Re: [PATCH 4/5] test: self: dm: Add test of linear target

[Tobias Waldekranz <tobias@waldekranz.com>]

On fre, sep 05, 2025 at 18:50, Ahmad Fatoum <a.fatoum@pengutronix.de> wrote:
> On 8/28/25 5:05 PM, Tobias Waldekranz wrote:
>> Verify that the 'linear' target works as expected.
>> 
>> Do this by (1) creating a dm device with a couple of linear mappings
>> to two underlying ramdisks, and then (2) verify that data is returned
>> in the expected order when reading it through the dm device.
>
> Thanks for writing a test! :)
>
>> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
>> ---
>>  test/self/Kconfig  |   7 ++
>>  test/self/Makefile |   1 +
>>  test/self/dm.c     | 159 +++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 167 insertions(+)
>
> Please add to common/boards/configs/enable_self_test.config, so CI also
> tests this.

Ah right, tests are more useful if you execute them :)

I have told SELFTEST_ENABLE_ALL to select SELFTEST_DM and all checks
pass (https://github.com/wkz/barebox/actions/runs/17545487677), but I'm
not exactly sure which job is running the selftests, and how I can see
whether the dm tests are included.

>>  create mode 100644 test/self/dm.c
>> 
>> diff --git a/test/self/Kconfig b/test/self/Kconfig
>> index 4c43dfe394..a6dfd5f9ae 100644
>> --- a/test/self/Kconfig
>> +++ b/test/self/Kconfig
>> @@ -125,4 +125,11 @@ config SELFTEST_TLV
>>  	select BASE64
>>  	select BOARD_LXA
>>  
>> +config SELFTEST_DM
>> +	bool "Device mapper selftest"
>> +	depends on DM_BLK
>> +	select RAMDISK_BLK
>> +	help
>> +	  Tests the available device mapper targets
>> +
>>  endif
>> diff --git a/test/self/Makefile b/test/self/Makefile
>> index 9aa8aab78b..3d74bf9e98 100644
>> --- a/test/self/Makefile
>> +++ b/test/self/Makefile
>> @@ -20,6 +20,7 @@ obj-$(CONFIG_SELFTEST_REGULATOR) += regulator.o test_regulator.dtbo.o
>>  obj-$(CONFIG_SELFTEST_TEST_COMMAND) += test_command.o
>>  obj-$(CONFIG_SELFTEST_IDR) += idr.o
>>  obj-$(CONFIG_SELFTEST_TLV) += tlv.o tlv.dtb.o
>> +obj-$(CONFIG_SELFTEST_DM) += dm.o
>>  
>>  ifdef REGENERATE_KEYTOC
>>  
>> diff --git a/test/self/dm.c b/test/self/dm.c
>> new file mode 100644
>> index 0000000000..e2add03a48
>> --- /dev/null
>> +++ b/test/self/dm.c
>> @@ -0,0 +1,159 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <common.h>
>> +#include <fcntl.h>
>> +#include <fs.h>
>> +#include <disks.h>
>> +#include <dirent.h>
>> +#include <libfile.h>
>> +#include <sys/stat.h>
>> +#include <unistd.h>
>> +#include <bselftest.h>
>> +#include <linux/sizes.h>
>> +#include <ramdisk.h>
>> +#include <dm.h>
>> +#include <driver.h>
>> +#include <block.h>
>> +
>> +BSELFTEST_GLOBALS();
>> +
>> +struct rdctx {
>> +	char mem[16][SECTOR_SIZE];
>> +	struct ramdisk *rd;
>> +	const char *name;
>> +};
>> +
>> +static struct rdctx rdctx[2];
>> +
>> +static int rd_create(void)
>> +{
>> +	struct block_device *blk;
>> +	struct rdctx *ctx;
>> +	char base;
>> +	int i, s;
>> +
>> +
>> +	for (i = 0, ctx = rdctx; i < 2; i++, ctx++) {
>> +		/* In case tests are run multiple times */
>> +		memset(ctx->mem, '\0', sizeof(ctx->mem));
