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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/slab.h>
33 #include <linux/sched.h>
34 #include <linux/uaccess.h>
35 #include <net/9p/9p.h>
36 #include <linux/parser.h>
37 #include <net/9p/client.h>
38 #include <net/9p/transport.h>
39 #include "protocol.h"
40
41 /*
42   * Client Option Parsing (code inspired by NFS code)
43   *  - a little lazy - parse all client options
44   */
45
46 enum {
47         Opt_msize,
48         Opt_trans,
49         Opt_legacy,
50         Opt_version,
51         Opt_err,
52 };
53
54 static const match_table_t tokens = {
55         {Opt_msize, "msize=%u"},
56         {Opt_legacy, "noextend"},
57         {Opt_trans, "trans=%s"},
58         {Opt_version, "version=%s"},
59         {Opt_err, NULL},
60 };
61
62 inline int p9_is_proto_dotl(struct p9_client *clnt)
63 {
64         return clnt->proto_version == p9_proto_2000L;
65 }
66 EXPORT_SYMBOL(p9_is_proto_dotl);
67
68 inline int p9_is_proto_dotu(struct p9_client *clnt)
69 {
70         return clnt->proto_version == p9_proto_2000u;
71 }
72 EXPORT_SYMBOL(p9_is_proto_dotu);
73
74 /* Interpret mount option for protocol version */
75 static int get_protocol_version(char *s)
76 {
77         int version = -EINVAL;
78
79         if (!strcmp(s, "9p2000")) {
80                 version = p9_proto_legacy;
81                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: Legacy\n");
82         } else if (!strcmp(s, "9p2000.u")) {
83                 version = p9_proto_2000u;
84                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
85         } else if (!strcmp(s, "9p2000.L")) {
86                 version = p9_proto_2000L;
87                 P9_DPRINTK(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
88         } else
89                 printk(KERN_INFO "9p: Unknown protocol version %s.\n", s);
90
91         return version;
92 }
93
94 /**
95  * parse_options - parse mount options into client structure
96  * @opts: options string passed from mount
97  * @clnt: existing v9fs client information
98  *
99  * Return 0 upon success, -ERRNO upon failure
100  */
101
102 static int parse_opts(char *opts, struct p9_client *clnt)
103 {
104         char *options, *tmp_options;
105         char *p;
106         substring_t args[MAX_OPT_ARGS];
107         int option;
108         char *s;
109         int ret = 0;
110
111         clnt->proto_version = p9_proto_2000u;
112         clnt->msize = 8192;
113
114         if (!opts)
115                 return 0;
116
117         tmp_options = kstrdup(opts, GFP_KERNEL);
118         if (!tmp_options) {
119                 P9_DPRINTK(P9_DEBUG_ERROR,
120                                 "failed to allocate copy of option string\n");
121                 return -ENOMEM;
122         }
123         options = tmp_options;
124
125         while ((p = strsep(&options, ",")) != NULL) {
126                 int token;
127                 if (!*p)
128                         continue;
129                 token = match_token(p, tokens, args);
130                 if (token < Opt_trans) {
131                         int r = match_int(&args[0], &option);
132                         if (r < 0) {
133                                 P9_DPRINTK(P9_DEBUG_ERROR,
134                                         "integer field, but no integer?\n");
135                                 ret = r;
136                                 continue;
137                         }
138                 }
139                 switch (token) {
140                 case Opt_msize:
141                         clnt->msize = option;
142                         break;
143                 case Opt_trans:
144                         s = match_strdup(&args[0]);
145                         if (!s) {
146                                 ret = -ENOMEM;
147                                 P9_DPRINTK(P9_DEBUG_ERROR,
148                                         "problem allocating copy of trans arg\n");
149                                 goto free_and_return;
150                          }
151                         clnt->trans_mod = v9fs_get_trans_by_name(s);
152                         if (clnt->trans_mod == NULL) {
153                                 printk(KERN_INFO
154                                         "9p: Could not find "
155                                         "request transport: %s\n", s);
156                                 ret = -EINVAL;
157                                 kfree(s);
158                                 goto free_and_return;
159                         }
160                         kfree(s);
161                         break;
162                 case Opt_legacy:
163                         clnt->proto_version = p9_proto_legacy;
164                         break;
165                 case Opt_version:
166                         s = match_strdup(&args[0]);
167                         if (!s) {
168                                 ret = -ENOMEM;
169                                 P9_DPRINTK(P9_DEBUG_ERROR,
170                                         "problem allocating copy of version arg\n");
171                                 goto free_and_return;
172                         }
173                         ret = get_protocol_version(s);
174                         if (ret == -EINVAL) {
175                                 kfree(s);
176                                 goto free_and_return;
177                         }
178                         kfree(s);
179                         clnt->proto_version = ret;
180                         break;
181                 default:
182                         continue;
183                 }
184         }
185
186 free_and_return:
187         kfree(tmp_options);
188         return ret;
189 }
190
191 /**
192  * p9_tag_alloc - lookup/allocate a request by tag
193  * @c: client session to lookup tag within
194  * @tag: numeric id for transaction
195  *
196  * this is a simple array lookup, but will grow the
197  * request_slots as necessary to accommodate transaction
198  * ids which did not previously have a slot.
199  *
200  * this code relies on the client spinlock to manage locks, its
201  * possible we should switch to something else, but I'd rather
202  * stick with something low-overhead for the common case.
