6004fded668267408a65c6862809cb6c40c46e54
[linux-2.6.git] / net / 9p / client.c
1 /*
2  * net/9p/clnt.c
3  *
4  * 9P Client
5  *
6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/poll.h>
30 #include <linux/idr.h>
31 #include <linux/mutex.h>
32 #include <linux/sched.h>
33 #include <linux/uaccess.h>
34 #include <net/9p/9p.h>
35 #include <linux/parser.h>
36 #include <net/9p/client.h>
37 #include <net/9p/transport.h>
38
39 /*
40   * Client Option Parsing (code inspired by NFS code)
41   *  - a little lazy - parse all client options
42   */
43
44 enum {
45         Opt_msize,
46         Opt_trans,
47         Opt_legacy,
48         Opt_err,
49 };
50
51 static const match_table_t tokens = {
52         {Opt_msize, "msize=%u"},
53         {Opt_legacy, "noextend"},
54         {Opt_trans, "trans=%s"},
55         {Opt_err, NULL},
56 };
57
58 static int
59 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc);
60
61 /**
62  * v9fs_parse_options - parse mount options into session structure
63  * @options: options string passed from mount
64  * @v9ses: existing v9fs session information
65  *
66  * Return 0 upon success, -ERRNO upon failure
67  */
68
69 static int parse_opts(char *opts, struct p9_client *clnt)
70 {
71         char *options;
72         char *p;
73         substring_t args[MAX_OPT_ARGS];
74         int option;
75         int ret = 0;
76
77         clnt->dotu = 1;
78         clnt->msize = 8192;
79
80         if (!opts)
81                 return 0;
82
83         options = kstrdup(opts, GFP_KERNEL);
84         if (!options) {
85                 P9_DPRINTK(P9_DEBUG_ERROR,
86                                 "failed to allocate copy of option string\n");
87                 return -ENOMEM;
88         }
89
90         while ((p = strsep(&options, ",")) != NULL) {
91                 int token;
92                 if (!*p)
93                         continue;
94                 token = match_token(p, tokens, args);
95                 if (token < Opt_trans) {
96                         int r = match_int(&args[0], &option);
97                         if (r < 0) {
98                                 P9_DPRINTK(P9_DEBUG_ERROR,
99                                         "integer field, but no integer?\n");
100                                 ret = r;
101                                 continue;
102                         }
103                 }
104                 switch (token) {
105                 case Opt_msize:
106                         clnt->msize = option;
107                         break;
108                 case Opt_trans:
109                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
110                         break;
111                 case Opt_legacy:
112                         clnt->dotu = 0;
113                         break;
114                 default:
115                         continue;
116                 }
117         }
118
119         if (!clnt->trans_mod)
120                 clnt->trans_mod = v9fs_get_default_trans();
121
122         kfree(options);
123         return ret;
124 }
125
126 /**
127  * p9_tag_alloc - lookup/allocate a request by tag
128  * @c: client session to lookup tag within
129  * @tag: numeric id for transaction
130  *
131  * this is a simple array lookup, but will grow the
132  * request_slots as necessary to accomodate transaction
133  * ids which did not previously have a slot.
134  *
135  * this code relies on the client spinlock to manage locks, its
136  * possible we should switch to something else, but I'd rather
137  * stick with something low-overhead for the common case.
