net/9p/client.c

   1 /*
   2  * net/9p/clnt.c
   3  *
   4  * 9P Client
   5  *
   6  *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/poll.h>
  30 #include <linux/idr.h>
  31 #include <linux/mutex.h>
  32 #include <linux/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         if (req->rc->id == P9_RERROR) {
 506                 int ecode = req->rc->params.rerror.errno;
 507                 struct p9_str *ename = &req->rc->params.rerror.error;
 508
 509                 P9_DPRINTK(P9_DEBUG_MUX, "Rerror %.*s\n", ename->len,
 510                                                                 ename->str);
 511
 512                 if (c->dotu)
 513                         err = -ecode;
 514
 515                 if (!err) {
 516                         err = p9_errstr2errno(ename->str, ename->len);
 517
 518                         /* string match failed */
 519                         if (!err) {
 520                                 PRINT_FCALL_ERROR("unknown error", req->rc);
 521                                 err = -ESERVERFAULT;
 522                         }
 523                 }
 524         } else
 525                 err = 0;
 526
 527 reterr:
 528         p9_free_req(c, req);
 529
 530         P9_DPRINTK(P9_DEBUG_9P, "returning %d\n", err);
 531         return err;
 532 }
 533
 534 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 535 {
 536         int err;
 537         struct p9_fid *fid;
 538
 539         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 540         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 541         if (!fid)
 542                 return ERR_PTR(-ENOMEM);
 543
 544         fid->fid = p9_idpool_get(clnt->fidpool);
 545         if (fid->fid < 0) {
 546                 err = -ENOSPC;
 547                 goto error;
 548         }
 549
 550         memset(&fid->qid, 0, sizeof(struct p9_qid));
 551         fid->mode = -1;
 552         fid->rdir_fpos = 0;
 553         fid->uid = current->fsuid;
 554         fid->clnt = clnt;
 555         fid->aux = NULL;
 556
 557         spin_lock(&clnt->lock);
 558         list_add(&fid->flist, &clnt->fidlist);
 559         spin_unlock(&clnt->lock);
 560
 561         return fid;
 562
 563 error:
 564         kfree(fid);
 565         return ERR_PTR(err);
 566 }
 567
 568 static void p9_fid_destroy(struct p9_fid *fid)
 569 {
 570         struct p9_client *clnt;
 571
 572         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 573         clnt = fid->clnt;
 574         p9_idpool_put(fid->fid, clnt->fidpool);
 575         spin_lock(&clnt->lock);
 576         list_del(&fid->flist);
 577         spin_unlock(&clnt->lock);
 578         kfree(fid);
 579 }
 580
 581 static int p9_client_version(struct p9_client *clnt)
 582 {
 583         int err = 0;
 584         struct p9_fcall *tc, *rc;
 585         struct p9_str *version;
 586
 587         P9_DPRINTK(P9_DEBUG_9P, "%p\n", clnt);
 588         err = 0;
 589         tc = NULL;
 590         rc = NULL;
 591
 592         tc = p9_create_tversion(clnt->msize,
 593                                         clnt->dotu ? "9P2000.u" : "9P2000");
 594         if (IS_ERR(tc)) {
 595                 err = PTR_ERR(tc);
 596                 tc = NULL;
 597                 goto error;
 598         }
 599
 600         err = p9_client_rpc(clnt, tc, &rc);
 601         if (err)
 602                 goto error;
 603
 604         version = &rc->params.rversion.version;
 605         if (version->len == 8 && !memcmp(version->str, "9P2000.u", 8))
 606                 clnt->dotu = 1;
 607         else if (version->len == 6 && !memcmp(version->str, "9P2000", 6))
 608                 clnt->dotu = 0;
 609         else {
 610                 err = -EREMOTEIO;
 611                 goto error;
 612         }
 613
 614         if (rc->params.rversion.msize < clnt->msize)
