9p: Embed wait_queue_head into p9_req_t
[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         if (pdu->size == 0)
473                 pdu->size = 7;
474
475         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
476         if (err)
477                 goto rewind_and_exit;
478
479         pdu->size = r_size;
480         pdu->id = r_type;
481         pdu->tag = r_tag;
482
483         p9_debug(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n",
484                  pdu->size, pdu->id, pdu->tag);
485
486         if (type)
487                 *type = r_type;
488         if (tag)
489                 *tag = r_tag;
490         if (size)
491                 *size = r_size;
492
493
494 rewind_and_exit:
495         if (rewind)
496                 pdu->offset = offset;
497         return err;
498 }
499 EXPORT_SYMBOL(p9_parse_header);
500
501 /**
502  * p9_check_errors - check 9p packet for error return and process it
503  * @c: current client instance
504  * @req: request to parse and check for error conditions
505  *
506  * returns error code if one is discovered, otherwise returns 0
507  *
508  * this will have to be more complicated if we have multiple
509  * error packet types
510  */
511
512 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
513 {
514         int8_t type;
515         int err;
516         int ecode;
517
518         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
519         /*
520          * dump the response from server
521          * This should be after check errors which poplulate pdu_fcall.
522          */
523         trace_9p_protocol_dump(c, req->rc);
524         if (err) {
525                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
526                 return err;
527         }
528         if (type != P9_RERROR && type != P9_RLERROR)
529                 return 0;
530
531         if (!p9_is_proto_dotl(c)) {
532                 char *ename;
533                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
534                                   &ename, &ecode);
535                 if (err)
536                         goto out_err;
537
538                 if (p9_is_proto_dotu(c) && ecode < 512)
539                         err = -ecode;
540
541                 if (!err) {
542                         err = p9_errstr2errno(ename, strlen(ename));
543
544                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
545                                  -ecode, ename);
546                 }
547                 kfree(ename);
548         } else {
549                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
550                 err = -ecode;
551
552                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
553         }
554
555         return err;
556
557 out_err:
558         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
559
560         return err;
561 }
562
563 /**
564  * p9_check_zc_errors - check 9p packet for error return and process it
565  * @c: current client instance
566  * @req: request to parse and check for error conditions
567  * @in_hdrlen: Size of response protocol buffer.
568  *
569  * returns error code if one is discovered, otherwise returns 0
570  *
571  * this will have to be more complicated if we have multiple
572  * error packet types
573  */
574
575 static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req,
576                               struct iov_iter *uidata, int in_hdrlen)
577 {
578         int err;
579         int ecode;
580         int8_t type;
581         char *ename = NULL;
582
583         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
584         /*
585          * dump the response from server
586          * This should be after parse_header which poplulate pdu_fcall.
587          */
588         trace_9p_protocol_dump(c, req->rc);
589         if (err) {
590                 p9_debug(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
591                 return err;
592         }
593
594         if (type != P9_RERROR && type != P9_RLERROR)
595                 return 0;
596
597         if (!p9_is_proto_dotl(c)) {
598                 /* Error is reported in string format */
599                 int len;
600                 /* 7 = header size for RERROR; */
601                 int inline_len = in_hdrlen - 7;
602
603                 len =  req->rc->size - req->rc->offset;
604                 if (len > (P9_ZC_HDR_SZ - 7)) {
605                         err = -EFAULT;
606                         goto out_err;
607                 }
608
609                 ename = &req->rc->sdata[req->rc->offset];
610                 if (len > inline_len) {
611                         /* We have error in external buffer */
612                         if (!copy_from_iter_full(ename + inline_len,
613                                              len - inline_len, uidata)) {
614                                 err = -EFAULT;
615                                 goto out_err;
616                         }
617                 }
618                 ename = NULL;
619                 err = p9pdu_readf(req->rc, c->proto_version, "s?d",
620                                   &ename, &ecode);
621                 if (err)
622                         goto out_err;
623
624                 if (p9_is_proto_dotu(c) && ecode < 512)
625                         err = -ecode;
626
627                 if (!err) {
628                         err = p9_errstr2errno(ename, strlen(ename));
629
630                         p9_debug(P9_DEBUG_9P, "<<< RERROR (%d) %s\n",
631                                  -ecode, ename);
632                 }
633                 kfree(ename);
634         } else {
635                 err = p9pdu_readf(req->rc, c->proto_version, "d", &ecode);
636                 err = -ecode;
637
638                 p9_debug(P9_DEBUG_9P, "<<< RLERROR (%d)\n", -ecode);
639         }
640         return err;
641
642 out_err:
643         p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err);
644         return err;
645 }
646
647 static struct p9_req_t *
648 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
649
650 /**
651  * p9_client_flush - flush (cancel) a request
652  * @c: client state
653  * @oldreq: request to cancel
654  *
655  * This sents a flush for a particular request and links
656  * the flush request to the original request.  The current
657  * code only supports a single flush request although the protocol
658  * allows for multiple flush requests to be sent for a single request.
659  *
660  */
661
662 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
663 {
664         struct p9_req_t *req;
665         int16_t oldtag;
666         int err;
667
668         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
669         if (err)
670                 return err;
671
672         p9_debug(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
673
674         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
675         if (IS_ERR(req))
676                 return PTR_ERR(req);
677
678         /*
679          * if we haven't received a response for oldreq,
680          * remove it from the list
681          */
682         if (oldreq->status == REQ_STATUS_SENT)
683                 if (c->trans_mod->cancelled)
684                         c->trans_mod->cancelled(c, oldreq);
685
686         p9_free_req(c, req);
687         return 0;
688 }
689
690 static struct p9_req_t *p9_client_prepare_req(struct p9_client *c,
691                                               int8_t type, int req_size,
692                                               const char *fmt, va_list ap)
693 {
694         int tag, err;
695         struct p9_req_t *req;
696
697         p9_debug(P9_DEBUG_MUX, "client %p op %d\n", c, type);
698
699         /* we allow for any status other than disconnected */
700         if (c->status == Disconnected)
701                 return ERR_PTR(-EIO);
702
703         /* if status is begin_disconnected we allow only clunk request */
704         if ((c->status == BeginDisconnect) && (type != P9_TCLUNK))
705                 return ERR_PTR(-EIO);
706
707         tag = P9_NOTAG;
708         if (type != P9_TVERSION) {
709                 tag = p9_idpool_get(c->tagpool);
710                 if (tag < 0)
711                         return ERR_PTR(-ENOMEM);
712         }
713
714         req = p9_tag_alloc(c, tag, req_size);
715         if (IS_ERR(req))
716                 return req;
717
718         /* marshall the data */
719         p9pdu_prepare(req->tc, tag, type);
