xref: /spdk/lib/blob/blobstore.c (revision 3fc824c834babab53b3188bef1d993f512b33dec)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include "spdk/blob.h"
37 #include "spdk/crc32.h"
38 #include "spdk/env.h"
39 #include "spdk/queue.h"
40 #include "spdk/thread.h"
41 #include "spdk/bit_array.h"
42 #include "spdk/likely.h"
43 #include "spdk/util.h"
44 
45 #include "spdk_internal/assert.h"
46 #include "spdk_internal/log.h"
47 
48 #include "blobstore.h"
49 
50 #define BLOB_CRC32C_INITIAL    0xffffffffUL
51 
52 static int spdk_bs_register_md_thread(struct spdk_blob_store *bs);
53 static int spdk_bs_unregister_md_thread(struct spdk_blob_store *bs);
54 static void _spdk_blob_close_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno);
55 static void _spdk_blob_insert_cluster_on_md_thread(struct spdk_blob *blob, uint32_t cluster_num,
56 		uint64_t cluster, spdk_blob_op_complete cb_fn, void *cb_arg);
57 
58 static int _spdk_blob_set_xattr(struct spdk_blob *blob, const char *name, const void *value,
59 				uint16_t value_len, bool internal);
60 static int _spdk_blob_get_xattr_value(struct spdk_blob *blob, const char *name,
61 				      const void **value, size_t *value_len, bool internal);
62 static int _spdk_blob_remove_xattr(struct spdk_blob *blob, const char *name, bool internal);
63 
64 static void
65 _spdk_blob_verify_md_op(struct spdk_blob *blob)
66 {
67 	assert(blob != NULL);
68 	assert(spdk_get_thread() == blob->bs->md_thread);
69 	assert(blob->state != SPDK_BLOB_STATE_LOADING);
70 }
71 
72 static void
73 _spdk_bs_claim_cluster(struct spdk_blob_store *bs, uint32_t cluster_num)
74 {
75 	assert(cluster_num < spdk_bit_array_capacity(bs->used_clusters));
76 	assert(spdk_bit_array_get(bs->used_clusters, cluster_num) == false);
77 	assert(bs->num_free_clusters > 0);
78 
79 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Claiming cluster %u\n", cluster_num);
80 
81 	spdk_bit_array_set(bs->used_clusters, cluster_num);
82 	bs->num_free_clusters--;
83 }
84 
85 static int
86 _spdk_blob_insert_cluster(struct spdk_blob *blob, uint32_t cluster_num, uint64_t cluster)
87 {
88 	uint64_t *cluster_lba = &blob->active.clusters[cluster_num];
89 
90 	_spdk_blob_verify_md_op(blob);
91 
92 	if (*cluster_lba != 0) {
93 		return -EEXIST;
94 	}
95 
96 	*cluster_lba = _spdk_bs_cluster_to_lba(blob->bs, cluster);
97 	return 0;
98 }
99 
100 static int
101 _spdk_bs_allocate_cluster(struct spdk_blob *blob, uint32_t cluster_num,
102 			  uint64_t *lowest_free_cluster, bool update_map)
103 {
104 	pthread_mutex_lock(&blob->bs->used_clusters_mutex);
105 	*lowest_free_cluster = spdk_bit_array_find_first_clear(blob->bs->used_clusters,
106 			       *lowest_free_cluster);
107 	if (*lowest_free_cluster == UINT32_MAX) {
108 		/* No more free clusters. Cannot satisfy the request */
109 		pthread_mutex_unlock(&blob->bs->used_clusters_mutex);
110 		return -ENOSPC;
111 	}
112 
113 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Claiming cluster %lu for blob %lu\n", *lowest_free_cluster, blob->id);
114 	_spdk_bs_claim_cluster(blob->bs, *lowest_free_cluster);
115 	pthread_mutex_unlock(&blob->bs->used_clusters_mutex);
116 
117 	if (update_map) {
118 		_spdk_blob_insert_cluster(blob, cluster_num, *lowest_free_cluster);
119 	}
120 
121 	return 0;
122 }
123 
124 static void
125 _spdk_bs_release_cluster(struct spdk_blob_store *bs, uint32_t cluster_num)
126 {
127 	assert(cluster_num < spdk_bit_array_capacity(bs->used_clusters));
128 	assert(spdk_bit_array_get(bs->used_clusters, cluster_num) == true);
129 	assert(bs->num_free_clusters < bs->total_clusters);
130 
131 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Releasing cluster %u\n", cluster_num);
132 
133 	pthread_mutex_lock(&bs->used_clusters_mutex);
134 	spdk_bit_array_clear(bs->used_clusters, cluster_num);
135 	bs->num_free_clusters++;
136 	pthread_mutex_unlock(&bs->used_clusters_mutex);
137 }
138 
139 static void
140 _spdk_blob_xattrs_init(struct spdk_blob_xattr_opts *xattrs)
141 {
142 	xattrs->count = 0;
143 	xattrs->names = NULL;
144 	xattrs->ctx = NULL;
145 	xattrs->get_value = NULL;
146 }
147 
148 void
149 spdk_blob_opts_init(struct spdk_blob_opts *opts)
150 {
151 	opts->num_clusters = 0;
152 	opts->thin_provision = false;
153 	_spdk_blob_xattrs_init(&opts->xattrs);
154 }
155 
156 void
157 spdk_blob_open_opts_init(struct spdk_blob_open_opts *opts)
158 {
159 	opts->clear_method = BLOB_CLEAR_WITH_UNMAP;
160 }
161 
162 static struct spdk_blob *
163 _spdk_blob_alloc(struct spdk_blob_store *bs, spdk_blob_id id)
164 {
165 	struct spdk_blob *blob;
166 
167 	blob = calloc(1, sizeof(*blob));
168 	if (!blob) {
169 		return NULL;
170 	}
171 
172 	blob->id = id;
173 	blob->bs = bs;
174 
175 	blob->parent_id = SPDK_BLOBID_INVALID;
176 
177 	blob->state = SPDK_BLOB_STATE_DIRTY;
178 	blob->active.num_pages = 1;
179 	blob->active.pages = calloc(1, sizeof(*blob->active.pages));
180 	if (!blob->active.pages) {
181 		free(blob);
182 		return NULL;
183 	}
184 
185 	blob->active.pages[0] = _spdk_bs_blobid_to_page(id);
186 
187 	TAILQ_INIT(&blob->xattrs);
188 	TAILQ_INIT(&blob->xattrs_internal);
189 
190 	return blob;
191 }
192 
193 static void
194 _spdk_xattrs_free(struct spdk_xattr_tailq *xattrs)
195 {
196 	struct spdk_xattr	*xattr, *xattr_tmp;
197 
198 	TAILQ_FOREACH_SAFE(xattr, xattrs, link, xattr_tmp) {
199 		TAILQ_REMOVE(xattrs, xattr, link);
200 		free(xattr->name);
201 		free(xattr->value);
202 		free(xattr);
203 	}
204 }
205 
206 static void
207 _spdk_blob_free(struct spdk_blob *blob)
208 {
209 	assert(blob != NULL);
210 
211 	free(blob->active.clusters);
212 	free(blob->clean.clusters);
213 	free(blob->active.pages);
214 	free(blob->clean.pages);
215 
216 	_spdk_xattrs_free(&blob->xattrs);
217 	_spdk_xattrs_free(&blob->xattrs_internal);
218 
219 	if (blob->back_bs_dev) {
220 		blob->back_bs_dev->destroy(blob->back_bs_dev);
221 	}
222 
223 	free(blob);
224 }
225 
226 struct freeze_io_ctx {
227 	struct spdk_bs_cpl cpl;
228 	struct spdk_blob *blob;
229 };
230 
231 static void
232 _spdk_blob_io_sync(struct spdk_io_channel_iter *i)
233 {
234 	spdk_for_each_channel_continue(i, 0);
235 }
236 
237 static void
238 _spdk_blob_execute_queued_io(struct spdk_io_channel_iter *i)
239 {
240 	struct spdk_io_channel *_ch = spdk_io_channel_iter_get_channel(i);
241 	struct spdk_bs_channel *ch = spdk_io_channel_get_ctx(_ch);
242 	struct freeze_io_ctx *ctx = spdk_io_channel_iter_get_ctx(i);
243 	struct spdk_bs_request_set	*set;
244 	struct spdk_bs_user_op_args	*args;
245 	spdk_bs_user_op_t *op, *tmp;
246 
247 	TAILQ_FOREACH_SAFE(op, &ch->queued_io, link, tmp) {
248 		set = (struct spdk_bs_request_set *)op;
249 		args = &set->u.user_op;
250 
251 		if (args->blob == ctx->blob) {
252 			TAILQ_REMOVE(&ch->queued_io, op, link);
253 			spdk_bs_user_op_execute(op);
254 		}
255 	}
256 
257 	spdk_for_each_channel_continue(i, 0);
258 }
259 
260 static void
261 _spdk_blob_io_cpl(struct spdk_io_channel_iter *i, int status)
262 {
263 	struct freeze_io_ctx *ctx = spdk_io_channel_iter_get_ctx(i);
264 
265 	ctx->cpl.u.blob_basic.cb_fn(ctx->cpl.u.blob_basic.cb_arg, 0);
266 
267 	free(ctx);
268 }
269 
270 static void
271 _spdk_blob_freeze_io(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
272 {
273 	struct freeze_io_ctx *ctx;
274 
275 	ctx = calloc(1, sizeof(*ctx));
276 	if (!ctx) {
277 		cb_fn(cb_arg, -ENOMEM);
278 		return;
279 	}
280 
281 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
282 	ctx->cpl.u.blob_basic.cb_fn = cb_fn;
283 	ctx->cpl.u.blob_basic.cb_arg = cb_arg;
284 	ctx->blob = blob;
285 
286 	/* Freeze I/O on blob */
287 	blob->frozen_refcnt++;
288 
289 	if (blob->frozen_refcnt == 1) {
290 		spdk_for_each_channel(blob->bs, _spdk_blob_io_sync, ctx, _spdk_blob_io_cpl);
291 	} else {
292 		cb_fn(cb_arg, 0);
293 		free(ctx);
294 	}
295 }
296 
297 static void
298 _spdk_blob_unfreeze_io(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
299 {
300 	struct freeze_io_ctx *ctx;
301 
302 	ctx = calloc(1, sizeof(*ctx));
303 	if (!ctx) {
304 		cb_fn(cb_arg, -ENOMEM);
305 		return;
306 	}
307 
308 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
309 	ctx->cpl.u.blob_basic.cb_fn = cb_fn;
310 	ctx->cpl.u.blob_basic.cb_arg = cb_arg;
311 	ctx->blob = blob;
312 
313 	assert(blob->frozen_refcnt > 0);
314 
315 	blob->frozen_refcnt--;
316 
317 	if (blob->frozen_refcnt == 0) {
318 		spdk_for_each_channel(blob->bs, _spdk_blob_execute_queued_io, ctx, _spdk_blob_io_cpl);
319 	} else {
320 		cb_fn(cb_arg, 0);
321 		free(ctx);
322 	}
323 }
324 
325 static int
326 _spdk_blob_mark_clean(struct spdk_blob *blob)
327 {
328 	uint64_t *clusters = NULL;
329 	uint32_t *pages = NULL;
330 
331 	assert(blob != NULL);
332 
333 	if (blob->active.num_clusters) {
334 		assert(blob->active.clusters);
335 		clusters = calloc(blob->active.num_clusters, sizeof(*blob->active.clusters));
336 		if (!clusters) {
337 			return -ENOMEM;
338 		}
339 		memcpy(clusters, blob->active.clusters, blob->active.num_clusters * sizeof(*clusters));
340 	}
341 
342 	if (blob->active.num_pages) {
343 		assert(blob->active.pages);
344 		pages = calloc(blob->active.num_pages, sizeof(*blob->active.pages));
345 		if (!pages) {
346 			free(clusters);
347 			return -ENOMEM;
348 		}
349 		memcpy(pages, blob->active.pages, blob->active.num_pages * sizeof(*pages));
350 	}
351 
352 	free(blob->clean.clusters);
353 	free(blob->clean.pages);
354 
355 	blob->clean.num_clusters = blob->active.num_clusters;
356 	blob->clean.clusters = blob->active.clusters;
357 	blob->clean.num_pages = blob->active.num_pages;
358 	blob->clean.pages = blob->active.pages;
359 
360 	blob->active.clusters = clusters;
361 	blob->active.pages = pages;
362 
363 	/* If the metadata was dirtied again while the metadata was being written to disk,
364 	 *  we do not want to revert the DIRTY state back to CLEAN here.
365 	 */
366 	if (blob->state == SPDK_BLOB_STATE_LOADING) {
367 		blob->state = SPDK_BLOB_STATE_CLEAN;
368 	}
369 
370 	return 0;
371 }
372 
373 static int
374 _spdk_blob_deserialize_xattr(struct spdk_blob *blob,
375 			     struct spdk_blob_md_descriptor_xattr *desc_xattr, bool internal)
376 {
377 	struct spdk_xattr                       *xattr;
378 
379 	if (desc_xattr->length != sizeof(desc_xattr->name_length) +
380 	    sizeof(desc_xattr->value_length) +
381 	    desc_xattr->name_length + desc_xattr->value_length) {
382 		return -EINVAL;
383 	}
384 
385 	xattr = calloc(1, sizeof(*xattr));
386 	if (xattr == NULL) {
387 		return -ENOMEM;
388 	}
389 
390 	xattr->name = malloc(desc_xattr->name_length + 1);
391 	if (xattr->name == NULL) {
392 		free(xattr);
393 		return -ENOMEM;
394 	}
395 	memcpy(xattr->name, desc_xattr->name, desc_xattr->name_length);
396 	xattr->name[desc_xattr->name_length] = '\0';
397 
398 	xattr->value = malloc(desc_xattr->value_length);
399 	if (xattr->value == NULL) {
400 		free(xattr->name);
401 		free(xattr);
402 		return -ENOMEM;
403 	}
404 	xattr->value_len = desc_xattr->value_length;
405 	memcpy(xattr->value,
406 	       (void *)((uintptr_t)desc_xattr->name + desc_xattr->name_length),
407 	       desc_xattr->value_length);
408 
409 	TAILQ_INSERT_TAIL(internal ? &blob->xattrs_internal : &blob->xattrs, xattr, link);
410 
411 	return 0;
412 }
413 
414 
415 static int
416 _spdk_blob_parse_page(const struct spdk_blob_md_page *page, struct spdk_blob *blob)
417 {
418 	struct spdk_blob_md_descriptor *desc;
419 	size_t	cur_desc = 0;
420 	void *tmp;
421 
422 	desc = (struct spdk_blob_md_descriptor *)page->descriptors;
423 	while (cur_desc < sizeof(page->descriptors)) {
424 		if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_PADDING) {
425 			if (desc->length == 0) {
426 				/* If padding and length are 0, this terminates the page */
427 				break;
428 			}
429 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_FLAGS) {
430 			struct spdk_blob_md_descriptor_flags	*desc_flags;
431 
432 			desc_flags = (struct spdk_blob_md_descriptor_flags *)desc;
433 
434 			if (desc_flags->length != sizeof(*desc_flags) - sizeof(*desc)) {
435 				return -EINVAL;
436 			}
437 
438 			if ((desc_flags->invalid_flags | SPDK_BLOB_INVALID_FLAGS_MASK) !=
439 			    SPDK_BLOB_INVALID_FLAGS_MASK) {
440 				return -EINVAL;
441 			}
442 
443 			if ((desc_flags->data_ro_flags | SPDK_BLOB_DATA_RO_FLAGS_MASK) !=
444 			    SPDK_BLOB_DATA_RO_FLAGS_MASK) {
445 				blob->data_ro = true;
446 				blob->md_ro = true;
447 			}
448 
449 			if ((desc_flags->md_ro_flags | SPDK_BLOB_MD_RO_FLAGS_MASK) !=
450 			    SPDK_BLOB_MD_RO_FLAGS_MASK) {
451 				blob->md_ro = true;
452 			}
453 
454 			if ((desc_flags->data_ro_flags & SPDK_BLOB_READ_ONLY)) {
455 				blob->data_ro = true;
456 				blob->md_ro = true;
457 			}
458 
459 			blob->invalid_flags = desc_flags->invalid_flags;
460 			blob->data_ro_flags = desc_flags->data_ro_flags;
461 			blob->md_ro_flags = desc_flags->md_ro_flags;
462 
463 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_EXTENT) {
464 			struct spdk_blob_md_descriptor_extent	*desc_extent;
465 			unsigned int				i, j;
466 			unsigned int				cluster_count = blob->active.num_clusters;
467 
468 			desc_extent = (struct spdk_blob_md_descriptor_extent *)desc;
469 
470 			if (desc_extent->length == 0 ||
471 			    (desc_extent->length % sizeof(desc_extent->extents[0]) != 0)) {
472 				return -EINVAL;
473 			}
474 
475 			for (i = 0; i < desc_extent->length / sizeof(desc_extent->extents[0]); i++) {
476 				for (j = 0; j < desc_extent->extents[i].length; j++) {
477 					if (desc_extent->extents[i].cluster_idx != 0) {
478 						if (!spdk_bit_array_get(blob->bs->used_clusters,
479 									desc_extent->extents[i].cluster_idx + j)) {
480 							return -EINVAL;
481 						}
482 					}
483 					cluster_count++;
484 				}
485 			}
486 
487 			if (cluster_count == 0) {
488 				return -EINVAL;
489 			}
490 			tmp = realloc(blob->active.clusters, cluster_count * sizeof(uint64_t));
491 			if (tmp == NULL) {
492 				return -ENOMEM;
493 			}
494 			blob->active.clusters = tmp;
495 			blob->active.cluster_array_size = cluster_count;
496 
497 			for (i = 0; i < desc_extent->length / sizeof(desc_extent->extents[0]); i++) {
498 				for (j = 0; j < desc_extent->extents[i].length; j++) {
499 					if (desc_extent->extents[i].cluster_idx != 0) {
500 						blob->active.clusters[blob->active.num_clusters++] = _spdk_bs_cluster_to_lba(blob->bs,
501 								desc_extent->extents[i].cluster_idx + j);
502 					} else if (spdk_blob_is_thin_provisioned(blob)) {
503 						blob->active.clusters[blob->active.num_clusters++] = 0;
504 					} else {
505 						return -EINVAL;
506 					}
507 				}
508 			}
509 
510 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR) {
511 			int rc;
512 
513 			rc = _spdk_blob_deserialize_xattr(blob,
514 							  (struct spdk_blob_md_descriptor_xattr *) desc, false);
515 			if (rc != 0) {
516 				return rc;
517 			}
518 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL) {
519 			int rc;
520 
521 			rc = _spdk_blob_deserialize_xattr(blob,
522 							  (struct spdk_blob_md_descriptor_xattr *) desc, true);
523 			if (rc != 0) {
524 				return rc;
525 			}
526 		} else {
527 			/* Unrecognized descriptor type.  Do not fail - just continue to the
528 			 *  next descriptor.  If this descriptor is associated with some feature
529 			 *  defined in a newer version of blobstore, that version of blobstore
530 			 *  should create and set an associated feature flag to specify if this
531 			 *  blob can be loaded or not.
532 			 */
533 		}
534 
535 		/* Advance to the next descriptor */
536 		cur_desc += sizeof(*desc) + desc->length;
537 		if (cur_desc + sizeof(*desc) > sizeof(page->descriptors)) {
538 			break;
539 		}
540 		desc = (struct spdk_blob_md_descriptor *)((uintptr_t)page->descriptors + cur_desc);
541 	}
542 
543 	return 0;
544 }
545 
546 static int
547 _spdk_blob_parse(const struct spdk_blob_md_page *pages, uint32_t page_count,
548 		 struct spdk_blob *blob)
549 {
550 	const struct spdk_blob_md_page *page;
551 	uint32_t i;
552 	int rc;
553 
554 	assert(page_count > 0);
555 	assert(pages[0].sequence_num == 0);
556 	assert(blob != NULL);
557 	assert(blob->state == SPDK_BLOB_STATE_LOADING);
558 	assert(blob->active.clusters == NULL);
559 
560 	/* The blobid provided doesn't match what's in the MD, this can
561 	 * happen for example if a bogus blobid is passed in through open.
562 	 */
563 	if (blob->id != pages[0].id) {
564 		SPDK_ERRLOG("Blobid (%lu) doesn't match what's in metadata (%lu)\n",
565 			    blob->id, pages[0].id);
566 		return -ENOENT;
567 	}
568 
569 	for (i = 0; i < page_count; i++) {
570 		page = &pages[i];
571 
572 		assert(page->id == blob->id);
573 		assert(page->sequence_num == i);
574 
575 		rc = _spdk_blob_parse_page(page, blob);
576 		if (rc != 0) {
577 			return rc;
578 		}
579 	}
580 
581 	return 0;
582 }
583 
584 static int
585 _spdk_blob_serialize_add_page(const struct spdk_blob *blob,
586 			      struct spdk_blob_md_page **pages,
587 			      uint32_t *page_count,
588 			      struct spdk_blob_md_page **last_page)
589 {
590 	struct spdk_blob_md_page *page;
591 
592 	assert(pages != NULL);
593 	assert(page_count != NULL);
594 
595 	if (*page_count == 0) {
596 		assert(*pages == NULL);
597 		*page_count = 1;
598 		*pages = spdk_dma_malloc(SPDK_BS_PAGE_SIZE,
599 					 SPDK_BS_PAGE_SIZE,
600 					 NULL);
601 	} else {
602 		assert(*pages != NULL);
603 		(*page_count)++;
604 		*pages = spdk_dma_realloc(*pages,
605 					  SPDK_BS_PAGE_SIZE * (*page_count),
606 					  SPDK_BS_PAGE_SIZE,
607 					  NULL);
608 	}
609 
610 	if (*pages == NULL) {
611 		*page_count = 0;
612 		*last_page = NULL;
613 		return -ENOMEM;
614 	}
615 
616 	page = &(*pages)[*page_count - 1];
617 	memset(page, 0, sizeof(*page));
618 	page->id = blob->id;
619 	page->sequence_num = *page_count - 1;
620 	page->next = SPDK_INVALID_MD_PAGE;
621 	*last_page = page;
622 
623 	return 0;
624 }
625 
626 /* Transform the in-memory representation 'xattr' into an on-disk xattr descriptor.
627  * Update required_sz on both success and failure.
628  *
629  */
630 static int
631 _spdk_blob_serialize_xattr(const struct spdk_xattr *xattr,
632 			   uint8_t *buf, size_t buf_sz,
633 			   size_t *required_sz, bool internal)
634 {
635 	struct spdk_blob_md_descriptor_xattr	*desc;
636 
637 	*required_sz = sizeof(struct spdk_blob_md_descriptor_xattr) +
638 		       strlen(xattr->name) +
639 		       xattr->value_len;
640 
641 	if (buf_sz < *required_sz) {
642 		return -1;
643 	}
644 
645 	desc = (struct spdk_blob_md_descriptor_xattr *)buf;
646 
647 	desc->type = internal ? SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL : SPDK_MD_DESCRIPTOR_TYPE_XATTR;
648 	desc->length = sizeof(desc->name_length) +
649 		       sizeof(desc->value_length) +
650 		       strlen(xattr->name) +
651 		       xattr->value_len;
652 	desc->name_length = strlen(xattr->name);
653 	desc->value_length = xattr->value_len;
654 
655 	memcpy(desc->name, xattr->name, desc->name_length);
656 	memcpy((void *)((uintptr_t)desc->name + desc->name_length),
657 	       xattr->value,
658 	       desc->value_length);
659 
660 	return 0;
661 }
662 
663 static void
664 _spdk_blob_serialize_extent(const struct spdk_blob *blob,
665 			    uint64_t start_cluster, uint64_t *next_cluster,
666 			    uint8_t *buf, size_t buf_sz)
667 {
668 	struct spdk_blob_md_descriptor_extent *desc;
669 	size_t cur_sz;
670 	uint64_t i, extent_idx;
671 	uint64_t lba, lba_per_cluster, lba_count;
672 
673 	/* The buffer must have room for at least one extent */
674 	cur_sz = sizeof(struct spdk_blob_md_descriptor) + sizeof(desc->extents[0]);
675 	if (buf_sz < cur_sz) {
676 		*next_cluster = start_cluster;
677 		return;
678 	}
679 
680 	desc = (struct spdk_blob_md_descriptor_extent *)buf;
681 	desc->type = SPDK_MD_DESCRIPTOR_TYPE_EXTENT;
682 
683 	lba_per_cluster = _spdk_bs_cluster_to_lba(blob->bs, 1);
684 
685 	lba = blob->active.clusters[start_cluster];
686 	lba_count = lba_per_cluster;
687 	extent_idx = 0;
688 	for (i = start_cluster + 1; i < blob->active.num_clusters; i++) {
689 		if ((lba + lba_count) == blob->active.clusters[i]) {
690 			lba_count += lba_per_cluster;
691 			continue;
692 		} else if (lba == 0 && blob->active.clusters[i] == 0) {
693 			lba_count += lba_per_cluster;
694 			continue;
695 		}
696 		desc->extents[extent_idx].cluster_idx = lba / lba_per_cluster;
697 		desc->extents[extent_idx].length = lba_count / lba_per_cluster;
698 		extent_idx++;
699 
700 		cur_sz += sizeof(desc->extents[extent_idx]);
701 
702 		if (buf_sz < cur_sz) {
703 			/* If we ran out of buffer space, return */
704 			desc->length = sizeof(desc->extents[0]) * extent_idx;
705 			*next_cluster = i;
706 			return;
707 		}
708 
709 		lba = blob->active.clusters[i];
710 		lba_count = lba_per_cluster;
711 	}
712 
713 	desc->extents[extent_idx].cluster_idx = lba / lba_per_cluster;
714 	desc->extents[extent_idx].length = lba_count / lba_per_cluster;
715 	extent_idx++;
716 
717 	desc->length = sizeof(desc->extents[0]) * extent_idx;
718 	*next_cluster = blob->active.num_clusters;
719 
720 	return;
721 }
722 
723 static void
724 _spdk_blob_serialize_flags(const struct spdk_blob *blob,
725 			   uint8_t *buf, size_t *buf_sz)
726 {
727 	struct spdk_blob_md_descriptor_flags *desc;
728 
729 	/*
730 	 * Flags get serialized first, so we should always have room for the flags
731 	 *  descriptor.
