9p: move dirread to fs layer
[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 #ifdef CONFIG_NET_9P_DEBUG
506         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
507                 char buf[150];
508
509                 p9_printfcall(buf, sizeof(buf), req->rc, c->dotu);
510                 printk(KERN_NOTICE ">>> %p %s\n", c, buf);
511         }
512 #endif
513
514         if (req->rc->id == P9_RERROR) {
515                 int ecode = req->rc->params.rerror.errno;
516                 struct p9_str *ename = &req->rc->params.rerror.error;
517
518                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
519                                                                 ename->str);
520
521                 if (c->dotu)
522                         err = -ecode;
523
524                 if (!err) {
525                         err = p9_errstr2errno(ename->str, ename->len);
526
527                         /* string match failed */
528                         if (!err) {
529                                 PRINT_FCALL_ERROR("unknown error", req->rc);
530                                 err = -ESERVERFAULT;
531                         }
532                 }
533         } else
534                 err = 0;
535
536 reterr:
537         p9_free_req(c, req);
538
539         P9_DPRINTK(P9_DEBUG_9P, "returning %d\n", err);
540         return err;
541 }
542
543 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
544 {
545         int err;
546         struct p9_fid *fid;
547
548         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
549         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
550         if (!fid)
551                 return ERR_PTR(-ENOMEM);
552
553         fid->fid = p9_idpool_get(clnt->fidpool);
554         if (fid->fid < 0) {
555                 err = -ENOSPC;
556                 goto error;
557         }
558
559         memset(&fid->qid, 0, sizeof(struct p9_qid));
560         fid->mode = -1;
561         fid->rdir_fpos = 0;
562         fid->uid = current->fsuid;
563         fid->clnt = clnt;
564         fid->aux = NULL;
565
566         spin_lock(&clnt->lock);
567         list_add(&fid->flist, &clnt->fidlist);
568         spin_unlock(&clnt->lock);
569
570         return fid;
571
572 error:
573         kfree(fid);
574         return ERR_PTR(err);
575 }
576
577 static void p9_fid_destroy(struct p9_fid *fid)
578 {
579         struct p9_client *clnt;
580
581         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
582         clnt = fid->clnt;
583         p9_idpool_put(fid->fid, clnt->fidpool);
584         spin_lock(&clnt->lock);
585         list_del(&fid->flist);
586         spin_unlock(&clnt->lock);
587         kfree(fid);
588 }
589
590 struct p9_client *p9_client_create(const char *dev_name, char *options)
591 {
592         int err, n;
593         struct p9_client *clnt;
594         struct p9_fcall *tc, *rc;
595         struct p9_str *version;
596
597         err = 0;
598         tc = NULL;
599         rc = NULL;
600         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
601         if (!clnt)
602                 return ERR_PTR(-ENOMEM);
603
604         clnt->trans_mod = NULL;
605         clnt->trans = NULL;
606         spin_lock_init(&clnt->lock);
607         INIT_LIST_HEAD(&clnt->fidlist);
608         clnt->fidpool = p9_idpool_create();
609         if (IS_ERR(clnt->fidpool)) {
610                 err = PTR_ERR(clnt->fidpool);
611                 clnt->fidpool = NULL;
612                 goto error;
613         }
614
615         p9_tag_init(clnt);
616
617         err = parse_opts(options, clnt);
618         if (err < 0)
619                 goto error;
620
621         if (clnt->trans_mod == NULL) {
622                 err = -EPROTONOSUPPORT;
623                 P9_DPRINTK(P9_DEBUG_ERROR,
624                                 "No transport defined or default transport\n");
625                 goto error;
626         }
627
628         P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
629                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
630
631
632         err = clnt->trans_mod->create(clnt, dev_name, options);
633         if (err)
634                 goto error;
635
636         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
637                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
638
639         tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
640         if (IS_ERR(tc)) {
