xref: /spdk/module/bdev/raid/raid0.c (revision eb7506a1b4fb1589911dbb1ffb5ac60a048202be)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2019 Intel Corporation.
3  *   All rights reserved.
4  *   Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
5  */
6 
7 #include "bdev_raid.h"
8 
9 #include "spdk/env.h"
10 #include "spdk/thread.h"
11 #include "spdk/string.h"
12 #include "spdk/util.h"
13 
14 #include "spdk/log.h"
15 
16 /*
17  * brief:
18  * raid0_bdev_io_completion function is called by lower layers to notify raid
19  * module that particular bdev_io is completed.
20  * params:
21  * bdev_io - pointer to bdev io submitted to lower layers, like child io
22  * success - bdev_io status
23  * cb_arg - function callback context (parent raid_bdev_io)
24  * returns:
25  * none
26  */
27 static void
28 raid0_bdev_io_completion(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
29 {
30 	struct raid_bdev_io *raid_io = cb_arg;
31 
32 	spdk_bdev_free_io(bdev_io);
33 
34 	if (success) {
35 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_SUCCESS);
36 	} else {
37 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
38 	}
39 }
40 
41 static void raid0_submit_rw_request(struct raid_bdev_io *raid_io);
42 
43 static void
44 _raid0_submit_rw_request(void *_raid_io)
45 {
46 	struct raid_bdev_io *raid_io = _raid_io;
47 
48 	raid0_submit_rw_request(raid_io);
49 }
50 
51 /*
52  * brief:
53  * raid0_submit_rw_request function is used to submit I/O to the correct
54  * member disk for raid0 bdevs.
55  * params:
56  * raid_io
57  * returns:
58  * none
59  */
60 static void
61 raid0_submit_rw_request(struct raid_bdev_io *raid_io)
62 {
63 	struct spdk_bdev_io		*bdev_io = spdk_bdev_io_from_ctx(raid_io);
64 	struct raid_bdev_io_channel	*raid_ch = raid_io->raid_ch;
65 	struct raid_bdev		*raid_bdev = raid_io->raid_bdev;
66 	uint64_t			pd_strip;
67 	uint32_t			offset_in_strip;
68 	uint64_t			pd_lba;
69 	uint64_t			pd_blocks;
70 	uint8_t				pd_idx;
71 	int				ret = 0;
72 	uint64_t			start_strip;
73 	uint64_t			end_strip;
74 	struct raid_base_bdev_info	*base_info;
75 	struct spdk_io_channel		*base_ch;
76 
77 	start_strip = bdev_io->u.bdev.offset_blocks >> raid_bdev->strip_size_shift;
78 	end_strip = (bdev_io->u.bdev.offset_blocks + bdev_io->u.bdev.num_blocks - 1) >>
79 		    raid_bdev->strip_size_shift;
80 	if (start_strip != end_strip && raid_bdev->num_base_bdevs > 1) {
81 		assert(false);
82 		SPDK_ERRLOG("I/O spans strip boundary!\n");
83 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
84 		return;
85 	}
86 
87 	pd_strip = start_strip / raid_bdev->num_base_bdevs;
88 	pd_idx = start_strip % raid_bdev->num_base_bdevs;
89 	offset_in_strip = bdev_io->u.bdev.offset_blocks & (raid_bdev->strip_size - 1);
90 	pd_lba = (pd_strip << raid_bdev->strip_size_shift) + offset_in_strip;
91 	pd_blocks = bdev_io->u.bdev.num_blocks;
92 	base_info = &raid_bdev->base_bdev_info[pd_idx];
93 	if (base_info->desc == NULL) {
94 		SPDK_ERRLOG("base bdev desc null for pd_idx %u\n", pd_idx);
95 		assert(0);
96 	}
97 
98 	/*
99 	 * Submit child io to bdev layer with using base bdev descriptors, base
100 	 * bdev lba, base bdev child io length in blocks, buffer, completion
101 	 * function and function callback context
102 	 */
103 	assert(raid_ch != NULL);
104 	assert(raid_ch->base_channel);
105 	base_ch = raid_ch->base_channel[pd_idx];
106 	if (bdev_io->type == SPDK_BDEV_IO_TYPE_READ) {
