net/9p: handle correctly interrupted 9P requests
[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 #include "protocol.h"
39
40 /*
41   * Client Option Parsing (code inspired by NFS code)
42   *  - a little lazy - parse all client options
43   */
44
45 enum {
46         Opt_msize,
47         Opt_trans,
48         Opt_legacy,
49         Opt_err,
50 };
51
52 static const match_table_t tokens = {
53         {Opt_msize, "msize=%u"},
54         {Opt_legacy, "noextend"},
55         {Opt_trans, "trans=%s"},
56         {Opt_err, NULL},
57 };
58
59 static struct p9_req_t *
60 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
61
62 /**
63  * v9fs_parse_options - parse mount options into session structure
64  * @options: options string passed from mount
65  * @v9ses: existing v9fs session information
66  *
67  * Return 0 upon success, -ERRNO upon failure
68  */
69
70 static int parse_opts(char *opts, struct p9_client *clnt)
71 {
72         char *options;
73         char *p;
74         substring_t args[MAX_OPT_ARGS];
75         int option;
76         int ret = 0;
77
78         clnt->dotu = 1;
79         clnt->msize = 8192;
80
81         if (!opts)
82                 return 0;
83
84         options = kstrdup(opts, GFP_KERNEL);
85         if (!options) {
86                 P9_DPRINTK(P9_DEBUG_ERROR,
87                                 "failed to allocate copy of option string\n");
88                 return -ENOMEM;
89         }
90
91         while ((p = strsep(&options, ",")) != NULL) {
92                 int token;
93                 if (!*p)
94                         continue;
95                 token = match_token(p, tokens, args);
96                 if (token < Opt_trans) {
97                         int r = match_int(&args[0], &option);
98                         if (r < 0) {
99                                 P9_DPRINTK(P9_DEBUG_ERROR,
100                                         "integer field, but no integer?\n");
101                                 ret = r;
102                                 continue;
103                         }
104                 }
105                 switch (token) {
106                 case Opt_msize:
107                         clnt->msize = option;
108                         break;
109                 case Opt_trans:
110                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
111                         break;
112                 case Opt_legacy:
113                         clnt->dotu = 0;
114                         break;
115                 default:
116                         continue;
117                 }
118         }
119
120         if (!clnt->trans_mod)
121                 clnt->trans_mod = v9fs_get_default_trans();
122
123         kfree(options);
124         return ret;
125 }
126
127 /**
128  * p9_tag_alloc - lookup/allocate a request by tag
129  * @c: client session to lookup tag within
130  * @tag: numeric id for transaction
131  *
132  * this is a simple array lookup, but will grow the
133  * request_slots as necessary to accomodate transaction
134  * ids which did not previously have a slot.
135  *
136  * this code relies on the client spinlock to manage locks, its
137  * possible we should switch to something else, but I'd rather
138  * stick with something low-overhead for the common case.
