ioengines.c revision bcdedd0ac6e9413258b608ecb3511867b1a9c534 
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	list_del(&ops->list);
60	INIT_LIST_HEAD(&ops->list);
61}
62
63void register_ioengine(struct ioengine_ops *ops)
64{
65	INIT_LIST_HEAD(&ops->list);
66	list_add_tail(&ops->list, &engine_list);
67}
68
69static struct ioengine_ops *find_ioengine(const char *name)
70{
71	struct ioengine_ops *ops;
72	struct list_head *entry;
73
74	list_for_each(entry, &engine_list) {
75		ops = list_entry(entry, struct ioengine_ops, list);
76		if (!strcmp(name, ops->name))
77			return ops;
78	}
79
80	return NULL;
81}
82
83static struct ioengine_ops *dlopen_ioengine(struct thread_data *td,
84					    const char *engine_lib)
85{
86	struct ioengine_ops *ops;
87	void *dlhandle;
88
89	dlerror();
90	dlhandle = dlopen(engine_lib, RTLD_LAZY);
91	if (!dlhandle) {
92		td_vmsg(td, -1, dlerror(), "dlopen");
93		return NULL;
94	}
95
96	/*
97	 * Unlike the included modules, external engines should have a
98	 * non-static ioengine structure that we can reference.
99	 */
100	ops = dlsym(dlhandle, "ioengine");
101	if (!ops) {
102		td_vmsg(td, -1, dlerror(), "dlsym");
103		dlclose(dlhandle);
104		return NULL;
105	}
106
107	ops->dlhandle = dlhandle;
108	return ops;
109}
110
111struct ioengine_ops *load_ioengine(struct thread_data *td, const char *name)
112{
113	struct ioengine_ops *ops, *ret;
114	char engine[16];
115
116	strncpy(engine, name, sizeof(engine) - 1);
117
118	/*
119	 * linux libaio has alias names, so convert to what we want
120	 */
121	if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3))
122		strcpy(engine, "libaio");
123
124	ops = find_ioengine(engine);
125	if (!ops)
126		ops = dlopen_ioengine(td, name);
127
128	if (!ops) {
129		log_err("fio: engine %s not loadable\n", name);
130		return NULL;
131	}
132
133	/*
134	 * Check that the required methods are there.
135	 */
136	if (check_engine_ops(ops))
137		return NULL;
138
139	ret = malloc(sizeof(*ret));
140	memcpy(ret, ops, sizeof(*ret));
141	ret->data = NULL;
142
143	return ret;
144}
145
146void close_ioengine(struct thread_data *td)
147{
148	if (td->io_ops->cleanup)
149		td->io_ops->cleanup(td);
150
151	if (td->io_ops->dlhandle)
152		dlclose(td->io_ops->dlhandle);
153
154	free(td->io_ops);
155	td->io_ops = NULL;
156}
157
158int td_io_prep(struct thread_data *td, struct io_u *io_u)
159{
160	if (td->io_ops->prep)
161		return td->io_ops->prep(td, io_u);
162
163	return 0;
164}
165
166int td_io_getevents(struct thread_data *td, int min, int max,
167		    struct timespec *t)
168{
169	if (min > 0 && td->io_ops->commit) {
170		int r = td->io_ops->commit(td);
171
172		if (r < 0)
173			return r;
174	}
175	if (td->io_ops->getevents)
176		return td->io_ops->getevents(td, min, max, t);
177
178	return 0;
179}
180
181int td_io_queue(struct thread_data *td, struct io_u *io_u)
182{
183	int ret;
184
185	assert((io_u->flags & IO_U_F_FLIGHT) == 0);
186	io_u->flags |= IO_U_F_FLIGHT;
187
188	assert(io_u->file->flags & FIO_FILE_OPEN);
189
190	io_u->error = 0;
191	io_u->resid = 0;
192
193	if (td->io_ops->flags & FIO_SYNCIO) {
194		fio_gettime(&io_u->issue_time, NULL);
195		memcpy(&td->last_issue, &io_u->issue_time, sizeof(struct timeval));
196
197		/*
