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>

6 files changed, 1187 insertions, 1145 deletions

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;
-
-error:
-	p9_conn_cancel(m, err);
-	clear_bit(Wworksched, &m->wsched);
-}
-
-static void process_request(struct p9_conn *m, struct p9_req *req)
-{
-	int ecode;
-	struct p9_str *ename;
-
-	if (!req->err && req->rcall->id == P9_RERROR) {
-		ecode = req->rcall->params.rerror.errno;
-		ename = &req->rcall->params.rerror.error;
-
-		P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
-								ename->str);
-
-		if (*m->extended)
-			req->err = -ecode;
-
-		if (!req->err) {
-			req->err = p9_errstr2errno(ename->str, ename->len);
-
-			if (!req->err) {	/* string match failed */
-				PRINT_FCALL_ERROR("unknown error", req->rcall);
-			}
-
-			if (!req->err)
-				req->err = -ESERVERFAULT;
-		}
-	} else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
-		P9_DPRINTK(P9_DEBUG_ERROR,
-				"fcall mismatch: expected %d, got %d\n",
-				req->tcall->id + 1, req->rcall->id);
-		if (!req->err)
-			req->err = -EIO;
-	}
-}
-
-/**
- * p9_read_work - called when there is some data to be read from a transport
- */
-static void p9_read_work(struct work_struct *work)
-{
-	int n, err;
-	struct p9_conn *m;
-	struct p9_req *req, *rptr, *rreq;
-	struct p9_fcall *rcall;
-	char *rbuf;
-
-	m = container_of(work, struct p9_conn, rq);
-
-	if (m->err < 0)
-		return;
-
-	rcall = NULL;
-	P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
-
-	if (!m->rcall) {
-		m->rcall =
-		    kmalloc(sizeof(struct p9_fcall) + m->msize, GFP_KERNEL);
-		if (!m->rcall) {
-			err = -ENOMEM;
-			goto error;
-		}
-
-		m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
-		m->rpos = 0;
-	}
-
-	clear_bit(Rpending, &m->wsched);
-	err = m->trans->read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
-	if (err == -EAGAIN) {
-		clear_bit(Rworksched, &m->wsched);
-		return;
-	}
-
-	if (err <= 0)
-		goto error;
-
-	m->rpos += err;
-	while (m->rpos > 4) {
-		n = le32_to_cpu(*(__le32 *) m->rbuf);
-		if (n >= m->msize) {
-			P9_DPRINTK(P9_DEBUG_ERROR,
-				"requested packet size too big: %d\n", n);
-			err = -EIO;
-			goto error;
-		}
-
-		if (m->rpos < n)
-			break;
-
-		err =
-		    p9_deserialize_fcall(m->rbuf, n, m->rcall, *m->extended);
-		if (err < 0) {
-			goto error;
-		}
-
-#ifdef CONFIG_NET_9P_DEBUG
-		if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
-			char buf[150];
-
-			p9_printfcall(buf, sizeof(buf), m->rcall,
-				*m->extended);
-			printk(KERN_NOTICE ">>> %p %s\n", m, buf);
-		}
-#endif
-
-		rcall = m->rcall;
-		rbuf = m->rbuf;
-		if (m->rpos > n) {
-			m->rcall = kmalloc(sizeof(struct p9_fcall) + m->msize,
-					   GFP_KERNEL);
-			if (!m->rcall) {
-				err = -ENOMEM;
-				goto error;
-			}
-
-			m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
-			memmove(m->rbuf, rbuf + n, m->rpos - n);
-			m->rpos -= n;
-		} else {
-			m->rcall = NULL;
-			m->rbuf = NULL;
-			m->rpos = 0;
-		}
-
-		P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
-							rcall->id, rcall->tag);
-
-		req = NULL;
-		spin_lock(&m->lock);
-		list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
-			if (rreq->tag == rcall->tag) {
-				req = rreq;
-				if (req->flush != Flushing)
-					list_del(&req->req_list);
-				break;
-			}
-		}
-		spin_unlock(&m->lock);
-
-		if (req) {
-			req->rcall = rcall;
-			process_request(m, req);
-
-			if (req->flush != Flushing) {
-				if (req->cb)
-					(*req->cb) (req, req->cba);
-				else
-					kfree(req->rcall);
-
-				wake_up(&m->equeue);
-			}
-		} else {
-			if (err >= 0 && rcall->id != P9_RFLUSH)
-				P9_DPRINTK(P9_DEBUG_ERROR,
-				  "unexpected response mux %p id %d tag %d\n",
-				  m, rcall->id, rcall->tag);
-			kfree(rcall);
-		}
-	}
-
-	if (!list_empty(&m->req_list)) {
-		if (test_and_clear_bit(Rpending, &m->wsched))
-			n = POLLIN;
-		else
-			n = m->trans->poll(m->trans, NULL);
-
-		if (n & POLLIN) {
-			P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
-			queue_work(p9_mux_wq, &m->rq);
-		} else
-			clear_bit(Rworksched, &m->wsched);
-	} else
-		clear_bit(Rworksched, &m->wsched);
-
-	return;
