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 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 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 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 67 static void free_stripe_array(struct stripe_array *s) 68 { 69 free(s); 70 } 71 72 static void calculate_stripe_array(const struct stripe_conf *conf, 73 const struct ublksrv_io_desc *iod, struct stripe_array *s) 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 *)(iod->addr + 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 } 113 114 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 } 125 126 static int stripe_queue_tgt_rw_io(struct ublk_queue *q, const struct ublksrv_io_desc *iod, int tag) 127 { 128 const struct stripe_conf *conf = get_chunk_shift(q); 129 int zc = !!(ublk_queue_use_zc(q) != 0); 130 enum io_uring_op op = stripe_to_uring_op(iod, zc); 131 struct io_uring_sqe *sqe[NR_STRIPE]; 132 struct stripe_array *s = alloc_stripe_array(conf, iod); 133 struct ublk_io *io = ublk_get_io(q, tag); 134 int i, extra = zc ? 2 : 0; 135 136 io->private_data = s; 137 calculate_stripe_array(conf, iod, s); 138 139 ublk_queue_alloc_sqes(q, sqe, s->nr + extra); 140 141 if (zc) { 142 io_uring_prep_buf_register(sqe[0], 0, tag, q->q_id, tag); 143 sqe[0]->flags |= IOSQE_CQE_SKIP_SUCCESS | IOSQE_IO_HARDLINK; 144 sqe[0]->user_data = build_user_data(tag, 145 ublk_cmd_op_nr(sqe[0]->cmd_op), 0, 1); 146 } 147 148 for (i = zc; i < s->nr + extra - zc; i++) { 149 struct stripe *t = &s->s[i - zc]; 150 151 io_uring_prep_rw(op, sqe[i], 152 t->seq + 1, 153 (void *)t->vec, 154 t->nr_vec, 155 t->start << 9); 156 if (zc) { 157 sqe[i]->buf_index = tag; 158 io_uring_sqe_set_flags(sqe[i], 159 IOSQE_FIXED_FILE | IOSQE_IO_HARDLINK); 160 } else { 161 io_uring_sqe_set_flags(sqe[i], IOSQE_FIXED_FILE); 162 } 163 /* bit63 marks us as tgt io */ 164 sqe[i]->user_data = build_user_data(tag, ublksrv_get_op(iod), i - zc, 1); 165 } 166 if (zc) { 167 struct io_uring_sqe *unreg = sqe[s->nr + 1]; 168 169 io_uring_prep_buf_unregister(unreg, 0, tag, q->q_id, tag); 170 unreg->user_data = build_user_data(tag, ublk_cmd_op_nr(unreg->cmd_op), 0, 1); 171 } 172 173 /* register buffer is skip_success */ 174 return s->nr + zc; 175 } 176 177 static int handle_flush(struct ublk_queue *q, const struct ublksrv_io_desc *iod, int tag) 178 { 179 const struct stripe_conf *conf = get_chunk_shift(q); 180 struct io_uring_sqe *sqe[NR_STRIPE]; 181 int i; 182 183 ublk_queue_alloc_sqes(q, sqe, conf->nr_files); 184 for (i = 0; i < conf->nr_files; i++) { 185 io_uring_prep_fsync(sqe[i], i + 1, IORING_FSYNC_DATASYNC); 186 io_uring_sqe_set_flags(sqe[i], IOSQE_FIXED_FILE); 187 sqe[i]->user_data = build_user_data(tag, UBLK_IO_OP_FLUSH, 0, 1); 188 } 189 return conf->nr_files; 190 } 191 192 static int stripe_queue_tgt_io(struct ublk_queue *q, int tag) 193 { 194 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag); 195 unsigned ublk_op = ublksrv_get_op(iod); 196 int ret = 0; 197 198 switch (ublk_op) { 199 case UBLK_IO_OP_FLUSH: 200 ret = handle_flush(q, iod, tag); 201 break; 202 case UBLK_IO_OP_WRITE_ZEROES: 203 case UBLK_IO_OP_DISCARD: 204 ret = -ENOTSUP; 205 break; 206 case UBLK_IO_OP_READ: 207 case UBLK_IO_OP_WRITE: 208 ret = stripe_queue_tgt_rw_io(q, iod, tag); 209 break; 210 default: 211 ret = -EINVAL; 212 break; 213 } 214 ublk_dbg(UBLK_DBG_IO, "%s: tag %d ublk io %x %llx %u ret %d\n", __func__, tag, 215 iod->op_flags, iod->start_sector, iod->nr_sectors << 9, ret); 216 return ret; 217 } 218 219 static int ublk_stripe_queue_io(struct ublk_queue *q, int tag) 220 { 221 int queued = stripe_queue_tgt_io(q, tag); 222 223 ublk_queued_tgt_io(q, tag, queued); 224 return 0; 225 } 226 227 static void ublk_stripe_io_done(struct ublk_queue *q, int tag, 228 const struct io_uring_cqe *cqe) 229 { 230 const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag); 231 unsigned op = user_data_to_op(cqe->user_data); 232 struct ublk_io *io = ublk_get_io(q, tag); 233 int res = cqe->res; 234 235 if (res < 0 || op != ublk_cmd_op_nr(UBLK_U_IO_UNREGISTER_IO_BUF)) { 