 615                 clnt->msize = rc->params.rversion.msize;
 616
 617 error:
 618         kfree(tc);
 619         kfree(rc);
 620
 621         return err;
 622 }
 623 EXPORT_SYMBOL(p9_client_auth);
 624
 625 struct p9_client *p9_client_create(const char *dev_name, char *options)
 626 {
 627         int err;
 628         struct p9_client *clnt;
 629
 630         err = 0;
 631         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 632         if (!clnt)
 633                 return ERR_PTR(-ENOMEM);
 634
 635         clnt->trans_mod = NULL;
 636         clnt->trans = NULL;
 637         spin_lock_init(&clnt->lock);
 638         INIT_LIST_HEAD(&clnt->fidlist);
 639         clnt->fidpool = p9_idpool_create();
 640         if (IS_ERR(clnt->fidpool)) {
 641                 err = PTR_ERR(clnt->fidpool);
 642                 clnt->fidpool = NULL;
 643                 goto error;
 644         }
 645
 646         p9_tag_init(clnt);
 647
 648         err = parse_opts(options, clnt);
 649         if (err < 0)
 650                 goto error;
 651
 652         if (clnt->trans_mod == NULL) {
 653                 err = -EPROTONOSUPPORT;
 654                 P9_DPRINTK(P9_DEBUG_ERROR,
 655                                 "No transport defined or default transport\n");
 656                 goto error;
 657         }
 658
 659         P9_DPRINTK(P9_DEBUG_9P, "clnt %p trans %p msize %d dotu %d\n",
 660                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 661
 662         err = clnt->trans_mod->create(clnt, dev_name, options);
 663         if (err)
 664                 goto error;
 665
 666         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 667                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 668
 669         err = p9_client_version(clnt);
 670         if (err)
 671                 goto error;
 672
 673         return clnt;
 674
 675 error:
 676         p9_client_destroy(clnt);
 677         return ERR_PTR(err);
 678 }
 679 EXPORT_SYMBOL(p9_client_create);
 680
 681 void p9_client_destroy(struct p9_client *clnt)
 682 {
 683         struct p9_fid *fid, *fidptr;
 684
 685         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 686
 687         if (clnt->trans_mod)
 688                 clnt->trans_mod->close(clnt);
 689
 690         v9fs_put_trans(clnt->trans_mod);
 691
 692         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 693                 p9_fid_destroy(fid);
 694
 695         if (clnt->fidpool)
 696                 p9_idpool_destroy(clnt->fidpool);
 697
 698         p9_tag_cleanup(clnt);
 699
 700         kfree(clnt);
 701 }
 702 EXPORT_SYMBOL(p9_client_destroy);
 703
 704 void p9_client_disconnect(struct p9_client *clnt)
 705 {
 706         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 707         clnt->status = Disconnected;
 708 }
 709 EXPORT_SYMBOL(p9_client_disconnect);
 710
 711 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 712         char *uname, u32 n_uname, char *aname)
 713 {
 714         int err;
 715         struct p9_fcall *tc, *rc;
 716         struct p9_fid *fid;
 717
 718         P9_DPRINTK(P9_DEBUG_9P, "clnt %p afid %d uname %s aname %s\n",
 719                 clnt, afid?afid->fid:-1, uname, aname);
 720         err = 0;
 721         tc = NULL;
 722         rc = NULL;
 723
 724         fid = p9_fid_create(clnt);
 725         if (IS_ERR(fid)) {
 726                 err = PTR_ERR(fid);
 727                 fid = NULL;
 728                 goto error;
 729         }
 730
 731         tc = p9_create_tattach(fid->fid, afid?afid->fid:P9_NOFID, uname, aname,
 732                 n_uname, clnt->dotu);
 733         if (IS_ERR(tc)) {
 734                 err = PTR_ERR(tc);
 735                 tc = NULL;
 736                 goto error;
 737         }
 738
 739         err = p9_client_rpc(clnt, tc, &rc);
 740         if (err)
