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oprofile: introduce module_param oprofile.cpu_type
[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 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 if (m->err) {
195 spin_unlock_irqrestore(&m->client->lock, flags);
196 return;
197 }
198
199 m->err = err;
200
201 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
202 req->status = REQ_STATUS_ERROR;
203 if (!req->t_err)
204 req->t_err = err;
205 list_move(&req->req_list, &cancel_list);
206 }
207 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
208 req->status = REQ_STATUS_ERROR;
209 if (!req->t_err)
210 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 list_del(&req->req_list);
217 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
218 p9_client_cb(m->client, req);
219 }
220 }
221
222 static unsigned int
223 p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
224 {
225 int ret, n;
226 struct p9_trans_fd *ts = NULL;
227
228 if (client && client->status == Connected)
229 ts = client->trans;
230
231 if (!ts)
232 return -EREMOTEIO;
233
234 if (!ts->rd->f_op || !ts->rd->f_op->poll)
235 return -EIO;
236
237 if (!ts->wr->f_op || !ts->wr->f_op->poll)
238 return -EIO;
239
240 ret = ts->rd->f_op->poll(ts->rd, pt);
241 if (ret < 0)
242 return ret;
243
244 if (ts->rd != ts->wr) {
245 n = ts->wr->f_op->poll(ts->wr, pt);
246 if (n < 0)
247 return n;
248 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
249 }
250
251 return ret;
252 }
253
254 /**
255 * p9_fd_read- read from a fd
256 * @client: client instance
257 * @v: buffer to receive data into
258 * @len: size of receive buffer
259 *
260 */
261
262 static int p9_fd_read(struct p9_client *client, void *v, int len)
263 {
264 int ret;
265 struct p9_trans_fd *ts = NULL;
266
267 if (client && client->status != Disconnected)
268 ts = client->trans;
269
270 if (!ts)
271 return -EREMOTEIO;
272
273 if (!(ts->rd->f_flags & O_NONBLOCK))
274 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
275
276 ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
277 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
278 client->status = Disconnected;
279 return ret;
280 }
281
282 /**
283 * p9_read_work - called when there is some data to be read from a transport
284 * @work: container of work to be done
285 *
286 */
287
288 static void p9_read_work(struct work_struct *work)
289 {
290 int n, err;
291 struct p9_conn *m;
292
293 m = container_of(work, struct p9_conn, rq);
294
295 if (m->err < 0)
296 return;
297
298 P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
299
300 if (!m->rbuf) {
301 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 if (err == -EAGAIN) {
313 clear_bit(Rworksched, &m->wsched);
314 return;
315 }
316
317 if (err <= 0)
318 goto error;
319
320 m->rpos += err;
321
322 if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
323 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 if (n >= m->client->msize) {
328 P9_DPRINTK(P9_DEBUG_ERROR,
329 "requested packet size too big: %d\n", n);
330 err = -EIO;
331 goto error;
332 }
333
334 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
335 P9_DPRINTK(P9_DEBUG_TRANS,
336 "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
337
338 m->req = p9_tag_lookup(m->client, tag);
339 if (!m->req) {
340 P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
341 tag);
342 err = -EIO;
343 goto error;
344 }
345
346 if (m->req->rc == NULL) {
347 m->req->rc = kmalloc(sizeof(struct p9_fcall) +
348 m->client->msize, GFP_KERNEL);
349 if (!m->req->rc) {
350 m->req = NULL;
351 err = -ENOMEM;
352 goto error;
353 }
354 }
355 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
356 memcpy(m->rbuf, m->tmp_buf, m->rsize);
357 m->rsize = n;
358 }
359
360 /* not an else because some packets (like clunk) have no payload */
361 if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
362 P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
363 spin_lock(&m->client->lock);
364 list_del(&m->req->req_list);
365 spin_unlock(&m->client->lock);
366 p9_client_cb(m->client, m->req);
367
368 m->rbuf = NULL;
369 m->rpos = 0;
370 m->rsize = 0;
371 m->req = NULL;
372 }
373
374 if (!list_empty(&m->req_list)) {
375 if (test_and_clear_bit(Rpending, &m->wsched))
376 n = POLLIN;
377 else
378 n = p9_fd_poll(m->client, NULL);
379
380 if (n & POLLIN) {
381 P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
382 queue_work(p9_mux_wq, &m->rq);
383 } else
384 clear_bit(Rworksched, &m->wsched);
385 } else
