Commit | Line | Data |
---|---|---|
ebac4655 JA |
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> | |
5c4e1dbc | 15 | #include <string.h> |
2866c82d | 16 | #include <dlfcn.h> |
ecc314ba | 17 | #include <fcntl.h> |
0c6e7517 | 18 | #include <assert.h> |
8c16d840 | 19 | |
ebac4655 | 20 | #include "fio.h" |
7c9b1bce | 21 | #include "diskutil.h" |
ebac4655 | 22 | |
01743ee1 | 23 | static FLIST_HEAD(engine_list); |
5f350952 | 24 | |
8c16d840 JA |
25 | static int check_engine_ops(struct ioengine_ops *ops) |
26 | { | |
5f350952 | 27 | if (ops->version != FIO_IOOPS_VERSION) { |
5ec10eaa JA |
28 | log_err("bad ioops version %d (want %d)\n", ops->version, |
29 | FIO_IOOPS_VERSION); | |
5f350952 JA |
30 | return 1; |
31 | } | |
32 | ||
36167d82 JA |
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; | |
5ec10eaa | 43 | |
8c16d840 | 44 | if (!ops->event) { |
36167d82 | 45 | log_err("%s: no event handler\n", ops->name); |
8c16d840 JA |
46 | return 1; |
47 | } | |
48 | if (!ops->getevents) { | |
36167d82 | 49 | log_err("%s: no getevents handler\n", ops->name); |
8c16d840 JA |
50 | return 1; |
51 | } | |
52 | if (!ops->queue) { | |
36167d82 | 53 | log_err("%s: no queue handler\n", ops->name); |
8c16d840 JA |
54 | return 1; |
55 | } | |
5ec10eaa | 56 | |
8c16d840 JA |
57 | return 0; |
58 | } | |
59 | ||
5f350952 | 60 | void unregister_ioengine(struct ioengine_ops *ops) |
ebac4655 | 61 | { |
ee56ad50 | 62 | dprint(FD_IO, "ioengine %s unregistered\n", ops->name); |
01743ee1 JA |
63 | flist_del(&ops->list); |
64 | INIT_FLIST_HEAD(&ops->list); | |
5f350952 JA |
65 | } |
66 | ||
b2fdda43 | 67 | void register_ioengine(struct ioengine_ops *ops) |
5f350952 | 68 | { |
ee56ad50 | 69 | dprint(FD_IO, "ioengine %s registered\n", ops->name); |
01743ee1 JA |
70 | INIT_FLIST_HEAD(&ops->list); |
71 | flist_add_tail(&ops->list, &engine_list); | |
5f350952 JA |
72 | } |
73 | ||
74 | static struct ioengine_ops *find_ioengine(const char *name) | |
75 | { | |
76 | struct ioengine_ops *ops; | |
01743ee1 | 77 | struct flist_head *entry; |
ebac4655 | 78 | |
01743ee1 JA |
79 | flist_for_each(entry, &engine_list) { |
80 | ops = flist_entry(entry, struct ioengine_ops, list); | |
bc5b77a8 | 81 | if (!strcmp(name, ops->name)) |
5f350952 JA |
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 | ||
ee56ad50 JA |
94 | dprint(FD_IO, "dload engine %s\n", engine_lib); |
95 | ||
2866c82d JA |
96 | dlerror(); |
97 | dlhandle = dlopen(engine_lib, RTLD_LAZY); | |
d4dbaaa8 | 98 | if (!dlhandle) { |
e1161c32 | 99 | td_vmsg(td, -1, dlerror(), "dlopen"); |
d4dbaaa8 JA |
100 | return NULL; |
101 | } | |
8756e4d4 | 102 | |
da51c050 JA |
103 | /* |
104 | * Unlike the included modules, external engines should have a | |
105 | * non-static ioengine structure that we can reference. | |
106 | */ | |
2866c82d | 107 | ops = dlsym(dlhandle, "ioengine"); |
d4dbaaa8 | 108 | if (!ops) { |
e1161c32 | 109 | td_vmsg(td, -1, dlerror(), "dlsym"); |
d4dbaaa8 JA |
110 | dlclose(dlhandle); |
