9p: Possible regression in p9_client_stat
[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         kfree(options);
121         return ret;
122 }
123
124 /**
125  * p9_tag_alloc - lookup/allocate a request by tag
126  * @c: client session to lookup tag within
127  * @tag: numeric id for transaction
128  *
129  * this is a simple array lookup, but will grow the
130  * request_slots as necessary to accomodate transaction
131  * ids which did not previously have a slot.
132  *
133  * this code relies on the client spinlock to manage locks, its
134  * possible we should switch to something else, but I'd rather
135  * stick with something low-overhead for the common case.
136  *
137  */
138
139 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
140 {
141         unsigned long flags;
142         int row, col;
143         struct p9_req_t *req;
144
145         /* This looks up the original request by tag so we know which
146          * buffer to read the data into */
147         tag++;
148
149         if (tag >= c->max_tag) {
150                 spin_lock_irqsave(&c->lock, flags);
151                 /* check again since original check was outside of lock */
152                 while (tag >= c->max_tag) {
153                         row = (tag / P9_ROW_MAXTAG);
154                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
155                                         sizeof(struct p9_req_t), GFP_ATOMIC);
156
157                         if (!c->reqs[row]) {
158                                 printk(KERN_ERR "Couldn't grow tag array\n");
159                                 spin_unlock_irqrestore(&c->lock, flags);
160                                 return ERR_PTR(-ENOMEM);
161                         }
162                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
163                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
164                                 c->reqs[row][col].tc = NULL;
165                         }
166                         c->max_tag += P9_ROW_MAXTAG;
167                 }
168                 spin_unlock_irqrestore(&c->lock, flags);
169         }
170         row = tag / P9_ROW_MAXTAG;
171         col = tag % P9_ROW_MAXTAG;
172
173         req = &c->reqs[row][col];
174         if (!req->tc) {
175                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
176                 if (!req->wq) {
177                         printk(KERN_ERR "Couldn't grow tag array\n");
178                         return ERR_PTR(-ENOMEM);
179                 }
180                 init_waitqueue_head(req->wq);
181                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
182                                                                 GFP_KERNEL);
183                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
184                                                                 GFP_KERNEL);
185                 if ((!req->tc) || (!req->rc)) {
186                         printk(KERN_ERR "Couldn't grow tag array\n");
187                         kfree(req->tc);
188                         kfree(req->rc);
189                         kfree(req->wq);
190                         req->tc = req->rc = NULL;
191                         req->wq = NULL;
192                         return ERR_PTR(-ENOMEM);
193                 }
194                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
195                 req->tc->capacity = c->msize;
196                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
197                 req->rc->capacity = c->msize;
198         }
199
200         p9pdu_reset(req->tc);
201         p9pdu_reset(req->rc);
202
203         req->tc->tag = tag-1;
204         req->status = REQ_STATUS_ALLOC;
205
206         return &c->reqs[row][col];
207 }
208
209 /**
210  * p9_tag_lookup - lookup a request by tag
211  * @c: client session to lookup tag within
212  * @tag: numeric id for transaction
213  *
214  */
215
216 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
217 {
218         int row, col;
219
220         /* This looks up the original request by tag so we know which
221          * buffer to read the data into */
222         tag++;
223
224         BUG_ON(tag >= c->max_tag);
225
226         row = tag / P9_ROW_MAXTAG;
227         col = tag % P9_ROW_MAXTAG;
228
229         return &c->reqs[row][col];
230 }
231 EXPORT_SYMBOL(p9_tag_lookup);
232
233 /**
234  * p9_tag_init - setup tags structure and contents
235  * @tags: tags structure from the client struct
236  *
237  * This initializes the tags structure for each client instance.
