1aa9d51753981c483b7778e28c0f9a026714c7c2
[linux-2.6.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/transport.h>
43
44 #define P9_PORT 564
45 #define MAX_SOCK_BUF (64*1024)
46 #define ERREQFLUSH      1
47 #define SCHED_TIMEOUT   10
48 #define MAXPOLLWADDR    2
49
50 struct p9_fd_opts {
51         int rfd;
52         int wfd;
53         u16 port;
54 };
55
56 struct p9_trans_fd {
57         struct file *rd;
58         struct file *wr;
59         struct p9_conn *conn;
60 };
61
62 /*
63   * Option Parsing (code inspired by NFS code)
64   *  - a little lazy - parse all fd-transport options
65   */
66
67 enum {
68         /* Options that take integer arguments */
69         Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
70 };
71
72 static match_table_t tokens = {
73         {Opt_port, "port=%u"},
74         {Opt_rfdno, "rfdno=%u"},
75         {Opt_wfdno, "wfdno=%u"},
76         {Opt_err, NULL},
77 };
78
79 enum {
80         Rworksched = 1,         /* read work scheduled or running */
81         Rpending = 2,           /* can read */
82         Wworksched = 4,         /* write work scheduled or running */
83         Wpending = 8,           /* can write */
84 };
85
86 enum {
87         None,
88         Flushing,
89         Flushed,
90 };
91
92 struct p9_req;
93
94 typedef void (*p9_conn_req_callback)(struct p9_req *req, void *a);
95 struct p9_req {
96         spinlock_t lock; /* protect request structure */
97         int tag;
98         struct p9_fcall *tcall;
99         struct p9_fcall *rcall;
100         int err;
101         p9_conn_req_callback cb;
102         void *cba;
103         int flush;
104         struct list_head req_list;
105 };
106
107 struct p9_mux_poll_task;
108
109 struct p9_conn {
110         spinlock_t lock; /* protect lock structure */
111         struct list_head mux_list;
112         struct p9_mux_poll_task *poll_task;
113         int msize;
114         unsigned char extended;
115         struct p9_trans *trans;
116         struct p9_idpool *tagpool;
117         int err;
118         wait_queue_head_t equeue;
119         struct list_head req_list;
120         struct list_head unsent_req_list;
121         struct p9_fcall *rcall;
122         int rpos;
123         char *rbuf;
124         int wpos;
125         int wsize;
126         char *wbuf;
127         wait_queue_t poll_wait[MAXPOLLWADDR];
128         wait_queue_head_t *poll_waddr[MAXPOLLWADDR];
129         poll_table pt;
130         struct work_struct rq;
131         struct work_struct wq;
132         unsigned long wsched;
133 };
134
135 struct p9_mux_poll_task {
136         struct task_struct *task;
137         struct list_head mux_list;
138         int muxnum;
139 };
140
141 struct p9_mux_rpc {
142         struct p9_conn *m;
143         int err;
144         struct p9_fcall *tcall;
145         struct p9_fcall *rcall;
146         wait_queue_head_t wqueue;
147 };
148
149 static int p9_poll_proc(void *);
150 static void p9_read_work(struct work_struct *work);
151 static void p9_write_work(struct work_struct *work);
152 static void p9_pollwait(struct file *filp, wait_queue_head_t *wait_address,
153                                                                 poll_table *p);
154 static int p9_fd_write(struct p9_trans *trans, void *v, int len);
155 static int p9_fd_read(struct p9_trans *trans, void *v, int len);
156
157 static DEFINE_MUTEX(p9_mux_task_lock);
158 static struct workqueue_struct *p9_mux_wq;
159
160 static int p9_mux_num;
161 static int p9_mux_poll_task_num;
162 static struct p9_mux_poll_task p9_mux_poll_tasks[100];
163
164 static void p9_conn_destroy(struct p9_conn *);
165 static unsigned int p9_fd_poll(struct p9_trans *trans,
166                                                 struct poll_table_struct *pt);
167
168 #ifdef P9_NONBLOCK
169 static int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
170         p9_conn_req_callback cb, void *a);
171 #endif /* P9_NONBLOCK */
172
173 static void p9_conn_cancel(struct p9_conn *m, int err);
174
175 static int p9_mux_global_init(void)
176 {
177         int i;
178
179         for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++)
180                 p9_mux_poll_tasks[i].task = NULL;
181
182         p9_mux_wq = create_workqueue("v9fs");
183         if (!p9_mux_wq) {
184                 printk(KERN_WARNING "v9fs: mux: creating workqueue failed\n");
185                 return -ENOMEM;
186         }
187
188         return 0;
189 }
190
191 static u16 p9_mux_get_tag(struct p9_conn *m)
192 {
193         int tag;
194
195         tag = p9_idpool_get(m->tagpool);
196         if (tag < 0)
197                 return P9_NOTAG;
198         else
199                 return (u16) tag;
200 }
201
202 static void p9_mux_put_tag(struct p9_conn *m, u16 tag)
203 {
204         if (tag != P9_NOTAG && p9_idpool_check(tag, m->tagpool))
205                 p9_idpool_put(tag, m->tagpool);
206 }
207
208 /**
209  * p9_mux_calc_poll_procs - calculates the number of polling procs
210  * based on the number of mounted v9fs filesystems.
211  *
212  * The current implementation returns sqrt of the number of mounts.
