diff options
| -rw-r--r-- | block/iscsi.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/block/iscsi.c b/block/iscsi.c index d8382fdd5d..259192f535 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -241,8 +241,17 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num, /* XXX we should pass the iovec to write16 to avoid the extra copy */ /* this will allow us to get rid of 'buf' completely */ size = nb_sectors * BDRV_SECTOR_SIZE; - acb->buf = g_malloc(size); - qemu_iovec_to_buf(acb->qiov, 0, acb->buf, size); + data.size = MIN(size, acb->qiov->size); + + /* if the iovec only contains one buffer we can pass it directly */ + if (acb->qiov->niov == 1) { + acb->buf = NULL; + data.data = acb->qiov->iov[0].iov_base; + } else { + acb->buf = g_malloc(data.size); + qemu_iovec_to_buf(acb->qiov, 0, acb->buf, data.size); + data.data = acb->buf; + } acb->task = malloc(sizeof(struct scsi_task)); if (acb->task == NULL) { @@ -263,9 +272,6 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num, *(uint32_t *)&acb->task->cdb[10] = htonl(num_sectors); acb->task->expxferlen = size; - data.data = acb->buf; - data.size = size; - if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task, iscsi_aio_write16_cb, &data, |