virtio: scsi: make it clear that virtqueue_add_buf() no longer returns > 0

We simplified virtqueue_add_buf(), make it clear in the callers.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 13 insertions, 11 deletions

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 595af1ae4421..d5f9f4516d88 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -215,7 +215,7 @@ static void virtscsi_ctrl_done(struct virtqueue *vq)
 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
                                struct virtio_scsi_event_node *event_node)
 {
-        int ret;
+        int err;
         struct scatterlist sg;
         unsigned long flags;
 
@@ -223,13 +223,14 @@ static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 
         spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
 
-        ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
-        if (ret >= 0)
+        err = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node,
+                                GFP_ATOMIC);
+        if (!err)
                 virtqueue_kick(vscsi->event_vq.vq);
 
         spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
 
-        return ret;
+        return err;
 }
 
 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
@@ -410,22 +411,23 @@ static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
 {
         unsigned int out_num, in_num;
         unsigned long flags;
-        int ret;
+        int err;
+        bool needs_kick = false;
 
         spin_lock_irqsave(&tgt->tgt_lock, flags);
         virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
 
         spin_lock(&vq->vq_lock);
-        ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
+        err = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
         spin_unlock(&tgt->tgt_lock);
-        if (ret >= 0)
-                ret = virtqueue_kick_prepare(vq->vq);
+        if (!err)
+                needs_kick = virtqueue_kick_prepare(vq->vq);
 
         spin_unlock_irqrestore(&vq->vq_lock, flags);
 
-        if (ret > 0)
+        if (needs_kick)
                 virtqueue_notify(vq->vq);
-        return ret;
+        return err;
 }
 
 static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
@@ -467,7 +469,7 @@ static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 
         if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
                               sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
-                              GFP_ATOMIC) >= 0)
+                              GFP_ATOMIC) == 0)
                 ret = 0;
 
 out: