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9p: make rpc code common and rework flush code
[deliverable/linux.git] / net / 9p / trans_fd.c
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 <net/9p/9p.h>
42 #include <net/9p/client.h>
43 #include <net/9p/transport.h>
44
45 #define P9_PORT 564
46 #define MAX_SOCK_BUF (64*1024)
47 #define MAXPOLLWADDR 2
48
49 /**
50 * struct p9_fd_opts - per-transport options
51 * @rfd: file descriptor for reading (trans=fd)
52 * @wfd: file descriptor for writing (trans=fd)
53 * @port: port to connect to (trans=tcp)
54 *
55 */
56
57 struct p9_fd_opts {
58 int rfd;
59 int wfd;
60 u16 port;
61 };
62
63 /**
64 * struct p9_trans_fd - transport state
65 * @rd: reference to file to read from
66 * @wr: reference of file to write to
67 * @conn: connection state reference
68 *
69 */
70
71 struct p9_trans_fd {
72 struct file *rd;
73 struct file *wr;
74 struct p9_conn *conn;
75 };
76
77 /*
78 * Option Parsing (code inspired by NFS code)
79 * - a little lazy - parse all fd-transport options
80 */
81
82 enum {
83 /* Options that take integer arguments */
84 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
85 };
86
87 static const match_table_t tokens = {
88 {Opt_port, "port=%u"},
89 {Opt_rfdno, "rfdno=%u"},
90 {Opt_wfdno, "wfdno=%u"},
91 {Opt_err, NULL},
92 };
93
94 enum {
95 Rworksched = 1, /* read work scheduled or running */
96 Rpending = 2, /* can read */
97 Wworksched = 4, /* write work scheduled or running */
98 Wpending = 8, /* can write */
99 };
100
101 struct p9_poll_wait {
102 struct p9_conn *conn;
103 wait_queue_t wait;
104 wait_queue_head_t *wait_addr;
105 };
106
107 /**
108 * struct p9_conn - fd mux connection state information
109 * @mux_list: list link for mux to manage multiple connections (?)
110 * @client: reference to client instance for this connection
111 * @err: error state
112 * @req_list: accounting for requests which have been sent
113 * @unsent_req_list: accounting for requests that haven't been sent
114 * @req: current request being processed (if any)
115 * @tmp_buf: temporary buffer to read in header
116 * @rsize: amount to read for current frame
117 * @rpos: read position in current frame
118 * @rbuf: current read buffer
119 * @wpos: write position for current frame
120 * @wsize: amount of data to write for current frame
121 * @wbuf: current write buffer
122 * @poll_wait: array of wait_q's for various worker threads
123 * @poll_waddr: ????
124 * @pt: poll state
125 * @rq: current read work
126 * @wq: current write work
127 * @wsched: ????
128 *
129 */
130
131 struct p9_conn {
132 struct list_head mux_list;
133 struct p9_client *client;
134 int err;
135 struct list_head req_list;
136 struct list_head unsent_req_list;
137 struct p9_req_t *req;
138 char tmp_buf[7];
139 int rsize;
140 int rpos;
141 char *rbuf;
142 int wpos;
143 int wsize;
144 char *wbuf;
145 struct list_head poll_pending_link;
146 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
147 poll_table pt;
148 struct work_struct rq;
149 struct work_struct wq;
150 unsigned long wsched;
151 };
152
153 static DEFINE_SPINLOCK(p9_poll_lock);
154 static LIST_HEAD(p9_poll_pending_list);
155 static struct workqueue_struct *p9_mux_wq;
156 static struct task_struct *p9_poll_task;
157
158 static void p9_mux_poll_stop(struct p9_conn *m)
159 {
160 unsigned long flags;
161 int i;
162
163 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
164 struct p9_poll_wait *pwait = &m->poll_wait[i];
165
166 if (pwait->wait_addr) {
167 remove_wait_queue(pwait->wait_addr, &pwait->wait);
168 pwait->wait_addr = NULL;
169 }
170 }
171
172 spin_lock_irqsave(&p9_poll_lock, flags);
173 list_del_init(&m->poll_pending_link);
174 spin_unlock_irqrestore(&p9_poll_lock, flags);
175 }
176
177 /**
178 * p9_conn_cancel - cancel all pending requests with error
179 * @m: mux data
180 * @err: error code
181 *
182 */
183
184 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 m->err = err;
