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   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/poll.h>
  30 #include <linux/idr.h>
  31 #include <linux/mutex.h>
  32 #include <linux/sched.h>
  33 #include <linux/uaccess.h>
  34 #include <net/9p/9p.h>
  35 #include <linux/parser.h>
  36 #include <net/9p/client.h>
  37 #include <net/9p/transport.h>
  38
  39 /*
  40   * Client Option Parsing (code inspired by NFS code)
  41   *  - a little lazy - parse all client options
  42   */
  43
  44 enum {
  45         Opt_msize,
  46         Opt_trans,
  47         Opt_legacy,
  48         Opt_err,
  49 };
  50
  51 static const match_table_t tokens = {
  52         {Opt_msize, "msize=%u"},
  53         {Opt_legacy, "noextend"},
  54         {Opt_trans, "trans=%s"},
  55         {Opt_err, NULL},
  56 };
  57
  58 static int
  59 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc);
  60
  61 /**
  62  * v9fs_parse_options - parse mount options into session structure
  63  * @options: options string passed from mount
  64  * @v9ses: existing v9fs session information
  65  *
  66  * Return 0 upon success, -ERRNO upon failure
  67  */
  68
  69 static int parse_opts(char *opts, struct p9_client *clnt)
  70 {
  71         char *options;
  72         char *p;
  73         substring_t args[MAX_OPT_ARGS];
  74         int option;
  75         int ret = 0;
  76
  77         clnt->dotu = 1;
  78         clnt->msize = 8192;
  79
  80         if (!opts)
  81                 return 0;
  82
  83         options = kstrdup(opts, GFP_KERNEL);
  84         if (!options) {
  85                 P9_DPRINTK(P9_DEBUG_ERROR,
  86                                 "failed to allocate copy of option string\n");
  87                 return -ENOMEM;
  88         }
  89
  90         while ((p = strsep(&options, ",")) != NULL) {
  91                 int token;
  92                 if (!*p)
  93                         continue;
  94                 token = match_token(p, tokens, args);
  95                 if (token < Opt_trans) {
  96                         int r = match_int(&args[0], &option);
  97                         if (r < 0) {
  98                                 P9_DPRINTK(P9_DEBUG_ERROR,
  99                                         "integer field, but no integer?\n");
 100                                 ret = r;
 101                                 continue;
 102                         }
 103                 }
 104                 switch (token) {
 105                 case Opt_msize:
 106                         clnt->msize = option;
 107                         break;
 108                 case Opt_trans:
 109                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
 110                         break;
 111                 case Opt_legacy:
 112                         clnt->dotu = 0;
 113                         break;
 114                 default:
 115                         continue;
 116                 }
 117         }
 118
 119         if (!clnt->trans_mod)
 120                 clnt->trans_mod = v9fs_get_default_trans();
 121
 122         kfree(options);
 123         return ret;
 124 }
 125
 126 /**
 127  * p9_tag_alloc - lookup/allocate a request by tag
 128  * @c: client session to lookup tag within
 129  * @tag: numeric id for transaction
 130  *
 131  * this is a simple array lookup, but will grow the
 132  * request_slots as necessary to accomodate transaction
 133  * ids which did not previously have a slot.
 134  *
 135  * this code relies on the client spinlock to manage locks, its
 136  * possible we should switch to something else, but I'd rather
 137  * stick with something low-overhead for the common case.
 138  *
 139  */
 140
 141 struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 142 {
 143         unsigned long flags;
 144         int row, col;
 145
 146         /* This looks up the original request by tag so we know which
 147          * buffer to read the data into */
 148         tag++;
 149
 150         if (tag >= c->max_tag) {
 151                 spin_lock_irqsave(&c->lock, flags);
 152                 /* check again since original check was outside of lock */
 153                 while (tag >= c->max_tag) {
 154                         row = (tag / P9_ROW_MAXTAG);
 155                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 156                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 157
 158                         if (!c->reqs[row]) {
 159                                 printk(KERN_ERR "Couldn't grow tag array\n");
 160                                 BUG();
 161                         }
 162                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 163                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 164                                 c->reqs[row][col].flush_tag = P9_NOTAG;
 165                                 c->reqs[row][col].wq = kmalloc(
 166                                         sizeof(wait_queue_head_t), GFP_ATOMIC);
 167                                 if (!c->reqs[row][col].wq) {
 168                                         printk(KERN_ERR
 169                                                 "Couldn't grow tag array\n");
 170                                         BUG();
 171                                 }
 172                                 init_waitqueue_head(c->reqs[row][col].wq);
 173                         }
 174                         c->max_tag += P9_ROW_MAXTAG;
 175                 }
 176                 spin_unlock_irqrestore(&c->lock, flags);
 177         }
 178         row = tag / P9_ROW_MAXTAG;
 179         col = tag % P9_ROW_MAXTAG;
 180
 181         c->reqs[row][col].status = REQ_STATUS_ALLOC;
 182         c->reqs[row][col].flush_tag = P9_NOTAG;
 183
 184         return &c->reqs[row][col];
 185 }
 186 EXPORT_SYMBOL(p9_tag_alloc);
 187
 188 /**
 189  * p9_tag_lookup - lookup a request by tag
 190  * @c: client session to lookup tag within
 191  * @tag: numeric id for transaction
 192  *
 193  */
 194
 195 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 196 {
 197         int row, col;
 198
 199         /* This looks up the original request by tag so we know which
 200          * buffer to read the data into */
 201         tag++;
 202
 203         BUG_ON(tag >= c->max_tag);
 204
 205         row = tag / P9_ROW_MAXTAG;
 206         col = tag % P9_ROW_MAXTAG;
 207
 208         return &c->reqs[row][col];
 209 }
 210 EXPORT_SYMBOL(p9_tag_lookup);
 211
 212 /**
 213  * p9_tag_init - setup tags structure and contents
 214  * @tags: tags structure from the client struct
 215  *
 216  * This initializes the tags structure for each client instance.
