trans_fd.c 35.4 KB
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/*
 * linux/fs/9p/trans_fd.c
 *
 * Fd transport layer.  Includes deprecated socket layer.
 *
 *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
 *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
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 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
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 *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.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
 *
 */

#include <linux/in.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.h>
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#include <linux/kthread.h>
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#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/un.h>
#include <linux/uaccess.h>
#include <linux/inet.h>
#include <linux/idr.h>
#include <linux/file.h>
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#include <linux/parser.h>
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#include <net/9p/9p.h>
#include <net/9p/transport.h>

#define P9_PORT 564
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#define MAX_SOCK_BUF (64*1024)
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#define ERREQFLUSH	1
#define SCHED_TIMEOUT	10
#define MAXPOLLWADDR	2
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/**
 * struct p9_fd_opts - per-transport options
 * @rfd: file descriptor for reading (trans=fd)
 * @wfd: file descriptor for writing (trans=fd)
 * @port: port to connect to (trans=tcp)
 *
 */

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struct p9_fd_opts {
	int rfd;
	int wfd;
	u16 port;
};
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/**
 * struct p9_trans_fd - transport state
 * @rd: reference to file to read from
 * @wr: reference of file to write to
 * @conn: connection state reference
 *
 */

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struct p9_trans_fd {
	struct file *rd;
	struct file *wr;
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	struct p9_conn *conn;
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};

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/*
  * Option Parsing (code inspired by NFS code)
  *  - a little lazy - parse all fd-transport options
  */
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enum {
	/* Options that take integer arguments */
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	Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
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};
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static match_table_t tokens = {
	{Opt_port, "port=%u"},
	{Opt_rfdno, "rfdno=%u"},
	{Opt_wfdno, "wfdno=%u"},
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	{Opt_err, NULL},
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};
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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);
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/**
 * struct p9_req - fd mux encoding of an rpc transaction
 * @lock: protects req_list
 * @tag: numeric tag for rpc transaction
 * @tcall: request &p9_fcall structure
 * @rcall: response &p9_fcall structure
 * @err: error state
 * @cb: callback for when response is received
 * @cba: argument to pass to callback
 * @flush: flag to indicate RPC has been flushed
 * @req_list: list link for higher level objects to chain requests
 *
 */

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struct p9_req {
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	spinlock_t lock;
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	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;
};

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struct p9_mux_poll_task {
	struct task_struct *task;
	struct list_head mux_list;
	int muxnum;
};

/**
 * struct p9_conn - fd mux connection state information
 * @lock: protects mux_list (?)
 * @mux_list: list link for mux to manage multiple connections (?)
 * @poll_task: task polling on this connection
 * @msize: maximum size for connection (dup)
 * @extended: 9p2000.u flag (dup)
 * @trans: reference to transport instance for this connection
 * @tagpool: id accounting for transactions
 * @err: error state
 * @equeue: event wait_q (?)
 * @req_list: accounting for requests which have been sent
 * @unsent_req_list: accounting for requests that haven't been sent
 * @rcall: current response &p9_fcall structure
 * @rpos: read position in current frame
 * @rbuf: current read buffer
 * @wpos: write position for current frame
 * @wsize: amount of data to write for current frame
 * @wbuf: current write buffer
 * @poll_wait: array of wait_q's for various worker threads
 * @poll_waddr: ????
 * @pt: poll state
 * @rq: current read work
 * @wq: current write work
 * @wsched: ????
 *
 */
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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;
};

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/**
 * struct p9_mux_rpc - fd mux rpc accounting structure
 * @m: connection this request was issued on
 * @err: error state
 * @tcall: request &p9_fcall
 * @rcall: response &p9_fcall
 * @wqueue: wait queue that client is blocked on for this rpc
 *
 * Bug: isn't this information duplicated elsewhere like &p9_req
 */
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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
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 * @muxnum: number of mounts
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 *
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 * Calculation is based on the number of mounted v9fs filesystems.
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 * The current implementation returns sqrt of the number of mounts.
 */
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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
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 * @trans: transport structure
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 *
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 * Note: Creates the polling task if this is the first session.
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 */
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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
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 * @m: mux to destroy
 *
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 */
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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);
}

/**
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 * p9_pollwait - add poll task to the wait queue
 * @filp: file pointer being polled
 * @wait_address: wait_q to block on
 * @p: poll state
 *
 * called by files poll operation to add v9fs-poll task to files wait queue
510
 */
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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
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 * @m: connection to poll
 *
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 */
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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);
		}
	}
}

/**
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 * p9_poll_proc - poll worker thread
 * @a: thread state and arguments
 *
 * polls all v9fs transports for new events and queues the appropriate
 * work to the work queue
 *
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 */
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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
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 * @work: container for work to be done
 *
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 */
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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
729 730
 * @work: container of work to be done
 *
731
 */
732