720         err = p9pdu_vwritef(req->tc, c->proto_version, fmt, ap);
721         if (err)
722                 goto reterr;
723         p9pdu_finalize(c, req->tc);
724         trace_9p_client_req(c, type, tag);
725         return req;
726 reterr:
727         p9_free_req(c, req);
728         return ERR_PTR(err);
729 }
730
731 /**
732  * p9_client_rpc - issue a request and wait for a response
733  * @c: client session
734  * @type: type of request
735  * @fmt: protocol format string (see protocol.c)
736  *
737  * Returns request structure (which client must free using p9_free_req)
738  */
739
740 static struct p9_req_t *
741 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
742 {
743         va_list ap;
744         int sigpending, err;
745         unsigned long flags;
746         struct p9_req_t *req;
747
748         va_start(ap, fmt);
749         req = p9_client_prepare_req(c, type, c->msize, fmt, ap);
750         va_end(ap);
751         if (IS_ERR(req))
752                 return req;
753
754         if (signal_pending(current)) {
755                 sigpending = 1;
756                 clear_thread_flag(TIF_SIGPENDING);
757         } else
758                 sigpending = 0;
759
760         err = c->trans_mod->request(c, req);
761         if (err < 0) {
762                 if (err != -ERESTARTSYS && err != -EFAULT)
763                         c->status = Disconnected;
764                 goto recalc_sigpending;
765         }
766 again:
767         /* Wait for the response */
768         err = wait_event_killable(req->wq, req->status >= REQ_STATUS_RCVD);
769
770         /*
771          * Make sure our req is coherent with regard to updates in other
772          * threads - echoes to wmb() in the callback
773          */
774         smp_rmb();
775
776         if ((err == -ERESTARTSYS) && (c->status == Connected)
777                                   && (type == P9_TFLUSH)) {
778                 sigpending = 1;
779                 clear_thread_flag(TIF_SIGPENDING);
780                 goto again;
781         }
782
783         if (req->status == REQ_STATUS_ERROR) {
784                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
785                 err = req->t_err;
786         }
787         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
788                 p9_debug(P9_DEBUG_MUX, "flushing\n");
789                 sigpending = 1;
790                 clear_thread_flag(TIF_SIGPENDING);
791
792                 if (c->trans_mod->cancel(c, req))
793                         p9_client_flush(c, req);
794
795                 /* if we received the response anyway, don't signal error */
796                 if (req->status == REQ_STATUS_RCVD)
797                         err = 0;
798         }
799 recalc_sigpending:
800         if (sigpending) {
801                 spin_lock_irqsave(&current->sighand->siglock, flags);
802                 recalc_sigpending();
803                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
804         }
805         if (err < 0)
806                 goto reterr;
807
808         err = p9_check_errors(c, req);
809         trace_9p_client_res(c, type, req->rc->tag, err);
810         if (!err)
811                 return req;
812 reterr:
813         p9_free_req(c, req);
814         return ERR_PTR(safe_errno(err));
815 }
816
817 /**
818  * p9_client_zc_rpc - issue a request and wait for a response
819  * @c: client session
820  * @type: type of request
821  * @uidata: destination for zero copy read
822  * @uodata: source for zero copy write
823  * @inlen: read buffer size
824  * @olen: write buffer size
825  * @hdrlen: reader header size, This is the size of response protocol data
826  * @fmt: protocol format string (see protocol.c)
827  *
828  * Returns request structure (which client must free using p9_free_req)
829  */
830 static struct p9_req_t *p9_client_zc_rpc(struct p9_client *c, int8_t type,
831                                          struct iov_iter *uidata,
832                                          struct iov_iter *uodata,
833                                          int inlen, int olen, int in_hdrlen,
834                                          const char *fmt, ...)
835 {
836         va_list ap;
837         int sigpending, err;
838         unsigned long flags;
839         struct p9_req_t *req;
840
841         va_start(ap, fmt);
842         /*
843          * We allocate a inline protocol data of only 4k bytes.
844          * The actual content is passed in zero-copy fashion.
845          */
846         req = p9_client_prepare_req(c, type, P9_ZC_HDR_SZ, fmt, ap);
847         va_end(ap);
848         if (IS_ERR(req))
849                 return req;
850
851         if (signal_pending(current)) {
852                 sigpending = 1;
853                 clear_thread_flag(TIF_SIGPENDING);
854         } else
855                 sigpending = 0;
856
857         err = c->trans_mod->zc_request(c, req, uidata, uodata,
858                                        inlen, olen, in_hdrlen);
859         if (err < 0) {
860                 if (err == -EIO)
861                         c->status = Disconnected;
862                 if (err != -ERESTARTSYS)
863                         goto recalc_sigpending;
864         }
865         if (req->status == REQ_STATUS_ERROR) {
866                 p9_debug(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
867                 err = req->t_err;
868         }
869         if ((err == -ERESTARTSYS) && (c->status == Connected)) {
870                 p9_debug(P9_DEBUG_MUX, "flushing\n");
871                 sigpending = 1;
872                 clear_thread_flag(TIF_SIGPENDING);
873
874                 if (c->trans_mod->cancel(c, req))
875                         p9_client_flush(c, req);
876
877                 /* if we received the response anyway, don't signal error */
878                 if (req->status == REQ_STATUS_RCVD)
879                         err = 0;
880         }
881 recalc_sigpending:
882         if (sigpending) {
883                 spin_lock_irqsave(&current->sighand->siglock, flags);
884                 recalc_sigpending();
885                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
886         }
887         if (err < 0)
888                 goto reterr;
889
890         err = p9_check_zc_errors(c, req, uidata, in_hdrlen);
891         trace_9p_client_res(c, type, req->rc->tag, err);
892         if (!err)
893                 return req;
894 reterr:
895         p9_free_req(c, req);
896         return ERR_PTR(safe_errno(err));
897 }
898
899 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
900 {
901         int ret;
902         struct p9_fid *fid;
903
904         p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);
905         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
906         if (!fid)
907                 return NULL;
908
909         memset(&fid->qid, 0, sizeof(struct p9_qid));
910         fid->mode = -1;
911         fid->uid = current_fsuid();
912         fid->clnt = clnt;
913         fid->rdir = NULL;
914         fid->fid = 0;
915
916         idr_preload(GFP_KERNEL);
917         spin_lock_irq(&clnt->lock);
918         ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,
919                             GFP_NOWAIT);
920         spin_unlock_irq(&clnt->lock);
921         idr_preload_end();
922
923         if (!ret)
924                 return fid;
925
926         kfree(fid);
927         return NULL;
928 }
929
930 static void p9_fid_destroy(struct p9_fid *fid)
931 {
932         struct p9_client *clnt;
933         unsigned long flags;
934
935         p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
936         clnt = fid->clnt;
937         spin_lock_irqsave(&clnt->lock, flags);
938         idr_remove(&clnt->fids, fid->fid);
939         spin_unlock_irqrestore(&clnt->lock, flags);
940         kfree(fid->rdir);
941         kfree(fid);
942 }
943
944 static int p9_client_version(struct p9_client *c)
945 {
946         int err = 0;
947         struct p9_req_t *req;
948         char *version = NULL;
949         int msize;
950
951         p9_debug(P9_DEBUG_9P, ">>> TVERSION msize %d protocol %d\n",
952                  c->msize, c->proto_version);
953
954         switch (c->proto_version) {
955         case p9_proto_2000L:
956                 req = p9_client_rpc(c, P9_TVERSION, "ds",
957                                         c->msize, "9P2000.L");
958                 break;
959         case p9_proto_2000u:
960                 req = p9_client_rpc(c, P9_TVERSION, "ds",
