trans_fd.c 24.5 KB
Newer Older
1 2 3 4 5 6 7
/*
 * 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>
8
 *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
 *  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>
32
#include <linux/kthread.h>
33 34 35 36 37 38 39
#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>
40
#include <linux/parser.h>
41
#include <net/9p/9p.h>
42
#include <net/9p/client.h>
43 44
#include <net/9p/transport.h>

Al Viro's avatar
Al Viro committed
45 46
#include <linux/syscalls.h> /* killme */

47
#define P9_PORT 564
48
#define MAX_SOCK_BUF (64*1024)
49
#define MAXPOLLWADDR	2
50

51 52 53 54 55 56 57 58
/**
 * 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)
 *
 */

59 60 61 62 63
struct p9_fd_opts {
	int rfd;
	int wfd;
	u16 port;
};
64

65 66 67 68 69 70 71 72
/**
 * struct p9_trans_fd - transport state
 * @rd: reference to file to read from
 * @wr: reference of file to write to
 * @conn: connection state reference
 *
 */

73 74 75
struct p9_trans_fd {
	struct file *rd;
	struct file *wr;
76
	struct p9_conn *conn;
77 78
};

79 80 81 82
/*
  * Option Parsing (code inspired by NFS code)
  *  - a little lazy - parse all fd-transport options
  */
83

84 85
enum {
	/* Options that take integer arguments */
86
	Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
87
};
88

89
static const match_table_t tokens = {
90 91 92
	{Opt_port, "port=%u"},
	{Opt_rfdno, "rfdno=%u"},
	{Opt_wfdno, "wfdno=%u"},
93
	{Opt_err, NULL},
94
};
95

96 97 98 99 100 101 102
enum {
	Rworksched = 1,		/* read work scheduled or running */
	Rpending = 2,		/* can read */
	Wworksched = 4,		/* write work scheduled or running */
	Wpending = 8,		/* can write */
};

Tejun Heo's avatar
Tejun Heo committed
103 104 105 106
struct p9_poll_wait {
	struct p9_conn *conn;
	wait_queue_t wait;
	wait_queue_head_t *wait_addr;
107 108 109 110 111
};

/**
 * struct p9_conn - fd mux connection state information
 * @mux_list: list link for mux to manage multiple connections (?)
112
 * @client: reference to client instance for this connection
113 114 115
 * @err: error state
 * @req_list: accounting for requests which have been sent
 * @unsent_req_list: accounting for requests that haven't been sent
116 117 118
 * @req: current request being processed (if any)
 * @tmp_buf: temporary buffer to read in header
 * @rsize: amount to read for current frame
119 120 121 122 123
 * @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
Abhishek Kulkarni's avatar
Abhishek Kulkarni committed
124
 * @poll_pending_link: pending links to be polled per conn
125 126 127 128 129 130 131
 * @poll_wait: array of wait_q's for various worker threads
 * @pt: poll state
 * @rq: current read work
 * @wq: current write work
 * @wsched: ????
 *
 */
132 133 134

struct p9_conn {
	struct list_head mux_list;
135
	struct p9_client *client;
136 137 138
	int err;
	struct list_head req_list;
	struct list_head unsent_req_list;
139 140 141
	struct p9_req_t *req;
	char tmp_buf[7];
	int rsize;
142 143 144 145 146
	int rpos;
	char *rbuf;
	int wpos;
	int wsize;
	char *wbuf;
Tejun Heo's avatar
Tejun Heo committed
147 148
	struct list_head poll_pending_link;
	struct p9_poll_wait poll_wait[MAXPOLLWADDR];
149 150 151 152 153 154
	poll_table pt;
	struct work_struct rq;
	struct work_struct wq;
	unsigned long wsched;
};

