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 #include "protocol.h"
  39
  40 /*
  41   * Client Option Parsing (code inspired by NFS code)
  42   *  - a little lazy - parse all client options
  43   */
  44
  45 enum {
  46         Opt_msize,
  47         Opt_trans,
  48         Opt_legacy,
  49         Opt_err,
  50 };
  51
  52 static const match_table_t tokens = {
  53         {Opt_msize, "msize=%u"},
  54         {Opt_legacy, "noextend"},
  55         {Opt_trans, "trans=%s"},
  56         {Opt_err, NULL},
  57 };
  58
  59 static struct p9_req_t *
  60 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
  61
  62 /**
  63  * v9fs_parse_options - parse mount options into session structure
  64  * @options: options string passed from mount
  65  * @v9ses: existing v9fs session information
  66  *
  67  * Return 0 upon success, -ERRNO upon failure
  68  */
  69
  70 static int parse_opts(char *opts, struct p9_client *clnt)
  71 {
  72         char *options;
  73         char *p;
  74         substring_t args[MAX_OPT_ARGS];
  75         int option;
  76         int ret = 0;
  77
  78         clnt->dotu = 1;
  79         clnt->msize = 8192;
  80
  81         if (!opts)
  82                 return 0;
  83
  84         options = kstrdup(opts, GFP_KERNEL);
  85         if (!options) {
  86                 P9_DPRINTK(P9_DEBUG_ERROR,
  87                                 "failed to allocate copy of option string\n");
  88                 return -ENOMEM;
  89         }
  90
  91         while ((p = strsep(&options, ",")) != NULL) {
  92                 int token;
  93                 if (!*p)
  94                         continue;
  95                 token = match_token(p, tokens, args);
  96                 if (token < Opt_trans) {
  97                         int r = match_int(&args[0], &option);
  98                         if (r < 0) {
  99                                 P9_DPRINTK(P9_DEBUG_ERROR,
 100                                         "integer field, but no integer?\n");
 101                                 ret = r;
 102                                 continue;
 103                         }
 104                 }
 105                 switch (token) {
 106                 case Opt_msize:
 107                         clnt->msize = option;
 108                         break;
 109                 case Opt_trans:
 110                         clnt->trans_mod = v9fs_get_trans_by_name(&args[0]);
 111                         break;
 112                 case Opt_legacy:
 113                         clnt->dotu = 0;
 114                         break;
 115                 default:
 116                         continue;
 117                 }
 118         }
 119
 120         if (!clnt->trans_mod)
 121                 clnt->trans_mod = v9fs_get_default_trans();
 122
 123         kfree(options);
 124         return ret;
 125 }
 126
 127 /**
 128  * p9_tag_alloc - lookup/allocate a request by tag
 129  * @c: client session to lookup tag within
 130  * @tag: numeric id for transaction
 131  *
 132  * this is a simple array lookup, but will grow the
 133  * request_slots as necessary to accomodate transaction
 134  * ids which did not previously have a slot.
 135  *
 136  * this code relies on the client spinlock to manage locks, its
 137  * possible we should switch to something else, but I'd rather
 138  * stick with something low-overhead for the common case.
 139  *
 140  */
 141
 142 static struct p9_req_t *p9_tag_alloc(struct p9_client *c, u16 tag)
 143 {
 144         unsigned long flags;
 145         int row, col;
 146         struct p9_req_t *req;
 147
 148         /* This looks up the original request by tag so we know which
 149          * buffer to read the data into */
 150         tag++;
 151
 152         if (tag >= c->max_tag) {
 153                 spin_lock_irqsave(&c->lock, flags);
 154                 /* check again since original check was outside of lock */
 155                 while (tag >= c->max_tag) {
 156                         row = (tag / P9_ROW_MAXTAG);
 157                         c->reqs[row] = kcalloc(P9_ROW_MAXTAG,
 158                                         sizeof(struct p9_req_t), GFP_ATOMIC);
 159
 160                         if (!c->reqs[row]) {
 161                                 printk(KERN_ERR "Couldn't grow tag array\n");
 162                                 spin_unlock_irqrestore(&c->lock, flags);
 163                                 return ERR_PTR(-ENOMEM);
 164                         }
 165                         for (col = 0; col < P9_ROW_MAXTAG; col++) {
 166                                 c->reqs[row][col].status = REQ_STATUS_IDLE;
 167                                 c->reqs[row][col].tc = NULL;
 168                         }
 169                         c->max_tag += P9_ROW_MAXTAG;
 170                 }
 171                 spin_unlock_irqrestore(&c->lock, flags);
 172         }
 173         row = tag / P9_ROW_MAXTAG;
 174         col = tag % P9_ROW_MAXTAG;
 175
 176         req = &c->reqs[row][col];
 177         if (!req->tc) {
 178                 req->wq = kmalloc(sizeof(wait_queue_head_t), GFP_KERNEL);
 179                 if (!req->wq) {
 180                         printk(KERN_ERR "Couldn't grow tag array\n");
 181                         return ERR_PTR(-ENOMEM);
 182                 }
 183                 init_waitqueue_head(req->wq);
 184                 req->tc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 185                                                                 GFP_KERNEL);
 186                 req->rc = kmalloc(sizeof(struct p9_fcall)+c->msize,
 187                                                                 GFP_KERNEL);
 188                 if ((!req->tc) || (!req->rc)) {
 189                         printk(KERN_ERR "Couldn't grow tag array\n");
 190                         kfree(req->tc);
 191                         kfree(req->rc);
 192                         kfree(req->wq);
 193                         req->tc = req->rc = NULL;
 194                         req->wq = NULL;
 195                         return ERR_PTR(-ENOMEM);
 196                 }
 197                 req->tc->sdata = (char *) req->tc + sizeof(struct p9_fcall);
 198                 req->tc->capacity = c->msize;
 199                 req->rc->sdata = (char *) req->rc + sizeof(struct p9_fcall);
 200                 req->rc->capacity = c->msize;
 201         }
 202
 203         p9pdu_reset(req->tc);
 204         p9pdu_reset(req->rc);
 205
 206         req->flush_tag = 0;
 207         req->tc->tag = tag-1;
 208         req->status = REQ_STATUS_ALLOC;
 209
 210         return &c->reqs[row][col];
 211 }
 212
 213 /**
 214  * p9_tag_lookup - lookup a request by tag
 215  * @c: client session to lookup tag within
 216  * @tag: numeric id for transaction
 217  *
 218  */
 219
 220 struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag)
 221 {
 222         int row, col;
 223
 224         /* This looks up the original request by tag so we know which
 225          * buffer to read the data into */
 226         tag++;
 227
 228         BUG_ON(tag >= c->max_tag);
 229
 230         row = tag / P9_ROW_MAXTAG;
 231         col = tag % P9_ROW_MAXTAG;
 232
 233         return &c->reqs[row][col];
 234 }
 235 EXPORT_SYMBOL(p9_tag_lookup);
 236
 237 /**
 238  * p9_tag_init - setup tags structure and contents
 239  * @tags: tags structure from the client struct
 240  *
 241  * This initializes the tags structure for each client instance.