732 	 */
733 	assert(*buf_sz >= sizeof(*desc));
734 
735 	desc = (struct spdk_blob_md_descriptor_flags *)buf;
736 	desc->type = SPDK_MD_DESCRIPTOR_TYPE_FLAGS;
737 	desc->length = sizeof(*desc) - sizeof(struct spdk_blob_md_descriptor);
738 	desc->invalid_flags = blob->invalid_flags;
739 	desc->data_ro_flags = blob->data_ro_flags;
740 	desc->md_ro_flags = blob->md_ro_flags;
741 
742 	*buf_sz -= sizeof(*desc);
743 }
744 
745 static int
746 _spdk_blob_serialize_xattrs(const struct spdk_blob *blob,
747 			    const struct spdk_xattr_tailq *xattrs, bool internal,
748 			    struct spdk_blob_md_page **pages,
749 			    struct spdk_blob_md_page *cur_page,
750 			    uint32_t *page_count, uint8_t **buf,
751 			    size_t *remaining_sz)
752 {
753 	const struct spdk_xattr	*xattr;
754 	int	rc;
755 
756 	TAILQ_FOREACH(xattr, xattrs, link) {
757 		size_t required_sz = 0;
758 
759 		rc = _spdk_blob_serialize_xattr(xattr,
760 						*buf, *remaining_sz,
761 						&required_sz, internal);
762 		if (rc < 0) {
763 			/* Need to add a new page to the chain */
764 			rc = _spdk_blob_serialize_add_page(blob, pages, page_count,
765 							   &cur_page);
766 			if (rc < 0) {
767 				spdk_dma_free(*pages);
768 				*pages = NULL;
769 				*page_count = 0;
770 				return rc;
771 			}
772 
773 			*buf = (uint8_t *)cur_page->descriptors;
774 			*remaining_sz = sizeof(cur_page->descriptors);
775 
776 			/* Try again */
777 			required_sz = 0;
778 			rc = _spdk_blob_serialize_xattr(xattr,
779 							*buf, *remaining_sz,
780 							&required_sz, internal);
781 
782 			if (rc < 0) {
783 				spdk_dma_free(*pages);
784 				*pages = NULL;
785 				*page_count = 0;
786 				return rc;
787 			}
788 		}
789 
790 		*remaining_sz -= required_sz;
791 		*buf += required_sz;
792 	}
793 
794 	return 0;
795 }
796 
797 static int
798 _spdk_blob_serialize(const struct spdk_blob *blob, struct spdk_blob_md_page **pages,
799 		     uint32_t *page_count)
800 {
801 	struct spdk_blob_md_page		*cur_page;
802 	int					rc;
803 	uint8_t					*buf;
804 	size_t					remaining_sz;
805 	uint64_t				last_cluster;
806 
807 	assert(pages != NULL);
808 	assert(page_count != NULL);
809 	assert(blob != NULL);
810 	assert(blob->state == SPDK_BLOB_STATE_DIRTY);
811 
812 	*pages = NULL;
813 	*page_count = 0;
814 
815 	/* A blob always has at least 1 page, even if it has no descriptors */
816 	rc = _spdk_blob_serialize_add_page(blob, pages, page_count, &cur_page);
817 	if (rc < 0) {
818 		return rc;
819 	}
820 
821 	buf = (uint8_t *)cur_page->descriptors;
822 	remaining_sz = sizeof(cur_page->descriptors);
823 
824 	/* Serialize flags */
825 	_spdk_blob_serialize_flags(blob, buf, &remaining_sz);
826 	buf += sizeof(struct spdk_blob_md_descriptor_flags);
827 
828 	/* Serialize xattrs */
829 	rc = _spdk_blob_serialize_xattrs(blob, &blob->xattrs, false,
830 					 pages, cur_page, page_count, &buf, &remaining_sz);
831 	if (rc < 0) {
832 		return rc;
833 	}
834 
835 	/* Serialize internal xattrs */
836 	rc = _spdk_blob_serialize_xattrs(blob, &blob->xattrs_internal, true,
837 					 pages, cur_page, page_count, &buf, &remaining_sz);
838 	if (rc < 0) {
839 		return rc;
840 	}
841 
842 	/* Serialize extents */
843 	last_cluster = 0;
844 	while (last_cluster < blob->active.num_clusters) {
845 		_spdk_blob_serialize_extent(blob, last_cluster, &last_cluster,
846 					    buf, remaining_sz);
847 
848 		if (last_cluster == blob->active.num_clusters) {
849 			break;
850 		}
851 
852 		rc = _spdk_blob_serialize_add_page(blob, pages, page_count,
853 						   &cur_page);
854 		if (rc < 0) {
855 			return rc;
856 		}
857 
858 		buf = (uint8_t *)cur_page->descriptors;
859 		remaining_sz = sizeof(cur_page->descriptors);
860 	}
861 
862 	return 0;
863 }
864 
865 struct spdk_blob_load_ctx {
866 	struct spdk_blob		*blob;
867 
868 	struct spdk_blob_md_page	*pages;
869 	uint32_t			num_pages;
870 	spdk_bs_sequence_t	        *seq;
871 
872 	spdk_bs_sequence_cpl		cb_fn;
873 	void				*cb_arg;
874 };
875 
876 static uint32_t
877 _spdk_blob_md_page_calc_crc(void *page)
878 {
879 	uint32_t		crc;
880 
881 	crc = BLOB_CRC32C_INITIAL;
882 	crc = spdk_crc32c_update(page, SPDK_BS_PAGE_SIZE - 4, crc);
883 	crc ^= BLOB_CRC32C_INITIAL;
884 
885 	return crc;
886 
887 }
888 
889 static void
890 _spdk_blob_load_final(void *cb_arg, int bserrno)
891 {
892 	struct spdk_blob_load_ctx	*ctx = cb_arg;
893 	struct spdk_blob		*blob = ctx->blob;
894 
895 	_spdk_blob_mark_clean(blob);
896 
897 	ctx->cb_fn(ctx->seq, ctx->cb_arg, bserrno);
898 
899 	/* Free the memory */
900 	spdk_dma_free(ctx->pages);
901 	free(ctx);
902 }
903 
904 static void
905 _spdk_blob_load_snapshot_cpl(void *cb_arg, struct spdk_blob *snapshot, int bserrno)
906 {
907 	struct spdk_blob_load_ctx	*ctx = cb_arg;
908 	struct spdk_blob		*blob = ctx->blob;
909 
910 	if (bserrno != 0) {
911 		goto error;
912 	}
913 
914 	blob->back_bs_dev = spdk_bs_create_blob_bs_dev(snapshot);
915 
916 	if (blob->back_bs_dev == NULL) {
917 		bserrno = -ENOMEM;
918 		goto error;
919 	}
920 
921 	_spdk_blob_load_final(ctx, bserrno);
922 	return;
923 
924 error:
925 	SPDK_ERRLOG("Snapshot fail\n");
926 	_spdk_blob_free(blob);
927 	ctx->cb_fn(ctx->seq, NULL, bserrno);
928 	spdk_dma_free(ctx->pages);
929 	free(ctx);
930 }
931 
932 static void
933 _spdk_blob_load_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
934 {
935 	struct spdk_blob_load_ctx	*ctx = cb_arg;
936 	struct spdk_blob		*blob = ctx->blob;
937 	struct spdk_blob_md_page	*page;
938 	const void			*value;
939 	size_t				len;
940 	int				rc;
941 	uint32_t			crc;
942 
943 	if (bserrno) {
944 		SPDK_ERRLOG("Metadata page read failed: %d\n", bserrno);
945 		_spdk_blob_free(blob);
946 		ctx->cb_fn(seq, NULL, bserrno);
947 		spdk_dma_free(ctx->pages);
948 		free(ctx);
949 		return;
950 	}
951 
952 	page = &ctx->pages[ctx->num_pages - 1];
953 	crc = _spdk_blob_md_page_calc_crc(page);
954 	if (crc != page->crc) {
955 		SPDK_ERRLOG("Metadata page %d crc mismatch\n", ctx->num_pages);
956 		_spdk_blob_free(blob);
957 		ctx->cb_fn(seq, NULL, -EINVAL);
958 		spdk_dma_free(ctx->pages);
959 		free(ctx);
960 		return;
961 	}
962 
963 	if (page->next != SPDK_INVALID_MD_PAGE) {
964 		uint32_t next_page = page->next;
965 		uint64_t next_lba = _spdk_bs_page_to_lba(blob->bs, blob->bs->md_start + next_page);
966 
967 
968 		assert(next_lba < (blob->bs->md_start + blob->bs->md_len));
969 
970 		/* Read the next page */
971 		ctx->num_pages++;
972 		ctx->pages = spdk_dma_realloc(ctx->pages, (sizeof(*page) * ctx->num_pages),
973 					      sizeof(*page), NULL);
974 		if (ctx->pages == NULL) {
975 			ctx->cb_fn(seq, ctx->cb_arg, -ENOMEM);
976 			free(ctx);
977 			return;
978 		}
979 
980 		spdk_bs_sequence_read_dev(seq, &ctx->pages[ctx->num_pages - 1],
981 					  next_lba,
982 					  _spdk_bs_byte_to_lba(blob->bs, sizeof(*page)),
983 					  _spdk_blob_load_cpl, ctx);
984 		return;
985 	}
986 
987 	/* Parse the pages */
988 	rc = _spdk_blob_parse(ctx->pages, ctx->num_pages, blob);
989 	if (rc) {
990 		_spdk_blob_free(blob);
991 		ctx->cb_fn(seq, NULL, rc);
992 		spdk_dma_free(ctx->pages);
993 		free(ctx);
994 		return;
995 	}
996 	ctx->seq = seq;
997 
998 
999 	if (spdk_blob_is_thin_provisioned(blob)) {
1000 		rc = _spdk_blob_get_xattr_value(blob, BLOB_SNAPSHOT, &value, &len, true);
1001 		if (rc == 0) {
1002 			if (len != sizeof(spdk_blob_id)) {
1003 				_spdk_blob_free(blob);
1004 				ctx->cb_fn(seq, NULL, -EINVAL);
1005 				spdk_dma_free(ctx->pages);
1006 				free(ctx);
1007 				return;
1008 			}
1009 			/* open snapshot blob and continue in the callback function */
1010 			blob->parent_id = *(spdk_blob_id *)value;
1011 			spdk_bs_open_blob(blob->bs, blob->parent_id,
1012 					  _spdk_blob_load_snapshot_cpl, ctx);
1013 			return;
1014 		} else {
1015 			/* add zeroes_dev for thin provisioned blob */
1016 			blob->back_bs_dev = spdk_bs_create_zeroes_dev();
1017 		}
1018 	} else {
1019 		/* standard blob */
1020 		blob->back_bs_dev = NULL;
1021 	}
1022 	_spdk_blob_load_final(ctx, bserrno);
1023 }
1024 
1025 /* Load a blob from disk given a blobid */
1026 static void
1027 _spdk_blob_load(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
1028 		spdk_bs_sequence_cpl cb_fn, void *cb_arg)
1029 {
1030 	struct spdk_blob_load_ctx *ctx;
1031 	struct spdk_blob_store *bs;
1032 	uint32_t page_num;
1033 	uint64_t lba;
1034 
1035 	_spdk_blob_verify_md_op(blob);
1036 
1037 	bs = blob->bs;
1038 
1039 	ctx = calloc(1, sizeof(*ctx));
1040 	if (!ctx) {
1041 		cb_fn(seq, cb_arg, -ENOMEM);
1042 		return;
1043 	}
1044 
1045 	ctx->blob = blob;
1046 	ctx->pages = spdk_dma_realloc(ctx->pages, SPDK_BS_PAGE_SIZE,
1047 				      SPDK_BS_PAGE_SIZE, NULL);
1048 	if (!ctx->pages) {
1049 		free(ctx);
1050 		cb_fn(seq, cb_arg, -ENOMEM);
1051 		return;
1052 	}
1053 	ctx->num_pages = 1;
1054 	ctx->cb_fn = cb_fn;
1055 	ctx->cb_arg = cb_arg;
1056 
1057 	page_num = _spdk_bs_blobid_to_page(blob->id);
1058 	lba = _spdk_bs_page_to_lba(blob->bs, bs->md_start + page_num);
1059 
1060 	blob->state = SPDK_BLOB_STATE_LOADING;
1061 
1062 	spdk_bs_sequence_read_dev(seq, &ctx->pages[0], lba,
1063 				  _spdk_bs_byte_to_lba(bs, SPDK_BS_PAGE_SIZE),
1064 				  _spdk_blob_load_cpl, ctx);
1065 }
1066 
1067 struct spdk_blob_persist_ctx {
1068 	struct spdk_blob		*blob;
1069 
1070 	struct spdk_bs_super_block	*super;
1071 
1072 	struct spdk_blob_md_page	*pages;
1073 
1074 	uint64_t			idx;
1075 
1076 	spdk_bs_sequence_t		*seq;
1077 	spdk_bs_sequence_cpl		cb_fn;
1078 	void				*cb_arg;
1079 };
1080 
1081 static void
1082 spdk_bs_batch_clear_dev(struct spdk_blob_persist_ctx *ctx, spdk_bs_batch_t *batch, uint64_t lba,
1083 			uint32_t lba_count)
1084 {
1085 	if (ctx->blob->clear_method == BLOB_CLEAR_WITH_DEFAULT ||
1086 	    ctx->blob->clear_method == BLOB_CLEAR_WITH_UNMAP) {
1087 		spdk_bs_batch_unmap_dev(batch, lba, lba_count);
1088 	} else if (ctx->blob->clear_method == BLOB_CLEAR_WITH_WRITE_ZEROES) {
1089 		spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1090 	}
1091 }
1092 
1093 static void
1094 _spdk_blob_persist_complete(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1095 {
1096 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1097 	struct spdk_blob		*blob = ctx->blob;
1098 
1099 	if (bserrno == 0) {
1100 		_spdk_blob_mark_clean(blob);
1101 	}
1102 
1103 	/* Call user callback */
1104 	ctx->cb_fn(seq, ctx->cb_arg, bserrno);
1105 
1106 	/* Free the memory */
1107 	spdk_dma_free(ctx->pages);
1108 	free(ctx);
1109 }
1110 
1111 static void
1112 _spdk_blob_persist_clear_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1113 {
1114 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1115 	struct spdk_blob		*blob = ctx->blob;
1116 	struct spdk_blob_store		*bs = blob->bs;
1117 	void				*tmp;
1118 	size_t				i;
1119 
1120 	/* Release all clusters that were truncated */
1121 	for (i = blob->active.num_clusters; i < blob->active.cluster_array_size; i++) {
1122 		uint32_t cluster_num = _spdk_bs_lba_to_cluster(bs, blob->active.clusters[i]);
1123 
1124 		/* Nothing to release if it was not allocated */
1125 		if (blob->active.clusters[i] != 0) {
1126 			_spdk_bs_release_cluster(bs, cluster_num);
1127 		}
1128 	}
1129 
1130 	if (blob->active.num_clusters == 0) {
1131 		free(blob->active.clusters);
1132 		blob->active.clusters = NULL;
1133 		blob->active.cluster_array_size = 0;
1134 	} else {
1135 		tmp = realloc(blob->active.clusters, sizeof(uint64_t) * blob->active.num_clusters);
1136 		assert(tmp != NULL);
1137 		blob->active.clusters = tmp;
1138 		blob->active.cluster_array_size = blob->active.num_clusters;
1139 	}
1140 
1141 	_spdk_blob_persist_complete(seq, ctx, bserrno);
1142 }
1143 
1144 static void
1145 _spdk_blob_persist_clear_clusters(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1146 {
1147 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1148 	struct spdk_blob		*blob = ctx->blob;
1149 	struct spdk_blob_store		*bs = blob->bs;
1150 	spdk_bs_batch_t			*batch;
1151 	size_t				i;
1152 	uint64_t			lba;
1153 	uint32_t			lba_count;
1154 
1155 	/* Clusters don't move around in blobs. The list shrinks or grows
1156 	 * at the end, but no changes ever occur in the middle of the list.
1157 	 */
1158 
1159 	batch = spdk_bs_sequence_to_batch(seq, _spdk_blob_persist_clear_clusters_cpl, ctx);
1160 
1161 	/* Clear all clusters that were truncated */
1162 	lba = 0;
1163 	lba_count = 0;
1164 	for (i = blob->active.num_clusters; i < blob->active.cluster_array_size; i++) {
1165 		uint64_t next_lba = blob->active.clusters[i];
1166 		uint32_t next_lba_count = _spdk_bs_cluster_to_lba(bs, 1);
1167 
1168 		if (next_lba > 0 && (lba + lba_count) == next_lba) {
1169 			/* This cluster is contiguous with the previous one. */
1170 			lba_count += next_lba_count;
1171 			continue;
1172 		}
1173 
1174 		/* This cluster is not contiguous with the previous one. */
1175 
1176 		/* If a run of LBAs previously existing, clear them now */
1177 		if (lba_count > 0) {
1178 			spdk_bs_batch_clear_dev(ctx, batch, lba, lba_count);
1179 		}
1180 
1181 		/* Start building the next batch */
1182 		lba = next_lba;
1183 		if (next_lba > 0) {
1184 			lba_count = next_lba_count;
1185 		} else {
1186 			lba_count = 0;
1187 		}
1188 	}
1189 
1190 	/* If we ended with a contiguous set of LBAs, clear them now */
1191 	if (lba_count > 0) {
1192 		spdk_bs_batch_clear_dev(ctx, batch, lba, lba_count);
1193 	}
1194 
1195 	spdk_bs_batch_close(batch);
1196 }
1197 
1198 static void
1199 _spdk_blob_persist_zero_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1200 {
1201 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1202 	struct spdk_blob		*blob = ctx->blob;
1203 	struct spdk_blob_store		*bs = blob->bs;
1204 	size_t				i;
1205 
1206 	/* This loop starts at 1 because the first page is special and handled
1207 	 * below. The pages (except the first) are never written in place,
1208 	 * so any pages in the clean list must be zeroed.
1209 	 */
1210 	for (i = 1; i < blob->clean.num_pages; i++) {
1211 		spdk_bit_array_clear(bs->used_md_pages, blob->clean.pages[i]);
1212 	}
1213 
1214 	if (blob->active.num_pages == 0) {
1215 		uint32_t page_num;
1216 
1217 		page_num = _spdk_bs_blobid_to_page(blob->id);
1218 		spdk_bit_array_clear(bs->used_md_pages, page_num);
1219 	}
1220 
1221 	/* Move on to clearing clusters */
1222 	_spdk_blob_persist_clear_clusters(seq, ctx, 0);
1223 }
1224 
1225 static void
1226 _spdk_blob_persist_zero_pages(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1227 {
1228 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1229 	struct spdk_blob		*blob = ctx->blob;
1230 	struct spdk_blob_store		*bs = blob->bs;
1231 	uint64_t			lba;
1232 	uint32_t			lba_count;
1233 	spdk_bs_batch_t			*batch;
1234 	size_t				i;
1235 
1236 	batch = spdk_bs_sequence_to_batch(seq, _spdk_blob_persist_zero_pages_cpl, ctx);
1237 
1238 	lba_count = _spdk_bs_byte_to_lba(bs, SPDK_BS_PAGE_SIZE);
1239 
1240 	/* This loop starts at 1 because the first page is special and handled
1241 	 * below. The pages (except the first) are never written in place,
1242 	 * so any pages in the clean list must be zeroed.
1243 	 */
1244 	for (i = 1; i < blob->clean.num_pages; i++) {
1245 		lba = _spdk_bs_page_to_lba(bs, bs->md_start + blob->clean.pages[i]);
1246 
1247 		spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1248 	}
1249 
1250 	/* The first page will only be zeroed if this is a delete. */
1251 	if (blob->active.num_pages == 0) {
1252 		uint32_t page_num;
1253 
1254 		/* The first page in the metadata goes where the blobid indicates */
1255 		page_num = _spdk_bs_blobid_to_page(blob->id);
1256 		lba = _spdk_bs_page_to_lba(bs, bs->md_start + page_num);
1257 
1258 		spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1259 	}
1260 
1261 	spdk_bs_batch_close(batch);
1262 }
1263 
1264 static void
1265 _spdk_blob_persist_write_page_root(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1266 {
1267 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1268 	struct spdk_blob		*blob = ctx->blob;
1269 	struct spdk_blob_store		*bs = blob->bs;
1270 	uint64_t			lba;
1271 	uint32_t			lba_count;
1272 	struct spdk_blob_md_page	*page;
1273 
1274 	if (blob->active.num_pages == 0) {
1275 		/* Move on to the next step */
1276 		_spdk_blob_persist_zero_pages(seq, ctx, 0);
1277 		return;
1278 	}
1279 
1280 	lba_count = _spdk_bs_byte_to_lba(bs, sizeof(*page));
1281 
1282 	page = &ctx->pages[0];
1283 	/* The first page in the metadata goes where the blobid indicates */
1284 	lba = _spdk_bs_page_to_lba(bs, bs->md_start + _spdk_bs_blobid_to_page(blob->id));
1285 
1286 	spdk_bs_sequence_write_dev(seq, page, lba, lba_count,
1287 				   _spdk_blob_persist_zero_pages, ctx);
1288 }
1289 
1290 static void
1291 _spdk_blob_persist_write_page_chain(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1292 {
1293 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1294 	struct spdk_blob		*blob = ctx->blob;
1295 	struct spdk_blob_store		*bs = blob->bs;
1296 	uint64_t			lba;
1297 	uint32_t			lba_count;
1298 	struct spdk_blob_md_page	*page;
1299 	spdk_bs_batch_t			*batch;
1300 	size_t				i;
1301 
1302 	/* Clusters don't move around in blobs. The list shrinks or grows
1303 	 * at the end, but no changes ever occur in the middle of the list.
1304 	 */
1305 
1306 	lba_count = _spdk_bs_byte_to_lba(bs, sizeof(*page));
1307 
1308 	batch = spdk_bs_sequence_to_batch(seq, _spdk_blob_persist_write_page_root, ctx);
1309 
1310 	/* This starts at 1. The root page is not written until
1311 	 * all of the others are finished
1312 	 */
1313 	for (i = 1; i < blob->active.num_pages; i++) {
1314 		page = &ctx->pages[i];
1315 		assert(page->sequence_num == i);
1316 
1317 		lba = _spdk_bs_page_to_lba(bs, bs->md_start + blob->active.pages[i]);
1318 
1319 		spdk_bs_batch_write_dev(batch, page, lba, lba_count);
1320 	}
1321 
1322 	spdk_bs_batch_close(batch);
1323 }
1324 
1325 static int
1326 _spdk_blob_resize(struct spdk_blob *blob, uint64_t sz)
1327 {
1328 	uint64_t	i;
1329 	uint64_t	*tmp;
1330 	uint64_t	lfc; /* lowest free cluster */
1331 	uint64_t	num_clusters;
1332 	struct spdk_blob_store *bs;
1333 
1334 	bs = blob->bs;
1335 
1336 	_spdk_blob_verify_md_op(blob);
1337 
1338 	if (blob->active.num_clusters == sz) {
1339 		return 0;
1340 	}
1341 
1342 	if (blob->active.num_clusters < blob->active.cluster_array_size) {
1343 		/* If this blob was resized to be larger, then smaller, then
1344 		 * larger without syncing, then the cluster array already
1345 		 * contains spare assigned clusters we can use.
1346 		 */
1347 		num_clusters = spdk_min(blob->active.cluster_array_size,
1348 					sz);
1349 	} else {
1350 		num_clusters = blob->active.num_clusters;
1351 	}
1352 
1353 	/* Do two passes - one to verify that we can obtain enough clusters
1354 	 * and another to actually claim them.
1355 	 */
1356 
1357 	if (spdk_blob_is_thin_provisioned(blob) == false) {
1358 		lfc = 0;
1359 		for (i = num_clusters; i < sz; i++) {
1360 			lfc = spdk_bit_array_find_first_clear(bs->used_clusters, lfc);
1361 			if (lfc == UINT32_MAX) {
1362 				/* No more free clusters. Cannot satisfy the request */
1363 				return -ENOSPC;
1364 			}
1365 			lfc++;
1366 		}
1367 	}
1368 
1369 	if (sz > num_clusters) {
1370 		/* Expand the cluster array if necessary.
1371 		 * We only shrink the array when persisting.
1372 		 */
1373 		tmp = realloc(blob->active.clusters, sizeof(uint64_t) * sz);
1374 		if (sz > 0 && tmp == NULL) {
1375 			return -ENOMEM;
1376 		}
1377 		memset(tmp + blob->active.cluster_array_size, 0,
1378 		       sizeof(uint64_t) * (sz - blob->active.cluster_array_size));
1379 		blob->active.clusters = tmp;
1380 		blob->active.cluster_array_size = sz;
1381 	}
1382 
1383 	blob->state = SPDK_BLOB_STATE_DIRTY;
1384 
1385 	if (spdk_blob_is_thin_provisioned(blob) == false) {
1386 		lfc = 0;
1387 		for (i = num_clusters; i < sz; i++) {
1388 			_spdk_bs_allocate_cluster(blob, i, &lfc, true);
1389 			lfc++;
1390 		}
1391 	}
1392 
1393 	blob->active.num_clusters = sz;
1394 
1395 	return 0;
1396 }
1397 
1398 static void
1399 _spdk_blob_persist_start(struct spdk_blob_persist_ctx *ctx)
1400 {
1401 	spdk_bs_sequence_t *seq = ctx->seq;
1402 	struct spdk_blob *blob = ctx->blob;
1403 	struct spdk_blob_store *bs = blob->bs;
1404 	uint64_t i;
1405 	uint32_t page_num;
1406 	void *tmp;
1407 	int rc;
1408 
1409 	if (blob->active.num_pages == 0) {
1410 		/* This is the signal that the blob should be deleted.
