xref: /spdk/module/bdev/null/bdev_null.c (revision 60982c759db49b4f4579f16e3b24df0725ba4b94)
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 	struct spdk_dif_ctx_init_ext_opts dif_opts;
82 
83 	if (SPDK_DIF_DISABLE != bdev->dif_type &&
84 	    (SPDK_BDEV_IO_TYPE_READ == bdev_io->type ||
85 	     SPDK_BDEV_IO_TYPE_WRITE == bdev_io->type)) {
86 		dif_opts.size = SPDK_SIZEOF(&dif_opts, dif_pi_format);
87 		dif_opts.dif_pi_format = SPDK_DIF_PI_FORMAT_16;
88 		rc = spdk_dif_ctx_init(&dif_ctx,
89 				       bdev->blocklen,
90 				       bdev->md_len,
91 				       bdev->md_interleave,
92 				       bdev->dif_is_head_of_md,
93 				       bdev->dif_type,
94 				       bdev->dif_check_flags,
95 				       bdev_io->u.bdev.offset_blocks & 0xFFFFFFFF,
96 				       0xFFFF, 0, 0, 0, &dif_opts);
97 		if (0 != rc) {
98 			SPDK_ERRLOG("Failed to initialize DIF context, error %d\n", rc);
99 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
100 			return;
101 		}
102 	}
103 
104 	switch (bdev_io->type) {
105 	case SPDK_BDEV_IO_TYPE_READ:
106 		if (bdev_io->u.bdev.iovs[0].iov_base == NULL) {
107 			assert(bdev_io->u.bdev.iovcnt == 1);
108 			if (spdk_likely(bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen <=
109 					SPDK_BDEV_LARGE_BUF_MAX_SIZE)) {
110 				bdev_io->u.bdev.iovs[0].iov_base = g_null_read_buf;
111 				bdev_io->u.bdev.iovs[0].iov_len = bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen;
112 			} else {
113 				SPDK_ERRLOG("Overflow occurred. Read I/O size %" PRIu64 " was larger than permitted %d\n",
114 					    bdev_io->u.bdev.num_blocks * bdev_io->bdev->blocklen,
115 					    SPDK_BDEV_LARGE_BUF_MAX_SIZE);
116 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
117 				return;
118 			}
119 		}
120 		if (SPDK_DIF_DISABLE != bdev->dif_type) {
121 			rc = spdk_dif_generate(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
122 					       bdev_io->u.bdev.num_blocks, &dif_ctx);
123 			if (0 != rc) {
124 				SPDK_ERRLOG("IO DIF generation failed: lba %" PRIu64 ", num_block %" PRIu64 "\n",
125 					    bdev_io->u.bdev.offset_blocks,
126 					    bdev_io->u.bdev.num_blocks);
127 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
128 				return;
129 			}
130 		}
131 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
132 		break;
133 	case SPDK_BDEV_IO_TYPE_WRITE:
134 		if (SPDK_DIF_DISABLE != bdev->dif_type) {
135 			rc = spdk_dif_verify(bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
136 					     bdev_io->u.bdev.num_blocks, &dif_ctx, &err_blk);
137 			if (0 != rc) {
138 				SPDK_ERRLOG("IO DIF verification failed: lba %" PRIu64 ", num_blocks %" PRIu64 ", "
139 					    "err_type %u, expected %lu, actual %lu, err_offset %u\n",
140 					    bdev_io->u.bdev.offset_blocks,
141 					    bdev_io->u.bdev.num_blocks,
142 					    err_blk.err_type,
143 					    err_blk.expected,
144 					    err_blk.actual,
145 					    err_blk.err_offset);
146 				spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
147 				return;
148 			}
149 		}
150 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
151 		break;
152 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
153 	case SPDK_BDEV_IO_TYPE_RESET:
154 		TAILQ_INSERT_TAIL(&ch->io, bdev_io, module_link);
155 		break;
156 	case SPDK_BDEV_IO_TYPE_ABORT:
