xref: /spdk/lib/bdev/part.c (revision d987d777d6b8ce05f11cb1d90f1241bfecfc9af4)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2018 Intel Corporation.
3  *   Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES.
4  *   All rights reserved.
5  */
6 
7 /*
8  * Common code for partition-like virtual bdevs.
9  */
10 
11 #include "spdk/bdev.h"
12 #include "spdk/likely.h"
13 #include "spdk/log.h"
14 #include "spdk/string.h"
15 #include "spdk/thread.h"
16 
17 #include "spdk/bdev_module.h"
18 
19 /* This namespace UUID was generated using uuid_generate() method. */
20 #define BDEV_PART_NAMESPACE_UUID "976b899e-3e1e-4d71-ab69-c2b08e9df8b8"
21 
22 struct spdk_bdev_part_base {
23 	struct spdk_bdev		*bdev;
24 	struct spdk_bdev_desc		*desc;
25 	uint32_t			ref;
26 	uint32_t			channel_size;
27 	spdk_bdev_part_base_free_fn	base_free_fn;
28 	void				*ctx;
29 	bool				claimed;
30 	struct spdk_bdev_module		*module;
31 	struct spdk_bdev_fn_table	*fn_table;
32 	struct bdev_part_tailq		*tailq;
33 	spdk_io_channel_create_cb	ch_create_cb;
34 	spdk_io_channel_destroy_cb	ch_destroy_cb;
35 	spdk_bdev_remove_cb_t		remove_cb;
36 	struct spdk_thread		*thread;
37 };
38 
39 struct spdk_bdev *
40 spdk_bdev_part_base_get_bdev(struct spdk_bdev_part_base *part_base)
41 {
42 	return part_base->bdev;
43 }
44 
45 struct spdk_bdev_desc *
46 spdk_bdev_part_base_get_desc(struct spdk_bdev_part_base *part_base)
47 {
48 	return part_base->desc;
49 }
50 
51 struct bdev_part_tailq *
52 spdk_bdev_part_base_get_tailq(struct spdk_bdev_part_base *part_base)
53 {
54 	return part_base->tailq;
55 }
56 
57 void *
58 spdk_bdev_part_base_get_ctx(struct spdk_bdev_part_base *part_base)
59 {
60 	return part_base->ctx;
61 }
62 
63 const char *
64 spdk_bdev_part_base_get_bdev_name(struct spdk_bdev_part_base *part_base)
65 {
66 	return part_base->bdev->name;
67 }
68 
69 static void
70 bdev_part_base_free(void *ctx)
71 {
72 	struct spdk_bdev_desc *desc = ctx;
73 
74 	spdk_bdev_close(desc);
75 }
76 
77 void
78 spdk_bdev_part_base_free(struct spdk_bdev_part_base *base)
79 {
80 	if (base->desc) {
81 		/* Close the underlying bdev on its same opened thread. */
82 		if (base->thread && base->thread != spdk_get_thread()) {
83 			spdk_thread_send_msg(base->thread, bdev_part_base_free, base->desc);
84 		} else {
85 			spdk_bdev_close(base->desc);
86 		}
87 	}
88 
89 	if (base->base_free_fn != NULL) {
90 		base->base_free_fn(base->ctx);
91 	}
92 
93 	free(base);
94 }
95 
96 static void
97 bdev_part_free_cb(void *io_device)
98 {
99 	struct spdk_bdev_part *part = io_device;
100 	struct spdk_bdev_part_base *base;
101 
102 	assert(part);
103 	assert(part->internal.base);
104 
105 	base = part->internal.base;
106 
107 	TAILQ_REMOVE(base->tailq, part, tailq);
108 
109 	if (--base->ref == 0) {
110 		spdk_bdev_module_release_bdev(base->bdev);
111 		spdk_bdev_part_base_free(base);
112 	}
113 
114 	spdk_bdev_destruct_done(&part->internal.bdev, 0);
115 	free(part->internal.bdev.name);
116 	free(part->internal.bdev.product_name);
117 	free(part);
118 }
119 
120 int
121 spdk_bdev_part_free(struct spdk_bdev_part *part)
122 {
123 	spdk_io_device_unregister(part, bdev_part_free_cb);
124 
125 	/* Return 1 to indicate that this is an asynchronous operation that isn't complete
126 	 * until spdk_bdev_destruct_done is called */
127 	return 1;
128 }
129 
130 void
131 spdk_bdev_part_base_hotremove(struct spdk_bdev_part_base *part_base, struct bdev_part_tailq *tailq)
132 {
133 	struct spdk_bdev_part *part, *tmp;
134 
135 	TAILQ_FOREACH_SAFE(part, tailq, tailq, tmp) {
136 		if (part->internal.base == part_base) {
137 			spdk_bdev_unregister(&part->internal.bdev, NULL, NULL);
138 		}
139 	}
140 }
141 
142 static bool
143 bdev_part_io_type_supported(void *_part, enum spdk_bdev_io_type io_type)
144 {
145 	struct spdk_bdev_part *part = _part;
146 
147 	/* We can't decode/modify passthrough NVMe commands, so don't report
148 	 *  that a partition supports these io types, even if the underlying
149 	 *  bdev does.
