1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "kublk.h"
4
5 #define NR_STRIPE MAX_BACK_FILES
6
7 struct stripe_conf {
8 unsigned nr_files;
9 unsigned shift;
10 };
11
12 struct stripe {
13 loff_t start;
14 unsigned nr_sects;
15 int seq;
16
17 struct iovec *vec;
18 unsigned nr_vec;
19 unsigned cap;
20 };
21
22 struct stripe_array {
23 struct stripe s[NR_STRIPE];
24 unsigned nr;
25 struct iovec _vec[];
26 };
27
get_chunk_shift(const struct ublk_queue * q)28 static inline const struct stripe_conf *get_chunk_shift(const struct ublk_queue *q)
29 {
30 return (struct stripe_conf *)q->dev->private_data;
31 }
32
calculate_nr_vec(const struct stripe_conf * conf,const struct ublksrv_io_desc * iod)33 static inline unsigned calculate_nr_vec(const struct stripe_conf *conf,
34 const struct ublksrv_io_desc *iod)
35 {
36 const unsigned shift = conf->shift - 9;
37 const unsigned unit_sects = conf->nr_files << shift;
38 loff_t start = iod->start_sector;
39 loff_t end = start + iod->nr_sectors;
40
41 return (end / unit_sects) - (start / unit_sects) + 1;
42 }
43
alloc_stripe_array(const struct stripe_conf * conf,const struct ublksrv_io_desc * iod)44 static struct stripe_array *alloc_stripe_array(const struct stripe_conf *conf,
45 const struct ublksrv_io_desc *iod)
46 {
47 unsigned nr_vecs = calculate_nr_vec(conf, iod);
48 unsigned total = nr_vecs * conf->nr_files;
49 struct stripe_array *s;
50 int i;
51
52 s = malloc(sizeof(*s) + total * sizeof(struct iovec));
53
54 s->nr = 0;
55 for (i = 0; i < conf->nr_files; i++) {
56 struct stripe *t = &s->s[i];
57
58 t->nr_vec = 0;
59 t->vec = &s->_vec[i * nr_vecs];
60 t->nr_sects = 0;
61 t->cap = nr_vecs;
62 }
63
64 return s;
65 }
66
free_stripe_array(struct stripe_array * s)67 static void free_stripe_array(struct stripe_array *s)
68 {
69 free(s);
70 }
71
calculate_stripe_array(const struct stripe_conf * conf,const struct ublksrv_io_desc * iod,struct stripe_array * s,void * base)72 static void calculate_stripe_array(const struct stripe_conf *conf,
73 const struct ublksrv_io_desc *iod, struct stripe_array *s, void *base)
74 {
75 const unsigned shift = conf->shift - 9;
76 const unsigned chunk_sects = 1 << shift;
77 const unsigned unit_sects = conf->nr_files << shift;
78 off64_t start = iod->start_sector;
79 off64_t end = start + iod->nr_sectors;
80 unsigned long done = 0;
81 unsigned idx = 0;
82
83 while (start < end) {
84 unsigned nr_sects = chunk_sects - (start & (chunk_sects - 1));
85 loff_t unit_off = (start / unit_sects) * unit_sects;
86 unsigned seq = (start - unit_off) >> shift;
87 struct stripe *this = &s->s[idx];
88 loff_t stripe_off = (unit_off / conf->nr_files) +
89 (start & (chunk_sects - 1));
90
91 if (nr_sects > end - start)
92 nr_sects = end - start;
93 if (this->nr_sects == 0) {
94 this->nr_sects = nr_sects;
95 this->start = stripe_off;
96 this->seq = seq;
97 s->nr += 1;
98 } else {
99 assert(seq == this->seq);
100 assert(this->start + this->nr_sects == stripe_off);
101 this->nr_sects += nr_sects;
102 }
103
104 assert(this->nr_vec < this->cap);
105 this->vec[this->nr_vec].iov_base = (void *)(base + done);
