9p: Implement TREADLINK operation for 9p2000.L

Synopsis

	size[4] TReadlink tag[2] fid[4]
	size[4] RReadlink tag[2] target[s]

Description
	Readlink is used to return the contents of the symoblic link
        referred by fid. Contents of symboic link is returned as a
        response.

	target[s] - Contents of the symbolic link referred by fid.

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/net/9p/client.c b/net/9p/client.c
index fc1b0579016a..2bc99e9031e7 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1870,3 +1870,29 @@ error:
         return err;
 }
 EXPORT_SYMBOL(p9_client_getlock_dotl);
+
+int p9_client_readlink(struct p9_fid *fid, char **target)
+{
+        int err;
+        struct p9_client *clnt;
+        struct p9_req_t *req;
+
+        err = 0;
+        clnt = fid->clnt;
+        P9_DPRINTK(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
+
+        req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
+        if (IS_ERR(req))
+                return PTR_ERR(req);
+
+        err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
+        if (err) {
+                p9pdu_dump(1, req->rc);
+                goto error;
+        }
+        P9_DPRINTK(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
+error:
+        p9_free_req(clnt, req);
+        return err;
+}
+EXPORT_SYMBOL(p9_client_readlink);