Issue time fixup for guasi/libaio
[fio.git] / engines / splice.c
CommitLineData
2866c82d 1/*
da751ca9
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2 * splice engine
3 *
4 * IO engine that transfers data by doing splices to/from pipes and
5 * the files.
2866c82d
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6 *
7 */
8#include <stdio.h>
9#include <stdlib.h>
10#include <unistd.h>
11#include <errno.h>
12#include <assert.h>
13#include <sys/poll.h>
81887d5d 14#include <sys/mman.h>
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15
16#include "../fio.h"
2866c82d 17
34cfcdaf
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18#ifdef FIO_HAVE_SPLICE
19
2866c82d 20struct spliceio_data {
2866c82d 21 int pipe[2];
f24254e1 22 int vmsplice_to_user;
8b850243 23 int vmsplice_to_user_map;
2866c82d
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24};
25
2866c82d 26/*
f24254e1
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27 * vmsplice didn't use to support splicing to user space, this is the old
28 * variant of getting that job done. Doesn't make a lot of sense, but it
29 * uses splices to move data from the source into a pipe.
2866c82d 30 */
f24254e1 31static int fio_splice_read_old(struct thread_data *td, struct io_u *io_u)
2866c82d
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32{
33 struct spliceio_data *sd = td->io_ops->data;
53cdc686 34 struct fio_file *f = io_u->file;
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35 int ret, ret2, buflen;
36 off_t offset;
37 void *p;
38
39 offset = io_u->offset;
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40 buflen = io_u->xfer_buflen;
41 p = io_u->xfer_buf;
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42 while (buflen) {
43 int this_len = buflen;
44
45 if (this_len > SPLICE_DEF_SIZE)
46 this_len = SPLICE_DEF_SIZE;
47
53cdc686 48 ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE);
2866c82d
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49 if (ret < 0) {
50 if (errno == ENODATA || errno == EAGAIN)
51 continue;
52
b4ba5f30 53 return -errno;
2866c82d
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54 }
55
56 buflen -= ret;
57
58 while (ret) {
59 ret2 = read(sd->pipe[0], p, ret);
60 if (ret2 < 0)
b4ba5f30 61 return -errno;
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62
63 ret -= ret2;
64 p += ret2;
65 }
66 }
67
cec6b55d 68 return io_u->xfer_buflen;
2866c82d
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69}
70
f24254e1
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71/*
72 * We can now vmsplice into userspace, so do the transfer by splicing into
73 * a pipe and vmsplicing that into userspace.
74 */
75static int fio_splice_read(struct thread_data *td, struct io_u *io_u)
76{
77 struct spliceio_data *sd = td->io_ops->data;
78 struct fio_file *f = io_u->file;
79 struct iovec iov;
8b850243 80 int ret , buflen, mmap_len;
f24254e1 81 off_t offset;
81887d5d 82 void *p, *map;
f24254e1 83
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84restart:
85 ret = 0;
f24254e1 86 offset = io_u->offset;
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87 mmap_len = buflen = io_u->xfer_buflen;
88
8b850243
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89 if (sd->vmsplice_to_user_map) {
90 map = mmap(io_u->xfer_buf, buflen, PROT_READ, MAP_PRIVATE|OS_MAP_ANON, 0, 0);
91 if (map == MAP_FAILED) {
92 td_verror(td, errno, "mmap io_u");
93 return -1;
94 }
95
96 p = map;
97 } else {
98 map = NULL;
99 p = io_u->xfer_buf;
81887d5d
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100 }
101
f24254e1
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102 while (buflen) {
103 int this_len = buflen;
81887d5d 104 int flags = 0;
f24254e1 105
81887d5d 106 if (this_len > SPLICE_DEF_SIZE) {
f24254e1 107 this_len = SPLICE_DEF_SIZE;
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108 flags = SPLICE_F_MORE;
109 }
f24254e1 110
81887d5d 111 ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len,flags);
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112 if (ret < 0) {
113 if (errno == ENODATA || errno == EAGAIN)
114 continue;
115
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116 td_verror(td, errno, "splice-from-fd");
117 break;
f24254e1
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118 }
119
120 buflen -= ret;
121 iov.iov_base = p;
122 iov.iov_len = ret;
123 p += ret;
124
125 while (iov.iov_len) {
126 ret = vmsplice(sd->pipe[0], &iov, 1, SPLICE_F_MOVE);
81887d5d 127 if (ret < 0) {
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128 if (errno == EFAULT && sd->vmsplice_to_user_map) {
129 sd->vmsplice_to_user_map = 0;
130 munmap(map, mmap_len);
131 goto restart;
132 }
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133 if (errno == EBADF) {
134 ret = -EBADF;
135 break;
136 }
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137 td_verror(td, errno, "vmsplice");
138 break;
139 } else if (!ret) {
140 td_verror(td, ENODATA, "vmsplice");
141 ret = -1;
142 break;
143 }
f24254e1
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144
145 iov.iov_len -= ret;
146 iov.iov_base += ret;
147 }
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148 if (ret < 0)
149 break;
150 }
151
8b850243 152 if (sd->vmsplice_to_user_map && munmap(map, mmap_len) < 0) {
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153 td_verror(td, errno, "munnap io_u");
154 return -1;
f24254e1 155 }
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156 if (ret < 0)
157 return ret;
f24254e1
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158
159 return io_u->xfer_buflen;
160}
161
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162/*
163 * For splice writing, we can vmsplice our data buffer directly into a
164 * pipe and then splice that to a file.