106 this->vec[this->nr_vec++].iov_len = nr_sects << 9;
107
108 start += nr_sects;
109 done += nr_sects << 9;
110 idx = (idx + 1) % conf->nr_files;
111 }
112 }
113
stripe_to_uring_op(const struct ublksrv_io_desc * iod,int zc)114 static inline enum io_uring_op stripe_to_uring_op(
115 const struct ublksrv_io_desc *iod, int zc)
116 {
117 unsigned ublk_op = ublksrv_get_op(iod);
118
119 if (ublk_op == UBLK_IO_OP_READ)
120 return zc ? IORING_OP_READV_FIXED : IORING_OP_READV;
121 else if (ublk_op == UBLK_IO_OP_WRITE)
122 return zc ? IORING_OP_WRITEV_FIXED : IORING_OP_WRITEV;
123 assert(0);
124 }
125
stripe_queue_tgt_rw_io(struct ublk_thread * t,struct ublk_queue * q,const struct ublksrv_io_desc * iod,int tag)126 static int stripe_queue_tgt_rw_io(struct ublk_thread *t, struct ublk_queue *q,
127 const struct ublksrv_io_desc *iod, int tag)
128 {
129 const struct stripe_conf *conf = get_chunk_shift(q);
130 unsigned auto_zc = (ublk_queue_use_auto_zc(q) != 0);
131 unsigned zc = (ublk_queue_use_zc(q) != 0);
132 enum io_uring_op op = stripe_to_uring_op(iod, zc | auto_zc);
133 struct io_uring_sqe *sqe[NR_STRIPE];
134 struct stripe_array *s = alloc_stripe_array(conf, iod);
135 struct ublk_io *io = ublk_get_io(q, tag);
136 int i, extra = zc ? 2 : 0;
137 void *base = (zc | auto_zc) ? NULL : (void *)iod->addr;
138
139 io->private_data = s;
140 calculate_stripe_array(conf, iod, s, base);
141
142 ublk_io_alloc_sqes(t, sqe, s->nr + extra);
143
144 if (zc) {
145 io_uring_prep_buf_register(sqe[0], 0, tag, q->q_id, io->buf_index);
146 sqe[0]->flags |= IOSQE_CQE_SKIP_SUCCESS | IOSQE_IO_HARDLINK;
147 sqe[0]->user_data = build_user_data(tag,
148 ublk_cmd_op_nr(sqe[0]->cmd_op), 0, q->q_id, 1);
149 }
150
151 for (i = zc; i < s->nr + extra - zc; i++) {
152 struct stripe *t = &s->s[i - zc];
153
154 io_uring_prep_rw(op, sqe[i],
155 t->seq + 1,
156 (void *)t->vec,
157 t->nr_vec,
158 t->start << 9);
159 io_uring_sqe_set_flags(sqe[i], IOSQE_FIXED_FILE);
160 if (auto_zc || zc) {
161 sqe[i]->buf_index = tag;
162 if (zc)
163 sqe[i]->flags |= IOSQE_IO_HARDLINK;
164 }
165 /* bit63 marks us as tgt io */
166 sqe[i]->user_data = build_user_data(tag, ublksrv_get_op(iod), i - zc, q->q_id, 1);
167 }
168 if (zc) {
169 struct io_uring_sqe *unreg = sqe[s->nr + 1];
170
171 io_uring_prep_buf_unregister(unreg, 0, tag, q->q_id, io->buf_index);
172 unreg->user_data = build_user_data(
173 tag, ublk_cmd_op_nr(unreg->cmd_op), 0, q->q_id, 1);
174 }
175
176 /* register buffer is skip_success */
177 return s->nr + zc;
178 }
179
handle_flush(struct ublk_thread * t,struct ublk_queue * q,const struct ublksrv_io_desc * iod,int tag)180 static int handle_flush(struct ublk_thread *t, struct ublk_queue *q,
181 const struct ublksrv_io_desc *iod, int tag)
182 {
183 const struct stripe_conf *conf = get_chunk_shift(q);
184 struct io_uring_sqe *sqe[NR_STRIPE];
185 int i;
186
187 ublk_io_alloc_sqes(t, sqe, conf->nr_files);
188 for (i = 0; i < conf->nr_files; i++) {
189 io_uring_prep_fsync(sqe[i], i + 1, IORING_FSYNC_DATASYNC);
190 io_uring_sqe_set_flags(sqe[i], IOSQE_FIXED_FILE);
