xref: /spdk/module/bdev/raid/bdev_raid.c (revision 60982c759db49b4f4579f16e3b24df0725ba4b94)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2018 Intel Corporation.
3  *   All rights reserved.
4  *   Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
5  */
6 
7 #include "bdev_raid.h"
8 #include "spdk/env.h"
9 #include "spdk/thread.h"
10 #include "spdk/log.h"
11 #include "spdk/string.h"
12 #include "spdk/util.h"
13 #include "spdk/json.h"
14 
15 static bool g_shutdown_started = false;
16 
17 /* List of all raid bdevs */
18 struct raid_all_tailq g_raid_bdev_list = TAILQ_HEAD_INITIALIZER(g_raid_bdev_list);
19 
20 static TAILQ_HEAD(, raid_bdev_module) g_raid_modules = TAILQ_HEAD_INITIALIZER(g_raid_modules);
21 
22 static struct raid_bdev_module *
23 raid_bdev_module_find(enum raid_level level)
24 {
25 	struct raid_bdev_module *raid_module;
26 
27 	TAILQ_FOREACH(raid_module, &g_raid_modules, link) {
28 		if (raid_module->level == level) {
29 			return raid_module;
30 		}
31 	}
32 
33 	return NULL;
34 }
35 
36 void
37 raid_bdev_module_list_add(struct raid_bdev_module *raid_module)
38 {
39 	if (raid_bdev_module_find(raid_module->level) != NULL) {
40 		SPDK_ERRLOG("module for raid level '%s' already registered.\n",
41 			    raid_bdev_level_to_str(raid_module->level));
42 		assert(false);
43 	} else {
44 		TAILQ_INSERT_TAIL(&g_raid_modules, raid_module, link);
45 	}
46 }
47 
48 /* Function declarations */
49 static void	raid_bdev_examine(struct spdk_bdev *bdev);
50 static int	raid_bdev_init(void);
51 static void	raid_bdev_deconfigure(struct raid_bdev *raid_bdev,
52 				      raid_bdev_destruct_cb cb_fn, void *cb_arg);
53 
54 /*
55  * brief:
56  * raid_bdev_create_cb function is a cb function for raid bdev which creates the
57  * hierarchy from raid bdev to base bdev io channels. It will be called per core
58  * params:
59  * io_device - pointer to raid bdev io device represented by raid_bdev
60  * ctx_buf - pointer to context buffer for raid bdev io channel
61  * returns:
62  * 0 - success
63  * non zero - failure
64  */
65 static int
66 raid_bdev_create_cb(void *io_device, void *ctx_buf)
67 {
68 	struct raid_bdev            *raid_bdev = io_device;
69 	struct raid_bdev_io_channel *raid_ch = ctx_buf;
70 	uint8_t i;
71 	int ret = 0;
72 
73 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_create_cb, %p\n", raid_ch);
74 
75 	assert(raid_bdev != NULL);
76 	assert(raid_bdev->state == RAID_BDEV_STATE_ONLINE);
77 
78 	raid_ch->num_channels = raid_bdev->num_base_bdevs;
79 
80 	raid_ch->base_channel = calloc(raid_ch->num_channels,
81 				       sizeof(struct spdk_io_channel *));
82 	if (!raid_ch->base_channel) {
83 		SPDK_ERRLOG("Unable to allocate base bdevs io channel\n");
84 		return -ENOMEM;
85 	}
86 
87 	spdk_spin_lock(&raid_bdev->base_bdev_lock);
88 	for (i = 0; i < raid_ch->num_channels; i++) {
89 		/*
90 		 * Get the spdk_io_channel for all the base bdevs. This is used during
91 		 * split logic to send the respective child bdev ios to respective base
92 		 * bdev io channel.
93 		 */
94 		if (raid_bdev->base_bdev_info[i].desc == NULL) {
95 			continue;
96 		}
97 		raid_ch->base_channel[i] = spdk_bdev_get_io_channel(
98 						   raid_bdev->base_bdev_info[i].desc);
99 		if (!raid_ch->base_channel[i]) {
100 			SPDK_ERRLOG("Unable to create io channel for base bdev\n");
101 			ret = -ENOMEM;
102 			break;
103 		}
104 	}
105 	spdk_spin_unlock(&raid_bdev->base_bdev_lock);
106 
107 	if (!ret && raid_bdev->module->get_io_channel) {
108 		raid_ch->module_channel = raid_bdev->module->get_io_channel(raid_bdev);
109 		if (!raid_ch->module_channel) {
110 			SPDK_ERRLOG("Unable to create io channel for raid module\n");
111 			ret = -ENOMEM;
112 		}
113 	}
114 
115 	if (ret) {
116 		for (i = 0; i < raid_ch->num_channels; i++) {
117 			if (raid_ch->base_channel[i] != NULL) {
118 				spdk_put_io_channel(raid_ch->base_channel[i]);
119 			}
120 		}
121 		free(raid_ch->base_channel);
122 		raid_ch->base_channel = NULL;
123 	}
124 	return ret;
125 }
126 
127 /*
128  * brief:
129  * raid_bdev_destroy_cb function is a cb function for raid bdev which deletes the
130  * hierarchy from raid bdev to base bdev io channels. It will be called per core
131  * params:
132  * io_device - pointer to raid bdev io device represented by raid_bdev
133  * ctx_buf - pointer to context buffer for raid bdev io channel
134  * returns:
135  * none
136  */
137 static void
138 raid_bdev_destroy_cb(void *io_device, void *ctx_buf)
139 {
140 	struct raid_bdev_io_channel *raid_ch = ctx_buf;
141 	uint8_t i;
142 
143 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_destroy_cb\n");
144 
145 	assert(raid_ch != NULL);
146 	assert(raid_ch->base_channel);
147 
148 	if (raid_ch->module_channel) {
149 		spdk_put_io_channel(raid_ch->module_channel);
150 	}
151 
152 	for (i = 0; i < raid_ch->num_channels; i++) {
153 		/* Free base bdev channels */
154 		if (raid_ch->base_channel[i] != NULL) {
155 			spdk_put_io_channel(raid_ch->base_channel[i]);
156 		}
157 	}
158 	free(raid_ch->base_channel);
159 	raid_ch->base_channel = NULL;
160 }
161 
162 /*
163  * brief:
164  * raid_bdev_cleanup is used to cleanup raid_bdev related data
165  * structures.