150 	 */
151 	switch (io_type) {
152 	case SPDK_BDEV_IO_TYPE_NVME_ADMIN:
153 	case SPDK_BDEV_IO_TYPE_NVME_IO:
154 	case SPDK_BDEV_IO_TYPE_NVME_IO_MD:
155 		return false;
156 	default:
157 		break;
158 	}
159 
160 	return part->internal.base->bdev->fn_table->io_type_supported(part->internal.base->bdev->ctxt,
161 			io_type);
162 }
163 
164 static struct spdk_io_channel *
165 bdev_part_get_io_channel(void *_part)
166 {
167 	struct spdk_bdev_part *part = _part;
168 
169 	return spdk_get_io_channel(part);
170 }
171 
172 struct spdk_bdev *
173 spdk_bdev_part_get_bdev(struct spdk_bdev_part *part)
174 {
175 	return &part->internal.bdev;
176 }
177 
178 struct spdk_bdev_part_base *
179 spdk_bdev_part_get_base(struct spdk_bdev_part *part)
180 {
181 	return part->internal.base;
182 }
183 
184 struct spdk_bdev *
185 spdk_bdev_part_get_base_bdev(struct spdk_bdev_part *part)
186 {
187 	return part->internal.base->bdev;
188 }
189 
190 uint64_t
191 spdk_bdev_part_get_offset_blocks(struct spdk_bdev_part *part)
192 {
193 	return part->internal.offset_blocks;
194 }
195 
196 static int
197 bdev_part_remap_dif(struct spdk_bdev_io *bdev_io, uint32_t offset,
198 		    uint32_t remapped_offset)
199 {
200 	struct spdk_bdev *bdev = bdev_io->bdev;
201 	struct spdk_dif_ctx dif_ctx;
202 	struct spdk_dif_error err_blk = {};
203 	int rc;
204 	struct spdk_dif_ctx_init_ext_opts dif_opts;
205 
206 	if (spdk_likely(!(bdev->dif_check_flags & SPDK_DIF_FLAGS_REFTAG_CHECK))) {
207 		return 0;
208 	}
209 
210 	dif_opts.size = SPDK_SIZEOF(&dif_opts, dif_pi_format);
211 	dif_opts.dif_pi_format = SPDK_DIF_PI_FORMAT_16;
212 	rc = spdk_dif_ctx_init(&dif_ctx,
213 			       bdev->blocklen, bdev->md_len, bdev->md_interleave,
214 			       bdev->dif_is_head_of_md, bdev->dif_type, bdev->dif_check_flags,
215 			       offset, 0, 0, 0, 0, &dif_opts);
216 	if (rc != 0) {
217 		SPDK_ERRLOG("Initialization of DIF context failed\n");
218 		return rc;
219 	}
220 
221 	spdk_dif_ctx_set_remapped_init_ref_tag(&dif_ctx, remapped_offset);
222 
223 	if (bdev->md_interleave) {
224 		rc = spdk_dif_remap_ref_tag(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
225 					    bdev_io->u.bdev.num_blocks, &dif_ctx, &err_blk, true);
226 	} else {
227 		struct iovec md_iov = {
228 			.iov_base	= bdev_io->u.bdev.md_buf,
229 			.iov_len	= bdev_io->u.bdev.num_blocks * bdev->md_len,
230 		};
231 
232 		rc = spdk_dix_remap_ref_tag(&md_iov, bdev_io->u.bdev.num_blocks, &dif_ctx, &err_blk, true);
233 	}
234 
235 	if (rc != 0) {
236 		SPDK_ERRLOG("Remapping reference tag failed. type=%d, offset=%" PRIu32 "\n",
237 			    err_blk.err_type, err_blk.err_offset);
238 	}
239 
240 	return rc;
241 }
242 
243 static void
244 bdev_part_complete_io(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
245 {
246 	struct spdk_bdev_io *part_io = cb_arg;
247 	uint32_t offset, remapped_offset;
248 	int rc;
249 
250 	switch (bdev_io->type) {
251 	case SPDK_BDEV_IO_TYPE_READ:
252 		if (success) {
253 			offset = bdev_io->u.bdev.offset_blocks;
