9p: transport API reorganization

This merges the mux.c (including the connection interface) with trans_fd
in preparation for transport API changes.  Ultimately, trans_fd will need
to be rewritten to clean it up and simplify the implementation, but this
reorganization is viewed as the first step.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

11 files changed, 1208 insertions, 1253 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index fbb12dadba83..9b0f0222e8bb 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -3,7 +3,7 @@
  *
  *  This file contains functions assisting in mapping VFS to 9P2000
  *
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -31,7 +31,6 @@
 #include <linux/idr.h>
 #include <net/9p/9p.h>
 #include <net/9p/transport.h>
-#include <net/9p/conn.h>
 #include <net/9p/client.h>
 #include "v9fs.h"
 #include "v9fs_vfs.h"
@@ -43,11 +42,11 @@
 
 enum {
 	/* Options that take integer arguments */
-	Opt_debug, Opt_msize, Opt_dfltuid, Opt_dfltgid, Opt_afid,
+	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
 	/* String options */
 	Opt_uname, Opt_remotename, Opt_trans,
 	/* Options that take no arguments */
-	Opt_legacy, Opt_nodevmap,
+	Opt_nodevmap,
 	/* Cache options */
 	Opt_cache_loose,
 	/* Access options */
@@ -58,14 +57,11 @@ enum {
 
 static match_table_t tokens = {
 	{Opt_debug, "debug=%x"},
-	{Opt_msize, "msize=%u"},
 	{Opt_dfltuid, "dfltuid=%u"},
 	{Opt_dfltgid, "dfltgid=%u"},
 	{Opt_afid, "afid=%u"},
 	{Opt_uname, "uname=%s"},
 	{Opt_remotename, "aname=%s"},
-	{Opt_trans, "trans=%s"},
-	{Opt_legacy, "noextend"},
 	{Opt_nodevmap, "nodevmap"},
 	{Opt_cache_loose, "cache=loose"},
 	{Opt_cache_loose, "loose"},
@@ -85,16 +81,14 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 	char *options;
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
-	int option;
-	int ret;
+	int option = 0;
 	char *s, *e;
+	int ret;
 
 	/* setup defaults */
-	v9ses->maxdata = 8192;
 	v9ses->afid = ~0;
 	v9ses->debug = 0;
 	v9ses->cache = 0;
-	v9ses->trans = v9fs_default_trans();
 
 	if (!v9ses->options)
 		return;
@@ -106,7 +100,8 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 			continue;
 		token = match_token(p, tokens, args);
 		if (token < Opt_uname) {
-			if ((ret = match_int(&args[0], &option)) < 0) {
+			ret = match_int(&args[0], &option);
+			if (ret < 0) {
 				P9_DPRINTK(P9_DEBUG_ERROR,
 					"integer field, but no integer?\n");
 				continue;
@@ -119,9 +114,7 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 			p9_debug_level = option;
 #endif
 			break;
-		case Opt_msize:
-			v9ses->maxdata = option;
-			break;
+
 		case Opt_dfltuid:
 			v9ses->dfltuid = option;
 			break;
@@ -131,18 +124,12 @@ static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 		case Opt_afid:
 			v9ses->afid = option;
 			break;
-		case Opt_trans:
-			v9ses->trans = v9fs_match_trans(&args[0]);
-			break;
 		case Opt_uname:
 			match_strcpy(v9ses->uname, &args[0]);
 			break;
 		case Opt_remotename:
 			match_strcpy(v9ses->aname, &args[0]);
 			break;
-		case Opt_legacy:
-			v9ses->flags &= ~V9FS_EXTENDED;
-			break;
 		case Opt_nodevmap:
 			v9ses->nodev = 1;
 			break;
@@ -185,7 +172,6 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		  const char *dev_name, char *data)
 {
 	int retval = -EINVAL;
-	struct p9_trans *trans = NULL;
 	struct p9_fid *fid;
 
 	v9ses->uname = __getname();
@@ -207,24 +193,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	v9ses->options = kstrdup(data, GFP_KERNEL);
 	v9fs_parse_options(v9ses);
 