166  * params:
167  * raid_bdev - pointer to raid_bdev
168  * returns:
169  * none
170  */
171 static void
172 raid_bdev_cleanup(struct raid_bdev *raid_bdev)
173 {
174 	struct raid_base_bdev_info *base_info;
175 
176 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_cleanup, %p name %s, state %s\n",
177 		      raid_bdev, raid_bdev->bdev.name, raid_bdev_state_to_str(raid_bdev->state));
178 	assert(raid_bdev->state != RAID_BDEV_STATE_ONLINE);
179 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
180 
181 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
182 		assert(base_info->desc == NULL);
183 		free(base_info->name);
184 	}
185 
186 	TAILQ_REMOVE(&g_raid_bdev_list, raid_bdev, global_link);
187 	free(raid_bdev->base_bdev_info);
188 }
189 
190 static void
191 raid_bdev_free(struct raid_bdev *raid_bdev)
192 {
193 	spdk_spin_destroy(&raid_bdev->base_bdev_lock);
194 	free(raid_bdev->bdev.name);
195 	free(raid_bdev);
196 }
197 
198 static void
199 raid_bdev_cleanup_and_free(struct raid_bdev *raid_bdev)
200 {
201 	raid_bdev_cleanup(raid_bdev);
202 	raid_bdev_free(raid_bdev);
203 }
204 
205 /*
206  * brief:
207  * free resource of base bdev for raid bdev
208  * params:
209  * base_info - raid base bdev info
210  * returns:
211  * 0 - success
212  * non zero - failure
213  */
214 static void
215 raid_bdev_free_base_bdev_resource(struct raid_base_bdev_info *base_info)
216 {
217 	struct raid_bdev *raid_bdev = base_info->raid_bdev;
218 
219 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
220 
221 	free(base_info->name);
222 	base_info->name = NULL;
223 
224 	if (base_info->desc == NULL) {
225 		return;
226 	}
227 
228 	spdk_bdev_module_release_bdev(spdk_bdev_desc_get_bdev(base_info->desc));
229 	spdk_bdev_close(base_info->desc);
230 	base_info->desc = NULL;
231 
232 	assert(raid_bdev->num_base_bdevs_discovered);
233 	raid_bdev->num_base_bdevs_discovered--;
234 }
235 
236 static void
237 raid_bdev_io_device_unregister_cb(void *io_device)
238 {
239 	struct raid_bdev *raid_bdev = io_device;
240 
241 	if (raid_bdev->num_base_bdevs_discovered == 0) {
242 		/* Free raid_bdev when there are no base bdevs left */
243 		SPDK_DEBUGLOG(bdev_raid, "raid bdev base bdevs is 0, going to free all in destruct\n");
244 		raid_bdev_cleanup(raid_bdev);
245 		spdk_bdev_destruct_done(&raid_bdev->bdev, 0);
246 		raid_bdev_free(raid_bdev);
247 	} else {
248 		spdk_bdev_destruct_done(&raid_bdev->bdev, 0);
249 	}
250 }
251 
252 void
253 raid_bdev_module_stop_done(struct raid_bdev *raid_bdev)
254 {
255 	if (raid_bdev->state != RAID_BDEV_STATE_CONFIGURING) {
256 		spdk_io_device_unregister(raid_bdev, raid_bdev_io_device_unregister_cb);
257 	}
258 }
259 
260 static void
261 _raid_bdev_destruct(void *ctxt)
262 {
263 	struct raid_bdev *raid_bdev = ctxt;
264 	struct raid_base_bdev_info *base_info;
265 
266 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_destruct\n");
267 
268 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
269 		/*
270 		 * Close all base bdev descriptors for which call has come from below
271 		 * layers.  Also close the descriptors if we have started shutdown.
272 		 */
273 		if (g_shutdown_started || base_info->remove_scheduled == true) {
274 			raid_bdev_free_base_bdev_resource(base_info);
275 		}
276 	}
277 
278 	if (g_shutdown_started) {
279 		raid_bdev->state = RAID_BDEV_STATE_OFFLINE;
280 	}
281 
282 	if (raid_bdev->module->stop != NULL) {
283 		if (raid_bdev->module->stop(raid_bdev) == false) {
284 			return;
285 		}
286 	}
287 
288 	raid_bdev_module_stop_done(raid_bdev);
289 }
290 
291 static int
292 raid_bdev_destruct(void *ctx)
293 {
294 	spdk_thread_exec_msg(spdk_thread_get_app_thread(), _raid_bdev_destruct, ctx);
295 
296 	return 1;
297 }
298 
299 void
300 raid_bdev_io_complete(struct raid_bdev_io *raid_io, enum spdk_bdev_io_status status)
301 {
302 	struct spdk_bdev_io *bdev_io = spdk_bdev_io_from_ctx(raid_io);
303 
304 	spdk_bdev_io_complete(bdev_io, status);
305 }
306 
307 /*
308  * brief:
309  * raid_bdev_io_complete_part - signal the completion of a part of the expected
310  * base bdev IOs and complete the raid_io if this is the final expected IO.
311  * The caller should first set raid_io->base_bdev_io_remaining. This function
312  * will decrement this counter by the value of the 'completed' parameter and
313  * complete the raid_io if the counter reaches 0. The caller is free to
314  * interpret the 'base_bdev_io_remaining' and 'completed' values as needed,
315  * it can represent e.g. blocks or IOs.
316  * params:
317  * raid_io - pointer to raid_bdev_io
318  * completed - the part of the raid_io that has been completed
319  * status - status of the base IO
320  * returns:
321  * true - if the raid_io is completed
322  * false - otherwise
323  */
324 bool
325 raid_bdev_io_complete_part(struct raid_bdev_io *raid_io, uint64_t completed,
326 			   enum spdk_bdev_io_status status)
327 {
328 	assert(raid_io->base_bdev_io_remaining >= completed);
329 	raid_io->base_bdev_io_remaining -= completed;
330 
331 	if (status != SPDK_BDEV_IO_STATUS_SUCCESS) {
332 		raid_io->base_bdev_io_status = status;
333 	}
334 
335 	if (raid_io->base_bdev_io_remaining == 0) {
336 		raid_bdev_io_complete(raid_io, raid_io->base_bdev_io_status);
337 		return true;
338 	} else {
339 		return false;
340 	}
341 }
342 
343 /*
344  * brief:
345  * raid_bdev_queue_io_wait function processes the IO which failed to submit.
346  * It will try to queue the IOs after storing the context to bdev wait queue logic.
347  * params:
348  * raid_io - pointer to raid_bdev_io
349  * bdev - the block device that the IO is submitted to
350  * ch - io channel
351  * cb_fn - callback when the spdk_bdev_io for bdev becomes available
352  * returns:
353  * none
354  */
355 void
356 raid_bdev_queue_io_wait(struct raid_bdev_io *raid_io, struct spdk_bdev *bdev,
357 			struct spdk_io_channel *ch, spdk_bdev_io_wait_cb cb_fn)
358 {
359 	raid_io->waitq_entry.bdev = bdev;
360 	raid_io->waitq_entry.cb_fn = cb_fn;
361 	raid_io->waitq_entry.cb_arg = raid_io;
362 	spdk_bdev_queue_io_wait(bdev, ch, &raid_io->waitq_entry);
363 }
364 
365 static void
366 raid_base_bdev_reset_complete(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
367 {
368 	struct raid_bdev_io *raid_io = cb_arg;
369 
370 	spdk_bdev_free_io(bdev_io);
371 
372 	raid_bdev_io_complete_part(raid_io, 1, success ?
373 				   SPDK_BDEV_IO_STATUS_SUCCESS :
374 				   SPDK_BDEV_IO_STATUS_FAILED);
375 }
376 
377 static void raid_bdev_submit_reset_request(struct raid_bdev_io *raid_io);
378 
379 static void
380 _raid_bdev_submit_reset_request(void *_raid_io)
381 {
382 	struct raid_bdev_io *raid_io = _raid_io;
383 
384 	raid_bdev_submit_reset_request(raid_io);
385 }
386 
387 /*
388  * brief:
389  * raid_bdev_submit_reset_request function submits reset requests
390  * to member disks; it will submit as many as possible unless a reset fails with -ENOMEM, in
391  * which case it will queue it for later submission
392  * params:
393  * raid_io
394  * returns:
395  * none
396  */
397 static void
398 raid_bdev_submit_reset_request(struct raid_bdev_io *raid_io)
399 {
400 	struct raid_bdev		*raid_bdev;
401 	int				ret;
402 	uint8_t				i;
403 	struct raid_base_bdev_info	*base_info;
404 	struct spdk_io_channel		*base_ch;
405 
406 	raid_bdev = raid_io->raid_bdev;
407 
408 	if (raid_io->base_bdev_io_remaining == 0) {
409 		raid_io->base_bdev_io_remaining = raid_bdev->num_base_bdevs;
410 	}
411 
412 	for (i = raid_io->base_bdev_io_submitted; i < raid_bdev->num_base_bdevs; i++) {
413 		base_info = &raid_bdev->base_bdev_info[i];
414 		base_ch = raid_io->raid_ch->base_channel[i];
415 		if (base_ch == NULL) {
416 			raid_io->base_bdev_io_submitted++;
417 			raid_bdev_io_complete_part(raid_io, 1, SPDK_BDEV_IO_STATUS_SUCCESS);
418 			continue;
419 		}
420 		ret = spdk_bdev_reset(base_info->desc, base_ch,
421 				      raid_base_bdev_reset_complete, raid_io);
422 		if (ret == 0) {
423 			raid_io->base_bdev_io_submitted++;
424 		} else if (ret == -ENOMEM) {
425 			raid_bdev_queue_io_wait(raid_io, spdk_bdev_desc_get_bdev(base_info->desc),
426 						base_ch, _raid_bdev_submit_reset_request);
427 			return;
428 		} else {
429 			SPDK_ERRLOG("bdev io submit error not due to ENOMEM, it should not happen\n");
430 			assert(false);
431 			raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
432 			return;
433 		}
434 	}
435 }
436 
437 /*
438  * brief:
439  * Callback function to spdk_bdev_io_get_buf.