139  *
140  */
141
142 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
143 {
144         unsigned long flags;
145         int row, col;
146         struct p9_req_t *req;
147
148         /* This looks up the original request by tag so we know which
149          * buffer to read the data into */
150         tag++;
151
152         if (tag >= c->max_tag) {
153                 spin_lock_irqsave(&c->lock, flags);
154                 /* check again since original check was outside of lock */
155                 while (tag >= c->max_tag) {
156                         row = (tag / P9_ROW_MAXTAG);
157                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
158                                         sizeof(struct p9_req_t), GFP_ATOMIC);
159
160                         if (!c->reqs[row]) {
161                                 printk(KERN_ERR "Couldn't grow tag array\n");
162                                 spin_unlock_irqrestore(&c->lock, flags);
163                                 return ERR_PTR(-ENOMEM);
164                         }
165                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
166                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
167                                 c->reqs[row][col].tc = NULL;
168                         }
169                         c->max_tag += P9_ROW_MAXTAG;
170                 }
171                 spin_unlock_irqrestore(&c->lock, flags);
172         }
173         row = tag / P9_ROW_MAXTAG;
174         col = tag % P9_ROW_MAXTAG;
175
176         req = &c->reqs[row][col];
177         if (!req->tc) {
178                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
179                 if (!req->wq) {
180                         printk(KERN_ERR "Couldn't grow tag array\n");
181                         return ERR_PTR(-ENOMEM);
182                 }
183                 init_waitqueue_head(req->wq);
184                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
185                                                                 GFP_KERNEL);
186                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
187                                                                 GFP_KERNEL);
188                 if ((!req->tc) || (!req->rc)) {
189                         printk(KERN_ERR "Couldn't grow tag array\n");
190                         kfree(req->tc);
191                         kfree(req->rc);
192                         kfree(req->wq);
193                         req->tc = req->rc = NULL;
194                         req->wq = NULL;
195                         return ERR_PTR(-ENOMEM);
196                 }
197                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
198                 req->tc->capacity = c->msize;
199                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
200                 req->rc->capacity = c->msize;
201         }
202
203         p9pdu_reset(req->tc);
204         p9pdu_reset(req->rc);
205
206         req->tc->tag = tag-1;
207         req->status = REQ_STATUS_ALLOC;
208
209         return &c->reqs[row][col];
210 }
211
212 /**
213  * p9_tag_lookup - lookup a request by tag
214  * @c: client session to lookup tag within
215  * @tag: numeric id for transaction
216  *
217  */
218
219 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
220 {
221         int row, col;
222
223         /* This looks up the original request by tag so we know which
224          * buffer to read the data into */
225         tag++;
226
227         BUG_ON(tag >= c->max_tag);
228
229         row = tag / P9_ROW_MAXTAG;
230         col = tag % P9_ROW_MAXTAG;
231
232         return &c->reqs[row][col];
233 }
234 EXPORT_SYMBOL(p9_tag_lookup);
235
236 /**
237  * p9_tag_init - setup tags structure and contents
238  * @tags: tags structure from the client struct
239  *
240  * This initializes the tags structure for each client instance.
241  *
242  */
243
244 static int p9_tag_init(struct p9_client *c)
245 {
246         int err = 0;
247
248         c->tagpool = p9_idpool_create();
249         if (IS_ERR(c->tagpool)) {
250                 err = PTR_ERR(c->tagpool);
251                 c->tagpool = NULL;
252                 goto error;
253         }
254
255         p9_idpool_get(c->tagpool); /* reserve tag 0 */
256
257         c->max_tag = 0;
258 error:
259         return err;
260 }
261
262 /**
263  * p9_tag_cleanup - cleans up tags structure and reclaims resources
264  * @tags: tags structure from the client struct
265  *
266  * This frees resources associated with the tags structure
267  *
268  */
269 static void p9_tag_cleanup(struct p9_client *c)
270 {
271         int row, col;
272
273         /* check to insure all requests are idle */
274         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
275                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
276                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
277                                 P9_DPRINTK(P9_DEBUG_MUX,
278                                   "Attempting to cleanup non-free tag %d,%d\n",
