xref: /spdk/module/bdev/null/bdev_null.c (revision 712a3f69d32632bf6c862f00200f7f437d3f7529)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019 Mellanox Technologies LTD. All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include "spdk/bdev.h"
37 #include "spdk/conf.h"
38 #include "spdk/env.h"
39 #include "spdk/thread.h"
40 #include "spdk/json.h"
41 #include "spdk/string.h"
42 #include "spdk/likely.h"
43 
44 #include "spdk/bdev_module.h"
45 #include "spdk_internal/log.h"
46 
47 #include "bdev_null.h"
48 
49 struct null_bdev {
50 	struct spdk_bdev	bdev;
51 	TAILQ_ENTRY(null_bdev)	tailq;
52 };
53 
54 struct null_io_channel {
55 	struct spdk_poller		*poller;
56 	TAILQ_HEAD(, spdk_bdev_io)	io;
57 };
58 
59 static TAILQ_HEAD(, null_bdev) g_null_bdev_head;
60 static void *g_null_read_buf;
61 
62 static int bdev_null_initialize(void);
63 static void bdev_null_finish(void);
64 static void bdev_null_get_spdk_running_config(FILE *fp);
65 
66 static struct spdk_bdev_module null_if = {
67 	.name = "null",
68 	.module_init = bdev_null_initialize,
69 	.module_fini = bdev_null_finish,
70 	.config_text = bdev_null_get_spdk_running_config,
71 	.async_fini = true,
72 };
73 
74 SPDK_BDEV_MODULE_REGISTER(null, &null_if)
75 
76 static int
77 bdev_null_destruct(void *ctx)
78 {
79 	struct null_bdev *bdev = ctx;
80 
81 	TAILQ_REMOVE(&g_null_bdev_head, bdev, tailq);
82 	free(bdev->bdev.name);
83 	free(bdev);
84 
85 	return 0;
86 }
87 
88 static void
89 bdev_null_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io)
90 {
91 	struct null_io_channel *ch = spdk_io_channel_get_ctx(_ch);
92 	struct spdk_bdev *bdev = bdev_io->bdev;
93 	struct spdk_dif_ctx dif_ctx;
94 	struct spdk_dif_error err_blk;
95 	int rc;
96 
97 	if (SPDK_DIF_DISABLE != bdev->dif_type &&
98 	    (SPDK_BDEV_IO_TYPE_READ == bdev_io->type ||
99 	     SPDK_BDEV_IO_TYPE_WRITE == bdev_io->type)) {
100 		rc = spdk_dif_ctx_init(&dif_ctx,
101 				       bdev->blocklen,
102 				       bdev->md_len,
103 				       bdev->md_interleave,
104 				       bdev->dif_is_head_of_md,
105 				       bdev->dif_type,
106 				       bdev->dif_check_flags,
107 				       bdev_io->u.bdev.offset_blocks & 0xFFFFFFFF,
108 				       0xFFFF, 0, 0, 0);
109 		if (0 != rc) {
110 			SPDK_ERRLOG("Failed to initialize DIF context, error %d\n", rc);
111 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
112 			return;
113 		}
114 	}
115 
116 	switch (bdev_io->type) {
117 	case SPDK_BDEV_IO_TYPE_READ:
118 		if (bdev_io->u.bdev.iovs[0].iov_base == NULL) {
119 			assert(bdev_io->u.bdev.iovcnt == 1);
120 			if (spdk_likely(bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen <=
121 					SPDK_BDEV_LARGE_BUF_MAX_SIZE)) {
122 				bdev_io->u.bdev.iovs[0].iov_base = g_null_read_buf;
123 				bdev_io->u.bdev.iovs[0].iov_len = bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen;
124 			} else {
125 				SPDK_ERRLOG("Overflow occurred. Read I/O size %" PRIu64 " was larger than permitted %d\n",
126 					    bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen,
127 					    SPDK_BDEV_LARGE_BUF_MAX_SIZE);
128 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
129 				return;
130 			}
131 		}
132 		if (SPDK_DIF_DISABLE != bdev->dif_type) {
133 			rc = spdk_dif_generate(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
134 					       bdev_io->u.bdev.num_blocks, &dif_ctx);
135 			if (0 != rc) {
136 				SPDK_ERRLOG("IO DIF generation failed: lba %lu, num_block %lu\n",
137 					    bdev_io->u.bdev.offset_blocks,
138 					    bdev_io->u.bdev.num_blocks);
139 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
140 				return;
141 			}
142 		}
143 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
144 		break;
145 	case SPDK_BDEV_IO_TYPE_WRITE:
146 		if (SPDK_DIF_DISABLE != bdev->dif_type) {
147 			rc = spdk_dif_verify(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
148 					     bdev_io->u.bdev.num_blocks, &dif_ctx, &err_blk);
149 			if (0 != rc) {
150 				SPDK_ERRLOG("IO DIF verification failed: lba %lu, num_blocks %lu, "
151 					    "err_type %u, expected %u, actual %u, err_offset %u\n",
152 					    bdev_io->u.bdev.offset_blocks,
153 					    bdev_io->u.bdev.num_blocks,
154 					    err_blk.err_type,
155 					    err_blk.expected,
