trans_fd.c 24.7 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 45
#include <net/9p/transport.h>

#define P9_PORT 564
46
#define MAX_SOCK_BUF (64*1024)
47
#define MAXPOLLWADDR	2
48

49 50 51 52 53 54 55 56
/**
 * 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)
 *
 */

57 58 59 60 61
struct p9_fd_opts {
	int rfd;
	int wfd;
	u16 port;
};
62

63 64 65 66 67 68 69 70
/**
 * struct p9_trans_fd - transport state
 * @rd: reference to file to read from
 * @wr: reference of file to write to
 * @conn: connection state reference
 *
 */

71 72 73
struct p9_trans_fd {
	struct file *rd;
	struct file *wr;
74
	struct p9_conn *conn;
75 76
};

77 78 79 80
/*
  * Option Parsing (code inspired by NFS code)
  *  - a little lazy - parse all fd-transport options
  */
81

82 83
enum {
	/* Options that take integer arguments */
84
	Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
85
};
86

87
static const match_table_t tokens = {
88 89 90
	{Opt_port, "port=%u"},
	{Opt_rfdno, "rfdno=%u"},
	{Opt_wfdno, "wfdno=%u"},
91
	{Opt_err, NULL},
92
};
93

94 95 96 97 98 99 100
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
101 102 103 104
struct p9_poll_wait {
	struct p9_conn *conn;
	wait_queue_t wait;
	wait_queue_head_t *wait_addr;
105 106 107 108 109
};

/**
 * struct p9_conn - fd mux connection state information
 * @mux_list: list link for mux to manage multiple connections (?)
110
 * @client: reference to client instance for this connection
111 112 113
 * @err: error state
 * @req_list: accounting for requests which have been sent
 * @unsent_req_list: accounting for requests that haven't been sent
114 115 116
 * @req: current request being processed (if any)
 * @tmp_buf: temporary buffer to read in header
 * @rsize: amount to read for current frame
117 118 119 120 121
 * @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
122
 * @poll_pending_link: pending links to be polled per conn
123 124 125 126 127 128 129
 * @poll_wait: array of wait_q's for various worker threads
 * @pt: poll state
 * @rq: current read work
 * @wq: current write work
 * @wsched: ????
 *
 */
130 131 132

struct p9_conn {
	struct list_head mux_list;
133
	struct p9_client *client;
134 135 136
	int err;
	struct list_head req_list;
	struct list_head unsent_req_list;
137 138 139
	struct p9_req_t *req;
	char tmp_buf[7];
	int rsize;
140 141 142 143 144
	int rpos;
	char *rbuf;
	int wpos;
	int wsize;
	char *wbuf;
Tejun Heo's avatar
Tejun Heo committed
145 146
	struct list_head poll_pending_link;
	struct p9_poll_wait poll_wait[MAXPOLLWADDR];
147 148 149 150 151 152
	poll_table pt;
	struct work_struct rq;
	struct work_struct wq;
	unsigned long wsched;
};

Tejun Heo's avatar
Tejun Heo committed
153 154
static DEFINE_SPINLOCK(p9_poll_lock);
static LIST_HEAD(p9_poll_pending_list);
155
static struct workqueue_struct *p9_mux_wq;
Tejun Heo's avatar
Tejun Heo committed
156
static struct task_struct *p9_poll_task;
157

Tejun Heo's avatar
Tejun Heo committed
158
static void p9_mux_poll_stop(struct p9_conn *m)
159
{
Tejun Heo's avatar
Tejun Heo committed
160 161
	unsigned long flags;
	int i;
162

Tejun Heo's avatar
Tejun Heo committed
163 164
	for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
		struct p9_poll_wait *pwait = &m->poll_wait[i];
165

Tejun Heo's avatar
Tejun Heo committed
166 167 168
		if (pwait->wait_addr) {
			remove_wait_queue(pwait->wait_addr, &pwait->wait);
			pwait->wait_addr = NULL;
169 170 171
		}
	}

Tejun Heo's avatar
Tejun Heo committed
172 173 174
	spin_lock_irqsave(&p9_poll_lock, flags);
	list_del_init(&m->poll_pending_link);
	spin_unlock_irqrestore(&p9_poll_lock, flags);
175 176 177
}

/**
178 179 180
 * p9_conn_cancel - cancel all pending requests with error
 * @m: mux data
 * @err: error code
181 182
 *
 */
183

184
static void p9_conn_cancel(struct p9_conn *m, int err)
185
{
186
	struct p9_req_t *req, *rtmp;
187
	unsigned long flags;
188
	LIST_HEAD(cancel_list);
189

190
	P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
191

192
	spin_lock_irqsave(&m->client->lock, flags);
193 194 195 196 197 198 199 200

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

	m->err = err;

