diff options
| -rw-r--r-- | tools/virtiofsd/fuse_virtio.c | 79 |
1 files changed, 73 insertions, 6 deletions
diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index fd588a4..872968f 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -454,6 +454,10 @@ static void *fv_queue_thread(void *opaque) __func__, qi->qidx, (size_t)evalue, in_bytes, out_bytes); while (1) { + bool allocated_bufv = false; + struct fuse_bufvec bufv; + struct fuse_bufvec *pbufv; + /* * An element contains one request and the space to send our * response They're spread over multiple descriptors in a @@ -495,14 +499,76 @@ static void *fv_queue_thread(void *opaque) __func__, elem->index); assert(0); /* TODO */ } - copy_from_iov(&fbuf, out_num, out_sg); - fbuf.size = out_len; + /* Copy just the first element and look at it */ + copy_from_iov(&fbuf, 1, out_sg); + + if (out_num > 2 && + out_sg[0].iov_len == sizeof(struct fuse_in_header) && + ((struct fuse_in_header *)fbuf.mem)->opcode == FUSE_WRITE && + out_sg[1].iov_len == sizeof(struct fuse_write_in)) { + /* + * For a write we don't actually need to copy the + * data, we can just do it straight out of guest memory + * but we must still copy the headers in case the guest + * was nasty and changed them while we were using them. + */ + fuse_log(FUSE_LOG_DEBUG, "%s: Write special case\n", __func__); + + /* copy the fuse_write_in header after the fuse_in_header */ + fbuf.mem += out_sg->iov_len; + copy_from_iov(&fbuf, 1, out_sg + 1); + fbuf.mem -= out_sg->iov_len; + fbuf.size = out_sg[0].iov_len + out_sg[1].iov_len; + + /* Allocate the bufv, with space for the rest of the iov */ + allocated_bufv = true; + pbufv = malloc(sizeof(struct fuse_bufvec) + + sizeof(struct fuse_buf) * (out_num - 2)); + if (!pbufv) { + vu_queue_unpop(dev, q, elem, 0); + free(elem); + fuse_log(FUSE_LOG_ERR, "%s: pbufv malloc failed\n", + __func__); + goto out; + } + + pbufv->count = 1; + pbufv->buf[0] = fbuf; + + size_t iovindex, pbufvindex; + iovindex = 2; /* 2 headers, separate iovs */ + pbufvindex = 1; /* 2 headers, 1 fusebuf */ + + for (; iovindex < out_num; iovindex++, pbufvindex++) { + pbufv->count++; + pbufv->buf[pbufvindex].pos = ~0; /* Dummy */ + pbufv->buf[pbufvindex].flags = 0; + pbufv->buf[pbufvindex].mem = out_sg[iovindex].iov_base; + pbufv->buf[pbufvindex].size = out_sg[iovindex].iov_len; + } + } else { + /* Normal (non fast write) path */ + + /* Copy the rest of the buffer */ + fbuf.mem += out_sg->iov_len; + copy_from_iov(&fbuf, out_num - 1, out_sg + 1); + fbuf.mem -= out_sg->iov_len; + fbuf.size = out_len; - /* TODO! Endianness of header */ + /* TODO! Endianness of header */ - /* TODO: Add checks for fuse_session_exited */ - struct fuse_bufvec bufv = { .buf[0] = fbuf, .count = 1 }; - fuse_session_process_buf_int(se, &bufv, &ch); + /* TODO: Add checks for fuse_session_exited */ + bufv.buf[0] = fbuf; + bufv.count = 1; + pbufv = &bufv; + } + pbufv->idx = 0; + pbufv->off = 0; + fuse_session_process_buf_int(se, pbufv, &ch); + + if (allocated_bufv) { + free(pbufv); + } if (!qi->reply_sent) { fuse_log(FUSE_LOG_DEBUG, "%s: elem %d no reply sent\n", @@ -516,6 +582,7 @@ static void *fv_queue_thread(void *opaque) elem = NULL; } } +out: pthread_mutex_destroy(&ch.lock); free(fbuf.mem); |