138  *
139  */
140
141 struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
142 {
143         unsigned long flags;
144         int row, col;
145
146         /* This looks up the original request by tag so we know which
147          * buffer to read the data into */
148         tag++;
149
150         if (tag >= c->max_tag) {
151                 spin_lock_irqsave(&c->lock, flags);
152                 /* check again since original check was outside of lock */
153                 while (tag >= c->max_tag) {
154                         row = (tag / P9_ROW_MAXTAG);
155                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
156                                         sizeof(struct p9_req_t), GFP_ATOMIC);
157
158                         if (!c->reqs[row]) {
159                                 printk(KERN_ERR "Couldn't grow tag array\n");
160                                 BUG();
161                         }
162                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
163                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
164                                 c->reqs[row][col].flush_tag = P9_NOTAG;
165                                 c->reqs[row][col].wq = kmalloc(
166                                         sizeof(wait_queue_head_t), GFP_ATOMIC);
167                                 if (!c->reqs[row][col].wq) {
168                                         printk(KERN_ERR
169                                                 "Couldn't grow tag array\n");
170                                         BUG();
171                                 }
172                                 init_waitqueue_head(c->reqs[row][col].wq);
173                         }
174                         c->max_tag += P9_ROW_MAXTAG;
175                 }
176                 spin_unlock_irqrestore(&c->lock, flags);
177         }
178         row = tag / P9_ROW_MAXTAG;
179         col = tag % P9_ROW_MAXTAG;
180
181         c->reqs[row][col].status = REQ_STATUS_ALLOC;
182         c->reqs[row][col].flush_tag = P9_NOTAG;
183
184         return &c->reqs[row][col];
185 }
186 EXPORT_SYMBOL(p9_tag_alloc);
187
188 /**
189  * p9_tag_lookup - lookup a request by tag
190  * @c: client session to lookup tag within
191  * @tag: numeric id for transaction
192  *
193  */
194
195 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
196 {
197         int row, col;
198
199         /* This looks up the original request by tag so we know which
200          * buffer to read the data into */
201         tag++;
202
203         BUG_ON(tag >= c->max_tag);
204
205         row = tag / P9_ROW_MAXTAG;
206         col = tag % P9_ROW_MAXTAG;
207
208         return &c->reqs[row][col];
209 }
210 EXPORT_SYMBOL(p9_tag_lookup);
211
212 /**
213  * p9_tag_init - setup tags structure and contents
214  * @tags: tags structure from the client struct
215  *
216  * This initializes the tags structure for each client instance.
217  *
218  */
219
220 static int p9_tag_init(struct p9_client *c)
221 {
222         int err = 0;
223
224         c->tagpool = p9_idpool_create();
225         if (IS_ERR(c->tagpool)) {
226                 err = PTR_ERR(c->tagpool);
227                 c->tagpool = NULL;
228                 goto error;
229         }
230
231         p9_idpool_get(c->tagpool); /* reserve tag 0 */
232
233         c->max_tag = 0;
234 error:
235         return err;
236 }
237
238 /**
239  * p9_tag_cleanup - cleans up tags structure and reclaims resources
240  * @tags: tags structure from the client struct
241  *
242  * This frees resources associated with the tags structure
243  *
244  */
245 static void p9_tag_cleanup(struct p9_client *c)
246 {
247         int row, col;
248
249         /* check to insure all requests are idle */
250         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
251                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
252                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
253                                 P9_DPRINTK(P9_DEBUG_MUX,
254                                   "Attempting to cleanup non-free tag %d,%d\n",
255                                   row, col);
256                                 /* TODO: delay execution of cleanup */
257                                 return;
258                         }
259                 }
260         }
261
262         if (c->tagpool)
263                 p9_idpool_destroy(c->tagpool);
264
265         /* free requests associated with tags */
266         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
267                 for (col = 0; col < P9_ROW_MAXTAG; col++)
268                         kfree(c->reqs[row][col].wq);
269                 kfree(c->reqs[row]);
270         }
271         c->max_tag = 0;
272 }
273
274 /**
275  * p9_client_flush - flush (cancel) a request
276  * c: client state
277  * req: request to cancel
278  *
279  * This sents a flush for a particular requests and links
