fs/9p: add 9P2000.L unlinkat operation
[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/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 p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1307 {
1308         int err = 0;
1309         struct p9_req_t *req;
1310         struct p9_client *clnt;
1311
1312         P9_DPRINTK(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1313                    dfid->fid, name, flags);
1314
1315         clnt = dfid->clnt;
1316         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1317         if (IS_ERR(req)) {
1318                 err = PTR_ERR(req);
1319                 goto error;
1320         }
1321         P9_DPRINTK(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1322
1323         p9_free_req(clnt, req);
1324 error:
1325         return err;
1326 }
1327 EXPORT_SYMBOL(p9_client_unlinkat);
1328
1329 int
1330 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1331                                                                 u32 count)
1332 {
1333         int err, rsize;
1334         struct p9_client *clnt;
1335         struct p9_req_t *req;
1336         char *dataptr;
1337
1338         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1339                                         (long long unsigned) offset, count);
1340         err = 0;
1341         clnt = fid->clnt;
1342
1343         rsize = fid->iounit;
1344         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1345                 rsize = clnt->msize - P9_IOHDRSZ;
1346
1347         if (count < rsize)
1348                 rsize = count;
1349
1350         /* Don't bother zerocopy for small IO (< 1024) */
1351         if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1352                         P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
1353                 req = p9_client_rpc(clnt, P9_TREAD, "dqE", fid->fid, offset,
1354                                 rsize, data, udata);
1355         } else {
1356                 req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1357                                 rsize);
1358         }
1359         if (IS_ERR(req)) {
1360                 err = PTR_ERR(req);
1361                 goto error;
1362         }
1363
1364         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1365         if (err) {
1366                 P9_DUMP_PKT(1, req->rc);
1367                 goto free_and_error;
1368         }
1369
1370         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1371         P9_DUMP_PKT(1, req->rc);
1372
1373         if (!req->tc->pbuf_size) {
1374                 if (data) {
1375                         memmove(data, dataptr, count);
1376                 } else {
1377                         err = copy_to_user(udata, dataptr, count);
1378                         if (err) {
1379                                 err = -EFAULT;
1380                                 goto free_and_error;
1381                         }
1382                 }
1383         }
1384         p9_free_req(clnt, req);
1385         return count;
1386
1387 free_and_error:
1388         p9_free_req(clnt, req);
1389 error:
1390         return err;
1391 }
1392 EXPORT_SYMBOL(p9_client_read);
1393
1394 int
1395 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1396                                                         u64 offset, u32 count)
1397 {
1398         int err, rsize;
1399         struct p9_client *clnt;
1400         struct p9_req_t *req;
1401
1402         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1403                                 fid->fid, (long long unsigned) offset, count);
1404         err = 0;
1405         clnt = fid->clnt;
1406
1407         rsize = fid->iounit;
1408         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1409                 rsize = clnt->msize - P9_IOHDRSZ;
1410
1411         if (count < rsize)
1412                 rsize = count;
1413
1414         /* Don't bother zerocopy form small IO (< 1024) */
1415         if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1416                                 P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
1417                 req = p9_client_rpc(clnt, P9_TWRITE, "dqE", fid->fid, offset,
1418                                 rsize, data, udata);
1419         } else {
1420
1421                 if (data)
1422                         req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid,
1423                                         offset, rsize, data);
1424                 else
1425                         req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid,
1426                                         offset, rsize, udata);
1427         }
1428         if (IS_ERR(req)) {
1429                 err = PTR_ERR(req);
1430                 goto error;
1431         }
1432
1433         err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1434         if (err) {
1435                 P9_DUMP_PKT(1, req->rc);
1436                 goto free_and_error;
1437         }
1438
1439         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1440
1441         p9_free_req(clnt, req);
1442         return count;
1443
1444 free_and_error:
1445         p9_free_req(clnt, req);
1446 error:
1447         return err;
1448 }
1449 EXPORT_SYMBOL(p9_client_write);
1450