1411 		 * Immediately jump to the clean up routine. */
1412 		assert(blob->clean.num_pages > 0);
1413 		ctx->idx = blob->clean.num_pages - 1;
1414 		blob->state = SPDK_BLOB_STATE_CLEAN;
1415 		_spdk_blob_persist_zero_pages(seq, ctx, 0);
1416 		return;
1417 
1418 	}
1419 
1420 	/* Generate the new metadata */
1421 	rc = _spdk_blob_serialize(blob, &ctx->pages, &blob->active.num_pages);
1422 	if (rc < 0) {
1423 		_spdk_blob_persist_complete(seq, ctx, rc);
1424 		return;
1425 	}
1426 
1427 	assert(blob->active.num_pages >= 1);
1428 
1429 	/* Resize the cache of page indices */
1430 	tmp = realloc(blob->active.pages, blob->active.num_pages * sizeof(*blob->active.pages));
1431 	if (!tmp) {
1432 		_spdk_blob_persist_complete(seq, ctx, -ENOMEM);
1433 		return;
1434 	}
1435 	blob->active.pages = tmp;
1436 
1437 	/* Assign this metadata to pages. This requires two passes -
1438 	 * one to verify that there are enough pages and a second
1439 	 * to actually claim them. */
1440 	page_num = 0;
1441 	/* Note that this loop starts at one. The first page location is fixed by the blobid. */
1442 	for (i = 1; i < blob->active.num_pages; i++) {
1443 		page_num = spdk_bit_array_find_first_clear(bs->used_md_pages, page_num);
1444 		if (page_num == UINT32_MAX) {
1445 			_spdk_blob_persist_complete(seq, ctx, -ENOMEM);
1446 			return;
1447 		}
1448 		page_num++;
1449 	}
1450 
1451 	page_num = 0;
1452 	blob->active.pages[0] = _spdk_bs_blobid_to_page(blob->id);
1453 	for (i = 1; i < blob->active.num_pages; i++) {
1454 		page_num = spdk_bit_array_find_first_clear(bs->used_md_pages, page_num);
1455 		ctx->pages[i - 1].next = page_num;
1456 		/* Now that previous metadata page is complete, calculate the crc for it. */
1457 		ctx->pages[i - 1].crc = _spdk_blob_md_page_calc_crc(&ctx->pages[i - 1]);
1458 		blob->active.pages[i] = page_num;
1459 		spdk_bit_array_set(bs->used_md_pages, page_num);
1460 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Claiming page %u for blob %lu\n", page_num, blob->id);
1461 		page_num++;
1462 	}
1463 	ctx->pages[i - 1].crc = _spdk_blob_md_page_calc_crc(&ctx->pages[i - 1]);
1464 	/* Start writing the metadata from last page to first */
1465 	ctx->idx = blob->active.num_pages - 1;
1466 	blob->state = SPDK_BLOB_STATE_CLEAN;
1467 	_spdk_blob_persist_write_page_chain(seq, ctx, 0);
1468 }
1469 
1470 static void
1471 _spdk_blob_persist_dirty_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1472 {
1473 	struct spdk_blob_persist_ctx *ctx = cb_arg;
1474 
1475 	ctx->blob->bs->clean = 0;
1476 
1477 	spdk_dma_free(ctx->super);
1478 
1479 	_spdk_blob_persist_start(ctx);
1480 }
1481 
1482 static void
1483 _spdk_bs_write_super(spdk_bs_sequence_t *seq, struct spdk_blob_store *bs,
1484 		     struct spdk_bs_super_block *super, spdk_bs_sequence_cpl cb_fn, void *cb_arg);
1485 
1486 
1487 static void
1488 _spdk_blob_persist_dirty(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1489 {
1490 	struct spdk_blob_persist_ctx *ctx = cb_arg;
1491 
1492 	ctx->super->clean = 0;
1493 	if (ctx->super->size == 0) {
1494 		ctx->super->size = ctx->blob->bs->dev->blockcnt * ctx->blob->bs->dev->blocklen;
1495 	}
1496 
1497 	_spdk_bs_write_super(seq, ctx->blob->bs, ctx->super, _spdk_blob_persist_dirty_cpl, ctx);
1498 }
1499 
1500 
1501 /* Write a blob to disk */
1502 static void
1503 _spdk_blob_persist(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
1504 		   spdk_bs_sequence_cpl cb_fn, void *cb_arg)
1505 {
1506 	struct spdk_blob_persist_ctx *ctx;
1507 
1508 	_spdk_blob_verify_md_op(blob);
1509 
1510 	if (blob->state == SPDK_BLOB_STATE_CLEAN) {
1511 		cb_fn(seq, cb_arg, 0);
1512 		return;
1513 	}
1514 
1515 	ctx = calloc(1, sizeof(*ctx));
1516 	if (!ctx) {
1517 		cb_fn(seq, cb_arg, -ENOMEM);
1518 		return;
1519 	}
1520 	ctx->blob = blob;
1521 	ctx->seq = seq;
1522 	ctx->cb_fn = cb_fn;
1523 	ctx->cb_arg = cb_arg;
1524 
1525 	if (blob->bs->clean) {
1526 		ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
1527 		if (!ctx->super) {
1528 			cb_fn(seq, cb_arg, -ENOMEM);
1529 			free(ctx);
1530 			return;
1531 		}
1532 
1533 		spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(blob->bs, 0),
1534 					  _spdk_bs_byte_to_lba(blob->bs, sizeof(*ctx->super)),
1535 					  _spdk_blob_persist_dirty, ctx);
1536 	} else {
1537 		_spdk_blob_persist_start(ctx);
1538 	}
1539 }
1540 
1541 struct spdk_blob_copy_cluster_ctx {
1542 	struct spdk_blob *blob;
1543 	uint8_t *buf;
1544 	uint64_t page;
1545 	uint64_t new_cluster;
1546 	spdk_bs_sequence_t *seq;
1547 };
1548 
1549 static void
1550 _spdk_blob_allocate_and_copy_cluster_cpl(void *cb_arg, int bserrno)
1551 {
1552 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1553 	struct spdk_bs_request_set *set = (struct spdk_bs_request_set *)ctx->seq;
1554 	TAILQ_HEAD(, spdk_bs_request_set) requests;
1555 	spdk_bs_user_op_t *op;
1556 
1557 	TAILQ_INIT(&requests);
1558 	TAILQ_SWAP(&set->channel->need_cluster_alloc, &requests, spdk_bs_request_set, link);
1559 
1560 	while (!TAILQ_EMPTY(&requests)) {
1561 		op = TAILQ_FIRST(&requests);
1562 		TAILQ_REMOVE(&requests, op, link);
1563 		if (bserrno == 0) {
1564 			spdk_bs_user_op_execute(op);
1565 		} else {
1566 			spdk_bs_user_op_abort(op);
1567 		}
1568 	}
1569 
1570 	spdk_dma_free(ctx->buf);
1571 	free(ctx);
1572 }
1573 
1574 static void
1575 _spdk_blob_insert_cluster_cpl(void *cb_arg, int bserrno)
1576 {
1577 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1578 
1579 	if (bserrno) {
1580 		uint32_t cluster_number;
1581 
1582 		if (bserrno == -EEXIST) {
1583 			/* The metadata insert failed because another thread
1584 			 * allocated the cluster first. Free our cluster
1585 			 * but continue without error. */
1586 			bserrno = 0;
1587 		}
1588 
1589 		cluster_number = _spdk_bs_page_to_cluster(ctx->blob->bs, ctx->page);
1590 		_spdk_bs_release_cluster(ctx->blob->bs, cluster_number);
1591 	}
1592 
1593 	spdk_bs_sequence_finish(ctx->seq, bserrno);
1594 }
1595 
1596 static void
1597 _spdk_blob_write_copy_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1598 {
1599 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1600 	uint32_t cluster_number;
1601 
1602 	if (bserrno) {
1603 		/* The write failed, so jump to the final completion handler */
1604 		spdk_bs_sequence_finish(seq, bserrno);
1605 		return;
1606 	}
1607 
1608 	cluster_number = _spdk_bs_page_to_cluster(ctx->blob->bs, ctx->page);
1609 
1610 	_spdk_blob_insert_cluster_on_md_thread(ctx->blob, cluster_number, ctx->new_cluster,
1611 					       _spdk_blob_insert_cluster_cpl, ctx);
1612 }
1613 
1614 static void
1615 _spdk_blob_write_copy(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1616 {
1617 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1618 
1619 	if (bserrno != 0) {
1620 		/* The read failed, so jump to the final completion handler */
1621 		spdk_bs_sequence_finish(seq, bserrno);
1622 		return;
1623 	}
1624 
1625 	/* Write whole cluster */
1626 	spdk_bs_sequence_write_dev(seq, ctx->buf,
1627 				   _spdk_bs_cluster_to_lba(ctx->blob->bs, ctx->new_cluster),
1628 				   _spdk_bs_cluster_to_lba(ctx->blob->bs, 1),
1629 				   _spdk_blob_write_copy_cpl, ctx);
1630 }
1631 
1632 static void
1633 _spdk_bs_allocate_and_copy_cluster(struct spdk_blob *blob,
1634 				   struct spdk_io_channel *_ch,
1635 				   uint64_t io_unit, spdk_bs_user_op_t *op)
1636 {
1637 	struct spdk_bs_cpl cpl;
1638 	struct spdk_bs_channel *ch;
1639 	struct spdk_blob_copy_cluster_ctx *ctx;
1640 	uint32_t cluster_start_page;
1641 	uint32_t cluster_number;
1642 	int rc;
1643 
1644 	ch = spdk_io_channel_get_ctx(_ch);
1645 
1646 	if (!TAILQ_EMPTY(&ch->need_cluster_alloc)) {
1647 		/* There are already operations pending. Queue this user op
1648 		 * and return because it will be re-executed when the outstanding
1649 		 * cluster allocation completes. */
1650 		TAILQ_INSERT_TAIL(&ch->need_cluster_alloc, op, link);
1651 		return;
1652 	}
1653 
1654 	/* Round the io_unit offset down to the first page in the cluster */
1655 	cluster_start_page = _spdk_bs_io_unit_to_cluster_start(blob, io_unit);
1656 
1657 	/* Calculate which index in the metadata cluster array the corresponding
1658 	 * cluster is supposed to be at. */
1659 	cluster_number = _spdk_bs_io_unit_to_cluster_number(blob, io_unit);
1660 
1661 	ctx = calloc(1, sizeof(*ctx));
1662 	if (!ctx) {
1663 		spdk_bs_user_op_abort(op);
1664 		return;
1665 	}
1666 
1667 	assert(blob->bs->cluster_sz % blob->back_bs_dev->blocklen == 0);
1668 
1669 	ctx->blob = blob;
1670 	ctx->page = cluster_start_page;
1671 
1672 	if (blob->parent_id != SPDK_BLOBID_INVALID) {
1673 		ctx->buf = spdk_dma_malloc(blob->bs->cluster_sz, blob->back_bs_dev->blocklen, NULL);
1674 		if (!ctx->buf) {
1675 			SPDK_ERRLOG("DMA allocation for cluster of size = %" PRIu32 " failed.\n",
1676 				    blob->bs->cluster_sz);
1677 			free(ctx);
1678 			spdk_bs_user_op_abort(op);
1679 			return;
1680 		}
1681 	}
1682 
1683 	rc = _spdk_bs_allocate_cluster(blob, cluster_number, &ctx->new_cluster, false);
1684 	if (rc != 0) {
1685 		spdk_dma_free(ctx->buf);
1686 		free(ctx);
1687 		spdk_bs_user_op_abort(op);
1688 		return;
1689 	}
1690 
1691 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
1692 	cpl.u.blob_basic.cb_fn = _spdk_blob_allocate_and_copy_cluster_cpl;
1693 	cpl.u.blob_basic.cb_arg = ctx;
1694 
1695 	ctx->seq = spdk_bs_sequence_start(_ch, &cpl);
1696 	if (!ctx->seq) {
1697 		_spdk_bs_release_cluster(blob->bs, ctx->new_cluster);
1698 		spdk_dma_free(ctx->buf);
1699 		free(ctx);
1700 		spdk_bs_user_op_abort(op);
1701 		return;
1702 	}
1703 
1704 	/* Queue the user op to block other incoming operations */
1705 	TAILQ_INSERT_TAIL(&ch->need_cluster_alloc, op, link);
1706 
1707 	if (blob->parent_id != SPDK_BLOBID_INVALID) {
1708 		/* Read cluster from backing device */
1709 		spdk_bs_sequence_read_bs_dev(ctx->seq, blob->back_bs_dev, ctx->buf,
1710 					     _spdk_bs_dev_page_to_lba(blob->back_bs_dev, cluster_start_page),
1711 					     _spdk_bs_dev_byte_to_lba(blob->back_bs_dev, blob->bs->cluster_sz),
1712 					     _spdk_blob_write_copy, ctx);
1713 	} else {
1714 		_spdk_blob_insert_cluster_on_md_thread(ctx->blob, cluster_number, ctx->new_cluster,
1715 						       _spdk_blob_insert_cluster_cpl, ctx);
1716 	}
1717 }
1718 
1719 static void
1720 _spdk_blob_calculate_lba_and_lba_count(struct spdk_blob *blob, uint64_t io_unit, uint64_t length,
1721 				       uint64_t *lba,	uint32_t *lba_count)
1722 {
1723 	*lba_count = length;
1724 
1725 	if (!_spdk_bs_io_unit_is_allocated(blob, io_unit)) {
1726 		assert(blob->back_bs_dev != NULL);
1727 		*lba = _spdk_bs_io_unit_to_back_dev_lba(blob, io_unit);
1728 		*lba_count = _spdk_bs_io_unit_to_back_dev_lba(blob, *lba_count);
1729 	} else {
1730 		*lba = _spdk_bs_blob_io_unit_to_lba(blob, io_unit);
1731 	}
1732 }
1733 
1734 struct op_split_ctx {
1735 	struct spdk_blob *blob;
1736 	struct spdk_io_channel *channel;
1737 	uint64_t io_unit_offset;
1738 	uint64_t io_units_remaining;
1739 	void *curr_payload;
1740 	enum spdk_blob_op_type op_type;
1741 	spdk_bs_sequence_t *seq;
1742 };
1743 
1744 static void
1745 _spdk_blob_request_submit_op_split_next(void *cb_arg, int bserrno)
1746 {
1747 	struct op_split_ctx	*ctx = cb_arg;
1748 	struct spdk_blob	*blob = ctx->blob;
1749 	struct spdk_io_channel	*ch = ctx->channel;
1750 	enum spdk_blob_op_type	op_type = ctx->op_type;
1751 	uint8_t			*buf = ctx->curr_payload;
1752 	uint64_t		offset = ctx->io_unit_offset;
1753 	uint64_t		length = ctx->io_units_remaining;
1754 	uint64_t		op_length;
1755 
1756 	if (bserrno != 0 || ctx->io_units_remaining == 0) {
1757 		spdk_bs_sequence_finish(ctx->seq, bserrno);
1758 		free(ctx);
1759 		return;
1760 	}
1761 
1762 	op_length = spdk_min(length, _spdk_bs_num_io_units_to_cluster_boundary(blob,
1763 			     offset));
1764 
1765 	/* Update length and payload for next operation */
1766 	ctx->io_units_remaining -= op_length;
1767 	ctx->io_unit_offset += op_length;
1768 	if (op_type == SPDK_BLOB_WRITE || op_type == SPDK_BLOB_READ) {
1769 		ctx->curr_payload += op_length * blob->bs->io_unit_size;
1770 	}
1771 
1772 	switch (op_type) {
1773 	case SPDK_BLOB_READ:
1774 		spdk_blob_io_read(blob, ch, buf, offset, op_length,
1775 				  _spdk_blob_request_submit_op_split_next, ctx);
1776 		break;
1777 	case SPDK_BLOB_WRITE:
1778 		spdk_blob_io_write(blob, ch, buf, offset, op_length,
1779 				   _spdk_blob_request_submit_op_split_next, ctx);
1780 		break;
1781 	case SPDK_BLOB_UNMAP:
1782 		spdk_blob_io_unmap(blob, ch, offset, op_length,
1783 				   _spdk_blob_request_submit_op_split_next, ctx);
1784 		break;
1785 	case SPDK_BLOB_WRITE_ZEROES:
1786 		spdk_blob_io_write_zeroes(blob, ch, offset, op_length,
1787 					  _spdk_blob_request_submit_op_split_next, ctx);
1788 		break;
1789 	case SPDK_BLOB_READV:
1790 	case SPDK_BLOB_WRITEV:
1791 		SPDK_ERRLOG("readv/write not valid for %s\n", __func__);
1792 		spdk_bs_sequence_finish(ctx->seq, -EINVAL);
1793 		free(ctx);
1794 		break;
1795 	}
1796 }
1797 
1798 static void
1799 _spdk_blob_request_submit_op_split(struct spdk_io_channel *ch, struct spdk_blob *blob,
1800 				   void *payload, uint64_t offset, uint64_t length,
1801 				   spdk_blob_op_complete cb_fn, void *cb_arg, enum spdk_blob_op_type op_type)
1802 {
1803 	struct op_split_ctx *ctx;
1804 	spdk_bs_sequence_t *seq;
1805 	struct spdk_bs_cpl cpl;
1806 
1807 	assert(blob != NULL);
1808 
1809 	ctx = calloc(1, sizeof(struct op_split_ctx));
1810 	if (ctx == NULL) {
1811 		cb_fn(cb_arg, -ENOMEM);
1812 		return;
1813 	}
1814 
1815 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
1816 	cpl.u.blob_basic.cb_fn = cb_fn;
1817 	cpl.u.blob_basic.cb_arg = cb_arg;
1818 
1819 	seq = spdk_bs_sequence_start(ch, &cpl);
1820 	if (!seq) {
1821 		free(ctx);
1822 		cb_fn(cb_arg, -ENOMEM);
1823 		return;
1824 	}
1825 
1826 	ctx->blob = blob;
1827 	ctx->channel = ch;
1828 	ctx->curr_payload = payload;
1829 	ctx->io_unit_offset = offset;
1830 	ctx->io_units_remaining = length;
1831 	ctx->op_type = op_type;
1832 	ctx->seq = seq;
1833 
1834 	_spdk_blob_request_submit_op_split_next(ctx, 0);
1835 }
1836 
1837 static void
1838 _spdk_blob_request_submit_op_single(struct spdk_io_channel *_ch, struct spdk_blob *blob,
1839 				    void *payload, uint64_t offset, uint64_t length,
1840 				    spdk_blob_op_complete cb_fn, void *cb_arg, enum spdk_blob_op_type op_type)
1841 {
1842 	struct spdk_bs_cpl cpl;
1843 	uint64_t lba;
1844 	uint32_t lba_count;
1845 
1846 	assert(blob != NULL);
1847 
1848 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
1849 	cpl.u.blob_basic.cb_fn = cb_fn;
1850 	cpl.u.blob_basic.cb_arg = cb_arg;
1851 
1852 	_spdk_blob_calculate_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
1853 
1854 	if (blob->frozen_refcnt) {
1855 		/* This blob I/O is frozen */
1856 		spdk_bs_user_op_t *op;
1857 		struct spdk_bs_channel *bs_channel = spdk_io_channel_get_ctx(_ch);
1858 
1859 		op = spdk_bs_user_op_alloc(_ch, &cpl, op_type, blob, payload, 0, offset, length);
1860 		if (!op) {
1861 			cb_fn(cb_arg, -ENOMEM);
1862 			return;
1863 		}
1864 
1865 		TAILQ_INSERT_TAIL(&bs_channel->queued_io, op, link);
1866 
1867 		return;
1868 	}
1869 
1870 	switch (op_type) {
1871 	case SPDK_BLOB_READ: {
1872 		spdk_bs_batch_t *batch;
1873 
1874 		batch = spdk_bs_batch_open(_ch, &cpl);
1875 		if (!batch) {
1876 			cb_fn(cb_arg, -ENOMEM);
1877 			return;
1878 		}
1879 
1880 		if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
1881 			/* Read from the blob */
1882 			spdk_bs_batch_read_dev(batch, payload, lba, lba_count);
1883 		} else {
1884 			/* Read from the backing block device */
1885 			spdk_bs_batch_read_bs_dev(batch, blob->back_bs_dev, payload, lba, lba_count);
1886 		}
1887 
1888 		spdk_bs_batch_close(batch);
1889 		break;
1890 	}
1891 	case SPDK_BLOB_WRITE:
1892 	case SPDK_BLOB_WRITE_ZEROES: {
1893 		if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
1894 			/* Write to the blob */
1895 			spdk_bs_batch_t *batch;
1896 
1897 			if (lba_count == 0) {
1898 				cb_fn(cb_arg, 0);
1899 				return;
1900 			}
1901 
1902 			batch = spdk_bs_batch_open(_ch, &cpl);
1903 			if (!batch) {
1904 				cb_fn(cb_arg, -ENOMEM);
1905 				return;
1906 			}
1907 
1908 			if (op_type == SPDK_BLOB_WRITE) {
1909 				spdk_bs_batch_write_dev(batch, payload, lba, lba_count);
1910 			} else {
1911 				spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1912 			}
1913 
1914 			spdk_bs_batch_close(batch);
1915 		} else {
1916 			/* Queue this operation and allocate the cluster */
1917 			spdk_bs_user_op_t *op;
1918 
1919 			op = spdk_bs_user_op_alloc(_ch, &cpl, op_type, blob, payload, 0, offset, length);
1920 			if (!op) {
1921 				cb_fn(cb_arg, -ENOMEM);
1922 				return;
1923 			}
1924 
1925 			_spdk_bs_allocate_and_copy_cluster(blob, _ch, offset, op);
1926 		}
1927 		break;
1928 	}
1929 	case SPDK_BLOB_UNMAP: {
1930 		spdk_bs_batch_t *batch;
1931 
1932 		batch = spdk_bs_batch_open(_ch, &cpl);
1933 		if (!batch) {
1934 			cb_fn(cb_arg, -ENOMEM);
1935 			return;
1936 		}
1937 
1938 		if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
1939 			spdk_bs_batch_unmap_dev(batch, lba, lba_count);
1940 		}
1941 
1942 		spdk_bs_batch_close(batch);
1943 		break;
1944 	}
1945 	case SPDK_BLOB_READV:
1946 	case SPDK_BLOB_WRITEV:
1947 		SPDK_ERRLOG("readv/write not valid\n");
1948 		cb_fn(cb_arg, -EINVAL);
1949 		break;
1950 	}
1951 }
1952 
1953 static void
1954 _spdk_blob_request_submit_op(struct spdk_blob *blob, struct spdk_io_channel *_channel,
1955 			     void *payload, uint64_t offset, uint64_t length,
1956 			     spdk_blob_op_complete cb_fn, void *cb_arg, enum spdk_blob_op_type op_type)
1957 {
1958 	assert(blob != NULL);
1959 
1960 	if (blob->data_ro && op_type != SPDK_BLOB_READ) {
1961 		cb_fn(cb_arg, -EPERM);
1962 		return;
1963 	}
1964 
1965 	if (offset + length > _spdk_bs_cluster_to_lba(blob->bs, blob->active.num_clusters)) {
1966 		cb_fn(cb_arg, -EINVAL);
1967 		return;
1968 	}
1969 	if (length <= _spdk_bs_num_io_units_to_cluster_boundary(blob, offset)) {
1970 		_spdk_blob_request_submit_op_single(_channel, blob, payload, offset, length,
1971 						    cb_fn, cb_arg, op_type);
1972 	} else {
1973 		_spdk_blob_request_submit_op_split(_channel, blob, payload, offset, length,
1974 						   cb_fn, cb_arg, op_type);
1975 	}
1976 }
1977 
1978 struct rw_iov_ctx {
1979 	struct spdk_blob *blob;
1980 	struct spdk_io_channel *channel;
1981 	spdk_blob_op_complete cb_fn;
1982 	void *cb_arg;
1983 	bool read;
1984 	int iovcnt;
1985 	struct iovec *orig_iov;
1986 	uint64_t io_unit_offset;
1987 	uint64_t io_units_remaining;
1988 	uint64_t io_units_done;
1989 	struct iovec iov[0];
1990 };
1991 
1992 static void
1993 _spdk_rw_iov_done(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1994 {
1995 	assert(cb_arg == NULL);
1996 	spdk_bs_sequence_finish(seq, bserrno);
1997 }
1998 
1999 static void
2000 _spdk_rw_iov_split_next(void *cb_arg, int bserrno)
2001 {
2002 	struct rw_iov_ctx *ctx = cb_arg;
2003 	struct spdk_blob *blob = ctx->blob;
2004 	struct iovec *iov, *orig_iov;
2005 	int iovcnt;
2006 	size_t orig_iovoff;
2007 	uint64_t io_units_count, io_units_to_boundary, io_unit_offset;
2008 	uint64_t byte_count;
2009 
2010 	if (bserrno != 0 || ctx->io_units_remaining == 0) {
2011 		ctx->cb_fn(ctx->cb_arg, bserrno);
2012 		free(ctx);
2013 		return;
2014 	}
2015 
2016 	io_unit_offset = ctx->io_unit_offset;
2017 	io_units_to_boundary = _spdk_bs_num_io_units_to_cluster_boundary(blob, io_unit_offset);
2018 	io_units_count = spdk_min(ctx->io_units_remaining, io_units_to_boundary);
2019 	/*
2020 	 * Get index and offset into the original iov array for our current position in the I/O sequence.
2021 	 *  byte_count will keep track of how many bytes remaining until orig_iov and orig_iovoff will
2022 	 *  point to the current position in the I/O sequence.
2023 	 */
2024 	byte_count = ctx->io_units_done * blob->bs->io_unit_size;
2025 	orig_iov = &ctx->orig_iov[0];
2026 	orig_iovoff = 0;
2027 	while (byte_count > 0) {
2028 		if (byte_count >= orig_iov->iov_len) {
2029 			byte_count -= orig_iov->iov_len;
2030 			orig_iov++;
2031 		} else {
2032 			orig_iovoff = byte_count;
2033 			byte_count = 0;
2034 		}
2035 	}
2036 
2037 	/*
2038 	 * Build an iov array for the next I/O in the sequence.  byte_count will keep track of how many
2039 	 *  bytes of this next I/O remain to be accounted for in the new iov array.
2040 	 */
2041 	byte_count = io_units_count * blob->bs->io_unit_size;
2042 	iov = &ctx->iov[0];
2043 	iovcnt = 0;
2044 	while (byte_count > 0) {
2045 		assert(iovcnt < ctx->iovcnt);
2046 		iov->iov_len = spdk_min(byte_count, orig_iov->iov_len - orig_iovoff);
2047 		iov->iov_base = orig_iov->iov_base + orig_iovoff;
2048 		byte_count -= iov->iov_len;
2049 		orig_iovoff = 0;
2050 		orig_iov++;
2051 		iov++;
2052 		iovcnt++;
2053 	}
2054 
2055 	ctx->io_unit_offset += io_units_count;
2056 	ctx->io_units_remaining -= io_units_count;
2057 	ctx->io_units_done += io_units_count;
2058 	iov = &ctx->iov[0];
2059 
2060 	if (ctx->read) {
2061 		spdk_blob_io_readv(ctx->blob, ctx->channel, iov, iovcnt, io_unit_offset,
2062 				   io_units_count, _spdk_rw_iov_split_next, ctx);
2063 	} else {
2064 		spdk_blob_io_writev(ctx->blob, ctx->channel, iov, iovcnt, io_unit_offset,
2065 				    io_units_count, _spdk_rw_iov_split_next, ctx);
2066 	}
2067 }
2068 
2069 static void
2070 _spdk_blob_request_submit_rw_iov(struct spdk_blob *blob, struct spdk_io_channel *_channel,
2071 				 struct iovec *iov, int iovcnt, uint64_t offset, uint64_t length,
2072 				 spdk_blob_op_complete cb_fn, void *cb_arg, bool read)
2073 {
2074 	struct spdk_bs_cpl	cpl;
2075 
2076 	assert(blob != NULL);
2077 
2078 	if (!read && blob->data_ro) {
2079 		cb_fn(cb_arg, -EPERM);
2080 		return;
2081 	}
2082 
2083 	if (length == 0) {
2084 		cb_fn(cb_arg, 0);
2085 		return;
2086 	}
2087 
2088 	if (offset + length > _spdk_bs_cluster_to_lba(blob->bs, blob->active.num_clusters)) {
2089 		cb_fn(cb_arg, -EINVAL);
2090 		return;
2091 	}
2092 
2093 	/*
2094 	 * For now, we implement readv/writev using a sequence (instead of a batch) to account for having
2095 	 *  to split a request that spans a cluster boundary.  For I/O that do not span a cluster boundary,
2096 	 *  there will be no noticeable difference compared to using a batch.  For I/O that do span a cluster
2097 	 *  boundary, the target LBAs (after blob offset to LBA translation) may not be contiguous, so we need
2098 	 *  to allocate a separate iov array and split the I/O such that none of the resulting
2099 	 *  smaller I/O cross a cluster boundary.  These smaller I/O will be issued in sequence (not in parallel)
2100 	 *  but since this case happens very infrequently, any performance impact will be negligible.
2101 	 *
2102 	 * This could be optimized in the future to allocate a big enough iov array to account for all of the iovs
2103 	 *  for all of the smaller I/Os, pre-build all of the iov arrays for the smaller I/Os, then issue them
2104 	 *  in a batch.  That would also require creating an intermediate spdk_bs_cpl that would get called
2105 	 *  when the batch was completed, to allow for freeing the memory for the iov arrays.
2106 	 */
2107 	if (spdk_likely(length <= _spdk_bs_num_io_units_to_cluster_boundary(blob, offset))) {
2108 		uint32_t lba_count;
2109 		uint64_t lba;
2110 
2111 		_spdk_blob_calculate_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
2112 
2113 		cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
2114 		cpl.u.blob_basic.cb_fn = cb_fn;
2115 		cpl.u.blob_basic.cb_arg = cb_arg;
2116 		if (blob->frozen_refcnt) {
2117 			/* This blob I/O is frozen */
2118 			spdk_bs_user_op_t *op;
2119 			struct spdk_bs_channel *bs_channel = spdk_io_channel_get_ctx(_channel);
2120 
2121 			op = spdk_bs_user_op_alloc(_channel, &cpl, read, blob, iov, iovcnt, offset, length);
2122 			if (!op) {
2123 				cb_fn(cb_arg, -ENOMEM);
2124 				return;
2125 			}
2126 
2127 			TAILQ_INSERT_TAIL(&bs_channel->queued_io, op, link);
2128 
2129 			return;
2130 		}
2131 
2132 		if (read) {
2133 			spdk_bs_sequence_t *seq;
2134 
2135 			seq = spdk_bs_sequence_start(_channel, &cpl);
2136 			if (!seq) {
2137 				cb_fn(cb_arg, -ENOMEM);
2138 				return;
2139 			}
2140 
2141 			if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
2142 				spdk_bs_sequence_readv_dev(seq, iov, iovcnt, lba, lba_count, _spdk_rw_iov_done, NULL);
2143 			} else {
2144 				spdk_bs_sequence_readv_bs_dev(seq, blob->back_bs_dev, iov, iovcnt, lba, lba_count,
2145 							      _spdk_rw_iov_done, NULL);
2146 			}
2147 		} else {
2148 			if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
2149 				spdk_bs_sequence_t *seq;
2150 
2151 				seq = spdk_bs_sequence_start(_channel, &cpl);
2152 				if (!seq) {
2153 					cb_fn(cb_arg, -ENOMEM);
2154 					return;
2155 				}
2156 
2157 				spdk_bs_sequence_writev_dev(seq, iov, iovcnt, lba, lba_count, _spdk_rw_iov_done, NULL);
2158 			} else {
2159 				/* Queue this operation and allocate the cluster */
2160 				spdk_bs_user_op_t *op;
2161 
2162 				op = spdk_bs_user_op_alloc(_channel, &cpl, SPDK_BLOB_WRITEV, blob, iov, iovcnt, offset,
2163 							   length);
2164 				if (!op) {
2165 					cb_fn(cb_arg, -ENOMEM);
2166 					return;
2167 				}
2168 
2169 				_spdk_bs_allocate_and_copy_cluster(blob, _channel, offset, op);
2170 			}
2171 		}
2172 	} else {
2173 		struct rw_iov_ctx *ctx;
2174 
2175 		ctx = calloc(1, sizeof(struct rw_iov_ctx) + iovcnt * sizeof(struct iovec));
2176 		if (ctx == NULL) {
2177 			cb_fn(cb_arg, -ENOMEM);
2178 			return;
2179 		}
2180 
2181 		ctx->blob = blob;
2182 		ctx->channel = _channel;
2183 		ctx->cb_fn = cb_fn;
2184 		ctx->cb_arg = cb_arg;
2185 		ctx->read = read;
2186 		ctx->orig_iov = iov;
2187 		ctx->iovcnt = iovcnt;
2188 		ctx->io_unit_offset = offset;
2189 		ctx->io_units_remaining = length;
2190 		ctx->io_units_done = 0;
2191 
2192 		_spdk_rw_iov_split_next(ctx, 0);
2193 	}
2194 }
2195 
2196 static struct spdk_blob *
2197 _spdk_blob_lookup(struct spdk_blob_store *bs, spdk_blob_id blobid)
2198 {
2199 	struct spdk_blob *blob;
2200 
2201 	TAILQ_FOREACH(blob, &bs->blobs, link) {
2202 		if (blob->id == blobid) {
2203 			return blob;
2204 		}
2205 	}
2206 
2207 	return NULL;
2208 }
2209 
2210 static int
2211 _spdk_bs_channel_create(void *io_device, void *ctx_buf)
2212 {
2213 	struct spdk_blob_store		*bs = io_device;
2214 	struct spdk_bs_channel		*channel = ctx_buf;
2215 	struct spdk_bs_dev		*dev;
2216 	uint32_t			max_ops = bs->max_channel_ops;
2217 	uint32_t			i;
2218 
2219 	dev = bs->dev;
2220 
2221 	channel->req_mem = calloc(max_ops, sizeof(struct spdk_bs_request_set));
2222 	if (!channel->req_mem) {
2223 		return -1;
2224 	}
2225 
2226 	TAILQ_INIT(&channel->reqs);
2227 
2228 	for (i = 0; i < max_ops; i++) {
2229 		TAILQ_INSERT_TAIL(&channel->reqs, &channel->req_mem[i], link);
2230 	}
2231 
2232 	channel->bs = bs;
2233 	channel->dev = dev;
2234 	channel->dev_channel = dev->create_channel(dev);
2235 
2236 	if (!channel->dev_channel) {
2237 		SPDK_ERRLOG("Failed to create device channel.\n");
2238 		free(channel->req_mem);
2239 		return -1;
2240 	}
2241 
2242 	TAILQ_INIT(&channel->need_cluster_alloc);
2243 	TAILQ_INIT(&channel->queued_io);
2244 
2245 	return 0;
2246 }
2247 
2248 static void
2249 _spdk_bs_channel_destroy(void *io_device, void *ctx_buf)
2250 {
2251 	struct spdk_bs_channel *channel = ctx_buf;
2252 	spdk_bs_user_op_t *op;
2253 
2254 	while (!TAILQ_EMPTY(&channel->need_cluster_alloc)) {
2255 		op = TAILQ_FIRST(&channel->need_cluster_alloc);
2256 		TAILQ_REMOVE(&channel->need_cluster_alloc, op, link);
2257 		spdk_bs_user_op_abort(op);
2258 	}
2259 
2260 	while (!TAILQ_EMPTY(&channel->queued_io)) {
2261 		op = TAILQ_FIRST(&channel->queued_io);
2262 		TAILQ_REMOVE(&channel->queued_io, op, link);
2263 		spdk_bs_user_op_abort(op);
2264 	}
2265 
2266 	free(channel->req_mem);
2267 	channel->dev->destroy_channel(channel->dev, channel->dev_channel);
2268 }
2269 
2270 static void
2271 _spdk_bs_dev_destroy(void *io_device)
2272 {
2273 	struct spdk_blob_store *bs = io_device;
2274 	struct spdk_blob	*blob, *blob_tmp;
2275 
2276 	bs->dev->destroy(bs->dev);
2277 
2278 	TAILQ_FOREACH_SAFE(blob, &bs->blobs, link, blob_tmp) {
2279 		TAILQ_REMOVE(&bs->blobs, blob, link);
2280 		_spdk_blob_free(blob);
2281 	}
2282 
2283 	pthread_mutex_destroy(&bs->used_clusters_mutex);
2284 
2285 	spdk_bit_array_free(&bs->used_blobids);
2286 	spdk_bit_array_free(&bs->used_md_pages);
2287 	spdk_bit_array_free(&bs->used_clusters);
2288 	/*
2289 	 * If this function is called for any reason except a successful unload,
2290 	 * the unload_cpl type will be NONE and this will be a nop.
