xref: /spdk/module/bdev/raid/bdev_raid.c (revision 03e3fc4f5835983a4e6602b4e770922e798ce263)
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 "bdev_raid.h"
35 #include "spdk/env.h"
36 #include "spdk/thread.h"
37 #include "spdk/conf.h"
38 #include "spdk_internal/log.h"
39 #include "spdk/string.h"
40 #include "spdk/util.h"
41 #include "spdk/json.h"
42 #include "spdk/string.h"
43 
44 static bool g_shutdown_started = false;
45 
46 /* raid bdev config as read from config file */
47 struct raid_config	g_raid_config = {
48 	.raid_bdev_config_head = TAILQ_HEAD_INITIALIZER(g_raid_config.raid_bdev_config_head),
49 };
50 
51 /*
52  * List of raid bdev in configured list, these raid bdevs are registered with
53  * bdev layer
54  */
55 struct raid_configured_tailq	g_raid_bdev_configured_list = TAILQ_HEAD_INITIALIZER(
56 			g_raid_bdev_configured_list);
57 
58 /* List of raid bdev in configuring list */
59 struct raid_configuring_tailq	g_raid_bdev_configuring_list = TAILQ_HEAD_INITIALIZER(
60 			g_raid_bdev_configuring_list);
61 
62 /* List of all raid bdevs */
63 struct raid_all_tailq		g_raid_bdev_list = TAILQ_HEAD_INITIALIZER(g_raid_bdev_list);
64 
65 /* List of all raid bdevs that are offline */
66 struct raid_offline_tailq	g_raid_bdev_offline_list = TAILQ_HEAD_INITIALIZER(
67 			g_raid_bdev_offline_list);
68 
69 static TAILQ_HEAD(, raid_bdev_module) g_raid_modules = TAILQ_HEAD_INITIALIZER(g_raid_modules);
70 
71 static struct raid_bdev_module *raid_bdev_module_find(enum raid_level level)
72 {
73 	struct raid_bdev_module *raid_module;
74 
75 	TAILQ_FOREACH(raid_module, &g_raid_modules, link) {
76 		if (raid_module->level == level) {
77 			return raid_module;
78 		}
79 	}
80 
81 	return NULL;
82 }
83 
84 void raid_bdev_module_list_add(struct raid_bdev_module *raid_module)
85 {
86 	if (raid_bdev_module_find(raid_module->level) != NULL) {
87 		SPDK_ERRLOG("module for raid level '%s' already registered.\n",
88 			    raid_bdev_level_to_str(raid_module->level));
89 		assert(false);
90 	} else {
91 		TAILQ_INSERT_TAIL(&g_raid_modules, raid_module, link);
92 	}
93 }
94 
95 /* Function declarations */
96 static void	raid_bdev_examine(struct spdk_bdev *bdev);
97 static int	raid_bdev_init(void);
98 static void	raid_bdev_deconfigure(struct raid_bdev *raid_bdev,
99 				      raid_bdev_destruct_cb cb_fn, void *cb_arg);
100 static void	raid_bdev_remove_base_bdev(void *ctx);
101 
102 /*
103  * brief:
104  * raid_bdev_create_cb function is a cb function for raid bdev which creates the
105  * hierarchy from raid bdev to base bdev io channels. It will be called per core
106  * params:
107  * io_device - pointer to raid bdev io device represented by raid_bdev
108  * ctx_buf - pointer to context buffer for raid bdev io channel
109  * returns:
110  * 0 - success
111  * non zero - failure
112  */
113 static int
114 raid_bdev_create_cb(void *io_device, void *ctx_buf)
115 {
116 	struct raid_bdev            *raid_bdev = io_device;
117 	struct raid_bdev_io_channel *raid_ch = ctx_buf;
118 	uint8_t i;
119 
120 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_create_cb, %p\n", raid_ch);
121 
122 	assert(raid_bdev != NULL);
123 	assert(raid_bdev->state == RAID_BDEV_STATE_ONLINE);
124 
125 	raid_ch->num_channels = raid_bdev->num_base_bdevs;
126 
127 	raid_ch->base_channel = calloc(raid_ch->num_channels,
128 				       sizeof(struct spdk_io_channel *));
129 	if (!raid_ch->base_channel) {
130 		SPDK_ERRLOG("Unable to allocate base bdevs io channel\n");
131 		return -ENOMEM;
132 	}
133 	for (i = 0; i < raid_ch->num_channels; i++) {
134 		/*
135 		 * Get the spdk_io_channel for all the base bdevs. This is used during
136 		 * split logic to send the respective child bdev ios to respective base
137 		 * bdev io channel.
138 		 */
139 		raid_ch->base_channel[i] = spdk_bdev_get_io_channel(
140 						   raid_bdev->base_bdev_info[i].desc);
141 		if (!raid_ch->base_channel[i]) {
142 			uint8_t j;
143 
144 			for (j = 0; j < i; j++) {
145 				spdk_put_io_channel(raid_ch->base_channel[j]);
146 			}
147 			free(raid_ch->base_channel);
148 			raid_ch->base_channel = NULL;
149 			SPDK_ERRLOG("Unable to create io channel for base bdev\n");
150 			return -ENOMEM;
151 		}
152 	}
153 
154 	return 0;
155 }
156 
157 /*
158  * brief:
159  * raid_bdev_destroy_cb function is a cb function for raid bdev which deletes the
160  * hierarchy from raid bdev to base bdev io channels. It will be called per core
161  * params:
162  * io_device - pointer to raid bdev io device represented by raid_bdev
163  * ctx_buf - pointer to context buffer for raid bdev io channel
164  * returns:
165  * none
166  */
167 static void
168 raid_bdev_destroy_cb(void *io_device, void *ctx_buf)
169 {
170 	struct raid_bdev_io_channel *raid_ch = ctx_buf;
171 	uint8_t i;
172 
173 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_destroy_cb\n");
174 
175 	assert(raid_ch != NULL);
176 	assert(raid_ch->base_channel);
177 	for (i = 0; i < raid_ch->num_channels; i++) {
178 		/* Free base bdev channels */
179 		assert(raid_ch->base_channel[i] != NULL);
180 		spdk_put_io_channel(raid_ch->base_channel[i]);
181 	}
182 	free(raid_ch->base_channel);
183 	raid_ch->base_channel = NULL;
184 }
185 
186 /*
187  * brief:
188  * raid_bdev_cleanup is used to cleanup and free raid_bdev related data
189  * structures.