 242  *
 243  */
 244
 245 static int p9_tag_init(struct p9_client *c)
 246 {
 247         int err = 0;
 248
 249         c->tagpool = p9_idpool_create();
 250         if (IS_ERR(c->tagpool)) {
 251                 err = PTR_ERR(c->tagpool);
 252                 c->tagpool = NULL;
 253                 goto error;
 254         }
 255
 256         p9_idpool_get(c->tagpool); /* reserve tag 0 */
 257
 258         c->max_tag = 0;
 259 error:
 260         return err;
 261 }
 262
 263 /**
 264  * p9_tag_cleanup - cleans up tags structure and reclaims resources
 265  * @tags: tags structure from the client struct
 266  *
 267  * This frees resources associated with the tags structure
 268  *
 269  */
 270 static void p9_tag_cleanup(struct p9_client *c)
 271 {
 272         int row, col;
 273
 274         /* check to insure all requests are idle */
 275         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 276                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 277                         if (c->reqs[row][col].status != REQ_STATUS_IDLE) {
 278                                 P9_DPRINTK(P9_DEBUG_MUX,
 279                                   "Attempting to cleanup non-free tag %d,%d\n",
 280                                   row, col);
 281                                 /* TODO: delay execution of cleanup */
 282                                 return;
 283                         }
 284                 }
 285         }
 286
 287         if (c->tagpool)
 288                 p9_idpool_destroy(c->tagpool);
 289
 290         /* free requests associated with tags */
 291         for (row = 0; row < (c->max_tag/P9_ROW_MAXTAG); row++) {
 292                 for (col = 0; col < P9_ROW_MAXTAG; col++) {
 293                         kfree(c->reqs[row][col].wq);
 294                         kfree(c->reqs[row][col].tc);
 295                         kfree(c->reqs[row][col].rc);
 296                 }
 297                 kfree(c->reqs[row]);
 298         }
 299         c->max_tag = 0;
 300 }
 301
 302 /**
 303  * p9_free_req - free a request and clean-up as necessary
 304  * c: client state
 305  * r: request to release
 306  *
 307  */
 308
 309 static void p9_free_req(struct p9_client *c, struct p9_req_t *r)
 310 {
 311         int tag = r->tc->tag;
 312         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p req %p tag: %d\n", c, r, tag);
 313
 314         r->status = REQ_STATUS_IDLE;
 315         if (tag != P9_NOTAG && p9_idpool_check(tag, c->tagpool))
 316                 p9_idpool_put(tag, c->tagpool);
 317 }
 318
 319 /**
 320  * p9_client_cb - call back from transport to client
 321  * c: client state
 322  * req: request received
 323  *
 324  */
 325 void p9_client_cb(struct p9_client *c, struct p9_req_t *req)
 326 {
 327         struct p9_req_t *other_req;
 328         unsigned long flags;
 329
 330         P9_DPRINTK(P9_DEBUG_MUX, " tag %d\n", req->tc->tag);
 331
 332         if (req->status == REQ_STATUS_ERROR)
 333                 wake_up(req->wq);
 334
 335         if (req->flush_tag) {                   /* flush receive path */
 336                 P9_DPRINTK(P9_DEBUG_9P, "<<< RFLUSH %d\n", req->tc->tag);
 337                 spin_lock_irqsave(&c->lock, flags);
 338                 other_req = p9_tag_lookup(c, req->flush_tag);
 339                 if (other_req->status != REQ_STATUS_FLSH) /* stale flush */
 340                         spin_unlock_irqrestore(&c->lock, flags);
 341                 else {
 342                         other_req->status = REQ_STATUS_FLSHD;
 343                         spin_unlock_irqrestore(&c->lock, flags);
 344                         wake_up(other_req->wq);
 345                 }
 346                 p9_free_req(c, req);
 347         } else {                                /* normal receive path */
 348                 P9_DPRINTK(P9_DEBUG_MUX, "normal: tag %d\n", req->tc->tag);
 349                 spin_lock_irqsave(&c->lock, flags);
 350                 if (req->status != REQ_STATUS_FLSHD)
 351                         req->status = REQ_STATUS_RCVD;
 352                 spin_unlock_irqrestore(&c->lock, flags);
 353                 wake_up(req->wq);
 354                 P9_DPRINTK(P9_DEBUG_MUX, "wakeup: %d\n", req->tc->tag);
 355         }
 356 }
 357 EXPORT_SYMBOL(p9_client_cb);
 358
 359 /**
 360  * p9_parse_header - parse header arguments out of a packet
 361  * @pdu: packet to parse
 362  * @size: size of packet
 363  * @type: type of request
 364  * @tag: tag of packet