280  * the flush request to the original request.  The current
281  * code only supports a single flush request although the protocol
282  * allows for multiple flush requests to be sent for a single request.
283  *
284  */
285
286 static int p9_client_flush(struct p9_client *c, struct p9_req_t *req)
287 {
288         struct p9_fcall *tc, *rc = NULL;
289         int err;
290
291         P9_DPRINTK(P9_DEBUG_9P, "client %p tag %d\n", c, req->tc->tag);
292
293         tc = p9_create_tflush(req->tc->tag);
294         if (IS_ERR(tc))
295                 return PTR_ERR(tc);
296
297         err = p9_client_rpc(c, tc, &rc);
298
299         /* we don't free anything here because RPC isn't complete */
300
301         return err;
302 }
303
304 /**
305  * p9_free_req - free a request and clean-up as necessary
306  * c: client state
307  * r: request to release
308  *
309  */
310
311 void p9_free_req(struct p9_client *c, struct p9_req_t *r)
312 {
313         r->flush_tag = P9_NOTAG;
314         r->status = REQ_STATUS_IDLE;
315         if (r->tc->tag != P9_NOTAG && p9_idpool_check(r->tc->tag, c->tagpool))
316                 p9_idpool_put(r->tc->tag, c->tagpool);
317
318         /* if this was a flush request we have to free response fcall */
319         if (r->tc->id == P9_TFLUSH) {
320                 kfree(r->tc);
321                 kfree(r->rc);
322         }
323 }
324
325 /**
326  * p9_client_cb - call back from transport to client
327  * c: client state
328  * req: request received
329  *
330  */
331 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
332 {
333         struct p9_req_t *other_req;
334         unsigned long flags;
335
336         P9_DPRINTK(P9_DEBUG_MUX, ": %d\n", req->tc->tag);
337
338         if (req->status == REQ_STATUS_ERROR)
339                 wake_up(req->wq);
340
341         if (req->tc->id == P9_TFLUSH) { /* flush receive path */
342                 P9_DPRINTK(P9_DEBUG_MUX, "flush: %d\n", req->tc->tag);
343                 spin_lock_irqsave(&c->lock, flags);
344                 other_req = p9_tag_lookup(c, req->tc->params.tflush.oldtag);
345                 if (other_req->flush_tag != req->tc->tag) /* stale flush */
346                         spin_unlock_irqrestore(&c->lock, flags);
347                 else {
348                         BUG_ON(other_req->status != REQ_STATUS_FLSH);
349                         other_req->status = REQ_STATUS_FLSHD;
350                         spin_unlock_irqrestore(&c->lock, flags);
351                         wake_up(other_req->wq);
352                 }
353                 p9_free_req(c, req);
354         } else {                                /* normal receive path */
355                 P9_DPRINTK(P9_DEBUG_MUX, "normal: %d\n", req->tc->tag);
356                 spin_lock_irqsave(&c->lock, flags);
357                 if (req->status != REQ_STATUS_FLSHD)
358                         req->status = REQ_STATUS_RCVD;
359                 req->flush_tag = P9_NOTAG;
360                 spin_unlock_irqrestore(&c->lock, flags);
361                 wake_up(req->wq);
362                 P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
363         }
364 }
365 EXPORT_SYMBOL(p9_client_cb);
366
367 /**
368  * p9_client_rpc - issue a request and wait for a response
369  * @c: client session
370  * @tc: &p9_fcall request to transmit
371  * @rc: &p9_fcall to put reponse into
372  *
373  * Returns 0 on success, error code on failure
374  */
375
376 static int
377 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
378 {
379         int tag, err, size;
380         char *rdata;
381         struct p9_req_t *req;
382         unsigned long flags;
383         int sigpending;
384         int flushed = 0;
385
386         P9_DPRINTK(P9_DEBUG_9P, "client %p tc %p rc %p\n", c, tc, rc);
387
388         if (c->status != Connected)
389                 return -EIO;
390
391         if (signal_pending(current)) {
392                 sigpending = 1;
393                 clear_thread_flag(TIF_SIGPENDING);
394         } else
395                 sigpending = 0;
396
397         tag = P9_NOTAG;
398         if (tc->id != P9_TVERSION) {
399                 tag = p9_idpool_get(c->tagpool);
400                 if (tag < 0)
401                         return -ENOMEM;
402         }
403
404         req = p9_tag_alloc(c, tag);
405
406         /* if this is a flush request, backlink flush request now to
407          * avoid race conditions later. */
408         if (tc->id == P9_TFLUSH) {
409                 struct p9_req_t *other_req =
410                                 p9_tag_lookup(c, tc->params.tflush.oldtag);
411                 if (other_req->status == REQ_STATUS_FLSH)
412                         other_req->flush_tag = tag;
413         }
414
415         p9_set_tag(tc, tag);
416
417         /*
418          * if client passed in a pre-allocated response fcall struct
419          * then we just use that, otherwise we allocate one.
