net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2
  10  *  as published by the Free Software Foundation.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to:
  19  *  Free Software Foundation
  20  *  51 Franklin Street, Fifth Floor
  21  *  Boston, MA  02111-1301  USA
  22  *
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/errno.h>
  27 #include <linux/fs.h>
  28 #include <linux/idr.h>
  29 #include <linux/mutex.h>
  30 #include <linux/sched.h>
  31 #include <linux/uaccess.h>
  32 #include <net/9p/9p.h>
  33 #include <linux/parser.h>
  34 #include <net/9p/transport.h>
  35 #include <net/9p/conn.h>
  36 #include <net/9p/client.h>
  37
  38 static struct p9_fid *p9_fid_create(struct p9_client *clnt);
  39 static void p9_fid_destroy(struct p9_fid *fid);
  40 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu);
  41
  42 struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
  43                                                                    int dotu)
  44 {
  45         int err, n;
  46         struct p9_client *clnt;
  47         struct p9_fcall *tc, *rc;
  48         struct p9_str *version;
  49
  50         err = 0;
  51         tc = NULL;
  52         rc = NULL;
  53         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
  54         if (!clnt)
  55                 return ERR_PTR(-ENOMEM);
  56
  57         P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
  58                 clnt, trans, msize, dotu);
  59         spin_lock_init(&clnt->lock);
  60         clnt->trans = trans;
  61         clnt->msize = msize;
  62         clnt->dotu = dotu;
  63         INIT_LIST_HEAD(&clnt->fidlist);
  64         clnt->fidpool = p9_idpool_create();
  65         if (!clnt->fidpool) {
  66                 err = PTR_ERR(clnt->fidpool);
  67                 clnt->fidpool = NULL;
  68                 goto error;
  69         }
  70
  71         clnt->conn = p9_conn_create(clnt->trans, clnt->msize, &clnt->dotu);
  72         if (IS_ERR(clnt->conn)) {
  73                 err = PTR_ERR(clnt->conn);
  74                 clnt->conn = NULL;
  75                 goto error;
  76         }
  77
  78         tc = p9_create_tversion(clnt->msize, clnt->dotu?"9P2000.u":"9P2000");
  79         if (IS_ERR(tc)) {
  80                 err = PTR_ERR(tc);
  81                 tc = NULL;
  82                 goto error;
  83         }
  84
  85         err = p9_conn_rpc(clnt->conn, tc, &rc);
  86         if (err)
  87                 goto error;
  88
  89         version = &rc->params.rversion.version;
  90         if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
  91                 clnt->dotu = 1;
  92         else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
  93                 clnt->dotu = 0;
  94         else {
  95                 err = -EREMOTEIO;
  96                 goto error;
  97         }
  98
  99         n = rc->params.rversion.msize;
 100         if (n < clnt->msize)
 101                 clnt->msize = n;
 102
 103         kfree(tc);
 104         kfree(rc);
 105         return clnt;
 106
 107 error:
 108         kfree(tc);
 109         kfree(rc);
 110         p9_client_destroy(clnt);
 111         return ERR_PTR(err);
 112 }
 113 EXPORT_SYMBOL(p9_client_create);
 114
 115 void p9_client_destroy(struct p9_client *clnt)
 116 {
 117         struct p9_fid *fid, *fidptr;
 118
 119         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 120         if (clnt->conn) {
 121                 p9_conn_destroy(clnt->conn);
 122                 clnt->conn = NULL;
 123         }
 124
 125         if (clnt->trans) {
 126                 clnt->trans->close(clnt->trans);
 127                 kfree(clnt->trans);
 128                 clnt->trans = NULL;
 129         }
 130
 131         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 132                 p9_fid_destroy(fid);
 133
 134         if (clnt->fidpool)
 135                 p9_idpool_destroy(clnt->fidpool);
 136
 137         kfree(clnt);
 138 }
 139 EXPORT_SYMBOL(p9_client_destroy);
 140
 141 void p9_client_disconnect(struct p9_client *clnt)
 142 {
 143         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 144         clnt->trans->status = Disconnected;