2291 	 */
2292 	spdk_bs_call_cpl(&bs->unload_cpl, bs->unload_err);
2293 
2294 	free(bs);
2295 }
2296 
2297 static int
2298 _spdk_bs_blob_list_add(struct spdk_blob *blob)
2299 {
2300 	spdk_blob_id snapshot_id;
2301 	struct spdk_blob_list *snapshot_entry = NULL;
2302 	struct spdk_blob_list *clone_entry = NULL;
2303 
2304 	assert(blob != NULL);
2305 
2306 	snapshot_id = blob->parent_id;
2307 	if (snapshot_id == SPDK_BLOBID_INVALID) {
2308 		return 0;
2309 	}
2310 
2311 	TAILQ_FOREACH(snapshot_entry, &blob->bs->snapshots, link) {
2312 		if (snapshot_entry->id == snapshot_id) {
2313 			break;
2314 		}
2315 	}
2316 
2317 	if (snapshot_entry == NULL) {
2318 		/* Snapshot not found */
2319 		snapshot_entry = calloc(1, sizeof(struct spdk_blob_list));
2320 		if (snapshot_entry == NULL) {
2321 			return -ENOMEM;
2322 		}
2323 		snapshot_entry->id = snapshot_id;
2324 		TAILQ_INIT(&snapshot_entry->clones);
2325 		TAILQ_INSERT_TAIL(&blob->bs->snapshots, snapshot_entry, link);
2326 	} else {
2327 		TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
2328 			if (clone_entry->id == blob->id) {
2329 				break;
2330 			}
2331 		}
2332 	}
2333 
2334 	if (clone_entry == NULL) {
2335 		/* Clone not found */
2336 		clone_entry = calloc(1, sizeof(struct spdk_blob_list));
2337 		if (clone_entry == NULL) {
2338 			return -ENOMEM;
2339 		}
2340 		clone_entry->id = blob->id;
2341 		TAILQ_INIT(&clone_entry->clones);
2342 		TAILQ_INSERT_TAIL(&snapshot_entry->clones, clone_entry, link);
2343 		snapshot_entry->clone_count++;
2344 	}
2345 
2346 	return 0;
2347 }
2348 
2349 static int
2350 _spdk_bs_blob_list_remove(struct spdk_blob *blob)
2351 {
2352 	struct spdk_blob_list *snapshot_entry = NULL;
2353 	struct spdk_blob_list *clone_entry = NULL;
2354 	spdk_blob_id snapshot_id;
2355 
2356 	assert(blob != NULL);
2357 
2358 	snapshot_id = blob->parent_id;
2359 	if (snapshot_id == SPDK_BLOBID_INVALID) {
2360 		return 0;
2361 	}
2362 
2363 	TAILQ_FOREACH(snapshot_entry, &blob->bs->snapshots, link) {
2364 		if (snapshot_entry->id == snapshot_id) {
2365 			break;
2366 		}
2367 	}
2368 
2369 	assert(snapshot_entry != NULL);
2370 
2371 	TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
2372 		if (clone_entry->id == blob->id) {
2373 			break;
2374 		}
2375 	}
2376 
2377 	assert(clone_entry != NULL);
2378 
2379 	blob->parent_id = SPDK_BLOBID_INVALID;
2380 	TAILQ_REMOVE(&snapshot_entry->clones, clone_entry, link);
2381 	free(clone_entry);
2382 
2383 	snapshot_entry->clone_count--;
2384 
2385 	return 0;
2386 }
2387 
2388 static int
2389 _spdk_bs_blob_list_free(struct spdk_blob_store *bs)
2390 {
2391 	struct spdk_blob_list *snapshot_entry;
2392 	struct spdk_blob_list *snapshot_entry_tmp;
2393 	struct spdk_blob_list *clone_entry;
2394 	struct spdk_blob_list *clone_entry_tmp;
2395 
2396 	TAILQ_FOREACH_SAFE(snapshot_entry, &bs->snapshots, link, snapshot_entry_tmp) {
2397 		TAILQ_FOREACH_SAFE(clone_entry, &snapshot_entry->clones, link, clone_entry_tmp) {
2398 			TAILQ_REMOVE(&snapshot_entry->clones, clone_entry, link);
2399 			free(clone_entry);
2400 		}
2401 		TAILQ_REMOVE(&bs->snapshots, snapshot_entry, link);
2402 		free(snapshot_entry);
2403 	}
2404 
2405 	return 0;
2406 }
2407 
2408 static void
2409 _spdk_bs_free(struct spdk_blob_store *bs)
2410 {
2411 	_spdk_bs_blob_list_free(bs);
2412 
2413 	spdk_bs_unregister_md_thread(bs);
2414 	spdk_io_device_unregister(bs, _spdk_bs_dev_destroy);
2415 }
2416 
2417 void
2418 spdk_bs_opts_init(struct spdk_bs_opts *opts)
2419 {
2420 	opts->cluster_sz = SPDK_BLOB_OPTS_CLUSTER_SZ;
2421 	opts->num_md_pages = SPDK_BLOB_OPTS_NUM_MD_PAGES;
2422 	opts->max_md_ops = SPDK_BLOB_OPTS_MAX_MD_OPS;
2423 	opts->max_channel_ops = SPDK_BLOB_OPTS_DEFAULT_CHANNEL_OPS;
2424 	opts->clear_method = BS_CLEAR_WITH_UNMAP;
2425 	memset(&opts->bstype, 0, sizeof(opts->bstype));
2426 	opts->iter_cb_fn = NULL;
2427 	opts->iter_cb_arg = NULL;
2428 }
2429 
2430 static int
2431 _spdk_bs_opts_verify(struct spdk_bs_opts *opts)
2432 {
2433 	if (opts->cluster_sz == 0 || opts->num_md_pages == 0 || opts->max_md_ops == 0 ||
2434 	    opts->max_channel_ops == 0) {
2435 		SPDK_ERRLOG("Blobstore options cannot be set to 0\n");
2436 		return -1;
2437 	}
2438 
2439 	return 0;
2440 }
2441 
2442 static int
2443 _spdk_bs_alloc(struct spdk_bs_dev *dev, struct spdk_bs_opts *opts, struct spdk_blob_store **_bs)
2444 {
2445 	struct spdk_blob_store	*bs;
2446 	uint64_t dev_size;
2447 	int rc;
2448 
2449 	dev_size = dev->blocklen * dev->blockcnt;
2450 	if (dev_size < opts->cluster_sz) {
2451 		/* Device size cannot be smaller than cluster size of blobstore */
2452 		SPDK_INFOLOG(SPDK_LOG_BLOB, "Device size %" PRIu64 " is smaller than cluster size %" PRIu32 "\n",
2453 			     dev_size, opts->cluster_sz);
2454 		return -ENOSPC;
2455 	}
2456 	if (opts->cluster_sz < SPDK_BS_PAGE_SIZE) {
2457 		/* Cluster size cannot be smaller than page size */
2458 		SPDK_ERRLOG("Cluster size %" PRIu32 " is smaller than page size %d\n",
2459 			    opts->cluster_sz, SPDK_BS_PAGE_SIZE);
2460 		return -EINVAL;
2461 	}
2462 	bs = calloc(1, sizeof(struct spdk_blob_store));
2463 	if (!bs) {
2464 		return -ENOMEM;
2465 	}
2466 
2467 	TAILQ_INIT(&bs->blobs);
2468 	TAILQ_INIT(&bs->snapshots);
2469 	bs->dev = dev;
2470 	bs->md_thread = spdk_get_thread();
2471 	assert(bs->md_thread != NULL);
2472 
2473 	/*
2474 	 * Do not use _spdk_bs_lba_to_cluster() here since blockcnt may not be an
2475 	 *  even multiple of the cluster size.
2476 	 */
2477 	bs->cluster_sz = opts->cluster_sz;
2478 	bs->total_clusters = dev->blockcnt / (bs->cluster_sz / dev->blocklen);
2479 	bs->pages_per_cluster = bs->cluster_sz / SPDK_BS_PAGE_SIZE;
2480 	bs->num_free_clusters = bs->total_clusters;
2481 	bs->used_clusters = spdk_bit_array_create(bs->total_clusters);
2482 	bs->io_unit_size = dev->blocklen;
2483 	if (bs->used_clusters == NULL) {
2484 		free(bs);
2485 		return -ENOMEM;
2486 	}
2487 
2488 	bs->max_channel_ops = opts->max_channel_ops;
2489 	bs->super_blob = SPDK_BLOBID_INVALID;
2490 	memcpy(&bs->bstype, &opts->bstype, sizeof(opts->bstype));
2491 
2492 	/* The metadata is assumed to be at least 1 page */
2493 	bs->used_md_pages = spdk_bit_array_create(1);
2494 	bs->used_blobids = spdk_bit_array_create(0);
2495 
2496 	pthread_mutex_init(&bs->used_clusters_mutex, NULL);
2497 
2498 	spdk_io_device_register(bs, _spdk_bs_channel_create, _spdk_bs_channel_destroy,
2499 				sizeof(struct spdk_bs_channel), "blobstore");
2500 	rc = spdk_bs_register_md_thread(bs);
2501 	if (rc == -1) {
2502 		spdk_io_device_unregister(bs, NULL);
2503 		pthread_mutex_destroy(&bs->used_clusters_mutex);
2504 		spdk_bit_array_free(&bs->used_blobids);
2505 		spdk_bit_array_free(&bs->used_md_pages);
2506 		spdk_bit_array_free(&bs->used_clusters);
2507 		free(bs);
2508 		/* FIXME: this is a lie but don't know how to get a proper error code here */
2509 		return -ENOMEM;
2510 	}
2511 
2512 	*_bs = bs;
2513 	return 0;
2514 }
2515 
2516 /* START spdk_bs_load, spdk_bs_load_ctx will used for both load and unload. */
2517 
2518 struct spdk_bs_load_ctx {
2519 	struct spdk_blob_store		*bs;
2520 	struct spdk_bs_super_block	*super;
2521 
2522 	struct spdk_bs_md_mask		*mask;
2523 	bool				in_page_chain;
2524 	uint32_t			page_index;
2525 	uint32_t			cur_page;
2526 	struct spdk_blob_md_page	*page;
2527 
2528 	spdk_bs_sequence_t			*seq;
2529 	spdk_blob_op_with_handle_complete	iter_cb_fn;
2530 	void					*iter_cb_arg;
2531 };
2532 
2533 static void
2534 _spdk_bs_load_ctx_fail(spdk_bs_sequence_t *seq, struct spdk_bs_load_ctx *ctx, int bserrno)
2535 {
2536 	assert(bserrno != 0);
2537 
2538 	spdk_dma_free(ctx->super);
2539 	spdk_bs_sequence_finish(seq, bserrno);
2540 	_spdk_bs_free(ctx->bs);
2541 	free(ctx);
2542 }
2543 
2544 static void
2545 _spdk_bs_set_mask(struct spdk_bit_array *array, struct spdk_bs_md_mask *mask)
2546 {
2547 	uint32_t i = 0;
2548 
2549 	while (true) {
2550 		i = spdk_bit_array_find_first_set(array, i);
2551 		if (i >= mask->length) {
2552 			break;
2553 		}
2554 		mask->mask[i / 8] |= 1U << (i % 8);
2555 		i++;
2556 	}
2557 }
2558 
2559 static int
2560 _spdk_bs_load_mask(struct spdk_bit_array **array_ptr, struct spdk_bs_md_mask *mask)
2561 {
2562 	struct spdk_bit_array *array;
2563 	uint32_t i;
2564 
2565 	if (spdk_bit_array_resize(array_ptr, mask->length) < 0) {
2566 		return -ENOMEM;
2567 	}
2568 
2569 	array = *array_ptr;
2570 	for (i = 0; i < mask->length; i++) {
2571 		if (mask->mask[i / 8] & (1U << (i % 8))) {
2572 			spdk_bit_array_set(array, i);
2573 		}
2574 	}
2575 
2576 	return 0;
2577 }
2578 
2579 static void
2580 _spdk_bs_write_super(spdk_bs_sequence_t *seq, struct spdk_blob_store *bs,
2581 		     struct spdk_bs_super_block *super, spdk_bs_sequence_cpl cb_fn, void *cb_arg)
2582 {
2583 	/* Update the values in the super block */
2584 	super->super_blob = bs->super_blob;
2585 	memcpy(&super->bstype, &bs->bstype, sizeof(bs->bstype));
2586 	super->crc = _spdk_blob_md_page_calc_crc(super);
2587 	spdk_bs_sequence_write_dev(seq, super, _spdk_bs_page_to_lba(bs, 0),
2588 				   _spdk_bs_byte_to_lba(bs, sizeof(*super)),
2589 				   cb_fn, cb_arg);
2590 }
2591 
2592 static void
2593 _spdk_bs_write_used_clusters(spdk_bs_sequence_t *seq, void *arg, spdk_bs_sequence_cpl cb_fn)
2594 {
2595 	struct spdk_bs_load_ctx	*ctx = arg;
2596 	uint64_t	mask_size, lba, lba_count;
2597 
2598 	/* Write out the used clusters mask */
2599 	mask_size = ctx->super->used_cluster_mask_len * SPDK_BS_PAGE_SIZE;
2600 	ctx->mask = spdk_dma_zmalloc(mask_size, 0x1000, NULL);
2601 	if (!ctx->mask) {
2602 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
2603 		return;
2604 	}
2605 
2606 	ctx->mask->type = SPDK_MD_MASK_TYPE_USED_CLUSTERS;
2607 	ctx->mask->length = ctx->bs->total_clusters;
2608 	assert(ctx->mask->length == spdk_bit_array_capacity(ctx->bs->used_clusters));
2609 
2610 	_spdk_bs_set_mask(ctx->bs->used_clusters, ctx->mask);
2611 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_start);
2612 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_len);
2613 	spdk_bs_sequence_write_dev(seq, ctx->mask, lba, lba_count, cb_fn, arg);
2614 }
2615 
2616 static void
2617 _spdk_bs_write_used_md(spdk_bs_sequence_t *seq, void *arg, spdk_bs_sequence_cpl cb_fn)
2618 {
2619 	struct spdk_bs_load_ctx	*ctx = arg;
2620 	uint64_t	mask_size, lba, lba_count;
2621 
2622 	if (seq->bserrno) {
2623 		_spdk_bs_load_ctx_fail(seq, ctx, seq->bserrno);
2624 		return;
2625 	}
2626 
2627 	mask_size = ctx->super->used_page_mask_len * SPDK_BS_PAGE_SIZE;
2628 	ctx->mask = spdk_dma_zmalloc(mask_size, 0x1000, NULL);
2629 	if (!ctx->mask) {
2630 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
2631 		return;
2632 	}
2633 
2634 	ctx->mask->type = SPDK_MD_MASK_TYPE_USED_PAGES;
2635 	ctx->mask->length = ctx->super->md_len;
2636 	assert(ctx->mask->length == spdk_bit_array_capacity(ctx->bs->used_md_pages));
2637 
2638 	_spdk_bs_set_mask(ctx->bs->used_md_pages, ctx->mask);
2639 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_start);
2640 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_len);
2641 	spdk_bs_sequence_write_dev(seq, ctx->mask, lba, lba_count, cb_fn, arg);
2642 }
2643 
2644 static void
2645 _spdk_bs_write_used_blobids(spdk_bs_sequence_t *seq, void *arg, spdk_bs_sequence_cpl cb_fn)
2646 {
2647 	struct spdk_bs_load_ctx	*ctx = arg;
2648 	uint64_t	mask_size, lba, lba_count;
2649 
2650 	if (ctx->super->used_blobid_mask_len == 0) {
2651 		/*
2652 		 * This is a pre-v3 on-disk format where the blobid mask does not get
2653 		 *  written to disk.
2654 		 */
2655 		cb_fn(seq, arg, 0);
2656 		return;
2657 	}
2658 
2659 	mask_size = ctx->super->used_blobid_mask_len * SPDK_BS_PAGE_SIZE;
2660 	ctx->mask = spdk_dma_zmalloc(mask_size, 0x1000, NULL);
2661 	if (!ctx->mask) {
2662 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
2663 		return;
2664 	}
2665 
2666 	ctx->mask->type = SPDK_MD_MASK_TYPE_USED_BLOBIDS;
2667 	ctx->mask->length = ctx->super->md_len;
2668 	assert(ctx->mask->length == spdk_bit_array_capacity(ctx->bs->used_blobids));
2669 
2670 	_spdk_bs_set_mask(ctx->bs->used_blobids, ctx->mask);
2671 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_start);
2672 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_len);
2673 	spdk_bs_sequence_write_dev(seq, ctx->mask, lba, lba_count, cb_fn, arg);
2674 }
2675 
2676 static void
2677 _spdk_bs_load_iter(void *arg, struct spdk_blob *blob, int bserrno)
2678 {
2679 	struct spdk_bs_load_ctx *ctx = arg;
2680 
2681 	if (bserrno == 0) {
2682 		if (ctx->iter_cb_fn) {
2683 			ctx->iter_cb_fn(ctx->iter_cb_arg, blob, 0);
2684 		}
2685 		_spdk_bs_blob_list_add(blob);
2686 		spdk_bs_iter_next(ctx->bs, blob, _spdk_bs_load_iter, ctx);
2687 		return;
2688 	}
2689 
2690 	if (bserrno == -ENOENT) {
2691 		bserrno = 0;
2692 	} else {
2693 		/*
2694 		 * This case needs to be looked at further.  Same problem
2695 		 *  exists with applications that rely on explicit blob
2696 		 *  iteration.  We should just skip the blob that failed
2697 		 *  to load and continue on to the next one.
2698 		 */
2699 		SPDK_ERRLOG("Error in iterating blobs\n");
2700 	}
2701 
2702 	ctx->iter_cb_fn = NULL;
2703 
2704 	spdk_dma_free(ctx->super);
2705 	spdk_dma_free(ctx->mask);
2706 	spdk_bs_sequence_finish(ctx->seq, bserrno);
2707 	free(ctx);
2708 }
2709 
2710 static void
2711 _spdk_bs_load_complete(spdk_bs_sequence_t *seq, struct spdk_bs_load_ctx *ctx, int bserrno)
2712 {
2713 	ctx->seq = seq;
2714 	spdk_bs_iter_first(ctx->bs, _spdk_bs_load_iter, ctx);
2715 }
2716 
2717 static void
2718 _spdk_bs_load_used_blobids_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2719 {
2720 	struct spdk_bs_load_ctx *ctx = cb_arg;
2721 	int rc;
2722 
2723 	/* The type must be correct */
2724 	assert(ctx->mask->type == SPDK_MD_MASK_TYPE_USED_BLOBIDS);
2725 
2726 	/* The length of the mask (in bits) must not be greater than
2727 	 * the length of the buffer (converted to bits) */
2728 	assert(ctx->mask->length <= (ctx->super->used_blobid_mask_len * SPDK_BS_PAGE_SIZE * 8));
2729 
2730 	/* The length of the mask must be exactly equal to the size
2731 	 * (in pages) of the metadata region */
2732 	assert(ctx->mask->length == ctx->super->md_len);
2733 
2734 	rc = _spdk_bs_load_mask(&ctx->bs->used_blobids, ctx->mask);
2735 	if (rc < 0) {
2736 		spdk_dma_free(ctx->mask);
2737 		_spdk_bs_load_ctx_fail(seq, ctx, rc);
2738 		return;
2739 	}
2740 
2741 	_spdk_bs_load_complete(seq, ctx, bserrno);
2742 }
2743 
2744 static void
2745 _spdk_bs_load_used_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2746 {
2747 	struct spdk_bs_load_ctx *ctx = cb_arg;
2748 	uint64_t		lba, lba_count, mask_size;
2749 	int			rc;
2750 
2751 	/* The type must be correct */
2752 	assert(ctx->mask->type == SPDK_MD_MASK_TYPE_USED_CLUSTERS);
2753 	/* The length of the mask (in bits) must not be greater than the length of the buffer (converted to bits) */
2754 	assert(ctx->mask->length <= (ctx->super->used_cluster_mask_len * sizeof(
2755 					     struct spdk_blob_md_page) * 8));
2756 	/* The length of the mask must be exactly equal to the total number of clusters */
2757 	assert(ctx->mask->length == ctx->bs->total_clusters);
2758 
2759 	rc = _spdk_bs_load_mask(&ctx->bs->used_clusters, ctx->mask);
2760 	if (rc < 0) {
2761 		spdk_dma_free(ctx->mask);
2762 		_spdk_bs_load_ctx_fail(seq, ctx, rc);
2763 		return;
2764 	}
2765 
2766 	ctx->bs->num_free_clusters = spdk_bit_array_count_clear(ctx->bs->used_clusters);
2767 	assert(ctx->bs->num_free_clusters <= ctx->bs->total_clusters);
2768 
2769 	spdk_dma_free(ctx->mask);
2770 
2771 	/* Read the used blobids mask */
2772 	mask_size = ctx->super->used_blobid_mask_len * SPDK_BS_PAGE_SIZE;
2773 	ctx->mask = spdk_dma_zmalloc(mask_size, 0x1000, NULL);
2774 	if (!ctx->mask) {
2775 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
2776 		return;
2777 	}
2778 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_start);
2779 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_len);
2780 	spdk_bs_sequence_read_dev(seq, ctx->mask, lba, lba_count,
2781 				  _spdk_bs_load_used_blobids_cpl, ctx);
2782 }
2783 
2784 static void
2785 _spdk_bs_load_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2786 {
2787 	struct spdk_bs_load_ctx *ctx = cb_arg;
2788 	uint64_t		lba, lba_count, mask_size;
2789 	int			rc;
2790 
2791 	/* The type must be correct */
2792 	assert(ctx->mask->type == SPDK_MD_MASK_TYPE_USED_PAGES);
2793 	/* The length of the mask (in bits) must not be greater than the length of the buffer (converted to bits) */
2794 	assert(ctx->mask->length <= (ctx->super->used_page_mask_len * SPDK_BS_PAGE_SIZE *
2795 				     8));
2796 	/* The length of the mask must be exactly equal to the size (in pages) of the metadata region */
2797 	assert(ctx->mask->length == ctx->super->md_len);
2798 
2799 	rc = _spdk_bs_load_mask(&ctx->bs->used_md_pages, ctx->mask);
2800 	if (rc < 0) {
2801 		spdk_dma_free(ctx->mask);
2802 		_spdk_bs_load_ctx_fail(seq, ctx, rc);
2803 		return;
2804 	}
2805 
2806 	spdk_dma_free(ctx->mask);
2807 
2808 	/* Read the used clusters mask */
2809 	mask_size = ctx->super->used_cluster_mask_len * SPDK_BS_PAGE_SIZE;
2810 	ctx->mask = spdk_dma_zmalloc(mask_size, 0x1000, NULL);
2811 	if (!ctx->mask) {
2812 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
2813 		return;
2814 	}
2815 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_start);
2816 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_len);
2817 	spdk_bs_sequence_read_dev(seq, ctx->mask, lba, lba_count,
2818 				  _spdk_bs_load_used_clusters_cpl, ctx);
2819 }
2820 
2821 static void
2822 _spdk_bs_load_read_used_pages(spdk_bs_sequence_t *seq, void *cb_arg)
2823 {
2824 	struct spdk_bs_load_ctx	*ctx = cb_arg;
2825 	uint64_t lba, lba_count, mask_size;
2826 
2827 	/* Read the used pages mask */
2828 	mask_size = ctx->super->used_page_mask_len * SPDK_BS_PAGE_SIZE;
2829 	ctx->mask = spdk_dma_zmalloc(mask_size, 0x1000, NULL);
2830 	if (!ctx->mask) {
2831 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
2832 		return;
2833 	}
2834 
2835 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_start);
2836 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_len);
2837 	spdk_bs_sequence_read_dev(seq, ctx->mask, lba, lba_count,
2838 				  _spdk_bs_load_used_pages_cpl, ctx);
2839 }
2840 
2841 static int
2842 _spdk_bs_load_replay_md_parse_page(const struct spdk_blob_md_page *page, struct spdk_blob_store *bs)
2843 {
2844 	struct spdk_blob_md_descriptor *desc;
2845 	size_t	cur_desc = 0;
2846 
2847 	desc = (struct spdk_blob_md_descriptor *)page->descriptors;
2848 	while (cur_desc < sizeof(page->descriptors)) {
2849 		if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_PADDING) {
2850 			if (desc->length == 0) {
2851 				/* If padding and length are 0, this terminates the page */
2852 				break;
2853 			}
2854 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_EXTENT) {
2855 			struct spdk_blob_md_descriptor_extent	*desc_extent;
2856 			unsigned int				i, j;
2857 			unsigned int				cluster_count = 0;
2858 			uint32_t				cluster_idx;
2859 
2860 			desc_extent = (struct spdk_blob_md_descriptor_extent *)desc;
2861 
2862 			for (i = 0; i < desc_extent->length / sizeof(desc_extent->extents[0]); i++) {
2863 				for (j = 0; j < desc_extent->extents[i].length; j++) {
2864 					cluster_idx = desc_extent->extents[i].cluster_idx;
2865 					/*
2866 					 * cluster_idx = 0 means an unallocated cluster - don't mark that
2867 					 * in the used cluster map.
