[LTP] [PATCH v1 04/10] syscalls/ioctl_loop02: Add LO_FLAGS_READ_ONLY and LOOP_CHANGE_FD test

[Yang Xu]

Hi Cyril

> Hi!
>> For LOOP_CHANGE_FD, this operation is possible only if the loop device
>> is read-only and the new backing store is the same size and type as the
>> old backing store.
>>
>> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
>> ---
>>   runtest/syscalls                              |   1 +
>>   testcases/kernel/syscalls/ioctl/.gitignore    |   1 +
>>   .../kernel/syscalls/ioctl/ioctl_loop02.c      | 148 ++++++++++++++++++
>>   3 files changed, 150 insertions(+)
>>   create mode 100644 testcases/kernel/syscalls/ioctl/ioctl_loop02.c
>>
>> diff --git a/runtest/syscalls b/runtest/syscalls
>> index 7fd67450e..719953497 100644
>> --- a/runtest/syscalls
>> +++ b/runtest/syscalls
>> @@ -528,6 +528,7 @@ ioctl07      ioctl07
>>   ioctl08      ioctl08
>>   
>>   ioctl_loop01 ioctl_loop01
>> +ioctl_loop02 ioctl_loop02
>>   
>>   ioctl_ns01 ioctl_ns01
>>   ioctl_ns02 ioctl_ns02
>> diff --git a/testcases/kernel/syscalls/ioctl/.gitignore b/testcases/kernel/syscalls/ioctl/.gitignore
>> index 4cfef2839..534c4ab34 100644
>> --- a/testcases/kernel/syscalls/ioctl/.gitignore
>> +++ b/testcases/kernel/syscalls/ioctl/.gitignore
>> @@ -7,6 +7,7 @@
>>   /ioctl07
>>   /ioctl08
>>   /ioctl_loop01
>> +/ioctl_loop02
>>   /ioctl_ns01
>>   /ioctl_ns02
>>   /ioctl_ns03
>> diff --git a/testcases/kernel/syscalls/ioctl/ioctl_loop02.c b/testcases/kernel/syscalls/ioctl/ioctl_loop02.c
>> new file mode 100644
>> index 000000000..ba3636aa9
>> --- /dev/null
>> +++ b/testcases/kernel/syscalls/ioctl/ioctl_loop02.c
>> @@ -0,0 +1,148 @@
>> +// 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 is designed to test LO_FLAGS_READ_ONLY(similar as losetup -r)
>> + * and LOOP_CHANGE_FD.
>> + *
>> + * For LOOP_CHANGE_FD, this operation is possible only if the loop device
>> + * is read-only and the new backing store is the same size and type as the
>> + * old backing store.
>> + */
>> +
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <string.h>
>> +#include "ioctl_loop_support.h"
>> +#include "lapi/loop.h"
>> +#include "tst_test.h"
>> +
>> +static int file_fd, file_change_fd, file_fd_invalid;
>> +static char backing_path[1024], backing_file_path[1024], backing_file_change_path[1024];
>> +static int attach_flag, dev_fd, file_fd;
>> +static char loop_ro_path[1024], dev_path[1024];
>> +static void attach_device(char *);
> 
> Just move the function here, there is no point in having the helper
> function after the test function.
>
OK.