 365  * @rewind: set if we need to rewind offset afterwards
 366  */
 367
 368 int
 369 p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, int16_t *tag,
 370                                                                 int rewind)
 371 {
 372         int8_t r_type;
 373         int16_t r_tag;
 374         int32_t r_size;
 375         int offset = pdu->offset;
 376         int err;
 377
 378         pdu->offset = 0;
 379         if (pdu->size == 0)
 380                 pdu->size = 7;
 381
 382         err = p9pdu_readf(pdu, 0, "dbw", &r_size, &r_type, &r_tag);
 383         if (err)
 384                 goto rewind_and_exit;
 385
 386         pdu->size = r_size;
 387         pdu->id = r_type;
 388         pdu->tag = r_tag;
 389
 390         P9_DPRINTK(P9_DEBUG_9P, "<<< size=%d type: %d tag: %d\n", pdu->size,
 391                                                         pdu->id, pdu->tag);
 392
 393         if (type)
 394                 *type = r_type;
 395         if (tag)
 396                 *tag = r_tag;
 397         if (size)
 398                 *size = r_size;
 399
 400
 401 rewind_and_exit:
 402         if (rewind)
 403                 pdu->offset = offset;
 404         return err;
 405 }
 406 EXPORT_SYMBOL(p9_parse_header);
 407
 408 /**
 409  * p9_check_errors - check 9p packet for error return and process it
 410  * @c: current client instance
 411  * @req: request to parse and check for error conditions
 412  *
 413  * returns error code if one is discovered, otherwise returns 0
 414  *
 415  * this will have to be more complicated if we have multiple
 416  * error packet types
 417  */
 418
 419 static int p9_check_errors(struct p9_client *c, struct p9_req_t *req)
 420 {
 421         int8_t type;
 422         int err;
 423
 424         err = p9_parse_header(req->rc, NULL, &type, NULL, 0);
 425         if (err) {
 426                 P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse header %d\n", err);
 427                 return err;
 428         }
 429
 430         if (type == P9_RERROR) {
 431                 int ecode;
 432                 char *ename;
 433
 434                 err = p9pdu_readf(req->rc, c->dotu, "s?d", &ename, &ecode);
 435                 if (err) {
 436                         P9_DPRINTK(P9_DEBUG_ERROR, "couldn't parse error%d\n",
 437                                                                         err);
 438                         return err;
 439                 }
 440
 441                 if (c->dotu)
 442                         err = -ecode;
 443
 444                 if (!err) {
 445                         err = p9_errstr2errno(ename, strlen(ename));
 446
 447                         /* string match failed */
 448                         if (!err)
 449                                 err = -ESERVERFAULT;
 450                 }
 451
 452                 P9_DPRINTK(P9_DEBUG_9P, "<<< RERROR (%d) %s\n", -ecode, ename);
 453
 454                 kfree(ename);
 455         } else
 456                 err = 0;
 457
 458         return err;
 459 }
 460
 461 /**
 462  * p9_client_flush - flush (cancel) a request
 463  * c: client state
 464  * req: request to cancel
 465  *
 466  * This sents a flush for a particular requests and links
 467  * the flush request to the original request.  The current
 468  * code only supports a single flush request although the protocol
 469  * allows for multiple flush requests to be sent for a single request.
 470  *
 471  */
 472
 473 static int p9_client_flush(struct p9_client *c, struct p9_req_t *oldreq)
 474 {
 475         struct p9_req_t *req;
 476         int16_t oldtag;
 477         int err;
 478
 479         err = p9_parse_header(oldreq->tc, NULL, NULL, &oldtag, 1);
 480         if (err)
 481                 return err;
 482
 483         P9_DPRINTK(P9_DEBUG_9P, ">>> TFLUSH tag %d\n", oldtag);
 484
 485         req = p9_client_rpc(c, P9_TFLUSH, "w", oldtag);
 486         if (IS_ERR(req))
 487                 return PTR_ERR(req);
 488
 489         req->flush_tag = oldtag;
 490
 491         /* we don't free anything here because RPC isn't complete */
 492         return 0;
 493 }
 494
 495 /**
 496  * p9_client_rpc - issue a request and wait for a response
 497  * @c: client session
 498  * @type: type of request
 499  * @fmt: protocol format string (see protocol.c)
 500  *
 501  * Returns request structure (which client must free using p9_free_req)
 502  */
 503
 504 static struct p9_req_t *
 505 p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...)