641                 err = PTR_ERR(tc);
642                 tc = NULL;
643                 goto error;
644         }
645
646         err = p9_client_rpc(clnt, tc, &rc);
647         if (err)
648                 goto error;
649
650         version = &rc->params.rversion.version;
651         if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
652                 clnt->dotu = 1;
653         else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
654                 clnt->dotu = 0;
655         else {
656                 err = -EREMOTEIO;
657                 goto error;
658         }
659
660         n = rc->params.rversion.msize;
661         if (n < clnt->msize)
662                 clnt->msize = n;
663
664         kfree(tc);
665         kfree(rc);
666         return clnt;
667
668 error:
669         kfree(tc);
670         kfree(rc);
671         p9_client_destroy(clnt);
672         return ERR_PTR(err);
673 }
674 EXPORT_SYMBOL(p9_client_create);
675
676 void p9_client_destroy(struct p9_client *clnt)
677 {
678         struct p9_fid *fid, *fidptr;
679
680         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
681
682         if (clnt->trans_mod)
683                 clnt->trans_mod->close(clnt);
684
685         v9fs_put_trans(clnt->trans_mod);
686
687         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
688                 p9_fid_destroy(fid);
689
690         if (clnt->fidpool)
691                 p9_idpool_destroy(clnt->fidpool);
692
693         p9_tag_cleanup(clnt);
694
695         kfree(clnt);
696 }
697 EXPORT_SYMBOL(p9_client_destroy);
698
699 void p9_client_disconnect(struct p9_client *clnt)
700 {
701         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
702         clnt->status = Disconnected;
703 }
704 EXPORT_SYMBOL(p9_client_disconnect);
705
706 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
707         char *uname, u32 n_uname, char *aname)
708 {
709         int err;
710         struct p9_fcall *tc, *rc;
711         struct p9_fid *fid;
712
713         P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
714                 clnt, afid?afid->fid:-1, uname, aname);
715         err = 0;
716         tc = NULL;
717         rc = NULL;
718
719         fid = p9_fid_create(clnt);
720         if (IS_ERR(fid)) {
721                 err = PTR_ERR(fid);
722                 fid = NULL;
723                 goto error;
724         }
725
726         tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
727                 n_uname, clnt->dotu);
728         if (IS_ERR(tc)) {
729                 err = PTR_ERR(tc);
730                 tc = NULL;
731                 goto error;
732         }
733
734         err = p9_client_rpc(clnt, tc, &rc);
735         if (err)
736                 goto error;
737
738         memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
739         kfree(tc);
740         kfree(rc);
741         return fid;
742
743 error:
744         kfree(tc);
745         kfree(rc);
746         if (fid)
747                 p9_fid_destroy(fid);
748         return ERR_PTR(err);
749 }
750 EXPORT_SYMBOL(p9_client_attach);
751
752 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
753         u32 n_uname, char *aname)
754 {
755         int err;
756         struct p9_fcall *tc, *rc;
757         struct p9_fid *fid;
758
759         P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
760                                                                         aname);
761         err = 0;
762         tc = NULL;
763         rc = NULL;
764
765         fid = p9_fid_create(clnt);
766         if (IS_ERR(fid)) {
767                 err = PTR_ERR(fid);
768                 fid = NULL;
769                 goto error;
770         }
771
772         tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
773         if (IS_ERR(tc)) {
774                 err = PTR_ERR(tc);
775                 tc = NULL;
776                 goto error;
777         }
778
779         err = p9_client_rpc(clnt, tc, &rc);
780         if (err)
781                 goto error;
782
783         memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
784         kfree(tc);
785         kfree(rc);
786         return fid;
787
788 error:
789         kfree(tc);
790         kfree(rc);
791         if (fid)
792                 p9_fid_destroy(fid);
793         return ERR_PTR(err);
794 }
795 EXPORT_SYMBOL(p9_client_auth);
796
797 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