420          */
421
422         if (rc == NULL)
423                 req->rc = NULL;
424         else
425                 req->rc = *rc;
426         if (req->rc == NULL) {
427                 req->rc = kmalloc(sizeof(struct p9_fcall) + c->msize,
428                                                                 GFP_KERNEL);
429                 if (!req->rc) {
430                         err = -ENOMEM;
431                         p9_idpool_put(tag, c->tagpool);
432                         p9_free_req(c, req);
433                         goto reterr;
434                 }
435                 *rc = req->rc;
436         }
437
438         rdata = (char *)req->rc+sizeof(struct p9_fcall);
439
440         req->tc = tc;
441         P9_DPRINTK(P9_DEBUG_9P, "request: tc: %p rc: %p\n", req->tc, req->rc);
442
443         err = c->trans_mod->request(c, req);
444         if (err < 0) {
445                 c->status = Disconnected;
446                 goto reterr;
447         }
448
449         /* if it was a flush we just transmitted, return our tag */
450         if (tc->id == P9_TFLUSH)
451                 return 0;
452 again:
453         P9_DPRINTK(P9_DEBUG_9P, "wait %p tag: %d\n", req->wq, tag);
454         err = wait_event_interruptible(*req->wq,
455                                                 req->status >= REQ_STATUS_RCVD);
456         P9_DPRINTK(P9_DEBUG_9P, "wait %p tag: %d returned %d (flushed=%d)\n",
457                                                 req->wq, tag, err, flushed);
458
459         if (req->status == REQ_STATUS_ERROR) {
460                 P9_DPRINTK(P9_DEBUG_9P, "req_status error %d\n", req->t_err);
461                 err = req->t_err;
462         } else if (err == -ERESTARTSYS && flushed) {
463                 P9_DPRINTK(P9_DEBUG_9P, "flushed - going again\n");
464                 goto again;
465         } else if (req->status == REQ_STATUS_FLSHD) {
466                 P9_DPRINTK(P9_DEBUG_9P, "flushed - erestartsys\n");
467                 err = -ERESTARTSYS;
468         }
469
470         if ((err == -ERESTARTSYS) && (c->status == Connected) && (!flushed)) {
471                 P9_DPRINTK(P9_DEBUG_9P, "flushing\n");
472                 spin_lock_irqsave(&c->lock, flags);
473                 if (req->status == REQ_STATUS_SENT)
474                         req->status = REQ_STATUS_FLSH;
475                 spin_unlock_irqrestore(&c->lock, flags);
476                 sigpending = 1;
477                 flushed = 1;
478                 clear_thread_flag(TIF_SIGPENDING);
479
480                 if (c->trans_mod->cancel(c, req)) {
481                         err = p9_client_flush(c, req);
482                         if (err == 0)
483                                 goto again;
484                 }
485         }
486
487         if (sigpending) {
488                 spin_lock_irqsave(&current->sighand->siglock, flags);
489                 recalc_sigpending();
490                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
491         }
492
493         if (err < 0)
494                 goto reterr;
495
496         size = le32_to_cpu(*(__le32 *) rdata);
497
498         err = p9_deserialize_fcall(rdata, size, req->rc, c->dotu);
499         if (err < 0) {
500                 P9_DPRINTK(P9_DEBUG_9P,
501                         "9p debug: client rpc deserialize returned %d\n", err);
502                 goto reterr;
503         }
504
505         if (req->rc->id == P9_RERROR) {
506                 int ecode = req->rc->params.rerror.errno;
507                 struct p9_str *ename = &req->rc->params.rerror.error;
508
509                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
510                                                                 ename->str);
511
512                 if (c->dotu)
513                         err = -ecode;
514
515                 if (!err) {
516                         err = p9_errstr2errno(ename->str, ename->len);
517
518                         /* string match failed */
519                         if (!err) {
520                                 PRINT_FCALL_ERROR("unknown error", req->rc);
521                                 err = -ESERVERFAULT;
522                         }
523                 }
524         } else
525                 err = 0;
526
527 reterr:
528         p9_free_req(c, req);
529
530         P9_DPRINTK(P9_DEBUG_9P, "returning %d\n", err);
531         return err;
532 }
533
534 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
535 {
536         int err;
537         struct p9_fid *fid;
538
539         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
540         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
541         if (!fid)
542                 return ERR_PTR(-ENOMEM);
543
544         fid->fid = p9_idpool_get(clnt->fidpool);
545         if (fid->fid < 0) {
546                 err = -ENOSPC;
547                 goto error;
548         }
549
550         memset(&fid->qid, 0, sizeof(struct p9_qid));
551         fid->mode = -1;
552         fid->rdir_fpos = 0;
553         fid->uid = current->fsuid;
554         fid->clnt = clnt;
555         fid->aux = NULL;
556