213  */
214 static int p9_mux_calc_poll_procs(int muxnum)
215 {
216         int n;
217
218         if (p9_mux_poll_task_num)
219                 n = muxnum / p9_mux_poll_task_num +
220                     (muxnum % p9_mux_poll_task_num ? 1 : 0);
221         else
222                 n = 1;
223
224         if (n > ARRAY_SIZE(p9_mux_poll_tasks))
225                 n = ARRAY_SIZE(p9_mux_poll_tasks);
226
227         return n;
228 }
229
230 static int p9_mux_poll_start(struct p9_conn *m)
231 {
232         int i, n;
233         struct p9_mux_poll_task *vpt, *vptlast;
234         struct task_struct *pproc;
235
236         P9_DPRINTK(P9_DEBUG_MUX, "mux %p muxnum %d procnum %d\n", m, p9_mux_num,
237                 p9_mux_poll_task_num);
238         mutex_lock(&p9_mux_task_lock);
239
240         n = p9_mux_calc_poll_procs(p9_mux_num + 1);
241         if (n > p9_mux_poll_task_num) {
242                 for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
243                         if (p9_mux_poll_tasks[i].task == NULL) {
244                                 vpt = &p9_mux_poll_tasks[i];
245                                 P9_DPRINTK(P9_DEBUG_MUX, "create proc %p\n",
246                                                                         vpt);
247                                 pproc = kthread_create(p9_poll_proc, vpt,
248                                                                 "v9fs-poll");
249
250                                 if (!IS_ERR(pproc)) {
251                                         vpt->task = pproc;
252                                         INIT_LIST_HEAD(&vpt->mux_list);
253                                         vpt->muxnum = 0;
254                                         p9_mux_poll_task_num++;
255                                         wake_up_process(vpt->task);
256                                 }
257                                 break;
258                         }
259                 }
260
261                 if (i >= ARRAY_SIZE(p9_mux_poll_tasks))
262                         P9_DPRINTK(P9_DEBUG_ERROR,
263                                         "warning: no free poll slots\n");
264         }
265
266         n = (p9_mux_num + 1) / p9_mux_poll_task_num +
267             ((p9_mux_num + 1) % p9_mux_poll_task_num ? 1 : 0);
268
269         vptlast = NULL;
270         for (i = 0; i < ARRAY_SIZE(p9_mux_poll_tasks); i++) {
271                 vpt = &p9_mux_poll_tasks[i];
272                 if (vpt->task != NULL) {
273                         vptlast = vpt;
274                         if (vpt->muxnum < n) {
275                                 P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
276                                 list_add(&m->mux_list, &vpt->mux_list);
277                                 vpt->muxnum++;
278                                 m->poll_task = vpt;
279                                 memset(&m->poll_waddr, 0,
280                                                         sizeof(m->poll_waddr));
281                                 init_poll_funcptr(&m->pt, p9_pollwait);
282                                 break;
283                         }
284                 }
285         }
286
287         if (i >= ARRAY_SIZE(p9_mux_poll_tasks)) {
288                 if (vptlast == NULL) {
289                         mutex_unlock(&p9_mux_task_lock);
290                         return -ENOMEM;
291                 }
292
293                 P9_DPRINTK(P9_DEBUG_MUX, "put in proc %d\n", i);
294                 list_add(&m->mux_list, &vptlast->mux_list);
295                 vptlast->muxnum++;
296                 m->poll_task = vptlast;
297                 memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
298                 init_poll_funcptr(&m->pt, p9_pollwait);
299         }
300
301         p9_mux_num++;
302         mutex_unlock(&p9_mux_task_lock);
303
304         return 0;
305 }
306
307 static void p9_mux_poll_stop(struct p9_conn *m)
308 {
309         int i;
310         struct p9_mux_poll_task *vpt;
311
312         mutex_lock(&p9_mux_task_lock);
313         vpt = m->poll_task;
314         list_del(&m->mux_list);
315         for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
316                 if (m->poll_waddr[i] != NULL) {
317                         remove_wait_queue(m->poll_waddr[i], &m->poll_wait[i]);
318                         m->poll_waddr[i] = NULL;
319                 }
320         }
321         vpt->muxnum--;
322         if (!vpt->muxnum) {
323                 P9_DPRINTK(P9_DEBUG_MUX, "destroy proc %p\n", vpt);
324                 kthread_stop(vpt->task);
325                 vpt->task = NULL;
326                 p9_mux_poll_task_num--;
327         }
328         p9_mux_num--;
329         mutex_unlock(&p9_mux_task_lock);
330 }
331
332 /**
333  * p9_conn_create - allocate and initialize the per-session mux data
334  * Creates the polling task if this is the first session.
335  *
336  * @trans - transport structure
337  * @msize - maximum message size
338  * @extended - extended flag
339  */
340 static struct p9_conn *p9_conn_create(struct p9_trans *trans)
341 {
342         int i, n;
343         struct p9_conn *m, *mtmp;
344
345         P9_DPRINTK(P9_DEBUG_MUX, "transport %p msize %d\n", trans,
346                                                                 trans->msize);
347         m = kmalloc(sizeof(struct p9_conn), GFP_KERNEL);
348         if (!m)
349                 return ERR_PTR(-ENOMEM);
350
351         spin_lock_init(&m->lock);
352         INIT_LIST_HEAD(&m->mux_list);
353         m->msize = trans->msize;
354         m->extended = trans->extended;
355         m->trans = trans;
356         m->tagpool = p9_idpool_create();
357         if (IS_ERR(m->tagpool)) {
358                 mtmp = ERR_PTR(-ENOMEM);
359                 kfree(m);
360                 return mtmp;
361         }
362
363         m->err = 0;
364         init_waitqueue_head(&m->equeue);
365         INIT_LIST_HEAD(&m->req_list);
366         INIT_LIST_HEAD(&m->unsent_req_list);
367         m->rcall = NULL;
368         m->rpos = 0;
369         m->rbuf = NULL;
370         m->wpos = m->wsize = 0;
371         m->wbuf = NULL;
372         INIT_WORK(&m->rq, p9_read_work);
373         INIT_WORK(&m->wq, p9_write_work);
374         m->wsched = 0;
375         memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
376         m->poll_task = NULL;
377         n = p9_mux_poll_start(m);
378         if (n) {
379                 kfree(m);
380                 return ERR_PTR(n);
381         }
382
383         n = p9_fd_poll(trans, &m->pt);
384         if (n & POLLIN) {
385                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
386                 set_bit(Rpending, &m->wsched);
387         }
388
389         if (n & POLLOUT) {
390                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
391                 set_bit(Wpending, &m->wsched);
392         }
393
394         for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++) {
395                 if (IS_ERR(m->poll_waddr[i])) {
396                         p9_mux_poll_stop(m);