798         int clone)
799 {
800         int err;
801         struct p9_fcall *tc, *rc;
802         struct p9_client *clnt;
803         struct p9_fid *fid;
804
805         P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
806                 oldfid->fid, nwname, wnames?wnames[0]:NULL);
807         err = 0;
808         tc = NULL;
809         rc = NULL;
810         clnt = oldfid->clnt;
811         if (clone) {
812                 fid = p9_fid_create(clnt);
813                 if (IS_ERR(fid)) {
814                         err = PTR_ERR(fid);
815                         fid = NULL;
816                         goto error;
817                 }
818
819                 fid->uid = oldfid->uid;
820         } else
821                 fid = oldfid;
822
823         tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
824         if (IS_ERR(tc)) {
825                 err = PTR_ERR(tc);
826                 tc = NULL;
827                 goto error;
828         }
829
830         err = p9_client_rpc(clnt, tc, &rc);
831         if (err) {
832                 if (rc && rc->id == P9_RWALK)
833                         goto clunk_fid;
834                 else
835                         goto error;
836         }
837
838         if (rc->params.rwalk.nwqid != nwname) {
839                 err = -ENOENT;
840                 goto clunk_fid;
841         }
842
843         if (nwname)
844                 memmove(&fid->qid,
845                         &rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
846                         sizeof(struct p9_qid));
847         else
848                 fid->qid = oldfid->qid;
849
850         kfree(tc);
851         kfree(rc);
852         return fid;
853
854 clunk_fid:
855         kfree(tc);
856         kfree(rc);
857         rc = NULL;
858         tc = p9_create_tclunk(fid->fid);
859         if (IS_ERR(tc)) {
860                 err = PTR_ERR(tc);
861                 tc = NULL;
862                 goto error;
863         }
864
865         p9_client_rpc(clnt, tc, &rc);
866
867 error:
868         kfree(tc);
869         kfree(rc);
870         if (fid && (fid != oldfid))
871                 p9_fid_destroy(fid);
872
873         return ERR_PTR(err);
874 }
875 EXPORT_SYMBOL(p9_client_walk);
876
877 int p9_client_open(struct p9_fid *fid, int mode)
878 {
879         int err;
880         struct p9_fcall *tc, *rc;
881         struct p9_client *clnt;
882
883         P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
884         err = 0;
885         tc = NULL;
886         rc = NULL;
887         clnt = fid->clnt;
888
889         if (fid->mode != -1)
890                 return -EINVAL;
891
892         tc = p9_create_topen(fid->fid, mode);
893         if (IS_ERR(tc)) {
894                 err = PTR_ERR(tc);
895                 tc = NULL;
896                 goto done;
897         }
898
899         err = p9_client_rpc(clnt, tc, &rc);
900         if (err)
901                 goto done;
902
903         fid->mode = mode;
904         fid->iounit = rc->params.ropen.iounit;
905
906 done:
907         kfree(tc);
908         kfree(rc);
909         return err;
910 }
911 EXPORT_SYMBOL(p9_client_open);
912
913 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
914                      char *extension)
915 {
916         int err;
917         struct p9_fcall *tc, *rc;
918         struct p9_client *clnt;
919
920         P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
921                 name, perm, mode);
922         err = 0;
923         tc = NULL;
924         rc = NULL;
925         clnt = fid->clnt;
926
927         if (fid->mode != -1)
928                 return -EINVAL;
929
930         tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
931                                                                clnt->dotu);
932         if (IS_ERR(tc)) {
933                 err = PTR_ERR(tc);
934                 tc = NULL;
935                 goto done;
936         }
937
938         err = p9_client_rpc(clnt, tc, &rc);
939         if (err)
940                 goto done;
941
942         fid->mode = mode;
943         fid->iounit = rc->params.ropen.iounit;
944
945 done:
946         kfree(tc);
947         kfree(rc);
948         return err;
949 }
950 EXPORT_SYMBOL(p9_client_fcreate);
951
952 int p9_client_clunk(struct p9_fid *fid)
953 {
954         int err;
955         struct p9_fcall *tc, *rc;
956         struct p9_client *clnt;
957
958         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
