| 1 | /* |
| 2 | * The io parts of the fio tool, includes workers for sync and mmap'ed |
| 3 | * io, as well as both posix and linux libaio support. |
| 4 | * |
| 5 | * sync io is implemented on top of aio. |
| 6 | * |
| 7 | * This is not really specific to fio, if the get_io_u/put_io_u and |
| 8 | * structures was pulled into this as well it would be a perfectly |
| 9 | * generic io engine that could be used for other projects. |
| 10 | * |
| 11 | */ |
| 12 | #include <stdio.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <unistd.h> |
| 15 | #include <string.h> |
| 16 | #include <dlfcn.h> |
| 17 | #include <fcntl.h> |
| 18 | #include <assert.h> |
| 19 | |
| 20 | #include "fio.h" |
| 21 | #include "diskutil.h" |
| 22 | |
| 23 | static FLIST_HEAD(engine_list); |
| 24 | |
| 25 | static int check_engine_ops(struct ioengine_ops *ops) |
| 26 | { |
| 27 | if (ops->version != FIO_IOOPS_VERSION) { |
| 28 | log_err("bad ioops version %d (want %d)\n", ops->version, |
| 29 | FIO_IOOPS_VERSION); |
| 30 | return 1; |
| 31 | } |
| 32 | |
| 33 | if (!ops->queue) { |
| 34 | log_err("%s: no queue handler\n", ops->name); |
| 35 | return 1; |
| 36 | } |
| 37 | |
| 38 | /* |
| 39 | * sync engines only need a ->queue() |
| 40 | */ |
| 41 | if (ops->flags & FIO_SYNCIO) |
| 42 | return 0; |
| 43 | |
| 44 | if (!ops->event) { |
| 45 | log_err("%s: no event handler\n", ops->name); |
| 46 | return 1; |
| 47 | } |
| 48 | if (!ops->getevents) { |
| 49 | log_err("%s: no getevents handler\n", ops->name); |
| 50 | return 1; |
| 51 | } |
| 52 | if (!ops->queue) { |
| 53 | log_err("%s: no queue handler\n", ops->name); |
| 54 | return 1; |
| 55 | } |
| 56 | |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | void unregister_ioengine(struct ioengine_ops *ops) |
| 61 | { |
| 62 | dprint(FD_IO, "ioengine %s unregistered\n", ops->name); |
| 63 | flist_del(&ops->list); |
| 64 | INIT_FLIST_HEAD(&ops->list); |
| 65 | } |
| 66 | |
| 67 | void register_ioengine(struct ioengine_ops *ops) |
| 68 | { |
| 69 | dprint(FD_IO, "ioengine %s registered\n", ops->name); |
| 70 | INIT_FLIST_HEAD(&ops->list); |
| 71 | flist_add_tail(&ops->list, &engine_list); |
| 72 | } |
| 73 | |
| 74 | static struct ioengine_ops *find_ioengine(const char *name) |
| 75 | { |
| 76 | struct ioengine_ops *ops; |
| 77 | struct flist_head *entry; |
| 78 | |
| 79 | flist_for_each(entry, &engine_list) { |
| 80 | ops = flist_entry(entry, struct ioengine_ops, list); |
| 81 | if (!strcmp(name, ops->name)) |
| 82 | return ops; |
| 83 | } |
| 84 | |
| 85 | return NULL; |
| 86 | } |
| 87 | |
| 88 | static struct ioengine_ops *dlopen_ioengine(struct thread_data *td, |
| 89 | const char *engine_lib) |
| 90 | { |
| 91 | struct ioengine_ops *ops; |
| 92 | void *dlhandle; |
| 93 | |
| 94 | dprint(FD_IO, "dload engine %s\n", engine_lib); |
| 95 | |
| 96 | dlerror(); |
| 97 | dlhandle = dlopen(engine_lib, RTLD_LAZY); |
| 98 | if (!dlhandle) { |
| 99 | td_vmsg(td, -1, dlerror(), "dlopen"); |
| 100 | return NULL; |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * Unlike the included modules, external engines should have a |
| 105 | * non-static ioengine structure that we can reference. |
