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writeback: split writeback_inodes_wb
[linux-2.6/next.git] / net / 9p / trans_fd.c
blob98ce9bcb0e15da4443ce08cd654576c2b235b69f
1 /*
2 * linux/fs/9p/trans_fd.c
3 *
4 * Fd transport layer. Includes deprecated socket layer.
5 *
6 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
7 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
8 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2
13 * as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to:
22 * Free Software Foundation
23 * 51 Franklin Street, Fifth Floor
24 * Boston, MA 02111-1301 USA
25 *
26 */
27
28 #include <linux/in.h>
29 #include <linux/module.h>
30 #include <linux/net.h>
31 #include <linux/ipv6.h>
32 #include <linux/kthread.h>
33 #include <linux/errno.h>
34 #include <linux/kernel.h>
35 #include <linux/un.h>
36 #include <linux/uaccess.h>
37 #include <linux/inet.h>
38 #include <linux/idr.h>
39 #include <linux/file.h>
40 #include <linux/parser.h>
41 #include <linux/slab.h>
42 #include <net/9p/9p.h>
43 #include <net/9p/client.h>
44 #include <net/9p/transport.h>
45
46 #include <linux/syscalls.h> /* killme */
47
48 #define P9_PORT 564
49 #define MAX_SOCK_BUF (64*1024)
50 #define MAXPOLLWADDR 2
51
52 /**
53 * struct p9_fd_opts - per-transport options
54 * @rfd: file descriptor for reading (trans=fd)
55 * @wfd: file descriptor for writing (trans=fd)
56 * @port: port to connect to (trans=tcp)
57 *
58 */
59
60 struct p9_fd_opts {
61 int rfd;
62 int wfd;
63 u16 port;
64 };
65
66 /**
67 * struct p9_trans_fd - transport state
68 * @rd: reference to file to read from
69 * @wr: reference of file to write to
70 * @conn: connection state reference
71 *
72 */
73
74 struct p9_trans_fd {
75 struct file *rd;
76 struct file *wr;
77 struct p9_conn *conn;
78 };
79
80 /*
81 * Option Parsing (code inspired by NFS code)
82 * - a little lazy - parse all fd-transport options
83 */
84
85 enum {
86 /* Options that take integer arguments */
87 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
88 };
89
90 static const match_table_t tokens = {
91 {Opt_port, "port=%u"},
92 {Opt_rfdno, "rfdno=%u"},
93 {Opt_wfdno, "wfdno=%u"},
94 {Opt_err, NULL},
95 };
96
97 enum {
98 Rworksched = 1, /* read work scheduled or running */
99 Rpending = 2, /* can read */
100 Wworksched = 4, /* write work scheduled or running */
101 Wpending = 8, /* can write */
102 };
103
104 struct p9_poll_wait {
105 struct p9_conn *conn;
106 wait_queue_t wait;
107 wait_queue_head_t *wait_addr;
108 };
109
110 /**
111 * struct p9_conn - fd mux connection state information
112 * @mux_list: list link for mux to manage multiple connections (?)
113 * @client: reference to client instance for this connection
114 * @err: error state
115 * @req_list: accounting for requests which have been sent
116 * @unsent_req_list: accounting for requests that haven't been sent
117 * @req: current request being processed (if any)
118 * @tmp_buf: temporary buffer to read in header
119 * @rsize: amount to read for current frame
120 * @rpos: read position in current frame
121 * @rbuf: current read buffer
122 * @wpos: write position for current frame
123 * @wsize: amount of data to write for current frame
124 * @wbuf: current write buffer
125 * @poll_pending_link: pending links to be polled per conn
126 * @poll_wait: array of wait_q's for various worker threads
127 * @pt: poll state
128 * @rq: current read work
129 * @wq: current write work
130 * @wsched: ????
