From: Eric Van Hensbergen <ericvh@gmail.com>

Add fd transport support to v9fs.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 fs/9p/trans_fd.c  |  136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/9p/transport.h |    1 
 2 files changed, 137 insertions(+)

diff -puN /dev/null fs/9p/trans_fd.c
--- /dev/null	2003-09-15 06:40:47.000000000 -0700
+++ devel-akpm/fs/9p/trans_fd.c	2005-07-28 11:53:14.000000000 -0700
@@ -0,0 +1,136 @@
+/*
+ * linux/fs/9p/trans_fd.c
+ *
+ * File Descriptor Transport Layer
+ *
+ *  Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to:
+ *  Free Software Foundation
+ *  51 Franklin Street, Fifth Floor
+ *  Boston, MA  02111-1301  USA
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/ipv6.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/un.h>
+#include <asm/uaccess.h>
+#include <linux/inet.h>
+#include <linux/idr.h>
+#include <linux/file.h>
+
+#include "debug.h"
+#include "v9fs.h"
+#include "transport.h"
+
+struct v9fs_trans_fd {
+	struct file *in_file;
+	struct file *out_file;
+};
+
+/**
+ * v9fs_fd_recv - receive from a socket
+ * @v9ses: session information
+ * @v: buffer to receive data into
+ * @len: size of receive buffer
+ *
+ */
+
+static int v9fs_fd_recv(struct v9fs_transport *trans, void *v, int len)
+{
+	struct v9fs_trans_fd *ts = trans ? trans->priv : NULL;
+
+	return kernel_read(ts->in_file, ts->in_file->f_pos, v, len);
+}
+
+/**
+ * v9fs_fd_send - send to a socket
+ * @v9ses: session information
+ * @v: buffer to send data from
+ * @len: size of send buffer
+ *
+ */
+
+static int v9fs_fd_send(struct v9fs_transport *trans, void *v, int len)
+{
+	struct v9fs_trans_fd *ts = trans ? trans->priv : NULL;
+	mm_segment_t oldfs = get_fs();
+	int ret = 0;
+
+	set_fs(get_ds());
+	/* The cast to a user pointer is valid due to the set_fs() */
+	ret = vfs_write(ts->out_file, (void __user *)v, len, &ts->out_file->f_pos);
+	set_fs(oldfs);
+
+	return ret;
+}
+
+/**
+ * v9fs_fd_init - initialize file descriptor transport
+ * @v9ses: session information
+ * @addr: address of server to mount
+ * @data: mount options
+ *
+ */
+
+static int
+v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
+{
+	struct v9fs_trans_fd *ts = NULL;
+	struct v9fs_transport *trans = v9ses->transport;
+
+	sema_init(&trans->writelock, 1);
+	sema_init(&trans->readlock, 1);
+
+	ts = kmalloc(sizeof(struct v9fs_trans_fd), GFP_KERNEL);
+
+	if (!ts)
+		return -ENOMEM;
+
+	trans->priv = ts;
+
+	ts->in_file = fget( v9ses->rfdno );
+	ts->out_file = fget( v9ses->wfdno );
+
+	trans->status = Connected;
+
+	return 0;
+}
+
+
+/**
+ * v9fs_fd_close - shutdown file descriptor
+ * @trans: private socket structure
+ *
+ */
+
+static void v9fs_fd_close(struct v9fs_transport *trans)
+{
+	struct v9fs_trans_fd *ts = trans ? trans->priv : NULL;
+
+	kfree(ts);
+}
+
+struct v9fs_transport v9fs_trans_fd = {
+	.init = v9fs_fd_init,
+	.write = v9fs_fd_send,
+	.read = v9fs_fd_recv,
+	.close = v9fs_fd_close,
+};
+
diff -puN fs/9p/transport.h~v9fs-transport-modules-add-fd-based-transport-module fs/9p/transport.h
--- devel/fs/9p/transport.h~v9fs-transport-modules-add-fd-based-transport-module	2005-07-28 11:53:14.000000000 -0700
+++ devel-akpm/fs/9p/transport.h	2005-07-28 11:53:14.000000000 -0700
@@ -43,3 +43,4 @@ struct v9fs_transport {
 
 extern struct v9fs_transport v9fs_trans_tcp;
 extern struct v9fs_transport v9fs_trans_unix;
+extern struct v9fs_transport v9fs_trans_fd;
_