xen_disk: remove dead code

Xen_disk.c has support for using synchronous I/O instead of asynchronous,
but it is compiled out by default.  Remove it.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

hw/xen_disk.c

@@ -49,7 +49,6 @@ static int syncwrite    = 0;
 static int batch_maps   = 0;
 
 static int max_requests = 32;
-static int use_aio      = 1;
 
 /* ------------------------------------------------------------- */
 
@@ -314,76 +313,6 @@ static int ioreq_map(struct ioreq *ioreq)
     return 0;
 }
 
-static int ioreq_runio_qemu_sync(struct ioreq *ioreq)
-{
-    struct XenBlkDev *blkdev = ioreq->blkdev;
-    int i, rc;
-    off_t pos;
-
-    if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) {
-        goto err_no_map;
-    }
-    if (ioreq->presync) {
-        bdrv_flush(blkdev->bs);
-    }
-
-    switch (ioreq->req.operation) {
-    case BLKIF_OP_READ:
-        pos = ioreq->start;
-        for (i = 0; i < ioreq->v.niov; i++) {
-            rc = bdrv_read(blkdev->bs, pos / BLOCK_SIZE,
-                           ioreq->v.iov[i].iov_base,
-                           ioreq->v.iov[i].iov_len / BLOCK_SIZE);
-            if (rc != 0) {
-                xen_be_printf(&blkdev->xendev, 0, "rd I/O error (%p, len %zd)\n",
-                              ioreq->v.iov[i].iov_base,
-                              ioreq->v.iov[i].iov_len);
-                goto err;
-            }
-            pos += ioreq->v.iov[i].iov_len;
-        }
-        break;
-    case BLKIF_OP_WRITE:
-    case BLKIF_OP_WRITE_BARRIER:
-        if (!ioreq->req.nr_segments) {
-            break;
-        }
-        pos = ioreq->start;
-        for (i = 0; i < ioreq->v.niov; i++) {
-            rc = bdrv_write(blkdev->bs, pos / BLOCK_SIZE,
-                            ioreq->v.iov[i].iov_base,
-                            ioreq->v.iov[i].iov_len / BLOCK_SIZE);
-            if (rc != 0) {
-                xen_be_printf(&blkdev->xendev, 0, "wr I/O error (%p, len %zd)\n",
-                              ioreq->v.iov[i].iov_base,
-                              ioreq->v.iov[i].iov_len);
-                goto err;
-            }
-            pos += ioreq->v.iov[i].iov_len;
-        }
-        break;
-    default:
-        /* unknown operation (shouldn't happen -- parse catches this) */
-        goto err;
-    }
-
-    if (ioreq->postsync) {
-        bdrv_flush(blkdev->bs);
-    }
-    ioreq->status = BLKIF_RSP_OKAY;
-
-    ioreq_unmap(ioreq);
-    ioreq_finish(ioreq);
-    return 0;
-
-err:
-    ioreq_unmap(ioreq);
-err_no_map:
-    ioreq_finish(ioreq);
-    ioreq->status = BLKIF_RSP_ERROR;
-    return -1;
-}
-
 static void qemu_aio_complete(void *opaque, int ret)
 {
     struct ioreq *ioreq = opaque;
@@ -554,9 +483,7 @@ static void blk_handle_requests(struct XenBlkDev *blkdev)
     rp = blkdev->rings.common.sring->req_prod;
     xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
 
-    if (use_aio) {
-        blk_send_response_all(blkdev);
-    }
+    blk_send_response_all(blkdev);
     while (rc != rp) {
         /* pull request from ring */
         if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
@@ -579,16 +506,7 @@ static void blk_handle_requests(struct XenBlkDev *blkdev)
             continue;
         }
 
-        if (use_aio) {
-            /* run i/o in aio mode */
-            ioreq_runio_qemu_aio(ioreq);
-        } else {
-            /* run i/o in sync mode */
-            ioreq_runio_qemu_sync(ioreq);
-        }
-    }
-    if (!use_aio) {
-        blk_send_response_all(blkdev);
+        ioreq_runio_qemu_aio(ioreq);
     }
 
     if (blkdev->more_work && blkdev->requests_inflight < max_requests) {