557         spin_lock(&clnt->lock);
558         list_add(&fid->flist, &clnt->fidlist);
559         spin_unlock(&clnt->lock);
560
561         return fid;
562
563 error:
564         kfree(fid);
565         return ERR_PTR(err);
566 }
567
568 static void p9_fid_destroy(struct p9_fid *fid)
569 {
570         struct p9_client *clnt;
571
572         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
573         clnt = fid->clnt;
574         p9_idpool_put(fid->fid, clnt->fidpool);
575         spin_lock(&clnt->lock);
576         list_del(&fid->flist);
577         spin_unlock(&clnt->lock);
578         kfree(fid);
579 }
580
581 static int p9_client_version(struct p9_client *clnt)
582 {
583         int err = 0;
584         struct p9_fcall *tc, *rc;
585         struct p9_str *version;
586
587         P9_DPRINTK(P9_DEBUG_9P, "%p\n", clnt);
588         err = 0;
589         tc = NULL;
590         rc = NULL;
591
592         tc = p9_create_tversion(clnt->msize,
593                                         clnt->dotu ? "9P2000.u" : "9P2000");
594         if (IS_ERR(tc)) {
595                 err = PTR_ERR(tc);
596                 tc = NULL;
597                 goto error;
598         }
599
600         err = p9_client_rpc(clnt, tc, &rc);
601         if (err)
602                 goto error;
603
604         version = &rc->params.rversion.version;
605         if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
606                 clnt->dotu = 1;
607         else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
608                 clnt->dotu = 0;
609         else {
610                 err = -EREMOTEIO;
611                 goto error;
612         }
613
614         if (rc->params.rversion.msize < clnt->msize)
615                 clnt->msize = rc->params.rversion.msize;
616
617 error:
618         kfree(tc);
619         kfree(rc);
620
621         return err;
622 }
623 EXPORT_SYMBOL(p9_client_auth);
624
625 struct p9_client *p9_client_create(const char *dev_name, char *options)
626 {
627         int err;
628         struct p9_client *clnt;
629
630         err = 0;
631         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
632         if (!clnt)
633                 return ERR_PTR(-ENOMEM);
634
635         clnt->trans_mod = NULL;
636         clnt->trans = NULL;
637         spin_lock_init(&clnt->lock);
638         INIT_LIST_HEAD(&clnt->fidlist);
639         clnt->fidpool = p9_idpool_create();
640         if (IS_ERR(clnt->fidpool)) {
641                 err = PTR_ERR(clnt->fidpool);
642                 clnt->fidpool = NULL;
643                 goto error;
644         }
645
646         p9_tag_init(clnt);
647
648         err = parse_opts(options, clnt);
649         if (err < 0)
650                 goto error;
651
652         if (clnt->trans_mod == NULL) {
653                 err = -EPROTONOSUPPORT;
654                 P9_DPRINTK(P9_DEBUG_ERROR,
655                                 "No transport defined or default transport\n");
656                 goto error;
657         }
658
659         P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
660                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
661
662         err = clnt->trans_mod->create(clnt, dev_name, options);
663         if (err)
664                 goto error;
665
666         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
667                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
668
669         err = p9_client_version(clnt);
670         if (err)
671                 goto error;
672
673         return clnt;
674
675 error:
676         p9_client_destroy(clnt);
677         return ERR_PTR(err);
678 }
679 EXPORT_SYMBOL(p9_client_create);
680
681 void p9_client_destroy(struct p9_client *clnt)
682 {
683         struct p9_fid *fid, *fidptr;
684
685         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
686
687         if (clnt->trans_mod)
688                 clnt->trans_mod->close(clnt);
689
690         v9fs_put_trans(clnt->trans_mod);
691
692         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
693                 p9_fid_destroy(fid);
694
695         if (clnt->fidpool)
696                 p9_idpool_destroy(clnt->fidpool);
697
698         p9_tag_cleanup(clnt);
699
700         kfree(clnt);
701 }
702 EXPORT_SYMBOL(p9_client_destroy);
703
704 void p9_client_disconnect(struct p9_client *clnt)
705 {
706         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
707         clnt->status = Disconnected;
708 }
709 EXPORT_SYMBOL(p9_client_disconnect);
710
711 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
712         char *uname, u32 n_uname, char *aname)
713 {
714         int err;
715         struct p9_fcall *tc, *rc;
716         struct p9_fid *fid;
717
718         P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
719                 clnt, afid?afid->fid:-1, uname, aname);
720         err = 0;
721         tc = NULL;
722         rc = NULL;
723
724         fid = p9_fid_create(clnt);
725         if (IS_ERR(fid)) {
726                 err = PTR_ERR(fid);
727                 fid = NULL;
728                 goto error;
729         }
730