386 clear_bit(Rworksched, &m->wsched);
387
388 return;
389 error:
390 p9_conn_cancel(m, err);
391 clear_bit(Rworksched, &m->wsched);
392 }
393
394 /**
395 * p9_fd_write - write to a socket
396 * @client: client instance
397 * @v: buffer to send data from
398 * @len: size of send buffer
399 *
400 */
401
402 static int p9_fd_write(struct p9_client *client, void *v, int len)
403 {
404 int ret;
405 mm_segment_t oldfs;
406 struct p9_trans_fd *ts = NULL;
407
408 if (client && client->status != Disconnected)
409 ts = client->trans;
410
411 if (!ts)
412 return -EREMOTEIO;
413
414 if (!(ts->wr->f_flags & O_NONBLOCK))
415 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
416
417 oldfs = get_fs();
418 set_fs(get_ds());
419 /* The cast to a user pointer is valid due to the set_fs() */
420 ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
421 set_fs(oldfs);
422
423 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
424 client->status = Disconnected;
425 return ret;
426 }
427
428 /**
429 * p9_write_work - called when a transport can send some data
430 * @work: container for work to be done
431 *
432 */
433
434 static void p9_write_work(struct work_struct *work)
435 {
436 int n, err;
437 struct p9_conn *m;
438 struct p9_req_t *req;
439
440 m = container_of(work, struct p9_conn, wq);
441
442 if (m->err < 0) {
443 clear_bit(Wworksched, &m->wsched);
444 return;
445 }
446
447 if (!m->wsize) {
448 if (list_empty(&m->unsent_req_list)) {
449 clear_bit(Wworksched, &m->wsched);
450 return;
451 }
452
453 spin_lock(&m->client->lock);
454 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
455 req_list);
456 req->status = REQ_STATUS_SENT;
457 list_move_tail(&req->req_list, &m->req_list);
458
459 m->wbuf = req->tc->sdata;
460 m->wsize = req->tc->size;
461 m->wpos = 0;
462 spin_unlock(&m->client->lock);
463 }
464
465 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
466 m->wsize);
467 clear_bit(Wpending, &m->wsched);
468 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
469 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
470 if (err == -EAGAIN) {
471 clear_bit(Wworksched, &m->wsched);
472 return;
473 }
474
475 if (err < 0)
476 goto error;
477 else if (err == 0) {
478 err = -EREMOTEIO;
479 goto error;
480 }
481
482 m->wpos += err;
483 if (m->wpos == m->wsize)
484 m->wpos = m->wsize = 0;
485
486 if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
487 if (test_and_clear_bit(Wpending, &m->wsched))
488 n = POLLOUT;
489 else
490 n = p9_fd_poll(m->client, NULL);
491
492 if (n & POLLOUT) {
493 P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
494 queue_work(p9_mux_wq, &m->wq);
495 } else
496 clear_bit(Wworksched, &m->wsched);
497 } else
498 clear_bit(Wworksched, &m->wsched);
499
500 return;
501
502 error:
503 p9_conn_cancel(m, err);
504 clear_bit(Wworksched, &m->wsched);
505 }
506
507 static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
508 {
509 struct p9_poll_wait *pwait =
510 container_of(wait, struct p9_poll_wait, wait);
511 struct p9_conn *m = pwait->conn;
512 unsigned long flags;
513 DECLARE_WAITQUEUE(dummy_wait, p9_poll_task);
514
515 spin_lock_irqsave(&p9_poll_lock, flags);
516 if (list_empty(&m->poll_pending_link))
517 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
518 spin_unlock_irqrestore(&p9_poll_lock, flags);
519
520 /* perform the default wake up operation */
521 return default_wake_function(&dummy_wait, mode, sync, key);
522 }
523
524 /**
525 * p9_pollwait - add poll task to the wait queue
526 * @filp: file pointer being polled
527 * @wait_address: wait_q to block on
528 * @p: poll state
529 *
530 * called by files poll operation to add v9fs-poll task to files wait queue
531 */
532
533 static void
534 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
535 {
536 struct p9_conn *m = container_of(p, struct p9_conn, pt);
537 struct p9_poll_wait *pwait = NULL;
538 int i;
539
540 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
541 if (m->poll_wait[i].wait_addr == NULL) {
542 pwait = &m->poll_wait[i];
543 break;
544 }
545 }
546
547 if (!pwait) {
548 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
549 return;
550 }
551
552 pwait->conn = m;
553 pwait->wait_addr = wait_address;
554 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
555 add_wait_queue(wait_address, &pwait->wait);
556 }
557
558 /**
559 * p9_conn_create - allocate and initialize the per-session mux data
560 * @client: client instance
561 *
562 * Note: Creates the polling task if this is the first session.