157 		if (bdev_null_abort_io(ch, bdev_io->u.abort.bio_to_abort)) {
158 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
159 		} else {
160 			spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
161 		}
162 		break;
163 	case SPDK_BDEV_IO_TYPE_FLUSH:
164 	case SPDK_BDEV_IO_TYPE_UNMAP:
165 	default:
166 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_FAILED);
167 		break;
168 	}
169 }
170 
171 static bool
172 bdev_null_io_type_supported(void *ctx, enum spdk_bdev_io_type io_type)
173 {
174 	switch (io_type) {
175 	case SPDK_BDEV_IO_TYPE_READ:
176 	case SPDK_BDEV_IO_TYPE_WRITE:
177 	case SPDK_BDEV_IO_TYPE_WRITE_ZEROES:
178 	case SPDK_BDEV_IO_TYPE_RESET:
179 	case SPDK_BDEV_IO_TYPE_ABORT:
180 		return true;
181 	case SPDK_BDEV_IO_TYPE_FLUSH:
182 	case SPDK_BDEV_IO_TYPE_UNMAP:
183 	default:
184 		return false;
185 	}
186 }
187 
188 static struct spdk_io_channel *
189 bdev_null_get_io_channel(void *ctx)
190 {
191 	return spdk_get_io_channel(&g_null_bdev_head);
192 }
193 
194 static void
195 bdev_null_write_config_json(struct spdk_bdev *bdev, struct spdk_json_write_ctx *w)
196 {
197 	char uuid_str[SPDK_UUID_STRING_LEN];
198 
199 	spdk_json_write_object_begin(w);
200 
201 	spdk_json_write_named_string(w, "method", "bdev_null_create");
202 
203 	spdk_json_write_named_object_begin(w, "params");
204 	spdk_json_write_named_string(w, "name", bdev->name);
205 	spdk_json_write_named_uint64(w, "num_blocks", bdev->blockcnt);
206 	spdk_json_write_named_uint32(w, "block_size", bdev->blocklen);
207 	spdk_json_write_named_uint32(w, "physical_block_size", bdev->phys_blocklen);
208 	spdk_json_write_named_uint32(w, "md_size", bdev->md_len);
209 	spdk_json_write_named_uint32(w, "dif_type", bdev->dif_type);
210 	spdk_json_write_named_bool(w, "dif_is_head_of_md", bdev->dif_is_head_of_md);
211 	spdk_uuid_fmt_lower(uuid_str, sizeof(uuid_str), &bdev->uuid);
212 	spdk_json_write_named_string(w, "uuid", uuid_str);
213 	spdk_json_write_object_end(w);
214 
215 	spdk_json_write_object_end(w);
216 }
217 
218 static const struct spdk_bdev_fn_table null_fn_table = {
219 	.destruct		= bdev_null_destruct,
220 	.submit_request		= bdev_null_submit_request,
221 	.io_type_supported	= bdev_null_io_type_supported,
222 	.get_io_channel		= bdev_null_get_io_channel,
223 	.write_config_json	= bdev_null_write_config_json,
224 };
225 
226 int
227 bdev_null_create(struct spdk_bdev **bdev, const struct spdk_null_bdev_opts *opts)
228 {
229 	struct null_bdev *null_disk;
230 	uint32_t data_block_size;
231 	int rc;
232 
233 	if (!opts) {
234 		SPDK_ERRLOG("No options provided for Null bdev.\n");
235 		return -EINVAL;
236 	}
237 
238 	if (opts->md_interleave) {
239 		if (opts->block_size < opts->md_size) {
240 			SPDK_ERRLOG("Interleaved metadata size can not be greater than block size.\n");
241 			return -EINVAL;
242 		}
243 		data_block_size = opts->block_size - opts->md_size;
244 	} else {
245 		if (opts->md_size != 0) {
246 			SPDK_ERRLOG("Metadata in separate buffer is not supported\n");
247 			return -ENOTSUP;
248 		}
249 		data_block_size = opts->block_size;
250 	}
251 
252 	if (data_block_size % 512 != 0) {
253 		SPDK_ERRLOG("Data block size %u is not a multiple of 512.\n", opts->block_size);
254 		return -EINVAL;
255 	}
256 
257 	if (opts->num_blocks == 0) {