-
-error:
-	p9_conn_cancel(m, err);
-	clear_bit(Rworksched, &m->wsched);
-}
-
-/**
- * p9_send_request - send 9P request
- * The function can sleep until the request is scheduled for sending.
- * The function can be interrupted. Return from the function is not
- * a guarantee that the request is sent successfully. Can return errors
- * that can be retrieved by PTR_ERR macros.
- *
- * @m: mux data
- * @tc: request to be sent
- * @cb: callback function to call when response is received
- * @cba: parameter to pass to the callback function
- */
-static struct p9_req *p9_send_request(struct p9_conn *m,
-					  struct p9_fcall *tc,
-					  p9_conn_req_callback cb, void *cba)
-{
-	int n;
-	struct p9_req *req;
-
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
-		tc, tc->id);
-	if (m->err < 0)
-		return ERR_PTR(m->err);
-
-	req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
-	if (!req)
-		return ERR_PTR(-ENOMEM);
-
-	if (tc->id == P9_TVERSION)
-		n = P9_NOTAG;
-	else
-		n = p9_mux_get_tag(m);
-
-	if (n < 0)
-		return ERR_PTR(-ENOMEM);
-
-	p9_set_tag(tc, n);
-
-#ifdef CONFIG_NET_9P_DEBUG
-	if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
-		char buf[150];
-
-		p9_printfcall(buf, sizeof(buf), tc, *m->extended);
-		printk(KERN_NOTICE "<<< %p %s\n", m, buf);
-	}
-#endif
-
-	spin_lock_init(&req->lock);
-	req->tag = n;
-	req->tcall = tc;
-	req->rcall = NULL;
-	req->err = 0;
-	req->cb = cb;
-	req->cba = cba;
-	req->flush = None;
-
-	spin_lock(&m->lock);
-	list_add_tail(&req->req_list, &m->unsent_req_list);
-	spin_unlock(&m->lock);
-
-	if (test_and_clear_bit(Wpending, &m->wsched))
-		n = POLLOUT;
-	else
-		n = m->trans->poll(m->trans, NULL);
-
-	if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
-		queue_work(p9_mux_wq, &m->wq);
-
-	return req;
-}
-
-static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
-{
-	p9_mux_put_tag(m, req->tag);
-	kfree(req);
-}
-
-static void p9_mux_flush_cb(struct p9_req *freq, void *a)
-{
-	p9_conn_req_callback cb;
-	int tag;
-	struct p9_conn *m;
-	struct p9_req *req, *rreq, *rptr;
-
-	m = a;
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
-		freq->tcall, freq->rcall, freq->err,
-		freq->tcall->params.tflush.oldtag);
-
-	spin_lock(&m->lock);
-	cb = NULL;
-	tag = freq->tcall->params.tflush.oldtag;
-	req = NULL;
-	list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
-		if (rreq->tag == tag) {
-			req = rreq;
-			list_del(&req->req_list);
-			break;
-		}
-	}
-	spin_unlock(&m->lock);
-
-	if (req) {
-		spin_lock(&req->lock);
-		req->flush = Flushed;
-		spin_unlock(&req->lock);
-
-		if (req->cb)
-			(*req->cb) (req, req->cba);
-		else
-			kfree(req->rcall);
-
-		wake_up(&m->equeue);
-	}
-
-	kfree(freq->tcall);
-	kfree(freq->rcall);
-	p9_mux_free_request(m, freq);
-}
-
-static int
-p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
-{
-	struct p9_fcall *fc;
-	struct p9_req *rreq, *rptr;
-
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
-
-	/* if a response was received for a request, do nothing */
-	spin_lock(&req->lock);
-	if (req->rcall || req->err) {
-		spin_unlock(&req->lock);
-		P9_DPRINTK(P9_DEBUG_MUX,
-			"mux %p req %p response already received\n", m, req);
-		return 0;
-	}
-
-	req->flush = Flushing;
-	spin_unlock(&req->lock);
-
-	spin_lock(&m->lock);
-	/* if the request is not sent yet, just remove it from the list */
-	list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
-		if (rreq->tag == req->tag) {
-			P9_DPRINTK(P9_DEBUG_MUX,
-			   "mux %p req %p request is not sent yet\n", m, req);
-			list_del(&rreq->req_list);
-			req->flush = Flushed;
-			spin_unlock(&m->lock);
-			if (req->cb)
-				(*req->cb) (req, req->cba);
-			return 0;
-		}
-	}
-	spin_unlock(&m->lock);
-
-	clear_thread_flag(TIF_SIGPENDING);
-	fc = p9_create_tflush(req->tag);
-	p9_send_request(m, fc, p9_mux_flush_cb, m);
-	return 1;
-}
-
-static void
-p9_conn_rpc_cb(struct p9_req *req, void *a)
-{
-	struct p9_mux_rpc *r;
-
-	P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
-	r = a;
-	r->rcall = req->rcall;
-	r->err = req->err;
-
-	if (req->flush != None && !req->err)
-		r->err = -ERESTARTSYS;
-
-	wake_up(&r->wqueue);
-}
