Merge tag '9p-for-4.19-2' of git://github.com/martinetd/linux
[muen/linux.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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/poll.h>
32 #include <linux/idr.h>
33 #include <linux/mutex.h>
34 #include <linux/slab.h>
35 #include <linux/sched/signal.h>
36 #include <linux/uaccess.h>
37 #include <linux/uio.h>
38 #include <net/9p/9p.h>
39 #include <linux/parser.h>
40 #include <linux/seq_file.h>
41 #include <net/9p/client.h>
42 #include <net/9p/transport.h>
43 #include "protocol.h"
44
45 #define CREATE_TRACE_POINTS
46 #include <trace/events/9p.h>
47
48 /*
49   * Client Option Parsing (code inspired by NFS code)
50   *  - a little lazy - parse all client options
51   */
52
53 enum {
54         Opt_msize,
55         Opt_trans,
56         Opt_legacy,
57         Opt_version,
58         Opt_err,
59 };
60
61 static const match_table_t tokens = {
62         {Opt_msize, "msize=%u"},
63         {Opt_legacy, "noextend"},
64         {Opt_trans, "trans=%s"},
65         {Opt_version, "version=%s"},
66         {Opt_err, NULL},
67 };
68
69 inline int p9_is_proto_dotl(struct p9_client *clnt)
70 {
71         return clnt->proto_version == p9_proto_2000L;
72 }
73 EXPORT_SYMBOL(p9_is_proto_dotl);
74
75 inline int p9_is_proto_dotu(struct p9_client *clnt)
76 {
77         return clnt->proto_version == p9_proto_2000u;
78 }
79 EXPORT_SYMBOL(p9_is_proto_dotu);
80
81 int p9_show_client_options(struct seq_file *m, struct p9_client *clnt)
82 {
83         if (clnt->msize != 8192)
84                 seq_printf(m, ",msize=%u", clnt->msize);
85         seq_printf(m, ",trans=%s", clnt->trans_mod->name);
86
87         switch (clnt->proto_version) {
88         case p9_proto_legacy:
89                 seq_puts(m, ",noextend");
90                 break;
91         case p9_proto_2000u:
92                 seq_puts(m, ",version=9p2000.u");
93                 break;
94         case p9_proto_2000L:
95                 /* Default */
96                 break;
97         }
98
99         if (clnt->trans_mod->show_options)
100                 return clnt->trans_mod->show_options(m, clnt);
101         return 0;
102 }
103 EXPORT_SYMBOL(p9_show_client_options);
104
105 /*
106  * Some error codes are taken directly from the server replies,
107  * make sure they are valid.
108  */
109 static int safe_errno(int err)
110 {
111         if ((err > 0) || (err < -MAX_ERRNO)) {
112                 p9_debug(P9_DEBUG_ERROR, "Invalid error code %d\n", err);
113                 return -EPROTO;
114         }
115         return err;
116 }
117
118
119 /* Interpret mount option for protocol version */
120 static int get_protocol_version(char *s)
121 {
122         int version = -EINVAL;
123
124         if (!strcmp(s, "9p2000")) {
125                 version = p9_proto_legacy;
126                 p9_debug(P9_DEBUG_9P, "Protocol version: Legacy\n");
127         } else if (!strcmp(s, "9p2000.u")) {
128                 version = p9_proto_2000u;
129                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.u\n");
130         } else if (!strcmp(s, "9p2000.L")) {
131                 version = p9_proto_2000L;
132                 p9_debug(P9_DEBUG_9P, "Protocol version: 9P2000.L\n");
133         } else
134                 pr_info("Unknown protocol version %s\n", s);
135
136         return version;
137 }
138
139 /**
140  * parse_options - parse mount options into client structure
141  * @opts: options string passed from mount
142  * @clnt: existing v9fs client information
143  *
144  * Return 0 upon success, -ERRNO upon failure
145  */
146
147 static int parse_opts(char *opts, struct p9_client *clnt)
148 {
149         char *options, *tmp_options;
150         char *p;
151         substring_t args[MAX_OPT_ARGS];
152         int option;
153         char *s;
154         int ret = 0;
155
156         clnt->proto_version = p9_proto_2000L;
157         clnt->msize = 8192;
158
159         if (!opts)
160                 return 0;
161
162         tmp_options = kstrdup(opts, GFP_KERNEL);
163         if (!tmp_options) {
164                 p9_debug(P9_DEBUG_ERROR,
165                          "failed to allocate copy of option string\n");
166                 return -ENOMEM;
167         }
168         options = tmp_options;
169
170         while ((p = strsep(&options, ",")) != NULL) {
171                 int token, r;
172                 if (!*p)
173                         continue;
174                 token = match_token(p, tokens, args);
175                 switch (token) {
176                 case Opt_msize:
177                         r = match_int(&args[0], &option);
178                         if (r < 0) {
179                                 p9_debug(P9_DEBUG_ERROR,
180                                          "integer field, but no integer?\n");
181                                 ret = r;
182                                 continue;
183                         }
184                         clnt->msize = option;
185                         break;
186                 case Opt_trans:
187                         s = match_strdup(&args[0]);
188                         if (!s) {
189                                 ret = -ENOMEM;
190                                 p9_debug(P9_DEBUG_ERROR,
191                                          "problem allocating copy of trans arg\n");
192                                 goto free_and_return;
193                         }
194
195                         v9fs_put_trans(clnt->trans_mod);
196                         clnt->trans_mod = v9fs_get_trans_by_name(s);
197                         if (clnt->trans_mod == NULL) {
198                                 pr_info("Could not find request transport: %s\n",
199                                         s);
200                                 ret = -EINVAL;
201                         }
202                         kfree(s);
203                         break;
204                 case Opt_legacy:
205                         clnt->proto_version = p9_proto_legacy;
206                         break;
207                 case Opt_version:
208                         s = match_strdup(&args[0]);
209                         if (!s) {
210                                 ret = -ENOMEM;
211                                 p9_debug(P9_DEBUG_ERROR,
212                                          "problem allocating copy of version arg\n");
213                                 goto free_and_return;
214                         }
215                         r = get_protocol_version(s);
216                         if (r < 0)
217                                 ret = r;
218                         else
219                                 clnt->proto_version = r;
220                         kfree(s);
221                         break;
222                 default:
223                         continue;
224                 }
225         }
226
227 free_and_return:
228         if (ret)
229                 v9fs_put_trans(clnt->trans_mod);
230         kfree(tmp_options);
231         return ret;
232 }
233
234 static struct p9_fcall *p9_fcall_alloc(int alloc_msize)
235 {
236         struct p9_fcall *fc;
237         fc = kmalloc(sizeof(struct p9_fcall) + alloc_msize, GFP_NOFS);
238         if (!fc)
239                 return NULL;
240         fc->capacity = alloc_msize;
241         fc->sdata = (char *) fc + sizeof(struct p9_fcall);
242         return fc;
243 }
244
245 /**
246  * p9_tag_alloc - lookup/allocate a request by tag
247  * @c: client session to lookup tag within
248  * @tag: numeric id for transaction
249  *
250  * this is a simple array lookup, but will grow the
251  * request_slots as necessary to accommodate transaction
252  * ids which did not previously have a slot.
253  *
254  * this code relies on the client spinlock to manage locks, its
255  * possible we should switch to something else, but I'd rather
256  * stick with something low-overhead for the common case.
