xref: /spdk/lib/bdev/bdev_rpc.c (revision 2d64c2871a4f9f6c7ae61edddc2407c23db832ed)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2018 Intel Corporation.
3  *   All rights reserved.
4  *   Copyright (c) 2022-2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
5  */
6 
7 #include "spdk/bdev.h"
8 
9 #include "spdk/env.h"
10 #include "spdk/rpc.h"
11 #include "spdk/util.h"
12 #include "spdk/string.h"
13 #include "spdk/base64.h"
14 #include "spdk/bdev_module.h"
15 #include "spdk/dma.h"
16 
17 #include "spdk/log.h"
18 
19 #include "bdev_internal.h"
20 
21 static void
22 dummy_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, void *ctx)
23 {
24 }
25 
26 static const struct spdk_json_object_decoder rpc_set_bdev_opts_decoders[] = {
27 	{"bdev_io_pool_size", offsetof(struct spdk_bdev_opts, bdev_io_pool_size), spdk_json_decode_uint32, true},
28 	{"bdev_io_cache_size", offsetof(struct spdk_bdev_opts, bdev_io_cache_size), spdk_json_decode_uint32, true},
29 	{"bdev_auto_examine", offsetof(struct spdk_bdev_opts, bdev_auto_examine), spdk_json_decode_bool, true},
30 	{"iobuf_small_cache_size", offsetof(struct spdk_bdev_opts, iobuf_small_cache_size), spdk_json_decode_uint32, true},
31 	{"iobuf_large_cache_size", offsetof(struct spdk_bdev_opts, iobuf_large_cache_size), spdk_json_decode_uint32, true},
32 };
33 
34 static void
35 rpc_bdev_set_options(struct spdk_jsonrpc_request *request, const struct spdk_json_val *params)
36 {
37 	struct spdk_bdev_opts opts;
38 	int rc;
39 
40 	spdk_bdev_get_opts(&opts, sizeof(opts));
41 	if (params != NULL) {
42 		if (spdk_json_decode_object(params, rpc_set_bdev_opts_decoders,
43 					    SPDK_COUNTOF(rpc_set_bdev_opts_decoders), &opts)) {
44 			SPDK_ERRLOG("spdk_json_decode_object() failed\n");
45 			spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
46 							 "Invalid parameters");
47 			return;
48 		}
49 	}
50 
51 	rc = spdk_bdev_set_opts(&opts);
52 	if (rc != 0) {
53 		spdk_jsonrpc_send_error_response_fmt(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
54 						     "Pool size %" PRIu32 " too small for cache size %" PRIu32,
55 						     opts.bdev_io_pool_size, opts.bdev_io_cache_size);
56 		return;
57 	}
58 
59 	spdk_jsonrpc_send_bool_response(request, true);
60 }
61 SPDK_RPC_REGISTER("bdev_set_options", rpc_bdev_set_options, SPDK_RPC_STARTUP)
62 
63 static void
64 rpc_bdev_wait_for_examine_cpl(void *arg)
65 {
66 	struct spdk_jsonrpc_request *request = arg;
67 
68 	spdk_jsonrpc_send_bool_response(request, true);
69 }
70 
71 static void
72 rpc_bdev_wait_for_examine(struct spdk_jsonrpc_request *request,
73 			  const struct spdk_json_val *params)
74 {
75 	int rc;
76 
77 	if (params != NULL) {
78 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
79 						 "bdev_wait_for_examine requires no parameters");
80 		return;
81 	}
82 
83 	rc = spdk_bdev_wait_for_examine(rpc_bdev_wait_for_examine_cpl, request);
84 	if (rc != 0) {
85 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
86 	}
87 }
88 SPDK_RPC_REGISTER("bdev_wait_for_examine", rpc_bdev_wait_for_examine, SPDK_RPC_RUNTIME)
89 
90 struct rpc_bdev_examine {
91 	char *name;
92 };
93 
94 static void
95 free_rpc_bdev_examine(struct rpc_bdev_examine *r)
96 {
97 	free(r->name);
98 }
99 
100 static const struct spdk_json_object_decoder rpc_examine_bdev_decoders[] = {
101 	{"name", offsetof(struct rpc_bdev_examine, name), spdk_json_decode_string},
102 };
103 
104 static void
105 rpc_bdev_examine_bdev(struct spdk_jsonrpc_request *request,
106 		      const struct spdk_json_val *params)
107 {
108 	struct rpc_bdev_examine req = {NULL};
109 	int rc;
110 
111 	if (spdk_json_decode_object(params, rpc_examine_bdev_decoders,
112 				    SPDK_COUNTOF(rpc_examine_bdev_decoders),
113 				    &req)) {
114 		SPDK_ERRLOG("spdk_json_decode_object() failed\n");
115 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
116 						 "spdk_json_decode_object failed");
117 		goto cleanup;
118 	}
119 
120 	rc = spdk_bdev_examine(req.name);
121 	if (rc != 0) {
122 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
123 		goto cleanup;
124 	}
125 
126 	spdk_jsonrpc_send_bool_response(request, true);
127 
128 cleanup:
129 	free_rpc_bdev_examine(&req);
130 }
131 SPDK_RPC_REGISTER("bdev_examine", rpc_bdev_examine_bdev, SPDK_RPC_RUNTIME)
132 
133 struct rpc_get_iostat_ctx {
134 	int bdev_count;
135 	int rc;
136 	struct spdk_jsonrpc_request *request;
137 	struct spdk_json_write_ctx *w;
138 	bool per_channel;
139 };
140 
141 struct bdev_get_iostat_ctx {
142 	struct spdk_bdev_io_stat *stat;
143 	struct rpc_get_iostat_ctx *rpc_ctx;
144 	struct spdk_bdev_desc *desc;
145 };
146 
147 static void
148 rpc_get_iostat_started(struct rpc_get_iostat_ctx *rpc_ctx)
149 {
150 	rpc_ctx->w = spdk_jsonrpc_begin_result(rpc_ctx->request);
151 
152 	spdk_json_write_object_begin(rpc_ctx->w);
153 	spdk_json_write_named_uint64(rpc_ctx->w, "tick_rate", spdk_get_ticks_hz());
154 	spdk_json_write_named_uint64(rpc_ctx->w, "ticks", spdk_get_ticks());
155 }
156 
157 static void
158 rpc_get_iostat_done(struct rpc_get_iostat_ctx *rpc_ctx)
159 {
160 	if (--rpc_ctx->bdev_count != 0) {
161 		return;
162 	}
163 
164 	if (rpc_ctx->rc == 0) {
165 		spdk_json_write_array_end(rpc_ctx->w);
166 		spdk_json_write_object_end(rpc_ctx->w);
167 		spdk_jsonrpc_end_result(rpc_ctx->request, rpc_ctx->w);
168 	} else {
169 		/* Return error response after processing all specified bdevs
170 		 * completed or failed.