192 spin_lock_irqsave(&m->client->lock, flags);
193 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
194 req->status = REQ_STATUS_ERROR;
195 if (!req->t_err)
196 req->t_err = err;
197 list_move(&req->req_list, &cancel_list);
198 }
199 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
200 req->status = REQ_STATUS_ERROR;
201 if (!req->t_err)
202 req->t_err = err;
203 list_move(&req->req_list, &cancel_list);
204 }
205 spin_unlock_irqrestore(&m->client->lock, flags);
206
207 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
208 list_del(&req->req_list);
209 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
210 p9_client_cb(m->client, req);
211 }
212 }
213
214 static unsigned int
215 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
216 {
217 int ret, n;
218 struct p9_trans_fd *ts = NULL;
219
220 if (client && client->status == Connected)
221 ts = client->trans;
222
223 if (!ts)
224 return -EREMOTEIO;
225
226 if (!ts->rd->f_op || !ts->rd->f_op->poll)
227 return -EIO;
228
229 if (!ts->wr->f_op || !ts->wr->f_op->poll)
230 return -EIO;
231
232 ret = ts->rd->f_op->poll(ts->rd, pt);
233 if (ret < 0)
234 return ret;
235
236 if (ts->rd != ts->wr) {
237 n = ts->wr->f_op->poll(ts->wr, pt);
238 if (n < 0)
239 return n;
240 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
241 }
242
243 return ret;
244 }
245
246 /**
247 * p9_fd_read- read from a fd
248 * @client: client instance
249 * @v: buffer to receive data into
250 * @len: size of receive buffer
251 *
252 */
253
254 static int p9_fd_read(struct p9_client *client, void *v, int len)
255 {
256 int ret;
257 struct p9_trans_fd *ts = NULL;
258
259 if (client && client->status != Disconnected)
260 ts = client->trans;
261
262 if (!ts)
263 return -EREMOTEIO;
264
265 if (!(ts->rd->f_flags & O_NONBLOCK))
266 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
267
268 ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
269 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
270 client->status = Disconnected;
271 return ret;
272 }
273
274 /**
275 * p9_read_work - called when there is some data to be read from a transport
276 * @work: container of work to be done
277 *
278 */
279
280 static void p9_read_work(struct work_struct *work)
281 {
282 int n, err;
283 struct p9_conn *m;
284
285 m = container_of(work, struct p9_conn, rq);
286
287 if (m->err < 0)
288 return;
289
290 P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
291
292 if (!m->rbuf) {
293 m->rbuf = m->tmp_buf;
294 m->rpos = 0;
295 m->rsize = 7; /* start by reading header */
296 }
297
298 clear_bit(Rpending, &m->wsched);
299 P9_DPRINTK(P9_DEBUG_MUX, "read mux %p pos %d size: %d = %d\n", m,
300 m->rpos, m->rsize, m->rsize-m->rpos);
301 err = p9_fd_read(m->client, m->rbuf + m->rpos,
302 m->rsize - m->rpos);
303 P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
304 if (err == -EAGAIN) {
305 clear_bit(Rworksched, &m->wsched);
306 return;
307 }
308
309 if (err <= 0)
310 goto error;
311
312 m->rpos += err;
313
314 if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
315 u16 tag;
316 P9_DPRINTK(P9_DEBUG_MUX, "got new header\n");
317
318 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
319 if (n >= m->client->msize) {
320 P9_DPRINTK(P9_DEBUG_ERROR,
321 "requested packet size too big: %d\n", n);
322 err = -EIO;
323 goto error;
324 }
325
326 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
327 P9_DPRINTK(P9_DEBUG_MUX, "mux %p pkt: size: %d bytes tag: %d\n",
328 m, n, tag);
329
330 m->req = p9_tag_lookup(m->client, tag);
331 if (!m->req) {
332 P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
333 tag);
334 err = -EIO;
335 goto error;
336 }
337
338 if (m->req->rc == NULL) {
339 m->req->rc = kmalloc(sizeof(struct p9_fcall) +
340 m->client->msize, GFP_KERNEL);
341 if (!m->req->rc) {
342 m->req = NULL;
343 err = -ENOMEM;
344 goto error;
345 }
346 }
347 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