| 106 | */ |
| 107 | ops = dlsym(dlhandle, engine_lib); |
| 108 | if (!ops) |
| 109 | ops = dlsym(dlhandle, "ioengine"); |
| 110 | |
| 111 | /* |
| 112 | * For some external engines (like C++ ones) it is not that trivial |
| 113 | * to provide a non-static ionengine structure that we can reference. |
| 114 | * Instead we call a method which allocates the required ioengine |
| 115 | * structure. |
| 116 | */ |
| 117 | if (!ops) { |
| 118 | get_ioengine_t get_ioengine = dlsym(dlhandle, "get_ioengine"); |
| 119 | |
| 120 | if (get_ioengine) |
| 121 | get_ioengine(&ops); |
| 122 | } |
| 123 | |
| 124 | if (!ops) { |
| 125 | td_vmsg(td, -1, dlerror(), "dlsym"); |
| 126 | dlclose(dlhandle); |
| 127 | return NULL; |
| 128 | } |
| 129 | |
| 130 | ops->dlhandle = dlhandle; |
| 131 | return ops; |
| 132 | } |
| 133 | |
| 134 | struct ioengine_ops *load_ioengine(struct thread_data *td, const char *name) |
| 135 | { |
| 136 | struct ioengine_ops *ops, *ret; |
| 137 | char engine[16]; |
| 138 | |
| 139 | dprint(FD_IO, "load ioengine %s\n", name); |
| 140 | |
| 141 | strncpy(engine, name, sizeof(engine) - 1); |
| 142 | |
| 143 | /* |
| 144 | * linux libaio has alias names, so convert to what we want |
| 145 | */ |
| 146 | if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3)) |
| 147 | strcpy(engine, "libaio"); |
| 148 | |
| 149 | ops = find_ioengine(engine); |
| 150 | if (!ops) |
| 151 | ops = dlopen_ioengine(td, name); |
| 152 | |
| 153 | if (!ops) { |
| 154 | log_err("fio: engine %s not loadable\n", name); |
| 155 | return NULL; |
| 156 | } |
| 157 | |
| 158 | /* |
| 159 | * Check that the required methods are there. |
| 160 | */ |
| 161 | if (check_engine_ops(ops)) |
| 162 | return NULL; |
| 163 | |
| 164 | ret = malloc(sizeof(*ret)); |
| 165 | memcpy(ret, ops, sizeof(*ret)); |
| 166 | ret->data = NULL; |
| 167 | |
| 168 | return ret; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * For cleaning up an ioengine which never made it to init(). |
| 173 | */ |
| 174 | void free_ioengine(struct thread_data *td) |
| 175 | { |
| 176 | dprint(FD_IO, "free ioengine %s\n", td->io_ops->name); |
| 177 | |
| 178 | if (td->eo && td->io_ops->options) { |
| 179 | options_free(td->io_ops->options, td->eo); |
| 180 | free(td->eo); |
| 181 | td->eo = NULL; |
| 182 | } |
| 183 | |
| 184 | if (td->io_ops->dlhandle) |
| 185 | dlclose(td->io_ops->dlhandle); |
| 186 | |
| 187 | free(td->io_ops); |
| 188 | td->io_ops = NULL; |
| 189 | } |
| 190 | |
| 191 | void close_ioengine(struct thread_data *td) |
| 192 | { |
| 193 | dprint(FD_IO, "close ioengine %s\n", td->io_ops->name); |
| 194 | |
| 195 | if (td->io_ops->cleanup) { |
| 196 | td->io_ops->cleanup(td); |
| 197 | td->io_ops->data = NULL; |
| 198 | } |
| 199 | |
| 200 | free_ioengine(td); |
| 201 | } |
| 202 | |
| 203 | int td_io_prep(struct thread_data *td, struct io_u *io_u) |
| 204 | { |
| 205 | dprint_io_u(io_u, "prep"); |
| 206 | fio_ro_check(td, io_u); |
| 207 | |
| 208 | lock_file(td, io_u->file, io_u->ddir); |
| 209 | |
| 210 | if (td->io_ops->prep) { |
| 211 | int ret = td->io_ops->prep(td, io_u); |
| 212 | |
| 213 | dprint(FD_IO, "->prep(%p)=%d\n", io_u, ret); |
| 214 | if (ret) |
