ioengines.c revision 6977bcd0e4ee3faa7ffd8f208e4031bdf906ed88 
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 <assert.h>
18
19#include "fio.h"
20
21static LIST_HEAD(engine_list);
22
23static int check_engine_ops(struct ioengine_ops *ops)
24{
25	if (ops->version != FIO_IOOPS_VERSION) {
26		log_err("bad ioops version %d (want %d)\n", ops->version, FIO_IOOPS_VERSION);
27		return 1;
28	}
29
30	if (!ops->queue) {
31		log_err("%s: no queue handler\n", ops->name);
32		return 1;
33	}
34
35	/*
36	 * sync engines only need a ->queue()
37	 */
38	if (ops->flags & FIO_SYNCIO)
39		return 0;
40
41	if (!ops->event) {
42		log_err("%s: no event handler\n", ops->name);
43		return 1;
44	}
45	if (!ops->getevents) {
46		log_err("%s: no getevents handler\n", ops->name);
47		return 1;
48	}
49	if (!ops->queue) {
50		log_err("%s: no queue handler\n", ops->name);
51		return 1;
52	}
53
54	return 0;
55}
56
57void unregister_ioengine(struct ioengine_ops *ops)
58{
59	dprint(FD_IO, "ioengine %s unregistered\n", ops->name);
60	list_del(&ops->list);
61	INIT_LIST_HEAD(&ops->list);
62}
63
64void register_ioengine(struct ioengine_ops *ops)
65{
66	dprint(FD_IO, "ioengine %s registered\n", ops->name);
67	INIT_LIST_HEAD(&ops->list);
68	list_add_tail(&ops->list, &engine_list);
69}
70
71static struct ioengine_ops *find_ioengine(const char *name)
72{
73	struct ioengine_ops *ops;
74	struct list_head *entry;
75
76	list_for_each(entry, &engine_list) {
77		ops = list_entry(entry, struct ioengine_ops, list);
78		if (!strcmp(name, ops->name))
79			return ops;
80	}
81
82	return NULL;
83}
84
85static struct ioengine_ops *dlopen_ioengine(struct thread_data *td,
86					    const char *engine_lib)
87{
88	struct ioengine_ops *ops;
89	void *dlhandle;
90
91	dprint(FD_IO, "dload engine %s\n", engine_lib);
92
93	dlerror();
94	dlhandle = dlopen(engine_lib, RTLD_LAZY);
95	if (!dlhandle) {
96		td_vmsg(td, -1, dlerror(), "dlopen");
97		return NULL;
98	}
99
100	/*
101	 * Unlike the included modules, external engines should have a
102	 * non-static ioengine structure that we can reference.
103	 */
104	ops = dlsym(dlhandle, "ioengine");
105	if (!ops) {
106		td_vmsg(td, -1, dlerror(), "dlsym");
107		dlclose(dlhandle);
108		return NULL;
109	}
110
111	ops->dlhandle = dlhandle;
112	return ops;
113}
114
115struct ioengine_ops *load_ioengine(struct thread_data *td, const char *name)
116{
117	struct ioengine_ops *ops, *ret;
118	char engine[16];
119
120	dprint(FD_IO, "load ioengine %s\n", name);
121
122	strncpy(engine, name, sizeof(engine) - 1);
123
124	/*
125	 * linux libaio has alias names, so convert to what we want
126	 */
127	if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3))
128		strcpy(engine, "libaio");
129
130	ops = find_ioengine(engine);
131	if (!ops)
132		ops = dlopen_ioengine(td, name);
133
134	if (!ops) {
135		log_err("fio: engine %s not loadable\n", name);
136		return NULL;
137	}
138
139	/*
140	 * Check that the required methods are there.