961                                         c->msize, "9P2000.u");
962                 break;
963         case p9_proto_legacy:
964                 req = p9_client_rpc(c, P9_TVERSION, "ds",
965                                         c->msize, "9P2000");
966                 break;
967         default:
968                 return -EINVAL;
969         }
970
971         if (IS_ERR(req))
972                 return PTR_ERR(req);
973
974         err = p9pdu_readf(req->rc, c->proto_version, "ds", &msize, &version);
975         if (err) {
976                 p9_debug(P9_DEBUG_9P, "version error %d\n", err);
977                 trace_9p_protocol_dump(c, req->rc);
978                 goto error;
979         }
980
981         p9_debug(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
982         if (!strncmp(version, "9P2000.L", 8))
983                 c->proto_version = p9_proto_2000L;
984         else if (!strncmp(version, "9P2000.u", 8))
985                 c->proto_version = p9_proto_2000u;
986         else if (!strncmp(version, "9P2000", 6))
987                 c->proto_version = p9_proto_legacy;
988         else {
989                 err = -EREMOTEIO;
990                 goto error;
991         }
992
993         if (msize < c->msize)
994                 c->msize = msize;
995
996 error:
997         kfree(version);
998         p9_free_req(c, req);
999
1000         return err;
1001 }
1002
1003 struct p9_client *p9_client_create(const char *dev_name, char *options)
1004 {
1005         int err;
1006         struct p9_client *clnt;
1007         char *client_id;
1008
1009         err = 0;
1010         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
1011         if (!clnt)
1012                 return ERR_PTR(-ENOMEM);
1013
1014         clnt->trans_mod = NULL;
1015         clnt->trans = NULL;
1016
1017         client_id = utsname()->nodename;
1018         memcpy(clnt->name, client_id, strlen(client_id) + 1);
1019
1020         spin_lock_init(&clnt->lock);
1021         idr_init(&clnt->fids);
1022
1023         err = p9_tag_init(clnt);
1024         if (err < 0)
1025                 goto free_client;
1026
1027         err = parse_opts(options, clnt);
1028         if (err < 0)
1029                 goto destroy_tagpool;
1030
1031         if (!clnt->trans_mod)
1032                 clnt->trans_mod = v9fs_get_default_trans();
1033
1034         if (clnt->trans_mod == NULL) {
1035                 err = -EPROTONOSUPPORT;
1036                 p9_debug(P9_DEBUG_ERROR,
1037                          "No transport defined or default transport\n");
1038                 goto destroy_tagpool;
1039         }
1040
1041         p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
1042                  clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
1043
1044         err = clnt->trans_mod->create(clnt, dev_name, options);
1045         if (err)
1046                 goto put_trans;
1047
1048         if (clnt->msize > clnt->trans_mod->maxsize)
1049                 clnt->msize = clnt->trans_mod->maxsize;
1050
1051         err = p9_client_version(clnt);
1052         if (err)
1053                 goto close_trans;
1054
1055         return clnt;
1056
1057 close_trans:
1058         clnt->trans_mod->close(clnt);
1059 put_trans:
1060         v9fs_put_trans(clnt->trans_mod);
1061 destroy_tagpool:
1062         p9_idpool_destroy(clnt->tagpool);
1063 free_client:
1064         kfree(clnt);
1065         return ERR_PTR(err);
1066 }
1067 EXPORT_SYMBOL(p9_client_create);
1068
1069 void p9_client_destroy(struct p9_client *clnt)
1070 {
1071         struct p9_fid *fid;
1072         int id;
1073
1074         p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
1075
1076         if (clnt->trans_mod)
1077                 clnt->trans_mod->close(clnt);
1078
1079         v9fs_put_trans(clnt->trans_mod);
1080
1081         idr_for_each_entry(&clnt->fids, fid, id) {
1082                 pr_info("Found fid %d not clunked\n", fid->fid);
1083                 p9_fid_destroy(fid);
1084         }
1085
1086         p9_tag_cleanup(clnt);
1087
1088         kfree(clnt);
1089 }
1090 EXPORT_SYMBOL(p9_client_destroy);
1091
1092 void p9_client_disconnect(struct p9_client *clnt)
1093 {
1094         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1095         clnt->status = Disconnected;
1096 }
1097 EXPORT_SYMBOL(p9_client_disconnect);
1098
1099 void p9_client_begin_disconnect(struct p9_client *clnt)
1100 {
1101         p9_debug(P9_DEBUG_9P, "clnt %p\n", clnt);
1102         clnt->status = BeginDisconnect;
1103 }
1104 EXPORT_SYMBOL(p9_client_begin_disconnect);
1105
1106 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
1107         const char *uname, kuid_t n_uname, const char *aname)
1108 {
1109         int err = 0;
1110         struct p9_req_t *req;
1111         struct p9_fid *fid;
1112         struct p9_qid qid;
1113
1114
1115         p9_debug(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
1116                  afid ? afid->fid : -1, uname, aname);
1117         fid = p9_fid_create(clnt);
1118         if (!fid) {
1119                 err = -ENOMEM;
1120                 goto error;
1121         }
1122         fid->uid = n_uname;
1123
1124         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?u", fid->fid,
1125                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
1126         if (IS_ERR(req)) {
1127                 err = PTR_ERR(req);
1128                 goto error;
1129         }
1130
1131         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", &qid);
1132         if (err) {
1133                 trace_9p_protocol_dump(clnt, req->rc);
1134                 p9_free_req(clnt, req);
1135                 goto error;
1136         }
1137
1138         p9_debug(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
1139                  qid.type, (unsigned long long)qid.path, qid.version);
1140
1141         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
1142
1143         p9_free_req(clnt, req);
1144         return fid;
1145
1146 error:
1147         if (fid)
1148                 p9_fid_destroy(fid);
1149         return ERR_PTR(err);
1150 }
1151 EXPORT_SYMBOL(p9_client_attach);
1152
1153 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
1154                 const unsigned char * const *wnames, int clone)
1155 {
1156         int err;
1157         struct p9_client *clnt;
1158         struct p9_fid *fid;
1159         struct p9_qid *wqids;
1160         struct p9_req_t *req;
1161         uint16_t nwqids, count;
1162
1163         err = 0;
1164         wqids = NULL;
1165         clnt = oldfid->clnt;
1166         if (clone) {
1167                 fid = p9_fid_create(clnt);
1168                 if (!fid) {
1169                         err = -ENOMEM;
1170                         goto error;
1171                 }
1172
1173                 fid->uid = oldfid->uid;
1174         } else
1175                 fid = oldfid;
1176
1177
1178         p9_debug(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %ud wname[0] %s\n",
1179                  oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
1180
1181         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
1182                                                                 nwname, wnames);
1183         if (IS_ERR(req)) {
1184                 err = PTR_ERR(req);
1185                 goto error;
1186         }
1187
1188         err = p9pdu_readf(req->rc, clnt->proto_version, "R", &nwqids, &wqids);
1189         if (err) {
1190                 trace_9p_protocol_dump(clnt, req->rc);
1191                 p9_free_req(clnt, req);
1192                 goto clunk_fid;
1193         }
1194         p9_free_req(clnt, req);
1195
1196         p9_debug(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
1197
1198         if (nwqids != nwname) {
1199                 err = -ENOENT;
1200                 goto clunk_fid;
1201         }
1202
1203         for (count = 0; count < nwqids; count++)
1204                 p9_debug(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
1205                         count, wqids[count].type,
1206                         (unsigned long long)wqids[count].path,
1207                         wqids[count].version);
1208
1209         if (nwname)
1210                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
1211         else
1212                 fid->qid = oldfid->qid;
1213
1214         kfree(wqids);
1215         return fid;
1216
1217 clunk_fid:
1218         kfree(wqids);
1219         p9_client_clunk(fid);
1220         fid = NULL;