| 215 | unlock_file(td, io_u->file); |
| 216 | return ret; |
| 217 | } |
| 218 | |
| 219 | return 0; |
| 220 | } |
| 221 | |
| 222 | int td_io_getevents(struct thread_data *td, unsigned int min, unsigned int max, |
| 223 | const struct timespec *t) |
| 224 | { |
| 225 | int r = 0; |
| 226 | |
| 227 | /* |
| 228 | * For ioengine=rdma one side operation RDMA_WRITE or RDMA_READ, |
| 229 | * server side gets a message from the client |
| 230 | * side that the task is finished, and |
| 231 | * td->done is set to 1 after td_io_commit(). In this case, |
| 232 | * there is no need to reap complete event in server side. |
| 233 | */ |
| 234 | if (td->done) |
| 235 | return 0; |
| 236 | |
| 237 | if (min > 0 && td->io_ops->commit) { |
| 238 | r = td->io_ops->commit(td); |
| 239 | if (r < 0) |
| 240 | goto out; |
| 241 | } |
| 242 | if (max > td->cur_depth) |
| 243 | max = td->cur_depth; |
| 244 | if (min > max) |
| 245 | max = min; |
| 246 | |
| 247 | r = 0; |
| 248 | if (max && td->io_ops->getevents) |
| 249 | r = td->io_ops->getevents(td, min, max, t); |
| 250 | out: |
| 251 | if (r >= 0) { |
| 252 | /* |
| 253 | * Reflect that our submitted requests were retrieved with |
| 254 | * whatever OS async calls are in the underlying engine. |
| 255 | */ |
| 256 | td->io_u_in_flight -= r; |
| 257 | io_u_mark_complete(td, r); |
| 258 | } else |
| 259 | td_verror(td, r, "get_events"); |
| 260 | |
| 261 | dprint(FD_IO, "getevents: %d\n", r); |
| 262 | return r; |
| 263 | } |
| 264 | |
| 265 | int td_io_queue(struct thread_data *td, struct io_u *io_u) |
| 266 | { |
| 267 | const enum fio_ddir ddir = acct_ddir(io_u); |
| 268 | unsigned long buflen = io_u->xfer_buflen; |
| 269 | int ret; |
| 270 | |
| 271 | dprint_io_u(io_u, "queue"); |
| 272 | fio_ro_check(td, io_u); |
| 273 | |
| 274 | assert((io_u->flags & IO_U_F_FLIGHT) == 0); |
| 275 | io_u_set(io_u, IO_U_F_FLIGHT); |
| 276 | |
| 277 | assert(fio_file_open(io_u->file)); |
| 278 | |
| 279 | /* |
| 280 | * If using a write iolog, store this entry. |
| 281 | */ |
| 282 | log_io_u(td, io_u); |
| 283 | |
| 284 | io_u->error = 0; |
| 285 | io_u->resid = 0; |
| 286 | |
| 287 | if (td->io_ops->flags & FIO_SYNCIO) { |
| 288 | if (fio_fill_issue_time(td)) |
| 289 | fio_gettime(&io_u->issue_time, NULL); |
| 290 | |
| 291 | /* |
| 292 | * only used for iolog |
| 293 | */ |
| 294 | if (td->o.read_iolog_file) |
| 295 | memcpy(&td->last_issue, &io_u->issue_time, |
| 296 | sizeof(struct timeval)); |
| 297 | } |
| 298 | |
| 299 | if (ddir_rw(ddir)) { |
| 300 | td->io_issues[ddir]++; |
| 301 | td->io_issue_bytes[ddir] += buflen; |
| 302 | td->rate_io_issue_bytes[ddir] += buflen; |
| 303 | } |
| 304 | |
| 305 | ret = td->io_ops->queue(td, io_u); |
| 306 | |
| 307 | unlock_file(td, io_u->file); |
| 308 | |
| 309 | if (ret == FIO_Q_BUSY && ddir_rw(ddir)) { |
| 310 | td->io_issues[ddir]--; |
| 311 | td->io_issue_bytes[ddir] -= buflen; |
| 312 | td->rate_io_issue_bytes[ddir] -= buflen; |
| 313 | } |
| 314 | |
| 315 | /* |
| 316 | * If an error was seen and the io engine didn't propagate it |
| 317 | * back to 'td', do so. |
| 318 | */ |
| 319 | if (io_u->error && !td->error) |
| 320 | td_verror(td, io_u->error, "td_io_queue"); |