131 *
132 */
133
134 struct p9_conn {
135 struct list_head mux_list;
136 struct p9_client *client;
137 int err;
138 struct list_head req_list;
139 struct list_head unsent_req_list;
140 struct p9_req_t *req;
141 char tmp_buf[7];
142 int rsize;
143 int rpos;
144 char *rbuf;
145 int wpos;
146 int wsize;
147 char *wbuf;
148 struct list_head poll_pending_link;
149 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
150 poll_table pt;
151 struct work_struct rq;
152 struct work_struct wq;
153 unsigned long wsched;
154 };
155
156 static DEFINE_SPINLOCK(p9_poll_lock);
157 static LIST_HEAD(p9_poll_pending_list);
158 static struct workqueue_struct *p9_mux_wq;
159 static struct task_struct *p9_poll_task;
160
161 static void p9_mux_poll_stop(struct p9_conn *m)
162 {
163 unsigned long flags;
164 int i;
165
166 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
167 struct p9_poll_wait *pwait = &m->poll_wait[i];
168
169 if (pwait->wait_addr) {
170 remove_wait_queue(pwait->wait_addr, &pwait->wait);
171 pwait->wait_addr = NULL;
172 }
173 }
174
175 spin_lock_irqsave(&p9_poll_lock, flags);
176 list_del_init(&m->poll_pending_link);
177 spin_unlock_irqrestore(&p9_poll_lock, flags);
178 }
179
180 /**
181 * p9_conn_cancel - cancel all pending requests with error
182 * @m: mux data
183 * @err: error code
184 *
185 */
186
187 static void p9_conn_cancel(struct p9_conn *m, int err)
188 {
189 struct p9_req_t *req, *rtmp;
190 unsigned long flags;
191 LIST_HEAD(cancel_list);
192
193 P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
194
195 spin_lock_irqsave(&m->client->lock, flags);
196
197 if (m->err) {
198 spin_unlock_irqrestore(&m->client->lock, flags);
199 return;
200 }
201
202 m->err = err;
203
204 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
205 req->status = REQ_STATUS_ERROR;
206 if (!req->t_err)
207 req->t_err = err;
208 list_move(&req->req_list, &cancel_list);
209 }
210 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
211 req->status = REQ_STATUS_ERROR;
212 if (!req->t_err)
213 req->t_err = err;
214 list_move(&req->req_list, &cancel_list);
215 }
216 spin_unlock_irqrestore(&m->client->lock, flags);
217
218 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
219 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
220 list_del(&req->req_list);
221 p9_client_cb(m->client, req);
222 }
223 }
224
225 static unsigned int
226 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
227 {
228 int ret, n;
229 struct p9_trans_fd *ts = NULL;
230
231 if (client && client->status == Connected)
232 ts = client->trans;
233
234 if (!ts)
235 return -EREMOTEIO;
236
237 if (!ts->rd->f_op || !ts->rd->f_op->poll)
238 return -EIO;
239
240 if (!ts->wr->f_op || !ts->wr->f_op->poll)
241 return -EIO;
242
243 ret = ts->rd->f_op->poll(ts->rd, pt);
244 if (ret < 0)
245 return ret;
246
247 if (ts->rd != ts->wr) {
248 n = ts->wr->f_op->poll(ts->wr, pt);
249 if (n < 0)
250 return n;
251 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
252 }
253
254 return ret;
255 }
256
257 /**
258 * p9_fd_read- read from a fd
259 * @client: client instance
260 * @v: buffer to receive data into
261 * @len: size of receive buffer
262 *
263 */
264
265 static int p9_fd_read(struct p9_client *client, void *v, int len)
266 {
267 int ret;
268 struct p9_trans_fd *ts = NULL;
269
270 if (client && client->status != Disconnected)
271 ts = client->trans;
272
273 if (!ts)
274 return -EREMOTEIO;
275
276 if (!(ts->rd->f_flags & O_NONBLOCK))
277 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
278
279 ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
280 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
281 client->status = Disconnected;
282 return ret;
283 }
284
285 /**
286 * p9_read_work - called when there is some data to be read from a transport
287 * @work: container of work to be done
288 *
289 */
290
291 static void p9_read_work(struct work_struct *work)
292 {
293 int n, err;
294 struct p9_conn *m;
295
296 m = container_of(work, struct p9_conn, rq);
297
298 if (m->err < 0)
299 return;
300
301 P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
302
303 if (!m->rbuf) {
304 m->rbuf = m->tmp_buf;
305 m->rpos = 0;
306 m->rsize = 7; /* start by reading header */
307 }
308
309 clear_bit(Rpending, &m->wsched);
310 P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
311 m->rpos, m->rsize, m->rsize-m->rpos);
312 err = p9_fd_read(m->client, m->rbuf + m->rpos,
