ublk: add an rpc method to get current ublk devices (90a6407d) · Commits · Public Repositories / spdk

CHANGELOG.md

+9 −0

Original line number	Diff line number	Diff line
		@@ -176,6 +176,15 @@ For the active-active policy of the multipath mode, in addition to the default r
		selector, the minimum queue depth path selector was added. The minimum queue depth path selector
		selects an I/O path according to the number of outstanding requests of each nvme qpair.

		### ublk device

		The ublk application supports the ublk kernel driver. It's implemented as a ublk backend
		in spdk_tgt and could be started with specifying configuration. See the
		[ublk](https://www.kernel.org/doc/html/latest/block/ublk.html) documentation for more details.

		ublk bdev could export a block device via Linux ublk. It will move this backend device into userspace
		as `/dev/ublkb*`. Before to adding ublk device, need to create ublk target by rpc methond.

		## v22.09

		### accel

doc/jsonrpc.md

+44 −0

Original line number	Diff line number	Diff line
		@@ -10831,6 +10831,50 @@ Example response:
		}
		~~~

		### ublk_get_disks {#rpc_ublk_get_disks}

		Display full or specified ublk device list

		#### Parameters

		Name \| Optional \| Type \| Description
		----------------------- \| -------- \| ----------- \| -----------
		ublk_id \| Optional \| int \| ublk device id to display

		#### Response

		Display ublk device list

		#### Example

		Example request:

		~~~json
		{
		"jsonrpc": "2.0",
		"method": "ublk_get_disks",
		"id": 1
		}
		~~~

		Example response:

		~~~json
		{
		"jsonrpc": "2.0",
		"id": 1,
		"result": [
		{
		"ublk_device": "/dev/ublkb1",
		"id": 1,
		"queue_depth": 512,
		"num_queues": 1,
		"bdev_name": "Malloc1"
		}
		]
		}
		~~~

		## Linux Network Block Device (NBD) {#jsonrpc_components_nbd}

		SPDK supports exporting bdevs through Linux nbd. These devices then appear as standard Linux kernel block devices

lib/ublk/ublk.c

+28 −0

Original line number	Diff line number	Diff line
		@@ -561,6 +561,34 @@ ublk_dev_find_by_id(uint32_t ublk_id)
		return NULL;
		}

		uint32_t
		ublk_dev_get_id(struct spdk_ublk_dev *ublk)
		{
		return ublk->ublk_id;
		}

		struct spdk_ublk_dev *ublk_dev_first(void)
		{
		return TAILQ_FIRST(&g_ublk_bdevs);
		}

		struct spdk_ublk_dev ublk_dev_next(struct spdk_ublk_dev prev)
		{
		return TAILQ_NEXT(prev, tailq);
		}

		uint32_t
		ublk_dev_get_queue_depth(struct spdk_ublk_dev *ublk)
		{
		return ublk->queue_depth;
		}

		uint32_t
		ublk_dev_get_num_queues(struct spdk_ublk_dev *ublk)
		{
		return ublk->num_queues;
		}

		const char *
		ublk_dev_get_bdev_name(struct spdk_ublk_dev *ublk)
		{

lib/ublk/ublk_internal.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -25,7 +25,12 @@ int ublk_start_disk(const char *bdev_name, uint32_t ublk_id,
		uint32_t num_queues, uint32_t queue_depth);
		int ublk_stop_disk(uint32_t ublk_id, ublk_del_cb del_cb, void *cb_arg);
		struct spdk_ublk_dev *ublk_dev_find_by_id(uint32_t ublk_id);
		uint32_t ublk_dev_get_id(struct spdk_ublk_dev *ublk);
		const char ublk_dev_get_bdev_name(struct spdk_ublk_dev ublk);
		struct spdk_ublk_dev *ublk_dev_first(void);
		struct spdk_ublk_dev ublk_dev_next(struct spdk_ublk_dev prev);
		uint32_t ublk_dev_get_queue_depth(struct spdk_ublk_dev *ublk);
		uint32_t ublk_dev_get_num_queues(struct spdk_ublk_dev *ublk);

		#ifdef __cplusplus
		}

lib/ublk/ublk_rpc.c

+72 −0

Original line number	Diff line number	Diff line
		@@ -187,3 +187,75 @@ invalid:
		}

		SPDK_RPC_REGISTER("ublk_stop_disk", rpc_ublk_stop_disk, SPDK_RPC_RUNTIME)

		static void
		rpc_dump_ublk_info(struct spdk_json_write_ctx *w,
		struct spdk_ublk_dev *ublk)
		{
		char ublk_path[32];

		snprintf(ublk_path, 32, "%s%u", "/dev/ublkb", ublk_dev_get_id(ublk));
		spdk_json_write_object_begin(w);

		spdk_json_write_named_string(w, "ublk_device", ublk_path);
		spdk_json_write_named_uint32(w, "id", ublk_dev_get_id(ublk));
		spdk_json_write_named_uint32(w, "queue_depth", ublk_dev_get_queue_depth(ublk));
		spdk_json_write_named_uint32(w, "num_queues", ublk_dev_get_num_queues(ublk));
		spdk_json_write_named_string(w, "bdev_name", ublk_dev_get_bdev_name(ublk));

		spdk_json_write_object_end(w);
		}

		struct rpc_ublk_get_disks {
		uint32_t ublk_id;
		};

		static const struct spdk_json_object_decoder rpc_ublk_get_disks_decoders[] = {
		{"ublk_id", offsetof(struct rpc_ublk_get_disks, ublk_id), spdk_json_decode_uint32, true},
		};

		static void
		rpc_ublk_get_disks(struct spdk_jsonrpc_request *request,
		const struct spdk_json_val *params)
		{
		struct rpc_ublk_get_disks req = {};
		struct spdk_json_write_ctx *w;
		struct spdk_ublk_dev *ublk = NULL;

		if (params != NULL) {
		if (spdk_json_decode_object(params, rpc_ublk_get_disks_decoders,
		SPDK_COUNTOF(rpc_ublk_get_disks_decoders),
		&req)) {
		SPDK_ERRLOG("spdk_json_decode_object failed\n");
		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
		"spdk_json_decode_object failed");
		return;
		}

		if (req.ublk_id) {
		ublk = ublk_dev_find_by_id(req.ublk_id);
		if (ublk == NULL) {
		SPDK_ERRLOG("ublk device '%d' does not exist\n", req.ublk_id);
		spdk_jsonrpc_send_error_response(request, -ENODEV, spdk_strerror(ENODEV));
		return;
		}
		}
		}

		w = spdk_jsonrpc_begin_result(request);
		spdk_json_write_array_begin(w);

		if (ublk != NULL) {
		rpc_dump_ublk_info(w, ublk);
		} else {
		for (ublk = ublk_dev_first(); ublk != NULL; ublk = ublk_dev_next(ublk)) {
		rpc_dump_ublk_info(w, ublk);
		}
		}

		spdk_json_write_array_end(w);
		spdk_jsonrpc_end_result(request, w);

		return;
		}
		SPDK_RPC_REGISTER("ublk_get_disks", rpc_ublk_get_disks, SPDK_RPC_RUNTIME)

Admin message