xref: /spdk/module/bdev/null/bdev_null.c (revision aaba5d9c9e8fca9925d5812030ff3ec9ba869fa3)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2017 Intel Corporation. All rights reserved.
3  *   Copyright (c) 2019 Mellanox Technologies LTD. All rights reserved.
4  */
5 
6 #include "spdk/stdinc.h"
7 
8 #include "spdk/bdev.h"
9 #include "spdk/env.h"
10 #include "spdk/thread.h"
11 #include "spdk/json.h"
12 #include "spdk/string.h"
13 #include "spdk/likely.h"
14 
15 #include "spdk/bdev_module.h"
16 #include "spdk/log.h"
17 
18 #include "bdev_null.h"
19 
20 struct null_bdev {
21 	struct spdk_bdev	bdev;
22 	TAILQ_ENTRY(null_bdev)	tailq;
23 };
24 
25 struct null_io_channel {
26 	struct spdk_poller		*poller;
27 	TAILQ_HEAD(, spdk_bdev_io)	io;
28 };
29 
30 static TAILQ_HEAD(, null_bdev) g_null_bdev_head = TAILQ_HEAD_INITIALIZER(g_null_bdev_head);
31 static void *g_null_read_buf;
32 
33 static int bdev_null_initialize(void);
34 static void bdev_null_finish(void);
35 
36 static struct spdk_bdev_module null_if = {
37 	.name = "null",
38 	.module_init = bdev_null_initialize,
39 	.module_fini = bdev_null_finish,
40 	.async_fini = true,
41 };
42 
43 SPDK_BDEV_MODULE_REGISTER(null, &null_if)
44 
45 static int
46 bdev_null_destruct(void *ctx)
47 {
48 	struct null_bdev *bdev = ctx;
49 
50 	TAILQ_REMOVE(&g_null_bdev_head, bdev, tailq);
51 	free(bdev->bdev.name);
52 	free(bdev);
53 
54 	return 0;
55 }
56 
57 static bool
58 bdev_null_abort_io(struct null_io_channel *ch, struct spdk_bdev_io *bio_to_abort)
59 {
60 	struct spdk_bdev_io *bdev_io;
61 
62 	TAILQ_FOREACH(bdev_io, &ch->io, module_link) {
63 		if (bdev_io == bio_to_abort) {
64 			TAILQ_REMOVE(&ch->io, bio_to_abort, module_link);
65 			spdk_bdev_io_complete(bio_to_abort, SPDK_BDEV_IO_STATUS_ABORTED);
66 			return true;
67 		}
68 	}
69 
70 	return false;
71 }
72 
73 static void
74 bdev_null_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_io)
75 {
76 	struct null_io_channel *ch = spdk_io_channel_get_ctx(_ch);
77 	struct spdk_bdev *bdev = bdev_io->bdev;
78 	struct spdk_dif_ctx dif_ctx;
79 	struct spdk_dif_error err_blk;
80 	int rc;
81 
82 	if (SPDK_DIF_DISABLE != bdev->dif_type &&
83 	    (SPDK_BDEV_IO_TYPE_READ == bdev_io->type ||
84 	     SPDK_BDEV_IO_TYPE_WRITE == bdev_io->type)) {
85 		rc = spdk_dif_ctx_init(&dif_ctx,
86 				       bdev->blocklen,
87 				       bdev->md_len,
88 				       bdev->md_interleave,
89 				       bdev->dif_is_head_of_md,
90 				       bdev->dif_type,
91 				       bdev->dif_check_flags,
92 				       bdev_io->u.bdev.offset_blocks & 0xFFFFFFFF,
93 				       0xFFFF, 0, 0, 0);
94 		if (0 != rc) {
95 			SPDK_ERRLOG("Failed to initialize DIF context, error %d\n", rc);
96 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
97 			return;
98 		}
99 	}
100 
101 	switch (bdev_io->type) {
102 	case SPDK_BDEV_IO_TYPE_READ:
103 		if (bdev_io->u.bdev.iovs[0].iov_base == NULL) {
104 			assert(bdev_io->u.bdev.iovcnt == 1);
105 			if (spdk_likely(bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen <=
106 					SPDK_BDEV_LARGE_BUF_MAX_SIZE)) {
107 				bdev_io->u.bdev.iovs[0].iov_base = g_null_read_buf;
108 				bdev_io->u.bdev.iovs[0].iov_len = bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen;
109 			} else {
110 				SPDK_ERRLOG("Overflow occurred. Read I/O size %" PRIu64 " was larger than permitted %d\n",
111 					    bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen,
112 					    SPDK_BDEV_LARGE_BUF_MAX_SIZE);
113 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