111 | return NULL; | |
112 | } | |
8756e4d4 | 113 | |
5f350952 JA |
114 | ops->dlhandle = dlhandle; |
115 | return ops; | |
116 | } | |
117 | ||
118 | struct ioengine_ops *load_ioengine(struct thread_data *td, const char *name) | |
119 | { | |
120 | struct ioengine_ops *ops, *ret; | |
121 | char engine[16]; | |
122 | ||
ee56ad50 JA |
123 | dprint(FD_IO, "load ioengine %s\n", name); |
124 | ||
5f350952 JA |
125 | strncpy(engine, name, sizeof(engine) - 1); |
126 | ||
127 | /* | |
128 | * linux libaio has alias names, so convert to what we want | |
129 | */ | |
130 | if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3)) | |
131 | strcpy(engine, "libaio"); | |
132 | ||
133 | ops = find_ioengine(engine); | |
134 | if (!ops) | |
135 | ops = dlopen_ioengine(td, name); | |
136 | ||
137 | if (!ops) { | |
138 | log_err("fio: engine %s not loadable\n", name); | |
b902ceb5 JA |
139 | return NULL; |
140 | } | |
141 | ||
8c16d840 JA |
142 | /* |
143 | * Check that the required methods are there. | |
144 | */ | |
5f350952 | 145 | if (check_engine_ops(ops)) |
8c16d840 | 146 | return NULL; |
8c16d840 | 147 | |
84585003 JA |
148 | ret = malloc(sizeof(*ret)); |
149 | memcpy(ret, ops, sizeof(*ret)); | |
150 | ret->data = NULL; | |
84585003 JA |
151 | |
152 | return ret; | |
8756e4d4 JA |
153 | } |
154 | ||
de890a1e SL |
155 | /* |
156 | * For cleaning up an ioengine which never made it to init(). | |
157 | */ | |
158 | void free_ioengine(struct thread_data *td) | |
8756e4d4 | 159 | { |
de890a1e | 160 | dprint(FD_IO, "free ioengine %s\n", td->io_ops->name); |
ee56ad50 | 161 | |
de890a1e SL |
162 | if (td->eo && td->io_ops->options) { |
163 | options_free(td->io_ops->options, td->eo); | |
164 | free(td->eo); | |
165 | td->eo = NULL; | |
2992b059 | 166 | } |
b990b5c0 | 167 | |
5f350952 JA |
168 | if (td->io_ops->dlhandle) |
169 | dlclose(td->io_ops->dlhandle); | |
170 | ||
84585003 JA |
171 | free(td->io_ops); |
172 | td->io_ops = NULL; | |
b990b5c0 | 173 | } |
10ba535a | 174 | |
de890a1e SL |
175 | void close_ioengine(struct thread_data *td) |
176 | { | |
177 | dprint(FD_IO, "close ioengine %s\n", td->io_ops->name); | |
178 | ||
179 | if (td->io_ops->cleanup) { | |
180 | td->io_ops->cleanup(td); | |
181 | td->io_ops->data = NULL; | |
182 | } | |
183 | ||
184 | free_ioengine(td); | |
185 | } | |
186 | ||
10ba535a JA |
187 | int td_io_prep(struct thread_data *td, struct io_u *io_u) |
188 | { | |
ee56ad50 | 189 | dprint_io_u(io_u, "prep"); |
7101d9c2 JA |
190 | fio_ro_check(td, io_u); |
191 | ||
4d4e80f2 | 192 | lock_file(td, io_u->file, io_u->ddir); |
b2bd2bd9 | 193 | |
2ba1c290 JA |
194 | if (td->io_ops->prep) { |
195 | int ret = td->io_ops->prep(td, io_u); | |
196 | ||
197 | dprint(FD_IO, "->prep(%p)=%d\n", io_u, ret); | |
b2bd2bd9 | 198 | if (ret) |
4d4e80f2 | 199 | unlock_file(td, io_u->file); |
2ba1c290 JA |
200 | return ret; |
201 | } | |
10ba535a JA |
202 | |
203 | return 0; | |
204 | } | |
205 | ||