254 			remapped_offset = part_io->u.bdev.offset_blocks;
255 
256 			rc = bdev_part_remap_dif(bdev_io, offset, remapped_offset);
257 			if (rc != 0) {
258 				success = false;
259 			}
260 		}
261 		break;
262 	case SPDK_BDEV_IO_TYPE_ZCOPY:
263 		spdk_bdev_io_set_buf(part_io, bdev_io->u.bdev.iovs[0].iov_base,
264 				     bdev_io->u.bdev.iovs[0].iov_len);
265 		break;
266 	default:
267 		break;
268 	}
269 
270 	if (part_io->internal.f.split) {
271 		part_io->internal.split.stored_user_cb(part_io, success, NULL);
272 	} else {
273 		spdk_bdev_io_complete_base_io_status(part_io, bdev_io);
274 	}
275 
276 	spdk_bdev_free_io(bdev_io);
277 }
278 
279 static inline void
280 bdev_part_init_ext_io_opts(struct spdk_bdev_io *bdev_io, struct spdk_bdev_ext_io_opts *opts)
281 {
282 	memset(opts, 0, sizeof(*opts));
283 	opts->size = sizeof(*opts);
284 	opts->memory_domain = bdev_io->u.bdev.memory_domain;
285 	opts->memory_domain_ctx = bdev_io->u.bdev.memory_domain_ctx;
286 	opts->metadata = bdev_io->u.bdev.md_buf;
287 }
288 
289 int
290 spdk_bdev_part_submit_request_ext(struct spdk_bdev_part_channel *ch, struct spdk_bdev_io *bdev_io,
291 				  spdk_bdev_io_completion_cb cb)
292 {
293 	struct spdk_bdev_part *part = ch->part;
294 	struct spdk_io_channel *base_ch = ch->base_ch;
295 	struct spdk_bdev_desc *base_desc = part->internal.base->desc;
296 	struct spdk_bdev_ext_io_opts io_opts;
297 	uint64_t offset, remapped_offset, remapped_src_offset;
298 	int rc = 0;
299 
300 	if (cb != NULL) {
301 		bdev_io->internal.f.split = true;
302 		bdev_io->internal.split.stored_user_cb = cb;
303 	}
304 
305 	offset = bdev_io->u.bdev.offset_blocks;
306 	remapped_offset = offset + part->internal.offset_blocks;
307 
308 	/* Modify the I/O to adjust for the offset within the base bdev. */
309 	switch (bdev_io->type) {
310 	case SPDK_BDEV_IO_TYPE_READ:
311 		bdev_part_init_ext_io_opts(bdev_io, &io_opts);
312 		rc = spdk_bdev_readv_blocks_ext(base_desc, base_ch, bdev_io->u.bdev.iovs,
313 						bdev_io->u.bdev.iovcnt, remapped_offset,
314 						bdev_io->u.bdev.num_blocks,
315 						bdev_part_complete_io, bdev_io, &io_opts);
316 		break;
317 	case SPDK_BDEV_IO_TYPE_WRITE:
318 		rc = bdev_part_remap_dif(bdev_io, offset, remapped_offset);
319 		if (rc != 0) {
320 			return SPDK_BDEV_IO_STATUS_FAILED;
321 		}
322 		bdev_part_init_ext_io_opts(bdev_io, &io_opts);
323 		rc = spdk_bdev_writev_blocks_ext(base_desc, base_ch, bdev_io->u.bdev.iovs,
324 						 bdev_io->u.bdev.iovcnt, remapped_offset,
325 						 bdev_io->u.bdev.num_blocks,
326 						 bdev_part_complete_io, bdev_io, &io_opts);
327 		break;
328 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
329 		rc = spdk_bdev_write_zeroes_blocks(base_desc, base_ch, remapped_offset,
330 						   bdev_io->u.bdev.num_blocks, bdev_part_complete_io,
331 						   bdev_io);
332 		break;
333 	case SPDK_BDEV_IO_TYPE_UNMAP:
334 		rc = spdk_bdev_unmap_blocks(base_desc, base_ch, remapped_offset,
335 					    bdev_io->u.bdev.num_blocks, bdev_part_complete_io,