257  *
258  */
259
260 static struct p9_req_t *
261 p9_tag_alloc(struct p9_client *c, u16 tag, unsigned int max_size)
262 {
263         unsigned long flags;
264         int row, col;
265         struct p9_req_t *req;
266         int alloc_msize = min(c->msize, max_size);
267
268         /* This looks up the original request by tag so we know which
269          * buffer to read the data into */
270         tag++;
271
272         if (tag >= c->max_tag) {
273                 spin_lock_irqsave(&c->lock, flags);
274                 /* check again since original check was outside of lock */
275                 while (tag >= c->max_tag) {
276                         row = (tag / P9_ROW_MAXTAG);
277                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
278                                         sizeof(struct p9_req_t), GFP_ATOMIC);
279
280                         if (!c->reqs[row]) {
281                                 pr_err("Couldn't grow tag array\n");
282                                 spin_unlock_irqrestore(&c->lock, flags);
283                                 return ERR_PTR(-ENOMEM);
284                         }
285                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
286                                 req = &c->reqs[row][col];
287                                 req->status = REQ_STATUS_IDLE;
288                                 init_waitqueue_head(&req->wq);
289                         }
290                         c->max_tag += P9_ROW_MAXTAG;
291                 }
292                 spin_unlock_irqrestore(&c->lock, flags);
293         }
294         row = tag / P9_ROW_MAXTAG;
295         col = tag % P9_ROW_MAXTAG;
296
297         req = &c->reqs[row][col];
298         if (!req->tc)
299                 req->tc = p9_fcall_alloc(alloc_msize);
300         if (!req->rc)
301                 req->rc = p9_fcall_alloc(alloc_msize);
302         if (!req->tc || !req->rc)
303                 goto grow_failed;
304
305         p9pdu_reset(req->tc);
306         p9pdu_reset(req->rc);
307
308         req->tc->tag = tag-1;
309         req->status = REQ_STATUS_ALLOC;
310
311         return req;
312
313 grow_failed:
314         pr_err("Couldn't grow tag array\n");
315         kfree(req->tc);
316         kfree(req->rc);
317         req->tc = req->rc = NULL;
318         return ERR_PTR(-ENOMEM);
319 }
320
321 /**
322  * p9_tag_lookup - lookup a request by tag
323  * @c: client session to lookup tag within
324  * @tag: numeric id for transaction
325  *
326  */
327
328 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
329 {
330         int row, col;
331
332         /* This looks up the original request by tag so we know which
333          * buffer to read the data into */
334         tag++;
335
336         if (tag >= c->max_tag)
337                 return NULL;
338
339         row = tag / P9_ROW_MAXTAG;
340         col = tag % P9_ROW_MAXTAG;
341
342         return &c->reqs[row][col];
343 }
344 EXPORT_SYMBOL(p9_tag_lookup);
345
346 /**
347  * p9_tag_init - setup tags structure and contents
348  * @c:  v9fs client struct
349  *
350  * This initializes the tags structure for each client instance.
351  *
352  */
353
354 static int p9_tag_init(struct p9_client *c)
355 {
356         int err = 0;
357
358         c->tagpool = p9_idpool_create();
359         if (IS_ERR(c->tagpool)) {
360                 err = PTR_ERR(c->tagpool);
361                 goto error;
362         }
363         err = p9_idpool_get(c->tagpool); /* reserve tag 0 */
364         if (err < 0) {
365                 p9_idpool_destroy(c->tagpool);
366                 goto error;
367         }
368         c->max_tag = 0;
369 error:
370         return err;
371 }
372
373 /**
374  * p9_tag_cleanup - cleans up tags structure and reclaims resources
375  * @c:  v9fs client struct
376  *
377  * This frees resources associated with the tags structure
378  *
379  */
380 static void p9_tag_cleanup(struct p9_client *c)
381 {
382         int row, col;
383
384         /* check to insure all requests are idle */
385         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
386                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
387                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
388                                 p9_debug(P9_DEBUG_MUX,
389                                          "Attempting to cleanup non-free tag %d,%d\n",
390                                          row, col);
391                                 /* TODO: delay execution of cleanup */
392                                 return;
393                         }
394                 }
395         }
396
397         if (c->tagpool) {
398                 p9_idpool_put(0, c->tagpool); /* free reserved tag 0 */
399                 p9_idpool_destroy(c->tagpool);
400         }
401
402         /* free requests associated with tags */
403         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
404                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
405                         kfree(c->reqs[row][col].tc);
406                         kfree(c->reqs[row][col].rc);
407                 }
408                 kfree(c->reqs[row]);
409         }
410         c->max_tag = 0;
411 }
412
413 /**
414  * p9_free_req - free a request and clean-up as necessary
415  * c: client state
416  * r: request to release
417  *
418  */
419
420 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
421 {
422         int tag = r->tc->tag;
423         p9_debug(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
424
425         r->status = REQ_STATUS_IDLE;
426         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
427                 p9_idpool_put(tag, c->tagpool);
428 }
429
430 /**
431  * p9_client_cb - call back from transport to client
432  * c: client state
433  * req: request received
434  *
435  */
436 void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status)
437 {
438         p9_debug(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
439
440         /*
441          * This barrier is needed to make sure any change made to req before
442          * the status change is visible to another thread
443          */
444         smp_wmb();
445         req->status = status;
446
447         wake_up(&req->wq);
448         p9_debug(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
449 }
450 EXPORT_SYMBOL(p9_client_cb);
451
452 /**
453  * p9_parse_header - parse header arguments out of a packet
454  * @pdu: packet to parse
455  * @size: size of packet
456  * @type: type of request
457  * @tag: tag of packet
458  * @rewind: set if we need to rewind offset afterwards
459  */
460
461 int
462 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
463                                                                 int rewind)
464 {
465         int8_t r_type;
466         int16_t r_tag;
467         int32_t r_size;
468         int offset = pdu->offset;
469         int err;
470
471         pdu->offset = 0;
472
473         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
474         if (err)
475                 goto rewind_and_exit;
476
477         if (type)
478                 *type = r_type;
479         if (tag)
480                 *tag = r_tag;
481         if (size)
482                 *size = r_size;
483
484         if (pdu->size != r_size || r_size < 7) {
485                 err = -EINVAL;
486                 goto rewind_and_exit;
487         }
488
489         pdu->id = r_type;
490         pdu->tag = r_tag;
491
492         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
493                  pdu->size, pdu->id, pdu->tag);
494
495 rewind_and_exit:
496         if (rewind)
497                 pdu->offset = offset;
498         return err;
499 }
500 EXPORT_SYMBOL(p9_parse_header);
501
502 /**
503  * p9_check_errors - check 9p packet for error return and process it
504  * @c: current client instance
505  * @req: request to parse and check for error conditions
506  *
507  * returns error code if one is discovered, otherwise returns 0
508  *
509  * this will have to be more complicated if we have multiple
510  * error packet types
511  */
512
513 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
514 {
515         int8_t type;
516         int err;
517         int ecode;
518
519         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
520         if (req->rc->size >= c->msize) {
521                 p9_debug(P9_DEBUG_ERROR,
522                          "requested packet size too big: %d\n",
523                          req->rc->size);
524                 return -EIO;
525         }
526         /*
527          * dump the response from server
528          * This should be after check errors which poplulate pdu_fcall.
529          */
530         trace_9p_protocol_dump(c, req->rc);
531         if (err) {
532                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
533                 return err;
534         }
535         if (type != P9_RERROR && type != P9_RLERROR)
536                 return 0;
537
538         if (!p9_is_proto_dotl(c)) {
539                 char *ename;
540                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
541                                   &ename, &ecode);
542                 if (err)
543                         goto out_err;
544
545                 if (p9_is_proto_dotu(c) && ecode < 512)
546                         err = -ecode;
547
548                 if (!err) {
549                         err = p9_errstr2errno(ename, strlen(ename));
550
551                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
552                                  -ecode, ename);
553                 }
554                 kfree(ename);
555         } else {
556                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
557                 err = -ecode;
558
559                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
560         }
561
562         return err;
563
564 out_err:
565         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
566
567         return err;
568 }
569
570 /**
571  * p9_check_zc_errors - check 9p packet for error return and process it
572  * @c: current client instance
573  * @req: request to parse and check for error conditions
574  * @in_hdrlen: Size of response protocol buffer.
