splice.c revision 36167d82e5f49dee91c6d2cd426068edee90e36f
12866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe/* 22866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * splice io engine 32866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * 42866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe */ 52866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe#include <stdio.h> 62866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe#include <stdlib.h> 72866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe#include <unistd.h> 82866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe#include <errno.h> 92866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe#include <assert.h> 102866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe#include <sys/poll.h> 115f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe 125f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe#include "../fio.h" 135f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe#include "../os.h" 142866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1534cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe#ifdef FIO_HAVE_SPLICE 1634cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe 172866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboestruct spliceio_data { 182866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe int pipe[2]; 192866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe}; 202866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 212866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe/* 222866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * For splice reading, we unfortunately cannot (yet) vmsplice the other way. 232866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * So just splice the data from the file into the pipe, and use regular 242866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * read to fill the buffer. Doesn't make a lot of sense, but... 252866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe */ 262866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboestatic int fio_splice_read(struct thread_data *td, struct io_u *io_u) 272866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe{ 282866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe struct spliceio_data *sd = td->io_ops->data; 2953cdc6864f7471b28cc9b40a5314ab43e5b1cb5eJens Axboe struct fio_file *f = io_u->file; 302866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe int ret, ret2, buflen; 312866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe off_t offset; 322866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe void *p; 332866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 342866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe offset = io_u->offset; 35cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe buflen = io_u->xfer_buflen; 36cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe p = io_u->xfer_buf; 372866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe while (buflen) { 382866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe int this_len = buflen; 392866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 402866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (this_len > SPLICE_DEF_SIZE) 412866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe this_len = SPLICE_DEF_SIZE; 422866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 4353cdc6864f7471b28cc9b40a5314ab43e5b1cb5eJens Axboe ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len, SPLICE_F_MORE); 442866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (ret < 0) { 452866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (errno == ENODATA || errno == EAGAIN) 462866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe continue; 472866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 482866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return errno; 492866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 502866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 512866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe buflen -= ret; 522866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 532866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe while (ret) { 542866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe ret2 = read(sd->pipe[0], p, ret); 552866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (ret2 < 0) 562866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return errno; 572866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 582866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe ret -= ret2; 592866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe p += ret2; 602866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 612866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 622866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 63cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe return io_u->xfer_buflen; 642866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe} 652866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 662866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe/* 672866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * For splice writing, we can vmsplice our data buffer directly into a 682866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe * pipe and then splice that to a file. 692866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe */ 702866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboestatic int fio_splice_write(struct thread_data *td, struct io_u *io_u) 712866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe{ 722866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe struct spliceio_data *sd = td->io_ops->data; 732866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe struct iovec iov[1] = { 742866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe { 75cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe .iov_base = io_u->xfer_buf, 76cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe .iov_len = io_u->xfer_buflen, 772866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 782866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe }; 792866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe struct pollfd pfd = { .fd = sd->pipe[1], .events = POLLOUT, }; 8053cdc6864f7471b28cc9b40a5314ab43e5b1cb5eJens Axboe struct fio_file *f = io_u->file; 812866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe off_t off = io_u->offset; 822866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe int ret, ret2; 832866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 842866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe while (iov[0].iov_len) { 852866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (poll(&pfd, 1, -1) < 0) 862866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return errno; 872866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 882866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe ret = vmsplice(sd->pipe[1], iov, 1, SPLICE_F_NONBLOCK); 892866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (ret < 0) 902866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return errno; 912866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 922866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe iov[0].iov_len -= ret; 932866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe iov[0].iov_base += ret; 942866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 952866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe while (ret) { 9653cdc6864f7471b28cc9b40a5314ab43e5b1cb5eJens Axboe ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0); 972866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (ret2 < 0) 982866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return