313 m->rsize - m->rpos);
314 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
315 if (err == -EAGAIN) {
316 clear_bit(Rworksched, &m->wsched);
317 return;
318 }
319
320 if (err <= 0)
321 goto error;
322
323 m->rpos += err;
324
325 if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
326 u16 tag;
327 P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
328
329 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
330 if (n >= m->client->msize) {
331 P9_DPRINTK(P9_DEBUG_ERROR,
332 "requested packet size too big: %d\n", n);
333 err = -EIO;
334 goto error;
335 }
336
337 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
338 P9_DPRINTK(P9_DEBUG_TRANS,
339 "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
340
341 m->req = p9_tag_lookup(m->client, tag);
342 if (!m->req || (m->req->status != REQ_STATUS_SENT &&
343 m->req->status != REQ_STATUS_FLSH)) {
344 P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
345 tag);
346 err = -EIO;
347 goto error;
348 }
349
350 if (m->req->rc == NULL) {
351 m->req->rc = kmalloc(sizeof(struct p9_fcall) +
352 m->client->msize, GFP_KERNEL);
353 if (!m->req->rc) {
354 m->req = NULL;
355 err = -ENOMEM;
356 goto error;
357 }
358 }
359 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
360 memcpy(m->rbuf, m->tmp_buf, m->rsize);
361 m->rsize = n;
362 }
363
364 /* not an else because some packets (like clunk) have no payload */
365 if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
366 P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
367 spin_lock(&m->client->lock);
368 if (m->req->status != REQ_STATUS_ERROR)
369 m->req->status = REQ_STATUS_RCVD;
370 list_del(&m->req->req_list);
371 spin_unlock(&m->client->lock);
372 p9_client_cb(m->client, m->req);
373 m->rbuf = NULL;
374 m->rpos = 0;
375 m->rsize = 0;
376 m->req = NULL;
377 }
378
379 if (!list_empty(&m->req_list)) {
380 if (test_and_clear_bit(Rpending, &m->wsched))
381 n = POLLIN;
382 else
383 n = p9_fd_poll(m->client, NULL);
384
385 if (n & POLLIN) {
386 P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
387 queue_work(p9_mux_wq, &m->rq);
388 } else
389 clear_bit(Rworksched, &m->wsched);
390 } else
391 clear_bit(Rworksched, &m->wsched);
392
393 return;
394 error:
395 p9_conn_cancel(m, err);
396 clear_bit(Rworksched, &m->wsched);
397 }
398
399 /**
400 * p9_fd_write - write to a socket
401 * @client: client instance
402 * @v: buffer to send data from
403 * @len: size of send buffer
404 *
405 */
406
407 static int p9_fd_write(struct p9_client *client, void *v, int len)
408 {
409 int ret;
410 mm_segment_t oldfs;
411 struct p9_trans_fd *ts = NULL;
412
413 if (client && client->status != Disconnected)
414 ts = client->trans;
415
416 if (!ts)
417 return -EREMOTEIO;
418
419 if (!(ts->wr->f_flags & O_NONBLOCK))
420 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
421
422 oldfs = get_fs();
423 set_fs(get_ds());
424 /* The cast to a user pointer is valid due to the set_fs() */
425 ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
426 set_fs(oldfs);
427
428 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
429 client->status = Disconnected;
430 return ret;
431 }
432
433 /**
434 * p9_write_work - called when a transport can send some data
435 * @work: container for work to be done
436 *
437 */
438
439 static void p9_write_work(struct work_struct *work)
440 {
441 int n, err;
442 struct p9_conn *m;
443 struct p9_req_t *req;
444
445 m = container_of(work, struct p9_conn, wq);
446
447 if (m->err < 0) {
448 clear_bit(Wworksched, &m->wsched);
449 return;
450 }
451
452 if (!m->wsize) {
453 if (list_empty(&m->unsent_req_list)) {
454 clear_bit(Wworksched, &m->wsched);
455 return;
456 }
457
458 spin_lock(&m->client->lock);
459 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
460 req_list);
461 req->status = REQ_STATUS_SENT;
462 P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
463 list_move_tail(&req->req_list, &m->req_list);
464
465 m->wbuf = req->tc->sdata;
466 m->wsize = req->tc->size;
467 m->wpos = 0;
468 spin_unlock(&m->client->lock);
469 }
470
471 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
472 m->wsize);
473 clear_bit(Wpending, &m->wsched);
474 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
475 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
476 if (err == -EAGAIN) {
477 clear_bit(Wworksched, &m->wsched);
478 return;
479 }
480