336 					    bdev_io);
337 		break;
338 	case SPDK_BDEV_IO_TYPE_FLUSH:
339 		rc = spdk_bdev_flush_blocks(base_desc, base_ch, remapped_offset,
340 					    bdev_io->u.bdev.num_blocks, bdev_part_complete_io,
341 					    bdev_io);
342 		break;
343 	case SPDK_BDEV_IO_TYPE_RESET:
344 		rc = spdk_bdev_reset(base_desc, base_ch,
345 				     bdev_part_complete_io, bdev_io);
346 		break;
347 	case SPDK_BDEV_IO_TYPE_ABORT:
348 		rc = spdk_bdev_abort(base_desc, base_ch, bdev_io->u.abort.bio_to_abort,
349 				     bdev_part_complete_io, bdev_io);
350 		break;
351 	case SPDK_BDEV_IO_TYPE_ZCOPY:
352 		rc = spdk_bdev_zcopy_start(base_desc, base_ch, NULL, 0, remapped_offset,
353 					   bdev_io->u.bdev.num_blocks, bdev_io->u.bdev.zcopy.populate,
354 					   bdev_part_complete_io, bdev_io);
355 		break;
356 	case SPDK_BDEV_IO_TYPE_COMPARE:
357 		if (!bdev_io->u.bdev.md_buf) {
358 			rc = spdk_bdev_comparev_blocks(base_desc, base_ch,
359 						       bdev_io->u.bdev.iovs,
360 						       bdev_io->u.bdev.iovcnt,
361 						       remapped_offset,
362 						       bdev_io->u.bdev.num_blocks,
363 						       bdev_part_complete_io, bdev_io);
364 		} else {
365 			rc = spdk_bdev_comparev_blocks_with_md(base_desc, base_ch,
366 							       bdev_io->u.bdev.iovs,
367 							       bdev_io->u.bdev.iovcnt,
368 							       bdev_io->u.bdev.md_buf,
369 							       remapped_offset,
370 							       bdev_io->u.bdev.num_blocks,
371 							       bdev_part_complete_io, bdev_io);
372 		}
373 		break;
374 	case SPDK_BDEV_IO_TYPE_COMPARE_AND_WRITE:
375 		rc = spdk_bdev_comparev_and_writev_blocks(base_desc, base_ch, bdev_io->u.bdev.iovs,
376 				bdev_io->u.bdev.iovcnt,
377 				bdev_io->u.bdev.fused_iovs,
378 				bdev_io->u.bdev.fused_iovcnt,
379 				remapped_offset,
380 				bdev_io->u.bdev.num_blocks,
381 				bdev_part_complete_io, bdev_io);
382 		break;
383 	case SPDK_BDEV_IO_TYPE_COPY:
384 		remapped_src_offset = bdev_io->u.bdev.copy.src_offset_blocks + part->internal.offset_blocks;
385 		rc = spdk_bdev_copy_blocks(base_desc, base_ch, remapped_offset, remapped_src_offset,
386 					   bdev_io->u.bdev.num_blocks, bdev_part_complete_io,
387 					   bdev_io);
388 		break;
389 	default:
390 		SPDK_ERRLOG("unknown I/O type %d\n", bdev_io->type);
391 		return SPDK_BDEV_IO_STATUS_FAILED;
392 	}
393 
394 	return rc;
395 }
396 
397 int
398 spdk_bdev_part_submit_request(struct spdk_bdev_part_channel *ch, struct spdk_bdev_io *bdev_io)
399 {
400 	return spdk_bdev_part_submit_request_ext(ch, bdev_io, NULL);
401 }
402 
403 static int
404 bdev_part_channel_create_cb(void *io_device, void *ctx_buf)
405 {
406 	struct spdk_bdev_part *part = (struct spdk_bdev_part *)io_device;
407 	struct spdk_bdev_part_channel *ch = ctx_buf;
408 
409 	ch->part = part;
410 	ch->base_ch = spdk_bdev_get_io_channel(part->internal.base->desc);
411 	if (ch->base_ch == NULL) {
412 		return -1;
413 	}
414 
415 	if (part->internal.base->ch_create_cb) {
416 		return part->internal.base->ch_create_cb(io_device, ctx_buf);