201
	list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
202 203 204
		req->status = REQ_STATUS_ERROR;
		if (!req->t_err)
			req->t_err = err;
205 206 207
		list_move(&req->req_list, &cancel_list);
	}
	list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
208 209 210
		req->status = REQ_STATUS_ERROR;
		if (!req->t_err)
			req->t_err = err;
211
		list_move(&req->req_list, &cancel_list);
212
	}
213
	spin_unlock_irqrestore(&m->client->lock, flags);
214

215
	list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
216
		P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
217
		list_del(&req->req_list);
218
		p9_client_cb(m->client, req);
219 220 221
	}
}

222 223
static unsigned int
p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
224
{
225 226
	int ret, n;
	struct p9_trans_fd *ts = NULL;
227

228 229
	if (client && client->status == Connected)
		ts = client->trans;
230

231 232
	if (!ts)
		return -EREMOTEIO;
233

234 235
	if (!ts->rd->f_op || !ts->rd->f_op->poll)
		return -EIO;
236

237 238
	if (!ts->wr->f_op || !ts->wr->f_op->poll)
		return -EIO;
Tejun Heo's avatar
Tejun Heo committed
239

240 241 242
	ret = ts->rd->f_op->poll(ts->rd, pt);
	if (ret < 0)
		return ret;
Tejun Heo's avatar
Tejun Heo committed
243

244 245 246 247 248 249 250 251
	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
252 253
}

254
/**
255 256 257 258
 * p9_fd_read- read from a fd
 * @client: client instance
 * @v: buffer to receive data into
 * @len: size of receive buffer
259
 *
260
 */
261

262
static int p9_fd_read(struct p9_client *client, void *v, int len)
263
{
264 265
	int ret;
	struct p9_trans_fd *ts = NULL;
266

267 268
	if (client && client->status != Disconnected)
		ts = client->trans;
269

270 271
	if (!ts)
		return -EREMOTEIO;
272

273 274
	if (!(ts->rd->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
275

276 277 278 279
	ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		client->status = Disconnected;
	return ret;
280 281 282
}

/**
283 284
 * p9_read_work - called when there is some data to be read from a transport
 * @work: container of work to be done
285
 *
286
 */
287

288
static void p9_read_work(struct work_struct *work)
289
{
290 291 292 293
	int n, err;
	struct p9_conn *m;

	m = container_of(work, struct p9_conn, rq);
294 295 296 297

	if (m->err < 0)
		return;

298
	P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
299

300 301
	if (!m->rbuf) {
		m->rbuf = m->tmp_buf;
302
		m->rpos = 0;
303
		m->rsize = 7; /* start by reading header */
304 305
	}

306
	clear_bit(Rpending, &m->wsched);
307
	P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
308
					m->rpos, m->rsize, m->rsize-m->rpos);
309
	err = p9_fd_read(m->client, m->rbuf + m->rpos,
310
						m->rsize - m->rpos);
311
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
312 313 314
	if (err == -EAGAIN) {
		clear_bit(Rworksched, &m->wsched);
		return;
315 316
	}

317 318 319 320
	if (err <= 0)
		goto error;

	m->rpos += err;
321 322 323

	if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
		u16 tag;
324
		P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
325 326

		n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
327 328 329 330 331 332 333
		if (n >= m->client->msize) {
			P9_DPRINTK(P9_DEBUG_ERROR,
				"requested packet size too big: %d\n", n);
			err = -EIO;
			goto error;
		}

334
		tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
335 336
		P9_DPRINTK(P9_DEBUG_TRANS,
			"mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
337 338

		m->req = p9_tag_lookup(m->client, tag);
339 340
		if (!m->req || (m->req->status != REQ_STATUS_SENT &&
					m->req->status != REQ_STATUS_FLSH)) {
341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359
			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;
	}
360

361 362
	/* not an else because some packets (like clunk) have no payload */
	if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
363
		P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
364
		spin_lock(&m->client->lock);
365 366
		if (m->req->status != REQ_STATUS_ERROR)
			m->req->status = REQ_STATUS_RCVD;
367
		list_del(&m->req->req_list);
368
		spin_unlock(&m->client->lock);
369
		p9_client_cb(m->client, m->req);
370 371 372 373
		m->rbuf = NULL;
		m->rpos = 0;
		m->rsize = 0;
		m->req = NULL;
374 375 376 377 378 379 380 381 382
	}

	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) {
383
			P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400
			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
401
 *
402
 */
403

404
static int p9_fd_write(struct p9_client *client, void *v, int len)
405
{
406 407 408
	int ret;
	mm_segment_t oldfs;
	struct p9_trans_fd *ts = NULL;
409

410 411
	if (client && client->status != Disconnected)
		ts = client->trans;
412

413 414
	if (!ts)
		return -EREMOTEIO;
415

416 417
	if (!(ts->wr->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
Tejun Heo's avatar
Tejun Heo committed
418

