selftests: ublk: add test case for UBLK_U_CMD_UPDATE_SIZE

Add test generic_10 for covering new control command of UBLK_U_CMD_UPDATE_SIZE.

Add 'update_size -s|--size size_in_bytes' sub-command on ublk utility for
supporting this feature, then verify the feature via generic_10.

Cc: Omri Mann <omri@nvidia.com>
Cc: Jared Holzman <jholzman@nvidia.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250522163523.406289-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

tools/testing/selftests/ublk/Makefile

@@ -17,6 +17,7 @@ TEST_PROGS += test_generic_07.sh
 
 TEST_PROGS += test_generic_08.sh
 TEST_PROGS += test_generic_09.sh
+TEST_PROGS += test_generic_10.sh
 
 TEST_PROGS += test_null_01.sh
 TEST_PROGS += test_null_02.sh

tools/testing/selftests/ublk/kublk.c

@@ -216,6 +216,18 @@ static int ublk_ctrl_get_features(struct ublk_dev *dev,
 	return __ublk_ctrl_cmd(dev, &data);
 }
 
+static int ublk_ctrl_update_size(struct ublk_dev *dev,
+		__u64 nr_sects)
+{
+	struct ublk_ctrl_cmd_data data = {
+		.cmd_op	= UBLK_U_CMD_UPDATE_SIZE,
+		.flags	= CTRL_CMD_HAS_DATA,
+	};
+
+	data.data[0] = nr_sects;
+	return __ublk_ctrl_cmd(dev, &data);
+}
+
 static const char *ublk_dev_state_desc(struct ublk_dev *dev)
 {
 	switch (dev->dev_info.state) {
@@ -1236,6 +1248,7 @@ static int cmd_dev_get_features(void)
 		[const_ilog2(UBLK_F_USER_COPY)] = "USER_COPY",
 		[const_ilog2(UBLK_F_ZONED)] = "ZONED",
 		[const_ilog2(UBLK_F_USER_RECOVERY_FAIL_IO)] = "RECOVERY_FAIL_IO",
+		[const_ilog2(UBLK_F_UPDATE_SIZE)] = "UPDATE_SIZE",
 		[const_ilog2(UBLK_F_AUTO_BUF_REG)] = "AUTO_BUF_REG",
 	};
 	struct ublk_dev *dev;
@@ -1270,6 +1283,39 @@ static int cmd_dev_get_features(void)
 	return ret;
 }
 
+static int cmd_dev_update_size(struct dev_ctx *ctx)
+{
+	struct ublk_dev *dev = ublk_ctrl_init();
+	struct ublk_params p;
+	int ret = -EINVAL;
+
+	if (!dev)
+		return -ENODEV;
+
+	if (ctx->dev_id < 0) {
+		fprintf(stderr, "device id isn't provided\n");
+		goto out;
+	}
+
+	dev->dev_info.dev_id = ctx->dev_id;
+	ret = ublk_ctrl_get_params(dev, &p);
+	if (ret < 0) {
+		ublk_err("failed to get params %d %s\n", ret, strerror(-ret));
+		goto out;
+	}
+
+	if (ctx->size & ((1 << p.basic.logical_bs_shift) - 1)) {
+		ublk_err("size isn't aligned with logical block size\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = ublk_ctrl_update_size(dev, ctx->size >> 9);
+out:
+	ublk_ctrl_deinit(dev);
+	return ret;
+}
+
 static void __cmd_create_help(char *exe, bool recovery)
 {
 	int i;
@@ -1312,6 +1358,7 @@ static int cmd_dev_help(char *exe)
 	printf("%s list [-n dev_id] -a \n", exe);
 	printf("\t -a list all devices, -n list specified device, default -a \n\n");
 	printf("%s features\n", exe);
+	printf("%s update_size -n dev_id -s|--size size_in_bytes \n", exe);
 	return 0;
 }
 
@@ -1333,6 +1380,7 @@ int main(int argc, char *argv[])
 		{ "get_data",		1,	NULL, 'g'},
 		{ "auto_zc",		0,	NULL,  0 },
 		{ "auto_zc_fallback", 	0,	NULL,  0 },
+		{ "size",		1,	NULL, 's'},
 		{ 0, 0, 0, 0 }
 	};
 	const struct ublk_tgt_ops *ops = NULL;
@@ -1354,7 +1402,7 @@ int main(int argc, char *argv[])
 
 	opterr = 0;
 	optind = 2;
-	while ((opt = getopt_long(argc, argv, "t:n:d:q:r:e:i:gaz",
+	while ((opt = getopt_long(argc, argv, "t:n:d:q:r:e:i:s:gaz",
 				  longopts, &option_idx)) != -1) {
 		switch (opt) {
 		case 'a':
@@ -1394,6 +1442,9 @@ int main(int argc, char *argv[])
 		case 'g':
 			ctx.flags |= UBLK_F_NEED_GET_DATA;
 			break;
+		case 's':
+			ctx.size = strtoull(optarg, NULL, 10);
+			break;
 		case 0:
 			if (!strcmp(longopts[option_idx].name, "debug_mask"))
 				ublk_dbg_mask = strtol(optarg, NULL, 16);
@@ -1470,6 +1521,8 @@ int main(int argc, char *argv[])
 		ret = cmd_dev_help(argv[0]);
 	else if (!strcmp(cmd, "features"))
 		ret = cmd_dev_get_features();
+	else if (!strcmp(cmd, "update_size"))
+		ret = cmd_dev_update_size(&ctx);
 	else
 		cmd_dev_help(argv[0]);
 

tools/testing/selftests/ublk/kublk.h

@@ -92,6 +92,9 @@ struct dev_ctx {
 	/* built from shmem, only for ublk_dump_dev() */
 	struct ublk_dev *shadow_dev;
 
+	/* for 'update_size' command */
+	unsigned long long size;
+
 	union {
 		struct stripe_ctx 	stripe;
 		struct fault_inject_ctx fault_inject;

tools/testing/selftests/ublk/test_common.sh

@@ -23,6 +23,11 @@ _get_disk_dev_t() {
 	echo $(( (major & 0xfff) << 20 | (minor & 0xfffff) ))
 }
 
+_get_disk_size()
+{
+	lsblk -b -o SIZE -n "$1"
+}
+
 _run_fio_verify_io() {
 	fio --name=verify --rw=randwrite --direct=1 --ioengine=libaio \
 		--bs=8k --iodepth=32 --verify=crc32c --do_verify=1 \

tools/testing/selftests/ublk/test_generic_10.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
+
+TID="generic_10"
+ERR_CODE=0
+
+if ! _have_feature "UPDATE_SIZE"; then
+	exit "$UBLK_SKIP_CODE"
+fi
+
+_prep_test "null" "check update size"
+
+dev_id=$(_add_ublk_dev -t null)
+_check_add_dev $TID $?
+
+size=$(_get_disk_size /dev/ublkb"${dev_id}")
+size=$(( size / 2 ))
+if ! "$UBLK_PROG" update_size -n "$dev_id" -s "$size"; then
+	ERR_CODE=255
+fi
+
+new_size=$(_get_disk_size /dev/ublkb"${dev_id}")
+if [ "$new_size" != "$size" ]; then
+	ERR_CODE=255
+fi
+
+_cleanup_test "null"
+_show_result $TID $ERR_CODE