 217  *
 218  */
 219
 220 static int p9_tag_init(struct p9_client *c)
 221 {
 222         int err = 0;
 223
 224         c->tagpool = p9_idpool_create();
 225         if (IS_ERR(c->tagpool)) {
 226                 err = PTR_ERR(c->tagpool);
 227                 c->tagpool = NULL;
 228                 goto error;
 229         }
 230
 231         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 232
 233         c->max_tag = 0;
 234 error:
 235         return err;
 236 }
 237
 238 /**
 239  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 240  * @tags: tags structure from the client struct
 241  *
 242  * This frees resources associated with the tags structure
 243  *
 244  */
 245 static void p9_tag_cleanup(struct p9_client *c)
 246 {
 247         int row, col;
 248
 249         /* check to insure all requests are idle */
 250         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 251                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 252                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 253                                 P9_DPRINTK(P9_DEBUG_MUX,
 254                                   "Attempting to cleanup non-free tag %d,%d\n",
 255                                   row, col);
 256                                 /* TODO: delay execution of cleanup */
 257                                 return;
 258                         }
 259                 }
 260         }
 261
 262         if (c->tagpool)
 263                 p9_idpool_destroy(c->tagpool);
 264
 265         /* free requests associated with tags */
 266         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 267                 for (col = 0; col < P9_ROW_MAXTAG; col++)
 268                         kfree(c->reqs[row][col].wq);
 269                 kfree(c->reqs[row]);
 270         }
 271         c->max_tag = 0;
 272 }
 273
 274 /**
 275  * p9_client_flush - flush (cancel) a request
 276  * c: client state
 277  * req: request to cancel
 278  *
 279  * This sents a flush for a particular requests and links
 280  * the flush request to the original request.  The current
 281  * code only supports a single flush request although the protocol
 282  * allows for multiple flush requests to be sent for a single request.
 283  *
 284  */
 285
 286 static int p9_client_flush(struct p9_client *c, struct p9_req_t *req)
 287 {
 288         struct p9_fcall *tc, *rc = NULL;
 289         int err;
 290
 291         P9_DPRINTK(P9_DEBUG_9P, "client %p tag %d\n", c, req->tc->tag);
 292
 293         tc = p9_create_tflush(req->tc->tag);
 294         if (IS_ERR(tc))
 295                 return PTR_ERR(tc);
 296
 297         err = p9_client_rpc(c, tc, &rc);
 298
 299         /* we don't free anything here because RPC isn't complete */
 300
 301         return err;
 302 }
 303
 304 /**
 305  * p9_free_req - free a request and clean-up as necessary
 306  * c: client state
 307  * r: request to release
 308  *
 309  */
 310
 311 void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 312 {
 313         r->flush_tag = P9_NOTAG;
 314         r->status = REQ_STATUS_IDLE;
 315         if (r->tc->tag != P9_NOTAG && p9_idpool_check(r->tc->tag, c->tagpool))
 316                 p9_idpool_put(r->tc->tag, c->tagpool);
 317
 318         /* if this was a flush request we have to free response fcall */
 319         if (r->tc->id == P9_TFLUSH) {
 320                 kfree(r->tc);
 321                 kfree(r->rc);
 322         }
 323 }
 324
 325 /**
 326  * p9_client_cb - call back from transport to client
 327  * c: client state
 328  * req: request received
 329  *
 330  */
 331 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 332 {
 333         struct p9_req_t *other_req;
 334         unsigned long flags;
 335
 336         P9_DPRINTK(P9_DEBUG_MUX, ": %d\n", req->tc->tag);
 337
 338         if (req->status == REQ_STATUS_ERROR)
 339                 wake_up(req->wq);
 340
 341         if (req->tc->id == P9_TFLUSH) { /* flush receive path */
 342                 P9_DPRINTK(P9_DEBUG_MUX, "flush: %d\n", req->tc->tag);
 343                 spin_lock_irqsave(&c->lock, flags);
 344                 other_req = p9_tag_lookup(c, req->tc->params.tflush.oldtag);
 345                 if (other_req->flush_tag != req->tc->tag) /* stale flush */
 346                         spin_unlock_irqrestore(&c->lock, flags);
 347                 else {
 348                         BUG_ON(other_req->status != REQ_STATUS_FLSH);
 349                         other_req->status = REQ_STATUS_FLSHD;
 350                         spin_unlock_irqrestore(&c->lock, flags);
 351                         wake_up(other_req->wq);
 352                 }
 353                 p9_free_req(c, req);
 354         } else {                                /* normal receive path */
 355                 P9_DPRINTK(P9_DEBUG_MUX, "normal: %d\n", req->tc->tag);
 356                 spin_lock_irqsave(&c->lock, flags);
 357                 if (req->status != REQ_STATUS_FLSHD)
 358                         req->status = REQ_STATUS_RCVD;
 359                 req->flush_tag = P9_NOTAG;
 360                 spin_unlock_irqrestore(&c->lock, flags);
 361                 wake_up(req->wq);
 362                 P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 363         }
 364 }
 365 EXPORT_SYMBOL(p9_client_cb);
 366
 367 /**
 368  * p9_client_rpc - issue a request and wait for a response
 369  * @c: client session
 370  * @tc: &p9_fcall request to transmit
 371  * @rc: &p9_fcall to put reponse into
 372  *
 373  * Returns 0 on success, error code on failure
 374  */
 375
 376 static int
 377 p9_client_rpc(struct p9_client *c, struct p9_fcall *tc, struct p9_fcall **rc)
 378 {
 379         int tag, err, size;
 380         char *rdata;
 381         struct p9_req_t *req;