419 420 421
	oldfs = get_fs();
	set_fs(get_ds());
	/* The cast to a user pointer is valid due to the set_fs() */
422
	ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
423
	set_fs(oldfs);
Tejun Heo's avatar
Tejun Heo committed
424

425 426 427
	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		client->status = Disconnected;
	return ret;
428 429 430 431
}

/**
 * p9_write_work - called when a transport can send some data
432 433
 * @work: container for work to be done
 *
434
 */
435

436 437 438 439
static void p9_write_work(struct work_struct *work)
{
	int n, err;
	struct p9_conn *m;
440
	struct p9_req_t *req;
441 442 443 444 445 446 447 448 449 450 451 452 453 454

	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;
		}

455 456
		spin_lock(&m->client->lock);
		req = list_entry(m->unsent_req_list.next, struct p9_req_t,
457
			       req_list);
458
		req->status = REQ_STATUS_SENT;
459
		P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
460 461
		list_move_tail(&req->req_list, &m->req_list);

462 463
		m->wbuf = req->tc->sdata;
		m->wsize = req->tc->size;
464
		m->wpos = 0;
465
		spin_unlock(&m->client->lock);
466 467
	}

468
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
469 470
								m->wsize);
	clear_bit(Wpending, &m->wsched);
471
	err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
472
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492
	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
493
			n = p9_fd_poll(m->client, NULL);
494 495

		if (n & POLLOUT) {
496
			P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
497 498 499 500 501 502 503 504 505 506 507 508 509
			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);
}

510
static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
511
{
512 513 514 515 516
	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);
517

518 519 520 521
	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);
522

523 524
	/* perform the default wake up operation */
	return default_wake_function(&dummy_wait, mode, sync, key);
525 526 527
}

/**
528 529 530 531
 * p9_pollwait - add poll task to the wait queue
 * @filp: file pointer being polled
 * @wait_address: wait_q to block on
 * @p: poll state
532
 *
533
 * called by files poll operation to add v9fs-poll task to files wait queue
534
 */
535

536 537
static void
p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
538
{
539 540 541
	struct p9_conn *m = container_of(p, struct p9_conn, pt);
	struct p9_poll_wait *pwait = NULL;
	int i;
542

543 544 545 546
	for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
		if (m->poll_wait[i].wait_addr == NULL) {
			pwait = &m->poll_wait[i];
			break;
547 548 549
		}
	}

550 551
	if (!pwait) {
		P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
552 553 554
		return;
	}

555 556 557 558 559
	pwait->conn = m;
	pwait->wait_addr = wait_address;
	init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
	add_wait_queue(wait_address, &pwait->wait);
}
560

561 562 563 564 565 566
/**
 * 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.
 */
567

568 569
static struct p9_conn *p9_conn_create(struct p9_client *client)
{
570
	int n;
571
	struct p9_conn *m;
572

573 574
	P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
								client->msize);
575 576 577
	m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
	if (!m)
		return ERR_PTR(-ENOMEM);
578

579 580
	INIT_LIST_HEAD(&m->mux_list);
	m->client = client;
581

582 583 584 585 586 587
	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);
588

589 590
	n = p9_fd_poll(client, &m->pt);
	if (n & POLLIN) {
591
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
592 593
		set_bit(Rpending, &m->wsched);
	}
594

595
	if (n & POLLOUT) {
596
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
597 598 599 600 601
		set_bit(Wpending, &m->wsched);
	}

	return m;
}
602

603 604 605 606 607 608 609 610 611 612 613 614 615 616 617
/**
 * 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)) {
618
		P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
619 620 621 622 623 624 625
		if (n >= 0)
			n = -ECONNRESET;
		p9_conn_cancel(m, n);
	}

	if (n & POLLIN) {
		set_bit(Rpending, &m->wsched);
626
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
627
		if (!test_and_set_bit(Rworksched, &m->wsched)) {
628
			P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
629
			queue_work(p9_mux_wq, &m->rq);
630 631
		}
	}
632

633 634
	if (n & POLLOUT) {
		set_bit(Wpending, &m->wsched);
635
		P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
636 637
		if ((m->wsize || !list_empty(&m->unsent_req_list))
		    && !test_and_set_bit(Wworksched, &m->wsched)) {
638
			P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
639 640 641
			queue_work(p9_mux_wq, &m->wq);
		}
	}
642 643 644
}

/**
645
 * p9_fd_request - send 9P request
646 647
 * The function can sleep until the request is scheduled for sending.
 * The function can be interrupted. Return from the function is not
648
 * a guarantee that the request is sent successfully.
649
 *
650 651
 * @client: client instance
 * @req: request to be sent
652
 *
653
 */
654

