1 files changed, 20 insertions, 24 deletions

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 7270e7b69262..4df9b40d6342 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -919,6 +919,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 		.pos = *ppos,
 		.u.data = &sgl,
 	};
+	unsigned int occupancy;
 
 	/*
 	 * Rproc_serial does not yet support splice. To support splice
@@ -929,21 +930,18 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 	if (is_rproc_serial(port->out_vq->vdev))
 		return -EINVAL;
 
-	/*
-	 * pipe->nrbufs == 0 means there are no data to transfer,
-	 * so this returns just 0 for no data.
-	 */
 	pipe_lock(pipe);
-	if (!pipe->nrbufs) {
-		ret = 0;
+	ret = 0;
+	if (pipe_empty(pipe->head, pipe->tail))
 		goto error_out;
-	}
 
 	ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
 	if (ret < 0)
 		goto error_out;
 
-	buf = alloc_buf(port->portdev->vdev, 0, pipe->nrbufs);
+	occupancy = pipe_occupancy(pipe->head, pipe->tail);
+	buf = alloc_buf(port->portdev->vdev, 0, occupancy);
+
 	if (!buf) {
 		ret = -ENOMEM;
 		goto error_out;
@@ -951,7 +949,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 
 	sgl.n = 0;
 	sgl.len = 0;
-	sgl.size = pipe->nrbufs;
+	sgl.size = occupancy;
 	sgl.sg = buf->sg;
 	sg_init_table(sgl.sg, sgl.size);
 	ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
@@ -1325,24 +1323,24 @@ static void set_console_size(struct port *port, u16 rows, u16 cols)
 	port->cons.ws.ws_col = cols;
 }
 
-static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
+static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
 {
 	struct port_buffer *buf;
-	unsigned int nr_added_bufs;
+	int nr_added_bufs;
 	int ret;
 
 	nr_added_bufs = 0;
 	do {
 		buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
 		if (!buf)
-			break;
+			return -ENOMEM;
 
 		spin_lock_irq(lock);
 		ret = add_inbuf(vq, buf);
 		if (ret < 0) {
 			spin_unlock_irq(lock);
 			free_buf(buf, true);
-			break;
+			return ret;
 		}
 		nr_added_bufs++;
 		spin_unlock_irq(lock);
@@ -1362,7 +1360,6 @@ static int add_port(struct ports_device *portdev, u32 id)
 	char debugfs_name[16];
 	struct port *port;
 	dev_t devt;
-	unsigned int nr_added_bufs;
 	int err;
 
 	port = kmalloc(sizeof(*port), GFP_KERNEL);
@@ -1421,11 +1418,13 @@ static int add_port(struct ports_device *portdev, u32 id)
 	spin_lock_init(&port->outvq_lock);
 	init_waitqueue_head(&port->waitqueue);
 
-	/* Fill the in_vq with buffers so the host can send us data. */
-	nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
-	if (!nr_added_bufs) {
+	/* We can safely ignore ENOSPC because it means
+	 * the queue already has buffers. Buffers are removed
+	 * only by virtcons_remove(), not by unplug_port()
+	 */
+	err = fill_queue(port->in_vq, &port->inbuf_lock);
+	if (err < 0 && err != -ENOSPC) {
 		dev_err(port->dev, "Error allocating inbufs\n");
-		err = -ENOMEM;
 		goto free_device;
 	}
 
@@ -2059,14 +2058,11 @@ static int virtcons_probe(struct virtio_device *vdev)
 	INIT_WORK(&portdev->control_work, &control_work_handler);
 
 	if (multiport) {
-		unsigned int nr_added_bufs;
-
 		spin_lock_init(&portdev->c_ivq_lock);
 		spin_lock_init(&portdev->c_ovq_lock);
 
-		nr_added_bufs = fill_queue(portdev->c_ivq,
-					   &portdev->c_ivq_lock);
-		if (!nr_added_bufs) {
+		err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
+		if (err < 0) {
 			dev_err(&vdev->dev,
 				"Error allocating buffers for control queue\n");
 			/*
@@ -2077,7 +2073,7 @@ static int virtcons_probe(struct virtio_device *vdev)
 					   VIRTIO_CONSOLE_DEVICE_READY, 0);
 			/* Device was functional: we need full cleanup. */
 			virtcons_remove(vdev);
-			return -ENOMEM;
+			return err;
 		}
 	} else {
 		/*