X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=engines%2Fsplice.c;h=feb764feb2f4f4766275dd53e938cab1ce3e5292;hp=c366a2ebef7fb0b6a67a0ec43dcfb2643a236283;hb=01bf5128d0581e267383f280c6a1dcd26517240f;hpb=b5af82930ccfd7dda6a1b11794efb452eb76d8dc diff --git a/engines/splice.c b/engines/splice.c index c366a2eb..feb764fe 100644 --- a/engines/splice.c +++ b/engines/splice.c @@ -1,35 +1,37 @@ /* - * splice io engine + * splice engine + * + * IO engine that transfers data by doing splices to/from pipes and + * the files. * */ #include #include #include #include -#include -#include +#include +#include #include "../fio.h" -#include "../os.h" - -#ifdef FIO_HAVE_SPLICE struct spliceio_data { int pipe[2]; + int vmsplice_to_user; + int vmsplice_to_user_map; }; /* - * 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... + * vmsplice didn't use to support splicing to user space, this is the old + * variant of getting that job done. Doesn't make a lot of sense, but it + * uses splices to move data from the source into a pipe. */ -static int fio_splice_read(struct thread_data *td, struct io_u *io_u) +static int fio_splice_read_old(struct thread_data *td, struct io_u *io_u) { - struct spliceio_data *sd = td->io_ops->data; + struct spliceio_data *sd = td->io_ops_data; struct fio_file *f = io_u->file; int ret, ret2, buflen; off_t offset; - void *p; + char *p; offset = io_u->offset; buflen = io_u->xfer_buflen; @@ -45,7 +47,7 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u) if (errno == ENODATA || errno == EAGAIN) continue; - return errno; + return -errno; } buflen -= ret; @@ -53,7 +55,7 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u) while (ret) { ret2 = read(sd->pipe[0], p, ret); if (ret2 < 0) - return errno; + return -errno; ret -= ret2; p += ret2; @@ -63,39 +65,132 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u) return io_u->xfer_buflen; } +/* + * We can now vmsplice into userspace, so do the transfer by splicing into + * a pipe and vmsplicing that into userspace. + */ +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; + struct iovec iov; + int ret , buflen, mmap_len; + off_t offset; + void *map; + char *p; + + ret = 0; + offset = io_u->offset; + mmap_len = buflen = io_u->xfer_buflen; + + if (sd->vmsplice_to_user_map) { + map = mmap(io_u->xfer_buf, buflen, PROT_READ, MAP_PRIVATE|OS_MAP_ANON, 0, 0); + if (map == MAP_FAILED) { + td_verror(td, errno, "mmap io_u"); + return -1; + } + + p = map; + } else { + map = NULL; + p = io_u->xfer_buf; + } + + while (buflen) { + int this_len = buflen; + int flags = 0; + + if (this_len > SPLICE_DEF_SIZE) { + this_len = SPLICE_DEF_SIZE; + flags = SPLICE_F_MORE; + } + + ret = splice(f->fd, &offset, sd->pipe[1], NULL, this_len,flags); + if (ret < 0) { + if (errno == ENODATA || errno == EAGAIN) + continue; + + td_verror(td, errno, "splice-from-fd"); + break; + } + + buflen -= ret; + iov.iov_base = p; + iov.iov_len = ret; + + while (iov.iov_len) { + ret = vmsplice(sd->pipe[0], &iov, 1, SPLICE_F_MOVE); + if (ret < 0) { + if (errno == EFAULT && + sd->vmsplice_to_user_map) { + sd->vmsplice_to_user_map = 0; + munmap(map, mmap_len); + map = NULL; + p = io_u->xfer_buf; + iov.iov_base = p; + continue; + } + if (errno == EBADF) { + ret = -EBADF; + break; + } + td_verror(td, errno, "vmsplice"); + break; + } else if (!ret) { + td_verror(td, ENODATA, "vmsplice"); + ret = -1; + break; + } + + iov.iov_len -= ret; + iov.iov_base += ret; + p += ret; + } + if (ret < 0) + break; + } + + if (sd->vmsplice_to_user_map && munmap(map, mmap_len) < 0) { + td_verror(td, errno, "munnap io_u"); + return -1; + } + if (ret < 0) + return ret; + + return io_u->xfer_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->xfer_buf, - .iov_len = io_u->xfer_buflen, - } + struct spliceio_data *sd = td->io_ops_data; + struct iovec iov = { + .iov_base = io_u->xfer_buf, + .iov_len = io_u->xfer_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) { + while (iov.iov_len) { if (poll(&pfd, 1, -1) < 0) return errno; - ret = vmsplice(sd->pipe[1], iov, 1, SPLICE_F_NONBLOCK); + ret = vmsplice(sd->pipe[1], &iov, 1, SPLICE_F_NONBLOCK); if (ret < 0) - return errno; + return -errno; - iov[0].iov_len -= ret; - iov[0].iov_base += ret; + iov.iov_len -= ret; + iov.iov_base += ret; while (ret) { ret2 = splice(sd->pipe[0], NULL, f->fd, &off, ret, 0); if (ret2 < 0) - return errno; + return -errno; ret -= ret2; } @@ -104,16 +199,33 @@ static int fio_splice_write(struct thread_data *td, struct io_u *io_u) return io_u->xfer_buflen; } -static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) +static enum fio_q_status fio_spliceio_queue(struct thread_data *td, + struct io_u *io_u) { - int ret; - - if (io_u->ddir == DDIR_READ) - ret = fio_splice_read(td, io_u); - else if (io_u->ddir == DDIR_WRITE) + struct spliceio_data *sd = td->io_ops_data; + int ret = 0; + + fio_ro_check(td, io_u); + + if (io_u->ddir == DDIR_READ) { + if (sd->vmsplice_to_user) { + ret = fio_splice_read(td, io_u); + /* + * This kernel doesn't support vmsplice to user + * space. Reset the vmsplice_to_user flag, so that + * we retry below and don't hit this path again. + */ + if (ret == -EBADF) + sd->vmsplice_to_user = 0; + } + if (!sd->vmsplice_to_user) + ret = fio_splice_read_old(td, io_u); + } else if (io_u->ddir == DDIR_WRITE) ret = fio_splice_write(td, io_u); + else if (io_u->ddir == DDIR_TRIM) + ret = do_io_u_trim(td, io_u); else - ret = fsync(io_u->file->fd); + ret = do_io_u_sync(td, io_u); if (ret != (int) io_u->xfer_buflen) { if (ret >= 0) { @@ -124,21 +236,24 @@ static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u) io_u->error = errno; } - if (io_u->error) + if (io_u->error) { td_verror(td, io_u->error, "xfer"); + if (io_u->error == EINVAL) + log_err("fio: looks like splice doesn't work on this" + " file system\n"); + } return FIO_Q_COMPLETED; } static void fio_spliceio_cleanup(struct thread_data *td) { - struct spliceio_data *sd = td->io_ops->data; + 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; } } @@ -152,7 +267,25 @@ static int fio_spliceio_init(struct thread_data *td) return 1; } - td->io_ops->data = sd; + /* + * Assume this work, we'll reset this if it doesn't + */ + sd->vmsplice_to_user = 1; + + /* + * Works with "real" vmsplice to user, eg mapping pages directly. + * Reset if we fail. + */ + sd->vmsplice_to_user_map = 1; + + /* + * And if vmsplice_to_user works, we definitely need aligned + * buffers. Just set ->odirect to force that. + */ + if (td_read(td)) + td->o.mem_align = 1; + + td->io_ops_data = sd; return 0; } @@ -164,30 +297,10 @@ static struct ioengine_ops ioengine = { .cleanup = fio_spliceio_cleanup, .open_file = generic_open_file, .close_file = generic_close_file, - .flags = FIO_SYNCIO, -}; - -#else /* FIO_HAVE_SPLICE */ - -/* - * When we have a proper configure system in place, we simply wont build - * and install this io engine. For now install a crippled version that - * just complains and fails to load. - */ -static int fio_spliceio_init(struct thread_data fio_unused *td) -{ - fprintf(stderr, "fio: splice not available\n"); - return 1; -} - -static struct ioengine_ops ioengine = { - .name = "splice", - .version = FIO_IOOPS_VERSION, - .init = fio_spliceio_init, + .get_file_size = generic_get_file_size, + .flags = FIO_SYNCIO | FIO_PIPEIO, }; -#endif - static void fio_init fio_spliceio_register(void) { register_ioengine(&ioengine);