348 memcpy(m->rbuf, m->tmp_buf, m->rsize);
349 m->rsize = n;
350 }
351
352 /* not an else because some packets (like clunk) have no payload */
353 if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
354 P9_DPRINTK(P9_DEBUG_MUX, "got new packet\n");
355
356 list_del(&m->req->req_list);
357 p9_client_cb(m->client, m->req);
358
359 m->rbuf = NULL;
360 m->rpos = 0;
361 m->rsize = 0;
362 m->req = NULL;
363 }
364
365 if (!list_empty(&m->req_list)) {
366 if (test_and_clear_bit(Rpending, &m->wsched))
367 n = POLLIN;
368 else
369 n = p9_fd_poll(m->client, NULL);
370
371 if (n & POLLIN) {
372 P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
373 queue_work(p9_mux_wq, &m->rq);
374 } else
375 clear_bit(Rworksched, &m->wsched);
376 } else
377 clear_bit(Rworksched, &m->wsched);
378
379 return;
380 error:
381 p9_conn_cancel(m, err);
382 clear_bit(Rworksched, &m->wsched);
383 }
384
385 /**
386 * p9_fd_write - write to a socket
387 * @client: client instance
388 * @v: buffer to send data from
389 * @len: size of send buffer
390 *
391 */
392
393 static int p9_fd_write(struct p9_client *client, void *v, int len)
394 {
395 int ret;
396 mm_segment_t oldfs;
397 struct p9_trans_fd *ts = NULL;
398
399 if (client && client->status != Disconnected)
400 ts = client->trans;
401
402 if (!ts)
403 return -EREMOTEIO;
404
405 if (!(ts->wr->f_flags & O_NONBLOCK))
406 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
407
408 oldfs = get_fs();
409 set_fs(get_ds());
410 /* The cast to a user pointer is valid due to the set_fs() */
411 ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
412 set_fs(oldfs);
413
414 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
415 client->status = Disconnected;
416 return ret;
417 }
418
419 /**
420 * p9_write_work - called when a transport can send some data
421 * @work: container for work to be done
422 *
423 */
424
425 static void p9_write_work(struct work_struct *work)
426 {
427 int n, err;
428 struct p9_conn *m;
429 struct p9_req_t *req;
430
431 m = container_of(work, struct p9_conn, wq);
432
433 if (m->err < 0) {
434 clear_bit(Wworksched, &m->wsched);
435 return;
436 }
437
438 if (!m->wsize) {
439 if (list_empty(&m->unsent_req_list)) {
440 clear_bit(Wworksched, &m->wsched);
441 return;
442 }
443
444 spin_lock(&m->client->lock);
445 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
446 req_list);
447 req->status = REQ_STATUS_SENT;
448 list_move_tail(&req->req_list, &m->req_list);
449
450 m->wbuf = req->tc->sdata;
451 m->wsize = req->tc->size;
452 m->wpos = 0;
453 spin_unlock(&m->client->lock);
454 }
455
456 P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
457 m->wsize);
458 clear_bit(Wpending, &m->wsched);
459 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
460 P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
461 if (err == -EAGAIN) {
462 clear_bit(Wworksched, &m->wsched);
463 return;
464 }
465
466 if (err < 0)
467 goto error;
468 else if (err == 0) {
469 err = -EREMOTEIO;
470 goto error;
471 }
472
473 m->wpos += err;
474 if (m->wpos == m->wsize)
475 m->wpos = m->wsize = 0;
476
477 if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
478 if (test_and_clear_bit(Wpending, &m->wsched))
479 n = POLLOUT;
480 else
481 n = p9_fd_poll(m->client, NULL);
482
483 if (n & POLLOUT) {
484 P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
485 queue_work(p9_mux_wq, &m->wq);
486 } else
487 clear_bit(Wworksched, &m->wsched);
488 } else
489 clear_bit(Wworksched, &m->wsched);
490
491 return;
492
493 error:
494 p9_conn_cancel(m, err);
495 clear_bit(Wworksched, &m->wsched);
496 }
497
498 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
499 {
500 struct p9_poll_wait *pwait =
501 container_of(wait, struct p9_poll_wait, wait);
502 struct p9_conn *m = pwait->conn;
503 unsigned long flags;
504 DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
505
506 spin_lock_irqsave(&p9_poll_lock, flags);
507 if (list_empty(&m->poll_pending_link))
