+/*
+ * 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 *p, *map;
+
+ 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;
+}
+