Tejun Heo's avatar
Tejun Heo committed
155 156
static DEFINE_SPINLOCK(p9_poll_lock);
static LIST_HEAD(p9_poll_pending_list);
157
static struct workqueue_struct *p9_mux_wq;
Tejun Heo's avatar
Tejun Heo committed
158
static struct task_struct *p9_poll_task;
159

Tejun Heo's avatar
Tejun Heo committed
160
static void p9_mux_poll_stop(struct p9_conn *m)
161
{
Tejun Heo's avatar
Tejun Heo committed
162 163
	unsigned long flags;
	int i;
164

Tejun Heo's avatar
Tejun Heo committed
165 166
	for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
		struct p9_poll_wait *pwait = &m->poll_wait[i];
167

Tejun Heo's avatar
Tejun Heo committed
168 169 170
		if (pwait->wait_addr) {
			remove_wait_queue(pwait->wait_addr, &pwait->wait);
			pwait->wait_addr = NULL;
171 172 173
		}
	}

Tejun Heo's avatar
Tejun Heo committed
174 175 176
	spin_lock_irqsave(&p9_poll_lock, flags);
	list_del_init(&m->poll_pending_link);
	spin_unlock_irqrestore(&p9_poll_lock, flags);
177 178 179
}

/**
180 181 182
 * p9_conn_cancel - cancel all pending requests with error
 * @m: mux data
 * @err: error code
183 184
 *
 */
185

186
static void p9_conn_cancel(struct p9_conn *m, int err)
187
{
188
	struct p9_req_t *req, *rtmp;
189
	unsigned long flags;
190
	LIST_HEAD(cancel_list);
191

192
	P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
193

194
	spin_lock_irqsave(&m->client->lock, flags);
195 196 197 198 199 200 201 202

	if (m->err) {
		spin_unlock_irqrestore(&m->client->lock, flags);
		return;
	}

	m->err = err;

203
	list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
204 205 206
		req->status = REQ_STATUS_ERROR;
		if (!req->t_err)
			req->t_err = err;
207 208 209
		list_move(&req->req_list, &cancel_list);
	}
	list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
210 211 212
		req->status = REQ_STATUS_ERROR;
		if (!req->t_err)
			req->t_err = err;
213
		list_move(&req->req_list, &cancel_list);
214
	}
215
	spin_unlock_irqrestore(&m->client->lock, flags);
216

217
	list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
218
		P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
219
		list_del(&req->req_list);
220
		p9_client_cb(m->client, req);
221 222 223
	}
}

224 225
static unsigned int
p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
226
{
227 228
	int ret, n;
	struct p9_trans_fd *ts = NULL;
229

230 231
	if (client && client->status == Connected)
		ts = client->trans;
232

233 234
	if (!ts)
		return -EREMOTEIO;
235

236 237
	if (!ts->rd->f_op || !ts->rd->f_op->poll)
		return -EIO;
238

239 240
	if (!ts->wr->f_op || !ts->wr->f_op->poll)
		return -EIO;
Tejun Heo's avatar
Tejun Heo committed
241

242 243 244
	ret = ts->rd->f_op->poll(ts->rd, pt);
	if (ret < 0)
		return ret;
Tejun Heo's avatar
Tejun Heo committed
245

246 247 248 249 250 251 252 253
	if (ts->rd != ts->wr) {
		n = ts->wr->f_op->poll(ts->wr, pt);
		if (n < 0)
			return n;
		ret = (ret & ~POLLOUT) | (n & ~POLLIN);
	}

	return ret;
Tejun Heo's avatar
Tejun Heo committed
254 255
}

256
/**
257 258 259 260
 * p9_fd_read- read from a fd
 * @client: client instance
 * @v: buffer to receive data into
 * @len: size of receive buffer
261
 *
262
 */
263

264
static int p9_fd_read(struct p9_client *client, void *v, int len)
265
{
266 267
	int ret;
	struct p9_trans_fd *ts = NULL;
268

