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

[Tobias Waldekranz <tobias@waldekranz.com>]

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.

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(+)
 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);
-- 
2.43.0