575  *
576  * returns error code if one is discovered, otherwise returns 0
577  *
578  * this will have to be more complicated if we have multiple
579  * error packet types
580  */
581
582 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
583                               struct iov_iter *uidata, int in_hdrlen)
584 {
585         int err;
586         int ecode;
587         int8_t type;
588         char *ename = NULL;
589
590         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
591         /*
592          * dump the response from server
593          * This should be after parse_header which poplulate pdu_fcall.
594          */
595         trace_9p_protocol_dump(c, req->rc);
596         if (err) {
597                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
598                 return err;
599         }
600
601         if (type != P9_RERROR && type != P9_RLERROR)
602                 return 0;
603
604         if (!p9_is_proto_dotl(c)) {
605                 /* Error is reported in string format */
606                 int len;
607                 /* 7 = header size for RERROR; */
608                 int inline_len = in_hdrlen - 7;
609
610                 len =  req->rc->size - req->rc->offset;
611                 if (len > (P9_ZC_HDR_SZ - 7)) {
612                         err = -EFAULT;
613                         goto out_err;
614                 }
615
616                 ename = &req->rc->sdata[req->rc->offset];
617                 if (len > inline_len) {
618                         /* We have error in external buffer */
619                         if (!copy_from_iter_full(ename + inline_len,
620                                              len - inline_len, uidata)) {
621                                 err = -EFAULT;
622                                 goto out_err;
623                         }
624                 }
625                 ename = NULL;
626                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
627                                   &ename, &ecode);
628                 if (err)
629                         goto out_err;
630
631                 if (p9_is_proto_dotu(c) && ecode < 512)
632                         err = -ecode;
633
634                 if (!err) {
635                         err = p9_errstr2errno(ename, strlen(ename));
636
637                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
638                                  -ecode, ename);
639                 }
640                 kfree(ename);
641         } else {
642                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
643                 err = -ecode;
644
645                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
646         }
647         return err;
648
649 out_err:
650         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
651         return err;
652 }
653
654 static struct p9_req_t *
655 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
656
657 /**
658  * p9_client_flush - flush (cancel) a request
659  * @c: client state
660  * @oldreq: request to cancel
661  *
662  * This sents a flush for a particular request and links
663  * the flush request to the original request.  The current
664  * code only supports a single flush request although the protocol
665  * allows for multiple flush requests to be sent for a single request.
666  *
667  */
668
669 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
670 {
671         struct p9_req_t *req;
672         int16_t oldtag;
673         int err;
674
675         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
676         if (err)
677                 return err;
678
679         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
680
681         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
682         if (IS_ERR(req))
683                 return PTR_ERR(req);
684
685         /*
686          * if we haven't received a response for oldreq,
687          * remove it from the list
688          */
689         if (oldreq->status == REQ_STATUS_SENT)
690                 if (c->trans_mod->cancelled)
691                         c->trans_mod->cancelled(c, oldreq);
692
693         p9_free_req(c, req);
694         return 0;
695 }
696
697 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
698                                               int8_t type, int req_size,
699                                               const char *fmt, va_list ap)
700 {
701         int tag, err;
702         struct p9_req_t *req;
703
704         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
705
706         /* we allow for any status other than disconnected */
707         if (c->status == Disconnected)
708                 return ERR_PTR(-EIO);
709
710         /* if status is begin_disconnected we allow only clunk request */
711         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
712                 return ERR_PTR(-EIO);
713
714         tag = P9_NOTAG;
715         if (type != P9_TVERSION) {
716                 tag = p9_idpool_get(c->tagpool);
717                 if (tag < 0)
718                         return ERR_PTR(-ENOMEM);
719         }
720
721         req = p9_tag_alloc(c, tag, req_size);
722         if (IS_ERR(req))
723                 return req;
724
725         /* marshall the data */
726         p9pdu_prepare(req->tc, tag, type);
727         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
728         if (err)
729                 goto reterr;
730         p9pdu_finalize(c, req->tc);
731         trace_9p_client_req(c, type, tag);
732         return req;
733 reterr:
734         p9_free_req(c, req);
735         return ERR_PTR(err);
736 }
737
738 /**
739  * p9_client_rpc - issue a request and wait for a response
740  * @c: client session
741  * @type: type of request
742  * @fmt: protocol format string (see protocol.c)
743  *
744  * Returns request structure (which client must free using p9_free_req)
745  */
746
747 static struct p9_req_t *
748 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
749 {
750         va_list ap;
751         int sigpending, err;
752         unsigned long flags;
753         struct p9_req_t *req;
754
755         va_start(ap, fmt);
756         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
757         va_end(ap);
758         if (IS_ERR(req))
759                 return req;
760
761         if (signal_pending(current)) {
762                 sigpending = 1;
763                 clear_thread_flag(TIF_SIGPENDING);
764         } else
765                 sigpending = 0;
766
767         err = c->trans_mod->request(c, req);
768         if (err < 0) {
769                 if (err != -ERESTARTSYS && err != -EFAULT)
770                         c->status = Disconnected;
771                 goto recalc_sigpending;
772         }
773 again:
774         /* Wait for the response */
775         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
776
777         /*
778          * Make sure our req is coherent with regard to updates in other
779          * threads - echoes to wmb() in the callback
780          */
781         smp_rmb();
782
783         if ((err == -ERESTARTSYS) && (c->status == Connected)
784                                   && (type == P9_TFLUSH)) {
785                 sigpending = 1;
786                 clear_thread_flag(TIF_SIGPENDING);
787                 goto again;
788         }
789
790         if (req->status == REQ_STATUS_ERROR) {
791                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
792                 err = req->t_err;
793         }
794         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
795                 p9_debug(P9_DEBUG_MUX, "flushing\n");
796                 sigpending = 1;
797                 clear_thread_flag(TIF_SIGPENDING);
798
799                 if (c->trans_mod->cancel(c, req))
800                         p9_client_flush(c, req);
801
802                 /* if we received the response anyway, don't signal error */
803                 if (req->status == REQ_STATUS_RCVD)
804                         err = 0;
805         }
806 recalc_sigpending:
807         if (sigpending) {
808                 spin_lock_irqsave(&current->sighand->siglock, flags);
809                 recalc_sigpending();
810                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
811         }
812         if (err < 0)
813                 goto reterr;
814
815         err = p9_check_errors(c, req);
816         trace_9p_client_res(c, type, req->rc->tag, err);
817         if (!err)
818                 return req;
819 reterr:
820         p9_free_req(c, req);
821         return ERR_PTR(safe_errno(err));
822 }
823
824 /**
825  * p9_client_zc_rpc - issue a request and wait for a response
826  * @c: client session
827  * @type: type of request
828  * @uidata: destination for zero copy read
829  * @uodata: source for zero copy write
830  * @inlen: read buffer size
831  * @olen: write buffer size
832  * @hdrlen: reader header size, This is the size of response protocol data
833  * @fmt: protocol format string (see protocol.c)
834  *
835  * Returns request structure (which client must free using p9_free_req)
836  */
837 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
838                                          struct iov_iter *uidata,
839                                          struct iov_iter *uodata,
840                                          int inlen, int olen, int in_hdrlen,
841                                          const char *fmt, ...)
842 {
843         va_list ap;
844         int sigpending, err;
845         unsigned long flags;
846         struct p9_req_t *req;
847
848         va_start(ap, fmt);
849         /*
850          * We allocate a inline protocol data of only 4k bytes.