 145         p9_conn_cancel(clnt->conn, -EIO);
 146 }
 147 EXPORT_SYMBOL(p9_client_disconnect);
 148
 149 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 150         char *uname, u32 n_uname, char *aname)
 151 {
 152         int err;
 153         struct p9_fcall *tc, *rc;
 154         struct p9_fid *fid;
 155
 156         P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
 157                 clnt, afid?afid->fid:-1, uname, aname);
 158         err = 0;
 159         tc = NULL;
 160         rc = NULL;
 161
 162         fid = p9_fid_create(clnt);
 163         if (IS_ERR(fid)) {
 164                 err = PTR_ERR(fid);
 165                 fid = NULL;
 166                 goto error;
 167         }
 168
 169         tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
 170                 n_uname, clnt->dotu);
 171         if (IS_ERR(tc)) {
 172                 err = PTR_ERR(tc);
 173                 tc = NULL;
 174                 goto error;
 175         }
 176
 177         err = p9_conn_rpc(clnt->conn, tc, &rc);
 178         if (err)
 179                 goto error;
 180
 181         memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
 182         kfree(tc);
 183         kfree(rc);
 184         return fid;
 185
 186 error:
 187         kfree(tc);
 188         kfree(rc);
 189         if (fid)
 190                 p9_fid_destroy(fid);
 191         return ERR_PTR(err);
 192 }
 193 EXPORT_SYMBOL(p9_client_attach);
 194
 195 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
 196         u32 n_uname, char *aname)
 197 {
 198         int err;
 199         struct p9_fcall *tc, *rc;
 200         struct p9_fid *fid;
 201
 202         P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
 203                                                                         aname);
 204         err = 0;
 205         tc = NULL;
 206         rc = NULL;
 207
 208         fid = p9_fid_create(clnt);
 209         if (IS_ERR(fid)) {
 210                 err = PTR_ERR(fid);
 211                 fid = NULL;
 212                 goto error;
 213         }
 214
 215         tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
 216         if (IS_ERR(tc)) {
 217                 err = PTR_ERR(tc);
 218                 tc = NULL;
 219                 goto error;
 220         }
 221
 222         err = p9_conn_rpc(clnt->conn, tc, &rc);
 223         if (err)
 224                 goto error;
 225
 226         memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
 227         kfree(tc);
 228         kfree(rc);
 229         return fid;
 230
 231 error:
 232         kfree(tc);
 233         kfree(rc);
 234         if (fid)
 235                 p9_fid_destroy(fid);
 236         return ERR_PTR(err);
 237 }
 238 EXPORT_SYMBOL(p9_client_auth);
 239
 240 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 241         int clone)
 242 {
 243         int err;
 244         struct p9_fcall *tc, *rc;
 245         struct p9_client *clnt;
 246         struct p9_fid *fid;
 247
 248         P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
 249                 oldfid->fid, nwname, wnames?wnames[0]:NULL);
 250         err = 0;
 251         tc = NULL;
 252         rc = NULL;
 253         clnt = oldfid->clnt;
 254         if (clone) {
 255                 fid = p9_fid_create(clnt);
 256                 if (IS_ERR(fid)) {
 257                         err = PTR_ERR(fid);
 258                         fid = NULL;
 259                         goto error;
 260                 }
 261
 262                 fid->uid = oldfid->uid;
 263         } else
 264                 fid = oldfid;
 265
 266         tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
 267         if (IS_ERR(tc)) {
 268                 err = PTR_ERR(tc);
 269                 tc = NULL;
 270                 goto error;
 271         }
 272
 273         err = p9_conn_rpc(clnt->conn, tc, &rc);
 274         if (err) {
 275                 if (rc && rc->id == P9_RWALK)
 276                         goto clunk_fid;
 277                 else
 278                         goto error;
 279         }
 280
 281         if (rc->params.rwalk.nwqid != nwname) {