2868 					 */
2869 					if (cluster_idx != 0) {
2870 						spdk_bit_array_set(bs->used_clusters, cluster_idx + j);
2871 						if (bs->num_free_clusters == 0) {
2872 							return -ENOSPC;
2873 						}
2874 						bs->num_free_clusters--;
2875 					}
2876 					cluster_count++;
2877 				}
2878 			}
2879 			if (cluster_count == 0) {
2880 				return -EINVAL;
2881 			}
2882 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR) {
2883 			/* Skip this item */
2884 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL) {
2885 			/* Skip this item */
2886 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_FLAGS) {
2887 			/* Skip this item */
2888 		} else {
2889 			/* Error */
2890 			return -EINVAL;
2891 		}
2892 		/* Advance to the next descriptor */
2893 		cur_desc += sizeof(*desc) + desc->length;
2894 		if (cur_desc + sizeof(*desc) > sizeof(page->descriptors)) {
2895 			break;
2896 		}
2897 		desc = (struct spdk_blob_md_descriptor *)((uintptr_t)page->descriptors + cur_desc);
2898 	}
2899 	return 0;
2900 }
2901 
2902 static bool _spdk_bs_load_cur_md_page_valid(struct spdk_bs_load_ctx *ctx)
2903 {
2904 	uint32_t crc;
2905 
2906 	crc = _spdk_blob_md_page_calc_crc(ctx->page);
2907 	if (crc != ctx->page->crc) {
2908 		return false;
2909 	}
2910 
2911 	if (_spdk_bs_page_to_blobid(ctx->cur_page) != ctx->page->id) {
2912 		return false;
2913 	}
2914 	return true;
2915 }
2916 
2917 static void
2918 _spdk_bs_load_replay_cur_md_page(spdk_bs_sequence_t *seq, void *cb_arg);
2919 
2920 static void
2921 _spdk_bs_load_write_used_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2922 {
2923 	struct spdk_bs_load_ctx	*ctx = cb_arg;
2924 
2925 	_spdk_bs_load_complete(seq, ctx, bserrno);
2926 }
2927 
2928 static void
2929 _spdk_bs_load_write_used_blobids_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2930 {
2931 	struct spdk_bs_load_ctx	*ctx = cb_arg;
2932 
2933 	spdk_dma_free(ctx->mask);
2934 	ctx->mask = NULL;
2935 
2936 	_spdk_bs_write_used_clusters(seq, cb_arg, _spdk_bs_load_write_used_clusters_cpl);
2937 }
2938 
2939 static void
2940 _spdk_bs_load_write_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2941 {
2942 	struct spdk_bs_load_ctx	*ctx = cb_arg;
2943 
2944 	spdk_dma_free(ctx->mask);
2945 	ctx->mask = NULL;
2946 
2947 	_spdk_bs_write_used_blobids(seq, cb_arg, _spdk_bs_load_write_used_blobids_cpl);
2948 }
2949 
2950 static void
2951 _spdk_bs_load_write_used_md(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2952 {
2953 	_spdk_bs_write_used_md(seq, cb_arg, _spdk_bs_load_write_used_pages_cpl);
2954 }
2955 
2956 static void
2957 _spdk_bs_load_replay_md_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2958 {
2959 	struct spdk_bs_load_ctx *ctx = cb_arg;
2960 	uint64_t num_md_clusters;
2961 	uint64_t i;
2962 	uint32_t page_num;
2963 
2964 	if (bserrno != 0) {
2965 		_spdk_bs_load_ctx_fail(seq, ctx, bserrno);
2966 		return;
2967 	}
2968 
2969 	page_num = ctx->cur_page;
2970 	if (_spdk_bs_load_cur_md_page_valid(ctx) == true) {
2971 		if (ctx->page->sequence_num == 0 || ctx->in_page_chain == true) {
2972 			spdk_bit_array_set(ctx->bs->used_md_pages, page_num);
2973 			if (ctx->page->sequence_num == 0) {
2974 				spdk_bit_array_set(ctx->bs->used_blobids, page_num);
2975 			}
2976 			if (_spdk_bs_load_replay_md_parse_page(ctx->page, ctx->bs)) {
2977 				_spdk_bs_load_ctx_fail(seq, ctx, -EILSEQ);
2978 				return;
2979 			}
2980 			if (ctx->page->next != SPDK_INVALID_MD_PAGE) {
2981 				ctx->in_page_chain = true;
2982 				ctx->cur_page = ctx->page->next;
2983 				_spdk_bs_load_replay_cur_md_page(seq, cb_arg);
2984 				return;
2985 			}
2986 		}
2987 	}
2988 
2989 	ctx->in_page_chain = false;
2990 
2991 	do {
2992 		ctx->page_index++;
2993 	} while (spdk_bit_array_get(ctx->bs->used_md_pages, ctx->page_index) == true);
2994 
2995 	if (ctx->page_index < ctx->super->md_len) {
2996 		ctx->cur_page = ctx->page_index;
2997 		_spdk_bs_load_replay_cur_md_page(seq, cb_arg);
2998 	} else {
2999 		/* Claim all of the clusters used by the metadata */
3000 		num_md_clusters = spdk_divide_round_up(ctx->super->md_len, ctx->bs->pages_per_cluster);
3001 		for (i = 0; i < num_md_clusters; i++) {
3002 			_spdk_bs_claim_cluster(ctx->bs, i);
3003 		}
3004 		spdk_dma_free(ctx->page);
3005 		_spdk_bs_load_write_used_md(seq, ctx, bserrno);
3006 	}
3007 }
3008 
3009 static void
3010 _spdk_bs_load_replay_cur_md_page(spdk_bs_sequence_t *seq, void *cb_arg)
3011 {
3012 	struct spdk_bs_load_ctx *ctx = cb_arg;
3013 	uint64_t lba;
3014 
3015 	assert(ctx->cur_page < ctx->super->md_len);
3016 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->md_start + ctx->cur_page);
3017 	spdk_bs_sequence_read_dev(seq, ctx->page, lba,
3018 				  _spdk_bs_byte_to_lba(ctx->bs, SPDK_BS_PAGE_SIZE),
3019 				  _spdk_bs_load_replay_md_cpl, ctx);
3020 }
3021 
3022 static void
3023 _spdk_bs_load_replay_md(spdk_bs_sequence_t *seq, void *cb_arg)
3024 {
3025 	struct spdk_bs_load_ctx *ctx = cb_arg;
3026 
3027 	ctx->page_index = 0;
3028 	ctx->cur_page = 0;
3029 	ctx->page = spdk_dma_zmalloc(SPDK_BS_PAGE_SIZE,
3030 				     SPDK_BS_PAGE_SIZE,
3031 				     NULL);
3032 	if (!ctx->page) {
3033 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
3034 		return;
3035 	}
3036 	_spdk_bs_load_replay_cur_md_page(seq, cb_arg);
3037 }
3038 
3039 static void
3040 _spdk_bs_recover(spdk_bs_sequence_t *seq, void *cb_arg)
3041 {
3042 	struct spdk_bs_load_ctx *ctx = cb_arg;
3043 	int		rc;
3044 
3045 	rc = spdk_bit_array_resize(&ctx->bs->used_md_pages, ctx->super->md_len);
3046 	if (rc < 0) {
3047 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
3048 		return;
3049 	}
3050 
3051 	rc = spdk_bit_array_resize(&ctx->bs->used_blobids, ctx->super->md_len);
3052 	if (rc < 0) {
3053 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
3054 		return;
3055 	}
3056 
3057 	rc = spdk_bit_array_resize(&ctx->bs->used_clusters, ctx->bs->total_clusters);
3058 	if (rc < 0) {
3059 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
3060 		return;
3061 	}
3062 
3063 	ctx->bs->num_free_clusters = ctx->bs->total_clusters;
3064 	_spdk_bs_load_replay_md(seq, cb_arg);
3065 }
3066 
3067 static void
3068 _spdk_bs_load_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3069 {
3070 	struct spdk_bs_load_ctx *ctx = cb_arg;
3071 	uint32_t	crc;
3072 	int		rc;
3073 	static const char zeros[SPDK_BLOBSTORE_TYPE_LENGTH];
3074 
3075 	if (ctx->super->version > SPDK_BS_VERSION ||
3076 	    ctx->super->version < SPDK_BS_INITIAL_VERSION) {
3077 		_spdk_bs_load_ctx_fail(seq, ctx, -EILSEQ);
3078 		return;
3079 	}
3080 
3081 	if (memcmp(ctx->super->signature, SPDK_BS_SUPER_BLOCK_SIG,
3082 		   sizeof(ctx->super->signature)) != 0) {
3083 		_spdk_bs_load_ctx_fail(seq, ctx, -EILSEQ);
3084 		return;
3085 	}
3086 
3087 	crc = _spdk_blob_md_page_calc_crc(ctx->super);
3088 	if (crc != ctx->super->crc) {
3089 		_spdk_bs_load_ctx_fail(seq, ctx, -EILSEQ);
3090 		return;
3091 	}
3092 
3093 	if (memcmp(&ctx->bs->bstype, &ctx->super->bstype, SPDK_BLOBSTORE_TYPE_LENGTH) == 0) {
3094 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Bstype matched - loading blobstore\n");
3095 	} else if (memcmp(&ctx->bs->bstype, zeros, SPDK_BLOBSTORE_TYPE_LENGTH) == 0) {
3096 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Bstype wildcard used - loading blobstore regardless bstype\n");
3097 	} else {
3098 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Unexpected bstype\n");
3099 		SPDK_LOGDUMP(SPDK_LOG_BLOB, "Expected:", ctx->bs->bstype.bstype, SPDK_BLOBSTORE_TYPE_LENGTH);
3100 		SPDK_LOGDUMP(SPDK_LOG_BLOB, "Found:", ctx->super->bstype.bstype, SPDK_BLOBSTORE_TYPE_LENGTH);
3101 		_spdk_bs_load_ctx_fail(seq, ctx, -ENXIO);
3102 		return;
3103 	}
3104 
3105 	if (ctx->super->size > ctx->bs->dev->blockcnt * ctx->bs->dev->blocklen) {
3106 		SPDK_NOTICELOG("Size mismatch, dev size: %lu, blobstore size: %lu\n",
3107 			       ctx->bs->dev->blockcnt * ctx->bs->dev->blocklen, ctx->super->size);
3108 		_spdk_bs_load_ctx_fail(seq, ctx, -EILSEQ);
3109 		return;
3110 	}
3111 
3112 	if (ctx->super->size == 0) {
3113 		ctx->super->size = ctx->bs->dev->blockcnt * ctx->bs->dev->blocklen;
3114 	}
3115 
3116 	if (ctx->super->io_unit_size == 0) {
3117 		ctx->super->io_unit_size = SPDK_BS_PAGE_SIZE;
3118 	}
3119 
3120 	/* Parse the super block */
3121 	ctx->bs->clean = 1;
3122 	ctx->bs->cluster_sz = ctx->super->cluster_size;
3123 	ctx->bs->total_clusters = ctx->super->size / ctx->super->cluster_size;
3124 	ctx->bs->pages_per_cluster = ctx->bs->cluster_sz / SPDK_BS_PAGE_SIZE;
3125 	ctx->bs->io_unit_size = ctx->super->io_unit_size;
3126 	rc = spdk_bit_array_resize(&ctx->bs->used_clusters, ctx->bs->total_clusters);
3127 	if (rc < 0) {
3128 		_spdk_bs_load_ctx_fail(seq, ctx, -ENOMEM);
3129 		return;
3130 	}
3131 	ctx->bs->md_start = ctx->super->md_start;
3132 	ctx->bs->md_len = ctx->super->md_len;
3133 	ctx->bs->total_data_clusters = ctx->bs->total_clusters - spdk_divide_round_up(
3134 					       ctx->bs->md_start + ctx->bs->md_len, ctx->bs->pages_per_cluster);
3135 	ctx->bs->super_blob = ctx->super->super_blob;
3136 	memcpy(&ctx->bs->bstype, &ctx->super->bstype, sizeof(ctx->super->bstype));
3137 
3138 	if (ctx->super->used_blobid_mask_len == 0 || ctx->super->clean == 0) {
3139 		_spdk_bs_recover(seq, ctx);
3140 	} else {
3141 		_spdk_bs_load_read_used_pages(seq, ctx);
3142 	}
3143 }
3144 
3145 void
3146 spdk_bs_load(struct spdk_bs_dev *dev, struct spdk_bs_opts *o,
3147 	     spdk_bs_op_with_handle_complete cb_fn, void *cb_arg)
3148 {
3149 	struct spdk_blob_store	*bs;
3150 	struct spdk_bs_cpl	cpl;
3151 	spdk_bs_sequence_t	*seq;
3152 	struct spdk_bs_load_ctx *ctx;
3153 	struct spdk_bs_opts	opts = {};
3154 	int err;
3155 
3156 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Loading blobstore from dev %p\n", dev);
3157 
3158 	if ((SPDK_BS_PAGE_SIZE % dev->blocklen) != 0) {
3159 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "unsupported dev block length of %d\n", dev->blocklen);
3160 		dev->destroy(dev);
3161 		cb_fn(cb_arg, NULL, -EINVAL);
3162 		return;
3163 	}
3164 
3165 	if (o) {
3166 		opts = *o;
3167 	} else {
3168 		spdk_bs_opts_init(&opts);
3169 	}
3170 
3171 	if (opts.max_md_ops == 0 || opts.max_channel_ops == 0) {
3172 		dev->destroy(dev);
3173 		cb_fn(cb_arg, NULL, -EINVAL);
3174 		return;
3175 	}
3176 
3177 	err = _spdk_bs_alloc(dev, &opts, &bs);
3178 	if (err) {
3179 		dev->destroy(dev);
3180 		cb_fn(cb_arg, NULL, err);
3181 		return;
3182 	}
3183 
3184 	ctx = calloc(1, sizeof(*ctx));
3185 	if (!ctx) {
3186 		_spdk_bs_free(bs);
3187 		cb_fn(cb_arg, NULL, -ENOMEM);
3188 		return;
3189 	}
3190 
3191 	ctx->bs = bs;
3192 	ctx->iter_cb_fn = opts.iter_cb_fn;
3193 	ctx->iter_cb_arg = opts.iter_cb_arg;
3194 
3195 	/* Allocate memory for the super block */
3196 	ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
3197 	if (!ctx->super) {
3198 		free(ctx);
3199 		_spdk_bs_free(bs);
3200 		cb_fn(cb_arg, NULL, -ENOMEM);
3201 		return;
3202 	}
3203 
3204 	cpl.type = SPDK_BS_CPL_TYPE_BS_HANDLE;
3205 	cpl.u.bs_handle.cb_fn = cb_fn;
3206 	cpl.u.bs_handle.cb_arg = cb_arg;
3207 	cpl.u.bs_handle.bs = bs;
3208 
3209 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3210 	if (!seq) {
3211 		spdk_dma_free(ctx->super);
3212 		free(ctx);
3213 		_spdk_bs_free(bs);
3214 		cb_fn(cb_arg, NULL, -ENOMEM);
3215 		return;
3216 	}
3217 
3218 	/* Read the super block */
3219 	spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
3220 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
3221 				  _spdk_bs_load_super_cpl, ctx);
3222 }
3223 
3224 /* END spdk_bs_load */
3225 
3226 /* START spdk_bs_dump */
3227 
3228 struct spdk_bs_dump_ctx {
3229 	struct spdk_blob_store		*bs;
3230 	struct spdk_bs_super_block	*super;
3231 	uint32_t			cur_page;
3232 	struct spdk_blob_md_page	*page;
3233 	spdk_bs_sequence_t		*seq;
3234 	FILE				*fp;
3235 	spdk_bs_dump_print_xattr	print_xattr_fn;
3236 	char				xattr_name[4096];
3237 };
3238 
3239 static void
3240 _spdk_bs_dump_finish(spdk_bs_sequence_t *seq, struct spdk_bs_dump_ctx *ctx, int bserrno)
3241 {
3242 	spdk_dma_free(ctx->super);
3243 
3244 	/*
3245 	 * We need to defer calling spdk_bs_call_cpl() until after
3246 	 * dev destruction, so tuck these away for later use.
3247 	 */
3248 	ctx->bs->unload_err = bserrno;
3249 	memcpy(&ctx->bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));
3250 	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;
3251 
3252 	spdk_bs_sequence_finish(seq, 0);
3253 	_spdk_bs_free(ctx->bs);
3254 	free(ctx);
3255 }
3256 
3257 static void _spdk_bs_dump_read_md_page(spdk_bs_sequence_t *seq, void *cb_arg);
3258 
3259 static void
3260 _spdk_bs_dump_print_md_page(struct spdk_bs_dump_ctx *ctx)
3261 {
3262 	uint32_t page_idx = ctx->cur_page;
3263 	struct spdk_blob_md_page *page = ctx->page;
3264 	struct spdk_blob_md_descriptor *desc;
3265 	size_t cur_desc = 0;
3266 	uint32_t crc;
3267 
3268 	fprintf(ctx->fp, "=========\n");
3269 	fprintf(ctx->fp, "Metadata Page Index: %" PRIu32 " (0x%" PRIx32 ")\n", page_idx, page_idx);
3270 	fprintf(ctx->fp, "Blob ID: 0x%" PRIx64 "\n", page->id);
3271 
3272 	crc = _spdk_blob_md_page_calc_crc(page);
3273 	fprintf(ctx->fp, "CRC: 0x%" PRIx32 " (%s)\n", page->crc, crc == page->crc ? "OK" : "Mismatch");
3274 
3275 	desc = (struct spdk_blob_md_descriptor *)page->descriptors;
3276 	while (cur_desc < sizeof(page->descriptors)) {
3277 		if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_PADDING) {
3278 			if (desc->length == 0) {
3279 				/* If padding and length are 0, this terminates the page */
3280 				break;
3281 			}
3282 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_EXTENT) {
3283 			struct spdk_blob_md_descriptor_extent	*desc_extent;
3284 			unsigned int				i;
3285 
3286 			desc_extent = (struct spdk_blob_md_descriptor_extent *)desc;
3287 
3288 			for (i = 0; i < desc_extent->length / sizeof(desc_extent->extents[0]); i++) {
3289 				if (desc_extent->extents[i].cluster_idx != 0) {
3290 					fprintf(ctx->fp, "Allocated Extent - Start: %" PRIu32,
3291 						desc_extent->extents[i].cluster_idx);
3292 				} else {
3293 					fprintf(ctx->fp, "Unallocated Extent - ");
3294 				}
3295 				fprintf(ctx->fp, " Length: %" PRIu32, desc_extent->extents[i].length);
3296 				fprintf(ctx->fp, "\n");
3297 			}
3298 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR) {
3299 			struct spdk_blob_md_descriptor_xattr *desc_xattr;
3300 			uint32_t i;
3301 
3302 			desc_xattr = (struct spdk_blob_md_descriptor_xattr *)desc;
3303 
3304 			if (desc_xattr->length !=
3305 			    sizeof(desc_xattr->name_length) + sizeof(desc_xattr->value_length) +
3306 			    desc_xattr->name_length + desc_xattr->value_length) {
3307 			}
3308 
3309 			memcpy(ctx->xattr_name, desc_xattr->name, desc_xattr->name_length);
3310 			ctx->xattr_name[desc_xattr->name_length] = '\0';
3311 			fprintf(ctx->fp, "XATTR: name = \"%s\"\n", ctx->xattr_name);
3312 			fprintf(ctx->fp, "       value = \"");
3313 			ctx->print_xattr_fn(ctx->fp, ctx->super->bstype.bstype, ctx->xattr_name,
3314 					    (void *)((uintptr_t)desc_xattr->name + desc_xattr->name_length),
3315 					    desc_xattr->value_length);
3316 			fprintf(ctx->fp, "\"\n");
3317 			for (i = 0; i < desc_xattr->value_length; i++) {
3318 				if (i % 16 == 0) {
3319 					fprintf(ctx->fp, "               ");
3320 				}
3321 				fprintf(ctx->fp, "%02" PRIx8 " ", *((uint8_t *)desc_xattr->name + desc_xattr->name_length + i));
3322 				if ((i + 1) % 16 == 0) {
3323 					fprintf(ctx->fp, "\n");
3324 				}
3325 			}
3326 			if (i % 16 != 0) {
3327 				fprintf(ctx->fp, "\n");
3328 			}
3329 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL) {
3330 			/* TODO */
3331 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_FLAGS) {
3332 			/* TODO */
3333 		} else {
3334 			/* Error */
3335 		}
3336 		/* Advance to the next descriptor */
3337 		cur_desc += sizeof(*desc) + desc->length;
3338 		if (cur_desc + sizeof(*desc) > sizeof(page->descriptors)) {
3339 			break;
3340 		}
3341 		desc = (struct spdk_blob_md_descriptor *)((uintptr_t)page->descriptors + cur_desc);
3342 	}
3343 }
3344 
3345 static void
3346 _spdk_bs_dump_read_md_page_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3347 {
3348 	struct spdk_bs_dump_ctx *ctx = cb_arg;
3349 
3350 	if (bserrno != 0) {
3351 		_spdk_bs_dump_finish(seq, ctx, bserrno);
3352 		return;
3353 	}
3354 
3355 	if (ctx->page->id != 0) {
3356 		_spdk_bs_dump_print_md_page(ctx);
3357 	}
3358 
3359 	ctx->cur_page++;
3360 
3361 	if (ctx->cur_page < ctx->super->md_len) {
3362 		_spdk_bs_dump_read_md_page(seq, cb_arg);
3363 	} else {
3364 		spdk_dma_free(ctx->page);
3365 		_spdk_bs_dump_finish(seq, ctx, 0);
3366 	}
3367 }
3368 
3369 static void
3370 _spdk_bs_dump_read_md_page(spdk_bs_sequence_t *seq, void *cb_arg)
3371 {
3372 	struct spdk_bs_dump_ctx *ctx = cb_arg;
3373 	uint64_t lba;
3374 
3375 	assert(ctx->cur_page < ctx->super->md_len);
3376 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->md_start + ctx->cur_page);
3377 	spdk_bs_sequence_read_dev(seq, ctx->page, lba,
3378 				  _spdk_bs_byte_to_lba(ctx->bs, SPDK_BS_PAGE_SIZE),
3379 				  _spdk_bs_dump_read_md_page_cpl, ctx);
3380 }
3381 
3382 static void
3383 _spdk_bs_dump_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3384 {
3385 	struct spdk_bs_dump_ctx *ctx = cb_arg;
3386 
3387 	fprintf(ctx->fp, "Signature: \"%.8s\" ", ctx->super->signature);
3388 	if (memcmp(ctx->super->signature, SPDK_BS_SUPER_BLOCK_SIG,
3389 		   sizeof(ctx->super->signature)) != 0) {
3390 		fprintf(ctx->fp, "(Mismatch)\n");
3391 		_spdk_bs_dump_finish(seq, ctx, bserrno);
3392 		return;
3393 	} else {
3394 		fprintf(ctx->fp, "(OK)\n");
3395 	}
3396 	fprintf(ctx->fp, "Version: %" PRIu32 "\n", ctx->super->version);
3397 	fprintf(ctx->fp, "CRC: 0x%x (%s)\n", ctx->super->crc,
3398 		(ctx->super->crc == _spdk_blob_md_page_calc_crc(ctx->super)) ? "OK" : "Mismatch");
3399 	fprintf(ctx->fp, "Blobstore Type: %.*s\n", SPDK_BLOBSTORE_TYPE_LENGTH, ctx->super->bstype.bstype);
3400 	fprintf(ctx->fp, "Cluster Size: %" PRIu32 "\n", ctx->super->cluster_size);
3401 	fprintf(ctx->fp, "Super Blob ID: ");
3402 	if (ctx->super->super_blob == SPDK_BLOBID_INVALID) {
3403 		fprintf(ctx->fp, "(None)\n");
3404 	} else {
3405 		fprintf(ctx->fp, "%" PRIu64 "\n", ctx->super->super_blob);
3406 	}
3407 	fprintf(ctx->fp, "Clean: %" PRIu32 "\n", ctx->super->clean);
3408 	fprintf(ctx->fp, "Used Metadata Page Mask Start: %" PRIu32 "\n", ctx->super->used_page_mask_start);
3409 	fprintf(ctx->fp, "Used Metadata Page Mask Length: %" PRIu32 "\n", ctx->super->used_page_mask_len);
3410 	fprintf(ctx->fp, "Used Cluster Mask Start: %" PRIu32 "\n", ctx->super->used_cluster_mask_start);
3411 	fprintf(ctx->fp, "Used Cluster Mask Length: %" PRIu32 "\n", ctx->super->used_cluster_mask_len);
3412 	fprintf(ctx->fp, "Used Blob ID Mask Start: %" PRIu32 "\n", ctx->super->used_blobid_mask_start);
3413 	fprintf(ctx->fp, "Used Blob ID Mask Length: %" PRIu32 "\n", ctx->super->used_blobid_mask_len);
3414 	fprintf(ctx->fp, "Metadata Start: %" PRIu32 "\n", ctx->super->md_start);
3415 	fprintf(ctx->fp, "Metadata Length: %" PRIu32 "\n", ctx->super->md_len);
3416 
3417 	ctx->cur_page = 0;
3418 	ctx->page = spdk_dma_zmalloc(SPDK_BS_PAGE_SIZE,
3419 				     SPDK_BS_PAGE_SIZE,
3420 				     NULL);
3421 	if (!ctx->page) {
3422 		_spdk_bs_dump_finish(seq, ctx, -ENOMEM);
3423 		return;
3424 	}
3425 	_spdk_bs_dump_read_md_page(seq, cb_arg);
3426 }
3427 
3428 void
3429 spdk_bs_dump(struct spdk_bs_dev *dev, FILE *fp, spdk_bs_dump_print_xattr print_xattr_fn,
3430 	     spdk_bs_op_complete cb_fn, void *cb_arg)
3431 {
3432 	struct spdk_blob_store	*bs;
3433 	struct spdk_bs_cpl	cpl;
3434 	spdk_bs_sequence_t	*seq;
3435 	struct spdk_bs_dump_ctx *ctx;
3436 	struct spdk_bs_opts	opts = {};
3437 	int err;
3438 
3439 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Dumping blobstore from dev %p\n", dev);
3440 
3441 	spdk_bs_opts_init(&opts);
3442 
3443 	err = _spdk_bs_alloc(dev, &opts, &bs);
3444 	if (err) {
3445 		dev->destroy(dev);
3446 		cb_fn(cb_arg, err);
3447 		return;
3448 	}
3449 
3450 	ctx = calloc(1, sizeof(*ctx));
3451 	if (!ctx) {
3452 		_spdk_bs_free(bs);
3453 		cb_fn(cb_arg, -ENOMEM);
3454 		return;
3455 	}
3456 
3457 	ctx->bs = bs;
3458 	ctx->fp = fp;
3459 	ctx->print_xattr_fn = print_xattr_fn;
3460 
3461 	/* Allocate memory for the super block */
3462 	ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
3463 	if (!ctx->super) {
3464 		free(ctx);
3465 		_spdk_bs_free(bs);
3466 		cb_fn(cb_arg, -ENOMEM);
3467 		return;
3468 	}
3469 
3470 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
3471 	cpl.u.bs_basic.cb_fn = cb_fn;
3472 	cpl.u.bs_basic.cb_arg = cb_arg;
3473 
3474 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3475 	if (!seq) {
3476 		spdk_dma_free(ctx->super);
3477 		free(ctx);
3478 		_spdk_bs_free(bs);
3479 		cb_fn(cb_arg, -ENOMEM);
3480 		return;
3481 	}
3482 
3483 	/* Read the super block */
3484 	spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
3485 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
3486 				  _spdk_bs_dump_super_cpl, ctx);
3487 }
3488 
3489 /* END spdk_bs_dump */
3490 
3491 /* START spdk_bs_init */
3492 
3493 struct spdk_bs_init_ctx {
3494 	struct spdk_blob_store		*bs;
3495 	struct spdk_bs_super_block	*super;
3496 };
3497 
3498 static void
3499 _spdk_bs_init_persist_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3500 {
3501 	struct spdk_bs_init_ctx *ctx = cb_arg;
3502 
3503 	spdk_dma_free(ctx->super);
3504 	free(ctx);
3505 
3506 	spdk_bs_sequence_finish(seq, bserrno);
3507 }
3508 
3509 static void
3510 _spdk_bs_init_trim_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3511 {
3512 	struct spdk_bs_init_ctx *ctx = cb_arg;
3513 
3514 	/* Write super block */
3515 	spdk_bs_sequence_write_dev(seq, ctx->super, _spdk_bs_page_to_lba(ctx->bs, 0),
3516 				   _spdk_bs_byte_to_lba(ctx->bs, sizeof(*ctx->super)),
3517 				   _spdk_bs_init_persist_super_cpl, ctx);
3518 }
3519 
3520 void
3521 spdk_bs_init(struct spdk_bs_dev *dev, struct spdk_bs_opts *o,
3522 	     spdk_bs_op_with_handle_complete cb_fn, void *cb_arg)
3523 {
3524 	struct spdk_bs_init_ctx *ctx;
3525 	struct spdk_blob_store	*bs;
3526 	struct spdk_bs_cpl	cpl;
3527 	spdk_bs_sequence_t	*seq;
3528 	spdk_bs_batch_t		*batch;
3529 	uint64_t		num_md_lba;
3530 	uint64_t		num_md_pages;
3531 	uint64_t		num_md_clusters;
3532 	uint32_t		i;
3533 	struct spdk_bs_opts	opts = {};
3534 	int			rc;
3535 
3536 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Initializing blobstore on dev %p\n", dev);
3537 
3538 	if ((SPDK_BS_PAGE_SIZE % dev->blocklen) != 0) {
3539 		SPDK_ERRLOG("unsupported dev block length of %d\n",
3540 			    dev->blocklen);
3541 		dev->destroy(dev);
3542 		cb_fn(cb_arg, NULL, -EINVAL);
3543 		return;
3544 	}
3545 
3546 	if (o) {
3547 		opts = *o;
3548 	} else {
3549 		spdk_bs_opts_init(&opts);
3550 	}
3551 
3552 	if (_spdk_bs_opts_verify(&opts) != 0) {
3553 		dev->destroy(dev);
3554 		cb_fn(cb_arg, NULL, -EINVAL);
3555 		return;
3556 	}
3557 
3558 	rc = _spdk_bs_alloc(dev, &opts, &bs);
3559 	if (rc) {
3560 		dev->destroy(dev);
3561 		cb_fn(cb_arg, NULL, rc);
3562 		return;
3563 	}
3564 
3565 	if (opts.num_md_pages == SPDK_BLOB_OPTS_NUM_MD_PAGES) {
3566 		/* By default, allocate 1 page per cluster.