203  *
204  */
205
206 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
207 {
208         unsigned long flags;
209         int row, col;
210         struct p9_req_t *req;
211
212         /* This looks up the original request by tag so we know which
213          * buffer to read the data into */
214         tag++;
215
216         if (tag >= c->max_tag) {
217                 spin_lock_irqsave(&c->lock, flags);
218                 /* check again since original check was outside of lock */
219                 while (tag >= c->max_tag) {
220                         row = (tag / P9_ROW_MAXTAG);
221                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
222                                         sizeof(struct p9_req_t), GFP_ATOMIC);
223
224                         if (!c->reqs[row]) {
225                                 printk(KERN_ERR "Couldn't grow tag array\n");
226                                 spin_unlock_irqrestore(&c->lock, flags);
227                                 return ERR_PTR(-ENOMEM);
228                         }
229                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
230                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
231                                 c->reqs[row][col].tc = NULL;
232                         }
233                         c->max_tag += P9_ROW_MAXTAG;
234                 }
235                 spin_unlock_irqrestore(&c->lock, flags);
236         }
237         row = tag / P9_ROW_MAXTAG;
238         col = tag % P9_ROW_MAXTAG;
239
240         req = &c->reqs[row][col];
241         if (!req->tc) {
242                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_NOFS);
243                 if (!req->wq) {
244                         printk(KERN_ERR "Couldn't grow tag array\n");
245                         return ERR_PTR(-ENOMEM);
246                 }
247                 init_waitqueue_head(req->wq);
248                 if ((c->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
249                                 P9_TRANS_PREF_PAYLOAD_SEP) {
250                         int alloc_msize = min(c->msize, 4096);
251                         req->tc = kmalloc(sizeof(struct p9_fcall)+alloc_msize,
252                                           GFP_NOFS);
253                         req->tc->capacity = alloc_msize;
254                         req->rc = kmalloc(sizeof(struct p9_fcall)+alloc_msize,
255                                           GFP_NOFS);
256                         req->rc->capacity = alloc_msize;
257                 } else {
258                         req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
259                                           GFP_NOFS);
260                         req->tc->capacity = c->msize;
261                         req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
262                                           GFP_NOFS);
263                         req->rc->capacity = c->msize;
264                 }
265                 if ((!req->tc) || (!req->rc)) {
266                         printk(KERN_ERR "Couldn't grow tag array\n");
267                         kfree(req->tc);
268                         kfree(req->rc);
269                         kfree(req->wq);
270                         req->tc = req->rc = NULL;
271                         req->wq = NULL;
272                         return ERR_PTR(-ENOMEM);
273                 }
274                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
275                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
276         }
277
278         p9pdu_reset(req->tc);
279         p9pdu_reset(req->rc);
280
281         req->tc->tag = tag-1;
282         req->status = REQ_STATUS_ALLOC;
283
284         return &c->reqs[row][col];
285 }
286
287 /**
288  * p9_tag_lookup - lookup a request by tag
289  * @c: client session to lookup tag within
290  * @tag: numeric id for transaction
291  *
292  */
293
294 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
295 {
296         int row, col;
297
298         /* This looks up the original request by tag so we know which
299          * buffer to read the data into */
300         tag++;
301
302         if(tag >= c->max_tag) 
303                 return NULL;
304
305         row = tag / P9_ROW_MAXTAG;
306         col = tag % P9_ROW_MAXTAG;
307
308         return &c->reqs[row][col];
309 }
310 EXPORT_SYMBOL(p9_tag_lookup);
311
312 /**
313  * p9_tag_init - setup tags structure and contents
314  * @c:  v9fs client struct
315  *
316  * This initializes the tags structure for each client instance.
317  *
318  */
319
320 static int p9_tag_init(struct p9_client *c)
321 {
322         int err = 0;
323
324         c->tagpool = p9_idpool_create();
325         if (IS_ERR(c->tagpool)) {
326                 err = PTR_ERR(c->tagpool);
327                 goto error;
328         }
329         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
330         if (err < 0) {
331                 p9_idpool_destroy(c->tagpool);
332                 goto error;
333         }
334         c->max_tag = 0;
335 error:
336         return err;
337 }
338
339 /**
340  * p9_tag_cleanup - cleans up tags structure and reclaims resources
341  * @c:  v9fs client struct
342  *
343  * This frees resources associated with the tags structure
344  *
345  */
346 static void p9_tag_cleanup(struct p9_client *c)
347 {
348         int row, col;
349
350         /* check to insure all requests are idle */
351         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
352                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
353                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
354                                 P9_DPRINTK(P9_DEBUG_MUX,
355                                   "Attempting to cleanup non-free tag %d,%d\n",
356                                   row, col);
357                                 /* TODO: delay execution of cleanup */
358                                 return;
359                         }
360                 }
361         }
362
363         if (c->tagpool) {
364                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
365                 p9_idpool_destroy(c->tagpool);
366         }
367
368         /* free requests associated with tags */
369         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
370                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
371                         kfree(c->reqs[row][col].wq);
372                         kfree(c->reqs[row][col].tc);
373                         kfree(c->reqs[row][col].rc);
374                 }
375                 kfree(c->reqs[row]);
376         }
377         c->max_tag = 0;
378 }
379
380 /**
381  * p9_free_req - free a request and clean-up as necessary
382  * c: client state
383  * r: request to release
384  *
385  */
386
387 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
388 {
389         int tag = r->tc->tag;
390         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
391
392         r->status = REQ_STATUS_IDLE;
393         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
394                 p9_idpool_put(tag, c->tagpool);
395 }
396
397 /**
398  * p9_client_cb - call back from transport to client
399  * c: client state
400  * req: request received
401  *
402  */
403 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
404 {
405         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
406         wake_up(req->wq);
407         P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
408 }
409 EXPORT_SYMBOL(p9_client_cb);
410
411 /**
412  * p9_parse_header - parse header arguments out of a packet
413  * @pdu: packet to parse
414  * @size: size of packet
415  * @type: type of request
416  * @tag: tag of packet
417  * @rewind: set if we need to rewind offset afterwards
418  */
419
420 int
421 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
422                                                                 int rewind)
423 {
424         int8_t r_type;
425         int16_t r_tag;
426         int32_t r_size;
427         int offset = pdu->offset;
428         int err;
429
430         pdu->offset = 0;
431         if (pdu->size == 0)
432                 pdu->size = 7;
433
434         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
435         if (err)
436                 goto rewind_and_exit;
437
438         pdu->size = r_size;
439         pdu->id = r_type;
440         pdu->tag = r_tag;
441
442         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
443                                                         pdu->id, pdu->tag);
444
445         if (type)
446                 *type = r_type;
447         if (tag)
448                 *tag = r_tag;
449         if (size)
450                 *size = r_size;
451
452
453 rewind_and_exit:
454         if (rewind)
455                 pdu->offset = offset;
456         return err;
457 }
458 EXPORT_SYMBOL(p9_parse_header);
459
460 /**
461  * p9_check_errors - check 9p packet for error return and process it
462  * @c: current client instance
463  * @req: request to parse and check for error conditions
464  *
465  * returns error code if one is discovered, otherwise returns 0
466  *
467  * this will have to be more complicated if we have multiple
468  * error packet types
469  */
470
471 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
472 {
473         int8_t type;
474         int err;
475         int ecode;
476
477         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
478         if (err) {
479                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
480                 return err;
481         }
482
483         if (type != P9_RERROR && type != P9_RLERROR)
484                 return 0;
485
486         if (!p9_is_proto_dotl(c)) {
487                 char *ename;
488
489                 if (req->tc->pbuf_size) {
490                         /* Handle user buffers */
491                         size_t len = req->rc->size - req->rc->offset;
492                         if (req->tc->pubuf) {
493                                 /* User Buffer */
494                                 err = copy_from_user(
495                                         &req->rc->sdata[req->rc->offset],
496                                         req->tc->pubuf, len);
497                                 if (err) {
498                                         err = -EFAULT;
499                                         goto out_err;
500                                 }
501                         } else {
502                                 /* Kernel Buffer */
503                                 memmove(&req->rc->sdata[req->rc->offset],
504                                                 req->tc->pkbuf, len);
505                         }
506                 }
507                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
508                                 &ename, &ecode);
509                 if (err)
510                         goto out_err;
511
512                 if (p9_is_proto_dotu(c))
513                         err = -ecode;
514
515                 if (!err || !IS_ERR_VALUE(err)) {
516                         err = p9_errstr2errno(ename, strlen(ename));
517
518                         P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode,
519                                         ename);
520
521                         kfree(ename);
522                 }
523         } else {
524                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
525                 err = -ecode;
526
527                 P9_DPRINTK(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
528         }
529
530
531         return err;
532
533 out_err:
534         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
535
536         return err;
537 }
538
539 static struct p9_req_t *
540 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
541
542 /**
543  * p9_client_flush - flush (cancel) a request
544  * @c: client state
545  * @oldreq: request to cancel
546  *
547  * This sents a flush for a particular request and links
548  * the flush request to the original request.  The current
549  * code only supports a single flush request although the protocol
550  * allows for multiple flush requests to be sent for a single request.