417 	} else {
418 		return 0;
419 	}
420 }
421 
422 static void
423 bdev_part_channel_destroy_cb(void *io_device, void *ctx_buf)
424 {
425 	struct spdk_bdev_part *part = (struct spdk_bdev_part *)io_device;
426 	struct spdk_bdev_part_channel *ch = ctx_buf;
427 
428 	if (part->internal.base->ch_destroy_cb) {
429 		part->internal.base->ch_destroy_cb(io_device, ctx_buf);
430 	}
431 	spdk_put_io_channel(ch->base_ch);
432 }
433 
434 static void
435 bdev_part_base_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,
436 			void *event_ctx)
437 {
438 	struct spdk_bdev_part_base *base = event_ctx;
439 
440 	switch (type) {
441 	case SPDK_BDEV_EVENT_REMOVE:
442 		base->remove_cb(base);
443 		break;
444 	default:
445 		SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type);
446 		break;
447 	}
448 }
449 
450 int
451 spdk_bdev_part_base_construct_ext(const char *bdev_name,
452 				  spdk_bdev_remove_cb_t remove_cb, struct spdk_bdev_module *module,
453 				  struct spdk_bdev_fn_table *fn_table, struct bdev_part_tailq *tailq,
454 				  spdk_bdev_part_base_free_fn free_fn, void *ctx,
455 				  uint32_t channel_size, spdk_io_channel_create_cb ch_create_cb,
456 				  spdk_io_channel_destroy_cb ch_destroy_cb,
457 				  struct spdk_bdev_part_base **_base)
458 {
459 	int rc;
460 	struct spdk_bdev_part_base *base;
461 
462 	if (_base == NULL) {
463 		return -EINVAL;
464 	}
465 
466 	base = calloc(1, sizeof(*base));
467 	if (!base) {
468 		SPDK_ERRLOG("Memory allocation failure\n");
469 		return -ENOMEM;
470 	}
471 	fn_table->get_io_channel = bdev_part_get_io_channel;
472 	fn_table->io_type_supported = bdev_part_io_type_supported;
473 
474 	base->desc = NULL;
475 	base->ref = 0;
476 	base->module = module;
477 	base->fn_table = fn_table;
478 	base->tailq = tailq;
479 	base->base_free_fn = free_fn;
480 	base->ctx = ctx;
481 	base->claimed = false;
482 	base->channel_size = channel_size;
483 	base->ch_create_cb = ch_create_cb;
484 	base->ch_destroy_cb = ch_destroy_cb;
485 	base->remove_cb = remove_cb;
486 
487 	rc = spdk_bdev_open_ext(bdev_name, false, bdev_part_base_event_cb, base, &base->desc);
488 	if (rc) {
489 		if (rc == -ENODEV) {
490 			free(base);
491 		} else {
492 			SPDK_ERRLOG("could not open bdev %s: %s\n", bdev_name, spdk_strerror(-rc));
493 			spdk_bdev_part_base_free(base);
494 		}
495 		return rc;
496 	}
497 
498 	base->bdev = spdk_bdev_desc_get_bdev(base->desc);
499 
500 	/* Save the thread where the base device is opened */
501 	base->thread = spdk_get_thread();
502 
503 	*_base = base;
504 
505 	return 0;
506 }
507 
508 void
509 spdk_bdev_part_construct_opts_init(struct spdk_bdev_part_construct_opts *opts, uint64_t size)
510 {
511 	if (opts == NULL) {
512 		SPDK_ERRLOG("opts should not be NULL\n");
513 		assert(opts != NULL);
514 		return;
515 	}
516 	if (size == 0) {
517 		SPDK_ERRLOG("size should not be zero\n");
518 		assert(size != 0);
519 		return;
520 	}
521 
522 	memset(opts, 0, size);
523 	opts->opts_size = size;
524 }
525 
526 static void