959         err = 0;
960         tc = NULL;
961         rc = NULL;
962         clnt = fid->clnt;
963
964         tc = p9_create_tclunk(fid->fid);
965         if (IS_ERR(tc)) {
966                 err = PTR_ERR(tc);
967                 tc = NULL;
968                 goto done;
969         }
970
971         err = p9_client_rpc(clnt, tc, &rc);
972         if (err)
973                 goto done;
974
975         p9_fid_destroy(fid);
976
977 done:
978         kfree(tc);
979         kfree(rc);
980         return err;
981 }
982 EXPORT_SYMBOL(p9_client_clunk);
983
984 int p9_client_remove(struct p9_fid *fid)
985 {
986         int err;
987         struct p9_fcall *tc, *rc;
988         struct p9_client *clnt;
989
990         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
991         err = 0;
992         tc = NULL;
993         rc = NULL;
994         clnt = fid->clnt;
995
996         tc = p9_create_tremove(fid->fid);
997         if (IS_ERR(tc)) {
998                 err = PTR_ERR(tc);
999                 tc = NULL;
1000                 goto done;
1001         }
1002
1003         err = p9_client_rpc(clnt, tc, &rc);
1004         if (err)
1005                 goto done;
1006
1007         p9_fid_destroy(fid);
1008
1009 done:
1010         kfree(tc);
1011         kfree(rc);
1012         return err;
1013 }
1014 EXPORT_SYMBOL(p9_client_remove);
1015
1016 int
1017 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1018                                                                 u32 count)
1019 {
1020         int err, n, rsize, total;
1021         struct p9_fcall *tc, *rc;
1022         struct p9_client *clnt;
1023
1024         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
1025                                         (long long unsigned) offset, count);
1026         err = 0;
1027         tc = NULL;
1028         rc = NULL;
1029         clnt = fid->clnt;
1030         total = 0;
1031
1032         rsize = fid->iounit;
1033         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1034                 rsize = clnt->msize - P9_IOHDRSZ;
1035
1036         do {
1037                 if (count < rsize)
1038                         rsize = count;
1039
1040                 tc = p9_create_tread(fid->fid, offset, rsize);
1041                 if (IS_ERR(tc)) {
1042                         err = PTR_ERR(tc);
1043                         tc = NULL;
1044                         goto error;
1045                 }
1046
1047                 err = p9_client_rpc(clnt, tc, &rc);
1048                 if (err)
1049                         goto error;
1050
1051                 n = rc->params.rread.count;
1052                 if (n > count)
1053                         n = count;
1054
1055                 if (data) {
1056                         memmove(data, rc->params.rread.data, n);
1057                         data += n;
1058                 }
1059
1060                 if (udata) {
1061                         err = copy_to_user(udata, rc->params.rread.data, n);
1062                         if (err) {
1063                                 err = -EFAULT;
1064                                 goto error;
1065                         }
1066                         udata += n;
1067                 }
1068
1069                 count -= n;
1070                 offset += n;
1071                 total += n;
1072                 kfree(tc);
1073                 tc = NULL;
1074                 kfree(rc);
1075                 rc = NULL;
1076         } while (count > 0 && n == rsize);
1077
1078         return total;
1079
1080 error:
1081         kfree(tc);
1082         kfree(rc);
1083         return err;
1084 }
1085 EXPORT_SYMBOL(p9_client_read);
1086
1087 int
1088 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1089                                                         u64 offset, u32 count)
1090 {
1091         int err, n, rsize, total;
1092         struct p9_fcall *tc, *rc;
1093         struct p9_client *clnt;
1094
1095         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1096                                         (long long unsigned) offset, count);
1097         err = 0;
1098         tc = NULL;
1099         rc = NULL;
1100         clnt = fid->clnt;
1101         total = 0;
1102
1103         rsize = fid->iounit;
1104         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1105                 rsize = clnt->msize - P9_IOHDRSZ;
1106
1107         do {