165 */
166static int fio_splice_write(struct thread_data *td, struct io_u *io_u)
167{
168 struct spliceio_data *sd = td->io_ops->data;
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169 struct iovec iov = {
170 .iov_base = io_u->xfer_buf,
171 .iov_len = io_u->xfer_buflen,
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172 };
173 struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, };
53cdc686 174 struct fio_file *f = io_u->file;
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175 off_t off = io_u->offset;
176 int ret, ret2;
177
f24254e1 178 while (iov.iov_len) {
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179 if (poll(&pfd, 1, -1) < 0)
180 return errno;
181
f24254e1 182 ret = vmsplice(sd->pipe[1], &iov, 1, SPLICE_F_NONBLOCK);
2866c82d 183 if (ret < 0)
b4ba5f30 184 return -errno;
2866c82d 185
f24254e1
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186 iov.iov_len -= ret;
187 iov.iov_base += ret;
2866c82d
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188
189 while (ret) {
53cdc686 190 ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0);
2866c82d 191 if (ret2 < 0)
b4ba5f30 192 return -errno;
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193
194 ret -= ret2;
195 }
196 }
197
cec6b55d 198 return io_u->xfer_buflen;
2866c82d
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199}
200
201static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u)
202{
f24254e1 203 struct spliceio_data *sd = td->io_ops->data;
f3f552b9 204 int uninitialized_var(ret);
2866c82d 205
7101d9c2
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206 fio_ro_check(td, io_u);
207
f24254e1 208 if (io_u->ddir == DDIR_READ) {
43688575 209 if (sd->vmsplice_to_user) {
f24254e1 210 ret = fio_splice_read(td, io_u);
43688575
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211 /*
212 * This kernel doesn't support vmsplice to user
213 * space. Reset the vmsplice_to_user flag, so that
214 * we retry below and don't hit this path again.
215 */
216 if (ret == -EBADF)
217 sd->vmsplice_to_user = 0;
218 }
219 if (!sd->vmsplice_to_user)
f24254e1
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220 ret = fio_splice_read_old(td, io_u);
221 } else if (io_u->ddir == DDIR_WRITE)
2866c82d 222 ret = fio_splice_write(td, io_u);
87dc1ab1
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223 else
224 ret = fsync(io_u->file->fd);
2866c82d 225
cec6b55d 226 if (ret != (int) io_u->xfer_buflen) {
22819ec2 227 if (ret >= 0) {
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228 io_u->resid = io_u->xfer_buflen - ret;
229 io_u->error = 0;
36167d82 230 return FIO_Q_COMPLETED;
2866c82d
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231 } else
232 io_u->error = errno;
233 }
234
0aa417a9 235 if (io_u->error) {
e1161c32 236 td_verror(td, io_u->error, "xfer");
0aa417a9
JA
237 if (io_u->error == EINVAL)
238 log_err("fio: looks like splice doesn't work on this"
239 " file system\n");
240 }
2866c82d 241
36167d82 242 return FIO_Q_COMPLETED;
2866c82d
JA
243}
244
245static void fio_spliceio_cleanup(struct thread_data *td)
246{
247 struct spliceio_data *sd = td->io_ops->data;
248
249 if (sd) {
250 close(sd->pipe[0]);
251 close(sd->pipe[1]);
252 free(sd);
2866c82d
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253 }
254}
255
256static int fio_spliceio_init(struct thread_data *td)
257{
258 struct spliceio_data *sd = malloc(sizeof(*sd));
259
2866c82d 260 if (pipe(sd->pipe) < 0) {
e1161c32 261 td_verror(td, errno, "pipe");
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262 free(sd);
263 return 1;
264 }
265
f24254e1 266 /*
43688575 267 * Assume this work, we'll reset this if it doesn't
f24254e1 268 */
43688575 269 sd->vmsplice_to_user = 1;
f24254e1 270
8b850243
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271 /*
272 * Works with "real" vmsplice to user, eg mapping pages directly.
273 * Reset if we fail.
274 */
275 sd->vmsplice_to_user_map = 1;
276
81887d5d
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277 /*
278 * And if vmsplice_to_user works, we definitely need aligned
279 * buffers. Just set ->odirect to force that.
280 */
281 if (td_read(td))
282 td->o.odirect = 1;
283
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284 td->io_ops->data = sd;
285 return 0;
286}
287
5f350952 288static struct ioengine_ops ioengine = {
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289 .name = "splice",
290 .version = FIO_IOOPS_VERSION,
291 .init = fio_spliceio_init,
292 .queue = fio_spliceio_queue,
2866c82d 293 .cleanup = fio_spliceio_cleanup,
b5af8293
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294 .open_file = generic_open_file,
295 .close_file = generic_close_file,
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296 .flags = FIO_SYNCIO,
297};
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298
299#else /* FIO_HAVE_SPLICE */
300
301/*
302 * When we have a proper configure system in place, we simply wont build
303 * and install this io engine. For now install a crippled version that
304 * just complains and fails to load.
305 */
306static int fio_spliceio_init(struct thread_data fio_unused *td)
307{
308 fprintf(stderr, "fio: splice not available\n");
309 return 1;
310}
311
5f350952 312static struct ioengine_ops ioengine = {
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313 .name = "splice",
314 .version = FIO_IOOPS_VERSION,
315 .init = fio_spliceio_init,
316};
317
318#endif
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319
320static void fio_init fio_spliceio_register(void)
321{
322 register_ioengine(&ioengine);
323}
324
325static void fio_exit fio_spliceio_unregister(void)
326{
327 unregister_ioengine(&ioengine);
328}