508 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
509 spin_unlock_irqrestore(&p9_poll_lock, flags);
510
511 /* perform the default wake up operation */
512 return default_wake_function(&dummy_wait, mode, sync, key);
513 }
514
515 /**
516 * p9_pollwait - add poll task to the wait queue
517 * @filp: file pointer being polled
518 * @wait_address: wait_q to block on
519 * @p: poll state
520 *
521 * called by files poll operation to add v9fs-poll task to files wait queue
522 */
523
524 static void
525 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
526 {
527 struct p9_conn *m = container_of(p, struct p9_conn, pt);
528 struct p9_poll_wait *pwait = NULL;
529 int i;
530
531 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
532 if (m->poll_wait[i].wait_addr == NULL) {
533 pwait = &m->poll_wait[i];
534 break;
535 }
536 }
537
538 if (!pwait) {
539 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
540 return;
541 }
542
543 if (!wait_address) {
544 P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
545 pwait->wait_addr = ERR_PTR(-EIO);
546 return;
547 }
548
549 pwait->conn = m;
550 pwait->wait_addr = wait_address;
551 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
552 add_wait_queue(wait_address, &pwait->wait);
553 }
554
555 /**
556 * p9_conn_create - allocate and initialize the per-session mux data
557 * @client: client instance
558 *
559 * Note: Creates the polling task if this is the first session.
560 */
561
562 static struct p9_conn *p9_conn_create(struct p9_client *client)
563 {
564 int i, n;
565 struct p9_conn *m;
566
567 P9_DPRINTK(P9_DEBUG_MUX, "client %p msize %d\n", client, client->msize);
568 m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
569 if (!m)
570 return ERR_PTR(-ENOMEM);
571
572 INIT_LIST_HEAD(&m->mux_list);
573 m->client = client;
574
575 INIT_LIST_HEAD(&m->req_list);
576 INIT_LIST_HEAD(&m->unsent_req_list);
577 INIT_WORK(&m->rq, p9_read_work);
578 INIT_WORK(&m->wq, p9_write_work);
579 INIT_LIST_HEAD(&m->poll_pending_link);
580 init_poll_funcptr(&m->pt, p9_pollwait);
581
582 n = p9_fd_poll(client, &m->pt);
583 if (n & POLLIN) {
584 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
585 set_bit(Rpending, &m->wsched);
586 }
587
588 if (n & POLLOUT) {
589 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
590 set_bit(Wpending, &m->wsched);
591 }
592
593 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
594 if (IS_ERR(m->poll_wait[i].wait_addr)) {
595 p9_mux_poll_stop(m);
596 kfree(m);
597 /* return the error code */
598 return (void *)m->poll_wait[i].wait_addr;
599 }
600 }
601
602 return m;
603 }
604
605 /**
606 * p9_poll_mux - polls a mux and schedules read or write works if necessary
607 * @m: connection to poll
608 *
609 */
610
611 static void p9_poll_mux(struct p9_conn *m)
612 {
613 int n;
614
615 if (m->err < 0)
616 return;
617
618 n = p9_fd_poll(m->client, NULL);
619 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
620 P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
621 if (n >= 0)
622 n = -ECONNRESET;
623 p9_conn_cancel(m, n);
624 }
625
626 if (n & POLLIN) {
627 set_bit(Rpending, &m->wsched);
628 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
629 if (!test_and_set_bit(Rworksched, &m->wsched)) {
630 P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
631 queue_work(p9_mux_wq, &m->rq);
632 }
633 }
634
635 if (n & POLLOUT) {
636 set_bit(Wpending, &m->wsched);
637 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
638 if ((m->wsize || !list_empty(&m->unsent_req_list))
639 && !test_and_set_bit(Wworksched, &m->wsched)) {
640 P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
641 queue_work(p9_mux_wq, &m->wq);
642 }
643 }
644 }
645
646 /**
647 * p9_fd_request - send 9P request
648 * The function can sleep until the request is scheduled for sending.
649 * The function can be interrupted. Return from the function is not
650 * a guarantee that the request is sent successfully.