551  *
552  */
553
554 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
555 {
556         struct p9_req_t *req;
557         int16_t oldtag;
558         int err;
559
560         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
561         if (err)
562                 return err;
563
564         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
565
566         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
567         if (IS_ERR(req))
568                 return PTR_ERR(req);
569
570
571         /* if we haven't received a response for oldreq,
572            remove it from the list. */
573         spin_lock(&c->lock);
574         if (oldreq->status == REQ_STATUS_FLSH)
575                 list_del(&oldreq->req_list);
576         spin_unlock(&c->lock);
577
578         p9_free_req(c, req);
579         return 0;
580 }
581
582 /**
583  * p9_client_rpc - issue a request and wait for a response
584  * @c: client session
585  * @type: type of request
586  * @fmt: protocol format string (see protocol.c)
587  *
588  * Returns request structure (which client must free using p9_free_req)
589  */
590
591 static struct p9_req_t *
592 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
593 {
594         va_list ap;
595         int tag, err;
596         struct p9_req_t *req;
597         unsigned long flags;
598         int sigpending;
599
600         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
601
602         /* we allow for any status other than disconnected */
603         if (c->status == Disconnected)
604                 return ERR_PTR(-EIO);
605
606         /* if status is begin_disconnected we allow only clunk request */
607         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
608                 return ERR_PTR(-EIO);
609
610         if (signal_pending(current)) {
611                 sigpending = 1;
612                 clear_thread_flag(TIF_SIGPENDING);
613         } else
614                 sigpending = 0;
615
616         tag = P9_NOTAG;
617         if (type != P9_TVERSION) {
618                 tag = p9_idpool_get(c->tagpool);
619                 if (tag < 0)
620                         return ERR_PTR(-ENOMEM);
621         }
622
623         req = p9_tag_alloc(c, tag);
624         if (IS_ERR(req))
625                 return req;
626
627         /* marshall the data */
628         p9pdu_prepare(req->tc, tag, type);
629         va_start(ap, fmt);
630         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
631         va_end(ap);
632         if (err)
633                 goto reterr;
634         p9pdu_finalize(req->tc);
635
636         err = c->trans_mod->request(c, req);
637         if (err < 0) {
638                 if (err != -ERESTARTSYS && err != -EFAULT)
639                         c->status = Disconnected;
640                 goto reterr;
641         }
642
643         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
644         err = wait_event_interruptible(*req->wq,
645                                                 req->status >= REQ_STATUS_RCVD);
646         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d\n",
647                                                 req->wq, tag, err);
648
649         if (req->status == REQ_STATUS_ERROR) {
650                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
651                 err = req->t_err;
652         }
653
654         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
655                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
656                 sigpending = 1;
657                 clear_thread_flag(TIF_SIGPENDING);
658
659                 if (c->trans_mod->cancel(c, req))
660                         p9_client_flush(c, req);
661
662                 /* if we received the response anyway, don't signal error */
663                 if (req->status == REQ_STATUS_RCVD)
664                         err = 0;
665         }
666
667         if (sigpending) {
668                 spin_lock_irqsave(&current->sighand->siglock, flags);
669                 recalc_sigpending();
670                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
671         }
672
673         if (err < 0)
674                 goto reterr;
675
676         err = p9_check_errors(c, req);
677         if (!err) {
678                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
679                 return req;
680         }
681
682 reterr:
683         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
684                                                                         err);
685         p9_free_req(c, req);
686         return ERR_PTR(err);
687 }
688
689 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
690 {
691         int ret;
692         struct p9_fid *fid;
693         unsigned long flags;
694
695         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
696         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
697         if (!fid)
698                 return ERR_PTR(-ENOMEM);
699
700         ret = p9_idpool_get(clnt->fidpool);
701         if (ret < 0) {
702                 ret = -ENOSPC;
703                 goto error;
704         }
705         fid->fid = ret;
706
707         memset(&fid->qid, 0, sizeof(struct p9_qid));
708         fid->mode = -1;
709         fid->uid = current_fsuid();
710         fid->clnt = clnt;
711         fid->rdir = NULL;
712         spin_lock_irqsave(&clnt->lock, flags);
713         list_add(&fid->flist, &clnt->fidlist);
714         spin_unlock_irqrestore(&clnt->lock, flags);
715
716         return fid;
717
718 error:
719         kfree(fid);
720         return ERR_PTR(ret);
721 }
722
723 static void p9_fid_destroy(struct p9_fid *fid)
724 {
725         struct p9_client *clnt;
726         unsigned long flags;
727
728         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
729         clnt = fid->clnt;
730         p9_idpool_put(fid->fid, clnt->fidpool);
731         spin_lock_irqsave(&clnt->lock, flags);
732         list_del(&fid->flist);
733         spin_unlock_irqrestore(&clnt->lock, flags);
734         kfree(fid->rdir);
735         kfree(fid);
736 }
737
738 static int p9_client_version(struct p9_client *c)
739 {
740         int err = 0;
741         struct p9_req_t *req;
742         char *version;
743         int msize;
744
745         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
746                                                 c->msize, c->proto_version);
747
748         switch (c->proto_version) {
749         case p9_proto_2000L:
750                 req = p9_client_rpc(c, P9_TVERSION, "ds",
751                                         c->msize, "9P2000.L");
752                 break;
753         case p9_proto_2000u:
754                 req = p9_client_rpc(c, P9_TVERSION, "ds",
755                                         c->msize, "9P2000.u");
756                 break;
757         case p9_proto_legacy:
758                 req = p9_client_rpc(c, P9_TVERSION, "ds",
759                                         c->msize, "9P2000");
760                 break;
761         default:
762                 return -EINVAL;
763                 break;
764         }
765
766         if (IS_ERR(req))
767                 return PTR_ERR(req);
768
769         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
770         if (err) {
771                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
772                 P9_DUMP_PKT(1, req->rc);
773                 goto error;
774         }
775
776         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
777         if (!strncmp(version, "9P2000.L", 8))
778                 c->proto_version = p9_proto_2000L;
779         else if (!strncmp(version, "9P2000.u", 8))
780                 c->proto_version = p9_proto_2000u;
781         else if (!strncmp(version, "9P2000", 6))
782                 c->proto_version = p9_proto_legacy;
783         else {
784                 err = -EREMOTEIO;
785                 goto error;
786         }
787
788         if (msize < c->msize)
789                 c->msize = msize;
790
791 error:
792         kfree(version);
793         p9_free_req(c, req);
794
795         return err;
796 }
797
798 struct p9_client *p9_client_create(const char *dev_name, char *options)
799 {
800         int err;
801         struct p9_client *clnt;
802
