xref: /spdk/lib/blob/blobstore.c (revision f7bd1e1eb9677ca90b228d2e879192d358e070f7)
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 #include "spdk/string.h"
45 
46 #include "spdk_internal/assert.h"
47 #include "spdk_internal/log.h"
48 
49 #include "blobstore.h"
50 
51 #define BLOB_CRC32C_INITIAL    0xffffffffUL
52 
53 static int spdk_bs_register_md_thread(struct spdk_blob_store *bs);
54 static int spdk_bs_unregister_md_thread(struct spdk_blob_store *bs);
55 static void _spdk_blob_close_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno);
56 static void _spdk_blob_insert_cluster_on_md_thread(struct spdk_blob *blob, uint32_t cluster_num,
57 		uint64_t cluster, spdk_blob_op_complete cb_fn, void *cb_arg);
58 
59 static int _spdk_blob_set_xattr(struct spdk_blob *blob, const char *name, const void *value,
60 				uint16_t value_len, bool internal);
61 static int _spdk_blob_get_xattr_value(struct spdk_blob *blob, const char *name,
62 				      const void **value, size_t *value_len, bool internal);
63 static int _spdk_blob_remove_xattr(struct spdk_blob *blob, const char *name, bool internal);
64 
65 static void
66 _spdk_blob_verify_md_op(struct spdk_blob *blob)
67 {
68 	assert(blob != NULL);
69 	assert(spdk_get_thread() == blob->bs->md_thread);
70 	assert(blob->state != SPDK_BLOB_STATE_LOADING);
71 }
72 
73 static struct spdk_blob_list *
74 _spdk_bs_get_snapshot_entry(struct spdk_blob_store *bs, spdk_blob_id blobid)
75 {
76 	struct spdk_blob_list *snapshot_entry = NULL;
77 
78 	TAILQ_FOREACH(snapshot_entry, &bs->snapshots, link) {
79 		if (snapshot_entry->id == blobid) {
80 			break;
81 		}
82 	}
83 
84 	return snapshot_entry;
85 }
86 
87 static void
88 _spdk_bs_claim_cluster(struct spdk_blob_store *bs, uint32_t cluster_num)
89 {
90 	assert(cluster_num < spdk_bit_array_capacity(bs->used_clusters));
91 	assert(spdk_bit_array_get(bs->used_clusters, cluster_num) == false);
92 	assert(bs->num_free_clusters > 0);
93 
94 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Claiming cluster %u\n", cluster_num);
95 
96 	spdk_bit_array_set(bs->used_clusters, cluster_num);
97 	bs->num_free_clusters--;
98 }
99 
100 static int
101 _spdk_blob_insert_cluster(struct spdk_blob *blob, uint32_t cluster_num, uint64_t cluster)
102 {
103 	uint64_t *cluster_lba = &blob->active.clusters[cluster_num];
104 
105 	_spdk_blob_verify_md_op(blob);
106 
107 	if (*cluster_lba != 0) {
108 		return -EEXIST;
109 	}
110 
111 	*cluster_lba = _spdk_bs_cluster_to_lba(blob->bs, cluster);
112 	return 0;
113 }
114 
115 static int
116 _spdk_bs_allocate_cluster(struct spdk_blob *blob, uint32_t cluster_num,
117 			  uint64_t *lowest_free_cluster, bool update_map)
118 {
119 	pthread_mutex_lock(&blob->bs->used_clusters_mutex);
120 	*lowest_free_cluster = spdk_bit_array_find_first_clear(blob->bs->used_clusters,
121 			       *lowest_free_cluster);
122 	if (*lowest_free_cluster == UINT32_MAX) {
123 		/* No more free clusters. Cannot satisfy the request */
124 		pthread_mutex_unlock(&blob->bs->used_clusters_mutex);
125 		return -ENOSPC;
126 	}
127 
128 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Claiming cluster %lu for blob %lu\n", *lowest_free_cluster, blob->id);
129 	_spdk_bs_claim_cluster(blob->bs, *lowest_free_cluster);
130 	pthread_mutex_unlock(&blob->bs->used_clusters_mutex);
131 
132 	if (update_map) {
133 		_spdk_blob_insert_cluster(blob, cluster_num, *lowest_free_cluster);
134 	}
135 
136 	return 0;
137 }
138 
139 static void
140 _spdk_bs_release_cluster(struct spdk_blob_store *bs, uint32_t cluster_num)
141 {
142 	assert(cluster_num < spdk_bit_array_capacity(bs->used_clusters));
143 	assert(spdk_bit_array_get(bs->used_clusters, cluster_num) == true);
144 	assert(bs->num_free_clusters < bs->total_clusters);
145 
146 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Releasing cluster %u\n", cluster_num);
147 
148 	pthread_mutex_lock(&bs->used_clusters_mutex);
149 	spdk_bit_array_clear(bs->used_clusters, cluster_num);
150 	bs->num_free_clusters++;
151 	pthread_mutex_unlock(&bs->used_clusters_mutex);
152 }
153 
154 static void
155 _spdk_blob_xattrs_init(struct spdk_blob_xattr_opts *xattrs)
156 {
157 	xattrs->count = 0;
158 	xattrs->names = NULL;
159 	xattrs->ctx = NULL;
160 	xattrs->get_value = NULL;
161 }
162 
163 void
164 spdk_blob_opts_init(struct spdk_blob_opts *opts)
165 {
166 	opts->num_clusters = 0;
167 	opts->thin_provision = false;
168 	opts->clear_method = BLOB_CLEAR_WITH_DEFAULT;
169 	_spdk_blob_xattrs_init(&opts->xattrs);
170 }
171 
172 void
173 spdk_blob_open_opts_init(struct spdk_blob_open_opts *opts)
174 {
175 	opts->clear_method = BLOB_CLEAR_WITH_DEFAULT;
176 }
177 
178 static struct spdk_blob *
179 _spdk_blob_alloc(struct spdk_blob_store *bs, spdk_blob_id id)
180 {
181 	struct spdk_blob *blob;
182 
183 	blob = calloc(1, sizeof(*blob));
184 	if (!blob) {
185 		return NULL;
186 	}
187 
188 	blob->id = id;
189 	blob->bs = bs;
190 
191 	blob->parent_id = SPDK_BLOBID_INVALID;
192 
193 	blob->state = SPDK_BLOB_STATE_DIRTY;
194 	blob->active.num_pages = 1;
195 	blob->active.pages = calloc(1, sizeof(*blob->active.pages));
196 	if (!blob->active.pages) {
197 		free(blob);
198 		return NULL;
199 	}
200 
201 	blob->active.pages[0] = _spdk_bs_blobid_to_page(id);
202 
203 	TAILQ_INIT(&blob->xattrs);
204 	TAILQ_INIT(&blob->xattrs_internal);
205 
206 	return blob;
207 }
208 
209 static void
210 _spdk_xattrs_free(struct spdk_xattr_tailq *xattrs)
211 {
212 	struct spdk_xattr	*xattr, *xattr_tmp;
213 
214 	TAILQ_FOREACH_SAFE(xattr, xattrs, link, xattr_tmp) {
215 		TAILQ_REMOVE(xattrs, xattr, link);
216 		free(xattr->name);
217 		free(xattr->value);
218 		free(xattr);
219 	}
220 }
221 
222 static void
223 _spdk_blob_free(struct spdk_blob *blob)
224 {
225 	assert(blob != NULL);
226 
227 	free(blob->active.clusters);
228 	free(blob->clean.clusters);
229 	free(blob->active.pages);
230 	free(blob->clean.pages);
231 
232 	_spdk_xattrs_free(&blob->xattrs);
233 	_spdk_xattrs_free(&blob->xattrs_internal);
234 
235 	if (blob->back_bs_dev) {
236 		blob->back_bs_dev->destroy(blob->back_bs_dev);
237 	}
238 
239 	free(blob);
240 }
241 
242 struct freeze_io_ctx {
243 	struct spdk_bs_cpl cpl;
244 	struct spdk_blob *blob;
245 };
246 
247 static void
248 _spdk_blob_io_sync(struct spdk_io_channel_iter *i)
249 {
250 	spdk_for_each_channel_continue(i, 0);
251 }
252 
253 static void
254 _spdk_blob_execute_queued_io(struct spdk_io_channel_iter *i)
255 {
256 	struct spdk_io_channel *_ch = spdk_io_channel_iter_get_channel(i);
257 	struct spdk_bs_channel *ch = spdk_io_channel_get_ctx(_ch);
258 	struct freeze_io_ctx *ctx = spdk_io_channel_iter_get_ctx(i);
259 	struct spdk_bs_request_set	*set;
260 	struct spdk_bs_user_op_args	*args;
261 	spdk_bs_user_op_t *op, *tmp;
262 
263 	TAILQ_FOREACH_SAFE(op, &ch->queued_io, link, tmp) {
264 		set = (struct spdk_bs_request_set *)op;
265 		args = &set->u.user_op;
266 
267 		if (args->blob == ctx->blob) {
268 			TAILQ_REMOVE(&ch->queued_io, op, link);
269 			spdk_bs_user_op_execute(op);
270 		}
271 	}
272 
273 	spdk_for_each_channel_continue(i, 0);
274 }
275 
276 static void
277 _spdk_blob_io_cpl(struct spdk_io_channel_iter *i, int status)
278 {
279 	struct freeze_io_ctx *ctx = spdk_io_channel_iter_get_ctx(i);
280 
281 	ctx->cpl.u.blob_basic.cb_fn(ctx->cpl.u.blob_basic.cb_arg, 0);
282 
283 	free(ctx);
284 }
285 
286 static void
287 _spdk_blob_freeze_io(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
288 {
289 	struct freeze_io_ctx *ctx;
290 
291 	ctx = calloc(1, sizeof(*ctx));
292 	if (!ctx) {
293 		cb_fn(cb_arg, -ENOMEM);
294 		return;
295 	}
296 
297 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
298 	ctx->cpl.u.blob_basic.cb_fn = cb_fn;
299 	ctx->cpl.u.blob_basic.cb_arg = cb_arg;
300 	ctx->blob = blob;
301 
302 	/* Freeze I/O on blob */
303 	blob->frozen_refcnt++;
304 
305 	if (blob->frozen_refcnt == 1) {
306 		spdk_for_each_channel(blob->bs, _spdk_blob_io_sync, ctx, _spdk_blob_io_cpl);
307 	} else {
308 		cb_fn(cb_arg, 0);
309 		free(ctx);
310 	}
311 }
312 
313 static void
314 _spdk_blob_unfreeze_io(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
315 {
316 	struct freeze_io_ctx *ctx;
317 
318 	ctx = calloc(1, sizeof(*ctx));
319 	if (!ctx) {
320 		cb_fn(cb_arg, -ENOMEM);
321 		return;
322 	}
323 
324 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
325 	ctx->cpl.u.blob_basic.cb_fn = cb_fn;
326 	ctx->cpl.u.blob_basic.cb_arg = cb_arg;
327 	ctx->blob = blob;
328 
329 	assert(blob->frozen_refcnt > 0);
330 
331 	blob->frozen_refcnt--;
332 
333 	if (blob->frozen_refcnt == 0) {
334 		spdk_for_each_channel(blob->bs, _spdk_blob_execute_queued_io, ctx, _spdk_blob_io_cpl);
335 	} else {
336 		cb_fn(cb_arg, 0);
337 		free(ctx);
338 	}
339 }
340 
341 static int
342 _spdk_blob_mark_clean(struct spdk_blob *blob)
343 {
344 	uint64_t *clusters = NULL;
345 	uint32_t *pages = NULL;
346 
347 	assert(blob != NULL);
348 
349 	if (blob->active.num_clusters) {
350 		assert(blob->active.clusters);
351 		clusters = calloc(blob->active.num_clusters, sizeof(*blob->active.clusters));
352 		if (!clusters) {
353 			return -ENOMEM;
354 		}
355 		memcpy(clusters, blob->active.clusters, blob->active.num_clusters * sizeof(*blob->active.clusters));
356 	}
357 
358 	if (blob->active.num_pages) {
359 		assert(blob->active.pages);
360 		pages = calloc(blob->active.num_pages, sizeof(*blob->active.pages));
361 		if (!pages) {
362 			free(clusters);
363 			return -ENOMEM;
364 		}
365 		memcpy(pages, blob->active.pages, blob->active.num_pages * sizeof(*blob->active.pages));
366 	}
367 
368 	free(blob->clean.clusters);
369 	free(blob->clean.pages);
370 
371 	blob->clean.num_clusters = blob->active.num_clusters;
372 	blob->clean.clusters = blob->active.clusters;
373 	blob->clean.num_pages = blob->active.num_pages;
374 	blob->clean.pages = blob->active.pages;
375 
376 	blob->active.clusters = clusters;
377 	blob->active.pages = pages;
378 
379 	/* If the metadata was dirtied again while the metadata was being written to disk,
380 	 *  we do not want to revert the DIRTY state back to CLEAN here.
381 	 */
382 	if (blob->state == SPDK_BLOB_STATE_LOADING) {
383 		blob->state = SPDK_BLOB_STATE_CLEAN;
384 	}
385 
386 	return 0;
387 }
388 
389 static int
390 _spdk_blob_deserialize_xattr(struct spdk_blob *blob,
391 			     struct spdk_blob_md_descriptor_xattr *desc_xattr, bool internal)
392 {
393 	struct spdk_xattr                       *xattr;
394 
395 	if (desc_xattr->length != sizeof(desc_xattr->name_length) +
396 	    sizeof(desc_xattr->value_length) +
397 	    desc_xattr->name_length + desc_xattr->value_length) {
398 		return -EINVAL;
399 	}
400 
401 	xattr = calloc(1, sizeof(*xattr));
402 	if (xattr == NULL) {
403 		return -ENOMEM;
404 	}
405 
406 	xattr->name = malloc(desc_xattr->name_length + 1);
407 	if (xattr->name == NULL) {
408 		free(xattr);
409 		return -ENOMEM;
410 	}
411 	memcpy(xattr->name, desc_xattr->name, desc_xattr->name_length);
412 	xattr->name[desc_xattr->name_length] = '\0';
413 
414 	xattr->value = malloc(desc_xattr->value_length);
415 	if (xattr->value == NULL) {
416 		free(xattr->name);
417 		free(xattr);
418 		return -ENOMEM;
419 	}
420 	xattr->value_len = desc_xattr->value_length;
421 	memcpy(xattr->value,
422 	       (void *)((uintptr_t)desc_xattr->name + desc_xattr->name_length),
423 	       desc_xattr->value_length);
424 
425 	TAILQ_INSERT_TAIL(internal ? &blob->xattrs_internal : &blob->xattrs, xattr, link);
426 
427 	return 0;
428 }
429 
430 
431 static int
432 _spdk_blob_parse_page(const struct spdk_blob_md_page *page, struct spdk_blob *blob)
433 {
434 	struct spdk_blob_md_descriptor *desc;
435 	size_t	cur_desc = 0;
436 	void *tmp;
437 
438 	desc = (struct spdk_blob_md_descriptor *)page->descriptors;
439 	while (cur_desc < sizeof(page->descriptors)) {
440 		if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_PADDING) {
441 			if (desc->length == 0) {
442 				/* If padding and length are 0, this terminates the page */
443 				break;
444 			}
445 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_FLAGS) {
446 			struct spdk_blob_md_descriptor_flags	*desc_flags;
447 
448 			desc_flags = (struct spdk_blob_md_descriptor_flags *)desc;
449 
450 			if (desc_flags->length != sizeof(*desc_flags) - sizeof(*desc)) {
451 				return -EINVAL;
452 			}
453 
454 			if ((desc_flags->invalid_flags | SPDK_BLOB_INVALID_FLAGS_MASK) !=
455 			    SPDK_BLOB_INVALID_FLAGS_MASK) {
456 				return -EINVAL;
457 			}
458 
459 			if ((desc_flags->data_ro_flags | SPDK_BLOB_DATA_RO_FLAGS_MASK) !=
460 			    SPDK_BLOB_DATA_RO_FLAGS_MASK) {
461 				blob->data_ro = true;
462 				blob->md_ro = true;
463 			}
464 
465 			if ((desc_flags->md_ro_flags | SPDK_BLOB_MD_RO_FLAGS_MASK) !=
466 			    SPDK_BLOB_MD_RO_FLAGS_MASK) {
467 				blob->md_ro = true;
468 			}
469 
470 			if ((desc_flags->data_ro_flags & SPDK_BLOB_READ_ONLY)) {
471 				blob->data_ro = true;
472 				blob->md_ro = true;
473 			}
474 
475 			blob->invalid_flags = desc_flags->invalid_flags;
476 			blob->data_ro_flags = desc_flags->data_ro_flags;
477 			blob->md_ro_flags = desc_flags->md_ro_flags;
478 
479 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_EXTENT_RLE) {
480 			struct spdk_blob_md_descriptor_extent_rle	*desc_extent_rle;
481 			unsigned int				i, j;
482 			unsigned int				cluster_count = blob->active.num_clusters;
483 
484 			desc_extent_rle = (struct spdk_blob_md_descriptor_extent_rle *)desc;
485 
486 			if (desc_extent_rle->length == 0 ||
487 			    (desc_extent_rle->length % sizeof(desc_extent_rle->extents[0]) != 0)) {
488 				return -EINVAL;
489 			}
490 
491 			for (i = 0; i < desc_extent_rle->length / sizeof(desc_extent_rle->extents[0]); i++) {
492 				for (j = 0; j < desc_extent_rle->extents[i].length; j++) {
493 					if (desc_extent_rle->extents[i].cluster_idx != 0) {
494 						if (!spdk_bit_array_get(blob->bs->used_clusters,
495 									desc_extent_rle->extents[i].cluster_idx + j)) {
496 							return -EINVAL;
497 						}
498 					}
499 					cluster_count++;
500 				}
501 			}
502 
503 			if (cluster_count == 0) {
504 				return -EINVAL;
505 			}
506 			tmp = realloc(blob->active.clusters, cluster_count * sizeof(*blob->active.clusters));
507 			if (tmp == NULL) {
508 				return -ENOMEM;
509 			}
510 			blob->active.clusters = tmp;
511 			blob->active.cluster_array_size = cluster_count;
512 
513 			for (i = 0; i < desc_extent_rle->length / sizeof(desc_extent_rle->extents[0]); i++) {
514 				for (j = 0; j < desc_extent_rle->extents[i].length; j++) {
515 					if (desc_extent_rle->extents[i].cluster_idx != 0) {
516 						blob->active.clusters[blob->active.num_clusters++] = _spdk_bs_cluster_to_lba(blob->bs,
517 								desc_extent_rle->extents[i].cluster_idx + j);
518 					} else if (spdk_blob_is_thin_provisioned(blob)) {
519 						blob->active.clusters[blob->active.num_clusters++] = 0;
520 					} else {
521 						return -EINVAL;
522 					}
523 				}
524 			}
525 
526 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR) {
527 			int rc;
528 
529 			rc = _spdk_blob_deserialize_xattr(blob,
530 							  (struct spdk_blob_md_descriptor_xattr *) desc, false);
531 			if (rc != 0) {
532 				return rc;
533 			}
534 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL) {
535 			int rc;
536 
537 			rc = _spdk_blob_deserialize_xattr(blob,
538 							  (struct spdk_blob_md_descriptor_xattr *) desc, true);
539 			if (rc != 0) {
540 				return rc;
541 			}
542 		} else {
543 			/* Unrecognized descriptor type.  Do not fail - just continue to the
544 			 *  next descriptor.  If this descriptor is associated with some feature
545 			 *  defined in a newer version of blobstore, that version of blobstore
546 			 *  should create and set an associated feature flag to specify if this
547 			 *  blob can be loaded or not.
548 			 */
549 		}
550 
551 		/* Advance to the next descriptor */
552 		cur_desc += sizeof(*desc) + desc->length;
553 		if (cur_desc + sizeof(*desc) > sizeof(page->descriptors)) {
554 			break;
555 		}
556 		desc = (struct spdk_blob_md_descriptor *)((uintptr_t)page->descriptors + cur_desc);
557 	}
558 
559 	return 0;
560 }
561 
562 static int
563 _spdk_blob_parse(const struct spdk_blob_md_page *pages, uint32_t page_count,
564 		 struct spdk_blob *blob)
565 {
566 	const struct spdk_blob_md_page *page;
567 	uint32_t i;
568 	int rc;
569 
570 	assert(page_count > 0);
571 	assert(pages[0].sequence_num == 0);
572 	assert(blob != NULL);
573 	assert(blob->state == SPDK_BLOB_STATE_LOADING);
574 	assert(blob->active.clusters == NULL);
575 
576 	/* The blobid provided doesn't match what's in the MD, this can
577 	 * happen for example if a bogus blobid is passed in through open.
578 	 */
579 	if (blob->id != pages[0].id) {
580 		SPDK_ERRLOG("Blobid (%lu) doesn't match what's in metadata (%lu)\n",
581 			    blob->id, pages[0].id);
582 		return -ENOENT;
583 	}
584 
585 	for (i = 0; i < page_count; i++) {
586 		page = &pages[i];
587 
588 		assert(page->id == blob->id);
589 		assert(page->sequence_num == i);
590 
591 		rc = _spdk_blob_parse_page(page, blob);
592 		if (rc != 0) {
593 			return rc;
594 		}
595 	}
596 
597 	return 0;
598 }
599 
600 static int
601 _spdk_blob_serialize_add_page(const struct spdk_blob *blob,
602 			      struct spdk_blob_md_page **pages,
603 			      uint32_t *page_count,
604 			      struct spdk_blob_md_page **last_page)
605 {
606 	struct spdk_blob_md_page *page;
607 
608 	assert(pages != NULL);
609 	assert(page_count != NULL);
610 
611 	if (*page_count == 0) {
612 		assert(*pages == NULL);
613 		*page_count = 1;
614 		*pages = spdk_malloc(SPDK_BS_PAGE_SIZE, SPDK_BS_PAGE_SIZE,
615 				     NULL, SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
616 	} else {
617 		assert(*pages != NULL);
618 		(*page_count)++;
619 		*pages = spdk_realloc(*pages,
620 				      SPDK_BS_PAGE_SIZE * (*page_count),
621 				      SPDK_BS_PAGE_SIZE);
622 	}
623 
624 	if (*pages == NULL) {
625 		*page_count = 0;
626 		*last_page = NULL;
627 		return -ENOMEM;
628 	}
629 
630 	page = &(*pages)[*page_count - 1];
631 	memset(page, 0, sizeof(*page));
632 	page->id = blob->id;
633 	page->sequence_num = *page_count - 1;
634 	page->next = SPDK_INVALID_MD_PAGE;
635 	*last_page = page;
636 
637 	return 0;
638 }
639 
640 /* Transform the in-memory representation 'xattr' into an on-disk xattr descriptor.
641  * Update required_sz on both success and failure.
642  *
643  */
644 static int
645 _spdk_blob_serialize_xattr(const struct spdk_xattr *xattr,
646 			   uint8_t *buf, size_t buf_sz,
647 			   size_t *required_sz, bool internal)
648 {
649 	struct spdk_blob_md_descriptor_xattr	*desc;
650 
651 	*required_sz = sizeof(struct spdk_blob_md_descriptor_xattr) +
652 		       strlen(xattr->name) +
653 		       xattr->value_len;
654 
655 	if (buf_sz < *required_sz) {
656 		return -1;
657 	}
658 
659 	desc = (struct spdk_blob_md_descriptor_xattr *)buf;
660 
661 	desc->type = internal ? SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL : SPDK_MD_DESCRIPTOR_TYPE_XATTR;
662 	desc->length = sizeof(desc->name_length) +
663 		       sizeof(desc->value_length) +
664 		       strlen(xattr->name) +
665 		       xattr->value_len;
666 	desc->name_length = strlen(xattr->name);
667 	desc->value_length = xattr->value_len;
668 
669 	memcpy(desc->name, xattr->name, desc->name_length);
670 	memcpy((void *)((uintptr_t)desc->name + desc->name_length),
671 	       xattr->value,
672 	       desc->value_length);
673 
674 	return 0;
675 }
676 
677 static void
678 _spdk_blob_serialize_extent_rle(const struct spdk_blob *blob,
679 				uint64_t start_cluster, uint64_t *next_cluster,
680 				uint8_t **buf, size_t *buf_sz)
681 {
682 	struct spdk_blob_md_descriptor_extent_rle *desc_extent_rle;
683 	size_t cur_sz;
684 	uint64_t i, extent_idx;
685 	uint64_t lba, lba_per_cluster, lba_count;
686 
687 	/* The buffer must have room for at least one extent */
688 	cur_sz = sizeof(struct spdk_blob_md_descriptor) + sizeof(desc_extent_rle->extents[0]);
689 	if (*buf_sz < cur_sz) {
690 		*next_cluster = start_cluster;
691 		return;
692 	}
693 
694 	desc_extent_rle = (struct spdk_blob_md_descriptor_extent_rle *)*buf;
695 	desc_extent_rle->type = SPDK_MD_DESCRIPTOR_TYPE_EXTENT_RLE;
696 
697 	lba_per_cluster = _spdk_bs_cluster_to_lba(blob->bs, 1);
698 
699 	lba = blob->active.clusters[start_cluster];
700 	lba_count = lba_per_cluster;
701 	extent_idx = 0;
702 	for (i = start_cluster + 1; i < blob->active.num_clusters; i++) {
703 		if ((lba + lba_count) == blob->active.clusters[i] && lba != 0) {
704 			/* Run-length encode sequential non-zero LBA */
705 			lba_count += lba_per_cluster;
706 			continue;
707 		} else if (lba == 0 && blob->active.clusters[i] == 0) {
708 			/* Run-length encode unallocated clusters */
709 			lba_count += lba_per_cluster;
710 			continue;
711 		}
712 		desc_extent_rle->extents[extent_idx].cluster_idx = lba / lba_per_cluster;
713 		desc_extent_rle->extents[extent_idx].length = lba_count / lba_per_cluster;
714 		extent_idx++;
715 
716 		cur_sz += sizeof(desc_extent_rle->extents[extent_idx]);
717 
718 		if (*buf_sz < cur_sz) {
719 			/* If we ran out of buffer space, return */
720 			*next_cluster = i;
721 			goto finish;
722 		}
723 
724 		lba = blob->active.clusters[i];
725 		lba_count = lba_per_cluster;
726 	}
727 
728 	desc_extent_rle->extents[extent_idx].cluster_idx = lba / lba_per_cluster;
729 	desc_extent_rle->extents[extent_idx].length = lba_count / lba_per_cluster;
730 	extent_idx++;
731 
732 	*next_cluster = blob->active.num_clusters;
733 
734 finish:
735 	desc_extent_rle->length = sizeof(desc_extent_rle->extents[0]) * extent_idx;
736 	*buf_sz -= sizeof(struct spdk_blob_md_descriptor) + desc_extent_rle->length;
737 	*buf += sizeof(struct spdk_blob_md_descriptor) + desc_extent_rle->length;
738 
739 	return;
740 }
741 
742 static int
743 _spdk_blob_serialize_extents_rle(const struct spdk_blob *blob,
744 				 struct spdk_blob_md_page **pages,
745 				 struct spdk_blob_md_page *cur_page,
746 				 uint32_t *page_count, uint8_t **buf,
747 				 size_t *remaining_sz)
748 {
749 	uint64_t				last_cluster;
750 	int					rc;
751 
752 	last_cluster = 0;
753 	while (last_cluster < blob->active.num_clusters) {
754 		_spdk_blob_serialize_extent_rle(blob, last_cluster, &last_cluster, buf, remaining_sz);
755 
756 		if (last_cluster == blob->active.num_clusters) {
757 			break;
758 		}
759 
760 		rc = _spdk_blob_serialize_add_page(blob, pages, page_count, &cur_page);
761 		if (rc < 0) {
762 			return rc;
763 		}
764 
765 		*buf = (uint8_t *)cur_page->descriptors;
766 		*remaining_sz = sizeof(cur_page->descriptors);
767 	}
768 
769 	return 0;
770 }
771 
772 static void
773 _spdk_blob_serialize_flags(const struct spdk_blob *blob,
774 			   uint8_t *buf, size_t *buf_sz)
775 {
776 	struct spdk_blob_md_descriptor_flags *desc;
777 
778 	/*
779 	 * Flags get serialized first, so we should always have room for the flags
780 	 *  descriptor.