238  *
239  */
240
241 static int p9_tag_init(struct p9_client *c)
242 {
243         int err = 0;
244
245         c->tagpool = p9_idpool_create();
246         if (IS_ERR(c->tagpool)) {
247                 err = PTR_ERR(c->tagpool);
248                 c->tagpool = NULL;
249                 goto error;
250         }
251
252         p9_idpool_get(c->tagpool); /* reserve tag 0 */
253
254         c->max_tag = 0;
255 error:
256         return err;
257 }
258
259 /**
260  * p9_tag_cleanup - cleans up tags structure and reclaims resources
261  * @tags: tags structure from the client struct
262  *
263  * This frees resources associated with the tags structure
264  *
265  */
266 static void p9_tag_cleanup(struct p9_client *c)
267 {
268         int row, col;
269
270         /* check to insure all requests are idle */
271         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
272                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
273                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
274                                 P9_DPRINTK(P9_DEBUG_MUX,
275                                   "Attempting to cleanup non-free tag %d,%d\n",
276                                   row, col);
277                                 /* TODO: delay execution of cleanup */
278                                 return;
279                         }
280                 }
281         }
282
283         if (c->tagpool)
284                 p9_idpool_destroy(c->tagpool);
285
286         /* free requests associated with tags */
287         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
288                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
289                         kfree(c->reqs[row][col].wq);
290                         kfree(c->reqs[row][col].tc);
291                         kfree(c->reqs[row][col].rc);
292                 }
293                 kfree(c->reqs[row]);
294         }
295         c->max_tag = 0;
296 }
297
298 /**
299  * p9_free_req - free a request and clean-up as necessary
300  * c: client state
301  * r: request to release
302  *
303  */
304
305 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
306 {
307         int tag = r->tc->tag;
308         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
309
310         r->status = REQ_STATUS_IDLE;
311         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
312                 p9_idpool_put(tag, c->tagpool);
313 }
314
315 /**
316  * p9_client_cb - call back from transport to client
317  * c: client state
318  * req: request received
319  *
320  */
321 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
322 {
323         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
324         wake_up(req->wq);
325         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
326 }
327 EXPORT_SYMBOL(p9_client_cb);
328
329 /**
330  * p9_parse_header - parse header arguments out of a packet
331  * @pdu: packet to parse
332  * @size: size of packet
333  * @type: type of request
334  * @tag: tag of packet
335  * @rewind: set if we need to rewind offset afterwards
336  */
337
338 int
339 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
340                                                                 int rewind)
341 {
342         int8_t r_type;
343         int16_t r_tag;
344         int32_t r_size;
345         int offset = pdu->offset;
346         int err;
347
348         pdu->offset = 0;
349         if (pdu->size == 0)
350                 pdu->size = 7;
351
352         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
353         if (err)
354                 goto rewind_and_exit;
355
356         pdu->size = r_size;
357         pdu->id = r_type;
358         pdu->tag = r_tag;
359
360         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
361                                                         pdu->id, pdu->tag);
362
363         if (type)
364                 *type = r_type;
365         if (tag)
366                 *tag = r_tag;
367         if (size)
368                 *size = r_size;
369
370
371 rewind_and_exit:
372         if (rewind)
373                 pdu->offset = offset;
374         return err;
375 }
376 EXPORT_SYMBOL(p9_parse_header);
377
378 /**
379  * p9_check_errors - check 9p packet for error return and process it
380  * @c: current client instance
381  * @req: request to parse and check for error conditions
382  *
383  * returns error code if one is discovered, otherwise returns 0
384  *
385  * this will have to be more complicated if we have multiple
386  * error packet types
387  */
388
389 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
390 {
391         int8_t type;
392         int err;
393
394         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
395         if (err) {
396                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
397                 return err;
398         }
399
400         if (type == P9_RERROR) {
401                 int ecode;
402                 char *ename;
403
404                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
405                 if (err) {
406                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
407                                                                         err);
408                         return err;
409                 }
410
411                 if (c->dotu)
412                         err = -ecode;
413
414                 if (!err) {
415                         err = p9_errstr2errno(ename, strlen(ename));
416
417                         /* string match failed */
418                         if (!err)
419                                 err = -ESERVERFAULT;
420                 }
421
422                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
423
424                 kfree(ename);
425         } else
426                 err = 0;
427
428         return err;
429 }
430
431 /**
432  * p9_client_flush - flush (cancel) a request
433  * c: client state
434  * req: request to cancel
435  *
436  * This sents a flush for a particular requests and links
437  * the flush request to the original request.  The current
438  * code only supports a single flush request although the protocol
439  * allows for multiple flush requests to be sent for a single request.