 506 {
 507         va_list ap;
 508         int tag, err;
 509         struct p9_req_t *req;
 510         unsigned long flags;
 511         int sigpending;
 512         int flushed = 0;
 513
 514         P9_DPRINTK(P9_DEBUG_MUX, "client %p op %d\n", c, type);
 515
 516         if (c->status != Connected)
 517                 return ERR_PTR(-EIO);
 518
 519         if (signal_pending(current)) {
 520                 sigpending = 1;
 521                 clear_thread_flag(TIF_SIGPENDING);
 522         } else
 523                 sigpending = 0;
 524
 525         tag = P9_NOTAG;
 526         if (type != P9_TVERSION) {
 527                 tag = p9_idpool_get(c->tagpool);
 528                 if (tag < 0)
 529                         return ERR_PTR(-ENOMEM);
 530         }
 531
 532         req = p9_tag_alloc(c, tag);
 533         if (IS_ERR(req))
 534                 return req;
 535
 536         /* marshall the data */
 537         p9pdu_prepare(req->tc, tag, type);
 538         va_start(ap, fmt);
 539         err = p9pdu_vwritef(req->tc, c->dotu, fmt, ap);
 540         va_end(ap);
 541         p9pdu_finalize(req->tc);
 542
 543         err = c->trans_mod->request(c, req);
 544         if (err < 0) {
 545                 c->status = Disconnected;
 546                 goto reterr;
 547         }
 548
 549         /* if it was a flush we just transmitted, return our tag */
 550         if (type == P9_TFLUSH)
 551                 return req;
 552 again:
 553         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d\n", req->wq, tag);
 554         err = wait_event_interruptible(*req->wq,
 555                                                 req->status >= REQ_STATUS_RCVD);
 556         P9_DPRINTK(P9_DEBUG_MUX, "wait %p tag: %d returned %d (flushed=%d)\n",
 557                                                 req->wq, tag, err, flushed);
 558
 559         if (req->status == REQ_STATUS_ERROR) {
 560                 P9_DPRINTK(P9_DEBUG_ERROR, "req_status error %d\n", req->t_err);
 561                 err = req->t_err;
 562         } else if (err == -ERESTARTSYS && flushed) {
 563                 P9_DPRINTK(P9_DEBUG_MUX, "flushed - going again\n");
 564                 goto again;
 565         } else if (req->status == REQ_STATUS_FLSHD) {
 566                 P9_DPRINTK(P9_DEBUG_MUX, "flushed - erestartsys\n");
 567                 err = -ERESTARTSYS;
 568         }
 569
 570         if ((err == -ERESTARTSYS) && (c->status == Connected) && (!flushed)) {
 571                 P9_DPRINTK(P9_DEBUG_MUX, "flushing\n");
 572                 spin_lock_irqsave(&c->lock, flags);
 573                 if (req->status == REQ_STATUS_SENT)
 574                         req->status = REQ_STATUS_FLSH;
 575                 spin_unlock_irqrestore(&c->lock, flags);
 576                 sigpending = 1;
 577                 flushed = 1;
 578                 clear_thread_flag(TIF_SIGPENDING);
 579
 580                 if (c->trans_mod->cancel(c, req)) {
 581                         err = p9_client_flush(c, req);
 582                         if (err == 0)
 583                                 goto again;
 584                 }
 585         }
 586
 587         if (sigpending) {
 588                 spin_lock_irqsave(&current->sighand->siglock, flags);
 589                 recalc_sigpending();
 590                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 591         }
 592
 593         if (err < 0)
 594                 goto reterr;
 595
 596         err = p9_check_errors(c, req);
 597         if (!err) {
 598                 P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d\n", c, type);
 599                 return req;
 600         }
 601
 602 reterr:
 603         P9_DPRINTK(P9_DEBUG_MUX, "exit: client %p op %d error: %d\n", c, type,
 604                                                                         err);
 605         p9_free_req(c, req);
 606         return ERR_PTR(err);
 607 }
 608
 609 static struct p9_fid *p9_fid_create(struct p9_client *clnt)
 610 {
 611         int ret;
 612         struct p9_fid *fid;
 613         unsigned long flags;
 614
 615         P9_DPRINTK(P9_DEBUG_FID, "clnt %p\n", clnt);
 616         fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);
 617         if (!fid)
 618                 return ERR_PTR(-ENOMEM);
 619
 620         ret = p9_idpool_get(clnt->fidpool);
 621         if (ret < 0) {
 622                 ret = -ENOSPC;
 623                 goto error;
 624         }
 625         fid->fid = ret;
 626
 627         memset(&fid->qid, 0, sizeof(struct p9_qid));
 628         fid->mode = -1;
 629         fid->rdir_fpos = 0;
 630         fid->uid = current_fsuid();
 631         fid->clnt = clnt;
 632         fid->aux = NULL;
 633
 634         spin_lock_irqsave(&clnt->lock, flags);
 635         list_add(&fid->flist, &clnt->fidlist);
 636         spin_unlock_irqrestore(&clnt->lock, flags);
 637
 638         return fid;
 639
 640 error:
 641         kfree(fid);
 642         return ERR_PTR(ret);
 643 }
 644
 645 static void p9_fid_destroy(struct p9_fid *fid)
 646 {
 647         struct p9_client *clnt;
 648         unsigned long flags;
 649
 650         P9_DPRINTK(P9_DEBUG_FID, "fid %d\n", fid->fid);
 651         clnt = fid->clnt;
 652         p9_idpool_put(fid->fid, clnt->fidpool);