563 */
564
565 static struct p9_conn *p9_conn_create(struct p9_client *client)
566 {
567 int n;
568 struct p9_conn *m;
569
570 P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
571 client->msize);
572 m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
573 if (!m)
574 return ERR_PTR(-ENOMEM);
575
576 INIT_LIST_HEAD(&m->mux_list);
577 m->client = client;
578
579 INIT_LIST_HEAD(&m->req_list);
580 INIT_LIST_HEAD(&m->unsent_req_list);
581 INIT_WORK(&m->rq, p9_read_work);
582 INIT_WORK(&m->wq, p9_write_work);
583 INIT_LIST_HEAD(&m->poll_pending_link);
584 init_poll_funcptr(&m->pt, p9_pollwait);
585
586 n = p9_fd_poll(client, &m->pt);
587 if (n & POLLIN) {
588 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
589 set_bit(Rpending, &m->wsched);
590 }
591
592 if (n & POLLOUT) {
593 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
594 set_bit(Wpending, &m->wsched);
595 }
596
597 return m;
598 }
599
600 /**
601 * p9_poll_mux - polls a mux and schedules read or write works if necessary
602 * @m: connection to poll
603 *
604 */
605
606 static void p9_poll_mux(struct p9_conn *m)
607 {
608 int n;
609
610 if (m->err < 0)
611 return;
612
613 n = p9_fd_poll(m->client, NULL);
614 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
615 P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
616 if (n >= 0)
617 n = -ECONNRESET;
618 p9_conn_cancel(m, n);
619 }
620
621 if (n & POLLIN) {
622 set_bit(Rpending, &m->wsched);
623 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
624 if (!test_and_set_bit(Rworksched, &m->wsched)) {
625 P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
626 queue_work(p9_mux_wq, &m->rq);
627 }
628 }
629
630 if (n & POLLOUT) {
631 set_bit(Wpending, &m->wsched);
632 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
633 if ((m->wsize || !list_empty(&m->unsent_req_list))
634 && !test_and_set_bit(Wworksched, &m->wsched)) {
635 P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
636 queue_work(p9_mux_wq, &m->wq);
637 }
638 }
639 }
640
641 /**
642 * p9_fd_request - send 9P request
643 * The function can sleep until the request is scheduled for sending.
644 * The function can be interrupted. Return from the function is not
645 * a guarantee that the request is sent successfully.