440  * params:
441  * ch - pointer to raid bdev io channel
442  * bdev_io - pointer to parent bdev_io on raid bdev device
443  * success - True if buffer is allocated or false otherwise.
444  * returns:
445  * none
446  */
447 static void
448 raid_bdev_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io,
449 		     bool success)
450 {
451 	struct raid_bdev_io *raid_io = (struct raid_bdev_io *)bdev_io->driver_ctx;
452 
453 	if (!success) {
454 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
455 		return;
456 	}
457 
458 	raid_io->raid_bdev->module->submit_rw_request(raid_io);
459 }
460 
461 /*
462  * brief:
463  * raid_bdev_submit_request function is the submit_request function pointer of
464  * raid bdev function table. This is used to submit the io on raid_bdev to below
465  * layers.
466  * params:
467  * ch - pointer to raid bdev io channel
468  * bdev_io - pointer to parent bdev_io on raid bdev device
469  * returns:
470  * none
471  */
472 static void
473 raid_bdev_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
474 {
475 	struct raid_bdev_io *raid_io = (struct raid_bdev_io *)bdev_io->driver_ctx;
476 
477 	raid_io->raid_bdev = bdev_io->bdev->ctxt;
478 	raid_io->raid_ch = spdk_io_channel_get_ctx(ch);
479 	raid_io->base_bdev_io_remaining = 0;
480 	raid_io->base_bdev_io_submitted = 0;
481 	raid_io->base_bdev_io_status = SPDK_BDEV_IO_STATUS_SUCCESS;
482 
483 	switch (bdev_io->type) {
484 	case SPDK_BDEV_IO_TYPE_READ:
485 		spdk_bdev_io_get_buf(bdev_io, raid_bdev_get_buf_cb,
486 				     bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
487 		break;
488 	case SPDK_BDEV_IO_TYPE_WRITE:
489 		raid_io->raid_bdev->module->submit_rw_request(raid_io);
490 		break;
491 
492 	case SPDK_BDEV_IO_TYPE_RESET:
493 		raid_bdev_submit_reset_request(raid_io);
494 		break;
495 
496 	case SPDK_BDEV_IO_TYPE_FLUSH:
497 	case SPDK_BDEV_IO_TYPE_UNMAP:
498 		raid_io->raid_bdev->module->submit_null_payload_request(raid_io);
499 		break;
500 
501 	default:
502 		SPDK_ERRLOG("submit request, invalid io type %u\n", bdev_io->type);
503 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
504 		break;
505 	}
506 }
507 
508 /*
509  * brief:
510  * _raid_bdev_io_type_supported checks whether io_type is supported in
511  * all base bdev modules of raid bdev module. If anyone among the base_bdevs
512  * doesn't support, the raid device doesn't supports.
513  *
514  * params:
515  * raid_bdev - pointer to raid bdev context
516  * io_type - io type
517  * returns:
518  * true - io_type is supported
519  * false - io_type is not supported
520  */
521 inline static bool
522 _raid_bdev_io_type_supported(struct raid_bdev *raid_bdev, enum spdk_bdev_io_type io_type)
523 {
524 	struct raid_base_bdev_info *base_info;
525 
526 	if (io_type == SPDK_BDEV_IO_TYPE_FLUSH ||
527 	    io_type == SPDK_BDEV_IO_TYPE_UNMAP) {
528 		if (raid_bdev->module->submit_null_payload_request == NULL) {
529 			return false;
530 		}
531 	}
532 
533 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
534 		if (base_info->desc == NULL) {
535 			continue;
536 		}
537 
538 		if (spdk_bdev_io_type_supported(spdk_bdev_desc_get_bdev(base_info->desc), io_type) == false) {
539 			return false;
540 		}
541 	}
542 
543 	return true;
544 }
545 
546 /*
547  * brief:
548  * raid_bdev_io_type_supported is the io_supported function for bdev function
549  * table which returns whether the particular io type is supported or not by
550  * raid bdev module
551  * params:
552  * ctx - pointer to raid bdev context
553  * type - io type
554  * returns:
555  * true - io_type is supported
556  * false - io_type is not supported
557  */
558 static bool
559 raid_bdev_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
560 {
561 	switch (io_type) {
562 	case SPDK_BDEV_IO_TYPE_READ:
563 	case SPDK_BDEV_IO_TYPE_WRITE:
564 		return true;
565 
566 	case SPDK_BDEV_IO_TYPE_FLUSH:
567 	case SPDK_BDEV_IO_TYPE_RESET:
568 	case SPDK_BDEV_IO_TYPE_UNMAP:
569 		return _raid_bdev_io_type_supported(ctx, io_type);
570 
571 	default:
572 		return false;
573 	}
574 
575 	return false;
576 }
577 
578 /*
579  * brief:
580  * raid_bdev_get_io_channel is the get_io_channel function table pointer for
581  * raid bdev. This is used to return the io channel for this raid bdev
582  * params:
583  * ctxt - pointer to raid_bdev
584  * returns:
585  * pointer to io channel for raid bdev
586  */
587 static struct spdk_io_channel *
588 raid_bdev_get_io_channel(void *ctxt)
589 {
590 	struct raid_bdev *raid_bdev = ctxt;
591 
592 	return spdk_get_io_channel(raid_bdev);
593 }
594 
595 void
596 raid_bdev_write_info_json(struct raid_bdev *raid_bdev, struct spdk_json_write_ctx *w)
597 {
598 	struct raid_base_bdev_info *base_info;
599 
600 	assert(raid_bdev != NULL);
601 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
602 
603 	spdk_json_write_named_uint32(w, "strip_size_kb", raid_bdev->strip_size_kb);
604 	spdk_json_write_named_string(w, "state", raid_bdev_state_to_str(raid_bdev->state));
605 	spdk_json_write_named_string(w, "raid_level", raid_bdev_level_to_str(raid_bdev->level));
606 	spdk_json_write_named_uint32(w, "num_base_bdevs", raid_bdev->num_base_bdevs);
607 	spdk_json_write_named_uint32(w, "num_base_bdevs_discovered", raid_bdev->num_base_bdevs_discovered);
608 	spdk_json_write_name(w, "base_bdevs_list");
609 	spdk_json_write_array_begin(w);
610 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
611 		if (base_info->desc) {
612 			spdk_json_write_string(w, spdk_bdev_desc_get_bdev(base_info->desc)->name);
613 		} else {
614 			spdk_json_write_null(w);
615 		}
616 	}
617 	spdk_json_write_array_end(w);
618 }
619 
620 /*
621  * brief:
622  * raid_bdev_dump_info_json is the function table pointer for raid bdev
623  * params:
624  * ctx - pointer to raid_bdev
625  * w - pointer to json context
626  * returns:
627  * 0 - success
628  * non zero - failure
629  */
630 static int
631 raid_bdev_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
632 {
633 	struct raid_bdev *raid_bdev = ctx;
634 
635 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_dump_config_json\n");
636 
637 	/* Dump the raid bdev configuration related information */