 382         unsigned long flags;
 383         int sigpending;
 384         int flushed = 0;
 385
 386         P9_DPRINTK(P9_DEBUG_9P, "client %p tc %p rc %p\n", c, tc, rc);
 387
 388         if (c->status != Connected)
 389                 return -EIO;
 390
 391         if (signal_pending(current)) {
 392                 sigpending = 1;
 393                 clear_thread_flag(TIF_SIGPENDING);
 394         } else
 395                 sigpending = 0;
 396
 397         tag = P9_NOTAG;
 398         if (tc->id != P9_TVERSION) {
 399                 tag = p9_idpool_get(c->tagpool);
 400                 if (tag < 0)
 401                         return -ENOMEM;
 402         }
 403
 404         req = p9_tag_alloc(c, tag);
 405
 406         /* if this is a flush request, backlink flush request now to
 407          * avoid race conditions later. */
 408         if (tc->id == P9_TFLUSH) {
 409                 struct p9_req_t *other_req =
 410                                 p9_tag_lookup(c, tc->params.tflush.oldtag);
 411                 if (other_req->status == REQ_STATUS_FLSH)
 412                         other_req->flush_tag = tag;
 413         }
 414
 415         p9_set_tag(tc, tag);
 416
 417         /*
 418          * if client passed in a pre-allocated response fcall struct
 419          * then we just use that, otherwise we allocate one.
 420          */
 421
 422         if (rc == NULL)
 423                 req->rc = NULL;
 424         else
 425                 req->rc = *rc;
 426         if (req->rc == NULL) {
 427                 req->rc = kmalloc(sizeof(struct p9_fcall) + c->msize,
 428                                                                 GFP_KERNEL);
 429                 if (!req->rc) {
 430                         err = -ENOMEM;
 431                         p9_idpool_put(tag, c->tagpool);
 432                         p9_free_req(c, req);
 433                         goto reterr;
 434                 }
 435                 *rc = req->rc;
 436         }
 437
 438         rdata = (char *)req->rc+sizeof(struct p9_fcall);
 439
 440         req->tc = tc;
 441         P9_DPRINTK(P9_DEBUG_9P, "request: tc: %p rc: %p\n", req->tc, req->rc);
 442
 443         err = c->trans_mod->request(c, req);
 444         if (err < 0) {
 445                 c->status = Disconnected;
 446                 goto reterr;
 447         }
 448
 449         /* if it was a flush we just transmitted, return our tag */
 450         if (tc->id == P9_TFLUSH)
 451                 return 0;
 452 again:
 453         P9_DPRINTK(P9_DEBUG_9P, "wait %p tag: %d\n", req->wq, tag);
 454         err = wait_event_interruptible(*req->wq,
 455                                                 req->status >= REQ_STATUS_RCVD);
 456         P9_DPRINTK(P9_DEBUG_9P, "wait %p tag: %d returned %d (flushed=%d)\n",
 457                                                 req->wq, tag, err, flushed);
 458
 459         if (req->status == REQ_STATUS_ERROR) {
 460                 P9_DPRINTK(P9_DEBUG_9P, "req_status error %d\n", req->t_err);
 461                 err = req->t_err;
 462         } else if (err == -ERESTARTSYS && flushed) {
 463                 P9_DPRINTK(P9_DEBUG_9P, "flushed - going again\n");
 464                 goto again;
 465         } else if (req->status == REQ_STATUS_FLSHD) {
 466                 P9_DPRINTK(P9_DEBUG_9P, "flushed - erestartsys\n");
 467                 err = -ERESTARTSYS;
 468         }
 469
 470         if ((err == -ERESTARTSYS) && (c->status == Connected) && (!flushed)) {
 471                 P9_DPRINTK(P9_DEBUG_9P, "flushing\n");
 472                 spin_lock_irqsave(&c->lock, flags);
 473                 if (req->status == REQ_STATUS_SENT)
 474                         req->status = REQ_STATUS_FLSH;
 475                 spin_unlock_irqrestore(&c->lock, flags);
 476                 sigpending = 1;
 477                 flushed = 1;
 478                 clear_thread_flag(TIF_SIGPENDING);
 479
 480                 if (c->trans_mod->cancel(c, req)) {
 481                         err = p9_client_flush(c, req);
 482                         if (err == 0)
 483                                 goto again;
 484                 }
 485         }
 486
 487         if (sigpending) {
 488                 spin_lock_irqsave(&current->sighand->siglock, flags);
 489                 recalc_sigpending();
 490                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 491         }
 492
 493         if (err < 0)
 494                 goto reterr;
 495
 496         size = le32_to_cpu(*(__le32 *) rdata);
 497
 498         err = p9_deserialize_fcall(rdata, size, req->rc, c->dotu);
 499         if (err < 0) {
 500                 P9_DPRINTK(P9_DEBUG_9P,
 501                         "9p debug: client rpc deserialize returned %d\n", err);
 502                 goto reterr;
 503         }
 504
 505 #ifdef CONFIG_NET_9P_DEBUG
 506         if ((p9_debug_level&P9_DEBUG_FCALL) == P9_DEBUG_FCALL) {
 507                 char buf[150];
 508
 509                 p9_printfcall(buf, sizeof(buf), req->rc, c->dotu);
 510                 printk(KERN_NOTICE ">>> %p %s\n", c, buf);
 511         }
 512 #endif
 513
 514         if (req->rc->id == P9_RERROR) {
 515                 int ecode = req->rc->params.rerror.errno;
 516                 struct p9_str *ename = &req->rc->params.rerror.error;
 517
 518                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
 519                                                                 ename->str);
 520
 521                 if (c->dotu)
 522                         err = -ecode;
 523
 524                 if (!err) {
 525                         err = p9_errstr2errno(ename->str, ename->len);
 526
 527                         /* string match failed */
 528                         if (!err) {