781 	 */
782 	assert(*buf_sz >= sizeof(*desc));
783 
784 	desc = (struct spdk_blob_md_descriptor_flags *)buf;
785 	desc->type = SPDK_MD_DESCRIPTOR_TYPE_FLAGS;
786 	desc->length = sizeof(*desc) - sizeof(struct spdk_blob_md_descriptor);
787 	desc->invalid_flags = blob->invalid_flags;
788 	desc->data_ro_flags = blob->data_ro_flags;
789 	desc->md_ro_flags = blob->md_ro_flags;
790 
791 	*buf_sz -= sizeof(*desc);
792 }
793 
794 static int
795 _spdk_blob_serialize_xattrs(const struct spdk_blob *blob,
796 			    const struct spdk_xattr_tailq *xattrs, bool internal,
797 			    struct spdk_blob_md_page **pages,
798 			    struct spdk_blob_md_page *cur_page,
799 			    uint32_t *page_count, uint8_t **buf,
800 			    size_t *remaining_sz)
801 {
802 	const struct spdk_xattr	*xattr;
803 	int	rc;
804 
805 	TAILQ_FOREACH(xattr, xattrs, link) {
806 		size_t required_sz = 0;
807 
808 		rc = _spdk_blob_serialize_xattr(xattr,
809 						*buf, *remaining_sz,
810 						&required_sz, internal);
811 		if (rc < 0) {
812 			/* Need to add a new page to the chain */
813 			rc = _spdk_blob_serialize_add_page(blob, pages, page_count,
814 							   &cur_page);
815 			if (rc < 0) {
816 				spdk_free(*pages);
817 				*pages = NULL;
818 				*page_count = 0;
819 				return rc;
820 			}
821 
822 			*buf = (uint8_t *)cur_page->descriptors;
823 			*remaining_sz = sizeof(cur_page->descriptors);
824 
825 			/* Try again */
826 			required_sz = 0;
827 			rc = _spdk_blob_serialize_xattr(xattr,
828 							*buf, *remaining_sz,
829 							&required_sz, internal);
830 
831 			if (rc < 0) {
832 				spdk_free(*pages);
833 				*pages = NULL;
834 				*page_count = 0;
835 				return rc;
836 			}
837 		}
838 
839 		*remaining_sz -= required_sz;
840 		*buf += required_sz;
841 	}
842 
843 	return 0;
844 }
845 
846 static int
847 _spdk_blob_serialize(const struct spdk_blob *blob, struct spdk_blob_md_page **pages,
848 		     uint32_t *page_count)
849 {
850 	struct spdk_blob_md_page		*cur_page;
851 	int					rc;
852 	uint8_t					*buf;
853 	size_t					remaining_sz;
854 
855 	assert(pages != NULL);
856 	assert(page_count != NULL);
857 	assert(blob != NULL);
858 	assert(blob->state == SPDK_BLOB_STATE_DIRTY);
859 
860 	*pages = NULL;
861 	*page_count = 0;
862 
863 	/* A blob always has at least 1 page, even if it has no descriptors */
864 	rc = _spdk_blob_serialize_add_page(blob, pages, page_count, &cur_page);
865 	if (rc < 0) {
866 		return rc;
867 	}
868 
869 	buf = (uint8_t *)cur_page->descriptors;
870 	remaining_sz = sizeof(cur_page->descriptors);
871 
872 	/* Serialize flags */
873 	_spdk_blob_serialize_flags(blob, buf, &remaining_sz);
874 	buf += sizeof(struct spdk_blob_md_descriptor_flags);
875 
876 	/* Serialize xattrs */
877 	rc = _spdk_blob_serialize_xattrs(blob, &blob->xattrs, false,
878 					 pages, cur_page, page_count, &buf, &remaining_sz);
879 	if (rc < 0) {
880 		return rc;
881 	}
882 
883 	/* Serialize internal xattrs */
884 	rc = _spdk_blob_serialize_xattrs(blob, &blob->xattrs_internal, true,
885 					 pages, cur_page, page_count, &buf, &remaining_sz);
886 	if (rc < 0) {
887 		return rc;
888 	}
889 
890 	/* Serialize extents */
891 	rc = _spdk_blob_serialize_extents_rle(blob, pages, cur_page, page_count, &buf, &remaining_sz);
892 
893 	return rc;
894 }
895 
896 struct spdk_blob_load_ctx {
897 	struct spdk_blob		*blob;
898 
899 	struct spdk_blob_md_page	*pages;
900 	uint32_t			num_pages;
901 	spdk_bs_sequence_t	        *seq;
902 
903 	spdk_bs_sequence_cpl		cb_fn;
904 	void				*cb_arg;
905 };
906 
907 static uint32_t
908 _spdk_blob_md_page_calc_crc(void *page)
909 {
910 	uint32_t		crc;
911 
912 	crc = BLOB_CRC32C_INITIAL;
913 	crc = spdk_crc32c_update(page, SPDK_BS_PAGE_SIZE - 4, crc);
914 	crc ^= BLOB_CRC32C_INITIAL;
915 
916 	return crc;
917 
918 }
919 
920 static void
921 _spdk_blob_load_final(void *cb_arg, int bserrno)
922 {
923 	struct spdk_blob_load_ctx	*ctx = cb_arg;
924 	struct spdk_blob		*blob = ctx->blob;
925 
926 	if (bserrno == 0) {
927 		_spdk_blob_mark_clean(blob);
928 	}
929 
930 	ctx->cb_fn(ctx->seq, ctx->cb_arg, bserrno);
931 
932 	/* Free the memory */
933 	spdk_free(ctx->pages);
934 	free(ctx);
935 }
936 
937 static void
938 _spdk_blob_load_snapshot_cpl(void *cb_arg, struct spdk_blob *snapshot, int bserrno)
939 {
940 	struct spdk_blob_load_ctx	*ctx = cb_arg;
941 	struct spdk_blob		*blob = ctx->blob;
942 
943 	if (bserrno == 0) {
944 		blob->back_bs_dev = spdk_bs_create_blob_bs_dev(snapshot);
945 		if (blob->back_bs_dev == NULL) {
946 			bserrno = -ENOMEM;
947 		}
948 	}
949 	if (bserrno != 0) {
950 		SPDK_ERRLOG("Snapshot fail\n");
951 	}
952 
953 	_spdk_blob_load_final(ctx, bserrno);
954 }
955 
956 static void _spdk_blob_update_clear_method(struct spdk_blob *blob);
957 
958 static void
959 _spdk_blob_load_backing_dev(void *cb_arg)
960 {
961 	struct spdk_blob_load_ctx	*ctx = cb_arg;
962 	struct spdk_blob		*blob = ctx->blob;
963 	const void			*value;
964 	size_t				len;
965 	int				rc;
966 
967 	if (spdk_blob_is_thin_provisioned(blob)) {
968 		rc = _spdk_blob_get_xattr_value(blob, BLOB_SNAPSHOT, &value, &len, true);
969 		if (rc == 0) {
970 			if (len != sizeof(spdk_blob_id)) {
971 				_spdk_blob_load_final(ctx, -EINVAL);
972 				return;
973 			}
974 			/* open snapshot blob and continue in the callback function */
975 			blob->parent_id = *(spdk_blob_id *)value;
976 			spdk_bs_open_blob(blob->bs, blob->parent_id,
977 					  _spdk_blob_load_snapshot_cpl, ctx);
978 			return;
979 		} else {
980 			/* add zeroes_dev for thin provisioned blob */
981 			blob->back_bs_dev = spdk_bs_create_zeroes_dev();
982 		}
983 	} else {
984 		/* standard blob */
985 		blob->back_bs_dev = NULL;
986 	}
987 	_spdk_blob_load_final(ctx, 0);
988 }
989 
990 static void
991 _spdk_blob_load_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
992 {
993 	struct spdk_blob_load_ctx	*ctx = cb_arg;
994 	struct spdk_blob		*blob = ctx->blob;
995 	struct spdk_blob_md_page	*page;
996 	int				rc;
997 	uint32_t			crc;
998 
999 	if (bserrno) {
1000 		SPDK_ERRLOG("Metadata page read failed: %d\n", bserrno);
1001 		_spdk_blob_load_final(ctx, bserrno);
1002 		return;
1003 	}
1004 
1005 	page = &ctx->pages[ctx->num_pages - 1];
1006 	crc = _spdk_blob_md_page_calc_crc(page);
1007 	if (crc != page->crc) {
1008 		SPDK_ERRLOG("Metadata page %d crc mismatch\n", ctx->num_pages);
1009 		_spdk_blob_load_final(ctx, -EINVAL);
1010 		return;
1011 	}
1012 
1013 	if (page->next != SPDK_INVALID_MD_PAGE) {
1014 		uint32_t next_page = page->next;
1015 		uint64_t next_lba = _spdk_bs_md_page_to_lba(blob->bs, next_page);
1016 
1017 		/* Read the next page */
1018 		ctx->num_pages++;
1019 		ctx->pages = spdk_realloc(ctx->pages, (sizeof(*page) * ctx->num_pages),
1020 					  sizeof(*page));
1021 		if (ctx->pages == NULL) {
1022 			_spdk_blob_load_final(ctx, -ENOMEM);
1023 			return;
1024 		}
1025 
1026 		spdk_bs_sequence_read_dev(seq, &ctx->pages[ctx->num_pages - 1],
1027 					  next_lba,
1028 					  _spdk_bs_byte_to_lba(blob->bs, sizeof(*page)),
1029 					  _spdk_blob_load_cpl, ctx);
1030 		return;
1031 	}
1032 
1033 	/* Parse the pages */
1034 	rc = _spdk_blob_parse(ctx->pages, ctx->num_pages, blob);
1035 	if (rc) {
1036 		_spdk_blob_load_final(ctx, rc);
1037 		return;
1038 	}
1039 	ctx->seq = seq;
1040 
1041 	/* Check the clear_method stored in metadata vs what may have been passed
1042 	 * via spdk_bs_open_blob_ext() and update accordingly.
1043 	 */
1044 	_spdk_blob_update_clear_method(blob);
1045 
1046 	_spdk_blob_load_backing_dev(ctx);
1047 }
1048 
1049 /* Load a blob from disk given a blobid */
1050 static void
1051 _spdk_blob_load(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
1052 		spdk_bs_sequence_cpl cb_fn, void *cb_arg)
1053 {
1054 	struct spdk_blob_load_ctx *ctx;
1055 	struct spdk_blob_store *bs;
1056 	uint32_t page_num;
1057 	uint64_t lba;
1058 
1059 	_spdk_blob_verify_md_op(blob);
1060 
1061 	bs = blob->bs;
1062 
1063 	ctx = calloc(1, sizeof(*ctx));
1064 	if (!ctx) {
1065 		cb_fn(seq, cb_arg, -ENOMEM);
1066 		return;
1067 	}
1068 
1069 	ctx->blob = blob;
1070 	ctx->pages = spdk_realloc(ctx->pages, SPDK_BS_PAGE_SIZE, SPDK_BS_PAGE_SIZE);
1071 	if (!ctx->pages) {
1072 		free(ctx);
1073 		cb_fn(seq, cb_arg, -ENOMEM);
1074 		return;
1075 	}
1076 	ctx->num_pages = 1;
1077 	ctx->cb_fn = cb_fn;
1078 	ctx->cb_arg = cb_arg;
1079 	ctx->seq = seq;
1080 
1081 	page_num = _spdk_bs_blobid_to_page(blob->id);
1082 	lba = _spdk_bs_md_page_to_lba(blob->bs, page_num);
1083 
1084 	blob->state = SPDK_BLOB_STATE_LOADING;
1085 
1086 	spdk_bs_sequence_read_dev(seq, &ctx->pages[0], lba,
1087 				  _spdk_bs_byte_to_lba(bs, SPDK_BS_PAGE_SIZE),
1088 				  _spdk_blob_load_cpl, ctx);
1089 }
1090 
1091 struct spdk_blob_persist_ctx {
1092 	struct spdk_blob		*blob;
1093 
1094 	struct spdk_bs_super_block	*super;
1095 
1096 	struct spdk_blob_md_page	*pages;
1097 
1098 	spdk_bs_sequence_t		*seq;
1099 	spdk_bs_sequence_cpl		cb_fn;
1100 	void				*cb_arg;
1101 };
1102 
1103 static void
1104 spdk_bs_batch_clear_dev(struct spdk_blob_persist_ctx *ctx, spdk_bs_batch_t *batch, uint64_t lba,
1105 			uint32_t lba_count)
1106 {
1107 	switch (ctx->blob->clear_method) {
1108 	case BLOB_CLEAR_WITH_DEFAULT:
1109 	case BLOB_CLEAR_WITH_UNMAP:
1110 		spdk_bs_batch_unmap_dev(batch, lba, lba_count);
1111 		break;
1112 	case BLOB_CLEAR_WITH_WRITE_ZEROES:
1113 		spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1114 		break;
1115 	case BLOB_CLEAR_WITH_NONE:
1116 	default:
1117 		break;
1118 	}
1119 }
1120 
1121 static void
1122 _spdk_blob_persist_complete(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1123 {
1124 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1125 	struct spdk_blob		*blob = ctx->blob;
1126 
1127 	if (bserrno == 0) {
1128 		_spdk_blob_mark_clean(blob);
1129 	}
1130 
1131 	/* Call user callback */
1132 	ctx->cb_fn(seq, ctx->cb_arg, bserrno);
1133 
1134 	/* Free the memory */
1135 	spdk_free(ctx->pages);
1136 	free(ctx);
1137 }
1138 
1139 static void
1140 _spdk_blob_persist_clear_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1141 {
1142 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1143 	struct spdk_blob		*blob = ctx->blob;
1144 	struct spdk_blob_store		*bs = blob->bs;
1145 	size_t				i;
1146 
1147 	/* Release all clusters that were truncated */
1148 	for (i = blob->active.num_clusters; i < blob->active.cluster_array_size; i++) {
1149 		uint32_t cluster_num = _spdk_bs_lba_to_cluster(bs, blob->active.clusters[i]);
1150 
1151 		/* Nothing to release if it was not allocated */
1152 		if (blob->active.clusters[i] != 0) {
1153 			_spdk_bs_release_cluster(bs, cluster_num);
1154 		}
1155 	}
1156 
1157 	if (blob->active.num_clusters == 0) {
1158 		free(blob->active.clusters);
1159 		blob->active.clusters = NULL;
1160 		blob->active.cluster_array_size = 0;
1161 	} else if (blob->active.num_clusters != blob->active.cluster_array_size) {
1162 #ifndef __clang_analyzer__
1163 		void *tmp;
1164 
1165 		/* scan-build really can't figure reallocs, workaround it */
1166 		tmp = realloc(blob->active.clusters, sizeof(*blob->active.clusters) * blob->active.num_clusters);
1167 		assert(tmp != NULL);
1168 		blob->active.clusters = tmp;
1169 #endif
1170 		blob->active.cluster_array_size = blob->active.num_clusters;
1171 	}
1172 
1173 	_spdk_blob_persist_complete(seq, ctx, bserrno);
1174 }
1175 
1176 static void
1177 _spdk_blob_persist_clear_clusters(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1178 {
1179 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1180 	struct spdk_blob		*blob = ctx->blob;
1181 	struct spdk_blob_store		*bs = blob->bs;
1182 	spdk_bs_batch_t			*batch;
1183 	size_t				i;
1184 	uint64_t			lba;
1185 	uint32_t			lba_count;
1186 
1187 	/* Clusters don't move around in blobs. The list shrinks or grows
1188 	 * at the end, but no changes ever occur in the middle of the list.
1189 	 */
1190 
1191 	batch = spdk_bs_sequence_to_batch(seq, _spdk_blob_persist_clear_clusters_cpl, ctx);
1192 
1193 	/* Clear all clusters that were truncated */
1194 	lba = 0;
1195 	lba_count = 0;
1196 	for (i = blob->active.num_clusters; i < blob->active.cluster_array_size; i++) {
1197 		uint64_t next_lba = blob->active.clusters[i];
1198 		uint32_t next_lba_count = _spdk_bs_cluster_to_lba(bs, 1);
1199 
1200 		if (next_lba > 0 && (lba + lba_count) == next_lba) {
1201 			/* This cluster is contiguous with the previous one. */
1202 			lba_count += next_lba_count;
1203 			continue;
1204 		}
1205 
1206 		/* This cluster is not contiguous with the previous one. */
1207 
1208 		/* If a run of LBAs previously existing, clear them now */
1209 		if (lba_count > 0) {
1210 			spdk_bs_batch_clear_dev(ctx, batch, lba, lba_count);
1211 		}
1212 
1213 		/* Start building the next batch */
1214 		lba = next_lba;
1215 		if (next_lba > 0) {
1216 			lba_count = next_lba_count;
1217 		} else {
1218 			lba_count = 0;
1219 		}
1220 	}
1221 
1222 	/* If we ended with a contiguous set of LBAs, clear them now */
1223 	if (lba_count > 0) {
1224 		spdk_bs_batch_clear_dev(ctx, batch, lba, lba_count);
1225 	}
1226 
1227 	spdk_bs_batch_close(batch);
1228 }
1229 
1230 static void
1231 _spdk_blob_persist_zero_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1232 {
1233 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1234 	struct spdk_blob		*blob = ctx->blob;
1235 	struct spdk_blob_store		*bs = blob->bs;
1236 	size_t				i;
1237 
1238 	/* This loop starts at 1 because the first page is special and handled
1239 	 * below. The pages (except the first) are never written in place,
1240 	 * so any pages in the clean list must be zeroed.
1241 	 */
1242 	for (i = 1; i < blob->clean.num_pages; i++) {
1243 		spdk_bit_array_clear(bs->used_md_pages, blob->clean.pages[i]);
1244 	}
1245 
1246 	if (blob->active.num_pages == 0) {
1247 		uint32_t page_num;
1248 
1249 		page_num = _spdk_bs_blobid_to_page(blob->id);
1250 		spdk_bit_array_clear(bs->used_md_pages, page_num);
1251 	}
1252 
1253 	/* Move on to clearing clusters */
1254 	_spdk_blob_persist_clear_clusters(seq, ctx, 0);
1255 }
1256 
1257 static void
1258 _spdk_blob_persist_zero_pages(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1259 {
1260 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1261 	struct spdk_blob		*blob = ctx->blob;
1262 	struct spdk_blob_store		*bs = blob->bs;
1263 	uint64_t			lba;
1264 	uint32_t			lba_count;
1265 	spdk_bs_batch_t			*batch;
1266 	size_t				i;
1267 
1268 	batch = spdk_bs_sequence_to_batch(seq, _spdk_blob_persist_zero_pages_cpl, ctx);
1269 
1270 	lba_count = _spdk_bs_byte_to_lba(bs, SPDK_BS_PAGE_SIZE);
1271 
1272 	/* This loop starts at 1 because the first page is special and handled
1273 	 * below. The pages (except the first) are never written in place,
1274 	 * so any pages in the clean list must be zeroed.
1275 	 */
1276 	for (i = 1; i < blob->clean.num_pages; i++) {
1277 		lba = _spdk_bs_md_page_to_lba(bs, blob->clean.pages[i]);
1278 
1279 		spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1280 	}
1281 
1282 	/* The first page will only be zeroed if this is a delete. */
1283 	if (blob->active.num_pages == 0) {
1284 		uint32_t page_num;
1285 
1286 		/* The first page in the metadata goes where the blobid indicates */
1287 		page_num = _spdk_bs_blobid_to_page(blob->id);
1288 		lba = _spdk_bs_md_page_to_lba(bs, page_num);
1289 
1290 		spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1291 	}
1292 
1293 	spdk_bs_batch_close(batch);
1294 }
1295 
1296 static void
1297 _spdk_blob_persist_write_page_root(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1298 {
1299 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1300 	struct spdk_blob		*blob = ctx->blob;
1301 	struct spdk_blob_store		*bs = blob->bs;
1302 	uint64_t			lba;
1303 	uint32_t			lba_count;
1304 	struct spdk_blob_md_page	*page;
1305 
1306 	if (blob->active.num_pages == 0) {
1307 		/* Move on to the next step */
1308 		_spdk_blob_persist_zero_pages(seq, ctx, 0);
1309 		return;
1310 	}
1311 
1312 	lba_count = _spdk_bs_byte_to_lba(bs, sizeof(*page));
1313 
1314 	page = &ctx->pages[0];
1315 	/* The first page in the metadata goes where the blobid indicates */
1316 	lba = _spdk_bs_md_page_to_lba(bs, _spdk_bs_blobid_to_page(blob->id));
1317 
1318 	spdk_bs_sequence_write_dev(seq, page, lba, lba_count,
1319 				   _spdk_blob_persist_zero_pages, ctx);
1320 }
1321 
1322 static void
1323 _spdk_blob_persist_write_page_chain(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1324 {
1325 	struct spdk_blob_persist_ctx	*ctx = cb_arg;
1326 	struct spdk_blob		*blob = ctx->blob;
1327 	struct spdk_blob_store		*bs = blob->bs;
1328 	uint64_t			lba;
1329 	uint32_t			lba_count;
1330 	struct spdk_blob_md_page	*page;
1331 	spdk_bs_batch_t			*batch;
1332 	size_t				i;
1333 
1334 	/* Clusters don't move around in blobs. The list shrinks or grows
1335 	 * at the end, but no changes ever occur in the middle of the list.
1336 	 */
1337 
1338 	lba_count = _spdk_bs_byte_to_lba(bs, sizeof(*page));
1339 
1340 	batch = spdk_bs_sequence_to_batch(seq, _spdk_blob_persist_write_page_root, ctx);
1341 
1342 	/* This starts at 1. The root page is not written until
1343 	 * all of the others are finished
1344 	 */
1345 	for (i = 1; i < blob->active.num_pages; i++) {
1346 		page = &ctx->pages[i];
1347 		assert(page->sequence_num == i);
1348 
1349 		lba = _spdk_bs_md_page_to_lba(bs, blob->active.pages[i]);
1350 
1351 		spdk_bs_batch_write_dev(batch, page, lba, lba_count);
1352 	}
1353 
1354 	spdk_bs_batch_close(batch);
1355 }
1356 
1357 static int
1358 _spdk_blob_resize(struct spdk_blob *blob, uint64_t sz)
1359 {
1360 	uint64_t	i;
1361 	uint64_t	*tmp;
1362 	uint64_t	lfc; /* lowest free cluster */
1363 	uint64_t	num_clusters;
1364 	struct spdk_blob_store *bs;
1365 
1366 	bs = blob->bs;
1367 
1368 	_spdk_blob_verify_md_op(blob);
1369 
1370 	if (blob->active.num_clusters == sz) {
1371 		return 0;
1372 	}
1373 
1374 	if (blob->active.num_clusters < blob->active.cluster_array_size) {
1375 		/* If this blob was resized to be larger, then smaller, then
1376 		 * larger without syncing, then the cluster array already
1377 		 * contains spare assigned clusters we can use.
1378 		 */
1379 		num_clusters = spdk_min(blob->active.cluster_array_size,
1380 					sz);
1381 	} else {
1382 		num_clusters = blob->active.num_clusters;
1383 	}
1384 
1385 	/* Do two passes - one to verify that we can obtain enough clusters
1386 	 * and another to actually claim them.
1387 	 */
1388 
1389 	if (spdk_blob_is_thin_provisioned(blob) == false) {
1390 		lfc = 0;
1391 		for (i = num_clusters; i < sz; i++) {
1392 			lfc = spdk_bit_array_find_first_clear(bs->used_clusters, lfc);
1393 			if (lfc == UINT32_MAX) {
1394 				/* No more free clusters. Cannot satisfy the request */
1395 				return -ENOSPC;
1396 			}
1397 			lfc++;
1398 		}
1399 	}
1400 
1401 	if (sz > num_clusters) {
1402 		/* Expand the cluster array if necessary.
1403 		 * We only shrink the array when persisting.
1404 		 */
1405 		tmp = realloc(blob->active.clusters, sizeof(*blob->active.clusters) * sz);
1406 		if (sz > 0 && tmp == NULL) {
1407 			return -ENOMEM;
1408 		}
1409 		memset(tmp + blob->active.cluster_array_size, 0,
1410 		       sizeof(*blob->active.clusters) * (sz - blob->active.cluster_array_size));
1411 		blob->active.clusters = tmp;
1412 		blob->active.cluster_array_size = sz;
1413 	}
1414 
1415 	blob->state = SPDK_BLOB_STATE_DIRTY;
1416 
1417 	if (spdk_blob_is_thin_provisioned(blob) == false) {
1418 		lfc = 0;
1419 		for (i = num_clusters; i < sz; i++) {
1420 			_spdk_bs_allocate_cluster(blob, i, &lfc, true);
1421 			lfc++;
1422 		}
1423 	}
1424 
1425 	blob->active.num_clusters = sz;
1426 
1427 	return 0;
1428 }
1429 
1430 static void
1431 _spdk_blob_persist_generate_new_md(struct spdk_blob_persist_ctx *ctx)
1432 {
1433 	spdk_bs_sequence_t *seq = ctx->seq;
1434 	struct spdk_blob *blob = ctx->blob;
1435 	struct spdk_blob_store *bs = blob->bs;
1436 	uint64_t i;
1437 	uint32_t page_num;
1438 	void *tmp;
1439 	int rc;
1440 
1441 	/* Generate the new metadata */
1442 	rc = _spdk_blob_serialize(blob, &ctx->pages, &blob->active.num_pages);
1443 	if (rc < 0) {
1444 		_spdk_blob_persist_complete(seq, ctx, rc);
1445 		return;
1446 	}
1447 
1448 	assert(blob->active.num_pages >= 1);
1449 
1450 	/* Resize the cache of page indices */
1451 	tmp = realloc(blob->active.pages, blob->active.num_pages * sizeof(*blob->active.pages));
1452 	if (!tmp) {
1453 		_spdk_blob_persist_complete(seq, ctx, -ENOMEM);
1454 		return;
1455 	}
1456 	blob->active.pages = tmp;
1457 
1458 	/* Assign this metadata to pages. This requires two passes -
1459 	 * one to verify that there are enough pages and a second
1460 	 * to actually claim them. */
1461 	page_num = 0;
1462 	/* Note that this loop starts at one. The first page location is fixed by the blobid. */
1463 	for (i = 1; i < blob->active.num_pages; i++) {
1464 		page_num = spdk_bit_array_find_first_clear(bs->used_md_pages, page_num);
1465 		if (page_num == UINT32_MAX) {
1466 			_spdk_blob_persist_complete(seq, ctx, -ENOMEM);
1467 			return;
1468 		}
1469 		page_num++;
1470 	}
1471 
1472 	page_num = 0;
1473 	blob->active.pages[0] = _spdk_bs_blobid_to_page(blob->id);
1474 	for (i = 1; i < blob->active.num_pages; i++) {
1475 		page_num = spdk_bit_array_find_first_clear(bs->used_md_pages, page_num);
1476 		ctx->pages[i - 1].next = page_num;
1477 		/* Now that previous metadata page is complete, calculate the crc for it. */
1478 		ctx->pages[i - 1].crc = _spdk_blob_md_page_calc_crc(&ctx->pages[i - 1]);
1479 		blob->active.pages[i] = page_num;
1480 		spdk_bit_array_set(bs->used_md_pages, page_num);
1481 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Claiming page %u for blob %lu\n", page_num, blob->id);
1482 		page_num++;
1483 	}
1484 	ctx->pages[i - 1].crc = _spdk_blob_md_page_calc_crc(&ctx->pages[i - 1]);
1485 	/* Start writing the metadata from last page to first */
1486 	blob->state = SPDK_BLOB_STATE_CLEAN;
1487 	_spdk_blob_persist_write_page_chain(seq, ctx, 0);
1488 }
1489 
1490 static void
1491 _spdk_blob_persist_start(struct spdk_blob_persist_ctx *ctx)
1492 {
1493 	spdk_bs_sequence_t *seq = ctx->seq;
1494 	struct spdk_blob *blob = ctx->blob;
1495 
1496 	if (blob->active.num_pages == 0) {
1497 		/* This is the signal that the blob should be deleted.