638 	spdk_json_write_named_object_begin(w, "raid");
639 	raid_bdev_write_info_json(raid_bdev, w);
640 	spdk_json_write_object_end(w);
641 
642 	return 0;
643 }
644 
645 /*
646  * brief:
647  * raid_bdev_write_config_json is the function table pointer for raid bdev
648  * params:
649  * bdev - pointer to spdk_bdev
650  * w - pointer to json context
651  * returns:
652  * none
653  */
654 static void
655 raid_bdev_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
656 {
657 	struct raid_bdev *raid_bdev = bdev->ctxt;
658 	struct raid_base_bdev_info *base_info;
659 
660 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
661 
662 	spdk_json_write_object_begin(w);
663 
664 	spdk_json_write_named_string(w, "method", "bdev_raid_create");
665 
666 	spdk_json_write_named_object_begin(w, "params");
667 	spdk_json_write_named_string(w, "name", bdev->name);
668 	spdk_json_write_named_uint32(w, "strip_size_kb", raid_bdev->strip_size_kb);
669 	spdk_json_write_named_string(w, "raid_level", raid_bdev_level_to_str(raid_bdev->level));
670 
671 	spdk_json_write_named_array_begin(w, "base_bdevs");
672 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
673 		if (base_info->desc) {
674 			spdk_json_write_string(w, spdk_bdev_desc_get_bdev(base_info->desc)->name);
675 		}
676 	}
677 	spdk_json_write_array_end(w);
678 	spdk_json_write_object_end(w);
679 
680 	spdk_json_write_object_end(w);
681 }
682 
683 static int
684 raid_bdev_get_memory_domains(void *ctx, struct spdk_memory_domain **domains, int array_size)
685 {
686 	struct raid_bdev *raid_bdev = ctx;
687 	struct raid_base_bdev_info *base_info;
688 	int domains_count = 0, rc = 0;
689 
690 	if (raid_bdev->module->memory_domains_supported == false) {
691 		return 0;
692 	}
693 
694 	spdk_spin_lock(&raid_bdev->base_bdev_lock);
695 
696 	/* First loop to get the number of memory domains */
697 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
698 		if (base_info->desc == NULL) {
699 			continue;
700 		}
701 		rc = spdk_bdev_get_memory_domains(spdk_bdev_desc_get_bdev(base_info->desc), NULL, 0);
702 		if (rc < 0) {
703 			goto out;
704 		}
705 		domains_count += rc;
706 	}
707 
708 	if (!domains || array_size < domains_count) {
709 		goto out;
710 	}
711 
712 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
713 		if (base_info->desc == NULL) {
714 			continue;
715 		}
716 		rc = spdk_bdev_get_memory_domains(spdk_bdev_desc_get_bdev(base_info->desc), domains, array_size);
717 		if (rc < 0) {
718 			goto out;
719 		}
720 		domains += rc;
721 		array_size -= rc;
722 	}
723 out:
724 	spdk_spin_unlock(&raid_bdev->base_bdev_lock);
725 
726 	if (rc < 0) {
727 		return rc;
728 	}
729 
730 	return domains_count;
731 }
732 
733 /* g_raid_bdev_fn_table is the function table for raid bdev */
734 static const struct spdk_bdev_fn_table g_raid_bdev_fn_table = {
735 	.destruct		= raid_bdev_destruct,
736 	.submit_request		= raid_bdev_submit_request,
737 	.io_type_supported	= raid_bdev_io_type_supported,
738 	.get_io_channel		= raid_bdev_get_io_channel,
739 	.dump_info_json		= raid_bdev_dump_info_json,
740 	.write_config_json	= raid_bdev_write_config_json,
741 	.get_memory_domains	= raid_bdev_get_memory_domains,
742 };
743 
744 struct raid_bdev *
745 raid_bdev_find_by_name(const char *name)
746 {
747 	struct raid_bdev *raid_bdev;
748 
749 	TAILQ_FOREACH(raid_bdev, &g_raid_bdev_list, global_link) {
750 		if (strcmp(raid_bdev->bdev.name, name) == 0) {
751 			return raid_bdev;
752 		}
753 	}
754 
755 	return NULL;
756 }
757 
758 static struct {
759 	const char *name;
760 	enum raid_level value;
761 } g_raid_level_names[] = {
762 	{ "raid0", RAID0 },
763 	{ "0", RAID0 },
764 	{ "raid1", RAID1 },
765 	{ "1", RAID1 },
766 	{ "raid5f", RAID5F },
767 	{ "5f", RAID5F },
768 	{ "concat", CONCAT },
769 	{ }
770 };
771 
772 static struct {
773 	const char *name;
774 	enum raid_bdev_state value;
775 } g_raid_state_names[] = {
776 	{ "online", RAID_BDEV_STATE_ONLINE },
777 	{ "configuring", RAID_BDEV_STATE_CONFIGURING },
778 	{ "offline", RAID_BDEV_STATE_OFFLINE },
779 	{ }
780 };
781 
782 /* We have to use the typedef in the function declaration to appease astyle. */
783 typedef enum raid_level raid_level_t;
784 typedef enum raid_bdev_state raid_bdev_state_t;
785 
786 raid_level_t
787 raid_bdev_str_to_level(const char *str)
788 {
789 	unsigned int i;
790 
791 	assert(str != NULL);
792 
793 	for (i = 0; g_raid_level_names[i].name != NULL; i++) {
794 		if (strcasecmp(g_raid_level_names[i].name, str) == 0) {
795 			return g_raid_level_names[i].value;
796 		}
797 	}
798 
799 	return INVALID_RAID_LEVEL;
800 }
801 
802 const char *
803 raid_bdev_level_to_str(enum raid_level level)
804 {
805 	unsigned int i;
806 
807 	for (i = 0; g_raid_level_names[i].name != NULL; i++) {
808 		if (g_raid_level_names[i].value == level) {
809 			return g_raid_level_names[i].name;
810 		}
811 	}
812 
813 	return "";
814 }
815 
816 raid_bdev_state_t
817 raid_bdev_str_to_state(const char *str)
818 {
819 	unsigned int i;
820 
821 	assert(str != NULL);
822 
823 	for (i = 0; g_raid_state_names[i].name != NULL; i++) {
824 		if (strcasecmp(g_raid_state_names[i].name, str) == 0) {
825 			return g_raid_state_names[i].value;
826 		}
827 	}
828 
829 	return RAID_BDEV_STATE_MAX;
830 }
831 
832 const char *
833 raid_bdev_state_to_str(enum raid_bdev_state state)
834 {
835 	unsigned int i;
836 
837 	for (i = 0; g_raid_state_names[i].name != NULL; i++) {
838 		if (g_raid_state_names[i].value == state) {
839 			return g_raid_state_names[i].name;
840 		}
841 	}
842 
843 	assert(false);
844 	return "";
845 }
846 
847 /*
848  * brief:
849  * raid_bdev_fini_start is called when bdev layer is starting the
850  * shutdown process
851  * params:
852  * none
853  * returns:
854  * none
855  */
856 static void
857 raid_bdev_fini_start(void)
858 {
859 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_fini_start\n");
860 	g_shutdown_started = true;
861 }
862 
863 /*
864  * brief:
865  * raid_bdev_exit is called on raid bdev module exit time by bdev layer
866  * params:
867  * none
868  * returns:
869  * none
870  */
871 static void
872 raid_bdev_exit(void)
873 {
874 	struct raid_bdev *raid_bdev, *tmp;