 529                                 PRINT_FCALL_ERROR("unknown error", req->rc);
 530                                 err = -ESERVERFAULT;
 531                         }
 532                 }
 533         } else
 534                 err = 0;
 535
 536 reterr:
 537         p9_free_req(c, req);
 538
 539         P9_DPRINTK(P9_DEBUG_9P, "returning %d\n", err);
 540         return err;
 541 }
 542
 543 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 544 {
 545         int err;
 546         struct p9_fid *fid;
 547
 548         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 549         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 550         if (!fid)
 551                 return ERR_PTR(-ENOMEM);
 552
 553         fid->fid = p9_idpool_get(clnt->fidpool);
 554         if (fid->fid < 0) {
 555                 err = -ENOSPC;
 556                 goto error;
 557         }
 558
 559         memset(&fid->qid, 0, sizeof(struct p9_qid));
 560         fid->mode = -1;
 561         fid->rdir_fpos = 0;
 562         fid->rdir_pos = 0;
 563         fid->rdir_fcall = NULL;
 564         fid->uid = current->fsuid;
 565         fid->clnt = clnt;
 566         fid->aux = NULL;
 567
 568         spin_lock(&clnt->lock);
 569         list_add(&fid->flist, &clnt->fidlist);
 570         spin_unlock(&clnt->lock);
 571
 572         return fid;
 573
 574 error:
 575         kfree(fid);
 576         return ERR_PTR(err);
 577 }
 578
 579 static void p9_fid_destroy(struct p9_fid *fid)
 580 {
 581         struct p9_client *clnt;
 582
 583         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 584         clnt = fid->clnt;
 585         p9_idpool_put(fid->fid, clnt->fidpool);
 586         spin_lock(&clnt->lock);
 587         list_del(&fid->flist);
 588         spin_unlock(&clnt->lock);
 589         kfree(fid->rdir_fcall);
 590         kfree(fid);
 591 }
 592
 593 struct p9_client *p9_client_create(const char *dev_name, char *options)
 594 {
 595         int err, n;
 596         struct p9_client *clnt;
 597         struct p9_fcall *tc, *rc;
 598         struct p9_str *version;
 599
 600         err = 0;
 601         tc = NULL;
 602         rc = NULL;
 603         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 604         if (!clnt)
 605                 return ERR_PTR(-ENOMEM);
 606
 607         clnt->trans_mod = NULL;
 608         clnt->trans = NULL;
 609         spin_lock_init(&clnt->lock);
 610         INIT_LIST_HEAD(&clnt->fidlist);
 611         clnt->fidpool = p9_idpool_create();
 612         if (IS_ERR(clnt->fidpool)) {
 613                 err = PTR_ERR(clnt->fidpool);
 614                 clnt->fidpool = NULL;
 615                 goto error;
 616         }
 617
 618         p9_tag_init(clnt);
 619
 620         err = parse_opts(options, clnt);
 621         if (err < 0)
 622                 goto error;
 623
 624         if (clnt->trans_mod == NULL) {
 625                 err = -EPROTONOSUPPORT;
 626                 P9_DPRINTK(P9_DEBUG_ERROR,
 627                                 "No transport defined or default transport\n");
 628                 goto error;
 629         }
 630
 631         P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
 632                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 633
 634
 635         err = clnt->trans_mod->create(clnt, dev_name, options);
 636         if (err)
 637                 goto error;
 638
 639         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 640                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 641
 642         tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
 643         if (IS_ERR(tc)) {
 644                 err = PTR_ERR(tc);
 645                 tc = NULL;
 646                 goto error;
 647         }
 648
 649         err = p9_client_rpc(clnt, tc, &rc);
 650         if (err)
 651                 goto error;
 652
 653         version = &rc->params.rversion.version;
 654         if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
 655                 clnt->dotu = 1;
 656         else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
 657                 clnt->dotu = 0;
 658         else {
 659                 err = -EREMOTEIO;
 660                 goto error;
 661         }
 662
 663         n = rc->params.rversion.msize;
 664         if (n < clnt->msize)
 665                 clnt->msize = n;
 666
 667         kfree(tc);
 668         kfree(rc);
 669         return clnt;
 670
 671 error:
 672         kfree(tc);
 673         kfree(rc);
 674         p9_client_destroy(clnt);
 675         return ERR_PTR(err);
 676 }
 677 EXPORT_SYMBOL(p9_client_create);
 678
 679 void p9_client_destroy(struct p9_client *clnt)
 680 {
 681         struct p9_fid *fid, *fidptr;
 682
 683         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 684
 685         if (clnt->trans_mod)
 686                 clnt->trans_mod->close(clnt);
 687
 688         v9fs_put_trans(clnt->trans_mod);
 689
 690         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 691                 p9_fid_destroy(fid);
 692
 693         if (clnt->fidpool)
 694                 p9_idpool_destroy(clnt->fidpool);
 695
 696         p9_tag_cleanup(clnt);
 697
 698         kfree(clnt);
 699 }
 700 EXPORT_SYMBOL(p9_client_destroy);
 701
 702 void p9_client_disconnect(struct p9_client *clnt)
 703 {
 704         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 705         clnt->status = Disconnected;
 706 }
 707 EXPORT_SYMBOL(p9_client_disconnect);
 708
 709 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 710         char *uname, u32 n_uname, char *aname)
 711 {
 712         int err;
 713         struct p9_fcall *tc, *rc;
 714         struct p9_fid *fid;
 715
 716         P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