 282                 err = -ENOENT;
 283                 goto clunk_fid;
 284         }
 285
 286         if (nwname)
 287                 memmove(&fid->qid,
 288                         &rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
 289                         sizeof(struct p9_qid));
 290         else
 291                 fid->qid = oldfid->qid;
 292
 293         kfree(tc);
 294         kfree(rc);
 295         return fid;
 296
 297 clunk_fid:
 298         kfree(tc);
 299         kfree(rc);
 300         rc = NULL;
 301         tc = p9_create_tclunk(fid->fid);
 302         if (IS_ERR(tc)) {
 303                 err = PTR_ERR(tc);
 304                 tc = NULL;
 305                 goto error;
 306         }
 307
 308         p9_conn_rpc(clnt->conn, tc, &rc);
 309
 310 error:
 311         kfree(tc);
 312         kfree(rc);
 313         if (fid && (fid != oldfid))
 314                 p9_fid_destroy(fid);
 315
 316         return ERR_PTR(err);
 317 }
 318 EXPORT_SYMBOL(p9_client_walk);
 319
 320 int p9_client_open(struct p9_fid *fid, int mode)
 321 {
 322         int err;
 323         struct p9_fcall *tc, *rc;
 324         struct p9_client *clnt;
 325
 326         P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
 327         err = 0;
 328         tc = NULL;
 329         rc = NULL;
 330         clnt = fid->clnt;
 331
 332         if (fid->mode != -1)
 333                 return -EINVAL;
 334
 335         tc = p9_create_topen(fid->fid, mode);
 336         if (IS_ERR(tc)) {
 337                 err = PTR_ERR(tc);
 338                 tc = NULL;
 339                 goto done;
 340         }
 341
 342         err = p9_conn_rpc(clnt->conn, tc, &rc);
 343         if (err)
 344                 goto done;
 345
 346         fid->mode = mode;
 347         fid->iounit = rc->params.ropen.iounit;
 348
 349 done:
 350         kfree(tc);
 351         kfree(rc);
 352         return err;
 353 }
 354 EXPORT_SYMBOL(p9_client_open);
 355
 356 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 357                      char *extension)
 358 {
 359         int err;
 360         struct p9_fcall *tc, *rc;
 361         struct p9_client *clnt;
 362
 363         P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
 364                 name, perm, mode);
 365         err = 0;
 366         tc = NULL;
 367         rc = NULL;
 368         clnt = fid->clnt;
 369
 370         if (fid->mode != -1)
 371                 return -EINVAL;
 372
 373         tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
 374                                                                clnt->dotu);
 375         if (IS_ERR(tc)) {
 376                 err = PTR_ERR(tc);
 377                 tc = NULL;
 378                 goto done;
 379         }
 380
 381         err = p9_conn_rpc(clnt->conn, tc, &rc);
 382         if (err)
 383                 goto done;
 384
 385         fid->mode = mode;
 386         fid->iounit = rc->params.ropen.iounit;
 387
 388 done:
 389         kfree(tc);
 390         kfree(rc);
 391         return err;
 392 }
 393 EXPORT_SYMBOL(p9_client_fcreate);
 394
 395 int p9_client_clunk(struct p9_fid *fid)
 396 {
 397         int err;
 398         struct p9_fcall *tc, *rc;
 399         struct p9_client *clnt;
 400
 401         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 402         err = 0;
 403         tc = NULL;
 404         rc = NULL;
 405         clnt = fid->clnt;
 406
 407         tc = p9_create_tclunk(fid->fid);
 408         if (IS_ERR(tc)) {
 409                 err = PTR_ERR(tc);
 410                 tc = NULL;
 411                 goto done;
 412         }
 413
 414         err = p9_conn_rpc(clnt->conn, tc, &rc);
 415         if (err)
 416                 goto done;
 417
 418         p9_fid_destroy(fid);
 419
 420 done:
 421         kfree(tc);
 422         kfree(rc);
 423         return err;
 424 }
 425 EXPORT_SYMBOL(p9_client_clunk);
 426
 427 int p9_client_remove(struct p9_fid *fid)
 428 {
 429         int err;
 430         struct p9_fcall *tc, *rc;
 431         struct p9_client *clnt;
 432
 433         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 434         err = 0;