3567 		 * Technically, this over-allocates metadata
3568 		 * because more metadata will reduce the number
3569 		 * of usable clusters. This can be addressed with
3570 		 * more complex math in the future.
3571 		 */
3572 		bs->md_len = bs->total_clusters;
3573 	} else {
3574 		bs->md_len = opts.num_md_pages;
3575 	}
3576 	rc = spdk_bit_array_resize(&bs->used_md_pages, bs->md_len);
3577 	if (rc < 0) {
3578 		_spdk_bs_free(bs);
3579 		cb_fn(cb_arg, NULL, -ENOMEM);
3580 		return;
3581 	}
3582 
3583 	rc = spdk_bit_array_resize(&bs->used_blobids, bs->md_len);
3584 	if (rc < 0) {
3585 		_spdk_bs_free(bs);
3586 		cb_fn(cb_arg, NULL, -ENOMEM);
3587 		return;
3588 	}
3589 
3590 	ctx = calloc(1, sizeof(*ctx));
3591 	if (!ctx) {
3592 		_spdk_bs_free(bs);
3593 		cb_fn(cb_arg, NULL, -ENOMEM);
3594 		return;
3595 	}
3596 
3597 	ctx->bs = bs;
3598 
3599 	/* Allocate memory for the super block */
3600 	ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
3601 	if (!ctx->super) {
3602 		free(ctx);
3603 		_spdk_bs_free(bs);
3604 		cb_fn(cb_arg, NULL, -ENOMEM);
3605 		return;
3606 	}
3607 	memcpy(ctx->super->signature, SPDK_BS_SUPER_BLOCK_SIG,
3608 	       sizeof(ctx->super->signature));
3609 	ctx->super->version = SPDK_BS_VERSION;
3610 	ctx->super->length = sizeof(*ctx->super);
3611 	ctx->super->super_blob = bs->super_blob;
3612 	ctx->super->clean = 0;
3613 	ctx->super->cluster_size = bs->cluster_sz;
3614 	ctx->super->io_unit_size = bs->io_unit_size;
3615 	memcpy(&ctx->super->bstype, &bs->bstype, sizeof(bs->bstype));
3616 
3617 	/* Calculate how many pages the metadata consumes at the front
3618 	 * of the disk.
3619 	 */
3620 
3621 	/* The super block uses 1 page */
3622 	num_md_pages = 1;
3623 
3624 	/* The used_md_pages mask requires 1 bit per metadata page, rounded
3625 	 * up to the nearest page, plus a header.
3626 	 */
3627 	ctx->super->used_page_mask_start = num_md_pages;
3628 	ctx->super->used_page_mask_len = spdk_divide_round_up(sizeof(struct spdk_bs_md_mask) +
3629 					 spdk_divide_round_up(bs->md_len, 8),
3630 					 SPDK_BS_PAGE_SIZE);
3631 	num_md_pages += ctx->super->used_page_mask_len;
3632 
3633 	/* The used_clusters mask requires 1 bit per cluster, rounded
3634 	 * up to the nearest page, plus a header.
3635 	 */
3636 	ctx->super->used_cluster_mask_start = num_md_pages;
3637 	ctx->super->used_cluster_mask_len = spdk_divide_round_up(sizeof(struct spdk_bs_md_mask) +
3638 					    spdk_divide_round_up(bs->total_clusters, 8),
3639 					    SPDK_BS_PAGE_SIZE);
3640 	num_md_pages += ctx->super->used_cluster_mask_len;
3641 
3642 	/* The used_blobids mask requires 1 bit per metadata page, rounded
3643 	 * up to the nearest page, plus a header.
3644 	 */
3645 	ctx->super->used_blobid_mask_start = num_md_pages;
3646 	ctx->super->used_blobid_mask_len = spdk_divide_round_up(sizeof(struct spdk_bs_md_mask) +
3647 					   spdk_divide_round_up(bs->md_len, 8),
3648 					   SPDK_BS_PAGE_SIZE);
3649 	num_md_pages += ctx->super->used_blobid_mask_len;
3650 
3651 	/* The metadata region size was chosen above */
3652 	ctx->super->md_start = bs->md_start = num_md_pages;
3653 	ctx->super->md_len = bs->md_len;
3654 	num_md_pages += bs->md_len;
3655 
3656 	num_md_lba = _spdk_bs_page_to_lba(bs, num_md_pages);
3657 
3658 	ctx->super->size = dev->blockcnt * dev->blocklen;
3659 
3660 	ctx->super->crc = _spdk_blob_md_page_calc_crc(ctx->super);
3661 
3662 	num_md_clusters = spdk_divide_round_up(num_md_pages, bs->pages_per_cluster);
3663 	if (num_md_clusters > bs->total_clusters) {
3664 		SPDK_ERRLOG("Blobstore metadata cannot use more clusters than is available, "
3665 			    "please decrease number of pages reserved for metadata "
3666 			    "or increase cluster size.\n");
3667 		spdk_dma_free(ctx->super);
3668 		free(ctx);
3669 		_spdk_bs_free(bs);
3670 		cb_fn(cb_arg, NULL, -ENOMEM);
3671 		return;
3672 	}
3673 	/* Claim all of the clusters used by the metadata */
3674 	for (i = 0; i < num_md_clusters; i++) {
3675 		_spdk_bs_claim_cluster(bs, i);
3676 	}
3677 
3678 	bs->total_data_clusters = bs->num_free_clusters;
3679 
3680 	cpl.type = SPDK_BS_CPL_TYPE_BS_HANDLE;
3681 	cpl.u.bs_handle.cb_fn = cb_fn;
3682 	cpl.u.bs_handle.cb_arg = cb_arg;
3683 	cpl.u.bs_handle.bs = bs;
3684 
3685 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3686 	if (!seq) {
3687 		spdk_dma_free(ctx->super);
3688 		free(ctx);
3689 		_spdk_bs_free(bs);
3690 		cb_fn(cb_arg, NULL, -ENOMEM);
3691 		return;
3692 	}
3693 
3694 	batch = spdk_bs_sequence_to_batch(seq, _spdk_bs_init_trim_cpl, ctx);
3695 
3696 	/* Clear metadata space */
3697 	spdk_bs_batch_write_zeroes_dev(batch, 0, num_md_lba);
3698 
3699 	if (opts.clear_method == BS_CLEAR_WITH_UNMAP) {
3700 		/* Trim data clusters */
3701 		spdk_bs_batch_unmap_dev(batch, num_md_lba, ctx->bs->dev->blockcnt - num_md_lba);
3702 	} else if (opts.clear_method == BS_CLEAR_WITH_WRITE_ZEROES) {
3703 		/* Write_zeroes to data clusters */
3704 		spdk_bs_batch_write_zeroes_dev(batch, num_md_lba, ctx->bs->dev->blockcnt - num_md_lba);
3705 	}
3706 
3707 	spdk_bs_batch_close(batch);
3708 }
3709 
3710 /* END spdk_bs_init */
3711 
3712 /* START spdk_bs_destroy */
3713 
3714 static void
3715 _spdk_bs_destroy_trim_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3716 {
3717 	struct spdk_bs_init_ctx *ctx = cb_arg;
3718 	struct spdk_blob_store *bs = ctx->bs;
3719 
3720 	/*
3721 	 * We need to defer calling spdk_bs_call_cpl() until after
3722 	 * dev destruction, so tuck these away for later use.
3723 	 */
3724 	bs->unload_err = bserrno;
3725 	memcpy(&bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));
3726 	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;
3727 
3728 	spdk_bs_sequence_finish(seq, bserrno);
3729 
3730 	_spdk_bs_free(bs);
3731 	free(ctx);
3732 }
3733 
3734 void
3735 spdk_bs_destroy(struct spdk_blob_store *bs, spdk_bs_op_complete cb_fn,
3736 		void *cb_arg)
3737 {
3738 	struct spdk_bs_cpl	cpl;
3739 	spdk_bs_sequence_t	*seq;
3740 	struct spdk_bs_init_ctx *ctx;
3741 
3742 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Destroying blobstore\n");
3743 
3744 	if (!TAILQ_EMPTY(&bs->blobs)) {
3745 		SPDK_ERRLOG("Blobstore still has open blobs\n");
3746 		cb_fn(cb_arg, -EBUSY);
3747 		return;
3748 	}
3749 
3750 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
3751 	cpl.u.bs_basic.cb_fn = cb_fn;
3752 	cpl.u.bs_basic.cb_arg = cb_arg;
3753 
3754 	ctx = calloc(1, sizeof(*ctx));
3755 	if (!ctx) {
3756 		cb_fn(cb_arg, -ENOMEM);
3757 		return;
3758 	}
3759 
3760 	ctx->bs = bs;
3761 
3762 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3763 	if (!seq) {
3764 		free(ctx);
3765 		cb_fn(cb_arg, -ENOMEM);
3766 		return;
3767 	}
3768 
3769 	/* Write zeroes to the super block */
3770 	spdk_bs_sequence_write_zeroes_dev(seq,
3771 					  _spdk_bs_page_to_lba(bs, 0),
3772 					  _spdk_bs_byte_to_lba(bs, sizeof(struct spdk_bs_super_block)),
3773 					  _spdk_bs_destroy_trim_cpl, ctx);
3774 }
3775 
3776 /* END spdk_bs_destroy */
3777 
3778 /* START spdk_bs_unload */
3779 
3780 static void
3781 _spdk_bs_unload_write_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3782 {
3783 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3784 
3785 	spdk_dma_free(ctx->super);
3786 
3787 	/*
3788 	 * We need to defer calling spdk_bs_call_cpl() until after
3789 	 * dev destruction, so tuck these away for later use.
3790 	 */
3791 	ctx->bs->unload_err = bserrno;
3792 	memcpy(&ctx->bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));
3793 	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;
3794 
3795 	spdk_bs_sequence_finish(seq, bserrno);
3796 
3797 	_spdk_bs_free(ctx->bs);
3798 	free(ctx);
3799 }
3800 
3801 static void
3802 _spdk_bs_unload_write_used_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3803 {
3804 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3805 
3806 	spdk_dma_free(ctx->mask);
3807 	ctx->super->clean = 1;
3808 
3809 	_spdk_bs_write_super(seq, ctx->bs, ctx->super, _spdk_bs_unload_write_super_cpl, ctx);
3810 }
3811 
3812 static void
3813 _spdk_bs_unload_write_used_blobids_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3814 {
3815 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3816 
3817 	spdk_dma_free(ctx->mask);
3818 	ctx->mask = NULL;
3819 
3820 	_spdk_bs_write_used_clusters(seq, cb_arg, _spdk_bs_unload_write_used_clusters_cpl);
3821 }
3822 
3823 static void
3824 _spdk_bs_unload_write_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3825 {
3826 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3827 
3828 	spdk_dma_free(ctx->mask);
3829 	ctx->mask = NULL;
3830 
3831 	_spdk_bs_write_used_blobids(seq, cb_arg, _spdk_bs_unload_write_used_blobids_cpl);
3832 }
3833 
3834 static void
3835 _spdk_bs_unload_read_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3836 {
3837 	_spdk_bs_write_used_md(seq, cb_arg, _spdk_bs_unload_write_used_pages_cpl);
3838 }
3839 
3840 void
3841 spdk_bs_unload(struct spdk_blob_store *bs, spdk_bs_op_complete cb_fn, void *cb_arg)
3842 {
3843 	struct spdk_bs_cpl	cpl;
3844 	spdk_bs_sequence_t	*seq;
3845 	struct spdk_bs_load_ctx *ctx;
3846 
3847 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Syncing blobstore\n");
3848 
3849 	if (!TAILQ_EMPTY(&bs->blobs)) {
3850 		SPDK_ERRLOG("Blobstore still has open blobs\n");
3851 		cb_fn(cb_arg, -EBUSY);
3852 		return;
3853 	}
3854 
3855 	ctx = calloc(1, sizeof(*ctx));
3856 	if (!ctx) {
3857 		cb_fn(cb_arg, -ENOMEM);
3858 		return;
3859 	}
3860 
3861 	ctx->bs = bs;
3862 
3863 	ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
3864 	if (!ctx->super) {
3865 		free(ctx);
3866 		cb_fn(cb_arg, -ENOMEM);
3867 		return;
3868 	}
3869 
3870 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
3871 	cpl.u.bs_basic.cb_fn = cb_fn;
3872 	cpl.u.bs_basic.cb_arg = cb_arg;
3873 
3874 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3875 	if (!seq) {
3876 		spdk_dma_free(ctx->super);
3877 		free(ctx);
3878 		cb_fn(cb_arg, -ENOMEM);
3879 		return;
3880 	}
3881 
3882 	/* Read super block */
3883 	spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
3884 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
3885 				  _spdk_bs_unload_read_super_cpl, ctx);
3886 }
3887 
3888 /* END spdk_bs_unload */
3889 
3890 /* START spdk_bs_set_super */
3891 
3892 struct spdk_bs_set_super_ctx {
3893 	struct spdk_blob_store		*bs;
3894 	struct spdk_bs_super_block	*super;
3895 };
3896 
3897 static void
3898 _spdk_bs_set_super_write_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3899 {
3900 	struct spdk_bs_set_super_ctx	*ctx = cb_arg;
3901 
3902 	if (bserrno != 0) {
3903 		SPDK_ERRLOG("Unable to write to super block of blobstore\n");
3904 	}
3905 
3906 	spdk_dma_free(ctx->super);
3907 
3908 	spdk_bs_sequence_finish(seq, bserrno);
3909 
3910 	free(ctx);
3911 }
3912 
3913 static void
3914 _spdk_bs_set_super_read_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3915 {
3916 	struct spdk_bs_set_super_ctx	*ctx = cb_arg;
3917 
3918 	if (bserrno != 0) {
3919 		SPDK_ERRLOG("Unable to read super block of blobstore\n");
3920 		spdk_dma_free(ctx->super);
3921 		spdk_bs_sequence_finish(seq, bserrno);
3922 		free(ctx);
3923 		return;
3924 	}
3925 
3926 	_spdk_bs_write_super(seq, ctx->bs, ctx->super, _spdk_bs_set_super_write_cpl, ctx);
3927 }
3928 
3929 void
3930 spdk_bs_set_super(struct spdk_blob_store *bs, spdk_blob_id blobid,
3931 		  spdk_bs_op_complete cb_fn, void *cb_arg)
3932 {
3933 	struct spdk_bs_cpl		cpl;
3934 	spdk_bs_sequence_t		*seq;
3935 	struct spdk_bs_set_super_ctx	*ctx;
3936 
3937 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Setting super blob id on blobstore\n");
3938 
3939 	ctx = calloc(1, sizeof(*ctx));
3940 	if (!ctx) {
3941 		cb_fn(cb_arg, -ENOMEM);
3942 		return;
3943 	}
3944 
3945 	ctx->bs = bs;
3946 
3947 	ctx->super = spdk_dma_zmalloc(sizeof(*ctx->super), 0x1000, NULL);
3948 	if (!ctx->super) {
3949 		free(ctx);
3950 		cb_fn(cb_arg, -ENOMEM);
3951 		return;
3952 	}
3953 
3954 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
3955 	cpl.u.bs_basic.cb_fn = cb_fn;
3956 	cpl.u.bs_basic.cb_arg = cb_arg;
3957 
3958 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3959 	if (!seq) {
3960 		spdk_dma_free(ctx->super);
3961 		free(ctx);
3962 		cb_fn(cb_arg, -ENOMEM);
3963 		return;
3964 	}
3965 
3966 	bs->super_blob = blobid;
3967 
3968 	/* Read super block */
3969 	spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
3970 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
3971 				  _spdk_bs_set_super_read_cpl, ctx);
3972 }
3973 
3974 /* END spdk_bs_set_super */
3975 
3976 void
3977 spdk_bs_get_super(struct spdk_blob_store *bs,
3978 		  spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
3979 {
3980 	if (bs->super_blob == SPDK_BLOBID_INVALID) {
3981 		cb_fn(cb_arg, SPDK_BLOBID_INVALID, -ENOENT);
3982 	} else {
3983 		cb_fn(cb_arg, bs->super_blob, 0);
3984 	}
3985 }
3986 
3987 uint64_t
3988 spdk_bs_get_cluster_size(struct spdk_blob_store *bs)
3989 {
3990 	return bs->cluster_sz;
3991 }
3992 
3993 uint64_t
3994 spdk_bs_get_page_size(struct spdk_blob_store *bs)
3995 {
3996 	return SPDK_BS_PAGE_SIZE;
3997 }
3998 
3999 uint64_t
4000 spdk_bs_get_io_unit_size(struct spdk_blob_store *bs)
4001 {
4002 	return bs->io_unit_size;
4003 }
4004 
4005 uint64_t
4006 spdk_bs_free_cluster_count(struct spdk_blob_store *bs)
4007 {
4008 	return bs->num_free_clusters;
4009 }
4010 
4011 uint64_t
4012 spdk_bs_total_data_cluster_count(struct spdk_blob_store *bs)
4013 {
4014 	return bs->total_data_clusters;
4015 }
4016 
4017 static int
4018 spdk_bs_register_md_thread(struct spdk_blob_store *bs)
4019 {
4020 	bs->md_channel = spdk_get_io_channel(bs);
4021 	if (!bs->md_channel) {
4022 		SPDK_ERRLOG("Failed to get IO channel.\n");
4023 		return -1;
4024 	}
4025 
4026 	return 0;
4027 }
4028 
4029 static int
4030 spdk_bs_unregister_md_thread(struct spdk_blob_store *bs)
4031 {
4032 	spdk_put_io_channel(bs->md_channel);
4033 
4034 	return 0;
4035 }
4036 
4037 spdk_blob_id spdk_blob_get_id(struct spdk_blob *blob)
4038 {
4039 	assert(blob != NULL);
4040 
4041 	return blob->id;
4042 }
4043 
4044 uint64_t spdk_blob_get_num_pages(struct spdk_blob *blob)
4045 {
4046 	assert(blob != NULL);
4047 
4048 	return _spdk_bs_cluster_to_page(blob->bs, blob->active.num_clusters);
4049 }
4050 
4051 uint64_t spdk_blob_get_num_io_units(struct spdk_blob *blob)
4052 {
4053 	assert(blob != NULL);
4054 
4055 	return spdk_blob_get_num_pages(blob) * _spdk_bs_io_unit_per_page(blob->bs);
4056 }
4057 
4058 uint64_t spdk_blob_get_num_clusters(struct spdk_blob *blob)
4059 {
4060 	assert(blob != NULL);
4061 
4062 	return blob->active.num_clusters;
4063 }
4064 
4065 /* START spdk_bs_create_blob */
4066 
4067 static void
4068 _spdk_bs_create_blob_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4069 {
4070 	struct spdk_blob *blob = cb_arg;
4071 
4072 	_spdk_blob_free(blob);
4073 
4074 	spdk_bs_sequence_finish(seq, bserrno);
4075 }
4076 
4077 static int
4078 _spdk_blob_set_xattrs(struct spdk_blob *blob, const struct spdk_blob_xattr_opts *xattrs,
4079 		      bool internal)
4080 {
4081 	uint64_t i;
4082 	size_t value_len = 0;
4083 	int rc;
4084 	const void *value = NULL;
4085 	if (xattrs->count > 0 && xattrs->get_value == NULL) {
4086 		return -EINVAL;
4087 	}
4088 	for (i = 0; i < xattrs->count; i++) {
4089 		xattrs->get_value(xattrs->ctx, xattrs->names[i], &value, &value_len);
4090 		if (value == NULL || value_len == 0) {
4091 			return -EINVAL;
4092 		}
4093 		rc = _spdk_blob_set_xattr(blob, xattrs->names[i], value, value_len, internal);
4094 		if (rc < 0) {
4095 			return rc;
4096 		}
4097 	}
4098 	return 0;
4099 }
4100 
4101 static void
4102 _spdk_blob_set_thin_provision(struct spdk_blob *blob)
4103 {
4104 	_spdk_blob_verify_md_op(blob);
4105 	blob->invalid_flags |= SPDK_BLOB_THIN_PROV;
4106 	blob->state = SPDK_BLOB_STATE_DIRTY;
4107 }
4108 
4109 static void
4110 _spdk_bs_create_blob(struct spdk_blob_store *bs,
4111 		     const struct spdk_blob_opts *opts,
4112 		     const struct spdk_blob_xattr_opts *internal_xattrs,
4113 		     spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4114 {
4115 	struct spdk_blob	*blob;
4116 	uint32_t		page_idx;
4117 	struct spdk_bs_cpl	cpl;
4118 	struct spdk_blob_opts	opts_default;
4119 	struct spdk_blob_xattr_opts internal_xattrs_default;
4120 	spdk_bs_sequence_t	*seq;
4121 	spdk_blob_id		id;
4122 	int rc;
4123 
4124 	assert(spdk_get_thread() == bs->md_thread);
4125 
4126 	page_idx = spdk_bit_array_find_first_clear(bs->used_md_pages, 0);
4127 	if (page_idx == UINT32_MAX) {
4128 		cb_fn(cb_arg, 0, -ENOMEM);
4129 		return;
4130 	}
4131 	spdk_bit_array_set(bs->used_blobids, page_idx);
4132 	spdk_bit_array_set(bs->used_md_pages, page_idx);
4133 
4134 	id = _spdk_bs_page_to_blobid(page_idx);
4135 
4136 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Creating blob with id %lu at page %u\n", id, page_idx);
4137 
4138 	blob = _spdk_blob_alloc(bs, id);
4139 	if (!blob) {
4140 		cb_fn(cb_arg, 0, -ENOMEM);
4141 		return;
4142 	}
4143 
4144 	if (!opts) {
4145 		spdk_blob_opts_init(&opts_default);
4146 		opts = &opts_default;
4147 	}
4148 	if (!internal_xattrs) {
4149 		_spdk_blob_xattrs_init(&internal_xattrs_default);
4150 		internal_xattrs = &internal_xattrs_default;
4151 	}
4152 
4153 	rc = _spdk_blob_set_xattrs(blob, &opts->xattrs, false);
4154 	if (rc < 0) {
4155 		_spdk_blob_free(blob);
4156 		cb_fn(cb_arg, 0, rc);
4157 		return;
4158 	}
4159 
4160 	rc = _spdk_blob_set_xattrs(blob, internal_xattrs, true);
4161 	if (rc < 0) {
4162 		_spdk_blob_free(blob);
4163 		cb_fn(cb_arg, 0, rc);
4164 		return;
4165 	}
4166 
4167 	if (opts->thin_provision) {
4168 		_spdk_blob_set_thin_provision(blob);
4169 	}
4170 
4171 	rc = _spdk_blob_resize(blob, opts->num_clusters);
4172 	if (rc < 0) {
4173 		_spdk_blob_free(blob);
4174 		cb_fn(cb_arg, 0, rc);
4175 		return;
4176 	}
4177 	cpl.type = SPDK_BS_CPL_TYPE_BLOBID;
4178 	cpl.u.blobid.cb_fn = cb_fn;
4179 	cpl.u.blobid.cb_arg = cb_arg;
4180 	cpl.u.blobid.blobid = blob->id;
4181 
4182 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
4183 	if (!seq) {
4184 		_spdk_blob_free(blob);
4185 		cb_fn(cb_arg, 0, -ENOMEM);
4186 		return;
4187 	}
4188 
4189 	_spdk_blob_persist(seq, blob, _spdk_bs_create_blob_cpl, blob);
4190 }
4191 
4192 void spdk_bs_create_blob(struct spdk_blob_store *bs,
4193 			 spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4194 {
4195 	_spdk_bs_create_blob(bs, NULL, NULL, cb_fn, cb_arg);
4196 }
4197 
4198 void spdk_bs_create_blob_ext(struct spdk_blob_store *bs, const struct spdk_blob_opts *opts,
4199 			     spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4200 {
4201 	_spdk_bs_create_blob(bs, opts, NULL, cb_fn, cb_arg);
4202 }
4203 
4204 /* END spdk_bs_create_blob */
4205 
4206 /* START blob_cleanup */
4207 
4208 struct spdk_clone_snapshot_ctx {
4209 	struct spdk_bs_cpl      cpl;
4210 	int bserrno;
4211 	bool frozen;
4212 
4213 	struct spdk_io_channel *channel;
4214 
4215 	/* Current cluster for inflate operation */
4216 	uint64_t cluster;
4217 
4218 	/* For inflation force allocation of all unallocated clusters and remove
4219 	 * thin-provisioning. Otherwise only decouple parent and keep clone thin. */
4220 	bool allocate_all;
4221 
4222 	struct {
4223 		spdk_blob_id id;
4224 		struct spdk_blob *blob;
4225 	} original;
4226 	struct {
4227 		spdk_blob_id id;
4228 		struct spdk_blob *blob;
4229 	} new;
4230 
4231 	/* xattrs specified for snapshot/clones only. They have no impact on
4232 	 * the original blobs xattrs. */
4233 	const struct spdk_blob_xattr_opts *xattrs;
4234 };
4235 
4236 static void
4237 _spdk_bs_clone_snapshot_cleanup_finish(void *cb_arg, int bserrno)
4238 {
4239 	struct spdk_clone_snapshot_ctx *ctx = cb_arg;
4240 	struct spdk_bs_cpl *cpl = &ctx->cpl;
4241 
4242 	if (bserrno != 0) {
4243 		if (ctx->bserrno != 0) {
4244 			SPDK_ERRLOG("Cleanup error %d\n", bserrno);
4245 		} else {
4246 			ctx->bserrno = bserrno;
4247 		}
4248 	}
4249 
4250 	switch (cpl->type) {
4251 	case SPDK_BS_CPL_TYPE_BLOBID:
4252 		cpl->u.blobid.cb_fn(cpl->u.blobid.cb_arg, cpl->u.blobid.blobid, ctx->bserrno);
4253 		break;
4254 	case SPDK_BS_CPL_TYPE_BLOB_BASIC:
4255 		cpl->u.blob_basic.cb_fn(cpl->u.blob_basic.cb_arg, ctx->bserrno);
4256 		break;
4257 	default:
4258 		SPDK_UNREACHABLE();
4259 		break;
4260 	}
4261 
4262 	free(ctx);
4263 }
4264 
4265 static void
4266 _spdk_bs_snapshot_unfreeze_cpl(void *cb_arg, int bserrno)
4267 {
4268 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4269 	struct spdk_blob *origblob = ctx->original.blob;
4270 
4271 	if (bserrno != 0) {
4272 		if (ctx->bserrno != 0) {
4273 			SPDK_ERRLOG("Unfreeze error %d\n", bserrno);
4274 		} else {
4275 			ctx->bserrno = bserrno;
4276 		}
4277 	}
4278 
4279 	ctx->original.id = origblob->id;
4280 	spdk_blob_close(origblob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
4281 }
4282 
4283 static void
4284 _spdk_bs_clone_snapshot_origblob_cleanup(void *cb_arg, int bserrno)
4285 {
4286 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4287 	struct spdk_blob *origblob = ctx->original.blob;
4288 
4289 	if (bserrno != 0) {
4290 		if (ctx->bserrno != 0) {
4291 			SPDK_ERRLOG("Cleanup error %d\n", bserrno);
4292 		} else {
4293 			ctx->bserrno = bserrno;
4294 		}
4295 	}
4296 
4297 	if (ctx->frozen) {
4298 		/* Unfreeze any outstanding I/O */
4299 		_spdk_blob_unfreeze_io(origblob, _spdk_bs_snapshot_unfreeze_cpl, ctx);
4300 	} else {
4301 		_spdk_bs_snapshot_unfreeze_cpl(ctx, 0);
4302 	}
4303 
4304 }
4305 
4306 static void
4307 _spdk_bs_clone_snapshot_newblob_cleanup(void *cb_arg, int bserrno)
4308 {
4309 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4310 	struct spdk_blob *newblob = ctx->new.blob;
4311 
4312 	if (bserrno != 0) {
4313 		if (ctx->bserrno != 0) {
4314 			SPDK_ERRLOG("Cleanup error %d\n", bserrno);
4315 		} else {
4316 			ctx->bserrno = bserrno;
4317 		}
4318 	}
4319 
4320 	ctx->new.id = newblob->id;
4321 	spdk_blob_close(newblob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4322 }
4323 
4324 /* END blob_cleanup */