114 				return;
115 			}
116 		}
117 		if (SPDK_DIF_DISABLE != bdev->dif_type) {
118 			rc = spdk_dif_generate(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
119 					       bdev_io->u.bdev.num_blocks, &dif_ctx);
120 			if (0 != rc) {
121 				SPDK_ERRLOG("IO DIF generation failed: lba %" PRIu64 ", num_block %" PRIu64 "\n",
122 					    bdev_io->u.bdev.offset_blocks,
123 					    bdev_io->u.bdev.num_blocks);
124 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
125 				return;
126 			}
127 		}
128 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
129 		break;
130 	case SPDK_BDEV_IO_TYPE_WRITE:
131 		if (SPDK_DIF_DISABLE != bdev->dif_type) {
132 			rc = spdk_dif_verify(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
133 					     bdev_io->u.bdev.num_blocks, &dif_ctx, &err_blk);
134 			if (0 != rc) {
135 				SPDK_ERRLOG("IO DIF verification failed: lba %" PRIu64 ", num_blocks %" PRIu64 ", "
136 					    "err_type %u, expected %u, actual %u, err_offset %u\n",
137 					    bdev_io->u.bdev.offset_blocks,
138 					    bdev_io->u.bdev.num_blocks,
139 					    err_blk.err_type,
140 					    err_blk.expected,
141 					    err_blk.actual,
142 					    err_blk.err_offset);
143 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
144 				return;
145 			}
146 		}
147 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
148 		break;
149 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
150 	case SPDK_BDEV_IO_TYPE_RESET:
151 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
152 		break;
153 	case SPDK_BDEV_IO_TYPE_ABORT:
154 		if (bdev_null_abort_io(ch, bdev_io->u.abort.bio_to_abort)) {
155 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
156 		} else {
157 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
158 		}
159 		break;
160 	case SPDK_BDEV_IO_TYPE_FLUSH:
161 	case SPDK_BDEV_IO_TYPE_UNMAP:
162 	default:
163 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
164 		break;
165 	}
166 }
167 
168 static bool
169 bdev_null_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
170 {
171 	switch (io_type) {
172 	case SPDK_BDEV_IO_TYPE_READ:
173 	case SPDK_BDEV_IO_TYPE_WRITE:
174 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
175 	case SPDK_BDEV_IO_TYPE_RESET:
176 	case SPDK_BDEV_IO_TYPE_ABORT:
177 		return true;
178 	case SPDK_BDEV_IO_TYPE_FLUSH:
179 	case SPDK_BDEV_IO_TYPE_UNMAP:
180 	default:
181 		return false;
182 	}
183 }
184 
185 static struct spdk_io_channel *
186 bdev_null_get_io_channel(void *ctx)
187 {
188 	return spdk_get_io_channel(&g_null_bdev_head);
189 }
190 
191 static void
192 bdev_null_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
193 {
194 	char uuid_str[SPDK_UUID_STRING_LEN];
195 
196 	spdk_json_write_object_begin(w);
197 
198 	spdk_json_write_named_string(w, "method", "bdev_null_create");
199 
200 	spdk_json_write_named_object_begin(w, "params");
201 	spdk_json_write_named_string(w, "name", bdev->name);
202 	spdk_json_write_named_uint64(w, "num_blocks", bdev->blockcnt);
203 	spdk_json_write_named_uint32(w, "block_size", bdev->blocklen);
204 	spdk_json_write_named_uint32(w, "physical_block_size", bdev->phys_blocklen);
205 	spdk_json_write_named_uint32(w, "md_size", bdev->md_len);
206 	spdk_json_write_named_uint32(w, "dif_type", bdev->dif_type);
207 	spdk_json_write_named_bool(w, "dif_is_head_of_md", bdev->dif_is_head_of_md);
208 	spdk_uuid_fmt_lower(uuid_str, sizeof(uuid_str), &bdev->uuid);
209 	spdk_json_write_named_string(w, "uuid", uuid_str);