 653         spin_lock_irqsave(&clnt->lock, flags);
 654         list_del(&fid->flist);
 655         spin_unlock_irqrestore(&clnt->lock, flags);
 656         kfree(fid);
 657 }
 658
 659 int p9_client_version(struct p9_client *c)
 660 {
 661         int err = 0;
 662         struct p9_req_t *req;
 663         char *version;
 664         int msize;
 665
 666         P9_DPRINTK(P9_DEBUG_9P, ">>> TVERSION msize %d extended %d\n",
 667                                                         c->msize, c->dotu);
 668         req = p9_client_rpc(c, P9_TVERSION, "ds", c->msize,
 669                                 c->dotu ? "9P2000.u" : "9P2000");
 670         if (IS_ERR(req))
 671                 return PTR_ERR(req);
 672
 673         err = p9pdu_readf(req->rc, c->dotu, "ds", &msize, &version);
 674         if (err) {
 675                 P9_DPRINTK(P9_DEBUG_9P, "version error %d\n", err);
 676                 p9pdu_dump(1, req->rc);
 677                 goto error;
 678         }
 679
 680         P9_DPRINTK(P9_DEBUG_9P, "<<< RVERSION msize %d %s\n", msize, version);
 681         if (!memcmp(version, "9P2000.u", 8))
 682                 c->dotu = 1;
 683         else if (!memcmp(version, "9P2000", 6))
 684                 c->dotu = 0;
 685         else {
 686                 err = -EREMOTEIO;
 687                 goto error;
 688         }
 689
 690         if (msize < c->msize)
 691                 c->msize = msize;
 692
 693 error:
 694         kfree(version);
 695         p9_free_req(c, req);
 696
 697         return err;
 698 }
 699 EXPORT_SYMBOL(p9_client_version);
 700
 701 struct p9_client *p9_client_create(const char *dev_name, char *options)
 702 {
 703         int err;
 704         struct p9_client *clnt;
 705
 706         err = 0;
 707         clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL);
 708         if (!clnt)
 709                 return ERR_PTR(-ENOMEM);
 710
 711         clnt->trans_mod = NULL;
 712         clnt->trans = NULL;
 713         spin_lock_init(&clnt->lock);
 714         INIT_LIST_HEAD(&clnt->fidlist);
 715         clnt->fidpool = p9_idpool_create();
 716         if (IS_ERR(clnt->fidpool)) {
 717                 err = PTR_ERR(clnt->fidpool);
 718                 clnt->fidpool = NULL;
 719                 goto error;
 720         }
 721
 722         p9_tag_init(clnt);
 723
 724         err = parse_opts(options, clnt);
 725         if (err < 0)
 726                 goto error;
 727
 728         if (clnt->trans_mod == NULL) {
 729                 err = -EPROTONOSUPPORT;
 730                 P9_DPRINTK(P9_DEBUG_ERROR,
 731                                 "No transport defined or default transport\n");
 732                 goto error;
 733         }
 734
 735         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p trans %p msize %d dotu %d\n",
 736                 clnt, clnt->trans_mod, clnt->msize, clnt->dotu);
 737
 738         err = clnt->trans_mod->create(clnt, dev_name, options);
 739         if (err)
 740                 goto error;
 741
 742         if ((clnt->msize+P9_IOHDRSZ) > clnt->trans_mod->maxsize)
 743                 clnt->msize = clnt->trans_mod->maxsize-P9_IOHDRSZ;
 744
 745         err = p9_client_version(clnt);
 746         if (err)
 747                 goto error;
 748
 749         return clnt;
 750
 751 error:
 752         p9_client_destroy(clnt);
 753         return ERR_PTR(err);
 754 }
 755 EXPORT_SYMBOL(p9_client_create);
 756
 757 void p9_client_destroy(struct p9_client *clnt)
 758 {
 759         struct p9_fid *fid, *fidptr;
 760
 761         P9_DPRINTK(P9_DEBUG_MUX, "clnt %p\n", clnt);
 762
 763         if (clnt->trans_mod)
 764                 clnt->trans_mod->close(clnt);
 765
 766         v9fs_put_trans(clnt->trans_mod);
 767
 768         list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist)
 769                 p9_fid_destroy(fid);
 770
 771         if (clnt->fidpool)
 772                 p9_idpool_destroy(clnt->fidpool);
 773
 774         p9_tag_cleanup(clnt);
 775
 776         kfree(clnt);
 777 }
 778 EXPORT_SYMBOL(p9_client_destroy);
 779
 780 void p9_client_disconnect(struct p9_client *clnt)
 781 {
 782         P9_DPRINTK(P9_DEBUG_9P, "clnt %p\n", clnt);
 783         clnt->status = Disconnected;
 784 }
 785 EXPORT_SYMBOL(p9_client_disconnect);
 786
 787 struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
 788         char *uname, u32 n_uname, char *aname)
 789 {
 790         int err;
 791         struct p9_req_t *req;
 792         struct p9_fid *fid;
 793         struct p9_qid qid;
 794
 795         P9_DPRINTK(P9_DEBUG_9P, ">>> TATTACH afid %d uname %s aname %s\n",
 796                                         afid ? afid->fid : -1, uname, aname);
 797         err = 0;
 798
 799         fid = p9_fid_create(clnt);
 800         if (IS_ERR(fid)) {
 801                 err = PTR_ERR(fid);
 802                 fid = NULL;
 803                 goto error;
 804         }
 805
 806         req = p9_client_rpc(clnt, P9_TATTACH, "ddss?d", fid->fid,
 807                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 808         if (IS_ERR(req)) {
 809                 err = PTR_ERR(req);
 810                 goto error;
 811         }
 812
 813         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 814         if (err) {