190  * params:
191  * raid_bdev - pointer to raid_bdev
192  * returns:
193  * none
194  */
195 static void
196 raid_bdev_cleanup(struct raid_bdev *raid_bdev)
197 {
198 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_cleanup, %p name %s, state %u, config %p\n",
199 		      raid_bdev,
200 		      raid_bdev->bdev.name, raid_bdev->state, raid_bdev->config);
201 	if (raid_bdev->state == RAID_BDEV_STATE_CONFIGURING) {
202 		TAILQ_REMOVE(&g_raid_bdev_configuring_list, raid_bdev, state_link);
203 	} else if (raid_bdev->state == RAID_BDEV_STATE_OFFLINE) {
204 		TAILQ_REMOVE(&g_raid_bdev_offline_list, raid_bdev, state_link);
205 	} else {
206 		assert(0);
207 	}
208 	TAILQ_REMOVE(&g_raid_bdev_list, raid_bdev, global_link);
209 	free(raid_bdev->bdev.name);
210 	free(raid_bdev->base_bdev_info);
211 	if (raid_bdev->config) {
212 		raid_bdev->config->raid_bdev = NULL;
213 	}
214 	free(raid_bdev);
215 }
216 
217 /*
218  * brief:
219  * wrapper for the bdev close operation
220  * params:
221  * base_info - raid base bdev info
222  * returns:
223  */
224 static void
225 _raid_bdev_free_base_bdev_resource(void *ctx)
226 {
227 	struct spdk_bdev_desc *desc = ctx;
228 
229 	spdk_bdev_close(desc);
230 }
231 
232 
233 /*
234  * brief:
235  * free resource of base bdev for raid bdev
236  * params:
237  * raid_bdev - pointer to raid bdev
238  * base_info - raid base bdev info
239  * returns:
240  * 0 - success
241  * non zero - failure
242  */
243 static void
244 raid_bdev_free_base_bdev_resource(struct raid_bdev *raid_bdev,
245 				  struct raid_base_bdev_info *base_info)
246 {
247 	spdk_bdev_module_release_bdev(base_info->bdev);
248 	if (base_info->thread && base_info->thread != spdk_get_thread()) {
249 		spdk_thread_send_msg(base_info->thread, _raid_bdev_free_base_bdev_resource, base_info->desc);
250 	} else {
251 		spdk_bdev_close(base_info->desc);
252 	}
253 	base_info->desc = NULL;
254 	base_info->bdev = NULL;
255 
256 	assert(raid_bdev->num_base_bdevs_discovered);
257 	raid_bdev->num_base_bdevs_discovered--;
258 }
259 
260 /*
261  * brief:
262  * raid_bdev_destruct is the destruct function table pointer for raid bdev
263  * params:
264  * ctxt - pointer to raid_bdev
265  * returns:
266  * 0 - success
267  * non zero - failure
268  */
269 static int
270 raid_bdev_destruct(void *ctxt)
271 {
272 	struct raid_bdev *raid_bdev = ctxt;
273 	struct raid_base_bdev_info *base_info;
274 
275 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_destruct\n");
276 
277 	raid_bdev->destruct_called = true;
278 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
279 		/*
280 		 * Close all base bdev descriptors for which call has come from below
281 		 * layers.  Also close the descriptors if we have started shutdown.
282 		 */
283 		if (g_shutdown_started ||
284 		    ((base_info->remove_scheduled == true) &&
285 		     (base_info->bdev != NULL))) {
286 			raid_bdev_free_base_bdev_resource(raid_bdev, base_info);
287 		}
288 	}
289 
290 	if (g_shutdown_started) {
291 		TAILQ_REMOVE(&g_raid_bdev_configured_list, raid_bdev, state_link);
292 		if (raid_bdev->module->stop != NULL) {
293 			raid_bdev->module->stop(raid_bdev);
294 		}
295 		raid_bdev->state = RAID_BDEV_STATE_OFFLINE;
296 		TAILQ_INSERT_TAIL(&g_raid_bdev_offline_list, raid_bdev, state_link);
297 	}
298 
299 	spdk_io_device_unregister(raid_bdev, NULL);
300 
301 	if (raid_bdev->num_base_bdevs_discovered == 0) {
302 		/* Free raid_bdev when there are no base bdevs left */
303 		SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid bdev base bdevs is 0, going to free all in destruct\n");
304 		raid_bdev_cleanup(raid_bdev);
305 	}
306 
307 	return 0;
308 }
309 
310 void
311 raid_bdev_io_complete(struct raid_bdev_io *raid_io, enum spdk_bdev_io_status status)
312 {
313 	struct spdk_bdev_io *bdev_io = spdk_bdev_io_from_ctx(raid_io);
314 
315 	spdk_bdev_io_complete(bdev_io, status);
316 }
317 
318 /*
319  * brief:
320  * raid_bdev_io_complete_part - signal the completion of a part of the expected
321  * base bdev IOs and complete the raid_io if this is the final expected IO.
322  * The caller should first set raid_io->base_bdev_io_remaining. This function
323  * will decrement this counter by the value of the 'completed' parameter and
324  * complete the raid_io if the counter reaches 0. The caller is free to
325  * interpret the 'base_bdev_io_remaining' and 'completed' values as needed,
326  * it can represent e.g. blocks or IOs.
327  * params:
328  * raid_io - pointer to raid_bdev_io
329  * completed - the part of the raid_io that has been completed
330  * status - status of the base IO
331  * returns:
332  * true - if the raid_io is completed
333  * false - otherwise
334  */
335 bool
336 raid_bdev_io_complete_part(struct raid_bdev_io *raid_io, uint64_t completed,
337 			   enum spdk_bdev_io_status status)
338 {
339 	assert(raid_io->base_bdev_io_remaining >= completed);
340 	raid_io->base_bdev_io_remaining -= completed;
341 
342 	if (status != SPDK_BDEV_IO_STATUS_SUCCESS) {
343 		raid_io->base_bdev_io_status = status;
344 	}
345 
346 	if (raid_io->base_bdev_io_remaining == 0) {
347 		raid_bdev_io_complete(raid_io, raid_io->base_bdev_io_status);
348 		return true;
349 	} else {
350 		return false;
351 	}
352 }
353 
354 /*
355  * brief:
356  * raid_bdev_queue_io_wait function processes the IO which failed to submit.
357  * It will try to queue the IOs after storing the context to bdev wait queue logic.
358  * params:
359  * raid_io - pointer to raid_bdev_io
360  * bdev - the block device that the IO is submitted to
361  * ch - io channel
362  * cb_fn - callback when the spdk_bdev_io for bdev becomes available
363  * returns:
364  * none
365  */
366 void
367 raid_bdev_queue_io_wait(struct raid_bdev_io *raid_io, struct spdk_bdev *bdev,
368 			struct spdk_io_channel *ch, spdk_bdev_io_wait_cb cb_fn)
369 {
370 	raid_io->waitq_entry.bdev = bdev;
371 	raid_io->waitq_entry.cb_fn = cb_fn;
372 	raid_io->waitq_entry.cb_arg = raid_io;
373 	spdk_bdev_queue_io_wait(bdev, ch, &raid_io->waitq_entry);
374 }
375 
376 static void
377 raid_base_bdev_reset_complete(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
378 {
379 	struct raid_bdev_io *raid_io = cb_arg;
380 
381 	spdk_bdev_free_io(bdev_io);
382 
383 	raid_bdev_io_complete_part(raid_io, 1, success ?
384 				   SPDK_BDEV_IO_STATUS_SUCCESS :
385 				   SPDK_BDEV_IO_STATUS_FAILED);
386 }
387 
388 static void
389 raid_bdev_submit_reset_request(struct raid_bdev_io *raid_io);
390 
391 static void
392 _raid_bdev_submit_reset_request(void *_raid_io)
393 {
394 	struct raid_bdev_io *raid_io = _raid_io;
395 
396 	raid_bdev_submit_reset_request(raid_io);
397 }
398 
399 /*
400  * brief:
401  * raid_bdev_submit_reset_request function submits reset requests
402  * to member disks; it will submit as many as possible unless a reset fails with -ENOMEM, in
403  * which case it will queue it for later submission
404  * params:
405  * raid_io
406  * returns:
407  * none
408  */
409 static void
410 raid_bdev_submit_reset_request(struct raid_bdev_io *raid_io)
411 {
412 	struct raid_bdev		*raid_bdev;
413 	int				ret;
414 	uint8_t				i;
415 	struct raid_base_bdev_info	*base_info;
416 	struct spdk_io_channel		*base_ch;
417 
418 	raid_bdev = raid_io->raid_bdev;
419 
420 	if (raid_io->base_bdev_io_remaining == 0) {
421 		raid_io->base_bdev_io_remaining = raid_bdev->num_base_bdevs;
422 	}
423 
424 	while (raid_io->base_bdev_io_submitted < raid_bdev->num_base_bdevs) {
425 		i = raid_io->base_bdev_io_submitted;
426 		base_info = &raid_bdev->base_bdev_info[i];
427 		base_ch = raid_io->raid_ch->base_channel[i];
428 		ret = spdk_bdev_reset(base_info->desc, base_ch,
429 				      raid_base_bdev_reset_complete, raid_io);
430 		if (ret == 0) {
431 			raid_io->base_bdev_io_submitted++;
432 		} else if (ret == -ENOMEM) {
433 			raid_bdev_queue_io_wait(raid_io, base_info->bdev, base_ch,
434 						_raid_bdev_submit_reset_request);
435 			return;
436 		} else {
437 			SPDK_ERRLOG("bdev io submit error not due to ENOMEM, it should not happen\n");
438 			assert(false);
439 			raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
440 			return;
441 		}
442 	}
443 }
444 
445 /*
446  * brief:
447  * Callback function to spdk_bdev_io_get_buf.