481 if (err < 0)
482 goto error;
483 else if (err == 0) {
484 err = -EREMOTEIO;
485 goto error;
486 }
487
488 m->wpos += err;
489 if (m->wpos == m->wsize)
490 m->wpos = m->wsize = 0;
491
492 if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
493 if (test_and_clear_bit(Wpending, &m->wsched))
494 n = POLLOUT;
495 else
496 n = p9_fd_poll(m->client, NULL);
497
498 if (n & POLLOUT) {
499 P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
500 queue_work(p9_mux_wq, &m->wq);
501 } else
502 clear_bit(Wworksched, &m->wsched);
503 } else
504 clear_bit(Wworksched, &m->wsched);
505
506 return;
507
508 error:
509 p9_conn_cancel(m, err);
510 clear_bit(Wworksched, &m->wsched);
511 }
512
513 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
514 {
515 struct p9_poll_wait *pwait =
516 container_of(wait, struct p9_poll_wait, wait);
517 struct p9_conn *m = pwait->conn;
518 unsigned long flags;
519 DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
520
521 spin_lock_irqsave(&p9_poll_lock, flags);
522 if (list_empty(&m->poll_pending_link))
523 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
524 spin_unlock_irqrestore(&p9_poll_lock, flags);
525
526 /* perform the default wake up operation */
527 return default_wake_function(&dummy_wait, mode, sync, key);
528 }
529
530 /**
531 * p9_pollwait - add poll task to the wait queue
532 * @filp: file pointer being polled
533 * @wait_address: wait_q to block on
534 * @p: poll state
535 *
536 * called by files poll operation to add v9fs-poll task to files wait queue
537 */
538
539 static void
540 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
541 {
542 struct p9_conn *m = container_of(p, struct p9_conn, pt);
543 struct p9_poll_wait *pwait = NULL;
544 int i;
545
546 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
547 if (m->poll_wait[i].wait_addr == NULL) {
548 pwait = &m->poll_wait[i];
549 break;
550 }
551 }
552
553 if (!pwait) {
554 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
555 return;
556 }
557
558 pwait->conn = m;
559 pwait->wait_addr = wait_address;
560 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
561 add_wait_queue(wait_address, &pwait->wait);
562 }
563
564 /**
565 * p9_conn_create - allocate and initialize the per-session mux data
566 * @client: client instance
567 *
568 * 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 {
573 int n;
574 struct p9_conn *m;
575
576 P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
577 client->msize);
578 m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
579 if (!m)
580 return ERR_PTR(-ENOMEM);
581
582 INIT_LIST_HEAD(&m->mux_list);
583 m->client = client;
584
585 INIT_LIST_HEAD(&m->req_list);
586 INIT_LIST_HEAD(&m->unsent_req_list);
587 INIT_WORK(&m->rq, p9_read_work);
588 INIT_WORK(&m->wq, p9_write_work);
589 INIT_LIST_HEAD(&m->poll_pending_link);
590 init_poll_funcptr(&m->pt, p9_pollwait);
591
592 n = p9_fd_poll(client, &m->pt);
593 if (n & POLLIN) {
594 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
595 set_bit(Rpending, &m->wsched);
596 }
597
598 if (n & POLLOUT) {
599 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
600 set_bit(Wpending, &m->wsched);
601 }
602
603 return m;
604 }
605
606 /**
607 * p9_poll_mux - polls a mux and schedules read or write works if necessary
608 * @m: connection to poll
609 *
610 */
611
612 static void p9_poll_mux(struct p9_conn *m)
613 {
614 int n;
615
616 if (m->err < 0)
617 return;
618
619 n = p9_fd_poll(m->client, NULL);
620 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
621 P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
622 if (n >= 0)
623 n = -ECONNRESET;
624 p9_conn_cancel(m, n);
625 }
626
627 if (n & POLLIN) {
628 set_bit(Rpending, &m->wsched);
629 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
630 if (!test_and_set_bit(Rworksched, &m->wsched)) {
631 P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
632 queue_work(p9_mux_wq, &m->rq);
633 }
634 }
635
636 if (n & POLLOUT) {
637 set_bit(Wpending, &m->wsched);
638 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
639 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
640 !test_and_set_bit(Wworksched, &m->wsched)) {
641 P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
642 queue_work(p9_mux_wq, &m->wq);
643 }
644 }
645 }
646
647 /**
648 * p9_fd_request - send 9P request
649 * The function can sleep until the request is scheduled for sending.
