[PATCH 2.6.13-rc3-mm2] v9fs: add fd based transport

From: ericvh
Date: Thu Jul 28 2005 - 09:04:29 EST

v9fs: add file-descriptor based transport as was requested by LANL and
Plan 9 from User Space folks.

Signed-off-by: Eric Van Hensbergen <ericvh@xxxxxxxxx>

---
commit e65b41c8081e0f7227a16d39a4bc65e2924d7680
tree 4cfd78c690d2e9852736499fe9d0a311c78beee8
parent eefccf73f82b2bdf353cd05b8e5d6142210bc80f
author Eric Van Hensbergen <ericvh@xxxxxxxxx> Thu, 28 Jul 2005 08:45:14 -0500
committer Eric Van Hensbergen <ericvh@xxxxxxxxx> Thu, 28 Jul 2005 08:45:14 -0500

Documentation/filesystems/v9fs.txt | 13 +++
fs/9p/Makefile | 1
fs/9p/trans_fd.c | 136 ++++++++++++++++++++++++++++++++++++
fs/9p/transport.h | 1
fs/9p/v9fs.c | 27 +++++++
fs/9p/v9fs.h | 4 +
6 files changed, 178 insertions(+), 4 deletions(-)

diff --git a/Documentation/filesystems/v9fs.txt b/Documentation/filesystems/v9fs.txt
--- a/Documentation/filesystems/v9fs.txt
+++ b/Documentation/filesystems/v9fs.txt
@@ -26,9 +26,12 @@ OPTIONS
=======

proto=name select an alternative transport. Valid options are
- currently either unix (specifying a named pipe mount
- point) or tcp (specifying a normal TCP/IP connection)
-
+ currently:
+ unix - specifying a named pipe mount point
+ tcp - specifying a normal TCP/IP connection
+ fd - used passed file descriptors for connection
+ (see rfdno and wfdno)
+
name=name user name to attempt mount as on the remote server. The
server may override or ignore this value. Certain user
names may require authentication.
@@ -46,6 +49,10 @@ OPTIONS
0x40 = display transport debug
0x80 = display allocation debug

+ rfdno=n the file descriptor for reading with proto=fd
+
+ wfdno=n the file descriptor for writing with proto=fd
+
maxdata=n the number of bytes to use for 9P packet payload (msize)

port=n port to connect to on the remote server
diff --git a/fs/9p/Makefile b/fs/9p/Makefile
--- a/fs/9p/Makefile
+++ b/fs/9p/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_9P_FS) := 9p2000.o
vfs_dentry.o \
error.o \
mux.o \
+ trans_fd.o \
trans_sock.o \
9p.o \
conv.o \
diff --git a/fs/9p/trans_fd.c b/fs/9p/trans_fd.c
new file mode 100644
--- /dev/null
+++ b/fs/9p/trans_fd.c
@@ -0,0 +1,136 @@
+/*
+ * linux/fs/9p/trans_fd.c
+ *
+ * File Descriptor Transport Layer
+ *
+ * Copyright (C) 2005 by Eric Van Hensbergen <ericvh@xxxxxxxxx>
+ *
+ * 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 --git a/fs/9p/transport.h b/fs/9p/transport.h
--- a/fs/9p/transport.h
+++ b/fs/9p/transport.h
@@ -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;
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -50,10 +50,11 @@ int v9fs_debug_level = 0; /* feature-rif
enum {
/* Options that take integer arguments */
Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid, Opt_debug,
+ Opt_rfdno, Opt_wfdno,
/* String options */
Opt_name, Opt_remotename,
/* Options that take no arguments */
- Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp,
+ Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd,
/* Error token */
Opt_err
};
@@ -64,13 +65,17 @@ static match_table_t tokens = {
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_afid, "afid=%u"},
+ {Opt_rfdno, "rfdno=%u"},
+ {Opt_wfdno, "wfdno=%u"},
{Opt_debug, "debug=%u"},
{Opt_name, "name=%s"},
{Opt_remotename, "aname=%s"},
{Opt_unix, "proto=unix"},
{Opt_tcp, "proto=tcp"},
+ {Opt_fd, "proto=fd"},
{Opt_tcp, "tcp"},
{Opt_unix, "unix"},
+ {Opt_fd, "fd"},
{Opt_legacy, "noextend"},
{Opt_nodevmap, "nodevmap"},
{Opt_err, NULL}
@@ -101,6 +106,8 @@ static void v9fs_parse_options(char *opt
v9ses->extended = 1;
v9ses->afid = ~0;
v9ses->debug = 0;
+ v9ses->rfdno = ~0;
+ v9ses->wfdno = ~0;

if (!options)
return;
@@ -134,6 +141,12 @@ static void v9fs_parse_options(char *opt
case Opt_afid:
v9ses->afid = option;
break;
+ case Opt_rfdno:
+ v9ses->rfdno = option;
+ break;
+ case Opt_wfdno:
+ v9ses->wfdno = option;
+ break;
case Opt_debug:
v9ses->debug = option;
break;
@@ -143,6 +156,9 @@ static void v9fs_parse_options(char *opt
case Opt_unix:
v9ses->proto = PROTO_UNIX;
break;
+ case Opt_fd:
+ v9ses->proto = PROTO_FD;
+ break;
case Opt_name:
match_strcpy(v9ses->name, &args[0]);
break;
@@ -277,6 +293,15 @@ v9fs_session_init(struct v9fs_session_in
trans_proto = &v9fs_trans_unix;
*v9ses->remotename = 0;
break;
+ case PROTO_FD:
+ trans_proto = &v9fs_trans_fd;
+ *v9ses->remotename = 0;
+ if((v9ses->wfdno == ~0) || (v9ses->rfdno == ~0)) {
+ printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
+ retval = -ENOPROTOOPT;
+ goto SessCleanUp;
+ }
+ break;
default:
printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
retval = -ENOPROTOOPT;
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -46,6 +46,9 @@ struct v9fs_session_info {
unsigned short debug; /* debug level */
unsigned short proto; /* protocol to use */
unsigned int afid; /* authentication fid */
+ unsigned int rfdno; /* read file descriptor number */
+ unsigned int wfdno; /* write file descriptor number */
+

char *name; /* user name to mount as */
char *remotename; /* name of remote hierarchy being mounted */
@@ -78,6 +81,7 @@ struct v9fs_session_info {
enum {
PROTO_TCP,
PROTO_UNIX,
+ PROTO_FD,
};

int v9fs_session_init(struct v9fs_session_info *, const char *, char *);
-
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