-
-/**
- * p9_mux_rpc - sends 9P request and waits until a response is available.
- *	The function can be interrupted.
- * @m: mux data
- * @tc: request to be sent
- * @rc: pointer where a pointer to the response is stored
- */
-int
-p9_conn_rpc(struct p9_conn *m, struct p9_fcall *tc,
-	     struct p9_fcall **rc)
-{
-	int err, sigpending;
-	unsigned long flags;
-	struct p9_req *req;
-	struct p9_mux_rpc r;
-
-	r.err = 0;
-	r.tcall = tc;
-	r.rcall = NULL;
-	r.m = m;
-	init_waitqueue_head(&r.wqueue);
-
-	if (rc)
-		*rc = NULL;
-
-	sigpending = 0;
-	if (signal_pending(current)) {
-		sigpending = 1;
-		clear_thread_flag(TIF_SIGPENDING);
-	}
-
-	req = p9_send_request(m, tc, p9_conn_rpc_cb, &r);
-	if (IS_ERR(req)) {
-		err = PTR_ERR(req);
-		P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
-		return err;
-	}
-
-	err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0);
-	if (r.err < 0)
-		err = r.err;
-
-	if (err == -ERESTARTSYS && m->trans->status == Connected
-							&& m->err == 0) {
-		if (p9_mux_flush_request(m, req)) {
-			/* wait until we get response of the flush message */
-			do {
-				clear_thread_flag(TIF_SIGPENDING);
-				err = wait_event_interruptible(r.wqueue,
-					r.rcall || r.err);
-			} while (!r.rcall && !r.err && err == -ERESTARTSYS &&
-				m->trans->status == Connected && !m->err);
-
-			err = -ERESTARTSYS;
-		}
-		sigpending = 1;
-	}
-
-	if (sigpending) {
-		spin_lock_irqsave(&current->sighand->siglock, flags);
-		recalc_sigpending();
-		spin_unlock_irqrestore(&current->sighand->siglock, flags);
-	}
-
-	if (rc)
-		*rc = r.rcall;
-	else
-		kfree(r.rcall);
-
-	p9_mux_free_request(m, req);
-	if (err > 0)
-		err = -EIO;
-
-	return err;
-}
-EXPORT_SYMBOL(p9_conn_rpc);
-
-#ifdef P9_NONBLOCK
-/**
- * p9_conn_rpcnb - sends 9P request without waiting for response.
- * @m: mux data
- * @tc: request to be sent
- * @cb: callback function to be called when response arrives
- * @cba: value to pass to the callback function
- */
-int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
-		   p9_conn_req_callback cb, void *a)
-{
-	int err;
-	struct p9_req *req;
-
-	req = p9_send_request(m, tc, cb, a);
-	if (IS_ERR(req)) {
-		err = PTR_ERR(req);
-		P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
-		return PTR_ERR(req);
-	}
-
-	P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
-	return 0;
-}
-EXPORT_SYMBOL(p9_conn_rpcnb);
-#endif /* P9_NONBLOCK */
-
-/**
- * p9_conn_cancel - cancel all pending requests with error
- * @m: mux data
- * @err: error code
- */
-void p9_conn_cancel(struct p9_conn *m, int err)
-{
-	struct p9_req *req, *rtmp;
-	LIST_HEAD(cancel_list);
-
-	P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
-	m->err = err;
-	spin_lock(&m->lock);
-	list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
-		list_move(&req->req_list, &cancel_list);
-	}
-	list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
-		list_move(&req->req_list, &cancel_list);
-	}
-	spin_unlock(&m->lock);
-
-	list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
-		list_del(&req->req_list);
-		if (!req->err)
-			req->err = err;
-
-		if (req->cb)
-			(*req->cb) (req, req->cba);
-		else
-			kfree(req->rcall);
-	}
-
-	wake_up(&m->equeue);
-}
-EXPORT_SYMBOL(p9_conn_cancel);
-
-static u16 p9_mux_get_tag(struct p9_conn *m)
-{
-	int tag;
-
-	tag = p9_idpool_get(m->tagpool);
-	if (tag < 0)
-		return P9_NOTAG;
-	else
-		return (u16) tag;
-}
-
-static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
-{
-	if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool))
-		p9_idpool_put(tag, m->tagpool);
-}
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 62332ed9da4a..1aa9d5175398 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -5,7 +5,7 @@
  *
  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
- *  Copyright (C) 2004-2007 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  *
  *  This program is free software; you can redistribute it and/or modify
@@ -29,6 +29,7 @@
 #include <linux/module.h>
 #include <linux/net.h>
 #include <linux/ipv6.h>
+#include <linux/kthread.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/un.h>
@@ -42,7 +43,9 @@
 