279                                   row, col);
280                                 /* TODO: delay execution of cleanup */
281                                 return;
282                         }
283                 }
284         }
285
286         if (c->tagpool)
287                 p9_idpool_destroy(c->tagpool);
288
289         /* free requests associated with tags */
290         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
291                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
292                         kfree(c->reqs[row][col].wq);
293                         kfree(c->reqs[row][col].tc);
294                         kfree(c->reqs[row][col].rc);
295                 }
296                 kfree(c->reqs[row]);
297         }
298         c->max_tag = 0;
299 }
300
301 /**
302  * p9_free_req - free a request and clean-up as necessary
303  * c: client state
304  * r: request to release
305  *
306  */
307
308 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
309 {
310         int tag = r->tc->tag;
311         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
312
313         r->status = REQ_STATUS_IDLE;
314         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
315                 p9_idpool_put(tag, c->tagpool);
316 }
317
318 /**
319  * p9_client_cb - call back from transport to client
320  * c: client state
321  * req: request received
322  *
323  */
324 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
325 {
326         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
327         wake_up(req->wq);
328         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
329 }
330 EXPORT_SYMBOL(p9_client_cb);
331
332 /**
333  * p9_parse_header - parse header arguments out of a packet
334  * @pdu: packet to parse
335  * @size: size of packet
336  * @type: type of request
337  * @tag: tag of packet
338  * @rewind: set if we need to rewind offset afterwards
339  */
340
341 int
342 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
343                                                                 int rewind)
344 {
345         int8_t r_type;
346         int16_t r_tag;
347         int32_t r_size;
348         int offset = pdu->offset;
349         int err;
350
351         pdu->offset = 0;
352         if (pdu->size == 0)
353                 pdu->size = 7;
354
355         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
356         if (err)
357                 goto rewind_and_exit;
358
359         pdu->size = r_size;
360         pdu->id = r_type;
361         pdu->tag = r_tag;
362
363         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
364                                                         pdu->id, pdu->tag);
365
366         if (type)
367                 *type = r_type;
368         if (tag)
369                 *tag = r_tag;
370         if (size)
371                 *size = r_size;
372
373
374 rewind_and_exit:
375         if (rewind)
376                 pdu->offset = offset;
377         return err;
378 }
379 EXPORT_SYMBOL(p9_parse_header);
380
381 /**
382  * p9_check_errors - check 9p packet for error return and process it
383  * @c: current client instance
384  * @req: request to parse and check for error conditions
385  *
386  * returns error code if one is discovered, otherwise returns 0
387  *
388  * this will have to be more complicated if we have multiple
389  * error packet types
390  */
391
392 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
393 {
394         int8_t type;
395         int err;
396
397         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
398         if (err) {
399                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
400                 return err;
401         }
402
403         if (type == P9_RERROR) {
404                 int ecode;
405                 char *ename;
406
407                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
408                 if (err) {
409                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
410                                                                         err);
411                         return err;
412                 }
413
414                 if (c->dotu)
415                         err = -ecode;
416
417                 if (!err) {
418                         err = p9_errstr2errno(ename, strlen(ename));
419
420                         /* string match failed */
421                         if (!err)
422                                 err = -ESERVERFAULT;
423                 }
424
425                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
426
427                 kfree(ename);
428         } else
429                 err = 0;
430
431         return err;
432 }
433
434 /**
435  * p9_client_flush - flush (cancel) a request
436  * c: client state
437  * req: request to cancel
438  *
439  * This sents a flush for a particular requests and links
440  * the flush request to the original request.  The current
441  * code only supports a single flush request although the protocol
442  * allows for multiple flush requests to be sent for a single request.