646 *
647 * @client: client instance
648 * @req: request to be sent
649 *
650 */
651
652 static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
653 {
654 int n;
655 struct p9_trans_fd *ts = client->trans;
656 struct p9_conn *m = ts->conn;
657
658 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
659 current, req->tc, req->tc->id);
660 if (m->err < 0)
661 return m->err;
662
663 spin_lock(&client->lock);
664 req->status = REQ_STATUS_UNSENT;
665 list_add_tail(&req->req_list, &m->unsent_req_list);
666 spin_unlock(&client->lock);
667
668 if (test_and_clear_bit(Wpending, &m->wsched))
669 n = POLLOUT;
670 else
671 n = p9_fd_poll(m->client, NULL);
672
673 if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
674 queue_work(p9_mux_wq, &m->wq);
675
676 return 0;
677 }
678
679 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
680 {
681 int ret = 1;
682
683 P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
684
685 spin_lock(&client->lock);
686 list_del(&req->req_list);
687
688 if (req->status == REQ_STATUS_UNSENT) {
689 req->status = REQ_STATUS_FLSHD;
690 ret = 0;
691 }
692
693 spin_unlock(&client->lock);
694
695 return ret;
696 }
697
698 /**
699 * parse_options - parse mount options into session structure
700 * @options: options string passed from mount
701 * @opts: transport-specific structure to parse options into
702 *
703 * Returns 0 upon success, -ERRNO upon failure
704 */
705
706 static int parse_opts(char *params, struct p9_fd_opts *opts)
707 {
708 char *p;
709 substring_t args[MAX_OPT_ARGS];
710 int option;
711 char *options;
712 int ret;
713
714 opts->port = P9_PORT;
715 opts->rfd = ~0;
716 opts->wfd = ~0;
717
718 if (!params)
719 return 0;
720
721 options = kstrdup(params, GFP_KERNEL);
722 if (!options) {
723 P9_DPRINTK(P9_DEBUG_ERROR,
724 "failed to allocate copy of option string\n");
725 return -ENOMEM;
726 }
727
728 while ((p = strsep(&options, ",")) != NULL) {
729 int token;
730 int r;
731 if (!*p)
732 continue;
733 token = match_token(p, tokens, args);
734 r = match_int(&args[0], &option);
735 if (r < 0) {
736 P9_DPRINTK(P9_DEBUG_ERROR,
737 "integer field, but no integer?\n");
738 ret = r;
739 continue;
740 }
741 switch (token) {
742 case Opt_port:
743 opts->port = option;
744 break;
745 case Opt_rfdno:
746 opts->rfd = option;
747 break;
748 case Opt_wfdno:
749 opts->wfd = option;
750 break;
751 default:
752 continue;
753 }
754 }
755 kfree(options);
756 return 0;
757 }
758
759 static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
760 {
761 struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
762 GFP_KERNEL);
763 if (!ts)
764 return -ENOMEM;
765
766 ts->rd = fget(rfd);
767 ts->wr = fget(wfd);
768 if (!ts->rd || !ts->wr) {
769 if (ts->rd)
770 fput(ts->rd);
771 if (ts->wr)
772 fput(ts->wr);
773 kfree(ts);
774 return -EIO;
775 }
776
777 client->trans = ts;
778 client->status = Connected;
779
780 return 0;
781 }
782
783 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
784 {
785 int fd, ret;
786
787 csocket->sk->sk_allocation = GFP_NOIO;
788 fd = sock_map_fd(csocket, 0);
789 if (fd < 0) {
790 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
791 return fd;
792 }
793
794 ret = p9_fd_open(client, fd, fd);
795 if (ret < 0) {
796 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
797 sockfd_put(csocket);
798 return ret;
799 }
800
801 ((struct p9_trans_fd *)client->trans)->rd->f_flags |= O_NONBLOCK;
802
803 return 0;
804 }
805
806 /**
807 * p9_mux_destroy - cancels all pending requests and frees mux resources
808 * @m: mux to destroy
809 *
810 */
811
812 static void p9_conn_destroy(struct p9_conn *m)
813 {
814 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
815 m->mux_list.prev, m->mux_list.next);
816
817 p9_mux_poll_stop(m);
818 cancel_work_sync(&m->rq);
819 cancel_work_sync(&m->wq);
820
821 p9_conn_cancel(m, -ECONNRESET);
822
823 m->client = NULL;
824 kfree(m);
825 }
826
827 /**
828 * p9_fd_close - shutdown file descriptor transport
829 * @client: client instance
830 *
831 */
832
833 static void p9_fd_close(struct p9_client *client)
834 {
835 struct p9_trans_fd *ts;
836
837 if (!client)
838 return;
839
840 ts = client->trans;
841 if (!ts)
842 return;
843
844 client->status = Disconnected;
845
846 p9_conn_destroy(ts->conn);
847
848 if (ts->rd)
849 fput(ts->rd);
850 if (ts->wr)
851 fput(ts->wr);
852
853 kfree(ts);
854 }
855
856 /*
857 * stolen from NFS - maybe should be made a generic function?