 435         tc = NULL;
 436         rc = NULL;
 437         clnt = fid->clnt;
 438
 439         tc = p9_create_tremove(fid->fid);
 440         if (IS_ERR(tc)) {
 441                 err = PTR_ERR(tc);
 442                 tc = NULL;
 443                 goto done;
 444         }
 445
 446         err = p9_conn_rpc(clnt->conn, tc, &rc);
 447         if (err)
 448                 goto done;
 449
 450         p9_fid_destroy(fid);
 451
 452 done:
 453         kfree(tc);
 454         kfree(rc);
 455         return err;
 456 }
 457 EXPORT_SYMBOL(p9_client_remove);
 458
 459 int p9_client_read(struct p9_fid *fid, char *data, u64 offset, u32 count)
 460 {
 461         int err, n, rsize, total;
 462         struct p9_fcall *tc, *rc;
 463         struct p9_client *clnt;
 464
 465         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
 466                                         (long long unsigned) offset, count);
 467         err = 0;
 468         tc = NULL;
 469         rc = NULL;
 470         clnt = fid->clnt;
 471         total = 0;
 472
 473         rsize = fid->iounit;
 474         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
 475                 rsize = clnt->msize - P9_IOHDRSZ;
 476
 477         do {
 478                 if (count < rsize)
 479                         rsize = count;
 480
 481                 tc = p9_create_tread(fid->fid, offset, rsize);
 482                 if (IS_ERR(tc)) {
 483                         err = PTR_ERR(tc);
 484                         tc = NULL;
 485                         goto error;
 486                 }
 487
 488                 err = p9_conn_rpc(clnt->conn, tc, &rc);
 489                 if (err)
 490                         goto error;
 491
 492                 n = rc->params.rread.count;
 493                 if (n > count)
 494                         n = count;
 495
 496                 memmove(data, rc->params.rread.data, n);
 497                 count -= n;
 498                 data += n;
 499                 offset += n;
 500                 total += n;
 501                 kfree(tc);
 502                 tc = NULL;
 503                 kfree(rc);
 504                 rc = NULL;
 505         } while (count > 0 && n == rsize);
 506
 507         return total;
 508
 509 error:
 510         kfree(tc);
 511         kfree(rc);
 512         return err;
 513 }
 514 EXPORT_SYMBOL(p9_client_read);
 515
 516 int p9_client_write(struct p9_fid *fid, char *data, u64 offset, u32 count)
 517 {
 518         int err, n, rsize, total;
 519         struct p9_fcall *tc, *rc;
 520         struct p9_client *clnt;
 521
 522         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
 523                                         (long long unsigned) offset, count);
 524         err = 0;
 525         tc = NULL;
 526         rc = NULL;
 527         clnt = fid->clnt;
 528         total = 0;
 529
 530         rsize = fid->iounit;
 531         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
 532                 rsize = clnt->msize - P9_IOHDRSZ;
 533
 534         do {
 535                 if (count < rsize)
 536                         rsize = count;
 537
 538                 tc = p9_create_twrite(fid->fid, offset, rsize, data);
 539                 if (IS_ERR(tc)) {
 540                         err = PTR_ERR(tc);
 541                         tc = NULL;
 542                         goto error;
 543                 }
 544
 545                 err = p9_conn_rpc(clnt->conn, tc, &rc);
 546                 if (err)
 547                         goto error;
 548
 549                 n = rc->params.rread.count;
 550                 count -= n;
 551                 data += n;
 552                 offset += n;
 553                 total += n;
 554                 kfree(tc);
 555                 tc = NULL;
 556                 kfree(rc);
 557                 rc = NULL;
 558         } while (count > 0);
 559
 560         return total;
 561
 562 error:
 563         kfree(tc);
 564         kfree(rc);
 565         return err;
 566 }
 567 EXPORT_SYMBOL(p9_client_write);
 568
 569 int
 570 p9_client_uread(struct p9_fid *fid, char __user *data, u64 offset, u32 count)
 571 {