191 sqe[i]->user_data = build_user_data(tag, UBLK_IO_OP_FLUSH, 0, q->q_id, 1);
192 }
193 return conf->nr_files;
194 }
195
stripe_queue_tgt_io(struct ublk_thread * t,struct ublk_queue * q,int tag)196 static int stripe_queue_tgt_io(struct ublk_thread *t, struct ublk_queue *q,
197 int tag)
198 {
199 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag);
200 unsigned ublk_op = ublksrv_get_op(iod);
201 int ret = 0;
202
203 switch (ublk_op) {
204 case UBLK_IO_OP_FLUSH:
205 ret = handle_flush(t, q, iod, tag);
206 break;
207 case UBLK_IO_OP_WRITE_ZEROES:
208 case UBLK_IO_OP_DISCARD:
209 ret = -ENOTSUP;
210 break;
211 case UBLK_IO_OP_READ:
212 case UBLK_IO_OP_WRITE:
213 ret = stripe_queue_tgt_rw_io(t, q, iod, tag);
214 break;
215 default:
216 ret = -EINVAL;
217 break;
218 }
219 ublk_dbg(UBLK_DBG_IO, "%s: tag %d ublk io %x %llx %u ret %d\n", __func__, tag,
220 iod->op_flags, iod->start_sector, iod->nr_sectors << 9, ret);
221 return ret;
222 }
223
ublk_stripe_queue_io(struct ublk_thread * t,struct ublk_queue * q,int tag)224 static int ublk_stripe_queue_io(struct ublk_thread *t, struct ublk_queue *q,
225 int tag)
226 {
227 int queued = stripe_queue_tgt_io(t, q, tag);
228
229 ublk_queued_tgt_io(t, q, tag, queued);
230 return 0;
231 }
232
ublk_stripe_io_done(struct ublk_thread * t,struct ublk_queue * q,const struct io_uring_cqe * cqe)233 static void ublk_stripe_io_done(struct ublk_thread *t, struct ublk_queue *q,
234 const struct io_uring_cqe *cqe)
235 {
236 unsigned tag = user_data_to_tag(cqe->user_data);
237 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag);
238 unsigned op = user_data_to_op(cqe->user_data);
239 struct ublk_io *io = ublk_get_io(q, tag);
240 int res = cqe->res;
241
242 if (res < 0 || op != ublk_cmd_op_nr(UBLK_U_IO_UNREGISTER_IO_BUF)) {
243 if (!io->result)
244 io->result = res;
245 if (res < 0)
246 ublk_err("%s: io failure %d tag %u\n", __func__, res, tag);
247 }
248
249 /* buffer register op is IOSQE_CQE_SKIP_SUCCESS */
250 if (op == ublk_cmd_op_nr(UBLK_U_IO_REGISTER_IO_BUF))
251 io->tgt_ios += 1;
252
253 /* fail short READ/WRITE simply */
254 if (op == UBLK_IO_OP_READ || op == UBLK_IO_OP_WRITE) {
255 unsigned seq = user_data_to_tgt_data(cqe->user_data);
256 struct stripe_array *s = io->private_data;
257
258 if (res < s->s[seq].nr_sects << 9) {
259 io->result = -EIO;
260 ublk_err("%s: short rw op %u res %d exp %u tag %u\n",
261 __func__, op, res, s->s[seq].vec->iov_len, tag);
262 }
263 }
264
265 if (ublk_completed_tgt_io(t, q, tag)) {
266 int res = io->result;
267
268 if (!res)
269 res = iod->nr_sectors << 9;
270
271 ublk_complete_io(t, q, tag, res);
272
273 free_stripe_array(io->private_data);
274 io->private_data = NULL;
275 }
276 }
277
ublk_stripe_tgt_init(const struct dev_ctx * ctx,struct ublk_dev * dev)278 static int ublk_stripe_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
279 {
280 struct ublk_params p = {
281 .types = UBLK_PARAM_TYPE_BASIC,
282 .basic = {
283 .attrs = UBLK_ATTR_VOLATILE_CACHE,
284 .logical_bs_shift = 9,
285 .physical_bs_shift = 12,
286 .io_opt_shift = 12,
287 .io_min_shift = 9,