443  *
444  */
445
446 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
447 {
448         struct p9_req_t *req;
449         int16_t oldtag;
450         int err;
451
452         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
453         if (err)
454                 return err;
455
456         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
457
458         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
459         if (IS_ERR(req))
460                 return PTR_ERR(req);
461
462
463         /* if we haven't received a response for oldreq,
464            remove it from the list. */
465         spin_lock(&c->lock);
466         if (oldreq->status == REQ_STATUS_FLSH)
467                 list_del(&oldreq->req_list);
468         spin_unlock(&c->lock);
469
470         p9_free_req(c, req);
471         return 0;
472 }
473
474 /**
475  * p9_client_rpc - issue a request and wait for a response
476  * @c: client session
477  * @type: type of request
478  * @fmt: protocol format string (see protocol.c)
479  *
480  * Returns request structure (which client must free using p9_free_req)
481  */
482
483 static struct p9_req_t *
484 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
485 {
486         va_list ap;
487         int tag, err;
488         struct p9_req_t *req;
489         unsigned long flags;
490         int sigpending;
491
492         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
493
494         if (c->status != Connected)
495                 return ERR_PTR(-EIO);
496
497         if (signal_pending(current)) {
498                 sigpending = 1;
499                 clear_thread_flag(TIF_SIGPENDING);
500         } else
501                 sigpending = 0;
502
503         tag = P9_NOTAG;
504         if (type != P9_TVERSION) {
505                 tag = p9_idpool_get(c->tagpool);
506                 if (tag < 0)
507                         return ERR_PTR(-ENOMEM);
508         }
509
510         req = p9_tag_alloc(c, tag);
511         if (IS_ERR(req))
512                 return req;
513
514         /* marshall the data */
515         p9pdu_prepare(req->tc, tag, type);
516         va_start(ap, fmt);
517         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
518         va_end(ap);
519         p9pdu_finalize(req->tc);
520
521         err = c->trans_mod->request(c, req);
522         if (err < 0) {
523                 c->status = Disconnected;
524                 goto reterr;
525         }
526
527         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
528         err = wait_event_interruptible(*req->wq,
529                                                 req->status >= REQ_STATUS_RCVD);
530         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
531                                                 req->wq, tag, err);
532
533         if (req->status == REQ_STATUS_ERROR) {
534                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
535                 err = req->t_err;
536         }
537
538         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
539                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
540                 sigpending = 1;
541                 clear_thread_flag(TIF_SIGPENDING);
542
543                 if (c->trans_mod->cancel(c, req))
544                         p9_client_flush(c, req);
545
546                 /* if we received the response anyway, don't signal error */
547                 if (req->status == REQ_STATUS_RCVD)
548                         err = 0;
549         }
550
551         if (sigpending) {
552                 spin_lock_irqsave(&current->sighand->siglock, flags);
553                 recalc_sigpending();
554                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
555         }
556
557         if (err < 0)
558                 goto reterr;
559
560         err = p9_check_errors(c, req);
561         if (!err) {
562                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
563                 return req;
564         }
565
566 reterr:
567         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
568                                                                         err);
569         p9_free_req(c, req);
570         return ERR_PTR(err);
571 }
572
573 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
574 {
575         int ret;
576         struct p9_fid *fid;
577         unsigned long flags;
578
579         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
580         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
581         if (!fid)
582                 return ERR_PTR(-ENOMEM);
583
584         ret = p9_idpool_get(clnt->fidpool);
585         if (ret < 0) {
586                 ret = -ENOSPC;
587                 goto error;
588         }
589         fid->fid = ret;
590
591         memset(&fid->qid, 0, sizeof(struct p9_qid));
592         fid->mode = -1;
593         fid->rdir_fpos = 0;
594         fid->uid = current_fsuid();
595         fid->clnt = clnt;
596         fid->aux = NULL;
597
598         spin_lock_irqsave(&clnt->lock, flags);
599         list_add(&fid->flist, &clnt->fidlist);
600         spin_unlock_irqrestore(&clnt->lock, flags);
601
602         return fid;
603
604 error:
605         kfree(fid);
606         return ERR_PTR(ret);
607 }
608
609 static void p9_fid_destroy(struct p9_fid *fid)
610 {
611         struct p9_client *clnt;