650 * The function can be interrupted. Return from the function is not
651 * a guarantee that the request is sent successfully.
652 *
653 * @client: client instance
654 * @req: request to be sent
655 *
656 */
657
658 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
659 {
660 int n;
661 struct p9_trans_fd *ts = client->trans;
662 struct p9_conn *m = ts->conn;
663
664 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
665 current, req->tc, req->tc->id);
666 if (m->err < 0)
667 return m->err;
668
669 spin_lock(&client->lock);
670 req->status = REQ_STATUS_UNSENT;
671 list_add_tail(&req->req_list, &m->unsent_req_list);
672 spin_unlock(&client->lock);
673
674 if (test_and_clear_bit(Wpending, &m->wsched))
675 n = POLLOUT;
676 else
677 n = p9_fd_poll(m->client, NULL);
678
679 if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
680 queue_work(p9_mux_wq, &m->wq);
681
682 return 0;
683 }
684
685 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
686 {
687 int ret = 1;
688
689 P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
690
691 spin_lock(&client->lock);
692
693 if (req->status == REQ_STATUS_UNSENT) {
694 list_del(&req->req_list);
695 req->status = REQ_STATUS_FLSHD;
696 ret = 0;
697 } else if (req->status == REQ_STATUS_SENT)
698 req->status = REQ_STATUS_FLSH;
699
700 spin_unlock(&client->lock);
701
702 return ret;
703 }
704
705 /**
706 * parse_opts - parse mount options into p9_fd_opts structure
707 * @params: options string passed from mount
708 * @opts: fd transport-specific structure to parse options into
709 *
710 * Returns 0 upon success, -ERRNO upon failure
711 */
712
713 static int parse_opts(char *params, struct p9_fd_opts *opts)
714 {
715 char *p;
716 substring_t args[MAX_OPT_ARGS];
717 int option;
718 char *options, *tmp_options;
719 int ret;
720
721 opts->port = P9_PORT;
722 opts->rfd = ~0;
723 opts->wfd = ~0;
724
725 if (!params)
726 return 0;
727
728 tmp_options = kstrdup(params, GFP_KERNEL);
729 if (!tmp_options) {
730 P9_DPRINTK(P9_DEBUG_ERROR,
731 "failed to allocate copy of option string\n");
732 return -ENOMEM;
733 }
734 options = tmp_options;
735
736 while ((p = strsep(&options, ",")) != NULL) {
737 int token;
738 int r;
739 if (!*p)
740 continue;
741 token = match_token(p, tokens, args);
742 if (token != Opt_err) {
743 r = match_int(&args[0], &option);
744 if (r < 0) {
745 P9_DPRINTK(P9_DEBUG_ERROR,
746 "integer field, but no integer?\n");
747 ret = r;
748 continue;
749 }
750 }
751 switch (token) {
752 case Opt_port:
753 opts->port = option;
754 break;
755 case Opt_rfdno:
756 opts->rfd = option;
757 break;
758 case Opt_wfdno:
759 opts->wfd = option;
760 break;
761 default:
762 continue;
763 }
764 }
765
766 kfree(tmp_options);
767 return 0;
768 }
769
770 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
771 {
772 struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
773 GFP_KERNEL);
774 if (!ts)
775 return -ENOMEM;
776
777 ts->rd = fget(rfd);
778 ts->wr = fget(wfd);
779 if (!ts->rd || !ts->wr) {
780 if (ts->rd)
781 fput(ts->rd);
782 if (ts->wr)
783 fput(ts->wr);
784 kfree(ts);
785 return -EIO;
786 }
787
788 client->trans = ts;
789 client->status = Connected;
790
791 return 0;
792 }
793
794 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
795 {
796 struct p9_trans_fd *p;
797 int ret, fd;
798
799 p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
800 if (!p)
801 return -ENOMEM;
802
803 csocket->sk->sk_allocation = GFP_NOIO;
804 fd = sock_map_fd(csocket, 0);
805 if (fd < 0) {
806 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
807 sock_release(csocket);
808 kfree(p);