>> +static void verify_ioctl_loop(void)
>> +{
>> +	struct loop_info loopinfoget;
>> +
>> +	attach_device("test.img");
>> +	attach_flag = 1;
>> +
>> +	check_sys_value(loop_ro_path, 1);
>> +	check_sys_string(backing_path, backing_file_path);
>> +
>> +	dev_fd = SAFE_OPEN(dev_path, O_RDWR);
>> +	file_change_fd = SAFE_OPEN("test1.img", O_RDWR);
>> +	file_fd_invalid = SAFE_OPEN("test2.img", O_RDWR);
>> +
>> +	memset(&loopinfoget, 0, sizeof(loopinfoget));
>> +	/*
>> +	 *In drivers/block/loop.c code, set status function doesn't handle
>> +	 *LO_FLAGS_READ_ONLY flag and ignore it. Only loop_set_fd with rondonly
>                                                                         ^
> 								       readonly
>> +	 *mode, lo_flags will include LO_FLAGS_READ_ONLY.
>> +	 */
> 
> Also it's customary to add a space between the asterisk and the comment
> text.
> 
OK.
>> +	SAFE_IOCTL(dev_fd, LOOP_GET_STATUS, &loopinfoget);
>> +
>> +	if (loopinfoget.lo_flags & ~LO_FLAGS_READ_ONLY)
>> +		tst_res(TFAIL, "lo_flags has unexpected %d flag", loopinfoget.lo_flags);
>> +	else
>> +		tst_res(TPASS, "lo_flags only has default LO_FLAGS_READ_ONLY flag");
>> +
>> +	TEST(write(dev_fd, "xx", 2));
>> +	if (TST_RET != -1)
>> +		tst_res(TFAIL, "write succeed unexpectedly");
>> +	else
>> +		tst_res(TPASS | TTERRNO, "Can not write data in RO mode");
>> +
>> +	TEST(ioctl(dev_fd, LOOP_CHANGE_FD, file_change_fd));
>> +	if (TST_RET) {
>> +		tst_res(TFAIL | TTERRNO, "LOOP_CHANGE_FD failed");
>> +	} else {
>> +		tst_res(TPASS, "LOOP_CHANGE_FD succeeded");
>> +		check_sys_value(loop_ro_path, 1);
>> +		check_sys_string(backing_path, backing_file_change_path);
>> +	}
>> +
>> +	TEST(ioctl(dev_fd, LOOP_CHANGE_FD, file_fd_invalid));
>> +	if (TST_RET) {
>> +		if (TST_ERR == EINVAL)
>> +			tst_res(TPASS | TTERRNO, "LOOP_CHANGE_FD failed as expected");
>> +		else
>> +			tst_res(TFAIL | TTERRNO, "LOOP_CHANGE_FD failed expected EINVAL got");
>> +	} else {
>> +		tst_res(TFAIL, "LOOP_CHANGE_FD succeeded");
>> +	}
>> +
>> +	SAFE_CLOSE(dev_fd);
>> +	SAFE_CLOSE(file_change_fd);
>> +	SAFE_CLOSE(file_fd_invalid);
>> +	tst_detach_device(dev_path);
>> +	attach_flag = 0;
>> +}
>> +
>> +/*
>> + * This function is different from tst_attach_dev lib/tst_device.c.
>> + * It only opens file_path with O_RDONLY mode before loop_set_fd.
>> + * So we can generate LO_FLAGS_READ_ONLY flag.
>> + */
>> +static void attach_device(char *img)
>> +{
>> +	dev_fd = SAFE_OPEN(dev_path, O_RDWR);
>> +	file_fd = SAFE_OPEN(img, O_RDONLY);
>> +
>> +	SAFE_IOCTL(dev_fd, LOOP_SET_FD, file_fd);
>> +
>> +	SAFE_CLOSE(dev_fd);
>> +	SAFE_CLOSE(file_fd);
>> +}
>> +
>> +static void setup(void)
>> +{
>> +	int dev_num;
>> +
>> +	char *tmpdir = tst_get_tmpdir();
>> +	dev_num = tst_find_free_loopdev(dev_path, sizeof(dev_path));
>> +	if (dev_num < 0)
>> +		tst_brk(TBROK, "Failed to find free loop device");
>> +
>> +	tst_fill_file("test.img", 0, 1024, 10);
>> +	tst_fill_file("test1.img", 0, 1024, 10);
>> +	tst_fill_file("test2.img", 0, 2048, 20);
>> +
>> +	sprintf(backing_path, "/sys/block/loop%d/loop/backing_file", dev_num);
>> +	sprintf(backing_file_path, "%s/test.img", tmpdir);
>> +	sprintf(backing_file_change_path, "%s/test1.img", tmpdir);
>> +	sprintf(loop_ro_path, "/sys/block/loop%d/ro", dev_num);
> 
> We should free the tmpdir here.
Yes, sorry for forgetting this.
> 
>> +}
>> +
>> +static void cleanup(void)
>> +{
>> +	if (dev_fd > 0)
>> +		SAFE_CLOSE(dev_fd);
>> +	if (file_fd > 0)
>> +		SAFE_CLOSE(file_fd);
>> +	if (file_change_fd > 0)
>> +		SAFE_CLOSE(file_change_fd);
>> +	if (file_fd_invalid > 0)
>> +		SAFE_CLOSE(file_fd_invalid);
>> +	if (attach_flag)
>> +		tst_detach_device(dev_path);
>> +}
>> +
>> +static struct tst_test test = {
>> +	.setup = setup,
>> +	.cleanup = cleanup,
>> +	.test_all = verify_ioctl_loop,
>> +	.needs_root = 1,
>> +	.needs_tmpdir = 1,
>> +	.needs_drivers = (const char *const []) {
>> +		"loop",
>> +		NULL
>> +	}
>> +};
>