-	if (v9ses->trans == NULL) {
-		retval = -EPROTONOSUPPORT;
-		P9_DPRINTK(P9_DEBUG_ERROR,
-				"No transport defined or default transport\n");
-		goto error;
-	}
-
-	trans = v9ses->trans->create(dev_name, v9ses->options);
-	if (IS_ERR(trans)) {
-		retval = PTR_ERR(trans);
-		trans = NULL;
-		goto error;
-	}
-	if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
-		v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;
-
-	v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
-		v9fs_extended(v9ses));
+	v9ses->clnt = p9_client_create(dev_name, v9ses->options);
 
 	if (IS_ERR(v9ses->clnt)) {
 		retval = PTR_ERR(v9ses->clnt);
@@ -236,6 +205,8 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	if (!v9ses->clnt->dotu)
 		v9ses->flags &= ~V9FS_EXTENDED;
 
+	v9ses->maxdata = v9ses->clnt->msize;
+
 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
 	if (!v9fs_extended(v9ses) &&
 		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index db4b4193f2e2..7d3a1018db52 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -1,7 +1,7 @@
 /*
  * V9FS definitions.
  *
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -28,7 +28,6 @@
 
 struct v9fs_session_info {
 	/* options */
-	unsigned int maxdata;
 	unsigned char flags;	/* session flags */
 	unsigned char nodev;	/* set to 1 if no disable device mapping */
 	unsigned short debug;	/* debug level */
@@ -38,10 +37,10 @@ struct v9fs_session_info {
 	char *options;		/* copy of mount options */
 	char *uname;		/* user name to mount as */
 	char *aname;		/* name of remote hierarchy being mounted */
+	unsigned int maxdata;	/* max data for client interface */
 	unsigned int dfltuid;	/* default uid/muid for legacy support */
 	unsigned int dfltgid;	/* default gid for legacy support */
 	u32 uid;		/* if ACCESS_SINGLE, the uid that has access */
-	struct p9_trans_module *trans; /* 9p transport */
 	struct p9_client *clnt;	/* 9p client */
 	struct dentry *debugfs_dir;
 };
diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index 9b9221a21392..e52f93d9ac5f 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -3,6 +3,7 @@
  *
  * 9P Client Definitions
  *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -29,6 +30,7 @@ struct p9_client {
 	spinlock_t lock; /* protect client structure */
 	int msize;
 	unsigned char dotu;
+	struct p9_trans_module *trans_mod;
 	struct p9_trans *trans;
 	struct p9_conn *conn;
 
@@ -52,8 +54,7 @@ struct p9_fid {
 	struct list_head dlist;	/* list of all fids attached to a dentry */
 };
 
-struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
-								int dotu);
+struct p9_client *p9_client_create(const char *dev_name, char *options);
 void p9_client_destroy(struct p9_client *clnt);
 void p9_client_disconnect(struct p9_client *clnt);
 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
diff --git a/include/net/9p/conn.h b/include/net/9p/conn.h
deleted file mode 100644
index 756d8784f953..000000000000
--- a/include/net/9p/conn.h
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * include/net/9p/conn.h
- *
- * Connection Definitions
- *
- *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
- *  Copyright (C) 2004 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 version 2
- *  as published by the Free Software Foundation.
- *
- *  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
- *
- */
-
-#ifndef NET_9P_CONN_H
-#define NET_9P_CONN_H
-
-#undef P9_NONBLOCK
-
-struct p9_conn;
-struct p9_req;
-
-/**
- * p9_mux_req_callback - callback function that is called when the
- * response of a request is received. The callback is called from
- * a workqueue and shouldn't block.
- *
- * @req - request
- * @a - the pointer that was specified when the request was send to be
- *      passed to the callback
- */
-typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
-
-struct p9_conn *p9_conn_create(struct p9_trans *trans, int msize,
-							unsigned char *dotu);
-void p9_conn_destroy(struct p9_conn *);
-int p9_conn_rpc(struct p9_conn *m, struct p9_fcall *tc, struct p9_fcall **rc);
-
-#ifdef P9_NONBLOCK
-int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
-	p9_conn_req_callback cb, void *a);
-#endif /* P9_NONBLOCK */
-
-void p9_conn_cancel(struct p9_conn *m, int err);
-
-#endif /* NET_9P_CONN_H */
diff --git a/include/net/9p/transport.h b/include/net/9p/transport.h
index f9f362e934c9..d2209ae9d18b 100644
--- a/include/net/9p/transport.h
+++ b/include/net/9p/transport.h
@@ -4,7 +4,7 @@
  * Transport Definition
  *
  *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 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 version 2
@@ -34,13 +34,12 @@ enum p9_trans_status {
 