156 					    err_blk.actual,
157 					    err_blk.err_offset);
158 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
159 				return;
160 			}
161 		}
162 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
163 		break;
164 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
165 	case SPDK_BDEV_IO_TYPE_RESET:
166 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
167 		break;
168 	case SPDK_BDEV_IO_TYPE_FLUSH:
169 	case SPDK_BDEV_IO_TYPE_UNMAP:
170 	default:
171 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
172 		break;
173 	}
174 }
175 
176 static bool
177 bdev_null_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
178 {
179 	switch (io_type) {
180 	case SPDK_BDEV_IO_TYPE_READ:
181 	case SPDK_BDEV_IO_TYPE_WRITE:
182 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
183 	case SPDK_BDEV_IO_TYPE_RESET:
184 		return true;
185 	case SPDK_BDEV_IO_TYPE_FLUSH:
186 	case SPDK_BDEV_IO_TYPE_UNMAP:
187 	default:
188 		return false;
189 	}
190 }
191 
192 static struct spdk_io_channel *
193 bdev_null_get_io_channel(void *ctx)
194 {
195 	return spdk_get_io_channel(&g_null_bdev_head);
196 }
197 
198 static void
199 bdev_null_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
200 {
201 	char uuid_str[SPDK_UUID_STRING_LEN];
202 
203 	spdk_json_write_object_begin(w);
204 
205 	spdk_json_write_named_string(w, "method", "bdev_null_create");
206 
207 	spdk_json_write_named_object_begin(w, "params");
208 	spdk_json_write_named_string(w, "name", bdev->name);
209 	spdk_json_write_named_uint64(w, "num_blocks", bdev->blockcnt);
210 	spdk_json_write_named_uint32(w, "block_size", bdev->blocklen);
211 	spdk_json_write_named_uint32(w, "md_size", bdev->md_len);
212 	spdk_json_write_named_uint32(w, "dif_type", bdev->dif_type);
213 	spdk_json_write_named_bool(w, "dif_is_head_of_md", bdev->dif_is_head_of_md);
214 	spdk_uuid_fmt_lower(uuid_str, sizeof(uuid_str), &bdev->uuid);
215 	spdk_json_write_named_string(w, "uuid", uuid_str);
216 	spdk_json_write_object_end(w);
217 
218 	spdk_json_write_object_end(w);
219 }
220 
221 static const struct spdk_bdev_fn_table null_fn_table = {
222 	.destruct		= bdev_null_destruct,
223 	.submit_request		= bdev_null_submit_request,
224 	.io_type_supported	= bdev_null_io_type_supported,
225 	.get_io_channel		= bdev_null_get_io_channel,
226 	.write_config_json	= bdev_null_write_config_json,
227 };
228 
229 int
230 bdev_null_create(struct spdk_bdev **bdev, const struct spdk_null_bdev_opts *opts)
231 {
232 	struct null_bdev *null_disk;
233 	uint32_t data_block_size;
234 	int rc;
235 
236 	if (!opts) {
237 		SPDK_ERRLOG("No options provided for Null bdev.\n");
238 		return -EINVAL;
239 	}
240 
241 	if (opts->md_interleave) {
242 		if (opts->block_size < opts->md_size) {
243 			SPDK_ERRLOG("Interleaved metadata size can not be greater than block size.\n");
244 			return -EINVAL;
245 		}
246 		data_block_size = opts->block_size - opts->md_size;
247 	} else {
248 		if (opts->md_size != 0) {
249 			SPDK_ERRLOG("Metadata in separate buffer is not supported\n");
250 			return -ENOTSUP;
251 		}
252 		data_block_size = opts->block_size;
253 	}
254 
255 	if (data_block_size % 512 != 0) {
256 		SPDK_ERRLOG("Data block size %u is not a multiple of 512.\n", opts->block_size);
257 		return -EINVAL;
258 	}
259 
260 	if (opts->num_blocks == 0) {
261 		SPDK_ERRLOG("Disk must be more than 0 blocks\n");
262 		return -EINVAL;
263 	}
264 
265 	null_disk = calloc(1, sizeof(*null_disk));
266 	if (!null_disk) {
267 		SPDK_ERRLOG("could not allocate null_bdev\n");
268 		return -ENOMEM;
269 	}
270 
271 	null_disk->bdev.name = strdup(opts->name);
272 	if (!null_disk->bdev.name) {
273 		free(null_disk);
274 		return -ENOMEM;
275 	}
276 	null_disk->bdev.product_name = "Null disk";
277 
278 	null_disk->bdev.write_cache = 0;
279 	null_disk->bdev.blocklen = opts->block_size;
280 	null_disk->bdev.blockcnt = opts->num_blocks;
281 	null_disk->bdev.md_len = opts->md_size;
282 	null_disk->bdev.md_interleave = opts->md_interleave;
283 	null_disk->bdev.dif_type = opts->dif_type;
284 	null_disk->bdev.dif_is_head_of_md = opts->dif_is_head_of_md;
285 	/* Current block device layer API does not propagate
286 	 * any DIF related information from user. So, we can
287 	 * not generate or verify Application Tag.
