ioengines.c revision 8c16d840377c1e6fb79f479ee60590a2da5b52ee 
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
18#include "fio.h"
19#include "os.h"
20
21static int check_engine_ops(struct ioengine_ops *ops)
22{
23	/*
24	 * cpu thread doesn't need to provide anything
25	 */
26	if (ops->flags & FIO_CPUIO)
27		return 0;
28
29	if (!ops->event) {
30		log_err("%s: no event handler)\n", ops->name);
31		return 1;
32	}
33	if (!ops->getevents) {
34		log_err("%s: no getevents handler)\n", ops->name);
35		return 1;
36	}
37	if (!ops->queue) {
38		log_err("%s: no queue handler)\n", ops->name);
39		return 1;
40	}
41
42	return 0;
43}
44
45struct ioengine_ops *load_ioengine(struct thread_data *td, char *name)
46{
47	char engine[16], engine_lib[256];
48	struct ioengine_ops *ops, *ret;
49	void *dlhandle;
50
51	strcpy(engine, name);
52
53	/*
54	 * linux libaio has alias names, so convert to what we want
55	 */
56	if (!strncmp(engine, "linuxaio", 8) || !strncmp(engine, "aio", 3))
57		strcpy(engine, "libaio");
58
59	sprintf(engine_lib, "%s/lib/fio/fio-engine-%s.o", fio_inst_prefix, engine);
60	dlerror();
61	dlhandle = dlopen(engine_lib, RTLD_LAZY);
62	if (!dlhandle) {
63		td_vmsg(td, -1, dlerror());
64		return NULL;
65	}
66
67	ops = dlsym(dlhandle, "ioengine");
68	if (!ops) {
69		td_vmsg(td, -1, dlerror());
70		dlclose(dlhandle);
71		return NULL;
72	}
73
74	if (ops->version != FIO_IOOPS_VERSION) {
75		log_err("bad ioops version %d (want %d)\n", ops->version, FIO_IOOPS_VERSION);
76		dlclose(dlhandle);
77		return NULL;
78	}
79
80	/*
81	 * Check that the required methods are there.
82	 */
83	if (check_engine_ops(ops)) {
84		dlclose(dlhandle);
85		return NULL;
86	}
87
88	ret = malloc(sizeof(*ret));
89	memcpy(ret, ops, sizeof(*ret));
90	ret->data = NULL;
91	ret->dlhandle = dlhandle;
92
93	return ret;
94}
95
96void close_ioengine(struct thread_data *td)
97{
98	if (td->io_ops->cleanup)
99		td->io_ops->cleanup(td);
100
101	dlclose(td->io_ops->dlhandle);
102	free(td->io_ops);
103	td->io_ops = NULL;
104}
105
106int td_io_prep(struct thread_data *td, struct io_u *io_u)
107{
108	if (td->io_ops->prep && td->io_ops->prep(td, io_u))
109		return 1;
110
111	return 0;
112}
113
114int td_io_sync(struct thread_data *td, struct fio_file *f)
115{
116	if (td->io_ops->sync)
117		return td->io_ops->sync(td, f);
118
119	return 0;
120}
121
122int td_io_getevents(struct thread_data *td, int min, int max,
123		    struct timespec *t)
124{
125	return td->io_ops->getevents(td, min, max, t);
126}
127
128int td_io_queue(struct thread_data *td, struct io_u *io_u)
129{
130	gettimeofday(&io_u->issue_time, NULL);
131
132	return td->io_ops->queue(td, io_u);
133}
134
135int td_io_init(struct thread_data *td)
136{
137	if (td->io_ops->init)
138		return td->io_ops->init(td);
139
140	return 0;
141}
142