um: Clean-up command processing in UML UBD driver

Clean-up command processing and return BLK_STS_NOTSUP for
uknown commands.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 3a8a3d4..58860ef 100644 (file)
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -1306,65 +1306,82 @@ static int ubd_queue_one_vec(struct blk_mq_hw_ctx *hctx, struct request *req,
                io_req->fds[0] = dev->fd;
        io_req->error = 0;
 
-       if (req_op(req) != REQ_OP_FLUSH) {
-               io_req->fds[1] = dev->fd;
-               io_req->cow_offset = -1;
-               io_req->offset = off;
-               io_req->length = bvec->bv_len;
-               io_req->sector_mask = 0;
-               io_req->offsets[0] = 0;
-               io_req->offsets[1] = dev->cow.data_offset;
+       if (bvec != NULL) {
                io_req->buffer = page_address(bvec->bv_page) + bvec->bv_offset;
-               io_req->sectorsize = SECTOR_SIZE;
-
-               if (dev->cow.file) {
-                       cowify_req(io_req, dev->cow.bitmap,
-                                  dev->cow.bitmap_offset, dev->cow.bitmap_len);
-               }
+               io_req->length = bvec->bv_len;
+       } else {
+               io_req->buffer = NULL;
+               io_req->length = blk_rq_bytes(req);
        }
 
+       io_req->sectorsize = SECTOR_SIZE;
+       io_req->fds[1] = dev->fd;
+       io_req->cow_offset = -1;
+       io_req->offset = off;
+       io_req->sector_mask = 0;
+       io_req->offsets[0] = 0;
+       io_req->offsets[1] = dev->cow.data_offset;
+
+       if (dev->cow.file)
+               cowify_req(io_req, dev->cow.bitmap,
+                          dev->cow.bitmap_offset, dev->cow.bitmap_len);
+
        ret = os_write_file(thread_fd, &io_req, sizeof(io_req));
        if (ret != sizeof(io_req)) {
                if (ret != -EAGAIN)
                        pr_err("write to io thread failed: %d\n", -ret);
                kfree(io_req);
        }
-
        return ret;
 }
 
+static int queue_rw_req(struct blk_mq_hw_ctx *hctx, struct request *req)
+{
+       struct req_iterator iter;
+       struct bio_vec bvec;
+       int ret;
+       u64 off = (u64)blk_rq_pos(req) << SECTOR_SHIFT;
+
+       rq_for_each_segment(bvec, req, iter) {
+               ret = ubd_queue_one_vec(hctx, req, off, &bvec);
+               if (ret < 0)
+                       return ret;
+               off += bvec.bv_len;
+       }
+       return 0;
+}
+
 static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx,
                                 const struct blk_mq_queue_data *bd)
 {
        struct ubd *ubd_dev = hctx->queue->queuedata;
        struct request *req = bd->rq;
-       int ret = 0;
+       int ret = 0, res = BLK_STS_OK;
 
        blk_mq_start_request(req);
 
        spin_lock_irq(&ubd_dev->lock);
 
-       if (req_op(req) == REQ_OP_FLUSH) {
+       switch (req_op(req)) {
+       /* operations with no lentgth/offset arguments */
+       case REQ_OP_FLUSH:
                ret = ubd_queue_one_vec(hctx, req, 0, NULL);
-       } else {
-               struct req_iterator iter;
-               struct bio_vec bvec;
-               u64 off = (u64)blk_rq_pos(req) << SECTOR_SHIFT;
-
-               rq_for_each_segment(bvec, req, iter) {
-                       ret = ubd_queue_one_vec(hctx, req, off, &bvec);
-                       if (ret < 0)
-                               goto out;
-                       off += bvec.bv_len;
-               }
+               break;
+       case REQ_OP_READ:
+       case REQ_OP_WRITE:
+               ret = queue_rw_req(hctx, req);
+               break;
+       default:
+               WARN_ON_ONCE(1);
+               res = BLK_STS_NOTSUPP;
        }
-out:
+
        spin_unlock_irq(&ubd_dev->lock);
 
        if (ret < 0)
                blk_mq_requeue_request(req, true);
 
-       return BLK_STS_OK;
+       return res;
 }
 
 static int ubd_getgeo(struct block_device *bdev, struct hd_geometry *geo)