net/9p: Add sysfs mount_tag file for virtio 9P device
This adds a new file for virtio 9P device. The file
contain details of the mount device name that should
be used to mount the 9P file system.
Ex: /sys/devices/virtio-pci/virtio1/mount_tag file now
contian the tag name to be used to mount the 9P file system.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index f508c65..40d1709 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -98,6 +98,7 @@
void *priv;
};
+#define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
int register_virtio_device(struct virtio_device *dev);
void unregister_virtio_device(struct virtio_device *dev);
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 026775a..afde1a8 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -220,6 +220,20 @@
return 0;
}
+static ssize_t p9_mount_tag_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_chan *chan;
+ struct virtio_device *vdev;
+
+ vdev = dev_to_virtio(dev);
+ chan = vdev->priv;
+
+ return snprintf(buf, chan->tag_len + 1, "%s", chan->tag);
+}
+
+static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL);
+
/**
* p9_virtio_probe - probe for existence of 9P virtio channels
* @vdev: virtio device to probe
@@ -273,6 +287,11 @@
tag, tag_len);
chan->tag = tag;
chan->tag_len = tag_len;
+ err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
+ if (err) {
+ kfree(tag);
+ goto out_free_vq;
+ }
mutex_lock(&virtio_9p_lock);
list_add_tail(&chan->chan_list, &virtio_chan_list);
mutex_unlock(&virtio_9p_lock);
@@ -348,6 +367,7 @@
mutex_lock(&virtio_9p_lock);
list_del(&chan->chan_list);
mutex_unlock(&virtio_9p_lock);
+ sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
kfree(chan->tag);
kfree(chan);