 815                 p9pdu_dump(1, req->rc);
 816                 p9_free_req(clnt, req);
 817                 goto error;
 818         }
 819
 820         P9_DPRINTK(P9_DEBUG_9P, "<<< RATTACH qid %x.%llx.%x\n",
 821                                         qid.type,
 822                                         (unsigned long long)qid.path,
 823                                         qid.version);
 824
 825         memmove(&fid->qid, &qid, sizeof(struct p9_qid));
 826
 827         p9_free_req(clnt, req);
 828         return fid;
 829
 830 error:
 831         if (fid)
 832                 p9_fid_destroy(fid);
 833         return ERR_PTR(err);
 834 }
 835 EXPORT_SYMBOL(p9_client_attach);
 836
 837 struct p9_fid *
 838 p9_client_auth(struct p9_client *clnt, char *uname, u32 n_uname, char *aname)
 839 {
 840         int err;
 841         struct p9_req_t *req;
 842         struct p9_qid qid;
 843         struct p9_fid *afid;
 844
 845         P9_DPRINTK(P9_DEBUG_9P, ">>> TAUTH uname %s aname %s\n", uname, aname);
 846         err = 0;
 847
 848         afid = p9_fid_create(clnt);
 849         if (IS_ERR(afid)) {
 850                 err = PTR_ERR(afid);
 851                 afid = NULL;
 852                 goto error;
 853         }
 854
 855         req = p9_client_rpc(clnt, P9_TAUTH, "dss?d",
 856                         afid ? afid->fid : P9_NOFID, uname, aname, n_uname);
 857         if (IS_ERR(req)) {
 858                 err = PTR_ERR(req);
 859                 goto error;
 860         }
 861
 862         err = p9pdu_readf(req->rc, clnt->dotu, "Q", &qid);
 863         if (err) {
 864                 p9pdu_dump(1, req->rc);
 865                 p9_free_req(clnt, req);
 866                 goto error;
 867         }
 868
 869         P9_DPRINTK(P9_DEBUG_9P, "<<< RAUTH qid %x.%llx.%x\n",
 870                                         qid.type,
 871                                         (unsigned long long)qid.path,
 872                                         qid.version);
 873
 874         memmove(&afid->qid, &qid, sizeof(struct p9_qid));
 875         p9_free_req(clnt, req);
 876         return afid;
 877
 878 error:
 879         if (afid)
 880                 p9_fid_destroy(afid);
 881         return ERR_PTR(err);
 882 }
 883 EXPORT_SYMBOL(p9_client_auth);
 884
 885 struct p9_fid *p9_client_walk(struct p9_fid *oldfid, int nwname, char **wnames,
 886         int clone)
 887 {
 888         int err;
 889         struct p9_client *clnt;
 890         struct p9_fid *fid;
 891         struct p9_qid *wqids;
 892         struct p9_req_t *req;
 893         int16_t nwqids, count;
 894
 895         err = 0;
 896         clnt = oldfid->clnt;
 897         if (clone) {
 898                 fid = p9_fid_create(clnt);
 899                 if (IS_ERR(fid)) {
 900                         err = PTR_ERR(fid);
 901                         fid = NULL;
 902                         goto error;
 903                 }
 904
 905                 fid->uid = oldfid->uid;
 906         } else
 907                 fid = oldfid;
 908
 909
 910         P9_DPRINTK(P9_DEBUG_9P, ">>> TWALK fids %d,%d nwname %d wname[0] %s\n",
 911                 oldfid->fid, fid->fid, nwname, wnames ? wnames[0] : NULL);
 912
 913         req = p9_client_rpc(clnt, P9_TWALK, "ddT", oldfid->fid, fid->fid,
 914                                                                 nwname, wnames);
 915         if (IS_ERR(req)) {
 916                 err = PTR_ERR(req);
 917                 goto error;
 918         }
 919
 920         err = p9pdu_readf(req->rc, clnt->dotu, "R", &nwqids, &wqids);
 921         if (err) {
 922                 p9pdu_dump(1, req->rc);
 923                 p9_free_req(clnt, req);
 924                 goto clunk_fid;
 925         }
 926         p9_free_req(clnt, req);
 927
 928         P9_DPRINTK(P9_DEBUG_9P, "<<< RWALK nwqid %d:\n", nwqids);
 929
 930         if (nwqids != nwname) {
 931                 err = -ENOENT;
 932                 goto clunk_fid;
 933         }
 934
 935         for (count = 0; count < nwqids; count++)
 936                 P9_DPRINTK(P9_DEBUG_9P, "<<<     [%d] %x.%llx.%x\n",
 937                         count, wqids[count].type,
 938                         (unsigned long long)wqids[count].path,
 939                         wqids[count].version);
 940
 941         if (nwname)
 942                 memmove(&fid->qid, &wqids[nwqids - 1], sizeof(struct p9_qid));
 943         else
 944                 fid->qid = oldfid->qid;
 945
 946         return fid;
 947
 948 clunk_fid:
 949         p9_client_clunk(fid);
 950         fid = NULL;
 951
 952 error:
 953         if (fid && (fid != oldfid))
 954                 p9_fid_destroy(fid);
 955
 956         return ERR_PTR(err);
 957 }
 958 EXPORT_SYMBOL(p9_client_walk);
 959
 960 int p9_client_open(struct p9_fid *fid, int mode)
 961 {
 962         int err;
 963         struct p9_client *clnt;
 964         struct p9_req_t *req;
 965         struct p9_qid qid;
 966         int iounit;
 967
 968         P9_DPRINTK(P9_DEBUG_9P, ">>> TOPEN fid %d mode %d\n", fid->fid, mode);
 969         err = 0;
 970         clnt = fid->clnt;
 971
 972         if (fid->mode != -1)
 973                 return -EINVAL;
 974