107 		if (bdev_io->u.bdev.ext_opts != NULL) {
108 			ret = spdk_bdev_readv_blocks_ext(base_info->desc, base_ch,
109 							 bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
110 							 pd_lba, pd_blocks, raid0_bdev_io_completion,
111 							 raid_io, bdev_io->u.bdev.ext_opts);
112 		} else {
113 			ret = spdk_bdev_readv_blocks_with_md(base_info->desc, base_ch,
114 							     bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
115 							     bdev_io->u.bdev.md_buf,
116 							     pd_lba, pd_blocks,
117 							     raid0_bdev_io_completion, raid_io);
118 		}
119 	} else if (bdev_io->type == SPDK_BDEV_IO_TYPE_WRITE) {
120 		if (bdev_io->u.bdev.ext_opts != NULL) {
121 			ret = spdk_bdev_writev_blocks_ext(base_info->desc, base_ch,
122 							  bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
123 							  pd_lba, pd_blocks, raid0_bdev_io_completion,
124 							  raid_io, bdev_io->u.bdev.ext_opts);
125 		} else {
126 			ret = spdk_bdev_writev_blocks_with_md(base_info->desc, base_ch,
127 							      bdev_io->u.bdev.iovs, bdev_io->u.bdev.iovcnt,
128 							      bdev_io->u.bdev.md_buf,
129 							      pd_lba, pd_blocks,
130 							      raid0_bdev_io_completion, raid_io);
131 		}
132 	} else {
133 		SPDK_ERRLOG("Recvd not supported io type %u\n", bdev_io->type);
134 		assert(0);
135 	}
136 
137 	if (ret == -ENOMEM) {
138 		raid_bdev_queue_io_wait(raid_io, base_info->bdev, base_ch,
139 					_raid0_submit_rw_request);
140 	} else if (ret != 0) {
141 		SPDK_ERRLOG("bdev io submit error not due to ENOMEM, it should not happen\n");
142 		assert(false);
143 		raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
144 	}
145 }
146 
147 /* raid0 IO range */
148 struct raid_bdev_io_range {
149 	uint64_t	strip_size;
150 	uint64_t	start_strip_in_disk;
151 	uint64_t	end_strip_in_disk;
152 	uint64_t	start_offset_in_strip;
153 	uint64_t	end_offset_in_strip;
154 	uint8_t		start_disk;
155 	uint8_t		end_disk;
156 	uint8_t		n_disks_involved;
157 };
158 
159 static inline void
160 _raid0_get_io_range(struct raid_bdev_io_range *io_range,
161 		    uint8_t num_base_bdevs, uint64_t strip_size, uint64_t strip_size_shift,
162 		    uint64_t offset_blocks, uint64_t num_blocks)
163 {
164 	uint64_t	start_strip;
165 	uint64_t	end_strip;
166 	uint64_t	total_blocks;
167 
168 	io_range->strip_size = strip_size;
169 	total_blocks = offset_blocks + num_blocks - (num_blocks > 0);
170 
171 	/* The start and end strip index in raid0 bdev scope */
172 	start_strip = offset_blocks >> strip_size_shift;
173 	end_strip = total_blocks >> strip_size_shift;
174 	io_range->start_strip_in_disk = start_strip / num_base_bdevs;
175 	io_range->end_strip_in_disk = end_strip / num_base_bdevs;
176 
177 	/* The first strip may have unaligned start LBA offset.
178 	 * The end strip may have unaligned end LBA offset.
179 	 * Strips between them certainly have aligned offset and length to boundaries.
180 	 */
181 	io_range->start_offset_in_strip = offset_blocks % strip_size;
182 	io_range->end_offset_in_strip = total_blocks % strip_size;
183 
184 	/* The base bdev indexes in which start and end strips are located */
185 	io_range->start_disk = start_strip % num_base_bdevs;
186 	io_range->end_disk = end_strip % num_base_bdevs;
187 
188 	/* Calculate how many base_bdevs are involved in io operation.
189 	 * Number of base bdevs involved is between 1 and num_base_bdevs.
190 	 * It will be 1 if the first strip and last strip are the same one.