288 .max_sectors = dev->dev_info.max_io_buf_bytes >> 9,
289 },
290 };
291 unsigned chunk_size = ctx->stripe.chunk_size;
292 struct stripe_conf *conf;
293 unsigned chunk_shift;
294 loff_t bytes = 0;
295 int ret, i, mul = 1;
296
297 if (ctx->auto_zc_fallback) {
298 ublk_err("%s: not support auto_zc_fallback\n", __func__);
299 return -EINVAL;
300 }
301
302 if ((chunk_size & (chunk_size - 1)) || !chunk_size) {
303 ublk_err("invalid chunk size %u\n", chunk_size);
304 return -EINVAL;
305 }
306
307 if (chunk_size < 4096 || chunk_size > 512 * 1024) {
308 ublk_err("invalid chunk size %u\n", chunk_size);
309 return -EINVAL;
310 }
311
312 chunk_shift = ilog2(chunk_size);
313
314 ret = backing_file_tgt_init(dev);
315 if (ret)
316 return ret;
317
318 if (!dev->tgt.nr_backing_files || dev->tgt.nr_backing_files > NR_STRIPE)
319 return -EINVAL;
320
321 assert(dev->nr_fds == dev->tgt.nr_backing_files + 1);
322
323 for (i = 0; i < dev->tgt.nr_backing_files; i++)
324 dev->tgt.backing_file_size[i] &= ~((1 << chunk_shift) - 1);
325
326 for (i = 0; i < dev->tgt.nr_backing_files; i++) {
327 unsigned long size = dev->tgt.backing_file_size[i];
328
329 if (size != dev->tgt.backing_file_size[0])
330 return -EINVAL;
331 bytes += size;
332 }
333
334 conf = malloc(sizeof(*conf));
335 conf->shift = chunk_shift;
336 conf->nr_files = dev->tgt.nr_backing_files;
337
338 dev->private_data = conf;
339 dev->tgt.dev_size = bytes;
340 p.basic.dev_sectors = bytes >> 9;
341 dev->tgt.params = p;
342
343 if (dev->dev_info.flags & UBLK_F_SUPPORT_ZERO_COPY)
344 mul = 2;
345 dev->tgt.sq_depth = mul * dev->dev_info.queue_depth * conf->nr_files;
346 dev->tgt.cq_depth = mul * dev->dev_info.queue_depth * conf->nr_files;
347
348 printf("%s: shift %u files %u\n", __func__, conf->shift, conf->nr_files);
349
350 return 0;
351 }
352
ublk_stripe_tgt_deinit(struct ublk_dev * dev)353 static void ublk_stripe_tgt_deinit(struct ublk_dev *dev)
354 {
355 free(dev->private_data);
356 backing_file_tgt_deinit(dev);
357 }
358
ublk_stripe_cmd_line(struct dev_ctx * ctx,int argc,char * argv[])359 static void ublk_stripe_cmd_line(struct dev_ctx *ctx, int argc, char *argv[])
360 {
361 static const struct option longopts[] = {
362 { "chunk_size", 1, NULL, 0 },
363 { 0, 0, 0, 0 }
364 };
365 int option_idx, opt;
366
367 ctx->stripe.chunk_size = 65536;
368 while ((opt = getopt_long(argc, argv, "",
369 longopts, &option_idx)) != -1) {
370 switch (opt) {
371 case 0:
372 if (!strcmp(longopts[option_idx].name, "chunk_size"))
373 ctx->stripe.chunk_size = strtol(optarg, NULL, 10);
374 }
375 }
376 }
377
ublk_stripe_usage(const struct ublk_tgt_ops * ops)378 static void ublk_stripe_usage(const struct ublk_tgt_ops *ops)
379 {
380 printf("\tstripe: [--chunk_size chunk_size (default 65536)]\n");
381 }
382
383 const struct ublk_tgt_ops stripe_tgt_ops = {
384 .name = "stripe",
385 .init_tgt = ublk_stripe_tgt_init,
386 .deinit_tgt = ublk_stripe_tgt_deinit,
387 .queue_io = ublk_stripe_queue_io,
388 .tgt_io_done = ublk_stripe_io_done,
389 .parse_cmd_line = ublk_stripe_cmd_line,
390 .usage = ublk_stripe_usage,
391 };
392