803         err = 0;
804         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
805         if (!clnt)
806                 return ERR_PTR(-ENOMEM);
807
808         clnt->trans_mod = NULL;
809         clnt->trans = NULL;
810         spin_lock_init(&clnt->lock);
811         INIT_LIST_HEAD(&clnt->fidlist);
812
813         err = p9_tag_init(clnt);
814         if (err < 0)
815                 goto free_client;
816
817         err = parse_opts(options, clnt);
818         if (err < 0)
819                 goto destroy_tagpool;
820
821         if (!clnt->trans_mod)
822                 clnt->trans_mod = v9fs_get_default_trans();
823
824         if (clnt->trans_mod == NULL) {
825                 err = -EPROTONOSUPPORT;
826                 P9_DPRINTK(P9_DEBUG_ERROR,
827                                 "No transport defined or default transport\n");
828                 goto destroy_tagpool;
829         }
830
831         clnt->fidpool = p9_idpool_create();
832         if (IS_ERR(clnt->fidpool)) {
833                 err = PTR_ERR(clnt->fidpool);
834                 goto put_trans;
835         }
836
837         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
838                 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
839
840         err = clnt->trans_mod->create(clnt, dev_name, options);
841         if (err)
842                 goto destroy_fidpool;
843
844         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
845                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
846
847         err = p9_client_version(clnt);
848         if (err)
849                 goto close_trans;
850
851         return clnt;
852
853 close_trans:
854         clnt->trans_mod->close(clnt);
855 destroy_fidpool:
856         p9_idpool_destroy(clnt->fidpool);
857 put_trans:
858         v9fs_put_trans(clnt->trans_mod);
859 destroy_tagpool:
860         p9_idpool_destroy(clnt->tagpool);
861 free_client:
862         kfree(clnt);
863         return ERR_PTR(err);
864 }
865 EXPORT_SYMBOL(p9_client_create);
866
867 void p9_client_destroy(struct p9_client *clnt)
868 {
869         struct p9_fid *fid, *fidptr;
870
871         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
872
873         if (clnt->trans_mod)
874                 clnt->trans_mod->close(clnt);
875
876         v9fs_put_trans(clnt->trans_mod);
877
878         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {
879                 printk(KERN_INFO "Found fid %d not clunked\n", fid->fid);
880                 p9_fid_destroy(fid);
881         }
882
883         if (clnt->fidpool)
884                 p9_idpool_destroy(clnt->fidpool);
885
886         p9_tag_cleanup(clnt);
887
888         kfree(clnt);
889 }
890 EXPORT_SYMBOL(p9_client_destroy);
891
892 void p9_client_disconnect(struct p9_client *clnt)
893 {
894         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
895         clnt->status = Disconnected;
896 }
897 EXPORT_SYMBOL(p9_client_disconnect);
898
899 void p9_client_begin_disconnect(struct p9_client *clnt)
900 {
901         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
902         clnt->status = BeginDisconnect;
903 }
904 EXPORT_SYMBOL(p9_client_begin_disconnect);
905
906 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
907         char *uname, u32 n_uname, char *aname)
908 {
909         int err;
910         struct p9_req_t *req;
911         struct p9_fid *fid;
912         struct p9_qid qid;
913
914         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
915                                         afid ? afid->fid : -1, uname, aname);
916         err = 0;
917
918         fid = p9_fid_create(clnt);
919         if (IS_ERR(fid)) {
920                 err = PTR_ERR(fid);
921                 fid = NULL;
922                 goto error;
923         }
924
925         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
926                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
927         if (IS_ERR(req)) {
928                 err = PTR_ERR(req);
929                 goto error;
930         }
931
932         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
933         if (err) {
934                 P9_DUMP_PKT(1, req->rc);
935                 p9_free_req(clnt, req);
936                 goto error;
937         }
938
939         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
940                                         qid.type,
941                                         (unsigned long long)qid.path,
942                                         qid.version);
943
944         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
945
946         p9_free_req(clnt, req);
947         return fid;
948
949 error:
950         if (fid)
951                 p9_fid_destroy(fid);
952         return ERR_PTR(err);
953 }
954 EXPORT_SYMBOL(p9_client_attach);
955
956 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
957                 char **wnames, int clone)
958 {
959         int err;
960         struct p9_client *clnt;
961         struct p9_fid *fid;
962         struct p9_qid *wqids;
963         struct p9_req_t *req;
964         uint16_t nwqids, count;
965
966         err = 0;
967         wqids = NULL;
968         clnt = oldfid->clnt;
969         if (clone) {
970                 fid = p9_fid_create(clnt);
971                 if (IS_ERR(fid)) {
972                         err = PTR_ERR(fid);
973                         fid = NULL;
974                         goto error;
975                 }
976
977                 fid->uid = oldfid->uid;
978         } else
979                 fid = oldfid;
980
981
982         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
983                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
984
985         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
986                                                                 nwname, wnames);
987         if (IS_ERR(req)) {
988                 err = PTR_ERR(req);
989                 goto error;
990         }
991
992         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
993         if (err) {
994                 P9_DUMP_PKT(1, req->rc);
995                 p9_free_req(clnt, req);
996                 goto clunk_fid;
997         }
998         p9_free_req(clnt, req);
999
1000         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1001
1002         if (nwqids != nwname) {
1003                 err = -ENOENT;
1004                 goto clunk_fid;
1005         }
1006
1007         for (count = 0; count < nwqids; count++)
1008                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1009                         count, wqids[count].type,
1010                         (unsigned long long)wqids[count].path,
1011                         wqids[count].version);
1012
1013         if (nwname)
1014                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1015         else
1016                 fid->qid = oldfid->qid;
1017
1018         kfree(wqids);
1019         return fid;
1020
1021 clunk_fid:
1022         kfree(wqids);
1023         p9_client_clunk(fid);
1024         fid = NULL;
1025
1026 error:
1027         if (fid && (fid != oldfid))
1028                 p9_fid_destroy(fid);
1029
1030         return ERR_PTR(err);
1031 }
1032 EXPORT_SYMBOL(p9_client_walk);
1033
1034 int p9_client_open(struct p9_fid *fid, int mode)
1035 {
1036         int err;
1037         struct p9_client *clnt;
1038         struct p9_req_t *req;
1039         struct p9_qid qid;
1040         int iounit;
1041
1042         clnt = fid->clnt;
1043         P9_DPRINTK(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1044                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1045         err = 0;
1046
1047         if (fid->mode != -1)
1048                 return -EINVAL;
1049
1050         if (p9_is_proto_dotl(clnt))
1051                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1052         else
1053                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1054         if (IS_ERR(req)) {
1055                 err = PTR_ERR(req);
1056                 goto error;
1057         }
1058
1059         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1060         if (err) {
1061                 P9_DUMP_PKT(1, req->rc);
1062                 goto free_and_error;
1063         }