851          * The actual content is passed in zero-copy fashion.
852          */
853         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
854         va_end(ap);
855         if (IS_ERR(req))
856                 return req;
857
858         if (signal_pending(current)) {
859                 sigpending = 1;
860                 clear_thread_flag(TIF_SIGPENDING);
861         } else
862                 sigpending = 0;
863
864         err = c->trans_mod->zc_request(c, req, uidata, uodata,
865                                        inlen, olen, in_hdrlen);
866         if (err < 0) {
867                 if (err == -EIO)
868                         c->status = Disconnected;
869                 if (err != -ERESTARTSYS)
870                         goto recalc_sigpending;
871         }
872         if (req->status == REQ_STATUS_ERROR) {
873                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
874                 err = req->t_err;
875         }
876         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
877                 p9_debug(P9_DEBUG_MUX, "flushing\n");
878                 sigpending = 1;
879                 clear_thread_flag(TIF_SIGPENDING);
880
881                 if (c->trans_mod->cancel(c, req))
882                         p9_client_flush(c, req);
883
884                 /* if we received the response anyway, don't signal error */
885                 if (req->status == REQ_STATUS_RCVD)
886                         err = 0;
887         }
888 recalc_sigpending:
889         if (sigpending) {
890                 spin_lock_irqsave(&current->sighand->siglock, flags);
891                 recalc_sigpending();
892                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
893         }
894         if (err < 0)
895                 goto reterr;
896
897         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
898         trace_9p_client_res(c, type, req->rc->tag, err);
899         if (!err)
900                 return req;
901 reterr:
902         p9_free_req(c, req);
903         return ERR_PTR(safe_errno(err));
904 }
905
906 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
907 {
908         int ret;
909         struct p9_fid *fid;
910
911         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
912         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
913         if (!fid)
914                 return NULL;
915
916         memset(&fid->qid, 0, sizeof(struct p9_qid));
917         fid->mode = -1;
918         fid->uid = current_fsuid();
919         fid->clnt = clnt;
920         fid->rdir = NULL;
921         fid->fid = 0;
922
923         idr_preload(GFP_KERNEL);
924         spin_lock_irq(&clnt->lock);
925         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
926                             GFP_NOWAIT);
927         spin_unlock_irq(&clnt->lock);
928         idr_preload_end();
929
930         if (!ret)
931                 return fid;
932
933         kfree(fid);
934         return NULL;
935 }
936
937 static void p9_fid_destroy(struct p9_fid *fid)
938 {
939         struct p9_client *clnt;
940         unsigned long flags;
941
942         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
943         clnt = fid->clnt;
944         spin_lock_irqsave(&clnt->lock, flags);
945         idr_remove(&clnt->fids, fid->fid);
946         spin_unlock_irqrestore(&clnt->lock, flags);
947         kfree(fid->rdir);
948         kfree(fid);
949 }
950
951 static int p9_client_version(struct p9_client *c)
952 {
953         int err = 0;
954         struct p9_req_t *req;
955         char *version = NULL;
956         int msize;
957
958         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
959                  c->msize, c->proto_version);
960
961         switch (c->proto_version) {
962         case p9_proto_2000L:
963                 req = p9_client_rpc(c, P9_TVERSION, "ds",
964                                         c->msize, "9P2000.L");
965                 break;
966         case p9_proto_2000u:
967                 req = p9_client_rpc(c, P9_TVERSION, "ds",
968                                         c->msize, "9P2000.u");
969                 break;
970         case p9_proto_legacy:
971                 req = p9_client_rpc(c, P9_TVERSION, "ds",
972                                         c->msize, "9P2000");
973                 break;
974         default:
975                 return -EINVAL;
976         }
977
978         if (IS_ERR(req))
979                 return PTR_ERR(req);
980
981         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
982         if (err) {
983                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
984                 trace_9p_protocol_dump(c, req->rc);
985                 goto error;
986         }
987
988         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
989         if (!strncmp(version, "9P2000.L", 8))
990                 c->proto_version = p9_proto_2000L;
991         else if (!strncmp(version, "9P2000.u", 8))
992                 c->proto_version = p9_proto_2000u;
993         else if (!strncmp(version, "9P2000", 6))
994                 c->proto_version = p9_proto_legacy;
995         else {
996                 err = -EREMOTEIO;
997                 goto error;
998         }
999
1000         if (msize < c->msize)
1001                 c->msize = msize;
1002
1003 error:
1004         kfree(version);
1005         p9_free_req(c, req);
1006
1007         return err;
1008 }
1009
1010 struct p9_client *p9_client_create(const char *dev_name, char *options)
1011 {
1012         int err;
1013         struct p9_client *clnt;
1014         char *client_id;
1015
1016         err = 0;
1017         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1018         if (!clnt)
1019                 return ERR_PTR(-ENOMEM);
1020
1021         clnt->trans_mod = NULL;
1022         clnt->trans = NULL;
1023
1024         client_id = utsname()->nodename;
1025         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1026
1027         spin_lock_init(&clnt->lock);
1028         idr_init(&clnt->fids);
1029
1030         err = p9_tag_init(clnt);
1031         if (err < 0)
1032                 goto free_client;
1033
1034         err = parse_opts(options, clnt);
1035         if (err < 0)
1036                 goto destroy_tagpool;
1037
1038         if (!clnt->trans_mod)
1039                 clnt->trans_mod = v9fs_get_default_trans();
1040
1041         if (clnt->trans_mod == NULL) {
1042                 err = -EPROTONOSUPPORT;
1043                 p9_debug(P9_DEBUG_ERROR,
1044                          "No transport defined or default transport\n");
1045                 goto destroy_tagpool;
1046         }
1047
1048         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1049                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1050
1051         err = clnt->trans_mod->create(clnt, dev_name, options);
1052         if (err)
1053                 goto put_trans;
1054
1055         if (clnt->msize > clnt->trans_mod->maxsize)
1056                 clnt->msize = clnt->trans_mod->maxsize;
1057
1058         err = p9_client_version(clnt);
1059         if (err)
1060                 goto close_trans;
1061
1062         return clnt;
1063
1064 close_trans:
1065         clnt->trans_mod->close(clnt);
1066 put_trans:
1067         v9fs_put_trans(clnt->trans_mod);
1068 destroy_tagpool:
1069         p9_idpool_destroy(clnt->tagpool);
1070 free_client:
1071         kfree(clnt);
1072         return ERR_PTR(err);
1073 }
1074 EXPORT_SYMBOL(p9_client_create);
1075
1076 void p9_client_destroy(struct p9_client *clnt)
1077 {
1078         struct p9_fid *fid;
1079         int id;
1080
1081         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1082
1083         if (clnt->trans_mod)
1084                 clnt->trans_mod->close(clnt);
1085
1086         v9fs_put_trans(clnt->trans_mod);
1087
1088         idr_for_each_entry(&clnt->fids, fid, id) {
1089                 pr_info("Found fid %d not clunked\n", fid->fid);
1090                 p9_fid_destroy(fid);
1091         }
1092
1093         p9_tag_cleanup(clnt);
1094
1095         kfree(clnt);
1096 }
1097 EXPORT_SYMBOL(p9_client_destroy);
1098
1099 void p9_client_disconnect(struct p9_client *clnt)
1100 {
1101         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1102         clnt->status = Disconnected;
1103 }
1104 EXPORT_SYMBOL(p9_client_disconnect);
1105
1106 void p9_client_begin_disconnect(struct p9_client *clnt)
1107 {
1108         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1109         clnt->status = BeginDisconnect;
1110 }
1111 EXPORT_SYMBOL(p9_client_begin_disconnect);
1112
1113 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1114         const char *uname, kuid_t n_uname, const char *aname)
1115 {
1116         int err = 0;
1117         struct p9_req_t *req;
1118         struct p9_fid *fid;
1119         struct p9_qid qid;
1120
1121
1122         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1123                  afid ? afid->fid : -1, uname, aname);
1124         fid = p9_fid_create(clnt);
1125         if (!fid) {
1126                 err = -ENOMEM;
1127                 goto error;
1128         }
1129         fid->uid = n_uname;
1130
1131         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1132                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1133         if (IS_ERR(req)) {
1134                 err = PTR_ERR(req);
1135                 goto error;
1136         }
1137
1138         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1139         if (err) {
1140                 trace_9p_protocol_dump(clnt, req->rc);
1141                 p9_free_req(clnt, req);
1142                 goto error;
1143         }
1144
1145         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1146                  qid.type, (unsigned long long)qid.path, qid.version);
1147
1148         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1149
1150         p9_free_req(clnt, req);
1151         return fid;
1152
1153 error:
1154         if (fid)
1155                 p9_fid_destroy(fid);
1156         return ERR_PTR(err);
1157 }
1158 EXPORT_SYMBOL(p9_client_attach);
1159
1160 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1161                 const unsigned char * const *wnames, int clone)
1162 {
1163         int err;
1164         struct p9_client *clnt;