397                         mtmp = (void *)m->poll_waddr;   /* the error code */
398                         kfree(m);
399                         m = mtmp;
400                         break;
401                 }
402         }
403
404         return m;
405 }
406
407 /**
408  * p9_mux_destroy - cancels all pending requests and frees mux resources
409  */
410 static void p9_conn_destroy(struct p9_conn *m)
411 {
412         P9_DPRINTK(P9_DEBUG_MUX, "mux %p prev %p next %p\n", m,
413                 m->mux_list.prev, m->mux_list.next);
414         p9_conn_cancel(m, -ECONNRESET);
415
416         if (!list_empty(&m->req_list)) {
417                 /* wait until all processes waiting on this session exit */
418                 P9_DPRINTK(P9_DEBUG_MUX,
419                         "mux %p waiting for empty request queue\n", m);
420                 wait_event_timeout(m->equeue, (list_empty(&m->req_list)), 5000);
421                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p request queue empty: %d\n", m,
422                         list_empty(&m->req_list));
423         }
424
425         p9_mux_poll_stop(m);
426         m->trans = NULL;
427         p9_idpool_destroy(m->tagpool);
428         kfree(m);
429 }
430
431 /**
432  * p9_pollwait - called by files poll operation to add v9fs-poll task
433  *      to files wait queue
434  */
435 static void
436 p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
437 {
438         int i;
439         struct p9_conn *m;
440
441         m = container_of(p, struct p9_conn, pt);
442         for (i = 0; i < ARRAY_SIZE(m->poll_waddr); i++)
443                 if (m->poll_waddr[i] == NULL)
444                         break;
445
446         if (i >= ARRAY_SIZE(m->poll_waddr)) {
447                 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
448                 return;
449         }
450
451         m->poll_waddr[i] = wait_address;
452
453         if (!wait_address) {
454                 P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
455                 m->poll_waddr[i] = ERR_PTR(-EIO);
456                 return;
457         }
458
459         init_waitqueue_entry(&m->poll_wait[i], m->poll_task->task);
460         add_wait_queue(wait_address, &m->poll_wait[i]);
461 }
462
463 /**
464  * p9_poll_mux - polls a mux and schedules read or write works if necessary
465  */
466 static void p9_poll_mux(struct p9_conn *m)
467 {
468         int n;
469
470         if (m->err < 0)
471                 return;
472
473         n = p9_fd_poll(m->trans, NULL);
474         if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
475                 P9_DPRINTK(P9_DEBUG_MUX, "error mux %p err %d\n", m, n);
476                 if (n >= 0)
477                         n = -ECONNRESET;
478                 p9_conn_cancel(m, n);
479         }
480
481         if (n & POLLIN) {
482                 set_bit(Rpending, &m->wsched);
483                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can read\n", m);
484                 if (!test_and_set_bit(Rworksched, &m->wsched)) {
485                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
486                         queue_work(p9_mux_wq, &m->rq);
487                 }
488         }
489
490         if (n & POLLOUT) {
491                 set_bit(Wpending, &m->wsched);
492                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p can write\n", m);
493                 if ((m->wsize || !list_empty(&m->unsent_req_list))
494                     && !test_and_set_bit(Wworksched, &m->wsched)) {
495                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
496                         queue_work(p9_mux_wq, &m->wq);
497                 }
498         }
499 }
500
501 /**
502  * p9_poll_proc - polls all v9fs transports for new events and queues
503  *      the appropriate work to the work queue
504  */
505 static int p9_poll_proc(void *a)
506 {
507         struct p9_conn *m, *mtmp;
508         struct p9_mux_poll_task *vpt;
509
510         vpt = a;
511         P9_DPRINTK(P9_DEBUG_MUX, "start %p %p\n", current, vpt);
512         while (!kthread_should_stop()) {
513                 set_current_state(TASK_INTERRUPTIBLE);
514
515                 list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
516                         p9_poll_mux(m);
517                 }
518
519                 P9_DPRINTK(P9_DEBUG_MUX, "sleeping...\n");
520                 schedule_timeout(SCHED_TIMEOUT * HZ);
521         }
522
523         __set_current_state(TASK_RUNNING);
524         P9_DPRINTK(P9_DEBUG_MUX, "finish\n");
525         return 0;
526 }
527
528 /**
529  * p9_write_work - called when a transport can send some data
530  */
531 static void p9_write_work(struct work_struct *work)
532 {
533         int n, err;
534         struct p9_conn *m;
535         struct p9_req *req;
536
537         m = container_of(work, struct p9_conn, wq);
538
539         if (m->err < 0) {
540                 clear_bit(Wworksched, &m->wsched);
541                 return;
542         }
543
544         if (!m->wsize) {
545                 if (list_empty(&m->unsent_req_list)) {
546                         clear_bit(Wworksched, &m->wsched);
547                         return;
548                 }
549
550                 spin_lock(&m->lock);
551 again:
552                 req = list_entry(m->unsent_req_list.next, struct p9_req,
553                                req_list);
554                 list_move_tail(&req->req_list, &m->req_list);
555                 if (req->err == ERREQFLUSH)
556                         goto again;
557
558                 m->wbuf = req->tcall->sdata;
559                 m->wsize = req->tcall->size;
560                 m->wpos = 0;
561                 spin_unlock(&m->lock);
562         }
563
564         P9_DPRINTK(P9_DEBUG_MUX, "mux %p pos %d size %d\n", m, m->wpos,
565                                                                 m->wsize);
566         clear_bit(Wpending, &m->wsched);
567         err = p9_fd_write(m->trans, m->wbuf + m->wpos, m->wsize - m->wpos);
568         P9_DPRINTK(P9_DEBUG_MUX, "mux %p sent %d bytes\n", m, err);
569         if (err == -EAGAIN) {
570                 clear_bit(Wworksched, &m->wsched);
571                 return;
572         }
573
574         if (err < 0)
575                 goto error;
576         else if (err == 0) {
577                 err = -EREMOTEIO;
578                 goto error;
579         }
580
581         m->wpos += err;
582         if (m->wpos == m->wsize)
583                 m->wpos = m->wsize = 0;
584
585         if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
586                 if (test_and_clear_bit(Wpending, &m->wsched))
587                         n = POLLOUT;
588                 else
589                         n = p9_fd_poll(m->trans, NULL);
590
591                 if (n & POLLOUT) {
592                         P9_DPRINTK(P9_DEBUG_MUX, "schedule write work %p\n", m);
593                         queue_work(p9_mux_wq, &m->wq);
594                 } else
595                         clear_bit(Wworksched, &m->wsched);
596         } else
597                 clear_bit(Wworksched, &m->wsched);
598