612         unsigned long flags;
613
614         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
615         clnt = fid->clnt;
616         p9_idpool_put(fid->fid, clnt->fidpool);
617         spin_lock_irqsave(&clnt->lock, flags);
618         list_del(&fid->flist);
619         spin_unlock_irqrestore(&clnt->lock, flags);
620         kfree(fid);
621 }
622
623 int p9_client_version(struct p9_client *c)
624 {
625         int err = 0;
626         struct p9_req_t *req;
627         char *version;
628         int msize;
629
630         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
631                                                         c->msize, c->dotu);
632         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
633                                 c->dotu ? "9P2000.u" : "9P2000");
634         if (IS_ERR(req))
635                 return PTR_ERR(req);
636
637         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
638         if (err) {
639                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
640                 p9pdu_dump(1, req->rc);
641                 goto error;
642         }
643
644         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
645         if (!memcmp(version, "9P2000.u", 8))
646                 c->dotu = 1;
647         else if (!memcmp(version, "9P2000", 6))
648                 c->dotu = 0;
649         else {
650                 err = -EREMOTEIO;
651                 goto error;
652         }
653
654         if (msize < c->msize)
655                 c->msize = msize;
656
657 error:
658         kfree(version);
659         p9_free_req(c, req);
660
661         return err;
662 }
663 EXPORT_SYMBOL(p9_client_version);
664
665 struct p9_client *p9_client_create(const char *dev_name, char *options)
666 {
667         int err;
668         struct p9_client *clnt;
669
670         err = 0;
671         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
672         if (!clnt)
673                 return ERR_PTR(-ENOMEM);
674
675         clnt->trans_mod = NULL;
676         clnt->trans = NULL;
677         spin_lock_init(&clnt->lock);
678         INIT_LIST_HEAD(&clnt->fidlist);
679         clnt->fidpool = p9_idpool_create();
680         if (IS_ERR(clnt->fidpool)) {
681                 err = PTR_ERR(clnt->fidpool);
682                 clnt->fidpool = NULL;
683                 goto error;
684         }
685
686         p9_tag_init(clnt);
687
688         err = parse_opts(options, clnt);
689         if (err < 0)
690                 goto error;
691
692         if (clnt->trans_mod == NULL) {
693                 err = -EPROTONOSUPPORT;
694                 P9_DPRINTK(P9_DEBUG_ERROR,
695                                 "No transport defined or default transport\n");
696                 goto error;
697         }
698
699         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
700                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
701
702         err = clnt->trans_mod->create(clnt, dev_name, options);
703         if (err)
704                 goto error;
705
706         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
707                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
708
709         err = p9_client_version(clnt);
710         if (err)
711                 goto error;
712
713         return clnt;
714
715 error:
716         p9_client_destroy(clnt);
717         return ERR_PTR(err);
718 }
719 EXPORT_SYMBOL(p9_client_create);
720
721 void p9_client_destroy(struct p9_client *clnt)
722 {
723         struct p9_fid *fid, *fidptr;
724
725         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
726
727         if (clnt->trans_mod)
728                 clnt->trans_mod->close(clnt);
729
730         v9fs_put_trans(clnt->trans_mod);
731
732         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
733                 p9_fid_destroy(fid);
734
735         if (clnt->fidpool)
736                 p9_idpool_destroy(clnt->fidpool);
737
738         p9_tag_cleanup(clnt);
739
740         kfree(clnt);
741 }
742 EXPORT_SYMBOL(p9_client_destroy);
743
744 void p9_client_disconnect(struct p9_client *clnt)
745 {
746         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
747         clnt->status = Disconnected;
748 }
749 EXPORT_SYMBOL(p9_client_disconnect);
750
751 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
752         char *uname, u32 n_uname, char *aname)
753 {
754         int err;
755         struct p9_req_t *req;
756         struct p9_fid *fid;
757         struct p9_qid qid;
758
759         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
760                                         afid ? afid->fid : -1, uname, aname);
761         err = 0;
762
763         fid = p9_fid_create(clnt);
764         if (IS_ERR(fid)) {
765                 err = PTR_ERR(fid);
766                 fid = NULL;
767                 goto error;
768         }
769
770         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
771                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
772         if (IS_ERR(req)) {
773                 err = PTR_ERR(req);
774                 goto error;
775         }
776
777         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
778         if (err) {
779                 p9pdu_dump(1, req->rc);
780                 p9_free_req(clnt, req);
