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> | |
11 | #include "fio.h" | |
12 | #include "os.h" | |
13 | ||
14 | struct spliceio_data { | |
15 | struct io_u *last_io_u; | |
16 | int pipe[2]; | |
17 | }; | |
18 | ||
53cdc686 | 19 | static int fio_spliceio_sync(struct thread_data *td, struct fio_file *f) |
2866c82d | 20 | { |
53cdc686 | 21 | return fsync(f->fd); |
2866c82d JA |
22 | } |
23 | ||
24 | static 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 | ||
39 | static 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 | */ | |
53 | static int fio_splice_read(struct thread_data *td, struct io_u *io_u) | |
54 | { | |
55 | struct spliceio_data *sd = td->io_ops->data; | |
53cdc686 | 56 | struct fio_file *f = io_u->file; |
2866c82d JA |
57 | int ret, ret2, buflen; |
58 | off_t offset; | |
59 | void *p; | |
60 | ||
61 | offset = io_u->offset; | |
62 | buflen = io_u->buflen; | |
63 | p = io_u->buf; | |
64 | while (buflen) { | |
65 | int this_len = buflen; | |
66 | ||
67 | if (this_len > SPLICE_DEF_SIZE) | |
68 | this_len = SPLICE_DEF_SIZE; | |
69 | ||
53cdc686 | 70 | ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE); |
2866c82d JA |
71 | if (ret < 0) { |
72 | if (errno == ENODATA || errno == EAGAIN) | |
73 | continue; | |
74 | ||
75 | return errno; | |
76 | } | |
77 | ||
78 | buflen -= ret; | |
79 | ||
80 | while (ret) { | |
81 | ret2 = read(sd->pipe[0], p, ret); | |
82 | if (ret2 < 0) | |
83 | return errno; | |
84 | ||
85 | ret -= ret2; | |
86 | p += ret2; | |
87 | } | |
88 | } | |
89 | ||
90 | return io_u->buflen; | |
91 | } | |
92 | ||
93 | /* | |
94 | * For splice writing, we can vmsplice our data buffer directly into a | |
95 | * pipe and then splice that to a file. | |
96 | */ | |
97 | static int fio_splice_write(struct thread_data *td, struct io_u *io_u) | |
98 | { | |
99 | struct spliceio_data *sd = td->io_ops->data; | |
100 | struct iovec iov[1] = { | |
101 | { | |
102 | .iov_base = io_u->buf, | |
103 | .iov_len = io_u->buflen, | |
104 | } | |
105 | }; | |
106 | struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, }; | |
53cdc686 | 107 | struct fio_file *f = io_u->file; |
2866c82d JA |
108 | off_t off = io_u->offset; |
109 | int ret, ret2; | |
110 | ||
111 | while (iov[0].iov_len) { | |
112 | if (poll(&pfd, 1, -1) < 0) | |
113 | return errno; | |
114 | ||
115 | ret = vmsplice(sd->pipe[1], iov, 1, SPLICE_F_NONBLOCK); | |
116 | if (ret < 0) | |
117 | return errno; | |
118 | ||
119 | iov[0].iov_len -= ret; | |
120 | iov[0].iov_base += ret; | |
121 | ||
122 | while (ret) { | |
53cdc686 | 123 | ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0); |
2866c82d JA |
124 | if (ret2 < 0) |
125 | return errno; | |
126 | ||
127 | ret -= ret2; | |
128 | } | |
129 | } | |
130 | ||
131 | return io_u->buflen; | |
132 | } | |
133 | ||
134 | static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) | |
135 | { | |
136 | struct spliceio_data *sd = td->io_ops->data; | |
137 | int ret; | |
138 | ||
139 | if (io_u->ddir == DDIR_READ) | |
140 | ret = fio_splice_read(td, io_u); | |
141 | else | |
142 | ret = fio_splice_write(td, io_u); | |
143 | ||
144 | if ((unsigned int) ret != io_u->buflen) { | |
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 | ||
185 | struct ioengine_ops ioengine = { | |
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, | |
193 | .sync = fio_spliceio_sync, | |
194 | .flags = FIO_SYNCIO, | |
195 | }; |