Commit | Line | Data |
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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 | 17 | struct spliceio_data { |
2866c82d JA |
18 | int pipe[2]; |
19 | }; | |
20 | ||
2866c82d JA |
21 | /* |
22 | * For splice reading, we unfortunately cannot (yet) vmsplice the other way. | |
23 | * So just splice the data from the file into the pipe, and use regular | |
24 | * read to fill the buffer. Doesn't make a lot of sense, but... | |
25 | */ | |
26 | static int fio_splice_read(struct thread_data *td, struct io_u *io_u) | |
27 | { | |
28 | struct spliceio_data *sd = td->io_ops->data; | |
53cdc686 | 29 | struct fio_file *f = io_u->file; |
2866c82d JA |
30 | int ret, ret2, buflen; |
31 | off_t offset; | |
32 | void *p; | |
33 | ||
34 | offset = io_u->offset; | |
cec6b55d JA |
35 | buflen = io_u->xfer_buflen; |
36 | p = io_u->xfer_buf; | |
2866c82d JA |
37 | while (buflen) { |
38 | int this_len = buflen; | |
39 | ||
40 | if (this_len > SPLICE_DEF_SIZE) | |
41 | this_len = SPLICE_DEF_SIZE; | |
42 | ||
53cdc686 | 43 | ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE); |
2866c82d JA |
44 | if (ret < 0) { |
45 | if (errno == ENODATA || errno == EAGAIN) | |
46 | continue; | |
47 | ||
48 | return errno; | |
49 | } | |
50 | ||
51 | buflen -= ret; | |
52 | ||
53 | while (ret) { | |
54 | ret2 = read(sd->pipe[0], p, ret); | |
55 | if (ret2 < 0) | |
56 | return errno; | |
57 | ||
58 | ret -= ret2; | |
59 | p += ret2; | |
60 | } | |
61 | } | |
62 | ||
cec6b55d | 63 | return io_u->xfer_buflen; |
2866c82d JA |
64 | } |
65 | ||
66 | /* | |
67 | * For splice writing, we can vmsplice our data buffer directly into a | |
68 | * pipe and then splice that to a file. | |
69 | */ | |
70 | static int fio_splice_write(struct thread_data *td, struct io_u *io_u) | |
71 | { | |
72 | struct spliceio_data *sd = td->io_ops->data; | |
73 | struct iovec iov[1] = { | |
74 | { | |
cec6b55d JA |
75 | .iov_base = io_u->xfer_buf, |
76 | .iov_len = io_u->xfer_buflen, | |
2866c82d JA |
77 | } |
78 | }; | |
79 | struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, }; | |
53cdc686 | 80 | struct fio_file *f = io_u->file; |
2866c82d JA |
81 | off_t off = io_u->offset; |
82 | int ret, ret2; | |
83 | ||
84 | while (iov[0].iov_len) { | |
85 | if (poll(&pfd, 1, -1) < 0) | |
86 | return errno; | |
87 | ||
88 | ret = vmsplice(sd->pipe[1], iov, 1, SPLICE_F_NONBLOCK); | |
89 | if (ret < 0) | |
90 | return errno; | |
91 | ||
92 | iov[0].iov_len -= ret; | |
93 | iov[0].iov_base += ret; | |
94 | ||
95 | while (ret) { | |
53cdc686 | 96 | ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0); |
2866c82d JA |
97 | if (ret2 < 0) |
98 | return errno; | |
99 | ||
100 | ret -= ret2; | |
101 | } | |
102 | } | |
103 | ||
cec6b55d | 104 | return io_u->xfer_buflen; |
2866c82d JA |
105 | } |
106 | ||
107 | static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) | |
108 | { | |
cec6b55d | 109 | int ret; |
2866c82d JA |
110 | |
111 | if (io_u->ddir == DDIR_READ) | |
112 | ret = fio_splice_read(td, io_u); | |
87dc1ab1 | 113 | else if (io_u->ddir == DDIR_WRITE) |
2866c82d | 114 | ret = fio_splice_write(td, io_u); |
87dc1ab1 JA |
115 | else |
116 | ret = fsync(io_u->file->fd); | |
2866c82d | 117 | |
cec6b55d | 118 | if (ret != (int) io_u->xfer_buflen) { |
22819ec2 | 119 | if (ret >= 0) { |
cec6b55d JA |
120 | io_u->resid = io_u->xfer_buflen - ret; |
121 | io_u->error = 0; | |
36167d82 | 122 | return FIO_Q_COMPLETED; |
2866c82d JA |
123 | } else |
124 | io_u->error = errno; | |
125 | } | |
126 | ||
36167d82 | 127 | if (io_u->error) |
e1161c32 | 128 | td_verror(td, io_u->error, "xfer"); |
2866c82d | 129 | |
36167d82 | 130 | return FIO_Q_COMPLETED; |
2866c82d JA |
131 | } |
132 | ||
133 | static void fio_spliceio_cleanup(struct thread_data *td) | |
134 | { | |
135 | struct spliceio_data *sd = td->io_ops->data; | |
136 | ||
137 | if (sd) { | |
138 | close(sd->pipe[0]); | |
139 | close(sd->pipe[1]); | |
140 | free(sd); | |
141 | td->io_ops->data = NULL; | |
142 | } | |
143 | } | |
144 | ||
145 | static int fio_spliceio_init(struct thread_data *td) | |
146 | { | |
147 | struct spliceio_data *sd = malloc(sizeof(*sd)); | |
148 | ||
2866c82d | 149 | if (pipe(sd->pipe) < 0) { |
e1161c32 | 150 | td_verror(td, errno, "pipe"); |
2866c82d JA |
151 | free(sd); |
152 | return 1; | |
153 | } | |
154 | ||
155 | td->io_ops->data = sd; | |
156 | return 0; | |
157 | } | |
158 | ||
5f350952 | 159 | static struct ioengine_ops ioengine = { |
2866c82d JA |
160 | .name = "splice", |
161 | .version = FIO_IOOPS_VERSION, | |
162 | .init = fio_spliceio_init, | |
163 | .queue = fio_spliceio_queue, | |
2866c82d | 164 | .cleanup = fio_spliceio_cleanup, |
2866c82d JA |
165 | .flags = FIO_SYNCIO, |
166 | }; | |
34cfcdaf JA |
167 | |
168 | #else /* FIO_HAVE_SPLICE */ | |
169 | ||
170 | /* | |
171 | * When we have a proper configure system in place, we simply wont build | |
172 | * and install this io engine. For now install a crippled version that | |
173 | * just complains and fails to load. | |
174 | */ | |
175 | static int fio_spliceio_init(struct thread_data fio_unused *td) | |
176 | { | |
177 | fprintf(stderr, "fio: splice not available\n"); | |
178 | return 1; | |
179 | } | |
180 | ||
5f350952 | 181 | static struct ioengine_ops ioengine = { |
34cfcdaf JA |
182 | .name = "splice", |
183 | .version = FIO_IOOPS_VERSION, | |
184 | .init = fio_spliceio_init, | |
185 | }; | |
186 | ||
187 | #endif | |
5f350952 JA |
188 | |
189 | static void fio_init fio_spliceio_register(void) | |
190 | { | |
191 | register_ioengine(&ioengine); | |
192 | } | |
193 | ||
194 | static void fio_exit fio_spliceio_unregister(void) | |
195 | { | |
196 | unregister_ioengine(&ioengine); | |
197 | } |