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