269 270
	if (client && client->status != Disconnected)
		ts = client->trans;
271

272 273
	if (!ts)
		return -EREMOTEIO;
274

275 276
	if (!(ts->rd->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
277

278 279 280 281
	ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		client->status = Disconnected;
	return ret;
282 283 284
}

/**
285 286
 * p9_read_work - called when there is some data to be read from a transport
 * @work: container of work to be done
287
 *
288
 */
289

290
static void p9_read_work(struct work_struct *work)
291
{
292 293 294 295
	int n, err;
	struct p9_conn *m;

	m = container_of(work, struct p9_conn, rq);
296 297 298 299

	if (m->err < 0)
		return;

300
	P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
301

302 303
	if (!m->rbuf) {
		m->rbuf = m->tmp_buf;
304
		m->rpos = 0;
305
		m->rsize = 7; /* start by reading header */
306 307
	}

308
	clear_bit(Rpending, &m->wsched);
309
	P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
310
					m->rpos, m->rsize, m->rsize-m->rpos);
311
	err = p9_fd_read(m->client, m->rbuf + m->rpos,
312
						m->rsize - m->rpos);
313
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
314 315 316
	if (err == -EAGAIN) {
		clear_bit(Rworksched, &m->wsched);
		return;
317 318
	}

319 320 321 322
	if (err <= 0)
		goto error;

	m->rpos += err;
323 324 325

	if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
		u16 tag;
326
		P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
327 328

		n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
329 330 331 332 333 334 335
		if (n >= m->client->msize) {
			P9_DPRINTK(P9_DEBUG_ERROR,
				"requested packet size too big: %d\n", n);
			err = -EIO;
			goto error;
		}

336
		tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
337 338
		P9_DPRINTK(P9_DEBUG_TRANS,
			"mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
339 340

		m->req = p9_tag_lookup(m->client, tag);
341 342
		if (!m->req || (m->req->status != REQ_STATUS_SENT &&
					m->req->status != REQ_STATUS_FLSH)) {
343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361
			P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
								 tag);
			err = -EIO;
			goto error;
		}

		if (m->req->rc == NULL) {
			m->req->rc = kmalloc(sizeof(struct p9_fcall) +
						m->client->msize, GFP_KERNEL);
			if (!m->req->rc) {
				m->req = NULL;
				err = -ENOMEM;
				goto error;
			}
		}
		m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
		memcpy(m->rbuf, m->tmp_buf, m->rsize);
		m->rsize = n;
	}
362

363 364
	/* not an else because some packets (like clunk) have no payload */
	if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
365
		P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
366
		spin_lock(&m->client->lock);
367 368
		if (m->req->status != REQ_STATUS_ERROR)
			m->req->status = REQ_STATUS_RCVD;
369
		list_del(&m->req->req_list);
370
		spin_unlock(&m->client->lock);
371
		p9_client_cb(m->client, m->req);
372 373 374 375
		m->rbuf = NULL;
		m->rpos = 0;
		m->rsize = 0;
		m->req = NULL;
376 377 378 379 380 381 382 383 384
	}

	if (!list_empty(&m->req_list)) {
		if (test_and_clear_bit(Rpending, &m->wsched))
			n = POLLIN;
		else
			n = p9_fd_poll(m->client, NULL);

		if (n & POLLIN) {
385
			P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402
			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_fd_write - write to a socket
 * @client: client instance
 * @v: buffer to send data from
 * @len: size of send buffer
403
 *
404
 */
405

406
static int p9_fd_write(struct p9_client *client, void *v, int len)
407
{
408 409 410
	int ret;
	mm_segment_t oldfs;
	struct p9_trans_fd *ts = NULL;
411

412 413
	if (client && client->status != Disconnected)
		ts = client->trans;
414

415 416
	if (!ts)
		return -EREMOTEIO;
417

418 419
	if (!(ts->wr->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
Tejun Heo's avatar
Tejun Heo committed
420

