Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty...

Pull virtio fixes from Rusty Russell:
 "More virtio console fixes than I'm happy with, but all real issues,
  and all CC:stable.."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio-scsi: Fix virtqueue affinity setup
  virtio: console: return -ENODEV on all read operations after unplug
  virtio: console: fix raising SIGIO after port unplug
  virtio: console: clean up port data immediately at time of unplug
  virtio: console: fix race in port_fops_open() and port unplug
  virtio: console: fix race with port unplug and open/close
  virtio/console: Add pipe_lock/unlock for splice_write
  virtio/console: Quit from splice_write if pipe->nrbufs is 0

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 1b456fe9b87a12f98e8a6d691487c252271cb3e6..fc45567ad3acef079db496c9a2f495e19e5b5bba 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -272,9 +272,12 @@ static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
        unsigned long flags;
 
        spin_lock_irqsave(&portdev->ports_lock, flags);
-       list_for_each_entry(port, &portdev->ports, list)
-               if (port->cdev->dev == dev)
+       list_for_each_entry(port, &portdev->ports, list) {
+               if (port->cdev->dev == dev) {
+                       kref_get(&port->kref);
                        goto out;
+               }
+       }
        port = NULL;
 out:
        spin_unlock_irqrestore(&portdev->ports_lock, flags);
@@ -746,6 +749,10 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
 
        port = filp->private_data;
 
+       /* Port is hot-unplugged. */
+       if (!port->guest_connected)
+               return -ENODEV;
+
        if (!port_has_data(port)) {
                /*
                 * If nothing's connected on the host just return 0 in
@@ -762,7 +769,7 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
                if (ret < 0)
                        return ret;
        }
-       /* Port got hot-unplugged. */
+       /* Port got hot-unplugged while we were waiting above. */
        if (!port->guest_connected)
                return -ENODEV;
        /*
@@ -932,13 +939,25 @@ 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;
+               goto error_out;
+       }
+
        ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
        if (ret < 0)
-               return ret;
+               goto error_out;
 
        buf = alloc_buf(port->out_vq, 0, pipe->nrbufs);
-       if (!buf)
-               return -ENOMEM;
+       if (!buf) {
+               ret = -ENOMEM;
+               goto error_out;
+       }
 
        sgl.n = 0;
        sgl.len = 0;
@@ -946,12 +965,17 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
        sgl.sg = buf->sg;
        sg_init_table(sgl.sg, sgl.size);
        ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
+       pipe_unlock(pipe);
        if (likely(ret > 0))
                ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
 
        if (unlikely(ret <= 0))
                free_buf(buf, true);
        return ret;
+
+error_out:
+       pipe_unlock(pipe);
+       return ret;
 }
 
 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
@@ -1019,14 +1043,14 @@ static int port_fops_open(struct inode *inode, struct file *filp)
        struct port *port;
        int ret;
 
+       /* We get the port with a kref here */
        port = find_port_by_devt(cdev->dev);
+       if (!port) {
+               /* Port was unplugged before we could proceed */
+               return -ENXIO;
+       }
        filp->private_data = port;
 
-       /* Prevent against a port getting hot-unplugged at the same time */
-       spin_lock_irq(&port->portdev->ports_lock);
-       kref_get(&port->kref);
-       spin_unlock_irq(&port->portdev->ports_lock);
-
        /*
         * Don't allow opening of console port devices -- that's done
         * via /dev/hvc
@@ -1498,14 +1522,6 @@ static void remove_port(struct kref *kref)
 
        port = container_of(kref, struct port, kref);
 
-       sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
-       device_destroy(pdrvdata.class, port->dev->devt);
-       cdev_del(port->cdev);
-
-       kfree(port->name);
-
-       debugfs_remove(port->debugfs_file);
-
        kfree(port);
 }
 
@@ -1539,12 +1555,14 @@ static void unplug_port(struct port *port)
        spin_unlock_irq(&port->portdev->ports_lock);
 
        if (port->guest_connected) {
+               /* Let the app know the port is going down. */
+               send_sigio_to_port(port);
+
+               /* Do this after sigio is actually sent */
                port->guest_connected = false;
                port->host_connected = false;
-               wake_up_interruptible(&port->waitqueue);
 
-               /* Let the app know the port is going down. */
-               send_sigio_to_port(port);
+               wake_up_interruptible(&port->waitqueue);
        }
 
        if (is_console_port(port)) {
@@ -1563,6 +1581,14 @@ static void unplug_port(struct port *port)
         */
        port->portdev = NULL;
 
+       sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
+       device_destroy(pdrvdata.class, port->dev->devt);
+       cdev_del(port->cdev);
+
+       kfree(port->name);
+
+       debugfs_remove(port->debugfs_file);
+
        /*
         * Locks around here are not necessary - a port can't be
         * opened after we removed the port struct from ports_list

diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 2168258fb2c3a2cf5374a3592a302062d75bb305..74b88efde6ad408123de6a9b96ec37460195fe82 100644 (file)
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -751,7 +751,7 @@ static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
 
                vscsi->affinity_hint_set = true;
        } else {
-               for (i = 0; i < vscsi->num_queues - VIRTIO_SCSI_VQ_BASE; i++)
+               for (i = 0; i < vscsi->num_queues; i++)
                        virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1);
 
                vscsi->affinity_hint_set = false;