258 		SPDK_ERRLOG("Disk must be more than 0 blocks\n");
259 		return -EINVAL;
260 	}
261 
262 	null_disk = calloc(1, sizeof(*null_disk));
263 	if (!null_disk) {
264 		SPDK_ERRLOG("could not allocate null_bdev\n");
265 		return -ENOMEM;
266 	}
267 
268 	null_disk->bdev.name = strdup(opts->name);
269 	if (!null_disk->bdev.name) {
270 		free(null_disk);
271 		return -ENOMEM;
272 	}
273 	null_disk->bdev.product_name = "Null disk";
274 
275 	null_disk->bdev.write_cache = 0;
276 	null_disk->bdev.blocklen = opts->block_size;
277 	null_disk->bdev.phys_blocklen = opts->physical_block_size;
278 	null_disk->bdev.blockcnt = opts->num_blocks;
279 	null_disk->bdev.md_len = opts->md_size;
280 	null_disk->bdev.md_interleave = opts->md_interleave;
281 	null_disk->bdev.dif_type = opts->dif_type;
282 	null_disk->bdev.dif_is_head_of_md = opts->dif_is_head_of_md;
283 	/* Current block device layer API does not propagate
284 	 * any DIF related information from user. So, we can
285 	 * not generate or verify Application Tag.
286 	 */
287 	switch (opts->dif_type) {
288 	case SPDK_DIF_TYPE1:
289 	case SPDK_DIF_TYPE2:
290 		null_disk->bdev.dif_check_flags = SPDK_DIF_FLAGS_GUARD_CHECK |
291 						  SPDK_DIF_FLAGS_REFTAG_CHECK;
292 		break;
293 	case SPDK_DIF_TYPE3:
294 		null_disk->bdev.dif_check_flags = SPDK_DIF_FLAGS_GUARD_CHECK;
295 		break;
296 	case SPDK_DIF_DISABLE:
297 		break;
298 	}
299 	if (opts->uuid) {
300 		null_disk->bdev.uuid = *opts->uuid;
301 	}
302 
303 	null_disk->bdev.ctxt = null_disk;
304 	null_disk->bdev.fn_table = &null_fn_table;
305 	null_disk->bdev.module = &null_if;
306 
307 	rc = spdk_bdev_register(&null_disk->bdev);
308 	if (rc) {
309 		free(null_disk->bdev.name);
310 		free(null_disk);
311 		return rc;
312 	}
313 
314 	*bdev = &(null_disk->bdev);
315 
316 	TAILQ_INSERT_TAIL(&g_null_bdev_head, null_disk, tailq);
317 
318 	return rc;
319 }
320 
321 void
322 bdev_null_delete(const char *bdev_name, spdk_delete_null_complete cb_fn, void *cb_arg)
323 {
324 	int rc;
325 
326 	rc = spdk_bdev_unregister_by_name(bdev_name, &null_if, cb_fn, cb_arg);
327 	if (rc != 0) {
328 		cb_fn(cb_arg, rc);
329 	}
330 }
331 
332 static int
333 null_io_poll(void *arg)
334 {
335 	struct null_io_channel		*ch = arg;
336 	TAILQ_HEAD(, spdk_bdev_io)	io;
337 	struct spdk_bdev_io		*bdev_io;
338 
339 	TAILQ_INIT(&io);
340 	TAILQ_SWAP(&ch->io, &io, spdk_bdev_io, module_link);
341 
342 	if (TAILQ_EMPTY(&io)) {
343 		return SPDK_POLLER_IDLE;
344 	}
345 
346 	while (!TAILQ_EMPTY(&io)) {
347 		bdev_io = TAILQ_FIRST(&io);
348 		TAILQ_REMOVE(&io, bdev_io, module_link);
349 		spdk_bdev_io_complete(bdev_io, SPDK_BDEV_IO_STATUS_SUCCESS);
350 	}
351 
352 	return SPDK_POLLER_BUSY;
353 }
354 
355 static int
356 null_bdev_create_cb(void *io_device, void *ctx_buf)
357 {
358 	struct null_io_channel *ch = ctx_buf;
359 
360 	TAILQ_INIT(&ch->io);
361 	ch->poller = SPDK_POLLER_REGISTER(null_io_poll, ch, 0);
362 
363 	return 0;
364 }
365 
366 static void
367 null_bdev_destroy_cb(void *io_device, void *ctx_buf)
368 {
369 	struct null_io_channel *ch = ctx_buf;
370 
371 	spdk_poller_unregister(&ch->poller);
372 }
373 
374 static int
375 bdev_null_initialize(void)
376 {
377 	/*
378 	 * This will be used if upper layer expects us to allocate the read buffer.