1064
1065         P9_DPRINTK(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1066                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1067                 (unsigned long long)qid.path, qid.version, iounit);
1068
1069         fid->mode = mode;
1070         fid->iounit = iounit;
1071
1072 free_and_error:
1073         p9_free_req(clnt, req);
1074 error:
1075         return err;
1076 }
1077 EXPORT_SYMBOL(p9_client_open);
1078
1079 int p9_client_create_dotl(struct p9_fid *ofid, char *name, u32 flags, u32 mode,
1080                 gid_t gid, struct p9_qid *qid)
1081 {
1082         int err = 0;
1083         struct p9_client *clnt;
1084         struct p9_req_t *req;
1085         int iounit;
1086
1087         P9_DPRINTK(P9_DEBUG_9P,
1088                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1089                         ofid->fid, name, flags, mode, gid);
1090         clnt = ofid->clnt;
1091
1092         if (ofid->mode != -1)
1093                 return -EINVAL;
1094
1095         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddd", ofid->fid, name, flags,
1096                         mode, gid);
1097         if (IS_ERR(req)) {
1098                 err = PTR_ERR(req);
1099                 goto error;
1100         }
1101
1102         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1103         if (err) {
1104                 P9_DUMP_PKT(1, req->rc);
1105                 goto free_and_error;
1106         }
1107
1108         P9_DPRINTK(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1109                         qid->type,
1110                         (unsigned long long)qid->path,
1111                         qid->version, iounit);
1112
1113         ofid->mode = mode;
1114         ofid->iounit = iounit;
1115
1116 free_and_error:
1117         p9_free_req(clnt, req);
1118 error:
1119         return err;
1120 }
1121 EXPORT_SYMBOL(p9_client_create_dotl);
1122
1123 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1124                      char *extension)
1125 {
1126         int err;
1127         struct p9_client *clnt;
1128         struct p9_req_t *req;
1129         struct p9_qid qid;
1130         int iounit;
1131
1132         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1133                                                 fid->fid, name, perm, mode);
1134         err = 0;
1135         clnt = fid->clnt;
1136
1137         if (fid->mode != -1)
1138                 return -EINVAL;
1139
1140         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1141                                 mode, extension);
1142         if (IS_ERR(req)) {
1143                 err = PTR_ERR(req);
1144                 goto error;
1145         }
1146
1147         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1148         if (err) {
1149                 P9_DUMP_PKT(1, req->rc);
1150                 goto free_and_error;
1151         }
1152
1153         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1154                                 qid.type,
1155                                 (unsigned long long)qid.path,
1156                                 qid.version, iounit);
1157
1158         fid->mode = mode;
1159         fid->iounit = iounit;
1160
1161 free_and_error:
1162         p9_free_req(clnt, req);
1163 error:
1164         return err;
1165 }
1166 EXPORT_SYMBOL(p9_client_fcreate);
1167
1168 int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid,
1169                 struct p9_qid *qid)
1170 {
1171         int err = 0;
1172         struct p9_client *clnt;
1173         struct p9_req_t *req;
1174
1175         P9_DPRINTK(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1176                         dfid->fid, name, symtgt);
1177         clnt = dfid->clnt;
1178
1179         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt,
1180                         gid);
1181         if (IS_ERR(req)) {
1182                 err = PTR_ERR(req);
1183                 goto error;
1184         }
1185
1186         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1187         if (err) {
1188                 P9_DUMP_PKT(1, req->rc);
1189                 goto free_and_error;
1190         }
1191
1192         P9_DPRINTK(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1193                         qid->type, (unsigned long long)qid->path, qid->version);
1194
1195 free_and_error:
1196         p9_free_req(clnt, req);
1197 error:
1198         return err;
1199 }
1200 EXPORT_SYMBOL(p9_client_symlink);
1201
1202 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname)
1203 {
1204         struct p9_client *clnt;
1205         struct p9_req_t *req;
1206
1207         P9_DPRINTK(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1208                         dfid->fid, oldfid->fid, newname);
1209         clnt = dfid->clnt;
1210         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1211                         newname);
1212         if (IS_ERR(req))
1213                 return PTR_ERR(req);
1214
1215         P9_DPRINTK(P9_DEBUG_9P, "<<< RLINK\n");
1216         p9_free_req(clnt, req);
1217         return 0;
1218 }
1219 EXPORT_SYMBOL(p9_client_link);
1220
1221 int p9_client_fsync(struct p9_fid *fid, int datasync)
1222 {
1223         int err;
1224         struct p9_client *clnt;
1225         struct p9_req_t *req;
1226
1227         P9_DPRINTK(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1228                         fid->fid, datasync);
1229         err = 0;
1230         clnt = fid->clnt;
1231
1232         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1233         if (IS_ERR(req)) {
1234                 err = PTR_ERR(req);
1235                 goto error;
1236         }
1237
1238         P9_DPRINTK(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1239
1240         p9_free_req(clnt, req);
1241
1242 error:
1243         return err;
1244 }
1245 EXPORT_SYMBOL(p9_client_fsync);
1246
1247 int p9_client_clunk(struct p9_fid *fid)
1248 {
1249         int err;
1250         struct p9_client *clnt;
1251         struct p9_req_t *req;
1252
1253         if (!fid) {
1254                 P9_EPRINTK(KERN_WARNING, "Trying to clunk with NULL fid\n");
1255                 dump_stack();
1256                 return 0;
1257         }
1258
1259         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1260         err = 0;
1261         clnt = fid->clnt;
1262
1263         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1264         if (IS_ERR(req)) {
1265                 err = PTR_ERR(req);
1266                 goto error;
1267         }
1268
1269         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1270
1271         p9_free_req(clnt, req);
1272 error:
1273         /*
1274          * Fid is not valid even after a failed clunk
1275          */
1276         p9_fid_destroy(fid);
1277         return err;
1278 }
1279 EXPORT_SYMBOL(p9_client_clunk);
1280
1281 int p9_client_remove(struct p9_fid *fid)
1282 {
1283         int err;
1284         struct p9_client *clnt;
1285         struct p9_req_t *req;
1286
1287         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1288         err = 0;
1289         clnt = fid->clnt;
1290
1291         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1292         if (IS_ERR(req)) {
1293                 err = PTR_ERR(req);
1294                 goto error;
1295         }
1296
1297         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1298
1299         p9_free_req(clnt, req);
1300 error:
1301         p9_fid_destroy(fid);
1302         return err;
1303 }
1304 EXPORT_SYMBOL(p9_client_remove);
1305
1306 int
1307 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1308                                                                 u32 count)
1309 {
1310         int err, rsize;
1311         struct p9_client *clnt;
1312         struct p9_req_t *req;
1313         char *dataptr;
1314
1315         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1316                                         (long long unsigned) offset, count);
1317         err = 0;
1318         clnt = fid->clnt;
1319
1320         rsize = fid->iounit;
1321         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1322                 rsize = clnt->msize - P9_IOHDRSZ;
1323
1324         if (count < rsize)
1325                 rsize = count;