 741                 goto error;
 742
 743         memmove(&fid->qid, &rc->params.rattach.qid, sizeof(struct p9_qid));
 744         kfree(tc);
 745         kfree(rc);
 746         return fid;
 747
 748 error:
 749         kfree(tc);
 750         kfree(rc);
 751         if (fid)
 752                 p9_fid_destroy(fid);
 753         return ERR_PTR(err);
 754 }
 755 EXPORT_SYMBOL(p9_client_attach);
 756
 757 struct p9_fid *p9_client_auth(struct p9_client *clnt, char *uname,
 758         u32 n_uname, char *aname)
 759 {
 760         int err;
 761         struct p9_fcall *tc, *rc;
 762         struct p9_fid *fid;
 763
 764         P9_DPRINTK(P9_DEBUG_9P, "clnt %p uname %s aname %s\n", clnt, uname,
 765                                                                         aname);
 766         err = 0;
 767         tc = NULL;
 768         rc = NULL;
 769
 770         fid = p9_fid_create(clnt);
 771         if (IS_ERR(fid)) {
 772                 err = PTR_ERR(fid);
 773                 fid = NULL;
 774                 goto error;
 775         }
 776
 777         tc = p9_create_tauth(fid->fid, uname, aname, n_uname, clnt->dotu);
 778         if (IS_ERR(tc)) {
 779                 err = PTR_ERR(tc);
 780                 tc = NULL;
 781                 goto error;
 782         }
 783
 784         err = p9_client_rpc(clnt, tc, &rc);
 785         if (err)
 786                 goto error;
 787
 788         memmove(&fid->qid, &rc->params.rauth.qid, sizeof(struct p9_qid));
 789         kfree(tc);
 790         kfree(rc);
 791         return fid;
 792
 793 error:
 794         kfree(tc);
 795         kfree(rc);
 796         if (fid)
 797                 p9_fid_destroy(fid);
 798         return ERR_PTR(err);
 799 }
 800 EXPORT_SYMBOL(p9_client_auth);
 801
 802 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 803         int clone)
 804 {
 805         int err;
 806         struct p9_fcall *tc, *rc;
 807         struct p9_client *clnt;
 808         struct p9_fid *fid;
 809
 810         P9_DPRINTK(P9_DEBUG_9P, "fid %d nwname %d wname[0] %s\n",
 811                 oldfid->fid, nwname, wnames?wnames[0]:NULL);
 812         err = 0;
 813         tc = NULL;
 814         rc = NULL;
 815         clnt = oldfid->clnt;
 816         if (clone) {
 817                 fid = p9_fid_create(clnt);
 818                 if (IS_ERR(fid)) {
 819                         err = PTR_ERR(fid);
 820                         fid = NULL;
 821                         goto error;
 822                 }
 823
 824                 fid->uid = oldfid->uid;
 825         } else
 826                 fid = oldfid;
 827
 828         tc = p9_create_twalk(oldfid->fid, fid->fid, nwname, wnames);
 829         if (IS_ERR(tc)) {
 830                 err = PTR_ERR(tc);
 831                 tc = NULL;
 832                 goto error;
 833         }
 834
 835         err = p9_client_rpc(clnt, tc, &rc);
 836         if (err) {
 837                 if (rc && rc->id == P9_RWALK)
 838                         goto clunk_fid;
 839                 else
 840                         goto error;
 841         }
 842
 843         if (rc->params.rwalk.nwqid != nwname) {
 844                 err = -ENOENT;
 845                 goto clunk_fid;
 846         }
 847
 848         if (nwname)
 849                 memmove(&fid->qid,
 850                         &rc->params.rwalk.wqids[rc->params.rwalk.nwqid - 1],
 851                         sizeof(struct p9_qid));
 852         else
 853                 fid->qid = oldfid->qid;
 854
 855         kfree(tc);
 856         kfree(rc);
 857         return fid;
 858
 859 clunk_fid:
 860         kfree(tc);
 861         kfree(rc);
 862         rc = NULL;
 863         tc = p9_create_tclunk(fid->fid);
 864         if (IS_ERR(tc)) {
 865                 err = PTR_ERR(tc);
 866                 tc = NULL;
 867                 goto error;