651 *
652 * @client: client instance
653 * @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 struct p9_trans_fd *ts = client->trans;
661 struct p9_conn *m = ts->conn;
662
663 P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
664 req->tc, req->tc->id);
665 if (m->err < 0)
666 return m->err;
667
668 #ifdef CONFIG_NET_9P_DEBUG
669 if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
670 char buf[150];
671
672 p9_printfcall(buf, sizeof(buf), req->tc, client->dotu);
673 printk(KERN_NOTICE "<<< %p %s\n", m, buf);
674 }
675 #endif
676
677 req->status = REQ_STATUS_UNSENT;
678
679 spin_lock(&client->lock);
680 list_add_tail(&req->req_list, &m->unsent_req_list);
681 spin_unlock(&client->lock);
682
683 if (test_and_clear_bit(Wpending, &m->wsched))
684 n = POLLOUT;
685 else
686 n = p9_fd_poll(m->client, NULL);
687
688 if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
689 queue_work(p9_mux_wq, &m->wq);
690
691 return 0;
692 }
693
694 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
695 {
696 struct p9_trans_fd *ts = client->trans;
697 struct p9_conn *m = ts->conn;
698
699 P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
700
701 spin_lock(&client->lock);
702 list_del(&req->req_list);
703 spin_unlock(&client->lock);
704
705 /* if a response was received for a request, do nothing */
706 if (req->rc || req->t_err) {
707 P9_DPRINTK(P9_DEBUG_MUX,
708 "mux %p req %p response already received\n", m, req);
709 return 0;
710 }
711
712 if (req->status == REQ_STATUS_UNSENT) {
713 req->status = REQ_STATUS_FLSHD;
714 return 0;
715 }
716
717 return 1;
718 }
719
720 /**
721 * parse_options - parse mount options into session structure
722 * @options: options string passed from mount
723 * @opts: transport-specific structure to parse options into
724 *
725 * Returns 0 upon success, -ERRNO upon failure
726 */
727
728 static int parse_opts(char *params, struct p9_fd_opts *opts)
729 {
730 char *p;
731 substring_t args[MAX_OPT_ARGS];
732 int option;
733 char *options;
734 int ret;
735
736 opts->port = P9_PORT;
737 opts->rfd = ~0;
738 opts->wfd = ~0;
739
740 if (!params)
741 return 0;
742
743 options = kstrdup(params, GFP_KERNEL);
744 if (!options) {
745 P9_DPRINTK(P9_DEBUG_ERROR,
746 "failed to allocate copy of option string\n");
747 return -ENOMEM;
748 }
749
750 while ((p = strsep(&options, ",")) != NULL) {
751 int token;
752 int r;
753 if (!*p)
754 continue;
755 token = match_token(p, tokens, args);
756 r = match_int(&args[0], &option);
757 if (r < 0) {
758 P9_DPRINTK(P9_DEBUG_ERROR,
759 "integer field, but no integer?\n");
760 ret = r;
761 continue;
762 }
763 switch (token) {
764 case Opt_port:
765 opts->port = option;
766 break;
767 case Opt_rfdno:
768 opts->rfd = option;
769 break;
770 case Opt_wfdno:
771 opts->wfd = option;
772 break;
773 default:
774 continue;
775 }
776 }
777 kfree(options);
778 return 0;
779 }
780
781 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
782 {
783 struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
784 GFP_KERNEL);
785 if (!ts)
786 return -ENOMEM;
787
788 ts->rd = fget(rfd);
789 ts->wr = fget(wfd);
790 if (!ts->rd || !ts->wr) {
791 if (ts->rd)
792 fput(ts->rd);
793 if (ts->wr)
794 fput(ts->wr);
795 kfree(ts);
796 return -EIO;
797 }
798
799 client->trans = ts;
800 client->status = Connected;
801
802 return 0;
803 }
804
805 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
806 {
807 int fd, ret;
808
809 csocket->sk->sk_allocation = GFP_NOIO;
810 fd = sock_map_fd(csocket, 0);
811 if (fd < 0) {
812 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
813 return fd;
814 }
815
816 ret = p9_fd_open(client, fd, fd);
817 if (ret < 0) {
818 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
819 sockfd_put(csocket);
820 return ret;
821 }
822
823 ((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
824
825 return 0;
826 }
827
828 /**
829 * p9_mux_destroy - cancels all pending requests and frees mux resources
830 * @m: mux to destroy
831 *
832 */
833
834 static void p9_conn_destroy(struct p9_conn *m)
835 {
836 P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
837 m->mux_list.prev, m->mux_list.next);
838
839 p9_mux_poll_stop(m);
840 cancel_work_sync(&m->rq);
841 cancel_work_sync(&m->wq);
842
843 p9_conn_cancel(m, -ECONNRESET);
844
845 m->client = NULL;
846 kfree(m);
847 }
848
849 /**
850 * p9_fd_close - shutdown file descriptor transport
851 * @client: client instance
852 *
853 */
854
855 static void p9_fd_close(struct p9_client *client)
856 {
857 struct p9_trans_fd *ts;
858
859 if (!client)
860 return;
861
862 ts = client->trans;
863 if (!ts)
864 return;
865
866 client->status = Disconnected;
867
868 p9_conn_destroy(ts->conn);
869
870 if (ts->rd)
871 fput(ts->rd);
872 if (ts->wr)
873 fput(ts->wr);
874
875 kfree(ts);
876 }
877
878 /*
879 * stolen from NFS - maybe should be made a generic function?