4325 
4326 /* START spdk_bs_create_snapshot */
4327 
4328 static void
4329 _spdk_bs_snapshot_origblob_sync_cpl(void *cb_arg, int bserrno)
4330 {
4331 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4332 	struct spdk_blob *newblob = ctx->new.blob;
4333 
4334 	if (bserrno != 0) {
4335 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4336 		return;
4337 	}
4338 
4339 	/* Remove metadata descriptor SNAPSHOT_IN_PROGRESS */
4340 	bserrno = _spdk_blob_remove_xattr(newblob, SNAPSHOT_IN_PROGRESS, true);
4341 	if (bserrno != 0) {
4342 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4343 		return;
4344 	}
4345 
4346 	_spdk_bs_blob_list_add(ctx->original.blob);
4347 
4348 	spdk_blob_set_read_only(newblob);
4349 
4350 	/* sync snapshot metadata */
4351 	spdk_blob_sync_md(newblob, _spdk_bs_clone_snapshot_origblob_cleanup, cb_arg);
4352 }
4353 
4354 static void
4355 _spdk_bs_snapshot_newblob_sync_cpl(void *cb_arg, int bserrno)
4356 {
4357 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4358 	struct spdk_blob *origblob = ctx->original.blob;
4359 	struct spdk_blob *newblob = ctx->new.blob;
4360 
4361 	if (bserrno != 0) {
4362 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4363 		return;
4364 	}
4365 
4366 	/* Set internal xattr for snapshot id */
4367 	bserrno = _spdk_blob_set_xattr(origblob, BLOB_SNAPSHOT, &newblob->id, sizeof(spdk_blob_id), true);
4368 	if (bserrno != 0) {
4369 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4370 		return;
4371 	}
4372 
4373 	_spdk_bs_blob_list_remove(origblob);
4374 	origblob->parent_id = newblob->id;
4375 
4376 	/* Create new back_bs_dev for snapshot */
4377 	origblob->back_bs_dev = spdk_bs_create_blob_bs_dev(newblob);
4378 	if (origblob->back_bs_dev == NULL) {
4379 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, -EINVAL);
4380 		return;
4381 	}
4382 
4383 	/* set clone blob as thin provisioned */
4384 	_spdk_blob_set_thin_provision(origblob);
4385 
4386 	_spdk_bs_blob_list_add(newblob);
4387 
4388 	/* Zero out origblob cluster map */
4389 	memset(origblob->active.clusters, 0,
4390 	       origblob->active.num_clusters * sizeof(origblob->active.clusters));
4391 
4392 	/* sync clone metadata */
4393 	spdk_blob_sync_md(origblob, _spdk_bs_snapshot_origblob_sync_cpl, ctx);
4394 }
4395 
4396 static void
4397 _spdk_bs_snapshot_freeze_cpl(void *cb_arg, int rc)
4398 {
4399 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4400 	struct spdk_blob *origblob = ctx->original.blob;
4401 	struct spdk_blob *newblob = ctx->new.blob;
4402 	int bserrno;
4403 
4404 	if (rc != 0) {
4405 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, rc);
4406 		return;
4407 	}
4408 
4409 	ctx->frozen = true;
4410 
4411 	/* set new back_bs_dev for snapshot */
4412 	newblob->back_bs_dev = origblob->back_bs_dev;
4413 	/* Set invalid flags from origblob */
4414 	newblob->invalid_flags = origblob->invalid_flags;
4415 
4416 	/* inherit parent from original blob if set */
4417 	newblob->parent_id = origblob->parent_id;
4418 	if (origblob->parent_id != SPDK_BLOBID_INVALID) {
4419 		/* Set internal xattr for snapshot id */
4420 		bserrno = _spdk_blob_set_xattr(newblob, BLOB_SNAPSHOT,
4421 					       &origblob->parent_id, sizeof(spdk_blob_id), true);
4422 		if (bserrno != 0) {
4423 			_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4424 			return;
4425 		}
4426 	}
4427 
4428 	/* Copy cluster map to snapshot */
4429 	memcpy(newblob->active.clusters, origblob->active.clusters,
4430 	       origblob->active.num_clusters * sizeof(origblob->active.clusters));
4431 
4432 	/* sync snapshot metadata */
4433 	spdk_blob_sync_md(newblob, _spdk_bs_snapshot_newblob_sync_cpl, ctx);
4434 }
4435 
4436 static void
4437 _spdk_bs_snapshot_newblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4438 {
4439 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4440 	struct spdk_blob *origblob = ctx->original.blob;
4441 	struct spdk_blob *newblob = _blob;
4442 
4443 	if (bserrno != 0) {
4444 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4445 		return;
4446 	}
4447 
4448 	ctx->new.blob = newblob;
4449 
4450 	_spdk_blob_freeze_io(origblob, _spdk_bs_snapshot_freeze_cpl, ctx);
4451 }
4452 
4453 static void
4454 _spdk_bs_snapshot_newblob_create_cpl(void *cb_arg, spdk_blob_id blobid, int bserrno)
4455 {
4456 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4457 	struct spdk_blob *origblob = ctx->original.blob;
4458 
4459 	if (bserrno != 0) {
4460 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4461 		return;
4462 	}
4463 
4464 	ctx->new.id = blobid;
4465 	ctx->cpl.u.blobid.blobid = blobid;
4466 
4467 	spdk_bs_open_blob(origblob->bs, ctx->new.id, _spdk_bs_snapshot_newblob_open_cpl, ctx);
4468 }
4469 
4470 
4471 static void
4472 _spdk_bs_xattr_snapshot(void *arg, const char *name,
4473 			const void **value, size_t *value_len)
4474 {
4475 	assert(strncmp(name, SNAPSHOT_IN_PROGRESS, sizeof(SNAPSHOT_IN_PROGRESS)) == 0);
4476 
4477 	struct spdk_blob *blob = (struct spdk_blob *)arg;
4478 	*value = &blob->id;
4479 	*value_len = sizeof(blob->id);
4480 }
4481 
4482 static void
4483 _spdk_bs_snapshot_origblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4484 {
4485 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4486 	struct spdk_blob_opts opts;
4487 	struct spdk_blob_xattr_opts internal_xattrs;
4488 	char *xattrs_names[] = { SNAPSHOT_IN_PROGRESS };
4489 
4490 	if (bserrno != 0) {
4491 		_spdk_bs_clone_snapshot_cleanup_finish(ctx, bserrno);
4492 		return;
4493 	}
4494 
4495 	ctx->original.blob = _blob;
4496 
4497 	if (_blob->data_ro || _blob->md_ro) {
4498 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot create snapshot from read only blob with id %lu\n",
4499 			      _blob->id);
4500 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, -EINVAL);
4501 		return;
4502 	}
4503 
4504 	spdk_blob_opts_init(&opts);
4505 	_spdk_blob_xattrs_init(&internal_xattrs);
4506 
4507 	/* Change the size of new blob to the same as in original blob,
4508 	 * but do not allocate clusters */
4509 	opts.thin_provision = true;
4510 	opts.num_clusters = spdk_blob_get_num_clusters(_blob);
4511 
4512 	/* If there are any xattrs specified for snapshot, set them now */
4513 	if (ctx->xattrs) {
4514 		memcpy(&opts.xattrs, ctx->xattrs, sizeof(*ctx->xattrs));
4515 	}
4516 	/* Set internal xattr SNAPSHOT_IN_PROGRESS */
4517 	internal_xattrs.count = 1;
4518 	internal_xattrs.ctx = _blob;
4519 	internal_xattrs.names = xattrs_names;
4520 	internal_xattrs.get_value = _spdk_bs_xattr_snapshot;
4521 
4522 	_spdk_bs_create_blob(_blob->bs, &opts, &internal_xattrs,
4523 			     _spdk_bs_snapshot_newblob_create_cpl, ctx);
4524 }
4525 
4526 void spdk_bs_create_snapshot(struct spdk_blob_store *bs, spdk_blob_id blobid,
4527 			     const struct spdk_blob_xattr_opts *snapshot_xattrs,
4528 			     spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4529 {
4530 	struct spdk_clone_snapshot_ctx *ctx = calloc(1, sizeof(*ctx));
4531 
4532 	if (!ctx) {
4533 		cb_fn(cb_arg, SPDK_BLOBID_INVALID, -ENOMEM);
4534 		return;
4535 	}
4536 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BLOBID;
4537 	ctx->cpl.u.blobid.cb_fn = cb_fn;
4538 	ctx->cpl.u.blobid.cb_arg = cb_arg;
4539 	ctx->cpl.u.blobid.blobid = SPDK_BLOBID_INVALID;
4540 	ctx->bserrno = 0;
4541 	ctx->frozen = false;
4542 	ctx->original.id = blobid;
4543 	ctx->xattrs = snapshot_xattrs;
4544 
4545 	spdk_bs_open_blob(bs, ctx->original.id, _spdk_bs_snapshot_origblob_open_cpl, ctx);
4546 }
4547 /* END spdk_bs_create_snapshot */
4548 
4549 /* START spdk_bs_create_clone */
4550 
4551 static void
4552 _spdk_bs_xattr_clone(void *arg, const char *name,
4553 		     const void **value, size_t *value_len)
4554 {
4555 	assert(strncmp(name, BLOB_SNAPSHOT, sizeof(BLOB_SNAPSHOT)) == 0);
4556 
4557 	struct spdk_blob *blob = (struct spdk_blob *)arg;
4558 	*value = &blob->id;
4559 	*value_len = sizeof(blob->id);
4560 }
4561 
4562 static void
4563 _spdk_bs_clone_newblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4564 {
4565 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4566 	struct spdk_blob *clone = _blob;
4567 
4568 	ctx->new.blob = clone;
4569 	_spdk_bs_blob_list_add(clone);
4570 
4571 	spdk_blob_close(clone, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4572 }
4573 
4574 static void
4575 _spdk_bs_clone_newblob_create_cpl(void *cb_arg, spdk_blob_id blobid, int bserrno)
4576 {
4577 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4578 
4579 	ctx->cpl.u.blobid.blobid = blobid;
4580 	spdk_bs_open_blob(ctx->original.blob->bs, blobid, _spdk_bs_clone_newblob_open_cpl, ctx);
4581 }
4582 
4583 static void
4584 _spdk_bs_clone_origblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4585 {
4586 	struct spdk_clone_snapshot_ctx	*ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4587 	struct spdk_blob_opts		opts;
4588 	struct spdk_blob_xattr_opts internal_xattrs;
4589 	char *xattr_names[] = { BLOB_SNAPSHOT };
4590 
4591 	if (bserrno != 0) {
4592 		_spdk_bs_clone_snapshot_cleanup_finish(ctx, bserrno);
4593 		return;
4594 	}
4595 
4596 	ctx->original.blob = _blob;
4597 
4598 	if (!_blob->data_ro || !_blob->md_ro) {
4599 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Clone not from read-only blob\n");
4600 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, -EINVAL);
4601 		return;
4602 	}
4603 
4604 	spdk_blob_opts_init(&opts);
4605 	_spdk_blob_xattrs_init(&internal_xattrs);
4606 
4607 	opts.thin_provision = true;
4608 	opts.num_clusters = spdk_blob_get_num_clusters(_blob);
4609 	if (ctx->xattrs) {
4610 		memcpy(&opts.xattrs, ctx->xattrs, sizeof(*ctx->xattrs));
4611 	}
4612 
4613 	/* Set internal xattr BLOB_SNAPSHOT */
4614 	internal_xattrs.count = 1;
4615 	internal_xattrs.ctx = _blob;
4616 	internal_xattrs.names = xattr_names;
4617 	internal_xattrs.get_value = _spdk_bs_xattr_clone;
4618 
4619 	_spdk_bs_create_blob(_blob->bs, &opts, &internal_xattrs,
4620 			     _spdk_bs_clone_newblob_create_cpl, ctx);
4621 }
4622 
4623 void spdk_bs_create_clone(struct spdk_blob_store *bs, spdk_blob_id blobid,
4624 			  const struct spdk_blob_xattr_opts *clone_xattrs,
4625 			  spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4626 {
4627 	struct spdk_clone_snapshot_ctx	*ctx = calloc(1, sizeof(*ctx));
4628 
4629 	if (!ctx) {
4630 		cb_fn(cb_arg, SPDK_BLOBID_INVALID, -ENOMEM);
4631 		return;
4632 	}
4633 
4634 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BLOBID;
4635 	ctx->cpl.u.blobid.cb_fn = cb_fn;
4636 	ctx->cpl.u.blobid.cb_arg = cb_arg;
4637 	ctx->cpl.u.blobid.blobid = SPDK_BLOBID_INVALID;
4638 	ctx->bserrno = 0;
4639 	ctx->xattrs = clone_xattrs;
4640 	ctx->original.id = blobid;
4641 
4642 	spdk_bs_open_blob(bs, ctx->original.id, _spdk_bs_clone_origblob_open_cpl, ctx);
4643 }
4644 
4645 /* END spdk_bs_create_clone */
4646 
4647 /* START spdk_bs_inflate_blob */
4648 
4649 static void
4650 _spdk_bs_inflate_blob_set_parent_cpl(void *cb_arg, struct spdk_blob *_parent, int bserrno)
4651 {
4652 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4653 	struct spdk_blob *_blob = ctx->original.blob;
4654 
4655 	if (bserrno != 0) {
4656 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4657 		return;
4658 	}
4659 
4660 	assert(_parent != NULL);
4661 
4662 	_spdk_bs_blob_list_remove(_blob);
4663 	_blob->parent_id = _parent->id;
4664 	_spdk_blob_set_xattr(_blob, BLOB_SNAPSHOT, &_blob->parent_id,
4665 			     sizeof(spdk_blob_id), true);
4666 
4667 	_blob->back_bs_dev->destroy(_blob->back_bs_dev);
4668 	_blob->back_bs_dev = spdk_bs_create_blob_bs_dev(_parent);
4669 	_spdk_bs_blob_list_add(_blob);
4670 
4671 	spdk_blob_sync_md(_blob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4672 }
4673 
4674 static void
4675 _spdk_bs_inflate_blob_done(void *cb_arg, int bserrno)
4676 {
4677 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4678 	struct spdk_blob *_blob = ctx->original.blob;
4679 	struct spdk_blob *_parent;
4680 
4681 	if (bserrno != 0) {
4682 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4683 		return;
4684 	}
4685 
4686 	if (ctx->allocate_all) {
4687 		/* remove thin provisioning */
4688 		_spdk_bs_blob_list_remove(_blob);
4689 		_spdk_blob_remove_xattr(_blob, BLOB_SNAPSHOT, true);
4690 		_blob->invalid_flags = _blob->invalid_flags & ~SPDK_BLOB_THIN_PROV;
4691 		_blob->back_bs_dev->destroy(_blob->back_bs_dev);
4692 		_blob->back_bs_dev = NULL;
4693 		_blob->parent_id = SPDK_BLOBID_INVALID;
4694 	} else {
4695 		_parent = ((struct spdk_blob_bs_dev *)(_blob->back_bs_dev))->blob;
4696 		if (_parent->parent_id != SPDK_BLOBID_INVALID) {
4697 			/* We must change the parent of the inflated blob */
4698 			spdk_bs_open_blob(_blob->bs, _parent->parent_id,
4699 					  _spdk_bs_inflate_blob_set_parent_cpl, ctx);
4700 			return;
4701 		}
4702 
4703 		_spdk_bs_blob_list_remove(_blob);
4704 		_spdk_blob_remove_xattr(_blob, BLOB_SNAPSHOT, true);
4705 		_blob->parent_id = SPDK_BLOBID_INVALID;
4706 		_blob->back_bs_dev->destroy(_blob->back_bs_dev);
4707 		_blob->back_bs_dev = spdk_bs_create_zeroes_dev();
4708 	}
4709 
4710 	_blob->state = SPDK_BLOB_STATE_DIRTY;
4711 	spdk_blob_sync_md(_blob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4712 }
4713 
4714 /* Check if cluster needs allocation */
4715 static inline bool
4716 _spdk_bs_cluster_needs_allocation(struct spdk_blob *blob, uint64_t cluster, bool allocate_all)
4717 {
4718 	struct spdk_blob_bs_dev *b;
4719 
4720 	assert(blob != NULL);
4721 
4722 	if (blob->active.clusters[cluster] != 0) {
4723 		/* Cluster is already allocated */
4724 		return false;
4725 	}
4726 
4727 	if (blob->parent_id == SPDK_BLOBID_INVALID) {
4728 		/* Blob have no parent blob */
4729 		return allocate_all;
4730 	}
4731 
4732 	b = (struct spdk_blob_bs_dev *)blob->back_bs_dev;
4733 	return (allocate_all || b->blob->active.clusters[cluster] != 0);
4734 }
4735 
4736 static void
4737 _spdk_bs_inflate_blob_touch_next(void *cb_arg, int bserrno)
4738 {
4739 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4740 	struct spdk_blob *_blob = ctx->original.blob;
4741 	uint64_t offset;
4742 
4743 	if (bserrno != 0) {
4744 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4745 		return;
4746 	}
4747 
4748 	for (; ctx->cluster < _blob->active.num_clusters; ctx->cluster++) {
4749 		if (_spdk_bs_cluster_needs_allocation(_blob, ctx->cluster, ctx->allocate_all)) {
4750 			break;
4751 		}
4752 	}
4753 
4754 	if (ctx->cluster < _blob->active.num_clusters) {
4755 		offset = _spdk_bs_cluster_to_lba(_blob->bs, ctx->cluster);
4756 
4757 		/* We may safely increment a cluster before write */
4758 		ctx->cluster++;
4759 
4760 		/* Use zero length write to touch a cluster */
4761 		spdk_blob_io_write(_blob, ctx->channel, NULL, offset, 0,
4762 				   _spdk_bs_inflate_blob_touch_next, ctx);
4763 	} else {
4764 		_spdk_bs_inflate_blob_done(cb_arg, bserrno);
4765 	}
4766 }
4767 
4768 static void
4769 _spdk_bs_inflate_blob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4770 {
4771 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4772 	uint64_t lfc; /* lowest free cluster */
4773 	uint64_t i;
4774 
4775 	if (bserrno != 0) {
4776 		_spdk_bs_clone_snapshot_cleanup_finish(ctx, bserrno);
4777 		return;
4778 	}
4779 	ctx->original.blob = _blob;
4780 
4781 	if (!ctx->allocate_all && _blob->parent_id == SPDK_BLOBID_INVALID) {
4782 		/* This blob have no parent, so we cannot decouple it. */
4783 		SPDK_ERRLOG("Cannot decouple parent of blob with no parent.\n");
4784 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, -EINVAL);
4785 		return;
4786 	}
4787 
4788 	if (spdk_blob_is_thin_provisioned(_blob) == false) {
4789 		/* This is not thin provisioned blob. No need to inflate. */
4790 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, 0);
4791 		return;
4792 	}
4793 
4794 	/* Do two passes - one to verify that we can obtain enough clusters
4795 	 * and another to actually claim them.
4796 	 */
4797 	lfc = 0;
4798 	for (i = 0; i < _blob->active.num_clusters; i++) {
4799 		if (_spdk_bs_cluster_needs_allocation(_blob, i, ctx->allocate_all)) {
4800 			lfc = spdk_bit_array_find_first_clear(_blob->bs->used_clusters, lfc);
4801 			if (lfc == UINT32_MAX) {
4802 				/* No more free clusters. Cannot satisfy the request */
4803 				_spdk_bs_clone_snapshot_origblob_cleanup(ctx, -ENOSPC);
4804 				return;
4805 			}
4806 			lfc++;
4807 		}
4808 	}
4809 
4810 	ctx->cluster = 0;
4811 	_spdk_bs_inflate_blob_touch_next(ctx, 0);
4812 }
4813 
4814 static void
4815 _spdk_bs_inflate_blob(struct spdk_blob_store *bs, struct spdk_io_channel *channel,
4816 		      spdk_blob_id blobid, bool allocate_all, spdk_blob_op_complete cb_fn, void *cb_arg)
4817 {
4818 	struct spdk_clone_snapshot_ctx *ctx = calloc(1, sizeof(*ctx));
4819 
4820 	if (!ctx) {
4821 		cb_fn(cb_arg, -ENOMEM);
4822 		return;
4823 	}
4824 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
4825 	ctx->cpl.u.bs_basic.cb_fn = cb_fn;
4826 	ctx->cpl.u.bs_basic.cb_arg = cb_arg;
4827 	ctx->bserrno = 0;
4828 	ctx->original.id = blobid;
4829 	ctx->channel = channel;
4830 	ctx->allocate_all = allocate_all;
4831 
4832 	spdk_bs_open_blob(bs, ctx->original.id, _spdk_bs_inflate_blob_open_cpl, ctx);
4833 }
4834 
4835 void
4836 spdk_bs_inflate_blob(struct spdk_blob_store *bs, struct spdk_io_channel *channel,
4837 		     spdk_blob_id blobid, spdk_blob_op_complete cb_fn, void *cb_arg)
4838 {
4839 	_spdk_bs_inflate_blob(bs, channel, blobid, true, cb_fn, cb_arg);
4840 }
4841 
4842 void
4843 spdk_bs_blob_decouple_parent(struct spdk_blob_store *bs, struct spdk_io_channel *channel,
4844 			     spdk_blob_id blobid, spdk_blob_op_complete cb_fn, void *cb_arg)
4845 {
4846 	_spdk_bs_inflate_blob(bs, channel, blobid, false, cb_fn, cb_arg);
4847 }
4848 /* END spdk_bs_inflate_blob */
4849 
4850 /* START spdk_blob_resize */
4851 struct spdk_bs_resize_ctx {
4852 	spdk_blob_op_complete cb_fn;
4853 	void *cb_arg;
4854 	struct spdk_blob *blob;
4855 	uint64_t sz;
4856 	int rc;
4857 };
4858 
4859 static void
4860 _spdk_bs_resize_unfreeze_cpl(void *cb_arg, int rc)
4861 {
4862 	struct spdk_bs_resize_ctx *ctx = (struct spdk_bs_resize_ctx *)cb_arg;
4863 
4864 	if (rc != 0) {
4865 		SPDK_ERRLOG("Unfreeze failed, rc=%d\n", rc);
4866 	}
4867 
4868 	if (ctx->rc != 0) {
4869 		SPDK_ERRLOG("Unfreeze failed, ctx->rc=%d\n", ctx->rc);
4870 		rc = ctx->rc;
4871 	}
4872 
4873 	ctx->blob->resize_in_progress = false;
4874 
4875 	ctx->cb_fn(ctx->cb_arg, rc);
4876 	free(ctx);
4877 }
4878 
4879 static void
4880 _spdk_bs_resize_freeze_cpl(void *cb_arg, int rc)
4881 {
4882 	struct spdk_bs_resize_ctx *ctx = (struct spdk_bs_resize_ctx *)cb_arg;
4883 
4884 	if (rc != 0) {
4885 		ctx->blob->resize_in_progress = false;
4886 		ctx->cb_fn(ctx->cb_arg, rc);
4887 		free(ctx);
4888 		return;
4889 	}
4890 
4891 	ctx->rc = _spdk_blob_resize(ctx->blob, ctx->sz);
4892 
4893 	_spdk_blob_unfreeze_io(ctx->blob, _spdk_bs_resize_unfreeze_cpl, ctx);
4894 }
4895 
4896 void
4897 spdk_blob_resize(struct spdk_blob *blob, uint64_t sz, spdk_blob_op_complete cb_fn, void *cb_arg)
4898 {
4899 	struct spdk_bs_resize_ctx *ctx;
4900 
4901 	_spdk_blob_verify_md_op(blob);
4902 
4903 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Resizing blob %lu to %lu clusters\n", blob->id, sz);
4904 
4905 	if (blob->md_ro) {
4906 		cb_fn(cb_arg, -EPERM);
4907 		return;
4908 	}
4909 
4910 	if (sz == blob->active.num_clusters) {
4911 		cb_fn(cb_arg, 0);
4912 		return;
4913 	}
4914 
4915 	if (blob->resize_in_progress) {
4916 		cb_fn(cb_arg, -EBUSY);
4917 		return;
4918 	}
4919 
4920 	ctx = calloc(1, sizeof(*ctx));
4921 	if (!ctx) {
4922 		cb_fn(cb_arg, -ENOMEM);
4923 		return;
4924 	}
4925 
4926 	blob->resize_in_progress = true;
4927 	ctx->cb_fn = cb_fn;
4928 	ctx->cb_arg = cb_arg;
4929 	ctx->blob = blob;
4930 	ctx->sz = sz;
4931 	_spdk_blob_freeze_io(blob, _spdk_bs_resize_freeze_cpl, ctx);
4932 }
4933 
4934 /* END spdk_blob_resize */
4935 
4936 
4937 /* START spdk_bs_delete_blob */
4938 
4939 static void
4940 _spdk_bs_delete_close_cpl(void *cb_arg, int bserrno)
4941 {
4942 	spdk_bs_sequence_t *seq = cb_arg;
4943 
4944 	spdk_bs_sequence_finish(seq, bserrno);
4945 }
4946 
4947 static void
4948 _spdk_bs_delete_persist_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4949 {
4950 	struct spdk_blob *blob = cb_arg;
4951 
4952 	if (bserrno != 0) {
4953 		/*
4954 		 * We already removed this blob from the blobstore tailq, so
4955 		 *  we need to free it here since this is the last reference
4956 		 *  to it.
4957 		 */
4958 		_spdk_blob_free(blob);
4959 		_spdk_bs_delete_close_cpl(seq, bserrno);
4960 		return;
4961 	}
4962 
4963 	/*
4964 	 * This will immediately decrement the ref_count and call
4965 	 *  the completion routine since the metadata state is clean.
4966 	 *  By calling spdk_blob_close, we reduce the number of call
4967 	 *  points into code that touches the blob->open_ref count
4968 	 *  and the blobstore's blob list.
4969 	 */
4970 	spdk_blob_close(blob, _spdk_bs_delete_close_cpl, seq);
4971 }
4972 
4973 static void
4974 _spdk_bs_delete_open_cpl(void *cb_arg, struct spdk_blob *blob, int bserrno)
4975 {
4976 	spdk_bs_sequence_t *seq = cb_arg;
4977 	struct spdk_blob_list *snapshot = NULL;
4978 	uint32_t page_num;
4979 
4980 	if (bserrno != 0) {
4981 		spdk_bs_sequence_finish(seq, bserrno);
4982 		return;
4983 	}
4984 
4985 	_spdk_blob_verify_md_op(blob);
4986 
4987 	if (blob->open_ref > 1) {
4988 		/*
4989 		 * Someone has this blob open (besides this delete context).
4990 		 *  Decrement the ref count directly and return -EBUSY.
4991 		 */
4992 		blob->open_ref--;
4993 		spdk_bs_sequence_finish(seq, -EBUSY);
4994 		return;
4995 	}
4996 
4997 	bserrno = _spdk_bs_blob_list_remove(blob);
4998 	if (bserrno != 0) {
4999 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Remove blob #%" PRIu64 " from a list\n", blob->id);
5000 		spdk_bs_sequence_finish(seq, bserrno);
5001 		return;
5002 	}
5003 
5004 	/*
5005 	 * Remove the blob from the blob_store list now, to ensure it does not
5006 	 *  get returned after this point by _spdk_blob_lookup().