 717                 clnt, afid?afid->fid:-1, uname, aname);
 718         err = 0;
 719         tc = NULL;
 720         rc = NULL;
 721
 722         fid = p9_fid_create(clnt);
 723         if (IS_ERR(fid)) {
 724                 err = PTR_ERR(fid);
 725                 fid = NULL;
 726                 goto error;
 727         }
 728
 729         tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
 730                 n_uname, clnt->dotu);
 731         if (IS_ERR(tc)) {
 732                 err = PTR_ERR(tc);
 733                 tc = NULL;
 734                 goto error;
 735         }
 736
 737         err = p9_client_rpc(clnt, tc, &rc);
 738         if (err)
 739                 goto error;
 740
 741         memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
 742         kfree(tc);
 743         kfree(rc);
 744         return fid;
 745
 746 error:
 747         kfree(tc);
 748         kfree(rc);
 749         if (fid)
 750                 p9_fid_destroy(fid);
 751         return ERR_PTR(err);
 752 }
 753 EXPORT_SYMBOL(p9_client_attach);
 754
 755 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
 756         u32 n_uname, char *aname)
 757 {
 758         int err;
 759         struct p9_fcall *tc, *rc;
 760         struct p9_fid *fid;
 761
 762         P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
 763                                                                         aname);
 764         err = 0;
 765         tc = NULL;
 766         rc = NULL;
 767
 768         fid = p9_fid_create(clnt);
 769         if (IS_ERR(fid)) {
 770                 err = PTR_ERR(fid);
 771                 fid = NULL;
 772                 goto error;
 773         }
 774
 775         tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
 776         if (IS_ERR(tc)) {
 777                 err = PTR_ERR(tc);
 778                 tc = NULL;
 779                 goto error;
 780         }
 781
 782         err = p9_client_rpc(clnt, tc, &rc);
 783         if (err)
 784                 goto error;
 785
 786         memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
 787         kfree(tc);
 788         kfree(rc);
 789         return fid;
 790
 791 error:
 792         kfree(tc);
 793         kfree(rc);
 794         if (fid)
 795                 p9_fid_destroy(fid);
 796         return ERR_PTR(err);
 797 }
 798 EXPORT_SYMBOL(p9_client_auth);
 799
 800 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 801         int clone)
 802 {
 803         int err;
 804         struct p9_fcall *tc, *rc;
 805         struct p9_client *clnt;
 806         struct p9_fid *fid;
 807
 808         P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
 809                 oldfid->fid, nwname, wnames?wnames[0]:NULL);
 810         err = 0;
 811         tc = NULL;
 812         rc = NULL;
 813         clnt = oldfid->clnt;
 814         if (clone) {
 815                 fid = p9_fid_create(clnt);
 816                 if (IS_ERR(fid)) {
 817                         err = PTR_ERR(fid);
 818                         fid = NULL;
 819                         goto error;
 820                 }
 821
 822                 fid->uid = oldfid->uid;
 823         } else
 824                 fid = oldfid;
 825
 826         tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
 827         if (IS_ERR(tc)) {
 828                 err = PTR_ERR(tc);
 829                 tc = NULL;
 830                 goto error;
 831         }
 832
 833         err = p9_client_rpc(clnt, tc, &rc);
 834         if (err) {
 835                 if (rc && rc->id == P9_RWALK)
 836                         goto clunk_fid;
 837                 else
 838                         goto error;
 839         }
 840
 841         if (rc->params.rwalk.nwqid != nwname) {
 842                 err = -ENOENT;
 843                 goto clunk_fid;
 844         }
 845
 846         if (nwname)
 847                 memmove(&fid->qid,
 848                         &rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
 849                         sizeof(struct p9_qid));
 850         else
 851                 fid->qid = oldfid->qid;
 852
 853         kfree(tc);
 854         kfree(rc);
 855         return fid;
 856
 857 clunk_fid:
 858         kfree(tc);
 859         kfree(rc);
 860         rc = NULL;
 861         tc = p9_create_tclunk(fid->fid);
 862         if (IS_ERR(tc)) {
 863                 err = PTR_ERR(tc);
 864                 tc = NULL;
 865                 goto error;
 866         }
 867
 868         p9_client_rpc(clnt, tc, &rc);
 869
 870 error:
 871         kfree(tc);
 872         kfree(rc);
 873         if (fid && (fid != oldfid))
 874                 p9_fid_destroy(fid);
 875
 876         return ERR_PTR(err);
 877 }
 878 EXPORT_SYMBOL(p9_client_walk);
 879
 880 int p9_client_open(struct p9_fid *fid, int mode)
 881 {
 882         int err;
 883         struct p9_fcall *tc, *rc;
 884         struct p9_client *clnt;
 885
 886         P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
 887         err = 0;
 888         tc = NULL;
 889         rc = NULL;
 890         clnt = fid->clnt;
 891
 892         if (fid->mode != -1)
 893                 return -EINVAL;
 894
 895         tc = p9_create_topen(fid->fid, mode);
 896         if (IS_ERR(tc)) {
 897                 err = PTR_ERR(tc);
 898                 tc = NULL;
 899                 goto done;
 900         }
 901
 902         err = p9_client_rpc(clnt, tc, &rc);
 903         if (err)
 904                 goto done;
 905
 906         fid->mode = mode;
 907         fid->iounit = rc->params.ropen.iounit;
 908
 909 done:
 910         kfree(tc);
 911         kfree(rc);
 912         return err;
 913 }
 914 EXPORT_SYMBOL(p9_client_open);
 915
 916 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 917                      char *extension)