733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886
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
887
 *
888
 */
889

890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056
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)
{
	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);
	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.
1057
 * @t: transport data
1058 1059
 * @tc: request to be sent
 * @rc: pointer where a pointer to the response is stored
1060
 *
1061
 */
1062

1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138
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
1139 1140
 * @a: value to pass to the callback function
 *
1141
 */
1142

1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164
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
1165
 *
1166
 */
1167

1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197
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);
}

1198
/**
1199
 * parse_options - parse mount options into session structure
1200
 * @options: options string passed from mount
1201
 * @opts: transport-specific structure to parse options into
1202
 *
1203
 * Returns 0 upon success, -ERRNO upon failure
1204
 */
1205

1206
static int parse_opts(char *params, struct p9_fd_opts *opts)
1207
{
1208 1209 1210
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;
1211
	char *options;
1212
	int ret;
1213

1214 1215 1216
	opts->port = P9_PORT;
	opts->rfd = ~0;
	opts->wfd = ~0;
1217

1218 1219 1220 1221 1222 1223 1224 1225 1226
	if (!params)
		return 0;

	options = kstrdup(params, GFP_KERNEL);
	if (!options) {
		P9_DPRINTK(P9_DEBUG_ERROR,
				"failed to allocate copy of option string\n");
		return -ENOMEM;
	}
1227

1228 1229
	while ((p = strsep(&options, ",")) != NULL) {
		int token;
1230
		int r;
1231 1232 1233
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
1234 1235
		r = match_int(&args[0], &option);
		if (r < 0) {
1236 1237
			P9_DPRINTK(P9_DEBUG_ERROR,
			 "integer field, but no integer?\n");
1238
			ret = r;
1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253
			continue;
		}
		switch (token) {
		case Opt_port:
			opts->port = option;
			break;
		case Opt_rfdno:
			opts->rfd = option;
			break;
		case Opt_wfdno:
			opts->wfd = option;
			break;
		default:
			continue;
		}
1254
	}
1255 1256
	kfree(options);
	return 0;
1257 1258
}

1259
static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
1260
{
1261 1262 1263 1264
	struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
					   GFP_KERNEL);
	if (!ts)
		return -ENOMEM;
1265

1266 1267 1268 1269 1270 1271 1272 1273 1274
	ts->rd = fget(rfd);
	ts->wr = fget(wfd);
	if (!ts->rd || !ts->wr) {
		if (ts->rd)
			fput(ts->rd);
		if (ts->wr)
			fput(ts->wr);
		kfree(ts);
		return -EIO;
1275 1276
	}

1277 1278
	trans->priv = ts;
	trans->status = Connected;
1279

1280
	return 0;
1281 1282
}

1283
static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307
{
	int fd, ret;

	csocket->sk->sk_allocation = GFP_NOIO;
	fd = sock_map_fd(csocket);
	if (fd < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
		return fd;
	}

	ret = p9_fd_open(trans, fd, fd);
	if (ret < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
		sockfd_put(csocket);
		return ret;
	}

	((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;

	return 0;
}

/**
 * p9_fd_read- read from a fd
1308
 * @trans: transport instance state
1309 1310 1311 1312
 * @v: buffer to receive data into
 * @len: size of receive buffer
 *
 */
1313

1314
static int p9_fd_read(struct p9_trans *trans, void *v, int len)
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335
{
	int ret;
	struct p9_trans_fd *ts = NULL;

	if (trans && trans->status != Disconnected)
		ts = trans->priv;

	if (!ts)
		return -EREMOTEIO;

	if (!(ts->rd->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");

	ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		trans->status = Disconnected;
	return ret;
}

/**
 * p9_fd_write - write to a socket
1336
 * @trans: transport instance state
1337 1338 1339 1340
 * @v: buffer to send data from
 * @len: size of send buffer
 *
 */
1341

1342
static int p9_fd_write(struct p9_trans *trans, void *v, int len)
1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368
{
	int ret;
	mm_segment_t oldfs;
	struct p9_trans_fd *ts = NULL;

	if (trans && trans->status != Disconnected)
		ts = trans->priv;

	if (!ts)
		return -EREMOTEIO;

	if (!(ts->wr->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");

	oldfs = get_fs();
	set_fs(get_ds());
	/* The cast to a user pointer is valid due to the set_fs() */
	ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
	set_fs(oldfs);