875 
876 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_exit\n");
877 
878 	TAILQ_FOREACH_SAFE(raid_bdev, &g_raid_bdev_list, global_link, tmp) {
879 		raid_bdev_cleanup_and_free(raid_bdev);
880 	}
881 }
882 
883 /*
884  * brief:
885  * raid_bdev_get_ctx_size is used to return the context size of bdev_io for raid
886  * module
887  * params:
888  * none
889  * returns:
890  * size of spdk_bdev_io context for raid
891  */
892 static int
893 raid_bdev_get_ctx_size(void)
894 {
895 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_get_ctx_size\n");
896 	return sizeof(struct raid_bdev_io);
897 }
898 
899 static struct spdk_bdev_module g_raid_if = {
900 	.name = "raid",
901 	.module_init = raid_bdev_init,
902 	.fini_start = raid_bdev_fini_start,
903 	.module_fini = raid_bdev_exit,
904 	.get_ctx_size = raid_bdev_get_ctx_size,
905 	.examine_config = raid_bdev_examine,
906 	.async_init = false,
907 	.async_fini = false,
908 };
909 SPDK_BDEV_MODULE_REGISTER(raid, &g_raid_if)
910 
911 /*
912  * brief:
913  * raid_bdev_init is the initialization function for raid bdev module
914  * params:
915  * none
916  * returns:
917  * 0 - success
918  * non zero - failure
919  */
920 static int
921 raid_bdev_init(void)
922 {
923 	return 0;
924 }
925 
926 /*
927  * brief:
928  * raid_bdev_create allocates raid bdev based on passed configuration
929  * params:
930  * name - name for raid bdev
931  * strip_size - strip size in KB
932  * num_base_bdevs - number of base bdevs
933  * level - raid level
934  * raid_bdev_out - the created raid bdev
935  * returns:
936  * 0 - success
937  * non zero - failure
938  */
939 int
940 raid_bdev_create(const char *name, uint32_t strip_size, uint8_t num_base_bdevs,
941 		 enum raid_level level, struct raid_bdev **raid_bdev_out, const struct spdk_uuid *uuid)
942 {
943 	struct raid_bdev *raid_bdev;
944 	struct spdk_bdev *raid_bdev_gen;
945 	struct raid_bdev_module *module;
946 	struct raid_base_bdev_info *base_info;
947 	uint8_t min_operational;
948 
949 	if (raid_bdev_find_by_name(name) != NULL) {
950 		SPDK_ERRLOG("Duplicate raid bdev name found: %s\n", name);
951 		return -EEXIST;
952 	}
953 
954 	if (level == RAID1) {
955 		if (strip_size != 0) {
956 			SPDK_ERRLOG("Strip size is not supported by raid1\n");
957 			return -EINVAL;
958 		}
959 	} else if (spdk_u32_is_pow2(strip_size) == false) {
960 		SPDK_ERRLOG("Invalid strip size %" PRIu32 "\n", strip_size);
961 		return -EINVAL;
962 	}
963 
964 	module = raid_bdev_module_find(level);
965 	if (module == NULL) {
966 		SPDK_ERRLOG("Unsupported raid level '%d'\n", level);
967 		return -EINVAL;
968 	}
969 
970 	assert(module->base_bdevs_min != 0);
971 	if (num_base_bdevs < module->base_bdevs_min) {
972 		SPDK_ERRLOG("At least %u base devices required for %s\n",
973 			    module->base_bdevs_min,
974 			    raid_bdev_level_to_str(level));
975 		return -EINVAL;
976 	}
977 
978 	switch (module->base_bdevs_constraint.type) {
979 	case CONSTRAINT_MAX_BASE_BDEVS_REMOVED:
980 		min_operational = num_base_bdevs - module->base_bdevs_constraint.value;
981 		break;
982 	case CONSTRAINT_MIN_BASE_BDEVS_OPERATIONAL:
983 		min_operational = module->base_bdevs_constraint.value;
984 		break;
985 	case CONSTRAINT_UNSET:
986 		if (module->base_bdevs_constraint.value != 0) {
987 			SPDK_ERRLOG("Unexpected constraint value '%u' provided for raid bdev '%s'.\n",
988 				    (uint8_t)module->base_bdevs_constraint.value, name);
989 			return -EINVAL;
990 		}
991 		min_operational = num_base_bdevs;
992 		break;
993 	default:
994 		SPDK_ERRLOG("Unrecognised constraint type '%u' in module for raid level '%s'.\n",
995 			    (uint8_t)module->base_bdevs_constraint.type,
996 			    raid_bdev_level_to_str(module->level));
997 		return -EINVAL;
998 	};
999 
1000 	if (min_operational == 0 || min_operational > num_base_bdevs) {
1001 		SPDK_ERRLOG("Wrong constraint value for raid level '%s'.\n",
1002 			    raid_bdev_level_to_str(module->level));
1003 		return -EINVAL;
1004 	}
1005 
1006 	raid_bdev = calloc(1, sizeof(*raid_bdev));
1007 	if (!raid_bdev) {
1008 		SPDK_ERRLOG("Unable to allocate memory for raid bdev\n");
1009 		return -ENOMEM;
1010 	}
1011 
1012 	raid_bdev->module = module;
1013 	raid_bdev->num_base_bdevs = num_base_bdevs;
1014 	raid_bdev->base_bdev_info = calloc(raid_bdev->num_base_bdevs,
1015 					   sizeof(struct raid_base_bdev_info));
1016 	if (!raid_bdev->base_bdev_info) {
1017 		SPDK_ERRLOG("Unable able to allocate base bdev info\n");
1018 		free(raid_bdev);
1019 		return -ENOMEM;
1020 	}
1021 
1022 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1023 		base_info->raid_bdev = raid_bdev;
1024 	}
1025 
1026 	/* strip_size_kb is from the rpc param.  strip_size is in blocks and used
1027 	 * internally and set later.
1028 	 */
1029 	raid_bdev->strip_size = 0;
1030 	raid_bdev->strip_size_kb = strip_size;
1031 	raid_bdev->state = RAID_BDEV_STATE_CONFIGURING;
1032 	raid_bdev->level = level;
1033 	raid_bdev->min_base_bdevs_operational = min_operational;
1034 
1035 	raid_bdev_gen = &raid_bdev->bdev;
1036 
1037 	raid_bdev_gen->name = strdup(name);
1038 	if (!raid_bdev_gen->name) {
1039 		SPDK_ERRLOG("Unable to allocate name for raid\n");
1040 		free(raid_bdev->base_bdev_info);
1041 		free(raid_bdev);
1042 		return -ENOMEM;
1043 	}
1044 
1045 	spdk_spin_init(&raid_bdev->base_bdev_lock);
1046 
1047 	raid_bdev_gen->product_name = "Raid Volume";
1048 	raid_bdev_gen->ctxt = raid_bdev;
1049 	raid_bdev_gen->fn_table = &g_raid_bdev_fn_table;
1050 	raid_bdev_gen->module = &g_raid_if;
1051 	raid_bdev_gen->write_cache = 0;
1052 
1053 	if (uuid) {
1054 		spdk_uuid_copy(&raid_bdev_gen->uuid, uuid);
1055 	}
1056 
1057 	TAILQ_INSERT_TAIL(&g_raid_bdev_list, raid_bdev, global_link);
1058 
1059 	*raid_bdev_out = raid_bdev;
1060 
1061 	return 0;
1062 }
1063 
1064 /*
1065  * brief:
1066  * Check underlying block devices against support for metadata. Do not configure
1067  * md support when parameters from block devices are inconsistent.
1068  * params:
1069  * raid_bdev - pointer to raid bdev
1070  * returns:
1071  * 0 - The raid bdev md parameters were successfully configured.
1072  * non zero - Failed to configure md.