1221
1222 error:
1223         if (fid && (fid != oldfid))
1224                 p9_fid_destroy(fid);
1225
1226         return ERR_PTR(err);
1227 }
1228 EXPORT_SYMBOL(p9_client_walk);
1229
1230 int p9_client_open(struct p9_fid *fid, int mode)
1231 {
1232         int err;
1233         struct p9_client *clnt;
1234         struct p9_req_t *req;
1235         struct p9_qid qid;
1236         int iounit;
1237
1238         clnt = fid->clnt;
1239         p9_debug(P9_DEBUG_9P, ">>> %s fid %d mode %d\n",
1240                 p9_is_proto_dotl(clnt) ? "TLOPEN" : "TOPEN", fid->fid, mode);
1241         err = 0;
1242
1243         if (fid->mode != -1)
1244                 return -EINVAL;
1245
1246         if (p9_is_proto_dotl(clnt))
1247                 req = p9_client_rpc(clnt, P9_TLOPEN, "dd", fid->fid, mode);
1248         else
1249                 req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
1250         if (IS_ERR(req)) {
1251                 err = PTR_ERR(req);
1252                 goto error;
1253         }
1254
1255         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1256         if (err) {
1257                 trace_9p_protocol_dump(clnt, req->rc);
1258                 goto free_and_error;
1259         }
1260
1261         p9_debug(P9_DEBUG_9P, "<<< %s qid %x.%llx.%x iounit %x\n",
1262                 p9_is_proto_dotl(clnt) ? "RLOPEN" : "ROPEN",  qid.type,
1263                 (unsigned long long)qid.path, qid.version, iounit);
1264
1265         fid->mode = mode;
1266         fid->iounit = iounit;
1267
1268 free_and_error:
1269         p9_free_req(clnt, req);
1270 error:
1271         return err;
1272 }
1273 EXPORT_SYMBOL(p9_client_open);
1274
1275 int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
1276                 kgid_t gid, struct p9_qid *qid)
1277 {
1278         int err = 0;
1279         struct p9_client *clnt;
1280         struct p9_req_t *req;
1281         int iounit;
1282
1283         p9_debug(P9_DEBUG_9P,
1284                         ">>> TLCREATE fid %d name %s flags %d mode %d gid %d\n",
1285                         ofid->fid, name, flags, mode,
1286                         from_kgid(&init_user_ns, gid));
1287         clnt = ofid->clnt;
1288
1289         if (ofid->mode != -1)
1290                 return -EINVAL;
1291
1292         req = p9_client_rpc(clnt, P9_TLCREATE, "dsddg", ofid->fid, name, flags,
1293                         mode, gid);
1294         if (IS_ERR(req)) {
1295                 err = PTR_ERR(req);
1296                 goto error;
1297         }
1298
1299         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", qid, &iounit);
1300         if (err) {
1301                 trace_9p_protocol_dump(clnt, req->rc);
1302                 goto free_and_error;
1303         }
1304
1305         p9_debug(P9_DEBUG_9P, "<<< RLCREATE qid %x.%llx.%x iounit %x\n",
1306                         qid->type,
1307                         (unsigned long long)qid->path,
1308                         qid->version, iounit);
1309
1310         ofid->mode = mode;
1311         ofid->iounit = iounit;
1312
1313 free_and_error:
1314         p9_free_req(clnt, req);
1315 error:
1316         return err;
1317 }
1318 EXPORT_SYMBOL(p9_client_create_dotl);
1319
1320 int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
1321                      char *extension)
1322 {
1323         int err;
1324         struct p9_client *clnt;
1325         struct p9_req_t *req;
1326         struct p9_qid qid;
1327         int iounit;
1328
1329         p9_debug(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1330                                                 fid->fid, name, perm, mode);
1331         err = 0;
1332         clnt = fid->clnt;
1333
1334         if (fid->mode != -1)
1335                 return -EINVAL;
1336
1337         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1338                                 mode, extension);
1339         if (IS_ERR(req)) {
1340                 err = PTR_ERR(req);
1341                 goto error;
1342         }
1343
1344         err = p9pdu_readf(req->rc, clnt->proto_version, "Qd", &qid, &iounit);
1345         if (err) {
1346                 trace_9p_protocol_dump(clnt, req->rc);
1347                 goto free_and_error;
1348         }
1349
1350         p9_debug(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1351                                 qid.type,
1352                                 (unsigned long long)qid.path,
1353                                 qid.version, iounit);
1354
1355         fid->mode = mode;
1356         fid->iounit = iounit;
1357
1358 free_and_error:
1359         p9_free_req(clnt, req);
1360 error:
1361         return err;
1362 }
1363 EXPORT_SYMBOL(p9_client_fcreate);
1364
1365 int p9_client_symlink(struct p9_fid *dfid, const char *name,
1366                 const char *symtgt, kgid_t gid, struct p9_qid *qid)
1367 {
1368         int err = 0;
1369         struct p9_client *clnt;
1370         struct p9_req_t *req;
1371
1372         p9_debug(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s  symtgt %s\n",
1373                         dfid->fid, name, symtgt);
1374         clnt = dfid->clnt;
1375
1376         req = p9_client_rpc(clnt, P9_TSYMLINK, "dssg", dfid->fid, name, symtgt,
1377                         gid);
1378         if (IS_ERR(req)) {
1379                 err = PTR_ERR(req);
1380                 goto error;
1381         }
1382
1383         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
1384         if (err) {
1385                 trace_9p_protocol_dump(clnt, req->rc);
1386                 goto free_and_error;
1387         }
1388
1389         p9_debug(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n",
1390                         qid->type, (unsigned long long)qid->path, qid->version);
1391
1392 free_and_error:
1393         p9_free_req(clnt, req);
1394 error:
1395         return err;
1396 }
1397 EXPORT_SYMBOL(p9_client_symlink);
1398
1399 int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, const char *newname)
1400 {
1401         struct p9_client *clnt;
1402         struct p9_req_t *req;
1403
1404         p9_debug(P9_DEBUG_9P, ">>> TLINK dfid %d oldfid %d newname %s\n",
1405                         dfid->fid, oldfid->fid, newname);
1406         clnt = dfid->clnt;
1407         req = p9_client_rpc(clnt, P9_TLINK, "dds", dfid->fid, oldfid->fid,
1408                         newname);
1409         if (IS_ERR(req))
1410                 return PTR_ERR(req);
1411
1412         p9_debug(P9_DEBUG_9P, "<<< RLINK\n");
1413         p9_free_req(clnt, req);
1414         return 0;
1415 }
1416 EXPORT_SYMBOL(p9_client_link);
1417
1418 int p9_client_fsync(struct p9_fid *fid, int datasync)
1419 {
1420         int err;
1421         struct p9_client *clnt;
1422         struct p9_req_t *req;
1423
1424         p9_debug(P9_DEBUG_9P, ">>> TFSYNC fid %d datasync:%d\n",
1425                         fid->fid, datasync);
1426         err = 0;
1427         clnt = fid->clnt;
1428
1429         req = p9_client_rpc(clnt, P9_TFSYNC, "dd", fid->fid, datasync);
1430         if (IS_ERR(req)) {
1431                 err = PTR_ERR(req);
1432                 goto error;
1433         }
1434
1435         p9_debug(P9_DEBUG_9P, "<<< RFSYNC fid %d\n", fid->fid);
1436
1437         p9_free_req(clnt, req);
1438
1439 error:
1440         return err;
1441 }
1442 EXPORT_SYMBOL(p9_client_fsync);
1443
1444 int p9_client_clunk(struct p9_fid *fid)
1445 {
1446         int err;
1447         struct p9_client *clnt;
1448         struct p9_req_t *req;
1449         int retries = 0;
1450
1451         if (!fid) {
1452                 pr_warn("%s (%d): Trying to clunk with NULL fid\n",
1453                         __func__, task_pid_nr(current));
1454                 dump_stack();
1455                 return 0;
1456         }
1457
1458 again:
1459         p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
1460                                                                 retries);
1461         err = 0;
1462         clnt = fid->clnt;
1463
1464         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1465         if (IS_ERR(req)) {
1466                 err = PTR_ERR(req);
1467                 goto error;
1468         }
1469
1470         p9_debug(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1471
1472         p9_free_req(clnt, req);
1473 error:
1474         /*
1475          * Fid is not valid even after a failed clunk
1476          * If interrupted, retry once then give up and
1477          * leak fid until umount.
