SUNRPC/NFS: make rpc pipe upcall generic

The same function is used by idmap, gss and blocklayout code. Make it
generic.

Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Cc: stable@kernel.org [3.0]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index b181e3441323..67dbc1884383 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -77,6 +77,26 @@ rpc_timeout_upcall_queue(struct work_struct *work)
         rpc_purge_list(rpci, &free_list, destroy_msg, -ETIMEDOUT);
 }
 
+ssize_t rpc_pipe_generic_upcall(struct file *filp, struct rpc_pipe_msg *msg,
+                                char __user *dst, size_t buflen)
+{
+        char *data = (char *)msg->data + msg->copied;
+        size_t mlen = min(msg->len - msg->copied, buflen);
+        unsigned long left;
+
+        left = copy_to_user(dst, data, mlen);
+        if (left == mlen) {
+                msg->errno = -EFAULT;
+                return -EFAULT;
+        }
+
+        mlen -= left;
+        msg->copied += mlen;
+        msg->errno = 0;
+        return mlen;
+}
+EXPORT_SYMBOL_GPL(rpc_pipe_generic_upcall);
+
 /**
  * rpc_queue_upcall - queue an upcall message to userspace
  * @inode: inode of upcall pipe on which to queue given message