 868         }
 869
 870         p9_client_rpc(clnt, tc, &rc);
 871
 872 error:
 873         kfree(tc);
 874         kfree(rc);
 875         if (fid && (fid != oldfid))
 876                 p9_fid_destroy(fid);
 877
 878         return ERR_PTR(err);
 879 }
 880 EXPORT_SYMBOL(p9_client_walk);
 881
 882 int p9_client_open(struct p9_fid *fid, int mode)
 883 {
 884         int err;
 885         struct p9_fcall *tc, *rc;
 886         struct p9_client *clnt;
 887
 888         P9_DPRINTK(P9_DEBUG_9P, "fid %d mode %d\n", fid->fid, mode);
 889         err = 0;
 890         tc = NULL;
 891         rc = NULL;
 892         clnt = fid->clnt;
 893
 894         if (fid->mode != -1)
 895                 return -EINVAL;
 896
 897         tc = p9_create_topen(fid->fid, mode);
 898         if (IS_ERR(tc)) {
 899                 err = PTR_ERR(tc);
 900                 tc = NULL;
 901                 goto done;
 902         }
 903
 904         err = p9_client_rpc(clnt, tc, &rc);
 905         if (err)
 906                 goto done;
 907
 908         fid->mode = mode;
 909         fid->iounit = rc->params.ropen.iounit;
 910
 911 done:
 912         kfree(tc);
 913         kfree(rc);
 914         return err;
 915 }
 916 EXPORT_SYMBOL(p9_client_open);
 917
 918 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
 919                      char *extension)
 920 {
 921         int err;
 922         struct p9_fcall *tc, *rc;
 923         struct p9_client *clnt;
 924
 925         P9_DPRINTK(P9_DEBUG_9P, "fid %d name %s perm %d mode %d\n", fid->fid,
 926                 name, perm, mode);
 927         err = 0;
 928         tc = NULL;
 929         rc = NULL;
 930         clnt = fid->clnt;
 931
 932         if (fid->mode != -1)
 933                 return -EINVAL;
 934
 935         tc = p9_create_tcreate(fid->fid, name, perm, mode, extension,
 936                                                                clnt->dotu);
 937         if (IS_ERR(tc)) {
 938                 err = PTR_ERR(tc);
 939                 tc = NULL;
 940                 goto done;
 941         }
 942
 943         err = p9_client_rpc(clnt, tc, &rc);
 944         if (err)
 945                 goto done;
 946
 947         fid->mode = mode;
 948         fid->iounit = rc->params.ropen.iounit;
 949
 950 done:
 951         kfree(tc);
 952         kfree(rc);
 953         return err;
 954 }
 955 EXPORT_SYMBOL(p9_client_fcreate);
 956
 957 int p9_client_clunk(struct p9_fid *fid)
 958 {
 959         int err;
 960         struct p9_fcall *tc, *rc;
 961         struct p9_client *clnt;
 962
 963         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 964         err = 0;
 965         tc = NULL;
 966         rc = NULL;
 967         clnt = fid->clnt;
 968
 969         tc = p9_create_tclunk(fid->fid);
 970         if (IS_ERR(tc)) {
 971                 err = PTR_ERR(tc);
 972                 tc = NULL;
 973                 goto done;
 974         }
 975
 976         err = p9_client_rpc(clnt, tc, &rc);
 977         if (err)
 978                 goto done;
 979
 980         p9_fid_destroy(fid);
 981
 982 done:
 983         kfree(tc);
 984         kfree(rc);
 985         return err;
 986 }
 987 EXPORT_SYMBOL(p9_client_clunk);
 988
 989 int p9_client_remove(struct p9_fid *fid)
 990 {
 991         int err;
 992         struct p9_fcall *tc, *rc;
 993         struct p9_client *clnt;
 994
 995         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
 996         err = 0;
 997         tc = NULL;
 998         rc = NULL;
 999         clnt = fid->clnt;
1000
1001         tc = p9_create_tremove(fid->fid);
1002         if (IS_ERR(tc)) {
1003                 err = PTR_ERR(tc);
1004                 tc = NULL;
1005                 goto done;
1006         }
1007
1008         err = p9_client_rpc(clnt, tc, &rc);
1009         if (err)
1010                 goto done;
1011