 #define P9_PORT 564
 #define MAX_SOCK_BUF (64*1024)
-
+#define ERREQFLUSH	1
+#define SCHED_TIMEOUT	10
+#define MAXPOLLWADDR	2
 
 struct p9_fd_opts {
 	int rfd;
@@ -53,6 +56,7 @@ struct p9_fd_opts {
 struct p9_trans_fd {
 	struct file *rd;
 	struct file *wr;
+	struct p9_conn *conn;
 };
 
 /*
@@ -72,6 +76,1028 @@ static match_table_t tokens = {
 	{Opt_err, NULL},
 };
 
+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_req;
+
+typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
+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_mux_poll_task;
+
+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 int p9_fd_write(struct p9_trans *trans, void *v, int len);
+static int p9_fd_read(struct p9_trans *trans, void *v, int len);
+
+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];
+
+static void p9_conn_destroy(struct p9_conn *);
+static unsigned int p9_fd_poll(struct p9_trans *trans,
+						struct poll_table_struct *pt);
+
+#ifdef P9_NONBLOCK
+static int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
+	p9_conn_req_callback cb, void *a);
+#endif /* P9_NONBLOCK */
+
+static void p9_conn_cancel(struct p9_conn *m, int err);
+
+static 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;
+}
+
+static u16 p9_mux_get_tag(struct p9_conn *m)
+{
+	int tag;
+
+	tag = p9_idpool_get(m->tagpool);
+	if (tag < 0)
+		return P9_NOTAG;
+	else
+		return (u16) tag;
+}
+
+static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
+{
+	if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool))
+		p9_idpool_put(tag, m->tagpool);
+}
+
+/**
+ * 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 - extended flag
+ */
+static struct p9_conn *p9_conn_create(struct p9_trans *trans)
+{
+	int i, n;
+	struct p9_conn *m, *mtmp;
+
+	P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans,
+								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 = trans->msize;
+	m->extended = trans->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 = p9_fd_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;
+}
+
+/**
+ * p9_mux_destroy - cancels all pending requests and frees mux resources
+ */
+static 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);
+}
+
+/**
+ * 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 = p9_fd_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 = p9_fd_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 = p9_fd_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;
+
+error:
+	p9_conn_cancel(m, err);
+	clear_bit(Wworksched, &m->wsched);
+}
+
+static void process_request(struct p9_conn *m, struct p9_req *req)
+{
+	int ecode;
+	struct p9_str *ename;
+
+	if (!req->err && req->rcall->id == P9_RERROR) {
+		ecode = req->rcall->params.rerror.errno;
+		ename = &req->rcall->params.rerror.error;
+
+		P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
+								ename->str);
+
+		if (m->extended)
+			req->err = -ecode;
+
+		if (!req->err) {
+			req->err = p9_errstr2errno(ename->str, ename->len);
+
+			/* string match failed */
+			if (!req->err) {
+				PRINT_FCALL_ERROR("unknown error", req->rcall);
+				req->err = -ESERVERFAULT;
+			}
+		}
+	} else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
+		P9_DPRINTK(P9_DEBUG_ERROR,
+				"fcall mismatch: expected %d, got %d\n",
+				req->tcall->id + 1, req->rcall->id);
+		if (!req->err)
+			req->err = -EIO;
+	}
+}
+
+/**
+ * p9_read_work - called when there is some data to be read from a transport
+ */
+static void p9_read_work(struct work_struct *work)
+{
+	int n, err;
+	struct p9_conn *m;
+	struct p9_req *req, *rptr, *rreq;
+	struct p9_fcall *rcall;
+	char *rbuf;
+
+	m = container_of(work, struct p9_conn, rq);
+
+	if (m->err < 0)
+		return;
+
+	rcall = NULL;
+	P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
+
+	if (!m->rcall) {
+		m->rcall =
+		    kmalloc(sizeof(struct p9_fcall) + m->msize, GFP_KERNEL);
+		if (!m->rcall) {
+			err = -ENOMEM;
+			goto error;
+		}
+
+		m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
+		m->rpos = 0;
+	}
+
+	clear_bit(Rpending, &m->wsched);
+	err = p9_fd_read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
+	P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
+	if (err == -EAGAIN) {
+		clear_bit(Rworksched, &m->wsched);
+		return;
+	}
+
+	if (err <= 0)
+		goto error;
+
+	m->rpos += err;
+	while (m->rpos > 4) {
+		n = le32_to_cpu(*(__le32 *) m->rbuf);
+		if (n >= m->msize) {
+			P9_DPRINTK(P9_DEBUG_ERROR,
+				"requested packet size too big: %d\n", n);
+			err = -EIO;
+			goto error;
+		}
+
+		if (m->rpos < n)
+			break;
+
+		err =
+		    p9_deserialize_fcall(m->rbuf, n, m->rcall, m->extended);
