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>

1 files changed, 0 insertions, 1060 deletions

diff --git a/net/9p/mux.c b/net/9p/mux.c
deleted file mode 100644
index c9f0805..0000000
--- 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);
-}