440  *
441  */
442
443 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
444 {
445         struct p9_req_t *req;
446         int16_t oldtag;
447         int err;
448
449         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
450         if (err)
451                 return err;
452
453         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
454
455         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
456         if (IS_ERR(req))
457                 return PTR_ERR(req);
458
459
460         /* if we haven't received a response for oldreq,
461            remove it from the list. */
462         spin_lock(&c->lock);
463         if (oldreq->status == REQ_STATUS_FLSH)
464                 list_del(&oldreq->req_list);
465         spin_unlock(&c->lock);
466
467         p9_free_req(c, req);
468         return 0;
469 }
470
471 /**
472  * p9_client_rpc - issue a request and wait for a response
473  * @c: client session
474  * @type: type of request
475  * @fmt: protocol format string (see protocol.c)
476  *
477  * Returns request structure (which client must free using p9_free_req)
478  */
479
480 static struct p9_req_t *
481 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
482 {
483         va_list ap;
484         int tag, err;
485         struct p9_req_t *req;
486         unsigned long flags;
487         int sigpending;
488
489         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
490
491         if (c->status != Connected)
492                 return ERR_PTR(-EIO);
493
494         if (signal_pending(current)) {
495                 sigpending = 1;
496                 clear_thread_flag(TIF_SIGPENDING);
497         } else
498                 sigpending = 0;
499
500         tag = P9_NOTAG;
501         if (type != P9_TVERSION) {
502                 tag = p9_idpool_get(c->tagpool);
503                 if (tag < 0)
504                         return ERR_PTR(-ENOMEM);
505         }
506
507         req = p9_tag_alloc(c, tag);
508         if (IS_ERR(req))
509                 return req;
510
511         /* marshall the data */
512         p9pdu_prepare(req->tc, tag, type);
513         va_start(ap, fmt);
514         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
515         va_end(ap);
516         p9pdu_finalize(req->tc);
517
518         err = c->trans_mod->request(c, req);
519         if (err < 0) {
520                 c->status = Disconnected;
521                 goto reterr;
522         }
523
524         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
525         err = wait_event_interruptible(*req->wq,
526                                                 req->status >= REQ_STATUS_RCVD);
527         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
528                                                 req->wq, tag, err);
529
530         if (req->status == REQ_STATUS_ERROR) {
531                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
532                 err = req->t_err;
533         }
534
535         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
536                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
537                 sigpending = 1;
538                 clear_thread_flag(TIF_SIGPENDING);
539
540                 if (c->trans_mod->cancel(c, req))
541                         p9_client_flush(c, req);
542
543                 /* if we received the response anyway, don't signal error */
544                 if (req->status == REQ_STATUS_RCVD)
545                         err = 0;
546         }
547
548         if (sigpending) {
549                 spin_lock_irqsave(&current->sighand->siglock, flags);
550                 recalc_sigpending();
551                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
552         }
553
554         if (err < 0)
555                 goto reterr;
556
557         err = p9_check_errors(c, req);
558         if (!err) {
559                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
560                 return req;
561         }
562
563 reterr:
564         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
565                                                                         err);
566         p9_free_req(c, req);
567         return ERR_PTR(err);
568 }
569
570 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
571 {
572         int ret;
573         struct p9_fid *fid;
574         unsigned long flags;
575
576         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
577         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
578         if (!fid)
579                 return ERR_PTR(-ENOMEM);
580
581         ret = p9_idpool_get(clnt->fidpool);
582         if (ret < 0) {
583                 ret = -ENOSPC;
584                 goto error;
