drbd: merge_bvec_fn: properly remap bvm->bi_bdev

[pandora-kernel.git] / drivers / char / virtio_console.c

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 8e3c46d..c68b8ad 100644 (file)
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -131,7 +131,8 @@ struct ports_device {
        spinlock_t ports_lock;
 
        /* To protect the vq operations for the control channel */
-       spinlock_t cvq_lock;
+       spinlock_t c_ivq_lock;
+       spinlock_t c_ovq_lock;
 
        /* The current config space is stored here */
        struct virtio_console_config config;
@@ -256,9 +257,12 @@ 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);
@@ -457,11 +461,14 @@ static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
        vq = portdev->c_ovq;
 
        sg_init_one(sg, &cpkt, sizeof(cpkt));
+
+       spin_lock(&portdev->c_ovq_lock);
        if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
                virtqueue_kick(vq);
                while (!virtqueue_get_buf(vq, &len))
                        cpu_relax();
        }
+       spin_unlock(&portdev->c_ovq_lock);
        return 0;
 }
 
@@ -630,6 +637,10 @@ 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
@@ -646,7 +657,7 @@ 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;
        /*
@@ -789,14 +800,14 @@ 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
@@ -1260,14 +1271,6 @@ 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);
 }
 
@@ -1285,12 +1288,14 @@ 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)) {
@@ -1316,6 +1321,14 @@ 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
@@ -1466,23 +1479,23 @@ static void control_work_handler(struct work_struct *work)
        portdev = container_of(work, struct ports_device, control_work);
        vq = portdev->c_ivq;
 
-       spin_lock(&portdev->cvq_lock);
+       spin_lock(&portdev->c_ivq_lock);
        while ((buf = virtqueue_get_buf(vq, &len))) {
-               spin_unlock(&portdev->cvq_lock);
+               spin_unlock(&portdev->c_ivq_lock);
 
                buf->len = len;
                buf->offset = 0;
 
                handle_control_message(portdev, buf);
 
-               spin_lock(&portdev->cvq_lock);
+               spin_lock(&portdev->c_ivq_lock);
                if (add_inbuf(portdev->c_ivq, buf) < 0) {
                        dev_warn(&portdev->vdev->dev,
                                 "Error adding buffer to queue\n");
                        free_buf(buf);
                }
        }
-       spin_unlock(&portdev->cvq_lock);
+       spin_unlock(&portdev->c_ivq_lock);
 }
 
 static void out_intr(struct virtqueue *vq)
@@ -1721,10 +1734,12 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
        if (multiport) {
                unsigned int nr_added_bufs;
 
-               spin_lock_init(&portdev->cvq_lock);
+               spin_lock_init(&portdev->c_ivq_lock);
+               spin_lock_init(&portdev->c_ovq_lock);
                INIT_WORK(&portdev->control_work, &control_work_handler);
 
-               nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
+               nr_added_bufs = fill_queue(portdev->c_ivq,
+                                          &portdev->c_ivq_lock);
                if (!nr_added_bufs) {
                        dev_err(&vdev->dev,
                                "Error allocating buffers for control queue\n");
@@ -1789,7 +1804,8 @@ static void virtcons_remove(struct virtio_device *vdev)
        /* Disable interrupts for vqs */
        vdev->config->reset(vdev);
        /* Finish up work that's lined up */
-       cancel_work_sync(&portdev->control_work);
+       if (use_multiport(portdev))
+               cancel_work_sync(&portdev->control_work);
 
        list_for_each_entry_safe(port, port2, &portdev->ports, list)
                unplug_port(port);