can: avoids a false warning

[safe/jmp/linux-2.6] / net / 9p / trans_virtio.c

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 0aaed48..7eb78ec 100644 (file)
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -37,6 +37,7 @@
 #include <linux/inet.h>
 #include <linux/idr.h>
 #include <linux/file.h>
+#include <linux/slab.h>
 #include <net/9p/9p.h>
 #include <linux/parser.h>
 #include <net/9p/client.h>
@@ -78,6 +79,12 @@ 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 +221,20 @@ 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 +245,8 @@ 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 +271,28 @@ 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 +329,7 @@ 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 +368,8 @@ 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 +379,19 @@ 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 = {