585         }
586         fid->fid = ret;
587
588         memset(&fid->qid, 0, sizeof(struct p9_qid));
589         fid->mode = -1;
590         fid->rdir_fpos = 0;
591         fid->uid = current_fsuid();
592         fid->clnt = clnt;
593         fid->aux = NULL;
594
595         spin_lock_irqsave(&clnt->lock, flags);
596         list_add(&fid->flist, &clnt->fidlist);
597         spin_unlock_irqrestore(&clnt->lock, flags);
598
599         return fid;
600
601 error:
602         kfree(fid);
603         return ERR_PTR(ret);
604 }
605
606 static void p9_fid_destroy(struct p9_fid *fid)
607 {
608         struct p9_client *clnt;
609         unsigned long flags;
610
611         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
612         clnt = fid->clnt;
613         p9_idpool_put(fid->fid, clnt->fidpool);
614         spin_lock_irqsave(&clnt->lock, flags);
615         list_del(&fid->flist);
616         spin_unlock_irqrestore(&clnt->lock, flags);
617         kfree(fid);
618 }
619
620 int p9_client_version(struct p9_client *c)
621 {
622         int err = 0;
623         struct p9_req_t *req;
624         char *version;
625         int msize;
626
627         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
628                                                         c->msize, c->dotu);
629         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
630                                 c->dotu ? "9P2000.u" : "9P2000");
631         if (IS_ERR(req))
632                 return PTR_ERR(req);
633
634         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
635         if (err) {
636                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
637                 p9pdu_dump(1, req->rc);
638                 goto error;
639         }
640
641         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
642         if (!memcmp(version, "9P2000.u", 8))
643                 c->dotu = 1;
644         else if (!memcmp(version, "9P2000", 6))
645                 c->dotu = 0;
646         else {
647                 err = -EREMOTEIO;
648                 goto error;
649         }
650
651         if (msize < c->msize)
652                 c->msize = msize;
653
654 error:
655         kfree(version);
656         p9_free_req(c, req);
657
658         return err;
659 }
660 EXPORT_SYMBOL(p9_client_version);
661
662 struct p9_client *p9_client_create(const char *dev_name, char *options)
663 {
664         int err;
665         struct p9_client *clnt;
666
667         err = 0;
668         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
669         if (!clnt)
670                 return ERR_PTR(-ENOMEM);
671
672         clnt->trans_mod = NULL;
673         clnt->trans = NULL;
674         spin_lock_init(&clnt->lock);
675         INIT_LIST_HEAD(&clnt->fidlist);
676         clnt->fidpool = p9_idpool_create();
677         if (IS_ERR(clnt->fidpool)) {
678                 err = PTR_ERR(clnt->fidpool);
679                 clnt->fidpool = NULL;
680                 goto error;
681         }
682
683         p9_tag_init(clnt);
684
685         err = parse_opts(options, clnt);
686         if (err < 0)
687                 goto error;
688
689         if (!clnt->trans_mod)
690                 clnt->trans_mod = v9fs_get_default_trans();
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         }
1102
1103         if (udata) {
1104                 err = copy_to_user(udata, dataptr, count);
1105                 if (err) {
1106                         err = -EFAULT;
1107                         goto free_and_error;
1108                 }
1109         }
1110
1111         p9_free_req(clnt, req);
1112         return count;
1113
1114 free_and_error:
1115         p9_free_req(clnt, req);
1116 error:
1117         return err;
1118 }
1119 EXPORT_SYMBOL(p9_client_read);
1120
1121 int
1122 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1123                                                         u64 offset, u32 count)
1124 {
1125         int err, rsize, total;
1126         struct p9_client *clnt;
1127         struct p9_req_t *req;
1128
1129         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1130                                 fid->fid, (long long unsigned) offset, count);
1131         err = 0;
1132         clnt = fid->clnt;
1133         total = 0;
1134
1135         rsize = fid->iounit;
1136         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1137                 rsize = clnt->msize - P9_IOHDRSZ;
1138
1139         if (count < rsize)
1140                 rsize = count;
1141         if (data)
1142                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1143                                                                 rsize, data);
1144         else