1012         p9_fid_destroy(fid);
1013
1014 done:
1015         kfree(tc);
1016         kfree(rc);
1017         return err;
1018 }
1019 EXPORT_SYMBOL(p9_client_remove);
1020
1021 int
1022 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1023                                                                 u32 count)
1024 {
1025         int err, n, rsize, total;
1026         struct p9_fcall *tc, *rc;
1027         struct p9_client *clnt;
1028
1029         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu %d\n", fid->fid,
1030                                         (long long unsigned) offset, count);
1031         err = 0;
1032         tc = NULL;
1033         rc = NULL;
1034         clnt = fid->clnt;
1035         total = 0;
1036
1037         rsize = fid->iounit;
1038         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1039                 rsize = clnt->msize - P9_IOHDRSZ;
1040
1041         do {
1042                 if (count < rsize)
1043                         rsize = count;
1044
1045                 tc = p9_create_tread(fid->fid, offset, rsize);
1046                 if (IS_ERR(tc)) {
1047                         err = PTR_ERR(tc);
1048                         tc = NULL;
1049                         goto error;
1050                 }
1051
1052                 err = p9_client_rpc(clnt, tc, &rc);
1053                 if (err)
1054                         goto error;
1055
1056                 n = rc->params.rread.count;
1057                 if (n > count)
1058                         n = count;
1059
1060                 if (data) {
1061                         memmove(data, rc->params.rread.data, n);
1062                         data += n;
1063                 }
1064
1065                 if (udata) {
1066                         err = copy_to_user(udata, rc->params.rread.data, n);
1067                         if (err) {
1068                                 err = -EFAULT;
1069                                 goto error;
1070                         }
1071                         udata += n;
1072                 }
1073
1074                 count -= n;
1075                 offset += n;
1076                 total += n;
1077                 kfree(tc);
1078                 tc = NULL;
1079                 kfree(rc);
1080                 rc = NULL;
1081         } while (count > 0 && n == rsize);
1082
1083         return total;
1084
1085 error:
1086         kfree(tc);
1087         kfree(rc);
1088         return err;
1089 }
1090 EXPORT_SYMBOL(p9_client_read);
1091
1092 int
1093 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1094                                                         u64 offset, u32 count)
1095 {
1096         int err, n, rsize, total;
1097         struct p9_fcall *tc, *rc;
1098         struct p9_client *clnt;
1099
1100         P9_DPRINTK(P9_DEBUG_9P, "fid %d offset %llu count %d\n", fid->fid,
1101                                         (long long unsigned) offset, count);
1102         err = 0;
1103         tc = NULL;
1104         rc = NULL;
1105         clnt = fid->clnt;
1106         total = 0;
1107
1108         rsize = fid->iounit;
1109         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1110                 rsize = clnt->msize - P9_IOHDRSZ;
1111
1112         do {
1113                 if (count < rsize)
1114                         rsize = count;
1115
1116                 if (data)
1117                         tc = p9_create_twrite(fid->fid, offset, rsize, data);
1118                 else
1119                         tc = p9_create_twrite_u(fid->fid, offset, rsize, udata);
1120                 if (IS_ERR(tc)) {
1121                         err = PTR_ERR(tc);
1122                         tc = NULL;
1123                         goto error;
1124                 }
1125
1126                 err = p9_client_rpc(clnt, tc, &rc);
1127                 if (err)