 918 {
 919         int err;
 920         struct p9_fcall *tc, *rc;
 921         struct p9_client *clnt;
 922
 923         P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
 924                 name, perm, mode);
 925         err = 0;
 926         tc = NULL;
 927         rc = NULL;
 928         clnt = fid->clnt;
 929
 930         if (fid->mode != -1)
 931                 return -EINVAL;
 932
 933         tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
 934                                                                clnt->dotu);
 935         if (IS_ERR(tc)) {
 936                 err = PTR_ERR(tc);
 937                 tc = NULL;
 938                 goto done;
 939         }
 940
 941         err = p9_client_rpc(clnt, tc, &rc);
 942         if (err)
 943                 goto done;
 944
 945         fid->mode = mode;
 946         fid->iounit = rc->params.ropen.iounit;
 947
 948 done:
 949         kfree(tc);
 950         kfree(rc);
 951         return err;
 952 }
 953 EXPORT_SYMBOL(p9_client_fcreate);
 954
 955 int p9_client_clunk(struct p9_fid *fid)
 956 {
 957         int err;
 958         struct p9_fcall *tc, *rc;
 959         struct p9_client *clnt;
 960
 961         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 962         err = 0;
 963         tc = NULL;
 964         rc = NULL;
 965         clnt = fid->clnt;
 966
 967         tc = p9_create_tclunk(fid->fid);
 968         if (IS_ERR(tc)) {
 969                 err = PTR_ERR(tc);
 970                 tc = NULL;
 971                 goto done;
 972         }
 973
 974         err = p9_client_rpc(clnt, tc, &rc);
 975         if (err)
 976                 goto done;
 977
 978         p9_fid_destroy(fid);
 979
 980 done:
 981         kfree(tc);
 982         kfree(rc);
 983         return err;
 984 }
 985 EXPORT_SYMBOL(p9_client_clunk);
 986
 987 int p9_client_remove(struct p9_fid *fid)
 988 {
 989         int err;
 990         struct p9_fcall *tc, *rc;
 991         struct p9_client *clnt;
 992
 993         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 994         err = 0;
 995         tc = NULL;
 996         rc = NULL;
 997         clnt = fid->clnt;
 998
 999         tc = p9_create_tremove(fid->fid);
1000         if (IS_ERR(tc)) {
1001                 err = PTR_ERR(tc);
1002                 tc = NULL;
1003                 goto done;
1004         }
1005
1006         err = p9_client_rpc(clnt, tc, &rc);
1007         if (err)
1008                 goto done;
1009
1010         p9_fid_destroy(fid);
1011
1012 done:
1013         kfree(tc);
1014         kfree(rc);
1015         return err;
1016 }
1017 EXPORT_SYMBOL(p9_client_remove);
1018
1019 int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count)
1020 {
1021         int err, n, rsize, total;
1022         struct p9_fcall *tc, *rc;
1023         struct p9_client *clnt;
1024
1025         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
1026                                         (long long unsigned) offset, count);
1027         err = 0;
1028         tc = NULL;
1029         rc = NULL;
1030         clnt = fid->clnt;
1031         total = 0;
1032
1033         rsize = fid->iounit;
1034         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1035                 rsize = clnt->msize - P9_IOHDRSZ;
1036
1037         do {
1038                 if (count < rsize)
1039                         rsize = count;
1040
1041                 tc = p9_create_tread(fid->fid, offset, rsize);
1042                 if (IS_ERR(tc)) {
1043                         err = PTR_ERR(tc);
1044                         tc = NULL;
1045                         goto error;
1046                 }
1047
1048                 err = p9_client_rpc(clnt, tc, &rc);
1049                 if (err)
1050                         goto error;
1051
1052                 n = rc->params.rread.count;
1053                 if (n > count)
1054                         n = count;
1055
1056                 memmove(data, rc->params.rread.data, n);
1057                 count -= n;
1058                 data += n;
1059                 offset += n;
1060                 total += n;
1061                 kfree(tc);
1062                 tc = NULL;
1063                 kfree(rc);
1064                 rc = NULL;
1065         } while (count > 0 && n == rsize);
1066
1067         return total;
1068
1069 error:
1070         kfree(tc);
1071         kfree(rc);
1072         return err;
1073 }
1074 EXPORT_SYMBOL(p9_client_read);
1075
1076 int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count)
1077 {
1078         int err, n, rsize, total;
1079         struct p9_fcall *tc, *rc;
1080         struct p9_client *clnt;
1081
1082         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1083                                         (long long unsigned) offset, count);
1084         err = 0;
1085         tc = NULL;
1086         rc = NULL;
1087         clnt = fid->clnt;
1088         total = 0;
1089
1090         rsize = fid->iounit;
1091         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1092                 rsize = clnt->msize - P9_IOHDRSZ;
1093
1094         do {
1095                 if (count < rsize)
1096                         rsize = count;
1097
1098                 tc = p9_create_twrite(fid->fid, offset, rsize, data);
1099                 if (IS_ERR(tc)) {
1100                         err = PTR_ERR(tc);
1101                         tc = NULL;
1102                         goto error;
1103                 }
1104
1105                 err = p9_client_rpc(clnt, tc, &rc);
1106                 if (err)
1107                         goto error;
1108
1109                 n = rc->params.rread.count;
1110                 count -= n;
1111                 data += n;
1112                 offset += n;
1113                 total += n;