141	 */
142	if (check_engine_ops(ops))
143		return NULL;
144
145	ret = malloc(sizeof(*ret));
146	memcpy(ret, ops, sizeof(*ret));
147	ret->data = NULL;
148
149	return ret;
150}
151
152void close_ioengine(struct thread_data *td)
153{
154	dprint(FD_IO, "close ioengine %s\n", td->io_ops->name);
155
156	if (td->io_ops->cleanup)
157		td->io_ops->cleanup(td);
158
159	if (td->io_ops->dlhandle)
160		dlclose(td->io_ops->dlhandle);
161
162	free(td->io_ops);
163	td->io_ops = NULL;
164}
165
166int td_io_prep(struct thread_data *td, struct io_u *io_u)
167{
168	dprint_io_u(io_u, "prep");
169	fio_ro_check(td, io_u);
170
171	if (td->io_ops->prep) {
172		int ret = td->io_ops->prep(td, io_u);
173
174		dprint(FD_IO, "->prep(%p)=%d\n", io_u, ret);
175		return ret;
176	}
177
178	return 0;
179}
180
181int td_io_getevents(struct thread_data *td, unsigned int min, unsigned int max,
182		    struct timespec *t)
183{
184	int r = 0;
185
186	if (min > 0 && td->io_ops->commit) {
187		r = td->io_ops->commit(td);
188		if (r < 0)
189			goto out;
190	}
191
192	r = 0;
193	if (td->io_ops->getevents)
194		r = td->io_ops->getevents(td, min, max, t);
195out:
196	dprint(FD_IO, "getevents: %d\n", r);
197	return r;
198}
199
200int td_io_queue(struct thread_data *td, struct io_u *io_u)
201{
202	int ret;
203
204	dprint_io_u(io_u, "queue");
205	fio_ro_check(td, io_u);
206
207	assert((io_u->flags & IO_U_F_FLIGHT) == 0);
208	io_u->flags |= IO_U_F_FLIGHT;
209
210	assert(io_u->file->flags & FIO_FILE_OPEN);
211
212	io_u->error = 0;
213	io_u->resid = 0;
214
215	if (td->io_ops->flags & FIO_SYNCIO) {
216		fio_gettime(&io_u->issue_time, NULL);
217		memcpy(&td->last_issue, &io_u->issue_time, sizeof(struct timeval));
218
219		/*
220		 * for a sync engine, set the timeout upfront
221		 */
222		if (mtime_since(&td->timeout_end, &io_u->issue_time) < IO_U_TIMEOUT)
223			io_u_set_timeout(td);
224	}
225
226	if (io_u->ddir != DDIR_SYNC)
227		td->io_issues[io_u->ddir]++;
228
229	ret = td->io_ops->queue(td, io_u);
230
231	if (ret != FIO_Q_BUSY)
232		io_u_mark_depth(td, io_u);
233
234	if (ret == FIO_Q_QUEUED) {
235		int r;
236
237		td->io_u_queued++;
238		if (td->io_u_queued > td->o.iodepth_batch) {
239			r = td_io_commit(td);
240			if (r < 0)
241				return r;
242		}
243	}
244
245	if ((td->io_ops->flags & FIO_SYNCIO) == 0) {
246		fio_gettime(&io_u->issue_time, NULL);
247		memcpy(&td->last_issue, &io_u->issue_time, sizeof(struct timeval));
248
249		/*
250		 * async engine, set the timeout here
251		 */
252		if (ret == FIO_Q_QUEUED &&
253		    mtime_since(&td->timeout_end, &io_u->issue_time) < IO_U_TIMEOUT)
254			io_u_set_timeout(td);
255	}
256
257	return ret;
258}
259
260int td_io_init(struct thread_data *td)
261{
262	int ret = 0;
263
264	if (td->io_ops->init) {
265		ret = td->io_ops->init(td);
266		if (ret && td->o.iodepth > 1)
267			log_err("fio: io engine init failed. Perhaps try reducing io depth?\n");
268	}
269
270	return ret;
271}
272
273int td_io_commit(struct thread_data *td)
274{
275	dprint(FD_IO, "calling ->commit(), depth %d\n", td->cur_depth);
276
277	if (!td->cur_depth)
278		return 0;
279
280	td->io_u_queued = 0;
281	if (td->io_ops->commit)
282		return td->io_ops->commit(td);
283
284	return 0;
285}
286
287int td_io_open_file(struct thread_data *td, struct fio_file *f)
288{
289	if (td->io_ops->open_file(td, f)) {
290		if (td->error == EINVAL && td->o.odirect)
291			log_err("fio: destination does not support O_DIRECT\n");
292		if (td->error == EMFILE)
293			log_err("fio: try reducing/setting openfiles (failed at %u of %u)\n", td->nr_open_files, td->o.nr_files);
294
295		return 1;
296	}
297
298	if (f->filetype == FIO_TYPE_PIPE) {
299		if (td_random(td)) {
300			log_err("fio: can't seek on pipes (no random io)\n");
301			goto err;
302		}
303	}
304
305	f->last_free_lookup = 0;
306	f->last_completed_pos = 0;
307	f->last_pos = f->file_offset;
308	f->flags |= FIO_FILE_OPEN;
309	f->flags &= ~FIO_FILE_CLOSING;
310
311	if (td->io_ops->flags & FIO_DISKLESSIO)
312		goto done;
313
314	if (td->o.invalidate_cache && file_invalidate_cache(td, f))
315		goto err;
316
317	if (td->o.fadvise_hint &&
318	    (f->filetype == FIO_TYPE_BD || f->filetype == FIO_TYPE_FILE)) {
319
320		int flags;
321
322		if (td_random(td))
323			flags = POSIX_FADV_RANDOM;
324		else
325			flags = POSIX_FADV_SEQUENTIAL;
326
327		if (fadvise(f->fd, f->file_offset, f->io_size, flags) < 0) {
328			td_verror(td, errno, "fadvise");
329			goto err;
330		}
331	}
332
333	if (f->file_map)
334		memset(f->file_map, 0, f->num_maps * sizeof(long));
335
336done:
337	log_file(td, f, FIO_LOG_OPEN_FILE);
338	td->nr_open_files++;
339	get_file(f);
340	return 0;
341err:
342	if (td->io_ops->close_file)
343		td->io_ops->close_file(td, f);
344	return 1;
345}
346
347int td_io_close_file(struct thread_data *td, struct fio_file *f)
348{
349	if (!(f->flags & FIO_FILE_CLOSING))
350		log_file(td, f, FIO_LOG_CLOSE_FILE);
351
352	/*
353	 * mark as closing, do real close when last io on it has completed
354	 */
355	f->flags |= FIO_FILE_CLOSING;
356
357	return put_file(td, f);
358}
359