1498 		 * Immediately jump to the clean up routine. */
1499 		assert(blob->clean.num_pages > 0);
1500 		blob->state = SPDK_BLOB_STATE_CLEAN;
1501 		_spdk_blob_persist_zero_pages(seq, ctx, 0);
1502 		return;
1503 
1504 	}
1505 
1506 	_spdk_blob_persist_generate_new_md(ctx);
1507 }
1508 
1509 static void
1510 _spdk_blob_persist_dirty_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1511 {
1512 	struct spdk_blob_persist_ctx *ctx = cb_arg;
1513 
1514 	ctx->blob->bs->clean = 0;
1515 
1516 	spdk_free(ctx->super);
1517 
1518 	_spdk_blob_persist_start(ctx);
1519 }
1520 
1521 static void
1522 _spdk_bs_write_super(spdk_bs_sequence_t *seq, struct spdk_blob_store *bs,
1523 		     struct spdk_bs_super_block *super, spdk_bs_sequence_cpl cb_fn, void *cb_arg);
1524 
1525 
1526 static void
1527 _spdk_blob_persist_dirty(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1528 {
1529 	struct spdk_blob_persist_ctx *ctx = cb_arg;
1530 
1531 	ctx->super->clean = 0;
1532 	if (ctx->super->size == 0) {
1533 		ctx->super->size = ctx->blob->bs->dev->blockcnt * ctx->blob->bs->dev->blocklen;
1534 	}
1535 
1536 	_spdk_bs_write_super(seq, ctx->blob->bs, ctx->super, _spdk_blob_persist_dirty_cpl, ctx);
1537 }
1538 
1539 
1540 /* Write a blob to disk */
1541 static void
1542 _spdk_blob_persist(spdk_bs_sequence_t *seq, struct spdk_blob *blob,
1543 		   spdk_bs_sequence_cpl cb_fn, void *cb_arg)
1544 {
1545 	struct spdk_blob_persist_ctx *ctx;
1546 
1547 	_spdk_blob_verify_md_op(blob);
1548 
1549 	if (blob->state == SPDK_BLOB_STATE_CLEAN) {
1550 		cb_fn(seq, cb_arg, 0);
1551 		return;
1552 	}
1553 
1554 	ctx = calloc(1, sizeof(*ctx));
1555 	if (!ctx) {
1556 		cb_fn(seq, cb_arg, -ENOMEM);
1557 		return;
1558 	}
1559 	ctx->blob = blob;
1560 	ctx->seq = seq;
1561 	ctx->cb_fn = cb_fn;
1562 	ctx->cb_arg = cb_arg;
1563 
1564 	if (blob->bs->clean) {
1565 		ctx->super = spdk_zmalloc(sizeof(*ctx->super), 0x1000, NULL,
1566 					  SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
1567 		if (!ctx->super) {
1568 			cb_fn(seq, cb_arg, -ENOMEM);
1569 			free(ctx);
1570 			return;
1571 		}
1572 
1573 		spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(blob->bs, 0),
1574 					  _spdk_bs_byte_to_lba(blob->bs, sizeof(*ctx->super)),
1575 					  _spdk_blob_persist_dirty, ctx);
1576 	} else {
1577 		_spdk_blob_persist_start(ctx);
1578 	}
1579 }
1580 
1581 struct spdk_blob_copy_cluster_ctx {
1582 	struct spdk_blob *blob;
1583 	uint8_t *buf;
1584 	uint64_t page;
1585 	uint64_t new_cluster;
1586 	spdk_bs_sequence_t *seq;
1587 };
1588 
1589 static void
1590 _spdk_blob_allocate_and_copy_cluster_cpl(void *cb_arg, int bserrno)
1591 {
1592 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1593 	struct spdk_bs_request_set *set = (struct spdk_bs_request_set *)ctx->seq;
1594 	TAILQ_HEAD(, spdk_bs_request_set) requests;
1595 	spdk_bs_user_op_t *op;
1596 
1597 	TAILQ_INIT(&requests);
1598 	TAILQ_SWAP(&set->channel->need_cluster_alloc, &requests, spdk_bs_request_set, link);
1599 
1600 	while (!TAILQ_EMPTY(&requests)) {
1601 		op = TAILQ_FIRST(&requests);
1602 		TAILQ_REMOVE(&requests, op, link);
1603 		if (bserrno == 0) {
1604 			spdk_bs_user_op_execute(op);
1605 		} else {
1606 			spdk_bs_user_op_abort(op);
1607 		}
1608 	}
1609 
1610 	spdk_free(ctx->buf);
1611 	free(ctx);
1612 }
1613 
1614 static void
1615 _spdk_blob_insert_cluster_cpl(void *cb_arg, int bserrno)
1616 {
1617 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1618 
1619 	if (bserrno) {
1620 		if (bserrno == -EEXIST) {
1621 			/* The metadata insert failed because another thread
1622 			 * allocated the cluster first. Free our cluster
1623 			 * but continue without error. */
1624 			bserrno = 0;
1625 		}
1626 		_spdk_bs_release_cluster(ctx->blob->bs, ctx->new_cluster);
1627 	}
1628 
1629 	spdk_bs_sequence_finish(ctx->seq, bserrno);
1630 }
1631 
1632 static void
1633 _spdk_blob_write_copy_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1634 {
1635 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1636 	uint32_t cluster_number;
1637 
1638 	if (bserrno) {
1639 		/* The write failed, so jump to the final completion handler */
1640 		spdk_bs_sequence_finish(seq, bserrno);
1641 		return;
1642 	}
1643 
1644 	cluster_number = _spdk_bs_page_to_cluster(ctx->blob->bs, ctx->page);
1645 
1646 	_spdk_blob_insert_cluster_on_md_thread(ctx->blob, cluster_number, ctx->new_cluster,
1647 					       _spdk_blob_insert_cluster_cpl, ctx);
1648 }
1649 
1650 static void
1651 _spdk_blob_write_copy(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
1652 {
1653 	struct spdk_blob_copy_cluster_ctx *ctx = cb_arg;
1654 
1655 	if (bserrno != 0) {
1656 		/* The read failed, so jump to the final completion handler */
1657 		spdk_bs_sequence_finish(seq, bserrno);
1658 		return;
1659 	}
1660 
1661 	/* Write whole cluster */
1662 	spdk_bs_sequence_write_dev(seq, ctx->buf,
1663 				   _spdk_bs_cluster_to_lba(ctx->blob->bs, ctx->new_cluster),
1664 				   _spdk_bs_cluster_to_lba(ctx->blob->bs, 1),
1665 				   _spdk_blob_write_copy_cpl, ctx);
1666 }
1667 
1668 static void
1669 _spdk_bs_allocate_and_copy_cluster(struct spdk_blob *blob,
1670 				   struct spdk_io_channel *_ch,
1671 				   uint64_t io_unit, spdk_bs_user_op_t *op)
1672 {
1673 	struct spdk_bs_cpl cpl;
1674 	struct spdk_bs_channel *ch;
1675 	struct spdk_blob_copy_cluster_ctx *ctx;
1676 	uint32_t cluster_start_page;
1677 	uint32_t cluster_number;
1678 	int rc;
1679 
1680 	ch = spdk_io_channel_get_ctx(_ch);
1681 
1682 	if (!TAILQ_EMPTY(&ch->need_cluster_alloc)) {
1683 		/* There are already operations pending. Queue this user op
1684 		 * and return because it will be re-executed when the outstanding
1685 		 * cluster allocation completes. */
1686 		TAILQ_INSERT_TAIL(&ch->need_cluster_alloc, op, link);
1687 		return;
1688 	}
1689 
1690 	/* Round the io_unit offset down to the first page in the cluster */
1691 	cluster_start_page = _spdk_bs_io_unit_to_cluster_start(blob, io_unit);
1692 
1693 	/* Calculate which index in the metadata cluster array the corresponding
1694 	 * cluster is supposed to be at. */
1695 	cluster_number = _spdk_bs_io_unit_to_cluster_number(blob, io_unit);
1696 
1697 	ctx = calloc(1, sizeof(*ctx));
1698 	if (!ctx) {
1699 		spdk_bs_user_op_abort(op);
1700 		return;
1701 	}
1702 
1703 	assert(blob->bs->cluster_sz % blob->back_bs_dev->blocklen == 0);
1704 
1705 	ctx->blob = blob;
1706 	ctx->page = cluster_start_page;
1707 
1708 	if (blob->parent_id != SPDK_BLOBID_INVALID) {
1709 		ctx->buf = spdk_malloc(blob->bs->cluster_sz, blob->back_bs_dev->blocklen,
1710 				       NULL, SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
1711 		if (!ctx->buf) {
1712 			SPDK_ERRLOG("DMA allocation for cluster of size = %" PRIu32 " failed.\n",
1713 				    blob->bs->cluster_sz);
1714 			free(ctx);
1715 			spdk_bs_user_op_abort(op);
1716 			return;
1717 		}
1718 	}
1719 
1720 	rc = _spdk_bs_allocate_cluster(blob, cluster_number, &ctx->new_cluster, false);
1721 	if (rc != 0) {
1722 		spdk_free(ctx->buf);
1723 		free(ctx);
1724 		spdk_bs_user_op_abort(op);
1725 		return;
1726 	}
1727 
1728 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
1729 	cpl.u.blob_basic.cb_fn = _spdk_blob_allocate_and_copy_cluster_cpl;
1730 	cpl.u.blob_basic.cb_arg = ctx;
1731 
1732 	ctx->seq = spdk_bs_sequence_start(_ch, &cpl);
1733 	if (!ctx->seq) {
1734 		_spdk_bs_release_cluster(blob->bs, ctx->new_cluster);
1735 		spdk_free(ctx->buf);
1736 		free(ctx);
1737 		spdk_bs_user_op_abort(op);
1738 		return;
1739 	}
1740 
1741 	/* Queue the user op to block other incoming operations */
1742 	TAILQ_INSERT_TAIL(&ch->need_cluster_alloc, op, link);
1743 
1744 	if (blob->parent_id != SPDK_BLOBID_INVALID) {
1745 		/* Read cluster from backing device */
1746 		spdk_bs_sequence_read_bs_dev(ctx->seq, blob->back_bs_dev, ctx->buf,
1747 					     _spdk_bs_dev_page_to_lba(blob->back_bs_dev, cluster_start_page),
1748 					     _spdk_bs_dev_byte_to_lba(blob->back_bs_dev, blob->bs->cluster_sz),
1749 					     _spdk_blob_write_copy, ctx);
1750 	} else {
1751 		_spdk_blob_insert_cluster_on_md_thread(ctx->blob, cluster_number, ctx->new_cluster,
1752 						       _spdk_blob_insert_cluster_cpl, ctx);
1753 	}
1754 }
1755 
1756 static void
1757 _spdk_blob_calculate_lba_and_lba_count(struct spdk_blob *blob, uint64_t io_unit, uint64_t length,
1758 				       uint64_t *lba,	uint32_t *lba_count)
1759 {
1760 	*lba_count = length;
1761 
1762 	if (!_spdk_bs_io_unit_is_allocated(blob, io_unit)) {
1763 		assert(blob->back_bs_dev != NULL);
1764 		*lba = _spdk_bs_io_unit_to_back_dev_lba(blob, io_unit);
1765 		*lba_count = _spdk_bs_io_unit_to_back_dev_lba(blob, *lba_count);
1766 	} else {
1767 		*lba = _spdk_bs_blob_io_unit_to_lba(blob, io_unit);
1768 	}
1769 }
1770 
1771 struct op_split_ctx {
1772 	struct spdk_blob *blob;
1773 	struct spdk_io_channel *channel;
1774 	uint64_t io_unit_offset;
1775 	uint64_t io_units_remaining;
1776 	void *curr_payload;
1777 	enum spdk_blob_op_type op_type;
1778 	spdk_bs_sequence_t *seq;
1779 };
1780 
1781 static void
1782 _spdk_blob_request_submit_op_split_next(void *cb_arg, int bserrno)
1783 {
1784 	struct op_split_ctx	*ctx = cb_arg;
1785 	struct spdk_blob	*blob = ctx->blob;
1786 	struct spdk_io_channel	*ch = ctx->channel;
1787 	enum spdk_blob_op_type	op_type = ctx->op_type;
1788 	uint8_t			*buf = ctx->curr_payload;
1789 	uint64_t		offset = ctx->io_unit_offset;
1790 	uint64_t		length = ctx->io_units_remaining;
1791 	uint64_t		op_length;
1792 
1793 	if (bserrno != 0 || ctx->io_units_remaining == 0) {
1794 		spdk_bs_sequence_finish(ctx->seq, bserrno);
1795 		free(ctx);
1796 		return;
1797 	}
1798 
1799 	op_length = spdk_min(length, _spdk_bs_num_io_units_to_cluster_boundary(blob,
1800 			     offset));
1801 
1802 	/* Update length and payload for next operation */
1803 	ctx->io_units_remaining -= op_length;
1804 	ctx->io_unit_offset += op_length;
1805 	if (op_type == SPDK_BLOB_WRITE || op_type == SPDK_BLOB_READ) {
1806 		ctx->curr_payload += op_length * blob->bs->io_unit_size;
1807 	}
1808 
1809 	switch (op_type) {
1810 	case SPDK_BLOB_READ:
1811 		spdk_blob_io_read(blob, ch, buf, offset, op_length,
1812 				  _spdk_blob_request_submit_op_split_next, ctx);
1813 		break;
1814 	case SPDK_BLOB_WRITE:
1815 		spdk_blob_io_write(blob, ch, buf, offset, op_length,
1816 				   _spdk_blob_request_submit_op_split_next, ctx);
1817 		break;
1818 	case SPDK_BLOB_UNMAP:
1819 		spdk_blob_io_unmap(blob, ch, offset, op_length,
1820 				   _spdk_blob_request_submit_op_split_next, ctx);
1821 		break;
1822 	case SPDK_BLOB_WRITE_ZEROES:
1823 		spdk_blob_io_write_zeroes(blob, ch, offset, op_length,
1824 					  _spdk_blob_request_submit_op_split_next, ctx);
1825 		break;
1826 	case SPDK_BLOB_READV:
1827 	case SPDK_BLOB_WRITEV:
1828 		SPDK_ERRLOG("readv/write not valid\n");
1829 		spdk_bs_sequence_finish(ctx->seq, -EINVAL);
1830 		free(ctx);
1831 		break;
1832 	}
1833 }
1834 
1835 static void
1836 _spdk_blob_request_submit_op_split(struct spdk_io_channel *ch, struct spdk_blob *blob,
1837 				   void *payload, uint64_t offset, uint64_t length,
1838 				   spdk_blob_op_complete cb_fn, void *cb_arg, enum spdk_blob_op_type op_type)
1839 {
1840 	struct op_split_ctx *ctx;
1841 	spdk_bs_sequence_t *seq;
1842 	struct spdk_bs_cpl cpl;
1843 
1844 	assert(blob != NULL);
1845 
1846 	ctx = calloc(1, sizeof(struct op_split_ctx));
1847 	if (ctx == NULL) {
1848 		cb_fn(cb_arg, -ENOMEM);
1849 		return;
1850 	}
1851 
1852 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
1853 	cpl.u.blob_basic.cb_fn = cb_fn;
1854 	cpl.u.blob_basic.cb_arg = cb_arg;
1855 
1856 	seq = spdk_bs_sequence_start(ch, &cpl);
1857 	if (!seq) {
1858 		free(ctx);
1859 		cb_fn(cb_arg, -ENOMEM);
1860 		return;
1861 	}
1862 
1863 	ctx->blob = blob;
1864 	ctx->channel = ch;
1865 	ctx->curr_payload = payload;
1866 	ctx->io_unit_offset = offset;
1867 	ctx->io_units_remaining = length;
1868 	ctx->op_type = op_type;
1869 	ctx->seq = seq;
1870 
1871 	_spdk_blob_request_submit_op_split_next(ctx, 0);
1872 }
1873 
1874 static void
1875 _spdk_blob_request_submit_op_single(struct spdk_io_channel *_ch, struct spdk_blob *blob,
1876 				    void *payload, uint64_t offset, uint64_t length,
1877 				    spdk_blob_op_complete cb_fn, void *cb_arg, enum spdk_blob_op_type op_type)
1878 {
1879 	struct spdk_bs_cpl cpl;
1880 	uint64_t lba;
1881 	uint32_t lba_count;
1882 
1883 	assert(blob != NULL);
1884 
1885 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
1886 	cpl.u.blob_basic.cb_fn = cb_fn;
1887 	cpl.u.blob_basic.cb_arg = cb_arg;
1888 
1889 	_spdk_blob_calculate_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
1890 
1891 	if (blob->frozen_refcnt) {
1892 		/* This blob I/O is frozen */
1893 		spdk_bs_user_op_t *op;
1894 		struct spdk_bs_channel *bs_channel = spdk_io_channel_get_ctx(_ch);
1895 
1896 		op = spdk_bs_user_op_alloc(_ch, &cpl, op_type, blob, payload, 0, offset, length);
1897 		if (!op) {
1898 			cb_fn(cb_arg, -ENOMEM);
1899 			return;
1900 		}
1901 
1902 		TAILQ_INSERT_TAIL(&bs_channel->queued_io, op, link);
1903 
1904 		return;
1905 	}
1906 
1907 	switch (op_type) {
1908 	case SPDK_BLOB_READ: {
1909 		spdk_bs_batch_t *batch;
1910 
1911 		batch = spdk_bs_batch_open(_ch, &cpl);
1912 		if (!batch) {
1913 			cb_fn(cb_arg, -ENOMEM);
1914 			return;
1915 		}
1916 
1917 		if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
1918 			/* Read from the blob */
1919 			spdk_bs_batch_read_dev(batch, payload, lba, lba_count);
1920 		} else {
1921 			/* Read from the backing block device */
1922 			spdk_bs_batch_read_bs_dev(batch, blob->back_bs_dev, payload, lba, lba_count);
1923 		}
1924 
1925 		spdk_bs_batch_close(batch);
1926 		break;
1927 	}
1928 	case SPDK_BLOB_WRITE:
1929 	case SPDK_BLOB_WRITE_ZEROES: {
1930 		if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
1931 			/* Write to the blob */
1932 			spdk_bs_batch_t *batch;
1933 
1934 			if (lba_count == 0) {
1935 				cb_fn(cb_arg, 0);
1936 				return;
1937 			}
1938 
1939 			batch = spdk_bs_batch_open(_ch, &cpl);
1940 			if (!batch) {
1941 				cb_fn(cb_arg, -ENOMEM);
1942 				return;
1943 			}
1944 
1945 			if (op_type == SPDK_BLOB_WRITE) {
1946 				spdk_bs_batch_write_dev(batch, payload, lba, lba_count);
1947 			} else {
1948 				spdk_bs_batch_write_zeroes_dev(batch, lba, lba_count);
1949 			}
1950 
1951 			spdk_bs_batch_close(batch);
1952 		} else {
1953 			/* Queue this operation and allocate the cluster */
1954 			spdk_bs_user_op_t *op;
1955 
1956 			op = spdk_bs_user_op_alloc(_ch, &cpl, op_type, blob, payload, 0, offset, length);
1957 			if (!op) {
1958 				cb_fn(cb_arg, -ENOMEM);
1959 				return;
1960 			}
1961 
1962 			_spdk_bs_allocate_and_copy_cluster(blob, _ch, offset, op);
1963 		}
1964 		break;
1965 	}
1966 	case SPDK_BLOB_UNMAP: {
1967 		spdk_bs_batch_t *batch;
1968 
1969 		batch = spdk_bs_batch_open(_ch, &cpl);
1970 		if (!batch) {
1971 			cb_fn(cb_arg, -ENOMEM);
1972 			return;
1973 		}
1974 
1975 		if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
1976 			spdk_bs_batch_unmap_dev(batch, lba, lba_count);
1977 		}
1978 
1979 		spdk_bs_batch_close(batch);
1980 		break;
1981 	}
1982 	case SPDK_BLOB_READV:
1983 	case SPDK_BLOB_WRITEV:
1984 		SPDK_ERRLOG("readv/write not valid\n");
1985 		cb_fn(cb_arg, -EINVAL);
1986 		break;
1987 	}
1988 }
1989 
1990 static void
1991 _spdk_blob_request_submit_op(struct spdk_blob *blob, struct spdk_io_channel *_channel,
1992 			     void *payload, uint64_t offset, uint64_t length,
1993 			     spdk_blob_op_complete cb_fn, void *cb_arg, enum spdk_blob_op_type op_type)
1994 {
1995 	assert(blob != NULL);
1996 
1997 	if (blob->data_ro && op_type != SPDK_BLOB_READ) {
1998 		cb_fn(cb_arg, -EPERM);
1999 		return;
2000 	}
2001 
2002 	if (offset + length > _spdk_bs_cluster_to_lba(blob->bs, blob->active.num_clusters)) {
2003 		cb_fn(cb_arg, -EINVAL);
2004 		return;
2005 	}
2006 	if (length <= _spdk_bs_num_io_units_to_cluster_boundary(blob, offset)) {
2007 		_spdk_blob_request_submit_op_single(_channel, blob, payload, offset, length,
2008 						    cb_fn, cb_arg, op_type);
2009 	} else {
2010 		_spdk_blob_request_submit_op_split(_channel, blob, payload, offset, length,
2011 						   cb_fn, cb_arg, op_type);
2012 	}
2013 }
2014 
2015 struct rw_iov_ctx {
2016 	struct spdk_blob *blob;
2017 	struct spdk_io_channel *channel;
2018 	spdk_blob_op_complete cb_fn;
2019 	void *cb_arg;
2020 	bool read;
2021 	int iovcnt;
2022 	struct iovec *orig_iov;
2023 	uint64_t io_unit_offset;
2024 	uint64_t io_units_remaining;
2025 	uint64_t io_units_done;
2026 	struct iovec iov[0];
2027 };
2028 
2029 static void
2030 _spdk_rw_iov_done(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2031 {
2032 	assert(cb_arg == NULL);
2033 	spdk_bs_sequence_finish(seq, bserrno);
2034 }
2035 
2036 static void
2037 _spdk_rw_iov_split_next(void *cb_arg, int bserrno)
2038 {
2039 	struct rw_iov_ctx *ctx = cb_arg;
2040 	struct spdk_blob *blob = ctx->blob;
2041 	struct iovec *iov, *orig_iov;
2042 	int iovcnt;
2043 	size_t orig_iovoff;
2044 	uint64_t io_units_count, io_units_to_boundary, io_unit_offset;
2045 	uint64_t byte_count;
2046 
2047 	if (bserrno != 0 || ctx->io_units_remaining == 0) {
2048 		ctx->cb_fn(ctx->cb_arg, bserrno);
2049 		free(ctx);
2050 		return;
2051 	}
2052 
2053 	io_unit_offset = ctx->io_unit_offset;
2054 	io_units_to_boundary = _spdk_bs_num_io_units_to_cluster_boundary(blob, io_unit_offset);
2055 	io_units_count = spdk_min(ctx->io_units_remaining, io_units_to_boundary);
2056 	/*
2057 	 * Get index and offset into the original iov array for our current position in the I/O sequence.
2058 	 *  byte_count will keep track of how many bytes remaining until orig_iov and orig_iovoff will
2059 	 *  point to the current position in the I/O sequence.
2060 	 */
2061 	byte_count = ctx->io_units_done * blob->bs->io_unit_size;
2062 	orig_iov = &ctx->orig_iov[0];
2063 	orig_iovoff = 0;
2064 	while (byte_count > 0) {
2065 		if (byte_count >= orig_iov->iov_len) {
2066 			byte_count -= orig_iov->iov_len;
2067 			orig_iov++;
2068 		} else {
2069 			orig_iovoff = byte_count;
2070 			byte_count = 0;
2071 		}
2072 	}
2073 
2074 	/*
2075 	 * Build an iov array for the next I/O in the sequence.  byte_count will keep track of how many
2076 	 *  bytes of this next I/O remain to be accounted for in the new iov array.
2077 	 */
2078 	byte_count = io_units_count * blob->bs->io_unit_size;
2079 	iov = &ctx->iov[0];
2080 	iovcnt = 0;
2081 	while (byte_count > 0) {
2082 		assert(iovcnt < ctx->iovcnt);
2083 		iov->iov_len = spdk_min(byte_count, orig_iov->iov_len - orig_iovoff);
2084 		iov->iov_base = orig_iov->iov_base + orig_iovoff;
2085 		byte_count -= iov->iov_len;
2086 		orig_iovoff = 0;
2087 		orig_iov++;
2088 		iov++;
2089 		iovcnt++;
2090 	}
2091 
2092 	ctx->io_unit_offset += io_units_count;
2093 	ctx->io_units_remaining -= io_units_count;
2094 	ctx->io_units_done += io_units_count;
2095 	iov = &ctx->iov[0];
2096 
2097 	if (ctx->read) {
2098 		spdk_blob_io_readv(ctx->blob, ctx->channel, iov, iovcnt, io_unit_offset,
2099 				   io_units_count, _spdk_rw_iov_split_next, ctx);
2100 	} else {
2101 		spdk_blob_io_writev(ctx->blob, ctx->channel, iov, iovcnt, io_unit_offset,
2102 				    io_units_count, _spdk_rw_iov_split_next, ctx);
2103 	}
2104 }
2105 
2106 static void
2107 _spdk_blob_request_submit_rw_iov(struct spdk_blob *blob, struct spdk_io_channel *_channel,
2108 				 struct iovec *iov, int iovcnt, uint64_t offset, uint64_t length,
2109 				 spdk_blob_op_complete cb_fn, void *cb_arg, bool read)
2110 {
2111 	struct spdk_bs_cpl	cpl;
2112 
2113 	assert(blob != NULL);
2114 
2115 	if (!read && blob->data_ro) {
2116 		cb_fn(cb_arg, -EPERM);
2117 		return;
2118 	}
2119 
2120 	if (length == 0) {
2121 		cb_fn(cb_arg, 0);
2122 		return;
2123 	}
2124 
2125 	if (offset + length > _spdk_bs_cluster_to_lba(blob->bs, blob->active.num_clusters)) {
2126 		cb_fn(cb_arg, -EINVAL);
2127 		return;
2128 	}
2129 
2130 	/*
2131 	 * For now, we implement readv/writev using a sequence (instead of a batch) to account for having
2132 	 *  to split a request that spans a cluster boundary.  For I/O that do not span a cluster boundary,
2133 	 *  there will be no noticeable difference compared to using a batch.  For I/O that do span a cluster
2134 	 *  boundary, the target LBAs (after blob offset to LBA translation) may not be contiguous, so we need
2135 	 *  to allocate a separate iov array and split the I/O such that none of the resulting
2136 	 *  smaller I/O cross a cluster boundary.  These smaller I/O will be issued in sequence (not in parallel)
2137 	 *  but since this case happens very infrequently, any performance impact will be negligible.
2138 	 *
2139 	 * This could be optimized in the future to allocate a big enough iov array to account for all of the iovs
2140 	 *  for all of the smaller I/Os, pre-build all of the iov arrays for the smaller I/Os, then issue them
2141 	 *  in a batch.  That would also require creating an intermediate spdk_bs_cpl that would get called
2142 	 *  when the batch was completed, to allow for freeing the memory for the iov arrays.
2143 	 */
2144 	if (spdk_likely(length <= _spdk_bs_num_io_units_to_cluster_boundary(blob, offset))) {
2145 		uint32_t lba_count;
2146 		uint64_t lba;
2147 
2148 		cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
2149 		cpl.u.blob_basic.cb_fn = cb_fn;
2150 		cpl.u.blob_basic.cb_arg = cb_arg;
2151 
2152 		if (blob->frozen_refcnt) {
2153 			/* This blob I/O is frozen */
2154 			enum spdk_blob_op_type op_type;
2155 			spdk_bs_user_op_t *op;
2156 			struct spdk_bs_channel *bs_channel = spdk_io_channel_get_ctx(_channel);
2157 
2158 			op_type = read ? SPDK_BLOB_READV : SPDK_BLOB_WRITEV;
2159 			op = spdk_bs_user_op_alloc(_channel, &cpl, op_type, blob, iov, iovcnt, offset, length);
2160 			if (!op) {
2161 				cb_fn(cb_arg, -ENOMEM);
2162 				return;
2163 			}
2164 
2165 			TAILQ_INSERT_TAIL(&bs_channel->queued_io, op, link);
2166 
2167 			return;
2168 		}
2169 
2170 		_spdk_blob_calculate_lba_and_lba_count(blob, offset, length, &lba, &lba_count);
2171 
2172 		if (read) {
2173 			spdk_bs_sequence_t *seq;
2174 
2175 			seq = spdk_bs_sequence_start(_channel, &cpl);
2176 			if (!seq) {
2177 				cb_fn(cb_arg, -ENOMEM);
2178 				return;
2179 			}
2180 
2181 			if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
2182 				spdk_bs_sequence_readv_dev(seq, iov, iovcnt, lba, lba_count, _spdk_rw_iov_done, NULL);
2183 			} else {
2184 				spdk_bs_sequence_readv_bs_dev(seq, blob->back_bs_dev, iov, iovcnt, lba, lba_count,
2185 							      _spdk_rw_iov_done, NULL);
2186 			}
2187 		} else {
2188 			if (_spdk_bs_io_unit_is_allocated(blob, offset)) {
2189 				spdk_bs_sequence_t *seq;
2190 
2191 				seq = spdk_bs_sequence_start(_channel, &cpl);
2192 				if (!seq) {
2193 					cb_fn(cb_arg, -ENOMEM);
2194 					return;
2195 				}
2196 
2197 				spdk_bs_sequence_writev_dev(seq, iov, iovcnt, lba, lba_count, _spdk_rw_iov_done, NULL);
2198 			} else {
2199 				/* Queue this operation and allocate the cluster */
2200 				spdk_bs_user_op_t *op;
2201 
2202 				op = spdk_bs_user_op_alloc(_channel, &cpl, SPDK_BLOB_WRITEV, blob, iov, iovcnt, offset,
2203 							   length);
2204 				if (!op) {
2205 					cb_fn(cb_arg, -ENOMEM);
2206 					return;
2207 				}
2208 
2209 				_spdk_bs_allocate_and_copy_cluster(blob, _channel, offset, op);
2210 			}
2211 		}
2212 	} else {
2213 		struct rw_iov_ctx *ctx;
2214 
2215 		ctx = calloc(1, sizeof(struct rw_iov_ctx) + iovcnt * sizeof(struct iovec));
2216 		if (ctx == NULL) {
2217 			cb_fn(cb_arg, -ENOMEM);
2218 			return;
2219 		}
2220 
2221 		ctx->blob = blob;
2222 		ctx->channel = _channel;
2223 		ctx->cb_fn = cb_fn;
2224 		ctx->cb_arg = cb_arg;
2225 		ctx->read = read;
2226 		ctx->orig_iov = iov;
2227 		ctx->iovcnt = iovcnt;
2228 		ctx->io_unit_offset = offset;
2229 		ctx->io_units_remaining = length;
2230 		ctx->io_units_done = 0;
2231 
2232 		_spdk_rw_iov_split_next(ctx, 0);
2233 	}
2234 }
2235 
2236 static struct spdk_blob *
2237 _spdk_blob_lookup(struct spdk_blob_store *bs, spdk_blob_id blobid)
2238 {
2239 	struct spdk_blob *blob;
2240 
2241 	TAILQ_FOREACH(blob, &bs->blobs, link) {
2242 		if (blob->id == blobid) {
2243 			return blob;
2244 		}
2245 	}
2246 
2247 	return NULL;
2248 }
2249 
2250 static void
2251 _spdk_blob_get_snapshot_and_clone_entries(struct spdk_blob *blob,
2252 		struct spdk_blob_list **snapshot_entry, struct spdk_blob_list **clone_entry)
2253 {
2254 	assert(blob != NULL);
2255 	*snapshot_entry = NULL;
2256 	*clone_entry = NULL;
2257 
2258 	if (blob->parent_id == SPDK_BLOBID_INVALID) {
2259 		return;
2260 	}
2261 
2262 	TAILQ_FOREACH(*snapshot_entry, &blob->bs->snapshots, link) {
2263 		if ((*snapshot_entry)->id == blob->parent_id) {
2264 			break;
2265 		}
2266 	}
2267 
2268 	if (*snapshot_entry != NULL) {
2269 		TAILQ_FOREACH(*clone_entry, &(*snapshot_entry)->clones, link) {
2270 			if ((*clone_entry)->id == blob->id) {
2271 				break;
2272 			}
2273 		}
2274 
2275 		assert(clone_entry != NULL);
2276 	}
2277 }
2278 
2279 static int
2280 _spdk_bs_channel_create(void *io_device, void *ctx_buf)
2281 {
2282 	struct spdk_blob_store		*bs = io_device;
2283 	struct spdk_bs_channel		*channel = ctx_buf;
2284 	struct spdk_bs_dev		*dev;
2285 	uint32_t			max_ops = bs->max_channel_ops;
2286 	uint32_t			i;
2287 
2288 	dev = bs->dev;
2289 
2290 	channel->req_mem = calloc(max_ops, sizeof(struct spdk_bs_request_set));
2291 	if (!channel->req_mem) {
2292 		return -1;
2293 	}
2294 
2295 	TAILQ_INIT(&channel->reqs);
2296 
2297 	for (i = 0; i < max_ops; i++) {
2298 		TAILQ_INSERT_TAIL(&channel->reqs, &channel->req_mem[i], link);
2299 	}
2300 
2301 	channel->bs = bs;
2302 	channel->dev = dev;
2303 	channel->dev_channel = dev->create_channel(dev);
2304 
2305 	if (!channel->dev_channel) {
2306 		SPDK_ERRLOG("Failed to create device channel.\n");
2307 		free(channel->req_mem);
2308 		return -1;
2309 	}
2310 
2311 	TAILQ_INIT(&channel->need_cluster_alloc);
2312 	TAILQ_INIT(&channel->queued_io);
2313 
2314 	return 0;
2315 }
2316 
2317 static void
2318 _spdk_bs_channel_destroy(void *io_device, void *ctx_buf)
2319 {
2320 	struct spdk_bs_channel *channel = ctx_buf;
2321 	spdk_bs_user_op_t *op;
2322 
2323 	while (!TAILQ_EMPTY(&channel->need_cluster_alloc)) {
2324 		op = TAILQ_FIRST(&channel->need_cluster_alloc);
2325 		TAILQ_REMOVE(&channel->need_cluster_alloc, op, link);
2326 		spdk_bs_user_op_abort(op);
2327 	}
2328 
2329 	while (!TAILQ_EMPTY(&channel->queued_io)) {
2330 		op = TAILQ_FIRST(&channel->queued_io);
2331 		TAILQ_REMOVE(&channel->queued_io, op, link);
2332 		spdk_bs_user_op_abort(op);
2333 	}
2334 
2335 	free(channel->req_mem);
2336 	channel->dev->destroy_channel(channel->dev, channel->dev_channel);
2337 }
2338 
2339 static void
2340 _spdk_bs_dev_destroy(void *io_device)
2341 {
2342 	struct spdk_blob_store *bs = io_device;
2343 	struct spdk_blob	*blob, *blob_tmp;
2344 
2345 	bs->dev->destroy(bs->dev);
2346 
2347 	TAILQ_FOREACH_SAFE(blob, &bs->blobs, link, blob_tmp) {
2348 		TAILQ_REMOVE(&bs->blobs, blob, link);
2349 		_spdk_blob_free(blob);
2350 	}
2351 
2352 	pthread_mutex_destroy(&bs->used_clusters_mutex);
2353 
2354 	spdk_bit_array_free(&bs->used_blobids);
2355 	spdk_bit_array_free(&bs->used_md_pages);
2356 	spdk_bit_array_free(&bs->used_clusters);
2357 	/*
2358 	 * If this function is called for any reason except a successful unload,
2359 	 * the unload_cpl type will be NONE and this will be a nop.
2360 	 */
2361 	spdk_bs_call_cpl(&bs->unload_cpl, bs->unload_err);
2362 
2363 	free(bs);
2364 }
2365 
2366 static int
2367 _spdk_bs_blob_list_add(struct spdk_blob *blob)
2368 {
2369 	spdk_blob_id snapshot_id;
2370 	struct spdk_blob_list *snapshot_entry = NULL;
2371 	struct spdk_blob_list *clone_entry = NULL;
2372 
2373 	assert(blob != NULL);
2374 
2375 	snapshot_id = blob->parent_id;
2376 	if (snapshot_id == SPDK_BLOBID_INVALID) {
2377 		return 0;
2378 	}
2379 
2380 	snapshot_entry = _spdk_bs_get_snapshot_entry(blob->bs, snapshot_id);
2381 	if (snapshot_entry == NULL) {
2382 		/* Snapshot not found */
2383 		snapshot_entry = calloc(1, sizeof(struct spdk_blob_list));
2384 		if (snapshot_entry == NULL) {
2385 			return -ENOMEM;
2386 		}
2387 		snapshot_entry->id = snapshot_id;
2388 		TAILQ_INIT(&snapshot_entry->clones);
2389 		TAILQ_INSERT_TAIL(&blob->bs->snapshots, snapshot_entry, link);
2390 	} else {
2391 		TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
2392 			if (clone_entry->id == blob->id) {
2393 				break;
2394 			}
2395 		}
2396 	}
2397 
2398 	if (clone_entry == NULL) {
2399 		/* Clone not found */
2400 		clone_entry = calloc(1, sizeof(struct spdk_blob_list));
2401 		if (clone_entry == NULL) {
2402 			return -ENOMEM;
2403 		}
2404 		clone_entry->id = blob->id;
2405 		TAILQ_INIT(&clone_entry->clones);
2406 		TAILQ_INSERT_TAIL(&snapshot_entry->clones, clone_entry, link);
2407 		snapshot_entry->clone_count++;
2408 	}
2409 
2410 	return 0;
2411 }
2412 
2413 static void
2414 _spdk_bs_blob_list_remove(struct spdk_blob *blob)
2415 {
2416 	struct spdk_blob_list *snapshot_entry = NULL;
2417 	struct spdk_blob_list *clone_entry = NULL;
2418 
2419 	_spdk_blob_get_snapshot_and_clone_entries(blob, &snapshot_entry, &clone_entry);
2420 
2421 	if (snapshot_entry == NULL) {
2422 		return;
2423 	}
2424 
2425 	blob->parent_id = SPDK_BLOBID_INVALID;
2426 	TAILQ_REMOVE(&snapshot_entry->clones, clone_entry, link);
2427 	free(clone_entry);
2428 
2429 	snapshot_entry->clone_count--;
2430 }
2431 
2432 static int
2433 _spdk_bs_blob_list_free(struct spdk_blob_store *bs)
2434 {
2435 	struct spdk_blob_list *snapshot_entry;
2436 	struct spdk_blob_list *snapshot_entry_tmp;
2437 	struct spdk_blob_list *clone_entry;
2438 	struct spdk_blob_list *clone_entry_tmp;
2439 
2440 	TAILQ_FOREACH_SAFE(snapshot_entry, &bs->snapshots, link, snapshot_entry_tmp) {
2441 		TAILQ_FOREACH_SAFE(clone_entry, &snapshot_entry->clones, link, clone_entry_tmp) {
2442 			TAILQ_REMOVE(&snapshot_entry->clones, clone_entry, link);
2443 			free(clone_entry);
2444 		}
2445 		TAILQ_REMOVE(&bs->snapshots, snapshot_entry, link);
2446 		free(snapshot_entry);
2447 	}
2448 
2449 	return 0;
2450 }
2451 
2452 static void
2453 _spdk_bs_free(struct spdk_blob_store *bs)
2454 {
2455 	_spdk_bs_blob_list_free(bs);
2456 
2457 	spdk_bs_unregister_md_thread(bs);
2458 	spdk_io_device_unregister(bs, _spdk_bs_dev_destroy);
2459 }
2460 
2461 void
2462 spdk_bs_opts_init(struct spdk_bs_opts *opts)
2463 {
2464 	opts->cluster_sz = SPDK_BLOB_OPTS_CLUSTER_SZ;
2465 	opts->num_md_pages = SPDK_BLOB_OPTS_NUM_MD_PAGES;
2466 	opts->max_md_ops = SPDK_BLOB_OPTS_MAX_MD_OPS;
2467 	opts->max_channel_ops = SPDK_BLOB_OPTS_DEFAULT_CHANNEL_OPS;
2468 	opts->clear_method = BS_CLEAR_WITH_UNMAP;
2469 	memset(&opts->bstype, 0, sizeof(opts->bstype));
2470 	opts->iter_cb_fn = NULL;
2471 	opts->iter_cb_arg = NULL;
2472 }
2473 
2474 static int
2475 _spdk_bs_opts_verify(struct spdk_bs_opts *opts)
2476 {
2477 	if (opts->cluster_sz == 0 || opts->num_md_pages == 0 || opts->max_md_ops == 0 ||
2478 	    opts->max_channel_ops == 0) {
2479 		SPDK_ERRLOG("Blobstore options cannot be set to 0\n");
2480 		return -1;
2481 	}
2482 
2483 	return 0;
2484 }
2485 
2486 static int
2487 _spdk_bs_alloc(struct spdk_bs_dev *dev, struct spdk_bs_opts *opts, struct spdk_blob_store **_bs)
2488 {
2489 	struct spdk_blob_store	*bs;
2490 	uint64_t dev_size;
2491 	int rc;
2492 
2493 	dev_size = dev->blocklen * dev->blockcnt;
2494 	if (dev_size < opts->cluster_sz) {
2495 		/* Device size cannot be smaller than cluster size of blobstore */
2496 		SPDK_INFOLOG(SPDK_LOG_BLOB, "Device size %" PRIu64 " is smaller than cluster size %" PRIu32 "\n",
2497 			     dev_size, opts->cluster_sz);
2498 		return -ENOSPC;
2499 	}
2500 	if (opts->cluster_sz < SPDK_BS_PAGE_SIZE) {
2501 		/* Cluster size cannot be smaller than page size */
2502 		SPDK_ERRLOG("Cluster size %" PRIu32 " is smaller than page size %d\n",
2503 			    opts->cluster_sz, SPDK_BS_PAGE_SIZE);
2504 		return -EINVAL;
2505 	}
2506 	bs = calloc(1, sizeof(struct spdk_blob_store));
2507 	if (!bs) {
2508 		return -ENOMEM;
2509 	}
2510 
2511 	TAILQ_INIT(&bs->blobs);
2512 	TAILQ_INIT(&bs->snapshots);
2513 	bs->dev = dev;
2514 	bs->md_thread = spdk_get_thread();
2515 	assert(bs->md_thread != NULL);
2516 
2517 	/*
2518 	 * Do not use _spdk_bs_lba_to_cluster() here since blockcnt may not be an
2519 	 *  even multiple of the cluster size.