599         return;
600
601 error:
602         p9_conn_cancel(m, err);
603         clear_bit(Wworksched, &m->wsched);
604 }
605
606 static void process_request(struct p9_conn *m, struct p9_req *req)
607 {
608         int ecode;
609         struct p9_str *ename;
610
611         if (!req->err && req->rcall->id == P9_RERROR) {
612                 ecode = req->rcall->params.rerror.errno;
613                 ename = &req->rcall->params.rerror.error;
614
615                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
616                                                                 ename->str);
617
618                 if (m->extended)
619                         req->err = -ecode;
620
621                 if (!req->err) {
622                         req->err = p9_errstr2errno(ename->str, ename->len);
623
624                         /* string match failed */
625                         if (!req->err) {
626                                 PRINT_FCALL_ERROR("unknown error", req->rcall);
627                                 req->err = -ESERVERFAULT;
628                         }
629                 }
630         } else if (req->tcall && req->rcall->id != req->tcall->id + 1) {
631                 P9_DPRINTK(P9_DEBUG_ERROR,
632                                 "fcall mismatch: expected %d, got %d\n",
633                                 req->tcall->id + 1, req->rcall->id);
634                 if (!req->err)
635                         req->err = -EIO;
636         }
637 }
638
639 /**
640  * p9_read_work - called when there is some data to be read from a transport
641  */
642 static void p9_read_work(struct work_struct *work)
643 {
644         int n, err;
645         struct p9_conn *m;
646         struct p9_req *req, *rptr, *rreq;
647         struct p9_fcall *rcall;
648         char *rbuf;
649
650         m = container_of(work, struct p9_conn, rq);
651
652         if (m->err < 0)
653                 return;
654
655         rcall = NULL;
656         P9_DPRINTK(P9_DEBUG_MUX, "start mux %p pos %d\n", m, m->rpos);
657
658         if (!m->rcall) {
659                 m->rcall =
660                     kmalloc(sizeof(struct p9_fcall) + m->msize, GFP_KERNEL);
661                 if (!m->rcall) {
662                         err = -ENOMEM;
663                         goto error;
664                 }
665
666                 m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
667                 m->rpos = 0;
668         }
669
670         clear_bit(Rpending, &m->wsched);
671         err = p9_fd_read(m->trans, m->rbuf + m->rpos, m->msize - m->rpos);
672         P9_DPRINTK(P9_DEBUG_MUX, "mux %p got %d bytes\n", m, err);
673         if (err == -EAGAIN) {
674                 clear_bit(Rworksched, &m->wsched);
675                 return;
676         }
677
678         if (err <= 0)
679                 goto error;
680
681         m->rpos += err;
682         while (m->rpos > 4) {
683                 n = le32_to_cpu(*(__le32 *) m->rbuf);
684                 if (n >= m->msize) {
685                         P9_DPRINTK(P9_DEBUG_ERROR,
686                                 "requested packet size too big: %d\n", n);
687                         err = -EIO;
688                         goto error;
689                 }
690
691                 if (m->rpos < n)
692                         break;
693
694                 err =
695                     p9_deserialize_fcall(m->rbuf, n, m->rcall, m->extended);
696                 if (err < 0)
697                         goto error;
698
699 #ifdef CONFIG_NET_9P_DEBUG
700                 if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
701                         char buf[150];
702
703                         p9_printfcall(buf, sizeof(buf), m->rcall,
704                                 m->extended);
705                         printk(KERN_NOTICE ">>> %p %s\n", m, buf);
706                 }
707 #endif
708
709                 rcall = m->rcall;
710                 rbuf = m->rbuf;
711                 if (m->rpos > n) {
712                         m->rcall = kmalloc(sizeof(struct p9_fcall) + m->msize,
713                                            GFP_KERNEL);
714                         if (!m->rcall) {
715                                 err = -ENOMEM;
716                                 goto error;
717                         }
718
719                         m->rbuf = (char *)m->rcall + sizeof(struct p9_fcall);
720                         memmove(m->rbuf, rbuf + n, m->rpos - n);
721                         m->rpos -= n;
722                 } else {
723                         m->rcall = NULL;
724                         m->rbuf = NULL;
725                         m->rpos = 0;
726                 }
727
728                 P9_DPRINTK(P9_DEBUG_MUX, "mux %p fcall id %d tag %d\n", m,
729                                                         rcall->id, rcall->tag);
730
731                 req = NULL;
732                 spin_lock(&m->lock);
733                 list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
734                         if (rreq->tag == rcall->tag) {
735                                 req = rreq;
736                                 if (req->flush != Flushing)
737                                         list_del(&req->req_list);
738                                 break;
739                         }
740                 }
741                 spin_unlock(&m->lock);
742
743                 if (req) {
744                         req->rcall = rcall;
745                         process_request(m, req);
746
747                         if (req->flush != Flushing) {
748                                 if (req->cb)
749                                         (*req->cb) (req, req->cba);
750                                 else
751                                         kfree(req->rcall);
752
753                                 wake_up(&m->equeue);
754                         }
755                 } else {
756                         if (err >= 0 && rcall->id != P9_RFLUSH)
757                                 P9_DPRINTK(P9_DEBUG_ERROR,
758                                   "unexpected response mux %p id %d tag %d\n",
759                                   m, rcall->id, rcall->tag);
760                         kfree(rcall);
761                 }
762         }
763
764         if (!list_empty(&m->req_list)) {
765                 if (test_and_clear_bit(Rpending, &m->wsched))
766                         n = POLLIN;
767                 else
768                         n = p9_fd_poll(m->trans, NULL);
769
770                 if (n & POLLIN) {
771                         P9_DPRINTK(P9_DEBUG_MUX, "schedule read work %p\n", m);
772                         queue_work(p9_mux_wq, &m->rq);
773                 } else
774                         clear_bit(Rworksched, &m->wsched);
775         } else
776                 clear_bit(Rworksched, &m->wsched);
777
778         return;
779
780 error:
781         p9_conn_cancel(m, err);
782         clear_bit(Rworksched, &m->wsched);
783 }
784
785 /**
786  * p9_send_request - send 9P request
787  * The function can sleep until the request is scheduled for sending.