288 	 */
289 	switch (opts->dif_type) {
290 	case SPDK_DIF_TYPE1:
291 	case SPDK_DIF_TYPE2:
292 		null_disk->bdev.dif_check_flags = SPDK_DIF_FLAGS_GUARD_CHECK |
293 						  SPDK_DIF_FLAGS_REFTAG_CHECK;
294 		break;
295 	case SPDK_DIF_TYPE3:
296 		null_disk->bdev.dif_check_flags = SPDK_DIF_FLAGS_GUARD_CHECK;
297 		break;
298 	case SPDK_DIF_DISABLE:
299 		break;
300 	}
301 	if (opts->uuid) {
302 		null_disk->bdev.uuid = *opts->uuid;
303 	} else {
304 		spdk_uuid_generate(&null_disk->bdev.uuid);
305 	}
306 
307 	null_disk->bdev.ctxt = null_disk;
308 	null_disk->bdev.fn_table = &null_fn_table;
309 	null_disk->bdev.module = &null_if;
310 
311 	rc = spdk_bdev_register(&null_disk->bdev);
312 	if (rc) {
313 		free(null_disk->bdev.name);
314 		free(null_disk);
315 		return rc;
316 	}
317 
318 	*bdev = &(null_disk->bdev);
319 
320 	TAILQ_INSERT_TAIL(&g_null_bdev_head, null_disk, tailq);
321 
322 	return rc;
323 }
324 
325 void
326 bdev_null_delete(struct spdk_bdev *bdev, spdk_delete_null_complete cb_fn, void *cb_arg)
327 {
328 	if (!bdev || bdev->module != &null_if) {
329 		cb_fn(cb_arg, -ENODEV);
330 		return;
331 	}
332 
333 	spdk_bdev_unregister(bdev, cb_fn, cb_arg);
334 }
335 
336 static int
337 null_io_poll(void *arg)
338 {
339 	struct null_io_channel		*ch = arg;
340 	TAILQ_HEAD(, spdk_bdev_io)	io;
341 	struct spdk_bdev_io		*bdev_io;
342 
343 	TAILQ_INIT(&io);
344 	TAILQ_SWAP(&ch->io, &io, spdk_bdev_io, module_link);
345 
346 	if (TAILQ_EMPTY(&io)) {
347 		return 0;
348 	}
349 
350 	while (!TAILQ_EMPTY(&io)) {
351 		bdev_io = TAILQ_FIRST(&io);
352 		TAILQ_REMOVE(&io, bdev_io, module_link);
353 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
354 	}
355 
356 	return 1;
357 }
358 
359 static int
360 null_bdev_create_cb(void *io_device, void *ctx_buf)
361 {
362 	struct null_io_channel *ch = ctx_buf;
363 
364 	TAILQ_INIT(&ch->io);
365 	ch->poller = spdk_poller_register(null_io_poll, ch, 0);
366 
367 	return 0;
368 }
369 
370 static void
371 null_bdev_destroy_cb(void *io_device, void *ctx_buf)
372 {
373 	struct null_io_channel *ch = ctx_buf;
374 
375 	spdk_poller_unregister(&ch->poller);
376 }
377 
378 static void
379 _bdev_null_cleanup_cb(void *arg)
380 {
381 	spdk_free(g_null_read_buf);
382 }
383 
384 static int
385 bdev_null_initialize(void)
386 {
387 	struct spdk_conf_section *sp = spdk_conf_find_section(NULL, "Null");
388 	uint64_t size_in_mb, num_blocks;
389 	int block_size, i, rc = 0;
390 	int md_size, dif_type;
391 	struct spdk_bdev *bdev;
392 	const char *name, *val;
393 	struct spdk_null_bdev_opts opts = {};
394 
395 	TAILQ_INIT(&g_null_bdev_head);
396 
397 	/*
398 	 * This will be used if upper layer expects us to allocate the read buffer.
399 	 *  Instead of using a real rbuf from the bdev pool, just always point to
400 	 *  this same zeroed buffer.