1326
1327         /* Don't bother zerocopy for small IO (< 1024) */
1328         if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1329                         P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
1330                 req = p9_client_rpc(clnt, P9_TREAD, "dqE", fid->fid, offset,
1331                                 rsize, data, udata);
1332         } else {
1333                 req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1334                                 rsize);
1335         }
1336         if (IS_ERR(req)) {
1337                 err = PTR_ERR(req);
1338                 goto error;
1339         }
1340
1341         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1342         if (err) {
1343                 P9_DUMP_PKT(1, req->rc);
1344                 goto free_and_error;
1345         }
1346
1347         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1348         P9_DUMP_PKT(1, req->rc);
1349
1350         if (!req->tc->pbuf_size) {
1351                 if (data) {
1352                         memmove(data, dataptr, count);
1353                 } else {
1354                         err = copy_to_user(udata, dataptr, count);
1355                         if (err) {
1356                                 err = -EFAULT;
1357                                 goto free_and_error;
1358                         }
1359                 }
1360         }
1361         p9_free_req(clnt, req);
1362         return count;
1363
1364 free_and_error:
1365         p9_free_req(clnt, req);
1366 error:
1367         return err;
1368 }
1369 EXPORT_SYMBOL(p9_client_read);
1370
1371 int
1372 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1373                                                         u64 offset, u32 count)
1374 {
1375         int err, rsize;
1376         struct p9_client *clnt;
1377         struct p9_req_t *req;
1378
1379         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1380                                 fid->fid, (long long unsigned) offset, count);
1381         err = 0;
1382         clnt = fid->clnt;
1383
1384         rsize = fid->iounit;
1385         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1386                 rsize = clnt->msize - P9_IOHDRSZ;
1387
1388         if (count < rsize)
1389                 rsize = count;
1390
1391         /* Don't bother zerocopy form small IO (< 1024) */
1392         if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1393                                 P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
1394                 req = p9_client_rpc(clnt, P9_TWRITE, "dqE", fid->fid, offset,
1395                                 rsize, data, udata);
1396         } else {
1397
1398                 if (data)
1399                         req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1400                                         offset, rsize, data);
1401                 else
1402                         req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1403                                         offset, rsize, udata);
1404         }
1405         if (IS_ERR(req)) {
1406                 err = PTR_ERR(req);
1407                 goto error;
1408         }
1409
1410         err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1411         if (err) {
1412                 P9_DUMP_PKT(1, req->rc);
1413                 goto free_and_error;
1414         }
1415
1416         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1417
1418         p9_free_req(clnt, req);
1419         return count;
1420
1421 free_and_error:
1422         p9_free_req(clnt, req);
1423 error:
1424         return err;
1425 }
1426 EXPORT_SYMBOL(p9_client_write);
1427
1428 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1429 {
1430         int err;
1431         struct p9_client *clnt;
1432         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1433         struct p9_req_t *req;
1434         u16 ignored;
1435
1436         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1437
1438         if (!ret)
1439                 return ERR_PTR(-ENOMEM);
1440
1441         err = 0;
1442         clnt = fid->clnt;
1443
1444         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1445         if (IS_ERR(req)) {
1446                 err = PTR_ERR(req);
1447                 goto error;
1448         }
1449
1450         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1451         if (err) {
1452                 P9_DUMP_PKT(1, req->rc);
1453                 p9_free_req(clnt, req);
1454                 goto error;
1455         }
1456
1457         P9_DPRINTK(P9_DEBUG_9P,
1458                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1459                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1460                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1461                 "<<<    uid=%d gid=%d n_muid=%d\n",
1462                 ret->size, ret->type, ret->dev, ret->qid.type,
1463                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1464                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1465                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1466                 ret->n_uid, ret->n_gid, ret->n_muid);
1467
1468         p9_free_req(clnt, req);
1469         return ret;
1470
1471 error:
1472         kfree(ret);
1473         return ERR_PTR(err);
1474 }
1475 EXPORT_SYMBOL(p9_client_stat);
1476
1477 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1478                                                         u64 request_mask)
1479 {
1480         int err;
1481         struct p9_client *clnt;
1482         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1483                                                                 GFP_KERNEL);
1484         struct p9_req_t *req;
1485
1486         P9_DPRINTK(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1487                                                         fid->fid, request_mask);
1488
1489         if (!ret)
1490                 return ERR_PTR(-ENOMEM);
1491
1492         err = 0;
1493         clnt = fid->clnt;
1494
1495         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1496         if (IS_ERR(req)) {
1497                 err = PTR_ERR(req);
1498                 goto error;
1499         }
1500
1501         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1502         if (err) {
1503                 P9_DUMP_PKT(1, req->rc);
1504                 p9_free_req(clnt, req);
1505                 goto error;
1506         }
1507
1508         P9_DPRINTK(P9_DEBUG_9P,
1509                 "<<< RGETATTR st_result_mask=%lld\n"
1510                 "<<< qid=%x.%llx.%x\n"
1511                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1512                 "<<< st_uid=%d st_gid=%d\n"
1513                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1514                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1515                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1516                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1517                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1518                 "<<< st_gen=%lld st_data_version=%lld",
1519                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1520                 ret->qid.version, ret->st_mode, ret->st_nlink, ret->st_uid,
1521                 ret->st_gid, ret->st_rdev, ret->st_size, ret->st_blksize,
1522                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1523                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1524                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1525                 ret->st_gen, ret->st_data_version);
1526
1527         p9_free_req(clnt, req);
1528         return ret;
1529
1530 error:
1531         kfree(ret);
1532         return ERR_PTR(err);
1533 }
1534 EXPORT_SYMBOL(p9_client_getattr_dotl);
1535
1536 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1537 {
1538         int ret;
1539
1540         /* NOTE: size shouldn't include its own length */
1541         /* size[2] type[2] dev[4] qid[13] */
1542         /* mode[4] atime[4] mtime[4] length[8]*/
1543         /* name[s] uid[s] gid[s] muid[s] */
1544         ret = 2+4+13+4+4+4+8+2+2+2+2;
1545