788  * The function can be interrupted. Return from the function is not
789  * a guarantee that the request is sent successfully. Can return errors
790  * that can be retrieved by PTR_ERR macros.
791  *
792  * @m: mux data
793  * @tc: request to be sent
794  * @cb: callback function to call when response is received
795  * @cba: parameter to pass to the callback function
796  */
797 static struct p9_req *p9_send_request(struct p9_conn *m,
798                                           struct p9_fcall *tc,
799                                           p9_conn_req_callback cb, void *cba)
800 {
801         int n;
802         struct p9_req *req;
803
804         P9_DPRINTK(P9_DEBUG_MUX, "mux %p task %p tcall %p id %d\n", m, current,
805                 tc, tc->id);
806         if (m->err < 0)
807                 return ERR_PTR(m->err);
808
809         req = kmalloc(sizeof(struct p9_req), GFP_KERNEL);
810         if (!req)
811                 return ERR_PTR(-ENOMEM);
812
813         if (tc->id == P9_TVERSION)
814                 n = P9_NOTAG;
815         else
816                 n = p9_mux_get_tag(m);
817
818         if (n < 0)
819                 return ERR_PTR(-ENOMEM);
820
821         p9_set_tag(tc, n);
822
823 #ifdef CONFIG_NET_9P_DEBUG
824         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
825                 char buf[150];
826
827                 p9_printfcall(buf, sizeof(buf), tc, m->extended);
828                 printk(KERN_NOTICE "<<< %p %s\n", m, buf);
829         }
830 #endif
831
832         spin_lock_init(&req->lock);
833         req->tag = n;
834         req->tcall = tc;
835         req->rcall = NULL;
836         req->err = 0;
837         req->cb = cb;
838         req->cba = cba;
839         req->flush = None;
840
841         spin_lock(&m->lock);
842         list_add_tail(&req->req_list, &m->unsent_req_list);
843         spin_unlock(&m->lock);
844
845         if (test_and_clear_bit(Wpending, &m->wsched))
846                 n = POLLOUT;
847         else
848                 n = p9_fd_poll(m->trans, NULL);
849
850         if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
851                 queue_work(p9_mux_wq, &m->wq);
852
853         return req;
854 }
855
856 static void p9_mux_free_request(struct p9_conn *m, struct p9_req *req)
857 {
858         p9_mux_put_tag(m, req->tag);
859         kfree(req);
860 }
861
862 static void p9_mux_flush_cb(struct p9_req *freq, void *a)
863 {
864         p9_conn_req_callback cb;
865         int tag;
866         struct p9_conn *m;
867         struct p9_req *req, *rreq, *rptr;
868
869         m = a;
870         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p rc %p err %d oldtag %d\n", m,
871                 freq->tcall, freq->rcall, freq->err,
872                 freq->tcall->params.tflush.oldtag);
873
874         spin_lock(&m->lock);
875         cb = NULL;
876         tag = freq->tcall->params.tflush.oldtag;
877         req = NULL;
878         list_for_each_entry_safe(rreq, rptr, &m->req_list, req_list) {
879                 if (rreq->tag == tag) {
880                         req = rreq;
881                         list_del(&req->req_list);
882                         break;
883                 }
884         }
885         spin_unlock(&m->lock);
886
887         if (req) {
888                 spin_lock(&req->lock);
889                 req->flush = Flushed;
890                 spin_unlock(&req->lock);
891
892                 if (req->cb)
893                         (*req->cb) (req, req->cba);
894                 else
895                         kfree(req->rcall);
896
897                 wake_up(&m->equeue);
898         }
899
900         kfree(freq->tcall);
901         kfree(freq->rcall);
902         p9_mux_free_request(m, freq);
903 }
904
905 static int
906 p9_mux_flush_request(struct p9_conn *m, struct p9_req *req)
907 {
908         struct p9_fcall *fc;
909         struct p9_req *rreq, *rptr;
910
911         P9_DPRINTK(P9_DEBUG_MUX, "mux %p req %p tag %d\n", m, req, req->tag);
912
913         /* if a response was received for a request, do nothing */
914         spin_lock(&req->lock);
915         if (req->rcall || req->err) {
916                 spin_unlock(&req->lock);
917                 P9_DPRINTK(P9_DEBUG_MUX,
918                         "mux %p req %p response already received\n", m, req);
919                 return 0;
920         }
921
922         req->flush = Flushing;
923         spin_unlock(&req->lock);
924
925         spin_lock(&m->lock);
926         /* if the request is not sent yet, just remove it from the list */
927         list_for_each_entry_safe(rreq, rptr, &m->unsent_req_list, req_list) {
928                 if (rreq->tag == req->tag) {
929                         P9_DPRINTK(P9_DEBUG_MUX,
930                            "mux %p req %p request is not sent yet\n", m, req);
931                         list_del(&rreq->req_list);
932                         req->flush = Flushed;
933                         spin_unlock(&m->lock);
934                         if (req->cb)
935                                 (*req->cb) (req, req->cba);
936                         return 0;
937                 }
938         }
939         spin_unlock(&m->lock);
940
941         clear_thread_flag(TIF_SIGPENDING);
942         fc = p9_create_tflush(req->tag);
943         p9_send_request(m, fc, p9_mux_flush_cb, m);
944         return 1;
945 }
946
947 static void
948 p9_conn_rpc_cb(struct p9_req *req, void *a)
949 {
950         struct p9_mux_rpc *r;
951
952         P9_DPRINTK(P9_DEBUG_MUX, "req %p r %p\n", req, a);
953         r = a;
954         r->rcall = req->rcall;
955         r->err = req->err;
956
957         if (req->flush != None && !req->err)
958                 r->err = -ERESTARTSYS;
959
960         wake_up(&r->wqueue);
961 }
962
963 /**
964  * p9_fd_rpc- sends 9P request and waits until a response is available.