448  * params:
449  * ch - pointer to raid bdev io channel
450  * bdev_io - pointer to parent bdev_io on raid bdev device
451  * success - True if buffer is allocated or false otherwise.
452  * returns:
453  * none
454  */
455 static void
456 raid_bdev_get_buf_cb(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io,
457 		     bool success)
458 {
459 	struct raid_bdev_io *raid_io = (struct raid_bdev_io *)bdev_io->driver_ctx;
460 
461 	if (!success) {
462 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
463 		return;
464 	}
465 
466 	raid_io->raid_bdev->module->submit_rw_request(raid_io);
467 }
468 
469 /*
470  * brief:
471  * raid_bdev_submit_request function is the submit_request function pointer of
472  * raid bdev function table. This is used to submit the io on raid_bdev to below
473  * layers.
474  * params:
475  * ch - pointer to raid bdev io channel
476  * bdev_io - pointer to parent bdev_io on raid bdev device
477  * returns:
478  * none
479  */
480 static void
481 raid_bdev_submit_request(struct spdk_io_channel *ch, struct spdk_bdev_io *bdev_io)
482 {
483 	struct raid_bdev_io *raid_io = (struct raid_bdev_io *)bdev_io->driver_ctx;
484 
485 	raid_io->raid_bdev = bdev_io->bdev->ctxt;
486 	raid_io->raid_ch = spdk_io_channel_get_ctx(ch);
487 	raid_io->base_bdev_io_remaining = 0;
488 	raid_io->base_bdev_io_submitted = 0;
489 	raid_io->base_bdev_io_status = SPDK_BDEV_IO_STATUS_SUCCESS;
490 
491 	switch (bdev_io->type) {
492 	case SPDK_BDEV_IO_TYPE_READ:
493 		spdk_bdev_io_get_buf(bdev_io, raid_bdev_get_buf_cb,
494 				     bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen);
495 		break;
496 	case SPDK_BDEV_IO_TYPE_WRITE:
497 		raid_io->raid_bdev->module->submit_rw_request(raid_io);
498 		break;
499 
500 	case SPDK_BDEV_IO_TYPE_RESET:
501 		raid_bdev_submit_reset_request(raid_io);
502 		break;
503 
504 	case SPDK_BDEV_IO_TYPE_FLUSH:
505 	case SPDK_BDEV_IO_TYPE_UNMAP:
506 		raid_io->raid_bdev->module->submit_null_payload_request(raid_io);
507 		break;
508 
509 	default:
510 		SPDK_ERRLOG("submit request, invalid io type %u\n", bdev_io->type);
511 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
512 		break;
513 	}
514 }
515 
516 /*
517  * brief:
518  * _raid_bdev_io_type_supported checks whether io_type is supported in
519  * all base bdev modules of raid bdev module. If anyone among the base_bdevs
520  * doesn't support, the raid device doesn't supports.
521  *
522  * params:
523  * raid_bdev - pointer to raid bdev context
524  * io_type - io type
525  * returns:
526  * true - io_type is supported
527  * false - io_type is not supported
528  */
529 inline static bool
530 _raid_bdev_io_type_supported(struct raid_bdev *raid_bdev, enum spdk_bdev_io_type io_type)
531 {
532 	struct raid_base_bdev_info *base_info;
533 
534 	if (io_type == SPDK_BDEV_IO_TYPE_FLUSH ||
535 	    io_type == SPDK_BDEV_IO_TYPE_UNMAP) {
536 		if (raid_bdev->module->submit_null_payload_request == NULL) {
537 			return false;
538 		}
539 	}
540 
541 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
542 		if (base_info->bdev == NULL) {
543 			assert(false);
544 			continue;
545 		}
546 
547 		if (spdk_bdev_io_type_supported(base_info->bdev, io_type) == false) {
548 			return false;
549 		}
550 	}
551 
552 	return true;
553 }
554 
555 /*
556  * brief:
557  * raid_bdev_io_type_supported is the io_supported function for bdev function
558  * table which returns whether the particular io type is supported or not by
559  * raid bdev module
560  * params:
561  * ctx - pointer to raid bdev context
562  * type - io type
563  * returns:
564  * true - io_type is supported
565  * false - io_type is not supported
566  */
567 static bool
568 raid_bdev_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
569 {
570 	switch (io_type) {
571 	case SPDK_BDEV_IO_TYPE_READ:
572 	case SPDK_BDEV_IO_TYPE_WRITE:
573 		return true;
574 
575 	case SPDK_BDEV_IO_TYPE_FLUSH:
576 	case SPDK_BDEV_IO_TYPE_RESET:
577 	case SPDK_BDEV_IO_TYPE_UNMAP:
578 		return _raid_bdev_io_type_supported(ctx, io_type);
579 
580 	default:
581 		return false;
582 	}
583 
584 	return false;
585 }
586 
587 /*
588  * brief:
589  * raid_bdev_get_io_channel is the get_io_channel function table pointer for
590  * raid bdev. This is used to return the io channel for this raid bdev
591  * params:
592  * ctxt - pointer to raid_bdev
593  * returns:
594  * pointer to io channel for raid bdev
595  */
596 static struct spdk_io_channel *
597 raid_bdev_get_io_channel(void *ctxt)
598 {
599 	struct raid_bdev *raid_bdev = ctxt;
600 
601 	return spdk_get_io_channel(raid_bdev);
602 }
603 
604 /*
605  * brief:
606  * raid_bdev_dump_info_json is the function table pointer for raid bdev
607  * params:
608  * ctx - pointer to raid_bdev
609  * w - pointer to json context
610  * returns:
611  * 0 - success
612  * non zero - failure
613  */
614 static int
615 raid_bdev_dump_info_json(void *ctx, struct spdk_json_write_ctx *w)
616 {
617 	struct raid_bdev *raid_bdev = ctx;
618 	struct raid_base_bdev_info *base_info;
619 
620 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_dump_config_json\n");
621 	assert(raid_bdev != NULL);
622 
623 	/* Dump the raid bdev configuration related information */
624 	spdk_json_write_named_object_begin(w, "raid");
625 	spdk_json_write_named_uint32(w, "strip_size", raid_bdev->strip_size);
626 	spdk_json_write_named_uint32(w, "strip_size_kb", raid_bdev->strip_size_kb);
627 	spdk_json_write_named_uint32(w, "state", raid_bdev->state);
628 	spdk_json_write_named_string(w, "raid_level", raid_bdev_level_to_str(raid_bdev->level));
629 	spdk_json_write_named_uint32(w, "destruct_called", raid_bdev->destruct_called);
630 	spdk_json_write_named_uint32(w, "num_base_bdevs", raid_bdev->num_base_bdevs);
631 	spdk_json_write_named_uint32(w, "num_base_bdevs_discovered", raid_bdev->num_base_bdevs_discovered);
632 	spdk_json_write_name(w, "base_bdevs_list");
633 	spdk_json_write_array_begin(w);
634 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
635 		if (base_info->bdev) {
636 			spdk_json_write_string(w, base_info->bdev->name);
637 		} else {
638 			spdk_json_write_null(w);
639 		}
640 	}
641 	spdk_json_write_array_end(w);
642 	spdk_json_write_object_end(w);
643 
644 	return 0;
645 }
646 
647 /*
648  * brief:
649  * raid_bdev_write_config_json is the function table pointer for raid bdev
650  * params:
651  * bdev - pointer to spdk_bdev
652  * w - pointer to json context
653  * returns:
654  * none
655  */
656 static void
657 raid_bdev_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
658 {
659 	struct raid_bdev *raid_bdev = bdev->ctxt;
660 	struct raid_base_bdev_info *base_info;
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", 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->bdev) {
674 			spdk_json_write_string(w, base_info->bdev->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 /* g_raid_bdev_fn_table is the function table for raid bdev */
684 static const struct spdk_bdev_fn_table g_raid_bdev_fn_table = {
685 	.destruct		= raid_bdev_destruct,
686 	.submit_request		= raid_bdev_submit_request,
687 	.io_type_supported	= raid_bdev_io_type_supported,
688 	.get_io_channel		= raid_bdev_get_io_channel,
689 	.dump_info_json		= raid_bdev_dump_info_json,
690 	.write_config_json	= raid_bdev_write_config_json,
691 };
692 
693 /*
694  * brief:
695  * raid_bdev_config_cleanup function is used to free memory for one raid_bdev in configuration
696  * params:
697  * raid_cfg - pointer to raid_bdev_config structure
698  * returns:
699  * none
700  */
701 void
702 raid_bdev_config_cleanup(struct raid_bdev_config *raid_cfg)
703 {
704 	uint8_t i;
705 
706 	TAILQ_REMOVE(&g_raid_config.raid_bdev_config_head, raid_cfg, link);
707 	g_raid_config.total_raid_bdev--;
708 
709 	if (raid_cfg->base_bdev) {
710 		for (i = 0; i < raid_cfg->num_base_bdevs; i++) {
711 			free(raid_cfg->base_bdev[i].name);
712 		}
713 		free(raid_cfg->base_bdev);
714 	}
715 	free(raid_cfg->name);
716 	free(raid_cfg);
717 }
718 
719 /*
720  * brief:
721  * raid_bdev_free is the raid bdev function table function pointer. This is
722  * called on bdev free path
723  * params:
724  * none
725  * returns:
726  * none
727  */
728 static void
729 raid_bdev_free(void)
730 {
731 	struct raid_bdev_config *raid_cfg, *tmp;
732 
733 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_free\n");
734 	TAILQ_FOREACH_SAFE(raid_cfg, &g_raid_config.raid_bdev_config_head, link, tmp) {
735 		raid_bdev_config_cleanup(raid_cfg);
736 	}
737 }
738 
739 /* brief
740  * raid_bdev_config_find_by_name is a helper function to find raid bdev config
741  * by name as key.