 struct p9_trans {
 	enum p9_trans_status status;
+	int msize;
+	unsigned char extended;
 	void *priv;
-	int (*write) (struct p9_trans *, void *, int);
-	int (*read) (struct p9_trans *, void *, int);
 	void (*close) (struct p9_trans *);
-	unsigned int (*poll)(struct p9_trans *, struct poll_table_struct *);
 	int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
-				struct p9_fcall **rc, int msize, int dotu);
+							struct p9_fcall **rc);
 };
 
 struct p9_trans_module {
@@ -48,7 +47,7 @@ struct p9_trans_module {
 	char *name;		/* name of transport */
 	int maxsize;		/* max message size of transport */
 	int def;		/* this transport should be default */
-	struct p9_trans * (*create)(const char *devname, char *options);
+	struct p9_trans * (*create)(const char *, char *, int, unsigned char);
 };
 
 void v9fs_register_trans(struct p9_trans_module *m);
diff --git a/net/9p/Makefile b/net/9p/Makefile
index d3abb246ccab..8a1051101898 100644
--- a/net/9p/Makefile
+++ b/net/9p/Makefile
@@ -4,7 +4,6 @@ obj-$(CONFIG_NET_9P_VIRTIO) += 9pnet_virtio.o
 
 9pnet-objs := \
 	mod.o \
-	mux.o \
 	client.o \
 	conv.o \
 	error.o \
diff --git a/net/9p/client.c b/net/9p/client.c
index 433b30713ef6..84e087e24146 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -3,6 +3,7 @@
  *
  * 9P Client
  *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -25,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
+#include <linux/poll.h>
 #include <linux/idr.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
@@ -32,13 +34,82 @@
 #include <net/9p/9p.h>
 #include <linux/parser.h>
 #include <net/9p/transport.h>
-#include <net/9p/conn.h>
 #include <net/9p/client.h>
 
 static struct p9_fid *p9_fid_create(struct p9_client *clnt);
 static void p9_fid_destroy(struct p9_fid *fid);
 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu);
 
+/*
+  * Client Option Parsing (code inspired by NFS code)
+  *  - a little lazy - parse all client options
+  */
+
+enum {
+	Opt_msize,
+	Opt_trans,
+	Opt_legacy,
+	Opt_err,
+};
+
+static match_table_t tokens = {
+	{Opt_msize, "msize=%u"},
+	{Opt_legacy, "noextend"},
+	{Opt_trans, "trans=%s"},
+	{Opt_err, NULL},
+};
+
+/**
+ * v9fs_parse_options - parse mount options into session structure
+ * @options: options string passed from mount
+ * @v9ses: existing v9fs session information
+ *
+ */
+
+static void parse_opts(char *options, struct p9_client *clnt)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+	int ret;
+
+	clnt->trans_mod = v9fs_default_trans();
+	clnt->dotu = 1;
+	clnt->msize = 8192;
+
+	if (!options)
+		return;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+		token = match_token(p, tokens, args);
+		if (token < Opt_trans) {
+			ret = match_int(&args[0], &option);
+			if (ret < 0) {
+				P9_DPRINTK(P9_DEBUG_ERROR,
+					"integer field, but no integer?\n");
+				continue;
+			}
+		}
+		switch (token) {
+		case Opt_msize:
+			clnt->msize = option;
+			break;
+		case Opt_trans:
+			clnt->trans_mod = v9fs_match_trans(&args[0]);
+			break;
+		case Opt_legacy:
+			clnt->dotu = 0;
+			break;
+		default:
+			continue;
+		}
+	}
+}
+
+
 /**
  * p9_client_rpc - sends 9P request and waits until a response is available.
  *      The function can be interrupted.
@@ -50,14 +121,10 @@ int
 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc,
 	struct p9_fcall **rc)
 {
-	if (c->trans->rpc)
-		return c->trans->rpc(c->trans, tc, rc, c->msize, c->dotu);
-	else
-		return p9_conn_rpc(c->conn, tc, rc);
+	return c->trans->rpc(c->trans, tc, rc);
 }
 
-struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
-								   int dotu)
+struct p9_client *p9_client_create(const char *dev_name, char *options)
 {
 	int err, n;
 	struct p9_client *clnt;
@@ -71,12 +138,7 @@ struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 	if (!clnt)
 		return ERR_PTR(-ENOMEM);
 
-	P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
-		clnt, trans, msize, dotu);
 	spin_lock_init(&clnt->lock);
-	clnt->trans = trans;
-	clnt->msize = msize;
-	clnt->dotu = dotu;
 	INIT_LIST_HEAD(&clnt->fidlist);
 	clnt->fidpool = p9_idpool_create();
 	if (!clnt->fidpool) {
@@ -85,13 +147,29 @@ struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 		goto error;
 	}
 
-	clnt->conn = p9_conn_create(clnt->trans, clnt->msize, &clnt->dotu);
-	if (IS_ERR(clnt->conn)) {
-		err = PTR_ERR(clnt->conn);
-		clnt->conn = NULL;
+	parse_opts(options, clnt);
+	if (clnt->trans_mod == NULL) {
+		err = -EPROTONOSUPPORT;
+		P9_DPRINTK(P9_DEBUG_ERROR,
+				"No transport defined or default transport\n");
+		goto error;
+	}
+
+	P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
+		clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
+
+
+	clnt->trans = clnt->trans_mod->create(dev_name, options, clnt->msize,
+								clnt->dotu);
+	if (IS_ERR(clnt->trans)) {
+		err = PTR_ERR(clnt->trans);
+		clnt->trans = NULL;
 		goto error;
 	}
 
+	if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
+		clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
+
 	tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
 	if (IS_ERR(tc)) {
 		err = PTR_ERR(tc);
@@ -134,10 +212,6 @@ void p9_client_destroy(struct p9_client *clnt)
 	struct p9_fid *fid, *fidptr;
 
 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
-	if (clnt->conn) {
-		p9_conn_destroy(clnt->conn);
-		clnt->conn = NULL;
-	}
 
 	if (clnt->trans) {
 		clnt->trans->close(clnt->trans);
@@ -159,7 +233,6 @@ void p9_client_disconnect(struct p9_client *clnt)
 {
 	P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 	clnt->trans->status = Disconnected;
-	p9_conn_cancel(clnt->conn, -EIO);
 }
 EXPORT_SYMBOL(p9_client_disconnect);
 
diff --git a/net/9p/mod.c b/net/9p/mod.c
index 8f9763a9dc12..c285aab2af04 100644
--- a/net/9p/mod.c
+++ b/net/9p/mod.c
@@ -106,15 +106,10 @@ EXPORT_SYMBOL(v9fs_default_trans);
  */
 static int __init init_p9(void)
 {
-	int ret;
+	int ret = 0;
 
 	p9_error_init();
 	printk(KERN_INFO "Installing 9P2000 support\n");
-	ret = p9_mux_global_init();
-	if (ret) {
-		printk(KERN_WARNING "9p: starting mux failed\n");
-		return ret;
-	}
 
 	return ret;
 }
@@ -126,7 +121,7 @@ static int __init init_p9(void)
 