 975         req = p9_client_rpc(clnt, P9_TOPEN, "db", fid->fid, mode);
 976         if (IS_ERR(req)) {
 977                 err = PTR_ERR(req);
 978                 goto error;
 979         }
 980
 981         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
 982         if (err) {
 983                 p9pdu_dump(1, req->rc);
 984                 goto free_and_error;
 985         }
 986
 987         P9_DPRINTK(P9_DEBUG_9P, "<<< ROPEN qid %x.%llx.%x iounit %x\n",
 988                                 qid.type,
 989                                 (unsigned long long)qid.path,
 990                                 qid.version, iounit);
 991
 992         fid->mode = mode;
 993         fid->iounit = iounit;
 994
 995 free_and_error:
 996         p9_free_req(clnt, req);
 997 error:
 998         return err;
 999 }
1000 EXPORT_SYMBOL(p9_client_open);
1001
1002 int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode,
1003                      char *extension)
1004 {
1005         int err;
1006         struct p9_client *clnt;
1007         struct p9_req_t *req;
1008         struct p9_qid qid;
1009         int iounit;
1010
1011         P9_DPRINTK(P9_DEBUG_9P, ">>> TCREATE fid %d name %s perm %d mode %d\n",
1012                                                 fid->fid, name, perm, mode);
1013         err = 0;
1014         clnt = fid->clnt;
1015
1016         if (fid->mode != -1)
1017                 return -EINVAL;
1018
1019         req = p9_client_rpc(clnt, P9_TCREATE, "dsdb?s", fid->fid, name, perm,
1020                                 mode, extension);
1021         if (IS_ERR(req)) {
1022                 err = PTR_ERR(req);
1023                 goto error;
1024         }
1025
1026         err = p9pdu_readf(req->rc, clnt->dotu, "Qd", &qid, &iounit);
1027         if (err) {
1028                 p9pdu_dump(1, req->rc);
1029                 goto free_and_error;
1030         }
1031
1032         P9_DPRINTK(P9_DEBUG_9P, "<<< RCREATE qid %x.%llx.%x iounit %x\n",
1033                                 qid.type,
1034                                 (unsigned long long)qid.path,
1035                                 qid.version, iounit);
1036
1037         fid->mode = mode;
1038         fid->iounit = iounit;
1039
1040 free_and_error:
1041         p9_free_req(clnt, req);
1042 error:
1043         return err;
1044 }
1045 EXPORT_SYMBOL(p9_client_fcreate);
1046
1047 int p9_client_clunk(struct p9_fid *fid)
1048 {
1049         int err;
1050         struct p9_client *clnt;
1051         struct p9_req_t *req;
1052
1053         P9_DPRINTK(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
1054         err = 0;
1055         clnt = fid->clnt;
1056
1057         req = p9_client_rpc(clnt, P9_TCLUNK, "d", fid->fid);
1058         if (IS_ERR(req)) {
1059                 err = PTR_ERR(req);
1060                 goto error;
1061         }
1062
1063         P9_DPRINTK(P9_DEBUG_9P, "<<< RCLUNK fid %d\n", fid->fid);
1064
1065         p9_free_req(clnt, req);
1066         p9_fid_destroy(fid);
1067
1068 error:
1069         return err;
1070 }
1071 EXPORT_SYMBOL(p9_client_clunk);
1072
1073 int p9_client_remove(struct p9_fid *fid)
1074 {
1075         int err;
1076         struct p9_client *clnt;
1077         struct p9_req_t *req;
1078
1079         P9_DPRINTK(P9_DEBUG_9P, ">>> TREMOVE fid %d\n", fid->fid);
1080         err = 0;
1081         clnt = fid->clnt;
1082
1083         req = p9_client_rpc(clnt, P9_TREMOVE, "d", fid->fid);
1084         if (IS_ERR(req)) {
1085                 err = PTR_ERR(req);
1086                 goto error;
1087         }
1088
1089         P9_DPRINTK(P9_DEBUG_9P, "<<< RREMOVE fid %d\n", fid->fid);
1090
1091         p9_free_req(clnt, req);
1092         p9_fid_destroy(fid);
1093
1094 error:
1095         return err;
1096 }
1097 EXPORT_SYMBOL(p9_client_remove);
1098
1099 int
1100 p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
1101                                                                 u32 count)
1102 {
1103         int err, rsize, total;
1104         struct p9_client *clnt;
1105         struct p9_req_t *req;
1106         char *dataptr;
1107
1108         P9_DPRINTK(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid,
1109                                         (long long unsigned) offset, count);
1110         err = 0;
1111         clnt = fid->clnt;
1112         total = 0;
1113
1114         rsize = fid->iounit;
1115         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1116                 rsize = clnt->msize - P9_IOHDRSZ;
1117
1118         if (count < rsize)
1119                 rsize = count;
1120
1121         req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
1122         if (IS_ERR(req)) {
1123                 err = PTR_ERR(req);
1124                 goto error;
1125         }
1126
1127         err = p9pdu_readf(req->rc, clnt->dotu, "D", &count, &dataptr);
1128         if (err) {
1129                 p9pdu_dump(1, req->rc);
1130                 goto free_and_error;
1131         }
1132
1133         P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
1134
1135         if (data) {
1136                 memmove(data, dataptr, count);
1137                 data += count;
1138         }
1139
1140         if (udata) {
1141                 err = copy_to_user(udata, dataptr, count);
