[PATCH] Remember to check ioops version in loaded module
[fio.git] / engines / fio-engine-splice.c
CommitLineData
2866c82d
JA
1/*
2 * splice io engine
3 *
4 */
5#include <stdio.h>
6#include <stdlib.h>
7#include <unistd.h>
8#include <errno.h>
9#include <assert.h>
10#include <sys/poll.h>
11#include "fio.h"
12#include "os.h"
13
14struct spliceio_data {
15 struct io_u *last_io_u;
16 int pipe[2];
17};
18
19static int fio_spliceio_sync(struct thread_data *td)
20{
21 return fsync(td->fd);
22}
23
24static int fio_spliceio_getevents(struct thread_data *td, int fio_unused min,
25 int max, struct timespec fio_unused *t)
26{
27 assert(max <= 1);
28
29 /*
30 * we can only have one finished io_u for sync io, since the depth
31 * is always 1
32 */
33 if (list_empty(&td->io_u_busylist))
34 return 0;
35
36 return 1;
37}
38
39static struct io_u *fio_spliceio_event(struct thread_data *td, int event)
40{
41 struct spliceio_data *sd = td->io_ops->data;
42
43 assert(event == 0);
44
45 return sd->last_io_u;
46}
47
48/*
49 * For splice reading, we unfortunately cannot (yet) vmsplice the other way.
50 * So just splice the data from the file into the pipe, and use regular
51 * read to fill the buffer. Doesn't make a lot of sense, but...
52 */
53static int fio_splice_read(struct thread_data *td, struct io_u *io_u)
54{
55 struct spliceio_data *sd = td->io_ops->data;
56 int ret, ret2, buflen;
57 off_t offset;
58 void *p;
59
60 offset = io_u->offset;
61 buflen = io_u->buflen;
62 p = io_u->buf;
63 while (buflen) {
64 int this_len = buflen;
65
66 if (this_len > SPLICE_DEF_SIZE)
67 this_len = SPLICE_DEF_SIZE;
68
69 ret = splice(td->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE);
70 if (ret < 0) {
71 if (errno == ENODATA || errno == EAGAIN)
72 continue;
73
74 return errno;
75 }
76
77 buflen -= ret;
78
79 while (ret) {
80 ret2 = read(sd->pipe[0], p, ret);
81 if (ret2 < 0)
82 return errno;
83
84 ret -= ret2;
85 p += ret2;
86 }
87 }
88
89 return io_u->buflen;
90}
91
92/*
93 * For splice writing, we can vmsplice our data buffer directly into a
94 * pipe and then splice that to a file.
95 */
96static int fio_splice_write(struct thread_data *td, struct io_u *io_u)
97{
98 struct spliceio_data *sd = td->io_ops->data;
99 struct iovec iov[1] = {
100 {
101 .iov_base = io_u->buf,
102 .iov_len = io_u->buflen,
103 }
104 };
105 struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, };
106 off_t off = io_u->offset;
107 int ret, ret2;
108
109 while (iov[0].iov_len) {
110 if (poll(&pfd, 1, -1) < 0)
111 return errno;
112
113 ret = vmsplice(sd->pipe[1], iov, 1, SPLICE_F_NONBLOCK);
114 if (ret < 0)
115 return errno;
116
117 iov[0].iov_len -= ret;
118 iov[0].iov_base += ret;
119
120 while (ret) {
121 ret2 = splice(sd->pipe[0], NULL, td->fd, &off, ret, 0);
122 if (ret2 < 0)
123 return errno;
124
125 ret -= ret2;
126 }
127 }
128
129 return io_u->buflen;
130}
131
132static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u)
133{
134 struct spliceio_data *sd = td->io_ops->data;
135 int ret;
136
137 if (io_u->ddir == DDIR_READ)
138 ret = fio_splice_read(td, io_u);
139 else
140 ret = fio_splice_write(td, io_u);
141
142 if ((unsigned int) ret != io_u->buflen) {
143 if (ret > 0) {
144 io_u->resid = io_u->buflen - ret;
145 io_u->error = ENODATA;
146 } else
147 io_u->error = errno;
148 }
149
150 if (!io_u->error)
151 sd->last_io_u = io_u;
152
153 return io_u->error;
154}
155
156static void fio_spliceio_cleanup(struct thread_data *td)
157{
158 struct spliceio_data *sd = td->io_ops->data;
159
160 if (sd) {
161 close(sd->pipe[0]);
162 close(sd->pipe[1]);
163 free(sd);
164 td->io_ops->data = NULL;
165 }
166}
167
168static int fio_spliceio_init(struct thread_data *td)
169{
170 struct spliceio_data *sd = malloc(sizeof(*sd));
171
172 sd->last_io_u = NULL;
173 if (pipe(sd->pipe) < 0) {
174 td_verror(td, errno);
175 free(sd);
176 return 1;
177 }
178
179 td->io_ops->data = sd;
180 return 0;
181}
182
183struct ioengine_ops ioengine = {
184 .name = "splice",
185 .version = FIO_IOOPS_VERSION,
186 .init = fio_spliceio_init,
187 .queue = fio_spliceio_queue,
188 .getevents = fio_spliceio_getevents,
189 .event = fio_spliceio_event,
190 .cleanup = fio_spliceio_cleanup,
191 .sync = fio_spliceio_sync,
192 .flags = FIO_SYNCIO,
193};