 static void __exit exit_p9(void)
 {
-	p9_mux_global_exit();
+	printk(KERN_INFO "Unloading 9P2000 support\n");
 }
 
 module_init(init_p9)
diff --git a/net/9p/mux.c b/net/9p/mux.c
deleted file mode 100644
index c9f0805048e4..000000000000
--- a/net/9p/mux.c
+++ /dev/null
@@ -1,1060 +0,0 @@
-/*
- * net/9p/mux.c
- *
- * Protocol Multiplexer
- *
- *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
- *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2
- *  as published by the Free Software Foundation.
- *
- *  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/module.h>
-#include <linux/errno.h>
-#include <linux/fs.h>
-#include <linux/poll.h>
-#include <linux/kthread.h>
-#include <linux/idr.h>
-#include <linux/mutex.h>
-#include <net/9p/9p.h>
-#include <linux/parser.h>
-#include <net/9p/transport.h>
-#include <net/9p/conn.h>
-
-#define ERREQFLUSH	1
-#define SCHED_TIMEOUT	10
-#define MAXPOLLWADDR	2
-
-enum {
-	Rworksched = 1,		/* read work scheduled or running */
-	Rpending = 2,		/* can read */
-	Wworksched = 4,		/* write work scheduled or running */
-	Wpending = 8,		/* can write */
-};
-
-enum {
-	None,
-	Flushing,
-	Flushed,
-};
-
-struct p9_mux_poll_task;
-
-struct p9_req {
-	spinlock_t lock; /* protect request structure */
-	int tag;
-	struct p9_fcall *tcall;
-	struct p9_fcall *rcall;
-	int err;
-	p9_conn_req_callback cb;
-	void *cba;
-	int flush;
-	struct list_head req_list;
-};
-
-struct p9_conn {
-	spinlock_t lock; /* protect lock structure */
-	struct list_head mux_list;
-	struct p9_mux_poll_task *poll_task;
-	int msize;
-	unsigned char *extended;
-	struct p9_trans *trans;
-	struct p9_idpool *tagpool;
-	int err;
-	wait_queue_head_t equeue;
-	struct list_head req_list;
-	struct list_head unsent_req_list;
-	struct p9_fcall *rcall;
-	int rpos;
-	char *rbuf;
-	int wpos;
-	int wsize;
-	char *wbuf;
-	wait_queue_t poll_wait[MAXPOLLWADDR];
-	wait_queue_head_t *poll_waddr[MAXPOLLWADDR];
-	poll_table pt;
-	struct work_struct rq;
-	struct work_struct wq;
-	unsigned long wsched;
-};
-
-struct p9_mux_poll_task {
-	struct task_struct *task;
-	struct list_head mux_list;
-	int muxnum;
-};
-
-struct p9_mux_rpc {
-	struct p9_conn *m;
-	int err;
-	struct p9_fcall *tcall;
-	struct p9_fcall *rcall;
-	wait_queue_head_t wqueue;
-};
-
-static int p9_poll_proc(void *);
-static void p9_read_work(struct work_struct *work);
-static void p9_write_work(struct work_struct *work);
-static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address,
-			  poll_table * p);
-static u16 p9_mux_get_tag(struct p9_conn *);
-static void p9_mux_put_tag(struct p9_conn *, u16);
-
-static DEFINE_MUTEX(p9_mux_task_lock);
-static struct workqueue_struct *p9_mux_wq;
-
-static int p9_mux_num;
-static int p9_mux_poll_task_num;
-static struct p9_mux_poll_task p9_mux_poll_tasks[100];
-
-int p9_mux_global_init(void)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++)
-		p9_mux_poll_tasks[i].task = NULL;
-
-	p9_mux_wq = create_workqueue("v9fs");
-	if (!p9_mux_wq) {
-		printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
-		return -ENOMEM;
-	}
-
-	return 0;
-}
-
-void p9_mux_global_exit(void)
-{
-	destroy_workqueue(p9_mux_wq);
-}
-
-/**
- * p9_mux_calc_poll_procs - calculates the number of polling procs