+		if (err < 0)
+			goto error;
+
+#ifdef CONFIG_NET_9P_DEBUG
+		if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
+			char buf[150];
+
+			p9_printfcall(buf, sizeof(buf), m->rcall,
+				m->extended);
+			printk(KERN_NOTICE ">>> %p %s\n", m, buf);
+		}
+#endif
+
+		rcall = m->rcall;
+		rbuf = m->rbuf;
+		if (m->rpos > n) {
+			m->rcall = kmalloc(sizeof(struct p9_fcall) + m->msize,
+					   GFP_KERNEL);
+			if (!m->rcall) {
+				err = -ENOMEM;
+				goto error;
+			}
+
+			m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
+			memmove(m->rbuf, rbuf + n, m->rpos - n);
+			m->rpos -= n;
+		} else {
+			m->rcall = NULL;
+			m->rbuf = NULL;
+			m->rpos = 0;
+		}
+
+		P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
+							rcall->id, rcall->tag);
+
+		req = NULL;
+		spin_lock(&m->lock);
+		list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
+			if (rreq->tag == rcall->tag) {
+				req = rreq;
+				if (req->flush != Flushing)
+					list_del(&req->req_list);
+				break;
+			}
+		}
+		spin_unlock(&m->lock);
+
+		if (req) {
+			req->rcall = rcall;
+			process_request(m, req);
+
+			if (req->flush != Flushing) {
+				if (req->cb)
+					(*req->cb) (req, req->cba);
+				else
+					kfree(req->rcall);
+
+				wake_up(&m->equeue);
+			}
+		} else {
+			if (err >= 0 && rcall->id != P9_RFLUSH)
+				P9_DPRINTK(P9_DEBUG_ERROR,
+				  "unexpected response mux %p id %d tag %d\n",
+				  m, rcall->id, rcall->tag);
+			kfree(rcall);
+		}
+	}
+
+	if (!list_empty(&m->req_list)) {
+		if (test_and_clear_bit(Rpending, &m->wsched))
+			n = POLLIN;
+		else
+			n = p9_fd_poll(m->trans, NULL);
+
+		if (n & POLLIN) {
+			P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
+			queue_work(p9_mux_wq, &m->rq);
+		} else
+			clear_bit(Rworksched, &m->wsched);
+	} else
+		clear_bit(Rworksched, &m->wsched);
+
+	return;
+
+error:
+	p9_conn_cancel(m, err);
+	clear_bit(Rworksched, &m->wsched);
+}
+
+/**
+ * p9_send_request - send 9P request
+ * The function can sleep until the request is scheduled for sending.
+ * The function can be interrupted. Return from the function is not
+ * a guarantee that the request is sent successfully. Can return errors
+ * that can be retrieved by PTR_ERR macros.
+ *
+ * @m: mux data
+ * @tc: request to be sent
+ * @cb: callback function to call when response is received
+ * @cba: parameter to pass to the callback function
+ */
+static struct p9_req *p9_send_request(struct p9_conn *m,
+					  struct p9_fcall *tc,
+					  p9_conn_req_callback cb, void *cba)
+{
+	int n;
+	struct p9_req *req;
+
+	P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
+		tc, tc->id);
+	if (m->err < 0)
+		return ERR_PTR(m->err);
+
+	req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	if (tc->id == P9_TVERSION)
+		n = P9_NOTAG;
+	else
+		n = p9_mux_get_tag(m);
+
+	if (n < 0)
+		return ERR_PTR(-ENOMEM);
+
+	p9_set_tag(tc, n);
+
+#ifdef CONFIG_NET_9P_DEBUG
+	if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
+		char buf[150];
+
+		p9_printfcall(buf, sizeof(buf), tc, m->extended);
+		printk(KERN_NOTICE "<<< %p %s\n", m, buf);
+	}
+#endif
+
+	spin_lock_init(&req->lock);
+	req->tag = n;
+	req->tcall = tc;
+	req->rcall = NULL;
+	req->err = 0;
+	req->cb = cb;
+	req->cba = cba;
+	req->flush = None;
+
+	spin_lock(&m->lock);
+	list_add_tail(&req->req_list, &m->unsent_req_list);
+	spin_unlock(&m->lock);
+
+	if (test_and_clear_bit(Wpending, &m->wsched))
+		n = POLLOUT;
+	else
+		n = p9_fd_poll(m->trans, NULL);
+
+	if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
+		queue_work(p9_mux_wq, &m->wq);
+
+	return req;
+}
+
+static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
+{
+	p9_mux_put_tag(m, req->tag);
+	kfree(req);
+}
+
+static void p9_mux_flush_cb(struct p9_req *freq, void *a)
+{
+	p9_conn_req_callback cb;
+	int tag;
+	struct p9_conn *m;
+	struct p9_req *req, *rreq, *rptr;
+
+	m = a;
+	P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
+		freq->tcall, freq->rcall, freq->err,
+		freq->tcall->params.tflush.oldtag);
+
+	spin_lock(&m->lock);
+	cb = NULL;
+	tag = freq->tcall->params.tflush.oldtag;
+	req = NULL;
+	list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
+		if (rreq->tag == tag) {
+			req = rreq;
+			list_del(&req->req_list);
+			break;
+		}
+	}
+	spin_unlock(&m->lock);
+
+	if (req) {
+		spin_lock(&req->lock);
+		req->flush = Flushed;
+		spin_unlock(&req->lock);
+
+		if (req->cb)
+			(*req->cb) (req, req->cba);
+		else
+			kfree(req->rcall);
+
+		wake_up(&m->equeue);
+	}
+
+	kfree(freq->tcall);
+	kfree(freq->rcall);
+	p9_mux_free_request(m, freq);
+}
+
+static int
+p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