 572         int err, n, rsize, total;
 573         struct p9_fcall *tc, *rc;
 574         struct p9_client *clnt;
 575
 576         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
 577                                         (long long unsigned) offset, count);
 578         err = 0;
 579         tc = NULL;
 580         rc = NULL;
 581         clnt = fid->clnt;
 582         total = 0;
 583
 584         rsize = fid->iounit;
 585         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
 586                 rsize = clnt->msize - P9_IOHDRSZ;
 587
 588         do {
 589                 if (count < rsize)
 590                         rsize = count;
 591
 592                 tc = p9_create_tread(fid->fid, offset, rsize);
 593                 if (IS_ERR(tc)) {
 594                         err = PTR_ERR(tc);
 595                         tc = NULL;
 596                         goto error;
 597                 }
 598
 599                 err = p9_conn_rpc(clnt->conn, tc, &rc);
 600                 if (err)
 601                         goto error;
 602
 603                 n = rc->params.rread.count;
 604                 if (n > count)
 605                         n = count;
 606
 607                 err = copy_to_user(data, rc->params.rread.data, n);
 608                 if (err) {
 609                         err = -EFAULT;
 610                         goto error;
 611                 }
 612
 613                 count -= n;
 614                 data += n;
 615                 offset += n;
 616                 total += n;
 617                 kfree(tc);
 618                 tc = NULL;
 619                 kfree(rc);
 620                 rc = NULL;
 621         } while (count > 0 && n == rsize);
 622
 623         return total;
 624
 625 error:
 626         kfree(tc);
 627         kfree(rc);
 628         return err;
 629 }
 630 EXPORT_SYMBOL(p9_client_uread);
 631
 632 int
 633 p9_client_uwrite(struct p9_fid *fid, const char __user *data, u64 offset,
 634                                                                    u32 count)
 635 {
 636         int err, n, rsize, total;
 637         struct p9_fcall *tc, *rc;
 638         struct p9_client *clnt;
 639
 640         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
 641                                         (long long unsigned) offset, count);
 642         err = 0;
 643         tc = NULL;
 644         rc = NULL;
 645         clnt = fid->clnt;
 646         total = 0;
 647
 648         rsize = fid->iounit;
 649         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
 650                 rsize = clnt->msize - P9_IOHDRSZ;
 651
 652         do {
 653                 if (count < rsize)
 654                         rsize = count;
 655
 656                 tc = p9_create_twrite_u(fid->fid, offset, rsize, data);
 657                 if (IS_ERR(tc)) {
 658                         err = PTR_ERR(tc);
 659                         tc = NULL;
 660                         goto error;
 661                 }
 662
 663                 err = p9_conn_rpc(clnt->conn, tc, &rc);
 664                 if (err)
 665                         goto error;
 666
 667                 n = rc->params.rread.count;
 668                 count -= n;
 669                 data += n;
 670                 offset += n;
 671                 total += n;
 672                 kfree(tc);
 673                 tc = NULL;
 674                 kfree(rc);
 675                 rc = NULL;
 676         } while (count > 0);
 677
 678         return total;
 679
 680 error:
 681         kfree(tc);
 682         kfree(rc);
 683         return err;
 684 }
 685 EXPORT_SYMBOL(p9_client_uwrite);
 686
 687 int p9_client_readn(struct p9_fid *fid, char *data, u64 offset, u32 count)
 688 {
 689         int n, total;
 690
 691         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
 692                                         (long long unsigned) offset, count);
 693         n = 0;
 694         total = 0;
 695         while (count) {
 696                 n = p9_client_read(fid, data, offset, count);
 697                 if (n <= 0)
 698                         break;
 699
 700                 data += n;