191 	 */
192 	io_range->n_disks_involved = spdk_min((end_strip - start_strip + 1), num_base_bdevs);
193 }
194 
195 static inline void
196 _raid0_split_io_range(struct raid_bdev_io_range *io_range, uint8_t disk_idx,
197 		      uint64_t *_offset_in_disk, uint64_t *_nblocks_in_disk)
198 {
199 	uint64_t n_strips_in_disk;
200 	uint64_t start_offset_in_disk;
201 	uint64_t end_offset_in_disk;
202 	uint64_t offset_in_disk;
203 	uint64_t nblocks_in_disk;
204 	uint64_t start_strip_in_disk;
205 	uint64_t end_strip_in_disk;
206 
207 	start_strip_in_disk = io_range->start_strip_in_disk;
208 	if (disk_idx < io_range->start_disk) {
209 		start_strip_in_disk += 1;
210 	}
211 
212 	end_strip_in_disk = io_range->end_strip_in_disk;
213 	if (disk_idx > io_range->end_disk) {
214 		end_strip_in_disk -= 1;
215 	}
216 
217 	assert(end_strip_in_disk >= start_strip_in_disk);
218 	n_strips_in_disk = end_strip_in_disk - start_strip_in_disk + 1;
219 
220 	if (disk_idx == io_range->start_disk) {
221 		start_offset_in_disk = io_range->start_offset_in_strip;
222 	} else {
223 		start_offset_in_disk = 0;
224 	}
225 
226 	if (disk_idx == io_range->end_disk) {
227 		end_offset_in_disk = io_range->end_offset_in_strip;
228 	} else {
229 		end_offset_in_disk = io_range->strip_size - 1;
230 	}
231 
232 	offset_in_disk = start_offset_in_disk + start_strip_in_disk * io_range->strip_size;
233 	nblocks_in_disk = (n_strips_in_disk - 1) * io_range->strip_size
234 			  + end_offset_in_disk - start_offset_in_disk + 1;
235 
236 	SPDK_DEBUGLOG(bdev_raid0,
237 		      "raid_bdev (strip_size 0x%" PRIx64 ") splits IO to base_bdev (%u) at (0x%" PRIx64 ", 0x%" PRIx64
238 		      ").\n",
239 		      io_range->strip_size, disk_idx, offset_in_disk, nblocks_in_disk);
240 
241 	*_offset_in_disk = offset_in_disk;
242 	*_nblocks_in_disk = nblocks_in_disk;
243 }
244 
245 static void raid0_submit_null_payload_request(struct raid_bdev_io *raid_io);
246 
247 static void
248 _raid0_submit_null_payload_request(void *_raid_io)
249 {
250 	struct raid_bdev_io *raid_io = _raid_io;
251 
252 	raid0_submit_null_payload_request(raid_io);
253 }
254 
255 static void
256 raid0_base_io_complete(struct spdk_bdev_io *bdev_io, bool success, void *cb_arg)
257 {
258 	struct raid_bdev_io *raid_io = cb_arg;
259 
260 	raid_bdev_io_complete_part(raid_io, 1, success ?
261 				   SPDK_BDEV_IO_STATUS_SUCCESS :
262 				   SPDK_BDEV_IO_STATUS_FAILED);
263 
264 	spdk_bdev_free_io(bdev_io);
265 }
266 
267 /*
268  * brief:
269  * raid0_submit_null_payload_request function submits the next batch of
270  * io requests with range but without payload, like FLUSH and UNMAP, to member disks;
271  * it will submit as many as possible unless one base io request fails with -ENOMEM,
272  * in which case it will queue itself for later submission.
273  * params:
274  * bdev_io - pointer to parent bdev_io on raid bdev device
275  * returns:
276  * none
277  */
278 static void
279 raid0_submit_null_payload_request(struct raid_bdev_io *raid_io)
280 {
281 	struct spdk_bdev_io		*bdev_io;
282 	struct raid_bdev		*raid_bdev;
283 	struct raid_bdev_io_range	io_range;
284 	int				ret;
285 	struct raid_base_bdev_info	*base_info;
286 	struct spdk_io_channel		*base_ch;
287 
288 	bdev_io = spdk_bdev_io_from_ctx(raid_io);
289 	raid_bdev = raid_io->raid_bdev;
290 
291 	_raid0_get_io_range(&io_range, raid_bdev->num_base_bdevs,
292 			    raid_bdev->strip_size, raid_bdev->strip_size_shift,
293 			    bdev_io->u.bdev.offset_blocks, bdev_io->u.bdev.num_blocks);
294 
295 	if (raid_io->base_bdev_io_remaining == 0) {
296 		raid_io->base_bdev_io_remaining = io_range.n_disks_involved;
297 	}
298 
299 	while (raid_io->base_bdev_io_submitted < io_range.n_disks_involved) {
300 		uint8_t disk_idx;
301 		uint64_t offset_in_disk;
302 		uint64_t nblocks_in_disk;
303 
304 		/* base_bdev is started from start_disk to end_disk.