171 		 */
172 		spdk_jsonrpc_send_error_response(rpc_ctx->request, rpc_ctx->rc,
173 						 spdk_strerror(-rpc_ctx->rc));
174 	}
175 
176 	free(rpc_ctx);
177 }
178 
179 static struct bdev_get_iostat_ctx *
180 bdev_iostat_ctx_alloc(bool iostat_ext)
181 {
182 	struct bdev_get_iostat_ctx *ctx;
183 
184 	ctx = calloc(1, sizeof(struct bdev_get_iostat_ctx));
185 	if (ctx == NULL) {
186 		return NULL;
187 	}
188 
189 	ctx->stat = bdev_alloc_io_stat(iostat_ext);
190 	if (ctx->stat == NULL) {
191 		free(ctx);
192 		return NULL;
193 	}
194 
195 	return ctx;
196 }
197 
198 static void
199 bdev_iostat_ctx_free(struct bdev_get_iostat_ctx *ctx)
200 {
201 	bdev_free_io_stat(ctx->stat);
202 	free(ctx);
203 }
204 
205 static void
206 bdev_get_iostat_done(struct spdk_bdev *bdev, struct spdk_bdev_io_stat *stat,
207 		     void *cb_arg, int rc)
208 {
209 	struct bdev_get_iostat_ctx *bdev_ctx = cb_arg;
210 	struct rpc_get_iostat_ctx *rpc_ctx = bdev_ctx->rpc_ctx;
211 	struct spdk_json_write_ctx *w = rpc_ctx->w;
212 
213 	if (rc != 0 || rpc_ctx->rc != 0) {
214 		if (rpc_ctx->rc == 0) {
215 			rpc_ctx->rc = rc;
216 		}
217 		goto done;
218 	}
219 
220 	assert(stat == bdev_ctx->stat);
221 
222 	spdk_json_write_object_begin(w);
223 
224 	spdk_json_write_named_string(w, "name", spdk_bdev_get_name(bdev));
225 
226 	spdk_bdev_dump_io_stat_json(stat, w);
227 
228 	if (spdk_bdev_get_qd_sampling_period(bdev)) {
229 		spdk_json_write_named_uint64(w, "queue_depth_polling_period",
230 					     spdk_bdev_get_qd_sampling_period(bdev));
231 
232 		spdk_json_write_named_uint64(w, "queue_depth", spdk_bdev_get_qd(bdev));
233 
234 		spdk_json_write_named_uint64(w, "io_time", spdk_bdev_get_io_time(bdev));
235 
236 		spdk_json_write_named_uint64(w, "weighted_io_time",
237 					     spdk_bdev_get_weighted_io_time(bdev));
238 	}
239 
240 	if (bdev->fn_table->dump_device_stat_json) {
241 		spdk_json_write_named_object_begin(w, "driver_specific");
242 		bdev->fn_table->dump_device_stat_json(bdev->ctxt, w);
243 		spdk_json_write_object_end(w);
244 	}
245 
246 	spdk_json_write_object_end(w);
247 
248 done:
249 	rpc_get_iostat_done(rpc_ctx);
250 
251 	spdk_bdev_close(bdev_ctx->desc);
252 	bdev_iostat_ctx_free(bdev_ctx);
253 }
254 
255 static int
256 bdev_get_iostat(void *ctx, struct spdk_bdev *bdev)
257 {
258 	struct rpc_get_iostat_ctx *rpc_ctx = ctx;
259 	struct bdev_get_iostat_ctx *bdev_ctx;
260 	int rc;
261 
262 	bdev_ctx = bdev_iostat_ctx_alloc(true);
263 	if (bdev_ctx == NULL) {
264 		SPDK_ERRLOG("Failed to allocate bdev_iostat_ctx struct\n");
265 		return -ENOMEM;
266 	}
267 
268 	rc = spdk_bdev_open_ext(spdk_bdev_get_name(bdev), false, dummy_bdev_event_cb, NULL,
269 				&bdev_ctx->desc);
270 	if (rc != 0) {
271 		bdev_iostat_ctx_free(bdev_ctx);
272 		SPDK_ERRLOG("Failed to open bdev\n");
273 		return rc;
274 	}
275 
276 	rpc_ctx->bdev_count++;
277 	bdev_ctx->rpc_ctx = rpc_ctx;
278 	spdk_bdev_get_device_stat(bdev, bdev_ctx->stat, bdev_get_iostat_done, bdev_ctx);
279 
280 	return 0;
281 }
282 
283 static void
284 bdev_get_per_channel_stat_done(struct spdk_bdev *bdev, void *ctx, int status)
285 {
286 	struct bdev_get_iostat_ctx *bdev_ctx = ctx;
287 
288 	rpc_get_iostat_done(bdev_ctx->rpc_ctx);
289 
290 	spdk_bdev_close(bdev_ctx->desc);
291 
292 	bdev_iostat_ctx_free(bdev_ctx);
293 }
294 
295 static void
296 bdev_get_per_channel_stat(struct spdk_bdev_channel_iter *i, struct spdk_bdev *bdev,
297 			  struct spdk_io_channel *ch, void *ctx)
298 {
299 	struct bdev_get_iostat_ctx *bdev_ctx = ctx;
300 	struct spdk_json_write_ctx *w = bdev_ctx->rpc_ctx->w;
301 
302 	spdk_bdev_get_io_stat(bdev, ch, bdev_ctx->stat);
303 
304 	spdk_json_write_object_begin(w);
305 	spdk_json_write_named_uint64(w, "thread_id", spdk_thread_get_id(spdk_get_thread()));
306 	spdk_bdev_dump_io_stat_json(bdev_ctx->stat, w);
307 	spdk_json_write_object_end(w);
308 
309 	spdk_bdev_for_each_channel_continue(i, 0);
310 }
311 
312 struct rpc_bdev_get_iostat {
313 	char *name;