1073  */
1074 static int
1075 raid_bdev_configure_md(struct raid_bdev *raid_bdev)
1076 {
1077 	struct spdk_bdev *base_bdev;
1078 	uint8_t i;
1079 
1080 	for (i = 0; i < raid_bdev->num_base_bdevs; i++) {
1081 		base_bdev = spdk_bdev_desc_get_bdev(raid_bdev->base_bdev_info[i].desc);
1082 
1083 		if (i == 0) {
1084 			raid_bdev->bdev.md_len = spdk_bdev_get_md_size(base_bdev);
1085 			raid_bdev->bdev.md_interleave = spdk_bdev_is_md_interleaved(base_bdev);
1086 			raid_bdev->bdev.dif_type = spdk_bdev_get_dif_type(base_bdev);
1087 			raid_bdev->bdev.dif_is_head_of_md = spdk_bdev_is_dif_head_of_md(base_bdev);
1088 			raid_bdev->bdev.dif_check_flags = base_bdev->dif_check_flags;
1089 			continue;
1090 		}
1091 
1092 		if (raid_bdev->bdev.md_len != spdk_bdev_get_md_size(base_bdev) ||
1093 		    raid_bdev->bdev.md_interleave != spdk_bdev_is_md_interleaved(base_bdev) ||
1094 		    raid_bdev->bdev.dif_type != spdk_bdev_get_dif_type(base_bdev) ||
1095 		    raid_bdev->bdev.dif_is_head_of_md != spdk_bdev_is_dif_head_of_md(base_bdev) ||
1096 		    raid_bdev->bdev.dif_check_flags != base_bdev->dif_check_flags) {
1097 			SPDK_ERRLOG("base bdevs are configured with different metadata formats\n");
1098 			return -EPERM;
1099 		}
1100 	}
1101 
1102 	return 0;
1103 }
1104 
1105 /*
1106  * brief:
1107  * If raid bdev config is complete, then only register the raid bdev to
1108  * bdev layer and remove this raid bdev from configuring list and
1109  * insert the raid bdev to configured list
1110  * params:
1111  * raid_bdev - pointer to raid bdev
1112  * returns:
1113  * 0 - success
1114  * non zero - failure
1115  */
1116 static int
1117 raid_bdev_configure(struct raid_bdev *raid_bdev)
1118 {
1119 	uint32_t blocklen = 0;
1120 	struct spdk_bdev *raid_bdev_gen;
1121 	struct raid_base_bdev_info *base_info;
1122 	struct spdk_bdev *base_bdev;
1123 	int rc = 0;
1124 
1125 	assert(raid_bdev->state == RAID_BDEV_STATE_CONFIGURING);
1126 	assert(raid_bdev->num_base_bdevs_discovered == raid_bdev->num_base_bdevs);
1127 
1128 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1129 		assert(base_info->desc != NULL);
1130 		base_bdev = spdk_bdev_desc_get_bdev(base_info->desc);
1131 		/* Check blocklen for all base bdevs that it should be same */
1132 		if (blocklen == 0) {
1133 			blocklen = base_bdev->blocklen;
1134 		} else if (blocklen != base_bdev->blocklen) {
1135 			/*
1136 			 * Assumption is that all the base bdevs for any raid bdev should
1137 			 * have same blocklen
1138 			 */
1139 			SPDK_ERRLOG("Blocklen of various bdevs not matching\n");
1140 			return -EINVAL;
1141 		}
1142 	}
1143 	assert(blocklen > 0);
1144 
1145 	/* The strip_size_kb is read in from user in KB. Convert to blocks here for
1146 	 * internal use.
1147 	 */
1148 	raid_bdev->strip_size = (raid_bdev->strip_size_kb * 1024) / blocklen;
1149 	if (raid_bdev->strip_size == 0 && raid_bdev->level != RAID1) {
1150 		SPDK_ERRLOG("Strip size cannot be smaller than the device block size\n");
1151 		return -EINVAL;
1152 	}
1153 	raid_bdev->strip_size_shift = spdk_u32log2(raid_bdev->strip_size);
1154 	raid_bdev->blocklen_shift = spdk_u32log2(blocklen);
1155 
1156 	raid_bdev_gen = &raid_bdev->bdev;
1157 	raid_bdev_gen->blocklen = blocklen;
1158 
1159 	rc = raid_bdev_configure_md(raid_bdev);
1160 	if (rc != 0) {
1161 		SPDK_ERRLOG("raid metadata configuration failed\n");
1162 		return rc;
1163 	}
1164 
1165 	rc = raid_bdev->module->start(raid_bdev);
1166 	if (rc != 0) {
1167 		SPDK_ERRLOG("raid module startup callback failed\n");
1168 		return rc;
1169 	}
1170 	raid_bdev->state = RAID_BDEV_STATE_ONLINE;
1171 	SPDK_DEBUGLOG(bdev_raid, "io device register %p\n", raid_bdev);
1172 	SPDK_DEBUGLOG(bdev_raid, "blockcnt %" PRIu64 ", blocklen %u\n",
1173 		      raid_bdev_gen->blockcnt, raid_bdev_gen->blocklen);
1174 	spdk_io_device_register(raid_bdev, raid_bdev_create_cb, raid_bdev_destroy_cb,
1175 				sizeof(struct raid_bdev_io_channel),
1176 				raid_bdev->bdev.name);
1177 	rc = spdk_bdev_register(raid_bdev_gen);
1178 	if (rc != 0) {
1179 		SPDK_ERRLOG("Unable to register raid bdev and stay at configuring state\n");
1180 		if (raid_bdev->module->stop != NULL) {
1181 			raid_bdev->module->stop(raid_bdev);
1182 		}
1183 		spdk_io_device_unregister(raid_bdev, NULL);
1184 		raid_bdev->state = RAID_BDEV_STATE_CONFIGURING;
1185 		return rc;
1186 	}
1187 	SPDK_DEBUGLOG(bdev_raid, "raid bdev generic %p\n", raid_bdev_gen);
1188 	SPDK_DEBUGLOG(bdev_raid, "raid bdev is created with name %s, raid_bdev %p\n",
1189 		      raid_bdev_gen->name, raid_bdev);
1190 
1191 	return 0;
1192 }
1193 
1194 /*
1195  * brief:
1196  * If raid bdev is online and registered, change the bdev state to
1197  * configuring and unregister this raid device. Queue this raid device
1198  * in configuring list
1199  * params:
1200  * raid_bdev - pointer to raid bdev
1201  * cb_fn - callback function
1202  * cb_arg - argument to callback function
1203  * returns:
1204  * none
1205  */
1206 static void
1207 raid_bdev_deconfigure(struct raid_bdev *raid_bdev, raid_bdev_destruct_cb cb_fn,
1208 		      void *cb_arg)
1209 {
1210 	if (raid_bdev->state != RAID_BDEV_STATE_ONLINE) {
1211 		if (cb_fn) {
1212 			cb_fn(cb_arg, 0);
1213 		}
1214 		return;
1215 	}
1216 
1217 	raid_bdev->state = RAID_BDEV_STATE_OFFLINE;
1218 	assert(raid_bdev->num_base_bdevs_discovered);
1219 	SPDK_DEBUGLOG(bdev_raid, "raid bdev state changing from online to offline\n");
1220 
1221 	spdk_bdev_unregister(&raid_bdev->bdev, cb_fn, cb_arg);
1222 }
1223 
1224 /*
1225  * brief:
1226  * raid_bdev_find_base_info_by_bdev function finds the base bdev info by bdev.
1227  * params:
1228  * base_bdev - pointer to base bdev
1229  * returns:
1230  * base bdev info if found, otherwise NULL.