1546         if (wst->name)
1547                 ret += strlen(wst->name);
1548         if (wst->uid)
1549                 ret += strlen(wst->uid);
1550         if (wst->gid)
1551                 ret += strlen(wst->gid);
1552         if (wst->muid)
1553                 ret += strlen(wst->muid);
1554
1555         if ((proto_version == p9_proto_2000u) ||
1556                 (proto_version == p9_proto_2000L)) {
1557                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1558                 if (wst->extension)
1559                         ret += strlen(wst->extension);
1560         }
1561
1562         return ret;
1563 }
1564
1565 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1566 {
1567         int err;
1568         struct p9_req_t *req;
1569         struct p9_client *clnt;
1570
1571         err = 0;
1572         clnt = fid->clnt;
1573         wst->size = p9_client_statsize(wst, clnt->proto_version);
1574         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1575         P9_DPRINTK(P9_DEBUG_9P,
1576                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1577                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1578                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1579                 "     uid=%d gid=%d n_muid=%d\n",
1580                 wst->size, wst->type, wst->dev, wst->qid.type,
1581                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1582                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1583                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1584                 wst->n_uid, wst->n_gid, wst->n_muid);
1585
1586         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1587         if (IS_ERR(req)) {
1588                 err = PTR_ERR(req);
1589                 goto error;
1590         }
1591
1592         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1593
1594         p9_free_req(clnt, req);
1595 error:
1596         return err;
1597 }
1598 EXPORT_SYMBOL(p9_client_wstat);
1599
1600 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1601 {
1602         int err;
1603         struct p9_req_t *req;
1604         struct p9_client *clnt;
1605
1606         err = 0;
1607         clnt = fid->clnt;
1608         P9_DPRINTK(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1609         P9_DPRINTK(P9_DEBUG_9P,
1610                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1611                 "    atime_sec=%lld atime_nsec=%lld\n"
1612                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1613                 p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid,
1614                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1615                 p9attr->mtime_sec, p9attr->mtime_nsec);
1616
1617         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1618
1619         if (IS_ERR(req)) {
1620                 err = PTR_ERR(req);
1621                 goto error;
1622         }
1623         P9_DPRINTK(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1624         p9_free_req(clnt, req);
1625 error:
1626         return err;
1627 }
1628 EXPORT_SYMBOL(p9_client_setattr);
1629
1630 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1631 {
1632         int err;
1633         struct p9_req_t *req;
1634         struct p9_client *clnt;
1635
1636         err = 0;
1637         clnt = fid->clnt;
1638
1639         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1640
1641         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1642         if (IS_ERR(req)) {
1643                 err = PTR_ERR(req);
1644                 goto error;
1645         }
1646
1647         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1648                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1649                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1650         if (err) {
1651                 P9_DUMP_PKT(1, req->rc);
1652                 p9_free_req(clnt, req);
1653                 goto error;
1654         }
1655
1656         P9_DPRINTK(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1657                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1658                 "fsid %llu namelen %ld\n",
1659                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1660                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1661                 sb->fsid, (long int)sb->namelen);
1662
1663         p9_free_req(clnt, req);
1664 error:
1665         return err;
1666 }
1667 EXPORT_SYMBOL(p9_client_statfs);
1668
1669 int p9_client_rename(struct p9_fid *fid,
1670                      struct p9_fid *newdirfid, const char *name)
1671 {
1672         int err;
1673         struct p9_req_t *req;
1674         struct p9_client *clnt;
1675
1676         err = 0;
1677         clnt = fid->clnt;
1678
1679         P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1680                         fid->fid, newdirfid->fid, name);
1681
1682         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1683                         newdirfid->fid, name);
1684         if (IS_ERR(req)) {
1685                 err = PTR_ERR(req);
1686                 goto error;
1687         }
1688
1689         P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1690
1691         p9_free_req(clnt, req);
1692 error:
1693         return err;
1694 }
1695 EXPORT_SYMBOL(p9_client_rename);
1696
1697 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1698                        struct p9_fid *newdirfid, const char *new_name)
1699 {
1700         int err;
1701         struct p9_req_t *req;
1702         struct p9_client *clnt;
1703
1704         err = 0;
1705         clnt = olddirfid->clnt;
1706
1707         P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1708                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1709                    newdirfid->fid, new_name);
1710
1711         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1712                             old_name, newdirfid->fid, new_name);
1713         if (IS_ERR(req)) {
1714                 err = PTR_ERR(req);
1715                 goto error;
1716         }
1717
1718         P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1719                    newdirfid->fid, new_name);
1720
1721         p9_free_req(clnt, req);
1722 error:
1723         return err;
1724 }
1725 EXPORT_SYMBOL(p9_client_renameat);
1726
1727 /*
1728  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1729  */
1730 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1731                                 const char *attr_name, u64 *attr_size)
1732 {
1733         int err;
1734         struct p9_req_t *req;
1735         struct p9_client *clnt;
1736         struct p9_fid *attr_fid;
1737
1738         err = 0;
1739         clnt = file_fid->clnt;
1740         attr_fid = p9_fid_create(clnt);
1741         if (IS_ERR(attr_fid)) {
1742                 err = PTR_ERR(attr_fid);
1743                 attr_fid = NULL;
1744                 goto error;
1745         }
1746         P9_DPRINTK(P9_DEBUG_9P,
1747                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1748                 file_fid->fid, attr_fid->fid, attr_name);
1749
1750         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1751                         file_fid->fid, attr_fid->fid, attr_name);
1752         if (IS_ERR(req)) {
1753                 err = PTR_ERR(req);
1754                 goto error;
1755         }
1756         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
1757         if (err) {
1758                 P9_DUMP_PKT(1, req->rc);
1759                 p9_free_req(clnt, req);
1760                 goto clunk_fid;
1761         }
1762         p9_free_req(clnt, req);
1763         P9_DPRINTK(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
1764                 attr_fid->fid, *attr_size);
1765         return attr_fid;
1766 clunk_fid:
1767         p9_client_clunk(attr_fid);
1768         attr_fid = NULL;
1769 error:
1770         if (attr_fid && (attr_fid != file_fid))
1771                 p9_fid_destroy(attr_fid);
1772
1773         return ERR_PTR(err);
1774 }
1775 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
1776
1777 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