1165         struct p9_fid *fid;
1166         struct p9_qid *wqids;
1167         struct p9_req_t *req;
1168         uint16_t nwqids, count;
1169
1170         err = 0;
1171         wqids = NULL;
1172         clnt = oldfid->clnt;
1173         if (clone) {
1174                 fid = p9_fid_create(clnt);
1175                 if (!fid) {
1176                         err = -ENOMEM;
1177                         goto error;
1178                 }
1179
1180                 fid->uid = oldfid->uid;
1181         } else
1182                 fid = oldfid;
1183
1184
1185         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1186                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1187
1188         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1189                                                                 nwname, wnames);
1190         if (IS_ERR(req)) {
1191                 err = PTR_ERR(req);
1192                 goto error;
1193         }
1194
1195         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1196         if (err) {
1197                 trace_9p_protocol_dump(clnt, req->rc);
1198                 p9_free_req(clnt, req);
1199                 goto clunk_fid;
1200         }
1201         p9_free_req(clnt, req);
1202
1203         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1204
1205         if (nwqids != nwname) {
1206                 err = -ENOENT;
1207                 goto clunk_fid;
1208         }
1209
1210         for (count = 0; count < nwqids; count++)
1211                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1212                         count, wqids[count].type,
1213                         (unsigned long long)wqids[count].path,
1214                         wqids[count].version);
1215
1216         if (nwname)
1217                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1218         else
1219                 fid->qid = oldfid->qid;
1220
1221         kfree(wqids);
1222         return fid;
1223
1224 clunk_fid:
1225         kfree(wqids);
1226         p9_client_clunk(fid);
1227         fid = NULL;
1228
1229 error:
1230         if (fid && (fid != oldfid))
1231                 p9_fid_destroy(fid);
1232
1233         return ERR_PTR(err);
1234 }
1235 EXPORT_SYMBOL(p9_client_walk);
1236
1237 int p9_client_open(struct p9_fid *fid, int mode)
1238 {
1239         int err;
1240         struct p9_client *clnt;
1241         struct p9_req_t *req;
1242         struct p9_qid qid;
1243         int iounit;
1244
1245         clnt = fid->clnt;
1246         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1247                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1248         err = 0;
1249
1250         if (fid->mode != -1)
1251                 return -EINVAL;
1252
1253         if (p9_is_proto_dotl(clnt))
1254                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1255         else
1256                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1257         if (IS_ERR(req)) {
1258                 err = PTR_ERR(req);
1259                 goto error;
1260         }
1261
1262         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1263         if (err) {
1264                 trace_9p_protocol_dump(clnt, req->rc);
1265                 goto free_and_error;
1266         }
1267
1268         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1269                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1270                 (unsigned long long)qid.path, qid.version, iounit);
1271
1272         fid->mode = mode;
1273         fid->iounit = iounit;
1274
1275 free_and_error:
1276         p9_free_req(clnt, req);
1277 error:
1278         return err;
1279 }
1280 EXPORT_SYMBOL(p9_client_open);
1281
1282 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1283                 kgid_t gid, struct p9_qid *qid)
1284 {
1285         int err = 0;
1286         struct p9_client *clnt;
1287         struct p9_req_t *req;
1288         int iounit;
1289
1290         p9_debug(P9_DEBUG_9P,
1291                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1292                         ofid->fid, name, flags, mode,
1293                         from_kgid(&init_user_ns, gid));
1294         clnt = ofid->clnt;
1295
1296         if (ofid->mode != -1)
1297                 return -EINVAL;
1298
1299         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1300                         mode, gid);
1301         if (IS_ERR(req)) {
1302                 err = PTR_ERR(req);
1303                 goto error;
1304         }
1305
1306         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1307         if (err) {
1308                 trace_9p_protocol_dump(clnt, req->rc);
1309                 goto free_and_error;
1310         }
1311
1312         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1313                         qid->type,
1314                         (unsigned long long)qid->path,
1315                         qid->version, iounit);
1316
1317         ofid->mode = mode;
1318         ofid->iounit = iounit;
1319
1320 free_and_error:
1321         p9_free_req(clnt, req);
1322 error:
1323         return err;
1324 }
1325 EXPORT_SYMBOL(p9_client_create_dotl);
1326
1327 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1328                      char *extension)
1329 {
1330         int err;
1331         struct p9_client *clnt;
1332         struct p9_req_t *req;
1333         struct p9_qid qid;
1334         int iounit;
1335
1336         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1337                                                 fid->fid, name, perm, mode);
1338         err = 0;
1339         clnt = fid->clnt;
1340
1341         if (fid->mode != -1)
1342                 return -EINVAL;
1343
1344         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1345                                 mode, extension);
1346         if (IS_ERR(req)) {
1347                 err = PTR_ERR(req);
1348                 goto error;
1349         }
1350
1351         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1352         if (err) {
1353                 trace_9p_protocol_dump(clnt, req->rc);
1354                 goto free_and_error;
1355         }
1356
1357         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1358                                 qid.type,
1359                                 (unsigned long long)qid.path,
1360                                 qid.version, iounit);
1361
1362         fid->mode = mode;
1363         fid->iounit = iounit;
1364
1365 free_and_error:
1366         p9_free_req(clnt, req);
1367 error:
1368         return err;
1369 }
1370 EXPORT_SYMBOL(p9_client_fcreate);
1371
1372 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1373                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1374 {
1375         int err = 0;
1376         struct p9_client *clnt;
1377         struct p9_req_t *req;
1378
1379         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1380                         dfid->fid, name, symtgt);
1381         clnt = dfid->clnt;
1382
1383         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1384                         gid);
1385         if (IS_ERR(req)) {
1386                 err = PTR_ERR(req);
1387                 goto error;
1388         }
1389
1390         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1391         if (err) {
1392                 trace_9p_protocol_dump(clnt, req->rc);
1393                 goto free_and_error;
1394         }
1395
1396         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1397                         qid->type, (unsigned long long)qid->path, qid->version);
1398
1399 free_and_error:
1400         p9_free_req(clnt, req);
1401 error:
1402         return err;
1403 }
1404 EXPORT_SYMBOL(p9_client_symlink);
1405
1406 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1407 {
1408         struct p9_client *clnt;
1409         struct p9_req_t *req;
1410
1411         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1412                         dfid->fid, oldfid->fid, newname);
1413         clnt = dfid->clnt;
1414         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1415                         newname);
1416         if (IS_ERR(req))
1417                 return PTR_ERR(req);
1418
1419         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1420         p9_free_req(clnt, req);
1421         return 0;
1422 }
1423 EXPORT_SYMBOL(p9_client_link);
1424
1425 int p9_client_fsync(struct p9_fid *fid, int datasync)
1426 {
1427         int err;
1428         struct p9_client *clnt;
1429         struct p9_req_t *req;
1430
1431         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1432                         fid->fid, datasync);
1433         err = 0;
1434         clnt = fid->clnt;
1435
1436         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1437         if (IS_ERR(req)) {
1438                 err = PTR_ERR(req);
1439                 goto error;
1440         }
1441
1442         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1443
1444         p9_free_req(clnt, req);
1445
1446 error:
1447         return err;
1448 }
1449 EXPORT_SYMBOL(p9_client_fsync);
1450
1451 int p9_client_clunk(struct p9_fid *fid)
1452 {
1453         int err;
1454         struct p9_client *clnt;
1455         struct p9_req_t *req;
1456         int retries = 0;
1457
1458         if (!fid) {
1459                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1460                         __func__, task_pid_nr(current));
1461                 dump_stack();
1462                 return 0;
1463         }
1464
1465 again:
1466         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1467                                                                 retries);
1468         err = 0;
1469         clnt = fid->clnt;
1470
1471         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1472         if (IS_ERR(req)) {
1473                 err = PTR_ERR(req);
1474                 goto error;
1475         }
1476
1477         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1478
1479         p9_free_req(clnt, req);
1480 error:
1481         /*
1482          * Fid is not valid even after a failed clunk
1483          * If interrupted, retry once then give up and
1484          * leak fid until umount.