1114                 kfree(tc);
1115                 tc = NULL;
1116                 kfree(rc);
1117                 rc = NULL;
1118         } while (count > 0);
1119
1120         return total;
1121
1122 error:
1123         kfree(tc);
1124         kfree(rc);
1125         return err;
1126 }
1127 EXPORT_SYMBOL(p9_client_write);
1128
1129 int
1130 p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset, u32 count)
1131 {
1132         int err, n, rsize, total;
1133         struct p9_fcall *tc, *rc;
1134         struct p9_client *clnt;
1135
1136         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1137                                         (long long unsigned) offset, count);
1138         err = 0;
1139         tc = NULL;
1140         rc = NULL;
1141         clnt = fid->clnt;
1142         total = 0;
1143
1144         rsize = fid->iounit;
1145         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1146                 rsize = clnt->msize - P9_IOHDRSZ;
1147
1148         do {
1149                 if (count < rsize)
1150                         rsize = count;
1151
1152                 tc = p9_create_tread(fid->fid, offset, rsize);
1153                 if (IS_ERR(tc)) {
1154                         err = PTR_ERR(tc);
1155                         tc = NULL;
1156                         goto error;
1157                 }
1158
1159                 err = p9_client_rpc(clnt, tc, &rc);
1160                 if (err)
1161                         goto error;
1162
1163                 n = rc->params.rread.count;
1164                 if (n > count)
1165                         n = count;
1166
1167                 err = copy_to_user(data, rc->params.rread.data, n);
1168                 if (err) {
1169                         err = -EFAULT;
1170                         goto error;
1171                 }
1172
1173                 count -= n;
1174                 data += n;
1175                 offset += n;
1176                 total += n;
1177                 kfree(tc);
1178                 tc = NULL;
1179                 kfree(rc);
1180                 rc = NULL;
1181         } while (count > 0 && n == rsize);
1182
1183         return total;
1184
1185 error:
1186         kfree(tc);
1187         kfree(rc);
1188         return err;
1189 }
1190 EXPORT_SYMBOL(p9_client_uread);
1191
1192 int
1193 p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
1194                                                                    u32 count)
1195 {
1196         int err, n, rsize, total;
1197         struct p9_fcall *tc, *rc;
1198         struct p9_client *clnt;
1199
1200         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1201                                         (long long unsigned) offset, count);
1202         err = 0;
1203         tc = NULL;
1204         rc = NULL;
1205         clnt = fid->clnt;
1206         total = 0;
1207
1208         rsize = fid->iounit;
1209         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1210                 rsize = clnt->msize - P9_IOHDRSZ;
1211
1212         do {
1213                 if (count < rsize)
1214                         rsize = count;
1215
1216                 tc = p9_create_twrite_u(fid->fid, offset, rsize, data);
1217                 if (IS_ERR(tc)) {
1218                         err = PTR_ERR(tc);
1219                         tc = NULL;
1220                         goto error;
1221                 }
1222
1223                 err = p9_client_rpc(clnt, tc, &rc);
1224                 if (err)
1225                         goto error;
1226
1227                 n = rc->params.rread.count;
1228                 count -= n;
1229                 data += n;
1230                 offset += n;
1231                 total += n;
1232                 kfree(tc);
1233                 tc = NULL;
1234                 kfree(rc);
1235                 rc = NULL;
1236         } while (count > 0);
1237
1238         return total;
1239
1240 error:
1241         kfree(tc);
1242         kfree(rc);
1243         return err;
1244 }
1245 EXPORT_SYMBOL(p9_client_uwrite);
1246
1247 int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count)
1248 {
1249         int n, total;
1250
1251         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1252                                         (long long unsigned) offset, count);
1253         n = 0;
1254         total = 0;
1255         while (count) {
1256                 n = p9_client_read(fid, data, offset, count);
1257                 if (n <= 0)
1258                         break;
1259
1260                 data += n;
1261                 offset += n;
1262                 count -= n;
1263                 total += n;
1264         }
1265
1266         if (n < 0)
1267                 total = n;
1268
1269         return total;
1270 }
1271 EXPORT_SYMBOL(p9_client_readn);
1272
1273 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
1274 {
1275         int n;
1276         char *p;
1277         struct p9_stat *ret;
1278
1279         n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
1280                 st->muid.len;
1281
1282         if (dotu)
1283                 n += st->extension.len;
1284
1285         ret = kmalloc(n, GFP_KERNEL);
1286         if (!ret)
1287                 return ERR_PTR(-ENOMEM);
1288
1289         memmove(ret, st, sizeof(struct p9_stat));
1290         p = ((char *) ret) + sizeof(struct p9_stat);
1291         memmove(p, st->name.str, st->name.len);
1292         ret->name.str = p;
1293         p += st->name.len;
1294         memmove(p, st->uid.str, st->uid.len);
1295         ret->uid.str = p;
1296         p += st->uid.len;
1297         memmove(p, st->gid.str, st->gid.len);
1298         ret->gid.str = p;
1299         p += st->gid.len;
1300         memmove(p, st->muid.str, st->muid.len);
1301         ret->muid.str = p;