527 part_construct_opts_copy(const struct spdk_bdev_part_construct_opts *src,
528 			 struct spdk_bdev_part_construct_opts *dst)
529 {
530 	if (src->opts_size == 0) {
531 		SPDK_ERRLOG("size should not be zero\n");
532 		assert(false);
533 	}
534 
535 	memset(dst, 0, sizeof(*dst));
536 	dst->opts_size = src->opts_size;
537 
538 #define FIELD_OK(field) \
539         offsetof(struct spdk_bdev_part_construct_opts, field) + sizeof(src->field) <= src->opts_size
540 
541 #define SET_FIELD(field) \
542         if (FIELD_OK(field)) { \
543                 dst->field = src->field; \
544         } \
545 
546 	SET_FIELD(uuid);
547 
548 	/* You should not remove this statement, but need to update the assert statement
549 	 * if you add a new field, and also add a corresponding SET_FIELD statement */
550 	SPDK_STATIC_ASSERT(sizeof(struct spdk_bdev_part_construct_opts) == 24, "Incorrect size");
551 
552 #undef FIELD_OK
553 #undef SET_FIELD
554 }
555 
556 int
557 spdk_bdev_part_construct_ext(struct spdk_bdev_part *part, struct spdk_bdev_part_base *base,
558 			     char *name, uint64_t offset_blocks, uint64_t num_blocks,
559 			     char *product_name, const struct spdk_bdev_part_construct_opts *_opts)
560 {
561 	int rc;
562 	bool first_claimed = false;
563 	struct spdk_bdev_part_construct_opts opts;
564 	struct spdk_uuid ns_uuid;
565 
566 	if (_opts == NULL) {
567 		spdk_bdev_part_construct_opts_init(&opts, sizeof(opts));
568 	} else {
569 		part_construct_opts_copy(_opts, &opts);
570 	}
571 
572 	part->internal.bdev.blocklen = base->bdev->blocklen;
573 	part->internal.bdev.blockcnt = num_blocks;
574 	part->internal.offset_blocks = offset_blocks;
575 
576 	part->internal.bdev.write_cache = base->bdev->write_cache;
577 	part->internal.bdev.required_alignment = base->bdev->required_alignment;
578 	part->internal.bdev.ctxt = part;
579 	part->internal.bdev.module = base->module;
580 	part->internal.bdev.fn_table = base->fn_table;
581 
582 	part->internal.bdev.md_interleave = base->bdev->md_interleave;
583 	part->internal.bdev.md_len = base->bdev->md_len;
584 	part->internal.bdev.dif_type = base->bdev->dif_type;
585 	part->internal.bdev.dif_is_head_of_md = base->bdev->dif_is_head_of_md;
586 	part->internal.bdev.dif_check_flags = base->bdev->dif_check_flags;
587 
588 	part->internal.bdev.name = strdup(name);
589 	if (part->internal.bdev.name == NULL) {
590 		SPDK_ERRLOG("Failed to allocate name for new part of bdev %s\n", spdk_bdev_get_name(base->bdev));
591 		return -1;
592 	}
593 
594 	part->internal.bdev.product_name = strdup(product_name);
595 	if (part->internal.bdev.product_name == NULL) {
596 		free(part->internal.bdev.name);
597 		SPDK_ERRLOG("Failed to allocate product name for new part of bdev %s\n",
598 			    spdk_bdev_get_name(base->bdev));
599 		return -1;
600 	}
601 
602 	/* The caller may have already specified a UUID.  If not, we'll generate one
603 	 * based on the namespace UUID, the base bdev's UUID and the block range of the
604 	 * partition.