1485          */
1486         if (err == -ERESTARTSYS) {
1487                 if (retries++ == 0)
1488                         goto again;
1489         } else
1490                 p9_fid_destroy(fid);
1491         return err;
1492 }
1493 EXPORT_SYMBOL(p9_client_clunk);
1494
1495 int p9_client_remove(struct p9_fid *fid)
1496 {
1497         int err;
1498         struct p9_client *clnt;
1499         struct p9_req_t *req;
1500
1501         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1502         err = 0;
1503         clnt = fid->clnt;
1504
1505         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1506         if (IS_ERR(req)) {
1507                 err = PTR_ERR(req);
1508                 goto error;
1509         }
1510
1511         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1512
1513         p9_free_req(clnt, req);
1514 error:
1515         if (err == -ERESTARTSYS)
1516                 p9_client_clunk(fid);
1517         else
1518                 p9_fid_destroy(fid);
1519         return err;
1520 }
1521 EXPORT_SYMBOL(p9_client_remove);
1522
1523 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1524 {
1525         int err = 0;
1526         struct p9_req_t *req;
1527         struct p9_client *clnt;
1528
1529         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1530                    dfid->fid, name, flags);
1531
1532         clnt = dfid->clnt;
1533         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1534         if (IS_ERR(req)) {
1535                 err = PTR_ERR(req);
1536                 goto error;
1537         }
1538         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1539
1540         p9_free_req(clnt, req);
1541 error:
1542         return err;
1543 }
1544 EXPORT_SYMBOL(p9_client_unlinkat);
1545
1546 int
1547 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1548 {
1549         struct p9_client *clnt = fid->clnt;
1550         struct p9_req_t *req;
1551         int total = 0;
1552         *err = 0;
1553
1554         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1555                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1556
1557         while (iov_iter_count(to)) {
1558                 int count = iov_iter_count(to);
1559                 int rsize, non_zc = 0;
1560                 char *dataptr;
1561
1562                 rsize = fid->iounit;
1563                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1564                         rsize = clnt->msize - P9_IOHDRSZ;
1565
1566                 if (count < rsize)
1567                         rsize = count;
1568
1569                 /* Don't bother zerocopy for small IO (< 1024) */
1570                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1571                         /*
1572                          * response header len is 11
1573                          * PDU Header(7) + IO Size (4)
1574                          */
1575                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1576                                                0, 11, "dqd", fid->fid,
1577                                                offset, rsize);
1578                 } else {
1579                         non_zc = 1;
1580                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1581                                             rsize);
1582                 }
1583                 if (IS_ERR(req)) {
1584                         *err = PTR_ERR(req);
1585                         break;
1586                 }
1587
1588                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1589                                    "D", &count, &dataptr);
1590                 if (*err) {
1591                         trace_9p_protocol_dump(clnt, req->rc);
1592                         p9_free_req(clnt, req);
1593                         break;
1594                 }
1595                 if (rsize < count) {
1596                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1597                         count = rsize;
1598                 }
1599
1600                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1601                 if (!count) {
1602                         p9_free_req(clnt, req);
1603                         break;
1604                 }
1605
1606                 if (non_zc) {
1607                         int n = copy_to_iter(dataptr, count, to);
1608                         total += n;
1609                         offset += n;
1610                         if (n != count) {
1611                                 *err = -EFAULT;
1612                                 p9_free_req(clnt, req);
1613                                 break;
1614                         }
1615                 } else {
1616                         iov_iter_advance(to, count);
1617                         total += count;
1618                         offset += count;
1619                 }
1620                 p9_free_req(clnt, req);
1621         }
1622         return total;
1623 }
1624 EXPORT_SYMBOL(p9_client_read);
1625
1626 int
1627 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1628 {
1629         struct p9_client *clnt = fid->clnt;
1630         struct p9_req_t *req;
1631         int total = 0;
1632         *err = 0;
1633
1634         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1635                                 fid->fid, (unsigned long long) offset,
1636                                 iov_iter_count(from));
1637
1638         while (iov_iter_count(from)) {
1639                 int count = iov_iter_count(from);
1640                 int rsize = fid->iounit;
1641                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1642                         rsize = clnt->msize - P9_IOHDRSZ;
1643
1644                 if (count < rsize)
1645                         rsize = count;
1646
1647                 /* Don't bother zerocopy for small IO (< 1024) */
1648                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1649                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1650                                                rsize, P9_ZC_HDR_SZ, "dqd",
1651                                                fid->fid, offset, rsize);
1652                 } else {
1653                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1654                                                     offset, rsize, from);
1655                 }
1656                 if (IS_ERR(req)) {
1657                         *err = PTR_ERR(req);
1658                         break;
1659                 }
1660
1661                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1662                 if (*err) {
1663                         trace_9p_protocol_dump(clnt, req->rc);
1664                         p9_free_req(clnt, req);
1665                         break;
1666                 }
1667                 if (rsize < count) {
1668                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1669                         count = rsize;
1670                 }
1671
1672                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1673
1674                 p9_free_req(clnt, req);
1675                 iov_iter_advance(from, count);
1676                 total += count;
1677                 offset += count;
1678         }
1679         return total;
1680 }
1681 EXPORT_SYMBOL(p9_client_write);
1682
1683 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1684 {
1685         int err;
1686         struct p9_client *clnt;
1687         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1688         struct p9_req_t *req;
1689         u16 ignored;
1690
1691         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1692
1693         if (!ret)
1694                 return ERR_PTR(-ENOMEM);
1695
1696         err = 0;
1697         clnt = fid->clnt;
1698
1699         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1700         if (IS_ERR(req)) {
1701                 err = PTR_ERR(req);
1702                 goto error;
1703         }
1704
1705         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1706         if (err) {
1707                 trace_9p_protocol_dump(clnt, req->rc);
1708                 p9_free_req(clnt, req);
1709                 goto error;
1710         }
1711
1712         p9_debug(P9_DEBUG_9P,
1713                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1714                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1715                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1716                 "<<<    uid=%d gid=%d n_muid=%d\n",
1717                 ret->size, ret->type, ret->dev, ret->qid.type,
1718                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1719                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1720                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1721                 from_kuid(&init_user_ns, ret->n_uid),
1722                 from_kgid(&init_user_ns, ret->n_gid),
1723                 from_kuid(&init_user_ns, ret->n_muid));
1724
1725         p9_free_req(clnt, req);
1726         return ret;
1727
1728 error:
1729         kfree(ret);
1730         return ERR_PTR(err);
1731 }
1732 EXPORT_SYMBOL(p9_client_stat);
1733
1734 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1735                                                         u64 request_mask)
1736 {
1737         int err;
1738         struct p9_client *clnt;
1739         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1740                                                                 GFP_KERNEL);
1741         struct p9_req_t *req;
1742
1743         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1744                                                         fid->fid, request_mask);
1745
1746         if (!ret)