781                 goto error;
782         }
783
784         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
785                                         qid.type,
786                                         (unsigned long long)qid.path,
787                                         qid.version);
788
789         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
790
791         p9_free_req(clnt, req);
792         return fid;
793
794 error:
795         if (fid)
796                 p9_fid_destroy(fid);
797         return ERR_PTR(err);
798 }
799 EXPORT_SYMBOL(p9_client_attach);
800
801 struct p9_fid *
802 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
803 {
804         int err;
805         struct p9_req_t *req;
806         struct p9_qid qid;
807         struct p9_fid *afid;
808
809         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
810         err = 0;
811
812         afid = p9_fid_create(clnt);
813         if (IS_ERR(afid)) {
814                 err = PTR_ERR(afid);
815                 afid = NULL;
816                 goto error;
817         }
818
819         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
820                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
821         if (IS_ERR(req)) {
822                 err = PTR_ERR(req);
823                 goto error;
824         }
825
826         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
827         if (err) {
828                 p9pdu_dump(1, req->rc);
829                 p9_free_req(clnt, req);
830                 goto error;
831         }
832
833         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
834                                         qid.type,
835                                         (unsigned long long)qid.path,
836                                         qid.version);
837
838         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
839         p9_free_req(clnt, req);
840         return afid;
841
842 error:
843         if (afid)
844                 p9_fid_destroy(afid);
845         return ERR_PTR(err);
846 }
847 EXPORT_SYMBOL(p9_client_auth);
848
849 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
850         int clone)
851 {
852         int err;
853         struct p9_client *clnt;
854         struct p9_fid *fid;
855         struct p9_qid *wqids;
856         struct p9_req_t *req;
857         int16_t nwqids, count;
858
859         err = 0;
860         clnt = oldfid->clnt;
861         if (clone) {
862                 fid = p9_fid_create(clnt);
863                 if (IS_ERR(fid)) {
864                         err = PTR_ERR(fid);
865                         fid = NULL;
866                         goto error;
867                 }
868
869                 fid->uid = oldfid->uid;
870         } else
871                 fid = oldfid;
872
873
874         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
875                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
876
877         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
878                                                                 nwname, wnames);
879         if (IS_ERR(req)) {
880                 err = PTR_ERR(req);
881                 goto error;
882         }
883
884         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
885         if (err) {
886                 p9pdu_dump(1, req->rc);
887                 p9_free_req(clnt, req);
888                 goto clunk_fid;
889         }
890         p9_free_req(clnt, req);
891
892         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
893
894         if (nwqids != nwname) {
895                 err = -ENOENT;
896                 goto clunk_fid;
897         }
898
899         for (count = 0; count < nwqids; count++)
900                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
901                         count, wqids[count].type,
902                         (unsigned long long)wqids[count].path,
903                         wqids[count].version);
904
905         if (nwname)
906                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
907         else
908                 fid->qid = oldfid->qid;
909
910         return fid;
911
912 clunk_fid:
913         p9_client_clunk(fid);
914         fid = NULL;
915
916 error:
917         if (fid && (fid != oldfid))
918                 p9_fid_destroy(fid);
919
920         return ERR_PTR(err);
921 }
922 EXPORT_SYMBOL(p9_client_walk);
923
924 int p9_client_open(struct p9_fid *fid, int mode)
925 {
926         int err;
927         struct p9_client *clnt;
928         struct p9_req_t *req;
929         struct p9_qid qid;
930         int iounit;
931
932         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
933         err = 0;
934         clnt = fid->clnt;
935
936         if (fid->mode != -1)
937                 return -EINVAL;
938
939         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
940         if (IS_ERR(req)) {
941                 err = PTR_ERR(req);
942                 goto error;
943         }
944
945         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
946         if (err) {
947                 p9pdu_dump(1, req->rc);
948                 goto free_and_error;
949         }
950
951         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
952                                 qid.type,