731         tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
732                 n_uname, clnt->dotu);
733         if (IS_ERR(tc)) {
734                 err = PTR_ERR(tc);
735                 tc = NULL;
736                 goto error;
737         }
738
739         err = p9_client_rpc(clnt, tc, &rc);
740         if (err)
741                 goto error;
742
743         memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
744         kfree(tc);
745         kfree(rc);
746         return fid;
747
748 error:
749         kfree(tc);
750         kfree(rc);
751         if (fid)
752                 p9_fid_destroy(fid);
753         return ERR_PTR(err);
754 }
755 EXPORT_SYMBOL(p9_client_attach);
756
757 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
758         u32 n_uname, char *aname)
759 {
760         int err;
761         struct p9_fcall *tc, *rc;
762         struct p9_fid *fid;
763
764         P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
765                                                                         aname);
766         err = 0;
767         tc = NULL;
768         rc = NULL;
769
770         fid = p9_fid_create(clnt);
771         if (IS_ERR(fid)) {
772                 err = PTR_ERR(fid);
773                 fid = NULL;
774                 goto error;
775         }
776
777         tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
778         if (IS_ERR(tc)) {
779                 err = PTR_ERR(tc);
780                 tc = NULL;
781                 goto error;
782         }
783
784         err = p9_client_rpc(clnt, tc, &rc);
785         if (err)
786                 goto error;
787
788         memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
789         kfree(tc);
790         kfree(rc);
791         return fid;
792
793 error:
794         kfree(tc);
795         kfree(rc);
796         if (fid)
797                 p9_fid_destroy(fid);
798         return ERR_PTR(err);
799 }
800 EXPORT_SYMBOL(p9_client_auth);
801
802 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
803         int clone)
804 {
805         int err;
806         struct p9_fcall *tc, *rc;
807         struct p9_client *clnt;
808         struct p9_fid *fid;
809
810         P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
811                 oldfid->fid, nwname, wnames?wnames[0]:NULL);
812         err = 0;
813         tc = NULL;
814         rc = NULL;
815         clnt = oldfid->clnt;
816         if (clone) {
817                 fid = p9_fid_create(clnt);
818                 if (IS_ERR(fid)) {
819                         err = PTR_ERR(fid);
820                         fid = NULL;
821                         goto error;
822                 }
823
824                 fid->uid = oldfid->uid;
825         } else
826                 fid = oldfid;
827
828         tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
829         if (IS_ERR(tc)) {
830                 err = PTR_ERR(tc);
831                 tc = NULL;
832                 goto error;
833         }
834
835         err = p9_client_rpc(clnt, tc, &rc);
836         if (err) {
837                 if (rc && rc->id == P9_RWALK)
838                         goto clunk_fid;
839                 else
840                         goto error;
841         }
842
843         if (rc->params.rwalk.nwqid != nwname) {
844                 err = -ENOENT;
845                 goto clunk_fid;
846         }
847
848         if (nwname)
849                 memmove(&fid->qid,
850                         &rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
851                         sizeof(struct p9_qid));
852         else
853                 fid->qid = oldfid->qid;
854
855         kfree(tc);
856         kfree(rc);
857         return fid;
858
859 clunk_fid:
860         kfree(tc);
861         kfree(rc);
862         rc = NULL;
863         tc = p9_create_tclunk(fid->fid);
864         if (IS_ERR(tc)) {
865                 err = PTR_ERR(tc);
866                 tc = NULL;
867                 goto error;
868         }
869
870         p9_client_rpc(clnt, tc, &rc);
871
872 error:
873         kfree(tc);
874         kfree(rc);
875         if (fid && (fid != oldfid))
876                 p9_fid_destroy(fid);
877
878         return ERR_PTR(err);
879 }
880 EXPORT_SYMBOL(p9_client_walk);
881
882 int p9_client_open(struct p9_fid *fid, int mode)
883 {
884         int err;
885         struct p9_fcall *tc, *rc;
886         struct p9_client *clnt;
887
888         P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
889         err = 0;
890         tc = NULL;
891         rc = NULL;
892         clnt = fid->clnt;
893
894         if (fid->mode != -1)
895                 return -EINVAL;
896
897         tc = p9_create_topen(fid->fid, mode);
898         if (IS_ERR(tc)) {
899                 err = PTR_ERR(tc);
900                 tc = NULL;
901                 goto done;
902         }
903
904         err = p9_client_rpc(clnt, tc, &rc);
905         if (err)
906                 goto done;
907
908         fid->mode = mode;
909         fid->iounit = rc->params.ropen.iounit;
910
911 done:
912         kfree(tc);
913         kfree(rc);