305 		 * It is possible that index of start_disk is larger than end_disk's.
306 		 */
307 		disk_idx = (io_range.start_disk + raid_io->base_bdev_io_submitted) % raid_bdev->num_base_bdevs;
308 		base_info = &raid_bdev->base_bdev_info[disk_idx];
309 		base_ch = raid_io->raid_ch->base_channel[disk_idx];
310 
311 		_raid0_split_io_range(&io_range, disk_idx, &offset_in_disk, &nblocks_in_disk);
312 
313 		switch (bdev_io->type) {
314 		case SPDK_BDEV_IO_TYPE_UNMAP:
315 			ret = spdk_bdev_unmap_blocks(base_info->desc, base_ch,
316 						     offset_in_disk, nblocks_in_disk,
317 						     raid0_base_io_complete, raid_io);
318 			break;
319 
320 		case SPDK_BDEV_IO_TYPE_FLUSH:
321 			ret = spdk_bdev_flush_blocks(base_info->desc, base_ch,
322 						     offset_in_disk, nblocks_in_disk,
323 						     raid0_base_io_complete, raid_io);
324 			break;
325 
326 		default:
327 			SPDK_ERRLOG("submit request, invalid io type with null payload %u\n", bdev_io->type);
328 			assert(false);
329 			ret = -EIO;
330 		}
331 
332 		if (ret == 0) {
333 			raid_io->base_bdev_io_submitted++;
334 		} else if (ret == -ENOMEM) {
335 			raid_bdev_queue_io_wait(raid_io, base_info->bdev, base_ch,
336 						_raid0_submit_null_payload_request);
337 			return;
338 		} else {
339 			SPDK_ERRLOG("bdev io submit error not due to ENOMEM, it should not happen\n");
340 			assert(false);
341 			raid_bdev_io_complete(raid_io, SPDK_BDEV_IO_STATUS_FAILED);
342 			return;
343 		}
344 	}
345 }
346 
347 static uint64_t
348 raid0_calculate_blockcnt(struct raid_bdev *raid_bdev)
349 {
350 	uint64_t min_blockcnt = UINT64_MAX;
351 	struct raid_base_bdev_info *base_info;
352 
353 	RAID_FOR_EACH_BASE_BDEV(raid_bdev, base_info) {
354 		/* Calculate minimum block count from all base bdevs */
355 		min_blockcnt = spdk_min(min_blockcnt, base_info->bdev->blockcnt);
356 	}
357 
358 	/*
359 	 * Take the minimum block count based approach where total block count
360 	 * of raid bdev is the number of base bdev times the minimum block count
361 	 * of any base bdev.
362 	 */
363 	SPDK_DEBUGLOG(bdev_raid0, "min blockcount %" PRIu64 ",  numbasedev %u, strip size shift %u\n",
364 		      min_blockcnt, raid_bdev->num_base_bdevs, raid_bdev->strip_size_shift);
365 
366 	return ((min_blockcnt >> raid_bdev->strip_size_shift) <<
367 		raid_bdev->strip_size_shift)  * raid_bdev->num_base_bdevs;
368 }
369 
370 static int
371 raid0_start(struct raid_bdev *raid_bdev)
372 {
373 	raid_bdev->bdev.blockcnt = raid0_calculate_blockcnt(raid_bdev);
374 
375 	if (raid_bdev->num_base_bdevs > 1) {
376 		raid_bdev->bdev.optimal_io_boundary = raid_bdev->strip_size;
377 		raid_bdev->bdev.split_on_optimal_io_boundary = true;
378 	} else {
379 		/* Do not need to split reads/writes on single bdev RAID modules. */
380 		raid_bdev->bdev.optimal_io_boundary = 0;
381 		raid_bdev->bdev.split_on_optimal_io_boundary = false;
382 	}
383 
384 	return 0;
385 }
386 
387 static struct raid_bdev_module g_raid0_module = {
388 	.level = RAID0,
389 	.base_bdevs_min = 1,
390 	.start = raid0_start,
391 	.submit_rw_request = raid0_submit_rw_request,
392 	.submit_null_payload_request = raid0_submit_null_payload_request,
393 };
394 RAID_MODULE_REGISTER(&g_raid0_module)
395 
396 SPDK_LOG_REGISTER_COMPONENT(bdev_raid0)
397