1231  */
1232 static struct raid_base_bdev_info *
1233 raid_bdev_find_base_info_by_bdev(struct spdk_bdev *base_bdev)
1234 {
1235 	struct raid_bdev *raid_bdev;
1236 	struct raid_base_bdev_info *base_info;
1237 
1238 	TAILQ_FOREACH(raid_bdev, &g_raid_bdev_list, global_link) {
1239 		RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1240 			if (base_info->desc != NULL &&
1241 			    spdk_bdev_desc_get_bdev(base_info->desc) == base_bdev) {
1242 				return base_info;
1243 			}
1244 		}
1245 	}
1246 
1247 	return NULL;
1248 }
1249 
1250 static void
1251 raid_bdev_remove_base_bdev_on_unquiesced(void *ctx, int status)
1252 {
1253 	struct raid_base_bdev_info *base_info = ctx;
1254 	struct raid_bdev *raid_bdev = base_info->raid_bdev;
1255 
1256 	base_info->remove_scheduled = false;
1257 
1258 	if (status != 0) {
1259 		SPDK_ERRLOG("Failed to unquiesce raid bdev %s: %s\n",
1260 			    raid_bdev->bdev.name, spdk_strerror(-status));
1261 		goto out;
1262 	}
1263 
1264 	spdk_spin_lock(&raid_bdev->base_bdev_lock);
1265 	raid_bdev_free_base_bdev_resource(base_info);
1266 	spdk_spin_unlock(&raid_bdev->base_bdev_lock);
1267 out:
1268 	if (base_info->remove_cb != NULL) {
1269 		base_info->remove_cb(base_info->remove_cb_ctx, status);
1270 	}
1271 }
1272 
1273 static void
1274 raid_bdev_channel_remove_base_bdev(struct spdk_io_channel_iter *i)
1275 {
1276 	struct raid_base_bdev_info *base_info = spdk_io_channel_iter_get_ctx(i);
1277 	struct spdk_io_channel *ch = spdk_io_channel_iter_get_channel(i);
1278 	struct raid_bdev_io_channel *raid_ch = spdk_io_channel_get_ctx(ch);
1279 	uint8_t idx = base_info - base_info->raid_bdev->base_bdev_info;
1280 
1281 	SPDK_DEBUGLOG(bdev_raid, "slot: %u raid_ch: %p\n", idx, raid_ch);
1282 
1283 	if (raid_ch->base_channel[idx] != NULL) {
1284 		spdk_put_io_channel(raid_ch->base_channel[idx]);
1285 		raid_ch->base_channel[idx] = NULL;
1286 	}
1287 
1288 	spdk_for_each_channel_continue(i, 0);
1289 }
1290 
1291 static void
1292 raid_bdev_channels_remove_base_bdev_done(struct spdk_io_channel_iter *i, int status)
1293 {
1294 	struct raid_base_bdev_info *base_info = spdk_io_channel_iter_get_ctx(i);
1295 	struct raid_bdev *raid_bdev = base_info->raid_bdev;
1296 
1297 	spdk_bdev_unquiesce(&raid_bdev->bdev, &g_raid_if, raid_bdev_remove_base_bdev_on_unquiesced,
1298 			    base_info);
1299 }
1300 
1301 static void
1302 raid_bdev_remove_base_bdev_on_quiesced(void *ctx, int status)
1303 {
1304 	struct raid_base_bdev_info *base_info = ctx;
1305 	struct raid_bdev *raid_bdev = base_info->raid_bdev;
1306 
1307 	if (status != 0) {
1308 		SPDK_ERRLOG("Failed to quiesce raid bdev %s: %s\n",
1309 			    raid_bdev->bdev.name, spdk_strerror(-status));
1310 		base_info->remove_scheduled = false;
1311 		if (base_info->remove_cb != NULL) {
1312 			base_info->remove_cb(base_info->remove_cb_ctx, status);
1313 		}
1314 		return;
1315 	}
1316 
1317 	spdk_for_each_channel(raid_bdev, raid_bdev_channel_remove_base_bdev, base_info,
1318 			      raid_bdev_channels_remove_base_bdev_done);
1319 }
1320 
1321 /*
1322  * brief:
1323  * raid_bdev_remove_base_bdev function is called by below layers when base_bdev
1324  * is removed. This function checks if this base bdev is part of any raid bdev
1325  * or not. If yes, it takes necessary action on that particular raid bdev.
1326  * params:
1327  * base_bdev - pointer to base bdev which got removed
1328  * cb_fn - callback function
1329  * cb_arg - argument to callback function
1330  * returns:
1331  * 0 - success
1332  * non zero - failure
1333  */
1334 int
1335 raid_bdev_remove_base_bdev(struct spdk_bdev *base_bdev, raid_bdev_remove_base_bdev_cb cb_fn,
1336 			   void *cb_ctx)
1337 {
1338 	struct raid_bdev *raid_bdev;
1339 	struct raid_base_bdev_info *base_info;
1340 
1341 	SPDK_DEBUGLOG(bdev_raid, "%s\n", base_bdev->name);
1342 
1343 	/* Find the raid_bdev which has claimed this base_bdev */
1344 	base_info = raid_bdev_find_base_info_by_bdev(base_bdev);
1345 	if (!base_info) {
1346 		SPDK_ERRLOG("bdev to remove '%s' not found\n", base_bdev->name);
1347 		return -ENODEV;
1348 	}
1349 	raid_bdev = base_info->raid_bdev;
1350 
1351 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
1352 
1353 	if (base_info->remove_scheduled) {
1354 		return 0;
1355 	}
1356 
1357 	assert(base_info->desc);
1358 	base_info->remove_scheduled = true;
1359 	base_info->remove_cb = cb_fn;
1360 	base_info->remove_cb_ctx = cb_ctx;
1361 
1362 	if (raid_bdev->state != RAID_BDEV_STATE_ONLINE) {
1363 		/*
1364 		 * As raid bdev is not registered yet or already unregistered,
1365 		 * so cleanup should be done here itself.
1366 		 */
1367 		raid_bdev_free_base_bdev_resource(base_info);
1368 		if (raid_bdev->num_base_bdevs_discovered == 0) {
1369 			/* There is no base bdev for this raid, so free the raid device. */
1370 			raid_bdev_cleanup_and_free(raid_bdev);
1371 		}
1372 	} else if (raid_bdev->num_base_bdevs_discovered == raid_bdev->min_base_bdevs_operational) {
1373 		/*
1374 		 * After this base bdev is removed there will not be enough base bdevs
1375 		 * to keep the raid bdev operational.
1376 		 */
1377 		raid_bdev_deconfigure(raid_bdev, cb_fn, cb_ctx);
1378 	} else {
1379 		int ret;
1380 
1381 		ret = spdk_bdev_quiesce(&raid_bdev->bdev, &g_raid_if,
1382 					raid_bdev_remove_base_bdev_on_quiesced, base_info);
1383 		if (ret != 0) {
1384 			base_info->remove_scheduled = false;
1385 		}
1386 	}
1387 
1388 	return 0;
1389 }
1390 
1391 /*
1392  * brief:
1393  * raid_bdev_resize_base_bdev function is called by below layers when base_bdev
1394  * is resized. This function checks if the smallest size of the base_bdevs is changed.
1395  * If yes, call module handler to resize the raid_bdev if implemented.
1396  * params:
1397  * base_bdev - pointer to base bdev which got resized.
1398  * returns:
1399  * none
1400  */
1401 static void
1402 raid_bdev_resize_base_bdev(struct spdk_bdev *base_bdev)
1403 {
1404 	struct raid_bdev *raid_bdev;
1405 	struct raid_base_bdev_info *base_info;
1406 
1407 	SPDK_DEBUGLOG(bdev_raid, "raid_bdev_resize_base_bdev\n");
1408 
1409 	base_info = raid_bdev_find_base_info_by_bdev(base_bdev);
1410 
1411 	/* Find the raid_bdev which has claimed this base_bdev */
1412 	if (!base_info) {
1413 		SPDK_ERRLOG("raid_bdev whose base_bdev '%s' not found\n", base_bdev->name);
1414 		return;
1415 	}
1416 	raid_bdev = base_info->raid_bdev;
1417 
1418 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
1419 
1420 	SPDK_NOTICELOG("base_bdev '%s' was resized: old size %" PRIu64 ", new size %" PRIu64 "\n",
1421 		       base_bdev->name, base_info->blockcnt, base_bdev->blockcnt);
1422 
1423 	if (raid_bdev->module->resize) {
1424 		raid_bdev->module->resize(raid_bdev);
1425 	}
1426 }
1427 
1428 /*
1429  * brief:
1430  * raid_bdev_event_base_bdev function is called by below layers when base_bdev
1431  * triggers asynchronous event.