953                                 (unsigned long long)qid.path,
954                                 qid.version, iounit);
955
956         fid->mode = mode;
957         fid->iounit = iounit;
958
959 free_and_error:
960         p9_free_req(clnt, req);
961 error:
962         return err;
963 }
964 EXPORT_SYMBOL(p9_client_open);
965
966 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
967                      char *extension)
968 {
969         int err;
970         struct p9_client *clnt;
971         struct p9_req_t *req;
972         struct p9_qid qid;
973         int iounit;
974
975         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
976                                                 fid->fid, name, perm, mode);
977         err = 0;
978         clnt = fid->clnt;
979
980         if (fid->mode != -1)
981                 return -EINVAL;
982
983         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
984                                 mode, extension);
985         if (IS_ERR(req)) {
986                 err = PTR_ERR(req);
987                 goto error;
988         }
989
990         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
991         if (err) {
992                 p9pdu_dump(1, req->rc);
993                 goto free_and_error;
994         }
995
996         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
997                                 qid.type,
998                                 (unsigned long long)qid.path,
999                                 qid.version, iounit);
1000
1001         fid->mode = mode;
1002         fid->iounit = iounit;
1003
1004 free_and_error:
1005         p9_free_req(clnt, req);
1006 error:
1007         return err;
1008 }
1009 EXPORT_SYMBOL(p9_client_fcreate);
1010
1011 int p9_client_clunk(struct p9_fid *fid)
1012 {
1013         int err;
1014         struct p9_client *clnt;
1015         struct p9_req_t *req;
1016
1017         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1018         err = 0;
1019         clnt = fid->clnt;
1020
1021         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1022         if (IS_ERR(req)) {
1023                 err = PTR_ERR(req);
1024                 goto error;
1025         }
1026
1027         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1028
1029         p9_free_req(clnt, req);
1030         p9_fid_destroy(fid);
1031
1032 error:
1033         return err;
1034 }
1035 EXPORT_SYMBOL(p9_client_clunk);
1036
1037 int p9_client_remove(struct p9_fid *fid)
1038 {
1039         int err;
1040         struct p9_client *clnt;
1041         struct p9_req_t *req;
1042
1043         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1044         err = 0;
1045         clnt = fid->clnt;
1046
1047         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1048         if (IS_ERR(req)) {
1049                 err = PTR_ERR(req);
1050                 goto error;
1051         }
1052
1053         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1054
1055         p9_free_req(clnt, req);
1056         p9_fid_destroy(fid);
1057
1058 error:
1059         return err;
1060 }
1061 EXPORT_SYMBOL(p9_client_remove);
1062
1063 int
1064 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1065                                                                 u32 count)
1066 {
1067         int err, rsize, total;
1068         struct p9_client *clnt;
1069         struct p9_req_t *req;
1070         char *dataptr;
1071
1072         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1073                                         (long long unsigned) offset, count);
1074         err = 0;
1075         clnt = fid->clnt;
1076         total = 0;
1077
1078         rsize = fid->iounit;
1079         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1080                 rsize = clnt->msize - P9_IOHDRSZ;
1081
1082         if (count < rsize)
1083                 rsize = count;
1084
1085         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1086         if (IS_ERR(req)) {
1087                 err = PTR_ERR(req);
1088                 goto error;
1089         }
1090
1091         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1092         if (err) {
1093                 p9pdu_dump(1, req->rc);
1094                 goto free_and_error;
1095         }
1096
1097         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1098
1099         if (data) {
1100                 memmove(data, dataptr, count);
1101                 data += count;
1102         }
1103
1104         if (udata) {
1105                 err = copy_to_user(udata, dataptr, count);
1106                 if (err) {
1107                         err = -EFAULT;
1108                         goto free_and_error;
1109                 }
1110         }
1111
1112         p9_free_req(clnt, req);
1113         return count;
1114
1115 free_and_error:
1116         p9_free_req(clnt, req);
1117 error:
1118         return err;
1119 }
1120 EXPORT_SYMBOL(p9_client_read);
1121
1122 int
1123 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1124                                                         u64 offset, u32 count)
1125 {
1126         int err, rsize, total;
1127         struct p9_client *clnt;
1128         struct p9_req_t *req;
1129
1130         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1131                                 fid->fid, (long long unsigned) offset, count);