| 321 | |
| 322 | /* |
| 323 | * Add warning for O_DIRECT so that users have an easier time |
| 324 | * spotting potentially bad alignment. If this triggers for the first |
| 325 | * IO, then it's likely an alignment problem or because the host fs |
| 326 | * does not support O_DIRECT |
| 327 | */ |
| 328 | if (io_u->error == EINVAL && td->io_issues[io_u->ddir & 1] == 1 && |
| 329 | td->o.odirect) { |
| 330 | |
| 331 | log_info("fio: first direct IO errored. File system may not " |
| 332 | "support direct IO, or iomem_align= is bad. Try " |
| 333 | "setting direct=0.\n"); |
| 334 | } |
| 335 | |
| 336 | if (!td->io_ops->commit || io_u->ddir == DDIR_TRIM) { |
| 337 | io_u_mark_submit(td, 1); |
| 338 | io_u_mark_complete(td, 1); |
| 339 | } |
| 340 | |
| 341 | if (ret == FIO_Q_COMPLETED) { |
| 342 | if (ddir_rw(io_u->ddir)) { |
| 343 | io_u_mark_depth(td, 1); |
| 344 | td->ts.total_io_u[io_u->ddir]++; |
| 345 | } |
| 346 | } else if (ret == FIO_Q_QUEUED) { |
| 347 | int r; |
| 348 | |
| 349 | if (ddir_rw(io_u->ddir)) { |
| 350 | td->io_u_queued++; |
| 351 | td->ts.total_io_u[io_u->ddir]++; |
| 352 | } |
| 353 | |
| 354 | if (td->io_u_queued >= td->o.iodepth_batch) { |
| 355 | r = td_io_commit(td); |
| 356 | if (r < 0) |
| 357 | return r; |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | if ((td->io_ops->flags & FIO_SYNCIO) == 0) { |
| 362 | if (fio_fill_issue_time(td)) |
| 363 | fio_gettime(&io_u->issue_time, NULL); |
| 364 | |
| 365 | /* |
| 366 | * only used for iolog |
| 367 | */ |
| 368 | if (td->o.read_iolog_file) |
| 369 | memcpy(&td->last_issue, &io_u->issue_time, |
| 370 | sizeof(struct timeval)); |
| 371 | } |
| 372 | |
| 373 | return ret; |
| 374 | } |
| 375 | |
| 376 | int td_io_init(struct thread_data *td) |
| 377 | { |
| 378 | int ret = 0; |
| 379 | |
| 380 | if (td->io_ops->init) { |
| 381 | ret = td->io_ops->init(td); |
| 382 | if (ret && td->o.iodepth > 1) { |
| 383 | log_err("fio: io engine init failed. Perhaps try" |
| 384 | " reducing io depth?\n"); |
| 385 | } |
| 386 | if (!td->error) |
| 387 | td->error = ret; |
| 388 | } |
| 389 | |
| 390 | if (!ret && (td->io_ops->flags & FIO_NOIO)) |
| 391 | td->flags |= TD_F_NOIO; |
| 392 | |
| 393 | return ret; |
| 394 | } |
| 395 | |
| 396 | int td_io_commit(struct thread_data *td) |
| 397 | { |
| 398 | int ret; |
| 399 | |
| 400 | dprint(FD_IO, "calling ->commit(), depth %d\n", td->cur_depth); |
| 401 | |
| 402 | if (!td->cur_depth || !td->io_u_queued) |
| 403 | return 0; |
| 404 | |
| 405 | io_u_mark_depth(td, td->io_u_queued); |
| 406 | |
| 407 | if (td->io_ops->commit) { |
| 408 | ret = td->io_ops->commit(td); |
| 409 | if (ret) |
| 410 | td_verror(td, -ret, "io commit"); |
| 411 | } |
| 412 | |
| 413 | /* |
| 414 | * Reflect that events were submitted as async IO requests. |
| 415 | */ |
| 416 | td->io_u_in_flight += td->io_u_queued; |
| 417 | td->io_u_queued = 0; |
| 418 | |
| 419 | return 0; |
| 420 | } |
| 421 | |
| 422 | int td_io_open_file(struct thread_data *td, struct fio_file *f) |
| 423 | { |
| 424 | assert(!fio_file_open(f)); |
| 425 | assert(f->fd == -1); |
| 426 | |
| 427 | if (td->io_ops->open_file(td, f)) { |