e7d2e616 | 206 | int td_io_getevents(struct thread_data *td, unsigned int min, unsigned int max, |
10ba535a JA |
207 | struct timespec *t) |
208 | { | |
ee56ad50 | 209 | int r = 0; |
face81b2 | 210 | |
ee56ad50 JA |
211 | if (min > 0 && td->io_ops->commit) { |
212 | r = td->io_ops->commit(td); | |
face81b2 | 213 | if (r < 0) |
ee56ad50 | 214 | goto out; |
face81b2 | 215 | } |
4950421a JA |
216 | if (max > td->cur_depth) |
217 | max = td->cur_depth; | |
218 | if (min > max) | |
219 | max = min; | |
36167d82 | 220 | |
ee56ad50 | 221 | r = 0; |
4950421a | 222 | if (max && td->io_ops->getevents) |
ee56ad50 JA |
223 | r = td->io_ops->getevents(td, min, max, t); |
224 | out: | |
422f9e4b RM |
225 | if (r >= 0) { |
226 | /* | |
227 | * Reflect that our submitted requests were retrieved with | |
228 | * whatever OS async calls are in the underlying engine. | |
229 | */ | |
230 | td->io_u_in_flight -= r; | |
838bc709 | 231 | io_u_mark_complete(td, r); |
422f9e4b | 232 | } else |
7c639b14 | 233 | td_verror(td, r, "get_events"); |
f3e11d05 | 234 | |
ee56ad50 JA |
235 | dprint(FD_IO, "getevents: %d\n", r); |
236 | return r; | |
10ba535a JA |
237 | } |
238 | ||
239 | int td_io_queue(struct thread_data *td, struct io_u *io_u) | |
240 | { | |
7e77dd02 JA |
241 | int ret; |
242 | ||
ee56ad50 | 243 | dprint_io_u(io_u, "queue"); |
7101d9c2 JA |
244 | fio_ro_check(td, io_u); |
245 | ||
0c6e7517 JA |
246 | assert((io_u->flags & IO_U_F_FLIGHT) == 0); |
247 | io_u->flags |= IO_U_F_FLIGHT; | |
248 | ||
d6aed795 | 249 | assert(fio_file_open(io_u->file)); |
3d7b485f | 250 | |
11786802 JA |
251 | io_u->error = 0; |
252 | io_u->resid = 0; | |
253 | ||
433afcb4 | 254 | if (td->io_ops->flags & FIO_SYNCIO) { |
12d9d841 | 255 | if (fio_fill_issue_time(td)) |
9520ebb9 | 256 | fio_gettime(&io_u->issue_time, NULL); |
d0c15328 JA |
257 | |
258 | /* | |
259 | * only used for iolog | |
260 | */ | |
261 | if (td->o.read_iolog_file) | |
262 | memcpy(&td->last_issue, &io_u->issue_time, | |
5ec10eaa | 263 | sizeof(struct timeval)); |
433afcb4 JA |
264 | } |
265 | ||
ff58fced | 266 | if (ddir_rw(io_u->ddir)) |
755200a3 JA |
267 | td->io_issues[io_u->ddir]++; |
268 | ||
7e77dd02 | 269 | ret = td->io_ops->queue(td, io_u); |
5aeb77df | 270 | |
4d4e80f2 | 271 | unlock_file(td, io_u->file); |
b2bd2bd9 | 272 | |
cb211682 JA |
273 | /* |
274 | * Add warning for O_DIRECT so that users have an easier time | |
275 | * spotting potentially bad alignment. If this triggers for the first | |
276 | * IO, then it's likely an alignment problem or because the host fs | |
277 | * does not support O_DIRECT | |
278 | */ | |
ff58fced | 279 | if (io_u->error == EINVAL && td->io_issues[io_u->ddir & 1] == 1 && |
cb211682 JA |
280 | td->o.odirect) { |
281 | log_info("fio: first direct IO errored. File system may not " | |
282 | "support direct IO, or iomem_align= is bad.\n"); | |
283 | } | |
284 | ||
838bc709 JA |
285 | if (!td->io_ops->commit) { |
286 | io_u_mark_submit(td, 1); | |
287 | io_u_mark_complete(td, 1); | |
288 | } | |