2520 	 */
2521 	bs->cluster_sz = opts->cluster_sz;
2522 	bs->total_clusters = dev->blockcnt / (bs->cluster_sz / dev->blocklen);
2523 	bs->pages_per_cluster = bs->cluster_sz / SPDK_BS_PAGE_SIZE;
2524 	bs->num_free_clusters = bs->total_clusters;
2525 	bs->used_clusters = spdk_bit_array_create(bs->total_clusters);
2526 	bs->io_unit_size = dev->blocklen;
2527 	if (bs->used_clusters == NULL) {
2528 		free(bs);
2529 		return -ENOMEM;
2530 	}
2531 
2532 	bs->max_channel_ops = opts->max_channel_ops;
2533 	bs->super_blob = SPDK_BLOBID_INVALID;
2534 	memcpy(&bs->bstype, &opts->bstype, sizeof(opts->bstype));
2535 
2536 	/* The metadata is assumed to be at least 1 page */
2537 	bs->used_md_pages = spdk_bit_array_create(1);
2538 	bs->used_blobids = spdk_bit_array_create(0);
2539 
2540 	pthread_mutex_init(&bs->used_clusters_mutex, NULL);
2541 
2542 	spdk_io_device_register(bs, _spdk_bs_channel_create, _spdk_bs_channel_destroy,
2543 				sizeof(struct spdk_bs_channel), "blobstore");
2544 	rc = spdk_bs_register_md_thread(bs);
2545 	if (rc == -1) {
2546 		spdk_io_device_unregister(bs, NULL);
2547 		pthread_mutex_destroy(&bs->used_clusters_mutex);
2548 		spdk_bit_array_free(&bs->used_blobids);
2549 		spdk_bit_array_free(&bs->used_md_pages);
2550 		spdk_bit_array_free(&bs->used_clusters);
2551 		free(bs);
2552 		/* FIXME: this is a lie but don't know how to get a proper error code here */
2553 		return -ENOMEM;
2554 	}
2555 
2556 	*_bs = bs;
2557 	return 0;
2558 }
2559 
2560 /* START spdk_bs_load, spdk_bs_load_ctx will used for both load and unload. */
2561 
2562 struct spdk_bs_load_ctx {
2563 	struct spdk_blob_store		*bs;
2564 	struct spdk_bs_super_block	*super;
2565 
2566 	struct spdk_bs_md_mask		*mask;
2567 	bool				in_page_chain;
2568 	uint32_t			page_index;
2569 	uint32_t			cur_page;
2570 	struct spdk_blob_md_page	*page;
2571 
2572 	spdk_bs_sequence_t			*seq;
2573 	spdk_blob_op_with_handle_complete	iter_cb_fn;
2574 	void					*iter_cb_arg;
2575 	struct spdk_blob			*blob;
2576 	spdk_blob_id				blobid;
2577 };
2578 
2579 static void
2580 _spdk_bs_load_ctx_fail(struct spdk_bs_load_ctx *ctx, int bserrno)
2581 {
2582 	assert(bserrno != 0);
2583 
2584 	spdk_free(ctx->super);
2585 	spdk_bs_sequence_finish(ctx->seq, bserrno);
2586 	_spdk_bs_free(ctx->bs);
2587 	free(ctx);
2588 }
2589 
2590 static void
2591 _spdk_bs_set_mask(struct spdk_bit_array *array, struct spdk_bs_md_mask *mask)
2592 {
2593 	uint32_t i = 0;
2594 
2595 	while (true) {
2596 		i = spdk_bit_array_find_first_set(array, i);
2597 		if (i >= mask->length) {
2598 			break;
2599 		}
2600 		mask->mask[i / 8] |= 1U << (i % 8);
2601 		i++;
2602 	}
2603 }
2604 
2605 static int
2606 _spdk_bs_load_mask(struct spdk_bit_array **array_ptr, struct spdk_bs_md_mask *mask)
2607 {
2608 	struct spdk_bit_array *array;
2609 	uint32_t i;
2610 
2611 	if (spdk_bit_array_resize(array_ptr, mask->length) < 0) {
2612 		return -ENOMEM;
2613 	}
2614 
2615 	array = *array_ptr;
2616 	for (i = 0; i < mask->length; i++) {
2617 		if (mask->mask[i / 8] & (1U << (i % 8))) {
2618 			spdk_bit_array_set(array, i);
2619 		}
2620 	}
2621 
2622 	return 0;
2623 }
2624 
2625 static void
2626 _spdk_bs_write_super(spdk_bs_sequence_t *seq, struct spdk_blob_store *bs,
2627 		     struct spdk_bs_super_block *super, spdk_bs_sequence_cpl cb_fn, void *cb_arg)
2628 {
2629 	/* Update the values in the super block */
2630 	super->super_blob = bs->super_blob;
2631 	memcpy(&super->bstype, &bs->bstype, sizeof(bs->bstype));
2632 	super->crc = _spdk_blob_md_page_calc_crc(super);
2633 	spdk_bs_sequence_write_dev(seq, super, _spdk_bs_page_to_lba(bs, 0),
2634 				   _spdk_bs_byte_to_lba(bs, sizeof(*super)),
2635 				   cb_fn, cb_arg);
2636 }
2637 
2638 static void
2639 _spdk_bs_write_used_clusters(spdk_bs_sequence_t *seq, void *arg, spdk_bs_sequence_cpl cb_fn)
2640 {
2641 	struct spdk_bs_load_ctx	*ctx = arg;
2642 	uint64_t	mask_size, lba, lba_count;
2643 
2644 	/* Write out the used clusters mask */
2645 	mask_size = ctx->super->used_cluster_mask_len * SPDK_BS_PAGE_SIZE;
2646 	ctx->mask = spdk_zmalloc(mask_size, 0x1000, NULL,
2647 				 SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
2648 	if (!ctx->mask) {
2649 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
2650 		return;
2651 	}
2652 
2653 	ctx->mask->type = SPDK_MD_MASK_TYPE_USED_CLUSTERS;
2654 	ctx->mask->length = ctx->bs->total_clusters;
2655 	assert(ctx->mask->length == spdk_bit_array_capacity(ctx->bs->used_clusters));
2656 
2657 	_spdk_bs_set_mask(ctx->bs->used_clusters, ctx->mask);
2658 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_start);
2659 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_len);
2660 	spdk_bs_sequence_write_dev(seq, ctx->mask, lba, lba_count, cb_fn, arg);
2661 }
2662 
2663 static void
2664 _spdk_bs_write_used_md(spdk_bs_sequence_t *seq, void *arg, spdk_bs_sequence_cpl cb_fn)
2665 {
2666 	struct spdk_bs_load_ctx	*ctx = arg;
2667 	uint64_t	mask_size, lba, lba_count;
2668 
2669 	if (seq->bserrno) {
2670 		_spdk_bs_load_ctx_fail(ctx, seq->bserrno);
2671 		return;
2672 	}
2673 
2674 	mask_size = ctx->super->used_page_mask_len * SPDK_BS_PAGE_SIZE;
2675 	ctx->mask = spdk_zmalloc(mask_size, 0x1000, NULL,
2676 				 SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
2677 	if (!ctx->mask) {
2678 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
2679 		return;
2680 	}
2681 
2682 	ctx->mask->type = SPDK_MD_MASK_TYPE_USED_PAGES;
2683 	ctx->mask->length = ctx->super->md_len;
2684 	assert(ctx->mask->length == spdk_bit_array_capacity(ctx->bs->used_md_pages));
2685 
2686 	_spdk_bs_set_mask(ctx->bs->used_md_pages, ctx->mask);
2687 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_start);
2688 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_len);
2689 	spdk_bs_sequence_write_dev(seq, ctx->mask, lba, lba_count, cb_fn, arg);
2690 }
2691 
2692 static void
2693 _spdk_bs_write_used_blobids(spdk_bs_sequence_t *seq, void *arg, spdk_bs_sequence_cpl cb_fn)
2694 {
2695 	struct spdk_bs_load_ctx	*ctx = arg;
2696 	uint64_t	mask_size, lba, lba_count;
2697 
2698 	if (ctx->super->used_blobid_mask_len == 0) {
2699 		/*
2700 		 * This is a pre-v3 on-disk format where the blobid mask does not get
2701 		 *  written to disk.
2702 		 */
2703 		cb_fn(seq, arg, 0);
2704 		return;
2705 	}
2706 
2707 	mask_size = ctx->super->used_blobid_mask_len * SPDK_BS_PAGE_SIZE;
2708 	ctx->mask = spdk_zmalloc(mask_size, 0x1000, NULL, SPDK_ENV_SOCKET_ID_ANY,
2709 				 SPDK_MALLOC_DMA);
2710 	if (!ctx->mask) {
2711 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
2712 		return;
2713 	}
2714 
2715 	ctx->mask->type = SPDK_MD_MASK_TYPE_USED_BLOBIDS;
2716 	ctx->mask->length = ctx->super->md_len;
2717 	assert(ctx->mask->length == spdk_bit_array_capacity(ctx->bs->used_blobids));
2718 
2719 	_spdk_bs_set_mask(ctx->bs->used_blobids, ctx->mask);
2720 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_start);
2721 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_len);
2722 	spdk_bs_sequence_write_dev(seq, ctx->mask, lba, lba_count, cb_fn, arg);
2723 }
2724 
2725 static void
2726 _spdk_blob_set_thin_provision(struct spdk_blob *blob)
2727 {
2728 	_spdk_blob_verify_md_op(blob);
2729 	blob->invalid_flags |= SPDK_BLOB_THIN_PROV;
2730 	blob->state = SPDK_BLOB_STATE_DIRTY;
2731 }
2732 
2733 static void
2734 _spdk_blob_set_clear_method(struct spdk_blob *blob, enum blob_clear_method clear_method)
2735 {
2736 	_spdk_blob_verify_md_op(blob);
2737 	blob->clear_method = clear_method;
2738 	blob->md_ro_flags |= (clear_method << SPDK_BLOB_CLEAR_METHOD_SHIFT);
2739 	blob->state = SPDK_BLOB_STATE_DIRTY;
2740 }
2741 
2742 static void _spdk_bs_load_iter(void *arg, struct spdk_blob *blob, int bserrno);
2743 
2744 static void
2745 _spdk_bs_delete_corrupted_blob_cpl(void *cb_arg, int bserrno)
2746 {
2747 	struct spdk_bs_load_ctx *ctx = cb_arg;
2748 	spdk_blob_id id;
2749 	int64_t page_num;
2750 
2751 	/* Iterate to next blob (we can't use spdk_bs_iter_next function as our
2752 	 * last blob has been removed */
2753 	page_num = _spdk_bs_blobid_to_page(ctx->blobid);
2754 	page_num++;
2755 	page_num = spdk_bit_array_find_first_set(ctx->bs->used_blobids, page_num);
2756 	if (page_num >= spdk_bit_array_capacity(ctx->bs->used_blobids)) {
2757 		_spdk_bs_load_iter(ctx, NULL, -ENOENT);
2758 		return;
2759 	}
2760 
2761 	id = _spdk_bs_page_to_blobid(page_num);
2762 
2763 	spdk_bs_open_blob(ctx->bs, id, _spdk_bs_load_iter, ctx);
2764 }
2765 
2766 static void
2767 _spdk_bs_delete_corrupted_close_cb(void *cb_arg, int bserrno)
2768 {
2769 	struct spdk_bs_load_ctx *ctx = cb_arg;
2770 
2771 	if (bserrno != 0) {
2772 		SPDK_ERRLOG("Failed to close corrupted blob\n");
2773 		spdk_bs_iter_next(ctx->bs, ctx->blob, _spdk_bs_load_iter, ctx);
2774 		return;
2775 	}
2776 
2777 	spdk_bs_delete_blob(ctx->bs, ctx->blobid, _spdk_bs_delete_corrupted_blob_cpl, ctx);
2778 }
2779 
2780 static void
2781 _spdk_bs_delete_corrupted_blob(void *cb_arg, int bserrno)
2782 {
2783 	struct spdk_bs_load_ctx *ctx = cb_arg;
2784 	uint64_t i;
2785 
2786 	if (bserrno != 0) {
2787 		SPDK_ERRLOG("Failed to close clone of a corrupted blob\n");
2788 		spdk_bs_iter_next(ctx->bs, ctx->blob, _spdk_bs_load_iter, ctx);
2789 		return;
2790 	}
2791 
2792 	/* Snapshot and clone have the same copy of cluster map at this point.
2793 	 * Let's clear cluster map for snpashot now so that it won't be cleared
2794 	 * for clone later when we remove snapshot. Also set thin provision to
2795 	 * pass data corruption check */
2796 	for (i = 0; i < ctx->blob->active.num_clusters; i++) {
2797 		ctx->blob->active.clusters[i] = 0;
2798 	}
2799 
2800 	ctx->blob->md_ro = false;
2801 
2802 	_spdk_blob_set_thin_provision(ctx->blob);
2803 
2804 	ctx->blobid = ctx->blob->id;
2805 
2806 	spdk_blob_close(ctx->blob, _spdk_bs_delete_corrupted_close_cb, ctx);
2807 }
2808 
2809 static void
2810 _spdk_bs_update_corrupted_blob(void *cb_arg, int bserrno)
2811 {
2812 	struct spdk_bs_load_ctx *ctx = cb_arg;
2813 
2814 	if (bserrno != 0) {
2815 		SPDK_ERRLOG("Failed to close clone of a corrupted blob\n");
2816 		spdk_bs_iter_next(ctx->bs, ctx->blob, _spdk_bs_load_iter, ctx);
2817 		return;
2818 	}
2819 
2820 	ctx->blob->md_ro = false;
2821 	_spdk_blob_remove_xattr(ctx->blob, SNAPSHOT_PENDING_REMOVAL, true);
2822 	_spdk_blob_remove_xattr(ctx->blob, SNAPSHOT_IN_PROGRESS, true);
2823 	spdk_blob_set_read_only(ctx->blob);
2824 
2825 	if (ctx->iter_cb_fn) {
2826 		ctx->iter_cb_fn(ctx->iter_cb_arg, ctx->blob, 0);
2827 	}
2828 	_spdk_bs_blob_list_add(ctx->blob);
2829 
2830 	spdk_bs_iter_next(ctx->bs, ctx->blob, _spdk_bs_load_iter, ctx);
2831 }
2832 
2833 static void
2834 _spdk_bs_examine_clone(void *cb_arg, struct spdk_blob *blob, int bserrno)
2835 {
2836 	struct spdk_bs_load_ctx *ctx = cb_arg;
2837 
2838 	if (bserrno != 0) {
2839 		SPDK_ERRLOG("Failed to open clone of a corrupted blob\n");
2840 		spdk_bs_iter_next(ctx->bs, ctx->blob, _spdk_bs_load_iter, ctx);
2841 		return;
2842 	}
2843 
2844 	if (blob->parent_id == ctx->blob->id) {
2845 		/* Power failure occured before updating clone (snapshot delete case)
2846 		 * or after updating clone (creating snapshot case) - keep snapshot */
2847 		spdk_blob_close(blob, _spdk_bs_update_corrupted_blob, ctx);
2848 	} else {
2849 		/* Power failure occured after updating clone (snapshot delete case)
2850 		 * or before updating clone (creating snapshot case) - remove snapshot */
2851 		spdk_blob_close(blob, _spdk_bs_delete_corrupted_blob, ctx);
2852 	}
2853 }
2854 
2855 static void
2856 _spdk_bs_load_iter(void *arg, struct spdk_blob *blob, int bserrno)
2857 {
2858 	struct spdk_bs_load_ctx *ctx = arg;
2859 	const void *value;
2860 	size_t len;
2861 	int rc = 0;
2862 
2863 	if (bserrno == 0) {
2864 		/* Examine blob if it is corrupted after power failure. Fix
2865 		 * the ones that can be fixed and remove any other corrupted
2866 		 * ones. If it is not corrupted just process it */
2867 		rc = _spdk_blob_get_xattr_value(blob, SNAPSHOT_PENDING_REMOVAL, &value, &len, true);
2868 		if (rc != 0) {
2869 			rc = _spdk_blob_get_xattr_value(blob, SNAPSHOT_IN_PROGRESS, &value, &len, true);
2870 			if (rc != 0) {
2871 				/* Not corrupted - process it and continue with iterating through blobs */
2872 				if (ctx->iter_cb_fn) {
2873 					ctx->iter_cb_fn(ctx->iter_cb_arg, blob, 0);
2874 				}
2875 				_spdk_bs_blob_list_add(blob);
2876 				spdk_bs_iter_next(ctx->bs, blob, _spdk_bs_load_iter, ctx);
2877 				return;
2878 			}
2879 
2880 		}
2881 
2882 		assert(len == sizeof(spdk_blob_id));
2883 
2884 		ctx->blob = blob;
2885 
2886 		/* Open clone to check if we are able to fix this blob or should we remove it */
2887 		spdk_bs_open_blob(ctx->bs, *(spdk_blob_id *)value, _spdk_bs_examine_clone, ctx);
2888 		return;
2889 	} else if (bserrno == -ENOENT) {
2890 		bserrno = 0;
2891 	} else {
2892 		/*
2893 		 * This case needs to be looked at further.  Same problem
2894 		 *  exists with applications that rely on explicit blob
2895 		 *  iteration.  We should just skip the blob that failed
2896 		 *  to load and continue on to the next one.
2897 		 */
2898 		SPDK_ERRLOG("Error in iterating blobs\n");
2899 	}
2900 
2901 	ctx->iter_cb_fn = NULL;
2902 
2903 	spdk_free(ctx->super);
2904 	spdk_free(ctx->mask);
2905 	spdk_bs_sequence_finish(ctx->seq, bserrno);
2906 	free(ctx);
2907 }
2908 
2909 static void
2910 _spdk_bs_load_complete(struct spdk_bs_load_ctx *ctx)
2911 {
2912 	spdk_bs_iter_first(ctx->bs, _spdk_bs_load_iter, ctx);
2913 }
2914 
2915 static void
2916 _spdk_bs_load_used_blobids_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2917 {
2918 	struct spdk_bs_load_ctx *ctx = cb_arg;
2919 	int rc;
2920 
2921 	/* The type must be correct */
2922 	assert(ctx->mask->type == SPDK_MD_MASK_TYPE_USED_BLOBIDS);
2923 
2924 	/* The length of the mask (in bits) must not be greater than
2925 	 * the length of the buffer (converted to bits) */
2926 	assert(ctx->mask->length <= (ctx->super->used_blobid_mask_len * SPDK_BS_PAGE_SIZE * 8));
2927 
2928 	/* The length of the mask must be exactly equal to the size
2929 	 * (in pages) of the metadata region */
2930 	assert(ctx->mask->length == ctx->super->md_len);
2931 
2932 	rc = _spdk_bs_load_mask(&ctx->bs->used_blobids, ctx->mask);
2933 	if (rc < 0) {
2934 		spdk_free(ctx->mask);
2935 		_spdk_bs_load_ctx_fail(ctx, rc);
2936 		return;
2937 	}
2938 
2939 	_spdk_bs_load_complete(ctx);
2940 }
2941 
2942 static void
2943 _spdk_bs_load_used_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2944 {
2945 	struct spdk_bs_load_ctx *ctx = cb_arg;
2946 	uint64_t		lba, lba_count, mask_size;
2947 	int			rc;
2948 
2949 	if (bserrno != 0) {
2950 		_spdk_bs_load_ctx_fail(ctx, bserrno);
2951 		return;
2952 	}
2953 
2954 	/* The type must be correct */
2955 	assert(ctx->mask->type == SPDK_MD_MASK_TYPE_USED_CLUSTERS);
2956 	/* The length of the mask (in bits) must not be greater than the length of the buffer (converted to bits) */
2957 	assert(ctx->mask->length <= (ctx->super->used_cluster_mask_len * sizeof(
2958 					     struct spdk_blob_md_page) * 8));
2959 	/* The length of the mask must be exactly equal to the total number of clusters */
2960 	assert(ctx->mask->length == ctx->bs->total_clusters);
2961 
2962 	rc = _spdk_bs_load_mask(&ctx->bs->used_clusters, ctx->mask);
2963 	if (rc < 0) {
2964 		spdk_free(ctx->mask);
2965 		_spdk_bs_load_ctx_fail(ctx, rc);
2966 		return;
2967 	}
2968 
2969 	ctx->bs->num_free_clusters = spdk_bit_array_count_clear(ctx->bs->used_clusters);
2970 	assert(ctx->bs->num_free_clusters <= ctx->bs->total_clusters);
2971 
2972 	spdk_free(ctx->mask);
2973 
2974 	/* Read the used blobids mask */
2975 	mask_size = ctx->super->used_blobid_mask_len * SPDK_BS_PAGE_SIZE;
2976 	ctx->mask = spdk_zmalloc(mask_size, 0x1000, NULL, SPDK_ENV_SOCKET_ID_ANY,
2977 				 SPDK_MALLOC_DMA);
2978 	if (!ctx->mask) {
2979 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
2980 		return;
2981 	}
2982 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_start);
2983 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_blobid_mask_len);
2984 	spdk_bs_sequence_read_dev(seq, ctx->mask, lba, lba_count,
2985 				  _spdk_bs_load_used_blobids_cpl, ctx);
2986 }
2987 
2988 static void
2989 _spdk_bs_load_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
2990 {
2991 	struct spdk_bs_load_ctx *ctx = cb_arg;
2992 	uint64_t		lba, lba_count, mask_size;
2993 	int			rc;
2994 
2995 	if (bserrno != 0) {
2996 		_spdk_bs_load_ctx_fail(ctx, bserrno);
2997 		return;
2998 	}
2999 
3000 	/* The type must be correct */
3001 	assert(ctx->mask->type == SPDK_MD_MASK_TYPE_USED_PAGES);
3002 	/* The length of the mask (in bits) must not be greater than the length of the buffer (converted to bits) */
3003 	assert(ctx->mask->length <= (ctx->super->used_page_mask_len * SPDK_BS_PAGE_SIZE *
3004 				     8));
3005 	/* The length of the mask must be exactly equal to the size (in pages) of the metadata region */
3006 	assert(ctx->mask->length == ctx->super->md_len);
3007 
3008 	rc = _spdk_bs_load_mask(&ctx->bs->used_md_pages, ctx->mask);
3009 	if (rc < 0) {
3010 		spdk_free(ctx->mask);
3011 		_spdk_bs_load_ctx_fail(ctx, rc);
3012 		return;
3013 	}
3014 
3015 	spdk_free(ctx->mask);
3016 
3017 	/* Read the used clusters mask */
3018 	mask_size = ctx->super->used_cluster_mask_len * SPDK_BS_PAGE_SIZE;
3019 	ctx->mask = spdk_zmalloc(mask_size, 0x1000, NULL, SPDK_ENV_SOCKET_ID_ANY,
3020 				 SPDK_MALLOC_DMA);
3021 	if (!ctx->mask) {
3022 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3023 		return;
3024 	}
3025 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_start);
3026 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_cluster_mask_len);
3027 	spdk_bs_sequence_read_dev(seq, ctx->mask, lba, lba_count,
3028 				  _spdk_bs_load_used_clusters_cpl, ctx);
3029 }
3030 
3031 static void
3032 _spdk_bs_load_read_used_pages(struct spdk_bs_load_ctx *ctx)
3033 {
3034 	uint64_t lba, lba_count, mask_size;
3035 
3036 	/* Read the used pages mask */
3037 	mask_size = ctx->super->used_page_mask_len * SPDK_BS_PAGE_SIZE;
3038 	ctx->mask = spdk_zmalloc(mask_size, 0x1000, NULL,
3039 				 SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
3040 	if (!ctx->mask) {
3041 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3042 		return;
3043 	}
3044 
3045 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_start);
3046 	lba_count = _spdk_bs_page_to_lba(ctx->bs, ctx->super->used_page_mask_len);
3047 	spdk_bs_sequence_read_dev(ctx->seq, ctx->mask, lba, lba_count,
3048 				  _spdk_bs_load_used_pages_cpl, ctx);
3049 }
3050 
3051 static int
3052 _spdk_bs_load_replay_md_parse_page(const struct spdk_blob_md_page *page, struct spdk_blob_store *bs)
3053 {
3054 	struct spdk_blob_md_descriptor *desc;
3055 	size_t	cur_desc = 0;
3056 
3057 	desc = (struct spdk_blob_md_descriptor *)page->descriptors;
3058 	while (cur_desc < sizeof(page->descriptors)) {
3059 		if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_PADDING) {
3060 			if (desc->length == 0) {
3061 				/* If padding and length are 0, this terminates the page */
3062 				break;
3063 			}
3064 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_EXTENT_RLE) {
3065 			struct spdk_blob_md_descriptor_extent_rle	*desc_extent_rle;
3066 			unsigned int				i, j;
3067 			unsigned int				cluster_count = 0;
3068 			uint32_t				cluster_idx;
3069 
3070 			desc_extent_rle = (struct spdk_blob_md_descriptor_extent_rle *)desc;
3071 
3072 			for (i = 0; i < desc_extent_rle->length / sizeof(desc_extent_rle->extents[0]); i++) {
3073 				for (j = 0; j < desc_extent_rle->extents[i].length; j++) {
3074 					cluster_idx = desc_extent_rle->extents[i].cluster_idx;
3075 					/*
3076 					 * cluster_idx = 0 means an unallocated cluster - don't mark that
3077 					 * in the used cluster map.