379 	 *  Instead of using a real rbuf from the bdev pool, just always point to
380 	 *  this same zeroed buffer.
381 	 */
382 	g_null_read_buf = spdk_zmalloc(SPDK_BDEV_LARGE_BUF_MAX_SIZE, 0, NULL,
383 				       SPDK_ENV_SOCKET_ID_ANY, SPDK_MALLOC_DMA);
384 	if (g_null_read_buf == NULL) {
385 		return -1;
386 	}
387 
388 	/*
389 	 * We need to pick some unique address as our "io device" - so just use the
390 	 *  address of the global tailq.
391 	 */
392 	spdk_io_device_register(&g_null_bdev_head, null_bdev_create_cb, null_bdev_destroy_cb,
393 				sizeof(struct null_io_channel), "null_bdev");
394 
395 	return 0;
396 }
397 
398 static void
399 dummy_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, void *ctx)
400 {
401 }
402 
403 int
404 bdev_null_resize(const char *bdev_name, const uint64_t new_size_in_mb)
405 {
406 	struct spdk_bdev_desc *desc;
407 	struct spdk_bdev *bdev;
408 	uint64_t current_size_in_mb;
409 	uint64_t new_size_in_byte;
410 	int rc = 0;
411 
412 	rc = spdk_bdev_open_ext(bdev_name, false, dummy_bdev_event_cb, NULL, &desc);
413 	if (rc != 0) {
414 		SPDK_ERRLOG("failed to open bdev; %s.\n", bdev_name);
415 		return rc;
416 	}
417 
418 	bdev = spdk_bdev_desc_get_bdev(desc);
419 
420 	if (bdev->module != &null_if) {
421 		rc = -EINVAL;
422 		goto exit;
423 	}
424 
425 	current_size_in_mb = bdev->blocklen * bdev->blockcnt / (1024 * 1024);
426 	if (new_size_in_mb < current_size_in_mb) {
427 		SPDK_ERRLOG("The new bdev size must not be smaller than current bdev size.\n");
428 		rc = -EINVAL;
429 		goto exit;
430 	}
431 
432 	new_size_in_byte = new_size_in_mb * 1024 * 1024;
433 
434 	rc = spdk_bdev_notify_blockcnt_change(bdev, new_size_in_byte / bdev->blocklen);
435 	if (rc != 0) {
436 		SPDK_ERRLOG("failed to notify block cnt change.\n");
437 	}
438 
439 exit:
440 	spdk_bdev_close(desc);
441 	return rc;
442 }
443 
444 static void
445 _bdev_null_finish_cb(void *arg)
446 {
447 	spdk_free(g_null_read_buf);
448 	spdk_bdev_module_fini_done();
449 }
450 
451 static void
452 bdev_null_finish(void)
453 {
454 	if (g_null_read_buf == NULL) {
455 		spdk_bdev_module_fini_done();
456 		return;
457 	}
458 	spdk_io_device_unregister(&g_null_bdev_head, _bdev_null_finish_cb);
459 }
460 
461 SPDK_LOG_REGISTER_COMPONENT(bdev_null)
462