314 	bool per_channel;
315 };
316 
317 static void
318 free_rpc_bdev_get_iostat(struct rpc_bdev_get_iostat *r)
319 {
320 	free(r->name);
321 }
322 
323 static const struct spdk_json_object_decoder rpc_bdev_get_iostat_decoders[] = {
324 	{"name", offsetof(struct rpc_bdev_get_iostat, name), spdk_json_decode_string, true},
325 	{"per_channel", offsetof(struct rpc_bdev_get_iostat, per_channel), spdk_json_decode_bool, true},
326 };
327 
328 static void
329 rpc_bdev_get_iostat(struct spdk_jsonrpc_request *request,
330 		    const struct spdk_json_val *params)
331 {
332 	struct rpc_bdev_get_iostat req = {};
333 	struct spdk_bdev_desc *desc = NULL;
334 	struct rpc_get_iostat_ctx *rpc_ctx;
335 	struct bdev_get_iostat_ctx *bdev_ctx;
336 	struct spdk_bdev *bdev;
337 	int rc;
338 
339 	if (params != NULL) {
340 		if (spdk_json_decode_object(params, rpc_bdev_get_iostat_decoders,
341 					    SPDK_COUNTOF(rpc_bdev_get_iostat_decoders),
342 					    &req)) {
343 			SPDK_ERRLOG("spdk_json_decode_object failed\n");
344 			spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
345 							 "spdk_json_decode_object failed");
346 			free_rpc_bdev_get_iostat(&req);
347 			return;
348 		}
349 
350 		if (req.per_channel == true && !req.name) {
351 			SPDK_ERRLOG("Bdev name is required for per channel IO statistics\n");
352 			spdk_jsonrpc_send_error_response(request, -EINVAL, spdk_strerror(EINVAL));
353 			free_rpc_bdev_get_iostat(&req);
354 			return;
355 		}
356 
357 		if (req.name) {
358 			rc = spdk_bdev_open_ext(req.name, false, dummy_bdev_event_cb, NULL, &desc);
359 			if (rc != 0) {
360 				SPDK_ERRLOG("Failed to open bdev '%s': %d\n", req.name, rc);
361 				spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
362 				free_rpc_bdev_get_iostat(&req);
363 				return;
364 			}
365 		}
366 	}
367 
368 	free_rpc_bdev_get_iostat(&req);
369 
370 	rpc_ctx = calloc(1, sizeof(struct rpc_get_iostat_ctx));
371 	if (rpc_ctx == NULL) {
372 		SPDK_ERRLOG("Failed to allocate rpc_iostat_ctx struct\n");
373 		spdk_jsonrpc_send_error_response(request, -ENOMEM, spdk_strerror(ENOMEM));
374 		return;
375 	}
376 
377 	/*
378 	 * Increment initial bdev_count so that it will never reach 0 in the middle
379 	 * of iterating.
380 	 */
381 	rpc_ctx->bdev_count++;
382 	rpc_ctx->request = request;
383 	rpc_ctx->per_channel = req.per_channel;
384 
385 	if (desc != NULL) {
386 		bdev = spdk_bdev_desc_get_bdev(desc);
387 
388 		bdev_ctx = bdev_iostat_ctx_alloc(req.per_channel == false);
389 		if (bdev_ctx == NULL) {
390 			SPDK_ERRLOG("Failed to allocate bdev_iostat_ctx struct\n");
391 			rpc_ctx->rc = -ENOMEM;
392 
393 			spdk_bdev_close(desc);
394 		} else {
395 			bdev_ctx->desc = desc;
396 
397 			rpc_ctx->bdev_count++;
398 			bdev_ctx->rpc_ctx = rpc_ctx;
399 			if (req.per_channel == false) {
400 				spdk_bdev_get_device_stat(bdev, bdev_ctx->stat, bdev_get_iostat_done,
401 							  bdev_ctx);
402 			} else {
403 				/* If per_channel is true, there is no failure after here and
404 				 * we have to start RPC response before executing
405 				 * spdk_bdev_for_each_channel().
406 				 */
407 				rpc_get_iostat_started(rpc_ctx);
408 				spdk_json_write_named_string(rpc_ctx->w, "name", spdk_bdev_get_name(bdev));
409 				spdk_json_write_named_array_begin(rpc_ctx->w, "channels");
410 
411 				spdk_bdev_for_each_channel(bdev,
412 							   bdev_get_per_channel_stat,
413 							   bdev_ctx,
414 							   bdev_get_per_channel_stat_done);
415 
416 				rpc_get_iostat_done(rpc_ctx);
417 				return;
418 			}
419 		}
420 	} else {
421 		rc = spdk_for_each_bdev(rpc_ctx, bdev_get_iostat);
422 		if (rc != 0 && rpc_ctx->rc == 0) {
423 			rpc_ctx->rc = rc;
424 		}
425 	}
426 
427 	if (rpc_ctx->rc == 0) {
428 		/* We want to fail the RPC for all failures. If per_channel is false,
429 		 * it is enough to defer starting RPC response until it is ensured that
430 		 * all spdk_bdev_for_each_channel() calls will succeed or there is no bdev.