3078 					 */
3079 					if (cluster_idx != 0) {
3080 						spdk_bit_array_set(bs->used_clusters, cluster_idx + j);
3081 						if (bs->num_free_clusters == 0) {
3082 							return -ENOSPC;
3083 						}
3084 						bs->num_free_clusters--;
3085 					}
3086 					cluster_count++;
3087 				}
3088 			}
3089 			if (cluster_count == 0) {
3090 				return -EINVAL;
3091 			}
3092 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR) {
3093 			/* Skip this item */
3094 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL) {
3095 			/* Skip this item */
3096 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_FLAGS) {
3097 			/* Skip this item */
3098 		} else {
3099 			/* Error */
3100 			return -EINVAL;
3101 		}
3102 		/* Advance to the next descriptor */
3103 		cur_desc += sizeof(*desc) + desc->length;
3104 		if (cur_desc + sizeof(*desc) > sizeof(page->descriptors)) {
3105 			break;
3106 		}
3107 		desc = (struct spdk_blob_md_descriptor *)((uintptr_t)page->descriptors + cur_desc);
3108 	}
3109 	return 0;
3110 }
3111 
3112 static bool _spdk_bs_load_cur_md_page_valid(struct spdk_bs_load_ctx *ctx)
3113 {
3114 	uint32_t crc;
3115 
3116 	crc = _spdk_blob_md_page_calc_crc(ctx->page);
3117 	if (crc != ctx->page->crc) {
3118 		return false;
3119 	}
3120 
3121 	if (ctx->page->sequence_num == 0 &&
3122 	    _spdk_bs_page_to_blobid(ctx->cur_page) != ctx->page->id) {
3123 		return false;
3124 	}
3125 	return true;
3126 }
3127 
3128 static void
3129 _spdk_bs_load_replay_cur_md_page(struct spdk_bs_load_ctx *ctx);
3130 
3131 static void
3132 _spdk_bs_load_write_used_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3133 {
3134 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3135 
3136 	if (bserrno != 0) {
3137 		_spdk_bs_load_ctx_fail(ctx, bserrno);
3138 		return;
3139 	}
3140 
3141 	_spdk_bs_load_complete(ctx);
3142 }
3143 
3144 static void
3145 _spdk_bs_load_write_used_blobids_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3146 {
3147 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3148 
3149 	spdk_free(ctx->mask);
3150 	ctx->mask = NULL;
3151 
3152 	if (bserrno != 0) {
3153 		_spdk_bs_load_ctx_fail(ctx, bserrno);
3154 		return;
3155 	}
3156 
3157 	_spdk_bs_write_used_clusters(seq, ctx, _spdk_bs_load_write_used_clusters_cpl);
3158 }
3159 
3160 static void
3161 _spdk_bs_load_write_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3162 {
3163 	struct spdk_bs_load_ctx	*ctx = cb_arg;
3164 
3165 	spdk_free(ctx->mask);
3166 	ctx->mask = NULL;
3167 
3168 	if (bserrno != 0) {
3169 		_spdk_bs_load_ctx_fail(ctx, bserrno);
3170 		return;
3171 	}
3172 
3173 	_spdk_bs_write_used_blobids(seq, ctx, _spdk_bs_load_write_used_blobids_cpl);
3174 }
3175 
3176 static void
3177 _spdk_bs_load_write_used_md(struct spdk_bs_load_ctx *ctx)
3178 {
3179 	_spdk_bs_write_used_md(ctx->seq, ctx, _spdk_bs_load_write_used_pages_cpl);
3180 }
3181 
3182 static void
3183 _spdk_bs_load_replay_md_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3184 {
3185 	struct spdk_bs_load_ctx *ctx = cb_arg;
3186 	uint64_t num_md_clusters;
3187 	uint64_t i;
3188 	uint32_t page_num;
3189 
3190 	if (bserrno != 0) {
3191 		_spdk_bs_load_ctx_fail(ctx, bserrno);
3192 		return;
3193 	}
3194 
3195 	page_num = ctx->cur_page;
3196 	if (_spdk_bs_load_cur_md_page_valid(ctx) == true) {
3197 		if (ctx->page->sequence_num == 0 || ctx->in_page_chain == true) {
3198 			spdk_bit_array_set(ctx->bs->used_md_pages, page_num);
3199 			if (ctx->page->sequence_num == 0) {
3200 				spdk_bit_array_set(ctx->bs->used_blobids, page_num);
3201 			}
3202 			if (_spdk_bs_load_replay_md_parse_page(ctx->page, ctx->bs)) {
3203 				_spdk_bs_load_ctx_fail(ctx, -EILSEQ);
3204 				return;
3205 			}
3206 			if (ctx->page->next != SPDK_INVALID_MD_PAGE) {
3207 				ctx->in_page_chain = true;
3208 				ctx->cur_page = ctx->page->next;
3209 				_spdk_bs_load_replay_cur_md_page(ctx);
3210 				return;
3211 			}
3212 		}
3213 	}
3214 
3215 	ctx->in_page_chain = false;
3216 
3217 	do {
3218 		ctx->page_index++;
3219 	} while (spdk_bit_array_get(ctx->bs->used_md_pages, ctx->page_index) == true);
3220 
3221 	if (ctx->page_index < ctx->super->md_len) {
3222 		ctx->cur_page = ctx->page_index;
3223 		_spdk_bs_load_replay_cur_md_page(ctx);
3224 	} else {
3225 		/* Claim all of the clusters used by the metadata */
3226 		num_md_clusters = spdk_divide_round_up(ctx->super->md_len, ctx->bs->pages_per_cluster);
3227 		for (i = 0; i < num_md_clusters; i++) {
3228 			_spdk_bs_claim_cluster(ctx->bs, i);
3229 		}
3230 		spdk_free(ctx->page);
3231 		_spdk_bs_load_write_used_md(ctx);
3232 	}
3233 }
3234 
3235 static void
3236 _spdk_bs_load_replay_cur_md_page(struct spdk_bs_load_ctx *ctx)
3237 {
3238 	uint64_t lba;
3239 
3240 	assert(ctx->cur_page < ctx->super->md_len);
3241 	lba = _spdk_bs_md_page_to_lba(ctx->bs, ctx->cur_page);
3242 	spdk_bs_sequence_read_dev(ctx->seq, ctx->page, lba,
3243 				  _spdk_bs_byte_to_lba(ctx->bs, SPDK_BS_PAGE_SIZE),
3244 				  _spdk_bs_load_replay_md_cpl, ctx);
3245 }
3246 
3247 static void
3248 _spdk_bs_load_replay_md(struct spdk_bs_load_ctx *ctx)
3249 {
3250 	ctx->page_index = 0;
3251 	ctx->cur_page = 0;
3252 	ctx->page = spdk_zmalloc(SPDK_BS_PAGE_SIZE, SPDK_BS_PAGE_SIZE,
3253 				 NULL, SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
3254 	if (!ctx->page) {
3255 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3256 		return;
3257 	}
3258 	_spdk_bs_load_replay_cur_md_page(ctx);
3259 }
3260 
3261 static void
3262 _spdk_bs_recover(struct spdk_bs_load_ctx *ctx)
3263 {
3264 	int		rc;
3265 
3266 	rc = spdk_bit_array_resize(&ctx->bs->used_md_pages, ctx->super->md_len);
3267 	if (rc < 0) {
3268 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3269 		return;
3270 	}
3271 
3272 	rc = spdk_bit_array_resize(&ctx->bs->used_blobids, ctx->super->md_len);
3273 	if (rc < 0) {
3274 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3275 		return;
3276 	}
3277 
3278 	rc = spdk_bit_array_resize(&ctx->bs->used_clusters, ctx->bs->total_clusters);
3279 	if (rc < 0) {
3280 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3281 		return;
3282 	}
3283 
3284 	ctx->bs->num_free_clusters = ctx->bs->total_clusters;
3285 	_spdk_bs_load_replay_md(ctx);
3286 }
3287 
3288 static void
3289 _spdk_bs_load_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3290 {
3291 	struct spdk_bs_load_ctx *ctx = cb_arg;
3292 	uint32_t	crc;
3293 	int		rc;
3294 	static const char zeros[SPDK_BLOBSTORE_TYPE_LENGTH];
3295 
3296 	if (ctx->super->version > SPDK_BS_VERSION ||
3297 	    ctx->super->version < SPDK_BS_INITIAL_VERSION) {
3298 		_spdk_bs_load_ctx_fail(ctx, -EILSEQ);
3299 		return;
3300 	}
3301 
3302 	if (memcmp(ctx->super->signature, SPDK_BS_SUPER_BLOCK_SIG,
3303 		   sizeof(ctx->super->signature)) != 0) {
3304 		_spdk_bs_load_ctx_fail(ctx, -EILSEQ);
3305 		return;
3306 	}
3307 
3308 	crc = _spdk_blob_md_page_calc_crc(ctx->super);
3309 	if (crc != ctx->super->crc) {
3310 		_spdk_bs_load_ctx_fail(ctx, -EILSEQ);
3311 		return;
3312 	}
3313 
3314 	if (memcmp(&ctx->bs->bstype, &ctx->super->bstype, SPDK_BLOBSTORE_TYPE_LENGTH) == 0) {
3315 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Bstype matched - loading blobstore\n");
3316 	} else if (memcmp(&ctx->bs->bstype, zeros, SPDK_BLOBSTORE_TYPE_LENGTH) == 0) {
3317 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Bstype wildcard used - loading blobstore regardless bstype\n");
3318 	} else {
3319 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Unexpected bstype\n");
3320 		SPDK_LOGDUMP(SPDK_LOG_BLOB, "Expected:", ctx->bs->bstype.bstype, SPDK_BLOBSTORE_TYPE_LENGTH);
3321 		SPDK_LOGDUMP(SPDK_LOG_BLOB, "Found:", ctx->super->bstype.bstype, SPDK_BLOBSTORE_TYPE_LENGTH);
3322 		_spdk_bs_load_ctx_fail(ctx, -ENXIO);
3323 		return;
3324 	}
3325 
3326 	if (ctx->super->size > ctx->bs->dev->blockcnt * ctx->bs->dev->blocklen) {
3327 		SPDK_NOTICELOG("Size mismatch, dev size: %lu, blobstore size: %lu\n",
3328 			       ctx->bs->dev->blockcnt * ctx->bs->dev->blocklen, ctx->super->size);
3329 		_spdk_bs_load_ctx_fail(ctx, -EILSEQ);
3330 		return;
3331 	}
3332 
3333 	if (ctx->super->size == 0) {
3334 		ctx->super->size = ctx->bs->dev->blockcnt * ctx->bs->dev->blocklen;
3335 	}
3336 
3337 	if (ctx->super->io_unit_size == 0) {
3338 		ctx->super->io_unit_size = SPDK_BS_PAGE_SIZE;
3339 	}
3340 
3341 	/* Parse the super block */
3342 	ctx->bs->clean = 1;
3343 	ctx->bs->cluster_sz = ctx->super->cluster_size;
3344 	ctx->bs->total_clusters = ctx->super->size / ctx->super->cluster_size;
3345 	ctx->bs->pages_per_cluster = ctx->bs->cluster_sz / SPDK_BS_PAGE_SIZE;
3346 	ctx->bs->io_unit_size = ctx->super->io_unit_size;
3347 	rc = spdk_bit_array_resize(&ctx->bs->used_clusters, ctx->bs->total_clusters);
3348 	if (rc < 0) {
3349 		_spdk_bs_load_ctx_fail(ctx, -ENOMEM);
3350 		return;
3351 	}
3352 	ctx->bs->md_start = ctx->super->md_start;
3353 	ctx->bs->md_len = ctx->super->md_len;
3354 	ctx->bs->total_data_clusters = ctx->bs->total_clusters - spdk_divide_round_up(
3355 					       ctx->bs->md_start + ctx->bs->md_len, ctx->bs->pages_per_cluster);
3356 	ctx->bs->super_blob = ctx->super->super_blob;
3357 	memcpy(&ctx->bs->bstype, &ctx->super->bstype, sizeof(ctx->super->bstype));
3358 
3359 	if (ctx->super->used_blobid_mask_len == 0 || ctx->super->clean == 0) {
3360 		_spdk_bs_recover(ctx);
3361 	} else {
3362 		_spdk_bs_load_read_used_pages(ctx);
3363 	}
3364 }
3365 
3366 void
3367 spdk_bs_load(struct spdk_bs_dev *dev, struct spdk_bs_opts *o,
3368 	     spdk_bs_op_with_handle_complete cb_fn, void *cb_arg)
3369 {
3370 	struct spdk_blob_store	*bs;
3371 	struct spdk_bs_cpl	cpl;
3372 	struct spdk_bs_load_ctx *ctx;
3373 	struct spdk_bs_opts	opts = {};
3374 	int err;
3375 
3376 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Loading blobstore from dev %p\n", dev);
3377 
3378 	if ((SPDK_BS_PAGE_SIZE % dev->blocklen) != 0) {
3379 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "unsupported dev block length of %d\n", dev->blocklen);
3380 		dev->destroy(dev);
3381 		cb_fn(cb_arg, NULL, -EINVAL);
3382 		return;
3383 	}
3384 
3385 	if (o) {
3386 		opts = *o;
3387 	} else {
3388 		spdk_bs_opts_init(&opts);
3389 	}
3390 
3391 	if (opts.max_md_ops == 0 || opts.max_channel_ops == 0) {
3392 		dev->destroy(dev);
3393 		cb_fn(cb_arg, NULL, -EINVAL);
3394 		return;
3395 	}
3396 
3397 	err = _spdk_bs_alloc(dev, &opts, &bs);
3398 	if (err) {
3399 		dev->destroy(dev);
3400 		cb_fn(cb_arg, NULL, err);
3401 		return;
3402 	}
3403 
3404 	ctx = calloc(1, sizeof(*ctx));
3405 	if (!ctx) {
3406 		_spdk_bs_free(bs);
3407 		cb_fn(cb_arg, NULL, -ENOMEM);
3408 		return;
3409 	}
3410 
3411 	ctx->bs = bs;
3412 	ctx->iter_cb_fn = opts.iter_cb_fn;
3413 	ctx->iter_cb_arg = opts.iter_cb_arg;
3414 
3415 	/* Allocate memory for the super block */
3416 	ctx->super = spdk_zmalloc(sizeof(*ctx->super), 0x1000, NULL,
3417 				  SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
3418 	if (!ctx->super) {
3419 		free(ctx);
3420 		_spdk_bs_free(bs);
3421 		cb_fn(cb_arg, NULL, -ENOMEM);
3422 		return;
3423 	}
3424 
3425 	cpl.type = SPDK_BS_CPL_TYPE_BS_HANDLE;
3426 	cpl.u.bs_handle.cb_fn = cb_fn;
3427 	cpl.u.bs_handle.cb_arg = cb_arg;
3428 	cpl.u.bs_handle.bs = bs;
3429 
3430 	ctx->seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3431 	if (!ctx->seq) {
3432 		spdk_free(ctx->super);
3433 		free(ctx);
3434 		_spdk_bs_free(bs);
3435 		cb_fn(cb_arg, NULL, -ENOMEM);
3436 		return;
3437 	}
3438 
3439 	/* Read the super block */
3440 	spdk_bs_sequence_read_dev(ctx->seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
3441 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
3442 				  _spdk_bs_load_super_cpl, ctx);
3443 }
3444 
3445 /* END spdk_bs_load */
3446 
3447 /* START spdk_bs_dump */
3448 
3449 struct spdk_bs_dump_ctx {
3450 	struct spdk_blob_store		*bs;
3451 	struct spdk_bs_super_block	*super;
3452 	uint32_t			cur_page;
3453 	struct spdk_blob_md_page	*page;
3454 	spdk_bs_sequence_t		*seq;
3455 	FILE				*fp;
3456 	spdk_bs_dump_print_xattr	print_xattr_fn;
3457 	char				xattr_name[4096];
3458 };
3459 
3460 static void
3461 _spdk_bs_dump_finish(spdk_bs_sequence_t *seq, struct spdk_bs_dump_ctx *ctx, int bserrno)
3462 {
3463 	spdk_free(ctx->super);
3464 
3465 	/*
3466 	 * We need to defer calling spdk_bs_call_cpl() until after
3467 	 * dev destruction, so tuck these away for later use.
3468 	 */
3469 	ctx->bs->unload_err = bserrno;
3470 	memcpy(&ctx->bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));
3471 	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;
3472 
3473 	spdk_bs_sequence_finish(seq, 0);
3474 	_spdk_bs_free(ctx->bs);
3475 	free(ctx);
3476 }
3477 
3478 static void _spdk_bs_dump_read_md_page(spdk_bs_sequence_t *seq, void *cb_arg);
3479 
3480 static void
3481 _spdk_bs_dump_print_md_page(struct spdk_bs_dump_ctx *ctx)
3482 {
3483 	uint32_t page_idx = ctx->cur_page;
3484 	struct spdk_blob_md_page *page = ctx->page;
3485 	struct spdk_blob_md_descriptor *desc;
3486 	size_t cur_desc = 0;
3487 	uint32_t crc;
3488 
3489 	fprintf(ctx->fp, "=========\n");
3490 	fprintf(ctx->fp, "Metadata Page Index: %" PRIu32 " (0x%" PRIx32 ")\n", page_idx, page_idx);
3491 	fprintf(ctx->fp, "Blob ID: 0x%" PRIx64 "\n", page->id);
3492 
3493 	crc = _spdk_blob_md_page_calc_crc(page);
3494 	fprintf(ctx->fp, "CRC: 0x%" PRIx32 " (%s)\n", page->crc, crc == page->crc ? "OK" : "Mismatch");
3495 
3496 	desc = (struct spdk_blob_md_descriptor *)page->descriptors;
3497 	while (cur_desc < sizeof(page->descriptors)) {
3498 		if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_PADDING) {
3499 			if (desc->length == 0) {
3500 				/* If padding and length are 0, this terminates the page */
3501 				break;
3502 			}
3503 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_EXTENT_RLE) {
3504 			struct spdk_blob_md_descriptor_extent_rle	*desc_extent_rle;
3505 			unsigned int				i;
3506 
3507 			desc_extent_rle = (struct spdk_blob_md_descriptor_extent_rle *)desc;
3508 
3509 			for (i = 0; i < desc_extent_rle->length / sizeof(desc_extent_rle->extents[0]); i++) {
3510 				if (desc_extent_rle->extents[i].cluster_idx != 0) {
3511 					fprintf(ctx->fp, "Allocated Extent - Start: %" PRIu32,
3512 						desc_extent_rle->extents[i].cluster_idx);
3513 				} else {
3514 					fprintf(ctx->fp, "Unallocated Extent - ");
3515 				}
3516 				fprintf(ctx->fp, " Length: %" PRIu32, desc_extent_rle->extents[i].length);
3517 				fprintf(ctx->fp, "\n");
3518 			}
3519 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR) {
3520 			struct spdk_blob_md_descriptor_xattr *desc_xattr;
3521 			uint32_t i;
3522 
3523 			desc_xattr = (struct spdk_blob_md_descriptor_xattr *)desc;
3524 
3525 			if (desc_xattr->length !=
3526 			    sizeof(desc_xattr->name_length) + sizeof(desc_xattr->value_length) +
3527 			    desc_xattr->name_length + desc_xattr->value_length) {
3528 			}
3529 
3530 			memcpy(ctx->xattr_name, desc_xattr->name, desc_xattr->name_length);
3531 			ctx->xattr_name[desc_xattr->name_length] = '\0';
3532 			fprintf(ctx->fp, "XATTR: name = \"%s\"\n", ctx->xattr_name);
3533 			fprintf(ctx->fp, "       value = \"");
3534 			ctx->print_xattr_fn(ctx->fp, ctx->super->bstype.bstype, ctx->xattr_name,
3535 					    (void *)((uintptr_t)desc_xattr->name + desc_xattr->name_length),
3536 					    desc_xattr->value_length);
3537 			fprintf(ctx->fp, "\"\n");
3538 			for (i = 0; i < desc_xattr->value_length; i++) {
3539 				if (i % 16 == 0) {
3540 					fprintf(ctx->fp, "               ");
3541 				}
3542 				fprintf(ctx->fp, "%02" PRIx8 " ", *((uint8_t *)desc_xattr->name + desc_xattr->name_length + i));
3543 				if ((i + 1) % 16 == 0) {
3544 					fprintf(ctx->fp, "\n");
3545 				}
3546 			}
3547 			if (i % 16 != 0) {
3548 				fprintf(ctx->fp, "\n");
3549 			}
3550 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_XATTR_INTERNAL) {
3551 			/* TODO */
3552 		} else if (desc->type == SPDK_MD_DESCRIPTOR_TYPE_FLAGS) {
3553 			/* TODO */
3554 		} else {
3555 			/* Error */
3556 		}
3557 		/* Advance to the next descriptor */
3558 		cur_desc += sizeof(*desc) + desc->length;
3559 		if (cur_desc + sizeof(*desc) > sizeof(page->descriptors)) {
3560 			break;
3561 		}
3562 		desc = (struct spdk_blob_md_descriptor *)((uintptr_t)page->descriptors + cur_desc);
3563 	}
3564 }
3565 
3566 static void
3567 _spdk_bs_dump_read_md_page_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3568 {
3569 	struct spdk_bs_dump_ctx *ctx = cb_arg;
3570 
3571 	if (bserrno != 0) {
3572 		_spdk_bs_dump_finish(seq, ctx, bserrno);
3573 		return;
3574 	}
3575 
3576 	if (ctx->page->id != 0) {
3577 		_spdk_bs_dump_print_md_page(ctx);
3578 	}
3579 
3580 	ctx->cur_page++;
3581 
3582 	if (ctx->cur_page < ctx->super->md_len) {
3583 		_spdk_bs_dump_read_md_page(seq, ctx);
3584 	} else {
3585 		spdk_free(ctx->page);
3586 		_spdk_bs_dump_finish(seq, ctx, 0);
3587 	}
3588 }
3589 
3590 static void
3591 _spdk_bs_dump_read_md_page(spdk_bs_sequence_t *seq, void *cb_arg)
3592 {
3593 	struct spdk_bs_dump_ctx *ctx = cb_arg;
3594 	uint64_t lba;
3595 
3596 	assert(ctx->cur_page < ctx->super->md_len);
3597 	lba = _spdk_bs_page_to_lba(ctx->bs, ctx->super->md_start + ctx->cur_page);
3598 	spdk_bs_sequence_read_dev(seq, ctx->page, lba,
3599 				  _spdk_bs_byte_to_lba(ctx->bs, SPDK_BS_PAGE_SIZE),
3600 				  _spdk_bs_dump_read_md_page_cpl, ctx);
3601 }
3602 
3603 static void
3604 _spdk_bs_dump_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3605 {
3606 	struct spdk_bs_dump_ctx *ctx = cb_arg;
3607 
3608 	fprintf(ctx->fp, "Signature: \"%.8s\" ", ctx->super->signature);
3609 	if (memcmp(ctx->super->signature, SPDK_BS_SUPER_BLOCK_SIG,
3610 		   sizeof(ctx->super->signature)) != 0) {
3611 		fprintf(ctx->fp, "(Mismatch)\n");
3612 		_spdk_bs_dump_finish(seq, ctx, bserrno);
3613 		return;
3614 	} else {
3615 		fprintf(ctx->fp, "(OK)\n");
3616 	}
3617 	fprintf(ctx->fp, "Version: %" PRIu32 "\n", ctx->super->version);
3618 	fprintf(ctx->fp, "CRC: 0x%x (%s)\n", ctx->super->crc,
3619 		(ctx->super->crc == _spdk_blob_md_page_calc_crc(ctx->super)) ? "OK" : "Mismatch");
3620 	fprintf(ctx->fp, "Blobstore Type: %.*s\n", SPDK_BLOBSTORE_TYPE_LENGTH, ctx->super->bstype.bstype);
3621 	fprintf(ctx->fp, "Cluster Size: %" PRIu32 "\n", ctx->super->cluster_size);
3622 	fprintf(ctx->fp, "Super Blob ID: ");
3623 	if (ctx->super->super_blob == SPDK_BLOBID_INVALID) {
3624 		fprintf(ctx->fp, "(None)\n");
3625 	} else {
3626 		fprintf(ctx->fp, "%" PRIu64 "\n", ctx->super->super_blob);
3627 	}
3628 	fprintf(ctx->fp, "Clean: %" PRIu32 "\n", ctx->super->clean);
3629 	fprintf(ctx->fp, "Used Metadata Page Mask Start: %" PRIu32 "\n", ctx->super->used_page_mask_start);
3630 	fprintf(ctx->fp, "Used Metadata Page Mask Length: %" PRIu32 "\n", ctx->super->used_page_mask_len);
3631 	fprintf(ctx->fp, "Used Cluster Mask Start: %" PRIu32 "\n", ctx->super->used_cluster_mask_start);
3632 	fprintf(ctx->fp, "Used Cluster Mask Length: %" PRIu32 "\n", ctx->super->used_cluster_mask_len);
3633 	fprintf(ctx->fp, "Used Blob ID Mask Start: %" PRIu32 "\n", ctx->super->used_blobid_mask_start);
3634 	fprintf(ctx->fp, "Used Blob ID Mask Length: %" PRIu32 "\n", ctx->super->used_blobid_mask_len);
3635 	fprintf(ctx->fp, "Metadata Start: %" PRIu32 "\n", ctx->super->md_start);
3636 	fprintf(ctx->fp, "Metadata Length: %" PRIu32 "\n", ctx->super->md_len);
3637 
3638 	ctx->cur_page = 0;
3639 	ctx->page = spdk_zmalloc(SPDK_BS_PAGE_SIZE, SPDK_BS_PAGE_SIZE,
3640 				 NULL, SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
3641 	if (!ctx->page) {
3642 		_spdk_bs_dump_finish(seq, ctx, -ENOMEM);
3643 		return;
3644 	}
3645 	_spdk_bs_dump_read_md_page(seq, ctx);
3646 }
3647 
3648 void
3649 spdk_bs_dump(struct spdk_bs_dev *dev, FILE *fp, spdk_bs_dump_print_xattr print_xattr_fn,
3650 	     spdk_bs_op_complete cb_fn, void *cb_arg)
3651 {
3652 	struct spdk_blob_store	*bs;
3653 	struct spdk_bs_cpl	cpl;
3654 	spdk_bs_sequence_t	*seq;
3655 	struct spdk_bs_dump_ctx *ctx;
3656 	struct spdk_bs_opts	opts = {};
3657 	int err;
3658 
3659 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Dumping blobstore from dev %p\n", dev);
3660 
3661 	spdk_bs_opts_init(&opts);
3662 
3663 	err = _spdk_bs_alloc(dev, &opts, &bs);
3664 	if (err) {
3665 		dev->destroy(dev);
3666 		cb_fn(cb_arg, err);
3667 		return;
3668 	}
3669 
3670 	ctx = calloc(1, sizeof(*ctx));
3671 	if (!ctx) {
3672 		_spdk_bs_free(bs);
3673 		cb_fn(cb_arg, -ENOMEM);
3674 		return;
3675 	}
3676 
3677 	ctx->bs = bs;
3678 	ctx->fp = fp;
3679 	ctx->print_xattr_fn = print_xattr_fn;
3680 
3681 	/* Allocate memory for the super block */
3682 	ctx->super = spdk_zmalloc(sizeof(*ctx->super), 0x1000, NULL,
3683 				  SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
3684 	if (!ctx->super) {
3685 		free(ctx);
3686 		_spdk_bs_free(bs);
3687 		cb_fn(cb_arg, -ENOMEM);
3688 		return;
3689 	}
3690 
3691 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
3692 	cpl.u.bs_basic.cb_fn = cb_fn;
3693 	cpl.u.bs_basic.cb_arg = cb_arg;
3694 
3695 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3696 	if (!seq) {
3697 		spdk_free(ctx->super);
3698 		free(ctx);
3699 		_spdk_bs_free(bs);
3700 		cb_fn(cb_arg, -ENOMEM);
3701 		return;
3702 	}
3703 
3704 	/* Read the super block */
3705 	spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
3706 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
3707 				  _spdk_bs_dump_super_cpl, ctx);
3708 }
3709 
3710 /* END spdk_bs_dump */
3711 
3712 /* START spdk_bs_init */
3713 
3714 struct spdk_bs_init_ctx {
3715 	struct spdk_blob_store		*bs;
3716 	struct spdk_bs_super_block	*super;
3717 };
3718 
3719 static void
3720 _spdk_bs_init_persist_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3721 {
3722 	struct spdk_bs_init_ctx *ctx = cb_arg;
3723 
3724 	spdk_free(ctx->super);
3725 	free(ctx);
3726 
3727 	spdk_bs_sequence_finish(seq, bserrno);
3728 }
3729 
3730 static void
3731 _spdk_bs_init_trim_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3732 {
3733 	struct spdk_bs_init_ctx *ctx = cb_arg;
3734 
3735 	/* Write super block */
3736 	spdk_bs_sequence_write_dev(seq, ctx->super, _spdk_bs_page_to_lba(ctx->bs, 0),
3737 				   _spdk_bs_byte_to_lba(ctx->bs, sizeof(*ctx->super)),
3738 				   _spdk_bs_init_persist_super_cpl, ctx);
3739 }
3740 
3741 void
3742 spdk_bs_init(struct spdk_bs_dev *dev, struct spdk_bs_opts *o,
3743 	     spdk_bs_op_with_handle_complete cb_fn, void *cb_arg)
3744 {
3745 	struct spdk_bs_init_ctx *ctx;
3746 	struct spdk_blob_store	*bs;
3747 	struct spdk_bs_cpl	cpl;
3748 	spdk_bs_sequence_t	*seq;
3749 	spdk_bs_batch_t		*batch;
3750 	uint64_t		num_md_lba;
3751 	uint64_t		num_md_pages;
3752 	uint64_t		num_md_clusters;
3753 	uint32_t		i;
3754 	struct spdk_bs_opts	opts = {};
3755 	int			rc;
3756 
3757 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Initializing blobstore on dev %p\n", dev);
3758 
3759 	if ((SPDK_BS_PAGE_SIZE % dev->blocklen) != 0) {
3760 		SPDK_ERRLOG("unsupported dev block length of %d\n",
3761 			    dev->blocklen);
3762 		dev->destroy(dev);
3763 		cb_fn(cb_arg, NULL, -EINVAL);
3764 		return;
3765 	}
3766 
3767 	if (o) {
3768 		opts = *o;
3769 	} else {
3770 		spdk_bs_opts_init(&opts);
3771 	}
3772 
3773 	if (_spdk_bs_opts_verify(&opts) != 0) {
3774 		dev->destroy(dev);
3775 		cb_fn(cb_arg, NULL, -EINVAL);
3776 		return;
3777 	}
3778 
3779 	rc = _spdk_bs_alloc(dev, &opts, &bs);
3780 	if (rc) {
3781 		dev->destroy(dev);
3782 		cb_fn(cb_arg, NULL, rc);
3783 		return;
3784 	}
3785 
3786 	if (opts.num_md_pages == SPDK_BLOB_OPTS_NUM_MD_PAGES) {
3787 		/* By default, allocate 1 page per cluster.
3788 		 * Technically, this over-allocates metadata
3789 		 * because more metadata will reduce the number
3790 		 * of usable clusters. This can be addressed with
3791 		 * more complex math in the future.
3792 		 */
3793 		bs->md_len = bs->total_clusters;
3794 	} else {
3795 		bs->md_len = opts.num_md_pages;
3796 	}
3797 	rc = spdk_bit_array_resize(&bs->used_md_pages, bs->md_len);
3798 	if (rc < 0) {
3799 		_spdk_bs_free(bs);
3800 		cb_fn(cb_arg, NULL, -ENOMEM);
3801 		return;
3802 	}
3803 
3804 	rc = spdk_bit_array_resize(&bs->used_blobids, bs->md_len);
3805 	if (rc < 0) {
3806 		_spdk_bs_free(bs);
3807 		cb_fn(cb_arg, NULL, -ENOMEM);
3808 		return;
3809 	}
3810 
3811 	ctx = calloc(1, sizeof(*ctx));
3812 	if (!ctx) {
3813 		_spdk_bs_free(bs);
3814 		cb_fn(cb_arg, NULL, -ENOMEM);
3815 		return;
3816 	}
3817 
3818 	ctx->bs = bs;
3819 
3820 	/* Allocate memory for the super block */
3821 	ctx->super = spdk_zmalloc(sizeof(*ctx->super), 0x1000, NULL,
3822 				  SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
3823 	if (!ctx->super) {
3824 		free(ctx);
3825 		_spdk_bs_free(bs);
3826 		cb_fn(cb_arg, NULL, -ENOMEM);
3827 		return;
3828 	}
3829 	memcpy(ctx->super->signature, SPDK_BS_SUPER_BLOCK_SIG,
3830 	       sizeof(ctx->super->signature));
3831 	ctx->super->version = SPDK_BS_VERSION;
3832 	ctx->super->length = sizeof(*ctx->super);
3833 	ctx->super->super_blob = bs->super_blob;
3834 	ctx->super->clean = 0;
3835 	ctx->super->cluster_size = bs->cluster_sz;
3836 	ctx->super->io_unit_size = bs->io_unit_size;
3837 	memcpy(&ctx->super->bstype, &bs->bstype, sizeof(bs->bstype));
3838 
3839 	/* Calculate how many pages the metadata consumes at the front
3840 	 * of the disk.
3841 	 */
3842 
3843 	/* The super block uses 1 page */
3844 	num_md_pages = 1;
3845 
3846 	/* The used_md_pages mask requires 1 bit per metadata page, rounded
3847 	 * up to the nearest page, plus a header.
3848 	 */
3849 	ctx->super->used_page_mask_start = num_md_pages;
3850 	ctx->super->used_page_mask_len = spdk_divide_round_up(sizeof(struct spdk_bs_md_mask) +
3851 					 spdk_divide_round_up(bs->md_len, 8),
3852 					 SPDK_BS_PAGE_SIZE);
3853 	num_md_pages += ctx->super->used_page_mask_len;
3854 
3855 	/* The used_clusters mask requires 1 bit per cluster, rounded
3856 	 * up to the nearest page, plus a header.
3857 	 */
3858 	ctx->super->used_cluster_mask_start = num_md_pages;
3859 	ctx->super->used_cluster_mask_len = spdk_divide_round_up(sizeof(struct spdk_bs_md_mask) +
3860 					    spdk_divide_round_up(bs->total_clusters, 8),
3861 					    SPDK_BS_PAGE_SIZE);
3862 	num_md_pages += ctx->super->used_cluster_mask_len;
3863 
3864 	/* The used_blobids mask requires 1 bit per metadata page, rounded
3865 	 * up to the nearest page, plus a header.
3866 	 */
3867 	ctx->super->used_blobid_mask_start = num_md_pages;
3868 	ctx->super->used_blobid_mask_len = spdk_divide_round_up(sizeof(struct spdk_bs_md_mask) +
3869 					   spdk_divide_round_up(bs->md_len, 8),
3870 					   SPDK_BS_PAGE_SIZE);
3871 	num_md_pages += ctx->super->used_blobid_mask_len;
3872 
3873 	/* The metadata region size was chosen above */
3874 	ctx->super->md_start = bs->md_start = num_md_pages;
3875 	ctx->super->md_len = bs->md_len;
3876 	num_md_pages += bs->md_len;
3877 
3878 	num_md_lba = _spdk_bs_page_to_lba(bs, num_md_pages);
3879 
3880 	ctx->super->size = dev->blockcnt * dev->blocklen;
3881 
3882 	ctx->super->crc = _spdk_blob_md_page_calc_crc(ctx->super);
3883 
3884 	num_md_clusters = spdk_divide_round_up(num_md_pages, bs->pages_per_cluster);
3885 	if (num_md_clusters > bs->total_clusters) {
3886 		SPDK_ERRLOG("Blobstore metadata cannot use more clusters than is available, "
3887 			    "please decrease number of pages reserved for metadata "
3888 			    "or increase cluster size.\n");
3889 		spdk_free(ctx->super);
3890 		free(ctx);
3891 		_spdk_bs_free(bs);
3892 		cb_fn(cb_arg, NULL, -ENOMEM);
3893 		return;
3894 	}
3895 	/* Claim all of the clusters used by the metadata */
3896 	for (i = 0; i < num_md_clusters; i++) {
3897 		_spdk_bs_claim_cluster(bs, i);
3898 	}
3899 
3900 	bs->total_data_clusters = bs->num_free_clusters;
3901 
3902 	cpl.type = SPDK_BS_CPL_TYPE_BS_HANDLE;
3903 	cpl.u.bs_handle.cb_fn = cb_fn;
3904 	cpl.u.bs_handle.cb_arg = cb_arg;
3905 	cpl.u.bs_handle.bs = bs;
3906 
3907 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3908 	if (!seq) {
3909 		spdk_free(ctx->super);
3910 		free(ctx);
3911 		_spdk_bs_free(bs);
3912 		cb_fn(cb_arg, NULL, -ENOMEM);
3913 		return;
3914 	}
3915 
3916 	batch = spdk_bs_sequence_to_batch(seq, _spdk_bs_init_trim_cpl, ctx);
3917 
3918 	/* Clear metadata space */
3919 	spdk_bs_batch_write_zeroes_dev(batch, 0, num_md_lba);
3920 
3921 	switch (opts.clear_method) {
3922 	case BS_CLEAR_WITH_UNMAP:
3923 		/* Trim data clusters */
3924 		spdk_bs_batch_unmap_dev(batch, num_md_lba, ctx->bs->dev->blockcnt - num_md_lba);
3925 		break;
3926 	case BS_CLEAR_WITH_WRITE_ZEROES:
3927 		/* Write_zeroes to data clusters */
3928 		spdk_bs_batch_write_zeroes_dev(batch, num_md_lba, ctx->bs->dev->blockcnt - num_md_lba);
3929 		break;
3930 	case BS_CLEAR_WITH_NONE:
3931 	default:
3932 		break;
3933 	}
3934 
3935 	spdk_bs_batch_close(batch);
3936 }
3937 
3938 /* END spdk_bs_init */
3939 
3940 /* START spdk_bs_destroy */
3941 
3942 static void
3943 _spdk_bs_destroy_trim_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
3944 {
3945 	struct spdk_bs_init_ctx *ctx = cb_arg;
3946 	struct spdk_blob_store *bs = ctx->bs;
3947 
3948 	/*
3949 	 * We need to defer calling spdk_bs_call_cpl() until after
3950 	 * dev destruction, so tuck these away for later use.