1108                 if (count < rsize)
1109                         rsize = count;
1110
1111                 if (data)
1112                         tc = p9_create_twrite(fid->fid, offset, rsize, data);
1113                 else
1114                         tc = p9_create_twrite_u(fid->fid, offset, rsize, udata);
1115                 if (IS_ERR(tc)) {
1116                         err = PTR_ERR(tc);
1117                         tc = NULL;
1118                         goto error;
1119                 }
1120
1121                 err = p9_client_rpc(clnt, tc, &rc);
1122                 if (err)
1123                         goto error;
1124
1125                 n = rc->params.rread.count;
1126                 count -= n;
1127
1128                 if (data)
1129                         data += n;
1130                 else
1131                         udata += n;
1132
1133                 offset += n;
1134                 total += n;
1135                 kfree(tc);
1136                 tc = NULL;
1137                 kfree(rc);
1138                 rc = NULL;
1139         } while (count > 0);
1140
1141         return total;
1142
1143 error:
1144         kfree(tc);
1145         kfree(rc);
1146         return err;
1147 }
1148 EXPORT_SYMBOL(p9_client_write);
1149
1150 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
1151 {
1152         int n;
1153         char *p;
1154         struct p9_stat *ret;
1155
1156         n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
1157                 st->muid.len;
1158
1159         if (dotu)
1160                 n += st->extension.len;
1161
1162         ret = kmalloc(n, GFP_KERNEL);
1163         if (!ret)
1164                 return ERR_PTR(-ENOMEM);
1165
1166         memmove(ret, st, sizeof(struct p9_stat));
1167         p = ((char *) ret) + sizeof(struct p9_stat);
1168         memmove(p, st->name.str, st->name.len);
1169         ret->name.str = p;
1170         p += st->name.len;
1171         memmove(p, st->uid.str, st->uid.len);
1172         ret->uid.str = p;
1173         p += st->uid.len;
1174         memmove(p, st->gid.str, st->gid.len);
1175         ret->gid.str = p;
1176         p += st->gid.len;
1177         memmove(p, st->muid.str, st->muid.len);
1178         ret->muid.str = p;
1179         p += st->muid.len;
1180
1181         if (dotu) {
1182                 memmove(p, st->extension.str, st->extension.len);
1183                 ret->extension.str = p;
1184                 p += st->extension.len;
1185         }
1186
1187         return ret;
1188 }
1189
1190 struct p9_stat *p9_client_stat(struct p9_fid *fid)
1191 {
1192         int err;
1193         struct p9_fcall *tc, *rc;
1194         struct p9_client *clnt;
1195         struct p9_stat *ret;
1196
1197         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1198         err = 0;
1199         tc = NULL;
1200         rc = NULL;
1201         ret = NULL;
1202         clnt = fid->clnt;
1203
1204         tc = p9_create_tstat(fid->fid);
1205         if (IS_ERR(tc)) {
1206                 err = PTR_ERR(tc);
1207                 tc = NULL;
1208                 goto error;
1209         }
1210
1211         err = p9_client_rpc(clnt, tc, &rc);
1212         if (err)
1213                 goto error;
1214
1215         ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
1216         if (IS_ERR(ret)) {
1217                 err = PTR_ERR(ret);
1218                 ret = NULL;
1219                 goto error;
1220         }
1221
1222         kfree(tc);
1223         kfree(rc);
1224         return ret;
1225
1226 error:
1227         kfree(tc);
1228         kfree(rc);
1229         kfree(ret);
1230         return ERR_PTR(err);
1231 }
1232 EXPORT_SYMBOL(p9_client_stat);
1233
1234 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1235 {
1236         int err;
1237         struct p9_fcall *tc, *rc;
1238         struct p9_client *clnt;
1239
1240         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1241         err = 0;
1242         tc = NULL;
1243         rc = NULL;
1244         clnt = fid->clnt;
1245
1246         tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
1247         if (IS_ERR(tc)) {
1248                 err = PTR_ERR(tc);
1249                 tc = NULL;
1250                 goto done;
1251         }
1252
1253         err = p9_client_rpc(clnt, tc, &rc);
1254
1255 done:
1256         kfree(tc);
1257         kfree(rc);
1258         return err;
1259 }
1260 EXPORT_SYMBOL(p9_client_wstat);