file = SAFE_FOPEN("1.txt", "r");
+
+	while (fgets(line, sizeof(line), file) != NULL) {
+		sscanf(line, "%s", buf);
+		if (strstr(buf, "/dev/") != NULL)
+			break;
+	}
+	SAFE_FCLOSE(file);
+}
+
+static void verify_ioctl_loop(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+
+	loopconfig.info.lo_offset = tc->multi * logical_block_size / 2;
+
+	tst_res(TINFO, "%s", tc->message);
+	/*
+	 * When we call loop_configure ioctl successfully and detach it,
+	 * the subquent loo_configure without non-zero lo_offset or sizelimit
+	 * may trigger the blk_update_request I/O error. To avoid this, sleep
+	 * 1s to ensure last blk_update_request has completed.
+	 */
+	sleep(1);
+
+	/*
+	 * loop_cofigure calls loop_update_dio() function, it will ignore the result
+	 * of setting dio. It is different from loop_set_dio.
+	 */
+	TST_RETRY_FUNC(ioctl(dev_fd, LOOP_CONFIGURE, &loopconfig), TST_RETVAL_EQ0);
+	check_dio_value(tc->dio_value);
+	TST_RETRY_FUNC(ioctl(dev_fd, LOOP_CLR_FD, 0), TST_RETVAL_EQ0);
+}
+
+static void setup(void)
+{
+	int ret;
+	char buf[100];
+
+	if (tst_fs_type(".") == TST_TMPFS_MAGIC)
+		tst_brk(TCONF, "tmpfd doesn't support O_DIRECT flag");
+
+	dev_num = tst_find_free_loopdev(dev_path, sizeof(dev_path));
+	if (dev_num < 0)
+		tst_brk(TBROK, "Failed to find free loop device");
+
+	sprintf(sys_loop_diopath, "/sys/block/loop%d/loop/dio", dev_num);
+	tst_fill_file("test.img", 0, 1024, 1024);
+	dev_fd = SAFE_OPEN(dev_path, O_RDWR);
+	file_fd = SAFE_OPEN("test.img", O_RDWR);
+
+	find_backing_bdpath(buf);
+	block_devfd = SAFE_OPEN(buf, O_RDWR);
+
+	SAFE_IOCTL(block_devfd, BLKSSZGET, &logical_block_size);
+	tst_res(TINFO, "backing dev logical_block_size is %d", logical_block_size);
+	SAFE_CLOSE(block_devfd);
+	loopconfig.fd = -1;
+	ret = ioctl(dev_fd, LOOP_CONFIGURE, &loopconfig);
+
+	if (ret && errno != EBADF)
+		tst_brk(TCONF | TERRNO, "LOOP_CONFIGURE is not supported");
+	loopconfig.fd = file_fd;
+	loopconfig.info.lo_flags = LO_FLAGS_DIRECT_IO;
+}
+
+static void cleanup(void)
+{
+	if (dev_fd > 0)
+		SAFE_CLOSE(dev_fd);
+	if (block_devfd > 0)
+		SAFE_CLOSE(block_devfd);
+	if (file_fd > 0)
+		SAFE_CLOSE(file_fd);
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.cleanup = cleanup,
+	.tcnt = ARRAY_SIZE(tcases),
+	.test = verify_ioctl_loop,
+	.needs_root = 1,
+	.needs_tmpdir = 1,
+	.needs_drivers = (const char *const []) {
+		"loop",
+		NULL
+	},
+	.needs_cmds = (const char *const []) {
+		"df",
+		NULL
+	}
+};
-- 
2.23.0