742  *
743  * params:
744  * raid_name - name for raid bdev.
745  */
746 struct raid_bdev_config *
747 raid_bdev_config_find_by_name(const char *raid_name)
748 {
749 	struct raid_bdev_config *raid_cfg;
750 
751 	TAILQ_FOREACH(raid_cfg, &g_raid_config.raid_bdev_config_head, link) {
752 		if (!strcmp(raid_cfg->name, raid_name)) {
753 			return raid_cfg;
754 		}
755 	}
756 
757 	return raid_cfg;
758 }
759 
760 /*
761  * brief
762  * raid_bdev_config_add function adds config for newly created raid bdev.
763  *
764  * params:
765  * raid_name - name for raid bdev.
766  * strip_size - strip size in KB
767  * num_base_bdevs - number of base bdevs.
768  * level - raid level.
769  * _raid_cfg - Pointer to newly added configuration
770  */
771 int
772 raid_bdev_config_add(const char *raid_name, uint32_t strip_size, uint8_t num_base_bdevs,
773 		     enum raid_level level, struct raid_bdev_config **_raid_cfg)
774 {
775 	struct raid_bdev_config *raid_cfg;
776 
777 	raid_cfg = raid_bdev_config_find_by_name(raid_name);
778 	if (raid_cfg != NULL) {
779 		SPDK_ERRLOG("Duplicate raid bdev name found in config file %s\n",
780 			    raid_name);
781 		return -EEXIST;
782 	}
783 
784 	if (spdk_u32_is_pow2(strip_size) == false) {
785 		SPDK_ERRLOG("Invalid strip size %" PRIu32 "\n", strip_size);
786 		return -EINVAL;
787 	}
788 
789 	if (num_base_bdevs == 0) {
790 		SPDK_ERRLOG("Invalid base device count %u\n", num_base_bdevs);
791 		return -EINVAL;
792 	}
793 
794 	raid_cfg = calloc(1, sizeof(*raid_cfg));
795 	if (raid_cfg == NULL) {
796 		SPDK_ERRLOG("unable to allocate memory\n");
797 		return -ENOMEM;
798 	}
799 
800 	raid_cfg->name = strdup(raid_name);
801 	if (!raid_cfg->name) {
802 		free(raid_cfg);
803 		SPDK_ERRLOG("unable to allocate memory\n");
804 		return -ENOMEM;
805 	}
806 	raid_cfg->strip_size = strip_size;
807 	raid_cfg->num_base_bdevs = num_base_bdevs;
808 	raid_cfg->level = level;
809 
810 	raid_cfg->base_bdev = calloc(num_base_bdevs, sizeof(*raid_cfg->base_bdev));
811 	if (raid_cfg->base_bdev == NULL) {
812 		free(raid_cfg->name);
813 		free(raid_cfg);
814 		SPDK_ERRLOG("unable to allocate memory\n");
815 		return -ENOMEM;
816 	}
817 
818 	TAILQ_INSERT_TAIL(&g_raid_config.raid_bdev_config_head, raid_cfg, link);
819 	g_raid_config.total_raid_bdev++;
820 
821 	*_raid_cfg = raid_cfg;
822 	return 0;
823 }
824 
825 /*
826  * brief:
827  * raid_bdev_config_add_base_bdev function add base bdev to raid bdev config.
828  *
829  * params:
830  * raid_cfg - pointer to raid bdev configuration
831  * base_bdev_name - name of base bdev
832  * slot - Position to add base bdev
833  */
834 int
835 raid_bdev_config_add_base_bdev(struct raid_bdev_config *raid_cfg, const char *base_bdev_name,
836 			       uint8_t slot)
837 {
838 	uint8_t i;
839 	struct raid_bdev_config *tmp;
840 
841 	if (slot >= raid_cfg->num_base_bdevs) {
842 		return -EINVAL;
843 	}
844 
845 	TAILQ_FOREACH(tmp, &g_raid_config.raid_bdev_config_head, link) {
846 		for (i = 0; i < tmp->num_base_bdevs; i++) {
847 			if (tmp->base_bdev[i].name != NULL) {
848 				if (!strcmp(tmp->base_bdev[i].name, base_bdev_name)) {
849 					SPDK_ERRLOG("duplicate base bdev name %s mentioned\n",
850 						    base_bdev_name);
851 					return -EEXIST;
852 				}
853 			}
854 		}
855 	}
856 
857 	raid_cfg->base_bdev[slot].name = strdup(base_bdev_name);
858 	if (raid_cfg->base_bdev[slot].name == NULL) {
859 		SPDK_ERRLOG("unable to allocate memory\n");
860 		return -ENOMEM;
861 	}
862 
863 	return 0;
864 }
865 
866 static struct {
867 	const char *name;
868 	enum raid_level value;
869 } g_raid_level_names[] = {
870 	{ "raid0", RAID0 },
871 	{ "0", RAID0 },
872 	{ "raid5", RAID5 },
873 	{ "5", RAID5 },
874 	{ }
875 };
876 
877 enum raid_level raid_bdev_parse_raid_level(const char *str)
878 {
879 	unsigned int i;
880 
881 	assert(str != NULL);
882 
883 	for (i = 0; g_raid_level_names[i].name != NULL; i++) {
884 		if (strcasecmp(g_raid_level_names[i].name, str) == 0) {
885 			return g_raid_level_names[i].value;
886 		}
887 	}
888 
889 	return INVALID_RAID_LEVEL;
890 }
891 
892 const char *
893 raid_bdev_level_to_str(enum raid_level level)
894 {
895 	unsigned int i;
896 
897 	for (i = 0; g_raid_level_names[i].name != NULL; i++) {
898 		if (g_raid_level_names[i].value == level) {
899 			return g_raid_level_names[i].name;
900 		}
901 	}
902 
903 	return "";
904 }
905 
906 /*
907  * brief:
908  * raid_bdev_parse_raid is used to parse the raid bdev from config file based on
909  * pre-defined raid bdev format in config file.