 701                 offset += n;
 702                 count -= n;
 703                 total += n;
 704         }
 705
 706         if (n < 0)
 707                 total = n;
 708
 709         return total;
 710 }
 711 EXPORT_SYMBOL(p9_client_readn);
 712
 713 struct p9_stat *p9_client_stat(struct p9_fid *fid)
 714 {
 715         int err;
 716         struct p9_fcall *tc, *rc;
 717         struct p9_client *clnt;
 718         struct p9_stat *ret;
 719
 720         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 721         err = 0;
 722         tc = NULL;
 723         rc = NULL;
 724         ret = NULL;
 725         clnt = fid->clnt;
 726
 727         tc = p9_create_tstat(fid->fid);
 728         if (IS_ERR(tc)) {
 729                 err = PTR_ERR(tc);
 730                 tc = NULL;
 731                 goto error;
 732         }
 733
 734         err = p9_conn_rpc(clnt->conn, tc, &rc);
 735         if (err)
 736                 goto error;
 737
 738         ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
 739         if (IS_ERR(ret)) {
 740                 err = PTR_ERR(ret);
 741                 ret = NULL;
 742                 goto error;
 743         }
 744
 745         kfree(tc);
 746         kfree(rc);
 747         return ret;
 748
 749 error:
 750         kfree(tc);
 751         kfree(rc);
 752         kfree(ret);
 753         return ERR_PTR(err);
 754 }
 755 EXPORT_SYMBOL(p9_client_stat);
 756
 757 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
 758 {
 759         int err;
 760         struct p9_fcall *tc, *rc;
 761         struct p9_client *clnt;
 762
 763         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 764         err = 0;
 765         tc = NULL;
 766         rc = NULL;
 767         clnt = fid->clnt;
 768
 769         tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
 770         if (IS_ERR(tc)) {
 771                 err = PTR_ERR(tc);
 772                 tc = NULL;
 773                 goto done;
 774         }
 775
 776         err = p9_conn_rpc(clnt->conn, tc, &rc);
 777
 778 done:
 779         kfree(tc);
 780         kfree(rc);
 781         return err;
 782 }
 783 EXPORT_SYMBOL(p9_client_wstat);
 784
 785 struct p9_stat *p9_client_dirread(struct p9_fid *fid, u64 offset)
 786 {
 787         int err, n, m;
 788         struct p9_fcall *tc, *rc;
 789         struct p9_client *clnt;
 790         struct p9_stat st, *ret;
 791
 792         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu\n", fid->fid,
 793                                                 (long long unsigned) offset);
 794         err = 0;
 795         tc = NULL;
 796         rc = NULL;
 797         ret = NULL;
 798         clnt = fid->clnt;
 799
 800         /* if the offset is below or above the current response, free it */
 801         if (offset < fid->rdir_fpos || (fid->rdir_fcall &&
 802                 offset >= fid->rdir_fpos+fid->rdir_fcall->params.rread.count)) {
 803                 fid->rdir_pos = 0;
 804                 if (fid->rdir_fcall)
 805                         fid->rdir_fpos += fid->rdir_fcall->params.rread.count;
 806
 807                 kfree(fid->rdir_fcall);
 808                 fid->rdir_fcall = NULL;
 809                 if (offset < fid->rdir_fpos)
 810                         fid->rdir_fpos = 0;
 811         }
 812
 813         if (!fid->rdir_fcall) {
 814                 n = fid->iounit;
 815                 if (!n || n > clnt->msize-P9_IOHDRSZ)
 816                         n = clnt->msize - P9_IOHDRSZ;
 817
 818                 while (1) {
 819                         if (fid->rdir_fcall) {
 820                                 fid->rdir_fpos +=
 821                                         fid->rdir_fcall->params.rread.count;
 822                                 kfree(fid->rdir_fcall);
 823                                 fid->rdir_fcall = NULL;
 824                         }
 825
 826                         tc = p9_create_tread(fid->fid, fid->rdir_fpos, n);
 827                         if (IS_ERR(tc)) {
 828                                 err = PTR_ERR(tc);
 829                                 tc = NULL;
 830                                 goto error;
