virtio-blk: modify the value type of num in virtio_queue_rq()

commit 0466a39bd0b6c462338f10d18076703d14a552de upstream.

This was found by coccicheck:
./drivers/block/virtio_blk.c, 334, 14-17, WARNING Unsigned expression
compared with zero  num < 0

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Ye Guojin <ye.guojin@zte.com.cn>
Link: https://lore.kernel.org/r/20211117063955.160777-1-ye.guojin@zte.com.cn
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fixes: 02746e26c39e ("virtio-blk: avoid preallocating big SGL for data")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index ccc5770..d2ba849 100644 (file)
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -308,7 +308,7 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
        struct request *req = bd->rq;
        struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
        unsigned long flags;
-       unsigned int num;
+       int num;
        int qid = hctx->queue_num;
        int err;
        bool notify = false;