| 428 | if (td->error == EINVAL && td->o.odirect) |
| 429 | log_err("fio: destination does not support O_DIRECT\n"); |
| 430 | if (td->error == EMFILE) { |
| 431 | log_err("fio: try reducing/setting openfiles (failed" |
| 432 | " at %u of %u)\n", td->nr_open_files, |
| 433 | td->o.nr_files); |
| 434 | } |
| 435 | |
| 436 | assert(f->fd == -1); |
| 437 | assert(!fio_file_open(f)); |
| 438 | return 1; |
| 439 | } |
| 440 | |
| 441 | fio_file_reset(td, f); |
| 442 | fio_file_set_open(f); |
| 443 | fio_file_clear_closing(f); |
| 444 | disk_util_inc(f->du); |
| 445 | |
| 446 | td->nr_open_files++; |
| 447 | get_file(f); |
| 448 | |
| 449 | if (f->filetype == FIO_TYPE_PIPE) { |
| 450 | if (td_random(td)) { |
| 451 | log_err("fio: can't seek on pipes (no random io)\n"); |
| 452 | goto err; |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | if (td->io_ops->flags & FIO_DISKLESSIO) |
| 457 | goto done; |
| 458 | |
| 459 | if (td->o.invalidate_cache && file_invalidate_cache(td, f)) |
| 460 | goto err; |
| 461 | |
| 462 | if (td->o.fadvise_hint && |
| 463 | (f->filetype == FIO_TYPE_BD || f->filetype == FIO_TYPE_FILE)) { |
| 464 | int flags; |
| 465 | |
| 466 | if (td_random(td)) |
| 467 | flags = POSIX_FADV_RANDOM; |
| 468 | else |
| 469 | flags = POSIX_FADV_SEQUENTIAL; |
| 470 | |
| 471 | if (posix_fadvise(f->fd, f->file_offset, f->io_size, flags) < 0) { |
| 472 | td_verror(td, errno, "fadvise"); |
| 473 | goto err; |
| 474 | } |
| 475 | } |
| 476 | #ifdef FIO_HAVE_STREAMID |
| 477 | if (td->o.fadvise_stream && |
| 478 | (f->filetype == FIO_TYPE_BD || f->filetype == FIO_TYPE_FILE)) { |
| 479 | off_t stream = td->o.fadvise_stream; |
| 480 | |
| 481 | if (posix_fadvise(f->fd, stream, f->io_size, POSIX_FADV_STREAMID) < 0) { |
| 482 | td_verror(td, errno, "fadvise streamid"); |
| 483 | goto err; |
| 484 | } |
| 485 | } |
| 486 | #endif |
| 487 | |
| 488 | #ifdef FIO_OS_DIRECTIO |
| 489 | /* |
| 490 | * Some OS's have a distinct call to mark the file non-buffered, |
| 491 | * instead of using O_DIRECT (Solaris) |
| 492 | */ |
| 493 | if (td->o.odirect) { |
| 494 | int ret = fio_set_odirect(f->fd); |
| 495 | |
| 496 | if (ret) { |
| 497 | td_verror(td, ret, "fio_set_odirect"); |
| 498 | log_err("fio: the file system does not seem to support direct IO\n"); |
| 499 | goto err; |
| 500 | } |
| 501 | } |
| 502 | #endif |
| 503 | |
| 504 | done: |
| 505 | log_file(td, f, FIO_LOG_OPEN_FILE); |
| 506 | return 0; |
| 507 | err: |
| 508 | disk_util_dec(f->du); |
| 509 | if (td->io_ops->close_file) |
| 510 | td->io_ops->close_file(td, f); |
| 511 | return 1; |
| 512 | } |
| 513 | |
| 514 | int td_io_close_file(struct thread_data *td, struct fio_file *f) |
| 515 | { |
| 516 | if (!fio_file_closing(f)) |
| 517 | log_file(td, f, FIO_LOG_CLOSE_FILE); |
| 518 | |
| 519 | /* |
| 520 | * mark as closing, do real close when last io on it has completed |
| 521 | */ |
| 522 | fio_file_set_closing(f); |
| 523 | |
| 524 | disk_util_dec(f->du); |
| 525 | |
| 526 | if (td->o.file_lock_mode != FILE_LOCK_NONE) |
| 527 | unlock_file_all(td, f); |
| 528 | |
| 529 | return put_file(td, f); |
| 530 | } |
| 531 | |
| 532 | int td_io_unlink_file(struct thread_data *td, struct fio_file *f) |