910  * Format of config file:
911  *   [RAID1]
912  *   Name raid1
913  *   StripSize 64
914  *   NumDevices 2
915  *   RaidLevel 0
916  *   Devices Nvme0n1 Nvme1n1
917  *
918  *   [RAID2]
919  *   Name raid2
920  *   StripSize 64
921  *   NumDevices 3
922  *   RaidLevel 0
923  *   Devices Nvme2n1 Nvme3n1 Nvme4n1
924  *
925  * params:
926  * conf_section - pointer to config section
927  * returns:
928  * 0 - success
929  * non zero - failure
930  */
931 static int
932 raid_bdev_parse_raid(struct spdk_conf_section *conf_section)
933 {
934 	const char *raid_name;
935 	uint32_t strip_size;
936 	uint8_t num_base_bdevs;
937 	const char *raid_level_str;
938 	enum raid_level level;
939 	const char *base_bdev_name;
940 	struct raid_bdev_config *raid_cfg;
941 	int rc, i, val;
942 
943 	raid_name = spdk_conf_section_get_val(conf_section, "Name");
944 	if (raid_name == NULL) {
945 		SPDK_ERRLOG("raid_name is null\n");
946 		return -EINVAL;
947 	}
948 
949 	val = spdk_conf_section_get_intval(conf_section, "StripSize");
950 	if (val < 0) {
951 		return -EINVAL;
952 	}
953 	strip_size = val;
954 
955 	val = spdk_conf_section_get_intval(conf_section, "NumDevices");
956 	if (val < 0) {
957 		return -EINVAL;
958 	}
959 	num_base_bdevs = val;
960 
961 	raid_level_str = spdk_conf_section_get_val(conf_section, "RaidLevel");
962 	if (raid_level_str == NULL) {
963 		SPDK_ERRLOG("Missing RaidLevel\n");
964 		return -EINVAL;
965 	}
966 	level = raid_bdev_parse_raid_level(raid_level_str);
967 	if (level == INVALID_RAID_LEVEL) {
968 		SPDK_ERRLOG("Invalid RaidLevel\n");
969 		return -EINVAL;
970 	}
971 
972 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "%s %" PRIu32 " %u %u\n",
973 		      raid_name, strip_size, num_base_bdevs, level);
974 
975 	rc = raid_bdev_config_add(raid_name, strip_size, num_base_bdevs, level,
976 				  &raid_cfg);
977 	if (rc != 0) {
978 		SPDK_ERRLOG("Failed to add raid bdev config\n");
979 		return rc;
980 	}
981 
982 	for (i = 0; true; i++) {
983 		base_bdev_name = spdk_conf_section_get_nmval(conf_section, "Devices", 0, i);
984 		if (base_bdev_name == NULL) {
985 			break;
986 		}
987 		if (i >= num_base_bdevs) {
988 			raid_bdev_config_cleanup(raid_cfg);
989 			SPDK_ERRLOG("Number of devices mentioned is more than count\n");
990 			return -EINVAL;
991 		}
992 
993 		rc = raid_bdev_config_add_base_bdev(raid_cfg, base_bdev_name, i);
994 		if (rc != 0) {
995 			raid_bdev_config_cleanup(raid_cfg);
996 			SPDK_ERRLOG("Failed to add base bdev to raid bdev config\n");
997 			return rc;
998 		}
999 	}
1000 
1001 	if (i != raid_cfg->num_base_bdevs) {
1002 		raid_bdev_config_cleanup(raid_cfg);
1003 		SPDK_ERRLOG("Number of devices mentioned is less than count\n");
1004 		return -EINVAL;
1005 	}
1006 
1007 	rc = raid_bdev_create(raid_cfg);
1008 	if (rc != 0) {
1009 		raid_bdev_config_cleanup(raid_cfg);
1010 		SPDK_ERRLOG("Failed to create raid bdev\n");
1011 		return rc;
1012 	}
1013 
1014 	rc = raid_bdev_add_base_devices(raid_cfg);
1015 	if (rc != 0) {
1016 		SPDK_ERRLOG("Failed to add any base bdev to raid bdev\n");
1017 		/* Config is not removed in this case. */
1018 	}
1019 
1020 	return 0;
1021 }
1022 
1023 /*
1024  * brief:
1025  * raid_bdev_parse_config is used to find the raid bdev config section and parse it
1026  * Format of config file:
1027  * params:
1028  * none
1029  * returns:
1030  * 0 - success
1031  * non zero - failure
1032  */
1033 static int
1034 raid_bdev_parse_config(void)
1035 {
1036 	int                      ret;
1037 	struct spdk_conf_section *conf_section;
1038 
1039 	conf_section = spdk_conf_first_section(NULL);
1040 	while (conf_section != NULL) {
1041 		if (spdk_conf_section_match_prefix(conf_section, "RAID")) {
1042 			ret = raid_bdev_parse_raid(conf_section);
1043 			if (ret < 0) {
1044 				SPDK_ERRLOG("Unable to parse raid bdev section\n");
1045 				return ret;
1046 			}
1047 		}
1048 		conf_section = spdk_conf_next_section(conf_section);
1049 	}
1050 
1051 	return 0;
1052 }
1053 
1054 /*
1055  * brief:
1056  * raid_bdev_fini_start is called when bdev layer is starting the
1057  * shutdown process
1058  * params:
1059  * none
1060  * returns:
1061  * none
1062  */
1063 static void
1064 raid_bdev_fini_start(void)
1065 {
1066 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_fini_start\n");
1067 	g_shutdown_started = true;
1068 }
1069 
1070 /*
1071  * brief:
1072  * raid_bdev_exit is called on raid bdev module exit time by bdev layer
1073  * params:
1074  * none
1075  * returns:
1076  * none
1077  */
1078 static void
1079 raid_bdev_exit(void)
1080 {
1081 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_exit\n");
1082 	raid_bdev_free();
1083 }
1084 
1085 /*
1086  * brief:
1087  * raid_bdev_get_ctx_size is used to return the context size of bdev_io for raid
1088  * module
1089  * params:
1090  * none
1091  * returns:
1092  * size of spdk_bdev_io context for raid
1093  */
1094 static int
1095 raid_bdev_get_ctx_size(void)
1096 {
1097 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_get_ctx_size\n");
1098 	return sizeof(struct raid_bdev_io);
1099 }
1100 
1101 /*
1102  * brief:
1103  * raid_bdev_get_running_config is used to get the configuration options.
1104  *
1105  * params:
1106  * fp - The pointer to a file that will be written to the configuration options.
1107  * returns:
1108  * none
1109  */
1110 static void
1111 raid_bdev_get_running_config(FILE *fp)
1112 {
1113 	struct raid_bdev *raid_bdev;
1114 	struct raid_base_bdev_info *base_info;
1115 	int index = 1;
1116 
1117 	TAILQ_FOREACH(raid_bdev, &g_raid_bdev_configured_list, state_link) {
1118 		fprintf(fp,
1119 			"\n"
1120 			"[RAID%d]\n"
1121 			"  Name %s\n"
1122 			"  StripSize %" PRIu32 "\n"
1123 			"  NumDevices %u\n"
1124 			"  RaidLevel %s\n",
1125 			index, raid_bdev->bdev.name, raid_bdev->strip_size_kb,
1126 			raid_bdev->num_base_bdevs,
1127 			raid_bdev_level_to_str(raid_bdev->level));
1128 		fprintf(fp,
1129 			"  Devices ");
1130 		RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1131 			if (base_info->bdev) {
1132 				fprintf(fp,
1133 					"%s ",
1134 					base_info->bdev->name);
1135 			}
1136 		}
1137 		fprintf(fp,
1138 			"\n");
1139 		index++;
1140 	}
1141 }
1142 
1143 /*
1144  * brief:
1145  * raid_bdev_can_claim_bdev is the function to check if this base_bdev can be
1146  * claimed by raid bdev or not.