210 	spdk_json_write_object_end(w);
211 
212 	spdk_json_write_object_end(w);
213 }
214 
215 static const struct spdk_bdev_fn_table null_fn_table = {
216 	.destruct		= bdev_null_destruct,
217 	.submit_request		= bdev_null_submit_request,
218 	.io_type_supported	= bdev_null_io_type_supported,
219 	.get_io_channel		= bdev_null_get_io_channel,
220 	.write_config_json	= bdev_null_write_config_json,
221 };
222 
223 int
224 bdev_null_create(struct spdk_bdev **bdev, const struct spdk_null_bdev_opts *opts)
225 {
226 	struct null_bdev *null_disk;
227 	uint32_t data_block_size;
228 	int rc;
229 
230 	if (!opts) {
231 		SPDK_ERRLOG("No options provided for Null bdev.\n");
232 		return -EINVAL;
233 	}
234 
235 	if (opts->md_interleave) {
236 		if (opts->block_size < opts->md_size) {
237 			SPDK_ERRLOG("Interleaved metadata size can not be greater than block size.\n");
238 			return -EINVAL;
239 		}
240 		data_block_size = opts->block_size - opts->md_size;
241 	} else {
242 		if (opts->md_size != 0) {
243 			SPDK_ERRLOG("Metadata in separate buffer is not supported\n");
244 			return -ENOTSUP;
245 		}
246 		data_block_size = opts->block_size;
247 	}
248 
249 	if (data_block_size % 512 != 0) {
250 		SPDK_ERRLOG("Data block size %u is not a multiple of 512.\n", opts->block_size);
251 		return -EINVAL;
252 	}
253 
254 	if (opts->num_blocks == 0) {
255 		SPDK_ERRLOG("Disk must be more than 0 blocks\n");
256 		return -EINVAL;
257 	}
258 
259 	null_disk = calloc(1, sizeof(*null_disk));
260 	if (!null_disk) {
261 		SPDK_ERRLOG("could not allocate null_bdev\n");
262 		return -ENOMEM;
263 	}
264 
265 	null_disk->bdev.name = strdup(opts->name);
266 	if (!null_disk->bdev.name) {
267 		free(null_disk);
268 		return -ENOMEM;
269 	}
270 	null_disk->bdev.product_name = "Null disk";
271 
272 	null_disk->bdev.write_cache = 0;
273 	null_disk->bdev.blocklen = opts->block_size;
274 	null_disk->bdev.phys_blocklen = opts->physical_block_size;
275 	null_disk->bdev.blockcnt = opts->num_blocks;
276 	null_disk->bdev.md_len = opts->md_size;
277 	null_disk->bdev.md_interleave = opts->md_interleave;
278 	null_disk->bdev.dif_type = opts->dif_type;
279 	null_disk->bdev.dif_is_head_of_md = opts->dif_is_head_of_md;
280 	/* Current block device layer API does not propagate
281 	 * any DIF related information from user. So, we can
282 	 * not generate or verify Application Tag.
283 	 */
284 	switch (opts->dif_type) {
285 	case SPDK_DIF_TYPE1:
286 	case SPDK_DIF_TYPE2:
287 		null_disk->bdev.dif_check_flags = SPDK_DIF_FLAGS_GUARD_CHECK |
288 						  SPDK_DIF_FLAGS_REFTAG_CHECK;
289 		break;
290 	case SPDK_DIF_TYPE3:
291 		null_disk->bdev.dif_check_flags = SPDK_DIF_FLAGS_GUARD_CHECK;
292 		break;
293 	case SPDK_DIF_DISABLE:
294 		break;
295 	}
296 	if (opts->uuid) {
297 		null_disk->bdev.uuid = *opts->uuid;
298 	} else {
299 		spdk_uuid_generate(&null_disk->bdev.uuid);
300 	}
301 
302 	null_disk->bdev.ctxt = null_disk;
303 	null_disk->bdev.fn_table = &null_fn_table;
304 	null_disk->bdev.module = &null_if;
305 
306 	rc = spdk_bdev_register(&null_disk->bdev);
307 	if (rc) {
308 		free(null_disk->bdev.name);
309 		free(null_disk);
310 		return rc;
311 	}
312 
313 	*bdev = &(null_disk->bdev);
314 
315 	TAILQ_INSERT_TAIL(&g_null_bdev_head, null_disk, tailq);
316 
317 	return rc;
318 }
319 
320 void
321 bdev_null_delete(const char *bdev_name, spdk_delete_null_complete cb_fn, void *cb_arg)
322 {
323 	int rc;
324 
325 	rc = spdk_bdev_unregister_by_name(bdev_name, &null_if, cb_fn, cb_arg);