289 | ||
d8005759 | 290 | if (ret == FIO_Q_COMPLETED) { |
ff58fced | 291 | if (ddir_rw(io_u->ddir)) { |
d8005759 JA |
292 | io_u_mark_depth(td, 1); |
293 | td->ts.total_io_u[io_u->ddir]++; | |
0d29de83 JA |
294 | } else if (io_u->ddir == DDIR_TRIM) |
295 | td->ts.total_io_u[2]++; | |
d8005759 | 296 | } else if (ret == FIO_Q_QUEUED) { |
eb7c8ae2 JA |
297 | int r; |
298 | ||
ff58fced | 299 | if (ddir_rw(io_u->ddir)) { |
d8005759 JA |
300 | td->io_u_queued++; |
301 | td->ts.total_io_u[io_u->ddir]++; | |
302 | } | |
303 | ||
304 | if (td->io_u_queued >= td->o.iodepth_batch) { | |
eb7c8ae2 JA |
305 | r = td_io_commit(td); |
306 | if (r < 0) | |
307 | return r; | |
308 | } | |
309 | } | |
cb5ab512 | 310 | |
433afcb4 | 311 | if ((td->io_ops->flags & FIO_SYNCIO) == 0) { |
12d9d841 | 312 | if (fio_fill_issue_time(td)) |
9520ebb9 | 313 | fio_gettime(&io_u->issue_time, NULL); |
d0c15328 JA |
314 | |
315 | /* | |
316 | * only used for iolog | |
317 | */ | |
318 | if (td->o.read_iolog_file) | |
319 | memcpy(&td->last_issue, &io_u->issue_time, | |
320 | sizeof(struct timeval)); | |
433afcb4 JA |
321 | } |
322 | ||
7e77dd02 | 323 | return ret; |
10ba535a | 324 | } |
8c16d840 JA |
325 | |
326 | int td_io_init(struct thread_data *td) | |
327 | { | |
eeb12160 | 328 | int ret = 0; |
8c16d840 | 329 | |
eeb12160 JA |
330 | if (td->io_ops->init) { |
331 | ret = td->io_ops->init(td); | |
5ec10eaa JA |
332 | if (ret && td->o.iodepth > 1) { |
333 | log_err("fio: io engine init failed. Perhaps try" | |
334 | " reducing io depth?\n"); | |
335 | } | |
7c973896 JA |
336 | if (!td->error) |
337 | td->error = ret; | |
eeb12160 JA |
338 | } |
339 | ||
340 | return ret; | |
8c16d840 | 341 | } |
755200a3 JA |
342 | |
343 | int td_io_commit(struct thread_data *td) | |
344 | { | |
f3e11d05 JA |
345 | int ret; |
346 | ||
ee56ad50 JA |
347 | dprint(FD_IO, "calling ->commit(), depth %d\n", td->cur_depth); |
348 | ||
d8005759 | 349 | if (!td->cur_depth || !td->io_u_queued) |
e1161c32 | 350 | return 0; |
cb5ab512 | 351 | |
422f9e4b | 352 | io_u_mark_depth(td, td->io_u_queued); |
d8005759 | 353 | |
f3e11d05 JA |
354 | if (td->io_ops->commit) { |
355 | ret = td->io_ops->commit(td); | |
356 | if (ret) | |
357 | td_verror(td, -ret, "io commit"); | |
358 | } | |
422f9e4b RM |
359 | |
360 | /* | |
361 | * Reflect that events were submitted as async IO requests. | |
362 | */ | |
363 | td->io_u_in_flight += td->io_u_queued; | |
364 | td->io_u_queued = 0; | |
755200a3 JA |
365 | |
366 | return 0; | |
367 | } | |
b5af8293 JA |
368 | |
369 | int td_io_open_file(struct thread_data *td, struct fio_file *f) | |
370 | { | |
22a57ba8 JA |
371 | assert(!fio_file_open(f)); |
372 | assert(f->fd == -1); | |
373 | ||
413d6693 JA |
374 | if (td->io_ops->open_file(td, f)) { |
375 | if (td->error == EINVAL && td->o.odirect) | |
376 | log_err("fio: destination does not support O_DIRECT\n"); | |
5ec10eaa JA |
377 | if (td->error == EMFILE) { |
378 | log_err("fio: try reducing/setting openfiles (failed" | |
