9p: Define and implement TLINK for 9P2000.L

This patch adds a helper function to get the dentry from inode and
uses it in creating a Hardlink

SYNOPSIS

size[4] Tlink tag[2] dfid[4] oldfid[4] newpath[s]

size[4] Rlink tag[2]

DESCRIPTION

Create a link 'newpath' in directory pointed by dfid linking to oldfid path.

[sripathik@in.ibm.com : p9_client_link should not free req structure
if p9_client_rpc has returned an error.]

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index afdc385..e36f116 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -226,6 +226,7 @@
 int p9_client_open(struct p9_fid *fid, int mode);
 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 							char *extension);
+int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname);
 int p9_client_clunk(struct p9_fid *fid);
 int p9_client_remove(struct p9_fid *fid);
 int p9_client_read(struct p9_fid *fid, char *data, char __user *udata,