655
static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
656 657
{
	int n;
658 659
	struct p9_trans_fd *ts = client->trans;
	struct p9_conn *m = ts->conn;
660

661 662
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
						current, req->tc, req->tc->id);
663
	if (m->err < 0)
664
		return m->err;
665

666
	spin_lock(&client->lock);
667
	req->status = REQ_STATUS_UNSENT;
668
	list_add_tail(&req->req_list, &m->unsent_req_list);
669
	spin_unlock(&client->lock);
670 671 672 673

	if (test_and_clear_bit(Wpending, &m->wsched))
		n = POLLOUT;
	else
674
		n = p9_fd_poll(m->client, NULL);
675 676 677 678

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

679
	return 0;
680 681
}

682
static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
683
{
684
	int ret = 1;
685

686
	P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
687

688 689 690
	spin_lock(&client->lock);

	if (req->status == REQ_STATUS_UNSENT) {
691
		list_del(&req->req_list);
692
		req->status = REQ_STATUS_FLSHD;
693
		ret = 0;
694 695
	} else if (req->status == REQ_STATUS_SENT)
		req->status = REQ_STATUS_FLSH;
696

697 698 699
	spin_unlock(&client->lock);

	return ret;
700 701
}

702
/**
Abhishek Kulkarni's avatar
Abhishek Kulkarni committed
703 704 705
 * 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
706
 *
707
 * Returns 0 upon success, -ERRNO upon failure
708
 */
709

710
static int parse_opts(char *params, struct p9_fd_opts *opts)
711
{
712 713 714
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;
715
	char *options;
716
	int ret;
717

718 719 720
	opts->port = P9_PORT;
	opts->rfd = ~0;
	opts->wfd = ~0;
721

722 723 724 725 726 727 728 729 730
	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;
	}
731

732 733
	while ((p = strsep(&options, ",")) != NULL) {
		int token;
734
		int r;
735 736 737
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
738 739 740 741 742 743 744 745
		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;
			}
746 747 748 749 750 751 752 753 754 755 756 757 758 759
		}
		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;
		}
760
	}
761 762
	kfree(options);
	return 0;
763 764
}

765
static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
766
{
767 768 769 770
	struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
					   GFP_KERNEL);
	if (!ts)
		return -ENOMEM;
771

772 773 774 775 776 777 778 779 780
	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;
781 782
	}

783 784
	client->trans = ts;
	client->status = Connected;
785

786
	return 0;
787 788
}

789
static int p9_socket_open(struct p9_client *client, struct socket *csocket)
790 791 792 793
{
	int fd, ret;

	csocket->sk->sk_allocation = GFP_NOIO;
794
	fd = sock_map_fd(csocket, 0);
795 796 797 798 799
	if (fd < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
		return fd;
	}

800
	ret = p9_fd_open(client, fd, fd);
801 802 803 804 805 806
	if (ret < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
		sockfd_put(csocket);
		return ret;
	}

807
	((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
808 809 810 811 812

	return 0;
}

/**
813 814
 * p9_mux_destroy - cancels all pending requests and frees mux resources
 * @m: mux to destroy
815 816
 *
 */
817

818
static void p9_conn_destroy(struct p9_conn *m)
819
{
820
	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
821
		m->mux_list.prev, m->mux_list.next);
822

823 824 825
	p9_mux_poll_stop(m);
	cancel_work_sync(&m->rq);
	cancel_work_sync(&m->wq);
826

827
	p9_conn_cancel(m, -ECONNRESET);
828

829 830
	m->client = NULL;
	kfree(m);
831 832 833
}

/**
834 835
 * p9_fd_close - shutdown file descriptor transport
 * @client: client instance
836 837
 *
 */
838

839
static void p9_fd_close(struct p9_client *client)
840 841 842
{
	struct p9_trans_fd *ts;

843
	if (!client)
844 845
		return;

846
	ts = client->trans;
847 848 849
	if (!ts)
		return;

850 851
	client->status = Disconnected;

852 853
	p9_conn_destroy(ts->conn);

854 855 856 857
	if (ts->rd)
		fput(ts->rd);
	if (ts->wr)
		fput(ts->wr);
858

859 860 861
	kfree(ts);
}

862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878
/*
 * stolen from NFS - maybe should be made a generic function?
 */
static inline int valid_ipaddr4(const char *buf)
{
	int rc, count, in[4];

	rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
	if (rc != 4)
		return -EINVAL;
	for (count = 0; count < 4; count++) {
		if (in[count] > 255)
			return -EINVAL;
	}
	return 0;
}

879 880
static int
p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
881 882 883 884 885
{
	int err;
	struct socket *csocket;
	struct sockaddr_in sin_server;
	struct p9_fd_opts opts;
886
	struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
887

888 889
	err = parse_opts