1451 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1452 {
1453         int err;
1454         struct p9_client *clnt;
1455         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1456         struct p9_req_t *req;
1457         u16 ignored;
1458
1459         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1460
1461         if (!ret)
1462                 return ERR_PTR(-ENOMEM);
1463
1464         err = 0;
1465         clnt = fid->clnt;
1466
1467         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1468         if (IS_ERR(req)) {
1469                 err = PTR_ERR(req);
1470                 goto error;
1471         }
1472
1473         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1474         if (err) {
1475                 P9_DUMP_PKT(1, req->rc);
1476                 p9_free_req(clnt, req);
1477                 goto error;
1478         }
1479
1480         P9_DPRINTK(P9_DEBUG_9P,
1481                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1482                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1483                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1484                 "<<<    uid=%d gid=%d n_muid=%d\n",
1485                 ret->size, ret->type, ret->dev, ret->qid.type,
1486                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1487                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1488                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1489                 ret->n_uid, ret->n_gid, ret->n_muid);
1490
1491         p9_free_req(clnt, req);
1492         return ret;
1493
1494 error:
1495         kfree(ret);
1496         return ERR_PTR(err);
1497 }
1498 EXPORT_SYMBOL(p9_client_stat);
1499
1500 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1501                                                         u64 request_mask)
1502 {
1503         int err;
1504         struct p9_client *clnt;
1505         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1506                                                                 GFP_KERNEL);
1507         struct p9_req_t *req;
1508
1509         P9_DPRINTK(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1510                                                         fid->fid, request_mask);
1511
1512         if (!ret)
1513                 return ERR_PTR(-ENOMEM);
1514
1515         err = 0;
1516         clnt = fid->clnt;
1517
1518         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1519         if (IS_ERR(req)) {
1520                 err = PTR_ERR(req);
1521                 goto error;
1522         }
1523
1524         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1525         if (err) {
1526                 P9_DUMP_PKT(1, req->rc);
1527                 p9_free_req(clnt, req);
1528                 goto error;
1529         }
1530
1531         P9_DPRINTK(P9_DEBUG_9P,
1532                 "<<< RGETATTR st_result_mask=%lld\n"
1533                 "<<< qid=%x.%llx.%x\n"
1534                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1535                 "<<< st_uid=%d st_gid=%d\n"
1536                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1537                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1538                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1539                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1540                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1541                 "<<< st_gen=%lld st_data_version=%lld",
1542                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1543                 ret->qid.version, ret->st_mode, ret->st_nlink, ret->st_uid,
1544                 ret->st_gid, ret->st_rdev, ret->st_size, ret->st_blksize,
1545                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1546                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1547                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1548                 ret->st_gen, ret->st_data_version);
1549
1550         p9_free_req(clnt, req);
1551         return ret;
1552
1553 error:
1554         kfree(ret);
1555         return ERR_PTR(err);
1556 }
1557 EXPORT_SYMBOL(p9_client_getattr_dotl);
1558
1559 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1560 {
1561         int ret;
1562
1563         /* NOTE: size shouldn't include its own length */
1564         /* size[2] type[2] dev[4] qid[13] */
1565         /* mode[4] atime[4] mtime[4] length[8]*/
1566         /* name[s] uid[s] gid[s] muid[s] */
1567         ret = 2+4+13+4+4+4+8+2+2+2+2;
1568
1569         if (wst->name)
1570                 ret += strlen(wst->name);
1571         if (wst->uid)
1572                 ret += strlen(wst->uid);
1573         if (wst->gid)
1574                 ret += strlen(wst->gid);
1575         if (wst->muid)
1576                 ret += strlen(wst->muid);
1577
1578         if ((proto_version == p9_proto_2000u) ||
1579                 (proto_version == p9_proto_2000L)) {
1580                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1581                 if (wst->extension)
1582                         ret += strlen(wst->extension);
1583         }
1584
1585         return ret;
1586 }
1587
1588 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1589 {
1590         int err;