421 422 423
	oldfs = get_fs();
	set_fs(get_ds());
	/* The cast to a user pointer is valid due to the set_fs() */
424
	ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
425
	set_fs(oldfs);
Tejun Heo's avatar
Tejun Heo committed
426

427 428 429
	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		client->status = Disconnected;
	return ret;
430 431 432 433
}

/**
 * p9_write_work - called when a transport can send some data
434 435
 * @work: container for work to be done
 *
436
 */
437

438 439 440 441
static void p9_write_work(struct work_struct *work)
{
	int n, err;
	struct p9_conn *m;
442
	struct p9_req_t *req;
443 444 445 446 447 448 449 450 451 452 453 454 455 456

	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;
		}

457 458
		spin_lock(&m->client->lock);
		req = list_entry(m->unsent_req_list.next, struct p9_req_t,
459
			       req_list);
460
		req->status = REQ_STATUS_SENT;
461
		P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
462 463
		list_move_tail(&req->req_list, &m->req_list);

464 465
		m->wbuf = req->tc->sdata;
		m->wsize = req->tc->size;
466
		m->wpos = 0;
467
		spin_unlock(&m->client->lock);
468 469
	}

470
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
471 472
								m->wsize);
	clear_bit(Wpending, &m->wsched);
473
	err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
474
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494
	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
495
			n = p9_fd_poll(m->client, NULL);
496 497

		if (n & POLLOUT) {
498
			P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
499 500 501 502 503 504 505 506 507 508 509 510 511
			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);
}

512
static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
513
{
514 515 516 517 518
	struct p9_poll_wait *pwait =
		container_of(wait, struct p9_poll_wait, wait);
	struct p9_conn *m = pwait->conn;
	unsigned long flags;
	DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
519

520 521 522 523
	spin_lock_irqsave(&p9_poll_lock, flags);
	if (list_empty(&m->poll_pending_link))
		list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
	spin_unlock_irqrestore(&p9_poll_lock, flags);
524

525 526
	/* perform the default wake up operation */
	return default_wake_function(&dummy_wait, mode, sync, key);
527 528 529
}

/**
530 531 532 533
 * p9_pollwait - add poll task to the wait queue
 * @filp: file pointer being polled
 * @wait_address: wait_q to block on
 * @p: poll state
534
 *
535
 * called by files poll operation to add v9fs-poll task to files wait queue
536
 */
537

538 539
static void
p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
540
{
541 542 543
	struct p9_conn *m = container_of(p, struct p9_conn, pt);
	struct p9_poll_wait *pwait = NULL;
	int i;
544

545 546 547 548
	for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
		if (m->poll_wait[i].wait_addr == NULL) {
			pwait = &m->poll_wait[i];
			break;
549 550 551
		}
	}

552 553
	if (!pwait) {
		P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
554 555 556
		return;
	}

557 558 559 560 561
	pwait->conn = m;
	pwait->wait_addr = wait_address;
	init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
	add_wait_queue(wait_address, &pwait->wait);
}
562

563 564 565 566 567 568
/**
 * p9_conn_create - allocate and initialize the per-session mux data
 * @client: client instance
 *
 * Note: Creates the polling task if this is the first session.
 */
569

570 571
static struct p9_conn *p9_conn_create(struct p9_client *client)
{
572
	int n;
573
	struct p9_conn *m;
574

575 576
	P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
								client->msize);
577 578 579
	m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
	if (!m)
		return ERR_PTR(-ENOMEM);
580

581 582
	INIT_LIST_HEAD(&m->mux_list);
	m->client = client;
583

584 585 586 587 588 589
	INIT_LIST_HEAD(&m->req_list);
	INIT_LIST_HEAD(&m->unsent_req_list);
	INIT_WORK(&m->rq, p9_read_work);
	INIT_WORK(&m->wq, p9_write_work);
	INIT_LIST_HEAD(&m->poll_pending_link);
	init_poll_funcptr(&m->pt, p9_pollwait);
590

