net/9p: Add multi channel support.

This is needed for supporting multiple mount points.

We can find out the device names to be used with mount by checking

/sys/devices/virtio-pci/virtio*/device file

if the device file have value 9 then the specific virtio device can
be used for mounting.

ex:
 #cat /sys/devices/virtio-pci/virtio1/device
 9

now we can mount using
# mount -t 9p -o trans=virtio virtio1  /mnt/

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

2 files changed, 9 insertions, 7 deletions

diff --git a/include/linux/virtio_9p.h b/include/linux/virtio_9p.h
index 095e10d148b4..7a615c3f5e3d 100644
--- a/include/linux/virtio_9p.h
+++ b/include/linux/virtio_9p.h
@@ -6,6 +6,6 @@
 #include <linux/virtio_config.h>
 
 /* Maximum number of virtio channels per partition (1 for now) */
-#define MAX_9P_CHAN     1
+#define MAX_9P_CHAN     10
 
 #endif /* _LINUX_VIRTIO_9P_H */
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index cb50f4ae5eef..df924e5657d3 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -296,13 +296,15 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
 
         mutex_lock(&virtio_9p_lock);
         while (index < MAX_9P_CHAN) {
-                if (chan->initialized && !chan->inuse) {
-                        chan->inuse = true;
-                        break;
-                } else {
-                        index++;
-                        chan = &channels[index];
+                if (chan->initialized &&
+                        !strcmp(devname, dev_name(&chan->vdev->dev))) {
+                        if (!chan->inuse) {
+                                chan->inuse = true;
+                                break;
+                        }
                 }
+                index++;
+                chan = &channels[index];
         }
         mutex_unlock(&virtio_9p_lock);