1747                 return ERR_PTR(-ENOMEM);
1748
1749         err = 0;
1750         clnt = fid->clnt;
1751
1752         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1753         if (IS_ERR(req)) {
1754                 err = PTR_ERR(req);
1755                 goto error;
1756         }
1757
1758         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1759         if (err) {
1760                 trace_9p_protocol_dump(clnt, req->rc);
1761                 p9_free_req(clnt, req);
1762                 goto error;
1763         }
1764
1765         p9_debug(P9_DEBUG_9P,
1766                 "<<< RGETATTR st_result_mask=%lld\n"
1767                 "<<< qid=%x.%llx.%x\n"
1768                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1769                 "<<< st_uid=%d st_gid=%d\n"
1770                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1771                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1772                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1773                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1774                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1775                 "<<< st_gen=%lld st_data_version=%lld\n",
1776                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1777                 ret->qid.version, ret->st_mode, ret->st_nlink,
1778                 from_kuid(&init_user_ns, ret->st_uid),
1779                 from_kgid(&init_user_ns, ret->st_gid),
1780                 ret->st_rdev, ret->st_size, ret->st_blksize,
1781                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1782                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1783                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1784                 ret->st_gen, ret->st_data_version);
1785
1786         p9_free_req(clnt, req);
1787         return ret;
1788
1789 error:
1790         kfree(ret);
1791         return ERR_PTR(err);
1792 }
1793 EXPORT_SYMBOL(p9_client_getattr_dotl);
1794
1795 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1796 {
1797         int ret;
1798
1799         /* NOTE: size shouldn't include its own length */
1800         /* size[2] type[2] dev[4] qid[13] */
1801         /* mode[4] atime[4] mtime[4] length[8]*/
1802         /* name[s] uid[s] gid[s] muid[s] */
1803         ret = 2+4+13+4+4+4+8+2+2+2+2;
1804
1805         if (wst->name)
1806                 ret += strlen(wst->name);
1807         if (wst->uid)
1808                 ret += strlen(wst->uid);
1809         if (wst->gid)
1810                 ret += strlen(wst->gid);
1811         if (wst->muid)
1812                 ret += strlen(wst->muid);
1813
1814         if ((proto_version == p9_proto_2000u) ||
1815                 (proto_version == p9_proto_2000L)) {
1816                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1817                 if (wst->extension)
1818                         ret += strlen(wst->extension);
1819         }
1820
1821         return ret;
1822 }
1823
1824 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1825 {
1826         int err;
1827         struct p9_req_t *req;
1828         struct p9_client *clnt;
1829
1830         err = 0;
1831         clnt = fid->clnt;
1832         wst->size = p9_client_statsize(wst, clnt->proto_version);
1833         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1834         p9_debug(P9_DEBUG_9P,
1835                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1836                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1837                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1838                 "     uid=%d gid=%d n_muid=%d\n",
1839                 wst->size, wst->type, wst->dev, wst->qid.type,
1840                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1841                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1842                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1843                 from_kuid(&init_user_ns, wst->n_uid),
1844                 from_kgid(&init_user_ns, wst->n_gid),
1845                 from_kuid(&init_user_ns, wst->n_muid));
1846
1847         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1848         if (IS_ERR(req)) {
1849                 err = PTR_ERR(req);
1850                 goto error;
1851         }
1852
1853         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1854
1855         p9_free_req(clnt, req);
1856 error:
1857         return err;
1858 }
1859 EXPORT_SYMBOL(p9_client_wstat);
1860
1861 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1862 {
1863         int err;
1864         struct p9_req_t *req;
1865         struct p9_client *clnt;
1866
1867         err = 0;
1868         clnt = fid->clnt;
1869         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1870         p9_debug(P9_DEBUG_9P,
1871                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1872                 "    atime_sec=%lld atime_nsec=%lld\n"
1873                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1874                 p9attr->valid, p9attr->mode,
1875                 from_kuid(&init_user_ns, p9attr->uid),
1876                 from_kgid(&init_user_ns, p9attr->gid),
1877                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1878                 p9attr->mtime_sec, p9attr->mtime_nsec);
1879
1880         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1881
1882         if (IS_ERR(req)) {
1883                 err = PTR_ERR(req);
1884                 goto error;
1885         }
1886         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1887         p9_free_req(clnt, req);
1888 error:
1889         return err;
1890 }
1891 EXPORT_SYMBOL(p9_client_setattr);
1892
1893 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1894 {
1895         int err;
1896         struct p9_req_t *req;
1897         struct p9_client *clnt;
1898
1899         err = 0;
1900         clnt = fid->clnt;
1901
1902         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1903
1904         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1905         if (IS_ERR(req)) {
1906                 err = PTR_ERR(req);
1907                 goto error;
1908         }
1909
1910         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1911                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1912                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1913         if (err) {
1914                 trace_9p_protocol_dump(clnt, req->rc);
1915                 p9_free_req(clnt, req);
1916                 goto error;
1917         }
1918
1919         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1920                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1921                 "fsid %llu namelen %ld\n",
1922                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1923                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1924                 sb->fsid, (long int)sb->namelen);
1925
1926         p9_free_req(clnt, req);
1927 error:
1928         return err;
1929 }
1930 EXPORT_SYMBOL(p9_client_statfs);
1931
1932 int p9_client_rename(struct p9_fid *fid,
1933                      struct p9_fid *newdirfid, const char *name)
1934 {
1935         int err;
1936         struct p9_req_t *req;
1937         struct p9_client *clnt;
1938
1939         err = 0;
1940         clnt = fid->clnt;
1941
1942         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1943                         fid->fid, newdirfid->fid, name);
1944
1945         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1946                         newdirfid->fid, name);
1947         if (IS_ERR(req)) {
1948                 err = PTR_ERR(req);
1949                 goto error;
1950         }
1951
1952         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1953
1954         p9_free_req(clnt, req);
1955 error:
1956         return err;
1957 }
1958 EXPORT_SYMBOL(p9_client_rename);
1959
1960 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1961                        struct p9_fid *newdirfid, const char *new_name)
1962 {
1963         int err;
1964         struct p9_req_t *req;
1965         struct p9_client *clnt;
1966
1967         err = 0;
1968         clnt = olddirfid->clnt;
1969
1970         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1971                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1972                    newdirfid->fid, new_name);
1973
1974         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1975                             old_name, newdirfid->fid, new_name);
1976         if (IS_ERR(req)) {
1977                 err = PTR_ERR(req);
1978                 goto error;
1979         }
1980
1981         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1982                    newdirfid->fid, new_name);
1983
1984         p9_free_req(clnt, req);
1985 error:
1986         return err;
1987 }
1988 EXPORT_SYMBOL(p9_client_renameat);
1989
1990 /*
1991  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1992  */
1993 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1994                                 const char *attr_name, u64 *attr_size)
1995 {
1996         int err;
1997         struct p9_req_t *req;
1998         struct p9_client *clnt;
1999         struct p9_fid *attr_fid;
2000
2001         err = 0;
2002         clnt = file_fid->clnt;
2003         attr_fid = p9_fid_create(clnt);
2004         if (!attr_fid) {
2005                 err = -ENOMEM;
2006                 goto error;
2007         }
2008         p9_debug(P9_DEBUG_9P,
2009                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2010                 file_fid->fid, attr_fid->fid, attr_name);
2011