1591         struct p9_req_t *req;
1592         struct p9_client *clnt;
1593
1594         err = 0;
1595         clnt = fid->clnt;
1596         wst->size = p9_client_statsize(wst, clnt->proto_version);
1597         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1598         P9_DPRINTK(P9_DEBUG_9P,
1599                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1600                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1601                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1602                 "     uid=%d gid=%d n_muid=%d\n",
1603                 wst->size, wst->type, wst->dev, wst->qid.type,
1604                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1605                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1606                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1607                 wst->n_uid, wst->n_gid, wst->n_muid);
1608
1609         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1610         if (IS_ERR(req)) {
1611                 err = PTR_ERR(req);
1612                 goto error;
1613         }
1614
1615         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1616
1617         p9_free_req(clnt, req);
1618 error:
1619         return err;
1620 }
1621 EXPORT_SYMBOL(p9_client_wstat);
1622
1623 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1624 {
1625         int err;
1626         struct p9_req_t *req;
1627         struct p9_client *clnt;
1628
1629         err = 0;
1630         clnt = fid->clnt;
1631         P9_DPRINTK(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1632         P9_DPRINTK(P9_DEBUG_9P,
1633                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1634                 "    atime_sec=%lld atime_nsec=%lld\n"
1635                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1636                 p9attr->valid, p9attr->mode, p9attr->uid, p9attr->gid,
1637                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1638                 p9attr->mtime_sec, p9attr->mtime_nsec);
1639
1640         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1641
1642         if (IS_ERR(req)) {
1643                 err = PTR_ERR(req);
1644                 goto error;
1645         }
1646         P9_DPRINTK(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1647         p9_free_req(clnt, req);
1648 error:
1649         return err;
1650 }
1651 EXPORT_SYMBOL(p9_client_setattr);
1652
1653 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1654 {
1655         int err;
1656         struct p9_req_t *req;
1657         struct p9_client *clnt;
1658
1659         err = 0;
1660         clnt = fid->clnt;
1661
1662         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1663
1664         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1665         if (IS_ERR(req)) {
1666                 err = PTR_ERR(req);
1667                 goto error;
1668         }
1669
1670         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1671                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1672                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1673         if (err) {
1674                 P9_DUMP_PKT(1, req->rc);
1675                 p9_free_req(clnt, req);
1676                 goto error;
1677         }
1678
1679         P9_DPRINTK(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1680                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1681                 "fsid %llu namelen %ld\n",
1682                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1683                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1684                 sb->fsid, (long int)sb->namelen);
1685
1686         p9_free_req(clnt, req);
1687 error:
1688         return err;
1689 }
1690 EXPORT_SYMBOL(p9_client_statfs);
1691
1692 int p9_client_rename(struct p9_fid *fid,
1693                      struct p9_fid *newdirfid, const char *name)
1694 {
1695         int err;
1696         struct p9_req_t *req;
1697         struct p9_client *clnt;
1698
1699         err = 0;
1700         clnt = fid->clnt;
1701
1702         P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1703                         fid->fid, newdirfid->fid, name);
1704
1705         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1706                         newdirfid->fid, name);
1707         if (IS_ERR(req)) {
1708                 err = PTR_ERR(req);
1709                 goto error;
1710         }
1711
1712         P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1713
1714         p9_free_req(clnt, req);
1715 error:
1716         return err;
1717 }
1718 EXPORT_SYMBOL(p9_client_rename);
1719
1720 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1721                        struct p9_fid *newdirfid, const char *new_name)
1722 {
1723         int err;
1724         struct p9_req_t *req;
1725         struct p9_client *clnt;
1726
1727         err = 0;
1728         clnt = olddirfid->clnt;
1729
1730         P9_DPRINTK(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1731                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1732                    newdirfid->fid, new_name);
1733
1734         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1735                             old_name, newdirfid->fid, new_name);
