9p: documentation update

This patch adds documentation for new 9P options introduced in
2.6.34.

Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/Documentation/filesystems/9p.txt b/Documentation/filesystems/9p.txt
index 57e0b80a5274..c0236e753bc8 100644
--- a/Documentation/filesystems/9p.txt
+++ b/Documentation/filesystems/9p.txt
@@ -37,6 +37,15 @@ For Plan 9 From User Space applications (http://swtch.com/plan9)
 
         mount -t 9p `namespace`/acme /mnt/9 -o trans=unix,uname=$USER
 
+For server running on QEMU host with virtio transport:
+
+        mount -t 9p -o trans=virtio <mount_tag> /mnt/9
+
+where mount_tag is the tag associated by the server to each of the exported
+mount points. Each 9P export is seen by the client as a virtio device with an
+associated "mount_tag" property. Available mount tags can be
+seen by reading /sys/bus/virtio/drivers/9pnet_virtio/virtio<n>/mount_tag files.
+
 OPTIONS
 =======
 
@@ -47,7 +56,7 @@ OPTIONS
                         fd      - used passed file descriptors for connection
                                 (see rfdno and wfdno)
                         virtio  - connect to the next virtio channel available
-                                (from lguest or KVM with trans_virtio module)
+                                (from QEMU with trans_virtio module)
                         rdma    - connect to a specified RDMA channel
 
   uname=name    user name to attempt mount as on the remote server.  The
@@ -85,7 +94,12 @@ OPTIONS
 
   port=n        port to connect to on the remote server
 
-  noextend      force legacy mode (no 9p2000.u semantics)
+  noextend      force legacy mode (no 9p2000.u or 9p2000.L semantics)
+
+  version=name  Select 9P protocol version. Valid options are:
+                        9p2000          - Legacy mode (same as noextend)
+                        9p2000.u        - Use 9P2000.u protocol
+                        9p2000.L        - Use 9P2000.L protocol
 
   dfltuid       attempt to mount as a particular uid