1147  * params:
1148  * bdev_name - represents base bdev name
1149  * _raid_cfg - pointer to raid bdev config parsed from config file
1150  * base_bdev_slot - if bdev can be claimed, it represents the base_bdev correct
1151  * slot. This field is only valid if return value of this function is true
1152  * returns:
1153  * true - if bdev can be claimed
1154  * false - if bdev can't be claimed
1155  */
1156 static bool
1157 raid_bdev_can_claim_bdev(const char *bdev_name, struct raid_bdev_config **_raid_cfg,
1158 			 uint8_t *base_bdev_slot)
1159 {
1160 	struct raid_bdev_config *raid_cfg;
1161 	uint8_t i;
1162 
1163 	TAILQ_FOREACH(raid_cfg, &g_raid_config.raid_bdev_config_head, link) {
1164 		for (i = 0; i < raid_cfg->num_base_bdevs; i++) {
1165 			/*
1166 			 * Check if the base bdev name is part of raid bdev configuration.
1167 			 * If match is found then return true and the slot information where
1168 			 * this base bdev should be inserted in raid bdev
1169 			 */
1170 			if (!strcmp(bdev_name, raid_cfg->base_bdev[i].name)) {
1171 				*_raid_cfg = raid_cfg;
1172 				*base_bdev_slot = i;
1173 				return true;
1174 			}
1175 		}
1176 	}
1177 
1178 	return false;
1179 }
1180 
1181 
1182 static struct spdk_bdev_module g_raid_if = {
1183 	.name = "raid",
1184 	.module_init = raid_bdev_init,
1185 	.fini_start = raid_bdev_fini_start,
1186 	.module_fini = raid_bdev_exit,
1187 	.get_ctx_size = raid_bdev_get_ctx_size,
1188 	.examine_config = raid_bdev_examine,
1189 	.config_text = raid_bdev_get_running_config,
1190 	.async_init = false,
1191 	.async_fini = false,
1192 };
1193 SPDK_BDEV_MODULE_REGISTER(raid, &g_raid_if)
1194 
1195 /*
1196  * brief:
1197  * raid_bdev_init is the initialization function for raid bdev module
1198  * params:
1199  * none
1200  * returns:
1201  * 0 - success
1202  * non zero - failure
1203  */
1204 static int
1205 raid_bdev_init(void)
1206 {
1207 	int ret;
1208 
1209 	/* Parse config file for raids */
1210 	ret = raid_bdev_parse_config();
1211 	if (ret < 0) {
1212 		SPDK_ERRLOG("raid bdev init failed parsing\n");
1213 		raid_bdev_free();
1214 		return ret;
1215 	}
1216 
1217 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_init completed successfully\n");
1218 
1219 	return 0;
1220 }
1221 
1222 /*
1223  * brief:
1224  * raid_bdev_create allocates raid bdev based on passed configuration
1225  * params:
1226  * raid_cfg - configuration of raid bdev
1227  * returns:
1228  * 0 - success
1229  * non zero - failure
1230  */
1231 int
1232 raid_bdev_create(struct raid_bdev_config *raid_cfg)
1233 {
1234 	struct raid_bdev *raid_bdev;
1235 	struct spdk_bdev *raid_bdev_gen;
1236 	struct raid_bdev_module *module;
1237 
1238 	module = raid_bdev_module_find(raid_cfg->level);
1239 	if (module == NULL) {
1240 		SPDK_ERRLOG("Unsupported raid level '%d'\n", raid_cfg->level);
1241 		return -EINVAL;
1242 	}
1243 
1244 	assert(module->base_bdevs_min != 0);
1245 	if (raid_cfg->num_base_bdevs < module->base_bdevs_min) {
1246 		SPDK_ERRLOG("At least %u base devices required for %s\n",
1247 			    module->base_bdevs_min,
1248 			    raid_bdev_level_to_str(raid_cfg->level));
1249 		return -EINVAL;
1250 	}
1251 
1252 	raid_bdev = calloc(1, sizeof(*raid_bdev));
1253 	if (!raid_bdev) {
1254 		SPDK_ERRLOG("Unable to allocate memory for raid bdev\n");
1255 		return -ENOMEM;
1256 	}
1257 
1258 	raid_bdev->module = module;
1259 	raid_bdev->num_base_bdevs = raid_cfg->num_base_bdevs;
1260 	raid_bdev->base_bdev_info = calloc(raid_bdev->num_base_bdevs,
1261 					   sizeof(struct raid_base_bdev_info));
1262 	if (!raid_bdev->base_bdev_info) {
1263 		SPDK_ERRLOG("Unable able to allocate base bdev info\n");
1264 		free(raid_bdev);
1265 		return -ENOMEM;
1266 	}
1267 
1268 	/* strip_size_kb is from the rpc param.  strip_size is in blocks and used
1269 	 * internally and set later.
1270 	 */
1271 	raid_bdev->strip_size = 0;
1272 	raid_bdev->strip_size_kb = raid_cfg->strip_size;
1273 	raid_bdev->state = RAID_BDEV_STATE_CONFIGURING;
1274 	raid_bdev->config = raid_cfg;
1275 	raid_bdev->level = raid_cfg->level;
1276 
1277 	raid_bdev_gen = &raid_bdev->bdev;
1278 
1279 	raid_bdev_gen->name = strdup(raid_cfg->name);
1280 	if (!raid_bdev_gen->name) {
1281 		SPDK_ERRLOG("Unable to allocate name for raid\n");
1282 		free(raid_bdev->base_bdev_info);
1283 		free(raid_bdev);
1284 		return -ENOMEM;
1285 	}
1286 
1287 	raid_bdev_gen->product_name = "Raid Volume";
1288 	raid_bdev_gen->ctxt = raid_bdev;
1289 	raid_bdev_gen->fn_table = &g_raid_bdev_fn_table;
1290 	raid_bdev_gen->module = &g_raid_if;
1291 	raid_bdev_gen->write_cache = 0;
1292 
1293 	TAILQ_INSERT_TAIL(&g_raid_bdev_configuring_list, raid_bdev, state_link);
1294 	TAILQ_INSERT_TAIL(&g_raid_bdev_list, raid_bdev, global_link);
1295 
1296 	raid_cfg->raid_bdev = raid_bdev;
1297 
1298 	return 0;
1299 }
1300 
1301 /*
1302  * brief
1303  * raid_bdev_alloc_base_bdev_resource allocates resource of base bdev.