2012         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2013                         file_fid->fid, attr_fid->fid, attr_name);
2014         if (IS_ERR(req)) {
2015                 err = PTR_ERR(req);
2016                 goto error;
2017         }
2018         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2019         if (err) {
2020                 trace_9p_protocol_dump(clnt, req->rc);
2021                 p9_free_req(clnt, req);
2022                 goto clunk_fid;
2023         }
2024         p9_free_req(clnt, req);
2025         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2026                 attr_fid->fid, *attr_size);
2027         return attr_fid;
2028 clunk_fid:
2029         p9_client_clunk(attr_fid);
2030         attr_fid = NULL;
2031 error:
2032         if (attr_fid && (attr_fid != file_fid))
2033                 p9_fid_destroy(attr_fid);
2034
2035         return ERR_PTR(err);
2036 }
2037 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2038
2039 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2040                         u64 attr_size, int flags)
2041 {
2042         int err;
2043         struct p9_req_t *req;
2044         struct p9_client *clnt;
2045
2046         p9_debug(P9_DEBUG_9P,
2047                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2048                 fid->fid, name, (long long)attr_size, flags);
2049         err = 0;
2050         clnt = fid->clnt;
2051         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2052                         fid->fid, name, attr_size, flags);
2053         if (IS_ERR(req)) {
2054                 err = PTR_ERR(req);
2055                 goto error;
2056         }
2057         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2058         p9_free_req(clnt, req);
2059 error:
2060         return err;
2061 }
2062 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2063
2064 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2065 {
2066         int err, rsize, non_zc = 0;
2067         struct p9_client *clnt;
2068         struct p9_req_t *req;
2069         char *dataptr;
2070         struct kvec kv = {.iov_base = data, .iov_len = count};
2071         struct iov_iter to;
2072
2073         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2074
2075         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2076                                 fid->fid, (unsigned long long) offset, count);
2077
2078         err = 0;
2079         clnt = fid->clnt;
2080
2081         rsize = fid->iounit;
2082         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2083                 rsize = clnt->msize - P9_READDIRHDRSZ;
2084
2085         if (count < rsize)
2086                 rsize = count;
2087
2088         /* Don't bother zerocopy for small IO (< 1024) */
2089         if (clnt->trans_mod->zc_request && rsize > 1024) {
2090                 /*
2091                  * response header len is 11
2092                  * PDU Header(7) + IO Size (4)
2093                  */
2094                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2095                                        11, "dqd", fid->fid, offset, rsize);
2096         } else {
2097                 non_zc = 1;
2098                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2099                                     offset, rsize);
2100         }
2101         if (IS_ERR(req)) {
2102                 err = PTR_ERR(req);
2103                 goto error;
2104         }
2105
2106         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2107         if (err) {
2108                 trace_9p_protocol_dump(clnt, req->rc);
2109                 goto free_and_error;
2110         }
2111         if (rsize < count) {
2112                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2113                 count = rsize;
2114         }
2115
2116         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2117
2118         if (non_zc)
2119                 memmove(data, dataptr, count);
2120
2121         p9_free_req(clnt, req);
2122         return count;
2123
2124 free_and_error:
2125         p9_free_req(clnt, req);
2126 error:
2127         return err;
2128 }
2129 EXPORT_SYMBOL(p9_client_readdir);
2130
2131 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2132                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2133 {
2134         int err;
2135         struct p9_client *clnt;
2136         struct p9_req_t *req;
2137
2138         err = 0;
2139         clnt = fid->clnt;
2140         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2141                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2142         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2143                 MAJOR(rdev), MINOR(rdev), gid);
2144         if (IS_ERR(req))
2145                 return PTR_ERR(req);
2146
2147         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2148         if (err) {
2149                 trace_9p_protocol_dump(clnt, req->rc);
2150                 goto error;
2151         }
2152         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2153                                 (unsigned long long)qid->path, qid->version);
2154
2155 error:
2156         p9_free_req(clnt, req);
2157         return err;
2158
2159 }
2160 EXPORT_SYMBOL(p9_client_mknod_dotl);
2161
2162 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2163                                 kgid_t gid, struct p9_qid *qid)
2164 {
2165         int err;
2166         struct p9_client *clnt;
2167         struct p9_req_t *req;
2168
2169         err = 0;
2170         clnt = fid->clnt;
2171         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2172                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2173         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2174                 gid);
2175         if (IS_ERR(req))
2176                 return PTR_ERR(req);
2177
2178         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2179         if (err) {
2180                 trace_9p_protocol_dump(clnt, req->rc);
2181                 goto error;
2182         }
2183         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2184                                 (unsigned long long)qid->path, qid->version);
2185
2186 error:
2187         p9_free_req(clnt, req);
2188         return err;
2189
2190 }
2191 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2192
2193 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2194 {
2195         int err;
2196         struct p9_client *clnt;
2197         struct p9_req_t *req;
2198
2199         err = 0;
2200         clnt = fid->clnt;
2201         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2202                         "start %lld length %lld proc_id %d client_id %s\n",
2203                         fid->fid, flock->type, flock->flags, flock->start,
2204                         flock->length, flock->proc_id, flock->client_id);
2205
2206         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2207                                 flock->flags, flock->start, flock->length,
2208                                         flock->proc_id, flock->client_id);
2209
2210         if (IS_ERR(req))
2211                 return PTR_ERR(req);
2212
2213         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2214         if (err) {
2215                 trace_9p_protocol_dump(clnt, req->rc);
2216                 goto error;
2217         }
2218         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2219 error:
2220         p9_free_req(clnt, req);
2221         return err;
2222
2223 }
2224 EXPORT_SYMBOL(p9_client_lock_dotl);
2225
2226 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2227 {
2228         int err;
2229         struct p9_client *clnt;
2230         struct p9_req_t *req;
2231
2232         err = 0;
2233         clnt = fid->clnt;
2234         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2235                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2236                 glock->start, glock->length, glock->proc_id, glock->client_id);
2237
2238         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2239                 glock->start, glock->length, glock->proc_id, glock->client_id);
2240
2241         if (IS_ERR(req))
2242                 return PTR_ERR(req);
2243
2244         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2245                         &glock->start, &glock->length, &glock->proc_id,
2246                         &glock->client_id);
2247         if (err) {
2248                 trace_9p_protocol_dump(clnt, req->rc);
2249                 goto error;
2250         }
2251         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2252                 "proc_id %d client_id %s\n", glock->type, glock->start,
2253                 glock->length, glock->proc_id, glock->client_id);
2254 error:
2255         p9_free_req(clnt, req);
2256         return err;
2257 }
2258 EXPORT_SYMBOL(p9_client_getlock_dotl);
2259
2260 int p9_client_readlink(struct p9_fid *fid, char **target)
2261 {
2262         int err;
2263         struct p9_client *clnt;
2264         struct p9_req_t *req;
2265
2266         err = 0;
2267         clnt = fid->clnt;
2268         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2269
2270         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2271         if (IS_ERR(req))
2272                 return PTR_ERR(req);
2273
2274         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2275         if (err) {
2276                 trace_9p_protocol_dump(clnt, req->rc);
2277                 goto error;
2278         }
2279         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2280 error:
2281         p9_free_req(clnt, req);
2282         return err;
2283 }
2284 EXPORT_SYMBOL(p9_client_readlink);