>> +
>> +		/* Add an identifying mark ('a'-'p' and 'A'-'P') at
>> +		 * the start and end of every sector in both disks, so
>> +		 * that we have something to compare against when we
>> +		 * read them back through the DM device.
>> +		 */
>> +		base = i ? 'A' : 'a';
>> +		for (s = 0; s < 16; s++) {
>> +			ctx->mem[s][0] = base + s;
>> +			ctx->mem[s][SECTOR_SIZE - 1] = base + s;
>> +		}
>> +
>> +		ctx->rd = ramdisk_init(SECTOR_SIZE);
>> +		if (!ctx->rd) {
>> +			failed_tests++;
>> +			pr_err("Could not create ramdisk\n");
>> +			return 1;
>> +		}
>> +
>> +		ramdisk_setup_rw(ctx->rd, ctx->mem, sizeof(ctx->mem));
>> +		blk = ramdisk_get_block_device(ctx->rd);
>> +		ctx->name = cdev_name(&blk->cdev);
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static void rd_destroy(void)
>> +{
>> +	ramdisk_free(rdctx[0].rd);
>> +	ramdisk_free(rdctx[1].rd);
>> +}
>> +
>> +static void verify_read(const char *pattern, const char *buf)
>> +{
>> +	off_t first, last;
>> +	int s, len;
>> +
>> +	for (s = 0, len = strlen(pattern); s < len; s++) {
>> +		first = s << SECTOR_SHIFT;
>> +		last = first + SECTOR_SIZE - 1;
>> +
>> +		if (buf[first] != pattern[s]) {
>> +			failed_tests++;
>> +			pr_err("Expected '%c' at beginning of sector %d, read '%c'\n",
>> +			       pattern[s], s, buf[first]);
>> +			return;
>> +		}
>> +
>> +		if (buf[last] != pattern[s]) {
>> +			failed_tests++;
>> +			pr_err("Expected '%c' at end of sector %d, read '%c'\n",
>> +			       pattern[s], s, buf[last]);
>> +			return;
>> +		}
>> +	}
>> +}
>> +
>> +static void test_dm_linear(void)
>> +{
>> +	static const char pattern[] = "DEFaghijklmnopNOP";
>> +	const size_t dmsize = (sizeof(pattern) - 1) * SECTOR_SIZE;
>> +	struct dm_device *dm;
>> +	struct cdev *cdev;
>> +	char *buf, *table;
>> +
>> +	total_tests++;
>> +
>> +	if (!IS_ENABLED(CONFIG_DM_BLK_LINEAR)) {
>> +		pr_info("skipping dm-linear test: disabled in config\n");
>> +		skipped_tests++;
>> +		return;
>> +	}
>> +
>> +	if (rd_create())
>> +		return;
>> +
>> +	table = xasprintf(" 0  3 linear /dev/%s  3\n" /* "DEF" */
>> +			  " 3  1 linear /dev/%s  0\n" /* "a"   */
>> +			  " 4 10 linear /dev/%s  6\n" /* "ghijklmnop" */
>> +			  "14  3 linear /dev/%s 13\n" /* "NOP" */,
>> +			  rdctx[1].name,
>> +			  rdctx[0].name,
>> +			  rdctx[0].name,
>> +			  rdctx[1].name);
>> +
>> +	dm = dm_create("dmtest", table);
>> +	free(table);
>> +
>> +	if (IS_ERR_OR_NULL(dm)) {
>> +		failed_tests++;
>> +		pr_err("Could not create dm device\n");
>> +		goto out_destroy;
>> +	}
>> +
>> +	cdev = cdev_by_name("dmtest");
>> +	if (!cdev) {
>> +		failed_tests++;
>> +		pr_err("Could not find dm device\n");
>> +		goto out_destroy;
>> +	}
>> +
>> +	buf = xmalloc(dmsize);
>> +
>> +	if (cdev_read(cdev, buf, dmsize, 0, 0) < dmsize) {
>> +		failed_tests++;
>> +		pr_err("Could not read dm device\n");
>> +		goto out_free_buf;
>> +	}
>> +
>> +	verify_read(pattern, buf);
>> +
>> +out_free_buf:
>> +	free(buf);
>> +out_destroy:
>> +	dm_destroy(dm);
>> +	rd_destroy();
>> +}
>> +bselftest(core, test_dm_linear);
>
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