+{
+	struct p9_fcall *fc;
+	struct p9_req *rreq, *rptr;
+
+	P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
+
+	/* if a response was received for a request, do nothing */
+	spin_lock(&req->lock);
+	if (req->rcall || req->err) {
+		spin_unlock(&req->lock);
+		P9_DPRINTK(P9_DEBUG_MUX,
+			"mux %p req %p response already received\n", m, req);
+		return 0;
+	}
+
+	req->flush = Flushing;
+	spin_unlock(&req->lock);
+
+	spin_lock(&m->lock);
+	/* if the request is not sent yet, just remove it from the list */
+	list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
+		if (rreq->tag == req->tag) {
+			P9_DPRINTK(P9_DEBUG_MUX,
+			   "mux %p req %p request is not sent yet\n", m, req);
+			list_del(&rreq->req_list);
+			req->flush = Flushed;
+			spin_unlock(&m->lock);
+			if (req->cb)
+				(*req->cb) (req, req->cba);
+			return 0;
+		}
+	}
+	spin_unlock(&m->lock);
+
+	clear_thread_flag(TIF_SIGPENDING);
+	fc = p9_create_tflush(req->tag);
+	p9_send_request(m, fc, p9_mux_flush_cb, m);
+	return 1;
+}
+
+static void
+p9_conn_rpc_cb(struct p9_req *req, void *a)
+{
+	struct p9_mux_rpc *r;
+
+	P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
+	r = a;
+	r->rcall = req->rcall;
+	r->err = req->err;
+
+	if (req->flush != None && !req->err)
+		r->err = -ERESTARTSYS;
+
+	wake_up(&r->wqueue);
+}
+
+/**
+ * p9_fd_rpc- sends 9P request and waits until a response is available.
+ *	The function can be interrupted.
+ * @m: mux data
+ * @tc: request to be sent
+ * @rc: pointer where a pointer to the response is stored
+ */
+int
+p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
+{
+	struct p9_trans_fd *p = t->priv;
+	struct p9_conn *m = p->conn;
+	int err, sigpending;
+	unsigned long flags;
+	struct p9_req *req;
+	struct p9_mux_rpc r;
+
+	r.err = 0;
+	r.tcall = tc;
+	r.rcall = NULL;
+	r.m = m;
+	init_waitqueue_head(&r.wqueue);
+
+	if (rc)
+		*rc = NULL;
+
+	sigpending = 0;
+	if (signal_pending(current)) {
+		sigpending = 1;
+		clear_thread_flag(TIF_SIGPENDING);
+	}
+
+	req = p9_send_request(m, tc, p9_conn_rpc_cb, &r);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
+		return err;
+	}
+
+	err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0);
+	if (r.err < 0)
+		err = r.err;
+
+	if (err == -ERESTARTSYS && m->trans->status == Connected
+							&& m->err == 0) {
+		if (p9_mux_flush_request(m, req)) {
+			/* wait until we get response of the flush message */
+			do {
+				clear_thread_flag(TIF_SIGPENDING);
+				err = wait_event_interruptible(r.wqueue,
+					r.rcall || r.err);
+			} while (!r.rcall && !r.err && err == -ERESTARTSYS &&
+				m->trans->status == Connected && !m->err);
+
+			err = -ERESTARTSYS;
+		}
+		sigpending = 1;
+	}
+
+	if (sigpending) {
+		spin_lock_irqsave(&current->sighand->siglock, flags);
+		recalc_sigpending();
+		spin_unlock_irqrestore(&current->sighand->siglock, flags);
+	}
+
+	if (rc)
+		*rc = r.rcall;
+	else
+		kfree(r.rcall);
+
+	p9_mux_free_request(m, req);
+	if (err > 0)
+		err = -EIO;
+
+	return err;
+}
+
+#ifdef P9_NONBLOCK
+/**
+ * p9_conn_rpcnb - sends 9P request without waiting for response.
+ * @m: mux data
+ * @tc: request to be sent
+ * @cb: callback function to be called when response arrives
+ * @cba: value to pass to the callback function
+ */
+int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
+		   p9_conn_req_callback cb, void *a)
+{
+	int err;
+	struct p9_req *req;
+
+	req = p9_send_request(m, tc, cb, a);
+	if (IS_ERR(req)) {
+		err = PTR_ERR(req);
+		P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
+		return PTR_ERR(req);
+	}
+
+	P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
+	return 0;
+}
+#endif /* P9_NONBLOCK */
+
+/**
+ * p9_conn_cancel - cancel all pending requests with error
+ * @m: mux data
+ * @err: error code
+ */
+void p9_conn_cancel(struct p9_conn *m, int err)
+{
+	struct p9_req *req, *rtmp;
+	LIST_HEAD(cancel_list);
+
+	P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
+	m->err = err;
+	spin_lock(&m->lock);
+	list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
+		list_move(&req->req_list, &cancel_list);
+	}
+	list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
+		list_move(&req->req_list, &cancel_list);
+	}
+	spin_unlock(&m->lock);
+
+	list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
+		list_del(&req->req_list);
+		if (!req->err)
+			req->err = err;
+
+		if (req->cb)
+			(*req->cb) (req, req->cba);
+		else
+			kfree(req->rcall);
+	}
+
+	wake_up(&m->equeue);
+}
+
 /**
  * v9fs_parse_options - parse mount options into session structure
  * @options: options string passed from mount
@@ -268,7 +1294,7 @@ end:
 }
 