379 | " at %u of %u)\n", td->nr_open_files, | |
380 | td->o.nr_files); | |
381 | } | |
413d6693 | 382 | |
22a57ba8 JA |
383 | assert(f->fd == -1); |
384 | assert(!fio_file_open(f)); | |
413d6693 JA |
385 | return 1; |
386 | } | |
387 | ||
d5707a35 | 388 | fio_file_reset(f); |
d6aed795 JA |
389 | fio_file_set_open(f); |
390 | fio_file_clear_closing(f); | |
c97bd0fa | 391 | disk_util_inc(f->du); |
d5707a35 JA |
392 | |
393 | td->nr_open_files++; | |
394 | get_file(f); | |
395 | ||
66159828 JA |
396 | if (f->filetype == FIO_TYPE_PIPE) { |
397 | if (td_random(td)) { | |
398 | log_err("fio: can't seek on pipes (no random io)\n"); | |
399 | goto err; | |
400 | } | |
401 | } | |
402 | ||
413d6693 JA |
403 | if (td->io_ops->flags & FIO_DISKLESSIO) |
404 | goto done; | |
405 | ||
406 | if (td->o.invalidate_cache && file_invalidate_cache(td, f)) | |
407 | goto err; | |
408 | ||
66159828 JA |
409 | if (td->o.fadvise_hint && |
410 | (f->filetype == FIO_TYPE_BD || f->filetype == FIO_TYPE_FILE)) { | |
413d6693 JA |
411 | int flags; |
412 | ||
413 | if (td_random(td)) | |
414 | flags = POSIX_FADV_RANDOM; | |
415 | else | |
416 | flags = POSIX_FADV_SEQUENTIAL; | |
417 | ||
ecc314ba | 418 | if (posix_fadvise(f->fd, f->file_offset, f->io_size, flags) < 0) { |
413d6693 JA |
419 | td_verror(td, errno, "fadvise"); |
420 | goto err; | |
421 | } | |
7bb48f84 | 422 | } |
a978ba68 | 423 | |
e116f2b9 JA |
424 | #ifdef FIO_OS_DIRECTIO |
425 | /* | |
426 | * Some OS's have a distinct call to mark the file non-buffered, | |
427 | * instead of using O_DIRECT (Solaris) | |
428 | */ | |
429 | if (td->o.odirect) { | |
430 | int ret = fio_set_odirect(f->fd); | |
431 | ||
432 | if (ret) { | |
433 | td_verror(td, ret, "fio_set_odirect"); | |
78e51c72 | 434 | log_err("fio: the file system does not seem to support direct IO\n"); |
e116f2b9 JA |
435 | goto err; |
436 | } | |
437 | } | |
438 | #endif | |
439 | ||
413d6693 | 440 | done: |
f29b25a3 | 441 | log_file(td, f, FIO_LOG_OPEN_FILE); |
413d6693 JA |
442 | return 0; |
443 | err: | |
c97bd0fa | 444 | disk_util_dec(f->du); |
b284075a JA |
445 | if (td->io_ops->close_file) |
446 | td->io_ops->close_file(td, f); | |
7bb48f84 | 447 | return 1; |
b5af8293 JA |
448 | } |
449 | ||
6977bcd0 | 450 | int td_io_close_file(struct thread_data *td, struct fio_file *f) |
b5af8293 | 451 | { |
d6aed795 | 452 | if (!fio_file_closing(f)) |
f29b25a3 JA |
453 | log_file(td, f, FIO_LOG_CLOSE_FILE); |
454 | ||
0ad920e7 JA |
455 | /* |
456 | * mark as closing, do real close when last io on it has completed | |
457 | */ | |
d6aed795 | 458 | fio_file_set_closing(f); |
0ad920e7 | 459 | |
c97bd0fa | 460 | disk_util_dec(f->du); |
4d4e80f2 | 461 | unlock_file_all(td, f); |
29c1349f | 462 | |
6977bcd0 | 463 | return put_file(td, f); |
b5af8293 | 464 | } |
df9c26b1 JA |
465 | |
466 | int td_io_get_file_size(struct thread_data *td, struct fio_file *f) | |
467 | { | |
468 | if (!td->io_ops->get_file_size) | |
469 | return 0; | |