1736         if (IS_ERR(req)) {
1737                 err = PTR_ERR(req);
1738                 goto error;
1739         }
1740
1741         P9_DPRINTK(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1742                    newdirfid->fid, new_name);
1743
1744         p9_free_req(clnt, req);
1745 error:
1746         return err;
1747 }
1748 EXPORT_SYMBOL(p9_client_renameat);
1749
1750 /*
1751  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1752  */
1753 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1754                                 const char *attr_name, u64 *attr_size)
1755 {
1756         int err;
1757         struct p9_req_t *req;
1758         struct p9_client *clnt;
1759         struct p9_fid *attr_fid;
1760
1761         err = 0;
1762         clnt = file_fid->clnt;
1763         attr_fid = p9_fid_create(clnt);
1764         if (IS_ERR(attr_fid)) {
1765                 err = PTR_ERR(attr_fid);
1766                 attr_fid = NULL;
1767                 goto error;
1768         }
1769         P9_DPRINTK(P9_DEBUG_9P,
1770                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
1771                 file_fid->fid, attr_fid->fid, attr_name);
1772
1773         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
1774                         file_fid->fid, attr_fid->fid, attr_name);
1775         if (IS_ERR(req)) {
1776                 err = PTR_ERR(req);
1777                 goto error;
1778         }
1779         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
1780         if (err) {
1781                 P9_DUMP_PKT(1, req->rc);
1782                 p9_free_req(clnt, req);
1783                 goto clunk_fid;
1784         }
1785         p9_free_req(clnt, req);
1786         P9_DPRINTK(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
1787                 attr_fid->fid, *attr_size);
1788         return attr_fid;
1789 clunk_fid:
1790         p9_client_clunk(attr_fid);
1791         attr_fid = NULL;
1792 error:
1793         if (attr_fid && (attr_fid != file_fid))
1794                 p9_fid_destroy(attr_fid);
1795
1796         return ERR_PTR(err);
1797 }
1798 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
1799
1800 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
1801                         u64 attr_size, int flags)
1802 {
1803         int err;
1804         struct p9_req_t *req;
1805         struct p9_client *clnt;
1806
1807         P9_DPRINTK(P9_DEBUG_9P,
1808                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
1809                 fid->fid, name, (long long)attr_size, flags);
1810         err = 0;
1811         clnt = fid->clnt;
1812         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
1813                         fid->fid, name, attr_size, flags);
1814         if (IS_ERR(req)) {
1815                 err = PTR_ERR(req);
1816                 goto error;
1817         }
1818         P9_DPRINTK(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
1819         p9_free_req(clnt, req);
1820 error:
1821         return err;
1822 }
1823 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
1824
1825 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
1826 {
1827         int err, rsize;
1828         struct p9_client *clnt;
1829         struct p9_req_t *req;
1830         char *dataptr;
1831
1832         P9_DPRINTK(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
1833                                 fid->fid, (long long unsigned) offset, count);
1834
1835         err = 0;
1836         clnt = fid->clnt;
1837
1838         rsize = fid->iounit;
1839         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
1840                 rsize = clnt->msize - P9_READDIRHDRSZ;
1841
1842         if (count < rsize)
1843                 rsize = count;
1844
1845         if ((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
1846                         P9_TRANS_PREF_PAYLOAD_SEP) {
1847                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqF", fid->fid,
1848                                 offset, rsize, data);
1849         } else {
1850                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
1851                                 offset, rsize);
1852         }
1853         if (IS_ERR(req)) {
1854                 err = PTR_ERR(req);
1855                 goto error;
1856         }
1857
1858         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
1859         if (err) {
1860                 P9_DUMP_PKT(1, req->rc);
1861                 goto free_and_error;
1862         }
1863
1864         P9_DPRINTK(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
1865
1866         if (!req->tc->pbuf_size && data)
1867                 memmove(data, dataptr, count);
1868
1869         p9_free_req(clnt, req);
1870         return count;
1871
1872 free_and_error:
1873         p9_free_req(clnt, req);
1874 error:
1875         return err;
1876 }
1877 EXPORT_SYMBOL(p9_client_readdir);
1878
1879 int p9_client_mknod_dotl(struct p9_fid *fid, char *name, int mode,
1880                         dev_t rdev, gid_t gid, struct p9_qid *qid)
1881 {
1882         int err;
1883         struct p9_client *clnt;
1884         struct p9_req_t *req;
1885
1886         err = 0;
1887         clnt = fid->clnt;
1888         P9_DPRINTK(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