1304  * params:
1305  * raid_bdev - pointer to raid bdev
1306  * bdev - pointer to base bdev
1307  * base_bdev_slot - position to add base bdev
1308  * returns:
1309  * 0 - success
1310  * non zero - failure
1311  */
1312 static int
1313 raid_bdev_alloc_base_bdev_resource(struct raid_bdev *raid_bdev, struct spdk_bdev *bdev,
1314 				   uint8_t base_bdev_slot)
1315 {
1316 	struct spdk_bdev_desc *desc;
1317 	int rc;
1318 
1319 	rc = spdk_bdev_open(bdev, true, raid_bdev_remove_base_bdev, bdev, &desc);
1320 	if (rc != 0) {
1321 		SPDK_ERRLOG("Unable to create desc on bdev '%s'\n", bdev->name);
1322 		return rc;
1323 	}
1324 
1325 	rc = spdk_bdev_module_claim_bdev(bdev, NULL, &g_raid_if);
1326 	if (rc != 0) {
1327 		SPDK_ERRLOG("Unable to claim this bdev as it is already claimed\n");
1328 		spdk_bdev_close(desc);
1329 		return rc;
1330 	}
1331 
1332 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "bdev %s is claimed\n", bdev->name);
1333 
1334 	assert(raid_bdev->state != RAID_BDEV_STATE_ONLINE);
1335 	assert(base_bdev_slot < raid_bdev->num_base_bdevs);
1336 
1337 	raid_bdev->base_bdev_info[base_bdev_slot].thread = spdk_get_thread();
1338 	raid_bdev->base_bdev_info[base_bdev_slot].bdev = bdev;
1339 	raid_bdev->base_bdev_info[base_bdev_slot].desc = desc;
1340 	raid_bdev->num_base_bdevs_discovered++;
1341 	assert(raid_bdev->num_base_bdevs_discovered <= raid_bdev->num_base_bdevs);
1342 
1343 	return 0;
1344 }
1345 
1346 /*
1347  * brief:
1348  * If raid bdev config is complete, then only register the raid bdev to
1349  * bdev layer and remove this raid bdev from configuring list and
1350  * insert the raid bdev to configured list
1351  * params:
1352  * raid_bdev - pointer to raid bdev
1353  * returns:
1354  * 0 - success
1355  * non zero - failure
1356  */
1357 static int
1358 raid_bdev_configure(struct raid_bdev *raid_bdev)
1359 {
1360 	uint32_t blocklen = 0;
1361 	struct spdk_bdev *raid_bdev_gen;
1362 	struct raid_base_bdev_info *base_info;
1363 	int rc = 0;
1364 
1365 	assert(raid_bdev->state == RAID_BDEV_STATE_CONFIGURING);
1366 	assert(raid_bdev->num_base_bdevs_discovered == raid_bdev->num_base_bdevs);
1367 
1368 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1369 		/* Check blocklen for all base bdevs that it should be same */
1370 		if (blocklen == 0) {
1371 			blocklen = base_info->bdev->blocklen;
1372 		} else if (blocklen != base_info->bdev->blocklen) {
1373 			/*
1374 			 * Assumption is that all the base bdevs for any raid bdev should
1375 			 * have same blocklen
1376 			 */
1377 			SPDK_ERRLOG("Blocklen of various bdevs not matching\n");
1378 			return -EINVAL;
1379 		}
1380 	}
1381 	assert(blocklen > 0);
1382 
1383 	/* The strip_size_kb is read in from user in KB. Convert to blocks here for
1384 	 * internal use.
1385 	 */
1386 	raid_bdev->strip_size = (raid_bdev->strip_size_kb * 1024) / blocklen;
1387 	raid_bdev->strip_size_shift = spdk_u32log2(raid_bdev->strip_size);
1388 	raid_bdev->blocklen_shift = spdk_u32log2(blocklen);
1389 
1390 	raid_bdev_gen = &raid_bdev->bdev;
1391 	raid_bdev_gen->blocklen = blocklen;
1392 
1393 	rc = raid_bdev->module->start(raid_bdev);
1394 	if (rc != 0) {
1395 		SPDK_ERRLOG("raid module startup callback failed\n");
1396 		return rc;
1397 	}
1398 	raid_bdev->state = RAID_BDEV_STATE_ONLINE;
1399 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "io device register %p\n", raid_bdev);
1400 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "blockcnt %lu, blocklen %u\n",
1401 		      raid_bdev_gen->blockcnt, raid_bdev_gen->blocklen);
1402 	spdk_io_device_register(raid_bdev, raid_bdev_create_cb, raid_bdev_destroy_cb,
1403 				sizeof(struct raid_bdev_io_channel),
1404 				raid_bdev->bdev.name);
1405 	rc = spdk_bdev_register(raid_bdev_gen);
1406 	if (rc != 0) {
1407 		SPDK_ERRLOG("Unable to register raid bdev and stay at configuring state\n");
1408 		if (raid_bdev->module->stop != NULL) {
1409 			raid_bdev->module->stop(raid_bdev);
1410 		}
1411 		spdk_io_device_unregister(raid_bdev, NULL);
1412 		raid_bdev->state = RAID_BDEV_STATE_CONFIGURING;
1413 		return rc;
1414 	}
1415 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid bdev generic %p\n", raid_bdev_gen);
1416 	TAILQ_REMOVE(&g_raid_bdev_configuring_list, raid_bdev, state_link);
1417 	TAILQ_INSERT_TAIL(&g_raid_bdev_configured_list, raid_bdev, state_link);
1418 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid bdev is created with name %s, raid_bdev %p\n",
1419 		      raid_bdev_gen->name, raid_bdev);
1420 
1421 	return 0;
1422 }
1423 
1424 /*
1425  * brief:
1426  * If raid bdev is online and registered, change the bdev state to
1427  * configuring and unregister this raid device. Queue this raid device
1428  * in configuring list
1429  * params:
1430  * raid_bdev - pointer to raid bdev
1431  * cb_fn - callback function
1432  * cb_arg - argument to callback function
1433  * returns:
1434  * none
1435  */
1436 static void
1437 raid_bdev_deconfigure(struct raid_bdev *raid_bdev, raid_bdev_destruct_cb cb_fn,
1438 		      void *cb_arg)
1439 {
1440 	if (raid_bdev->state != RAID_BDEV_STATE_ONLINE) {
1441 		if (cb_fn) {
1442 			cb_fn(cb_arg, 0);
1443 		}
1444 		return;
1445 	}
1446 
1447 	assert(raid_bdev->num_base_bdevs == raid_bdev->num_base_bdevs_discovered);
1448 	TAILQ_REMOVE(&g_raid_bdev_configured_list, raid_bdev, state_link);
1449 	if (raid_bdev->module->stop != NULL) {
1450 		raid_bdev->module->stop(raid_bdev);
1451 	}
1452 	raid_bdev->state = RAID_BDEV_STATE_OFFLINE;
1453 	assert(raid_bdev->num_base_bdevs_discovered);
1454 	TAILQ_INSERT_TAIL(&g_raid_bdev_offline_list, raid_bdev, state_link);
1455 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid bdev state chaning from online to offline\n");
1456 
1457 	spdk_bdev_unregister(&raid_bdev->bdev, cb_fn, cb_arg);
1458 }
1459 
1460 /*
1461  * brief:
1462  * raid_bdev_find_by_base_bdev function finds the raid bdev which has
1463  *  claimed the base bdev.
1464  * params:
1465  * base_bdev - pointer to base bdev pointer
1466  * _raid_bdev - Reference to pointer to raid bdev
1467  * _base_info - Reference to the raid base bdev info.
1468  * returns:
1469  * true - if the raid bdev is found.
1470  * false - if the raid bdev is not found.
1471  */
1472 static bool
1473 raid_bdev_find_by_base_bdev(struct spdk_bdev *base_bdev, struct raid_bdev **_raid_bdev,
1474 			    struct raid_base_bdev_info **_base_info)
1475 {
1476 	struct raid_bdev *raid_bdev;
1477 	struct raid_base_bdev_info *base_info;
1478 
1479 	TAILQ_FOREACH(raid_bdev, &g_raid_bdev_list, global_link) {
1480 		RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1481 			if (base_info->bdev == base_bdev) {
1482 				*_raid_bdev = raid_bdev;
1483 				*_base_info = base_info;
1484 				return true;
1485 			}
1486 		}
1487 	}
1488 
1489 	return false;
1490 }
1491 
1492 /*
1493  * brief:
1494  * raid_bdev_remove_base_bdev function is called by below layers when base_bdev
1495  * is removed. This function checks if this base bdev is part of any raid bdev
1496  * or not. If yes, it takes necessary action on that particular raid bdev.
1497  * params:
1498  * ctx - pointer to base bdev pointer which got removed
1499  * returns:
1500  * none
1501  */
1502 static void
1503 raid_bdev_remove_base_bdev(void *ctx)
1504 {
1505 	struct spdk_bdev	*base_bdev = ctx;
1506 	struct raid_bdev	*raid_bdev = NULL;
1507 	struct raid_base_bdev_info *base_info;
1508 
1509 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_remove_base_bdev\n");
1510 
1511 	/* Find the raid_bdev which has claimed this base_bdev */
1512 	if (!raid_bdev_find_by_base_bdev(base_bdev, &raid_bdev, &base_info)) {
1513 		SPDK_ERRLOG("bdev to remove '%s' not found\n", base_bdev->name);
1514 		return;
1515 	}
1516 
1517 	assert(base_info->desc);
1518 	base_info->remove_scheduled = true;
1519 
1520 	if (raid_bdev->destruct_called == true ||
1521 	    raid_bdev->state == RAID_BDEV_STATE_CONFIGURING) {
1522 		/*
1523 		 * As raid bdev is not registered yet or already unregistered,
1524 		 * so cleanup should be done here itself.