965  *      The function can be interrupted.
966  * @m: mux data
967  * @tc: request to be sent
968  * @rc: pointer where a pointer to the response is stored
969  */
970 int
971 p9_fd_rpc(struct p9_trans *t, struct p9_fcall *tc, struct p9_fcall **rc)
972 {
973         struct p9_trans_fd *p = t->priv;
974         struct p9_conn *m = p->conn;
975         int err, sigpending;
976         unsigned long flags;
977         struct p9_req *req;
978         struct p9_mux_rpc r;
979
980         r.err = 0;
981         r.tcall = tc;
982         r.rcall = NULL;
983         r.m = m;
984         init_waitqueue_head(&r.wqueue);
985
986         if (rc)
987                 *rc = NULL;
988
989         sigpending = 0;
990         if (signal_pending(current)) {
991                 sigpending = 1;
992                 clear_thread_flag(TIF_SIGPENDING);
993         }
994
995         req = p9_send_request(m, tc, p9_conn_rpc_cb, &r);
996         if (IS_ERR(req)) {
997                 err = PTR_ERR(req);
998                 P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
999                 return err;
1000         }
1001
1002         err = wait_event_interruptible(r.wqueue, r.rcall != NULL || r.err < 0);
1003         if (r.err < 0)
1004                 err = r.err;
1005
1006         if (err == -ERESTARTSYS && m->trans->status == Connected
1007                                                         && m->err == 0) {
1008                 if (p9_mux_flush_request(m, req)) {
1009                         /* wait until we get response of the flush message */
1010                         do {
1011                                 clear_thread_flag(TIF_SIGPENDING);
1012                                 err = wait_event_interruptible(r.wqueue,
1013                                         r.rcall || r.err);
1014                         } while (!r.rcall && !r.err && err == -ERESTARTSYS &&
1015                                 m->trans->status == Connected && !m->err);
1016
1017                         err = -ERESTARTSYS;
1018                 }
1019                 sigpending = 1;
1020         }
1021
1022         if (sigpending) {
1023                 spin_lock_irqsave(&current->sighand->siglock, flags);
1024                 recalc_sigpending();
1025                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
1026         }
1027
1028         if (rc)
1029                 *rc = r.rcall;
1030         else
1031                 kfree(r.rcall);
1032
1033         p9_mux_free_request(m, req);
1034         if (err > 0)
1035                 err = -EIO;
1036
1037         return err;
1038 }
1039
1040 #ifdef P9_NONBLOCK
1041 /**
1042  * p9_conn_rpcnb - sends 9P request without waiting for response.
1043  * @m: mux data
1044  * @tc: request to be sent
1045  * @cb: callback function to be called when response arrives
1046  * @cba: value to pass to the callback function
1047  */
1048 int p9_conn_rpcnb(struct p9_conn *m, struct p9_fcall *tc,
1049                    p9_conn_req_callback cb, void *a)
1050 {
1051         int err;
1052         struct p9_req *req;
1053
1054         req = p9_send_request(m, tc, cb, a);
1055         if (IS_ERR(req)) {
1056                 err = PTR_ERR(req);
1057                 P9_DPRINTK(P9_DEBUG_MUX, "error %d\n", err);
1058                 return PTR_ERR(req);
1059         }
1060
1061         P9_DPRINTK(P9_DEBUG_MUX, "mux %p tc %p tag %d\n", m, tc, req->tag);
1062         return 0;
1063 }
1064 #endif /* P9_NONBLOCK */
1065
1066 /**
1067  * p9_conn_cancel - cancel all pending requests with error
1068  * @m: mux data
1069  * @err: error code
1070  */
1071 void p9_conn_cancel(struct p9_conn *m, int err)
1072 {
1073         struct p9_req *req, *rtmp;
1074         LIST_HEAD(cancel_list);
1075
1076         P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
1077         m->err = err;
1078         spin_lock(&m->lock);
1079         list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
1080                 list_move(&req->req_list, &cancel_list);
1081         }
1082         list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
1083                 list_move(&req->req_list, &cancel_list);
1084         }
1085         spin_unlock(&m->lock);
1086
1087         list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
1088                 list_del(&req->req_list);
1089                 if (!req->err)
1090                         req->err = err;
1091
1092                 if (req->cb)
1093                         (*req->cb) (req, req->cba);
1094                 else
1095                         kfree(req->rcall);
1096         }
1097
1098         wake_up(&m->equeue);
1099 }
1100
1101 /**
1102  * v9fs_parse_options - parse mount options into session structure
1103  * @options: options string passed from mount
1104  * @v9ses: existing v9fs session information
1105  *
1106  */
1107
1108 static void parse_opts(char *options, struct p9_fd_opts *opts)
1109 {
1110         char *p;
1111         substring_t args[MAX_OPT_ARGS];
1112         int option;
1113         int ret;
1114
1115         opts->port = P9_PORT;
1116         opts->rfd = ~0;
1117         opts->wfd = ~0;
1118
1119         if (!options)
1120                 return;
1121
1122         while ((p = strsep(&options, ",")) != NULL) {
1123                 int token;
1124                 if (!*p)
1125                         continue;
1126                 token = match_token(p, tokens, args);
1127                 ret = match_int(&args[0], &option);
1128                 if (ret < 0) {
1129                         P9_DPRINTK(P9_DEBUG_ERROR,
1130                          "integer field, but no integer?\n");
1131                         continue;
1132                 }
1133                 switch (token) {
1134                 case Opt_port:
1135                         opts->port = option;
1136                         break;
1137                 case Opt_rfdno:
1138                         opts->rfd = option;
1139                         break;
1140                 case Opt_wfdno:
1141                         opts->wfd = option;
1142                         break;
1143                 default:
1144                         continue;
1145                 }
1146         }
1147 }
1148
1149 static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
1150 {
1151         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
1152                                            GFP_KERNEL);
1153         if (!ts)
1154                 return -ENOMEM;
1155
1156         ts->rd = fget(rfd);
1157         ts->wr = fget(wfd);
1158         if (!ts->rd || !ts->wr) {
1159                 if (ts->rd)
1160                         fput(ts->rd);
1161                 if (ts->wr)
1162                         fput(ts->wr);
1163                 kfree(ts);
1164                 return -EIO;
1165         }
1166
1167         trans->priv = ts;
1168         trans->status = Connected;
1169
1170         return 0;
1171 }
1172
1173 static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
1174 {
1175         int fd, ret;
1176
1177         csocket->sk->sk_allocation = GFP_NOIO;
1178         fd = sock_map_fd(csocket);
1179         if (fd < 0) {
1180                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
1181                 return fd;
1182         }
1183
1184         ret = p9_fd_open(trans, fd, fd);
1185         if (ret < 0) {
1186                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
1187                 sockfd_put(csocket);
1188                 return ret;
1189         }
1190
1191         ((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;
1192
1193         return 0;
1194 }
1195
1196 /**
1197  * p9_fd_read- read from a fd
1198  * @v9ses: session information
1199  * @v: buffer to receive data into
1200  * @len: size of receive buffer
1201  *
1202  */
1203 static int p9_fd_read(struct p9_trans *trans, void *v, int len)
1204 {
1205         int ret;
1206         struct p9_trans_fd *ts = NULL;
1207
1208         if (trans && trans->status != Disconnected)
1209                 ts = trans->priv;
1210
1211         if (!ts)
1212                 return -EREMOTEIO;
1213
1214         if (!(ts->rd->f_flags & O_NONBLOCK))
1215                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
1216
1217         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
1218         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
1219                 trans->status = Disconnected;
1220         return ret;
1221 }
1222
1223 /**
1224  * p9_fd_write - write to a socket
1225  * @v9ses: session information
1226  * @v: buffer to send data from
1227  * @len: size of send buffer
1228  *
1229  */
1230 static int p9_fd_write(struct p9_trans *trans, void *v, int len)
1231 {
1232         int ret;
1233         mm_segment_t oldfs;
1234         struct p9_trans_fd *ts = NULL;
1235
1236         if (trans && trans->status != Disconnected)
1237                 ts = trans->priv;
1238
1239         if (!ts)
1240                 return -EREMOTEIO;
1241
1242         if (!(ts->wr->f_flags & O_NONBLOCK))
1243                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
1244
1245         oldfs = get_fs();
1246         set_fs(get_ds());
1247         /* The cast to a user pointer is valid due to the set_fs() */
1248         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
1249         set_fs(oldfs);
1250
1251         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
1252                 trans->status = Disconnected;
1253         return ret;
1254 }
1255
1256 static unsigned int
1257 p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
1258 {
1259         int ret, n;
1260         struct p9_trans_fd *ts = NULL;
1261         mm_segment_t oldfs;
1262
1263         if (trans && trans->status == Connected)
1264                 ts = trans->priv;
1265
1266         if (!ts)
1267                 return -EREMOTEIO;
1268
1269         if (!ts->rd->f_op || !ts->rd->f_op->poll)
1270                 return -EIO;
1271
1272         if (!ts->wr->f_op || !ts->wr->f_op->poll)
1273                 return -EIO;
1274
1275         oldfs = get_fs();
1276         set_fs(get_ds());
1277
1278         ret = ts->rd->f_op->poll(ts->rd, pt);
1279         if (ret < 0)
1280                 goto end;
1281
1282         if (ts->rd != ts->wr) {
1283                 n = ts->wr->f_op->poll(ts->wr, pt);
1284                 if (n < 0) {
1285                         ret = n;
1286                         goto end;
1287                 }
1288                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
1289         }
1290
1291 end:
1292         set_fs(oldfs);
1293         return ret;
1294 }
1295
1296 /**
1297  * p9_fd_close - shutdown socket
1298  * @trans: private socket structure
1299  *
1300  */
1301 static void p9_fd_close(struct p9_trans *trans)
1302 {
1303         struct p9_trans_fd *ts;
1304
1305         if (!trans)
1306                 return;
1307
1308         ts = xchg(&trans->priv, NULL);
1309
1310         if (!ts)
1311                 return;
1312
1313         p9_conn_destroy(ts->conn);
1314
1315         trans->status = Disconnected;
1316         if (ts->rd)
1317                 fput(ts->rd);
1318         if (ts->wr)
1319                 fput(ts->wr);
1320         kfree(ts);
1321 }
1322
1323 static struct p9_trans *
1324 p9_trans_create_tcp(const char *addr, char *args, int msize, unsigned char dotu)
1325 {
1326         int err;
1327         struct p9_trans *trans;
1328         struct socket *csocket;
1329         struct sockaddr_in sin_server;
1330         struct p9_fd_opts opts;
1331         struct p9_trans_fd *p;
1332
1333         parse_opts(args, &opts);
1334
1335         csocket = NULL;
1336         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
1337         if (!trans)
1338                 return ERR_PTR(-ENOMEM);
1339         trans->msize = msize;
1340         trans->extended = dotu;
1341         trans->rpc = p9_fd_rpc;
1342         trans->close = p9_fd_close;
1343
1344         sin_server.sin_family = AF_INET;