858 */
859 static inline int valid_ipaddr4(const char *buf)
860 {
861 int rc, count, in[4];
862
863 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
864 if (rc != 4)
865 return -EINVAL;
866 for (count = 0; count < 4; count++) {
867 if (in[count] > 255)
868 return -EINVAL;
869 }
870 return 0;
871 }
872
873 static int
874 p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
875 {
876 int err;
877 struct socket *csocket;
878 struct sockaddr_in sin_server;
879 struct p9_fd_opts opts;
880 struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
881
882 err = parse_opts(args, &opts);
883 if (err < 0)
884 return err;
885
886 if (valid_ipaddr4(addr) < 0)
887 return -EINVAL;
888
889 csocket = NULL;
890
891 sin_server.sin_family = AF_INET;
892 sin_server.sin_addr.s_addr = in_aton(addr);
893 sin_server.sin_port = htons(opts.port);
894 sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
895
896 if (!csocket) {
897 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
898 err = -EIO;
899 goto error;
900 }
901
902 err = csocket->ops->connect(csocket,
903 (struct sockaddr *)&sin_server,
904 sizeof(struct sockaddr_in), 0);
905 if (err < 0) {
906 P9_EPRINTK(KERN_ERR,
907 "p9_trans_tcp: problem connecting socket to %s\n",
908 addr);
909 goto error;
910 }
911
912 err = p9_socket_open(client, csocket);
913 if (err < 0)
914 goto error;
915
916 p = (struct p9_trans_fd *) client->trans;
917 p->conn = p9_conn_create(client);
918 if (IS_ERR(p->conn)) {
919 err = PTR_ERR(p->conn);
920 p->conn = NULL;
921 goto error;
922 }
923
924 return 0;
925
926 error:
927 if (csocket)
928 sock_release(csocket);
929
930 kfree(p);
931
932 return err;
933 }
934
935 static int
936 p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
937 {
938 int err;
939 struct socket *csocket;
940 struct sockaddr_un sun_server;
941 struct p9_trans_fd *p = NULL; /* this gets allocated in p9_fd_open */
942
943 csocket = NULL;
944
945 if (strlen(addr) > UNIX_PATH_MAX) {
946 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
947 addr);
948 err = -ENAMETOOLONG;
949 goto error;
950 }
951
952 sun_server.sun_family = PF_UNIX;
953 strcpy(sun_server.sun_path, addr);
954 sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
955 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
956 sizeof(struct sockaddr_un) - 1, 0);
957 if (err < 0) {
958 P9_EPRINTK(KERN_ERR,
959 "p9_trans_unix: problem connecting socket: %s: %d\n",
960 addr, err);
961 goto error;
962 }
963
964 err = p9_socket_open(client, csocket);
965 if (err < 0)
966 goto error;
967
968 p = (struct p9_trans_fd *) client->trans;
969 p->conn = p9_conn_create(client);
970 if (IS_ERR(p->conn)) {
971 err = PTR_ERR(p->conn);
972 p->conn = NULL;
973 goto error;
974 }
975
976 return 0;
977
978 error:
979 if (csocket)
980 sock_release(csocket);
981
982 kfree(p);
983 return err;
984 }
985
986 static int
987 p9_fd_create(struct p9_client *client, const char *addr, char *args)
988 {
989 int err;
990 struct p9_fd_opts opts;
991 struct p9_trans_fd *p = NULL; /* this get allocated in p9_fd_open */
992
993 parse_opts(args, &opts);
994
995 if (opts.rfd == ~0 || opts.wfd == ~0) {
996 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