198		 * for a sync engine, set the timeout upfront
199		 */
200		if (mtime_since(&td->timeout_end, &io_u->issue_time) < IO_U_TIMEOUT)
201			io_u_set_timeout(td);
202	}
203
204	if (io_u->ddir != DDIR_SYNC)
205		td->io_issues[io_u->ddir]++;
206
207	io_u_mark_depth(td, io_u);
208
209	ret = td->io_ops->queue(td, io_u);
210
211	if (ret == FIO_Q_QUEUED) {
212		int r;
213
214		td->io_u_queued++;
215		if (td->io_u_queued > td->o.iodepth_batch) {
216			r = td_io_commit(td);
217			if (r < 0)
218				return r;
219		}
220	}
221
222	if ((td->io_ops->flags & FIO_SYNCIO) == 0) {
223		fio_gettime(&io_u->issue_time, NULL);
224		memcpy(&td->last_issue, &io_u->issue_time, sizeof(struct timeval));
225
226		/*
227		 * async engine, set the timeout here
228		 */
229		if (ret == FIO_Q_QUEUED &&
230		    mtime_since(&td->timeout_end, &io_u->issue_time) < IO_U_TIMEOUT)
231			io_u_set_timeout(td);
232	}
233
234	return ret;
235}
236
237int td_io_init(struct thread_data *td)
238{
239	int ret = 0;
240
241	if (td->io_ops->init) {
242		ret = td->io_ops->init(td);
243		if (ret && td->o.iodepth > 1)
244			log_err("fio: io engine init failed. Perhaps try reducing io dpeth?\n");
245	}
246
247	return ret;
248}
249
250int td_io_commit(struct thread_data *td)
251{
252	if (!td->cur_depth)
253		return 0;
254
255	td->io_u_queued = 0;
256	if (td->io_ops->commit)
257		return td->io_ops->commit(td);
258
259	return 0;
260}
261
262int td_io_open_file(struct thread_data *td, struct fio_file *f)
263{
264	if (td->io_ops->open_file(td, f)) {
265		if (td->error == EINVAL && td->o.odirect)
266			log_err("fio: destination does not support O_DIRECT\n");
267		if (td->error == EMFILE)
268			log_err("fio: try reducing/setting openfiles (failed at %u of %u)\n", td->nr_open_files, td->o.nr_files);
269
270		return 1;
271	}
272
273	if (f->filetype == FIO_TYPE_PIPE) {
274		if (td_random(td)) {
275			log_err("fio: can't seek on pipes (no random io)\n");
276			goto err;
277		}
278	}
279
280	f->last_free_lookup = 0;
281	f->last_completed_pos = 0;
282	f->last_pos = f->file_offset;
283	f->flags |= FIO_FILE_OPEN;
284	f->flags &= ~FIO_FILE_CLOSING;
285
286	if (td->io_ops->flags & FIO_DISKLESSIO)
287		goto done;
288
289	if (td->o.invalidate_cache && file_invalidate_cache(td, f))
290		goto err;
291
292	if (td->o.fadvise_hint &&
293	    (f->filetype == FIO_TYPE_BD || f->filetype == FIO_TYPE_FILE)) {
294
295		int flags;
296
297		if (td_random(td))
298			flags = POSIX_FADV_RANDOM;
299		else
300			flags = POSIX_FADV_SEQUENTIAL;
301
302		if (fadvise(f->fd, f->file_offset, f->io_size, flags) < 0) {
303			td_verror(td, errno, "fadvise");
304			goto err;
305		}
306	}
307
308	if (f->file_map)
309		memset(f->file_map, 0, f->num_maps * sizeof(long));
310
311done:
312	log_file(td, f, FIO_LOG_OPEN_FILE);
313	td->nr_open_files++;
314	get_file(f);
315	return 0;
316err:
317	if (td->io_ops->close_file)
318		td->io_ops->close_file(td, f);
319	return 1;
320}
321
322void td_io_close_file(struct thread_data *td, struct fio_file *f)
323{
324	if (!(f->flags & FIO_FILE_CLOSING))
325		log_file(td, f, FIO_LOG_CLOSE_FILE);
326
327	/*
328	 * mark as closing, do real close when last io on it has completed
329	 */
330	f->flags |= FIO_FILE_CLOSING;
331
332	put_file(td, f);
333}
334