1478          */
1479         if (err == -ERESTARTSYS) {
1480                 if (retries++ == 0)
1481                         goto again;
1482         } else
1483                 p9_fid_destroy(fid);
1484         return err;
1485 }
1486 EXPORT_SYMBOL(p9_client_clunk);
1487
1488 int p9_client_remove(struct p9_fid *fid)
1489 {
1490         int err;
1491         struct p9_client *clnt;
1492         struct p9_req_t *req;
1493
1494         p9_debug(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1495         err = 0;
1496         clnt = fid->clnt;
1497
1498         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1499         if (IS_ERR(req)) {
1500                 err = PTR_ERR(req);
1501                 goto error;
1502         }
1503
1504         p9_debug(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1505
1506         p9_free_req(clnt, req);
1507 error:
1508         if (err == -ERESTARTSYS)
1509                 p9_client_clunk(fid);
1510         else
1511                 p9_fid_destroy(fid);
1512         return err;
1513 }
1514 EXPORT_SYMBOL(p9_client_remove);
1515
1516 int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags)
1517 {
1518         int err = 0;
1519         struct p9_req_t *req;
1520         struct p9_client *clnt;
1521
1522         p9_debug(P9_DEBUG_9P, ">>> TUNLINKAT fid %d %s %d\n",
1523                    dfid->fid, name, flags);
1524
1525         clnt = dfid->clnt;
1526         req = p9_client_rpc(clnt, P9_TUNLINKAT, "dsd", dfid->fid, name, flags);
1527         if (IS_ERR(req)) {
1528                 err = PTR_ERR(req);
1529                 goto error;
1530         }
1531         p9_debug(P9_DEBUG_9P, "<<< RUNLINKAT fid %d %s\n", dfid->fid, name);
1532
1533         p9_free_req(clnt, req);
1534 error:
1535         return err;
1536 }
1537 EXPORT_SYMBOL(p9_client_unlinkat);
1538
1539 int
1540 p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err)
1541 {
1542         struct p9_client *clnt = fid->clnt;
1543         struct p9_req_t *req;
1544         int total = 0;
1545         *err = 0;
1546
1547         p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n",
1548                    fid->fid, (unsigned long long) offset, (int)iov_iter_count(to));
1549
1550         while (iov_iter_count(to)) {
1551                 int count = iov_iter_count(to);
1552                 int rsize, non_zc = 0;
1553                 char *dataptr;
1554                         
1555                 rsize = fid->iounit;
1556                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1557                         rsize = clnt->msize - P9_IOHDRSZ;
1558
1559                 if (count < rsize)
1560                         rsize = count;
1561
1562                 /* Don't bother zerocopy for small IO (< 1024) */
1563                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1564                         /*
1565                          * response header len is 11
1566                          * PDU Header(7) + IO Size (4)
1567                          */
1568                         req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize,
1569                                                0, 11, "dqd", fid->fid,
1570                                                offset, rsize);
1571                 } else {
1572                         non_zc = 1;
1573                         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
1574                                             rsize);
1575                 }
1576                 if (IS_ERR(req)) {
1577                         *err = PTR_ERR(req);
1578                         break;
1579                 }
1580
1581                 *err = p9pdu_readf(req->rc, clnt->proto_version,
1582                                    "D", &count, &dataptr);
1583                 if (*err) {
1584                         trace_9p_protocol_dump(clnt, req->rc);
1585                         p9_free_req(clnt, req);
1586                         break;
1587                 }
1588                 if (rsize < count) {
1589                         pr_err("bogus RREAD count (%d > %d)\n", count, rsize);
1590                         count = rsize;
1591                 }
1592
1593                 p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1594                 if (!count) {
1595                         p9_free_req(clnt, req);
1596                         break;
1597                 }
1598
1599                 if (non_zc) {
1600                         int n = copy_to_iter(dataptr, count, to);
1601                         total += n;
1602                         offset += n;
1603                         if (n != count) {
1604                                 *err = -EFAULT;
1605                                 p9_free_req(clnt, req);
1606                                 break;
1607                         }
1608                 } else {
1609                         iov_iter_advance(to, count);
1610                         total += count;
1611                         offset += count;
1612                 }
1613                 p9_free_req(clnt, req);
1614         }
1615         return total;
1616 }
1617 EXPORT_SYMBOL(p9_client_read);
1618
1619 int
1620 p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err)
1621 {
1622         struct p9_client *clnt = fid->clnt;
1623         struct p9_req_t *req;
1624         int total = 0;
1625         *err = 0;
1626
1627         p9_debug(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %zd\n",
1628                                 fid->fid, (unsigned long long) offset,
1629                                 iov_iter_count(from));
1630
1631         while (iov_iter_count(from)) {
1632                 int count = iov_iter_count(from);
1633                 int rsize = fid->iounit;
1634                 if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1635                         rsize = clnt->msize - P9_IOHDRSZ;
1636
1637                 if (count < rsize)
1638                         rsize = count;
1639
1640                 /* Don't bother zerocopy for small IO (< 1024) */
1641                 if (clnt->trans_mod->zc_request && rsize > 1024) {
1642                         req = p9_client_zc_rpc(clnt, P9_TWRITE, NULL, from, 0,
1643                                                rsize, P9_ZC_HDR_SZ, "dqd",
1644                                                fid->fid, offset, rsize);
1645                 } else {
1646                         req = p9_client_rpc(clnt, P9_TWRITE, "dqV", fid->fid,
1647                                                     offset, rsize, from);
1648                 }
1649                 if (IS_ERR(req)) {
1650                         *err = PTR_ERR(req);
1651                         break;
1652                 }
1653
1654                 *err = p9pdu_readf(req->rc, clnt->proto_version, "d", &count);
1655                 if (*err) {
1656                         trace_9p_protocol_dump(clnt, req->rc);
1657                         p9_free_req(clnt, req);
1658                         break;
1659                 }
1660                 if (rsize < count) {
1661                         pr_err("bogus RWRITE count (%d > %d)\n", count, rsize);
1662                         count = rsize;
1663                 }
1664
1665                 p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1666
1667                 p9_free_req(clnt, req);
1668                 iov_iter_advance(from, count);
1669                 total += count;
1670                 offset += count;
1671         }
1672         return total;
1673 }
