1 files changed, 58 insertions, 6 deletions

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 0aaed4819379..afde1a89fbb3 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -78,6 +78,12 @@ struct virtio_chan {
         /* Scatterlist: can be too big for stack. */
         struct scatterlist sg[VIRTQUEUE_NUM];
 
+        int tag_len;
+        /*
+         * tag name to identify a mount Non-null terminated
+         */
+        char *tag;
+
         struct list_head chan_list;
 };
 
@@ -214,6 +220,20 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
         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
@@ -224,6 +244,8 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 
 static int p9_virtio_probe(struct virtio_device *vdev)
 {
+        __u16 tag_len;
+        char *tag;
         int err;
         struct virtio_chan *chan;
 
@@ -248,6 +270,28 @@ static int p9_virtio_probe(struct virtio_device *vdev)
         sg_init_table(chan->sg, VIRTQUEUE_NUM);
 
         chan->inuse = false;
+        if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
+                vdev->config->get(vdev,
+                                offsetof(struct virtio_9p_config, tag_len),
+                                &tag_len, sizeof(tag_len));
+        } else {
+                err = -EINVAL;
+                goto out_free_vq;
+        }
+        tag = kmalloc(tag_len, GFP_KERNEL);
+        if (!tag) {
+                err = -ENOMEM;
+                goto out_free_vq;
+        }
+        vdev->config->get(vdev, offsetof(struct virtio_9p_config, tag),
+                        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);
@@ -284,7 +328,7 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
 
         mutex_lock(&virtio_9p_lock);
         list_for_each_entry(chan, &virtio_chan_list, chan_list) {
-                if (!strcmp(devname, dev_name(&chan->vdev->dev))) {
+                if (!strncmp(devname, chan->tag, chan->tag_len)) {
                         if (!chan->inuse) {
                                 chan->inuse = true;
                                 found = 1;
@@ -323,6 +367,8 @@ static void p9_virtio_remove(struct virtio_device *vdev)
         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);
 
 }
@@ -332,13 +378,19 @@ static struct virtio_device_id id_table[] = {
         { 0 },
 };
 
+static unsigned int features[] = {
+        VIRTIO_9P_MOUNT_TAG,
+};
+
 /* The standard "struct lguest_driver": */
 static struct virtio_driver p9_virtio_drv = {
-        .driver.name =  KBUILD_MODNAME,
-        .driver.owner = THIS_MODULE,
-        .id_table =     id_table,
-        .probe =        p9_virtio_probe,
-        .remove =       p9_virtio_remove,
+        .feature_table  = features,
+        .feature_table_size = ARRAY_SIZE(features),
+        .driver.name    = KBUILD_MODNAME,
+        .driver.owner   = THIS_MODULE,
+        .id_table       = id_table,
+        .probe          = p9_virtio_probe,
+        .remove         = p9_virtio_remove,
 };
 
 static struct p9_trans_module p9_virtio_trans = {