3951 	 */
3952 	bs->unload_err = bserrno;
3953 	memcpy(&bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));
3954 	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;
3955 
3956 	spdk_bs_sequence_finish(seq, bserrno);
3957 
3958 	_spdk_bs_free(bs);
3959 	free(ctx);
3960 }
3961 
3962 void
3963 spdk_bs_destroy(struct spdk_blob_store *bs, spdk_bs_op_complete cb_fn,
3964 		void *cb_arg)
3965 {
3966 	struct spdk_bs_cpl	cpl;
3967 	spdk_bs_sequence_t	*seq;
3968 	struct spdk_bs_init_ctx *ctx;
3969 
3970 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Destroying blobstore\n");
3971 
3972 	if (!TAILQ_EMPTY(&bs->blobs)) {
3973 		SPDK_ERRLOG("Blobstore still has open blobs\n");
3974 		cb_fn(cb_arg, -EBUSY);
3975 		return;
3976 	}
3977 
3978 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
3979 	cpl.u.bs_basic.cb_fn = cb_fn;
3980 	cpl.u.bs_basic.cb_arg = cb_arg;
3981 
3982 	ctx = calloc(1, sizeof(*ctx));
3983 	if (!ctx) {
3984 		cb_fn(cb_arg, -ENOMEM);
3985 		return;
3986 	}
3987 
3988 	ctx->bs = bs;
3989 
3990 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
3991 	if (!seq) {
3992 		free(ctx);
3993 		cb_fn(cb_arg, -ENOMEM);
3994 		return;
3995 	}
3996 
3997 	/* Write zeroes to the super block */
3998 	spdk_bs_sequence_write_zeroes_dev(seq,
3999 					  _spdk_bs_page_to_lba(bs, 0),
4000 					  _spdk_bs_byte_to_lba(bs, sizeof(struct spdk_bs_super_block)),
4001 					  _spdk_bs_destroy_trim_cpl, ctx);
4002 }
4003 
4004 /* END spdk_bs_destroy */
4005 
4006 /* START spdk_bs_unload */
4007 
4008 static void
4009 _spdk_bs_unload_write_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4010 {
4011 	struct spdk_bs_load_ctx	*ctx = cb_arg;
4012 
4013 	spdk_free(ctx->super);
4014 
4015 	/*
4016 	 * We need to defer calling spdk_bs_call_cpl() until after
4017 	 * dev destruction, so tuck these away for later use.
4018 	 */
4019 	ctx->bs->unload_err = bserrno;
4020 	memcpy(&ctx->bs->unload_cpl, &seq->cpl, sizeof(struct spdk_bs_cpl));
4021 	seq->cpl.type = SPDK_BS_CPL_TYPE_NONE;
4022 
4023 	spdk_bs_sequence_finish(seq, bserrno);
4024 
4025 	_spdk_bs_free(ctx->bs);
4026 	free(ctx);
4027 }
4028 
4029 static void
4030 _spdk_bs_unload_write_used_clusters_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4031 {
4032 	struct spdk_bs_load_ctx	*ctx = cb_arg;
4033 
4034 	spdk_free(ctx->mask);
4035 	ctx->super->clean = 1;
4036 
4037 	_spdk_bs_write_super(seq, ctx->bs, ctx->super, _spdk_bs_unload_write_super_cpl, ctx);
4038 }
4039 
4040 static void
4041 _spdk_bs_unload_write_used_blobids_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4042 {
4043 	struct spdk_bs_load_ctx	*ctx = cb_arg;
4044 
4045 	spdk_free(ctx->mask);
4046 	ctx->mask = NULL;
4047 
4048 	_spdk_bs_write_used_clusters(seq, ctx, _spdk_bs_unload_write_used_clusters_cpl);
4049 }
4050 
4051 static void
4052 _spdk_bs_unload_write_used_pages_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4053 {
4054 	struct spdk_bs_load_ctx	*ctx = cb_arg;
4055 
4056 	spdk_free(ctx->mask);
4057 	ctx->mask = NULL;
4058 
4059 	_spdk_bs_write_used_blobids(seq, ctx, _spdk_bs_unload_write_used_blobids_cpl);
4060 }
4061 
4062 static void
4063 _spdk_bs_unload_read_super_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4064 {
4065 	_spdk_bs_write_used_md(seq, cb_arg, _spdk_bs_unload_write_used_pages_cpl);
4066 }
4067 
4068 void
4069 spdk_bs_unload(struct spdk_blob_store *bs, spdk_bs_op_complete cb_fn, void *cb_arg)
4070 {
4071 	struct spdk_bs_cpl	cpl;
4072 	struct spdk_bs_load_ctx *ctx;
4073 
4074 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Syncing blobstore\n");
4075 
4076 	if (!TAILQ_EMPTY(&bs->blobs)) {
4077 		SPDK_ERRLOG("Blobstore still has open blobs\n");
4078 		cb_fn(cb_arg, -EBUSY);
4079 		return;
4080 	}
4081 
4082 	ctx = calloc(1, sizeof(*ctx));
4083 	if (!ctx) {
4084 		cb_fn(cb_arg, -ENOMEM);
4085 		return;
4086 	}
4087 
4088 	ctx->bs = bs;
4089 
4090 	ctx->super = spdk_zmalloc(sizeof(*ctx->super), 0x1000, NULL,
4091 				  SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
4092 	if (!ctx->super) {
4093 		free(ctx);
4094 		cb_fn(cb_arg, -ENOMEM);
4095 		return;
4096 	}
4097 
4098 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
4099 	cpl.u.bs_basic.cb_fn = cb_fn;
4100 	cpl.u.bs_basic.cb_arg = cb_arg;
4101 
4102 	ctx->seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
4103 	if (!ctx->seq) {
4104 		spdk_free(ctx->super);
4105 		free(ctx);
4106 		cb_fn(cb_arg, -ENOMEM);
4107 		return;
4108 	}
4109 
4110 	/* Read super block */
4111 	spdk_bs_sequence_read_dev(ctx->seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
4112 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
4113 				  _spdk_bs_unload_read_super_cpl, ctx);
4114 }
4115 
4116 /* END spdk_bs_unload */
4117 
4118 /* START spdk_bs_set_super */
4119 
4120 struct spdk_bs_set_super_ctx {
4121 	struct spdk_blob_store		*bs;
4122 	struct spdk_bs_super_block	*super;
4123 };
4124 
4125 static void
4126 _spdk_bs_set_super_write_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4127 {
4128 	struct spdk_bs_set_super_ctx	*ctx = cb_arg;
4129 
4130 	if (bserrno != 0) {
4131 		SPDK_ERRLOG("Unable to write to super block of blobstore\n");
4132 	}
4133 
4134 	spdk_free(ctx->super);
4135 
4136 	spdk_bs_sequence_finish(seq, bserrno);
4137 
4138 	free(ctx);
4139 }
4140 
4141 static void
4142 _spdk_bs_set_super_read_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4143 {
4144 	struct spdk_bs_set_super_ctx	*ctx = cb_arg;
4145 
4146 	if (bserrno != 0) {
4147 		SPDK_ERRLOG("Unable to read super block of blobstore\n");
4148 		spdk_free(ctx->super);
4149 		spdk_bs_sequence_finish(seq, bserrno);
4150 		free(ctx);
4151 		return;
4152 	}
4153 
4154 	_spdk_bs_write_super(seq, ctx->bs, ctx->super, _spdk_bs_set_super_write_cpl, ctx);
4155 }
4156 
4157 void
4158 spdk_bs_set_super(struct spdk_blob_store *bs, spdk_blob_id blobid,
4159 		  spdk_bs_op_complete cb_fn, void *cb_arg)
4160 {
4161 	struct spdk_bs_cpl		cpl;
4162 	spdk_bs_sequence_t		*seq;
4163 	struct spdk_bs_set_super_ctx	*ctx;
4164 
4165 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Setting super blob id on blobstore\n");
4166 
4167 	ctx = calloc(1, sizeof(*ctx));
4168 	if (!ctx) {
4169 		cb_fn(cb_arg, -ENOMEM);
4170 		return;
4171 	}
4172 
4173 	ctx->bs = bs;
4174 
4175 	ctx->super = spdk_zmalloc(sizeof(*ctx->super), 0x1000, NULL,
4176 				  SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
4177 	if (!ctx->super) {
4178 		free(ctx);
4179 		cb_fn(cb_arg, -ENOMEM);
4180 		return;
4181 	}
4182 
4183 	cpl.type = SPDK_BS_CPL_TYPE_BS_BASIC;
4184 	cpl.u.bs_basic.cb_fn = cb_fn;
4185 	cpl.u.bs_basic.cb_arg = cb_arg;
4186 
4187 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
4188 	if (!seq) {
4189 		spdk_free(ctx->super);
4190 		free(ctx);
4191 		cb_fn(cb_arg, -ENOMEM);
4192 		return;
4193 	}
4194 
4195 	bs->super_blob = blobid;
4196 
4197 	/* Read super block */
4198 	spdk_bs_sequence_read_dev(seq, ctx->super, _spdk_bs_page_to_lba(bs, 0),
4199 				  _spdk_bs_byte_to_lba(bs, sizeof(*ctx->super)),
4200 				  _spdk_bs_set_super_read_cpl, ctx);
4201 }
4202 
4203 /* END spdk_bs_set_super */
4204 
4205 void
4206 spdk_bs_get_super(struct spdk_blob_store *bs,
4207 		  spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4208 {
4209 	if (bs->super_blob == SPDK_BLOBID_INVALID) {
4210 		cb_fn(cb_arg, SPDK_BLOBID_INVALID, -ENOENT);
4211 	} else {
4212 		cb_fn(cb_arg, bs->super_blob, 0);
4213 	}
4214 }
4215 
4216 uint64_t
4217 spdk_bs_get_cluster_size(struct spdk_blob_store *bs)
4218 {
4219 	return bs->cluster_sz;
4220 }
4221 
4222 uint64_t
4223 spdk_bs_get_page_size(struct spdk_blob_store *bs)
4224 {
4225 	return SPDK_BS_PAGE_SIZE;
4226 }
4227 
4228 uint64_t
4229 spdk_bs_get_io_unit_size(struct spdk_blob_store *bs)
4230 {
4231 	return bs->io_unit_size;
4232 }
4233 
4234 uint64_t
4235 spdk_bs_free_cluster_count(struct spdk_blob_store *bs)
4236 {
4237 	return bs->num_free_clusters;
4238 }
4239 
4240 uint64_t
4241 spdk_bs_total_data_cluster_count(struct spdk_blob_store *bs)
4242 {
4243 	return bs->total_data_clusters;
4244 }
4245 
4246 static int
4247 spdk_bs_register_md_thread(struct spdk_blob_store *bs)
4248 {
4249 	bs->md_channel = spdk_get_io_channel(bs);
4250 	if (!bs->md_channel) {
4251 		SPDK_ERRLOG("Failed to get IO channel.\n");
4252 		return -1;
4253 	}
4254 
4255 	return 0;
4256 }
4257 
4258 static int
4259 spdk_bs_unregister_md_thread(struct spdk_blob_store *bs)
4260 {
4261 	spdk_put_io_channel(bs->md_channel);
4262 
4263 	return 0;
4264 }
4265 
4266 spdk_blob_id spdk_blob_get_id(struct spdk_blob *blob)
4267 {
4268 	assert(blob != NULL);
4269 
4270 	return blob->id;
4271 }
4272 
4273 uint64_t spdk_blob_get_num_pages(struct spdk_blob *blob)
4274 {
4275 	assert(blob != NULL);
4276 
4277 	return _spdk_bs_cluster_to_page(blob->bs, blob->active.num_clusters);
4278 }
4279 
4280 uint64_t spdk_blob_get_num_io_units(struct spdk_blob *blob)
4281 {
4282 	assert(blob != NULL);
4283 
4284 	return spdk_blob_get_num_pages(blob) * _spdk_bs_io_unit_per_page(blob->bs);
4285 }
4286 
4287 uint64_t spdk_blob_get_num_clusters(struct spdk_blob *blob)
4288 {
4289 	assert(blob != NULL);
4290 
4291 	return blob->active.num_clusters;
4292 }
4293 
4294 /* START spdk_bs_create_blob */
4295 
4296 static void
4297 _spdk_bs_create_blob_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
4298 {
4299 	struct spdk_blob *blob = cb_arg;
4300 
4301 	_spdk_blob_free(blob);
4302 
4303 	spdk_bs_sequence_finish(seq, bserrno);
4304 }
4305 
4306 static int
4307 _spdk_blob_set_xattrs(struct spdk_blob *blob, const struct spdk_blob_xattr_opts *xattrs,
4308 		      bool internal)
4309 {
4310 	uint64_t i;
4311 	size_t value_len = 0;
4312 	int rc;
4313 	const void *value = NULL;
4314 	if (xattrs->count > 0 && xattrs->get_value == NULL) {
4315 		return -EINVAL;
4316 	}
4317 	for (i = 0; i < xattrs->count; i++) {
4318 		xattrs->get_value(xattrs->ctx, xattrs->names[i], &value, &value_len);
4319 		if (value == NULL || value_len == 0) {
4320 			return -EINVAL;
4321 		}
4322 		rc = _spdk_blob_set_xattr(blob, xattrs->names[i], value, value_len, internal);
4323 		if (rc < 0) {
4324 			return rc;
4325 		}
4326 	}
4327 	return 0;
4328 }
4329 
4330 static void
4331 _spdk_bs_create_blob(struct spdk_blob_store *bs,
4332 		     const struct spdk_blob_opts *opts,
4333 		     const struct spdk_blob_xattr_opts *internal_xattrs,
4334 		     spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4335 {
4336 	struct spdk_blob	*blob;
4337 	uint32_t		page_idx;
4338 	struct spdk_bs_cpl	cpl;
4339 	struct spdk_blob_opts	opts_default;
4340 	struct spdk_blob_xattr_opts internal_xattrs_default;
4341 	spdk_bs_sequence_t	*seq;
4342 	spdk_blob_id		id;
4343 	int rc;
4344 
4345 	assert(spdk_get_thread() == bs->md_thread);
4346 
4347 	page_idx = spdk_bit_array_find_first_clear(bs->used_md_pages, 0);
4348 	if (page_idx == UINT32_MAX) {
4349 		cb_fn(cb_arg, 0, -ENOMEM);
4350 		return;
4351 	}
4352 	spdk_bit_array_set(bs->used_blobids, page_idx);
4353 	spdk_bit_array_set(bs->used_md_pages, page_idx);
4354 
4355 	id = _spdk_bs_page_to_blobid(page_idx);
4356 
4357 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Creating blob with id %lu at page %u\n", id, page_idx);
4358 
4359 	blob = _spdk_blob_alloc(bs, id);
4360 	if (!blob) {
4361 		cb_fn(cb_arg, 0, -ENOMEM);
4362 		return;
4363 	}
4364 
4365 	if (!opts) {
4366 		spdk_blob_opts_init(&opts_default);
4367 		opts = &opts_default;
4368 	}
4369 	if (!internal_xattrs) {
4370 		_spdk_blob_xattrs_init(&internal_xattrs_default);
4371 		internal_xattrs = &internal_xattrs_default;
4372 	}
4373 
4374 	rc = _spdk_blob_set_xattrs(blob, &opts->xattrs, false);
4375 	if (rc < 0) {
4376 		_spdk_blob_free(blob);
4377 		cb_fn(cb_arg, 0, rc);
4378 		return;
4379 	}
4380 
4381 	rc = _spdk_blob_set_xattrs(blob, internal_xattrs, true);
4382 	if (rc < 0) {
4383 		_spdk_blob_free(blob);
4384 		cb_fn(cb_arg, 0, rc);
4385 		return;
4386 	}
4387 
4388 	if (opts->thin_provision) {
4389 		_spdk_blob_set_thin_provision(blob);
4390 	}
4391 
4392 	_spdk_blob_set_clear_method(blob, opts->clear_method);
4393 
4394 	rc = _spdk_blob_resize(blob, opts->num_clusters);
4395 	if (rc < 0) {
4396 		_spdk_blob_free(blob);
4397 		cb_fn(cb_arg, 0, rc);
4398 		return;
4399 	}
4400 	cpl.type = SPDK_BS_CPL_TYPE_BLOBID;
4401 	cpl.u.blobid.cb_fn = cb_fn;
4402 	cpl.u.blobid.cb_arg = cb_arg;
4403 	cpl.u.blobid.blobid = blob->id;
4404 
4405 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
4406 	if (!seq) {
4407 		_spdk_blob_free(blob);
4408 		cb_fn(cb_arg, 0, -ENOMEM);
4409 		return;
4410 	}
4411 
4412 	_spdk_blob_persist(seq, blob, _spdk_bs_create_blob_cpl, blob);
4413 }
4414 
4415 void spdk_bs_create_blob(struct spdk_blob_store *bs,
4416 			 spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4417 {
4418 	_spdk_bs_create_blob(bs, NULL, NULL, cb_fn, cb_arg);
4419 }
4420 
4421 void spdk_bs_create_blob_ext(struct spdk_blob_store *bs, const struct spdk_blob_opts *opts,
4422 			     spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4423 {
4424 	_spdk_bs_create_blob(bs, opts, NULL, cb_fn, cb_arg);
4425 }
4426 
4427 /* END spdk_bs_create_blob */
4428 
4429 /* START blob_cleanup */
4430 
4431 struct spdk_clone_snapshot_ctx {
4432 	struct spdk_bs_cpl      cpl;
4433 	int bserrno;
4434 	bool frozen;
4435 
4436 	struct spdk_io_channel *channel;
4437 
4438 	/* Current cluster for inflate operation */
4439 	uint64_t cluster;
4440 
4441 	/* For inflation force allocation of all unallocated clusters and remove
4442 	 * thin-provisioning. Otherwise only decouple parent and keep clone thin. */
4443 	bool allocate_all;
4444 
4445 	struct {
4446 		spdk_blob_id id;
4447 		struct spdk_blob *blob;
4448 	} original;
4449 	struct {
4450 		spdk_blob_id id;
4451 		struct spdk_blob *blob;
4452 	} new;
4453 
4454 	/* xattrs specified for snapshot/clones only. They have no impact on
4455 	 * the original blobs xattrs. */
4456 	const struct spdk_blob_xattr_opts *xattrs;
4457 };
4458 
4459 static void
4460 _spdk_bs_clone_snapshot_cleanup_finish(void *cb_arg, int bserrno)
4461 {
4462 	struct spdk_clone_snapshot_ctx *ctx = cb_arg;
4463 	struct spdk_bs_cpl *cpl = &ctx->cpl;
4464 
4465 	if (bserrno != 0) {
4466 		if (ctx->bserrno != 0) {
4467 			SPDK_ERRLOG("Cleanup error %d\n", bserrno);
4468 		} else {
4469 			ctx->bserrno = bserrno;
4470 		}
4471 	}
4472 
4473 	switch (cpl->type) {
4474 	case SPDK_BS_CPL_TYPE_BLOBID:
4475 		cpl->u.blobid.cb_fn(cpl->u.blobid.cb_arg, cpl->u.blobid.blobid, ctx->bserrno);
4476 		break;
4477 	case SPDK_BS_CPL_TYPE_BLOB_BASIC:
4478 		cpl->u.blob_basic.cb_fn(cpl->u.blob_basic.cb_arg, ctx->bserrno);
4479 		break;
4480 	default:
4481 		SPDK_UNREACHABLE();
4482 		break;
4483 	}
4484 
4485 	free(ctx);
4486 }
4487 
4488 static void
4489 _spdk_bs_snapshot_unfreeze_cpl(void *cb_arg, int bserrno)
4490 {
4491 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4492 	struct spdk_blob *origblob = ctx->original.blob;
4493 
4494 	if (bserrno != 0) {
4495 		if (ctx->bserrno != 0) {
4496 			SPDK_ERRLOG("Unfreeze error %d\n", bserrno);
4497 		} else {
4498 			ctx->bserrno = bserrno;
4499 		}
4500 	}
4501 
4502 	ctx->original.id = origblob->id;
4503 	origblob->locked_operation_in_progress = false;
4504 
4505 	spdk_blob_close(origblob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
4506 }
4507 
4508 static void
4509 _spdk_bs_clone_snapshot_origblob_cleanup(void *cb_arg, int bserrno)
4510 {
4511 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4512 	struct spdk_blob *origblob = ctx->original.blob;
4513 
4514 	if (bserrno != 0) {
4515 		if (ctx->bserrno != 0) {
4516 			SPDK_ERRLOG("Cleanup error %d\n", bserrno);
4517 		} else {
4518 			ctx->bserrno = bserrno;
4519 		}
4520 	}
4521 
4522 	if (ctx->frozen) {
4523 		/* Unfreeze any outstanding I/O */
4524 		_spdk_blob_unfreeze_io(origblob, _spdk_bs_snapshot_unfreeze_cpl, ctx);
4525 	} else {
4526 		_spdk_bs_snapshot_unfreeze_cpl(ctx, 0);
4527 	}
4528 
4529 }
4530 
4531 static void
4532 _spdk_bs_clone_snapshot_newblob_cleanup(void *cb_arg, int bserrno)
4533 {
4534 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4535 	struct spdk_blob *newblob = ctx->new.blob;
4536 
4537 	if (bserrno != 0) {
4538 		if (ctx->bserrno != 0) {
4539 			SPDK_ERRLOG("Cleanup error %d\n", bserrno);
4540 		} else {
4541 			ctx->bserrno = bserrno;
4542 		}
4543 	}
4544 
4545 	ctx->new.id = newblob->id;
4546 	spdk_blob_close(newblob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4547 }
4548 
4549 /* END blob_cleanup */
4550 
4551 /* START spdk_bs_create_snapshot */
4552 
4553 static void
4554 _spdk_bs_snapshot_swap_cluster_maps(struct spdk_blob *blob1, struct spdk_blob *blob2)
4555 {
4556 	uint64_t *cluster_temp;
4557 
4558 	cluster_temp = blob1->active.clusters;
4559 	blob1->active.clusters = blob2->active.clusters;
4560 	blob2->active.clusters = cluster_temp;
4561 }
4562 
4563 static void
4564 _spdk_bs_snapshot_origblob_sync_cpl(void *cb_arg, int bserrno)
4565 {
4566 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4567 	struct spdk_blob *origblob = ctx->original.blob;
4568 	struct spdk_blob *newblob = ctx->new.blob;
4569 
4570 	if (bserrno != 0) {
4571 		_spdk_bs_snapshot_swap_cluster_maps(newblob, origblob);
4572 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4573 		return;
4574 	}
4575 
4576 	/* Remove metadata descriptor SNAPSHOT_IN_PROGRESS */
4577 	bserrno = _spdk_blob_remove_xattr(newblob, SNAPSHOT_IN_PROGRESS, true);
4578 	if (bserrno != 0) {
4579 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4580 		return;
4581 	}
4582 
4583 	_spdk_bs_blob_list_add(ctx->original.blob);
4584 
4585 	spdk_blob_set_read_only(newblob);
4586 
4587 	/* sync snapshot metadata */
4588 	spdk_blob_sync_md(newblob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4589 }
4590 
4591 static void
4592 _spdk_bs_snapshot_newblob_sync_cpl(void *cb_arg, int bserrno)
4593 {
4594 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4595 	struct spdk_blob *origblob = ctx->original.blob;
4596 	struct spdk_blob *newblob = ctx->new.blob;
4597 
4598 	if (bserrno != 0) {
4599 		/* return cluster map back to original */
4600 		_spdk_bs_snapshot_swap_cluster_maps(newblob, origblob);
4601 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4602 		return;
4603 	}
4604 
4605 	/* Set internal xattr for snapshot id */
4606 	bserrno = _spdk_blob_set_xattr(origblob, BLOB_SNAPSHOT, &newblob->id, sizeof(spdk_blob_id), true);
4607 	if (bserrno != 0) {
4608 		/* return cluster map back to original */
4609 		_spdk_bs_snapshot_swap_cluster_maps(newblob, origblob);
4610 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4611 		return;
4612 	}
4613 
4614 	_spdk_bs_blob_list_remove(origblob);
4615 	origblob->parent_id = newblob->id;
4616 
4617 	/* Create new back_bs_dev for snapshot */
4618 	origblob->back_bs_dev = spdk_bs_create_blob_bs_dev(newblob);
4619 	if (origblob->back_bs_dev == NULL) {
4620 		/* return cluster map back to original */
4621 		_spdk_bs_snapshot_swap_cluster_maps(newblob, origblob);
4622 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, -EINVAL);
4623 		return;
4624 	}
4625 
4626 	/* set clone blob as thin provisioned */
4627 	_spdk_blob_set_thin_provision(origblob);
4628 
4629 	_spdk_bs_blob_list_add(newblob);
4630 
4631 	/* sync clone metadata */
4632 	spdk_blob_sync_md(origblob, _spdk_bs_snapshot_origblob_sync_cpl, ctx);
4633 }
4634 
4635 static void
4636 _spdk_bs_snapshot_freeze_cpl(void *cb_arg, int rc)
4637 {
4638 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4639 	struct spdk_blob *origblob = ctx->original.blob;
4640 	struct spdk_blob *newblob = ctx->new.blob;
4641 	int bserrno;
4642 
4643 	if (rc != 0) {
4644 		_spdk_bs_clone_snapshot_newblob_cleanup(ctx, rc);
4645 		return;
4646 	}
4647 
4648 	ctx->frozen = true;
4649 
4650 	/* set new back_bs_dev for snapshot */
4651 	newblob->back_bs_dev = origblob->back_bs_dev;
4652 	/* Set invalid flags from origblob */
4653 	newblob->invalid_flags = origblob->invalid_flags;
4654 
4655 	/* inherit parent from original blob if set */
4656 	newblob->parent_id = origblob->parent_id;
4657 	if (origblob->parent_id != SPDK_BLOBID_INVALID) {
4658 		/* Set internal xattr for snapshot id */
4659 		bserrno = _spdk_blob_set_xattr(newblob, BLOB_SNAPSHOT,
4660 					       &origblob->parent_id, sizeof(spdk_blob_id), true);
4661 		if (bserrno != 0) {
4662 			_spdk_bs_clone_snapshot_newblob_cleanup(ctx, bserrno);
4663 			return;
4664 		}
4665 	}
4666 
4667 	/* swap cluster maps */
4668 	_spdk_bs_snapshot_swap_cluster_maps(newblob, origblob);
4669 
4670 	/* Set the clear method on the new blob to match the original. */
4671 	_spdk_blob_set_clear_method(newblob, origblob->clear_method);
4672 
4673 	/* sync snapshot metadata */
4674 	spdk_blob_sync_md(newblob, _spdk_bs_snapshot_newblob_sync_cpl, ctx);
4675 }
4676 
4677 static void
4678 _spdk_bs_snapshot_newblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4679 {
4680 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4681 	struct spdk_blob *origblob = ctx->original.blob;
4682 	struct spdk_blob *newblob = _blob;
4683 
4684 	if (bserrno != 0) {
4685 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4686 		return;
4687 	}
4688 
4689 	ctx->new.blob = newblob;
4690 	assert(spdk_blob_is_thin_provisioned(newblob));
4691 	assert(spdk_mem_all_zero(newblob->active.clusters,
4692 				 newblob->active.num_clusters * sizeof(*newblob->active.clusters)));
4693 
4694 	_spdk_blob_freeze_io(origblob, _spdk_bs_snapshot_freeze_cpl, ctx);
4695 }
4696 
4697 static void
4698 _spdk_bs_snapshot_newblob_create_cpl(void *cb_arg, spdk_blob_id blobid, int bserrno)
4699 {
4700 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4701 	struct spdk_blob *origblob = ctx->original.blob;
4702 
4703 	if (bserrno != 0) {
4704 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4705 		return;
4706 	}
4707 
4708 	ctx->new.id = blobid;
4709 	ctx->cpl.u.blobid.blobid = blobid;
4710 
4711 	spdk_bs_open_blob(origblob->bs, ctx->new.id, _spdk_bs_snapshot_newblob_open_cpl, ctx);
4712 }
4713 
4714 
4715 static void
4716 _spdk_bs_xattr_snapshot(void *arg, const char *name,
4717 			const void **value, size_t *value_len)
4718 {
4719 	assert(strncmp(name, SNAPSHOT_IN_PROGRESS, sizeof(SNAPSHOT_IN_PROGRESS)) == 0);
4720 
4721 	struct spdk_blob *blob = (struct spdk_blob *)arg;
4722 	*value = &blob->id;
4723 	*value_len = sizeof(blob->id);
4724 }
4725 
4726 static void
4727 _spdk_bs_snapshot_origblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4728 {
4729 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4730 	struct spdk_blob_opts opts;
4731 	struct spdk_blob_xattr_opts internal_xattrs;
4732 	char *xattrs_names[] = { SNAPSHOT_IN_PROGRESS };
4733 
4734 	if (bserrno != 0) {
4735 		_spdk_bs_clone_snapshot_cleanup_finish(ctx, bserrno);
4736 		return;
4737 	}
4738 
4739 	ctx->original.blob = _blob;
4740 
4741 	if (_blob->data_ro || _blob->md_ro) {
4742 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot create snapshot from read only blob with id %lu\n",
4743 			      _blob->id);
4744 		ctx->bserrno = -EINVAL;
4745 		spdk_blob_close(_blob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
4746 		return;
4747 	}
4748 
4749 	if (_blob->locked_operation_in_progress) {
4750 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot create snapshot - another operation in progress\n");
4751 		ctx->bserrno = -EBUSY;
4752 		spdk_blob_close(_blob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
4753 		return;
4754 	}
4755 
4756 	_blob->locked_operation_in_progress = true;
4757 
4758 	spdk_blob_opts_init(&opts);
4759 	_spdk_blob_xattrs_init(&internal_xattrs);
4760 
4761 	/* Change the size of new blob to the same as in original blob,
4762 	 * but do not allocate clusters */
4763 	opts.thin_provision = true;
4764 	opts.num_clusters = spdk_blob_get_num_clusters(_blob);
4765 
4766 	/* If there are any xattrs specified for snapshot, set them now */
4767 	if (ctx->xattrs) {
4768 		memcpy(&opts.xattrs, ctx->xattrs, sizeof(*ctx->xattrs));
4769 	}
4770 	/* Set internal xattr SNAPSHOT_IN_PROGRESS */
4771 	internal_xattrs.count = 1;
4772 	internal_xattrs.ctx = _blob;
4773 	internal_xattrs.names = xattrs_names;
4774 	internal_xattrs.get_value = _spdk_bs_xattr_snapshot;
4775 
4776 	_spdk_bs_create_blob(_blob->bs, &opts, &internal_xattrs,
4777 			     _spdk_bs_snapshot_newblob_create_cpl, ctx);
4778 }
4779 
4780 void spdk_bs_create_snapshot(struct spdk_blob_store *bs, spdk_blob_id blobid,
4781 			     const struct spdk_blob_xattr_opts *snapshot_xattrs,
4782 			     spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4783 {
4784 	struct spdk_clone_snapshot_ctx *ctx = calloc(1, sizeof(*ctx));
4785 
4786 	if (!ctx) {
4787 		cb_fn(cb_arg, SPDK_BLOBID_INVALID, -ENOMEM);
4788 		return;
4789 	}
4790 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BLOBID;
4791 	ctx->cpl.u.blobid.cb_fn = cb_fn;
4792 	ctx->cpl.u.blobid.cb_arg = cb_arg;
4793 	ctx->cpl.u.blobid.blobid = SPDK_BLOBID_INVALID;
4794 	ctx->bserrno = 0;
4795 	ctx->frozen = false;
4796 	ctx->original.id = blobid;
4797 	ctx->xattrs = snapshot_xattrs;
4798 
4799 	spdk_bs_open_blob(bs, ctx->original.id, _spdk_bs_snapshot_origblob_open_cpl, ctx);
4800 }
4801 /* END spdk_bs_create_snapshot */
4802 
4803 /* START spdk_bs_create_clone */
4804 
4805 static void
4806 _spdk_bs_xattr_clone(void *arg, const char *name,
4807 		     const void **value, size_t *value_len)
4808 {
4809 	assert(strncmp(name, BLOB_SNAPSHOT, sizeof(BLOB_SNAPSHOT)) == 0);
4810 
4811 	struct spdk_blob *blob = (struct spdk_blob *)arg;
4812 	*value = &blob->id;
4813 	*value_len = sizeof(blob->id);
4814 }
4815 
4816 static void
4817 _spdk_bs_clone_newblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4818 {
4819 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4820 	struct spdk_blob *clone = _blob;
4821 
4822 	ctx->new.blob = clone;
4823 	_spdk_bs_blob_list_add(clone);
4824 
4825 	spdk_blob_close(clone, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4826 }
4827 
4828 static void
4829 _spdk_bs_clone_newblob_create_cpl(void *cb_arg, spdk_blob_id blobid, int bserrno)
4830 {
4831 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4832 
4833 	ctx->cpl.u.blobid.blobid = blobid;
4834 	spdk_bs_open_blob(ctx->original.blob->bs, blobid, _spdk_bs_clone_newblob_open_cpl, ctx);
4835 }
4836 
4837 static void
4838 _spdk_bs_clone_origblob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
4839 {
4840 	struct spdk_clone_snapshot_ctx	*ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4841 	struct spdk_blob_opts		opts;
4842 	struct spdk_blob_xattr_opts internal_xattrs;
4843 	char *xattr_names[] = { BLOB_SNAPSHOT };
4844 
4845 	if (bserrno != 0) {
4846 		_spdk_bs_clone_snapshot_cleanup_finish(ctx, bserrno);
4847 		return;
4848 	}
4849 
4850 	ctx->original.blob = _blob;
4851 
4852 	if (!_blob->data_ro || !_blob->md_ro) {
4853 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Clone not from read-only blob\n");
4854 		ctx->bserrno = -EINVAL;
4855 		spdk_blob_close(_blob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
4856 		return;
4857 	}
4858 
4859 	if (_blob->locked_operation_in_progress) {
4860 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot create clone - another operation in progress\n");
4861 		ctx->bserrno = -EBUSY;
4862 		spdk_blob_close(_blob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
4863 		return;
4864 	}
4865 
4866 	_blob->locked_operation_in_progress = true;
4867 
4868 	spdk_blob_opts_init(&opts);
4869 	_spdk_blob_xattrs_init(&internal_xattrs);
4870 
4871 	opts.thin_provision = true;
4872 	opts.num_clusters = spdk_blob_get_num_clusters(_blob);
4873 	if (ctx->xattrs) {
4874 		memcpy(&opts.xattrs, ctx->xattrs, sizeof(*ctx->xattrs));
4875 	}
4876 
4877 	/* Set internal xattr BLOB_SNAPSHOT */
4878 	internal_xattrs.count = 1;
4879 	internal_xattrs.ctx = _blob;
4880 	internal_xattrs.names = xattr_names;
4881 	internal_xattrs.get_value = _spdk_bs_xattr_clone;
4882 
4883 	_spdk_bs_create_blob(_blob->bs, &opts, &internal_xattrs,
4884 			     _spdk_bs_clone_newblob_create_cpl, ctx);
4885 }
4886 
4887 void spdk_bs_create_clone(struct spdk_blob_store *bs, spdk_blob_id blobid,
4888 			  const struct spdk_blob_xattr_opts *clone_xattrs,
4889 			  spdk_blob_op_with_id_complete cb_fn, void *cb_arg)
4890 {
4891 	struct spdk_clone_snapshot_ctx	*ctx = calloc(1, sizeof(*ctx));
4892 
4893 	if (!ctx) {
4894 		cb_fn(cb_arg, SPDK_BLOBID_INVALID, -ENOMEM);
4895 		return;
4896 	}
4897 
4898 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BLOBID;
4899 	ctx->cpl.u.blobid.cb_fn = cb_fn;
4900 	ctx->cpl.u.blobid.cb_arg = cb_arg;
4901 	ctx->cpl.u.blobid.blobid = SPDK_BLOBID_INVALID;
4902 	ctx->bserrno = 0;
4903 	ctx->xattrs = clone_xattrs;
4904 	ctx->original.id = blobid;
4905 
4906 	spdk_bs_open_blob(bs, ctx->original.id, _spdk_bs_clone_origblob_open_cpl, ctx);
4907 }
4908 
4909 /* END spdk_bs_create_clone */
4910 
4911 /* START spdk_bs_inflate_blob */
4912 
4913 static void
4914 _spdk_bs_inflate_blob_set_parent_cpl(void *cb_arg, struct spdk_blob *_parent, int bserrno)
4915 {
4916 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4917 	struct spdk_blob *_blob = ctx->original.blob;
4918 
4919 	if (bserrno != 0) {
4920 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4921 		return;
4922 	}
4923 
4924 	assert(_parent != NULL);
4925 
4926 	_spdk_bs_blob_list_remove(_blob);
4927 	_blob->parent_id = _parent->id;
4928 	_spdk_blob_set_xattr(_blob, BLOB_SNAPSHOT, &_blob->parent_id,
4929 			     sizeof(spdk_blob_id), true);
4930 
4931 	_blob->back_bs_dev->destroy(_blob->back_bs_dev);
4932 	_blob->back_bs_dev = spdk_bs_create_blob_bs_dev(_parent);
4933 	_spdk_bs_blob_list_add(_blob);
4934 
4935 	spdk_blob_sync_md(_blob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4936 }
4937 
4938 static void
4939 _spdk_bs_inflate_blob_done(void *cb_arg, int bserrno)
4940 {
4941 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
4942 	struct spdk_blob *_blob = ctx->original.blob;
4943 	struct spdk_blob *_parent;
4944 
4945 	if (bserrno != 0) {
4946 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
4947 		return;
4948 	}
4949 
4950 	if (ctx->allocate_all) {
4951 		/* remove thin provisioning */
4952 		_spdk_bs_blob_list_remove(_blob);
4953 		_spdk_blob_remove_xattr(_blob, BLOB_SNAPSHOT, true);
4954 		_blob->invalid_flags = _blob->invalid_flags & ~SPDK_BLOB_THIN_PROV;
4955 		_blob->back_bs_dev->destroy(_blob->back_bs_dev);
4956 		_blob->back_bs_dev = NULL;
4957 		_blob->parent_id = SPDK_BLOBID_INVALID;
4958 	} else {
4959 		_parent = ((struct spdk_blob_bs_dev *)(_blob->back_bs_dev))->blob;
4960 		if (_parent->parent_id != SPDK_BLOBID_INVALID) {
4961 			/* We must change the parent of the inflated blob */
4962 			spdk_bs_open_blob(_blob->bs, _parent->parent_id,
4963 					  _spdk_bs_inflate_blob_set_parent_cpl, ctx);
4964 			return;
4965 		}
4966 
4967 		_spdk_bs_blob_list_remove(_blob);
4968 		_spdk_blob_remove_xattr(_blob, BLOB_SNAPSHOT, true);
4969 		_blob->parent_id = SPDK_BLOBID_INVALID;
4970 		_blob->back_bs_dev->destroy(_blob->back_bs_dev);
4971 		_blob->back_bs_dev = spdk_bs_create_zeroes_dev();
4972 	}
4973 
4974 	_blob->state = SPDK_BLOB_STATE_DIRTY;
4975 	spdk_blob_sync_md(_blob, _spdk_bs_clone_snapshot_origblob_cleanup, ctx);
4976 }
4977 
4978 /* Check if cluster needs allocation */
4979 static inline bool
4980 _spdk_bs_cluster_needs_allocation(struct spdk_blob *blob, uint64_t cluster, bool allocate_all)
4981 {
4982 	struct spdk_blob_bs_dev *b;
4983 
4984 	assert(blob != NULL);
4985 
4986 	if (blob->active.clusters[cluster] != 0) {
4987 		/* Cluster is already allocated */
4988 		return false;
4989 	}
4990 
4991 	if (blob->parent_id == SPDK_BLOBID_INVALID) {
4992 		/* Blob have no parent blob */
4993 		return allocate_all;
4994 	}
4995 
4996 	b = (struct spdk_blob_bs_dev *)blob->back_bs_dev;
4997 	return (allocate_all || b->blob->active.clusters[cluster] != 0);
4998 }
4999 
5000 static void
5001 _spdk_bs_inflate_blob_touch_next(void *cb_arg, int bserrno)
5002 {
5003 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
5004 	struct spdk_blob *_blob = ctx->original.blob;
5005 	uint64_t offset;
5006 
5007 	if (bserrno != 0) {
5008 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, bserrno);
5009 		return;
5010 	}
5011 
5012 	for (; ctx->cluster < _blob->active.num_clusters; ctx->cluster++) {
5013 		if (_spdk_bs_cluster_needs_allocation(_blob, ctx->cluster, ctx->allocate_all)) {
5014 			break;
5015 		}
5016 	}
5017 
5018 	if (ctx->cluster < _blob->active.num_clusters) {
5019 		offset = _spdk_bs_cluster_to_lba(_blob->bs, ctx->cluster);
5020 
5021 		/* We may safely increment a cluster before write */
5022 		ctx->cluster++;
5023 
5024 		/* Use zero length write to touch a cluster */
5025 		spdk_blob_io_write(_blob, ctx->channel, NULL, offset, 0,
5026 				   _spdk_bs_inflate_blob_touch_next, ctx);
5027 	} else {
5028 		_spdk_bs_inflate_blob_done(cb_arg, bserrno);
5029 	}
5030 }
5031 
5032 static void
5033 _spdk_bs_inflate_blob_open_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
5034 {
5035 	struct spdk_clone_snapshot_ctx *ctx = (struct spdk_clone_snapshot_ctx *)cb_arg;
5036 	uint64_t lfc; /* lowest free cluster */
5037 	uint64_t i;
5038 
5039 	if (bserrno != 0) {
5040 		_spdk_bs_clone_snapshot_cleanup_finish(ctx, bserrno);
5041 		return;
5042 	}
5043 
5044 	ctx->original.blob = _blob;
5045 
5046 	if (_blob->locked_operation_in_progress) {
5047 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot inflate blob - another operation in progress\n");
5048 		ctx->bserrno = -EBUSY;
5049 		spdk_blob_close(_blob, _spdk_bs_clone_snapshot_cleanup_finish, ctx);
5050 		return;
5051 	}
5052 
5053 	_blob->locked_operation_in_progress = true;
5054 
5055 	if (!ctx->allocate_all && _blob->parent_id == SPDK_BLOBID_INVALID) {
5056 		/* This blob have no parent, so we cannot decouple it. */
5057 		SPDK_ERRLOG("Cannot decouple parent of blob with no parent.\n");
5058 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, -EINVAL);
5059 		return;
5060 	}
5061 
5062 	if (spdk_blob_is_thin_provisioned(_blob) == false) {
5063 		/* This is not thin provisioned blob. No need to inflate. */
5064 		_spdk_bs_clone_snapshot_origblob_cleanup(ctx, 0);
5065 		return;
5066 	}
5067 
5068 	/* Do two passes - one to verify that we can obtain enough clusters
5069 	 * and another to actually claim them.