1128                         goto error;
1129
1130                 n = rc->params.rread.count;
1131                 count -= n;
1132
1133                 if (data)
1134                         data += n;
1135                 else
1136                         udata += n;
1137
1138                 offset += n;
1139                 total += n;
1140                 kfree(tc);
1141                 tc = NULL;
1142                 kfree(rc);
1143                 rc = NULL;
1144         } while (count > 0);
1145
1146         return total;
1147
1148 error:
1149         kfree(tc);
1150         kfree(rc);
1151         return err;
1152 }
1153 EXPORT_SYMBOL(p9_client_write);
1154
1155 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu)
1156 {
1157         int n;
1158         char *p;
1159         struct p9_stat *ret;
1160
1161         n = sizeof(struct p9_stat) + st->name.len + st->uid.len + st->gid.len +
1162                 st->muid.len;
1163
1164         if (dotu)
1165                 n += st->extension.len;
1166
1167         ret = kmalloc(n, GFP_KERNEL);
1168         if (!ret)
1169                 return ERR_PTR(-ENOMEM);
1170
1171         memmove(ret, st, sizeof(struct p9_stat));
1172         p = ((char *) ret) + sizeof(struct p9_stat);
1173         memmove(p, st->name.str, st->name.len);
1174         ret->name.str = p;
1175         p += st->name.len;
1176         memmove(p, st->uid.str, st->uid.len);
1177         ret->uid.str = p;
1178         p += st->uid.len;
1179         memmove(p, st->gid.str, st->gid.len);
1180         ret->gid.str = p;
1181         p += st->gid.len;
1182         memmove(p, st->muid.str, st->muid.len);
1183         ret->muid.str = p;
1184         p += st->muid.len;
1185
1186         if (dotu) {
1187                 memmove(p, st->extension.str, st->extension.len);
1188                 ret->extension.str = p;
1189                 p += st->extension.len;
1190         }
1191
1192         return ret;
1193 }
1194
1195 struct p9_stat *p9_client_stat(struct p9_fid *fid)
1196 {
1197         int err;
1198         struct p9_fcall *tc, *rc;
1199         struct p9_client *clnt;
1200         struct p9_stat *ret;
1201
1202         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1203         err = 0;
1204         tc = NULL;
1205         rc = NULL;
1206         ret = NULL;
1207         clnt = fid->clnt;
1208
1209         tc = p9_create_tstat(fid->fid);
1210         if (IS_ERR(tc)) {
1211                 err = PTR_ERR(tc);
1212                 tc = NULL;
1213                 goto error;
1214         }
1215
1216         err = p9_client_rpc(clnt, tc, &rc);
1217         if (err)
1218                 goto error;
1219
1220         ret = p9_clone_stat(&rc->params.rstat.stat, clnt->dotu);
1221         if (IS_ERR(ret)) {
1222                 err = PTR_ERR(ret);
1223                 ret = NULL;
1224                 goto error;
1225         }
1226
1227         kfree(tc);
1228         kfree(rc);
1229         return ret;
1230
1231 error:
1232         kfree(tc);
1233         kfree(rc);
1234         kfree(ret);
1235         return ERR_PTR(err);
1236 }
1237 EXPORT_SYMBOL(p9_client_stat);
1238
1239 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1240 {
1241         int err;
1242         struct p9_fcall *tc, *rc;
1243         struct p9_client *clnt;
1244
1245         P9_DPRINTK(P9_DEBUG_9P, "fid %d\n", fid->fid);
1246         err = 0;
1247         tc = NULL;
1248         rc = NULL;
1249         clnt = fid->clnt;
1250
1251         tc = p9_create_twstat(fid->fid, wst, clnt->dotu);
1252         if (IS_ERR(tc)) {
1253                 err = PTR_ERR(tc);
1254                 tc = NULL;
1255                 goto done;
1256         }
1257
1258         err = p9_client_rpc(clnt, tc, &rc);
1259
1260 done:
1261         kfree(tc);
1262         kfree(rc);
1263         return err;
1264 }
1265 EXPORT_SYMBOL(p9_client_wstat);