errno; 992866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1002866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe ret -= ret2; 1012866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 1022866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 1032866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 104cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe return io_u->xfer_buflen; 1052866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe} 1062866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1072866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboestatic int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) 1082866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe{ 109cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe int ret; 1102866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1112866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (io_u->ddir == DDIR_READ) 1122866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe ret = fio_splice_read(td, io_u); 11387dc1ab1b4df7b977f60e3d43533a896e2ee665bJens Axboe else if (io_u->ddir == DDIR_WRITE) 1142866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe ret = fio_splice_write(td, io_u); 11587dc1ab1b4df7b977f60e3d43533a896e2ee665bJens Axboe else 11687dc1ab1b4df7b977f60e3d43533a896e2ee665bJens Axboe ret = fsync(io_u->file->fd); 1172866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 118cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe if (ret != (int) io_u->xfer_buflen) { 1192866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (ret > 0) { 120cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe io_u->resid = io_u->xfer_buflen - ret; 121cec6b55da1c282b5b91ad346c7804171fccf151eJens Axboe io_u->error = 0; 12236167d82e5f49dee91c6d2cd426068edee90e36fJens Axboe return FIO_Q_COMPLETED; 1232866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } else 1242866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe io_u->error = errno; 1252866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 1262866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 12736167d82e5f49dee91c6d2cd426068edee90e36fJens Axboe if (io_u->error) 12895bcd815e5ce55d6cdd8eb83bda5ee411f37bdc9Jens Axboe td_verror(td, io_u->error); 1292866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 13036167d82e5f49dee91c6d2cd426068edee90e36fJens Axboe return FIO_Q_COMPLETED; 1312866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe} 1322866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1332866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboestatic void fio_spliceio_cleanup(struct thread_data *td) 1342866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe{ 1352866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe struct spliceio_data *sd = td->io_ops->data; 1362866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1372866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (sd) { 1382866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe close(sd->pipe[0]); 1392866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe close(sd->pipe[1]); 1402866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe free(sd); 1412866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe td->io_ops->data = NULL; 1422866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 1432866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe} 1442866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1452866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboestatic int fio_spliceio_init(struct thread_data *td) 1462866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe{ 1472866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe struct spliceio_data *sd = malloc(sizeof(*sd)); 1482866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1492866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe if (pipe(sd->pipe) < 0) { 1502866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe td_verror(td, errno); 1512866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe free(sd); 1522866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return 1; 1532866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe } 1542866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1552866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe td->io_ops->data = sd; 1562866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe return 0; 1572866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe} 1582866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe 1595f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboestatic struct ioengine_ops ioengine = { 1602866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe .name = "splice", 1612866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe .version = FIO_IOOPS_VERSION, 1622866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe .init = fio_spliceio_init, 1632866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe .queue = fio_spliceio_queue, 1642866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe .cleanup = fio_spliceio_cleanup, 1652866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe .flags = FIO_SYNCIO, 1662866c82d598e30604d8a92723c664ee6ced90fb0Jens Axboe}; 16734cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe 16834cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe#else /* FIO_HAVE_SPLICE */ 16934cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe 17034cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe/* 17134cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe * When we have a proper configure system in place, we simply wont build 17234cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe * and install this io engine. For now install a crippled version that 17334cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe * just complains and fails to load. 17434cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe */ 17534cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboestatic int fio_spliceio_init(struct thread_data fio_unused *td) 17634cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe{ 17734cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe fprintf(stderr, "fio: splice not available\n"); 17834cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe return 1; 17934cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe} 18034cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe 1815f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboestatic struct ioengine_ops ioengine = { 18234cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe .name = "splice", 18334cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe .version = FIO_IOOPS_VERSION, 18434cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe .init = fio_spliceio_init, 18534cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe}; 18634cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe 18734cfcdafa994a0a75120e498c51eda08bde5df72Jens Axboe#endif 1885f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe 1895f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboestatic void fio_init fio_spliceio_register(void) 1905f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe{ 1915f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe register_ioengine(&ioengine); 1925f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe} 1935f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe 1945f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboestatic void fio_exit fio_spliceio_unregister(void) 1955f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe{ 1965f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe unregister_ioengine(&ioengine); 1975f350952eff89948bfbf1eb6ac4d3d08a9109581Jens Axboe} 198