diff options
Diffstat (limited to 'example/passthrough_hp.cc')
| -rw-r--r-- | example/passthrough_hp.cc | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/example/passthrough_hp.cc b/example/passthrough_hp.cc index a0bf0d5..2bdfc0a 100644 --- a/example/passthrough_hp.cc +++ b/example/passthrough_hp.cc @@ -1158,10 +1158,38 @@ static void sfs_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, static void do_read(fuse_req_t req, size_t size, off_t off, fuse_file_info *fi) { fuse_bufvec buf = FUSE_BUFVEC_INIT(size); - buf.buf[0].flags = - static_cast<fuse_buf_flags>(FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK); - buf.buf[0].fd = fi->fh; - buf.buf[0].pos = off; + char *payload = NULL; + size_t payload_size = 0; + int res = fuse_req_get_payload(req, &payload, &payload_size, NULL); + + /* + * This is a demonstration how to use io-uring payload. For FUSE_BUF_IS_FD + * it shouldn't make much of a difference because fuse_reply_data() -> + * fuse_reply_data_uring() also has access to the payload and will + * read directly from the FD into the payload. + * It is more useful for file systems that need a buffer for decryption, + * decompression, etc. + */ + if (res == 0) { + /* This is an io-uring request - write directly to the payload */ + assert(payload_size >= size); + + buf.buf[0].mem = payload; + buf.buf[0].size = payload_size; + + res = pread(fi->fh, payload, size, off); + if (res < 0) { + fuse_reply_err(req, errno); + return; + } + + buf.buf[0].size = res; + } else { + buf.buf[0].flags = static_cast<fuse_buf_flags>( + FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK); + buf.buf[0].fd = fi->fh; + buf.buf[0].pos = off; + } fuse_reply_data(req, &buf, FUSE_BUF_COPY_FLAGS); } |