326 	if (rc != 0) {
327 		cb_fn(cb_arg, rc);
328 	}
329 }
330 
331 static int
332 null_io_poll(void *arg)
333 {
334 	struct null_io_channel		*ch = arg;
335 	TAILQ_HEAD(, spdk_bdev_io)	io;
336 	struct spdk_bdev_io		*bdev_io;
337 
338 	TAILQ_INIT(&io);
339 	TAILQ_SWAP(&ch->io, &io, spdk_bdev_io, module_link);
340 
341 	if (TAILQ_EMPTY(&io)) {
342 		return SPDK_POLLER_IDLE;
343 	}
344 
345 	while (!TAILQ_EMPTY(&io)) {
346 		bdev_io = TAILQ_FIRST(&io);
347 		TAILQ_REMOVE(&io, bdev_io, module_link);
348 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
349 	}
350 
351 	return SPDK_POLLER_BUSY;
352 }
353 
354 static int
355 null_bdev_create_cb(void *io_device, void *ctx_buf)
356 {
357 	struct null_io_channel *ch = ctx_buf;
358 
359 	TAILQ_INIT(&ch->io);
360 	ch->poller = SPDK_POLLER_REGISTER(null_io_poll, ch, 0);
361 
362 	return 0;
363 }
364 
365 static void
366 null_bdev_destroy_cb(void *io_device, void *ctx_buf)
367 {
368 	struct null_io_channel *ch = ctx_buf;
369 
370 	spdk_poller_unregister(&ch->poller);
371 }
372 
373 static int
374 bdev_null_initialize(void)
375 {
376 	/*
377 	 * This will be used if upper layer expects us to allocate the read buffer.
378 	 *  Instead of using a real rbuf from the bdev pool, just always point to
379 	 *  this same zeroed buffer.
380 	 */
381 	g_null_read_buf = spdk_zmalloc(SPDK_BDEV_LARGE_BUF_MAX_SIZE, 0, NULL,
382 				       SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
383 	if (g_null_read_buf == NULL) {
384 		return -1;
385 	}
386 
387 	/*
388 	 * We need to pick some unique address as our "io device" - so just use the
389 	 *  address of the global tailq.
390 	 */
391 	spdk_io_device_register(&g_null_bdev_head, null_bdev_create_cb, null_bdev_destroy_cb,
392 				sizeof(struct null_io_channel), "null_bdev");
393 
394 	return 0;
395 }
396 
397 static void
398 dummy_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, void *ctx)
399 {
400 }
401 
402 int
403 bdev_null_resize(const char *bdev_name, const uint64_t new_size_in_mb)
404 {
405 	struct spdk_bdev_desc *desc;
406 	struct spdk_bdev *bdev;
407 	uint64_t current_size_in_mb;
408 	uint64_t new_size_in_byte;
409 	int rc = 0;
410 
411 	rc = spdk_bdev_open_ext(bdev_name, false, dummy_bdev_event_cb, NULL, &desc);
412 	if (rc != 0) {
413 		SPDK_ERRLOG("failed to open bdev; %s.\n", bdev_name);
414 		return rc;
415 	}
416 
417 	bdev = spdk_bdev_desc_get_bdev(desc);
418 
419 	if (bdev->module != &null_if) {
420 		rc = -EINVAL;
421 		goto exit;
422 	}
423 
424 	current_size_in_mb = bdev->blocklen * bdev->blockcnt / (1024 * 1024);
425 	if (new_size_in_mb < current_size_in_mb) {
426 		SPDK_ERRLOG("The new bdev size must not be smaller than current bdev size.\n");
427 		rc = -EINVAL;
428 		goto exit;
429 	}
430 
431 	new_size_in_byte = new_size_in_mb * 1024 * 1024;
432 
433 	rc = spdk_bdev_notify_blockcnt_change(bdev, new_size_in_byte / bdev->blocklen);
434 	if (rc != 0) {
435 		SPDK_ERRLOG("failed to notify block cnt change.\n");
436 	}
437 
438 exit:
439 	spdk_bdev_close(desc);
440 	return rc;
441 }
442 
443 static void
444 _bdev_null_finish_cb(void *arg)
445 {
446 	spdk_free(g_null_read_buf);
447 	spdk_bdev_module_fini_done();
448 }
449 
450 static void
451 bdev_null_finish(void)
452 {
453 	if (g_null_read_buf == NULL) {
454 		spdk_bdev_module_fini_done();
455 		return;
456 	}
457 	spdk_io_device_unregister(&g_null_bdev_head, _bdev_null_finish_cb);
458 }
459 
460 SPDK_LOG_REGISTER_COMPONENT(bdev_null)
461