1432  * params:
1433  * type - event details.
1434  * bdev - bdev that triggered event.
1435  * event_ctx - context for event.
1436  * returns:
1437  * none
1438  */
1439 static void
1440 raid_bdev_event_base_bdev(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,
1441 			  void *event_ctx)
1442 {
1443 	int rc;
1444 
1445 	switch (type) {
1446 	case SPDK_BDEV_EVENT_REMOVE:
1447 		rc = raid_bdev_remove_base_bdev(bdev, NULL, NULL);
1448 		if (rc != 0) {
1449 			SPDK_ERRLOG("Failed to remove base bdev %s: %s\n",
1450 				    spdk_bdev_get_name(bdev), spdk_strerror(-rc));
1451 		}
1452 		break;
1453 	case SPDK_BDEV_EVENT_RESIZE:
1454 		raid_bdev_resize_base_bdev(bdev);
1455 		break;
1456 	default:
1457 		SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type);
1458 		break;
1459 	}
1460 }
1461 
1462 /*
1463  * brief:
1464  * Deletes the specified raid bdev
1465  * params:
1466  * raid_bdev - pointer to raid bdev
1467  * cb_fn - callback function
1468  * cb_arg - argument to callback function
1469  */
1470 void
1471 raid_bdev_delete(struct raid_bdev *raid_bdev, raid_bdev_destruct_cb cb_fn, void *cb_arg)
1472 {
1473 	struct raid_base_bdev_info *base_info;
1474 
1475 	SPDK_DEBUGLOG(bdev_raid, "delete raid bdev: %s\n", raid_bdev->bdev.name);
1476 
1477 	if (raid_bdev->destroy_started) {
1478 		SPDK_DEBUGLOG(bdev_raid, "destroying raid bdev %s is already started\n",
1479 			      raid_bdev->bdev.name);
1480 		if (cb_fn) {
1481 			cb_fn(cb_arg, -EALREADY);
1482 		}
1483 		return;
1484 	}
1485 
1486 	raid_bdev->destroy_started = true;
1487 
1488 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1489 		base_info->remove_scheduled = true;
1490 
1491 		if (raid_bdev->state != RAID_BDEV_STATE_ONLINE) {
1492 			/*
1493 			 * As raid bdev is not registered yet or already unregistered,
1494 			 * so cleanup should be done here itself.
1495 			 */
1496 			raid_bdev_free_base_bdev_resource(base_info);
1497 		}
1498 	}
1499 
1500 	if (raid_bdev->num_base_bdevs_discovered == 0) {
1501 		/* There is no base bdev for this raid, so free the raid device. */
1502 		raid_bdev_cleanup_and_free(raid_bdev);
1503 		if (cb_fn) {
1504 			cb_fn(cb_arg, 0);
1505 		}
1506 	} else {
1507 		raid_bdev_deconfigure(raid_bdev, cb_fn, cb_arg);
1508 	}
1509 }
1510 
1511 static int
1512 raid_bdev_configure_base_bdev(struct raid_base_bdev_info *base_info)
1513 {
1514 	struct raid_bdev *raid_bdev = base_info->raid_bdev;
1515 	struct spdk_bdev_desc *desc;
1516 	struct spdk_bdev *bdev;
1517 	int rc;
1518 
1519 	assert(spdk_get_thread() == spdk_thread_get_app_thread());
1520 	assert(base_info->name != NULL);
1521 	assert(base_info->desc == NULL);
1522 
1523 	rc = spdk_bdev_open_ext(base_info->name, true, raid_bdev_event_base_bdev, NULL, &desc);
1524 	if (rc != 0) {
1525 		if (rc != -ENODEV) {
1526 			SPDK_ERRLOG("Unable to create desc on bdev '%s'\n", base_info->name);
1527 		}
1528 		return rc;
1529 	}
1530 
1531 	bdev = spdk_bdev_desc_get_bdev(desc);
1532 
1533 	rc = spdk_bdev_module_claim_bdev(bdev, NULL, &g_raid_if);
1534 	if (rc != 0) {
1535 		SPDK_ERRLOG("Unable to claim this bdev as it is already claimed\n");
1536 		spdk_bdev_close(desc);
1537 		return rc;
1538 	}
1539 
1540 	SPDK_DEBUGLOG(bdev_raid, "bdev %s is claimed\n", bdev->name);
1541 
1542 	assert(raid_bdev->state != RAID_BDEV_STATE_ONLINE);
1543 
1544 	base_info->desc = desc;
1545 	base_info->blockcnt = bdev->blockcnt;
1546 	raid_bdev->num_base_bdevs_discovered++;
1547 	assert(raid_bdev->num_base_bdevs_discovered <= raid_bdev->num_base_bdevs);
1548 
1549 	if (raid_bdev->num_base_bdevs_discovered == raid_bdev->num_base_bdevs) {
1550 		rc = raid_bdev_configure(raid_bdev);
1551 		if (rc != 0) {
1552 			SPDK_ERRLOG("Failed to configure raid bdev\n");
1553 			return rc;
1554 		}
1555 	}
1556 
1557 	return 0;
1558 }
1559 
1560 /*
1561  * brief:
1562  * raid_bdev_add_base_device function is the actual function which either adds
1563  * the nvme base device to existing raid bdev or create a new raid bdev. It also claims
1564  * the base device and keep the open descriptor.
1565  * params:
1566  * raid_bdev - pointer to raid bdev
1567  * name - name of the base bdev
1568  * slot - position to add base bdev
1569  * returns:
1570  * 0 - success
1571  * non zero - failure
1572  */
1573 int
1574 raid_bdev_add_base_device(struct raid_bdev *raid_bdev, const char *name, uint8_t slot)
1575 {
1576 	struct raid_base_bdev_info *base_info;
1577 	int rc;
1578 
1579 	if (slot >= raid_bdev->num_base_bdevs) {
1580 		return -EINVAL;
1581 	}
1582 
1583 	base_info = &raid_bdev->base_bdev_info[slot];
1584 
1585 	if (base_info->name != NULL) {
1586 		SPDK_ERRLOG("Slot %u on raid bdev '%s' already assigned to bdev '%s'\n",
1587 			    slot, raid_bdev->bdev.name, base_info->name);
1588 		return -EBUSY;
1589 	}
1590 
1591 	base_info->name = strdup(name);
1592 	if (base_info->name == NULL) {
1593 		return -ENOMEM;
1594 	}
1595 
1596 	rc = raid_bdev_configure_base_bdev(base_info);
1597 	if (rc != 0) {
1598 		if (rc != -ENODEV) {
1599 			SPDK_ERRLOG("Failed to allocate resource for bdev '%s'\n", name);
1600 		}
1601 		return rc;
1602 	}
1603 
1604 	return 0;
1605 }
1606 
1607 /*
1608  * brief:
1609  * raid_bdev_examine function is the examine function call by the below layers
1610  * like bdev_nvme layer. This function will check if this base bdev can be
1611  * claimed by this raid bdev or not.
1612  * params:
1613  * bdev - pointer to base bdev
1614  * returns:
1615  * none
1616  */
1617 static void
1618 raid_bdev_examine(struct spdk_bdev *bdev)
1619 {
1620 	struct raid_bdev *raid_bdev;
1621 	struct raid_base_bdev_info *base_info;
1622 
1623 	TAILQ_FOREACH(raid_bdev, &g_raid_bdev_list, global_link) {
1624 		RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1625 			if (base_info->desc == NULL && base_info->name != NULL &&
1626 			    strcmp(bdev->name, base_info->name) == 0) {
1627 				raid_bdev_configure_base_bdev(base_info);
1628 				break;
1629 			}
1630 		}
1631 	}
1632 
1633 	spdk_bdev_module_examine_done(&g_raid_if);
1634 }
1635 
1636 /* Log component for bdev raid bdev module */
1637 SPDK_LOG_REGISTER_COMPONENT(bdev_raid)
1638