 831                         }
 832
 833                         err = p9_conn_rpc(clnt->conn, tc, &rc);
 834                         if (err)
 835                                 goto error;
 836
 837                         n = rc->params.rread.count;
 838                         if (n == 0)
 839                                 goto done;
 840
 841                         fid->rdir_fcall = rc;
 842                         rc = NULL;
 843                         if (offset >= fid->rdir_fpos &&
 844                                                 offset < fid->rdir_fpos+n)
 845                                 break;
 846                 }
 847
 848                 fid->rdir_pos = 0;
 849         }
 850
 851         m = offset - fid->rdir_fpos;
 852         if (m < 0)
 853                 goto done;
 854
 855         n = p9_deserialize_stat(fid->rdir_fcall->params.rread.data + m,
 856                 fid->rdir_fcall->params.rread.count - m, &st, clnt->dotu);
 857
 858         if (!n) {
 859                 err = -EIO;
 860                 goto error;
 861         }
 862
 863         fid->rdir_pos += n;
 864         st.size = n;
 865         ret = p9_clone_stat(&st, clnt->dotu);
 866         if (IS_ERR(ret)) {
 867                 err = PTR_ERR(ret);
 868                 ret = NULL;
 869                 goto error;
 870         }
 871
 872 done:
 873         kfree(tc);
 874         kfree(rc);
 875         return ret;
 876
 877 error:
 878         kfree(tc);
 879         kfree(rc);
 880         kfree(ret);
 881         return ERR_PTR(err);
 882 }
 883 EXPORT_SYMBOL(p9_client_dirread);
 884
 885 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
 886 {
 887         int n;
 888         char *p;
 889         struct p9_stat *ret;
 890
 891         n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
 892                 st->muid.len;
 893
 894         if (dotu)
 895                 n += st->extension.len;
 896
 897         ret = kmalloc(n, GFP_KERNEL);
 898         if (!ret)
 899                 return ERR_PTR(-ENOMEM);
 900
 901         memmove(ret, st, sizeof(struct p9_stat));
 902         p = ((char *) ret) + sizeof(struct p9_stat);
 903         memmove(p, st->name.str, st->name.len);
 904         p += st->name.len;
 905         memmove(p, st->uid.str, st->uid.len);
 906         p += st->uid.len;
 907         memmove(p, st->gid.str, st->gid.len);
 908         p += st->gid.len;
 909         memmove(p, st->muid.str, st->muid.len);
 910         p += st->muid.len;
 911
 912         if (dotu) {
 913                 memmove(p, st->extension.str, st->extension.len);
 914                 p += st->extension.len;
 915         }
 916
 917         return ret;
 918 }
 919
 920 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 921 {
 922         int err;
 923         struct p9_fid *fid;
 924
 925         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 926         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 927         if (!fid)
 928                 return ERR_PTR(-ENOMEM);
 929
 930         fid->fid = p9_idpool_get(clnt->fidpool);
 931         if (fid->fid < 0) {
 932                 err = -ENOSPC;
 933                 goto error;
 934         }
 935
 936         memset(&fid->qid, 0, sizeof(struct p9_qid));
 937         fid->mode = -1;
 938         fid->rdir_fpos = 0;
 939         fid->rdir_pos = 0;
 940         fid->rdir_fcall = NULL;
 941         fid->uid = current->fsuid;
 942         fid->clnt = clnt;
 943         fid->aux = NULL;
 944
 945         spin_lock(&clnt->lock);
 946         list_add(&fid->flist, &clnt->fidlist);
 947         spin_unlock(&clnt->lock);
 948
 949         return fid;
 950
 951 error:
 952         kfree(fid);
 953         return ERR_PTR(err);
 954 }
 955
 956 static void p9_fid_destroy(struct p9_fid *fid)
 957 {
 958         struct p9_client *clnt;
 959
 960         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 961         clnt = fid->clnt;
 962         p9_idpool_put(fid->fid, clnt->fidpool);
 963         spin_lock(&clnt->lock);
 964         list_del(&fid->flist);
 965         spin_unlock(&clnt->lock);
 966         kfree(fid->rdir_fcall);
 967         kfree(fid);
 968 }