- * based on the number of mounted v9fs filesystems.
- *
- * The current implementation returns sqrt of the number of mounts.
- */
-static int p9_mux_calc_poll_procs(int muxnum)
-{
-	int n;
-
-	if (p9_mux_poll_task_num)
-		n = muxnum / p9_mux_poll_task_num +
-		    (muxnum % p9_mux_poll_task_num ? 1 : 0);
-	else
-		n = 1;
-
-	if (n > ARRAY_SIZE(p9_mux_poll_tasks))
-		n = ARRAY_SIZE(p9_mux_poll_tasks);
-
-	return n;
-}
-
-static int p9_mux_poll_start(struct p9_conn *m)
-{
-	int i, n;
-	struct p9_mux_poll_task *vpt, *vptlast;
-	struct task_struct *pproc;
-
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, p9_mux_num,
-		p9_mux_poll_task_num);
-	mutex_lock(&p9_mux_task_lock);
-
-	n = p9_mux_calc_poll_procs(p9_mux_num + 1);
-	if (n > p9_mux_poll_task_num) {
-		for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
-			if (p9_mux_poll_tasks[i].task == NULL) {
-				vpt = &p9_mux_poll_tasks[i];
-				P9_DPRINTK(P9_DEBUG_MUX, "create proc %p\n",
-									vpt);
-				pproc = kthread_create(p9_poll_proc, vpt,
-								"v9fs-poll");
-
-				if (!IS_ERR(pproc)) {
-					vpt->task = pproc;
-					INIT_LIST_HEAD(&vpt->mux_list);
-					vpt->muxnum = 0;
-					p9_mux_poll_task_num++;
-					wake_up_process(vpt->task);
-				}
-				break;
-			}
-		}
-
-		if (i >= ARRAY_SIZE(p9_mux_poll_tasks))
-			P9_DPRINTK(P9_DEBUG_ERROR,
-					"warning: no free poll slots\n");
-	}
-
-	n = (p9_mux_num + 1) / p9_mux_poll_task_num +
-	    ((p9_mux_num + 1) % p9_mux_poll_task_num ? 1 : 0);
-
-	vptlast = NULL;
-	for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
-		vpt = &p9_mux_poll_tasks[i];
-		if (vpt->task != NULL) {
-			vptlast = vpt;
-			if (vpt->muxnum < n) {
-				P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
-				list_add(&m->mux_list, &vpt->mux_list);
-				vpt->muxnum++;
-				m->poll_task = vpt;
-				memset(&m->poll_waddr, 0,
-							sizeof(m->poll_waddr));
-				init_poll_funcptr(&m->pt, p9_pollwait);
-				break;
-			}
-		}
-	}
-
-	if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) {
-		if (vptlast == NULL) {
-			mutex_unlock(&p9_mux_task_lock);
-			return -ENOMEM;
-		}
-
-		P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
-		list_add(&m->mux_list, &vptlast->mux_list);
-		vptlast->muxnum++;
-		m->poll_task = vptlast;
-		memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
-		init_poll_funcptr(&m->pt, p9_pollwait);
-	}
-
-	p9_mux_num++;
-	mutex_unlock(&p9_mux_task_lock);
-
-	return 0;
-}
-
-static void p9_mux_poll_stop(struct p9_conn *m)
-{
-	int i;
-	struct p9_mux_poll_task *vpt;
-
-	mutex_lock(&p9_mux_task_lock);
-	vpt = m->poll_task;
-	list_del(&m->mux_list);
-	for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
-		if (m->poll_waddr[i] != NULL) {
-			remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]);
-			m->poll_waddr[i] = NULL;
-		}
-	}
-	vpt->muxnum--;
-	if (!vpt->muxnum) {
-		P9_DPRINTK(P9_DEBUG_MUX, "destroy proc %p\n", vpt);
-		kthread_stop(vpt->task);
-		vpt->task = NULL;
-		p9_mux_poll_task_num--;
-	}
-	p9_mux_num--;
-	mutex_unlock(&p9_mux_task_lock);
-}
-
-/**
- * p9_conn_create - allocate and initialize the per-session mux data
- * Creates the polling task if this is the first session.
- *
- * @trans - transport structure
- * @msize - maximum message size