	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		trans->status = Disconnected;
	return ret;
}

static unsigned int
1369
p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408
{
	int ret, n;
	struct p9_trans_fd *ts = NULL;
	mm_segment_t oldfs;

	if (trans && trans->status == Connected)
		ts = trans->priv;

	if (!ts)
		return -EREMOTEIO;

	if (!ts->rd->f_op || !ts->rd->f_op->poll)
		return -EIO;

	if (!ts->wr->f_op || !ts->wr->f_op->poll)
		return -EIO;

	oldfs = get_fs();
	set_fs(get_ds());

	ret = ts->rd->f_op->poll(ts->rd, pt);
	if (ret < 0)
		goto end;

	if (ts->rd != ts->wr) {
		n = ts->wr->f_op->poll(ts->wr, pt);
		if (n < 0) {
			ret = n;
			goto end;
		}
		ret = (ret & ~POLLOUT) | (n & ~POLLIN);
	}

end:
	set_fs(oldfs);
	return ret;
}

/**
1409
 * p9_fd_close - shutdown socket
1410 1411 1412
 * @trans: private socket structure
 *
 */
1413

1414
static void p9_fd_close(struct p9_trans *trans)
1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425
{
	struct p9_trans_fd *ts;

	if (!trans)
		return;

	ts = xchg(&trans->priv, NULL);

	if (!ts)
		return;

1426 1427
	p9_conn_destroy(ts->conn);

1428 1429 1430 1431 1432 1433 1434 1435
	trans->status = Disconnected;
	if (ts->rd)
		fput(ts->rd);
	if (ts->wr)
		fput(ts->wr);
	kfree(ts);
}

1436 1437
static struct p9_trans *
p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
1438 1439 1440 1441 1442 1443
{
	int err;
	struct p9_trans *trans;
	struct socket *csocket;
	struct sockaddr_in sin_server;
	struct p9_fd_opts opts;
1444
	struct p9_trans_fd *p;
1445

1446 1447 1448
	err = parse_opts(args, &opts);
	if (err < 0)
		return ERR_PTR(err);
1449 1450 1451 1452 1453

	csocket = NULL;
	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
	if (!trans)
		return ERR_PTR(-ENOMEM);
1454 1455 1456
	trans->msize = msize;
	trans->extended = dotu;
	trans->rpc = p9_fd_rpc;
1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483
	trans->close = p9_fd_close;

	sin_server.sin_family = AF_INET;
	sin_server.sin_addr.s_addr = in_aton(addr);
	sin_server.sin_port = htons(opts.port);
	sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);

	if (!csocket) {
		P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
		err = -EIO;
		goto error;
	}

	err = csocket->ops->connect(csocket,
				    (struct sockaddr *)&sin_server,
				    sizeof(struct sockaddr_in), 0);
	if (err < 0) {
		P9_EPRINTK(KERN_ERR,
			"p9_trans_tcp: problem connecting socket to %s\n",
			addr);
		goto error;
	}

	err = p9_socket_open(trans, csocket);
	if (err < 0)
		goto error;

1484 1485 1486 1487 1488 1489 1490 1491
	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;
	}

1492 1493 1494 1495 1496 1497 1498 1499 1500 1501
	return trans;

error:
	if (csocket)
		sock_release(csocket);

	kfree(trans);
	return ERR_PTR(err);
}

1502 1503 1504
static struct p9_trans *
p9_trans_create_unix(const char *addr, char *args, int msize,
							unsigned char dotu)
1505 1506 1507 1508 1509
{
	int err;
	struct socket *csocket;
	struct sockaddr_un sun_server;
	struct p9_trans *trans;
1510
	struct p9_trans_fd *p;
1511 1512 1513 1514 1515 1516

	csocket = NULL;
	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
	if (!trans)
		return ERR_PTR(-ENOMEM);

1517
	trans->rpc = p9_fd_rpc;
1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542
	trans->close = p9_fd_close;

	if (strlen(addr) > UNIX_PATH_MAX) {
		P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
			addr);
		err = -ENAMETOOLONG;
		goto error;
	}

	sun_server.sun_family = PF_UNIX;
	strcpy(sun_server.sun_path, addr);
	sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
	err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
			sizeof(struct sockaddr_un) - 1, 0);
	if (err < 0) {
		P9_EPRINTK(KERN_ERR,
			"p9_trans_unix: problem connecting socket: %s: %d\n",
			addr, err);
		goto error;
	}

	err = p9_socket_open(trans, csocket);
	if (err < 0)
		goto error;

1543 1544 1545 1546 1547 1548 1549 1550 1551 1552
	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;
	}

1553 1554 1555 1556 1557 1558 1559 1560 1561 1562
	return trans;

error:
	if (csocket)
		sock_release(csocket);

	kfree(trans);
	return ERR_PTR(err);
}

1563 1564 1565
static struct p9_trans *
p9_trans_create_fd(const char *name, char *args, int msize,
							unsigned char extended)
1566 1567 1568 1569
{
	int err;
	struct p9_trans *trans;
	struct p9_fd_opts opts;
1570
	struct p9_trans_fd *p;
1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582

	parse_opts(args, &opts);

	if (opts.rfd == ~0 || opts.wfd == ~0) {
		printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
		return ERR_PTR(-ENOPROTOOPT);
	}

	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
	if (!trans)
		return ERR_PTR(-ENOMEM);

1583