1889                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
1890         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddd", fid->fid, name, mode,
1891                 MAJOR(rdev), MINOR(rdev), gid);
1892         if (IS_ERR(req))
1893                 return PTR_ERR(req);
1894
1895         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1896         if (err) {
1897                 P9_DUMP_PKT(1, req->rc);
1898                 goto error;
1899         }
1900         P9_DPRINTK(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
1901                                 (unsigned long long)qid->path, qid->version);
1902
1903 error:
1904         p9_free_req(clnt, req);
1905         return err;
1906
1907 }
1908 EXPORT_SYMBOL(p9_client_mknod_dotl);
1909
1910 int p9_client_mkdir_dotl(struct p9_fid *fid, char *name, int mode,
1911                                 gid_t gid, struct p9_qid *qid)
1912 {
1913         int err;
1914         struct p9_client *clnt;
1915         struct p9_req_t *req;
1916
1917         err = 0;
1918         clnt = fid->clnt;
1919         P9_DPRINTK(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
1920                  fid->fid, name, mode, gid);
1921         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdd", fid->fid, name, mode,
1922                 gid);
1923         if (IS_ERR(req))
1924                 return PTR_ERR(req);
1925
1926         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1927         if (err) {
1928                 P9_DUMP_PKT(1, req->rc);
1929                 goto error;
1930         }
1931         P9_DPRINTK(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
1932                                 (unsigned long long)qid->path, qid->version);
1933
1934 error:
1935         p9_free_req(clnt, req);
1936         return err;
1937
1938 }
1939 EXPORT_SYMBOL(p9_client_mkdir_dotl);
1940
1941 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
1942 {
1943         int err;
1944         struct p9_client *clnt;
1945         struct p9_req_t *req;
1946
1947         err = 0;
1948         clnt = fid->clnt;
1949         P9_DPRINTK(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
1950                         "start %lld length %lld proc_id %d client_id %s\n",
1951                         fid->fid, flock->type, flock->flags, flock->start,
1952                         flock->length, flock->proc_id, flock->client_id);
1953
1954         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
1955                                 flock->flags, flock->start, flock->length,
1956                                         flock->proc_id, flock->client_id);
1957
1958         if (IS_ERR(req))
1959                 return PTR_ERR(req);
1960
1961         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
1962         if (err) {
1963                 P9_DUMP_PKT(1, req->rc);
1964                 goto error;
1965         }
1966         P9_DPRINTK(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
1967 error:
1968         p9_free_req(clnt, req);
1969         return err;
1970
1971 }
1972 EXPORT_SYMBOL(p9_client_lock_dotl);
1973
1974 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
1975 {
1976         int err;
1977         struct p9_client *clnt;
1978         struct p9_req_t *req;
1979
1980         err = 0;
1981         clnt = fid->clnt;
1982         P9_DPRINTK(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
1983                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
1984                 glock->start, glock->length, glock->proc_id, glock->client_id);
1985
1986         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
1987                 glock->start, glock->length, glock->proc_id, glock->client_id);
1988
1989         if (IS_ERR(req))
1990                 return PTR_ERR(req);
1991
1992         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
1993                         &glock->start, &glock->length, &glock->proc_id,
1994                         &glock->client_id);
1995         if (err) {
1996                 P9_DUMP_PKT(1, req->rc);
1997                 goto error;
1998         }
1999         P9_DPRINTK(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2000                 "proc_id %d client_id %s\n", glock->type, glock->start,
2001                 glock->length, glock->proc_id, glock->client_id);
2002 error:
2003         p9_free_req(clnt, req);
2004         return err;
2005 }
2006 EXPORT_SYMBOL(p9_client_getlock_dotl);
2007
2008 int p9_client_readlink(struct p9_fid *fid, char **target)
2009 {
2010         int err;
2011         struct p9_client *clnt;
2012         struct p9_req_t *req;
2013
2014         err = 0;
2015         clnt = fid->clnt;
2016         P9_DPRINTK(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2017
2018         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2019         if (IS_ERR(req))
2020                 return PTR_ERR(req);
2021
2022         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2023         if (err) {
2024                 P9_DUMP_PKT(1, req->rc);
2025                 goto error;
2026         }
2027         P9_DPRINTK(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2028 error:
2029         p9_free_req(clnt, req);
2030         return err;
2031 }
2032 EXPORT_SYMBOL(p9_client_readlink);