431 		 */
432 		rpc_get_iostat_started(rpc_ctx);
433 		spdk_json_write_named_array_begin(rpc_ctx->w, "bdevs");
434 	}
435 
436 	rpc_get_iostat_done(rpc_ctx);
437 }
438 SPDK_RPC_REGISTER("bdev_get_iostat", rpc_bdev_get_iostat, SPDK_RPC_RUNTIME)
439 
440 struct rpc_reset_iostat_ctx {
441 	int bdev_count;
442 	int rc;
443 	struct spdk_jsonrpc_request *request;
444 	struct spdk_json_write_ctx *w;
445 	enum spdk_bdev_reset_stat_mode mode;
446 };
447 
448 struct bdev_reset_iostat_ctx {
449 	struct rpc_reset_iostat_ctx *rpc_ctx;
450 	struct spdk_bdev_desc *desc;
451 };
452 
453 static void
454 rpc_reset_iostat_done(struct rpc_reset_iostat_ctx *rpc_ctx)
455 {
456 	if (--rpc_ctx->bdev_count != 0) {
457 		return;
458 	}
459 
460 	if (rpc_ctx->rc == 0) {
461 		spdk_jsonrpc_send_bool_response(rpc_ctx->request, true);
462 	} else {
463 		spdk_jsonrpc_send_error_response(rpc_ctx->request, rpc_ctx->rc,
464 						 spdk_strerror(-rpc_ctx->rc));
465 	}
466 
467 	free(rpc_ctx);
468 }
469 
470 static void
471 bdev_reset_iostat_done(struct spdk_bdev *bdev, void *cb_arg, int rc)
472 {
473 	struct bdev_reset_iostat_ctx *bdev_ctx = cb_arg;
474 	struct rpc_reset_iostat_ctx *rpc_ctx = bdev_ctx->rpc_ctx;
475 
476 	if (rc != 0 || rpc_ctx->rc != 0) {
477 		if (rpc_ctx->rc == 0) {
478 			rpc_ctx->rc = rc;
479 		}
480 	}
481 
482 	rpc_reset_iostat_done(rpc_ctx);
483 
484 	spdk_bdev_close(bdev_ctx->desc);
485 	free(bdev_ctx);
486 }
487 
488 static int
489 bdev_reset_iostat(void *ctx, struct spdk_bdev *bdev)
490 {
491 	struct rpc_reset_iostat_ctx *rpc_ctx = ctx;
492 	struct bdev_reset_iostat_ctx *bdev_ctx;
493 	int rc;
494 
495 	bdev_ctx = calloc(1, sizeof(struct bdev_reset_iostat_ctx));
496 	if (bdev_ctx == NULL) {
497 		SPDK_ERRLOG("Failed to allocate bdev_iostat_ctx struct\n");
498 		return -ENOMEM;
499 	}
500 
501 	rc = spdk_bdev_open_ext(spdk_bdev_get_name(bdev), false, dummy_bdev_event_cb, NULL,
502 				&bdev_ctx->desc);
503 	if (rc != 0) {
504 		free(bdev_ctx);
505 		SPDK_ERRLOG("Failed to open bdev\n");
506 		return rc;
507 	}
508 
509 	if (bdev->fn_table->reset_device_stat) {
510 		bdev->fn_table->reset_device_stat(bdev->ctxt);
511 	}
512 
513 	rpc_ctx->bdev_count++;
514 	bdev_ctx->rpc_ctx = rpc_ctx;
515 	bdev_reset_device_stat(bdev, rpc_ctx->mode, bdev_reset_iostat_done, bdev_ctx);
516 
517 	return 0;
518 }
519 
520 struct rpc_bdev_reset_iostat {
521 	char *name;
522 	enum spdk_bdev_reset_stat_mode mode;
523 };
524 
525 static void
526 free_rpc_bdev_reset_iostat(struct rpc_bdev_reset_iostat *r)
527 {
528 	free(r->name);
529 }
530 
531 static int
532 rpc_decode_reset_iostat_mode(const struct spdk_json_val *val, void *out)
533 {
534 	enum spdk_bdev_reset_stat_mode *mode = out;
535 
536 	if (spdk_json_strequal(val, "all") == true) {
537 		*mode = SPDK_BDEV_RESET_STAT_ALL;
538 	} else if (spdk_json_strequal(val, "maxmin") == true) {
539 		*mode = SPDK_BDEV_RESET_STAT_MAXMIN;
540 	} else {
541 		SPDK_NOTICELOG("Invalid parameter value: mode\n");
542 		return -EINVAL;
543 	}
544 
545 	return 0;
546 }
547 
548 static const struct spdk_json_object_decoder rpc_bdev_reset_iostat_decoders[] = {
549 	{"name", offsetof(struct rpc_bdev_reset_iostat, name), spdk_json_decode_string, true},
550 	{"mode", offsetof(struct rpc_bdev_reset_iostat, mode), rpc_decode_reset_iostat_mode, true},
551 };
552 
553 static void
554 rpc_bdev_reset_iostat(struct spdk_jsonrpc_request *request, const struct spdk_json_val *params)
555 {
556 	struct rpc_bdev_reset_iostat req = { .mode = SPDK_BDEV_RESET_STAT_ALL, };
557 	struct spdk_bdev_desc *desc = NULL;
558 	struct rpc_reset_iostat_ctx *rpc_ctx;
559 	struct bdev_reset_iostat_ctx *bdev_ctx;
560 	int rc;
561 
562 	if (params != NULL) {
563 		if (spdk_json_decode_object(params, rpc_bdev_reset_iostat_decoders,
564 					    SPDK_COUNTOF(rpc_bdev_reset_iostat_decoders),
565 					    &req)) {
566 			SPDK_ERRLOG("spdk_json_decode_object failed\n");
567 			spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
568 							 "spdk_json_decode_object failed");
569 			free_rpc_bdev_reset_iostat(&req);
570 			return;
571 		}
572 
573 		if (req.name) {
574 			rc = spdk_bdev_open_ext(req.name, false, dummy_bdev_event_cb, NULL, &desc);
575 			if (rc != 0) {
576 				SPDK_ERRLOG("Failed to open bdev '%s': %d\n", req.name, rc);
577 				spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
578 				free_rpc_bdev_reset_iostat(&req);
579 				return;
580 			}
581 		}
582 	}
583 
584 
585 	rpc_ctx = calloc(1, sizeof(struct rpc_reset_iostat_ctx));
586 	if (rpc_ctx == NULL) {
587 		SPDK_ERRLOG("Failed to allocate rpc_iostat_ctx struct\n");
588 		spdk_jsonrpc_send_error_response(request, -ENOMEM, spdk_strerror(ENOMEM));
589 		free_rpc_bdev_reset_iostat(&req);
590 		return;
591 	}
592 
593 	/*
594 	 * Increment initial bdev_count so that it will never reach 0 in the middle
595 	 * of iterating.