5007 	 */
5008 	TAILQ_REMOVE(&blob->bs->blobs, blob, link);
5009 
5010 	/* If blob is a snapshot then remove it from the list */
5011 	TAILQ_FOREACH(snapshot, &blob->bs->snapshots, link) {
5012 		if (snapshot->id == blob->id) {
5013 			TAILQ_REMOVE(&blob->bs->snapshots, snapshot, link);
5014 			free(snapshot);
5015 			break;
5016 		}
5017 	}
5018 
5019 	page_num = _spdk_bs_blobid_to_page(blob->id);
5020 	spdk_bit_array_clear(blob->bs->used_blobids, page_num);
5021 	blob->state = SPDK_BLOB_STATE_DIRTY;
5022 	blob->active.num_pages = 0;
5023 	_spdk_blob_resize(blob, 0);
5024 
5025 	_spdk_blob_persist(seq, blob, _spdk_bs_delete_persist_cpl, blob);
5026 }
5027 
5028 void
5029 spdk_bs_delete_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
5030 		    spdk_blob_op_complete cb_fn, void *cb_arg)
5031 {
5032 	struct spdk_bs_cpl	cpl;
5033 	spdk_bs_sequence_t	*seq;
5034 	struct spdk_blob_list	*snapshot_entry = NULL;
5035 
5036 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Deleting blob %lu\n", blobid);
5037 
5038 	assert(spdk_get_thread() == bs->md_thread);
5039 
5040 	/* Check if this is a snapshot with clones */
5041 	TAILQ_FOREACH(snapshot_entry, &bs->snapshots, link) {
5042 		if (snapshot_entry->id == blobid) {
5043 			break;
5044 		}
5045 	}
5046 	if (snapshot_entry != NULL) {
5047 		/* If snapshot have clones, we cannot remove it */
5048 		if (!TAILQ_EMPTY(&snapshot_entry->clones)) {
5049 			SPDK_ERRLOG("Cannot remove snapshot with clones\n");
5050 			cb_fn(cb_arg, -EBUSY);
5051 			return;
5052 		}
5053 	}
5054 
5055 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5056 	cpl.u.blob_basic.cb_fn = cb_fn;
5057 	cpl.u.blob_basic.cb_arg = cb_arg;
5058 
5059 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
5060 	if (!seq) {
5061 		cb_fn(cb_arg, -ENOMEM);
5062 		return;
5063 	}
5064 
5065 	spdk_bs_open_blob(bs, blobid, _spdk_bs_delete_open_cpl, seq);
5066 }
5067 
5068 /* END spdk_bs_delete_blob */
5069 
5070 /* START spdk_bs_open_blob */
5071 
5072 static void
5073 _spdk_bs_open_blob_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5074 {
5075 	struct spdk_blob *blob = cb_arg;
5076 
5077 	/* If the blob have crc error, we just return NULL. */
5078 	if (blob == NULL) {
5079 		seq->cpl.u.blob_handle.blob = NULL;
5080 		spdk_bs_sequence_finish(seq, bserrno);
5081 		return;
5082 	}
5083 
5084 	blob->open_ref++;
5085 
5086 	TAILQ_INSERT_HEAD(&blob->bs->blobs, blob, link);
5087 
5088 	spdk_bs_sequence_finish(seq, bserrno);
5089 }
5090 
5091 static void _spdk_bs_open_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
5092 			       struct spdk_blob_open_opts *opts, spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5093 {
5094 	struct spdk_blob		*blob;
5095 	struct spdk_bs_cpl		cpl;
5096 	struct spdk_blob_open_opts	opts_default;
5097 	spdk_bs_sequence_t		*seq;
5098 	uint32_t			page_num;
5099 
5100 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Opening blob %lu\n", blobid);
5101 	assert(spdk_get_thread() == bs->md_thread);
5102 
5103 	page_num = _spdk_bs_blobid_to_page(blobid);
5104 	if (spdk_bit_array_get(bs->used_blobids, page_num) == false) {
5105 		/* Invalid blobid */
5106 		cb_fn(cb_arg, NULL, -ENOENT);
5107 		return;
5108 	}
5109 
5110 	blob = _spdk_blob_lookup(bs, blobid);
5111 	if (blob) {
5112 		blob->open_ref++;
5113 		cb_fn(cb_arg, blob, 0);
5114 		return;
5115 	}
5116 
5117 	blob = _spdk_blob_alloc(bs, blobid);
5118 	if (!blob) {
5119 		cb_fn(cb_arg, NULL, -ENOMEM);
5120 		return;
5121 	}
5122 
5123 	if (!opts) {
5124 		spdk_blob_open_opts_init(&opts_default);
5125 		opts = &opts_default;
5126 	}
5127 
5128 	blob->clear_method = opts->clear_method;
5129 
5130 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_HANDLE;
5131 	cpl.u.blob_handle.cb_fn = cb_fn;
5132 	cpl.u.blob_handle.cb_arg = cb_arg;
5133 	cpl.u.blob_handle.blob = blob;
5134 
5135 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
5136 	if (!seq) {
5137 		_spdk_blob_free(blob);
5138 		cb_fn(cb_arg, NULL, -ENOMEM);
5139 		return;
5140 	}
5141 
5142 	_spdk_blob_load(seq, blob, _spdk_bs_open_blob_cpl, blob);
5143 }
5144 
5145 void spdk_bs_open_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
5146 		       spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5147 {
5148 	_spdk_bs_open_blob(bs, blobid, NULL, cb_fn, cb_arg);
5149 }
5150 
5151 void spdk_bs_open_blob_ext(struct spdk_blob_store *bs, spdk_blob_id blobid,
5152 			   struct spdk_blob_open_opts *opts, spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5153 {
5154 	_spdk_bs_open_blob(bs, blobid, opts, cb_fn, cb_arg);
5155 }
5156 
5157 /* END spdk_bs_open_blob */
5158 
5159 /* START spdk_blob_set_read_only */
5160 int spdk_blob_set_read_only(struct spdk_blob *blob)
5161 {
5162 	_spdk_blob_verify_md_op(blob);
5163 
5164 	blob->data_ro_flags |= SPDK_BLOB_READ_ONLY;
5165 
5166 	blob->state = SPDK_BLOB_STATE_DIRTY;
5167 	return 0;
5168 }
5169 /* END spdk_blob_set_read_only */
5170 
5171 /* START spdk_blob_sync_md */
5172 
5173 static void
5174 _spdk_blob_sync_md_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5175 {
5176 	struct spdk_blob *blob = cb_arg;
5177 
5178 	if (bserrno == 0 && (blob->data_ro_flags & SPDK_BLOB_READ_ONLY)) {
5179 		blob->data_ro = true;
5180 		blob->md_ro = true;
5181 	}
5182 
5183 	spdk_bs_sequence_finish(seq, bserrno);
5184 }
5185 
5186 static void
5187 _spdk_blob_sync_md(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
5188 {
5189 	struct spdk_bs_cpl	cpl;
5190 	spdk_bs_sequence_t	*seq;
5191 
5192 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5193 	cpl.u.blob_basic.cb_fn = cb_fn;
5194 	cpl.u.blob_basic.cb_arg = cb_arg;
5195 
5196 	seq = spdk_bs_sequence_start(blob->bs->md_channel, &cpl);
5197 	if (!seq) {
5198 		cb_fn(cb_arg, -ENOMEM);
5199 		return;
5200 	}
5201 
5202 	_spdk_blob_persist(seq, blob, _spdk_blob_sync_md_cpl, blob);
5203 }
5204 
5205 void
5206 spdk_blob_sync_md(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
5207 {
5208 	_spdk_blob_verify_md_op(blob);
5209 
5210 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Syncing blob %lu\n", blob->id);
5211 
5212 	if (blob->md_ro) {
5213 		assert(blob->state == SPDK_BLOB_STATE_CLEAN);
5214 		cb_fn(cb_arg, 0);
5215 		return;
5216 	}
5217 
5218 	_spdk_blob_sync_md(blob, cb_fn, cb_arg);
5219 }
5220 
5221 /* END spdk_blob_sync_md */
5222 
5223 struct spdk_blob_insert_cluster_ctx {
5224 	struct spdk_thread	*thread;
5225 	struct spdk_blob	*blob;
5226 	uint32_t		cluster_num;	/* cluster index in blob */
5227 	uint32_t		cluster;	/* cluster on disk */
5228 	int			rc;
5229 	spdk_blob_op_complete	cb_fn;
5230 	void			*cb_arg;
5231 };
5232 
5233 static void
5234 _spdk_blob_insert_cluster_msg_cpl(void *arg)
5235 {
5236 	struct spdk_blob_insert_cluster_ctx *ctx = arg;
5237 
5238 	ctx->cb_fn(ctx->cb_arg, ctx->rc);
5239 	free(ctx);
5240 }
5241 
5242 static void
5243 _spdk_blob_insert_cluster_msg_cb(void *arg, int bserrno)
5244 {
5245 	struct spdk_blob_insert_cluster_ctx *ctx = arg;
5246 
5247 	ctx->rc = bserrno;
5248 	spdk_thread_send_msg(ctx->thread, _spdk_blob_insert_cluster_msg_cpl, ctx);
5249 }
5250 
5251 static void
5252 _spdk_blob_insert_cluster_msg(void *arg)
5253 {
5254 	struct spdk_blob_insert_cluster_ctx *ctx = arg;
5255 
5256 	ctx->rc = _spdk_blob_insert_cluster(ctx->blob, ctx->cluster_num, ctx->cluster);
5257 	if (ctx->rc != 0) {
5258 		spdk_thread_send_msg(ctx->thread, _spdk_blob_insert_cluster_msg_cpl, ctx);
5259 		return;
5260 	}
5261 
5262 	ctx->blob->state = SPDK_BLOB_STATE_DIRTY;
5263 	_spdk_blob_sync_md(ctx->blob, _spdk_blob_insert_cluster_msg_cb, ctx);
5264 }
5265 
5266 static void
5267 _spdk_blob_insert_cluster_on_md_thread(struct spdk_blob *blob, uint32_t cluster_num,
5268 				       uint64_t cluster, spdk_blob_op_complete cb_fn, void *cb_arg)
5269 {
5270 	struct spdk_blob_insert_cluster_ctx *ctx;
5271 
5272 	ctx = calloc(1, sizeof(*ctx));
5273 	if (ctx == NULL) {
5274 		cb_fn(cb_arg, -ENOMEM);
5275 		return;
5276 	}
5277 
5278 	ctx->thread = spdk_get_thread();
5279 	ctx->blob = blob;
5280 	ctx->cluster_num = cluster_num;
5281 	ctx->cluster = cluster;
5282 	ctx->cb_fn = cb_fn;
5283 	ctx->cb_arg = cb_arg;
5284 
5285 	spdk_thread_send_msg(blob->bs->md_thread, _spdk_blob_insert_cluster_msg, ctx);
5286 }
5287 
5288 /* START spdk_blob_close */
5289 
5290 static void
5291 _spdk_blob_close_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5292 {
5293 	struct spdk_blob *blob = cb_arg;
5294 
5295 	if (bserrno == 0) {
5296 		blob->open_ref--;
5297 		if (blob->open_ref == 0) {
5298 			/*
5299 			 * Blobs with active.num_pages == 0 are deleted blobs.
5300 			 *  these blobs are removed from the blob_store list
5301 			 *  when the deletion process starts - so don't try to
5302 			 *  remove them again.
5303 			 */
5304 			if (blob->active.num_pages > 0) {
5305 				TAILQ_REMOVE(&blob->bs->blobs, blob, link);
5306 			}
5307 			_spdk_blob_free(blob);
5308 		}
5309 	}
5310 
5311 	spdk_bs_sequence_finish(seq, bserrno);
5312 }
5313 
5314 void spdk_blob_close(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
5315 {
5316 	struct spdk_bs_cpl	cpl;
5317 	spdk_bs_sequence_t	*seq;
5318 
5319 	_spdk_blob_verify_md_op(blob);
5320 
5321 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Closing blob %lu\n", blob->id);
5322 
5323 	if (blob->open_ref == 0) {
5324 		cb_fn(cb_arg, -EBADF);
5325 		return;
5326 	}
5327 
5328 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5329 	cpl.u.blob_basic.cb_fn = cb_fn;
5330 	cpl.u.blob_basic.cb_arg = cb_arg;
5331 
5332 	seq = spdk_bs_sequence_start(blob->bs->md_channel, &cpl);
5333 	if (!seq) {
5334 		cb_fn(cb_arg, -ENOMEM);
5335 		return;
5336 	}
5337 
5338 	/* Sync metadata */
5339 	_spdk_blob_persist(seq, blob, _spdk_blob_close_cpl, blob);
5340 }
5341 
5342 /* END spdk_blob_close */
5343 
5344 struct spdk_io_channel *spdk_bs_alloc_io_channel(struct spdk_blob_store *bs)
5345 {
5346 	return spdk_get_io_channel(bs);
5347 }
5348 
5349 void spdk_bs_free_io_channel(struct spdk_io_channel *channel)
5350 {
5351 	spdk_put_io_channel(channel);
5352 }
5353 
5354 void spdk_blob_io_unmap(struct spdk_blob *blob, struct spdk_io_channel *channel,
5355 			uint64_t offset, uint64_t length, spdk_blob_op_complete cb_fn, void *cb_arg)
5356 {
5357 	_spdk_blob_request_submit_op(blob, channel, NULL, offset, length, cb_fn, cb_arg,
5358 				     SPDK_BLOB_UNMAP);
5359 }
5360 
5361 void spdk_blob_io_write_zeroes(struct spdk_blob *blob, struct spdk_io_channel *channel,
5362 			       uint64_t offset, uint64_t length, spdk_blob_op_complete cb_fn, void *cb_arg)
5363 {
5364 	_spdk_blob_request_submit_op(blob, channel, NULL, offset, length, cb_fn, cb_arg,
5365 				     SPDK_BLOB_WRITE_ZEROES);
5366 }
5367 
5368 void spdk_blob_io_write(struct spdk_blob *blob, struct spdk_io_channel *channel,
5369 			void *payload, uint64_t offset, uint64_t length,
5370 			spdk_blob_op_complete cb_fn, void *cb_arg)
5371 {
5372 	_spdk_blob_request_submit_op(blob, channel, payload, offset, length, cb_fn, cb_arg,
5373 				     SPDK_BLOB_WRITE);
5374 }
5375 
5376 void spdk_blob_io_read(struct spdk_blob *blob, struct spdk_io_channel *channel,
5377 		       void *payload, uint64_t offset, uint64_t length,
5378 		       spdk_blob_op_complete cb_fn, void *cb_arg)
5379 {
5380 	_spdk_blob_request_submit_op(blob, channel, payload, offset, length, cb_fn, cb_arg,
5381 				     SPDK_BLOB_READ);
5382 }
5383 
5384 void spdk_blob_io_writev(struct spdk_blob *blob, struct spdk_io_channel *channel,
5385 			 struct iovec *iov, int iovcnt, uint64_t offset, uint64_t length,
5386 			 spdk_blob_op_complete cb_fn, void *cb_arg)
5387 {
5388 	_spdk_blob_request_submit_rw_iov(blob, channel, iov, iovcnt, offset, length, cb_fn, cb_arg, false);
5389 }
5390 
5391 void spdk_blob_io_readv(struct spdk_blob *blob, struct spdk_io_channel *channel,
5392 			struct iovec *iov, int iovcnt, uint64_t offset, uint64_t length,
5393 			spdk_blob_op_complete cb_fn, void *cb_arg)
5394 {
5395 	_spdk_blob_request_submit_rw_iov(blob, channel, iov, iovcnt, offset, length, cb_fn, cb_arg, true);
5396 }
5397 
5398 struct spdk_bs_iter_ctx {
5399 	int64_t page_num;
5400 	struct spdk_blob_store *bs;
5401 
5402 	spdk_blob_op_with_handle_complete cb_fn;
5403 	void *cb_arg;
5404 };
5405 
5406 static void
5407 _spdk_bs_iter_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
5408 {
5409 	struct spdk_bs_iter_ctx *ctx = cb_arg;
5410 	struct spdk_blob_store *bs = ctx->bs;
5411 	spdk_blob_id id;
5412 
5413 	if (bserrno == 0) {
5414 		ctx->cb_fn(ctx->cb_arg, _blob, bserrno);
5415 		free(ctx);
5416 		return;
5417 	}
5418 
5419 	ctx->page_num++;
5420 	ctx->page_num = spdk_bit_array_find_first_set(bs->used_blobids, ctx->page_num);
5421 	if (ctx->page_num >= spdk_bit_array_capacity(bs->used_blobids)) {
5422 		ctx->cb_fn(ctx->cb_arg, NULL, -ENOENT);
5423 		free(ctx);
5424 		return;
5425 	}
5426 
5427 	id = _spdk_bs_page_to_blobid(ctx->page_num);
5428 
5429 	spdk_bs_open_blob(bs, id, _spdk_bs_iter_cpl, ctx);
5430 }
5431 
5432 void
5433 spdk_bs_iter_first(struct spdk_blob_store *bs,
5434 		   spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5435 {
5436 	struct spdk_bs_iter_ctx *ctx;
5437 
5438 	ctx = calloc(1, sizeof(*ctx));
5439 	if (!ctx) {
5440 		cb_fn(cb_arg, NULL, -ENOMEM);
5441 		return;
5442 	}
5443 
5444 	ctx->page_num = -1;
5445 	ctx->bs = bs;
5446 	ctx->cb_fn = cb_fn;
5447 	ctx->cb_arg = cb_arg;
5448 
5449 	_spdk_bs_iter_cpl(ctx, NULL, -1);
5450 }
5451 
5452 static void
5453 _spdk_bs_iter_close_cpl(void *cb_arg, int bserrno)
5454 {
5455 	struct spdk_bs_iter_ctx *ctx = cb_arg;
5456 
5457 	_spdk_bs_iter_cpl(ctx, NULL, -1);
5458 }
5459 
5460 void
5461 spdk_bs_iter_next(struct spdk_blob_store *bs, struct spdk_blob *blob,
5462 		  spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5463 {
5464 	struct spdk_bs_iter_ctx *ctx;
5465 
5466 	assert(blob != NULL);
5467 
5468 	ctx = calloc(1, sizeof(*ctx));
5469 	if (!ctx) {
5470 		cb_fn(cb_arg, NULL, -ENOMEM);
5471 		return;
5472 	}
5473 
5474 	ctx->page_num = _spdk_bs_blobid_to_page(blob->id);
5475 	ctx->bs = bs;
5476 	ctx->cb_fn = cb_fn;
5477 	ctx->cb_arg = cb_arg;
5478 
5479 	/* Close the existing blob */
5480 	spdk_blob_close(blob, _spdk_bs_iter_close_cpl, ctx);
5481 }
5482 
5483 static int
5484 _spdk_blob_set_xattr(struct spdk_blob *blob, const char *name, const void *value,
5485 		     uint16_t value_len, bool internal)
5486 {
5487 	struct spdk_xattr_tailq *xattrs;
5488 	struct spdk_xattr	*xattr;
5489 
5490 	_spdk_blob_verify_md_op(blob);
5491 
5492 	if (blob->md_ro) {
5493 		return -EPERM;
5494 	}
5495 
5496 	if (internal) {
5497 		xattrs = &blob->xattrs_internal;
5498 		blob->invalid_flags |= SPDK_BLOB_INTERNAL_XATTR;
5499 	} else {
5500 		xattrs = &blob->xattrs;
5501 	}
5502 
5503 	TAILQ_FOREACH(xattr, xattrs, link) {
5504 		if (!strcmp(name, xattr->name)) {
5505 			free(xattr->value);
5506 			xattr->value_len = value_len;
5507 			xattr->value = malloc(value_len);
5508 			memcpy(xattr->value, value, value_len);
5509 
5510 			blob->state = SPDK_BLOB_STATE_DIRTY;
5511 
5512 			return 0;
5513 		}
5514 	}
5515 
5516 	xattr = calloc(1, sizeof(*xattr));
5517 	if (!xattr) {
5518 		return -ENOMEM;
5519 	}
5520 	xattr->name = strdup(name);
5521 	xattr->value_len = value_len;
5522 	xattr->value = malloc(value_len);
5523 	memcpy(xattr->value, value, value_len);
5524 	TAILQ_INSERT_TAIL(xattrs, xattr, link);
5525 
5526 	blob->state = SPDK_BLOB_STATE_DIRTY;
5527 
5528 	return 0;
5529 }
5530 
5531 int
5532 spdk_blob_set_xattr(struct spdk_blob *blob, const char *name, const void *value,
5533 		    uint16_t value_len)
5534 {
5535 	return _spdk_blob_set_xattr(blob, name, value, value_len, false);
5536 }
5537 
5538 static int
5539 _spdk_blob_remove_xattr(struct spdk_blob *blob, const char *name, bool internal)
5540 {
5541 	struct spdk_xattr_tailq *xattrs;
5542 	struct spdk_xattr	*xattr;
5543 
5544 	_spdk_blob_verify_md_op(blob);
5545 
5546 	if (blob->md_ro) {
5547 		return -EPERM;
5548 	}
5549 	xattrs = internal ? &blob->xattrs_internal : &blob->xattrs;
5550 
5551 	TAILQ_FOREACH(xattr, xattrs, link) {
5552 		if (!strcmp(name, xattr->name)) {
5553 			TAILQ_REMOVE(xattrs, xattr, link);
5554 			free(xattr->value);
5555 			free(xattr->name);
5556 			free(xattr);
5557 
5558 			if (internal && TAILQ_EMPTY(&blob->xattrs_internal)) {
5559 				blob->invalid_flags &= ~SPDK_BLOB_INTERNAL_XATTR;
5560 			}
5561 			blob->state = SPDK_BLOB_STATE_DIRTY;
5562 
5563 			return 0;
5564 		}
5565 	}
5566 
5567 	return -ENOENT;
5568 }
5569 
5570 int
5571 spdk_blob_remove_xattr(struct spdk_blob *blob, const char *name)
5572 {
5573 	return _spdk_blob_remove_xattr(blob, name, false);
5574 }
5575 
5576 static int
5577 _spdk_blob_get_xattr_value(struct spdk_blob *blob, const char *name,
5578 			   const void **value, size_t *value_len, bool internal)
5579 {
5580 	struct spdk_xattr	*xattr;
5581 	struct spdk_xattr_tailq *xattrs;
5582 
5583 	xattrs = internal ? &blob->xattrs_internal : &blob->xattrs;
5584 
5585 	TAILQ_FOREACH(xattr, xattrs, link) {
5586 		if (!strcmp(name, xattr->name)) {
5587 			*value = xattr->value;
5588 			*value_len = xattr->value_len;
5589 			return 0;
5590 		}
5591 	}
5592 	return -ENOENT;
5593 }
5594 
5595 int
5596 spdk_blob_get_xattr_value(struct spdk_blob *blob, const char *name,
5597 			  const void **value, size_t *value_len)
5598 {
5599 	_spdk_blob_verify_md_op(blob);
5600 
5601 	return _spdk_blob_get_xattr_value(blob, name, value, value_len, false);
5602 }
5603 
5604 struct spdk_xattr_names {
5605 	uint32_t	count;
5606 	const char	*names[0];
5607 };
5608 
5609 static int
5610 _spdk_blob_get_xattr_names(struct spdk_xattr_tailq *xattrs, struct spdk_xattr_names **names)
5611 {
5612 	struct spdk_xattr	*xattr;
5613 	int			count = 0;
5614 
5615 	TAILQ_FOREACH(xattr, xattrs, link) {
5616 		count++;
5617 	}
5618 
5619 	*names = calloc(1, sizeof(struct spdk_xattr_names) + count * sizeof(char *));
5620 	if (*names == NULL) {
5621 		return -ENOMEM;
5622 	}
5623 
5624 	TAILQ_FOREACH(xattr, xattrs, link) {
5625 		(*names)->names[(*names)->count++] = xattr->name;
5626 	}
5627 
5628 	return 0;
5629 }
5630 
5631 int
5632 spdk_blob_get_xattr_names(struct spdk_blob *blob, struct spdk_xattr_names **names)
5633 {
5634 	_spdk_blob_verify_md_op(blob);
5635 
5636 	return _spdk_blob_get_xattr_names(&blob->xattrs, names);
5637 }
5638 
5639 uint32_t
5640 spdk_xattr_names_get_count(struct spdk_xattr_names *names)
5641 {
5642 	assert(names != NULL);
5643 
5644 	return names->count;
5645 }
5646 
5647 const char *
5648 spdk_xattr_names_get_name(struct spdk_xattr_names *names, uint32_t index)
5649 {
5650 	if (index >= names->count) {
5651 		return NULL;
5652 	}
5653 
5654 	return names->names[index];
5655 }
5656 
5657 void
5658 spdk_xattr_names_free(struct spdk_xattr_names *names)
5659 {
5660 	free(names);
5661 }
5662 
5663 struct spdk_bs_type
5664 spdk_bs_get_bstype(struct spdk_blob_store *bs)
5665 {
5666 	return bs->bstype;
5667 }
5668 
5669 void
5670 spdk_bs_set_bstype(struct spdk_blob_store *bs, struct spdk_bs_type bstype)
5671 {
5672 	memcpy(&bs->bstype, &bstype, sizeof(bstype));
5673 }
5674 
5675 bool
5676 spdk_blob_is_read_only(struct spdk_blob *blob)
5677 {
5678 	assert(blob != NULL);
5679 	return (blob->data_ro || blob->md_ro);
5680 }
5681 
5682 bool
5683 spdk_blob_is_snapshot(struct spdk_blob *blob)
5684 {
5685 	struct spdk_blob_list *snapshot_entry;
5686 
5687 	assert(blob != NULL);
5688 
5689 	TAILQ_FOREACH(snapshot_entry, &blob->bs->snapshots, link) {
5690 		if (snapshot_entry->id == blob->id) {
5691 			break;
5692 		}
5693 	}
5694 
5695 	if (snapshot_entry == NULL) {
5696 		return false;
5697 	}
5698 
5699 	return true;
5700 }
5701 
5702 bool
5703 spdk_blob_is_clone(struct spdk_blob *blob)
5704 {
5705 	assert(blob != NULL);
5706 
5707 	if (blob->parent_id != SPDK_BLOBID_INVALID) {
5708 		assert(spdk_blob_is_thin_provisioned(blob));
5709 		return true;
5710 	}
5711 
5712 	return false;
5713 }
5714 
5715 bool
5716 spdk_blob_is_thin_provisioned(struct spdk_blob *blob)
5717 {
5718 	assert(blob != NULL);
5719 	return !!(blob->invalid_flags & SPDK_BLOB_THIN_PROV);
5720 }
5721 
5722 spdk_blob_id
5723 spdk_blob_get_parent_snapshot(struct spdk_blob_store *bs, spdk_blob_id blob_id)
5724 {
5725 	struct spdk_blob_list *snapshot_entry = NULL;
5726 	struct spdk_blob_list *clone_entry = NULL;
5727 
5728 	TAILQ_FOREACH(snapshot_entry, &bs->snapshots, link) {
5729 		TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
5730 			if (clone_entry->id == blob_id) {
5731 				return snapshot_entry->id;
5732 			}
5733 		}
5734 	}
5735 
5736 	return SPDK_BLOBID_INVALID;
5737 }
5738 
5739 int
5740 spdk_blob_get_clones(struct spdk_blob_store *bs, spdk_blob_id blobid, spdk_blob_id *ids,
5741 		     size_t *count)
5742 {
5743 	struct spdk_blob_list *snapshot_entry, *clone_entry;
5744 	size_t n;
5745 
5746 	TAILQ_FOREACH(snapshot_entry, &bs->snapshots, link) {
5747 		if (snapshot_entry->id == blobid) {
5748 			break;
5749 		}
5750 	}
5751 	if (snapshot_entry == NULL) {
5752 		*count = 0;
5753 		return 0;
5754 	}
5755 
5756 	if (ids == NULL || *count < snapshot_entry->clone_count) {
5757 		*count = snapshot_entry->clone_count;
5758 		return -ENOMEM;
5759 	}
5760 	*count = snapshot_entry->clone_count;
5761 
5762 	n = 0;
5763 	TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
5764 		ids[n++] = clone_entry->id;
5765 	}
5766 
5767 	return 0;
5768 }
5769 
5770 SPDK_LOG_REGISTER_COMPONENT("blob", SPDK_LOG_BLOB)
5771