 /**
- * p9_sock_close - shutdown socket
+ * p9_fd_close - shutdown socket
  * @trans: private socket structure
  *
  */
@@ -284,6 +1310,8 @@ static void p9_fd_close(struct p9_trans *trans)
 	if (!ts)
 		return;
 
+	p9_conn_destroy(ts->conn);
+
 	trans->status = Disconnected;
 	if (ts->rd)
 		fput(ts->rd);
@@ -292,13 +1320,15 @@ static void p9_fd_close(struct p9_trans *trans)
 	kfree(ts);
 }
 
-static struct p9_trans *p9_trans_create_tcp(const char *addr, char *args)
+static struct p9_trans *
+p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
 {
 	int err;
 	struct p9_trans *trans;
 	struct socket *csocket;
 	struct sockaddr_in sin_server;
 	struct p9_fd_opts opts;
+	struct p9_trans_fd *p;
 
 	parse_opts(args, &opts);
 
@@ -306,11 +1336,10 @@ static struct p9_trans *p9_trans_create_tcp(const char *addr, char *args)
 	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
 	if (!trans)
 		return ERR_PTR(-ENOMEM);
-
-	trans->write = p9_fd_write;
-	trans->read = p9_fd_read;
+	trans->msize = msize;
+	trans->extended = dotu;
+	trans->rpc = p9_fd_rpc;
 	trans->close = p9_fd_close;
-	trans->poll = p9_fd_poll;
 
 	sin_server.sin_family = AF_INET;
 	sin_server.sin_addr.s_addr = in_aton(addr);
@@ -337,6 +1366,14 @@ static struct p9_trans *p9_trans_create_tcp(const char *addr, char *args)
 	if (err < 0)
 		goto error;
 
+	p = (struct p9_trans_fd *) trans->priv;
+	p->conn = p9_conn_create(trans);
+	if (IS_ERR(p->conn)) {
+		err = PTR_ERR(p->conn);
+		p->conn = NULL;
+		goto error;
+	}
+
 	return trans;
 
 error:
@@ -347,22 +1384,23 @@ error:
 	return ERR_PTR(err);
 }
 
-static struct p9_trans *p9_trans_create_unix(const char *addr, char *args)
+static struct p9_trans *
+p9_trans_create_unix(const char *addr, char *args, int msize,
+							unsigned char dotu)
 {
 	int err;
 	struct socket *csocket;
 	struct sockaddr_un sun_server;
 	struct p9_trans *trans;
+	struct p9_trans_fd *p;
 
 	csocket = NULL;
 	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
 	if (!trans)
 		return ERR_PTR(-ENOMEM);
 
-	trans->write = p9_fd_write;
-	trans->read = p9_fd_read;
+	trans->rpc = p9_fd_rpc;
 	trans->close = p9_fd_close;
-	trans->poll = p9_fd_poll;
 
 	if (strlen(addr) > UNIX_PATH_MAX) {
 		P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
@@ -387,6 +1425,16 @@ static struct p9_trans *p9_trans_create_unix(const char *addr, char *args)
 	if (err < 0)
 		goto error;
 
+	trans->msize = msize;
+	trans->extended = dotu;
+	p = (struct p9_trans_fd *) trans->priv;
+	p->conn = p9_conn_create(trans);
+	if (IS_ERR(p->conn)) {
+		err = PTR_ERR(p->conn);
+		p->conn = NULL;
+		goto error;
+	}
+
 	return trans;
 
 error:
@@ -397,11 +1445,14 @@ error:
 	return ERR_PTR(err);
 }
 
-static struct p9_trans *p9_trans_create_fd(const char *name, char *args)
+static struct p9_trans *
+p9_trans_create_fd(const char *name, char *args, int msize,
+							unsigned char extended)
 {
 	int err;
 	struct p9_trans *trans;
 	struct p9_fd_opts opts;
+	struct p9_trans_fd *p;
 
 	parse_opts(args, &opts);
 
@@ -414,15 +1465,23 @@ static struct p9_trans *p9_trans_create_fd(const char *name, char *args)
 	if (!trans)
 		return ERR_PTR(-ENOMEM);
 
-	trans->write = p9_fd_write;
-	trans->read = p9_fd_read;
+	trans->rpc = p9_fd_rpc;
 	trans->close = p9_fd_close;
-	trans->poll = p9_fd_poll;
 
 	err = p9_fd_open(trans, opts.rfd, opts.wfd);
 	if (err < 0)
 		goto error;
 
