| /* |
| * splice io engine |
| * |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <assert.h> |
| #include <sys/poll.h> |
| #include "fio.h" |
| #include "os.h" |
| |
| struct spliceio_data { |
| struct io_u *last_io_u; |
| int pipe[2]; |
| }; |
| |
| static int fio_spliceio_sync(struct thread_data *td, struct fio_file *f) |
| { |
| return fsync(f->fd); |
| } |
| |
| static int fio_spliceio_getevents(struct thread_data *td, int fio_unused min, |
| int max, struct timespec fio_unused *t) |
| { |
| assert(max <= 1); |
| |
| /* |
| * we can only have one finished io_u for sync io, since the depth |
| * is always 1 |
| */ |
| if (list_empty(&td->io_u_busylist)) |
| return 0; |
| |
| return 1; |
| } |
| |
| static struct io_u *fio_spliceio_event(struct thread_data *td, int event) |
| { |
| struct spliceio_data *sd = td->io_ops->data; |
| |
| assert(event == 0); |
| |
| return sd->last_io_u; |
| } |
| |
| /* |
| * For splice reading, we unfortunately cannot (yet) vmsplice the other way. |
| * So just splice the data from the file into the pipe, and use regular |
| * read to fill the buffer. Doesn't make a lot of sense, but... |
| */ |
| static int fio_splice_read(struct thread_data *td, struct io_u *io_u) |
| { |
| struct spliceio_data *sd = td->io_ops->data; |
| struct fio_file *f = io_u->file; |
| int ret, ret2, buflen; |
| off_t offset; |
| void *p; |
| |
| offset = io_u->offset; |
| buflen = io_u->buflen; |
| p = io_u->buf; |
| while (buflen) { |
| int this_len = buflen; |
| |
| if (this_len > SPLICE_DEF_SIZE) |
| this_len = SPLICE_DEF_SIZE; |
| |
| ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE); |
| if (ret < 0) { |
| if (errno == ENODATA || errno == EAGAIN) |
| continue; |
| |
| return errno; |
| } |
| |
| buflen -= ret; |
| |
| while (ret) { |
| ret2 = read(sd->pipe[0], p, ret); |
| if (ret2 < 0) |
| return errno; |
| |
| ret -= ret2; |
| p += ret2; |
| } |
| } |
| |
| return io_u->buflen; |
| } |
| |
| /* |
| * For splice writing, we can vmsplice our data buffer directly into a |
| * pipe and then splice that to a file. |
| */ |
| static int fio_splice_write(struct thread_data *td, struct io_u *io_u) |
| { |
| struct spliceio_data *sd = td->io_ops->data; |
| struct iovec iov[1] = { |
| { |
| .iov_base = io_u->buf, |
| .iov_len = io_u->buflen, |
| } |
| }; |
| struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, }; |
| struct fio_file *f = io_u->file; |
| off_t off = io_u->offset; |
| int ret, ret2; |
| |
| while (iov[0].iov_len) { |
| if (poll(&pfd, 1, -1) < 0) |
| return errno; |
| |
| ret = vmsplice(sd->pipe[1], iov, 1, SPLICE_F_NONBLOCK); |
| if (ret < 0) |
| return errno; |
| |
| iov[0].iov_len -= ret; |
| iov[0].iov_base += ret; |
| |
| while (ret) { |
| ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0); |
| if (ret2 < 0) |
| return errno; |
| |
| ret -= ret2; |
| } |
| } |
| |
| return io_u->buflen; |
| } |
| |
| static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) |
| { |
| struct spliceio_data *sd = td->io_ops->data; |
| int ret; |
| |
| if (io_u->ddir == DDIR_READ) |
| ret = fio_splice_read(td, io_u); |
| else |
| ret = fio_splice_write(td, io_u); |
| |
| if ((unsigned int) ret != io_u->buflen) { |
| if (ret > 0) { |
| io_u->resid = io_u->buflen - ret; |
| io_u->error = ENODATA; |
| } else |
| io_u->error = errno; |
| } |
| |
| if (!io_u->error) |
| sd->last_io_u = io_u; |
| |
| return io_u->error; |
| } |
| |
| static void fio_spliceio_cleanup(struct thread_data *td) |
| { |
| struct spliceio_data *sd = td->io_ops->data; |
| |
| if (sd) { |
| close(sd->pipe[0]); |
| close(sd->pipe[1]); |
| free(sd); |
| td->io_ops->data = NULL; |
| } |
| } |
| |
| static int fio_spliceio_init(struct thread_data *td) |
| { |
| struct spliceio_data *sd = malloc(sizeof(*sd)); |
| |
| sd->last_io_u = NULL; |
| if (pipe(sd->pipe) < 0) { |
| td_verror(td, errno); |
| free(sd); |
| return 1; |
| } |
| |
| td->io_ops->data = sd; |
| return 0; |
| } |
| |
| struct ioengine_ops ioengine = { |
| .name = "splice", |
| .version = FIO_IOOPS_VERSION, |
| .init = fio_spliceio_init, |
| .queue = fio_spliceio_queue, |
| .getevents = fio_spliceio_getevents, |
| .event = fio_spliceio_event, |
| .cleanup = fio_spliceio_cleanup, |
| .sync = fio_spliceio_sync, |
| .flags = FIO_SYNCIO, |
| }; |