809 return fd;
810 }
811
812 get_file(csocket->file);
813 get_file(csocket->file);
814 p->wr = p->rd = csocket->file;
815 client->trans = p;
816 client->status = Connected;
817
818 sys_close(fd); /* still racy */
819
820 p->rd->f_flags |= O_NONBLOCK;
821
822 p->conn = p9_conn_create(client);
823 if (IS_ERR(p->conn)) {
824 ret = PTR_ERR(p->conn);
825 p->conn = NULL;
826 kfree(p);
827 sockfd_put(csocket);
828 sockfd_put(csocket);
829 return ret;
830 }
831 return 0;
832 }
833
834 /**
835 * p9_mux_destroy - cancels all pending requests and frees mux resources
836 * @m: mux to destroy
837 *
838 */
839
840 static void p9_conn_destroy(struct p9_conn *m)
841 {
842 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
843 m->mux_list.prev, m->mux_list.next);
844
845 p9_mux_poll_stop(m);
846 cancel_work_sync(&m->rq);
847 cancel_work_sync(&m->wq);
848
849 p9_conn_cancel(m, -ECONNRESET);
850
851 m->client = NULL;
852 kfree(m);
853 }
854
855 /**
856 * p9_fd_close - shutdown file descriptor transport
857 * @client: client instance
858 *
859 */
860
861 static void p9_fd_close(struct p9_client *client)
862 {
863 struct p9_trans_fd *ts;
864
865 if (!client)
866 return;
867
868 ts = client->trans;
869 if (!ts)
870 return;
871
872 client->status = Disconnected;
873
874 p9_conn_destroy(ts->conn);
875
876 if (ts->rd)
877 fput(ts->rd);
878 if (ts->wr)
879 fput(ts->wr);
880
881 kfree(ts);
882 }
883
884 /*
885 * stolen from NFS - maybe should be made a generic function?
886 */
887 static inline int valid_ipaddr4(const char *buf)
888 {
889 int rc, count, in[4];
890
891 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
892 if (rc != 4)
893 return -EINVAL;
894 for (count = 0; count < 4; count++) {
895 if (in[count] > 255)
896 return -EINVAL;
897 }
898 return 0;
899 }
900
901 static int
902 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
903 {
904 int err;
905 struct socket *csocket;
906 struct sockaddr_in sin_server;
907 struct p9_fd_opts opts;
908
909 err = parse_opts(args, &opts);
910 if (err < 0)
911 return err;
912
913 if (valid_ipaddr4(addr) < 0)
914 return -EINVAL;
915
916 csocket = NULL;
917
918 sin_server.sin_family = AF_INET;
919 sin_server.sin_addr.s_addr = in_aton(addr);
920 sin_server.sin_port = htons(opts.port);
921 err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
922
923 if (err) {
924 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
925 return err;
926 }
927
928 err = csocket->ops->connect(csocket,
929 (struct sockaddr *)&sin_server,
930 sizeof(struct sockaddr_in), 0);
931 if (err < 0) {
932 P9_EPRINTK(KERN_ERR,
933 "p9_trans_tcp: problem connecting socket to %s\n",
934 addr);
935 sock_release(csocket);
936 return err;
937 }
938
939 return p9_socket_open(client, csocket);
940 }
941
942 static int
943 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
944 {
945 int err;
946 struct socket *csocket;
947 struct sockaddr_un sun_server;
948
949 csocket = NULL;
950
951 if (strlen(addr) > UNIX_PATH_MAX) {
952 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
953 addr);
954 return -ENAMETOOLONG;
955 }
956
957 sun_server.sun_family = PF_UNIX;
958 strcpy(sun_server.sun_path, addr);
959 err = sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
960 if (err < 0) {
961 P9_EPRINTK(KERN_ERR, "p9_trans_unix: problem creating socket\n");
962 return err;
963 }
964 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
965 sizeof(struct sockaddr_un) - 1, 0);
966 if (err < 0) {
967 P9_EPRINTK(KERN_ERR,
968 "p9_trans_unix: problem connecting socket: %s: %d\n",
969 addr, err);
970 sock_release(csocket);