+	trans->msize = msize;
+	trans->extended = extended;
+	p = (struct p9_trans_fd *) trans->priv;
+	p->conn = p9_conn_create(trans);
+	if (IS_ERR(p->conn)) {
+		err = PTR_ERR(p->conn);
+		p->conn = NULL;
+		goto error;
+	}
+
 	return trans;
 
 error:
@@ -453,6 +1512,12 @@ static struct p9_trans_module p9_fd_trans = {
 
 static int __init p9_trans_fd_init(void)
 {
+	int ret = p9_mux_global_init();
+	if (ret) {
+		printk(KERN_WARNING "9p: starting mux failed\n");
+		return ret;
+	}
+
 	v9fs_register_trans(&p9_tcp_trans);
 	v9fs_register_trans(&p9_unix_trans);
 	v9fs_register_trans(&p9_fd_trans);
@@ -460,13 +1525,7 @@ static int __init p9_trans_fd_init(void)
 	return 1;
 }
 
-static void __exit p9_trans_fd_exit(void) {
-	printk(KERN_ERR "Removal of 9p transports not implemented\n");
-	BUG();
-}
-
 module_init(p9_trans_fd_init);
-module_exit(p9_trans_fd_exit);
 
 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index c957080966b4..0117b9fb8480 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -130,29 +130,6 @@ static unsigned int rest_of_page(void *data)
 	return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
 }
 
-static int p9_virtio_write(struct p9_trans *trans, void *buf, int count)
-{
-	/* Only use the rpc mechanism for now */
-	return count;
-}
-
-static int p9_virtio_read(struct p9_trans *trans, void *buf, int count)
-{
-	/* Only use the rpc mechanism for now */
-	return 0;
-}
-
-/* The poll function is used by 9p transports to determine if there
- * is there is activity available on a particular channel.  In our case
- * we use it to wait for a callback from the input routines.
- */
-static unsigned int
-p9_virtio_poll(struct p9_trans *trans, struct poll_table_struct *pt)
-{
-	/* Only use the rpc mechanism for now */
-	return 0;
-}
-
 static void p9_virtio_close(struct p9_trans *trans)
 {
 	struct virtio_chan *chan = trans->priv;
@@ -214,8 +191,7 @@ pack_sg_list(struct scatterlist *sg, int start, int limit, char *data,
 }
 
 static int
-p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc,
-		int msize, int dotu)
+p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
 {
 	int in, out;
 	int n, err, size;
@@ -225,7 +201,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc,
 	unsigned long flags;
 
 	if (*rc == NULL) {
-		*rc = kmalloc(sizeof(struct p9_fcall) + msize, GFP_KERNEL);
+		*rc = kmalloc(sizeof(struct p9_fcall) + t->msize, GFP_KERNEL);
 		if (!*rc)
 			return -ENOMEM;
 	}
@@ -248,7 +224,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc,
 	P9_DPRINTK(P9_DEBUG_TRANS, "9p debug: virtio rpc tag %d\n", n);
 
 	out = pack_sg_list(chan->sg, 0, VIRTQUEUE_NUM, tc->sdata, tc->size);
-	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, msize);
+	in = pack_sg_list(chan->sg, out, VIRTQUEUE_NUM-out, rdata, t->msize);
 
 	req->status = REQ_STATUS_SENT;
 
@@ -264,7 +240,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc,
 
 	size = le32_to_cpu(*(__le32 *) rdata);
 
-	err = p9_deserialize_fcall(rdata, size, *rc, dotu);
+	err = p9_deserialize_fcall(rdata, size, *rc, t->extended);
 	if (err < 0) {
 		P9_DPRINTK(P9_DEBUG_TRANS,
 			"9p debug: virtio rpc deserialize returned %d\n", err);
@@ -275,7 +251,7 @@ p9_virtio_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc,
 	if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 		char buf[150];
 
-		p9_printfcall(buf, sizeof(buf), *rc, dotu);
+		p9_printfcall(buf, sizeof(buf), *rc, t->extended);
 		printk(KERN_NOTICE ">>> %p %s\n", t, buf);
 	}
 #endif
@@ -337,7 +313,9 @@ fail:
  * alternate channels by matching devname versus a virtio_config entry.
  * We use a simple reference count mechanism to ensure that only a single
  * mount has a channel open at a time. */
-static struct p9_trans *p9_virtio_create(const char *devname, char *args)
+static struct p9_trans *
+p9_virtio_create(const char *devname, char *args, int msize,
+							unsigned char extended)
 {
 	struct p9_trans *trans;
 	struct virtio_chan *chan = channels;
@@ -374,11 +352,9 @@ static struct p9_trans *p9_virtio_create(const char *devname, char *args)
 		printk(KERN_ERR "9p: couldn't allocate transport\n");
 		return ERR_PTR(-ENOMEM);
 	}
-
-	trans->write = p9_virtio_write;
-	trans->read = p9_virtio_read;
+	trans->extended = extended;
+	trans->msize = msize;
 	trans->close = p9_virtio_close;
-	trans->poll = p9_virtio_poll;
 	trans->rpc = p9_virtio_rpc;
 	trans->priv = chan;