880 */
881 static inline int valid_ipaddr4(const char *buf)
882 {
883 int rc, count, in[4];
884
885 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
886 if (rc != 4)
887 return -EINVAL;
888 for (count = 0; count < 4; count++) {
889 if (in[count] > 255)
890 return -EINVAL;
891 }
892 return 0;
893 }
894
895 static int
896 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
897 {
898 int err;
899 struct socket *csocket;
900 struct sockaddr_in sin_server;
901 struct p9_fd_opts opts;
902 struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
903
904 err = parse_opts(args, &opts);
905 if (err < 0)
906 return err;
907
908 if (valid_ipaddr4(addr) < 0)
909 return -EINVAL;
910
911 csocket = NULL;
912
913 sin_server.sin_family = AF_INET;
914 sin_server.sin_addr.s_addr = in_aton(addr);
915 sin_server.sin_port = htons(opts.port);
916 sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
917
918 if (!csocket) {
919 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
920 err = -EIO;
921 goto error;
922 }
923
924 err = csocket->ops->connect(csocket,
925 (struct sockaddr *)&sin_server,
926 sizeof(struct sockaddr_in), 0);
927 if (err < 0) {
928 P9_EPRINTK(KERN_ERR,
929 "p9_trans_tcp: problem connecting socket to %s\n",
930 addr);
931 goto error;
932 }
933
934 err = p9_socket_open(client, csocket);
935 if (err < 0)
936 goto error;
937
938 p = (struct p9_trans_fd *) client->trans;
939 p->conn = p9_conn_create(client);
940 if (IS_ERR(p->conn)) {
941 err = PTR_ERR(p->conn);
942 p->conn = NULL;
943 goto error;
944 }
945
946 return 0;
947
948 error:
949 if (csocket)
950 sock_release(csocket);
951
952 kfree(p);
953
954 return err;
955 }
956
957 static int
958 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
959 {
960 int err;
961 struct socket *csocket;
962 struct sockaddr_un sun_server;
963 struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
964
965 csocket = NULL;
966
967 if (strlen(addr) > UNIX_PATH_MAX) {
968 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
969 addr);
970 err = -ENAMETOOLONG;
971 goto error;
972 }
973
974 sun_server.sun_family = PF_UNIX;
975 strcpy(sun_server.sun_path, addr);
976 sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
977 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
978 sizeof(struct sockaddr_un) - 1, 0);
979 if (err < 0) {
980 P9_EPRINTK(KERN_ERR,
981 "p9_trans_unix: problem connecting socket: %s: %d\n",
982 addr, err);
983 goto error;
984 }
985
986 err = p9_socket_open(client, csocket);
987 if (err < 0)
988 goto error;
989
990 p = (struct p9_trans_fd *) client->trans;
991 p->conn = p9_conn_create(client);
992 if (IS_ERR(p->conn)) {
993 err = PTR_ERR(p->conn);
994 p->conn = NULL;
995 goto error;
996 }
997
998 return 0;
999
1000 error:
1001 if (csocket)
1002 sock_release(csocket);
1003
1004 kfree(p);
1005 return err;
1006 }
1007
1008 static int
1009 p9_fd_create(struct p9_client *client, const char *addr, char *args)
1010 {
1011 int err;
1012 struct p9_fd_opts opts;
1013 struct p9_trans_fd *p = NULL; /* this get allocated in p9_fd_open */
1014
1015 parse_opts(args, &opts);
1016
1017 if (opts.rfd == ~0 || opts.wfd == ~0) {
1018 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
1019 return -ENOPROTOOPT;
1020 }
1021