1674 EXPORT_SYMBOL(p9_client_write);
1675
1676 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1677 {
1678         int err;
1679         struct p9_client *clnt;
1680         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1681         struct p9_req_t *req;
1682         u16 ignored;
1683
1684         p9_debug(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1685
1686         if (!ret)
1687                 return ERR_PTR(-ENOMEM);
1688
1689         err = 0;
1690         clnt = fid->clnt;
1691
1692         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1693         if (IS_ERR(req)) {
1694                 err = PTR_ERR(req);
1695                 goto error;
1696         }
1697
1698         err = p9pdu_readf(req->rc, clnt->proto_version, "wS", &ignored, ret);
1699         if (err) {
1700                 trace_9p_protocol_dump(clnt, req->rc);
1701                 p9_free_req(clnt, req);
1702                 goto error;
1703         }
1704
1705         p9_debug(P9_DEBUG_9P,
1706                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1707                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1708                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1709                 "<<<    uid=%d gid=%d n_muid=%d\n",
1710                 ret->size, ret->type, ret->dev, ret->qid.type,
1711                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1712                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1713                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1714                 from_kuid(&init_user_ns, ret->n_uid),
1715                 from_kgid(&init_user_ns, ret->n_gid),
1716                 from_kuid(&init_user_ns, ret->n_muid));
1717
1718         p9_free_req(clnt, req);
1719         return ret;
1720
1721 error:
1722         kfree(ret);
1723         return ERR_PTR(err);
1724 }
1725 EXPORT_SYMBOL(p9_client_stat);
1726
1727 struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
1728                                                         u64 request_mask)
1729 {
1730         int err;
1731         struct p9_client *clnt;
1732         struct p9_stat_dotl *ret = kmalloc(sizeof(struct p9_stat_dotl),
1733                                                                 GFP_KERNEL);
1734         struct p9_req_t *req;
1735
1736         p9_debug(P9_DEBUG_9P, ">>> TGETATTR fid %d, request_mask %lld\n",
1737                                                         fid->fid, request_mask);
1738
1739         if (!ret)
1740                 return ERR_PTR(-ENOMEM);
1741
1742         err = 0;
1743         clnt = fid->clnt;
1744
1745         req = p9_client_rpc(clnt, P9_TGETATTR, "dq", fid->fid, request_mask);
1746         if (IS_ERR(req)) {
1747                 err = PTR_ERR(req);
1748                 goto error;
1749         }
1750
1751         err = p9pdu_readf(req->rc, clnt->proto_version, "A", ret);
1752         if (err) {
1753                 trace_9p_protocol_dump(clnt, req->rc);
1754                 p9_free_req(clnt, req);
1755                 goto error;
1756         }
1757
1758         p9_debug(P9_DEBUG_9P,
1759                 "<<< RGETATTR st_result_mask=%lld\n"
1760                 "<<< qid=%x.%llx.%x\n"
1761                 "<<< st_mode=%8.8x st_nlink=%llu\n"
1762                 "<<< st_uid=%d st_gid=%d\n"
1763                 "<<< st_rdev=%llx st_size=%llx st_blksize=%llu st_blocks=%llu\n"
1764                 "<<< st_atime_sec=%lld st_atime_nsec=%lld\n"
1765                 "<<< st_mtime_sec=%lld st_mtime_nsec=%lld\n"
1766                 "<<< st_ctime_sec=%lld st_ctime_nsec=%lld\n"
1767                 "<<< st_btime_sec=%lld st_btime_nsec=%lld\n"
1768                 "<<< st_gen=%lld st_data_version=%lld\n",
1769                 ret->st_result_mask, ret->qid.type, ret->qid.path,
1770                 ret->qid.version, ret->st_mode, ret->st_nlink,
1771                 from_kuid(&init_user_ns, ret->st_uid),
1772                 from_kgid(&init_user_ns, ret->st_gid),
1773                 ret->st_rdev, ret->st_size, ret->st_blksize,
1774                 ret->st_blocks, ret->st_atime_sec, ret->st_atime_nsec,
1775                 ret->st_mtime_sec, ret->st_mtime_nsec, ret->st_ctime_sec,
1776                 ret->st_ctime_nsec, ret->st_btime_sec, ret->st_btime_nsec,
1777                 ret->st_gen, ret->st_data_version);
1778
1779         p9_free_req(clnt, req);
1780         return ret;
1781
1782 error:
1783         kfree(ret);
1784         return ERR_PTR(err);
1785 }
1786 EXPORT_SYMBOL(p9_client_getattr_dotl);
1787
1788 static int p9_client_statsize(struct p9_wstat *wst, int proto_version)
1789 {
1790         int ret;
1791
1792         /* NOTE: size shouldn't include its own length */
1793         /* size[2] type[2] dev[4] qid[13] */
1794         /* mode[4] atime[4] mtime[4] length[8]*/
1795         /* name[s] uid[s] gid[s] muid[s] */
1796         ret = 2+4+13+4+4+4+8+2+2+2+2;
1797
1798         if (wst->name)
1799                 ret += strlen(wst->name);
1800         if (wst->uid)
1801                 ret += strlen(wst->uid);
1802         if (wst->gid)
1803                 ret += strlen(wst->gid);
1804         if (wst->muid)
1805                 ret += strlen(wst->muid);
1806
1807         if ((proto_version == p9_proto_2000u) ||
1808                 (proto_version == p9_proto_2000L)) {
1809                 ret += 2+4+4+4; /* extension[s] n_uid[4] n_gid[4] n_muid[4] */
1810                 if (wst->extension)
1811                         ret += strlen(wst->extension);
1812         }
1813
1814         return ret;
1815 }
1816
1817 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1818 {
1819         int err;
1820         struct p9_req_t *req;
1821         struct p9_client *clnt;
1822
1823         err = 0;
1824         clnt = fid->clnt;
1825         wst->size = p9_client_statsize(wst, clnt->proto_version);
1826         p9_debug(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1827         p9_debug(P9_DEBUG_9P,
1828                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1829                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1830                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1831                 "     uid=%d gid=%d n_muid=%d\n",
1832                 wst->size, wst->type, wst->dev, wst->qid.type,
1833                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1834                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1835                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1836                 from_kuid(&init_user_ns, wst->n_uid),
1837                 from_kgid(&init_user_ns, wst->n_gid),
1838                 from_kuid(&init_user_ns, wst->n_muid));
1839
1840         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, wst->size+2, wst);
1841         if (IS_ERR(req)) {
1842                 err = PTR_ERR(req);
1843                 goto error;
1844         }
1845
1846         p9_debug(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1847
1848         p9_free_req(clnt, req);
1849 error:
1850         return err;
1851 }
1852 EXPORT_SYMBOL(p9_client_wstat);
1853
1854 int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *p9attr)
1855 {
1856         int err;
1857         struct p9_req_t *req;
1858         struct p9_client *clnt;
1859
1860         err = 0;
1861         clnt = fid->clnt;
1862         p9_debug(P9_DEBUG_9P, ">>> TSETATTR fid %d\n", fid->fid);
1863         p9_debug(P9_DEBUG_9P,
1864                 "    valid=%x mode=%x uid=%d gid=%d size=%lld\n"