- * @extended - pointer to the extended flag
- */
-struct p9_conn *p9_conn_create(struct p9_trans *trans, int msize,
-				    unsigned char *extended)
-{
-	int i, n;
-	struct p9_conn *m, *mtmp;
-
-	P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans, msize);
-	m = kmalloc(sizeof(struct p9_conn), GFP_KERNEL);
-	if (!m)
-		return ERR_PTR(-ENOMEM);
-
-	spin_lock_init(&m->lock);
-	INIT_LIST_HEAD(&m->mux_list);
-	m->msize = msize;
-	m->extended = extended;
-	m->trans = trans;
-	m->tagpool = p9_idpool_create();
-	if (IS_ERR(m->tagpool)) {
-		mtmp = ERR_PTR(-ENOMEM);
-		kfree(m);
-		return mtmp;
-	}
-
-	m->err = 0;
-	init_waitqueue_head(&m->equeue);
-	INIT_LIST_HEAD(&m->req_list);
-	INIT_LIST_HEAD(&m->unsent_req_list);
-	m->rcall = NULL;
-	m->rpos = 0;
-	m->rbuf = NULL;
-	m->wpos = m->wsize = 0;
-	m->wbuf = NULL;
-	INIT_WORK(&m->rq, p9_read_work);
-	INIT_WORK(&m->wq, p9_write_work);
-	m->wsched = 0;
-	memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
-	m->poll_task = NULL;
-	n = p9_mux_poll_start(m);
-	if (n) {
-		kfree(m);
-		return ERR_PTR(n);
-	}
-
-	n = trans->poll(trans, &m->pt);
-	if (n & POLLIN) {
-		P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
-		set_bit(Rpending, &m->wsched);
-	}
-
-	if (n & POLLOUT) {
-		P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
-		set_bit(Wpending, &m->wsched);
-	}
-
-	for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
-		if (IS_ERR(m->poll_waddr[i])) {
-			p9_mux_poll_stop(m);
-			mtmp = (void *)m->poll_waddr;	/* the error code */
-			kfree(m);
-			m = mtmp;
-			break;
-		}
-	}
-
-	return m;
-}
-EXPORT_SYMBOL(p9_conn_create);
-
-/**
- * p9_mux_destroy - cancels all pending requests and frees mux resources
- */
-void p9_conn_destroy(struct p9_conn *m)
-{
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
-		m->mux_list.prev, m->mux_list.next);
-	p9_conn_cancel(m, -ECONNRESET);
-
-	if (!list_empty(&m->req_list)) {
-		/* wait until all processes waiting on this session exit */
-		P9_DPRINTK(P9_DEBUG_MUX,
-			"mux %p waiting for empty request queue\n", m);
-		wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
-		P9_DPRINTK(P9_DEBUG_MUX, "mux %p request queue empty: %d\n", m,
-			list_empty(&m->req_list));
-	}
-
-	p9_mux_poll_stop(m);
-	m->trans = NULL;
-	p9_idpool_destroy(m->tagpool);
-	kfree(m);
-}
-EXPORT_SYMBOL(p9_conn_destroy);
-
-/**
- * p9_pollwait - called by files poll operation to add v9fs-poll task
- * 	to files wait queue
- */
-static void
-p9_pollwait(struct file *filp, wait_queue_head_t *wait_address,
-	      poll_table * p)
-{
-	int i;
-	struct p9_conn *m;
-
-	m = container_of(p, struct p9_conn, pt);
-	for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++)
-		if (m->poll_waddr[i] == NULL)
-			break;
-
-	if (i >= ARRAY_SIZE(m->poll_waddr)) {
-		P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
-		return;
-	}
-
-	m->poll_waddr[i] = wait_address;
-
-	if (!wait_address) {
-		P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
-		m->poll_waddr[i] = ERR_PTR(-EIO);
-		return;
-	}
-
-	init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
-	add_wait_queue(wait_address, &m->poll_wait[i]);
-}
-
-/**
- * p9_poll_mux - polls a mux and schedules read or write works if necessary
- */