470 | ||
471 | return td->io_ops->get_file_size(td, f); | |
472 | } | |
44f29692 | 473 | |
0a28ecda | 474 | static int do_sync_file_range(struct thread_data *td, struct fio_file *f) |
44f29692 JA |
475 | { |
476 | off64_t offset, nbytes; | |
477 | ||
478 | offset = f->first_write; | |
479 | nbytes = f->last_write - f->first_write; | |
480 | ||
3843deb3 JA |
481 | if (!nbytes) |
482 | return 0; | |
44f29692 | 483 | |
3843deb3 | 484 | return sync_file_range(f->fd, offset, nbytes, td->o.sync_file_range); |
44f29692 | 485 | } |
0a28ecda JA |
486 | |
487 | int do_io_u_sync(struct thread_data *td, struct io_u *io_u) | |
488 | { | |
489 | int ret; | |
490 | ||
491 | if (io_u->ddir == DDIR_SYNC) { | |
492 | ret = fsync(io_u->file->fd); | |
493 | } else if (io_u->ddir == DDIR_DATASYNC) { | |
494 | #ifdef FIO_HAVE_FDATASYNC | |
495 | ret = fdatasync(io_u->file->fd); | |
496 | #else | |
497 | ret = io_u->xfer_buflen; | |
498 | io_u->error = EINVAL; | |
499 | #endif | |
500 | } else if (io_u->ddir == DDIR_SYNC_FILE_RANGE) | |
501 | ret = do_sync_file_range(td, io_u->file); | |
502 | else { | |
503 | ret = io_u->xfer_buflen; | |
504 | io_u->error = EINVAL; | |
505 | } | |
506 | ||
cb849a79 JA |
507 | if (ret < 0) |
508 | io_u->error = errno; | |
509 | ||
0a28ecda JA |
510 | return ret; |
511 | } | |
a5f3027c JA |
512 | |
513 | int do_io_u_trim(struct thread_data *td, struct io_u *io_u) | |
514 | { | |
515 | #ifndef FIO_HAVE_TRIM | |
516 | io_u->error = EINVAL; | |
ff58fced | 517 | return 0; |
a5f3027c JA |
518 | #else |
519 | struct fio_file *f = io_u->file; | |
520 | int ret; | |
521 | ||
c6404a44 | 522 | ret = os_trim(f->fd, io_u->offset, io_u->xfer_buflen); |
a5f3027c | 523 | if (!ret) |
ff58fced | 524 | return io_u->xfer_buflen;; |
a5f3027c | 525 | |
ff58fced JA |
526 | io_u->error = ret; |
527 | return 0; | |
a5f3027c JA |
528 | #endif |
529 | } | |
de890a1e SL |
530 | |
531 | int fio_show_ioengine_help(const char *engine) | |
532 | { | |
533 | struct flist_head *entry; | |
534 | struct thread_data td; | |
535 | char *sep; | |
536 | int ret = 1; | |
537 | ||
538 | if (!engine || !*engine) { | |
539 | log_info("Available IO engines:\n"); | |
540 | flist_for_each(entry, &engine_list) { | |
541 | td.io_ops = flist_entry(entry, struct ioengine_ops, | |
542 | list); | |
543 | log_info("\t%s\n", td.io_ops->name); | |
544 | } | |
545 | return 0; | |
546 | } | |
547 | sep = strchr(engine, ','); | |
548 | if (sep) { | |
549 | *sep = 0; | |
550 | sep++; | |
551 | } | |
552 | ||
553 | memset(&td, 0, sizeof(td)); | |
554 | ||
555 | td.io_ops = load_ioengine(&td, engine); | |
556 | if (!td.io_ops) { | |
557 | log_info("IO engine %s not found\n", engine); | |
558 | return 1; | |
559 | } | |
560 | ||
561 | if (td.io_ops->options) | |
562 | ret = show_cmd_help(td.io_ops->options, sep); | |
563 | else | |
564 | log_info("IO engine %s has no options\n", td.io_ops->name); | |
565 | ||
566 | free_ioengine(&td); | |
567 | ||
568 | return ret; | |
569 | } |