1865                 "    atime_sec=%lld atime_nsec=%lld\n"
1866                 "    mtime_sec=%lld mtime_nsec=%lld\n",
1867                 p9attr->valid, p9attr->mode,
1868                 from_kuid(&init_user_ns, p9attr->uid),
1869                 from_kgid(&init_user_ns, p9attr->gid),
1870                 p9attr->size, p9attr->atime_sec, p9attr->atime_nsec,
1871                 p9attr->mtime_sec, p9attr->mtime_nsec);
1872
1873         req = p9_client_rpc(clnt, P9_TSETATTR, "dI", fid->fid, p9attr);
1874
1875         if (IS_ERR(req)) {
1876                 err = PTR_ERR(req);
1877                 goto error;
1878         }
1879         p9_debug(P9_DEBUG_9P, "<<< RSETATTR fid %d\n", fid->fid);
1880         p9_free_req(clnt, req);
1881 error:
1882         return err;
1883 }
1884 EXPORT_SYMBOL(p9_client_setattr);
1885
1886 int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb)
1887 {
1888         int err;
1889         struct p9_req_t *req;
1890         struct p9_client *clnt;
1891
1892         err = 0;
1893         clnt = fid->clnt;
1894
1895         p9_debug(P9_DEBUG_9P, ">>> TSTATFS fid %d\n", fid->fid);
1896
1897         req = p9_client_rpc(clnt, P9_TSTATFS, "d", fid->fid);
1898         if (IS_ERR(req)) {
1899                 err = PTR_ERR(req);
1900                 goto error;
1901         }
1902
1903         err = p9pdu_readf(req->rc, clnt->proto_version, "ddqqqqqqd", &sb->type,
1904                 &sb->bsize, &sb->blocks, &sb->bfree, &sb->bavail,
1905                 &sb->files, &sb->ffree, &sb->fsid, &sb->namelen);
1906         if (err) {
1907                 trace_9p_protocol_dump(clnt, req->rc);
1908                 p9_free_req(clnt, req);
1909                 goto error;
1910         }
1911
1912         p9_debug(P9_DEBUG_9P, "<<< RSTATFS fid %d type 0x%lx bsize %ld "
1913                 "blocks %llu bfree %llu bavail %llu files %llu ffree %llu "
1914                 "fsid %llu namelen %ld\n",
1915                 fid->fid, (long unsigned int)sb->type, (long int)sb->bsize,
1916                 sb->blocks, sb->bfree, sb->bavail, sb->files,  sb->ffree,
1917                 sb->fsid, (long int)sb->namelen);
1918
1919         p9_free_req(clnt, req);
1920 error:
1921         return err;
1922 }
1923 EXPORT_SYMBOL(p9_client_statfs);
1924
1925 int p9_client_rename(struct p9_fid *fid,
1926                      struct p9_fid *newdirfid, const char *name)
1927 {
1928         int err;
1929         struct p9_req_t *req;
1930         struct p9_client *clnt;
1931
1932         err = 0;
1933         clnt = fid->clnt;
1934
1935         p9_debug(P9_DEBUG_9P, ">>> TRENAME fid %d newdirfid %d name %s\n",
1936                         fid->fid, newdirfid->fid, name);
1937
1938         req = p9_client_rpc(clnt, P9_TRENAME, "dds", fid->fid,
1939                         newdirfid->fid, name);
1940         if (IS_ERR(req)) {
1941                 err = PTR_ERR(req);
1942                 goto error;
1943         }
1944
1945         p9_debug(P9_DEBUG_9P, "<<< RRENAME fid %d\n", fid->fid);
1946
1947         p9_free_req(clnt, req);
1948 error:
1949         return err;
1950 }
1951 EXPORT_SYMBOL(p9_client_rename);
1952
1953 int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
1954                        struct p9_fid *newdirfid, const char *new_name)
1955 {
1956         int err;
1957         struct p9_req_t *req;
1958         struct p9_client *clnt;
1959
1960         err = 0;
1961         clnt = olddirfid->clnt;
1962
1963         p9_debug(P9_DEBUG_9P, ">>> TRENAMEAT olddirfid %d old name %s"
1964                    " newdirfid %d new name %s\n", olddirfid->fid, old_name,
1965                    newdirfid->fid, new_name);
1966
1967         req = p9_client_rpc(clnt, P9_TRENAMEAT, "dsds", olddirfid->fid,
1968                             old_name, newdirfid->fid, new_name);
1969         if (IS_ERR(req)) {
1970                 err = PTR_ERR(req);
1971                 goto error;
1972         }
1973
1974         p9_debug(P9_DEBUG_9P, "<<< RRENAMEAT newdirfid %d new name %s\n",
1975                    newdirfid->fid, new_name);
1976
1977         p9_free_req(clnt, req);
1978 error:
1979         return err;
1980 }
1981 EXPORT_SYMBOL(p9_client_renameat);
1982
1983 /*
1984  * An xattrwalk without @attr_name gives the fid for the lisxattr namespace
1985  */
1986 struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
1987                                 const char *attr_name, u64 *attr_size)
1988 {
1989         int err;
1990         struct p9_req_t *req;
1991         struct p9_client *clnt;
1992         struct p9_fid *attr_fid;
1993
1994         err = 0;
1995         clnt = file_fid->clnt;
1996         attr_fid = p9_fid_create(clnt);
1997         if (!attr_fid) {
1998                 err = -ENOMEM;
1999                 goto error;
2000         }
2001         p9_debug(P9_DEBUG_9P,
2002                 ">>> TXATTRWALK file_fid %d, attr_fid %d name %s\n",
2003                 file_fid->fid, attr_fid->fid, attr_name);
2004
2005         req = p9_client_rpc(clnt, P9_TXATTRWALK, "dds",
2006                         file_fid->fid, attr_fid->fid, attr_name);
2007         if (IS_ERR(req)) {
2008                 err = PTR_ERR(req);
2009                 goto error;
2010         }
2011         err = p9pdu_readf(req->rc, clnt->proto_version, "q", attr_size);
2012         if (err) {
2013                 trace_9p_protocol_dump(clnt, req->rc);
2014                 p9_free_req(clnt, req);
2015                 goto clunk_fid;
2016         }
2017         p9_free_req(clnt, req);
2018         p9_debug(P9_DEBUG_9P, "<<<  RXATTRWALK fid %d size %llu\n",
2019                 attr_fid->fid, *attr_size);
2020         return attr_fid;
2021 clunk_fid:
2022         p9_client_clunk(attr_fid);
2023         attr_fid = NULL;
2024 error:
2025         if (attr_fid && (attr_fid != file_fid))
2026                 p9_fid_destroy(attr_fid);
2027
2028         return ERR_PTR(err);
2029 }
2030 EXPORT_SYMBOL_GPL(p9_client_xattrwalk);
2031
2032 int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
2033                         u64 attr_size, int flags)
2034 {
2035         int err;
2036         struct p9_req_t *req;
2037         struct p9_client *clnt;
2038
2039         p9_debug(P9_DEBUG_9P,
2040                 ">>> TXATTRCREATE fid %d name  %s size %lld flag %d\n",
2041                 fid->fid, name, (long long)attr_size, flags);
2042         err = 0;
2043         clnt = fid->clnt;
2044         req = p9_client_rpc(clnt, P9_TXATTRCREATE, "dsqd",
2045                         fid->fid, name, attr_size, flags);
2046         if (IS_ERR(req)) {
2047                 err = PTR_ERR(req);
2048                 goto error;
2049         }
2050         p9_debug(P9_DEBUG_9P, "<<< RXATTRCREATE fid %d\n", fid->fid);
2051         p9_free_req(clnt, req);
2052 error:
2053         return err;
2054 }
2055 EXPORT_SYMBOL_GPL(p9_client_xattrcreate);
2056
2057 int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
2058 {
2059         int err, rsize, non_zc = 0;
2060         struct p9_client *clnt;
2061         struct p9_req_t *req;
2062         char *dataptr;
2063         struct kvec kv = {.iov_base = data, .iov_len = count};
2064         struct iov_iter to;
2065
2066         iov_iter_kvec(&to, READ | ITER_KVEC, &kv, 1, count);
2067
2068         p9_debug(P9_DEBUG_9P, ">>> TREADDIR fid %d offset %llu count %d\n",
2069                                 fid->fid, (unsigned long long) offset, count);
2070
2071         err = 0;
2072         clnt = fid->clnt;
2073
2074         rsize = fid->iounit;
2075         if (!rsize || rsize > clnt->msize-P9_READDIRHDRSZ)