| 533 | { |
| 534 | if (td->io_ops->unlink_file) |
| 535 | return td->io_ops->unlink_file(td, f); |
| 536 | else |
| 537 | return unlink(f->file_name); |
| 538 | } |
| 539 | |
| 540 | int td_io_get_file_size(struct thread_data *td, struct fio_file *f) |
| 541 | { |
| 542 | if (!td->io_ops->get_file_size) |
| 543 | return 0; |
| 544 | |
| 545 | return td->io_ops->get_file_size(td, f); |
| 546 | } |
| 547 | |
| 548 | static int do_sync_file_range(const struct thread_data *td, |
| 549 | struct fio_file *f) |
| 550 | { |
| 551 | off64_t offset, nbytes; |
| 552 | |
| 553 | offset = f->first_write; |
| 554 | nbytes = f->last_write - f->first_write; |
| 555 | |
| 556 | if (!nbytes) |
| 557 | return 0; |
| 558 | |
| 559 | return sync_file_range(f->fd, offset, nbytes, td->o.sync_file_range); |
| 560 | } |
| 561 | |
| 562 | int do_io_u_sync(const struct thread_data *td, struct io_u *io_u) |
| 563 | { |
| 564 | int ret; |
| 565 | |
| 566 | if (io_u->ddir == DDIR_SYNC) { |
| 567 | ret = fsync(io_u->file->fd); |
| 568 | } else if (io_u->ddir == DDIR_DATASYNC) { |
| 569 | #ifdef CONFIG_FDATASYNC |
| 570 | ret = fdatasync(io_u->file->fd); |
| 571 | #else |
| 572 | ret = io_u->xfer_buflen; |
| 573 | io_u->error = EINVAL; |
| 574 | #endif |
| 575 | } else if (io_u->ddir == DDIR_SYNC_FILE_RANGE) |
| 576 | ret = do_sync_file_range(td, io_u->file); |
| 577 | else { |
| 578 | ret = io_u->xfer_buflen; |
| 579 | io_u->error = EINVAL; |
| 580 | } |
| 581 | |
| 582 | if (ret < 0) |
| 583 | io_u->error = errno; |
| 584 | |
| 585 | return ret; |
| 586 | } |
| 587 | |
| 588 | int do_io_u_trim(const struct thread_data *td, struct io_u *io_u) |
| 589 | { |
| 590 | #ifndef FIO_HAVE_TRIM |
| 591 | io_u->error = EINVAL; |
| 592 | return 0; |
| 593 | #else |
| 594 | struct fio_file *f = io_u->file; |
| 595 | int ret; |
| 596 | |
| 597 | ret = os_trim(f->fd, io_u->offset, io_u->xfer_buflen); |
| 598 | if (!ret) |
| 599 | return io_u->xfer_buflen; |
| 600 | |
| 601 | io_u->error = ret; |
| 602 | return 0; |
| 603 | #endif |
| 604 | } |
| 605 | |
| 606 | int fio_show_ioengine_help(const char *engine) |
| 607 | { |
| 608 | struct flist_head *entry; |
| 609 | struct thread_data td; |
| 610 | char *sep; |
| 611 | int ret = 1; |
| 612 | |
| 613 | if (!engine || !*engine) { |
| 614 | log_info("Available IO engines:\n"); |
| 615 | flist_for_each(entry, &engine_list) { |
| 616 | td.io_ops = flist_entry(entry, struct ioengine_ops, |
| 617 | list); |
| 618 | log_info("\t%s\n", td.io_ops->name); |
| 619 | } |
| 620 | return 0; |
| 621 | } |
| 622 | sep = strchr(engine, ','); |
| 623 | if (sep) { |
| 624 | *sep = 0; |
| 625 | sep++; |
| 626 | } |
| 627 | |
| 628 | memset(&td, 0, sizeof(td)); |
| 629 | |
| 630 | td.io_ops = load_ioengine(&td, engine); |
| 631 | if (!td.io_ops) { |
| 632 | log_info("IO engine %s not found\n", engine); |
| 633 | return 1; |
| 634 | } |
| 635 | |
| 636 | if (td.io_ops->options) |
| 637 | ret = show_cmd_help(td.io_ops->options, sep); |
| 638 | else |
| 639 | log_info("IO engine %s has no options\n", td.io_ops->name); |
| 640 | |
| 641 | free_ioengine(&td); |
| 642 | |
| 643 | return ret; |
| 644 | } |