971 return err;
972 }
973
974 return p9_socket_open(client, csocket);
975 }
976
977 static int
978 p9_fd_create(struct p9_client *client, const char *addr, char *args)
979 {
980 int err;
981 struct p9_fd_opts opts;
982 struct p9_trans_fd *p;
983
984 parse_opts(args, &opts);
985
986 if (opts.rfd == ~0 || opts.wfd == ~0) {
987 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
988 return -ENOPROTOOPT;
989 }
990
991 err = p9_fd_open(client, opts.rfd, opts.wfd);
992 if (err < 0)
993 return err;
994
995 p = (struct p9_trans_fd *) client->trans;
996 p->conn = p9_conn_create(client);
997 if (IS_ERR(p->conn)) {
998 err = PTR_ERR(p->conn);
999 p->conn = NULL;
1000 fput(p->rd);
1001 fput(p->wr);
1002 return err;
1003 }
1004
1005 return 0;
1006 }
1007
1008 static struct p9_trans_module p9_tcp_trans = {
1009 .name = "tcp",
1010 .maxsize = MAX_SOCK_BUF,
1011 .def = 1,
1012 .create = p9_fd_create_tcp,
1013 .close = p9_fd_close,
1014 .request = p9_fd_request,
1015 .cancel = p9_fd_cancel,
1016 .owner = THIS_MODULE,
1017 };
1018
1019 static struct p9_trans_module p9_unix_trans = {
1020 .name = "unix",
1021 .maxsize = MAX_SOCK_BUF,
1022 .def = 0,
1023 .create = p9_fd_create_unix,
1024 .close = p9_fd_close,
1025 .request = p9_fd_request,
1026 .cancel = p9_fd_cancel,
1027 .owner = THIS_MODULE,
1028 };
1029
1030 static struct p9_trans_module p9_fd_trans = {
1031 .name = "fd",
1032 .maxsize = MAX_SOCK_BUF,
1033 .def = 0,
1034 .create = p9_fd_create,
1035 .close = p9_fd_close,
1036 .request = p9_fd_request,
1037 .cancel = p9_fd_cancel,
1038 .owner = THIS_MODULE,
1039 };
1040
1041 /**
1042 * p9_poll_proc - poll worker thread
1043 * @a: thread state and arguments
1044 *
1045 * polls all v9fs transports for new events and queues the appropriate
1046 * work to the work queue
1047 *
1048 */
1049
1050 static int p9_poll_proc(void *a)
1051 {
1052 unsigned long flags;
1053
1054 P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
1055 repeat:
1056 spin_lock_irqsave(&p9_poll_lock, flags);
1057 while (!list_empty(&p9_poll_pending_list)) {
1058 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1059 struct p9_conn,
1060 poll_pending_link);
1061 list_del_init(&conn->poll_pending_link);
1062 spin_unlock_irqrestore(&p9_poll_lock, flags);
1063
1064 p9_poll_mux(conn);
1065
1066 spin_lock_irqsave(&p9_poll_lock, flags);
1067 }
1068 spin_unlock_irqrestore(&p9_poll_lock, flags);
1069
1070 set_current_state(TASK_INTERRUPTIBLE);
1071 if (list_empty(&p9_poll_pending_list)) {
1072 P9_DPRINTK(P9_DEBUG_TRANS, "sleeping...\n");
1073 schedule();
1074 }
1075 __set_current_state(TASK_RUNNING);
1076
1077 if (!kthread_should_stop())
1078 goto repeat;
1079
1080 P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
1081 return 0;
1082 }
1083
1084 int p9_trans_fd_init(void)
1085 {
1086 p9_mux_wq = create_workqueue("v9fs");
1087 if (!p9_mux_wq) {
1088 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1089 return -ENOMEM;
1090 }
1091
1092 p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1093 if (IS_ERR(p9_poll_task)) {
1094 destroy_workqueue(p9_mux_wq);
1095 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1096 return PTR_ERR(p9_poll_task);
1097 }
1098
1099 v9fs_register_trans(&p9_tcp_trans);
1100 v9fs_register_trans(&p9_unix_trans);
1101 v9fs_register_trans(&p9_fd_trans);
1102
1103 return 0;
1104 }
1105
1106 void p9_trans_fd_exit(void)
1107 {
1108 kthread_stop(p9_poll_task);
1109 v9fs_unregister_trans(&p9_tcp_trans);
1110 v9fs_unregister_trans(&p9_unix_trans);
1111 v9fs_unregister_trans(&p9_fd_trans);
1112
1113 destroy_workqueue(p9_mux_wq);
1114 }
linux-next