401 	 */
402 	g_null_read_buf = spdk_zmalloc(SPDK_BDEV_LARGE_BUF_MAX_SIZE, 0, NULL,
403 				       SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
404 
405 	/*
406 	 * We need to pick some unique address as our "io device" - so just use the
407 	 *  address of the global tailq.
408 	 */
409 	spdk_io_device_register(&g_null_bdev_head, null_bdev_create_cb, null_bdev_destroy_cb,
410 				sizeof(struct null_io_channel),
411 				"null_bdev");
412 
413 	if (sp == NULL) {
414 		goto end;
415 	}
416 
417 	for (i = 0; ; ++i) {
418 		val = spdk_conf_section_get_nval(sp, "Dev", i);
419 		if (val == NULL) {
420 			break;
421 		}
422 
423 		name = spdk_conf_section_get_nmval(sp, "Dev", i, 0);
424 		if (name == NULL) {
425 			SPDK_ERRLOG("Null entry %d: Name must be provided\n", i);
426 			continue;
427 		}
428 
429 		val = spdk_conf_section_get_nmval(sp, "Dev", i, 1);
430 		if (val == NULL) {
431 			SPDK_ERRLOG("Null entry %d: Size in MB must be provided\n", i);
432 			continue;
433 		}
434 
435 		errno = 0;
436 		size_in_mb = strtoull(val, NULL, 10);
437 		if (errno) {
438 			SPDK_ERRLOG("Null entry %d: Invalid size in MB %s\n", i, val);
439 			continue;
440 		}
441 
442 		val = spdk_conf_section_get_nmval(sp, "Dev", i, 2);
443 		if (val == NULL) {
444 			block_size = 512;
445 		} else {
446 			block_size = (int)spdk_strtol(val, 10);
447 			if (block_size <= 0) {
448 				SPDK_ERRLOG("Null entry %d: Invalid block size %s\n", i, val);
449 				continue;
450 			}
451 		}
452 
453 		val = spdk_conf_section_get_nmval(sp, "Dev", i, 3);
454 		if (val == NULL) {
455 			md_size = 0;
456 		} else {
457 			md_size = (int)spdk_strtol(val, 10);
458 			if (md_size < 0) {
459 				SPDK_ERRLOG("Null entry %d: Invalid metadata size %s\n", i, val);
460 				continue;
461 			}
462 		}
463 
464 		val = spdk_conf_section_get_nmval(sp, "Dev", i, 4);
465 		if (val == NULL) {
466 			dif_type = SPDK_DIF_DISABLE;
467 		} else {
468 			dif_type = (int)spdk_strtol(val, 10);
469 			if (dif_type < SPDK_DIF_DISABLE || dif_type > SPDK_DIF_TYPE3) {
470 				SPDK_ERRLOG("Null entry %d: Invalid data protection type %s\n", i, val);
471 				continue;
472 			}
473 		}
474 		num_blocks = size_in_mb * (1024 * 1024) / block_size;
475 
476 		opts.name = name;
477 		opts.num_blocks = num_blocks;
478 		opts.block_size = block_size;
479 		opts.md_size = md_size;
480 		opts.md_interleave = true;
481 		opts.dif_type = dif_type;
482 		opts.dif_is_head_of_md = false;
483 		rc = bdev_null_create(&bdev, &opts);
484 		if (rc) {
485 			SPDK_ERRLOG("Could not create null bdev\n");
486 			goto end;
487 		}
488 	}
489 end:
490 	if (rc) {
491 		spdk_io_device_unregister(&g_null_bdev_head, _bdev_null_cleanup_cb);
492 	}
493 	return rc;
494 }
495 
496 static void
497 _bdev_null_finish_cb(void *arg)
498 {
499 	spdk_free(g_null_read_buf);
500 	spdk_bdev_module_finish_done();
501 }
502 
503 static void
504 bdev_null_finish(void)
505 {
506 	spdk_io_device_unregister(&g_null_bdev_head, _bdev_null_finish_cb);
507 }
508 
509 static void
510 bdev_null_get_spdk_running_config(FILE *fp)
511 {
512 	struct null_bdev *bdev;
513 	uint64_t null_bdev_size;
514 
515 	fprintf(fp, "\n[Null]\n");
516 
517 	TAILQ_FOREACH(bdev, &g_null_bdev_head, tailq) {
518 		null_bdev_size = bdev->bdev.blocklen * bdev->bdev.blockcnt;
519 		null_bdev_size /= (1024 * 1024);
520 		fprintf(fp, "  Dev %s %" PRIu64 " %d %d %d\n",
521 			bdev->bdev.name, null_bdev_size, bdev->bdev.blocklen, bdev->bdev.md_len,
522 			bdev->bdev.dif_type);
523 	}
524 }
525 
526 SPDK_LOG_REGISTER_COMPONENT("bdev_null", SPDK_LOG_BDEV_NULL)
527