1145                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1146                                                                 rsize, udata);
1147         if (IS_ERR(req)) {
1148                 err = PTR_ERR(req);
1149                 goto error;
1150         }
1151
1152         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1153         if (err) {
1154                 p9pdu_dump(1, req->rc);
1155                 goto free_and_error;
1156         }
1157
1158         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1159
1160         p9_free_req(clnt, req);
1161         return count;
1162
1163 free_and_error:
1164         p9_free_req(clnt, req);
1165 error:
1166         return err;
1167 }
1168 EXPORT_SYMBOL(p9_client_write);
1169
1170 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1171 {
1172         int err;
1173         struct p9_client *clnt;
1174         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1175         struct p9_req_t *req;
1176         u16 ignored;
1177
1178         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1179
1180         if (!ret)
1181                 return ERR_PTR(-ENOMEM);
1182
1183         err = 0;
1184         clnt = fid->clnt;
1185
1186         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1187         if (IS_ERR(req)) {
1188                 err = PTR_ERR(req);
1189                 goto error;
1190         }
1191
1192         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1193         if (err) {
1194                 p9pdu_dump(1, req->rc);
1195                 p9_free_req(clnt, req);
1196                 goto error;
1197         }
1198
1199         P9_DPRINTK(P9_DEBUG_9P,
1200                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1201                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1202                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1203                 "<<<    uid=%d gid=%d n_muid=%d\n",
1204                 ret->size, ret->type, ret->dev, ret->qid.type,
1205                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1206                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1207                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1208                 ret->n_uid, ret->n_gid, ret->n_muid);
1209
1210         p9_free_req(clnt, req);
1211         return ret;
1212
1213 error:
1214         kfree(ret);
1215         return ERR_PTR(err);
1216 }
1217 EXPORT_SYMBOL(p9_client_stat);
1218
1219 static int p9_client_statsize(struct p9_wstat *wst, int optional)
1220 {
1221         int ret;
1222
1223         /* size[2] type[2] dev[4] qid[13] */
1224         /* mode[4] atime[4] mtime[4] length[8]*/
1225         /* name[s] uid[s] gid[s] muid[s] */
1226         ret = 2+2+4+13+4+4+4+8+2+2+2+2;
1227
1228         if (wst->name)
1229                 ret += strlen(wst->name);
1230         if (wst->uid)
1231                 ret += strlen(wst->uid);
1232         if (wst->gid)
1233                 ret += strlen(wst->gid);
1234         if (wst->muid)
1235                 ret += strlen(wst->muid);
1236
1237         if (optional) {
1238                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1239                 if (wst->extension)
1240                         ret += strlen(wst->extension);
1241         }
1242
1243         return ret;
1244 }
1245
1246 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1247 {
1248         int err;
1249         struct p9_req_t *req;
1250         struct p9_client *clnt;
1251
1252         err = 0;
1253         clnt = fid->clnt;
1254         wst->size = p9_client_statsize(wst, clnt->dotu);
1255         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1256         P9_DPRINTK(P9_DEBUG_9P,
1257                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1258                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1259                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1260                 "     uid=%d gid=%d n_muid=%d\n",
1261                 wst->size, wst->type, wst->dev, wst->qid.type,
1262                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1263                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1264                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1265                 wst->n_uid, wst->n_gid, wst->n_muid);
1266
1267         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size, wst);
1268         if (IS_ERR(req)) {
1269                 err = PTR_ERR(req);
1270                 goto error;
1271         }
1272
1273         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1274
1275         p9_free_req(clnt, req);
1276 error:
1277         return err;
1278 }
1279 EXPORT_SYMBOL(p9_client_wstat);