591 592
	n = p9_fd_poll(client, &m->pt);
	if (n & POLLIN) {
593
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
594 595
		set_bit(Rpending, &m->wsched);
	}
596

597
	if (n & POLLOUT) {
598
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
599 600 601 602 603
		set_bit(Wpending, &m->wsched);
	}

	return m;
}
604

605 606 607 608 609 610 611 612 613 614 615 616 617 618 619
/**
 * p9_poll_mux - polls a mux and schedules read or write works if necessary
 * @m: connection to poll
 *
 */

static void p9_poll_mux(struct p9_conn *m)
{
	int n;

	if (m->err < 0)
		return;

	n = p9_fd_poll(m->client, NULL);
	if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
620
		P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
621 622 623 624 625 626 627
		if (n >= 0)
			n = -ECONNRESET;
		p9_conn_cancel(m, n);
	}

	if (n & POLLIN) {
		set_bit(Rpending, &m->wsched);
628
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
629
		if (!test_and_set_bit(Rworksched, &m->wsched)) {
630
			P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
631
			queue_work(p9_mux_wq, &m->rq);
632 633
		}
	}
634

635 636
	if (n & POLLOUT) {
		set_bit(Wpending, &m->wsched);
637
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
638 639
		if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
		    !test_and_set_bit(Wworksched, &m->wsched)) {
640
			P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
641 642 643
			queue_work(p9_mux_wq, &m->wq);
		}
	}
644 645 646
}

/**
647
 * p9_fd_request - send 9P request
648 649
 * The function can sleep until the request is scheduled for sending.
 * The function can be interrupted. Return from the function is not
650
 * a guarantee that the request is sent successfully.
651
 *
652 653
 * @client: client instance
 * @req: request to be sent
654
 *
655
 */
656

657
static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
658 659
{
	int n;
660 661
	struct p9_trans_fd *ts = client->trans;
	struct p9_conn *m = ts->conn;
662

663 664
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
						current, req->tc, req->tc->id);
665
	if (m->err < 0)
666
		return m->err;
667

668
	spin_lock(&client->lock);
669
	req->status = REQ_STATUS_UNSENT;
670
	list_add_tail(&req->req_list, &m->unsent_req_list);
671
	spin_unlock(&client->lock);
672 673 674 675

	if (test_and_clear_bit(Wpending, &m->wsched))
		n = POLLOUT;
	else
676
		n = p9_fd_poll(m->client, NULL);
677 678 679 680

	if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
		queue_work(p9_mux_wq, &m->wq);

681
	return 0;
682 683
}

684
static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
685
{
686
	int ret = 1;
687

688
	P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
689

690 691 692
	spin_lock(&client->lock);

	if (req->status == REQ_STATUS_UNSENT) {
693
		list_del(&req->req_list);
694
		req->status = REQ_STATUS_FLSHD;
695
		ret = 0;
696 697
	} else if (req->status == REQ_STATUS_SENT)
		req->status = REQ_STATUS_FLSH;
698

699 700 701
	spin_unlock(&client->lock);

	return ret;
702 703
}

704
/**
Abhishek Kulkarni's avatar
Abhishek Kulkarni committed
705 706 707
 * parse_opts - parse mount options into p9_fd_opts structure
 * @params: options string passed from mount
 * @opts: fd transport-specific structure to parse options into
708
 *
709
 * Returns 0 upon success, -ERRNO upon failure
710
 */
711

712
static int parse_opts(char *params, struct p9_fd_opts *opts)
713
{
714 715 716
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;
Eric Van Hensbergen's avatar
Eric Van Hensbergen committed
717
	char *options, *tmp_options;
718
	int ret;
719

720 721 722
	opts->port = P9_PORT;
	opts->rfd = ~0;
	opts->wfd = ~0;
723

724 725 726
	if (!params)
		return 0;