1525 		 */
1526 		raid_bdev_free_base_bdev_resource(raid_bdev, base_info);
1527 		if (raid_bdev->num_base_bdevs_discovered == 0) {
1528 			/* There is no base bdev for this raid, so free the raid device. */
1529 			raid_bdev_cleanup(raid_bdev);
1530 			return;
1531 		}
1532 	}
1533 
1534 	raid_bdev_deconfigure(raid_bdev, NULL, NULL);
1535 }
1536 
1537 /*
1538  * brief:
1539  * Remove base bdevs from the raid bdev one by one.  Skip any base bdev which
1540  *  doesn't exist.
1541  * params:
1542  * raid_cfg - pointer to raid bdev config.
1543  * cb_fn - callback function
1544  * cb_ctx - argument to callback function
1545  */
1546 void
1547 raid_bdev_remove_base_devices(struct raid_bdev_config *raid_cfg,
1548 			      raid_bdev_destruct_cb cb_fn, void *cb_arg)
1549 {
1550 	struct raid_bdev		*raid_bdev;
1551 	struct raid_base_bdev_info	*base_info;
1552 
1553 	SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid_bdev_remove_base_devices\n");
1554 
1555 	raid_bdev = raid_cfg->raid_bdev;
1556 	if (raid_bdev == NULL) {
1557 		SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "raid bdev %s doesn't exist now\n", raid_cfg->name);
1558 		if (cb_fn) {
1559 			cb_fn(cb_arg, 0);
1560 		}
1561 		return;
1562 	}
1563 
1564 	if (raid_bdev->destroy_started) {
1565 		SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "destroying raid bdev %s is already started\n",
1566 			      raid_cfg->name);
1567 		if (cb_fn) {
1568 			cb_fn(cb_arg, -EALREADY);
1569 		}
1570 		return;
1571 	}
1572 
1573 	raid_bdev->destroy_started = true;
1574 
1575 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
1576 		if (base_info->bdev == NULL) {
1577 			continue;
1578 		}
1579 
1580 		assert(base_info->desc);
1581 		base_info->remove_scheduled = true;
1582 
1583 		if (raid_bdev->destruct_called == true ||
1584 		    raid_bdev->state == RAID_BDEV_STATE_CONFIGURING) {
1585 			/*
1586 			 * As raid bdev is not registered yet or already unregistered,
1587 			 * so cleanup should be done here itself.
1588 			 */
1589 			raid_bdev_free_base_bdev_resource(raid_bdev, base_info);
1590 			if (raid_bdev->num_base_bdevs_discovered == 0) {
1591 				/* There is no base bdev for this raid, so free the raid device. */
1592 				raid_bdev_cleanup(raid_bdev);
1593 				if (cb_fn) {
1594 					cb_fn(cb_arg, 0);
1595 				}
1596 				return;
1597 			}
1598 		}
1599 	}
1600 
1601 	raid_bdev_deconfigure(raid_bdev, cb_fn, cb_arg);
1602 }
1603 
1604 /*
1605  * brief:
1606  * raid_bdev_add_base_device function is the actual function which either adds
1607  * the nvme base device to existing raid bdev or create a new raid bdev. It also claims
1608  * the base device and keep the open descriptor.
1609  * params:
1610  * raid_cfg - pointer to raid bdev config
1611  * bdev - pointer to base bdev
1612  * base_bdev_slot - position to add base bdev
1613  * returns:
1614  * 0 - success
1615  * non zero - failure
1616  */
1617 static int
1618 raid_bdev_add_base_device(struct raid_bdev_config *raid_cfg, struct spdk_bdev *bdev,
1619 			  uint8_t base_bdev_slot)
1620 {
1621 	struct raid_bdev	*raid_bdev;
1622 	int			rc;
1623 
1624 	raid_bdev = raid_cfg->raid_bdev;
1625 	if (!raid_bdev) {
1626 		SPDK_ERRLOG("Raid bdev '%s' is not created yet\n", raid_cfg->name);
1627 		return -ENODEV;
1628 	}
1629 
1630 	rc = raid_bdev_alloc_base_bdev_resource(raid_bdev, bdev, base_bdev_slot);
1631 	if (rc != 0) {
1632 		SPDK_ERRLOG("Failed to allocate resource for bdev '%s'\n", bdev->name);
1633 		return rc;
1634 	}
1635 
1636 	assert(raid_bdev->num_base_bdevs_discovered <= raid_bdev->num_base_bdevs);
1637 
1638 	if (raid_bdev->num_base_bdevs_discovered == raid_bdev->num_base_bdevs) {
1639 		rc = raid_bdev_configure(raid_bdev);
1640 		if (rc != 0) {
1641 			SPDK_ERRLOG("Failed to configure raid bdev\n");
1642 			return rc;
1643 		}
1644 	}
1645 
1646 	return 0;
1647 }
1648 
1649 /*
1650  * brief:
1651  * Add base bdevs to the raid bdev one by one.  Skip any base bdev which doesn't
1652  *  exist or fails to add. If all base bdevs are successfully added, the raid bdev
1653  *  moves to the configured state and becomes available. Otherwise, the raid bdev
1654  *  stays at the configuring state with added base bdevs.
1655  * params:
1656  * raid_cfg - pointer to raid bdev config
1657  * returns:
1658  * 0 - The raid bdev moves to the configured state or stays at the configuring
1659  *     state with added base bdevs due to any nonexistent base bdev.
1660  * non zero - Failed to add any base bdev and stays at the configuring state with
1661  *            added base bdevs.
1662  */
1663 int
1664 raid_bdev_add_base_devices(struct raid_bdev_config *raid_cfg)
1665 {
1666 	struct spdk_bdev	*base_bdev;
1667 	uint8_t			i;
1668 	int			rc = 0, _rc;
1669 
1670 	for (i = 0; i < raid_cfg->num_base_bdevs; i++) {
1671 		base_bdev = spdk_bdev_get_by_name(raid_cfg->base_bdev[i].name);
1672 		if (base_bdev == NULL) {
1673 			SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "base bdev %s doesn't exist now\n",
1674 				      raid_cfg->base_bdev[i].name);
1675 			continue;
1676 		}
1677 
1678 		_rc = raid_bdev_add_base_device(raid_cfg, base_bdev, i);
1679 		if (_rc != 0) {
1680 			SPDK_ERRLOG("Failed to add base bdev %s to RAID bdev %s: %s\n",
1681 				    raid_cfg->base_bdev[i].name, raid_cfg->name,
1682 				    spdk_strerror(-_rc));
1683 			if (rc == 0) {
1684 				rc = _rc;
1685 			}
1686 		}
1687 	}
1688 
1689 	return rc;
1690 }
1691 
1692 /*
1693  * brief:
1694  * raid_bdev_examine function is the examine function call by the below layers
1695  * like bdev_nvme layer. This function will check if this base bdev can be
1696  * claimed by this raid bdev or not.
1697  * params:
1698  * bdev - pointer to base bdev
1699  * returns:
1700  * none
1701  */
1702 static void
1703 raid_bdev_examine(struct spdk_bdev *bdev)
1704 {
1705 	struct raid_bdev_config	*raid_cfg;
1706 	uint8_t			base_bdev_slot;
1707 
1708 	if (raid_bdev_can_claim_bdev(bdev->name, &raid_cfg, &base_bdev_slot)) {
1709 		raid_bdev_add_base_device(raid_cfg, bdev, base_bdev_slot);
1710 	} else {
1711 		SPDK_DEBUGLOG(SPDK_LOG_BDEV_RAID, "bdev %s can't be claimed\n",
1712 			      bdev->name);
1713 	}
1714 
1715 	spdk_bdev_module_examine_done(&g_raid_if);
1716 }
1717 
1718 /* Log component for bdev raid bdev module */
1719 SPDK_LOG_REGISTER_COMPONENT("bdev_raid", SPDK_LOG_BDEV_RAID)
1720