605 	 */
606 	if (!spdk_uuid_is_null(&opts.uuid)) {
607 		spdk_uuid_copy(&part->internal.bdev.uuid, &opts.uuid);
608 	} else {
609 		struct {
610 			struct spdk_uuid	uuid;
611 			uint64_t		offset_blocks;
612 			uint64_t		num_blocks;
613 		} base_name;
614 
615 		/* We need to create a unique base name for this partition.  We can't just use
616 		 * the base bdev's UUID, since it may be used for multiple partitions.  So
617 		 * construct a binary name consisting of the uuid + the block range for this
618 		 * partition.
619 		 */
620 		spdk_uuid_copy(&base_name.uuid, &base->bdev->uuid);
621 		base_name.offset_blocks = offset_blocks;
622 		base_name.num_blocks = num_blocks;
623 
624 		spdk_uuid_parse(&ns_uuid, BDEV_PART_NAMESPACE_UUID);
625 		rc = spdk_uuid_generate_sha1(&part->internal.bdev.uuid, &ns_uuid,
626 					     (const char *)&base_name, sizeof(base_name));
627 		if (rc) {
628 			SPDK_ERRLOG("Could not generate new UUID\n");
629 			free(part->internal.bdev.name);
630 			free(part->internal.bdev.product_name);
631 			return -1;
632 		}
633 	}
634 
635 	base->ref++;
636 	part->internal.base = base;
637 
638 	if (!base->claimed) {
639 		int rc;
640 
641 		rc = spdk_bdev_module_claim_bdev(base->bdev, base->desc, base->module);
642 		if (rc) {
643 			SPDK_ERRLOG("could not claim bdev %s\n", spdk_bdev_get_name(base->bdev));
644 			free(part->internal.bdev.name);
645 			free(part->internal.bdev.product_name);
646 			base->ref--;
647 			return -1;
648 		}
649 		base->claimed = true;
650 		first_claimed = true;
651 	}
652 
653 	spdk_io_device_register(part, bdev_part_channel_create_cb,
654 				bdev_part_channel_destroy_cb,
655 				base->channel_size,
656 				name);
657 
658 	rc = spdk_bdev_register(&part->internal.bdev);
659 	if (rc == 0) {
660 		TAILQ_INSERT_TAIL(base->tailq, part, tailq);
661 	} else {
662 		spdk_io_device_unregister(part, NULL);
663 		if (--base->ref == 0) {
664 			spdk_bdev_module_release_bdev(base->bdev);
665 		}
666 		free(part->internal.bdev.name);
667 		free(part->internal.bdev.product_name);
668 		if (first_claimed == true) {
669 			base->claimed = false;
670 		}
671 	}
672 
673 	return rc;
674 }
675 
676 int
677 spdk_bdev_part_construct(struct spdk_bdev_part *part, struct spdk_bdev_part_base *base,
678 			 char *name, uint64_t offset_blocks, uint64_t num_blocks,
679 			 char *product_name)
680 {
681 	return spdk_bdev_part_construct_ext(part, base, name, offset_blocks, num_blocks,
682 					    product_name, NULL);
683 }
684