914         return err;
915 }
916 EXPORT_SYMBOL(p9_client_open);
917
918 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
919                      char *extension)
920 {
921         int err;
922         struct p9_fcall *tc, *rc;
923         struct p9_client *clnt;
924
925         P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
926                 name, perm, mode);
927         err = 0;
928         tc = NULL;
929         rc = NULL;
930         clnt = fid->clnt;
931
932         if (fid->mode != -1)
933                 return -EINVAL;
934
935         tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
936                                                                clnt->dotu);
937         if (IS_ERR(tc)) {
938                 err = PTR_ERR(tc);
939                 tc = NULL;
940                 goto done;
941         }
942
943         err = p9_client_rpc(clnt, tc, &rc);
944         if (err)
945                 goto done;
946
947         fid->mode = mode;
948         fid->iounit = rc->params.ropen.iounit;
949
950 done:
951         kfree(tc);
952         kfree(rc);
953         return err;
954 }
955 EXPORT_SYMBOL(p9_client_fcreate);
956
957 int p9_client_clunk(struct p9_fid *fid)
958 {
959         int err;
960         struct p9_fcall *tc, *rc;
961         struct p9_client *clnt;
962
963         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
964         err = 0;
965         tc = NULL;
966         rc = NULL;
967         clnt = fid->clnt;
968
969         tc = p9_create_tclunk(fid->fid);
970         if (IS_ERR(tc)) {
971                 err = PTR_ERR(tc);
972                 tc = NULL;
973                 goto done;
974         }
975
976         err = p9_client_rpc(clnt, tc, &rc);
977         if (err)
978                 goto done;
979
980         p9_fid_destroy(fid);
981
982 done:
983         kfree(tc);
984         kfree(rc);
985         return err;
986 }
987 EXPORT_SYMBOL(p9_client_clunk);
988
989 int p9_client_remove(struct p9_fid *fid)
990 {
991         int err;
992         struct p9_fcall *tc, *rc;
993         struct p9_client *clnt;
994
995         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
996         err = 0;
997         tc = NULL;
998         rc = NULL;
999         clnt = fid->clnt;
1000
1001         tc = p9_create_tremove(fid->fid);
1002         if (IS_ERR(tc)) {
1003                 err = PTR_ERR(tc);
1004                 tc = NULL;
1005                 goto done;
1006         }
1007
1008         err = p9_client_rpc(clnt, tc, &rc);
1009         if (err)
1010                 goto done;
1011
1012         p9_fid_destroy(fid);
1013
1014 done:
1015         kfree(tc);
1016         kfree(rc);
1017         return err;
1018 }
1019 EXPORT_SYMBOL(p9_client_remove);
1020
1021 int
1022 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1023                                                                 u32 count)
1024 {
1025         int err, n, rsize, total;
1026         struct p9_fcall *tc, *rc;
1027         struct p9_client *clnt;
1028
1029         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
1030                                         (long long unsigned) offset, count);
1031         err = 0;
1032         tc = NULL;
1033         rc = NULL;
1034         clnt = fid->clnt;
1035         total = 0;
1036
1037         rsize = fid->iounit;
1038         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1039                 rsize = clnt->msize - P9_IOHDRSZ;
1040
1041         do {
1042                 if (count < rsize)
1043                         rsize = count;
1044
1045                 tc = p9_create_tread(fid->fid, offset, rsize);
1046                 if (IS_ERR(tc)) {
1047                         err = PTR_ERR(tc);
1048                         tc = NULL;
1049                         goto error;
1050                 }
1051
1052                 err = p9_client_rpc(clnt, tc, &rc);
1053                 if (err)
1054                         goto error;
1055
1056                 n = rc->params.rread.count;
1057                 if (n > count)
1058                         n = count;
1059
1060                 if (data) {
1061                         memmove(data, rc->params.rread.data, n);
1062                         data += n;
1063                 }
1064
1065                 if (udata) {
1066                         err = copy_to_user(udata, rc->params.rread.data, n);
1067                         if (err) {
1068                                 err = -EFAULT;
1069                                 goto error;
1070                         }
1071                         udata += n;
1072                 }
1073
1074                 count -= n;
1075                 offset += n;
1076                 total += n;
1077                 kfree(tc);
1078                 tc = NULL;
1079                 kfree(rc);
1080                 rc = NULL;
1081         } while (count > 0 && n == rsize);
1082
1083         return total;
1084
1085 error:
1086         kfree(tc);
1087         kfree(rc);
1088         return err;
1089 }
1090 EXPORT_SYMBOL(p9_client_read);
1091
1092 int