5070 	 */
5071 	lfc = 0;
5072 	for (i = 0; i < _blob->active.num_clusters; i++) {
5073 		if (_spdk_bs_cluster_needs_allocation(_blob, i, ctx->allocate_all)) {
5074 			lfc = spdk_bit_array_find_first_clear(_blob->bs->used_clusters, lfc);
5075 			if (lfc == UINT32_MAX) {
5076 				/* No more free clusters. Cannot satisfy the request */
5077 				_spdk_bs_clone_snapshot_origblob_cleanup(ctx, -ENOSPC);
5078 				return;
5079 			}
5080 			lfc++;
5081 		}
5082 	}
5083 
5084 	ctx->cluster = 0;
5085 	_spdk_bs_inflate_blob_touch_next(ctx, 0);
5086 }
5087 
5088 static void
5089 _spdk_bs_inflate_blob(struct spdk_blob_store *bs, struct spdk_io_channel *channel,
5090 		      spdk_blob_id blobid, bool allocate_all, spdk_blob_op_complete cb_fn, void *cb_arg)
5091 {
5092 	struct spdk_clone_snapshot_ctx *ctx = calloc(1, sizeof(*ctx));
5093 
5094 	if (!ctx) {
5095 		cb_fn(cb_arg, -ENOMEM);
5096 		return;
5097 	}
5098 	ctx->cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5099 	ctx->cpl.u.bs_basic.cb_fn = cb_fn;
5100 	ctx->cpl.u.bs_basic.cb_arg = cb_arg;
5101 	ctx->bserrno = 0;
5102 	ctx->original.id = blobid;
5103 	ctx->channel = channel;
5104 	ctx->allocate_all = allocate_all;
5105 
5106 	spdk_bs_open_blob(bs, ctx->original.id, _spdk_bs_inflate_blob_open_cpl, ctx);
5107 }
5108 
5109 void
5110 spdk_bs_inflate_blob(struct spdk_blob_store *bs, struct spdk_io_channel *channel,
5111 		     spdk_blob_id blobid, spdk_blob_op_complete cb_fn, void *cb_arg)
5112 {
5113 	_spdk_bs_inflate_blob(bs, channel, blobid, true, cb_fn, cb_arg);
5114 }
5115 
5116 void
5117 spdk_bs_blob_decouple_parent(struct spdk_blob_store *bs, struct spdk_io_channel *channel,
5118 			     spdk_blob_id blobid, spdk_blob_op_complete cb_fn, void *cb_arg)
5119 {
5120 	_spdk_bs_inflate_blob(bs, channel, blobid, false, cb_fn, cb_arg);
5121 }
5122 /* END spdk_bs_inflate_blob */
5123 
5124 /* START spdk_blob_resize */
5125 struct spdk_bs_resize_ctx {
5126 	spdk_blob_op_complete cb_fn;
5127 	void *cb_arg;
5128 	struct spdk_blob *blob;
5129 	uint64_t sz;
5130 	int rc;
5131 };
5132 
5133 static void
5134 _spdk_bs_resize_unfreeze_cpl(void *cb_arg, int rc)
5135 {
5136 	struct spdk_bs_resize_ctx *ctx = (struct spdk_bs_resize_ctx *)cb_arg;
5137 
5138 	if (rc != 0) {
5139 		SPDK_ERRLOG("Unfreeze failed, rc=%d\n", rc);
5140 	}
5141 
5142 	if (ctx->rc != 0) {
5143 		SPDK_ERRLOG("Unfreeze failed, ctx->rc=%d\n", ctx->rc);
5144 		rc = ctx->rc;
5145 	}
5146 
5147 	ctx->blob->locked_operation_in_progress = false;
5148 
5149 	ctx->cb_fn(ctx->cb_arg, rc);
5150 	free(ctx);
5151 }
5152 
5153 static void
5154 _spdk_bs_resize_freeze_cpl(void *cb_arg, int rc)
5155 {
5156 	struct spdk_bs_resize_ctx *ctx = (struct spdk_bs_resize_ctx *)cb_arg;
5157 
5158 	if (rc != 0) {
5159 		ctx->blob->locked_operation_in_progress = false;
5160 		ctx->cb_fn(ctx->cb_arg, rc);
5161 		free(ctx);
5162 		return;
5163 	}
5164 
5165 	ctx->rc = _spdk_blob_resize(ctx->blob, ctx->sz);
5166 
5167 	_spdk_blob_unfreeze_io(ctx->blob, _spdk_bs_resize_unfreeze_cpl, ctx);
5168 }
5169 
5170 void
5171 spdk_blob_resize(struct spdk_blob *blob, uint64_t sz, spdk_blob_op_complete cb_fn, void *cb_arg)
5172 {
5173 	struct spdk_bs_resize_ctx *ctx;
5174 
5175 	_spdk_blob_verify_md_op(blob);
5176 
5177 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Resizing blob %lu to %lu clusters\n", blob->id, sz);
5178 
5179 	if (blob->md_ro) {
5180 		cb_fn(cb_arg, -EPERM);
5181 		return;
5182 	}
5183 
5184 	if (sz == blob->active.num_clusters) {
5185 		cb_fn(cb_arg, 0);
5186 		return;
5187 	}
5188 
5189 	if (blob->locked_operation_in_progress) {
5190 		cb_fn(cb_arg, -EBUSY);
5191 		return;
5192 	}
5193 
5194 	ctx = calloc(1, sizeof(*ctx));
5195 	if (!ctx) {
5196 		cb_fn(cb_arg, -ENOMEM);
5197 		return;
5198 	}
5199 
5200 	blob->locked_operation_in_progress = true;
5201 	ctx->cb_fn = cb_fn;
5202 	ctx->cb_arg = cb_arg;
5203 	ctx->blob = blob;
5204 	ctx->sz = sz;
5205 	_spdk_blob_freeze_io(blob, _spdk_bs_resize_freeze_cpl, ctx);
5206 }
5207 
5208 /* END spdk_blob_resize */
5209 
5210 
5211 /* START spdk_bs_delete_blob */
5212 
5213 static void
5214 _spdk_bs_delete_close_cpl(void *cb_arg, int bserrno)
5215 {
5216 	spdk_bs_sequence_t *seq = cb_arg;
5217 
5218 	spdk_bs_sequence_finish(seq, bserrno);
5219 }
5220 
5221 static void
5222 _spdk_bs_delete_persist_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5223 {
5224 	struct spdk_blob *blob = cb_arg;
5225 
5226 	if (bserrno != 0) {
5227 		/*
5228 		 * We already removed this blob from the blobstore tailq, so
5229 		 *  we need to free it here since this is the last reference
5230 		 *  to it.
5231 		 */
5232 		_spdk_blob_free(blob);
5233 		_spdk_bs_delete_close_cpl(seq, bserrno);
5234 		return;
5235 	}
5236 
5237 	/*
5238 	 * This will immediately decrement the ref_count and call
5239 	 *  the completion routine since the metadata state is clean.
5240 	 *  By calling spdk_blob_close, we reduce the number of call
5241 	 *  points into code that touches the blob->open_ref count
5242 	 *  and the blobstore's blob list.
5243 	 */
5244 	spdk_blob_close(blob, _spdk_bs_delete_close_cpl, seq);
5245 }
5246 
5247 struct delete_snapshot_ctx {
5248 	struct spdk_blob_list *parent_snapshot_entry;
5249 	struct spdk_blob *snapshot;
5250 	bool snapshot_md_ro;
5251 	struct spdk_blob *clone;
5252 	bool clone_md_ro;
5253 	spdk_blob_op_with_handle_complete cb_fn;
5254 	void *cb_arg;
5255 	int bserrno;
5256 };
5257 
5258 static void
5259 _spdk_delete_blob_cleanup_finish(void *cb_arg, int bserrno)
5260 {
5261 	struct delete_snapshot_ctx *ctx = cb_arg;
5262 
5263 	if (bserrno != 0) {
5264 		SPDK_ERRLOG("Snapshot cleanup error %d\n", bserrno);
5265 	}
5266 
5267 	assert(ctx != NULL);
5268 
5269 	if (bserrno != 0 && ctx->bserrno == 0) {
5270 		ctx->bserrno = bserrno;
5271 	}
5272 
5273 	ctx->cb_fn(ctx->cb_arg, ctx->snapshot, ctx->bserrno);
5274 	free(ctx);
5275 }
5276 
5277 static void
5278 _spdk_delete_snapshot_cleanup_snapshot(void *cb_arg, int bserrno)
5279 {
5280 	struct delete_snapshot_ctx *ctx = cb_arg;
5281 
5282 	if (bserrno != 0) {
5283 		ctx->bserrno = bserrno;
5284 		SPDK_ERRLOG("Clone cleanup error %d\n", bserrno);
5285 	}
5286 
5287 	/* open_ref == 1 menas that only deletion context has opened this snapshot
5288 	 * open_ref == 2 menas that clone has opened this snapshot as well,
5289 	 * so we have to add it back to the blobs list */
5290 	if (ctx->snapshot->open_ref == 2) {
5291 		TAILQ_INSERT_HEAD(&ctx->snapshot->bs->blobs, ctx->snapshot, link);
5292 	}
5293 
5294 	ctx->snapshot->locked_operation_in_progress = false;
5295 	ctx->snapshot->md_ro = ctx->snapshot_md_ro;
5296 
5297 	spdk_blob_close(ctx->snapshot, _spdk_delete_blob_cleanup_finish, ctx);
5298 }
5299 
5300 static void
5301 _spdk_delete_snapshot_cleanup_clone(void *cb_arg, int bserrno)
5302 {
5303 	struct delete_snapshot_ctx *ctx = cb_arg;
5304 
5305 	ctx->clone->locked_operation_in_progress = false;
5306 	ctx->clone->md_ro = ctx->clone_md_ro;
5307 
5308 	spdk_blob_close(ctx->clone, _spdk_delete_snapshot_cleanup_snapshot, ctx);
5309 }
5310 
5311 static void
5312 _spdk_delete_snapshot_unfreeze_cpl(void *cb_arg, int bserrno)
5313 {
5314 	struct delete_snapshot_ctx *ctx = cb_arg;
5315 
5316 	if (bserrno) {
5317 		ctx->bserrno = bserrno;
5318 		_spdk_delete_snapshot_cleanup_clone(ctx, 0);
5319 		return;
5320 	}
5321 
5322 	ctx->clone->locked_operation_in_progress = false;
5323 	spdk_blob_close(ctx->clone, _spdk_delete_blob_cleanup_finish, ctx);
5324 }
5325 
5326 static void
5327 _spdk_delete_snapshot_sync_snapshot_cpl(void *cb_arg, int bserrno)
5328 {
5329 	struct delete_snapshot_ctx *ctx = cb_arg;
5330 	struct spdk_blob_list *parent_snapshot_entry = NULL;
5331 	struct spdk_blob_list *snapshot_entry = NULL;
5332 	struct spdk_blob_list *clone_entry = NULL;
5333 	struct spdk_blob_list *snapshot_clone_entry = NULL;
5334 
5335 	if (bserrno) {
5336 		SPDK_ERRLOG("Failed to sync MD on blob\n");
5337 		ctx->bserrno = bserrno;
5338 		_spdk_delete_snapshot_cleanup_clone(ctx, 0);
5339 		return;
5340 	}
5341 
5342 	/* Get snapshot entry for the snapshot we want to remove */
5343 	snapshot_entry = _spdk_bs_get_snapshot_entry(ctx->snapshot->bs, ctx->snapshot->id);
5344 
5345 	assert(snapshot_entry != NULL);
5346 
5347 	/* Remove clone entry in this snapshot (at this point there can be only one clone) */
5348 	clone_entry = TAILQ_FIRST(&snapshot_entry->clones);
5349 	assert(clone_entry != NULL);
5350 	TAILQ_REMOVE(&snapshot_entry->clones, clone_entry, link);
5351 	snapshot_entry->clone_count--;
5352 	assert(TAILQ_EMPTY(&snapshot_entry->clones));
5353 
5354 	if (ctx->snapshot->parent_id != SPDK_BLOBID_INVALID) {
5355 		/* This snapshot is at the same time a clone of another snapshot - we need to
5356 		 * update parent snapshot (remove current clone, add new one inherited from
5357 		 * the snapshot that is being removed) */
5358 
5359 		/* Get snapshot entry for parent snapshot and clone entry within that snapshot for
5360 		 * snapshot that we are removing */
5361 		_spdk_blob_get_snapshot_and_clone_entries(ctx->snapshot, &parent_snapshot_entry,
5362 				&snapshot_clone_entry);
5363 
5364 		/* Switch clone entry in parent snapshot */
5365 		TAILQ_INSERT_TAIL(&parent_snapshot_entry->clones, clone_entry, link);
5366 		TAILQ_REMOVE(&parent_snapshot_entry->clones, snapshot_clone_entry, link);
5367 		free(snapshot_clone_entry);
5368 	} else {
5369 		/* No parent snapshot - just remove clone entry */
5370 		free(clone_entry);
5371 	}
5372 
5373 	/* Restore md_ro flags */
5374 	ctx->clone->md_ro = ctx->clone_md_ro;
5375 	ctx->snapshot->md_ro = ctx->snapshot_md_ro;
5376 
5377 	_spdk_blob_unfreeze_io(ctx->clone, _spdk_delete_snapshot_unfreeze_cpl, ctx);
5378 }
5379 
5380 static void
5381 _spdk_delete_snapshot_sync_clone_cpl(void *cb_arg, int bserrno)
5382 {
5383 	struct delete_snapshot_ctx *ctx = cb_arg;
5384 	uint64_t i;
5385 
5386 	ctx->snapshot->md_ro = false;
5387 
5388 	if (bserrno) {
5389 		SPDK_ERRLOG("Failed to sync MD on clone\n");
5390 		ctx->bserrno = bserrno;
5391 
5392 		/* Restore snapshot to previous state */
5393 		bserrno = _spdk_blob_remove_xattr(ctx->snapshot, SNAPSHOT_PENDING_REMOVAL, true);
5394 		if (bserrno != 0) {
5395 			_spdk_delete_snapshot_cleanup_clone(ctx, bserrno);
5396 			return;
5397 		}
5398 
5399 		spdk_blob_sync_md(ctx->snapshot, _spdk_delete_snapshot_cleanup_clone, ctx);
5400 		return;
5401 	}
5402 
5403 	/* Clear cluster map entries for snapshot */
5404 	for (i = 0; i < ctx->snapshot->active.num_clusters && i < ctx->clone->active.num_clusters; i++) {
5405 		if (ctx->clone->active.clusters[i] == ctx->snapshot->active.clusters[i]) {
5406 			ctx->snapshot->active.clusters[i] = 0;
5407 		}
5408 	}
5409 
5410 	ctx->snapshot->state = SPDK_BLOB_STATE_DIRTY;
5411 
5412 	if (ctx->parent_snapshot_entry != NULL) {
5413 		ctx->snapshot->back_bs_dev = NULL;
5414 	}
5415 
5416 	spdk_blob_sync_md(ctx->snapshot, _spdk_delete_snapshot_sync_snapshot_cpl, ctx);
5417 }
5418 
5419 static void
5420 _spdk_delete_snapshot_sync_snapshot_xattr_cpl(void *cb_arg, int bserrno)
5421 {
5422 	struct delete_snapshot_ctx *ctx = cb_arg;
5423 	uint64_t i;
5424 
5425 	/* Temporarily override md_ro flag for clone for MD modification */
5426 	ctx->clone_md_ro = ctx->clone->md_ro;
5427 	ctx->clone->md_ro = false;
5428 
5429 	if (bserrno) {
5430 		SPDK_ERRLOG("Failed to sync MD with xattr on blob\n");
5431 		ctx->bserrno = bserrno;
5432 		_spdk_delete_snapshot_cleanup_clone(ctx, 0);
5433 		return;
5434 	}
5435 
5436 	/* Copy snapshot map to clone map (only unallocated clusters in clone) */
5437 	for (i = 0; i < ctx->snapshot->active.num_clusters && i < ctx->clone->active.num_clusters; i++) {
5438 		if (ctx->clone->active.clusters[i] == 0) {
5439 			ctx->clone->active.clusters[i] = ctx->snapshot->active.clusters[i];
5440 		}
5441 	}
5442 
5443 	/* Delete old backing bs_dev from clone (related to snapshot that will be removed) */
5444 	ctx->clone->back_bs_dev->destroy(ctx->clone->back_bs_dev);
5445 
5446 	/* Set/remove snapshot xattr and switch parent ID and backing bs_dev on clone... */
5447 	if (ctx->parent_snapshot_entry != NULL) {
5448 		/* ...to parent snapshot */
5449 		ctx->clone->parent_id = ctx->parent_snapshot_entry->id;
5450 		ctx->clone->back_bs_dev = ctx->snapshot->back_bs_dev;
5451 		_spdk_blob_set_xattr(ctx->clone, BLOB_SNAPSHOT, &ctx->parent_snapshot_entry->id,
5452 				     sizeof(spdk_blob_id),
5453 				     true);
5454 	} else {
5455 		/* ...to blobid invalid and zeroes dev */
5456 		ctx->clone->parent_id = SPDK_BLOBID_INVALID;
5457 		ctx->clone->back_bs_dev = spdk_bs_create_zeroes_dev();
5458 		_spdk_blob_remove_xattr(ctx->clone, BLOB_SNAPSHOT, true);
5459 	}
5460 
5461 	spdk_blob_sync_md(ctx->clone, _spdk_delete_snapshot_sync_clone_cpl, ctx);
5462 }
5463 
5464 static void
5465 _spdk_delete_snapshot_freeze_io_cb(void *cb_arg, int bserrno)
5466 {
5467 	struct delete_snapshot_ctx *ctx = cb_arg;
5468 
5469 	if (bserrno) {
5470 		SPDK_ERRLOG("Failed to freeze I/O on clone\n");
5471 		ctx->bserrno = bserrno;
5472 		_spdk_delete_snapshot_cleanup_clone(ctx, 0);
5473 		return;
5474 	}
5475 
5476 	/* Temporarily override md_ro flag for snapshot for MD modification */
5477 	ctx->snapshot_md_ro = ctx->snapshot->md_ro;
5478 	ctx->snapshot->md_ro = false;
5479 
5480 	/* Mark blob as pending for removal for power failure safety, use clone id for recovery */
5481 	ctx->bserrno = _spdk_blob_set_xattr(ctx->snapshot, SNAPSHOT_PENDING_REMOVAL, &ctx->clone->id,
5482 					    sizeof(spdk_blob_id), true);
5483 	if (ctx->bserrno != 0) {
5484 		_spdk_delete_snapshot_cleanup_clone(ctx, 0);
5485 		return;
5486 	}
5487 
5488 	spdk_blob_sync_md(ctx->snapshot, _spdk_delete_snapshot_sync_snapshot_xattr_cpl, ctx);
5489 }
5490 
5491 static void
5492 _spdk_delete_snapshot_open_clone_cb(void *cb_arg, struct spdk_blob *clone, int bserrno)
5493 {
5494 	struct delete_snapshot_ctx *ctx = cb_arg;
5495 
5496 	if (bserrno) {
5497 		SPDK_ERRLOG("Failed to open clone\n");
5498 		ctx->bserrno = bserrno;
5499 		_spdk_delete_snapshot_cleanup_snapshot(ctx, 0);
5500 		return;
5501 	}
5502 
5503 	ctx->clone = clone;
5504 
5505 	if (clone->locked_operation_in_progress) {
5506 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot remove blob - another operation in progress on its clone\n");
5507 		ctx->bserrno = -EBUSY;
5508 		spdk_blob_close(ctx->clone, _spdk_delete_snapshot_cleanup_snapshot, ctx);
5509 		return;
5510 	}
5511 
5512 	clone->locked_operation_in_progress = true;
5513 
5514 	_spdk_blob_freeze_io(clone, _spdk_delete_snapshot_freeze_io_cb, ctx);
5515 }
5516 
5517 static void
5518 _spdk_update_clone_on_snapshot_deletion(struct spdk_blob *snapshot, struct delete_snapshot_ctx *ctx)
5519 {
5520 	struct spdk_blob_list *snapshot_entry = NULL;
5521 	struct spdk_blob_list *clone_entry = NULL;
5522 	struct spdk_blob_list *snapshot_clone_entry = NULL;
5523 
5524 	/* Get snapshot entry for the snapshot we want to remove */
5525 	snapshot_entry = _spdk_bs_get_snapshot_entry(snapshot->bs, snapshot->id);
5526 
5527 	assert(snapshot_entry != NULL);
5528 
5529 	/* Get clone of the snapshot (at this point there can be only one clone) */
5530 	clone_entry = TAILQ_FIRST(&snapshot_entry->clones);
5531 	assert(snapshot_entry->clone_count == 1);
5532 	assert(clone_entry != NULL);
5533 
5534 	/* Get snapshot entry for parent snapshot and clone entry within that snapshot for
5535 	 * snapshot that we are removing */
5536 	_spdk_blob_get_snapshot_and_clone_entries(snapshot, &ctx->parent_snapshot_entry,
5537 			&snapshot_clone_entry);
5538 
5539 	spdk_bs_open_blob(snapshot->bs, clone_entry->id, _spdk_delete_snapshot_open_clone_cb, ctx);
5540 }
5541 
5542 static void
5543 _spdk_bs_delete_blob_finish(void *cb_arg, struct spdk_blob *blob, int bserrno)
5544 {
5545 	spdk_bs_sequence_t *seq = cb_arg;
5546 	struct spdk_blob_list *snapshot_entry = NULL;
5547 	uint32_t page_num;
5548 
5549 	if (bserrno) {
5550 		SPDK_ERRLOG("Failed to remove blob\n");
5551 		spdk_bs_sequence_finish(seq, bserrno);
5552 		return;
5553 	}
5554 
5555 	/* Remove snapshot from the list */
5556 	snapshot_entry = _spdk_bs_get_snapshot_entry(blob->bs, blob->id);
5557 	if (snapshot_entry != NULL) {
5558 		TAILQ_REMOVE(&blob->bs->snapshots, snapshot_entry, link);
5559 		free(snapshot_entry);
5560 	}
5561 
5562 	page_num = _spdk_bs_blobid_to_page(blob->id);
5563 	spdk_bit_array_clear(blob->bs->used_blobids, page_num);
5564 	blob->state = SPDK_BLOB_STATE_DIRTY;
5565 	blob->active.num_pages = 0;
5566 	_spdk_blob_resize(blob, 0);
5567 
5568 	_spdk_blob_persist(seq, blob, _spdk_bs_delete_persist_cpl, blob);
5569 }
5570 
5571 static int
5572 _spdk_bs_is_blob_deletable(struct spdk_blob *blob, bool *update_clone)
5573 {
5574 	struct spdk_blob_list *snapshot_entry = NULL;
5575 	struct spdk_blob_list *clone_entry = NULL;
5576 	struct spdk_blob *clone = NULL;
5577 	bool has_one_clone = false;
5578 
5579 	/* Check if this is a snapshot with clones */
5580 	snapshot_entry = _spdk_bs_get_snapshot_entry(blob->bs, blob->id);
5581 	if (snapshot_entry != NULL) {
5582 		if (snapshot_entry->clone_count > 1) {
5583 			SPDK_ERRLOG("Cannot remove snapshot with more than one clone\n");
5584 			return -EBUSY;
5585 		} else if (snapshot_entry->clone_count == 1) {
5586 			has_one_clone = true;
5587 		}
5588 	}
5589 
5590 	/* Check if someone has this blob open (besides this delete context):
5591 	 * - open_ref = 1 - only this context opened blob, so it is ok to remove it
5592 	 * - open_ref <= 2 && has_one_clone = true - clone is holding snapshot
5593 	 *	and that is ok, because we will update it accordingly */
5594 	if (blob->open_ref <= 2 && has_one_clone) {
5595 		clone_entry = TAILQ_FIRST(&snapshot_entry->clones);
5596 		assert(clone_entry != NULL);
5597 		clone = _spdk_blob_lookup(blob->bs, clone_entry->id);
5598 
5599 		if (blob->open_ref == 2 && clone == NULL) {
5600 			/* Clone is closed and someone else opened this blob */
5601 			SPDK_ERRLOG("Cannot remove snapshot because it is open\n");
5602 			return -EBUSY;
5603 		}
5604 
5605 		*update_clone = true;
5606 		return 0;
5607 	}
5608 
5609 	if (blob->open_ref > 1) {
5610 		SPDK_ERRLOG("Cannot remove snapshot because it is open\n");
5611 		return -EBUSY;
5612 	}
5613 
5614 	assert(has_one_clone == false);
5615 	*update_clone = false;
5616 	return 0;
5617 }
5618 
5619 static void
5620 _spdk_bs_delete_enomem_close_cpl(void *cb_arg, int bserrno)
5621 {
5622 	spdk_bs_sequence_t *seq = cb_arg;
5623 
5624 	spdk_bs_sequence_finish(seq, -ENOMEM);
5625 }
5626 
5627 static void
5628 _spdk_bs_delete_open_cpl(void *cb_arg, struct spdk_blob *blob, int bserrno)
5629 {
5630 	spdk_bs_sequence_t *seq = cb_arg;
5631 	struct delete_snapshot_ctx *ctx;
5632 	bool update_clone = false;
5633 
5634 	if (bserrno != 0) {
5635 		spdk_bs_sequence_finish(seq, bserrno);
5636 		return;
5637 	}
5638 
5639 	_spdk_blob_verify_md_op(blob);
5640 
5641 	ctx = calloc(1, sizeof(*ctx));
5642 	if (ctx == NULL) {
5643 		spdk_blob_close(blob, _spdk_bs_delete_enomem_close_cpl, seq);
5644 		return;
5645 	}
5646 
5647 	ctx->snapshot = blob;
5648 	ctx->cb_fn = _spdk_bs_delete_blob_finish;
5649 	ctx->cb_arg = seq;
5650 
5651 	/* Check if blob can be removed and if it is a snapshot with clone on top of it */
5652 	ctx->bserrno = _spdk_bs_is_blob_deletable(blob, &update_clone);
5653 	if (ctx->bserrno) {
5654 		spdk_blob_close(blob, _spdk_delete_blob_cleanup_finish, ctx);
5655 		return;
5656 	}
5657 
5658 	if (blob->locked_operation_in_progress) {
5659 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Cannot remove blob - another operation in progress\n");
5660 		ctx->bserrno = -EBUSY;
5661 		spdk_blob_close(blob, _spdk_delete_blob_cleanup_finish, ctx);
5662 		return;
5663 	}
5664 
5665 	blob->locked_operation_in_progress = true;
5666 
5667 	/*
5668 	 * Remove the blob from the blob_store list now, to ensure it does not
5669 	 *  get returned after this point by _spdk_blob_lookup().