1142                 if (err) {
1143                         err = -EFAULT;
1144                         goto free_and_error;
1145                 }
1146         }
1147
1148         p9_free_req(clnt, req);
1149         return count;
1150
1151 free_and_error:
1152         p9_free_req(clnt, req);
1153 error:
1154         return err;
1155 }
1156 EXPORT_SYMBOL(p9_client_read);
1157
1158 int
1159 p9_client_write(struct p9_fid *fid, char *data, const char __user *udata,
1160                                                         u64 offset, u32 count)
1161 {
1162         int err, rsize, total;
1163         struct p9_client *clnt;
1164         struct p9_req_t *req;
1165
1166         P9_DPRINTK(P9_DEBUG_9P, ">>> TWRITE fid %d offset %llu count %d\n",
1167                                 fid->fid, (long long unsigned) offset, count);
1168         err = 0;
1169         clnt = fid->clnt;
1170         total = 0;
1171
1172         rsize = fid->iounit;
1173         if (!rsize || rsize > clnt->msize-P9_IOHDRSZ)
1174                 rsize = clnt->msize - P9_IOHDRSZ;
1175
1176         if (count < rsize)
1177                 rsize = count;
1178         if (data)
1179                 req = p9_client_rpc(clnt, P9_TWRITE, "dqD", fid->fid, offset,
1180                                                                 rsize, data);
1181         else
1182                 req = p9_client_rpc(clnt, P9_TWRITE, "dqU", fid->fid, offset,
1183                                                                 rsize, udata);
1184         if (IS_ERR(req)) {
1185                 err = PTR_ERR(req);
1186                 goto error;
1187         }
1188
1189         err = p9pdu_readf(req->rc, clnt->dotu, "d", &count);
1190         if (err) {
1191                 p9pdu_dump(1, req->rc);
1192                 goto free_and_error;
1193         }
1194
1195         P9_DPRINTK(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);
1196
1197         p9_free_req(clnt, req);
1198         return count;
1199
1200 free_and_error:
1201         p9_free_req(clnt, req);
1202 error:
1203         return err;
1204 }
1205 EXPORT_SYMBOL(p9_client_write);
1206
1207 struct p9_wstat *p9_client_stat(struct p9_fid *fid)
1208 {
1209         int err;
1210         struct p9_client *clnt;
1211         struct p9_wstat *ret = kmalloc(sizeof(struct p9_wstat), GFP_KERNEL);
1212         struct p9_req_t *req;
1213         u16 ignored;
1214
1215         P9_DPRINTK(P9_DEBUG_9P, ">>> TSTAT fid %d\n", fid->fid);
1216
1217         if (!ret)
1218                 return ERR_PTR(-ENOMEM);
1219
1220         err = 0;
1221         clnt = fid->clnt;
1222
1223         req = p9_client_rpc(clnt, P9_TSTAT, "d", fid->fid);
1224         if (IS_ERR(req)) {
1225                 err = PTR_ERR(req);
1226                 goto error;
1227         }
1228
1229         err = p9pdu_readf(req->rc, clnt->dotu, "wS", &ignored, ret);
1230         if (err) {
1231                 ret = ERR_PTR(err);
1232                 p9pdu_dump(1, req->rc);
1233                 goto free_and_error;
1234         }
1235
1236         P9_DPRINTK(P9_DEBUG_9P,
1237                 "<<< RSTAT sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1238                 "<<<    mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1239                 "<<<    name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1240                 "<<<    uid=%d gid=%d n_muid=%d\n",
1241                 ret->size, ret->type, ret->dev, ret->qid.type,
1242                 (unsigned long long)ret->qid.path, ret->qid.version, ret->mode,
1243                 ret->atime, ret->mtime, (unsigned long long)ret->length,
1244                 ret->name, ret->uid, ret->gid, ret->muid, ret->extension,
1245                 ret->n_uid, ret->n_gid, ret->n_muid);
1246
1247 free_and_error:
1248         p9_free_req(clnt, req);
1249 error:
1250         return ret;
1251 }
1252 EXPORT_SYMBOL(p9_client_stat);
1253
1254 int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst)
1255 {
1256         int err;
1257         struct p9_req_t *req;
1258         struct p9_client *clnt;
1259
1260         P9_DPRINTK(P9_DEBUG_9P, ">>> TWSTAT fid %d\n", fid->fid);
1261         P9_DPRINTK(P9_DEBUG_9P,
1262                 "     sz=%x type=%x dev=%x qid=%x.%llx.%x\n"
1263                 "     mode=%8.8x atime=%8.8x mtime=%8.8x length=%llx\n"
1264                 "     name=%s uid=%s gid=%s muid=%s extension=(%s)\n"
1265                 "     uid=%d gid=%d n_muid=%d\n",
1266                 wst->size, wst->type, wst->dev, wst->qid.type,
1267                 (unsigned long long)wst->qid.path, wst->qid.version, wst->mode,
1268                 wst->atime, wst->mtime, (unsigned long long)wst->length,
1269                 wst->name, wst->uid, wst->gid, wst->muid, wst->extension,
1270                 wst->n_uid, wst->n_gid, wst->n_muid);
1271         err = 0;
1272         clnt = fid->clnt;
1273
1274         req = p9_client_rpc(clnt, P9_TWSTAT, "dwS", fid->fid, 0, wst);
1275         if (IS_ERR(req)) {
1276                 err = PTR_ERR(req);
1277                 goto error;
1278         }
1279
1280         P9_DPRINTK(P9_DEBUG_9P, "<<< RWSTAT fid %d\n", fid->fid);
1281
1282         p9_free_req(clnt, req);
1283 error:
1284         return err;
1285 }
1286 EXPORT_SYMBOL(p9_client_wstat);