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Diffstat (limited to 'tools/io_uring/io_uring-cp.c')
| -rw-r--r-- | tools/io_uring/io_uring-cp.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/tools/io_uring/io_uring-cp.c b/tools/io_uring/io_uring-cp.c new file mode 100644 index 000000000000..633f65bb43a7 --- /dev/null +++ b/tools/io_uring/io_uring-cp.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Simple test program that demonstrates a file copy through io_uring. This + * uses the API exposed by liburing. + * + * Copyright (C) 2018-2019 Jens Axboe + */ +#include <stdio.h> +#include <fcntl.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <assert.h> +#include <errno.h> +#include <inttypes.h> +#include <sys/stat.h> +#include <sys/ioctl.h> + +#include "liburing.h" + +#define QD 64 +#define BS (32*1024) + +static int infd, outfd; + +struct io_data { + int read; + off_t first_offset, offset; + size_t first_len; + struct iovec iov; +}; + +static int setup_context(unsigned entries, struct io_uring *ring) +{ + int ret; + + ret = io_uring_queue_init(entries, ring, 0); + if (ret < 0) { + fprintf(stderr, "queue_init: %s\n", strerror(-ret)); + return -1; + } + + return 0; +} + +static int get_file_size(int fd, off_t *size) +{ + struct stat st; + + if (fstat(fd, &st) < 0) + return -1; + if (S_ISREG(st.st_mode)) { + *size = st.st_size; + return 0; + } else if (S_ISBLK(st.st_mode)) { + unsigned long long bytes; + + if (ioctl(fd, BLKGETSIZE64, &bytes) != 0) + return -1; + + *size = bytes; + return 0; + } + + return -1; +} + +static void queue_prepped(struct io_uring *ring, struct io_data *data) +{ + struct io_uring_sqe *sqe; + + sqe = io_uring_get_sqe(ring); + assert(sqe); + + if (data->read) + io_uring_prep_readv(sqe, infd, &data->iov, 1, data->offset); + else + io_uring_prep_writev(sqe, outfd, &data->iov, 1, data->offset); + + io_uring_sqe_set_data(sqe, data); +} + +static int queue_read(struct io_uring *ring, off_t size, off_t offset) +{ + struct io_uring_sqe *sqe; + struct io_data *data; + + sqe = io_uring_get_sqe(ring); + if (!sqe) + return 1; + + data = malloc(size + sizeof(*data)); + data->read = 1; + data->offset = data->first_offset = offset; + + data->iov.iov_base = data + 1; + data->iov.iov_len = size; + data->first_len = size; + + io_uring_prep_readv(sqe, infd, &data->iov, 1, offset); + io_uring_sqe_set_data(sqe, data); + return 0; +} + +static void queue_write(struct io_uring *ring, struct io_data *data) +{ + data->read = 0; + data->offset = data->first_offset; + + data->iov.iov_base = data + 1; + data->iov.iov_len = data->first_len; + + queue_prepped(ring, data); + io_uring_submit(ring); +} + +static int copy_file(struct io_uring *ring, off_t insize) +{ + unsigned long reads, writes; + struct io_uring_cqe *cqe; + off_t write_left, offset; + int ret; + + write_left = insize; + writes = reads = offset = 0; + + while (insize || write_left) { + unsigned long had_reads; + int got_comp; + + /* + * Queue up as many reads as we can + */ + had_reads = reads; + while (insize) { + off_t this_size = insize; + + if (reads + writes >= QD) + break; + if (this_size > BS) + this_size = BS; + else if (!this_size) + break; + + if (queue_read(ring, this_size, offset)) + break; + + insize -= this_size; + offset += this_size; + reads++; + } + + if (had_reads != reads) { + ret = io_uring_submit(ring); + if (ret < 0) { + fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret)); + break; + } + } + + /* + * Queue is full at this point. Find at least one completion. + */ + got_comp = 0; + while (write_left) { + struct io_data *data; + + if (!got_comp) { + ret = io_uring_wait_completion(ring, &cqe); + got_comp = 1; + } else + ret = io_uring_get_completion(ring, &cqe); + if (ret < 0) { + fprintf(stderr, "io_uring_get_completion: %s\n", + strerror(-ret)); + return 1; + } + if (!cqe) + break; + + data = (struct io_data *) (uintptr_t) cqe->user_data; + if (cqe->res < 0) { + if (cqe->res == -EAGAIN) { + queue_prepped(ring, data); + continue; + } + fprintf(stderr, "cqe failed: %s\n", + strerror(-cqe->res)); + return 1; + } else if ((size_t) cqe->res != data->iov.iov_len) { + /* Short read/write, adjust and requeue */ + data->iov.iov_base += cqe->res; + data->iov.iov_len -= cqe->res; + data->offset += cqe->res; + queue_prepped(ring, data); + continue; + } + + /* + * All done. if write, nothing else to do. if read, + * queue up corresponding write. + */ + if (data->read) { + queue_write(ring, data); + write_left -= data->first_len; + reads--; + writes++; + } else { + free(data); + writes--; + } + } + } + + return 0; +} + +int main(int argc, char *argv[]) +{ + struct io_uring ring; + off_t insize; + int ret; + + if (argc < 3) { + printf("%s: infile outfile\n", argv[0]); + return 1; + } + + infd = open(argv[1], O_RDONLY); + if (infd < 0) { + perror("open infile"); + return 1; + } + outfd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644); + if (outfd < 0) { + perror("open outfile"); + return 1; + } + + if (setup_context(QD, &ring)) + return 1; + if (get_file_size(infd, &insize)) + return 1; + + ret = copy_file(&ring, insize); + + close(infd); + close(outfd); + io_uring_queue_exit(&ring); + return ret; +} |