-static void p9_poll_mux(struct p9_conn *m)
-{
-	int n;
-
-	if (m->err < 0)
-		return;
-
-	n = m->trans->poll(m->trans, NULL);
-	if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
-		P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
-		if (n >= 0)
-			n = -ECONNRESET;
-		p9_conn_cancel(m, n);
-	}
-
-	if (n & POLLIN) {
-		set_bit(Rpending, &m->wsched);
-		P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
-		if (!test_and_set_bit(Rworksched, &m->wsched)) {
-			P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
-			queue_work(p9_mux_wq, &m->rq);
-		}
-	}
-
-	if (n & POLLOUT) {
-		set_bit(Wpending, &m->wsched);
-		P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
-		if ((m->wsize || !list_empty(&m->unsent_req_list))
-		    && !test_and_set_bit(Wworksched, &m->wsched)) {
-			P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
-			queue_work(p9_mux_wq, &m->wq);
-		}
-	}
-}
-
-/**
- * p9_poll_proc - polls all v9fs transports for new events and queues
- * 	the appropriate work to the work queue
- */
-static int p9_poll_proc(void *a)
-{
-	struct p9_conn *m, *mtmp;
-	struct p9_mux_poll_task *vpt;
-
-	vpt = a;
-	P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt);
-	while (!kthread_should_stop()) {
-		set_current_state(TASK_INTERRUPTIBLE);
-
-		list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
-			p9_poll_mux(m);
-		}
-
-		P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
-		schedule_timeout(SCHED_TIMEOUT * HZ);
-	}
-
-	__set_current_state(TASK_RUNNING);
-	P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
-	return 0;
-}
-
-/**
- * p9_write_work - called when a transport can send some data
- */
-static void p9_write_work(struct work_struct *work)
-{
-	int n, err;
-	struct p9_conn *m;
-	struct p9_req *req;
-
-	m = container_of(work, struct p9_conn, wq);
-
-	if (m->err < 0) {
-		clear_bit(Wworksched, &m->wsched);
-		return;
-	}
-
-	if (!m->wsize) {
-		if (list_empty(&m->unsent_req_list)) {
-			clear_bit(Wworksched, &m->wsched);
-			return;
-		}
-
-		spin_lock(&m->lock);
-again:
-		req = list_entry(m->unsent_req_list.next, struct p9_req,
-			       req_list);
-		list_move_tail(&req->req_list, &m->req_list);
-		if (req->err == ERREQFLUSH)
-			goto again;
-
-		m->wbuf = req->tcall->sdata;
-		m->wsize = req->tcall->size;
-		m->wpos = 0;
-		spin_unlock(&m->lock);
-	}
-
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
-								m->wsize);
-	clear_bit(Wpending, &m->wsched);
-	err = m->trans->write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos);
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
-	if (err == -EAGAIN) {
-		clear_bit(Wworksched, &m->wsched);
-		return;
-	}
-
-	if (err < 0)
-		goto error;
-	else if (err == 0) {
-		err = -EREMOTEIO;
-		goto error;
-	}
-
-	m->wpos += err;
-	if (m->wpos == m->wsize)
-		m->wpos = m->wsize = 0;
-
-	if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
-		if (test_and_clear_bit(Wpending, &m->wsched))
-			n = POLLOUT;
-		else
-			n = m->trans->poll(m->trans, NULL);
-
-		if (n & POLLOUT) {
-			P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
-			queue_work(p9_mux_wq, &m->wq);
-		} else
-			clear_bit(Wworksched, &m->wsched);
-	} else
-		clear_bit(Wworksched, &m->wsched);
-
-	return;
-