5670 	 */
5671 	TAILQ_REMOVE(&blob->bs->blobs, blob, link);
5672 
5673 	if (update_clone) {
5674 		/* This blob is a snapshot with active clone - update clone first */
5675 		_spdk_update_clone_on_snapshot_deletion(blob, ctx);
5676 	} else {
5677 		/* This blob does not have any clones - just remove it */
5678 		_spdk_bs_blob_list_remove(blob);
5679 		_spdk_bs_delete_blob_finish(seq, blob, 0);
5680 		free(ctx);
5681 	}
5682 }
5683 
5684 void
5685 spdk_bs_delete_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
5686 		    spdk_blob_op_complete cb_fn, void *cb_arg)
5687 {
5688 	struct spdk_bs_cpl	cpl;
5689 	spdk_bs_sequence_t	*seq;
5690 
5691 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Deleting blob %lu\n", blobid);
5692 
5693 	assert(spdk_get_thread() == bs->md_thread);
5694 
5695 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5696 	cpl.u.blob_basic.cb_fn = cb_fn;
5697 	cpl.u.blob_basic.cb_arg = cb_arg;
5698 
5699 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
5700 	if (!seq) {
5701 		cb_fn(cb_arg, -ENOMEM);
5702 		return;
5703 	}
5704 
5705 	spdk_bs_open_blob(bs, blobid, _spdk_bs_delete_open_cpl, seq);
5706 }
5707 
5708 /* END spdk_bs_delete_blob */
5709 
5710 /* START spdk_bs_open_blob */
5711 
5712 static void
5713 _spdk_bs_open_blob_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5714 {
5715 	struct spdk_blob *blob = cb_arg;
5716 
5717 	if (bserrno != 0) {
5718 		_spdk_blob_free(blob);
5719 		seq->cpl.u.blob_handle.blob = NULL;
5720 		spdk_bs_sequence_finish(seq, bserrno);
5721 		return;
5722 	}
5723 
5724 	blob->open_ref++;
5725 
5726 	TAILQ_INSERT_HEAD(&blob->bs->blobs, blob, link);
5727 
5728 	spdk_bs_sequence_finish(seq, bserrno);
5729 }
5730 
5731 static void _spdk_bs_open_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
5732 			       struct spdk_blob_open_opts *opts, spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5733 {
5734 	struct spdk_blob		*blob;
5735 	struct spdk_bs_cpl		cpl;
5736 	struct spdk_blob_open_opts	opts_default;
5737 	spdk_bs_sequence_t		*seq;
5738 	uint32_t			page_num;
5739 
5740 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Opening blob %lu\n", blobid);
5741 	assert(spdk_get_thread() == bs->md_thread);
5742 
5743 	page_num = _spdk_bs_blobid_to_page(blobid);
5744 	if (spdk_bit_array_get(bs->used_blobids, page_num) == false) {
5745 		/* Invalid blobid */
5746 		cb_fn(cb_arg, NULL, -ENOENT);
5747 		return;
5748 	}
5749 
5750 	blob = _spdk_blob_lookup(bs, blobid);
5751 	if (blob) {
5752 		blob->open_ref++;
5753 		cb_fn(cb_arg, blob, 0);
5754 		return;
5755 	}
5756 
5757 	blob = _spdk_blob_alloc(bs, blobid);
5758 	if (!blob) {
5759 		cb_fn(cb_arg, NULL, -ENOMEM);
5760 		return;
5761 	}
5762 
5763 	if (!opts) {
5764 		spdk_blob_open_opts_init(&opts_default);
5765 		opts = &opts_default;
5766 	}
5767 
5768 	blob->clear_method = opts->clear_method;
5769 
5770 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_HANDLE;
5771 	cpl.u.blob_handle.cb_fn = cb_fn;
5772 	cpl.u.blob_handle.cb_arg = cb_arg;
5773 	cpl.u.blob_handle.blob = blob;
5774 
5775 	seq = spdk_bs_sequence_start(bs->md_channel, &cpl);
5776 	if (!seq) {
5777 		_spdk_blob_free(blob);
5778 		cb_fn(cb_arg, NULL, -ENOMEM);
5779 		return;
5780 	}
5781 
5782 	_spdk_blob_load(seq, blob, _spdk_bs_open_blob_cpl, blob);
5783 }
5784 
5785 void spdk_bs_open_blob(struct spdk_blob_store *bs, spdk_blob_id blobid,
5786 		       spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5787 {
5788 	_spdk_bs_open_blob(bs, blobid, NULL, cb_fn, cb_arg);
5789 }
5790 
5791 void spdk_bs_open_blob_ext(struct spdk_blob_store *bs, spdk_blob_id blobid,
5792 			   struct spdk_blob_open_opts *opts, spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
5793 {
5794 	_spdk_bs_open_blob(bs, blobid, opts, cb_fn, cb_arg);
5795 }
5796 
5797 /* END spdk_bs_open_blob */
5798 
5799 /* START spdk_blob_set_read_only */
5800 int spdk_blob_set_read_only(struct spdk_blob *blob)
5801 {
5802 	_spdk_blob_verify_md_op(blob);
5803 
5804 	blob->data_ro_flags |= SPDK_BLOB_READ_ONLY;
5805 
5806 	blob->state = SPDK_BLOB_STATE_DIRTY;
5807 	return 0;
5808 }
5809 /* END spdk_blob_set_read_only */
5810 
5811 /* START spdk_blob_sync_md */
5812 
5813 static void
5814 _spdk_blob_sync_md_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5815 {
5816 	struct spdk_blob *blob = cb_arg;
5817 
5818 	if (bserrno == 0 && (blob->data_ro_flags & SPDK_BLOB_READ_ONLY)) {
5819 		blob->data_ro = true;
5820 		blob->md_ro = true;
5821 	}
5822 
5823 	spdk_bs_sequence_finish(seq, bserrno);
5824 }
5825 
5826 static void
5827 _spdk_blob_sync_md(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
5828 {
5829 	struct spdk_bs_cpl	cpl;
5830 	spdk_bs_sequence_t	*seq;
5831 
5832 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5833 	cpl.u.blob_basic.cb_fn = cb_fn;
5834 	cpl.u.blob_basic.cb_arg = cb_arg;
5835 
5836 	seq = spdk_bs_sequence_start(blob->bs->md_channel, &cpl);
5837 	if (!seq) {
5838 		cb_fn(cb_arg, -ENOMEM);
5839 		return;
5840 	}
5841 
5842 	_spdk_blob_persist(seq, blob, _spdk_blob_sync_md_cpl, blob);
5843 }
5844 
5845 void
5846 spdk_blob_sync_md(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
5847 {
5848 	_spdk_blob_verify_md_op(blob);
5849 
5850 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Syncing blob %lu\n", blob->id);
5851 
5852 	if (blob->md_ro) {
5853 		assert(blob->state == SPDK_BLOB_STATE_CLEAN);
5854 		cb_fn(cb_arg, 0);
5855 		return;
5856 	}
5857 
5858 	_spdk_blob_sync_md(blob, cb_fn, cb_arg);
5859 }
5860 
5861 /* END spdk_blob_sync_md */
5862 
5863 struct spdk_blob_insert_cluster_ctx {
5864 	struct spdk_thread	*thread;
5865 	struct spdk_blob	*blob;
5866 	uint32_t		cluster_num;	/* cluster index in blob */
5867 	uint32_t		cluster;	/* cluster on disk */
5868 	int			rc;
5869 	spdk_blob_op_complete	cb_fn;
5870 	void			*cb_arg;
5871 };
5872 
5873 static void
5874 _spdk_blob_insert_cluster_msg_cpl(void *arg)
5875 {
5876 	struct spdk_blob_insert_cluster_ctx *ctx = arg;
5877 
5878 	ctx->cb_fn(ctx->cb_arg, ctx->rc);
5879 	free(ctx);
5880 }
5881 
5882 static void
5883 _spdk_blob_insert_cluster_msg_cb(void *arg, int bserrno)
5884 {
5885 	struct spdk_blob_insert_cluster_ctx *ctx = arg;
5886 
5887 	ctx->rc = bserrno;
5888 	spdk_thread_send_msg(ctx->thread, _spdk_blob_insert_cluster_msg_cpl, ctx);
5889 }
5890 
5891 static void
5892 _spdk_blob_insert_cluster_msg(void *arg)
5893 {
5894 	struct spdk_blob_insert_cluster_ctx *ctx = arg;
5895 
5896 	ctx->rc = _spdk_blob_insert_cluster(ctx->blob, ctx->cluster_num, ctx->cluster);
5897 	if (ctx->rc != 0) {
5898 		spdk_thread_send_msg(ctx->thread, _spdk_blob_insert_cluster_msg_cpl, ctx);
5899 		return;
5900 	}
5901 
5902 	ctx->blob->state = SPDK_BLOB_STATE_DIRTY;
5903 	_spdk_blob_sync_md(ctx->blob, _spdk_blob_insert_cluster_msg_cb, ctx);
5904 }
5905 
5906 static void
5907 _spdk_blob_insert_cluster_on_md_thread(struct spdk_blob *blob, uint32_t cluster_num,
5908 				       uint64_t cluster, spdk_blob_op_complete cb_fn, void *cb_arg)
5909 {
5910 	struct spdk_blob_insert_cluster_ctx *ctx;
5911 
5912 	ctx = calloc(1, sizeof(*ctx));
5913 	if (ctx == NULL) {
5914 		cb_fn(cb_arg, -ENOMEM);
5915 		return;
5916 	}
5917 
5918 	ctx->thread = spdk_get_thread();
5919 	ctx->blob = blob;
5920 	ctx->cluster_num = cluster_num;
5921 	ctx->cluster = cluster;
5922 	ctx->cb_fn = cb_fn;
5923 	ctx->cb_arg = cb_arg;
5924 
5925 	spdk_thread_send_msg(blob->bs->md_thread, _spdk_blob_insert_cluster_msg, ctx);
5926 }
5927 
5928 /* START spdk_blob_close */
5929 
5930 static void
5931 _spdk_blob_close_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserrno)
5932 {
5933 	struct spdk_blob *blob = cb_arg;
5934 
5935 	if (bserrno == 0) {
5936 		blob->open_ref--;
5937 		if (blob->open_ref == 0) {
5938 			/*
5939 			 * Blobs with active.num_pages == 0 are deleted blobs.
5940 			 *  these blobs are removed from the blob_store list
5941 			 *  when the deletion process starts - so don't try to
5942 			 *  remove them again.
5943 			 */
5944 			if (blob->active.num_pages > 0) {
5945 				TAILQ_REMOVE(&blob->bs->blobs, blob, link);
5946 			}
5947 			_spdk_blob_free(blob);
5948 		}
5949 	}
5950 
5951 	spdk_bs_sequence_finish(seq, bserrno);
5952 }
5953 
5954 void spdk_blob_close(struct spdk_blob *blob, spdk_blob_op_complete cb_fn, void *cb_arg)
5955 {
5956 	struct spdk_bs_cpl	cpl;
5957 	spdk_bs_sequence_t	*seq;
5958 
5959 	_spdk_blob_verify_md_op(blob);
5960 
5961 	SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Closing blob %lu\n", blob->id);
5962 
5963 	if (blob->open_ref == 0) {
5964 		cb_fn(cb_arg, -EBADF);
5965 		return;
5966 	}
5967 
5968 	cpl.type = SPDK_BS_CPL_TYPE_BLOB_BASIC;
5969 	cpl.u.blob_basic.cb_fn = cb_fn;
5970 	cpl.u.blob_basic.cb_arg = cb_arg;
5971 
5972 	seq = spdk_bs_sequence_start(blob->bs->md_channel, &cpl);
5973 	if (!seq) {
5974 		cb_fn(cb_arg, -ENOMEM);
5975 		return;
5976 	}
5977 
5978 	/* Sync metadata */
5979 	_spdk_blob_persist(seq, blob, _spdk_blob_close_cpl, blob);
5980 }
5981 
5982 /* END spdk_blob_close */
5983 
5984 struct spdk_io_channel *spdk_bs_alloc_io_channel(struct spdk_blob_store *bs)
5985 {
5986 	return spdk_get_io_channel(bs);
5987 }
5988 
5989 void spdk_bs_free_io_channel(struct spdk_io_channel *channel)
5990 {
5991 	spdk_put_io_channel(channel);
5992 }
5993 
5994 void spdk_blob_io_unmap(struct spdk_blob *blob, struct spdk_io_channel *channel,
5995 			uint64_t offset, uint64_t length, spdk_blob_op_complete cb_fn, void *cb_arg)
5996 {
5997 	_spdk_blob_request_submit_op(blob, channel, NULL, offset, length, cb_fn, cb_arg,
5998 				     SPDK_BLOB_UNMAP);
5999 }
6000 
6001 void spdk_blob_io_write_zeroes(struct spdk_blob *blob, struct spdk_io_channel *channel,
6002 			       uint64_t offset, uint64_t length, spdk_blob_op_complete cb_fn, void *cb_arg)
6003 {
6004 	_spdk_blob_request_submit_op(blob, channel, NULL, offset, length, cb_fn, cb_arg,
6005 				     SPDK_BLOB_WRITE_ZEROES);
6006 }
6007 
6008 void spdk_blob_io_write(struct spdk_blob *blob, struct spdk_io_channel *channel,
6009 			void *payload, uint64_t offset, uint64_t length,
6010 			spdk_blob_op_complete cb_fn, void *cb_arg)
6011 {
6012 	_spdk_blob_request_submit_op(blob, channel, payload, offset, length, cb_fn, cb_arg,
6013 				     SPDK_BLOB_WRITE);
6014 }
6015 
6016 void spdk_blob_io_read(struct spdk_blob *blob, struct spdk_io_channel *channel,
6017 		       void *payload, uint64_t offset, uint64_t length,
6018 		       spdk_blob_op_complete cb_fn, void *cb_arg)
6019 {
6020 	_spdk_blob_request_submit_op(blob, channel, payload, offset, length, cb_fn, cb_arg,
6021 				     SPDK_BLOB_READ);
6022 }
6023 
6024 void spdk_blob_io_writev(struct spdk_blob *blob, struct spdk_io_channel *channel,
6025 			 struct iovec *iov, int iovcnt, uint64_t offset, uint64_t length,
6026 			 spdk_blob_op_complete cb_fn, void *cb_arg)
6027 {
6028 	_spdk_blob_request_submit_rw_iov(blob, channel, iov, iovcnt, offset, length, cb_fn, cb_arg, false);
6029 }
6030 
6031 void spdk_blob_io_readv(struct spdk_blob *blob, struct spdk_io_channel *channel,
6032 			struct iovec *iov, int iovcnt, uint64_t offset, uint64_t length,
6033 			spdk_blob_op_complete cb_fn, void *cb_arg)
6034 {
6035 	_spdk_blob_request_submit_rw_iov(blob, channel, iov, iovcnt, offset, length, cb_fn, cb_arg, true);
6036 }
6037 
6038 struct spdk_bs_iter_ctx {
6039 	int64_t page_num;
6040 	struct spdk_blob_store *bs;
6041 
6042 	spdk_blob_op_with_handle_complete cb_fn;
6043 	void *cb_arg;
6044 };
6045 
6046 static void
6047 _spdk_bs_iter_cpl(void *cb_arg, struct spdk_blob *_blob, int bserrno)
6048 {
6049 	struct spdk_bs_iter_ctx *ctx = cb_arg;
6050 	struct spdk_blob_store *bs = ctx->bs;
6051 	spdk_blob_id id;
6052 
6053 	if (bserrno == 0) {
6054 		ctx->cb_fn(ctx->cb_arg, _blob, bserrno);
6055 		free(ctx);
6056 		return;
6057 	}
6058 
6059 	ctx->page_num++;
6060 	ctx->page_num = spdk_bit_array_find_first_set(bs->used_blobids, ctx->page_num);
6061 	if (ctx->page_num >= spdk_bit_array_capacity(bs->used_blobids)) {
6062 		ctx->cb_fn(ctx->cb_arg, NULL, -ENOENT);
6063 		free(ctx);
6064 		return;
6065 	}
6066 
6067 	id = _spdk_bs_page_to_blobid(ctx->page_num);
6068 
6069 	spdk_bs_open_blob(bs, id, _spdk_bs_iter_cpl, ctx);
6070 }
6071 
6072 void
6073 spdk_bs_iter_first(struct spdk_blob_store *bs,
6074 		   spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
6075 {
6076 	struct spdk_bs_iter_ctx *ctx;
6077 
6078 	ctx = calloc(1, sizeof(*ctx));
6079 	if (!ctx) {
6080 		cb_fn(cb_arg, NULL, -ENOMEM);
6081 		return;
6082 	}
6083 
6084 	ctx->page_num = -1;
6085 	ctx->bs = bs;
6086 	ctx->cb_fn = cb_fn;
6087 	ctx->cb_arg = cb_arg;
6088 
6089 	_spdk_bs_iter_cpl(ctx, NULL, -1);
6090 }
6091 
6092 static void
6093 _spdk_bs_iter_close_cpl(void *cb_arg, int bserrno)
6094 {
6095 	struct spdk_bs_iter_ctx *ctx = cb_arg;
6096 
6097 	_spdk_bs_iter_cpl(ctx, NULL, -1);
6098 }
6099 
6100 void
6101 spdk_bs_iter_next(struct spdk_blob_store *bs, struct spdk_blob *blob,
6102 		  spdk_blob_op_with_handle_complete cb_fn, void *cb_arg)
6103 {
6104 	struct spdk_bs_iter_ctx *ctx;
6105 
6106 	assert(blob != NULL);
6107 
6108 	ctx = calloc(1, sizeof(*ctx));
6109 	if (!ctx) {
6110 		cb_fn(cb_arg, NULL, -ENOMEM);
6111 		return;
6112 	}
6113 
6114 	ctx->page_num = _spdk_bs_blobid_to_page(blob->id);
6115 	ctx->bs = bs;
6116 	ctx->cb_fn = cb_fn;
6117 	ctx->cb_arg = cb_arg;
6118 
6119 	/* Close the existing blob */
6120 	spdk_blob_close(blob, _spdk_bs_iter_close_cpl, ctx);
6121 }
6122 
6123 static int
6124 _spdk_blob_set_xattr(struct spdk_blob *blob, const char *name, const void *value,
6125 		     uint16_t value_len, bool internal)
6126 {
6127 	struct spdk_xattr_tailq *xattrs;
6128 	struct spdk_xattr	*xattr;
6129 	size_t			desc_size;
6130 
6131 	_spdk_blob_verify_md_op(blob);
6132 
6133 	if (blob->md_ro) {
6134 		return -EPERM;
6135 	}
6136 
6137 	desc_size = sizeof(struct spdk_blob_md_descriptor_xattr) + strlen(name) + value_len;
6138 	if (desc_size > SPDK_BS_MAX_DESC_SIZE) {
6139 		SPDK_DEBUGLOG(SPDK_LOG_BLOB, "Xattr '%s' of size %ld does not fix into single page %ld\n", name,
6140 			      desc_size, SPDK_BS_MAX_DESC_SIZE);
6141 		return -ENOMEM;
6142 	}
6143 
6144 	if (internal) {
6145 		xattrs = &blob->xattrs_internal;
6146 		blob->invalid_flags |= SPDK_BLOB_INTERNAL_XATTR;
6147 	} else {
6148 		xattrs = &blob->xattrs;
6149 	}
6150 
6151 	TAILQ_FOREACH(xattr, xattrs, link) {
6152 		if (!strcmp(name, xattr->name)) {
6153 			free(xattr->value);
6154 			xattr->value_len = value_len;
6155 			xattr->value = malloc(value_len);
6156 			memcpy(xattr->value, value, value_len);
6157 
6158 			blob->state = SPDK_BLOB_STATE_DIRTY;
6159 
6160 			return 0;
6161 		}
6162 	}
6163 
6164 	xattr = calloc(1, sizeof(*xattr));
6165 	if (!xattr) {
6166 		return -ENOMEM;
6167 	}
6168 	xattr->name = strdup(name);
6169 	xattr->value_len = value_len;
6170 	xattr->value = malloc(value_len);
6171 	memcpy(xattr->value, value, value_len);
6172 	TAILQ_INSERT_TAIL(xattrs, xattr, link);
6173 
6174 	blob->state = SPDK_BLOB_STATE_DIRTY;
6175 
6176 	return 0;
6177 }
6178 
6179 int
6180 spdk_blob_set_xattr(struct spdk_blob *blob, const char *name, const void *value,
6181 		    uint16_t value_len)
6182 {
6183 	return _spdk_blob_set_xattr(blob, name, value, value_len, false);
6184 }
6185 
6186 static int
6187 _spdk_blob_remove_xattr(struct spdk_blob *blob, const char *name, bool internal)
6188 {
6189 	struct spdk_xattr_tailq *xattrs;
6190 	struct spdk_xattr	*xattr;
6191 
6192 	_spdk_blob_verify_md_op(blob);
6193 
6194 	if (blob->md_ro) {
6195 		return -EPERM;
6196 	}
6197 	xattrs = internal ? &blob->xattrs_internal : &blob->xattrs;
6198 
6199 	TAILQ_FOREACH(xattr, xattrs, link) {
6200 		if (!strcmp(name, xattr->name)) {
6201 			TAILQ_REMOVE(xattrs, xattr, link);
6202 			free(xattr->value);
6203 			free(xattr->name);
6204 			free(xattr);
6205 
6206 			if (internal && TAILQ_EMPTY(&blob->xattrs_internal)) {
6207 				blob->invalid_flags &= ~SPDK_BLOB_INTERNAL_XATTR;
6208 			}
6209 			blob->state = SPDK_BLOB_STATE_DIRTY;
6210 
6211 			return 0;
6212 		}
6213 	}
6214 
6215 	return -ENOENT;
6216 }
6217 
6218 int
6219 spdk_blob_remove_xattr(struct spdk_blob *blob, const char *name)
6220 {
6221 	return _spdk_blob_remove_xattr(blob, name, false);
6222 }
6223 
6224 static int
6225 _spdk_blob_get_xattr_value(struct spdk_blob *blob, const char *name,
6226 			   const void **value, size_t *value_len, bool internal)
6227 {
6228 	struct spdk_xattr	*xattr;
6229 	struct spdk_xattr_tailq *xattrs;
6230 
6231 	xattrs = internal ? &blob->xattrs_internal : &blob->xattrs;
6232 
6233 	TAILQ_FOREACH(xattr, xattrs, link) {
6234 		if (!strcmp(name, xattr->name)) {
6235 			*value = xattr->value;
6236 			*value_len = xattr->value_len;
6237 			return 0;
6238 		}
6239 	}
6240 	return -ENOENT;
6241 }
6242 
6243 int
6244 spdk_blob_get_xattr_value(struct spdk_blob *blob, const char *name,
6245 			  const void **value, size_t *value_len)
6246 {
6247 	_spdk_blob_verify_md_op(blob);
6248 
6249 	return _spdk_blob_get_xattr_value(blob, name, value, value_len, false);
6250 }
6251 
6252 struct spdk_xattr_names {
6253 	uint32_t	count;
6254 	const char	*names[0];
6255 };
6256 
6257 static int
6258 _spdk_blob_get_xattr_names(struct spdk_xattr_tailq *xattrs, struct spdk_xattr_names **names)
6259 {
6260 	struct spdk_xattr	*xattr;
6261 	int			count = 0;
6262 
6263 	TAILQ_FOREACH(xattr, xattrs, link) {
6264 		count++;
6265 	}
6266 
6267 	*names = calloc(1, sizeof(struct spdk_xattr_names) + count * sizeof(char *));
6268 	if (*names == NULL) {
6269 		return -ENOMEM;
6270 	}
6271 
6272 	TAILQ_FOREACH(xattr, xattrs, link) {
6273 		(*names)->names[(*names)->count++] = xattr->name;
6274 	}
6275 
6276 	return 0;
6277 }
6278 
6279 int
6280 spdk_blob_get_xattr_names(struct spdk_blob *blob, struct spdk_xattr_names **names)
6281 {
6282 	_spdk_blob_verify_md_op(blob);
6283 
6284 	return _spdk_blob_get_xattr_names(&blob->xattrs, names);
6285 }
6286 
6287 uint32_t
6288 spdk_xattr_names_get_count(struct spdk_xattr_names *names)
6289 {
6290 	assert(names != NULL);
6291 
6292 	return names->count;
6293 }
6294 
6295 const char *
6296 spdk_xattr_names_get_name(struct spdk_xattr_names *names, uint32_t index)
6297 {
6298 	if (index >= names->count) {
6299 		return NULL;
6300 	}
6301 
6302 	return names->names[index];
6303 }
6304 
6305 void
6306 spdk_xattr_names_free(struct spdk_xattr_names *names)
6307 {
6308 	free(names);
6309 }
6310 
6311 struct spdk_bs_type
6312 spdk_bs_get_bstype(struct spdk_blob_store *bs)
6313 {
6314 	return bs->bstype;
6315 }
6316 
6317 void
6318 spdk_bs_set_bstype(struct spdk_blob_store *bs, struct spdk_bs_type bstype)
6319 {
6320 	memcpy(&bs->bstype, &bstype, sizeof(bstype));
6321 }
6322 
6323 bool
6324 spdk_blob_is_read_only(struct spdk_blob *blob)
6325 {
6326 	assert(blob != NULL);
6327 	return (blob->data_ro || blob->md_ro);
6328 }
6329 
6330 bool
6331 spdk_blob_is_snapshot(struct spdk_blob *blob)
6332 {
6333 	struct spdk_blob_list *snapshot_entry;
6334 
6335 	assert(blob != NULL);
6336 
6337 	snapshot_entry = _spdk_bs_get_snapshot_entry(blob->bs, blob->id);
6338 	if (snapshot_entry == NULL) {
6339 		return false;
6340 	}
6341 
6342 	return true;
6343 }
6344 
6345 bool
6346 spdk_blob_is_clone(struct spdk_blob *blob)
6347 {
6348 	assert(blob != NULL);
6349 
6350 	if (blob->parent_id != SPDK_BLOBID_INVALID) {
6351 		assert(spdk_blob_is_thin_provisioned(blob));
6352 		return true;
6353 	}
6354 
6355 	return false;
6356 }
6357 
6358 bool
6359 spdk_blob_is_thin_provisioned(struct spdk_blob *blob)
6360 {
6361 	assert(blob != NULL);
6362 	return !!(blob->invalid_flags & SPDK_BLOB_THIN_PROV);
6363 }
6364 
6365 static void
6366 _spdk_blob_update_clear_method(struct spdk_blob *blob)
6367 {
6368 	enum blob_clear_method stored_cm;
6369 
6370 	assert(blob != NULL);
6371 
6372 	/* If BLOB_CLEAR_WITH_DEFAULT was passed in, use the setting stored
6373 	 * in metadata previously.  If something other than the default was
6374 	 * specified, ignore stored value and used what was passed in.
6375 	 */
6376 	stored_cm = ((blob->md_ro_flags & SPDK_BLOB_CLEAR_METHOD) >> SPDK_BLOB_CLEAR_METHOD_SHIFT);
6377 
6378 	if (blob->clear_method == BLOB_CLEAR_WITH_DEFAULT) {
6379 		blob->clear_method = stored_cm;
6380 	} else if (blob->clear_method != stored_cm) {
6381 		SPDK_WARNLOG("Using passed in clear method 0x%x instead of stored value of 0x%x\n",
6382 			     blob->clear_method, stored_cm);
6383 	}
6384 }
6385 
6386 spdk_blob_id
6387 spdk_blob_get_parent_snapshot(struct spdk_blob_store *bs, spdk_blob_id blob_id)
6388 {
6389 	struct spdk_blob_list *snapshot_entry = NULL;
6390 	struct spdk_blob_list *clone_entry = NULL;
6391 
6392 	TAILQ_FOREACH(snapshot_entry, &bs->snapshots, link) {
6393 		TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
6394 			if (clone_entry->id == blob_id) {
6395 				return snapshot_entry->id;
6396 			}
6397 		}
6398 	}
6399 
6400 	return SPDK_BLOBID_INVALID;
6401 }
6402 
6403 int
6404 spdk_blob_get_clones(struct spdk_blob_store *bs, spdk_blob_id blobid, spdk_blob_id *ids,
6405 		     size_t *count)
6406 {
6407 	struct spdk_blob_list *snapshot_entry, *clone_entry;
6408 	size_t n;
6409 
6410 	snapshot_entry = _spdk_bs_get_snapshot_entry(bs, blobid);
6411 	if (snapshot_entry == NULL) {
6412 		*count = 0;
6413 		return 0;
6414 	}
6415 
6416 	if (ids == NULL || *count < snapshot_entry->clone_count) {
6417 		*count = snapshot_entry->clone_count;
6418 		return -ENOMEM;
6419 	}
6420 	*count = snapshot_entry->clone_count;
6421 
6422 	n = 0;
6423 	TAILQ_FOREACH(clone_entry, &snapshot_entry->clones, link) {
6424 		ids[n++] = clone_entry->id;
6425 	}
6426 
6427 	return 0;
6428 }
6429 
6430 SPDK_LOG_REGISTER_COMPONENT("blob", SPDK_LOG_BLOB)
6431