1345         sin_server.sin_addr.s_addr = in_aton(addr);
1346         sin_server.sin_port = htons(opts.port);
1347         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
1348
1349         if (!csocket) {
1350                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
1351                 err = -EIO;
1352                 goto error;
1353         }
1354
1355         err = csocket->ops->connect(csocket,
1356                                     (struct sockaddr *)&sin_server,
1357                                     sizeof(struct sockaddr_in), 0);
1358         if (err < 0) {
1359                 P9_EPRINTK(KERN_ERR,
1360                         "p9_trans_tcp: problem connecting socket to %s\n",
1361                         addr);
1362                 goto error;
1363         }
1364
1365         err = p9_socket_open(trans, csocket);
1366         if (err < 0)
1367                 goto error;
1368
1369         p = (struct p9_trans_fd *) trans->priv;
1370         p->conn = p9_conn_create(trans);
1371         if (IS_ERR(p->conn)) {
1372                 err = PTR_ERR(p->conn);
1373                 p->conn = NULL;
1374                 goto error;
1375         }
1376
1377         return trans;
1378
1379 error:
1380         if (csocket)
1381                 sock_release(csocket);
1382
1383         kfree(trans);
1384         return ERR_PTR(err);
1385 }
1386
1387 static struct p9_trans *
1388 p9_trans_create_unix(const char *addr, char *args, int msize,
1389                                                         unsigned char dotu)
1390 {
1391         int err;
1392         struct socket *csocket;
1393         struct sockaddr_un sun_server;
1394         struct p9_trans *trans;
1395         struct p9_trans_fd *p;
1396
1397         csocket = NULL;
1398         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
1399         if (!trans)
1400                 return ERR_PTR(-ENOMEM);
1401
1402         trans->rpc = p9_fd_rpc;
1403         trans->close = p9_fd_close;
1404
1405         if (strlen(addr) > UNIX_PATH_MAX) {
1406                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
1407                         addr);
1408                 err = -ENAMETOOLONG;
1409                 goto error;
1410         }
1411
1412         sun_server.sun_family = PF_UNIX;
1413         strcpy(sun_server.sun_path, addr);
1414         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
1415         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
1416                         sizeof(struct sockaddr_un) - 1, 0);
1417         if (err < 0) {
1418                 P9_EPRINTK(KERN_ERR,
1419                         "p9_trans_unix: problem connecting socket: %s: %d\n",
1420                         addr, err);
1421                 goto error;
1422         }
1423
1424         err = p9_socket_open(trans, csocket);
1425         if (err < 0)
1426                 goto error;
1427
1428         trans->msize = msize;
1429         trans->extended = dotu;
1430         p = (struct p9_trans_fd *) trans->priv;
1431         p->conn = p9_conn_create(trans);
1432         if (IS_ERR(p->conn)) {
1433                 err = PTR_ERR(p->conn);
1434                 p->conn = NULL;
1435                 goto error;
1436         }
1437
1438         return trans;
1439
1440 error:
1441         if (csocket)
1442                 sock_release(csocket);
1443
1444         kfree(trans);
1445         return ERR_PTR(err);
1446 }
1447
1448 static struct p9_trans *
1449 p9_trans_create_fd(const char *name, char *args, int msize,
1450                                                         unsigned char extended)
1451 {
1452         int err;
1453         struct p9_trans *trans;
1454         struct p9_fd_opts opts;
1455         struct p9_trans_fd *p;
1456
1457         parse_opts(args, &opts);
1458
1459         if (opts.rfd == ~0 || opts.wfd == ~0) {
1460                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
1461                 return ERR_PTR(-ENOPROTOOPT);
1462         }
1463
1464         trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
1465         if (!trans)
1466                 return ERR_PTR(-ENOMEM);
1467
1468         trans->rpc = p9_fd_rpc;
1469         trans->close = p9_fd_close;
1470
1471         err = p9_fd_open(trans, opts.rfd, opts.wfd);
1472         if (err < 0)
1473                 goto error;
1474
1475         trans->msize = msize;
1476         trans->extended = extended;
1477         p = (struct p9_trans_fd *) trans->priv;
1478         p->conn = p9_conn_create(trans);
1479         if (IS_ERR(p->conn)) {
1480                 err = PTR_ERR(p->conn);
1481                 p->conn = NULL;
1482                 goto error;
1483         }
1484
1485         return trans;
1486
1487 error:
1488         kfree(trans);
1489         return ERR_PTR(err);
1490 }
1491
1492 static struct p9_trans_module p9_tcp_trans = {
1493         .name = "tcp",
1494         .maxsize = MAX_SOCK_BUF,
1495         .def = 1,
1496         .create = p9_trans_create_tcp,
1497 };
1498
1499 static struct p9_trans_module p9_unix_trans = {
1500         .name = "unix",
1501         .maxsize = MAX_SOCK_BUF,
1502         .def = 0,
1503         .create = p9_trans_create_unix,
1504 };
1505
1506 static struct p9_trans_module p9_fd_trans = {
1507         .name = "fd",
1508         .maxsize = MAX_SOCK_BUF,
1509         .def = 0,
1510         .create = p9_trans_create_fd,
1511 };
1512
1513 static int __init p9_trans_fd_init(void)
1514 {
1515         int ret = p9_mux_global_init();
1516         if (ret) {
1517                 printk(KERN_WARNING "9p: starting mux failed\n");
1518                 return ret;
1519         }
1520
1521         v9fs_register_trans(&p9_tcp_trans);
1522         v9fs_register_trans(&p9_unix_trans);
1523         v9fs_register_trans(&p9_fd_trans);
1524
1525         return 1;
1526 }
1527
1528 module_init(p9_trans_fd_init);
1529
1530 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
1531 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
1532 MODULE_LICENSE("GPL");