236 if (!io->result) 237 io->result = res; 238 if (res < 0) 239 ublk_err("%s: io failure %d tag %u\n", __func__, res, tag); 240 } 241 242 /* buffer register op is IOSQE_CQE_SKIP_SUCCESS */ 243 if (op == ublk_cmd_op_nr(UBLK_U_IO_REGISTER_IO_BUF)) 244 io->tgt_ios += 1; 245 246 /* fail short READ/WRITE simply */ 247 if (op == UBLK_IO_OP_READ || op == UBLK_IO_OP_WRITE) { 248 unsigned seq = user_data_to_tgt_data(cqe->user_data); 249 struct stripe_array *s = io->private_data; 250 251 if (res < s->s[seq].nr_sects << 9) { 252 io->result = -EIO; 253 ublk_err("%s: short rw op %u res %d exp %u tag %u\n", 254 __func__, op, res, s->s[seq].vec->iov_len, tag); 255 } 256 } 257 258 if (ublk_completed_tgt_io(q, tag)) { 259 int res = io->result; 260 261 if (!res) 262 res = iod->nr_sectors << 9; 263 264 ublk_complete_io(q, tag, res); 265 266 free_stripe_array(io->private_data); 267 io->private_data = NULL; 268 } 269 } 270 271 static int ublk_stripe_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev) 272 { 273 struct ublk_params p = { 274 .types = UBLK_PARAM_TYPE_BASIC, 275 .basic = { 276 .attrs = UBLK_ATTR_VOLATILE_CACHE, 277 .logical_bs_shift = 9, 278 .physical_bs_shift = 12, 279 .io_opt_shift = 12, 280 .io_min_shift = 9, 281 .max_sectors = dev->dev_info.max_io_buf_bytes >> 9, 282 }, 283 }; 284 unsigned chunk_size = ctx->stripe.chunk_size; 285 struct stripe_conf *conf; 286 unsigned chunk_shift; 287 loff_t bytes = 0; 288 int ret, i, mul = 1; 289 290 if ((chunk_size & (chunk_size - 1)) || !chunk_size) { 291 ublk_err("invalid chunk size %u\n", chunk_size); 292 return -EINVAL; 293 } 294 295 if (chunk_size < 4096 || chunk_size > 512 * 1024) { 296 ublk_err("invalid chunk size %u\n", chunk_size); 297 return -EINVAL; 298 } 299 300 chunk_shift = ilog2(chunk_size); 301 302 ret = backing_file_tgt_init(dev); 303 if (ret) 304 return ret; 305 306 if (!dev->tgt.nr_backing_files || dev->tgt.nr_backing_files > NR_STRIPE) 307 return -EINVAL; 308 309 assert(dev->nr_fds == dev->tgt.nr_backing_files + 1); 310 311 for (i = 0; i < dev->tgt.nr_backing_files; i++) 312 dev->tgt.backing_file_size[i] &= ~((1 << chunk_shift) - 1); 313 314 for (i = 0; i < dev->tgt.nr_backing_files; i++) { 315 unsigned long size = dev->tgt.backing_file_size[i]; 316 317 if (size != dev->tgt.backing_file_size[0]) 318 return -EINVAL; 319 bytes += size; 320 } 321 322 conf = malloc(sizeof(*conf)); 323 conf->shift = chunk_shift; 324 conf->nr_files = dev->tgt.nr_backing_files; 325 326 dev->private_data = conf; 327 dev->tgt.dev_size = bytes; 328 p.basic.dev_sectors = bytes >> 9; 329 dev->tgt.params = p; 330 331 if (dev->dev_info.flags & UBLK_F_SUPPORT_ZERO_COPY) 332 mul = 2; 333 dev->tgt.sq_depth = mul * dev->dev_info.queue_depth * conf->nr_files; 334 dev->tgt.cq_depth = mul * dev->dev_info.queue_depth * conf->nr_files; 335 336 printf("%s: shift %u files %u\n", __func__, conf->shift, conf->nr_files); 337 338 return 0; 339 } 340 341 static void ublk_stripe_tgt_deinit(struct ublk_dev *dev) 342 { 343 free(dev->private_data); 344 backing_file_tgt_deinit(dev); 345 } 346 347 static void ublk_stripe_cmd_line(struct dev_ctx *ctx, int argc, char *argv[]) 348 { 349 static const struct option longopts[] = { 350 { "chunk_size", 1, NULL, 0 }, 351 { 0, 0, 0, 0 } 352 }; 353 int option_idx, opt; 354 355 ctx->stripe.chunk_size = 65536; 356 while ((opt = getopt_long(argc, argv, "", 357 longopts, &option_idx)) != -1) { 358 switch (opt) { 359 case 0: 360 if (!strcmp(longopts[option_idx].name, "chunk_size")) 361 ctx->stripe.chunk_size = strtol(optarg, NULL, 10); 362 } 363 } 364 } 365 366 static void ublk_stripe_usage(const struct ublk_tgt_ops *ops) 367 { 368 printf("\tstripe: [--chunk_size chunk_size (default 65536)]\n"); 369 } 370 371 const struct ublk_tgt_ops stripe_tgt_ops = { 372 .name = "stripe", 373 .init_tgt = ublk_stripe_tgt_init, 374 .deinit_tgt = ublk_stripe_tgt_deinit, 375 .queue_io = ublk_stripe_queue_io, 376 .tgt_io_done = ublk_stripe_io_done, 377 .parse_cmd_line = ublk_stripe_cmd_line, 378 .usage = ublk_stripe_usage, 379 }; 380