1022 err = p9_fd_open(client, opts.rfd, opts.wfd);
1023 if (err < 0)
1024 goto error;
1025
1026 p = (struct p9_trans_fd *) client->trans;
1027 p->conn = p9_conn_create(client);
1028 if (IS_ERR(p->conn)) {
1029 err = PTR_ERR(p->conn);
1030 p->conn = NULL;
1031 goto error;
1032 }
1033
1034 return 0;
1035
1036 error:
1037 kfree(p);
1038 return err;
1039 }
1040
1041 static struct p9_trans_module p9_tcp_trans = {
1042 .name = "tcp",
1043 .maxsize = MAX_SOCK_BUF,
1044 .def = 1,
1045 .create = p9_fd_create_tcp,
1046 .close = p9_fd_close,
1047 .request = p9_fd_request,
1048 .cancel = p9_fd_cancel,
1049 .owner = THIS_MODULE,
1050 };
1051
1052 static struct p9_trans_module p9_unix_trans = {
1053 .name = "unix",
1054 .maxsize = MAX_SOCK_BUF,
1055 .def = 0,
1056 .create = p9_fd_create_unix,
1057 .close = p9_fd_close,
1058 .request = p9_fd_request,
1059 .cancel = p9_fd_cancel,
1060 .owner = THIS_MODULE,
1061 };
1062
1063 static struct p9_trans_module p9_fd_trans = {
1064 .name = "fd",
1065 .maxsize = MAX_SOCK_BUF,
1066 .def = 0,
1067 .create = p9_fd_create,
1068 .close = p9_fd_close,
1069 .request = p9_fd_request,
1070 .cancel = p9_fd_cancel,
1071 .owner = THIS_MODULE,
1072 };
1073
1074 /**
1075 * p9_poll_proc - poll worker thread
1076 * @a: thread state and arguments
1077 *
1078 * polls all v9fs transports for new events and queues the appropriate
1079 * work to the work queue
1080 *
1081 */
1082
1083 static int p9_poll_proc(void *a)
1084 {
1085 unsigned long flags;
1086
1087 P9_DPRINTK(P9_DEBUG_MUX, "start %p\n", current);
1088 repeat:
1089 spin_lock_irqsave(&p9_poll_lock, flags);
1090 while (!list_empty(&p9_poll_pending_list)) {
1091 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1092 struct p9_conn,
1093 poll_pending_link);
1094 list_del_init(&conn->poll_pending_link);
1095 spin_unlock_irqrestore(&p9_poll_lock, flags);
1096
1097 p9_poll_mux(conn);
1098
1099 spin_lock_irqsave(&p9_poll_lock, flags);
1100 }
1101 spin_unlock_irqrestore(&p9_poll_lock, flags);
1102
1103 set_current_state(TASK_INTERRUPTIBLE);
1104 if (list_empty(&p9_poll_pending_list)) {
1105 P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
1106 schedule();
1107 }
1108 __set_current_state(TASK_RUNNING);
1109
1110 if (!kthread_should_stop())
1111 goto repeat;
1112
1113 P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
1114 return 0;
1115 }
1116
1117 int p9_trans_fd_init(void)
1118 {
1119 p9_mux_wq = create_workqueue("v9fs");
1120 if (!p9_mux_wq) {
1121 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1122 return -ENOMEM;
1123 }
1124
1125 p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1126 if (IS_ERR(p9_poll_task)) {
1127 destroy_workqueue(p9_mux_wq);
1128 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1129 return PTR_ERR(p9_poll_task);
1130 }
1131
1132 v9fs_register_trans(&p9_tcp_trans);
1133 v9fs_register_trans(&p9_unix_trans);
1134 v9fs_register_trans(&p9_fd_trans);
1135
1136 return 0;
1137 }
1138
1139 void p9_trans_fd_exit(void)
1140 {
1141 kthread_stop(p9_poll_task);
1142 v9fs_unregister_trans(&p9_tcp_trans);
1143 v9fs_unregister_trans(&p9_unix_trans);
1144 v9fs_unregister_trans(&p9_fd_trans);
1145
1146 destroy_workqueue(p9_mux_wq);
1147 }
Linux kernel - Deliverables
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