Commit | Line | Data |
---|---|---|
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> | |
5f350952 JA |
11 | |
12 | #include "../fio.h" | |
13 | #include "../os.h" | |
2866c82d | 14 | |
34cfcdaf JA |
15 | #ifdef FIO_HAVE_SPLICE |
16 | ||
2866c82d JA |
17 | struct spliceio_data { |
18 | struct io_u *last_io_u; | |
19 | int pipe[2]; | |
20 | }; | |
21 | ||
2866c82d JA |
22 | static int fio_spliceio_getevents(struct thread_data *td, int fio_unused min, |
23 | int max, struct timespec fio_unused *t) | |
24 | { | |
25 | assert(max <= 1); | |
26 | ||
27 | /* | |
28 | * we can only have one finished io_u for sync io, since the depth | |
29 | * is always 1 | |
30 | */ | |
31 | if (list_empty(&td->io_u_busylist)) | |
32 | return 0; | |
33 | ||
34 | return 1; | |
35 | } | |
36 | ||
37 | static struct io_u *fio_spliceio_event(struct thread_data *td, int event) | |
38 | { | |
39 | struct spliceio_data *sd = td->io_ops->data; | |
40 | ||
41 | assert(event == 0); | |
42 | ||
43 | return sd->last_io_u; | |
44 | } | |
45 | ||
46 | /* | |
47 | * For splice reading, we unfortunately cannot (yet) vmsplice the other way. | |
48 | * So just splice the data from the file into the pipe, and use regular | |
49 | * read to fill the buffer. Doesn't make a lot of sense, but... | |
50 | */ | |
51 | static int fio_splice_read(struct thread_data *td, struct io_u *io_u) | |
52 | { | |
53 | struct spliceio_data *sd = td->io_ops->data; | |
53cdc686 | 54 | struct fio_file *f = io_u->file; |
2866c82d JA |
55 | int ret, ret2, buflen; |
56 | off_t offset; | |
57 | void *p; | |
58 | ||
59 | offset = io_u->offset; | |
60 | buflen = io_u->buflen; | |
61 | p = io_u->buf; | |
62 | while (buflen) { | |
63 | int this_len = buflen; | |
64 | ||
65 | if (this_len > SPLICE_DEF_SIZE) | |
66 | this_len = SPLICE_DEF_SIZE; | |
67 | ||
53cdc686 | 68 | ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE); |
2866c82d JA |
69 | if (ret < 0) { |
70 | if (errno == ENODATA || errno == EAGAIN) | |
71 | continue; | |
72 | ||
73 | return errno; | |
74 | } | |
75 | ||
76 | buflen -= ret; | |
77 | ||
78 | while (ret) { | |
79 | ret2 = read(sd->pipe[0], p, ret); | |
80 | if (ret2 < 0) | |
81 | return errno; | |
82 | ||
83 | ret -= ret2; | |
84 | p += ret2; | |
85 | } | |
86 | } | |
87 | ||
88 | return io_u->buflen; | |
89 | } | |
90 | ||
91 | /* | |
92 | * For splice writing, we can vmsplice our data buffer directly into a | |
93 | * pipe and then splice that to a file. | |
94 | */ | |
95 | static int fio_splice_write(struct thread_data *td, struct io_u *io_u) | |
96 | { | |
97 | struct spliceio_data *sd = td->io_ops->data; | |
98 | struct iovec iov[1] = { | |
99 | { | |
100 | .iov_base = io_u->buf, | |
101 | .iov_len = io_u->buflen, | |
102 | } | |
103 | }; | |
104 | struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, }; | |
53cdc686 | 105 | struct fio_file *f = io_u->file; |
2866c82d JA |
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) { | |
53cdc686 | 121 | ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0); |
2866c82d JA |