2076                 rsize = clnt->msize - P9_READDIRHDRSZ;
2077
2078         if (count < rsize)
2079                 rsize = count;
2080
2081         /* Don't bother zerocopy for small IO (< 1024) */
2082         if (clnt->trans_mod->zc_request && rsize > 1024) {
2083                 /*
2084                  * response header len is 11
2085                  * PDU Header(7) + IO Size (4)
2086                  */
2087                 req = p9_client_zc_rpc(clnt, P9_TREADDIR, &to, NULL, rsize, 0,
2088                                        11, "dqd", fid->fid, offset, rsize);
2089         } else {
2090                 non_zc = 1;
2091                 req = p9_client_rpc(clnt, P9_TREADDIR, "dqd", fid->fid,
2092                                     offset, rsize);
2093         }
2094         if (IS_ERR(req)) {
2095                 err = PTR_ERR(req);
2096                 goto error;
2097         }
2098
2099         err = p9pdu_readf(req->rc, clnt->proto_version, "D", &count, &dataptr);
2100         if (err) {
2101                 trace_9p_protocol_dump(clnt, req->rc);
2102                 goto free_and_error;
2103         }
2104         if (rsize < count) {
2105                 pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
2106                 count = rsize;
2107         }
2108
2109         p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);
2110
2111         if (non_zc)
2112                 memmove(data, dataptr, count);
2113
2114         p9_free_req(clnt, req);
2115         return count;
2116
2117 free_and_error:
2118         p9_free_req(clnt, req);
2119 error:
2120         return err;
2121 }
2122 EXPORT_SYMBOL(p9_client_readdir);
2123
2124 int p9_client_mknod_dotl(struct p9_fid *fid, const char *name, int mode,
2125                         dev_t rdev, kgid_t gid, struct p9_qid *qid)
2126 {
2127         int err;
2128         struct p9_client *clnt;
2129         struct p9_req_t *req;
2130
2131         err = 0;
2132         clnt = fid->clnt;
2133         p9_debug(P9_DEBUG_9P, ">>> TMKNOD fid %d name %s mode %d major %d "
2134                 "minor %d\n", fid->fid, name, mode, MAJOR(rdev), MINOR(rdev));
2135         req = p9_client_rpc(clnt, P9_TMKNOD, "dsdddg", fid->fid, name, mode,
2136                 MAJOR(rdev), MINOR(rdev), gid);
2137         if (IS_ERR(req))
2138                 return PTR_ERR(req);
2139
2140         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2141         if (err) {
2142                 trace_9p_protocol_dump(clnt, req->rc);
2143                 goto error;
2144         }
2145         p9_debug(P9_DEBUG_9P, "<<< RMKNOD qid %x.%llx.%x\n", qid->type,
2146                                 (unsigned long long)qid->path, qid->version);
2147
2148 error:
2149         p9_free_req(clnt, req);
2150         return err;
2151
2152 }
2153 EXPORT_SYMBOL(p9_client_mknod_dotl);
2154
2155 int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
2156                                 kgid_t gid, struct p9_qid *qid)
2157 {
2158         int err;
2159         struct p9_client *clnt;
2160         struct p9_req_t *req;
2161
2162         err = 0;
2163         clnt = fid->clnt;
2164         p9_debug(P9_DEBUG_9P, ">>> TMKDIR fid %d name %s mode %d gid %d\n",
2165                  fid->fid, name, mode, from_kgid(&init_user_ns, gid));
2166         req = p9_client_rpc(clnt, P9_TMKDIR, "dsdg", fid->fid, name, mode,
2167                 gid);
2168         if (IS_ERR(req))
2169                 return PTR_ERR(req);
2170
2171         err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid);
2172         if (err) {
2173                 trace_9p_protocol_dump(clnt, req->rc);
2174                 goto error;
2175         }
2176         p9_debug(P9_DEBUG_9P, "<<< RMKDIR qid %x.%llx.%x\n", qid->type,
2177                                 (unsigned long long)qid->path, qid->version);
2178
2179 error:
2180         p9_free_req(clnt, req);
2181         return err;
2182
2183 }
2184 EXPORT_SYMBOL(p9_client_mkdir_dotl);
2185
2186 int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status)
2187 {
2188         int err;
2189         struct p9_client *clnt;
2190         struct p9_req_t *req;
2191
2192         err = 0;
2193         clnt = fid->clnt;
2194         p9_debug(P9_DEBUG_9P, ">>> TLOCK fid %d type %i flags %d "
2195                         "start %lld length %lld proc_id %d client_id %s\n",
2196                         fid->fid, flock->type, flock->flags, flock->start,
2197                         flock->length, flock->proc_id, flock->client_id);
2198
2199         req = p9_client_rpc(clnt, P9_TLOCK, "dbdqqds", fid->fid, flock->type,
2200                                 flock->flags, flock->start, flock->length,
2201                                         flock->proc_id, flock->client_id);
2202
2203         if (IS_ERR(req))
2204                 return PTR_ERR(req);
2205
2206         err = p9pdu_readf(req->rc, clnt->proto_version, "b", status);
2207         if (err) {
2208                 trace_9p_protocol_dump(clnt, req->rc);
2209                 goto error;
2210         }
2211         p9_debug(P9_DEBUG_9P, "<<< RLOCK status %i\n", *status);
2212 error:
2213         p9_free_req(clnt, req);
2214         return err;
2215
2216 }
2217 EXPORT_SYMBOL(p9_client_lock_dotl);
2218
2219 int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *glock)
2220 {
2221         int err;
2222         struct p9_client *clnt;
2223         struct p9_req_t *req;
2224
2225         err = 0;
2226         clnt = fid->clnt;
2227         p9_debug(P9_DEBUG_9P, ">>> TGETLOCK fid %d, type %i start %lld "
2228                 "length %lld proc_id %d client_id %s\n", fid->fid, glock->type,
2229                 glock->start, glock->length, glock->proc_id, glock->client_id);
2230
2231         req = p9_client_rpc(clnt, P9_TGETLOCK, "dbqqds", fid->fid,  glock->type,
2232                 glock->start, glock->length, glock->proc_id, glock->client_id);
2233
2234         if (IS_ERR(req))
2235                 return PTR_ERR(req);
2236
2237         err = p9pdu_readf(req->rc, clnt->proto_version, "bqqds", &glock->type,
2238                         &glock->start, &glock->length, &glock->proc_id,
2239                         &glock->client_id);
2240         if (err) {
2241                 trace_9p_protocol_dump(clnt, req->rc);
2242                 goto error;
2243         }
2244         p9_debug(P9_DEBUG_9P, "<<< RGETLOCK type %i start %lld length %lld "
2245                 "proc_id %d client_id %s\n", glock->type, glock->start,
2246                 glock->length, glock->proc_id, glock->client_id);
2247 error:
2248         p9_free_req(clnt, req);
2249         return err;
2250 }
2251 EXPORT_SYMBOL(p9_client_getlock_dotl);
2252
2253 int p9_client_readlink(struct p9_fid *fid, char **target)
2254 {
2255         int err;
2256         struct p9_client *clnt;
2257         struct p9_req_t *req;
2258
2259         err = 0;
2260         clnt = fid->clnt;
2261         p9_debug(P9_DEBUG_9P, ">>> TREADLINK fid %d\n", fid->fid);
2262
2263         req = p9_client_rpc(clnt, P9_TREADLINK, "d", fid->fid);
2264         if (IS_ERR(req))
2265                 return PTR_ERR(req);
2266
2267         err = p9pdu_readf(req->rc, clnt->proto_version, "s", target);
2268         if (err) {
2269                 trace_9p_protocol_dump(clnt, req->rc);
2270                 goto error;
2271         }
2272         p9_debug(P9_DEBUG_9P, "<<< RREADLINK target %s\n", *target);
2273 error:
2274         p9_free_req(clnt, req);
2275         return err;
2276 }
2277 EXPORT_SYMBOL(p9_client_readlink);