1093 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1094                                                         u64 offset, u32 count)
1095 {
1096         int err, n, rsize, total;
1097         struct p9_fcall *tc, *rc;
1098         struct p9_client *clnt;
1099
1100         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1101                                         (long long unsigned) offset, count);
1102         err = 0;
1103         tc = NULL;
1104         rc = NULL;
1105         clnt = fid->clnt;
1106         total = 0;
1107
1108         rsize = fid->iounit;
1109         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1110                 rsize = clnt->msize - P9_IOHDRSZ;
1111
1112         do {
1113                 if (count < rsize)
1114                         rsize = count;
1115
1116                 if (data)
1117                         tc = p9_create_twrite(fid->fid, offset, rsize, data);
1118                 else
1119                         tc = p9_create_twrite_u(fid->fid, offset, rsize, udata);
1120                 if (IS_ERR(tc)) {
1121                         err = PTR_ERR(tc);
1122                         tc = NULL;
1123                         goto error;
1124                 }
1125
1126                 err = p9_client_rpc(clnt, tc, &rc);
1127                 if (err)
1128                         goto error;
1129
1130                 n = rc->params.rread.count;
1131                 count -= n;
1132
1133                 if (data)
1134                         data += n;
1135                 else
1136                         udata += n;
1137
1138                 offset += n;
1139                 total += n;
1140                 kfree(tc);
1141                 tc = NULL;
1142                 kfree(rc);
1143                 rc = NULL;
1144         } while (count > 0);
1145
1146         return total;
1147
1148 error:
1149         kfree(tc);
1150         kfree(rc);
1151         return err;
1152 }
1153 EXPORT_SYMBOL(p9_client_write);
1154
1155 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
1156 {
1157         int n;
1158         char *p;
1159         struct p9_stat *ret;
1160
1161         n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
1162                 st->muid.len;
1163
1164         if (dotu)
1165                 n += st->extension.len;
1166
1167         ret = kmalloc(n, GFP_KERNEL);
1168         if (!ret)
1169                 return ERR_PTR(-ENOMEM);
1170
1171         memmove(ret, st, sizeof(struct p9_stat));
1172         p = ((char *) ret) + sizeof(struct p9_stat);
1173         memmove(p, st->name.str, st->name.len);
1174         ret->name.str = p;
1175         p += st->name.len;
1176         memmove(p, st->uid.str, st->uid.len);
1177         ret->uid.str = p;
1178         p += st->uid.len;
1179         memmove(p, st->gid.str, st->gid.len);
1180         ret->gid.str = p;
1181         p += st->gid.len;
1182         memmove(p, st->muid.str, st->muid.len);
1183         ret->muid.str = p;
1184         p += st->muid.len;
1185
1186         if (dotu) {
1187                 memmove(p, st->extension.str, st->extension.len);
1188                 ret->extension.str = p;
1189                 p += st->extension.len;
1190         }
1191
1192         return ret;
1193 }
1194
1195 struct p9_stat *p9_client_stat(struct p9_fid *fid)
1196 {
1197         int err;
1198         struct p9_fcall *tc, *rc;
1199         struct p9_client *clnt;
1200         struct p9_stat *ret;
1201
1202         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1203         err = 0;
1204         tc = NULL;
1205         rc = NULL;
1206         ret = NULL;
1207         clnt = fid->clnt;
1208
1209         tc = p9_create_tstat(fid->fid);
1210         if (IS_ERR(tc)) {
1211                 err = PTR_ERR(tc);
1212                 tc = NULL;
1213                 goto error;
1214         }
1215
1216         err = p9_client_rpc(clnt, tc, &rc);
1217         if (err)
1218                 goto error;
1219
1220         ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
1221         if (IS_ERR(ret)) {
1222                 err = PTR_ERR(ret);
1223                 ret = NULL;
1224                 goto error;
1225         }
1226
1227         kfree(tc);
1228         kfree(rc);
1229         return ret;
1230
1231 error:
1232         kfree(tc);
1233         kfree(rc);
1234         kfree(ret);
1235         return ERR_PTR(err);
1236 }
1237 EXPORT_SYMBOL(p9_client_stat);
1238
1239 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1240 {
1241         int err;
1242         struct p9_fcall *tc, *rc;
1243         struct p9_client *clnt;
1244
1245         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1246         err = 0;
1247         tc = NULL;
1248         rc = NULL;
1249         clnt = fid->clnt;
1250
1251         tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
1252         if (IS_ERR(tc)) {
1253                 err = PTR_ERR(tc);
1254                 tc = NULL;
1255                 goto done;
1256         }
1257
1258         err = p9_client_rpc(clnt, tc, &rc);
1259
1260 done:
1261         kfree(tc);
1262         kfree(rc);
1263         return err;
1264 }
1265 EXPORT_SYMBOL(p9_client_wstat);