1132         err = 0;
1133         clnt = fid->clnt;
1134         total = 0;
1135
1136         rsize = fid->iounit;
1137         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1138                 rsize = clnt->msize - P9_IOHDRSZ;
1139
1140         if (count < rsize)
1141                 rsize = count;
1142         if (data)
1143                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1144                                                                 rsize, data);
1145         else
1146                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1147                                                                 rsize, udata);
1148         if (IS_ERR(req)) {
1149                 err = PTR_ERR(req);
1150                 goto error;
1151         }
1152
1153         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1154         if (err) {
1155                 p9pdu_dump(1, req->rc);
1156                 goto free_and_error;
1157         }
1158
1159         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1160
1161         p9_free_req(clnt, req);
1162         return count;
1163
1164 free_and_error:
1165         p9_free_req(clnt, req);
1166 error:
1167         return err;
1168 }
1169 EXPORT_SYMBOL(p9_client_write);
1170
1171 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1172 {
1173         int err;
1174         struct p9_client *clnt;
1175         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1176         struct p9_req_t *req;
1177         u16 ignored;
1178
1179         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1180
1181         if (!ret)
1182                 return ERR_PTR(-ENOMEM);
1183
1184         err = 0;
1185         clnt = fid->clnt;
1186
1187         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1188         if (IS_ERR(req)) {
1189                 err = PTR_ERR(req);
1190                 goto error;
1191         }
1192
1193         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1194         if (err) {
1195                 ret = ERR_PTR(err);
1196                 p9pdu_dump(1, req->rc);
1197                 goto free_and_error;
1198         }
1199
1200         P9_DPRINTK(P9_DEBUG_9P,
1201                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1202                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1203                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1204                 "<<<    uid=%d gid=%d n_muid=%d\n",
1205                 ret->size, ret->type, ret->dev, ret->qid.type,
1206                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1207                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1208                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1209                 ret->n_uid, ret->n_gid, ret->n_muid);
1210
1211         p9_free_req(clnt, req);
1212         return ret;
1213
1214 free_and_error:
1215         p9_free_req(clnt, req);
1216 error:
1217         kfree(ret);
1218         return ERR_PTR(err);
1219 }
1220 EXPORT_SYMBOL(p9_client_stat);
1221
1222 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1223 {
1224         int ret;
1225
1226         /* size[2] type[2] dev[4] qid[13] */
1227         /* mode[4] atime[4] mtime[4] length[8]*/
1228         /* name[s] uid[s] gid[s] muid[s] */
1229         ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1230
1231         if (wst->name)
1232                 ret += strlen(wst->name);
1233         if (wst->uid)
1234                 ret += strlen(wst->uid);
1235         if (wst->gid)
1236                 ret += strlen(wst->gid);
1237         if (wst->muid)
1238                 ret += strlen(wst->muid);
1239
1240         if (optional) {
1241                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1242                 if (wst->extension)
1243                         ret += strlen(wst->extension);
1244         }
1245
1246         return ret;
1247 }
1248
1249 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1250 {
1251         int err;
1252         struct p9_req_t *req;
1253         struct p9_client *clnt;
1254
1255         err = 0;
1256         clnt = fid->clnt;
1257         wst->size = p9_client_statsize(wst, clnt->dotu);
1258         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1259         P9_DPRINTK(P9_DEBUG_9P,
1260                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1261                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1262                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1263                 "     uid=%d gid=%d n_muid=%d\n",
1264                 wst->size, wst->type, wst->dev, wst->qid.type,
1265                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1266                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1267                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1268                 wst->n_uid, wst->n_gid, wst->n_muid);
1269
1270         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, wst);
1271         if (IS_ERR(req)) {
1272                 err = PTR_ERR(req);
1273                 goto error;
1274         }
1275
1276         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1277
1278         p9_free_req(clnt, req);
1279 error:
1280         return err;
1281 }
1282 EXPORT_SYMBOL(p9_client_wstat);