1778                         u64 attr_size, int flags)
1779 {
1780         int err;
1781         struct p9_req_t *req;
1782         struct p9_client *clnt;
1783
1784         P9_DPRINTK(P9_DEBUG_9P,
1785                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
1786                 fid->fid, name, (long long)attr_size, flags);
1787         err = 0;
1788         clnt = fid->clnt;
1789         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
1790                         fid->fid, name, attr_size, flags);
1791         if (IS_ERR(req)) {
1792                 err = PTR_ERR(req);
1793                 goto error;
1794         }
1795         P9_DPRINTK(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
1796         p9_free_req(clnt, req);
1797 error:
1798         return err;
1799 }
1800 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
1801
1802 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
1803 {
1804         int err, rsize;
1805         struct p9_client *clnt;
1806         struct p9_req_t *req;
1807         char *dataptr;
1808
1809         P9_DPRINTK(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
1810                                 fid->fid, (long long unsigned) offset, count);
1811
1812         err = 0;
1813         clnt = fid->clnt;
1814
1815         rsize = fid->iounit;
1816         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
1817                 rsize = clnt->msize - P9_READDIRHDRSZ;
1818
1819         if (count < rsize)
1820                 rsize = count;
1821
1822         if ((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1823                         P9_TRANS_PREF_PAYLOAD_SEP) {
1824                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqF", fid->fid,
1825                                 offset, rsize, data);
1826         } else {
1827                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
1828                                 offset, rsize);
1829         }
1830         if (IS_ERR(req)) {
1831                 err = PTR_ERR(req);
1832                 goto error;
1833         }
1834
1835         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1836         if (err) {
1837                 P9_DUMP_PKT(1, req->rc);
1838                 goto free_and_error;
1839         }
1840
1841         P9_DPRINTK(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
1842
1843         if (!req->tc->pbuf_size && data)
1844                 memmove(data, dataptr, count);
1845
1846         p9_free_req(clnt, req);
1847         return count;
1848
1849 free_and_error:
1850         p9_free_req(clnt, req);
1851 error:
1852         return err;
1853 }
1854 EXPORT_SYMBOL(p9_client_readdir);
1855
1856 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
1857                         dev_t rdev, gid_t gid, struct p9_qid *qid)
1858 {
1859         int err;
1860         struct p9_client *clnt;
1861         struct p9_req_t *req;
1862
1863         err = 0;
1864         clnt = fid->clnt;
1865         P9_DPRINTK(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
1866                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
1867         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
1868                 MAJOR(rdev), MINOR(rdev), gid);
1869         if (IS_ERR(req))
1870                 return PTR_ERR(req);
1871
1872         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1873         if (err) {
1874                 P9_DUMP_PKT(1, req->rc);
1875                 goto error;
1876         }
1877         P9_DPRINTK(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
1878                                 (unsigned long long)qid->path, qid->version);
1879
1880 error:
1881         p9_free_req(clnt, req);
1882         return err;
1883
1884 }
1885 EXPORT_SYMBOL(p9_client_mknod_dotl);
1886
1887 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
1888                                 gid_t gid, struct p9_qid *qid)
1889 {
1890         int err;
1891         struct p9_client *clnt;
1892         struct p9_req_t *req;
1893
1894         err = 0;
1895         clnt = fid->clnt;
1896         P9_DPRINTK(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
1897                  fid->fid, name, mode, gid);
1898         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
1899                 gid);
1900         if (IS_ERR(req))
1901                 return PTR_ERR(req);
1902
1903         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1904         if (err) {
1905                 P9_DUMP_PKT(1, req->rc);
1906                 goto error;
1907         }
1908         P9_DPRINTK(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
1909                                 (unsigned long long)qid->path, qid->version);
1910
1911 error:
1912         p9_free_req(clnt, req);
1913         return err;
1914
1915 }
1916 EXPORT_SYMBOL(p9_client_mkdir_dotl);
1917
1918 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
1919 {
1920         int err;
1921         struct p9_client *clnt;
1922         struct p9_req_t *req;
1923
1924         err = 0;
1925         clnt = fid->clnt;
1926         P9_DPRINTK(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
1927                         "start %lld length %lld proc_id %d client_id %s\n",
1928                         fid->fid, flock->type, flock->flags, flock->start,
1929                         flock->length, flock->proc_id, flock->client_id);
1930
1931         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
1932                                 flock->flags, flock->start, flock->length,
1933                                         flock->proc_id, flock->client_id);
1934
1935         if (IS_ERR(req))
1936                 return PTR_ERR(req);
1937
1938         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
1939         if (err) {
1940                 P9_DUMP_PKT(1, req->rc);
1941                 goto error;
1942         }
1943         P9_DPRINTK(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
1944 error:
1945         p9_free_req(clnt, req);
1946         return err;
1947
1948 }
1949 EXPORT_SYMBOL(p9_client_lock_dotl);
1950
1951 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
1952 {
1953         int err;
1954         struct p9_client *clnt;
1955         struct p9_req_t *req;
1956
1957         err = 0;
1958         clnt = fid->clnt;
1959         P9_DPRINTK(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
1960                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
1961                 glock->start, glock->length, glock->proc_id, glock->client_id);
1962
1963         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
1964                 glock->start, glock->length, glock->proc_id, glock->client_id);
1965
1966         if (IS_ERR(req))
1967                 return PTR_ERR(req);
1968
1969         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
1970                         &glock->start, &glock->length, &glock->proc_id,
1971                         &glock->client_id);
1972         if (err) {
1973                 P9_DUMP_PKT(1, req->rc);
1974                 goto error;
1975         }
1976         P9_DPRINTK(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
1977                 "proc_id %d client_id %s\n", glock->type, glock->start,
1978                 glock->length, glock->proc_id, glock->client_id);
1979 error:
1980         p9_free_req(clnt, req);
1981         return err;
1982 }
1983 EXPORT_SYMBOL(p9_client_getlock_dotl);
1984
1985 int p9_client_readlink(struct p9_fid *fid, char **target)
1986 {
1987         int err;
1988         struct p9_client *clnt;
1989         struct p9_req_t *req;
1990
1991         err = 0;
1992         clnt = fid->clnt;
1993         P9_DPRINTK(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
1994
1995         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
1996         if (IS_ERR(req))
1997                 return PTR_ERR(req);
1998
1999         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2000         if (err) {
2001                 P9_DUMP_PKT(1, req->rc);
2002                 goto error;
2003         }
2004         P9_DPRINTK(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2005 error:
2006         p9_free_req(clnt, req);
2007         return err;
2008 }
2009 EXPORT_SYMBOL(p9_client_readlink);