997 return -ENOPROTOOPT;
998 }
999
1000 err = p9_fd_open(client, opts.rfd, opts.wfd);
1001 if (err < 0)
1002 goto error;
1003
1004 p = (struct p9_trans_fd *) client->trans;
1005 p->conn = p9_conn_create(client);
1006 if (IS_ERR(p->conn)) {
1007 err = PTR_ERR(p->conn);
1008 p->conn = NULL;
1009 goto error;
1010 }
1011
1012 return 0;
1013
1014 error:
1015 kfree(p);
1016 return err;
1017 }
1018
1019 static struct p9_trans_module p9_tcp_trans = {
1020 .name = "tcp",
1021 .maxsize = MAX_SOCK_BUF,
1022 .def = 1,
1023 .create = p9_fd_create_tcp,
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_unix_trans = {
1031 .name = "unix",
1032 .maxsize = MAX_SOCK_BUF,
1033 .def = 0,
1034 .create = p9_fd_create_unix,
1035 .close = p9_fd_close,
1036 .request = p9_fd_request,
1037 .cancel = p9_fd_cancel,
1038 .owner = THIS_MODULE,
1039 };
1040
1041 static struct p9_trans_module p9_fd_trans = {
1042 .name = "fd",
1043 .maxsize = MAX_SOCK_BUF,
1044 .def = 0,
1045 .create = p9_fd_create,
1046 .close = p9_fd_close,
1047 .request = p9_fd_request,
1048 .cancel = p9_fd_cancel,
1049 .owner = THIS_MODULE,
1050 };
1051
1052 /**
1053 * p9_poll_proc - poll worker thread
1054 * @a: thread state and arguments
1055 *
1056 * polls all v9fs transports for new events and queues the appropriate
1057 * work to the work queue
1058 *
1059 */
1060
1061 static int p9_poll_proc(void *a)
1062 {
1063 unsigned long flags;
1064
1065 P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
1066 repeat:
1067 spin_lock_irqsave(&p9_poll_lock, flags);
1068 while (!list_empty(&p9_poll_pending_list)) {
1069 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1070 struct p9_conn,
1071 poll_pending_link);
1072 list_del_init(&conn->poll_pending_link);
1073 spin_unlock_irqrestore(&p9_poll_lock, flags);
1074
1075 p9_poll_mux(conn);
1076
1077 spin_lock_irqsave(&p9_poll_lock, flags);
1078 }
1079 spin_unlock_irqrestore(&p9_poll_lock, flags);
1080
1081 set_current_state(TASK_INTERRUPTIBLE);
1082 if (list_empty(&p9_poll_pending_list)) {
1083 P9_DPRINTK(P9_DEBUG_TRANS, "sleeping...\n");
1084 schedule();
1085 }
1086 __set_current_state(TASK_RUNNING);
1087
1088 if (!kthread_should_stop())
1089 goto repeat;
1090
1091 P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
1092 return 0;
1093 }
1094
1095 int p9_trans_fd_init(void)
1096 {
1097 p9_mux_wq = create_workqueue("v9fs");
1098 if (!p9_mux_wq) {
1099 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
1100 return -ENOMEM;
1101 }
1102
1103 p9_poll_task = kthread_run(p9_poll_proc, NULL, "v9fs-poll");
1104 if (IS_ERR(p9_poll_task)) {
1105 destroy_workqueue(p9_mux_wq);
1106 printk(KERN_WARNING "v9fs: mux: creating poll task failed\n");
1107 return PTR_ERR(p9_poll_task);
1108 }
1109
1110 v9fs_register_trans(&p9_tcp_trans);
1111 v9fs_register_trans(&p9_unix_trans);
1112 v9fs_register_trans(&p9_fd_trans);
1113
1114 return 0;
1115 }
1116
1117 void p9_trans_fd_exit(void)
1118 {
1119 kthread_stop(p9_poll_task);
1120 v9fs_unregister_trans(&p9_tcp_trans);
1121 v9fs_unregister_trans(&p9_unix_trans);
1122 v9fs_unregister_trans(&p9_fd_trans);
1123
1124 destroy_workqueue(p9_mux_wq);
1125 }
Linux kernel - Deliverables
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