1302         p += st->muid.len;
1303
1304         if (dotu) {
1305                 memmove(p, st->extension.str, st->extension.len);
1306                 ret->extension.str = p;
1307                 p += st->extension.len;
1308         }
1309
1310         return ret;
1311 }
1312
1313 struct p9_stat *p9_client_stat(struct p9_fid *fid)
1314 {
1315         int err;
1316         struct p9_fcall *tc, *rc;
1317         struct p9_client *clnt;
1318         struct p9_stat *ret;
1319
1320         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1321         err = 0;
1322         tc = NULL;
1323         rc = NULL;
1324         ret = NULL;
1325         clnt = fid->clnt;
1326
1327         tc = p9_create_tstat(fid->fid);
1328         if (IS_ERR(tc)) {
1329                 err = PTR_ERR(tc);
1330                 tc = NULL;
1331                 goto error;
1332         }
1333
1334         err = p9_client_rpc(clnt, tc, &rc);
1335         if (err)
1336                 goto error;
1337
1338         ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
1339         if (IS_ERR(ret)) {
1340                 err = PTR_ERR(ret);
1341                 ret = NULL;
1342                 goto error;
1343         }
1344
1345         kfree(tc);
1346         kfree(rc);
1347         return ret;
1348
1349 error:
1350         kfree(tc);
1351         kfree(rc);
1352         kfree(ret);
1353         return ERR_PTR(err);
1354 }
1355 EXPORT_SYMBOL(p9_client_stat);
1356
1357 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1358 {
1359         int err;
1360         struct p9_fcall *tc, *rc;
1361         struct p9_client *clnt;
1362
1363         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1364         err = 0;
1365         tc = NULL;
1366         rc = NULL;
1367         clnt = fid->clnt;
1368
1369         tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
1370         if (IS_ERR(tc)) {
1371                 err = PTR_ERR(tc);
1372                 tc = NULL;
1373                 goto done;
1374         }
1375
1376         err = p9_client_rpc(clnt, tc, &rc);
1377
1378 done:
1379         kfree(tc);
1380         kfree(rc);
1381         return err;
1382 }
1383 EXPORT_SYMBOL(p9_client_wstat);
1384
1385 struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset)
1386 {
1387         int err, n, m;
1388         struct p9_fcall *tc, *rc;
1389         struct p9_client *clnt;
1390         struct p9_stat st, *ret;
1391
1392         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu\n", fid->fid,
1393                                                 (long long unsigned) offset);
1394         err = 0;
1395         tc = NULL;
1396         rc = NULL;
1397         ret = NULL;
1398         clnt = fid->clnt;
1399
1400         /* if the offset is below or above the current response, free it */
1401         if (offset < fid->rdir_fpos || (fid->rdir_fcall &&
1402                 offset >= fid->rdir_fpos+fid->rdir_fcall->params.rread.count)) {
1403                 fid->rdir_pos = 0;
1404                 if (fid->rdir_fcall)
1405                         fid->rdir_fpos += fid->rdir_fcall->params.rread.count;
1406
1407                 kfree(fid->rdir_fcall);
1408                 fid->rdir_fcall = NULL;
1409                 if (offset < fid->rdir_fpos)
1410                         fid->rdir_fpos = 0;
1411         }
1412
1413         if (!fid->rdir_fcall) {
1414                 n = fid->iounit;
1415                 if (!n || n > clnt->msize-P9_IOHDRSZ)
1416                         n = clnt->msize - P9_IOHDRSZ;
1417
1418                 while (1) {
1419                         if (fid->rdir_fcall) {
1420                                 fid->rdir_fpos +=
1421                                         fid->rdir_fcall->params.rread.count;
1422                                 kfree(fid->rdir_fcall);
1423                                 fid->rdir_fcall = NULL;
1424                         }
1425
1426                         tc = p9_create_tread(fid->fid, fid->rdir_fpos, n);
1427                         if (IS_ERR(tc)) {
1428                                 err = PTR_ERR(tc);
1429                                 tc = NULL;
1430                                 goto error;
1431                         }
1432
1433                         err = p9_client_rpc(clnt, tc, &rc);
1434                         if (err)
1435                                 goto error;
1436
1437                         n = rc->params.rread.count;
1438                         if (n == 0)
1439                                 goto done;
1440
1441                         fid->rdir_fcall = rc;
1442                         rc = NULL;
1443                         if (offset >= fid->rdir_fpos &&
1444                                                 offset < fid->rdir_fpos+n)
1445                                 break;
1446                 }
1447
1448                 fid->rdir_pos = 0;
1449         }
1450
1451         m = offset - fid->rdir_fpos;
1452         if (m < 0)
1453                 goto done;
1454
1455         n = p9_deserialize_stat(fid->rdir_fcall->params.rread.data + m,
1456                 fid->rdir_fcall->params.rread.count - m, &st, clnt->dotu);
1457
1458         if (!n) {
1459                 err = -EIO;
1460                 goto error;
1461         }
1462
1463         fid->rdir_pos += n;
1464         st.size = n;
1465         ret = p9_clone_stat(&st, clnt->dotu);
1466         if (IS_ERR(ret)) {
1467                 err = PTR_ERR(ret);
1468                 ret = NULL;
1469                 goto error;
1470         }
1471
1472 done:
1473         kfree(tc);
1474         kfree(rc);
1475         return ret;
1476
1477 error:
1478         kfree(tc);
1479         kfree(rc);
1480         kfree(ret);
1481         return ERR_PTR(err);
1482 }
1483 EXPORT_SYMBOL(p9_client_dirread);