596 	 */
597 	rpc_ctx->bdev_count++;
598 	rpc_ctx->request = request;
599 	rpc_ctx->mode = req.mode;
600 
601 	free_rpc_bdev_reset_iostat(&req);
602 
603 	if (desc != NULL) {
604 		bdev_ctx = calloc(1, sizeof(struct bdev_reset_iostat_ctx));
605 		if (bdev_ctx == NULL) {
606 			SPDK_ERRLOG("Failed to allocate bdev_iostat_ctx struct\n");
607 			rpc_ctx->rc = -ENOMEM;
608 
609 			spdk_bdev_close(desc);
610 		} else {
611 			bdev_ctx->desc = desc;
612 
613 			rpc_ctx->bdev_count++;
614 			bdev_ctx->rpc_ctx = rpc_ctx;
615 			bdev_reset_device_stat(spdk_bdev_desc_get_bdev(desc), rpc_ctx->mode,
616 					       bdev_reset_iostat_done, bdev_ctx);
617 		}
618 	} else {
619 		rc = spdk_for_each_bdev(rpc_ctx, bdev_reset_iostat);
620 		if (rc != 0 && rpc_ctx->rc == 0) {
621 			rpc_ctx->rc = rc;
622 		}
623 	}
624 
625 	rpc_reset_iostat_done(rpc_ctx);
626 }
627 SPDK_RPC_REGISTER("bdev_reset_iostat", rpc_bdev_reset_iostat, SPDK_RPC_RUNTIME)
628 
629 static int
630 rpc_dump_bdev_info(void *ctx, struct spdk_bdev *bdev)
631 {
632 	struct spdk_json_write_ctx *w = ctx;
633 	struct spdk_bdev_alias *tmp;
634 	uint64_t qos_limits[SPDK_BDEV_QOS_NUM_RATE_LIMIT_TYPES];
635 	struct spdk_memory_domain **domains;
636 	enum spdk_bdev_io_type io_type;
637 	const char *name = NULL;
638 	int i, rc;
639 
640 	spdk_json_write_object_begin(w);
641 
642 	spdk_json_write_named_string(w, "name", spdk_bdev_get_name(bdev));
643 
644 	spdk_json_write_named_array_begin(w, "aliases");
645 
646 	TAILQ_FOREACH(tmp, spdk_bdev_get_aliases(bdev), tailq) {
647 		spdk_json_write_string(w, tmp->alias.name);
648 	}
649 
650 	spdk_json_write_array_end(w);
651 
652 	spdk_json_write_named_string(w, "product_name", spdk_bdev_get_product_name(bdev));
653 	spdk_json_write_named_uint32(w, "block_size", spdk_bdev_get_block_size(bdev));
654 	spdk_json_write_named_uint64(w, "num_blocks", spdk_bdev_get_num_blocks(bdev));
655 	spdk_json_write_named_uuid(w, "uuid", &bdev->uuid);
656 
657 	if (spdk_bdev_get_md_size(bdev) != 0) {
658 		spdk_json_write_named_uint32(w, "md_size", spdk_bdev_get_md_size(bdev));
659 		spdk_json_write_named_bool(w, "md_interleave", spdk_bdev_is_md_interleaved(bdev));
660 		spdk_json_write_named_uint32(w, "dif_type", spdk_bdev_get_dif_type(bdev));
661 		if (spdk_bdev_get_dif_type(bdev) != SPDK_DIF_DISABLE) {
662 			spdk_json_write_named_bool(w, "dif_is_head_of_md", spdk_bdev_is_dif_head_of_md(bdev));
663 			spdk_json_write_named_object_begin(w, "enabled_dif_check_types");
664 			spdk_json_write_named_bool(w, "reftag",
665 						   spdk_bdev_is_dif_check_enabled(bdev, SPDK_DIF_CHECK_TYPE_REFTAG));
666 			spdk_json_write_named_bool(w, "apptag",
667 						   spdk_bdev_is_dif_check_enabled(bdev, SPDK_DIF_CHECK_TYPE_APPTAG));
668 			spdk_json_write_named_bool(w, "guard",
669 						   spdk_bdev_is_dif_check_enabled(bdev, SPDK_DIF_CHECK_TYPE_GUARD));
670 			spdk_json_write_object_end(w);
671 		}
672 	}
673 
674 	spdk_json_write_named_object_begin(w, "assigned_rate_limits");
675 	spdk_bdev_get_qos_rate_limits(bdev, qos_limits);
676 	for (i = 0; i < SPDK_BDEV_QOS_NUM_RATE_LIMIT_TYPES; i++) {
677 		spdk_json_write_named_uint64(w, spdk_bdev_get_qos_rpc_type(i), qos_limits[i]);
678 	}
679 	spdk_json_write_object_end(w);
680 
681 	spdk_json_write_named_bool(w, "claimed",
682 				   (bdev->internal.claim_type != SPDK_BDEV_CLAIM_NONE));
683 	if (bdev->internal.claim_type != SPDK_BDEV_CLAIM_NONE) {
684 		spdk_json_write_named_string(w, "claim_type",
685 					     spdk_bdev_claim_get_name(bdev->internal.claim_type));
686 	}
687 
688 	spdk_json_write_named_bool(w, "zoned", bdev->zoned);
689 	if (bdev->zoned) {
690 		spdk_json_write_named_uint64(w, "zone_size", bdev->zone_size);
691 		spdk_json_write_named_uint64(w, "max_open_zones", bdev->max_open_zones);
692 		spdk_json_write_named_uint64(w, "optimal_open_zones", bdev->optimal_open_zones);
693 	}
694 
695 	spdk_json_write_named_object_begin(w, "supported_io_types");
696 	for (io_type = SPDK_BDEV_IO_TYPE_READ; io_type < SPDK_BDEV_NUM_IO_TYPES; ++io_type) {
697 		name = spdk_bdev_get_io_type_name(io_type);
698 		spdk_json_write_named_bool(w, name, spdk_bdev_io_type_supported(bdev, io_type));
699 	}
700 	spdk_json_write_object_end(w);
701 
702 	rc = spdk_bdev_get_memory_domains(bdev, NULL, 0);
703 	if (rc > 0) {
704 		domains = calloc(rc, sizeof(struct spdk_memory_domain *));
705 		if (domains) {
706 			i = spdk_bdev_get_memory_domains(bdev, domains, rc);
707 			if (i == rc) {
708 				spdk_json_write_named_array_begin(w, "memory_domains");
709 				for (i = 0; i < rc; i++) {
710 					spdk_json_write_object_begin(w);
711 					spdk_json_write_named_string(w, "dma_device_id", spdk_memory_domain_get_dma_device_id(domains[i]));