Eric Van Hensbergen's avatar
Eric Van Hensbergen committed
727 728
	tmp_options = kstrdup(params, GFP_KERNEL);
	if (!tmp_options) {
729 730 731 732
		P9_DPRINTK(P9_DEBUG_ERROR,
				"failed to allocate copy of option string\n");
		return -ENOMEM;
	}
Eric Van Hensbergen's avatar
Eric Van Hensbergen committed
733
	options = tmp_options;
734

735 736
	while ((p = strsep(&options, ",")) != NULL) {
		int token;
737
		int r;
738 739 740
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
741 742 743 744 745 746 747 748
		if (token != Opt_err) {
			r = match_int(&args[0], &option);
			if (r < 0) {
				P9_DPRINTK(P9_DEBUG_ERROR,
				"integer field, but no integer?\n");
				ret = r;
				continue;
			}
749 750 751 752 753 754 755 756 757 758 759 760 761 762
		}
		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;
		}
763
	}
Eric Van Hensbergen's avatar
Eric Van Hensbergen committed
764 765

	kfree(tmp_options);
766
	return 0;
767 768
}

769
static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
770
{
771 772 773 774
	struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
					   GFP_KERNEL);
	if (!ts)
		return -ENOMEM;
775

776 777 778 779 780 781 782 783 784
	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;
785 786
	}

787 788
	client->trans = ts;
	client->status = Connected;
789

790
	return 0;
791 792
}

793
static int p9_socket_open(struct p9_client *client, struct socket *csocket)
794
{
Al Viro's avatar
Al Viro committed
795 796 797 798 799 800
	struct p9_trans_fd *p;
	int ret, fd;

	p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
	if (!p)
		return -ENOMEM;
801 802

	csocket->sk->sk_allocation = GFP_NOIO;
803
	fd = sock_map_fd(csocket, 0);
804 805
	if (fd < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
Al Viro's avatar
Al Viro committed
806 807
		sock_release(csocket);
		kfree(p);
808 809 810
		return fd;
	}

Al Viro's avatar
Al Viro committed
811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826
	get_file(csocket->file);
	get_file(csocket->file);
	p->wr = p->rd = csocket->file;
	client->trans = p;
	client->status = Connected;

	sys_close(fd);	/* still racy */

	p->rd->f_flags |= O_NONBLOCK;

	p->conn = p9_conn_create(client);
	if (IS_ERR(p->conn)) {
		ret = PTR_ERR(p->conn);
		p->conn = NULL;
		kfree(p);
		sockfd_put(csocket);
827 828 829 830 831 832 833
		sockfd_put(csocket);
		return ret;
	}
	return 0;
}

/**
834 835
 * p9_mux_destroy - cancels all pending requests and frees mux resources
 * @m: mux to destroy
836 837
 *
 */
838

839
static void p9_conn_destroy(struct p9_conn *m)
840
{
841
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
842
		m->mux_list.prev, m->mux_list.next);
843

844 845 846
	p9_mux_poll_stop(m);
	cancel_work_sync(&m->rq);
	cancel_work_sync(&m->wq);
847

848
	p9_conn_cancel(m, -ECONNRESET);
849

850 851
	m->client = NULL;
	kfree(m);
852 853 854
}

/**
855 856
 * p9_fd_close - shutdown file descriptor transport
 * @client: client instance
857 858
 *
 */
859

860
static void p9_fd_close(struct p9_client *client)
861 862 863
{
	struct p9_trans_fd *ts;

864
	if (!client)
865 866
		return;

867
	ts = client->trans;
868 869 870
	if (!ts)
		return;

871 872
	client->status = Disconnected;

873 874
	p9_conn_destroy(ts->conn);

875 876 877 878
	if (ts->rd)
		fput(ts->rd);
	if (ts->wr)
		fput(ts->wr);
879

880 881 882
	kfree(ts);
}