diff options
| -rw-r--r-- | tools/virtiofsd/fuse_lowlevel.c | 5 | ||||
| -rw-r--r-- | tools/virtiofsd/fuse_virtio.c | 162 | ||||
| -rw-r--r-- | tools/virtiofsd/fuse_virtio.h | 4 |
3 files changed, 171 insertions, 0 deletions
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 380d93b..4f4684d 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -475,6 +475,11 @@ static int fuse_send_data_iov_fallback(struct fuse_session *se, return fuse_send_msg(se, ch, iov, iov_count); } + if (fuse_lowlevel_is_virtio(se) && buf->count == 1 && + buf->buf[0].flags == (FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK)) { + return virtio_send_data_iov(se, ch, iov, iov_count, buf, len); + } + abort(); /* Will have taken vhost path */ return 0; } diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index f1adeb6..7e2711b 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -230,6 +230,168 @@ err: return ret; } +/* + * Callback from fuse_send_data_iov_* when it's virtio and the buffer + * is a single FD with FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK + * We need send the iov and then the buffer. + * Return 0 on success + */ +int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch, + struct iovec *iov, int count, struct fuse_bufvec *buf, + size_t len) +{ + int ret = 0; + VuVirtqElement *elem; + VuVirtq *q; + + assert(count >= 1); + assert(iov[0].iov_len >= sizeof(struct fuse_out_header)); + + struct fuse_out_header *out = iov[0].iov_base; + /* TODO: Endianness! */ + + size_t iov_len = iov_size(iov, count); + size_t tosend_len = iov_len + len; + + out->len = tosend_len; + + fuse_log(FUSE_LOG_DEBUG, "%s: count=%d len=%zd iov_len=%zd\n", __func__, + count, len, iov_len); + + /* unique == 0 is notification which we don't support */ + assert(out->unique); + + /* For virtio we always have ch */ + assert(ch); + assert(!ch->qi->reply_sent); + elem = ch->qi->qe; + q = &ch->qi->virtio_dev->dev.vq[ch->qi->qidx]; + + /* The 'in' part of the elem is to qemu */ + unsigned int in_num = elem->in_num; + struct iovec *in_sg = elem->in_sg; + size_t in_len = iov_size(in_sg, in_num); + fuse_log(FUSE_LOG_DEBUG, "%s: elem %d: with %d in desc of length %zd\n", + __func__, elem->index, in_num, in_len); + + /* + * The elem should have room for a 'fuse_out_header' (out from fuse) + * plus the data based on the len in the header. + */ + if (in_len < sizeof(struct fuse_out_header)) { + fuse_log(FUSE_LOG_ERR, "%s: elem %d too short for out_header\n", + __func__, elem->index); + ret = E2BIG; + goto err; + } + if (in_len < tosend_len) { + fuse_log(FUSE_LOG_ERR, "%s: elem %d too small for data len %zd\n", + __func__, elem->index, tosend_len); + ret = E2BIG; + goto err; + } + + /* TODO: Limit to 'len' */ + + /* First copy the header data from iov->in_sg */ + copy_iov(iov, count, in_sg, in_num, iov_len); + + /* + * Build a copy of the the in_sg iov so we can skip bits in it, + * including changing the offsets + */ + struct iovec *in_sg_cpy = calloc(sizeof(struct iovec), in_num); + assert(in_sg_cpy); + memcpy(in_sg_cpy, in_sg, sizeof(struct iovec) * in_num); + /* These get updated as we skip */ + struct iovec *in_sg_ptr = in_sg_cpy; + int in_sg_cpy_count = in_num; + + /* skip over parts of in_sg that contained the header iov */ + size_t skip_size = iov_len; + + size_t in_sg_left = 0; + do { + while (skip_size != 0 && in_sg_cpy_count) { + if (skip_size >= in_sg_ptr[0].iov_len) { + skip_size -= in_sg_ptr[0].iov_len; + in_sg_ptr++; + in_sg_cpy_count--; + } else { + in_sg_ptr[0].iov_len -= skip_size; + in_sg_ptr[0].iov_base += skip_size; + break; + } + } + + int i; + for (i = 0, in_sg_left = 0; i < in_sg_cpy_count; i++) { + in_sg_left += in_sg_ptr[i].iov_len; + } + fuse_log(FUSE_LOG_DEBUG, + "%s: after skip skip_size=%zd in_sg_cpy_count=%d " + "in_sg_left=%zd\n", + __func__, skip_size, in_sg_cpy_count, in_sg_left); + ret = preadv(buf->buf[0].fd, in_sg_ptr, in_sg_cpy_count, + buf->buf[0].pos); + + if (ret == -1) { + ret = errno; + fuse_log(FUSE_LOG_DEBUG, "%s: preadv failed (%m) len=%zd\n", + __func__, len); + free(in_sg_cpy); + goto err; + } + fuse_log(FUSE_LOG_DEBUG, "%s: preadv ret=%d len=%zd\n", __func__, + ret, len); + if (ret < len && ret) { + fuse_log(FUSE_LOG_DEBUG, "%s: ret < len\n", __func__); + /* Skip over this much next time around */ + skip_size = ret; + buf->buf[0].pos += ret; + len -= ret; + + /* Lets do another read */ + continue; + } + if (!ret) { + /* EOF case? */ + fuse_log(FUSE_LOG_DEBUG, "%s: !ret in_sg_left=%zd\n", __func__, + in_sg_left); + break; + } + if (ret != len) { + fuse_log(FUSE_LOG_DEBUG, "%s: ret!=len\n", __func__); + ret = EIO; + free(in_sg_cpy); + goto err; + } + in_sg_left -= ret; + len -= ret; + } while (in_sg_left); + free(in_sg_cpy); + + /* Need to fix out->len on EOF */ + if (len) { + struct fuse_out_header *out_sg = in_sg[0].iov_base; + + tosend_len -= len; + out_sg->len = tosend_len; + } + + ret = 0; + + vu_queue_push(&se->virtio_dev->dev, q, elem, tosend_len); + vu_queue_notify(&se->virtio_dev->dev, q); + +err: + if (ret == 0) { + ch->qi->reply_sent = true; + } + + return ret; +} + /* Thread function for individual queues, created when a queue is 'started' */ static void *fv_queue_thread(void *opaque) { diff --git a/tools/virtiofsd/fuse_virtio.h b/tools/virtiofsd/fuse_virtio.h index 135a148..cc676b9 100644 --- a/tools/virtiofsd/fuse_virtio.h +++ b/tools/virtiofsd/fuse_virtio.h @@ -26,4 +26,8 @@ int virtio_loop(struct fuse_session *se); int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch, struct iovec *iov, int count); +int virtio_send_data_iov(struct fuse_session *se, struct fuse_chan *ch, + struct iovec *iov, int count, + struct fuse_bufvec *buf, size_t len); + #endif |