712 					spdk_json_write_named_int32(w, "dma_device_type",
713 								    spdk_memory_domain_get_dma_device_type(domains[i]));
714 					spdk_json_write_object_end(w);
715 				}
716 				spdk_json_write_array_end(w);
717 			} else {
718 				SPDK_ERRLOG("Unexpected number of memory domains %d (should be %d)\n", i, rc);
719 			}
720 
721 			free(domains);
722 		} else {
723 			SPDK_ERRLOG("Memory allocation failed\n");
724 		}
725 	}
726 
727 	spdk_json_write_named_object_begin(w, "driver_specific");
728 	spdk_bdev_dump_info_json(bdev, w);
729 	spdk_json_write_object_end(w);
730 
731 	spdk_json_write_object_end(w);
732 
733 	return 0;
734 }
735 
736 struct rpc_bdev_get_bdevs {
737 	char		*name;
738 	uint64_t	timeout;
739 };
740 
741 struct rpc_bdev_get_bdevs_ctx {
742 	struct rpc_bdev_get_bdevs	rpc;
743 	struct spdk_jsonrpc_request	*request;
744 	struct spdk_poller		*poller;
745 	uint64_t			timeout_ticks;
746 };
747 
748 static void
749 free_rpc_bdev_get_bdevs(struct rpc_bdev_get_bdevs *r)
750 {
751 	free(r->name);
752 }
753 
754 static const struct spdk_json_object_decoder rpc_bdev_get_bdevs_decoders[] = {
755 	{"name", offsetof(struct rpc_bdev_get_bdevs, name), spdk_json_decode_string, true},
756 	{"timeout", offsetof(struct rpc_bdev_get_bdevs, timeout), spdk_json_decode_uint64, true},
757 };
758 
759 static void
760 rpc_bdev_get_bdev_cb(struct spdk_bdev_desc *desc, int rc, void *cb_arg)
761 {
762 	struct spdk_jsonrpc_request *request = cb_arg;
763 	struct spdk_json_write_ctx *w;
764 
765 	if (rc == 0) {
766 		w = spdk_jsonrpc_begin_result(request);
767 
768 		spdk_json_write_array_begin(w);
769 		rpc_dump_bdev_info(w, spdk_bdev_desc_get_bdev(desc));
770 		spdk_json_write_array_end(w);
771 		spdk_jsonrpc_end_result(request, w);
772 
773 		spdk_bdev_close(desc);
774 	} else {
775 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
776 	}
777 }
778 
779 static void
780 rpc_bdev_get_bdevs(struct spdk_jsonrpc_request *request,
781 		   const struct spdk_json_val *params)
782 {
783 	struct rpc_bdev_get_bdevs req = {};
784 	struct spdk_bdev_open_async_opts opts = {};
785 	struct spdk_json_write_ctx *w;
786 	int rc;
787 
788 	if (params && spdk_json_decode_object(params, rpc_bdev_get_bdevs_decoders,
789 					      SPDK_COUNTOF(rpc_bdev_get_bdevs_decoders),
790 					      &req)) {
791 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
792 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
793 						 "spdk_json_decode_object failed");
794 		free_rpc_bdev_get_bdevs(&req);
795 		return;
796 	}
797 
798 	if (req.name) {
799 		opts.size = sizeof(opts);
800 		opts.timeout_ms = req.timeout;
801 
802 		rc = spdk_bdev_open_async(req.name, false, dummy_bdev_event_cb, NULL, &opts,
803 					  rpc_bdev_get_bdev_cb, request);
804 		if (rc != 0) {
805 			SPDK_ERRLOG("spdk_bdev_open_async failed for '%s': rc=%d\n", req.name, rc);
806 			spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
807 		}
808 
809 		free_rpc_bdev_get_bdevs(&req);
810 		return;
811 	}
812 
813 	free_rpc_bdev_get_bdevs(&req);
814 
815 	w = spdk_jsonrpc_begin_result(request);
816 	spdk_json_write_array_begin(w);
817 
818 	spdk_for_each_bdev(w, rpc_dump_bdev_info);
819 
820 	spdk_json_write_array_end(w);
821 
822 	spdk_jsonrpc_end_result(request, w);
823 }
824 SPDK_RPC_REGISTER("bdev_get_bdevs", rpc_bdev_get_bdevs, SPDK_RPC_RUNTIME)
825 
826 struct rpc_bdev_set_qd_sampling_period {
827 	char *name;
828 	uint64_t period;
829 };
830 
831 static void
832 free_rpc_bdev_set_qd_sampling_period(struct rpc_bdev_set_qd_sampling_period *r)
833 {
834 	free(r->name);
835 }
836 
837 static const struct spdk_json_object_decoder
838 	rpc_bdev_set_qd_sampling_period_decoders[] = {
839 	{"name", offsetof(struct rpc_bdev_set_qd_sampling_period, name), spdk_json_decode_string},
840 	{"period", offsetof(struct rpc_bdev_set_qd_sampling_period, period), spdk_json_decode_uint64},
841 };
842 
843 static void
844 rpc_bdev_set_qd_sampling_period(struct spdk_jsonrpc_request *request,
845 				const struct spdk_json_val *params)
846 {
847 	struct rpc_bdev_set_qd_sampling_period req = {0};
848 	struct spdk_bdev_desc *desc;
849 	int rc;
850 
851 	if (spdk_json_decode_object(params, rpc_bdev_set_qd_sampling_period_decoders,
852 				    SPDK_COUNTOF(rpc_bdev_set_qd_sampling_period_decoders),
853 				    &req)) {
854 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
855 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
856 						 "spdk_json_decode_object failed");
857 		goto cleanup;
858 	}
859 
860 	rc = spdk_bdev_open_ext(req.name, false, dummy_bdev_event_cb, NULL, &desc);