122 | if (ret2 < 0) |
123 | return errno; | |
124 | ||
125 | ret -= ret2; | |
126 | } | |
127 | } | |
128 | ||
129 | return io_u->buflen; | |
130 | } | |
131 | ||
132 | static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) | |
133 | { | |
134 | struct spliceio_data *sd = td->io_ops->data; | |
6040dabc | 135 | unsigned int ret; |
2866c82d JA |
136 | |
137 | if (io_u->ddir == DDIR_READ) | |
138 | ret = fio_splice_read(td, io_u); | |
87dc1ab1 | 139 | else if (io_u->ddir == DDIR_WRITE) |
2866c82d | 140 | ret = fio_splice_write(td, io_u); |
87dc1ab1 JA |
141 | else |
142 | ret = fsync(io_u->file->fd); | |
2866c82d | 143 | |
6040dabc | 144 | if (ret != io_u->buflen) { |
2866c82d JA |
145 | if (ret > 0) { |
146 | io_u->resid = io_u->buflen - ret; | |
147 | io_u->error = ENODATA; | |
148 | } else | |
149 | io_u->error = errno; | |
150 | } | |
151 | ||
152 | if (!io_u->error) | |
153 | sd->last_io_u = io_u; | |
154 | ||
155 | return io_u->error; | |
156 | } | |
157 | ||
158 | static void fio_spliceio_cleanup(struct thread_data *td) | |
159 | { | |
160 | struct spliceio_data *sd = td->io_ops->data; | |
161 | ||
162 | if (sd) { | |
163 | close(sd->pipe[0]); | |
164 | close(sd->pipe[1]); | |
165 | free(sd); | |
166 | td->io_ops->data = NULL; | |
167 | } | |
168 | } | |
169 | ||
170 | static int fio_spliceio_init(struct thread_data *td) | |
171 | { | |
172 | struct spliceio_data *sd = malloc(sizeof(*sd)); | |
173 | ||
174 | sd->last_io_u = NULL; | |
175 | if (pipe(sd->pipe) < 0) { | |
176 | td_verror(td, errno); | |
177 | free(sd); | |
178 | return 1; | |
179 | } | |
180 | ||
181 | td->io_ops->data = sd; | |
182 | return 0; | |
183 | } | |
184 | ||
5f350952 | 185 | static struct ioengine_ops ioengine = { |
2866c82d JA |
186 | .name = "splice", |
187 | .version = FIO_IOOPS_VERSION, | |
188 | .init = fio_spliceio_init, | |
189 | .queue = fio_spliceio_queue, | |
190 | .getevents = fio_spliceio_getevents, | |
191 | .event = fio_spliceio_event, | |
192 | .cleanup = fio_spliceio_cleanup, | |
2866c82d JA |
193 | .flags = FIO_SYNCIO, |
194 | }; | |
34cfcdaf JA |
195 | |
196 | #else /* FIO_HAVE_SPLICE */ | |
197 | ||
198 | /* | |
199 | * When we have a proper configure system in place, we simply wont build | |
200 | * and install this io engine. For now install a crippled version that | |
201 | * just complains and fails to load. | |
202 | */ | |
203 | static int fio_spliceio_init(struct thread_data fio_unused *td) | |
204 | { | |
205 | fprintf(stderr, "fio: splice not available\n"); | |
206 | return 1; | |
207 | } | |
208 | ||
5f350952 | 209 | static struct ioengine_ops ioengine = { |
34cfcdaf JA |
210 | .name = "splice", |
211 | .version = FIO_IOOPS_VERSION, | |
212 | .init = fio_spliceio_init, | |
213 | }; | |
214 | ||
215 | #endif | |
5f350952 JA |
216 | |
217 | static void fio_init fio_spliceio_register(void) | |
218 | { | |
219 | register_ioengine(&ioengine); | |
220 | } | |
221 | ||
222 | static void fio_exit fio_spliceio_unregister(void) | |
223 | { | |
224 | unregister_ioengine(&ioengine); | |
225 | } |