861 	if (rc != 0) {
862 		SPDK_ERRLOG("Failed to open bdev '%s': %d\n", req.name, rc);
863 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
864 		goto cleanup;
865 	}
866 
867 	spdk_bdev_set_qd_sampling_period(spdk_bdev_desc_get_bdev(desc), req.period);
868 	spdk_jsonrpc_send_bool_response(request, true);
869 
870 	spdk_bdev_close(desc);
871 
872 cleanup:
873 	free_rpc_bdev_set_qd_sampling_period(&req);
874 }
875 SPDK_RPC_REGISTER("bdev_set_qd_sampling_period",
876 		  rpc_bdev_set_qd_sampling_period,
877 		  SPDK_RPC_RUNTIME)
878 
879 struct rpc_bdev_set_qos_limit {
880 	char		*name;
881 	uint64_t	limits[SPDK_BDEV_QOS_NUM_RATE_LIMIT_TYPES];
882 };
883 
884 static void
885 free_rpc_bdev_set_qos_limit(struct rpc_bdev_set_qos_limit *r)
886 {
887 	free(r->name);
888 }
889 
890 static const struct spdk_json_object_decoder rpc_bdev_set_qos_limit_decoders[] = {
891 	{"name", offsetof(struct rpc_bdev_set_qos_limit, name), spdk_json_decode_string},
892 	{
893 		"rw_ios_per_sec", offsetof(struct rpc_bdev_set_qos_limit,
894 					   limits[SPDK_BDEV_QOS_RW_IOPS_RATE_LIMIT]),
895 		spdk_json_decode_uint64, true
896 	},
897 	{
898 		"rw_mbytes_per_sec", offsetof(struct rpc_bdev_set_qos_limit,
899 					      limits[SPDK_BDEV_QOS_RW_BPS_RATE_LIMIT]),
900 		spdk_json_decode_uint64, true
901 	},
902 	{
903 		"r_mbytes_per_sec", offsetof(struct rpc_bdev_set_qos_limit,
904 					     limits[SPDK_BDEV_QOS_R_BPS_RATE_LIMIT]),
905 		spdk_json_decode_uint64, true
906 	},
907 	{
908 		"w_mbytes_per_sec", offsetof(struct rpc_bdev_set_qos_limit,
909 					     limits[SPDK_BDEV_QOS_W_BPS_RATE_LIMIT]),
910 		spdk_json_decode_uint64, true
911 	},
912 };
913 
914 static void
915 rpc_bdev_set_qos_limit_complete(void *cb_arg, int status)
916 {
917 	struct spdk_jsonrpc_request *request = cb_arg;
918 
919 	if (status != 0) {
920 		spdk_jsonrpc_send_error_response_fmt(request, SPDK_JSONRPC_ERROR_INVALID_PARAMS,
921 						     "Failed to configure rate limit: %s",
922 						     spdk_strerror(-status));
923 		return;
924 	}
925 
926 	spdk_jsonrpc_send_bool_response(request, true);
927 }
928 
929 static void
930 rpc_bdev_set_qos_limit(struct spdk_jsonrpc_request *request,
931 		       const struct spdk_json_val *params)
932 {
933 	struct rpc_bdev_set_qos_limit req = {NULL, {UINT64_MAX, UINT64_MAX, UINT64_MAX, UINT64_MAX}};
934 	struct spdk_bdev_desc *desc;
935 	int i, rc;
936 
937 	if (spdk_json_decode_object(params, rpc_bdev_set_qos_limit_decoders,
938 				    SPDK_COUNTOF(rpc_bdev_set_qos_limit_decoders),
939 				    &req)) {
940 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
941 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
942 						 "spdk_json_decode_object failed");
943 		goto cleanup;
944 	}
945 
946 	rc = spdk_bdev_open_ext(req.name, false, dummy_bdev_event_cb, NULL, &desc);
947 	if (rc != 0) {
948 		SPDK_ERRLOG("Failed to open bdev '%s': %d\n", req.name, rc);
949 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
950 		goto cleanup;
951 	}
952 
953 	for (i = 0; i < SPDK_BDEV_QOS_NUM_RATE_LIMIT_TYPES; i++) {
954 		if (req.limits[i] != UINT64_MAX) {
955 			break;
956 		}
957 	}
958 	if (i == SPDK_BDEV_QOS_NUM_RATE_LIMIT_TYPES) {
959 		SPDK_ERRLOG("no rate limits specified\n");
960 		spdk_bdev_close(desc);
961 		spdk_jsonrpc_send_error_response(request, -EINVAL, "No rate limits specified");
962 		goto cleanup;
963 	}
964 
965 	spdk_bdev_set_qos_rate_limits(spdk_bdev_desc_get_bdev(desc), req.limits,
966 				      rpc_bdev_set_qos_limit_complete, request);
967 
968 	spdk_bdev_close(desc);
969 
970 cleanup:
971 	free_rpc_bdev_set_qos_limit(&req);
972 }
973 
974 SPDK_RPC_REGISTER("bdev_set_qos_limit", rpc_bdev_set_qos_limit, SPDK_RPC_RUNTIME)
975 
976 /* SPDK_RPC_ENABLE_BDEV_HISTOGRAM */
977 
978 struct rpc_bdev_enable_histogram_request {
979 	char *name;
980 	bool enable;
981 };
982 
983 static void
984 free_rpc_bdev_enable_histogram_request(struct rpc_bdev_enable_histogram_request *r)
985 {
986 	free(r->name);
987 }
988 
989 static const struct spdk_json_object_decoder rpc_bdev_enable_histogram_request_decoders[] = {
990 	{"name", offsetof(struct rpc_bdev_enable_histogram_request, name), spdk_json_decode_string},
991 	{"enable", offsetof(struct rpc_bdev_enable_histogram_request, enable), spdk_json_decode_bool},
992 };
993 
994 static void
995 bdev_histogram_status_cb(void *cb_arg, int status)
996 {
997 	struct spdk_jsonrpc_request *request = cb_arg;
998 
999 	if (status == 0) {
1000 		spdk_jsonrpc_send_bool_response(request, true);
1001 	} else {
1002 		spdk_jsonrpc_send_error_response(request, status, spdk_strerror(-status));
1003 	}
1004 }
1005 
1006 static void
1007 rpc_bdev_enable_histogram(struct spdk_jsonrpc_request *request,
1008 			  const struct spdk_json_val *params)
1009 {
1010 	struct rpc_bdev_enable_histogram_request req = {NULL};
1011 	struct spdk_bdev_desc *desc;
1012 	int rc;
1013 
1014 	if (spdk_json_decode_object(params, rpc_bdev_enable_histogram_request_decoders,
1015 				    SPDK_COUNTOF(rpc_bdev_enable_histogram_request_decoders),
1016 				    &req)) {
1017 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
1018 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
1019 						 "spdk_json_decode_object failed");
1020 		goto cleanup;
1021 	}
1022 
1023 	rc = spdk_bdev_open_ext(req.name, false, dummy_bdev_event_cb, NULL, &desc);
1024 	if (rc != 0) {
1025 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
1026 		goto cleanup;
1027 	}
1028 
1029 	spdk_bdev_histogram_enable(spdk_bdev_desc_get_bdev(desc), bdev_histogram_status_cb,
1030 				   request, req.enable);
1031 
1032 	spdk_bdev_close(desc);
1033 
1034 cleanup:
1035 	free_rpc_bdev_enable_histogram_request(&req);
1036 }
1037 
1038 SPDK_RPC_REGISTER("bdev_enable_histogram", rpc_bdev_enable_histogram, SPDK_RPC_RUNTIME)
1039 
1040 /* SPDK_RPC_GET_BDEV_HISTOGRAM */
1041 
1042 struct rpc_bdev_get_histogram_request {
1043 	char *name;
1044 };
1045 
1046 static const struct spdk_json_object_decoder rpc_bdev_get_histogram_request_decoders[] = {
1047 	{"name", offsetof(struct rpc_bdev_get_histogram_request, name), spdk_json_decode_string}
1048 };
1049 
1050 static void
1051 free_rpc_bdev_get_histogram_request(struct rpc_bdev_get_histogram_request *r)
1052 {
1053 	free(r->name);
1054 }
1055 
1056 static void
1057 _rpc_bdev_histogram_data_cb(void *cb_arg, int status, struct spdk_histogram_data *histogram)
1058 {
1059 	struct spdk_jsonrpc_request *request = cb_arg;
1060 	struct spdk_json_write_ctx *w;
1061 	int rc;
1062 	char *encoded_histogram;
1063 	size_t src_len, dst_len;
1064 
1065 
1066 	if (status != 0) {
1067 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
1068 						 spdk_strerror(-status));
1069 		goto invalid;
1070 	}
1071 
1072 	src_len = SPDK_HISTOGRAM_NUM_BUCKETS(histogram) * sizeof(uint64_t);
1073 	dst_len = spdk_base64_get_encoded_strlen(src_len) + 1;
1074 
1075 	encoded_histogram = malloc(dst_len);
1076 	if (encoded_histogram == NULL) {
1077 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
1078 						 spdk_strerror(ENOMEM));
1079 		goto invalid;
1080 	}
1081 
1082 	rc = spdk_base64_encode(encoded_histogram, histogram->bucket, src_len);
1083 	if (rc != 0) {
1084 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
1085 						 spdk_strerror(-rc));
1086 		goto free_encoded_histogram;
1087 	}
1088 
1089 	w = spdk_jsonrpc_begin_result(request);
1090 	spdk_json_write_object_begin(w);
1091 	spdk_json_write_named_string(w, "histogram", encoded_histogram);
1092 	spdk_json_write_named_int64(w, "bucket_shift", histogram->bucket_shift);
1093 	spdk_json_write_named_int64(w, "tsc_rate", spdk_get_ticks_hz());
1094 	spdk_json_write_object_end(w);
1095 	spdk_jsonrpc_end_result(request, w);
1096 
1097 free_encoded_histogram:
1098 	free(encoded_histogram);
1099 invalid:
1100 	spdk_histogram_data_free(histogram);
1101 }
1102 
1103 static void
1104 rpc_bdev_get_histogram(struct spdk_jsonrpc_request *request,
1105 		       const struct spdk_json_val *params)
1106 {
1107 	struct rpc_bdev_get_histogram_request req = {NULL};
1108 	struct spdk_histogram_data *histogram;
1109 	struct spdk_bdev_desc *desc;
1110 	int rc;
1111 
1112 	if (spdk_json_decode_object(params, rpc_bdev_get_histogram_request_decoders,
1113 				    SPDK_COUNTOF(rpc_bdev_get_histogram_request_decoders),
1114 				    &req)) {
1115 		SPDK_ERRLOG("spdk_json_decode_object failed\n");
1116 		spdk_jsonrpc_send_error_response(request, SPDK_JSONRPC_ERROR_INTERNAL_ERROR,
1117 						 "spdk_json_decode_object failed");
1118 		goto cleanup;
1119 	}
1120 
1121 	rc = spdk_bdev_open_ext(req.name, false, dummy_bdev_event_cb, NULL, &desc);
1122 	if (rc != 0) {
1123 		spdk_jsonrpc_send_error_response(request, rc, spdk_strerror(-rc));
1124 		goto cleanup;
1125 	}
1126 
1127 	histogram = spdk_histogram_data_alloc();
1128 	if (histogram == NULL) {
1129 		spdk_bdev_close(desc);
1130 		spdk_jsonrpc_send_error_response(request, -ENOMEM, spdk_strerror(ENOMEM));
1131 		goto cleanup;
1132 	}
1133 
1134 	spdk_bdev_histogram_get(spdk_bdev_desc_get_bdev(desc), histogram,
1135 				_rpc_bdev_histogram_data_cb, request);
1136 
1137 	spdk_bdev_close(desc);
1138 
1139 cleanup:
1140 	free_rpc_bdev_get_histogram_request(&req);
1141 }
1142 
1143 SPDK_RPC_REGISTER("bdev_get_histogram", rpc_bdev_get_histogram, SPDK_RPC_RUNTIME)
1144